U.S. patent application number 17/725488 was filed with the patent office on 2022-08-04 for context scores to enhance accuracy of ecg readings.
The applicant listed for this patent is Physio-Control, Inc.. Invention is credited to Daniel W. Piraino, Robert G. Walker.
Application Number | 20220240831 17/725488 |
Document ID | / |
Family ID | 1000006284751 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220240831 |
Kind Code |
A1 |
Walker; Robert G. ; et
al. |
August 4, 2022 |
CONTEXT SCORES TO ENHANCE ACCURACY OF ECG READINGS
Abstract
The present disclosure encompasses an "artifact score" derived
from the signal characteristics of an acquired 12-lead ECG, (2) a
"patient context score" derived from key elements of the patient's
history, presentation, and pre-hospital emergency care, and (3)
techniques for integrating these scores into an emergency medical
care system.
Inventors: |
Walker; Robert G.; (Seattle,
WA) ; Piraino; Daniel W.; (Seattle, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Physio-Control, Inc. |
Redmond |
WA |
US |
|
|
Family ID: |
1000006284751 |
Appl. No.: |
17/725488 |
Filed: |
April 20, 2022 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16443726 |
Jun 17, 2019 |
11317846 |
|
|
17725488 |
|
|
|
|
15365938 |
Nov 30, 2016 |
10321836 |
|
|
16443726 |
|
|
|
|
62261231 |
Nov 30, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 1/3925 20130101;
A61B 5/332 20210101; A61B 5/358 20210101; A61B 5/7221 20130101;
A61N 1/3904 20170801; A61B 5/282 20210101; A61B 5/361 20210101;
A61B 5/316 20210101 |
International
Class: |
A61B 5/358 20060101
A61B005/358; A61B 5/00 20060101 A61B005/00; A61B 5/316 20060101
A61B005/316; A61B 5/282 20060101 A61B005/282 |
Claims
1. A medical device, comprising: a measurement circuit configured
to detect a physiological parameter of a patient; an output device;
a processor configured to: identify data indicative of the
physiological parameter over time; identify a shape in the data,
the shape being indicative of a physiological condition of the
patient; identify an artifact in the data; generate an artifact
score as a function of a magnitude of the artifact in the data;
determine, by analyzing the artifact score, a likelihood that the
shape in the data accurately indicates the physiological condition;
and cause the output device to output an indication of the
physiological condition with the likelihood that the shape in the
data accurately indicates the physiological condition.
2. The medical device of claim 1, wherein the output device
comprises: a screen configured to visually output the indication of
the physiological condition with the likelihood that the shape in
the data accurately indicates the physiological condition; or a
transmitter configured to transmit a signal to an external device,
the signal comprising the indication of the physiological condition
with the likelihood that the shape in the data accurately indicates
the physiological condition.
3. The medical device of claim 1, wherein the shape comprises a
first shape and the data comprises first data indicative of the
physiological parameter during a first time, wherein the processor
is further configured to: identify second data indicative of the
physiological parameter during a second time; and identify a second
shape in the second data, the second shape being indicative of the
physiological condition, and wherein the processor is configured to
determine the likelihood further by analyzing the second shape in
the second data.
4. An apparatus, comprising: a processor configured to: identify
data indicative of a physiological parameter over time; identify a
shape in the data, the shape being indicative of a physiological
condition; identify an artifact in the data; generate an artifact
score as a function of a magnitude of the artifact in the data;
determine, by analyzing the artifact score, a likelihood that the
shape in the data accurately indicates the physiological condition;
and provide an indication of the physiological condition with the
likelihood that the shape in the data accurately indicates the
physiological condition.
5. The apparatus of claim 4, further comprising: a transmitter,
wherein the processor is configured to provide the indication by
causing the transmitter to communicate the indication to an
external device.
6. The apparatus of claim 4, further comprising: a screen, wherein
the processor is configured to provide the indication by causing
the screen to visually output the indication.
7. The apparatus of claim 4, further comprising: a measurement
circuit configured to detect the physiological parameter.
8. The apparatus of claim 4, wherein the processor is further
configured to: determine that the likelihood is greater than a
threshold, and wherein the processor is configured to provide the
indication in response to determining that the likelihood is
greater than the threshold.
9. The apparatus of claim 4, wherein the physiological parameter is
of a patient, and wherein the processor is further configured to:
identify a medication or symptom of the patient, and wherein the
processor is configured to determine the likelihood further by
analyzing the medication or symptom of the patient.
10. The apparatus of claim 4, wherein the shape comprises a first
shape and the data comprises first data indicative of the
physiological parameter during a first time, wherein the processor
is further configured to: identify second data indicative of the
physiological parameter during a second time; and identify a second
shape in the second data, the second shape being indicative of the
physiological condition, and wherein the processor is configured to
determine the likelihood further by analyzing the second shape in
the second data.
11. The apparatus of claim 4, wherein the physiological parameter
comprises an electrocardiogram (ECG).
12. The apparatus of claim 4, wherein the physiological condition
comprises an ST elevated myocardial infarction (STEMI).
13. A method, comprising: identifying data indicative of a
physiological parameter over time; identifying a shape in the data,
the shape being indicative of a physiological condition;
identifying an artifact in the data; generating an artifact score
as a function of a magnitude of the artifact in the data;
determining, by analyzing the artifact score, a likelihood that the
shape in the data accurately indicates the physiological condition;
and providing an indication of the physiological condition with the
likelihood that the shape in the data accurately indicates the
physiological condition.
14. The method of claim 13, wherein providing the indication
comprises transmitting the indication to an external device.
15. The method of claim 13, wherein providing the indication
comprises displaying the indication.
16. The method of claim 13, further comprising: determining that
the likelihood is greater than a threshold, and wherein providing
the indication is in response to determining that the likelihood is
greater than the threshold.
17. The method of claim 13, the physiological parameter being of a
patient, the method further comprising: identifying a medication or
symptom of the patient, and wherein the determining the likelihood
is further by analyzing the medication or symptom of the
patient.
18. The method of claim 13, the shape comprising a first shape and
the data comprising first data indicative of the physiological
parameter during a first time, the method further comprising:
identifying second data indicative of the physiological parameter
during a second time; identifying a second shape in the second
data, the second shape being indicative of the physiological
condition, and wherein determining the likelihood is further by
analyzing the second shape in the second data.
19. The method of claim 13, wherein the physiological parameter
comprises an electrocardiogram (ECG).
20. The method of claim 13, wherein the physiological condition
comprises an ST elevated myocardial infarction (STEMI).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S.
application Ser. No. 16/443,726, filed Jun. 17, 2019, which will
issue on May 3, 2022 as U.S. Pat. No. 11,317,846, which is a
continuation of U.S. application Ser. No. 15/365,938, filed Nov.
30, 2016, issued on Jun. 18, 2019 as U.S. Pat. No. 10,321,836,
which claims the benefit of and priority to U.S. Provisional Patent
Application Ser. No. 62/261,231 filed on Nov. 30, 2015, entitled
"Design and System Integration of 12-Lead ECG `Context Scores` to
Enhance Accuracy and Usability of Pre-Hospital 12-Lead ECGs," the
disclosure of which is hereby incorporated by reference for all
purposes.
BACKGROUND INFORMATION
[0002] It is well known that a leading cause of death is heart
disease. One of the most serious incidences of heart disease is an
ST Elevated Myocardial Infarction (STEMI), commonly known as a
heart attack. Heart attacks are often, although not always, sudden
and critical. Urgent medical attention is typically required for
the sufferer to have a reasonable chance at survival.
[0003] Medical professionals have several ways of detecting the
occurrence of a STEMI. One common method is the use of an
electrocardiogram (ECG) to evaluate the heart rhythm of the
patient, often at the scene where the patient is first encountered.
The ECG is typically measured using some form of mobile heart
monitor (e.g., a portable defibrillator or defibrillator/monitor).
Modern medical devices both measure the patient's heart rhythm and
automatically interpret the ECG data to perform a machine diagnosis
of the patient's heart condition. Accordingly, modern medical
devices are configured to automatically interpret the patient's
heart rhythm to diagnose certain abnormalities, such as a STEMI. If
a STEMI is indicated, the treating individual (e.g., an EMT,
paramedic, or first responder) typically notifies an urgent care
facility that a STEMI patient will be arriving shortly. In
response, most urgent care facilities will prepare a
catheterization laboratory or "cath lab" to treat the patient.
[0004] A cath lab is an examination room in a hospital or clinic
with diagnostic imaging equipment used to visualize the arteries of
the heart and the chambers of the heart and treat any stenosis or
abnormality found. Cath labs are critically important to the
effective treatment of a STEMI patient. However, they are also
extremely expensive and resource-consuming to prepare for use.
Activating a cath lab for a patient who is not actually
experiencing a STEMI is very wasteful. Accordingly, false positive
and false negative cath lab activations triggered by misinterpreted
pre-hospital 12-lead ECGs cause patient harm, hospital resource
waste, and customer dissatisfaction.
[0005] Improvements in the proper diagnosis of a patient
experiencing STEMI or other urgent cardiac abnormalities are
constantly being sought. Reducing false diagnoses of STEMI may
reduce wasteful expenditures of time and resources treating a STEMI
patient who is not actually experiencing STEMI.
SUMMARY OF THE DISCLOSURE
[0006] The disclosure is directed at performing an analysis to
assist in determining a likelihood that a STEMI diagnosis is
accurate. Generally stated, embodiments are directed at a method
for diagnosis a cardiac condition, including:
[0007] capturing electrocardiogram data indicative of a cardiac
condition of a patient;
[0008] performing an automated analysis of the electrocardiogram
data to identify a possible diagnosis of the cardiac condition;
[0009] performing a second analysis of the electrocardiogram data
to generate a qualitative value associated with the
electrocardiogram data, the qualitative value being associated with
a likelihood that the electrocardiogram data accurately reflects
the cardiac condition of the patient; and
[0010] providing an indication of the likelihood in conjunction
with the possible diagnosis of the cardiac condition of the
patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram of a scene where an external
defibrillator is used to try and save the life of a person in
accordance with an embodiment.
[0012] FIG. 2 is a table listing two main types of the external
defibrillator shown in FIG. 1, and by whom they might be used.
[0013] FIG. 3 is a diagram showing components of an external
defibrillator made according to embodiments.
[0014] FIG. 4 is a conceptual illustration of various types of ECG
traces.
[0015] FIG. 5 is a functional flow diagram of a method of
performing a qualitative analysis on a potential diagnosis of a
patient experiencing a cardiac event.
DETAILED DESCRIPTION OF EMBODIMENTS
[0016] Embodiments are disclosed that at least address certain
problems with misdiagnosis of STEMI. Generally stated, embodiments
are directed at systems and methods for providing a "context score"
that may be used, either in an automated fashion or manually, to
indicate a likelihood that a STEMI diagnosis is correct. Various
criteria may be evaluated to influence the context score.
[0017] The disclosed embodiments couple a 12-lead ECG (and/or the
automated interpretation derived from the 12-lead ECG) used in
cardiac care medical devices with meaningful context about the
likelihood that an initial diagnosis is wrong to allow any
downstream person or process using the results of that 12-lead ECG
to better gauge the degree of confidence that should be placed in
the 12-lead ECG results, and the actions that should or shouldn't
be taken based on those results.
[0018] Embodiments of the present disclosure implement techniques
to provide valuable context to help interpret and decide
actionability of a 12-lead ECG, or its derived automated
interpretive statement, or both. In addition, disclosed are methods
for integrating these context elements into an emergency medical
care system, which may include vital-signs monitors or
monitor/defibrillators, data telecommunication functionality,
patient encounter documentation tools, and post-event data review
and QA/QI tools.
[0019] This disclosure is structured as follows: First, an
illustrative medical device is disclosed in which embodiments may
be implemented. Next, specific embodiments of context scores are
disclosed that provide insight to inform possible diagnosis based
on a 12-lead ECG reading. Finally, specific embodiments of methods
are described to employ context scores into an emergency medical
care system.
DESCRIPTION OF OPERATIVE ENVIRONMENT FOR EMBODIMENTS
[0020] FIG. 1 is a diagram of a defibrillation scene. A person 82
is lying supine. Person 82 could be a patient in a hospital or
someone found unconscious. Person 82 is experiencing a medical
emergency, which could be, by way of an example, Ventricular
Fibrillation (VF).
[0021] A portable external defibrillator 100 has been brought close
to person 82. The portable external defibrillator can also be a
hybrid monitor/defibrillator 100. At least two defibrillation
electrodes 104, 108 are usually provided with external
defibrillator 100. Electrodes 104, 108 are coupled with external
defibrillator 100 via electrode leads 109. A rescuer (not shown)
has attached electrodes 104, 108 to the skin of person 82.
Defibrillator 100 is monitoring cardiac rhythms and potentially
administering, via electrodes 104, 108, a brief, strong electric
pulse through the body of person 82. The pulse, also known as a
defibrillation shock, goes through the person's heart in an attempt
to restart it, for saving the life of person 82.
[0022] Defibrillator 100 can be one of different types, each with
different sets of features and capabilities. The set of
capabilities of defibrillator 100 is determined by planning who
would use it, and what training they would be likely to have.
Examples are now described.
[0023] FIG. 2 is a table listing examples of types of external
defibrillators and their primary intended users. A first type of
defibrillator 100 is generally called a defibrillator-monitor (or
monitor-defibrillator) because it is typically formed as a single
unit in combination with a patient monitor. Alternatively, the
defibrillator-monitor may be a modular device with separable
components. For example, in one alternative embodiment, the
defibrillator-monitor may include a base component and a plurality
of detachable pods or modules. Each pod communicates with the base
component, perhaps wirelessly. Certain pods may be used to collect
information about a patient, such as vital statistics. One example
of such an alternative system is described in U.S. Pat. No.
8,738,128 entitled "Defibrillator/Monitor System Having A Pod With
Leads Capable Of Wirelessly Communicating," the disclosure of which
is hereby incorporated by reference for all purposes. A
defibrillator-monitor is intended to be used by medical
professionals, such as doctors, nurses, paramedics, emergency
medical technicians, etc. Such a defibrillator-monitor is generally
intended to be used in a pre-hospital or hospital scenario.
[0024] As a defibrillator, the device can be one of different
varieties, or even versatile enough to be able to switch among
different modes that individually correspond to the varieties. One
variety is that of an automated external defibrillator (AED), which
can determine whether a shock is needed and, if so, charge to a
predetermined energy level and instruct the user to administer the
shock. Another variety is that of a manual defibrillator, where the
user determines the need and controls administering the shock.
[0025] As a patient monitor, the device has features additional to
what is minimally needed for mere operation as a defibrillator.
These features can be for monitoring physiological indicators of a
person in an emergency scenario. These physiological indicators are
typically monitored as signals, such as a person's full ECG
(electrocardiogram) signals, or impedance between two electrodes.
Additionally, these signals can be about the person's temperature,
non-invasive blood pressure (NIBP), arterial oxygen
saturation/pulse oximetry (Sp02), the concentration or partial
pressure of carbon dioxide in the respiratory gases, which is also
known as capnography, and so on. These signals can be further
stored and/or transmitted as patient data. In some embodiments, a
patient monitor device does not include defibrillation functions
and may optionally include other functions such as, for example,
blood marker testing functionality, ventilation functionality,
airway management functionality, CPR feedback functionality, and/or
chest compression functionality.
[0026] A second type of external defibrillator 100 is generally
called an AED, An AED typically makes the shock/no shock
determination by itself, automatically. It can typically sense
enough physiological conditions of the person 82 using only the
defibrillation electrodes 104, 108 shown in FIG. 1. An AED can
either administer the shock automatically, or instruct the user to
do so, e.g. by pushing a button.
[0027] There are other types of external defibrillators in addition
to those listed in FIG. 2. For example, a hybrid defibrillator can
have aspects of an AED and also of a defibrillator-monitor. A usual
such aspect is additional ECG monitoring capability.
[0028] FIG. 3 is a diagram showing components of an external
defibrillator 300 made according to embodiments. These components
can be, for example, in external defibrillator 100 of FIG. 1. The
components shown in FIG. 3 can be provided in a housing 301, also
known as a casing. It will be appreciated that, in other
embodiments, these components may be implemented in separate
housings or as sub-components of various other devices.
[0029] External defibrillator 300 is intended for use by a user,
who is frequently the rescuer. Defibrillator 300 typically includes
a defibrillation port 310, such as a socket in housing 301.
Defibrillation port 310 includes nodes 314, 318. Defibrillation
electrodes 304, 308, which can be similar to electrodes 104, 108,
can be plugged in defibrillation port 310, so as to make electrical
contact with nodes 314, 318, respectively. It is also possible that
electrodes can be connected continuously to defibrillation port
310, etc. Either way, defibrillation port 310 can be used for
guiding an electrical charge to person 82 via electrodes 304, 308.
The electrical charge may be stored in defibrillator 300, as
discussed below.
[0030] If defibrillator 300 is a defibrillator-monitor, as was
described with reference to FIG. 2, it will frequently also have an
ECG port 319 in housing 301, for plugging in ECG lead wires 309.
ECG lead wires 309 can sense an ECG signal, such as any of the ECG
lead signals that comprise a common 12-lead ECG recording. Although
frequently referred to as a 12-lead ECG throughout this document,
other types of ECG lead signals are equally applicable. The use of
the common term "12-lead" or "12-lead ECG" is merely for
convenience and simplicity of discussion, and is not to be viewed
as limiting. A defibrillator-monitor could have additional ports
that are not shown.
[0031] Defibrillator 300 may also include a measurement circuit
320, which receives physiological signals from ECG port 319, and
also from other ports, if provided. These physiological signals are
sensed, and information about them is rendered by measurement
circuit 320 as data, or other signals, etc.
[0032] Defibrillator 300 also includes a processor 330, which may
be implemented in any number of ways. Such ways include, by way of
example and not of limitation, digital and/or analog processors
such as microprocessors and digital-signal processors (DSPs);
controllers such as microcontrollers; software running in a
machine; programmable circuits such as Field Programmable Gate
Arrays (FPGAs), Field-Programmable Analog Arrays (FPAAs),
Programmable Logic Devices (PLDs), Application Specific Integrated
Circuits (ASICs), any combination of one or more of these, and so
on.
[0033] Processor 330 can be considered to have a number of modules.
One such module can be a detection module 332, which senses outputs
of measurement circuit 320. Detection module 332 can include a VF
detector. Thus, the person's sensed ECG can be used to determine
whether the person is experiencing VF. Another such module in
processor 330 can be an advice module 334, which arrives at advice
based on outputs of detection module 332. The advice can be to
shock, to not shock, to administer other forms of therapy, and so
on. If the advice is to shock, the AED will automatically charge
the energy storage module 350. Some external defibrillator
embodiments merely report the shock advice to the user, and prompt
them to do it. Other embodiments further execute the advice, by
administering the shock automatically. If the advice is to
administer CPR, defibrillator 300 may further issue prompts for it,
and so on. Processor 330 can include additional modules, such as
other module 336, for other functions too numerous to list
here.
[0034] Defibrillator 300 optionally further includes a memory 338,
which can work together with processor 330. Memory 338 may be
implemented in any number of ways. Such ways include, by way of
example and not of limitation, nonvolatile memories (NVM),
read-only memories (ROM), random access memories (RAM), any
combination of these, and so on. Memory 338, if provided, can
include programs for processor 330, and so on. In addition, memory
338 can store prompts for the user, etc. Moreover, memory 338 can
store patient data, such as, for example, data regarding how much
fluid may have been administered to patient 82 as detected by a
flow monitor component.
[0035] In one embodiment, the defibrillator 300 includes a "context
score" component 325. In one specific implementation, the context
score component 325 includes functions which, when executed by
processor 330, operate to compute a value which may be used in a
qualitative analysis of a diagnosis derived from ECG signals. For
instance, if ECG signals collected via ECG port 319 are used in a
machine-generated diagnosis of a patient's heart condition, the
context score component 325 may perform a qualitative analysis of
that diagnosis based on, for example, characteristics of the ECG
signals. The qualitative analysis may then result in a report which
may be output via user interface 370, described below.
[0036] Defibrillator 300 typically also includes a power source
340. To enable portability of defibrillator 300, power source 340
typically includes a battery. Such a battery is typically
implemented as a battery pack, which can be rechargeable or not.
Sometimes, a combination of rechargeable and non-rechargeable
battery packs is used. Other embodiments of power source 340 can
include AC power override, for where AC power will be available,
and so on. In some embodiments, power source 340 is controlled by
processor 330.
[0037] Defibrillator 300 additionally includes an energy storage
module 350. Module 350 is where some electrical energy is stored,
when preparing it for sudden discharge to administer a shock.
Module 350 can be charged from power source 340 to the right amount
of energy, as controlled by processor 330. In typical
implementations, module 350 includes one or more capacitors 352, or
the like.
[0038] Defibrillator 300 moreover includes a discharge circuit 355.
Discharge circuit 355 can be controlled to permit some or all of
the energy stored in module 350 to be discharged to nodes 314, 318,
and thus also to defibrillation electrodes 304, 308. Discharge
circuit 355 can include one or more relays or switches 357. Those
can be made in a number of ways, such as by an H-bridge, or the
like.
[0039] Defibrillator 300 further includes a user interface 370.
User interface 370 can be made in any number of ways. For example,
interface 370 may include a screen, to display what is detected and
measured, provide visual feedback to a rescuer for their
resuscitation attempts, and so on. User interface 370 may also
include a speaker to issue audible signals, such as voice prompts,
or the like. The user interface 370 may issue prompts to the user,
visually or audibly, so that the user can administer CPR, for
example. Interface 370 may additionally include various controls,
such as pushbuttons, keyboards, touch screens, and so on. In
addition, discharge circuit 355 can be controlled by processor 330,
or directly by user via user interface 370, and so on.
[0040] Defibrillator 300 can optionally include other components.
For example, a communication module 390 may be provided for
communicating with other machines. Such communication can be
performed wirelessly, or via wire, or by infrared communication,
and so on. This way, data can be communicated, such as patient
data, incident information, therapy attempted, CPR performance, and
so on.
"ECG Artifact Context Score"
[0041] One common contributing factor to false positive and false
negative STEMI detections, particularly by automated 12-lead
interpretation algorithms, is artifact in the ECG signal. Turning
briefly to FIG. 4, three conceptual ECG traces are shown: a normal
ECG 401, an ECG of a patient experiencing STEMI 402, and an ECG of
an otherwise normal ECG 403 but which has significant ECG artifact
411. ECG artifacts are distorted signals caused by a secondary
internal or external source, such as muscle movement or
interference from an electrical device. As will be appreciated by
those skilled in the art, the ECG artifact 411 may confuse an
auto-generated analysis of the ECG into concluding that the
artifact 411 actually represents an ST elevated signal, and thus an
incorrect diagnosis of STEMI.
[0042] There are strategies to minimize artifact and optimize ECG
acquisition conditions, but paramedics frequently eschew such
strategies for the sake of saving time or coping with the
circumstances of the patient care event. Accordingly, ECG artifact
is a very common occurrence in ECG traces captured by first
responders treating a cardiac patient.
[0043] In accordance with this disclosed embodiment, ECG artifact
is quantified via signal processing means, and can thus be turned
in to a numeric or categorical index representative of the
magnitude/severity of artifact contamination of the acquired ECG.
In one specific embodiment, the context score component 325
evaluates the presence and nature of artifacts occurring throughout
the ECG. The presence of significant artifacts may indicate that an
auto-generated diagnosis of STEMI may be unreliable and should be
reviewed manually. Alternatively, the absence of significant ECG
artifact may indicate that an autogenerated diagnosis of STEMI is
likely accurate.
[0044] In an enhanced embodiment, the index is designed to
represent the probability that the apparent interpretation of the
12-lead is confounded by the magnitude/severity of the artifact,
and/or the nature of the artifact. This enhanced embodiment takes
advantage of the insight that some apparent interpretations of the
ECG may be more or less susceptible to potential corruption by the
type or amount of artifact present than others.
[0045] In one example, an extensive anterior STEMI with tombstoning
may be confidently discernable despite a large amount of motion
and/or muscle artifact, whereas a borderline STEMI may be
exquisitely sensitive to even moderate motion or muscle artifact
even if just one lead is affected. Thus, the apparent
interpretation of the 12-lead can be used to modify/combine with
the raw "artifact score" to produce a resultant probability or
"believability" of that apparent interpretation. It will be
appreciated that such a scheme can be applied both to situations
where the emergency care system relies strictly on the results of
the automated 12-lead interpretative algorithm, as well as to
situations where the emergency care system involves pre-hospital
provider interpretation of the 12-lead ECG. In the latter scenario,
the probability/believability score produced based on the automated
12-lead interpretive algorithm would provide just as useful context
for a provider-interpreted 12-lead as a machine-interpreted
12-lead.
"Patient Context Score"
[0046] Another potential contributing factor to false positive and
false negative STEMI detections is statistical in nature. Over
testing for a condition that has low prevalence in a general
population is guaranteed to produce false positive detections,
since no test can be 100% accurate. Stated differently, the lower
the pre-test probability that a given patient has a given condition
(STEMI, for example), the higher the probability of a false
positive detection. In some EMS systems, paramedics are judicious
about which patients they take 12-leads on, while in other EMS
systems, paramedics will "take a 12-lead on any patient with a
chest." Individual paramedics will also vary in their use of
12-lead ECGs within a given EMS system.
[0047] Emergency medicine confronts the challenge of low-prevalence
conditions with concomitant over testing risk with numerous other
disease states, such as pulmonary embolism. One embodiment of the
disclosure pairs a diagnostic test with a clinical decision rule or
instrument that either recommends for/against performing the test,
or provides additional context to help interpret or gauge
actionability of the result of the diagnostic test. The "patient
context score" is constructed, for example, using numeric scores
assigned to the presence/absence of key elements of the patient's
history, presentation, and/or pre-hospital emergency care (e.g.,
risk factors, symptoms, medications, etc.), summed to produce a
composite score.
[0048] Many or all of the data elements used to create the patient
context score may already have been documented early during the
patient contact in an electronic patient care documentation system.
Thus, embodiments of this disclosure incorporate automatically
obtaining pertinent data elements from the electronic
documentation, reducing the amount of dedicated data entry needed
to produce the score.
"Repeated ECG Context Score"
[0049] Yet another factor to consider when assessing the quality of
a cardiac diagnosis is the extent to which a current ECG agrees or
disagrees with prior ECGs, if any. More specifically, a context
score may be based on the number of 12-lead ECGs that have been
taken during the patient encounter prior to the currently
considered one. The results of multiple 12-leads (e.g., STEMI
positive/negative, or STEMI positive/borderline/negative) can also
be incorporated into a "Repeated ECG Context Score" patient context
component. For example, if the paramedic has taken 12
STEMI-negative 12-leads, but the subsequent ECG reading produces a
borderline positive result, the fact that 12 prior ECGs had been
acquired with negative results is potentially valuable context
suggesting the borderline positive result may be more likely to be
a false positive than if that result had been obtained on a first
ECG. Conversely, a non-borderline positive STEMI interpretation,
obtained three times in a row, may suggest the positive result is
even more believable and actionable than if only one ECG had
produced that result.
Integrating Context Elements into an Emergency Medical Care
System:
[0050] The several context scores just described may be used
individually or in various combinations. Examples are numerous, and
include the following: [0051] Real-time display for the provider
obtaining the 12-lead. [0052] Incorporated into an algorithm
recommending whether or not the 12-lead should be transmitted (or
the results verbally communicated) to a remote destination. This
can be more applicable to the artifact score. [0053] Incorporated
into an algorithm determining whether the 12-lead should be acted
upon (e.g., direct activation of a cath lab) without any ECG
over-read or other input from a more senior medical provider (e.g.,
ED physician, consulting cardiologist). [0054] Printed on the
12-lead image/printout. [0055] Recorded in the patient care
documentation.
[0056] Derived from printed on the 12-lead image/printout a QA/QI
"dashboard" can facilitate system optimization. Since the patient
care documentation would have the name of the provider who obtained
the 12-lead, along with the artifact score and patient context
score, a report/dashboard could be created showing aggregate scores
for different providers over a period of time. This would allow a
system to identify whether artifact or over testing are common
problems, as well as identify whether there are specific providers
who could benefit from more training or focus on optimal 12-lead
practices.
[0057] The score(s) could be transmitted in conjunction with the
12-lead through the Lifenet system, and stored by Physio-Control,
tagged with key non-PHI information such as date, agency, device
type/serial number, configuration, etc. It should be noted that
these scores could be transmitted into the Lifenet system for
Physio-Control to record, even if they are not transmitted through
the system to a customer final destination. The scores could even
be transmitted into the Lifenet system (e.g., via Lifenet Asset)
even if the 12-leads themselves are not transmitted through the
Lifenet system. The accumulated database of artifact scores and
patient context scores could be valuable for:
[0058] a. investigation of customer complaints
[0059] b. proactive communication with customers who may have
significant unrecognized performance issues in their system (e.g.,
"we noticed that an inordinate number of your 12-leads have
excessive artifact scores. We know that can compromise the accuracy
of the diagnosis, and here are some tools and strategies that could
help you."),
[0060] c. [Per artifact score] creating an automated "registry" of
aggregate artifact scores accessible by customers, allowing
customers to benchmark themselves against their anonymized peer
agencies, thus creating a competitive marketplace incenting all
customers to improve their 12-lead ECG quality, benefiting the
patients, the customers, etc.
[0061] In summary, the disclosed embodiments overcome shortcomings
of existing systems by obviating the need to either manually
attempt to detect a pulse (which can be unreliable) and eliminating
any need to align an ultrasound transducer with a vein or artery of
the patient's heart. In these and other ways, which will become
apparent upon a study of the disclosed teachings, these embodiments
provide a superior treatment technique and transducer assembly for
the detection of ROSC in a patient experiencing a cardiac
incident.
[0062] Other embodiments may include combinations and
sub-combinations of features described above or shown in the
Figures, including, for example, embodiments that are equivalent to
providing or applying a feature in a different order than in a
described embodiment, extracting an individual feature from one
embodiment and inserting such feature into another embodiment;
removing one or more features from an embodiment; or both removing
one or more features from an embodiment and adding one or more
features extracted from one or more other embodiments, while
providing the advantages of the features incorporated in such
combinations and sub-combinations. As used in this paragraph,
"feature" or "features" can refer to structures and/or functions of
an apparatus, article of manufacture or system, and/or the steps,
acts, or modalities of a method.
[0063] In the foregoing description, numerous details have been set
forth in order to provide a sufficient understanding of the
described embodiments. In other instances, well-known features have
been omitted or simplified to not unnecessarily obscure the
description. A person skilled in the art in view of this
description will be able to practice the disclosed teachings. The
specific embodiments disclosed and illustrated herein are not to be
considered in a limiting sense. Indeed, it should be readily
apparent to those skilled in the art that what is described herein
may be modified in numerous ways. Such ways can include equivalents
to what is described herein. In addition, embodiments may be
implemented in combination with other systems.
[0064] In general, the various features and processes described
above may be used independently of one another, or may be combined
in different ways. For example, this disclosure includes other
combinations and sub-combinations equivalent to: extracting an
individual feature from one embodiment and inserting such feature
into another embodiment; removing one or more features from an
embodiment; or both removing a feature from an embodiment and
adding a feature extracted from another embodiment, while providing
the advantages of the features incorporated in such combinations
and sub-combinations irrespective of other features in relation to
which it is described. All possible combinations and
subcombinations are intended to fall within the scope of this
disclosure.
[0065] Certain method or process blocks may be omitted in some
implementations. The methods and processes described herein are
also not limited to any particular sequence, and the blocks or
states relating thereto can be performed in other sequences that
are appropriate. For example, described blocks or states may be
performed in an order other than that specifically disclosed, or
multiple blocks or states may be combined in a single block or
state. The example blocks or states may be performed in serial, in
parallel, or in some other manner. Blocks or states may be added to
or removed from the disclosed example examples. The example systems
and components described herein may be configured differently than
described. For example, elements may be added to, removed from, or
rearranged compared to the disclosed example examples. The
following claims define certain combinations and subcombinations of
elements, features, steps, and/or functions, which are regarded as
novel and non-obvious. Additional claims for other combinations and
subcombinations may be presented in this or a related document.
* * * * *