U.S. patent application number 10/827192 was filed with the patent office on 2004-12-09 for computerized medical diagnostic and treatment advice system and method including mental status examination.
Invention is credited to Iliff, Edwin C..
Application Number | 20040249778 10/827192 |
Document ID | / |
Family ID | 32072688 |
Filed Date | 2004-12-09 |
United States Patent
Application |
20040249778 |
Kind Code |
A1 |
Iliff, Edwin C. |
December 9, 2004 |
Computerized medical diagnostic and treatment advice system and
method including mental status examination
Abstract
A system and method for providing computerized, knowledge-based
medical diagnostic and treatment advice. The medical advice is
provided to the general public over a telephone network. Two new
authoring languages, interactive voice response and speech
recognition are used to enable expert and general practitioner
knowledge to be encoded for access by the public. "Meta" functions
for time-density analysis of a number of factors regarding the
number of medical complaints per unit of time are an integral part
of the system. A semantic discrepancy evaluator routine along with
a mental status examination are used to detect the consciousness
level of a user of the system. A re-enter feature monitors the
user's changing condition over time. A symptom severity analysis
helps to respond to the changing conditions. System sensitivity
factors may be changed at a global level or other levels to adjust
the system advice as necessary.
Inventors: |
Iliff, Edwin C.; (La Jolla,
CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
32072688 |
Appl. No.: |
10/827192 |
Filed: |
April 16, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10827192 |
Apr 16, 2004 |
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09588881 |
Jun 6, 2000 |
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6725209 |
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09588881 |
Jun 6, 2000 |
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09088940 |
Jun 2, 1998 |
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6071236 |
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09088940 |
Jun 2, 1998 |
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08176041 |
Dec 29, 1993 |
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5660176 |
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Current U.S.
Class: |
706/45 ;
434/236 |
Current CPC
Class: |
G16H 15/00 20180101;
G16H 10/60 20180101; G16H 40/67 20180101; G16H 20/70 20180101; G16H
50/20 20180101; G16H 10/20 20180101; G16H 40/63 20180101; A61B
5/0002 20130101; A61B 5/7465 20130101 |
Class at
Publication: |
706/045 ;
434/236 |
International
Class: |
G09B 019/00; G06F
017/00; G06N 005/00 |
Claims
What is claimed is:
1. A method of mental status examination while performing an
automated diagnostic consultation using an automated medical advice
or diagnostic system including a computing device and input and
output devices, the method comprising: prestoring a plurality of
questions and corresponding expected answers in a computing device
memory; automatically asking a patient a one of the plurality of
prestored questions; automatically comparing the answer to a
corresponding prestored expected answer; automatically ascribing a
score to a result of the comparison; and automatically comparing
the score to a predetermined threshold value so as to determine a
mental status of the patient.
2. The method defined in claim 1, wherein the mental status
examination takes place during a telephone consultation.
3. The method defined in claim 2, additionally comprising
transferring the telephone consultation with the patient to a
medical staff person if the threshold value is not achieved and an
assistant for the patient is not available.
4. The method defined in claim 1, additionally comprising providing
situation-specific advice to the patient if the threshold value is
not achieved.
5. The method defined in claim 1, additionally comprising
continuing an automated diagnostic consultation if the threshold
value is achieved.
6. The method defined in claim 5, wherein continuing the automated
diagnostic consultation includes collecting medical information
from the patient.
7. The method defined in claim 6, wherein new medical information
collected for the patient is added to a patient's past medical
history file at the completion of the automated diagnostic
consultation.
8. The method defined in claim 5, wherein continuing the automated
diagnostic consultation occurs when an assistant for the patient is
available and logs into an automated medical advice or diagnostic
system.
9. The method defined in claim 1, wherein a determination of mental
status of the patient is invoked in an automated diagnostic
consultation for a medical problem whose presentation can include
an altered level of consciousness.
10. An automated medical advice or diagnostic system configured to
conduct a mental status examination while performing an automated
diagnostic, the system comprising: storage means for prestoring a
plurality of questions and corresponding expected answers; means
for automatically asking a patient a one of the plurality of
prestored questions; means for automatically comparing the answer
to a corresponding prestored expected answer; means for
automatically ascribing a score to a result of the comparison; and
means for automatically comparing the score to a predetermined
threshold value so as to determine a mental status of the
patient.
11. The system defined in claim 10, additionally comprising means
for providing situation-specific advice to the patient if the
threshold value is not achieved.
12. An automated medical advice or diagnostic system configured to
conduct a mental status examination while performing an automated
diagnosis, the system comprising: a computing device; a storage
associated with the computing device configured to prestore a
plurality of questions and corresponding expected answers; and a
software program executed on the computing device and configured to
automatically ask a patient a one of the plurality of prestored
questions, automatically compare the answer to a corresponding
prestored expected answer, automatically ascribe a score to a
result of the comparison, and automatically compare the score to a
predetermined threshold value so as to determine a mental status of
the patient.
13. The system defined in claim 12, wherein the software program is
additionally configured to provide situation-specific advice to the
patient if the threshold value is not achieved.
14. A method of mental status examination, using an automated
medical advice or diagnostic system including a computing device
and input and output devices, the method comprising: automatically
providing a patient an item of information prestored in a computing
device memory; automatically waiting a predetermined time interval;
automatically asking the patient about the item of information;
automatically comparing an answer from the patient to a prestored
expected answer; and automatically evaluating a mental status of a
patient based on the comparison.
15. The method defined in claim 14, additionally comprising
resuming system operation if the results from the mental status
evaluation match.
16. The method defined in claim 14, additionally comprising
terminating system operation with the patient based on the mental
status of the patient if the results from the mental status
evaluation do not match.
17. The method defined in claim 14, wherein the method of mental
status examination is randomly invoked by the system.
18. A method of mental status examination, using an automated
medical advice or diagnostic system including a computing device
and input and output devices, the method comprising: automatically
asking a patient for an item of information, wherein a first
request for the item of information is prestored in a computing
device memory; automatically receiving a first answer;
automatically waiting a predetermined time interval; automatically
asking the patient about the item of information in a different
manner, wherein a second request for the item of information is
prestored in the computing device memory; automatically receiving a
second answer; automatically comparing the first answer to the
second answer; and automatically evaluating mental status of a
patient based on the comparison.
19. The method defined in claim 18, additionally comprising
resuming system operation if the results from the mental status
evaluation are consistent.
20. The method defined in claim 18, additionally comprising
terminating system operation with the patient based on a mental
status of the patient if the results from the mental status
evaluation are not consistent.
21. The method defined in claim 18, wherein the first request and
the second request are similar.
22. The method defined in claim 18, wherein the first request and
the second request are different.
23. An automated medical advice or diagnostic system configured to
conduct a mental status examination while performing an automated
diagnosis of a patient, the system comprising: storage means for
automatically providing a patient an item of prestored information;
means for automatically waiting a predetermined time interval;
means for automatically asking the patient about the item of
information; means for automatically comparing an answer from the
patient about the item of information to the prestored information;
and means for automatically evaluating a mental status of a patient
based on the comparison.
24. The system defined in claim 23, additionally comprising means
for resuming system operation if the results from the mental status
evaluation match.
25. The system defined in claim 23, additionally comprising means
for terminating system operation with the patient based on the
mental status of the patient if the results from the mental status
evaluation do not match.
26. An automated medical advice or diagnostic system configured to
conduct a mental status examination while performing an automated
diagnosis of a patient, the system comprising: a computing device;
a storage associated with the computing device configured to
prestore an item of information; and a software program executed on
the computing device and configured to automatically provide a
patient the item of prestored information, automatically wait a
predetermined time interval, automatically ask the patient about
the item of information, automatically compare an answer from the
patient about the item of information to the prestored information,
and automatically evaluate a mental status of a patient based on
the comparison.
27. The system defined in claim 26, wherein the software program is
additionally configured to resume system operation if the results
from the mental status evaluation match.
28. The system defined in claim 26, wherein the software program is
additionally configured to terminate system operation with the
patient based on the mental status of the patient if the results
from the mental status evaluation do not match.
29. An automated medical advice or diagnostic system configured to
conduct a mental status examination while performing an automated
diagnosis of a patient, the system comprising: means for
automatically asking a patient for an item of information, wherein
a first request for the item of information is prestored in a
computing device memory; means for automatically receiving a first
answer; means for automatically waiting a predetermined time
interval; means for automatically asking the patient about the item
of information in a different manner, wherein a second request for
the item of information is prestored in the computing device
memory; means for automatically receiving a second answer; means
for automatically comparing the first answer to the second answer;
and means for automatically evaluating mental status of a patient
based on the comparison.
30. The system defined in claim 29, additionally comprising means
for resuming system operation if the results from the mental status
evaluation are consistent.
31. The system defined in claim 29, additionally comprising means
for terminating system operation with the patient based on a mental
status of the patient if the results from the mental status
evaluation are not consistent.
32. The system defined in claim 29, wherein the first request and
the second request are similar.
33. The system defined in claim 29, wherein the first request and
the second request are different.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of prior application Ser.
No. 09/588,881, filed Jun. 6, 2000, which is a divisional of prior
application Ser. No. 09/088,940, filed Jun. 2, 1998, now U.S. Pat.
No. 6,071,236, issued Jun. 6, 2000, which is a divisional of prior
application Ser. No. 08/176,041, filed Dec. 29, 1993, now U.S. Pat.
No. 5,660,176, issued Aug. 26, 1997.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to medical knowledge systems
and, more particularly, to systems for giving medical advice to the
general public over a telephone network.
[0004] 2. Description of the Related Technology
[0005] Health care costs currently represent 14% of the United
States Gross National Product and are rising faster than any other
component of the Consumer Price Index. Moreover, usually because of
an inability to pay for medical services, many people are deprived
of access to even the most basic medical care and information.
[0006] Many people delay in obtaining, or are prevented from
seeking, medical attention because of cost, time constraints, or
inconvenience. If the public had universal, unrestricted and easy
access to medical information, many diseases could be prevented.
Likewise, the early detection and treatment of numerous diseases
could keep many patients from reaching the advanced stages of
illness, the treatment of which is a significant part of the
financial burden attributed to our nation's health care system. It
is obvious that the United States is facing health-related issues
of enormous proportions and that present solutions are not
robust.
[0007] One prior attempt at a solution to the health care problem
is called Ask-A-Nurse, wherein a group of nurses provide health
information by telephone around-the-clock. A person with a medical
problem calls an 800 number and describes the problem to the nurse.
The nurse uses a computer for general or diagnostic information on
the ailment or complaint mentioned by the caller. The nurse may
then refer the caller to a doctor from a computerized referral list
for a contracting hospital or group of hospitals. Client hospitals
contract with Ask-A-Nurse to provide patient referrals. A managed
care option called Personal Health Advisor is similar and adds the
capability for the caller to hear prerecorded messages on health
topics 24 hours a day. Several problems exist with these prior
medical advice systems. First, these systems have high costs
associated with having a nurse answer each telephone call. Second,
the caller may have to belong to a participating health plan to
utilize the service. Third, if for some reason all nurses on a
particular shift happen to be busy and the caller has an emergency
condition (that is not known by the caller to be an emergency),
precious time in getting emergency services may be lost during the
delay.
[0008] Another prior health system was developed by InterPractice
Systems which provides a computerized service that answers health
care questions and advises people in their homes. A health
maintenance organization (HMO) may provide this service to its
members in a particular geographic area. To get advice at home, an
HMO member connects a toaster-sized box to a telephone and calls a
toll-free 800 number. Using a keyboard that is part of the box, the
user answers questions displayed on a screen of the box relating to
the user's symptoms. Depending on the answers, the user might be
told to try a home remedy, be called by a nurse or doctor, or be
given an appointment to be examined. A limitation of this system is
the additional expense of the electronics box, which could either
be purchased by the user for approximately $300 or purchased by the
health organization with the expense to be passed on to the users.
Another limitation is that this service is directed to members of a
particular contracting health organization, such as an HMO. What is
desired is a system that does not require additional hardware for
the basic service, but that utilizes the existing communication
network. The desired system should be available for use by any
person, not just members of a certain organization.
[0009] A prior attempt at a health care solution for a limited set
of conditions is described in U.S. Pat. No. 4,712,562. A patient's
blood pressure and heart rate are measured and the measurements are
sent via telephone to a remote central computer for storage and
analysis. Reports are generated for submission to a physician or
the patient. U.S. Pat. No. 4,531,527 describes a similar system,
wherein the receiving office unit automatically communicates with
the physician under predetermined emergency circumstances.
[0010] U.S. Pat. No. 4,838,275 discloses a device for a patient to
lay on or sit in having electronics to measure multiple parameters
related to a patient's health. These parameters are electronically
transmitted to a central surveillance and control office where a
highly trained observer interacts with the patient. The observer
conducts routine diagnostic sessions except when an emergency is
noted or from a patient-initiated communication. The observer
determines if a nonroutine therapeutic response is required, and if
so facilitates such a response. As previously mentioned, highly
trained people are needed by this system along with the special
measurement apparatus (embedded in a bed or chair).
[0011] Other prior attempts at a health care solution are typified
by U.S. Pat. No. 5,012,411 which describes a portable
self-contained apparatus for measuring, storing and transmitting
detected physiological information to a remote location over a
communication system. The information is evaluated by a physician
or other health professional. As before, highly trained people are
necessary to utilize such an apparatus.
[0012] Several services to provide medical or pharmaceutical advice
are now available via "1-900" telephone numbers, e.g., "Doctors by
Phone." These services are available 24 hours a day and 7 days a
week. A group of doctors, including some specialties, is available
to answer questions about health care or medical conditions for
people anywhere in the United States who call the "1-900" telephone
of one of the services. A group of registered pharmacists answers
questions about medications for the "1-900" pharmaceutical
service.
SUMMARY OF THE INVENTION
[0013] The present solution to the health care problem is a
computerized medical diagnostic and treatment advice (MDATA) system
that is a medical knowledge-based system designed to give medical
advice to the general public over the telephone network. The goal
of the MDATA system is to provide everyone with equal access to
high quality, 100%-consistent medical advice at a reasonable cost.
The MDATA system provides callers with extremely fast and virtually
unlimited access to health care information, twenty-four hours a
day, from any location around the world. Health care advice is made
available to an entire spectrum of users, from elderly patients
confined to their homes to travelers in a foreign country with
telephones in their cars.
[0014] The central ideas leading to the development of the MDATA
system are based on the following assumptions:
[0015] Nearly 90% of all patient complaints are confined to
approximately 100 medical problems.
[0016] Almost all primary care decisions involved in these 100
problems can be made based upon information learned solely by
obtaining a detailed medical history. The results of the physical
examination, laboratory, and imaging studies only tend to confirm a
diagnosis.
[0017] The minimal amount of information that many doctors believe
can only be obtained from the physical examination can actually be
directly acquired from the patient when given appropriate
instructions.
[0018] In most cases, a face-to-face interaction between the doctor
and patient is not necessary. A detailed and well-constructed
history, along with physical findings elicited from the patient,
can be obtained over the telephone.
[0019] Medicine is basically diagnosis and treatment. Although
treatment recommendations change frequently, the fundamental
principles of making the diagnosis do not.
[0020] There is a significant delay between the time a new therapy
is recognized as safe and effective and the time physicians are
able to provide it to their patients.
[0021] These central ideas are utilized in the implementation of
the MDATA system.
[0022] A goal of the MDATA system is to give better medical advice
than a family practitioner who is unfamiliar with a patient, e.g.,
an on-call physician. A person seeking medical advice frequently
will not be able to see or speak with his or her personal physician
in a timely manner. The MDATA system provides medical advice
whenever desired by the caller--seven days a week/24 hours a
day.
[0023] All previous medical algorithms, including those used in the
military, are designed for face-to-face interactions. Self-help
books generally do not consider age and sex in their algorithms.
Furthermore, a book cannot take into account how many times a
person has consulted the same algorithm within a short period of
time for the same problem. The medical algorithms used by the MDATA
system are designed for use in a telecommunications setting and
overcome the deficiencies of self-help books.
[0024] Previous medical advice systems do not do a time-density
analysis for a number of factors with regard to the number of
complaints per unit of time. The MDATA system uses "meta" functions
to perform these analyses.
[0025] Previous medical advice algorithms do not have a way of
detecting the consciousness level of the person seeking
consultation. The MDATA system invokes a "mental status
examination" whenever a complaint or problem has the possibility of
an altered level of consciousness. In addition, the MDATA system
uses "semantic discrepancy evaluator loops" which allow the system
to invoke the mental status exam if there are differences in
answers to the parallel threads of thought that are woven or
embedded into the system.
[0026] Other medical advice systems do not have a "re-enter"
feature to monitor a patient's progress or worsening over time. The
MDATA system checks for and responds to changing conditions over
time.
[0027] Prior medical advice systems suffer from the inability to be
nearly instantly up-dated as new medical information is made
available. The MDATA system regularly and frequently updates the
treatment aspect of the system.
[0028] The computerized medical diagnostic and treatment advice
(MDATA) system is a medical knowledge-based system designed to give
medical advice to the general public over the telephone network.
Using a new authoring language, interactive voice response and
speech recognition technology, the MDATA system encodes a highly
useful core of expert and general practitioner diagnostic and
treatment knowledge into a computerized system for access by
non-medically trained personnel.
[0029] The MDATA system does not provide advice for every medical
problem, nor does it make an exhaustive study of one vertical
cross-section of medicine. Instead, the MDATA system provides
up-to-date medical advice for approximately one hundred of the most
commonly encountered problems in general practice and emergency
medicine. It also provides valuable information to the public on
any number of other medical topics.
[0030] As another embodiment of the MDATA system, a person desiring
medical advice and having access to a personal computer (PC) loads
a program into the PC to produce a stand-alone medical diagnostic
and treatment advice (SA-MDATA) system. Rather than listening to
questions and responding via touch tone keypresses or via voice,
the user responds to questions and directions displayed on the
computer screen via a computer input device, such as a keyboard or
mouse. The diagnosis and/or treatment recommendations provided by
the MDATA system are the same as that provided by the SA-MDATA
system. The user of the SA-MDATA system can procure updates by
contacting the MDATA system sponsor/administrator to obtain the
most current treatment table information for a particular
diagnosis.
[0031] In one embodiment of the invention, there is a method of
mental status examination while performing an automated diagnostic
consultation using an automated medical advice or diagnostic system
including a computing device and input and output devices, the
method comprising prestoring a plurality of questions and
corresponding expected answers in a computing device memory,
automatically asking a patient a one of the plurality of prestored
questions, automatically comparing the answer to a corresponding
prestored expected answer, automatically ascribing a score to a
result of the comparison, and automatically comparing the score to
a predetermined threshold value so as to determine a mental status
of the patient.
[0032] In another embodiment of the invention, there is an
automated medical advice or diagnostic system configured to conduct
a mental status examination while performing an automated
diagnostic, the system comprising storage means for prestoring a
plurality of questions and corresponding expected answers, means
for automatically asking a patient a one of the plurality of
prestored questions, means for automatically comparing the answer
to a corresponding prestored expected answer, means for
automatically ascribing a score to a result of the comparison, and
means for automatically comparing the score to a predetermined
threshold value so as to determine a mental status of the
patient.
[0033] In another embodiment of the invention, there is an
automated medical advice or diagnostic system configured to conduct
a mental status examination while performing an automated
diagnosis, the system comprising a computing device, a storage
associated with the computing device configured to prestore a
plurality of questions and corresponding expected answers, and a
software program executed on the computing device and configured to
automatically ask a patient a one of the plurality of prestored
questions, automatically compare the answer to a corresponding
prestored expected answer, automatically ascribe a score to a
result of the comparison, and automatically compare the score to a
predetermined threshold value so as to determine a mental status of
the patient.
[0034] In another embodiment of the invention, there is a method of
mental status examination, using an automated medical advice or
diagnostic system including a computing device and input and output
devices, the method comprising automatically providing a patient an
item of information prestored in a computing device memory,
automatically waiting a predetermined time interval, automatically
asking the patient about the item of information, automatically
comparing an answer from the patient to a prestored expected
answer, and automatically evaluating a mental status of a patient
based on the comparison.
[0035] In another embodiment of the invention, there is a method of
mental status examination, using an automated medical advice or
diagnostic system including a computing device and input and output
devices, the method comprising automatically asking a patient for
an item of information, wherein a first request for the item of
information is prestored in a computing device memory;
automatically receiving a first answer; automatically waiting a
predetermined time interval; automatically asking the patient about
the item of information in a different manner, wherein a second
request for the item of information is prestored in the computing
device memory; automatically receiving a second answer;
automatically comparing the first answer to the second answer; and
automatically evaluating mental status of a patient based on the
comparison.
[0036] In another embodiment of the invention, there is an
automated medical advice or diagnostic system configured to conduct
a mental status examination while performing an automated diagnosis
of a patient, the system comprising storage means for automatically
providing a patient an item of prestored information, means for
automatically waiting a predetermined time interval, means for
automatically asking the patient about the item of information,
means for automatically comparing an answer from the patient about
the item of information to the prestored information, and means for
automatically evaluating a mental status of a patient based on the
comparison.
[0037] In another embodiment of the invention, there is an
automated medical advice or diagnostic system configured to conduct
a mental status examination while performing an automated diagnosis
of a patient, the system comprising a computing device, a storage
associated with the computing device configured to prestore an item
of information, and a software program executed on the computing
device and configured to automatically provide a patient the item
of prestored information, automatically wait a predetermined time
interval, automatically ask the patient about the item of
information, automatically compare an answer from the patient about
the item of information to the prestored information, and
automatically evaluate a mental status of a patient based on the
comparison.
[0038] In another embodiment of the invention, there is an
automated medical advice or diagnostic system configured to conduct
a mental status examination while performing an automated diagnosis
of a patient, the system comprising means for automatically asking
a patient for an item of information, wherein a first request for
the item of information is prestored in a computing device memory;
means for automatically receiving a first answer; means for
automatically waiting a predetermined time interval; means for
automatically asking the patient about the item of information in a
different manner, wherein a second request for the item of
information is prestored in the computing device memory; means for
automatically receiving a second answer; means for automatically
comparing the first answer to the second answer; and means for
automatically evaluating mental status of a patient based on the
comparison.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a block diagram illustrating the components of a
presently preferred embodiment of the computerized medical
diagnostic and treatment advice (MDATA) system of the present
invention;
[0040] FIG. 2 is a diagram of the off-line process used in
producing the speech files shown in FIG. 1;
[0041] FIG. 3 is a diagram of the Node Translation process used in
creating files for use by the system of FIG. 1;
[0042] FIG. 4 is a diagram of some of the files and components of
FIGS. 1 and 3 that are utilized at run time;
[0043] FIG. 5a is a diagram of the utilization of the files shown
in FIG. 3 at run time;
[0044] FIGS. 5b-5g are an exemplary sequence of data structures of
the system shown in FIG. 1 at run time;
[0045] FIG. 6 is a block diagram illustrating a conceptual view of
the database files and processes of the system of FIG. 1;
[0046] FIGS. 7a, 7b, 7c and 7d are a top-level flow diagram of the
MDATA system of FIG. 1;
[0047] FIGS. 8a and 8b are a flow diagram of the patient login
process 250 defined in FIG. 7a;
[0048] FIGS. 9a and 9b are a flow diagram of the patient
registration process 252 defined in FIG. 7a;
[0049] FIGS. 10a and 10b are a flow diagram of the evaluation
process 254 defined in FIG. 7d;
[0050] FIGS. 11a and 11b are a flow diagram of the meta function
500 defined in FIG. 10b;
[0051] FIGS. 12a and 12b are a flow diagram of the assistant login
process 272 defined in FIG. 7b;
[0052] FIGS. 13a and 13b are a flow diagram of the assisted patient
login process 276 defined in FIG. 7b;
[0053] FIGS. 14a and 14b are a flow diagram of the assistant
registration process 274 defined in FIG. 7b;
[0054] FIGS. 15a and 15b are a flow diagram of the assisted patient
registration process 278 defined in FIG. 7b;
[0055] FIGS. 16a and 16b are a flow diagram of the mental status
examination function 508 defined in FIG. 10b;
[0056] FIG. 17 is a flow diagram of the semantic discrepancy
evaluator routine (SDER) 510 defined in FIG. 10b;
[0057] FIG. 18 is a flow diagram of the past medical history
routine 512 defined in FIG. 10b;
[0058] FIG. 19 is a flow diagram of the physical self examination
function 514 defined in FIG. 10b;
[0059] FIG. 20 is a flow diagram of the patient medical condition
routine 516 defined in FIG. 10b;
[0060] FIG. 21 is a flow diagram of the symptom severity analysis
function 518 defined in FIG. 10b;
[0061] FIG. 22 is a flow diagram of the treatment table process 256
defined in FIG. 7d; and
[0062] FIG. 23 is a flow diagram of the menu-driven treatment
selection process 864 defined in FIG. 22.
[0063] FIG. 24 is Table 3, a two dimensional array of causes of
diseases plotted against anatomical systems.
[0064] FIG. 25 is Table 4, an exemplary plot of symptom severity
versus time.
[0065] FIG. 26 is Table 5, another exemplary plot of symptom
severity versus time.
[0066] FIG. 27 is Table 9, a plot of sensitivity and selectivity
versus time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0067] The following detailed description of the preferred
embodiments presents a description of certain specific embodiments
to assist in understanding the claims. However, the present
invention can be embodied in a multitude of different ways as
defined and covered by the claims.
[0068] For convenience, the following description will be outlined
into the following 22 principal sections: Introduction, System
Overview, Operating Features of the MDATA System, Authoring
Language, Run-Time Operation, Software Structure, Top-Level Flow,
Login Process, Registration Process, Evaluation Process, The Meta
Function, Mental Status Examination, Semantic Discrepancy Evaluator
Routine, Past Medical History Routine, Physical Self Examination,
Symptom Severity Analysis, Treatment Table, The MDATA System
Paradigm, Video Imaging, Benefits of the MDATA System, Optional
System Configuration, and Summary of Advantages of the Present
Invention.
I. Introduction
[0069] A consultation for a person seeking medical advice begins
with a telephone call to the medical diagnostic and treatment
advice (MDATA) system of the present invention. The MDATA system
asks the caller specific questions and then analyzes each
response.
[0070] Voice recognition and interactive voice response technology
allow callers to respond to yes/no and multiple choice questions
either by speaking directly into the telephone or by using the
touch tone pad of their telephone.
[0071] Easy access to the information in the MDATA system is made
possible by a natural user interface. The computer-driven dialogue
consists of simple yes/no and multiple choice questions. The
questions and treatment recommendations are very simply worded yet
skillfully designed to reflect the accumulated experience of many
physicians in conducting patient interviews.
[0072] Although all the MDATA system's questions are designed to be
easily understood, unforeseen situations will inevitably arise. For
this reason, hierarchical staffing is implemented. As an example,
for every 10 telephone lines, one operator fully trained in triage
and the MDATA system will be available. For every 10 operators
there will be one registered nurse in attendance; and for every 10
registered nurses, there will be one physician in attendance.
Staffing requirements are adjusted as the system is refined toward
optimal efficiency. The MDATA system does not require the operator
or the registered nurse to make any medical decisions.
II. System Overview
[0073] Referring to FIG. 1, the components of a presently preferred
embodiment of the computerized medical diagnostic and treatment
advice (MDATA) system 100 of the present invention are shown. A
personal computer (PC) 102 includes a plurality of components
within an enclosure 104. A plurality of telephone lines 106
interface the public telephone network 108 to the computer 102. As
an example, one of telephone lines 106 is shown to be switched via
network 108 to connect with a telephone 110 that is used by a
person desiring medical advice (user) 112. Throughout this
document, the words user, caller and patient are used
interchangeably. However, it will be understood that the caller may
be acting as a proxy for the patient. If this is the case, the
caller will be registered as an assistant for the patient.
[0074] The hardware and system software were assembled with two
basic concepts in mind: portability to other operating systems and
the use of industry standard components. In this way, the system
can be more flexible and will allow free market competition to
continuously improve the product, while, at the same time, decrease
costs. While specific hardware and software will be referenced, it
will be understood that a panoply of different components could be
used in the present system.
[0075] The system currently runs on the PC 102 with an Intel 80486
microprocessor. "Telephony" functions use Dialogic Corporation's
D/41D voice processing board 122 based on a digital signal
processor (DSP). The voice processing (VP) board 122 performs
several functions including interfacing the telephone lines,
decoding touch tone signals, speech recording and speech playback.
Touch tone signals are also known as "dual tone multiple frequency"
(DTMF) signals. A group of one to four telephone lines 106 connect
to the VP board 122. The computer 102 may include a plurality of VP
boards 122 based on how many phone line connections are desired for
the system 100. Speech recognition is achieved using Voice
Processing Corporation's speech recognition VPRO-4 board 124 (also
DSP based). The voice recognition (VR) board 124 performs several
functions including recognizing utterances and returning an index
number of a recognition confidence level. The VR board 124 and the
VP board 122 both connect to an industry standard architecture
(ISA) bus 126. The ISA bus 126 interconnects the microprocessor 120
with a plurality of peripherals through controller circuits (chips
or boards).
[0076] The VP board 122 also connects to a VPRO-Adapt board 128 via
an analog audio bus 130 that is called Analog Extension Bus. Four
simultaneous channels provide a 96 kbit/second data transfer rate.
Each channel corresponds to a telephone line connected to the VP
board 122 and is associated with a current patient consultation.
The Adapt board 128 further connects to a digital audio bus 132.
The VR board 124 also connects to the digital audio bus 132. The
Adapt board 128 performs analog to digital signal conversion to a
VPC-proprietary digital pulse code modulation (PCM) format. The
digital bus 132 can accommodate 32 channels and has a data transfer
rate of 2.048 Mbits/second.
[0077] The computer ISA bus 126 has a plurality of peripherals
connected to it through adapters or controllers. A video adapter
board 136, preferably at VGA or better resolution, interconnects to
a video monitor 138. A serial communication circuit 140 interfaces
a pointing device, such as a mouse 142. A parallel communication
circuit may be used in place of circuit 140 in another embodiment.
A keyboard controller circuit 144 interfaces a keyboard 146. A
small computer systems interface (SCSI) adapter, such as model
1542C made by Adaptec, provides a SCSI bus 150 to which a 500 Mb or
greater hard disk drive 152 and dual Bernoulli 150 Mb disk drives
are preferably attached. The hard drive 152 stores database files
such as the patient files, speech files, and binary support
files.
[0078] A main memory 156 connects to the microprocessor 120. In the
presently preferred embodiment, the MDATA system 100 operates under
DOS version 5.0 operating system 158. The system software is
written in Microsoft C.backslash.C++ version 7.0 using structured
programming techniques. An algorithm processor 160 includes a
parser and supporting functions that manipulate a memory variable
symbol table and a run time stack, which will be described
hereinbelow. Sequiter Software Inc. Codebase 5.0 allows access to
X-base compatible database records stored on the hard drive 152.
The MDATA system 100 also includes two new authoring languages (one
each is used in two embodiments of the system), which will be
discussed hereinbelow.
[0079] The system software includes the following code modules:
[0080] A. main.c--a collection of functions that mostly deal with
telephony functions, such as answering the phone line, speech file
playback, and DTMF tone collection. Global data structures are
defined here.
[0081] B. base.c--functions that invoke the CodeBase revision 5.0
library to perform xbase file manipulation.
[0082] C. pars.c--the parse function, and supporting functions that
manipulate the memory variable symbol table and run time stack.
[0083] D. regi.c--an on-line patient registration module.
[0084] E. resp.c--gets the caller's responses, either DTMF or
voice, and figures out what to do next by obeying a command (e.g.,
"repeat" or "backup"), or traversing through the algorithm node
map.
[0085] F. term.c--a useful collection of text phrases for Dialogic
and VPC board termination events and error codes.
[0086] G. user.c--"non-diagnostic" portions of the caller session:
initial screening questions, caller login, and the next node
playback initiator.
[0087] H. util.c--a collection of general purpose functions shared
by a run time executable, a node editor and ASCII translator
tools.
[0088] I. view.c--a module that controls the graphics system
display.
[0089] J. x10.c--an X-10 computer interface routine for fault
recovery.
[0090] K. xlat.c--a module linked with pars.c and util.c object
modules to build xlat.exe, a stand-alone translation executable for
offline ASCII text file translation.
[0091] The application is compiled with the Microsoft graphics,
Dialogic board, VPC board and CodeBase database libraries.
[0092] The Voice Processing Corporation (VPC) VPro-4 VR board has
eight voice recognition channels, which by default are associated
one-to-one with the Dialogic D/41D channels. VPC's pioneering work
in the voice processing field is in the area of continuous speech.
This allows a person to speak a multiple digit number in a natural
manner, without pausing after each digit. VPC supplies two
continuous speech vocabularies: one vocabulary contains the digits
1 through 9, plus "zero" and "oh", and the other contains just the
two words "yes" and "no". The vendor-supplied digits continuous
speech vocabulary is used by the system 100. In the presently
preferred embodiment, if the score is 75% or better, the response
is unconditionally accepted. If the score is between 20% and 74%,
the digits recognized are read back, and the caller is asked to
accept or reject the digits. In another embodiment of the system
100, the above score thresholds are implemented as tunable
parameters. The scoring parameters are stored in a configuration
file that is manipulated off-line by a utility program and is read
by the run-time system at initialization.
[0093] VPC also provides a few discrete vocabularies. Discrete
vocabularies contain one or two word utterances. The
vendor-supplied discrete speech vocabulary of the months of the
year is used in the on-line patient registration process. A
speaker-independent discrete speech vocabulary consisting of the
words "yes", "no", "backup", "continue", "help", "operator",
"pause", "quit" and "repeat" has been developed using a very
powerful set of utilities supplied by VPC, Scripter and Trainer.
These utilities are for collecting samples and training the
vocabulary.
[0094] The VR board 124 has the minimum of two MB memory installed.
The default memory configuration has a partition for both
continuous vocabularies and a partition for one discrete
vocabulary. Additional discrete vocabularies may be downloaded if
the on-board memory is reconfigured.
[0095] The VR board 124 has four digital signal processors (DSP's)
from which VPC derived eight voice recognition channels. Each of
these eight recognition resources is referred to as a VPro Speech
Processor (VSP). Discrete vocabulary recognition requires one VSP;
continuous vocabulary recognition requires two adjacent VSP's. The
MDATA system 100 has a VSP resource manager in the resp.c software
module. This resource manager allocates VSP's in a dynamic manner
to VP board 122 channels on a demand basis. As soon as the system
receives a response, voice or DTMF, it releases the VSP's
associated with the caller's VP board 122 channel.
[0096] The MDATA system 100 uses VPC's application programming
interface (API) for the C programming language. This makes the
application vendor specific to VPC, but also allows the system 100
to utilize all the powerful API features, e.g., on-line creation of
discrete speaker dependent vocabularies used for voice pattern
matching or voice printing.
[0097] The VPC API supports both continuous speech vocabulary (CSV)
and discrete speech vocabulary (DSV) recognition.
[0098] The voice processing (VP) board 122 supports speech
recording and playback, as well as touch tone (DTMF) signal
detection and decoding. A device driver, associated with the VP
board 122, is loaded into system memory during load operations. The
device driver supports communications between the VP board 122 and
the application code at run time (e.g., when a person is seeking
medical advice). Through a shared memory segment, the device driver
sends event and status data to the application code in real-time as
events occur on the associated telephone line. These events include
the ring of an incoming call, touch tone key pressed by the caller,
and the hang-up signal. The VP board 122 plays back speech messages
that are stored on the hard drive 152. The algorithm processor 160
sends a selected speech file having an encoded speech message that
is retrieved from the hard drive 152 to the VP board 122 at the
appropriate time for speech message playback. A speech message can
be of variable length with a typical message about one to two
minutes in length. Several speech messages may be chained together
to produce an extended spoken message, e.g., giving instructions to
the patient. During speech file playback, the VP board 122 is
monitoring touch tone response from the caller. The VP board 122
may be configured to interrupt speech file playback when a touch
tone signal is detected.
[0099] System Operating Contexts
[0100] The system has an activity flag in the port status block for
each patient currently using the system to keep track of which
state the associated VP board channel is in:
[0101] a. Idle Mode--an idle channel waiting for a telephone
call;
[0102] b. Login Mode--a condition where a patient is in the login
process;
[0103] c. Registration Mode--a condition where a patient is in the
registration process;
[0104] d. Real Mode--a condition where a patient is consulting for
an actual medical problem;
[0105] e. Info (Information) Mode--a condition where a patient is
consulting for information or a hypothetical situation;
[0106] f. Pause Mode--a patient-initiated pause condition;
[0107] g. Pending Mode--similar to Real mode except that new
medical information gathered for a patient is not automatically
added to the patient's medical record, but rather written to a
"Pending" file where it will be verified off-line by a staff
person.
[0108] Voice Keywords and DTMF Command Keys
[0109] The system is responsive to the following voice keywords and
DTMF keys when it is in a prompting state, i.e., not in response to
a menu message:
1 Voice DTMF yes 1 Useful for answering yes/no questions. no 2
backup # Causes the system to back up to the "predecessor" message
(see below), then resume playback. help * Plays helpful
information: either the node's help message list, or the DTMF
command explanation message. operator 0 Causes the system to
transfer the caller to a live person. pause 7 Transitions to pause
mode. The system default pause period is 30 seconds. quit 9 Quits
the current algorithm, and takes the caller to node 110, which asks
the caller if (s)he wishes to select another algorithm. repeat 3
Repeats the current node's play message list. If this command is
given in the middle of a long play list, then playback restarts
with the first message in the list. Pause Mode Commands yes 1
Extends the pause period by one default pause interval (30
seconds). continue 2 Ends pause mode. If this occurs at a Yes/No
node, the system will repeat the question. If this occurs at a Link
node, the system will resume playback with the "current" message.
The system resolves the DTMF digit "2" ambiguity, "no" versus
"continue" , by examining the pause mode flag.
[0110] FIG. 2 illustrates how speech files are created. A person
programming medical algorithms uses speech messages to communicate
with the person seeking medical advice. As previously mentioned,
these speech messages are of variable length. The programmer
typically writes a script for the speech message. Then using the
handset of the telephone 110, a speakerphone feature, or other
voice-input device, e.g., a microphone, the programmer reads the
script into the voice-input device which is connected to the VP
board 122. The VP board converts the speech into a digital format
and records the digitized speech to a file that is stored on the
hard drive 152. In the presently preferred embodiment, a
subdirectory named vox contains the system speech files, and
subdirectories for each medical algorithm. System speech files are
of the form sysxxx, where xxx is some arbitrarily assigned number.
The system messages are used by the "fixed" parts of the system,
e.g., greeting, login process, registration process. There are a
few speech files of the form msgxxx. These are the past medical
history questionnaire messages, and response acknowledgements.
There are additional speech files of the form msgxxxx in each of
algorithm subdirectories, where xxxx generally matches the node
number, which will be explained hereinbelow. Node messages include
information, question, menu and help messages.
III. Operating Features of the MDATA System
[0111] One of the MDATA system's main objectives is to bring
together highly-qualified medical experts, encode their knowledge
in a central location, and make it available to everyone. A new and
unique authoring language is used by the MDATA system to help
accomplish this objective.
[0112] Each day, specialists perform the same tasks over and over.
They enact the same diagnostic ritual of solving a familiar
problem. At the same time, however, primary care physicians attempt
to find the best path through the diagnostic maze of an unfamiliar
problem. This process is inefficient and fraught with error.
[0113] In medicine, there is generally one best way to do things.
Instead of physicians spending valuable time duplicating tasks, the
MDATA system utilizes medical experts from each medical specialty
who write detailed algorithms for the treatment of the 100 or so
most commonly encountered complaints in family practice and
emergency medicine. These algorithms are carefully and specifically
designed to elicit historical data and physical findings over the
telephone, rather than in face-to-face interactions.
[0114] Several experts could work together to thoroughly research
one particular complaint as well as to anticipate the full spectrum
of possible problems and patient responses. These experts could
also provide and maintain the MDATA system treatment table as well
as the imaging modality of choice and laboratory test of choice
tables. These concepts will be described hereinbelow.
[0115] Carefully crafted questions, used in the taking of a medical
history, are the main tools that the NDATA system uses to assess
the problems of patients. The key to getting a good history is to
ask the right questions. In a sense, in the diagnostic process
questions are like tests. It is important to note that the right
questions are basically always right; they don't change. Although
they may be refined over time, in general, once excellent and
well-crafted questions are developed they are good for a very long
time. Of course, as new diseases are discovered, e.g., toxic shock
syndrome and AIDS, new sets of diagnostic questions are developed
that are disease specific.
[0116] The questions used by an earlier generation of physicians,
who did not have any of the latest imaging modalities (types or
methods), are far more sensitive and precise in diagnosing a
patient's problem than the questions used by doctors today. The
MDATA system makes use of fine nuances of language to diagnose
patients as well as to determine when certain tests or imaging
studies are necessary.
[0117] The MDATA system's statistic generating capabilities enable
the system to analyze the effectiveness of the questions used in
the diagnostic process. As a result, physicians benefit from the
immense amount of statistical information that is gathered
regarding the wording of questions asked in taking medical
histories. For example, exactly what percentage of patients who
answer "yes" to the question, "Is this the worst headache of your
life?" actually have a subarachnoid hemorrhage? Although this is a
classic description of this problem, the exact probability of
having this kind of brain hemorrhage after answering "yes" to this
question is not presently known. Currently, doctors can only
estimate the probability of certain conditions based on history. By
applying the statistical information that is generated, the MDATA
system not only provides the patient with advice that is
continually improving, but it will also be able to pass along these
probabilities to the entire medical community.
[0118] To function optimally, the MDATA system tries to gain as
much medical information about its patients as possible. Although a
first-time caller is given excellent advice, more specific advice
can be given if the system has more information. Therefore, the
MDATA system asks patients for their complete medical history. The
MDATA system can either obtain the patient's medical record over
the telephone or it can mail or fax a detailed questionnaire to
each patient. The patient can then gather the necessary information
at their convenience. The MDATA system will always be available by
telephone to clarify any questions the patient may have.
[0119] The MDATA system uses the "International Classification of
Diseases" (ICD.quadrature.9.quadrature.CM) codes to help summarize
the information it has about a patient. This world standard is a
comprehensive numerical system used to classify the entire spectrum
of medical diseases. ICD.quadrature.9.quadrature.CM codes are also
used to classify specific procedures performed (e.g., appendectomy)
as well as the morphology of neoplasm (i.e., tissue diagnosis of a
cancer).
[0120] In addition, the MDATA system 100 uses
ICD.quadrature.9.quadrature.- CM "E-Codes" to classify
environmental events, circumstances, and conditions as the cause of
injury, poisoning, and other adverse effects. These codes are
particularly helpful for storing information about what drugs the
patient has taken or is currently taking, as well as the context
(e.g., therapeutic use, accident, poisoning, suicide attempt) in
which they were or are being taken. For example, E942.1 is the code
for the therapeutic use of digoxin. Medications are also
cross-categorized according to the classification done by the
American Hospital Formulary Service List (AHFS) Numbers. The MDATA
system 100 also uses "V-Codes" to classify other types of
circumstances or events such as vaccinations, potential health
hazards related to personal and family history, and exposure to
toxic chemicals.
[0121] It is estimated that the alphanumeric component of a
patient's medical history will not exceed 1,000 atoms or pieces of
information. An atom is considered herein to be a separate
identifiable data item or point. With this assumption, the medical
records of every person on the planet could currently be stored on
approximately 1,000 optical disks.
[0122] While a patient interacts with the MDATA system, the system
is constantly determining what questions to ask, based upon the
information it has about the patient. Just as a physician gathers
relevant pieces of information from his or her dialogue with a
patient, the MDATA system flags and later stores all pertinent
pieces of information that it learns from each interaction with its
patient. Therefore, certain questions, because their answers remain
the same, need not be repeated. For example, if the MDATA system
learns that a patient's mother has suffered from migraine
headaches, it will never have to ask for this information
again.
[0123] Again, the more information the MDATA system has about a
patient, the more specific is its advice. It is not uncommon for
the MDATA system to give different advice to different patients
calling for the same complaint. In other words, the advice given is
patient-specific. Not only can the MDATA system's advice be
different for different patients, but there are times when the
advice given to the same patient (calling for the same complaint
but at different times) is different. For example, one of a group
of functions called "meta" keeps track of the number of times the
MDATA system has been consulted for the same problem. Once a
threshold is reached, the MDATA system advises the patient that the
number of consultations alone, for the same complaint, may signify
a problem. The system then makes an appropriate recommendation.
[0124] Before the MDATA system stores any information, the system
verifies its accuracy. To accomplish this task, "confirmation
loops" are used. Any piece of information that will become a part
of the patient's medical record is sent through a confirmation loop
where the system asks the patient to verify the accuracy of the
information that the system has collected. The confirmation loop
enables the system to verify new patient information and make
corrections before it enters this information into the patient's
medical record.
IV. Authoring Language
[0125] The MDATA system uses a new authoring language that is
specifically designed to allow medical knowledge to be encoded into
a usable computer program. The presently preferred voice response
or telephony version of the MDATA system is written in
object-oriented Microsoft C.backslash.C++ version 7.0. This allows
the MDATA system to easily interface with industry-standard
database programs, including those that are SQL-based, as well as
to be portable to other operating systems. The operating system is
transparent to the user.
[0126] Before the development of the MDATA system's authoring
language, there was no practical way for medical experts to encode
their knowledge into a meaningful, useful, and accessible
structure. Although other computer languages have been used to
build medical expert systems, they have almost always required a
knowledge engineer and a programmer to be involved. Quite often,
the knowledge encoded in these systems could only be accessed and
fully understood by physicians. Typically, the programmer would try
to translate the doctor's diagnostic skills and treatment rules
into computer code. This separation of the physician's knowledge
from the encoded treatment recommendations often engendered anxiety
in the physician and has, at times, led to inaccurate treatment
recommendations.
[0127] The MDATA system's authoring language, however, is designed
to allow physicians to transfer their knowledge into a computer
program that can be directly accessed by non-medically trained
personnel. Recursive and iterative techniques are used to acquire
the knowledge from the expert and assemble it in a way that allows
it to be immediately transposed into the MDATA system's algorithms.
Because of the simple interface of the language, and because a
formula for writing the algorithms has already been developed,
physicians who are not computer literate can encode their knowledge
as well as understand exactly how that process takes place.
[0128] The MDATA system's authoring language allows flat
information to be restructured into a hierarchical or layered
format in which the arrangement of the knowledge conveys meaning.
Thus, a textbook description of a disease can be transposed into a
form that allows useful treatment recommendations to be made.
[0129] The new language also allows the formation of a structure in
which multiple overlays of screening questions, combined with the
application of recursive techniques, sequentially exclude some
diagnoses while at the same time reaching treatment
recommendations. The MDATA system's simplicity and elegance would
not be possible without the new language.
[0130] The MDATA system's authoring language allows an algorithm
programmer to retrieve information from a patient's medical record,
request additional information from the patient, and guide the flow
of algorithm execution based on medical history and the patient's
responses. The language allows the programmer to implement an
algorithm in a natural scripted style.
[0131] The course of an algorithm is determined by caller responses
to questions that the MDATA system asks. For simple "yes/no"
questions, the flow of interaction can be described by a binary
tree. Multiple-choice questions (e.g., menus) provide multiple
branches in the tree. Each question can be considered a node, and
the acceptable responses to this question are branches leading to
the next question (node). Using this abstraction of an algorithm,
one can draw a directed graph (also known as a node map) of the
nodes and branches of an algorithm, beginning with the initial
question, and ending with all possible terminal points.
[0132] The node table is built in this manner:
[0133] 1. An author develops an algorithm.
[0134] 2. The algorithm is broken up into separate nodes.
[0135] 3. A directed graph is drawn up, which is a flow chart of
the algorithm's operation.
[0136] 4. Each node's definition is entered into the MDATA system,
either by:
[0137] a. using an ednode utility to write each node's definition
into the system's machine readable node table, or
[0138] b. using an xlat utility to translate an ASCII file of
human-readable node definitions into the system's machine readable
node table.
[0139] Referring to FIG. 3, a process for translating a medical
algorithm written in the authoring language will be described. FIG.
3 illustrates an ASCII (American Standard Code for Information
Interchange) format text file 170 as an input to a translation
utility 172. An ASCII file can be created by use of a text editor
or a word processing program (may need to export to the ASCII
format). The ASCII file 170 contains node definitions conforming to
the syntax briefly described hereinbelow.
[0140] The purpose of the ASCII node definition translator utility
172 (xlat.exe, along with functions in pars.c and util.c) is to
convert a human-readable document into a machine readable format
that the MDATA system reads at run time to process an algorithm.
This utility 172 may be considered to be a preprocessor; the
translation must be accomplished prior to run time.
[0141] The output of the utility 172 is a set of binary (NOD_BLK)
records written to a node table 174 (filename of node.fos), and a
set of binary list files 176 (in a subdirectory
.backslash.list.backslash.listxx.backsl- ash.xxyy, where xx is the
first two digits of the node number, and yy are the last two
digits). Four list files 176a-176d are shown as an example. Each
"list" file, e.g., 176a, contains a "next" table (i.e., the `next
node after this one`), a message play list for this node, and a
"work" list (i.e., one or more "things to do" at this node before
beginning speech playback). The binary record written to the node
table 174 (node.fos) has fields containing the node number (which
is redundant; the record's position in this file also indicates the
node number), the node's "type" attribute (Menu, Link, Prompt,
Yes/No, Return, Hangup) and a parent node number.
[0142] The node table 174 is a table of 10,000 NOD_BLK records.
This table 174 is indexed by a node number, e.g., the fiftieth
record corresponds to node 50. The contents of the individual node
records may be viewed by selecting "Display Node" while running the
ednode utility. The node records are modified by either using the
ednode utility, or when translating node definitions from ASCII to
the node file with the xlat utility.
[0143] One of the following keywords is necessary as the first item
on each line, but only one keyword is accepted per line; any excess
information will be discarded.
[0144] Node The Node keyword denotes the beginning of a new node
and defines the node number.
[0145] Parent The Parent keyword defines the parent of the node
being defined.
[0146] Type The Type keyword defines the class of the node being
defined. Acceptable type names are:
[0147] Menu This node presents a multiple choice question.
[0148] YesNo This node presents a simple Yes/No type question.
[0149] Link No caller response is required at this node, algorithm
processing will continue at a predetermined node.
[0150] Prompt This node requests some numeric information from the
caller. The information is placed in a DTMF buffer which is then
stored in the next node.
[0151] Return Returns from a subroutine call (e.g., after
configuring a past medical history object).
[0152] Hangup The system will release this caller after it finishes
speech file playback, or if the caller interrupts playback with a
DTMF key press.
[0153] Wait nn This node will play the message list, then pause for
the specified nonzero number of seconds before continuing.
[0154] @ The @ keyword defines the action to be taken for a
response to either a Menu or YesNo type node.
[0155] Digits The Digits keyword is used in conjunction with Type
Prompt to indicate the maximum number of DTMF digits to collect
from the caller.
[0156] Play The Play keyword defines a play list of one or more
messages to be played at this node.
[0157] Help The Help keyword defines a play list of one or more
messages containing useful hints for interacting with the system.
These messages provide helpful instructions for a new or confused
caller.
[0158] Next The Next keyword defines the next node to jump to after
the node being defined. It is used in conjunction with node types
Link and Prompt.
[0159] Work The Work keyword indicates a sequence of one or more
operations to perform when arriving at the node being defined. This
processing occurs before speech playback begins.
[0160] A select set of math functions, relational operators, and
nested if-then-else statements are supported. A pound sign (`#`) or
a hyphen (`-`) in the first position on a new line will cause the
translator to skip over the rest of the line. This is useful for
inserting comments, or delimiting between individual node
definitions. The translator also disregards blank lines.
[0161] In order for a node to be properly defined, a minimum number
of keywords must be present for each node, and other keywords must
be included depending on the node type. The minimum keyword set for
a properly defined node is:
[0162] Node, Parent, Type, and Play.
[0163] Dependency rules:
[0164] (1) The Menu type requires at least an @ 1 line and an @ 2
line.
[0165] (2) The YesNo type requires an @ 1 and an @ 2 line (@ 3,
etc. are ignored).
[0166] (3) The Link type requires a Next line.
[0167] (4) The Prompt type requires a Digits line and a Next
line.
[0168] The first keyword in a node definition must be Node. The
other keywords may be given in any order. The next occurrence of
the Node keyword will invoke a completeness test. If the
completeness test is successful, then the node definition is saved
in machine readable (binary) format, and translation continues with
the new Node line. A set of reserved language keywords is listed in
Table 1.
2TABLE 1 Reserved language keywords (case insensitive): @ and
digbuf digits else essf flush hangup help if keep link menu meta
next node parent play pop prompt push reenter return test then type
wait write work xor yesno
V. Run-Time Operation
[0169] Referring to FIG. 4, the run time interaction among the
hardware and software components of the MDATA system 100 will be
described. As previously mentioned, algorithm processor 160
includes the parser and supporting functions that manipulate the
memory variable symbol table and the run time stack. For a selected
medical algorithm, a node record is read from the node table 174
and a list file is read from the plurality of list files 176. The
algorithm processor also interacts with the Vpro voice recognition
(VR) board 124 for speech recognition and with the Dialogic voice
processing (VP) board 122 for speech playback and DTMF detection.
The VP board 122 further is interconnected with a set of speech
files 180 that are stored on a portion of hard disk 152 and with
one of the telephone lines 106 that connects via the telephone
network 108 (FIG. 1) to the patient's telephone 110. The VR board
124 further connects with the voice print vocabularies 182,
previously described, also stored on a portion of hard disk 152.
The algorithm processor 160 utilizes the speech recognition, speech
playback, and DTMF detection resources as directed by the medical
algorithm that is retrieved from the node table 174 and the list
files 176.
[0170] Referring to FIGS. 4, 5a and 5b, several data structures are
utilized at run time. These data structures are described as
follows:
[0171] A. Port Status Block (PSB). A port status block is created
at run time for each VP board 122 channel. The PSB contains flags,
buffers and tables that hold the state information of the channel,
retain responses from the caller, and keep track of where to
transfer control in response to voice recognition and telephony
events. The PSB keeps track of whether the caller prefers to use
spoken or touch tone responses, the caller's last response, the
number of consecutive errors the caller has made, and other context
sensitive parameters.
[0172] B. Node Block. This structure 196 contains the node number,
the type attribute (link, menu, yes/no, hangup, prompt, wait,
return) and pointers to:
[0173] a. Help list--a Play list of help information;
[0174] b. Play or Message list--a list of one or more messages or
speech files to play in sequence at each node;
[0175] c. Next table or list--contains entries for each possible
response to a yes/no or menu node that are evaluated at run time to
determine the next node to branch to; and
[0176] d. Work list--things to do before message playback
starts.
[0177] The load_node( ) routine 194 in util.c builds the node block
structure 196 in memory by first reading in a node record 190 from
the node table 174. Then linked lists are attached to the pointers
help, play, next and work. These lists come from the list files
176, in subdirectory path
.backslash.list.backslash.listxx.backslash.xxyy, where xxyy is the
node number, wherein each list file 192 is associated with a unique
node.
[0178] C. Symbol Table. Each patient has their own associated
symbol table. A portion of a symbol table 212 is shown in FIG. 5b.
The symbol table is loaded at run time with memory variables that
hold patient specific data (age, sex, and items from medical
history) and algorithm specific data. The items in the symbol table
can be flagged for storage to the patient's medical history.
[0179] D. Run Time Stack (RTS). Each Dialogic VP board 122 channel
has a RTS associated with it. The RTS is used by the parser. The
algorithm programmer can push to and pop from the RTS, e.g. to
temporarily store a value of a variable.
[0180] The work list has the non-playback tasks that are performed
at each node. There is one work list for each node, and it is
identified with the work keyword in the ASCII node definition file.
The work list may be empty. Each time the system transits to a new
node, it will execute the work list. If the patient repeats a node,
the system will not execute the work list again; it will simply
replay the message(s). If the patient requests the system 100 to
back up the node map, the system will execute the work list of the
node it backs up to. Typical tasks in the work list involve
manipulating objects on the run time stack or in the symbol table,
testing for the presence of memory variables, configuring past
medical history or current medical condition objects, or writing
database records. An example of a complex work list follows:
[0181] "Test OBJECT2; Phone=DIGBUF; Push Age"
[0182] This example tests for the presence of a patient record
object labelled "OBJECT2", loads the contents of the digit buffer
into memory variable Phone, and pushes the value of memory variable
Age onto the run time stack.
[0183] Each node has the "next" table or list. The next list
indices range from 1 to 9, inclusive. The next list contains either
a single node number, or an if expression. For all node types,
except the Hangup node, there will be at least one next list:
[0184] Link and Prompt nodes: the next node is stored at table
index 1.
[0185] Yes/No node: the next node for the Yes response is stored at
table index 1, and the No response is stored at index 2. This
corresponds to the prompt, "if the answer is yes, press 1; if no,
press 2."
[0186] Menu node: the response number and the table index are the
same. Even though the actual data structure has a `0` index in the
C programming language, this index is not used in the next table
because a `0` response is reserved for operator assistance.
[0187] Following is an example of a next list:
[0188] "If Male and Age >55 then 100 else 200" is interpreted
as:
[0189] If the patient is both male and over 55 years old then go to
node 100 else go to node 200.
[0190] Speech files 180 may be of an arbitrary length. A message
may be informational, a list of menu options, or a yes/no question.
A "two paragraph" or "under one minute" limit has been adopted as a
style convention for the presently preferred embodiment. Typically,
a node is programmed as a sequence of Yes/No nodes, with
"informational" Link nodes interspersed as needed. When there is a
lengthy discussion, the speech is recorded in multiple files. To
simplify algorithm programming and enhance readability (viz.,
eliminate long chains of link nodes), the Link node's play list may
contain up to ten message numbers.
[0191] Upon arrival at a Link node, the system positions a "current
message" pointer at the beginning of the play list (trivial case:
single message play list; interesting case: multiple message play
list). As playback proceeds, the current message pointer moves down
the play list. After the system plays the last message on the list,
it moves on to the next node.
[0192] If the caller issues a "backup" command, the system will
move the current message pointer back one message, and resume
playback. If the pointer was at the beginning of the list (e.g.,
trivial case), the system backs up to the previous node and places
the current message pointer at the beginning of the play list. If
there is more than one message in the list, the system cues the
pointer to the last message in the list. The system then resumes
playback. In the "pause" mode, when the caller issues the
"continue" command, the system will resume playback at the current
message.
[0193] The MDATA system 100 uses three basic operating modes:
[0194] A. Real Mode--involves an actual medical problem. In this
mode the system 100 loads the past medical history, saves new past
medical history objects, and writes a meta record for each
algorithm consulted. The medical algorithm programmer is
responsible for providing code to jump past meta analysis in
Information mode.
[0195] B. Information Mode--involves a "what if" scenario. In the
Information mode the system 100 disregards past medical history,
does not save newly configured past medical history objects, does
not write a meta record for each algorithm consulted, and does not
perform meta analysis. The patient has an option in Information
mode to change the age and sex parameters to emulate a hypothetical
patient.
[0196] C. Pending Mode--handles the situation when a patient's
voice sample does not match the patient's reference sample. Pending
mode is utilized also when an assistant is interacting with the
MDATA system 100 on behalf of a patient and both the assistant's
and the patient's voice samples fail the voice printing test. In
the case where the assistant's voice sample fails the voice
printing test but the patient's voice sample passes the test,
Pending mode is not utilized. In Pending mode, the NDATA system 100
considers the patient's medical history and performs meta analysis
during this consultation. However, a meta record is not written for
this consultation and any new medical information gathered on this
patient will not be written to the patient's medical record. The
new medical information is written to a "Pending" file. The Pending
file is verified off-line by a system administrator or staff
person, and then is added to the patient's medical record only if
the information can be verified.
[0197] One of the drawbacks of the traditional doctor-patient
relationship is the short amount of time that physicians are able
to spend with patients. The MDATA system 100, however, allows
patients as much time as they wish to learn about their problem as
well as to obtain information on any number of other medical
topics.
[0198] Through the "Information mode" feature of the MDATA system
100, callers can learn about a disease process, an illness or the
latest treatment for any disease, without adding any information to
their personal medical record. Although the system 100 keeps track
of the interaction, it is labeled as an "Information mode session."
The record of the caller's path through the system is not used as
the basis for any future advice, nor is it considered in generating
system statistics.
[0199] The Information mode is not limited to complaints for which
the MDATA system 100 offers medical advice. Information about early
detection and treatment of many other diseases as well as the
latest advances in medicine can be made available through the
Information mode.
[0200] Referring to FIGS. 5b through 5g, as an example, a run time
sequence of steps of how a patient may traverse a main menu node
map several steps into a chest pain algorithm node map will be
described. Six nodes with a portion of an associated symbol table
will be discussed.
[0201] At FIG. 5b, the algorithm processor 160 loads the first node
#100, represented by node block 210. The variables for Age, Sex,
and Real mode were loaded into the symbol table 212 during the
login process (which will be described hereinbelow). Throughout
this example, the help list is empty, i.e., no help information is
played for the patient. The work list sets the Problem variable of
the symbol table 212 to be Menu. Then the system 100 begins
playback of message#100. This message gives the patient a menu of
choices to choose from. The Digits entry equal to one means that a
one digit response is expected from the patient. The patient may
respond by pressing a touch tone (DTMF) key on the telephone or
speak the choice response into the telephone handset microphone. In
this example, the patient selects menu option "1". The parser
evaluates the Next list based on the patient selection and branches
to node #101.
[0202] At FIG. 5c, the algorithm processor 160 loads node #101,
represented by node block 214. The work list is empty, so the
system 100 goes right to playing back message#101 which presents
another menu of choices to the user. The Next list has four nodes
for possible branch points. In this example, the patient selects
menu option "1" for a chest pain complaint. The parser evaluates
the Next list based on the patient selection and branches to node
#2200.
[0203] At FIG. 5d, the algorithm processor 160 loads node #2200,
represented by node block 218. The work list command is to update
the value of Problem in symbol table 220 to CCHP (chest pain). Then
the system 100 begins playback of message#2200. No response is
required from the patient for a Link type node. The Next list has
two nodes for possible branch points depending on the value of
symbol table variable Real. The parser evaluates the If expression
in the Next list for the value of Real and, in this example,
branches to node #2201.
[0204] At FIG. 5e, the algorithm processor 160 loads node #2201,
represented by node block 222. The work list command is to write a
Meta consultation record for future use by a Meta function. The
play list is empty so no message is played. No response is required
from the patient for a Link type node. The main purpose of this
node is to write the Meta consultation record (because the system
is currently in Real mode for this patient). The Next list has only
one node so no decisions are necessary by the parser which, in this
example, branches to node #2205.
[0205] At FIG. 5f, the algorithm processor 160 loads node #2205,
represented by node block 226. The work list is empty in this node
so the system 100 goes right to playing back message#2205 which
presents a yes/no type of question to the user. The Next list has
two nodes for possible branch points depending on the response of
the patient. In this example, the patient responds "no", and the
parser evaluates the Next list based on the patient selection and
branches to node #2210.
[0206] At FIG. 5g, the algorithm processor 160 loads node #2210,
represented by node block 230. The work list is empty in this node
so the system 100 goes right to playing back message#2210 which
presents a yes/no type of question to the user. The Next list has
two nodes for possible branch points depending on the response of
the patient. If the patient answers "yes" to the question, the
parser branches to node #2211, but if the patient answers "no" to
the question, the parser branches to node #2215.
VI. Software Structure
[0207] Referring to FIG. 6, the system utilizes eight principal,
separate processes and seven related databases. A patient login
process 250 is used by the system 100 to identify a patient who has
previously registered into the system by prompting for a patient
identification number (PIN). An assistant login process 272 is used
by the system 100 to identify an assistant who has previously
registered into the system by prompting for an assistant
identification number (AIN). An assisted patient login process 276
is used by the system 100 to identify a patient who has previously
registered into the system by prompting for the patient
identification number. If the caller is the patient, a patient
registration process 252 is used by the system to register new or
first-time patients. If the caller is not the patient, an assistant
registration process 274 is used by the system to register new or
first-time assistants. Then, if the patient is not already
registered, an assisted patient registration process 278 is used by
the system to register the patient. These processes will be further
described hereinbelow.
[0208] Once a caller has logged in or registered, the system
provides a choice of two other processes in the current embodiment.
The first of these processes is the evaluation process 254 that
performs a patient diagnosis. The second of these is a treatment
table process 256 to obtain current treatment information for a
particular disease or diagnosis. In another embodiment, other
choices are added to access other medical information
processes.
[0209] Associated with these eight processes are a patient and
assistant enrollment database 260, a consultation history database
262, a patient response database 264, a medical history objects
database 266, a patient medical history database 268, a pending
database 269, and a patient medication database 270 that are
described as follows:
[0210] A. The master patient and assistant enrollment database 260
is created at run-time by one of the registration processes 252,
274, or 278. This database 260 is read by the patient login process
250 or the assisted patient login process 276 to validate a
patient's identity at login time and by the assistant login process
272 to validate an assistant's identity at login time. The database
260 is essentially a master file of all registered patients and
assistants indexed by their patient ID number or assistant ID
number, respectively. The patient ID or assistant ID, date of birth
and gender fields are entered by the on-line registration process;
the system administrator manually enters the name of the patient or
assistant in an off-line manner.
[0211] The patient and assistant database 260 contains one record
for each patient or assistant. This database 260 is indexed by the
identification number. The system appends the enrollment database
260 after a caller is successfully registered. The "next ID number"
is stored in a binary file, config.fos, and is incremented after
each successful registration. Each record has the following
fields:
3 Field Name Data Type Width Usage ID Numeric 10 ID number TYPE
Character 1 User type: "P"-patient, "A"- assistant ASST_PERM
Boolean 1 Permanent assistant flag ASST_EXP Date 8 Expiration for
permanent assistant RELATIONS Pointer 20 Pointers to related
patients/ assistants ORGZTN Character 8 Organization alphanumeric
code NAME Character 20 Patient/Assistant name SEX Character 1
Gender YEAR Numeric 4 Year of birth MONTH Numeric 2 Month of birth
DAY Numeric 2 Day of birth ACCESS Date 8 Last access RV_PATH
Character 20 Path name of recorded voice file
[0212] B. The consultation history or meta database 262 is created
at run-time by the evaluation process 254. A consultation record
contains alpha-numeric codes for the patient's complaint, the
affected anatomic system and the diagnosed cause of the patient's
complaint. When the meta function is invoked at run-time, it
compares alphanumeric strings provided by the evaluation process
with the fields of all the patient's meta records that fall within
a time window specified by the evaluation process. The meta
function returns the number of matches found, and an indication of
the frequency of the patient's complaint.
[0213] Each patient has an individual meta file that is part of the
consultation history database 262. At the conclusion of the
evaluation process and dependent on the run-time operating mode
flag, the system will create a new meta record, populate its fields
with the information gathered during the evaluation process, and
append this record to either the consultation history database 262
or the Pending file 269. For example, information used in the new
meta record may come from a "Write Meta" command in a node Work
list. Each record has the following fields:
4 Field Name Data Type Width Usage DATE Date 8 Date stamp PROBLEM
Character 5 Patient complaint/symptom SYSTEM Character 5 Anatomical
system affected CAUSE Character 5 Diagnosed cause of complaint
[0214] C. The patient response database 264 is created at run-time
by the evaluation process 254. The response database 264 is an
audit trail: each record is time stamped and registers the
patient's response to each question. This database 264 can later be
analyzed off-line with a database program such as FoxPro/FoxBase to
reveal how the patient responded to questions during the evaluation
process 254, or a database program can be developed to gather
response patterns and statistics and generate appropriate
reports.
[0215] Each patient has a response trace file that is part of the
patient response database 264. The system 100 appends this response
trace file with a response record every time the patient answers a
question or provides algorithm-requested data. For human
readability, the system also inserts "Begin Call" and "End of Call"
records in this file. Each record has the following fields:
5 Field Name Data Type Width Usage DATE Date 8 Date stamp MM/DD/YY
TIME Character 8 Time stamp HH:MM:SS NODE Numeric 6 Current node
number TYPE Character 5 Response type: DTMF or VOICE RESP Character
5 Response command or digit string MODE Character 1 Consultation
operating context VERSION Character 20 Version or Begin/End call
comment SENS_FACT Character 20 Current sensitivity factor
settings
[0216] D. The medical history objects database 266 is an auxiliary
database that supports a key feature of the MDATA system 100: past
medical history. The medical history objects database is a catalog
of unique alphanumeric codes, each code corresponding to a medical
condition or diagnosis that is not expected to change during the
life of the patient (e.g., a diagnosis for asthma is coded as
"RWHZAST").
[0217] In addition to the alphanumeric codes, the MDATA system 100
uses the "memo" field in a Foxpro database to store binary objects.
Currently, these binary objects are clinical sounds obtained from
the patient over the telephone.
[0218] It is anticipated, that as database technology gets more
sophisticated (moving toward multi-media and so forth), it will
allow storing of larger and more complicated binary files such as
the following: a digitized x-ray, a digitized CAT scan, a digitized
MRI scan. In addition, as video-telephone technology advances, it
is anticipated that the system 100 will store video images or even
holographic images of the patient.
[0219] For every past medical condition there is a record in the
medical history objects database that contains the attributes of
the medical condition, and contains a pointer into the past medical
history questionnaire. The attributes of a medical condition
include its data type (e.g., boolean or numeric) and the number of
digit positions needed to store the value of a numeric value
associated with this condition (not applicable to boolean
type).
[0220] The pointer field is useful for obtaining medical history at
run-time. If a patient has an incomplete medical history
questionnaire on file with the MDATA system 100, then the pointer
field allows the evaluation process to momentarily suspend the
evaluation, go to the medical questionnaire and ask an individual
question, collect and verify the patient's response, and then
resume the evaluation process. This "ask-when-you-need-it" approach
relieves the new patient of going through an exhaustive medical
history questionnaire before the first consultation of the
diagnostic process.
[0221] Each record of the medical history objects database has the
following fields:
6 Field Name Data Type Width Usage LABEL Character 8 Object code
name TYPE Character 1 Object data type DIGITS Numeric 3 Maximum
number of digits in response CALL Pointer 6 Identifies question(s)
to be asked to configure this object AUDIO Binary N/A Voice print
IMAGERY Binary N/A Face print RFU Character 20 (For future use)
[0222] E. The patient medical history (PMH) database 268 is created
at run-time by the evaluation process 254 or by use of a past
medical history questionnaire. The PMH database 268 is read by the
evaluation process during run-time. This database 268 contains each
patient's individual medical history. A new patient has an option
to go through the entire medical questionnaire at one time, thereby
configuring all the past medical history objects listed in the
objects database 266. Alternately, the new patient can bypass the
questionnaire and go right into the diagnosis of a medical
complaint. Then, if a medical algorithm requires a past medical
history object that has not yet been configured, the evaluation
process 254 invokes a past medical history function before it
continues with the algorithm.
[0223] Each patient has their own past medical history file, which
is part of the PMH database 268, that contains records which
describe medical events or conditions from the patient's life. The
system 100 appends a record to this file each time a past medical
history object is configured for the patient. The contents of this
file are installed in the symbol table when the patient logs in to
the system 100. The medical algorithm programmer is responsible for
using a TEST command to verify that necessary items are present in
the symbol table before algorithm execution. A side effect of a
negative TEST result is that the system 100 prompts the patient to
provide that information. The system 100 flags any new or modified
items, and asks the patient to confirm these values during an Exit
Confirmation Loop which will be described hereinbelow. Each record
has the following fields:
7 Field Name Data Type Width Usage LABEL Character 20 The object's
label TYPE Character 1 Object data type VALUE Character 10 Object's
configured value CERT Numeric 3 Certainty of object's value DATE
Date 8 Object configuration date ICD9A Float 5 First ICD-9 code . .
. . . . . . . . . . ICD9E Float 5 Fifth ICD-9 code
[0224] F. The "Pending" database file 269 holds medical information
gathered during Pending mode for offline verification. The Pending
database record structure is the same as that used for the past
medical history (PMH) database 268. The evaluation process writes
to the Pending database at run-time when it configures a new past
medical history object for a patient during a Pending mode
interaction. The contents of the Pending database are reviewed
off-line by a staff person, and if the information is verified, the
staff person appends the information to the patient's past medical
history file.
[0225] G. An optional patient medication database 270 contains a
file for each patient containing information about medication they
are taking, or have taken in the past. The medication database 270
is created by the evaluation process 254 at run time. A "Write
Drug" command builds a record and fills its fields with same-named
memory variables from the symbol table. The evaluation process 254
may read the medication database 270 during run time as needed. The
treatment table 256 optionally reads the medication database 270 to
determine the medication(s) being used by the patient.
8 Field Name Data Type Width GENERIC_NAME Character 20 TRADE_NAME1
Character 20 TRADE_NAME2 Character 20 TRADE_NAME3 Character 20
ICD-9-CM_CODE Character 10 ICD-9-CM_ECODE Character 10
ICD-9-CM_VCODE Character 10 OTHER Character 20 DOSAGE Character 20
ROUTE_OF.sub.-- Character 10 ADMINISTRATION FREQUENCY Character 10
USE Character 20 START_DATE Date 8 STOP_DATE Date 8 OTHER1
Character 20 OTHER2 Character 20
VII. Top-Level Flow
[0226] Referring to FIGS. 7a, 7b, 7c and 7d, the top level flow 300
of the MDATA system 100 software will be described. The telephone
number used to access the MDATA system 100 may vary in various
embodiments of the system. If the sponsoring agency or hospital
wishes to provide access to the MDATA system 100 at no cost to the
caller, then a toll-free 800 service number can be used. If the
sponsoring agency or hospital wishes to recover the costs of
running the MDATA system 100 from the caller, it may use a
pay-per-call or premium charge number (e.g., 900 service). "Current
Procedural Terminology" (CPT-4) codes are available to describe and
bill third party payers for telephone consultations. They are a
listing of the descriptive terms and identifying codes for
reporting medical services and procedures. CPT-4 codes are the most
widely accepted nomenclature for reporting physician services to
insurance companies.
[0227] Beginning at a start state 302, a person 112 (FIG. 1)
desiring medical advice calls the telephone number for the MDATA
system 100 on a telephone line 106. The caller may be the patient
or may be an "assistant", e.g., parent, relative, or friend, that
is helping the patient. Moving to state 304, the system 100 answers
the call automatically and greets the caller 112 with an
introductory greeting message by playing back a speech file stored
on the hard drive 152 by use of the VP board 122. Proceeding at
state 306, the MDATA system 100 asks each patient who calls the
system a series of "initial screening questions." These questions
are designed to identify patients who are critically ill; they are
not designed to identify the patient's problem. The initial
screening questions enable the system to filter out patients who
require immediate medical attention.
[0228] Moving to decision state 308, any patient found to be
critically ill is instructed to dial the emergency response
telephone number "911" at state 309 or will be automatically
connected to the nearest emergency medical services system in the
patient's area. The telephone call is terminated by the computer
102 at state 310. The following are examples of initial screening
questions:
[0229] IS THIS A MEDICAL EMERGENCY?
[0230] ARE YOU HAVING DIFFICULTY BREATHING?
[0231] ARE YOU EXPERIENCING SEVERE PAIN OR PRESSURE IN YOUR
CHEST?
[0232] If the system determines that the patient is experiencing a
medical emergency, it may provide the patient with a menu of
emergency medical procedures at state 311. In situations where the
patient or the caller for the patient is far from the nearest
emergency help, e.g., a rural setting, the caller may need to
initiate emergency procedures immediately. The menu of emergency
medical procedures provides several choices to the caller. If the
caller presses touch tone key "1" or speaks the word "one" into the
telephone mouthpiece, the computer 102 branches to state 312
wherein well known CPR (cardiopulmonary resuscitation) information
is recited. If the caller has a speakerphone capability associated
with the telephone 110 being used, the caller may be able to listen
to and perform the instructions given by the system 100 in a
hands-free manner away from the telephone. If the caller presses
touch tone key "2" or speaks the word "two" into the telephone
mouthpiece, the computer 102 branches to state 313 wherein well
known Heimlich Hug information for choking is recited. At the
completion of either state 312 or state 313, the telephone call
ends at state 314.
[0233] If the patient is determined at state 308 not to have a
medical emergency, i.e., the MDATA system 100 is satisfied that no
immediately life threatening condition is present, the computer 102
moves to a decision state 315 to determine if the caller is the
actual patient. If so, the computer 102 proceeds to a decision
state 316 to determine if the patient has previously registered or
ever consulted with the system 100, i.e., is not a new or
first-time caller. If so, the system 100 verifies the patient's
identification and retrieves their medical record at the patient
login process 250, which will be further described hereinbelow. At
the completion of process 250, the computer 102 proceeds through
off-page connector C 317 to state 344 (FIG. 7d). If the patient is
not registered, the MDATA system 100 proceeds to the patient
registration process 252 for a new patient, which will be described
hereinbelow. At the completion of process 252, the computer 102
proceeds through off-page connector C 317 to state 344 on FIG.
7d.
[0234] If the caller is not the patient, as determined at state
315, the computer 102 proceeds through off-page connector A 318 to
state 320 on FIG. 7b. There will be times when the patient may not
be able to use the MDATA system 100 directly, e.g., due to injury,
weakness or altered level of consciousness. In these cases, an
"assistant" may interact with the system on behalf of the
patient.
[0235] An assistant registers with the system through the assistant
registration process 274 which will be described hereinbelow. The
assistant registration record is identical to the patient
registration record in structure, but three fields have special
significance for an assistant: ASST_PERM, ASST_EXP, and RELATIONS.
The ASST_PERM field is a boolean flag that can only be set true
off-line by the system administrator who has verified, through
separate means, that a relationship exists between a patient and an
assistant. The relationships are one-to-many, i.e., a patient may
have one or more assistants, and an assistant may be related to
more than one patient. The ASST_PERM flag may also be constrained
by the ASST_EXP field, which contains a timestamp for the
expiration of the ASST_PERM attribute. If the ASST_PERM flag is
true, then the RELATIONS pointers will point to one or more patient
records for whom this assistant is a "permanent assistant;"
otherwise the RELATIONS field will be empty.
[0236] The medical information gathered during an assisted
consultation is written to the patient's medical record only if the
following three conditions are met:
[0237] (a) the assistant's ASST_PERM flag is True
[0238] (b) the ASST_EXP timestamp has not been reached
[0239] (c) the assistant has a relationship pointer to the patient
record
[0240] If any of these conditions are not met, then any new medical
information gathered on this patient will be saved to the Pending
file 269 for off-line verification by the system administrator.
[0241] The system 100 establishes at state 315 whether the caller
is the patient, or an assistant. If the caller is not the patient,
then the system asserts that the caller is an assistant and, at a
decision state 320, determines if the assistant is registered. If
the assistant is not already registered with the system, the system
enrolls the new assistant at the assistant registration process
274. If the assistant is already registered with the system 100,
the computer 102 performs the assistant login process 272. At the
completion of either process 272 or process 274, the computer 102
advances to a decision state 321.
[0242] If the patient is not already registered with the system
100, as determined at decision state 321, then the system allows
the assistant to register a new patient at the assisted patient
registration process 278. However, if the patient is already
registered with the system 100, as determined at state 321, the
computer 102 performs the assisted patient login process 276. At
the completion of process 278 or process 276, the computer 102
proceeds through off-page connector B 327 to a decision state 334
on FIG. 7c.
[0243] At decision state 334, the computer 102 determines if the
patient's date of birth is in the patient's medical record. If so,
the computer proceeds through off-page connector C 317 to state 344
on FIG. 7d. If not, the system 100 attempts to get the patient's
date of birth. Moving to state 335, the system 100 asks the
assistant if the patient's date of birth is known. If so, the
computer 102 advances to state 336 to request the patient's date of
birth. At state 337, the system 100 recites the patient's date of
birth obtained at state 336. At a decision state 338, the assistant
determines if the date of birth is correct as recited by the system
100. If not, the computer 102 loops back to state 336 to request
the patient's date of birth again. If the patient's date of birth
is correct, as determined at state 338, the computer 102 flags the
date of birth for saving in the patient's medical record at state
339, and proceeds to state 344 on FIG. 7d.
[0244] If the patient's date of birth is not known, as determined
at state 335, the computer 102 proceeds to state 340 wherein the
system requests the assistant to provide an approximate age of the
patient. The age is an important parameter used in the evaluation
process 254 and treatment table 256. At state 341, the system 100
recites the patient's approximate age obtained at state 340. At a
decision state 342, the assistant determines if the age is correct
as recited by the system 100. If not, the computer 102 loops back
to state 340 to request the patient's approximate age again. If the
patient's approximate age is correct, as determined at state 342,
the system 100 advises the assistant at state 343 to get the
patient's actual date of birth before the next consultation, and
proceeds to state 344 on FIG. 7d. The system 100 uses the
approximate age in the consultation during the evaluation process
254 and the treatment table 256.
[0245] At state 344 on FIG. 7d, the system 100 presents the caller
with a system selection menu. Here, the caller is asked to select
from among four choices: diagnostic system, treatment table, a
future process/function, or end call as described below:
[0246] A. Diagnostic System: The system starts the evaluation
process 254 at a menu, where it asks the patient to begin
identification of the complaint.
[0247] B. Treatment Table: The system takes the patient to the
treatment table process 256 at a menu, where it asks the patient to
select a treatment selection method.
[0248] C. Future Process/Function: A future process or function
280, undefined in the present embodiment, that reads and/or writes
the databases shown in FIG. 6.
[0249] D. End Call: The system performs several steps and then
terminates the telephone call.
[0250] In either process 254 or 256, the computer 102 functions as
an interpreter as performed by algorithm processor 160 in following
the node map created by the algorithm programmer. At the exit point
of the evaluation process 254, the system 100 gives the patient the
option of selecting another complaint. At the end of the treatment
table process 256, the system gives the patient the option of
selecting another treatment.
[0251] At the completion of the evaluation process 254, treatment
table process 256, or future process 280, the system 100 loops back
to state 344 and recites the system selection menu to the caller.
If the caller chooses the End Call selection at state 344, the
MDATA system 100 moves to a decision state 345. At decision state
345, the system 100 determines if process 254, process 256, or
process 280 did not occur in Information mode, i.e., did occur in
either Real mode or Pending Mode, and examines the patient's symbol
table to determine if any of the configured memory variables are
past medical history conditions that need to be saved to the
patient's medical history file. If both conditions are true at
state 345, the system 100 advances to a decision state 346 to
determine if the consultation is being performed in Real mode. If
not, the consultation is being performed in Pending mode, and the
system 100 then writes any new patient information obtained during
the consultation to the Pending file 269. If state 346 proves to be
true, i.e., Real mode, for each past medical condition that needs
to be saved, the MDATA system 100 asks the patient at state 348 to
grant permission to save the datum to the patient's medical history
file and to confirm that the datum is correct. For example, during
a consultation for cough, the MDATA system 100 learned that the
patient has been diagnosed as being HIV positive. The system 100
will ask, "May I record the information about your HIV diagnosis in
your medical record?" If the patient responds "yes", then the
system 100 will ask, "Please verify that your diagnosis for HIV was
positive, is this correct?" If the patient responds "yes", then the
system 100 writes this fact to the patient's medical history file.
After confirmation, each data item is stored in the patient's file
in the patient medical history database 268 (FIG. 6).
[0252] At the completion of either updating the history database
268 at state 348, state 345 proves to be false, or at the
completion of state 347, the system 100 moves to a decision state
349. Before the MDATA system 100 ends the consultation with the
patient, it presents a summary of all the advice it has given. The
patient is asked to write down and repeat back the key points. The
MDATA system 100 then gives the patient the option of receiving a
summary of the consultation session and specific recommendations
provided by the system by either facsimile or first class mail. If
a fax is desired, the system 100 asks the patient for a fax number
at state 350. The patient also has the option to send a summary of
the consultation to his or her health care provider or specialist.
Proceeding to state 351, the computer 102 adds the transcript of
the current telephone session to a fax queue for subsequent
transmission. At the completion of state 351 or if the system 100
determined at state 349 that the session transcript was not to be
faxed, the telephone call is terminated at state 352.
VIII. Login Process
[0253] Referring now to FIGS. 8a and 8b, the patient login process
250 defined in FIG. 7a will be described. This process 250 is
called if the patient has previously called and registered with the
system 100. Beginning at a start state 358, the computer 102 moves
to state 359 and initializes a match flag to true. The match flag
is checked later in this process 250 in conjunction with setting
the mode of the consultation. Proceeding to state 360, the computer
102 prompts the patient for the patient ID (identification) number
(PIN) that is assigned during the registration process. The patient
registration process 252 will be described in conjunction with
FIGS. 9a and 9b. Proceeding to a decision state 361, the computer
102 determines whether the PIN is valid. If not, the computer 102
determines, at a decision state 362, if less than three tries at
entering the PIN have been attempted. If so, the computer 102 loops
back to state 360 to repeat the request for the PIN. However, if
three attempts at entering the PIN have been made, as determined at
state 362, the computer 102 plays a polite message that advises the
patient that the login attempt failed and terminates the call at
state 363. The computer 102 reports the failed login attempt to the
system administrator at the sponsoring agency, hospital or other
organization. The patient is allowed to reregister as a new
patient, however, to permit access to the needed medical
information. The system administrator resolves this type of
situation off-line.
[0254] If the patient has correctly entered a valid PIN, as
determined at state 361, the computer 102 moves to a decision state
364 to determine if the patient identified by the PIN has a voice
print or sample voice waveform on file in the system 100. If not,
the computer 102 proceeds to state 365 to record the voice print of
the patient, e.g. the patient's pronunciation of his or her full
name. The patient's voice print may not be on file, for example, if
the patient could not provide a voice print during the assisted
patient registration process 278 in a prior consultation. At the
completion of recording the voice print at state 365, the computer
102 advances to state 366 wherein the match flag is set to false to
indicate that the patient's voice print was recorded during the
current login.
[0255] If the patient identified by the PIN has a voice print on
file in the system 100, as determined at state 364, the computer
102 proceeds to state 367 and prompts the patient to pronounce his
or her full name. Moving to a decision state 368, the computer 102
determines whether the voice sample obtained at state 367 passes
the matching criteria. If not, the computer proceeds to state 369
and recites a message that the current voice sample does not pass
the matching criteria. In the presently preferred embodiment, the
current voice sample is compared to the reference voice sample
recorded during the patient registration process 252 or the
assisted patient registration process 278. Because the voice
samples did not match, as determined at state 368, the computer 102
sets the match flag to false at state 370. In this case, the match
flag is set to false to indicate that one of the security checking
methods has failed. However, the process 250 continues at state 372
after the match flag is set to false at either state 366 or
370.
[0256] If the voice sample passed the matching criteria at state
368, the computer 102 advances to state 371 and recites a message
that the current voice sample passed the matching criteria. This
security check condition is now satisfied, and the match flag
remains set to true. At the completion of state 371 the computer
102 moves to state 372. At state 372, the computer 102 verifies the
sex and age of the patient by reciting the sex and age, as stored
in the enrollment database 260 (obtained during the patient
registration process 252), to the patient. At a decision state 373,
the patient responds to the correctness of the recited information.
If the sex or birth date information is not correct, the computer
102 moves to state 374 to request the correct information. The
computer 102 then proceeds back to state 372 to verify the
information received at state 374. If the result of the decision
state 373 is true, i.e., the sex and age are correct, the computer
moves through off-page connector A 375 to a decision state 376 on
FIG. 8b to determine if the patient desires to conduct the
telephone session in Real mode or Information mode. If Information
mode is desired, the computer 102 moves to a decision state 377 to
determine if the patient's sex and age are to be used during the
Information mode consultation. If not, the computer 102 moves to
state 378 to request an age and sex to use in a hypothetical
situation during the Information mode session. Moving to a decision
state 379, the computer 102 recites the sex and age obtained at
state 378, and asks the patient to confirm that this information is
correct. If not, the computer 102 moves back to state 378 to
request the age and sex again. When decision state 379 is true or
the patient's age and sex are to be used during this consultation,
as determined at state 377, the computer 102 moves to state 380 and
sets the operating mode to be Information mode.
[0257] If decision state 376 is determined to be Real mode, the
computer 102 moves to a decision state 381 to check if the match
flag is true. If not, the system 100 advises the patient, at state
382, that the current consultation is to be performed in Pending
mode. The operating mode is set to be Pending mode at state 383. If
the match flag is true, as determined at state 381, the computer
102 sets the operating mode to be Real mode at state 384.
[0258] At the completion of setting the operating mode at either
state 380, state 383, or state 384, the computer moves to a
decision state 386. At decision state 386, the computer 102
determines if the patient desires to review the touch tone commands
described during the registration process. If so, the computer 102
advances to state 388 and recites the touch tone commands. At the
completion of state 388 or if the patient did not wish to review
the touch tone commands, the computer 102 proceeds to a decision
state 390 wherein the computer 102 determines if the patient
desires to review the voice keywords described during the
registration process. If so, the computer 102 advances to state 392
and recites the voice keywords. At the completion of state 392 or
if the patient did not wish to review the voice keywords, the
computer 102 proceeds to a decision state 394 wherein the computer
102 determines if the patient desires to enable prompting. If so,
the computer 102 advances to state 396 and enables prompting. If
not, prompting is disabled at state 398. To "enable prompting"
means that the patient would like to be prompted for responses.
This is referred to as "hard" prompting, since this will remain in
effect for the duration of the call. If hard prompting is off, and
the system 100 has difficulty recognizing patient responses, the
computer 102 turns on "soft" prompting. After the next successful
recognition, the computer 102 turns off soft prompting. At the
completion of state 396 or 398, the computer 102 returns at state
400 to the top level flow (FIG. 7).
[0259] Referring now to FIGS. 12a and 12b, the assistant login
process 272 defined in FIG. 7b will be described. This process 272
is called if the assistant has previously called and registered
with the system 100. Beginning at a start state 940, the computer
102 moves to a state 942 and prompts the assistant for the
assistant ID (identification) number (AIN) that is assigned during
the registration process. The assistant registration process 274
will be described in conjunction with FIGS. 14a and 14b. Proceeding
to a decision state 944, the computer 102 determines whether the
AIN is valid. If not, the computer 102 determines, at a decision
state 946, if less than three tries at entering the AIN have been
attempted. If so, the computer 102 loops back to state 942 to
repeat the request for the AIN. However, if three attempts at
entering the AIN have been made, as determined at state 946, the
computer 102 plays a polite message that advises the assistant that
the login attempt failed and terminates the call at state 948. The
computer 102 reports the failed login attempt to the system
administrator at the sponsoring agency, hospital or other
organization.
[0260] If the assistant has correctly entered a valid AIN, as
determined at state 944, the computer 102 proceeds to state 950 and
prompts the caller to pronounce his or her full name. Moving to a
decision state 951, the computer 102 determines whether the voice
sample obtained at state 950 passes the matching criteria. If not,
the computer proceeds to state 952 and recites a message that the
current voice sample does not pass the matching criteria. In the
presently preferred embodiment, the current voice sample is
compared to the reference voice sample recorded during the
assistant registration process 274. Because the voice samples did
not match, as determined at state 951, the computer 102 sets the
operating mode to Pending at state 953. In this case, Pending mode
is set to indicate that one of the security checking methods has
failed. However, the process 272 continues at state 960 on FIG. 12b
after Pending mode is set at state 953.
[0261] If the voice sample passed the matching criteria at state
951, the computer 102 advances to state 954 and recites a message
that the current voice sample passed the matching criteria. This
security check condition is now satisfied. Next, three additional
checks are performed on the assistant identified by the AIN
obtained at state 942. At a decision state 955, the computer 102
determines if the permanent assistant flag is true, as stored in
the patient and assistant enrollment database 260. If so, the
computer 102 advances to a decision state 956 to determine if the
expiration date for the permanent assistant is in the future, i.e.,
the expiration date has not been reached yet. If so, the computer
102 advances to a decision state 957 to determine if a relationship
exists between the assistant and a patient, i.e., the assistant has
a relationship pointer to the patient record. If so, the operating
mode is set to Real at state 958, and then the computer 102
advances through off-page connector A 959 to state 960 on FIG. 12b.
However, if any of the decision states 955, 956, or 957 prove to be
false, the computer 102 moves to state 953 wherein the operating
mode is set to Pending.
[0262] States 960 through 964 are similar to states 372 through 374
of the patient login process 250 (FIG. 8). Because of this
similarity, only significant differences are discussed in the
interest of avoiding repetitiveness. States 960, 962 and 964 verify
the assistant's age and sex, rather than the patient as in states
372, 373 and 374. States 966 through 980 are similar to states 386
through 400 of the patient login process 250 (FIG. 8b). The main
distinction is that states 966-980 pertain to the assistant and
states 386-400 pertain to the patient.
[0263] Referring now to FIGS. 13a and 13b, the assisted patient
login process 276 defined in FIG. 7b will be described. This
process 276 is called if both the patient and the assistant have
previously called and registered with the system 100. This process
allows the patient flexibility by permitting the assistant to
provide help during the login and subsequent consultation.
Beginning at a start state 990, the computer 102 moves a state 992
and prompts the assistant for the patient ID (identification)
number (PIN) that is assigned during the registration process. As
previously defined in FIG. 7, the assisted patient registration
process 278 is called if the patient is not already registered.
Process 278 will be described in conjunction with FIGS. 15a and
15b. Proceeding to a decision state 994, the computer 102
determines whether the PIN is valid. If not, the computer 102
determines, at a decision state 996, if less than three tries at
entering the PIN have been attempted. If so, the computer 102 loops
back to state 992 to repeat the request for the PIN. However, if
three attempts at entering the PIN have been made, as determined at
state 996, the computer 102 plays a polite message that advises the
caller that the login attempt failed and terminates the call at
state 998. The computer 102 reports the failed login attempt to the
system administrator at the sponsoring agency, hospital or other
organization. If the assistant doesn't know the PIN and the patient
cannot provide it, the assistant is allowed to reregister the
patient as a new patient at process 278 to permit access to the
needed medical information. In this case, the assistant may have to
estimate the age of the patient if the patient has, for example, an
altered state of consciousness. The system administrator resolves
the record-keeping in this situation off-line.
[0264] If the assistant has correctly provided a valid PIN to the
system 100 at state 994, the computer 102 moves to a decision state
993 to determine if the patient identified by the PIN has a voice
print or sample voice waveform on file in the system 100. If not,
the computer 102 moves to a decision state 1003 to determine if the
patient can provide a voice sample. If not, the computer 102
proceeds through off-page connector B 997 to state 1008 on FIG.
13b. If the patient can provide a voice sample, as determined at
state 1003, the computer 102 moves to state 995 to record the voice
print of the patient, e.g. the patient's pronunciation of his or
her full name. The patient's voice print may not be on file, for
example, if the patient could not provide a voice print during the
assisted patient registration process 278 in a prior consultation.
At the completion of recording the voice print at state 995, the
computer proceeds through off-page connector B 997 to state 1008 on
FIG. 13b.
[0265] If the patient identified by the PIN has a voice print on
file in the system 100, as determined at state 993, the computer
102 proceeds to state 999 and asks whether the patient can provide
a voice sample to the system. If not, the computer 102 proceeds
through off-page connector B 997 to state 1008 on FIG. 13b. States
1000, 1002, 1004, 1006 are similar to states 367, 368, 369, 371,
respectively, of the patient login process 250 (FIG. 8). Because of
this similarity, only significant differences are discussed in the
interest of avoiding repetitiveness. At the completion of state
1004, i.e., the patient's voice sample does not pass the matching
criteria, the computer 102 proceeds through off-page connector B
997 to state 1008 on FIG. 13b. At the completion of state 1006,
i.e., the patient's voice sample does pass the matching criteria,
the computer 102 proceeds through off-page connector A 1001 to
state 1005 on FIG. 13b.
[0266] At the completion of state 995, i.e., the patient's voice
print is recorded, state 999 or state 1003, i.e., the patient
cannot provide a voice sample, or state 1004, i.e., the voice
sample match fails, the system continues process 276 at state 1008
on FIG. 13b. For the three situations just described in this
process 276, the computer 102 sets the operating mode to Pending at
state 1008. The system 100 then advises the caller at state 1009
that new patient information will not be saved to the patient's
medical record because the consultation is in Pending mode until
the information is verified off-line.
[0267] At the completion of state 1006, i.e., the voice sample
passes, the computer 102 continues process 276 at state 1005
wherein the operating mode is set to Real. The system 100 then
advises the caller at state 1007 that new patient information will
be saved to the patient's medical record.
[0268] At the completion of state 1009 or state 1007, the computer
102 moves to state 1010. States 1010, 1012 and 1014 verify the
patient's age and sex, similar to states 372, 373 and 374 (FIG. 8).
States 1016 through 1030 are similar to states 386 through 400 of
the patient login process 250 (FIG. 8). The main distinction is
that states 1016-1030 are directed to the assistant and states
386-400 are directed to the patient.
IX. Registration Process
[0269] Referring now to FIGS. 9a and 9b, the patient registration
process 252 defined in FIG. 7a will be described. This process 252
is called if the patient has not previously called and registered
with the system 100. During the first consultation, the MDATA
system 100 obtains the patient's age and sex. This is the minimum
amount of information that the MDATA system requires in order to
give medical advice. The more information the MDATA system has
about a patient, however, the more specific is its advice.
[0270] The MDATA system 100 assigns each of its patients a unique
patient identification number. In addition, when a patient
initially registers, the patient's own pronunciation of his or her
name is recorded, digitized and saved to their medical record.
Then, when the patient calls back, the previous recording is
retrieved and the patient is asked to repeat their name exactly as
they did during registration. The two recordings are then compared
to see if they match. This use of "voice printing" helps to further
ensure the security and confidentiality of a patient's medical
record.
[0271] Beginning at a start state 420, the computer 102 proceeds to
state 422, requests the sex of the patient, and verifies by
repeating the response given by the patient. Moving to a decision
state 424, the patient responds by indicating to the system 100,
via touch tone key or a voice response, whether the repeated
information is correct. If not, the computer 102 loops back to
state 422 to request the information again. When the information is
correct at state 424, the computer 102 proceeds to states 426 and
428 to request and verify the birth date of the patient in a
similar fashion to states 422 and 424.
[0272] When the decision state 428 is determined to be true, the
computer 102 proceeds to state 427 and requests the patient to
pronounce his or her full name. Moving to state 429, the full name
is digitized and stored in a subdirectory on the hard drive 152
(FIG. 1) indexed by a Patient Identification Number (PIN). File
names are of the form: <PIN>.vox. The computer 102 accesses a
file to retrieve the next available PIN. The path name to the
recorded voice file is saved in the patient's record in the
enrollment database 260. In subsequent telephone sessions with the
system 100, the patient's voice waveform will be compared to the
recorded voice waveform for security and other optional purposes.
When the voice waveform is stored, the computer 102 moves to state
431 and provides the PIN to the patient. The patient is informed of
the importance to save the PIN for use in future consultations with
the system 100.
[0273] At the completion of state 431, the computer 102 moves to a
decision state 430 to determine if the patient has a MDATA system
user pamphlet available. If so, the computer 102 moves to state 436
and requests the patient to turn to the pamphlet page that
documents the touch tone keys, voice keywords, and modes. If not,
the computer 102 moves to a decision state 432 to determine if the
patient would like the system 100 to pause to enable the patient to
get paper and a writing instrument for writing user instructions.
If so, the computer 102 pauses at state 434 for 30 seconds. At the
completion of the pause at state 434, if the user did not desire a
pause at state 432, or after the patient is instructed to turn to
the proper page of the pamphlet, the computer 102 proceeds to state
440 of FIG. 9b via the off-page connector A 438.
[0274] At state 440, the system 100 provides an explanation of the
touch tone keys to the patient. These keys were described above in
relation to the discussion on Voice Keywords and DTMF Command Keys.
Moving to state 442, the computer 102 asks if the patient desires
to hear the explanation of keys again. If so, the computer 102
repeats state 440. If not, the computer 102 advances to state 444
wherein an explanation of the voice keywords is provided to the
patient. These keywords were previously described above. Moving to
state 446, the computer 102 asks if the patient desires to hear the
explanation of keywords again. If so, the computer 102 repeats
state 444. If not, the computer 102 advances to state 448 wherein
an explanation of Real and Information modes is provided to the
patient. These modes were previously described above. Moving to
state 450, the computer 102 asks if the patient desires to hear the
explanation of the modes again. If so, the computer 102 repeats
state 448. If not, the computer 102 advances to state 452 wherein a
summary of new user information is recited to the patient. The
summary includes a recap of the two methods of controlling the
system: voice key words and DTMF, and the two interaction modes:
Real and Info. The computer 102 returns at state 454 to the top
level flow (FIG. 7).
[0275] Referring now to FIGS. 14a and 14b, the assistant
registration process 274 defined in FIG. 7b will be described. This
process 274 is called if the caller is not a registered patient and
has not previously called and registered as an assistant with the
system 100. States 1050 through 1090 are similar to states 420
through 454 of the patient registration process 252 (FIG. 9).
Because of this similarity, only significant differences are
discussed in the interest of avoiding repetitiveness. States 1052,
1056, 1060, 1062 and 1064 pertain to the assistant rather than the
patient as in states 422, 426, 427, 429 and 431 (FIG. 9a),
respectively. State 1060 records the assistant's pronunciation of
his or her full name and state 1062 saves it in the patient and
assistant enrollment database 260. The system 100 provides an
assistant identification number (AIN) at state 1064. The AIN is
used similarly to the PIN in the access of files or records. The
remaining states 1066-1090 are directed to the assistant also.
[0276] Referring now to FIGS. 15a and 15b, the assisted patient
registration process 278 defined in FIG. 7b will be described. This
process 278 is evoked if the caller is not the patient and the
patient has not previously called and registered with the system
100. States 1110 through 1150 are similar to states 420 through 454
of the patient registration process 252 (FIG. 9). Because of this
similarity, only significant differences are discussed in the
interest of avoiding repetitiveness. The main difference is that
the assistant is interacting with the system 100 on behalf of the
patient during this process 278, and therefore, the operating mode
is set to Pending at state 1111. States 1112 and 1116 obtain the
patient's sex and age, respectively. If the patient cannot provide
the age to the assistant and the system, the assistant provides an
estimated age. The estimated age can be corrected during a
subsequent consultation with the system 100. At state 1119, the
system 100 asks whether the patient can provide a voice sample of
his or her full name. If so, the voice waveform is recorded and
saved in enrollment database 260 (FIG. 6) at states 1120 and 1122.
If the patient cannot provide a voice sample at state 1119, the
system 100 informs the assistant, at state 1121, that the patient's
voice sample will be requested during the subsequent consultation.
Then, whether or not a voice sample is recorded, the system 100
provides a patient identification number (PIN) of the patient to
the assistant and the patient (if coherent) at state 1123. The
caller is instructed to safeguard the PIN for future consultations
by either the patient or the assistant on behalf of the patient. If
the assistant and/or patient desires to hear the PIN again, as
determined at a decision state 1124, the computer 102 repeats the
PIN at state 1123. The computer 102 proceeds through off-page
connector A 1125 to a decision state 1126 on FIG. 15b. The
remaining states 1126-1150 in process 278 are directed to the
assistant rather than the patient, as in states 430-454 of process
252 (FIG. 9).
X. Evaluation Process
[0277] Referring now to FIGS. 10a and 10b, the evaluation process
254 defined in FIG. 7d will be described. This process 254 is
called if the patient has selected the Diagnostic System choice in
the system selection menu (FIG. 7d, state 344). Beginning at a
start state 470, the computer moves to state 471 and recites a
identification method menu to request complaint identification.
After the initial screening questions (state 306, FIG. 7a) are
completed and a medical record (registration function 252) has been
opened, the MDATA system 100 asks the patient to describe the
complaint. The identification of the patient's problem is one of
the most important steps in the evaluation process. The system 100
has built-in safeguards to ensure that the patient understands the
questions and that the MDATA system 100 understands the patient's
complaint. For example, the system keeps tables of synonyms so that
any problem regarding the semantics of a question or a response can
be quickly resolved. The complaint may be identified in one of four
ways: by anatomic system 472, by cause 476, by alphabetic groups
480 or by catalog number 482.
[0278] The easiest and most frequently used way to identify the
complaint is by anatomic system, i.e., "what system is your problem
in?". Anatomic system 472 refers to basic body systems such as
cardiovascular, respiratory, nervous system, digestive,
ear/nose/throat, ophthalmology, gynecology/obstetrics, urology,
blood/hematology, skin, and endocrine. After the patient has
identified the anatomic system of their complaint, they are asked a
series of "System Screening Questions" at state 473. For each
anatomic system, there are some symptoms or combinations of
symptoms that, if present, would mandate immediate intervention,
such that any delay, even to go any further through the menuing
process, could cause harm. For example, if the patient has
identified the cardiovascular system as the anatomic system in
which his or her complaint lies (i.e., chest pain), the MDATA
system 100 will ask the cardiovascular system screening questions.
For example, the patient would be asked, "Do you have both pressure
in your chest and shortness of breath? If these symptoms are
present together, immediate intervention is necessary. With the
thrombolytic agents that are available today, time is critical in
order to save myocardial cells. Just a few minutes can mean the
difference between being able to resuscitate a patient or not.
[0279] Therefore, at state 474, the system 100 determines if a
serious medical condition exists. If so, the system 100 moves to
state 486, plays a message that advises the patient to seek
immediate medical attention and ends the evaluation process 254 at
a terminal state 488. If it is determined at state 474 that a
serious medical condition does not exist, the system 100 proceeds
to a complaint menu at state 475 and recites a list of algorithms
dealing with the problem that corresponds to the anatomic system
selected. The patient then selects an algorithm from the list.
[0280] If the patient is not sure of the anatomic system, the
system 100 attempts to identify the problem by requesting the
cause. Cause 476 refers to a cause for an illness or disease such
as trauma, infection, allergy/immune, poisoning, environmental,
vascular, mental, genetic, endocrine/metabolic, and tumor. Once the
patient has identified what they think is the cause of their
problem (e.g., trauma, infection), the MDATA system 100 asks the
"Cause Screening Questions" at state 477. These questions are asked
to make sure that the patient is not suffering from an immediate
life-threatening problem. For example, if infection were chosen as
the cause, the system would first rule out the possibility of
epiglottitis or meningitis before proceeding. Therefore, at state
478, the system 100 determines if a serious medical condition
exists. If so, the system 100 moves to state 486, plays a message
that advises the patient to seek immediate medical attention and
ends the evaluation process 254 at a terminal state 488. If it is
determined at state 478 that a serious medical condition does not
exist, the system 100 proceeds to a complaint menu at state 479 and
recites a list of algorithms dealing with the problem that
corresponds to the cause selected. The patient then selects an
algorithm from the list.
[0281] Alphabetic groups 480 lists the items in the anatomic system
group and the cause group together in alphabetic order. Moving to
state 481, the system determines if the selected item is from the
cause subgroup of the combined alphabetic groups. If so, the system
100 proceeds to the "Cause Screening Questions" at state 477. If
not, the system moves to the "System Screening Questions" at state
473.
[0282] Enter Catalog number state 482 refers to the ability of the
patient to select and enter an individual medical algorithm from a
catalog of medical algorithms listed in the patient guide
distributed to all patients. At the completion of state 475, 479,
or 482, the complaint has been identified, and the computer 102
proceeds to state 483 wherein a series of "initial" problem
screening questions are presented to the patient. There is a
different set of problem screening questions for every complaint
for which advice is offered.
[0283] For the purpose of this discussion, "Headache" will be used
as an example to describe how the system approaches the diagnosis
of a problem and provides treatment recommendations. As with many
problems, there are some causes of headache that require immediate
medical attention. Quite often, when a problem is very serious, any
delay, even to discuss it further, can adversely affect the
patient's outcome. The problem screening questions identify, at a
decision state 484, the subset of patients whose headaches may
require immediate medical care. If a serious medical condition
exists, the patient is advised to seek immediate medical attention
at state 486. The computer 102 then ends the evaluation process at
state 488 and returns to state 344 in FIG. 7d.
[0284] The following is an example of a problem screening question
for headache:
[0285] ARE YOU CONFUSED, LETHARGIC, OR LESS ORIENTED THAN
USUAL?
[0286] By asking a question about the patient's level of
consciousness, a dilemma has been confronted. What does the MDATA
system 100 do about the patient whose problem itself prevents them
from appropriately responding to questions or following advice?
[0287] There are some conditions that, by their very nature, may
prevent patients from answering questions correctly. For this
reason, the MDATA system 100 utilizes a "mental status examination"
function 508. The mental status examination is a series of
questions used to assess the patient's orientation. This function
508 allows the MDATA system 100 to assess the patient's ability to
respond to questions and to follow advice. Although only shown in
FIG. 10b, the mental status examination function 508 is
incorporated into the dialogue of any problem whose presentation
could include an altered level of consciousness. Function 508 will
be further described in conjunction with FIG. 16.
[0288] The MDATA system 100 will, of course, be accessed by
patients in whom an altered level of consciousness is not expected
based on the problem that the patient has. The system 100 does
anticipate the possibility of the patient having an altered level
of consciousness in some problems, e.g., when a patient consults
the system for striking his or her head, and invokes the mental
status exam function 508. However, an intoxicated patient, calling
for some other complaint, e.g., a sprained ankle, is one example
where the patient may not be able to understand instructions from
the system 100. For this reason, the MDATA system also utilizes a
"semantic discrepancy evaluator routine" (SDER) function 510. The
SDER function provides information to the patient and then, after a
predetermined period of time, asks the patient to repeat or select
the information. The patient's answer is then evaluated within
system 100. If discrepancies are determined, the system
automatically invokes the mental status examination function 508.
In another embodiment, the system 100 asks the patient for some
information in different ways at different times, and then compares
the patient's responses to determine if they are consistent. If
not, the system automatically invokes the mental status examination
function 508. Although only shown in FIG. 10b, the SDER function
510 is embedded throughout system 100, and is randomly evoked by
the computer 102. Function 510 will be further described in
conjunction with FIG. 17.
[0289] Continuing with the headache example at state 483, the MDATA
system 100 asks the next problem screening question in order to
help exclude the possibility of meningitis, a very serious
infection of the central nervous system.
[0290] IS BENDING YOUR NECK FORWARD SO THAT YOUR CHIN TOUCHES YOUR
CHEST EITHER PAINFUL OR NOT POSSIBLE?
[0291] If the answer to this question is "yes", a serious medical
condition exists at state 484 and the system 100 instructs the
patient to seek immediate medical attention at state 486.
[0292] The initial screening questions (state 306, FIG. 7a) and the
problem screening questions (state 483) can usually be completed
within a minute or so. Once the MDATA system 100 has excluded the
causes of headache that require immediate medical attention, the
system becomes a little less formal and more conversational in the
subsequent states. The examples given, of course, do not represent
all the initial or problem screening questions.
[0293] If no serious medical condition exists, as determined at
state 484, the computer 102 proceeds to a decision state 490
wherein the system 100 identifies those patients who are
"re-entering" the system from an earlier consultation. This occurs
most frequently when the system 100 needs to monitor a patient's
symptom over time, or if the system is initially unable to make a
specific diagnosis and would like the patient to re-enter the
system again, typically within a few hours. The system sets an
internal re-enter flag to identify the situation where a patient is
calling again for the same complaint. If the flag is set at state
490, the computer 102 proceeds to state 492 and branches to a
re-enter point in the evaluation process depending on which medical
algorithm has been evoked. The computer 102 moves via off-page
connector A 494 to state 506 (FIG. 10b) to the appropriate re-enter
point.
[0294] If the re-enter flag is not set, as determined at state 490,
the computer 102 moves via off-page connector B 496 to a decision
state 499 to determine if the consultation is being performed in
Real mode or Pending mode. If not (i.e., the consultation is in
Information mode), the computer proceeds to state 506 to continue
the evaluation process. If the consultation is in Real or Pending
mode, the computer 102 calls a "meta" function 500 wherein patients
are subjected to several "meta" analyses. This concept will be
explained in conjunction with FIG. 11, but, in general, it refers
to the system's ability to evaluate the patient's present problem
in the context of their past use of the system. The Meta function
500 matches various parameters against a predetermined meta
threshold. When the MDATA system 100 opens a patient's consultation
history file in database 262 (FIG. 6), it calculates how many times
the patient has consulted the system for the same complaint. For
each problem, the MDATA system 100 allows a specified number of
system consultations, per unit of time, before it takes action. If
the meta threshold is reached, as determined at a decision state
502, the MDATA system 100 makes a recommendation based on this fact
alone at state 504. For example, let us assume that the threshold
was set at five headaches in two months. If the patient consulted
the MDATA system 100 for headache more than four times in two
months, the threshold would be reached and the system would make an
appropriate recommendation. The threshold, of course, is different
for each complaint, and may be modified by a set of sensitivity
factors that will be described hereinbelow. Alternately, the system
100 uses a time density ratio (TDR) calculated by the meta function
500 to determine if a recommendation should be given to the
patient.
[0295] At the completion of state 504, or if the meta threshold was
not reached at state 502, the computer 102 proceeds to state 506 to
continue the evaluation process. State 506 includes a medical
algorithm as selected by the patient in states 475, 479, or 482.
Although not necessarily a complete list, other types of medical
algorithms include: Chest Pain, Heatstroke, Altered Level of
Consciousness, Tremor, Dizziness, Irregular Heartbeat, Fainting,
Shortness of Breath, Chest Injury, Depression, Head Injury, Cough,
Croup, High Blood Pressure, Hyperventilation, Numbness, Wheezing,
Inhalation Injury, and Strokes. In addition to meta and past
medical history functionality, at least some of the listed medical
algorithms rely upon knowledge of age and/or sex of the patient as
provided in the presently described system 100 at time of
registration (see FIGS. 9a and 13a).
[0296] Depending on the medical algorithm and the exact patient
condition, one or more auxiliary functions may be called by state
506 as follows: the mental status examination function 508, the
SDER function 510, a past medical history function 512, a physical
self examination function 514, a patient medical condition function
516, and a symptom severity analysis function 518. These functions
will be described hereinbelow.
[0297] Returning to the headache example, after the meta analyses
(function 500) are completed, the MDATA system 100 assesses the
severity of the patient's headache on a one-to-ten scale. The
importance of this purely subjective quantization of the symptom's
severity will become apparent later in this description.
[0298] Although the MDATA system's paradigm is fundamentally an
algorithmic one, the underlying logic of the diagnostic process for
headache will be described. The MDATA system 100 begins the
diagnostic process for headache by referring to three lists stored
internally in the computer 102.
[0299] The first list is a ranking of the most common causes of
headache in the general population. The most common cause is ranked
first, the second most common is ranked second, and so on. In other
words, the first list ranks all the causes of headache in the
general population in decreasing frequency of occurrence.
[0300] The second list is a ranking of the various causes of
headache according to the seriousness of the underlying cause. The
more serious causes are positioned toward the top of the list, the
less serious toward the bottom. For example, meningitis, brain
tumor, and subarachnoid hemorrhage would be the top three causes on
the second list.
[0301] The third list is quite similar to the second list. It ranks
the causes of headache according to the rapidity with which
intervention is necessary. The causes of headache that require
immediate intervention, such as meningitis and subarachnoid
hemorrhage, are toward the top. The problem screening questions
(state 483) were developed from this list.
[0302] During the evaluation process 254, the MDATA system 100 asks
the patient a series of "diagnostic screening questions." From the
answers to these questions, along with any physical signs elicited
from the patient (from function 514), under the direction of the
MDATA system 100, the system establishes the most likely cause of
the patient's headache.
[0303] The following are examples of diagnostic screening questions
for headache:
[0304] DO YOU EXPERIENCE MORE THAN ONE KIND OF HEADACHE?
[0305] DO YOU, OR DOES ANYONE ELSE, KNOW THAT YOU ARE GOING TO GET
A HEADACHE BEFORE THE ACTUAL PAIN BEGINS?
[0306] DO YOUR HEADACHES FREQUENTLY WAKE YOU UP AT NIGHT?
[0307] DO YOUR HEADACHES USUALLY BEGIN SUDDENLY?
[0308] Based upon the answers to the diagnostic screening
questions, the MDATA system 100 reorders the first list. The first
list then becomes a list of the possible causes of headache in
decreasing levels of probability in the patient seeking
consultation. The first list is now patient specific. If the MDATA
system 100 concludes that migraine is the most likely cause of the
patient's headache, then migraine will now be ranked at the top of
the first list.
[0309] The MDATA system 100 is knowledgeable about the difference
between classic, common, and all other variants of migraine, but
for this discussion the general term "migraine" will be used. After
reordering the first list and placing migraine at the top, the
MDATA system 100 then asks several questions related specifically
to migraine headaches. These are called the "migraine screening
questions." The probability that the patient actually has a
migraine headache is calculated from the answers to these
questions. Each cause of headache has its own set of screening
questions, physical examination signs, and, if the patient has the
MDATA system's Home Diagnostic and Treatment Kit, appropriate
laboratory tests.
[0310] The following are examples of migraine screening
questions:
[0311] IS EITHER NAUSEA OR VOMITING ASSOCIATED WITH YOUR
HEADACHE?
[0312] ARE VISUAL DISTURBANCES ASSOCIATED WITH YOUR HEADACHE?
[0313] After obtaining the answers to the migraine screening
questions, if the probability that the patient is suffering from a
migraine headache does not reach an established threshold, the next
cause of headache on the reordered first list is considered and
pursued as a diagnosis.
[0314] If the probability of having a migraine headache does reach
the threshold, the MDATA system 100 asks the patient several more
questions designed to confirm the presence of migraine, given the
fact that the system has already determined that it is the most
likely diagnosis. These are called the "migraine confirmation
questions." Just as each cause of headache has a set of screening
questions, each cause of headache also has a set of confirmation
questions.
[0315] The following are examples of migraine confirmation
questions:
[0316] DOES ANYONE WHO IS RELATED TO YOU BY BLOOD HAVE MIGRAINE
HEADACHES?
[0317] WHEN YOU HAVE A HEADACHE DO YOU FEEL MORE LIKE LYING DOWN OR
WALKING AROUND?
[0318] From the answers to the migraine confirmation questions, the
MDATA system 100 calculates the probability of confirmation of
migraine. In Bayes' terms (which refer to the probability of
certainty of a diagnosis) this is called a "conditional
probability."
[0319] If the probability of migraine headaches reaches threshold,
but the probability of confirmation of migraine does not reach
threshold, then, as mentioned, the system pursues the next
diagnostic cause of headache on the patient specific list.
[0320] If the probability of the second cause of headache (say
cluster) reaches threshold, then the "cluster confirmation
questions" are asked. If they reach threshold, then again the
serious causes of headache are excluded as a diagnosis.
[0321] The MDATA system 100 stores the scores of all the screening
and confirmation questions in what are called "session memory
variables" that are installed in the symbol table. It is, in part,
these scores that are then used to determine the probability of one
diagnosis versus another.
[0322] For example, if the answers to the cluster confirmation
questions do not reach threshold, then the scores of the screening
and confirmation questions of migraine and cluster are compared to
see which cause is the more probable.
[0323] Whichever has the higher score, or exceeds the other by a
predetermined threshold, is then assumed to be the more probable
cause. The list is, if necessary, again reordered. This time it
becomes the final diagnostic list which is a list of differential
diagnoses in decreasing levels of probability for this patient.
[0324] All of the headache scoring thresholds are modified or
modulated by a series of sensitivity factors as are all aspects of
the system in which scalar thresholds are used. The sensitivity
factors are discussed hereinbelow in section XVIII. For example, if
it was found that a subset of patients in which the diagnosis of
meningitis was not being made as early as it should be, then the
sensitivity factor modifying the temperature threshold could be
decreased so that now, a patient with a lower temperature would be
instructed to seek an immediate evaluation.
[0325] Before discussing the results with the patient, however, the
MDATA system 100 must again rule out the serious causes of
headache. The problem screening questions have already filtered out
those patients who have a serious cause of headache, such as
meningitis, that requires immediate medical intervention.
[0326] The MDATA system 100 now proceeds to eliminate those causes
of headache that, although serious, do not require immediate
medical attention. For example, although a brain tumor is a serious
cause of headache, it is not as immediately life threatening as
meningitis or subarachnoid hemorrhage. To accomplish this task, the
MDATA system 100 sequentially analyzes the serious causes of
headache that are located at the top of the second list. The MDATA
system 100 again asks the patient the set of screening questions
associated with each of the serious causes of headache. This time,
however, the MDATA system 100 makes sure that the probability of
having any of the serious causes of headache is sufficiently low in
order to exclude them from diagnostic consideration. Only after
this is accomplished will the system discuss its conclusion and
recommendations with the patient.
[0327] The discussion that the MDATA system would have with the
migraine headache patient would include the following:
[0328] Its diagnostic impression, or its diagnostic impressions in
decreasing levels of probability.
[0329] Its estimate of the level of probability of migraine.
[0330] Whether or not the system feels it has excluded the serious
causes of headache to a level of certainty that satisfies the
system.
[0331] What tests, if any, should be obtained to confirm or exclude
a diagnosis.
[0332] How soon to see a physician.
[0333] What kind of physician to see (e.g., family practitioner,
internist, or neurologist).
[0334] What kind of information to bring to the physician when a
consultation is obtained.
[0335] Questions to ask the physician.
[0336] The latest treatment for migraine.
[0337] Even if the MDATA system 100 cannot determine with
sufficient certainty what is causing the headache, it can still
provide patients with valuable information and advice. For example,
the patient may be told the following:
[0338] "At this time, the MDATA system is unable to pinpoint a
particular cause of your headache with the degree of certainty
required to make specific recommendations. The MDATA system,
however, suggests a consultation with a neurologist. You can either
call your family practitioner or internist and ask for a
referral.
[0339] "While you are waiting to be seen by the neurologist, there
are many things that you can do in order to help the physician
diagnose your headache. Many headache experts have found that a
record of when their patients' headaches occur and how bad they are
is very helpful in finding both the cause of the headache as well
as the best treatment.
[0340] "In order to assist you, the MDATA system will send you a
blank calendar on which you can record the time and severity of
your headaches. In addition, there is space for you to record what
seems to bring on the headaches, makes them worse, or makes them
better. The MDATA system will also send you a questionnaire to fill
out and give to your doctor, containing a list of questions asked
by some of the world's leading headache experts when they are
trying to arrive at a diagnosis."
[0341] A full set of instructions will be provided.
[0342] The MDATA system is able to customize the information given
to patients to accommodate the individual needs of a sponsoring
agency or group such as a Health Maintenance Organization (HMO) or
a Managed Care Plan. For example, if the system finds that the
patient should see a physician, the MDATA system can determine from
a patient's medical record whether they have an established
relationship with an appropriate specialist. If they do, the
specialist's name and phone number, or a list of participating
specialists for their HMO or Managed Care Plan and any specific
instructions, will be given to the patient with the recommendation
to make an appointment within a specific time frame.
[0343] At the conclusion of state 506, the system may or may not
have a reasonably certain diagnosis available. For example, the
headache algorithm provides a diagnosis of migraine in response to
a particular set of patient symptoms. In situations where the MDATA
system 100 cannot determine with sufficient certainty what is
causing a particular problem (no diagnosis) or in a situation where
a diagnosis is available but additional information is desirable,
e.g., to determine a trend, a re-enter flag may be set by the
system 100. At a decision state 520, the computer 102 determines if
re-enter criteria are met for the current algorithm and patient
situation. If so, the computer sets the re-enter flag at state 522
for this problem so a subsequent telephone consultation by the
patient will allow for additional information to be added to the
patient record by the system in full knowledge of the previous
call. This additional information may yield a better diagnosis.
[0344] If the re-enter criteria were not met, as determined at
state 520, the computer 102 proceeds to a decision state 524 to
determine if the patient desires to hear treatment information for
the current problem. If so, the computer 102 calls the treatment
table process 256, which will be described in conjunction with
FIGS. 22 and 23. If the patient does not wish to hear treatment
information at this time, the computer 102 advances to a decision
state 528 to determine if the patient would like to investigate
another complaint through the evaluation process 254. If so, the
computer 102 moves via off-page connector C 530 to state 471 on
FIG. 10a to repeat the process 254. However, if the patient does
not wish to pursue another complaint, the computer returns at state
532 to the top level flow (FIG. 7d).
XI. The Meta Function
[0345] Referring now to FIGS. 11a and 11b, the meta function 500
defined in FIG. 10b will be described. One of the many ways the
MDATA system 100 is qualitatively different from prior ways of
providing medical advice is in its use of the "meta function." As
mentioned earlier, "meta" refers to the system's ability to
evaluate the patient's present problem in the context of his or her
past use of the system. The meta function allows the system 100 to
make an inference based upon the number and frequency of previous
patient consultations (or, "medical complaints") and the system's
previous diagnostic assessments. Every patient who has previously
used the MDATA system 100 undergoes the meta analysis.
[0346] Input Parameters
[0347] The meta function 500 has five input parameters listed at
state 540 as follows:
[0348] i. Problem String (PS)--a four character alphanumeric string
indicating the patient's complaint. The first character of this
string is taken from the Systems column of Table 2. For example,
`N` denotes the nervous system. The second through fourth
characters identify an individual complaint, e.g., "NHDA"
identifies headache. Other examples:
[0349] CCHP Chest Pain
[0350] NINJ Head injury
[0351] RINH Inhalation of toxic fumes
[0352] ii. System String (SS)--a four character alphanumeric string
that indicates the affected anatomic system. The first character is
taken from the Systems column of Table 2. The second through fourth
characters are encoded with subsystem identification, or filled
with the `*` wildcard character. For example, "N***" will match all
cases that involve the nervous system.
[0353] iii. Cause String (CS)--a ten character alphanumeric string
that indicates the cause of the patient's complaint. The first
character is taken from the Causes column of Table 2. The second
through tenth characters are filled in as needed to more closely
specify the cause of interest. A very broad example is "I*********"
which denotes any infection. Other examples which illustrate how
the cause string can become very specific:
[0354] IV******** Viral infection
[0355] IB******** Bacterial infection
[0356] IBN*******Gram negative bacterial infection
[0357] IBNM******Meningococcal gram negative bacterial
infection
[0358] iv. Beginning Time (T.sub.1)--a timestamp value which
indicates the date and time to be used for the beginning of the
time window under consideration.
[0359] v. Ending Time (T.sub.2)--a timestamp value which indicates
the date and time to be used for the end of the time window.
[0360] Table 2 lists code letters used as the first letter of the
meta string parameter:
9 TABLE 2 Causes Systems A--allergy B--bones/orthopedics
E--environment C--cardiology I--infection D--gastro--intestinal
M--mental G--gynecology P--poison H--hematology (blood) T--trauma
L--larynx (ENT) V--vascular N--nervous X--genetic (chromosomal)
O--opthamology Y--nutritional/metabolic/endocrine R--respiratory
Z--tumor (cancer) S--skin U--urology
[0361] A set of meta function analyses involves the identification
of trends in the patient's medical history. For example, if a
patient went to his or her doctor with a history of gradually
worsening headaches (either more painful, more frequent, or both)
the physician would consider this worsening trend in his or her
management of the case. The MDATA system 100 also does this.
[0362] Meta Analysis
[0363] The algorithm author passes input parameters to the meta
function by using the keyword Meta, followed by the input
parameters enclosed in parentheses. The format for the meta
function is:
[0364] Meta(PS, SS, CS, T.sub.1, T.sub.2)
[0365] Two types of analysis are performed by the meta
function:
[0366] i. Pattern Matching
[0367] ii. Time density
[0368] i. Pattern Matching
[0369] In pattern matching analysis, the meta function compares the
input strings with the record fields in the patient's consultation
history database 262. The use of the `*` wildcard character in the
input string will cause the meta function to ignore the
corresponding character position in the record field, thereby
enabling the meta function to examine only the fields of interest.
By providing input strings that are either general or specific, the
fields of interest for analysis are selected. For example,
[0370] Meta("NHDA", "****", "**********", T.sub.1, T.sub.2)
[0371] will cause the meta function to only consider past
consultations for the problem of headache, regardless of the
anatomic system and cause involved.
[0372] Through the use of a common syntax, the meta process
supports four types or modes of pattern matching analysis, shown
here through examples:
[0373] (a) Problem analysis:
[0374] Meta("HDA", "****", "**********", 06/01/93, 12/31/93)
[0375] Here the meta function will find the number of complaints of
headaches that occurred between Jun. 1, 1993 and Dec. 31, 1993.
[0376] (b) Anatomic System analysis:
[0377] Meta("****", "D***", "***********", 06/01/93, 12/31/93)
[0378] Here the meta function will find the number of complaints
involving the gastro-intestinal system between Jun. 1, 1993 and
Dec. 31, 1993. For example, if a patient consulted the MDATA system
100 once for abdominal pain, once for vomiting, and once for
diarrhea, but each on a different occasion, the system would
recognize that these are all problems involving the
gastrointestinal tract.
[0379] (c) Cause analysis:
[0380] Meta("****", "****", "IB*********", 06/01/93, 12/31/93)
[0381] Here the meta function will find the number of complaints
that were found to be caused by bacterial infection between Jun. 1,
1993 and Dec. 31, 1993. The problems (complaints) caused by
bacterial infection could be in different parts of the body.
[0382] (d) Combination analysis:
[0383] Meta("NHDA", "****", "I**********", 06/01/93, 12/31/93)
[0384] Here the meta function will find the number of complaints of
headache that were found to be caused by infection between Jun. 1,
1993 and Dec. 31, 1993.
[0385] ii. Time Density
[0386] If the pattern matching analysis finds at least three
matching records in the patient's consultation history database
262, then the meta function performs a time density analysis. Time
density refers to the amount of time between each consultation. If
the amount of time between consultations is getting shorter, then
the frequency of consultation suggests that the nature of the
complaint is getting worse. Time density analysis reveals when a
problem is getting better, and when it is getting worse.
[0387] Time density analysis uses the meta records that matched the
pattern matching criteria. The computer designates the most recent
meta record `n`, the next most recent is record `n-1`, and the
second most recent is record `n-2`. The time stamp of each meta
record is examined, and two time difference values, X and Y, are
determined according to the formula:
X=time difference (n-2, n-1)
Y=time difference (n-1, n)
[0388] The ratio of these time differences produces the time
density ratio (TDR):
Time Density Ratio=X/Y
[0389] The significance of the time density ratio value can be seen
through the following examples:
EXAMPLE 1
Time Between Consultations is the Same
[0390]
10 Consultation Date of Consultation n - 2 Jun. 01, 1993 n - 1 Jun.
08, 1993 n Jun. 15, 1993
[0391] Calculate:
X=time difference (06/01/93, 06/08/93)=7 days
Y=time difference (06/29/93, 06/15/93)=7 days
Time Density Ratio=7 days/7 days=1.0
EXAMPLE 2
Time Between Consultations is Getting Shorter
[0392]
11 Consultation Date of Consultation n - 2 Jun. 1, 1993 n - 1 Jun.
22, 1993 n Jun. 29, 1993
[0393] Calculate:
X=time difference (06/0/93, 06/22/93)=21 days
Y=time difference (06/29/93, 06/22/93)=7 days
Time Density Ratio=21 days/7 days=3.0
[0394] When consultations are occurring at even intervals, then the
TDR value is close to unity. If the frequency of consultations is
decreasing, then the TDR value will be less than 1.0. This would be
typical of a problem that is resolving itself. If the frequency of
consultations increases, then the TDR value will be greater than
one. In the second example, the TDR value of 3.0 indicates a
consultation rate increase of three times during the analysis
period. This would be typical of a problem that is rapidly getting
worse.
[0395] Return Values
[0396] After the meta function returns, two local memory variables
are installed in the symbol table and contain the results of the
meta analysis:
[0397] i. Match Counter (MC)--an integer that contains the number
of meta string matches found within the time window.
[0398] ii. Time Density Ratio (TDR)--a floating point value that
expresses whether the frequency of meta string matches is
increasing or decreasing.
[0399] After calling the meta function, the algorithm author can
then make decisions based upon the values returned in these two
memory variables.
[0400] For example:
[0401] Meta("NHDA", "****", "**********", 06/01/93, 12/31/93)
[0402] If MC>=3 then 100 else 101
[0403] The meta function counts the number of complaints of
headache between Jun. 1, 1993 and Dec. 31, 1993. If the number of
complaints found (MC) is greater than or equal to 3, then the
evaluation process branches to node 100; otherwise it branches to
node 101.
[0404] Another example:
[0405] Meta("****", "****", "I*********", 06/01/93, 12/31/93)
[0406] If TDR>=2.0 then 200 else 201
[0407] The meta function is invoked to count the number of
diagnoses attributed to a cause of infection. If the infection
caused diagnoses found have a time density ratio greater than or
equal to 2.0, then the evaluation process branches to node 200;
otherwise it branches to node 201.
[0408] Referring again to FIG. 11a, the meta function 500
initializes at state 540 by popping the input parameters off the
run-time stack and storing them in local memory variables: PS for
problem string, SS for anatomic system string, CS for cause string,
T.sub.1 for the beginning date and T.sub.2 for the ending date.
After the start state 542, the computer moves to state 544 and
initializes the pattern match counter to zero.
[0409] The computer 102 then moves to state 546 wherein it begins
the pattern matching analysis. The computer 102 reads the first
meta record in the patient's consultation history database 262 and
moves to a decision state 548 wherein it examines the record's
timestamp. If the timestamp falls within the time window
established by the input parameters T.sub.1 and T.sub.2, then the
computer will move to state 550; otherwise it moves to state 554.
At state 550, the computer 102 compares the contents of the meta
record problem field with the input string PS, the meta record
anatomic system field with the input string SS and the meta record
cause field with the input string CS. If all these fields match the
respective input strings, then the computer moves to state 552
wherein the match counter MC is incremented, and then the computer
moves to state 554. If there is any mismatch between a meta record
field and its respective input string, then the computer moves to
state 554 and does not increment MC.
[0410] At decision state 554, the computer 102 determines if there
are more meta records to process. If so, the computer 102 moves to
state 556 wherein it reads the next record and then moves back to
state 548 to perform the time window determination. The meta
function iterates through this pattern matching until all of the
meta records have been read. When there are no more meta records to
be processed, the computer moves through off-page connector A 558
to a decision state 560 on FIG. 11b wherein a determination is made
if the value of the match counter MC is greater than or equal to 3.
If so, then the computer moves to state 564 wherein it begins the
time density analysis.
[0411] At state 564, the computer 102 locates the three most recent
meta records whose fields matched the input strings. The computer
designates the most recent meta record `n`, the next most recent is
record `n-1`, and the second most recent is record `n-2`. The
computer then moves to state 566 wherein it calculates X, the time
difference between the timestamps of records n-2 and n-1, and Y,
the time difference between records n-1 and n. The computer 102
then moves to state 568 wherein it calculates the time density
ratio (TDR) as the time X divided by time Y.
[0412] If the computer 102 determined at state 560 that there were
less than three matches, then it would move to state 562 wherein it
sets the value of the time density ratio (TDR) to 0.0, which
indicates that the time density analysis could not be performed. At
the completion of establishing the value of TDR at either state 562
or 568, the computer 102 moves to terminal state 570 wherein the
meta process terminates, returns the match counter MC and the time
density ratio TDR, and returns control to the evaluation process
254 (FIG. 10).
[0413] The interaction of the meta analyses for cause and for
anatomic system can be conceptualized by means of a simple
geometric metaphor. Consider a two dimensional array in which the
causes of disease (trauma, infection, allergy/immune, and so forth)
are placed on the "Y" axis, or ordinate, and the anatomic systems
of the body (cardiac, respiratory, nervous system, and so forth)
are placed on the "X" axis or abscissa. Disease then can be
represented by, or is produced at, the intersection of the lines
drawn from the applicable cause and the anatomic system.
[0414] As a very simple illustration, consider the two-dimensional
array shown in Table 3 (FIG. 24). The array of Table 3 shows an
infection in the central nervous system represented at the
intersection of the cause of disease (infection) and the anatomic
system involved (the nervous system).
[0415] Of course, each cause of disease can be further divided into
subcauses. For example, infection would be broken down (or
subdivided) into bacterial and viral, and bacterial would be
further broken down into gram positive and gram negative, and gram
positive would be further yet broken down into streptococcus, and
so on. The anatomic systems could be broken down in a similar
way.
[0416] As a patient uses the system 100, and as the meta analyses
for cause and for anatomic system attribute causes to disease
processes and record the anatomic systems involved, a
three-dimensional cube (a "meta cube") is produced composed of
these stacked two-dimensional arrays. The "Z" axis coordinate of
each layer is the time of the patient's consultation obtained from
the system clock (i.e., the moment that the actual intersection of
the cause and anatomic system occurs indicating the diagnosis).
[0417] The "meta cube" then represents a summation of the patient's
interaction with the system 100 through time. Although much of the
patient's past history is stored using
ICD.quadrature.9.quadrature.CM codes as well as conventional text
strings in fields of the patient's medical record, the "meta cube"
technique allows very useful analyses to be done.
[0418] Using the same modeling metaphor, the "Z" axis coordinate
can be used to represent the practice of medicine. Here the "Z"
coordinate is again time, but in this representation, time refers
to a spectrum of ages from pediatrics to geriatrics. Thus, each
coronal plane represents specialties by time, e.g., pediatrics,
adolescent medicine, adult, geriatric. A vertical plane describes a
specialty by anatomic site, such as neurology or cardiology, while
a horizontal plane describes a specialty which practice is bounded
(subsumed) by (on) cause, such as oncology or infectious disease.
To further this metaphor, the rapidity with which intervention is
necessary could be a fourth dimension of the model, and the
frequency of an occurrence of a disease is the fifth dimension.
Ethical and moral responsibility could be a sixth dimension of the
model.
[0419] Node Map Traverse Analysis
[0420] The MDATA system 100 uses a "neural net emulator" program to
determine if patterns produced by patients, as they traverse down
the nodes (creating "node tracks" of the algorithms in the course
of a consultation, may be early predictors of disease. Somewhat
like the "meta cube," the "node tracks" can be superimposed, rather
than stacked, upon one another to create a two-dimensional array.
This time, however, the pattern produced represents the sum of the
patient's previous consultations. In the MDATA system 100, this is
called a "node track traverse analysis."
[0421] For example, the MDATA system 100 may discover that the
pattern that is produced when a patient consults the system, at
different times, for episodes of diarrhea, cough, and oral
candidiasis may be predictive of AIDS. Or, that the pattern
produced when a patient consults the system for increased frequency
of urination and weight loss may be predictive of diabetes
mellitus.
XII. Mental Status Examination
[0422] Referring to FIGS. 16a and 16b, the mental status
examination function 508 defined in FIG. 10b will be described. The
mental status examination is a series of questions used to assess
the patient's orientation that allows the system 100 to determine
the patient's ability to respond to questions and to follow advice.
The examination is automatically incorporated into the dialogue of
any problem whose presentation could include an altered level of
consciousness. If an operator or nurse monitoring a telephone
consultation at any time feels there may be a problem with the
caller's ability to understand or respond to questions, the mental
status examination may also be manually invoked.
[0423] If the MDATA system 100 determines that the patient is not
sufficiently oriented based on the results of the mental status
examination, the system 100 will ask to speak to someone other than
the patient. If no one else is available, the MDATA system 100 can
contact the emergency medical services system in the patient's area
if the system knows the patient's present geographic position.
[0424] Beginning at a start state 680 of FIG. 16a, the computer 102
initializes the value of a variable Score to be zero. Moving to
state 682, the computer asks the patient Question #1. In the
presently preferred embodiment, the question is "what day of the
week is it?" If the person answers the question correctly, as
determined by a decision state 684, the computer 102 increments the
value of Score by one. After Score is incremented or if the patient
did not answer the first question correctly, the computer 102 moves
to state 688 wherein the computer 102 asks the patient Question #2.
In the presently preferred embodiment, the question is "what month
of the year is it?" If the person answers the question correctly,
as determined by a decision state 690, the computer 102 increments
the value of Score by one. After Score is incremented or if the
patient did not answer the second question correctly, the computer
102 moves to state 694 wherein the computer 102 asks the patient
Question #3. In the presently preferred embodiment, the question is
"who is the President of the United States?" If the person answers
the question correctly, as determined by a decision state 696, the
computer increments the value of Score by one. After Score is
incremented at state 698 or if the patient did not answer the third
question correctly, the computer 102 moves through off-page
connector A 699 to a decision state 700 on FIG. 16b.
[0425] At decision state 700, the computer 102 compares the score
to the mental status exam threshold at a decision state 700. If the
score meets or exceeds the threshold, then the mental status exam
returns to the evaluation process at state 701 and the diagnostic
evaluation continues. If the score does not reach or exceed the
threshold value, the computer 102 moves to state 702 wherein the
operating mode flag is set to Pending. The MDATA system 100 will
then ask, at a decision state 703, if someone else is available to
continue the consultation. If no one else is available, any new
information gathered up to this point in the session is saved to
Pending file 269 at state 704 and then, at state 705, the telephone
call with the patient is transferred to a medical staff person. If
someone else is available, as determined at state 703, and is able
and willing to continue the evaluation process of the patient, as
determined at state 706, the computer 102 asks the person if he or
she is a registered assistant at state 707. If the person responds
"yes", the computer 102 invokes the assistant login process 272 at
start state 940 on FIG. 12a. If the person is not a registered
assistant, the computer 102 invokes the assistant registration
process 274 at start state 1050 on FIG. 14a. After assistant
registration or login, the computer 102 moves to terminal state 708
wherein the mental status examination process terminates and the
evaluation process 254 resumes. At the end of the evaluation
process 254, any new information gathered during the session will
be written to the patient's past medical history file at state 348
or to pending file 269 at state 347 on FIG. 7d, depending on
whether the session continued in real or pending mode. In the
presently preferred embodiment, the value of Score could be zero,
one, two, or three. Of course, in other embodiments, different
questions to be asked of the patient may be utilized in the mental
status exam function 508.
XIII. Semantic Discrepancy Evaluator Routine
[0426] Referring to FIG. 17, the semantic discrepancy evaluator
routine (SDER) 510 defined in FIG. 10b will be described. The SDER
510 uses one or more questions that ask for the same information at
different times, and in other embodiments, in different ways. The
answers given by the patient are then compared within the system
100 to help determine the mental status of the patient.
[0427] Beginning at a start state 712, the computer 102 moves to
state 716 and recites a message to the patient. In the presently
preferred embodiment, the message is "remember this three digit
number . . . NUMBER", where the computer generates a random three
digit number (i.e., in the range 100 to 999 inclusive) as NUMBER
which is kept in a session memory variable.
[0428] Then, after a predetermined time interval at state 718, the
computer 102 moves to state 720 and recites a request of the
patient. In the presently preferred embodiment, the request is
"please tell me the three digit number." The computer 102 then
compares the number given by the patient in response to state 720
against the NUMBER kept in the memory variable at a decision state
722. If the numbers match, the computer 102 returns at state 724
with a status of pass to the evaluation process (FIG. 10b). If the
numbers do not match, the computer 102 returns at state 726 with a
status of fail to the evaluation process. In the presently
preferred embodiment, if the return status of the SDER 510 is
"fail", the evaluation process 254 automatically invokes the mental
status examination function 508.
XIV. Past Medical History Routine
[0429] Referring to FIG. 18, the Past Medical History Routine
(PMHR) 512 defined in FIG. 10b will be described. The contents of a
patient's past medical history file, which is part of the PMH
database 268, are loaded to the symbol table when the patient logs
in to the system 100. During the evaluation process 254, a TEST is
performed by the computer 102 before a particular medical algorithm
is initiated to verify that necessary items are present in the
symbol table. The effect of a negative TEST result is that the
system 100 prompts the patient to provide the missing past medical
history information via the PMHR 512.
[0430] The PMHR 512 uses an input parameter "condition label" (L)
as indicated at State 740. The "Condition label" is unique, e.g.,
PMHRLTB1 corresponds to the first PMH object tested in the croup
(RLTB) algorithm: diagnosis for croup in children. The label is
passed so that PMHR 512 knows what questions to ask. The ability of
the system 100 to ask a past medical history question in the middle
of the evaluation process 254 is a feature that saves the patient
from having to answer the entire PMH questionnaire during the
registration process. The boolean result, or scalar value, is
stored in the symbol table under this label (PMHRLTB1), and the
algorithm can use it in decision making, e.g., If PMHRLTB1=True
Then 4310 Else 4320.
[0431] Beginning at a start state 742, the computer 102 moves to
state 744 and prompts the patient for the missing medical condition
data. Moving to state 746, the computer 102 repeats the information
provided at state 744 and asks the patient if the repeated
information is correct. Moving to a decision state 748, the patient
responds by indicating whether the repeated information is correct.
If the data is not correct, the computer 102 proceeds to state 750
to determine if the patient would like to attempt the data entry
step again. If so, the computer 102 loops back to state 744 and
prompts the patient for the data again. If not, the computer 102
returns at state 754 to the evaluation process (FIG. 10b).
[0432] If the newly-entered data is correct, as determined at state
748, the computer 102 advances to state 752 and installs the
condition label (L) and the data value in the symbol table for the
patient. The computer 102 then returns at state 754 to the
evaluation process 254.
XV. Physical Self Examination
[0433] Referring to FIG. 19, the Physical Self Examination function
514 defined in FIG. 10b will be described. A physical examination
can actually be done by the patient under the direction of the
MDATA system 100. The MDATA system 100 is designed to function
primarily based upon responses to carefully crafted questions,
i.e., history, and physical findings elicited from the patient.
There are times, however, when the addition of certain laboratory
tests can increase the accuracy of the diagnosis as well as help
determine the appropriate treatment recommendations. For this
reason, a MDATA system Home Diagnostic and Treatment Kit is
available for use by patients. If the patient has the Home
Diagnostic and Treatment Kit, including visual field cards,
Snelling chart, and possibly the MDATA system's "tele-stethoscope"
to assess intracranial or carotid bruits, this information will be
used in the diagnostic process as well.
[0434] The MDATA system 100 is also able to play tones of different
frequencies and intensities to emulate audiometric testing for
hearing acuity. This allows, for example, the MDATA system 100 to
detect the unilateral decrease in hearing caused by an acoustic
neuroma.
[0435] Beginning at a start state 770, the computer 102 branches to
one or more physical self examination procedures depending on the
current problem and what equipment if any is available for use by
the patient. These procedures include: home diagnostic tests 772,
vital signs 774, observable physical signs 776, clinical sound
recording 778, and tele-stethoscope 780.
[0436] A variety of home diagnostic tests 772 are available for use
by the patient. New advances in biotechnology, including a new
generation of urine dipsticks such as a "Multistix 8 SG" produced
by Ames and monoclonal antibody tests such as "ICON.RTM. STREP B"
produced by Hybritech.RTM., allow an entire spectrum of laboratory
tests to be performed at home by the patient under the direction of
the MDATA system. For example, urine dipsticks can be used to check
for blood, nitrites, leukocytes, or leukocyte esterase indicating
cystitis or a bladder infection.
[0437] In order to use much of the monoclonal antibody technology,
however, a small amount of blood must be obtained by using a
fingertip lancet. This is already successfully being done by
diabetics at home who use a glucometer to measure their blood sugar
after pricking their finger to get a small sample of blood.
[0438] The MDATA system Home Diagnostic and Treatment Kit also
contains equipment to allow the patient, or someone else, to
measure the patient's vital signs 774. A blood pressure cuff and
thermometer are included with instructions for their use as well as
instructions to measure pulse and respiratory rate.
[0439] The patient may be directed by the system 100 to observe
various physical signs 776. For example, a headache patient will be
asked to palpate their temporal artery area, and to look at
themselves in the mirror to identify the ptosis and tearing of a
cluster headache or to identify the steamy cornea that may occur
with acute narrow angle glaucoma.
[0440] As an example of how the MDATA system Home diagnostic and
Treatment Kit could be helpful, consider a woman who (using the
MDATA system's urine pregnancy test based on ICON.RTM. II HCG
ImmunoConcentration.TM. Assay, produced by Hybritech.RTM.) finds
out that she is pregnant. This is her first pregnancy. Later, when
consulting the system for headache, a urine dipstick indicates
protein in her urine and the measurement of her vital signs shows a
significant rise in her blood pressure. This is a classic
presentation of preeclampsia.
[0441] Instead of going to a doctor's office, patients could also
use the MDATA system's Home Diagnostic and Treatment Kit to collect
samples at home and then send them to a designated lab for analysis
as needed. This saves time for the patient and is especially useful
if the patient has difficulty in traveling. Costs should also be
minimized in this type of laboratory analysis.
[0442] The MDATA system 100 records clinically relevant sounds 778
of a patient such as the cough of bronchitis, the seal bark cough
of croup or the inspiratory stridor of epiglottitis. These sounds
are digitized and stored in the patient's medical record. Then,
using the re-enter feature of the system 100, the system can
monitor, for example, a patient's cough over time to be sure that
the cough is resolving as it should.
[0443] The general concept of recording and analyzing a cough is
disclosed in the article A microcomputer-based interactive cough
sound analysis system, C. William Thorpe, et al., published in
Computer Methods and Programs in Biomedicine, 1991. The cough sound
analysis system describes the filtering, amplification, recording,
and software processing of a cough sound. The MDATA system 100 uses
the telephone handset microphone in conjunction with an amplifier
to procure the clinical sounds. These sounds are then transmitted
to the system 100 where they are filtered, digitized using VP board
122 and recorded to a file in the patient medical history database
268 on the hard drive 152 (FIG. 1).
[0444] The MDATA system 100 is building a library of clinical
sounds that allows patterns or profiles to be developed that relate
the wave form of the clinical sound to the probability of a
particular diagnosis. For example, the MDATA system 100 could
compare the cough of a patient to the sound library to see if the
cough of the patient is similar to those that eventually have been
diagnosed as lung cancer.
[0445] In addition, the patient's record of the pronunciation of
his or her name may be periodically recorded and compared to
previous recordings. This allows the MDATA system 100 to
potentially detect and evaluate the hoarseness that could be
produced by a nodule on the patient's vocal cords.
[0446] A "tele-stethoscope" 780 is a device that allows the sounds
a physician would hear through a stethoscope to be transmitted over
the telephone. The tele-stethoscope 780 is functionally similar to
that described in the 1992 Arthur D. Little report entitled
"Telecommunications: Can It Help Solve America's Health Care
Problems?". The tele-stethoscope 780 permits the MDATA system 100
to greatly expand the spectrum of its sound analyses to include
heart murmurs, the bruits of intracranial aneurysms, breathing
sounds like the wheezes of asthma and the rales of congestive heart
failure, or even the bowel sounds of an intestinal obstruction.
[0447] There is more information in clinical sounds than can be
represented by a two-dimensional pattern matching model.
Transforms, e.g., Fourier, are used to shift different aspects of
sounds into domains that can be quantified. The sounds are then
pattern matched using an n-dimensional array. Consider a simple two
dimensional array where time is represented on the X coordinate and
amplitude is measured on the Y coordinate. For example, a cough may
be recorded at two times several days apart. In this example, the
computer 102 superimposes the waveform from one cough upon the
other cough. The non-overlapping parts of the pattern both above
and below represent the difference in the domain being measured
between the two sounds. The area under these two curves is
integrated to obtain the area. The sum of the areas of the two
curves represents the difference between the two sounds in the
domain being measured. The resultant area is then subjected to one
or more sensitivity factors which are discussed hereinbelow. Hence,
the more sensitive the system, the sooner it makes a match.
[0448] In a similar way, a sound pattern may be considered with
time on the X coordinate and frequency on the Y coordinate. The
same methodology is used to quantify the differences between the
two curves. Thus, in a similar way, all aspects of sound can be
measured.
[0449] In this pattern matching scheme, different weights are given
to the different aspects of the sound depending upon which clinical
sound is measured. In most sounds, the amplitude and frequency are
the most important aspects. The weight or the relative importance
of an aspect is different for each of various clinical sounds, such
as heart murmurs, bruits, wheezes, coughs, stridor and so
forth.
[0450] When value(s) from any of the procedures 772-780 are
procured by the system 100, the computer 102 moves to state 782,
recites the value and requests the patient to confirm the value. If
the patient indicates that the value is correct, as determined at a
decision state 784, the computer 102 proceeds to state 786 and
installs the value into the symbol table associated with the
current patient. If the value is not correct, as determined at
decision state 784, the computer 102 proceeds to state 790 to
determine if the patient would like to try providing the value
again. If so, the computer 102 loops back to the beginning of the
function 514. If the patient does not wish to try again, as
determined at state 790, or if state 786 is completed, the computer
102 returns at state 788 to the evaluation process (FIG. 10b).
[0451] Referring to FIG. 20, the Patient Medical Condition Routine
516 defined in FIG. 10b will be described. In the course of
executing a particular medical algorithm in the evaluation process
254 (as shown at state 506), the computer 102 may request
additional medical condition information of the patient. This
information reflects the current condition of the patient, which is
in contrast to the information requested by the past medical
history routine 512 (FIG. 18) for past history information. The
states 800 through 814 of the routine 516 are essentially the same
as states 740 through 754 of routine 512, except that in routine
512 the condition label (L) denotes a value for which a past
medical history question is to be asked during the evaluation
process, while in routine 516 the condition label denotes a new
value desired by the algorithm. Therefore, states 800-814 are not
further described herein.
XVI. Symptom Severity Analysis
[0452] Referring now to FIGS. 10a, 10b, and 21, the symptom
severity analysis function 518 defined in FIG. 10b will be
described. A review and further description of the re-enter
feature, which is associated with symptom severity analysis, is
also provided here.
[0453] An important feature of the MDATA system 100 is its ability
to follow or monitor a patient over time. If the MDATA system 100
is in the process of diagnosing a patient's complaint but is not
certain what action should be taken (states 520-522 of FIG. 10b),
system 100 may ask the patient to re-enter the system at a
designated time, usually within a few hours.
[0454] When the patient calls the MDATA system at the designated
time, the system takes the patient through the initial problem
screening questions (state 483 of FIG. 10a) in order to exclude
those problems that require immediate medical attention. The system
detects that the patient is a re-enter case (state 490 of FIG.
10a), and then determines the re-entry point in the evaluation
process based upon the patient's previous interaction with the
system (state 492 of FIG. 10a). For example, if the MDATA system
established a diagnosis of migraine, that is, if both the
probability of migraine and the probability of confirmation of
migraine reached threshold values, the patient would not repeat the
diagnostic process, which is the usual case.
[0455] Occasionally, however, a patient for whom a diagnosis has
not been established will be asked to re-enter the system 100. This
patient is again asked the diagnostic screening questions, in
addition to the initial screening questions (state 306 of FIG. 7a)
and problem screening questions (state 483 of FIG. 10a). If the
MDATA system 100 is not able to establish a diagnosis for a
re-enter patient, he or she is referred to a physician for further
evaluation.
[0456] In addition to the re-enter feature, the MDATA system 100
has the capability to call patients back in order to monitor their
progress. The same trending methodologies are used regardless of
who initiates the call, i.e., the system or the patient. Using this
capability, the MDATA system 100 can provide regular or periodic
monitoring of elderly patients in their homes as well as inform
patients when a new therapy becomes available.
[0457] Many problems for which the MDATA system 100 offers advice
have absolute thresholds for the initial quantization of the
severity of a symptom. For example, chest pain that is described by
a patient as being 10 on a 10-scale of severity, would reach the
problem-specific initial symptom-severity threshold and would
mandate a consultation with a physician.
[0458] Interestingly, with headache, an initial severity
characterized by the patient as 10 on a 10-scale would not, in
itself, necessarily require an immediate consultation with a
physician. If, in addition, the headache came on suddenly and, as
was mentioned earlier, was described as the worst headache of the
patient's life, the MDATA system 100 would consider this to be
suggestive enough of a subarachnoid hemorrhage to advise an
immediate consultation with a physician.
[0459] Continuing in the headache example, after a re-enter patient
with an established diagnosis is asked the initial and problem
screening questions, the MDATA system 100 again assesses the
severity of the patient's headache. Reassessing the severity of the
headache, by having the patient re-enter the system, establishes
two points of reference. The system 100 is now able to analyze any
changes in the level of severity as well as calculate the rate of
change in severity over time.
[0460] The symptom severity analysis function 518 has a Number of
Points (N) as an input parameter as indicated at state 830. Number
of Points refers to the points of reference established during the
initial consultation for a particular problem and during subsequent
re-enter consultation(s). Beginning at a start state 832, the
computer determines the value of (N), i.e., the number of reference
points, at a decision state 834. If it is determined that N=2, the
computer 102 moves to state 836 to compute the slope of a line
connecting the two reference points using standard mathematical
techniques. Proceeding to state 838, a variable named Power is set
to be one because only two reference points are used at state 836.
The computer 102 returns at state 840, with output parameters Slope
and Power as determined by function 518, to the evaluation process
(FIG. 10b).
[0461] Using the returned Slope and Power parameters in the
evaluation process 254, if the MDATA system 100 determines that the
severity of the headache, for example, is increasing too rapidly,
that is, if a slope of the line connecting two points on a graph of
the severity reaches a set threshold, system 100 will make an
appropriate recommendation.
[0462] If the MDATA system 100 finds that the severity of the
headache is staying the same or is getting worse but is doing so at
a relatively slow rate, it may ask the patient to re-enter the
system a second time (i.e., for a third consultation), usually
within a shorter period of time. The third consultation gives the
MDATA system 100 three points of reference from which to trend the
severity of the headache. Thus, when the function 518 is called by
the evaluation process, the value of (N) is three, as determined at
state 834, and the computer 102 branches to state 844. At state
844, the computer 102 determines the slope and power of a line
connecting the three reference points. The presently preferred
embodiment uses the well-known Runge-Kutta method, which is a
numerical approximation technique for solving differential
equations. Other embodiments may use other well-known, standard
curve fitting functions at state 844.
[0463] If the system 100 determines that yet one or more additional
consultations, i.e., beyond three consultations, are desired, e.g.,
to establish a trend with certainty, it will again request the
patient to re-enter the system at a later time. In this situation,
the three most recent reference points are used in the calculation
at state 844.
[0464] The system 100 then performs a "sequential symptom-severity
slope analysis" to determine if the symptom is getting worse too
rapidly as follows. The slopes of the lines connecting the first
and second point, the second and third point, and then the first
and third point are calculated. If any of these reach a
problem-specific threshold, the appropriate recommendation is
given.
[0465] If the sequential symptom-severity slope analysis does not
reveal the need to seek medical attention, then the MDATA system
100, in addition to calculating the rate of change in the severity
of the symptom with respect to time (the slope analysis), now
calculates the rate of change of the rapidity with which the
headache is getting worse. This is the first derivative.
[0466] Table 4 (FIG. 25) illustrates this relationship. Time maps
onto the "X" axis and the symptom's severity maps onto the "Y"
axis. Note that a line connecting these three points forms a gently
sloping straight line. The MDATA system 100 using this data
determines that, although the symptom is getting worse, it is doing
so in an arithmetical or linear way. That is, although the severity
of the symptom is increasing, the symptom's rate of change is not
increasing.
[0467] In contrast, a line connecting the three points on the graph
of Table 5 (FIG. 26) forms a sharply upturned curve. The MDATA
system 100 using the data of Table 5 determines that, not only is
the symptom rapidly getting worse, but more significantly, the rate
at which the symptom is getting worse is also increasing. In the
MDATA system 100, this analysis is termed an "exponential
symptom-severity filter." All patients who re-enter the system a
second time are subjected to this analysis.
[0468] It is important to note that the severity of a problem,
e.g., a headache, is not necessarily related to the seriousness of
the underlying cause. The MDATA system 100 is programmed such that
when any symptom gets rapidly worse, medical intervention is
frequently advised as necessary. This concept is valid for many
symptoms.
[0469] Returning to the symptom severity analysis function 518
(FIG. 21), if the function 518 is called with N=0, or N=1, the
computer branches to state 842. At state 842, the Slope and Power
parameters are set to zero, and the computer 102 returns these
parameters at state 840 to the evaluation process (FIG. 10b). The
values set at state 842 essentially flag an error condition that is
acted on by the evaluation process 254.
XVII. Treatment Table
[0470] Referring to FIG. 22, the Treatment Table process 256
defined in FIG. 7d will be described. The MDATA system 100 is
modularized in its approach to diagnosis and treatment. In
medicine, diagnosis simply means figuring out what is causing the
problem, and treatment refers to what action should be taken once
the cause of the problem is known.
[0471] Diagnosis is composed of history, physical examination,
imaging studies, and laboratory tests. Again, history is by far the
most important factor in making the diagnosis. In fact, in medical
school, students are taught that if they don't have a good idea of
the diagnosis by the end of the history, they are doing something
wrong.
[0472] The treatment side of medicine is conceptually different
from diagnosis in that, while the basic principles of making the
diagnosis remain the same, treatment is continually changing.
Treatment is fundamentally a "look-up" table with the diagnosis,
age and sex on the left and the most current treatment on the right
as shown in Table 6. Or, treatment can be thought of like the
cubbyholes or boxes of a post office. Each individual box holds the
treatment for a given disease. The information given is age and sex
specific. The contents of the box are constantly changing, but the
location of the box does not. For example, what is thought to be
the best antibiotic to treat meningitis in a two-year-old child
could literally change from week to week as more antibiotics are
developed and approved or more controlled studies are
published.
12TABLE 6 Simplified TREATMENT TABLE Example Diagnosis Treatment
meningitis in a antibiotic of choice two-year old child as of
current date
[0473] The MDATA system 100 maintains a treatment table that can be
updated instantaneously to provide the most current treatment
recommendations.
[0474] The treatment table can be directly accessed by patients who
already know their diagnosis. For example, asthma patients can
consult the system as often as they wish to see what the absolute
latest treatment is for their condition. In fact, links are
maintained between the treatment table and the patient medical
history files 268. In this way, when a new treatment is introduced
for any of the ICD.quadrature.9.quadrature.M codes listed in the
MDATA system 100, patients can be contacted and asked to either
call the system 100 back at their convenience or have the MDATA
system 100 fax or mail the information to them. The MDATA system
100 can also notify patients' doctors when a new treatment is
identified.
[0475] The concept of using a table is also helpful with regard to
two aspects of the diagnostic process that often do change: the
imaging modality of choice (like X-ray, Computerized Tomography
(CT), Magnetic Resonance Imaging (MRI)), and the laboratory test(s)
of choice. Therefore, the MDATA system 100 also maintains a table
for imaging modality of choice as well as laboratory test(s) of
choice in the work-up or diagnosis of a particular complaint. By
modularizing these aspects of the diagnosis, as new imaging
techniques, like Positron Emission Tomography (PET) scanning, and
new laboratory tests, like recombinant DNA technology, are
discovered, only the tables have to be altered, not the medical
algorithms themselves.
[0476] The treatment table will be further described in a general
way as process 256 in FIG. 22. The treatment table process 256
begins at start state 860 and proceeds to state 862 wherein the
computer prompts the caller to choose a treatment selection
method:
[0477] i. Treatment selected from layered menus, or
[0478] ii. Treatment selected via direct entry of a catalog
number.
[0479] The first selection method entails the use of the
menu-driven treatment selection process 864 which will be described
hereinbelow in conjunction with FIG. 23. The second selection
method at state 866 uses a treatment table catalog message number.
This catalog is part of the patient information package, a section
of which appears in Table 7. The treatment table catalog is
organized by anatomic area and diagnosis, and when applicable, by
age and gender. After the patient selects a catalog number, the
computer 102 stores the selection in a memory variable `M`. As an
alternate selection method, the system 100 allows the patient to
directly enter the ICD.quadrature.9.quadrature.CM code for their
problem. In this case, the computer 102 will look-up the
ICD.quadrature.9.quadratu- re.CM code in an internal
cross-reference table to identify the catalog number, and set the
memory variable `M` to this catalog number.
13TABLE 7 Portion of Treatment Table Catalog NEUROLOGY Diagnosis
Message Epilepsy 1101 Meningitis 2 years old & younger 1201
over 2 years old 1202 Depression Male Under age 50 1301 50 years
and older 1303 Female Under age 50 1302 50 years and older 1304
[0480] Once the value of the memory variable `M` is established by
process 864 or state 866, the computer 102 moves to state 868 and
plays treatment message `M` to the patient. At the conclusion of
treatment message playback, the computer 102 moves to a decision
state 870.
[0481] At state 870 the computer 102 checks for existence of
society message `M`. The society message category contains
information about organizations that assist patients with a
particular disease. If the society message `M` does not exist, the
computer 102 moves to a decision state 874. Otherwise, the computer
102 will move to state 872 wherein it plays society message `M` to
the patient. At the end of the society message `M`, the computer
moves to state 874.
[0482] At state 874, the computer 102 checks for the existence of
an over-the-counter (OTC) message `M`. The OTC message category
contains information about generally available over-the-counter
medications and home treatment for a particular diagnosis. If the
OTC message `M` does not exist, the computer moves to state 878.
Otherwise, the computer 102 moves to state 876 wherein it play OTC
message `M` to the patient. At the end of the OTC message `M`, the
computer 102 moves to state 878.
[0483] At state 878 the computer 102 plays a terminal menu to the
patient which allows the patient to either select another
treatment, or to exit from the treatment table process 256. If the
patient wishes to hear another treatment message, the computer 102
moves back to the treatment selection method menu state 862. If the
patient wishes to exit the treatment table process 256, the system
moves to state 880, wherein the treatment table process 256
terminates and returns to the top level flow (FIG. 7d) at state
344.
[0484] An example of the treatment, society and OTC messages for
epilepsy are given in Table 8. Note that since the OTC message is
empty, the computer 102 would skip over the OTC message playback
and proceed directly to the terminal menu.
Table 8
Treatment Table Messages for Epilepsy
[0485] Treatment Message
[0486] As of Dec. 20, 1993, according to Emergency Medicine:
Concepts and Clinical Practice, Third Edition, by Drs. Rosen,
Barkin, et. al., pages 1800 and 1801, the initial treatment of
generalized tonic-clonic seizures, i.e., grand mal seizures, is as
follows:
[0487] After efforts to discover and treat acutely correctable
causes like hypoglycemia, the following pharmacologic agents are
indicated:
[0488] 1. Intravenous administration of lorazepam, with a loading
dose of 0.1 mg/kg and an infusion rate not to exceed 2 mg/min.
[0489] Which is usually followed by:
[0490] 2. Intravenous administration of phenyloin, with a loading
dose of 15 to 18 mg/kg and an infusion rate not to exceed 0.75
mg/kg per minute.
[0491] If lorazepam is not effective, and in those individuals
allergic to phenyloin:
[0492] 3. Intravenous administration of phenobarbital, with a
loading dose of 8 to 20 mg/kg and an infusion rate not to exceed
0.75 mg/kg per minute.
[0493] If the above is not successful:
[0494] 4. A neuromuscular blocking agent like pancuronium, with an
intravenous dose of 0.03 to 0.1 mg/kg.
[0495] 5. Intravenous administration of paraldehyde, with a loading
dose of 0.1 to 0.15 ml/kg, diluted with saline to a 4% to 6%
solution and slowly infused over 1 hour.
[0496] Society Message
[0497] "For further information on epilepsy, contact:
[0498] Epilepsy Foundation of America
[0499] 1828 L Street, N.W., Suite 406
[0500] Washington, D.C. 20036
[0501] (202) 293-2930
[0502] In addition to the national headquarters, there are 100
local chapters. The San Diego chapter can be contacted at (619)
296-0161."
[0503] OTC Message
[0504] None.
[0505] Referring now to FIG. 23, the menu-drive treatment selection
process 864 defined in FIG. 22 will be described. The menu-driven
treatment selection process 864 begins with start state 890 and
proceeds to state 892 wherein the computer 102 recites an area menu
to the patient and requests selection of one area. The complete
menu is not shown in state 892. The areas are arranged by anatomic
system. For example, if a patient has epilepsy, the patient can
simply select this from the anatomic system menu for the
neurological system.
[0506] Based on the patient's selection, the computer 102 branches
to a selection area menu state, such as neurological area menu
state 894, wherein the computer 102 recites a list of diagnoses to
the patient and requests selection of a diagnosis. In some cases
the diagnosis is further subdivided by gender, age or both gender
and age. At state 904, for example, for a diagnosis of meningitis,
the computer 102 would prompt the patient to select from a
secondary menu between a treatment for a child two years old or
younger and a treatment for somebody over two years old. Then,
based on the patient's selection, the computer 102 sets a memory
variable `M` to the value of the selected diagnosis message number
at state 908 or 910. State 906 is another example secondary level
menu which has four choices based on gender and age. These four
choices are associated with four states, 912, 914, 916, 918,
wherein the computer 102 sets the memory variable `M` to the value
of the diagnosis message number that was selected at state 906.
After the catalog number has been stored in memory variable `M`,
the computer 102 moves to return state 923 wherein the menu-driven
treatment selection process terminates and returns control to the
treatment table process 256.
[0507] Area2 menu 896 and AreaN menu 898 are indicative of menus
similar to menu 894 but for different anatomic systems. Menu 896
and 898 may have secondary menus, similar to menus 904 and 906
under menu 894. Then, states 920 and 922 are indicative of the
computer 102 setting memory variable `M` to the value of the
diagnosis message number selected from the parent menu 896 or 898,
respectively.
XVIII. The MDATA System Paradigm
[0508] The MDATA system paradigm is based on several fundamental
principles. They are as follows:
[0509] Centralization of medical information
[0510] Accessibility of medical information
[0511] Modularity of medical information
[0512] Modifiability of the system.
[0513] As mentioned earlier, one of the purposes of the MDATA
system 100 is to bring together highly qualified medical experts,
encode their knowledge in a central location, and make this
information available to everyone.
[0514] Although the issue of accessibility has been discussed
several times, it is important to understand its significance.
Accessibility in the MDATA system 100 refers both to the way in
which the medical information can be retrieved from the system 100
by non-medically trained personnel as well as to the need for
people everywhere to easily and promptly obtain medical
information. By using the already established worldwide
telecommunications network, the MDATA system 100 can provide
universal and nearly instantaneous access to high quality,
100%-consistent medical advice.
[0515] In the MDATA system 100, the concepts of modularity and
modifiability are inextricably intertwined. Modularity is the key
to the MDATA system's ability to provide patients with the most
current medical information available. The MDATA system's modular
design and object oriented techniques allow the individual
components of the system to be modified or updated without
generating a ripple effect on other information in the system
100.
[0516] In contrast, the print media suffers from an inability to
quickly adapt to changing information. Once a book or journal is
published, it cannot be modified until its next publishing date.
The MDATA system 100, however, can be modified within hours of a
new discovery in medicine. Easy modifiability is another way in
which the MDATA system 100 is qualitatively different from
previously published algorithms.
[0517] Once the medical algorithms for the MDATA system 100 are
written and programmed, they can then be continuously updated and
refined as advances in medicine are made. Unfortunately, physicians
today are simply not able to keep up with the explosion of new
medical information and technology. This ability to nearly
instantaneously modify the MDATA system 100 is a powerful feature
of the system.
[0518] It is presently possible for a computer to search the
world's medical literature daily. Any articles pertaining to a
particular topic can automatically be requested and the information
used to update the system.
[0519] In addition, the MDATA system 100 is currently using optical
character recognition technology to digitize its medical database.
Then, using indexing techniques, the MDATA system 100 is able to
search for and retrieve any information desired. For example, the
system can search for the character string "headache" and retrieve
any amount of surrounding text or graphic information. This
information is then collected, collated, printed and referred to
the physician(s) maintaining the headache algorithm. This process
will become easier as more of the world's medical literature is
digitized.
[0520] Global Factors--Sensitivity and Selectivity
[0521] Another way in which the MDATA system is modifiable is in
its use of global sensitivity/selectivity factors. As with every
decision, there is always a balance to be achieved between risk and
benefit, and so with the MDATA system 100. One of the questions the
MDATA system 100 tries to answer is whether the patient needs to be
seen immediately by a physician. This leads to this discussion
about sensitivity and selectivity.
[0522] Sensitivity and selectivity are statistical terms that refer
to how accurately a decision can be made. In this case, sensitivity
refers to the number of patients which the MDATA system 100 did not
think needed to be seen by a physician but that actually did.
[0523] If the program were to be so sensitive that no disease
process that eventually required meaningful physician intervention
would be treated at home (no false negatives), then every single
complaint would necessitate a visit to the doctor, which is a
useless system. On the other hand, too selective a system (no false
positives) i.e., no unnecessary visits to the doctor's office,
would necessitate that an attempt be made at home treatment for
every complaint, which is a useless and dangerous system.
[0524] So again, a balance must be reached between these two ends
of the spectrum. To achieve this, the sensitivity/selectivity ratio
of the entire MDATA system 100 can be changed by setting or tuning
a plurality of sensitivity factors. These sensitivity factors
affect the following functions: meta thresholds, reenter horizon
threshold, frequency of call back, symptom-severity filters,
sequential slope filters, exponential symptom-severity filters, and
probabilities of diagnoses in the treatment table. In addition, as
in the headache example, the scoring of the screening questions
already weighted is modulated or modified by the sensitivity
factors.
[0525] Experience from the regionalization of trauma centers in
this country shows an interesting trend over time with respect to
sensitivity and selectivity. It has been shown that the inverse
relationship between sensitivity and selectivity, when plotted over
time, yields a sinusoidal wave form in which the amplitude of the
wave form gradually decreases with time as the system is "fined
tuned" as shown in Table 9 (FIG. 27). The MDATA system's
sensitivity factors are designed to do just that, i.e., fine tune
the system over time to find the right balance between sensitivity
and selectivity.
[0526] In addition to the use of global factors, the MDATA system
100 maintains what are termed "emergency filter response sets."
When a patient replies "yes" to any of the problem screening
questions, the recommendation or message that follows is called an
emergency filter response or "EFR." The EFR sets are modularized so
that the system can customize the message that the patient hears.
This allows the system 100 to match the EFR sets to the desired
level of sensitivity or selectivity as well as provide information
specific to an HMO or Managed Care Plan.
[0527] System Sensitivity Factors
[0528] There are ten sensitivity factors that affect threshold
determination in the MDATA system 100:
[0529] S1=system-wide (usually established by the system
administrator and affects the entire MDATA system)
[0530] S2=the anatomic system of the body involved (e.g., nervous
system in headache example)
[0531] S3=cause (e.g., infection causes meningitis)
[0532] S4=problem specific (established by the algorithm author at
the beginning of an algorithm)
[0533] S5=question specific (within a particular algorithm)
[0534] S6=organizational specific (e.g., HMO, hospital)
[0535] S7=patient specific
[0536] S8=a reserved sensitivity factor for later use
[0537] S9=a reserved sensitivity factor for later use
[0538] S10=a reserved sensitivity factor for later use
[0539] Initially, the sensitivity factors have a value of 1.0. The
sensitivity factor's value is usually inversely proportional to
sensitivity; i.e., if the value is decreased, sensitivity
increases.
[0540] The sensitivity factors are applied to the threshold
constant value in the relational expression component of an IF-Then
or If-Then-Else statement of a medical algorithm. For example,
let's assume that the system 100 is in the meningitis algorithm and
that a temperature greater than 102 degrees will trigger a
recommendation to go to a hospital. An example of a threshold
calculation without sensitivity factors follows:
[0541] If temp>102 then X else Y
[0542] where X denotes the recommendation to go to the hospital and
Y denotes a different branch point. Following is the same example,
but including sensitivity factors:
[0543] If temp>(102*S1*S2*S3*S4*S5*S6*S7*S8*S9*S10) then X else
Y
[0544] The use of the sensitivity factors permits anticipation of
change. Tuning the initial product of the sensitivity factors from
"1.00" to "0.95" would decrease the temperature at which the system
recommends a trip to the hospital. Each threshold calculation or
other use of the sensitivity factors may use any number of (e.g.,
two factors) and any combination of the factors. Additionally, any
combination of factors may be modified from the initial 1.0 value
in any particular threshold calculation.
[0545] Age criteria is also modified by use of the sensitivity
factors. For example: If Age>45*S1*S4 then X else Y.
[0546] Examples of areas the system 100 could be tuned follow:
[0547] Anatomic system (e.g., cardiovascular)--the system is
missing too many heart attacks;
[0548] Cause (infection)--the system is missing too many injuries
(trauma);
[0549] Problem specific (e.g., headache)--the headache algorithm is
missing too many cases of meningitis or subarachnoid bleeds;
[0550] Question specific (each question in an algorithm can be
modified)--this would change the "weight" of a question in a series
of weighted questions like the migraine screening questions;
[0551] Patient specific--one patient might want to be VERY careful
while another might say, "in general I don't go to the doctor until
I'm really sure something is wrong with me";
[0552] Organizational (e.g., Kaiser patients)--Kaiser hospital
management may say that the system is missing too many cases of
meningitis and may request to be more careful with their patients
(send them in with a lower temperature).
[0553] The sensitivity factors affect the following system 100
functions:
[0554] (a) Re-enter Feature--the sensitivity factors affect the
re-enter horizon, i.e., the amount of time after which the system
100 considers a repetition of the same complaint to be a new
problem. If sensitivity increases, the re-enter horizon becomes
sooner.
[0555] (b) Meta Function--the sensitivity factors affect the
matching and time density ratio thresholds. By reducing the values
of the system-wide and problem sensitivity factors, e.g., from 1.0
to 0.9, the matching threshold and the time density ratio are
decreased:
EXAMPLE 1
Without Sensitivity Factors
[0556] Meta("NHDA", "****", "**********", 06/01/93, 12/31/93)
[0557] If MC>=3 then 100 else 101
EXAMPLE 1
With Sensitivity Factors
[0558] Meta("NHDA", "****", "**********", 06/01/93, 12/31/93)
[0559] If MC>=(3*S1*S4) then 100 else 101
EXAMPLE 2
Without Sensitivity Factors
[0560] Meta("****", "****", "I**********", 06/01/93, 12/31/93)
[0561] If TDR>=2.0 then 200 else 201
EXAMPLE 2
With Sensitivity Factors
[0562] Meta("****", "****", "I*********", 06/01/93, 12/31/93)
[0563] If TDR>=(2.0*S1*S4) then 200 else 201
[0564] Thus, there is no necessity to change the algorithms
themselves. In other words, the factors can be modified rather than
changing the algorithms.
[0565] (c) Problem Questions--To take the headache example
previously used, the sum of the scores of the screening and
confirmation questions (and sometimes the questions themselves) is
multiplied by the sensitivity factors. The questions are also
weighted, of course, depending upon how important each question is
to the diagnosis. The sum of the weighted scores is compared
against the threshold value that will result in either making the
diagnosis of say migraine (in response to the migraine screening
questions) or confirming the diagnosis of migraine in response to
the migraine confirmation questions.
[0566] Thus, if we wanted to increase the sensitivity of diagnosing
subarachnoid hemorrhage, we would not have to write another
algorithm, but rather, simply multiply the screening and
confirmation scores by the sensitivity factors.
[0567] For example, if the threshold for the MDATA system 100 to
make a diagnosis of subarachnoid hemorrhage based on the sum of the
weighted subarachnoid screening questions threshold is set at, say
75%, then that percentage of the sensitivity variable would make
this diagnosis with a smaller score and, thus, pick up more cases.
Thus, individual diagnoses within an algorithm can be "tuned"
independently, and in some cases, this even applies to the
individual questions themselves.
[0568] (d) Symptom Severity and Symptom Severity Trend
Analysis--the sensitivity factors alter the absolute value, the
first, second and third slope thresholds. With increased
sensitivity, a more gently sloping line triggers an earlier medical
evaluation. In the algorithm, when the system 100 makes use of any
quantitatable parameter to make a decision, all of these are
joined, influenced or multiplied by the sensitivity factors. As a
very simple example, if the MDATA system 100 would normally make a
recommendation, partly based on the age of the patient (e.g., if
you are male and you are over 50 and . . . ), the decision can be
triggered if the patient is 49 or 48 and so on.
[0569] (e) Home Diagnostic and Treatment Kit--if the patient has a
MDATA system treatment kit or a blood pressure cuff, the level at
which a fever or blood pressure effects a decision can be
changed.
[0570] (f) Mental Status Examination--the mental status examination
can be modified at a system, or problem (algorithm) level.
[0571] (g) Clinical Sound Library--the pattern matching process (as
in the clinical sound library) is quantifiable by modifying the
sensitivity factors.
XIX. Video Imaging of the Patient
[0572] There are four main types of video imaging: static black and
white, static color, video black and white and video color. Each of
these main types is now discussed.
[0573] Images as basic as static black and white images can provide
useful information to the system 100. Static black and white
imaging is used with neural net pattern matching. This process
permits analyzing for example, facial features to aid in the
detection of certain diseases, such as the characteristic facies of
Cushing's syndrome or the exophthalmos of Graves disease.
[0574] Color static imaging allows color frequency analysis to
detect diseases that are not as readily detected with static black
and white imaging, such as cyanosis of respiratory failure or the
scleral icterus of hepatitis. Color thus provides an incremental
benefit in the level of disease detection.
[0575] Real time black and white video imaging allows for the
evaluation of physical signs such as pupillary responses, extra
ocular muscle function, lid lag, and nystagmus. Cranial nerve
function can be remotely evaluated, along with, for example, the
distinction between central and peripheral VII nerve function.
[0576] Color video imaging, especially using fiber optics, adds
much more capability in the evaluation of a patient's condition.
For example, color video imaging is very useful in evaluating
capillary refill or monitoring the response of a patient with
cyanosis to supplemental oxygen. Another embodiment of the system
100 may employ inexpensive laser sources to perform real time
holographic imaging.
XX. Benefits of the MDATA System
[0577] It is rare when the humanitarian and entrepreneurial
interests of a venture overlap. The confluence of purpose that
exists in the MDATA system is striking. It is a "win-win"
proposition from every perspective.
[0578] Not only will the MDATA system 100 substantially reduce the
overwhelming costs of our current health care system, but for the
first time in history, every person can have access to high
quality, 100%-consistent and affordable medical advice and
information. No matter from what perspective one views the MDATA
system 100, its benefits are substantial.
[0579] The health care consumer obviously gains the most. Now,
whenever he or she has a medical problem, or any member of their
family, an immediate consultation can be obtained. The knowledge
that the best health care information and medical advice is only a
telephone call away can assuage the anxiety of everyone from new
mothers to elderly patients confined to their homes.
[0580] By endorsing the MDATA system 100, federal, state and local
governments could discharge their obligation to provide a universal
and affordable level of health care for all of their citizens. In
addition, the MDATA system 100 helps care for patients who cannot
pay, thus relieving primary care physicians of the necessity to
provide care without reimbursement. For the first time, Health
Maintenance Organizations and Managed Care Plans will be able to
effectively screen patients by telephone in order to ensure that
patients are best matched with the services they need.
[0581] Specialists can use their talents, not on the repetition of
familiar rituals, but will be free to concentrate on those more
challenging problems that cannot easily be resolved by the MDATA
system 100. They will also benefit from an increased number of
patient referrals as well as having a well-constructed patient
history when a consultation is sought.
[0582] Physicians themselves can access the MDATA system 100 in
order to stay informed about new information and technological
advances in the medical field. This is particularly true with the
treatment, imaging, and laboratory test databases.
[0583] Medical information is a continually renewable resource
because it is not consumed in its dissemination. The opportunity
exists, through the MDATA system 100, for the United States to
provide much needed medical information to the world and, at the
same time, bring capital into this country. In the process, this
country could maintain its leadership in innovation, technology,
and software development.
[0584] The United States and the world are facing a health care
crisis so monumental that it is difficult to comprehend. There are
diseases that threaten our very survival as a species. All of us
know the apprehension and bewilderment we feel when an illness
strikes. When this occurs, we need answers to specific medical
questions, answers that are absolutely up-to-date, instantly
available, and affordable.
[0585] The key is information: information about prevention, early
detection of disease, and about its most efficient treatment. The
MDATA system 100 can provide this information through the simple
use of the telephone, to nearly every inhabitant of the planet. In
addition, the MDATA system 100 converts and explains complicated
medical terminology and concepts into language easily understood by
everyone.
[0586] People do not have to be ill to consult the MDATA system
100, just curious. Patients do not have to schedule appointments,
they can simply pick up the telephone. Although many patients will
later be seen by a physician, the MDATA system 100 can provide
immediate help for everyone. The MDATA system 100 at once
establishes egalitarian access to health care information. Although
many patients in this country receive state-of-the art medical
care, there is a large segment of the population that is deprived
of one the most basic health care and medical information. The
MDATA system 100 begins to close this enormous gap.
[0587] The MDATA system 100 begins to effect a restructuring of the
health care delivery system in which both health care consumers and
providers participate in the improvement of the system itself. The
MDATA system 100 and its patients will be in partnership to provide
the most current, economical, and concise treatment available. The
upside potential is unlimited. Whether one believes health care is
a right or a privilege, there can be no doubt that it is
fundamentally necessary. Whether one believes we have a civic
responsibility or a moral obligation to care for one another, it
must be done. The fundamental simplicity of the structure of the
MDATA system 100 belies its power as a highly useful tool in the
delivery of health care.
XXI. Optional System Configuration
[0588] A second embodiment of the MDATA system entails a major
shift of how the questions and responses are delivered to the
patient. Rather than the use of a telephone, the voice processing
and voice response technology, the system software is published via
media such as floppy disks, CD ROM, or PCMCIA cards for use on a
patient's personal computer. This second embodiment is referred to
as the screen version or the (Stand-Alone) SA-MDATA system. The
computer could be, for example, a desktop computer, a laptop or
notebook computer, or a handheld, pen-driven computer. The system
questions are displayed on a display screen that is part of the
computer or is connected to the computer. The patient uses a
keyboard or a pointing/writing device connected to the computer to
respond to the questions. The patient files are maintained and
updated within the computer or on removable storage devices. The
diagnosis, advice, and treatments can be displayed on the screen
and also printed in hardcopy form on a printer (if available). New
versions of the SA-MDATA system are either mailed to subscribers
are available via modem. These new versions may include updates of
the treatment table for new treatments. Another embodiment of the
SA-MDATA system may include using specialized receiver devices that
receive encoded FM signals on a demand basis when an event (a new
treatment) triggers the device, such as described in U.S. Pat. No.
5,030,948.
[0589] A unique and separate authoring language (called File Output
or FO) was used to develop the medical algorithms used in the
screen version embodiment of the system 100. Through the use of FO,
the contents of text files are presented online to users, and then
the users respond to questions and directions issued by the text
files.
[0590] FO is designed as a typical, generalized authoring language,
in which commands are embedded into text files (herein called FO
files) to perform specific screen and keyboard functions. FO files
are in effect programs written in the FO "language" that
communicate (via FO) with the user online.
[0591] FO adds no text of its own. In fact, FO does not need to
know what text file content it is executing. The programmer or
author of a FO file is in complete control of the text content and
the sequence in which it is presented. Using the various commands,
the author can display text, format the screen, ask the user
questions, input responses from the user, select different text
files for execution, and generally control and direct the entire
session.
[0592] This version of FO is intended as a development version that
gives the user much freedom at the keyboard. The user can interrupt
a presentation and edit the FO file being presented. The assumption
here is that the user is in fact the author or an alpha tester
charged with verifying and correcting file content.
[0593] A FO file is any standard sequential ASCII text file with
variable-length lines terminating with a Carriage Return (ASCII
13). Any line with a period in column one is treated as a command.
A line without a leading period is treated as a print command.
[0594] The FO program processes a FO file by reading it one line at
a time into memory. If the line is a text line, it is printed and
the next line is loaded. If the line is a command line, the command
is executed. If the command involves a wait on the user (such as a
.M command), FO continues loading the FO file behind the scenes
until it has been completely loaded. In this manner, FO executes
the FO file as it is loading it. Once loaded, the FO file remains
entirely in memory.
[0595] The system software for the screen version embodiment is
written in Borland Turbo Pascal version 3.0. A second version of
the system software for the screen version embodiment of the system
100 is written in Microsoft G.W. Basic and is run in interpretive
mode.
[0596] In yet other embodiments, other databases/files or
algorithms can be used. The general system, method and procedures
would remain the same. For example, a specialty field such as
sports medicine could be added to the system.
[0597] The MDATA system 100 described herein finds application in
many environments, and is readily adaptable for use therein. For
example, the system finds use in any application that is
step-oriented and can be algorithmically described. For example,
the system could give car diagnostic services over the phone to a
caller. Then, when the car is brought to a service facility for
repairs (treatment), the caller will be informed and have a good
idea of what the problem is and probable repairs will be.
Accordingly, the claims are to be interpreted to encompass these
and other applications of the invention within their scope and are
not to be limited to the embodiments described herein.
XXII. Summary of Advantages of the Present Invention
[0598] One of the main problems of the health care crisis is the
limited access to health care information when it is needed. The
MDATA system provides up-to-date medical information and advice
that is instantly available twenty-four hours a day. The advice
that is given is 100% consistent.
[0599] The quality of the advice is much better if a physician can
stop, research, and anticipate all possible causes of a problem and
then systematically go about dealing with all of these possible
causes. In medical practice, a physician just does this from
memory.
[0600] No humans are necessary to actually give the medical advice.
The MDATA system is automated which helps to bring down the cost of
health care.
[0601] An exact record of the questions asked and the answers given
is stored in the patient's database. The MDATA system time-and-date
stamps the responses to the questions (as transaction records) so
that an exact reconstruction of the patient's interview(s) can be
generated for use by a physician or other health care professional.
The system also keeps a record of what version of an algorithm has
been consulted as well as the sensitivity factor set for that
consultation. At the conclusion of the interaction, the MDATA
system can tell the patient how long the consultation has taken and
what charges have been incurred, if any.
[0602] When possible, the MDATA system 100 takes into account the
past medical history of the patient, especially those pieces of
information learned from past consultations with the MDATA system
100, before advice is given. In addition, the advice given is
different depending upon the age and sex of the patient. The "meta"
functions provide another advantage by allowing the MDATA system
100 to evaluate a problem in the context of the patient's prior
consultations with the system.
[0603] While the above detailed description has shown, described
and pointed out the fundamental novel features of the invention as
applied to various embodiments, it will be understood that various
omissions and substitutions and changes in the form and details of
the device illustrated may be made by those skilled in the art,
without departing from the spirit of the invention.
* * * * *