U.S. patent application number 12/094213 was filed with the patent office on 2008-10-16 for patient monitor with user-defined monitored parameters.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONICS N. V.. Invention is credited to Larry Nielsen, Mohammed Saeed.
Application Number | 20080255432 12/094213 |
Document ID | / |
Family ID | 38067610 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080255432 |
Kind Code |
A1 |
Nielsen; Larry ; et
al. |
October 16, 2008 |
Patient Monitor with User-Defined Monitored Parameters
Abstract
In a medical monitoring system (10), one or more biometric
monitors (20, 21, 22, 23, 24, 26, 66) collect data of a plurality
of monitored biometric parameters. An expression evaluator (72)
evaluates a user-defined expression incorporating one or more of
the monitored biometric parameters to generate data for a
user-defined biometric parameter. A further processing component
(32, 50, 52, 54, 55, 56, 57, 58, 60, 62, 88) performs processing
and display of data of at least one parameter selected from the
monitored bio-metric parameters and the user-defined biometric
parameter. The further processing component operates in the same
way regardless of whether the at least one parameter is selected
from the monitored biometric parameters or the user-defined
biometric parameter.
Inventors: |
Nielsen; Larry; (Burlington,
MA) ; Saeed; Mohammed; (Cambridge, MA) |
Correspondence
Address: |
PHILIPS INTELLECTUAL PROPERTY & STANDARDS
595 MINER ROAD
CLEVELAND
OH
44143
US
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONICS N.
V.
Eindhoven
NL
|
Family ID: |
38067610 |
Appl. No.: |
12/094213 |
Filed: |
October 30, 2006 |
PCT Filed: |
October 30, 2006 |
PCT NO: |
PCT/IB2006/054016 |
371 Date: |
May 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60739744 |
Nov 23, 2005 |
|
|
|
Current U.S.
Class: |
600/301 |
Current CPC
Class: |
A61B 5/021 20130101;
G16H 40/67 20180101; G16H 40/63 20180101; A61B 5/024 20130101; A61B
5/14542 20130101; A61B 5/318 20210101; A61B 5/7475 20130101; A61B
5/00 20130101; G16H 10/20 20180101; A61B 5/02055 20130101; A61B
5/742 20130101 |
Class at
Publication: |
600/301 |
International
Class: |
A61B 5/0205 20060101
A61B005/0205 |
Claims
1. A medical monitoring system comprising: one or more biometric
monitors configured to collect samples of a plurality of monitored
biometric parameters; an expression evaluator configured to
evaluate a user-defined expression incorporating one or more of the
monitored biometric parameters to generate samples of a
user-defined biometric parameters; and a further processing
component configured to perform processing and display of samples
of at Least one parameter selected from the monitored biometric
parameters and the user-defined biometric parameter, the further
processing component operating in the same way regardless of
whether the at least one parameter is selected from the monitored
biometric parameters or the user-defined biometric parameter.
2. The medical monitoring system as set forth in claim 1, wherein
the user-defined expression evaluated by the expression evaluator
further incorporates at least one patient-specific input as a
monitored biometric parameter.
3. The medical monitoring system as set forth in claim 2, wherein
the at least one patient-specific input is selected from a group
consisting of patient weight, patient age, patient gender, patient
disease type, and patient disease severity.
4. The medical monitoring system as set forth in claim 1, wherein
the user-defined expression evaluated by the expression evaluator
further incorporates at least one clinical monitored biometric
parameter received from a network.
5. The medical monitoring system as set forth in claim 4, wherein
the at least one clinical monitored biometric parameter received
from the network is selected from a group consisting of blood gas
data, or lab results obtained via an input/output (I/O) portion
from the network.
6. The medical monitoring system as set forth in claim 1, wherein
the user-defined biometric parameter includes two or more biometric
parameters defined by corresponding two or more user-defined
expressions each incorporating one or more of the monitored
biometric parameters.
7. The medical monitoring system as set forth in claim 1, wherein
the monitored biometric parameters include at least two monitored
biometric parameters selected from the group consisting of: heart
rate, blood pressure, temperature, blood oxygen saturation
(SpO.sub.2), and electrocardiographic (ECG) data.
8. The medical monitoring system as set forth in claim 1, wherein
an alarm is configured to activate responsive to one or more of (i)
the monitored biometric parameters, (ii) the user-defined biometric
parameters, (iii) patient-specific input parameters, or (iv)
clinical monitored biometric parameters, satisfying a pre-selected
alarm criterion.
9. The medical monitoring system as set forth in claim 1, wherein
the further processing component comprises: a display configured to
display trend samples of the at least one parameter selected from
the monitored biometric parameters and the user-derived biometric
parameters respective to time.
10. The medical monitoring system as set forth in claim 9, wherein
the further processing component further comprises: a data storage
configured to store the samples of each of the monitored biometric
parameters and the user-defined biometric parameter using the same
data storage format for both the monitored biometric parameters and
the user-defined biometric parameter, the display recalling and
retrospectively displaying the stored trend samples of the at least
one parameter selected from the monitored biometric parameters and
the user-derived biometric parameter respective to time.
11. The medical monitoring system as set forth in claim 1, wherein
the further processing component comprises: a display configured to
trend in real-time the samples of the at least one parameter
selected from the monitored biometric parameters and the
user-derived biometric parameter respective to time.
12. The medical monitoring system as set forth in claim 1, wherein
the further processing component comprises: a data storage
configured to store the samples of each of the monitored biometric
parameters and the user-defined biometric parameter using a common
data storage format.
13. The medical monitoring system as set forth in claim 1, wherein
the further processing component comprises: a numeric display
configured to display in real-time the samples of the at least one
parameter selected from the monitored biometric parameters and the
user-derived biometric parameter.
14. The medical monitoring system as set forth in claim 1, further
comprising: a user interface for user input of the user-defined
expression.
15. The medical monitoring system as set forth in claim 14, wherein
the user interface comprises at least one of: a user-selectable
list of the plurality of monitored biometric parameters, and a
user-selectable list of functions selectable from a library for
incorporation into the user-defined expression.
16. The medical monitoring system as set forth in claim 15, wherein
at least some of the selectable functions of the library are
functionally dependent upon one or more of the plurality of
monitored biometric parameters.
17. The medical monitoring system as set forth in claim 15, wherein
the selectable functions of the library include at least a systolic
arterial blood pressure (ABPsys) function and a diastolic arterial
blood pressure (ABPdia) function.
18. The medical monitoring system as set forth in claim 15, wherein
the selectable functions of the library include at least one of a
calculus function and a statistical function.
19. The medical monitoring system as set forth in claim 15, wherein
the monitored biometric parameters include heart rate and blood
pressure, and the user-defined biometric parameter includes a
cardiac output parameter defined by the user-defined expression
(K1/MABP).times.(ABPsys-ABPdia).times.HR where "HR" denotes the
heart rate, and "K1" is a constant factor that is a function of age
or disease state, "MABP" denotes a mean arterial blood pressure
library function, "ABPsys" denotes a systolic arterial blood
pressure library function, and "ABPdia" denotes a diastolic
arterial blood pressure library function, and wherein the "MABP",
"ABPsys" and "ABPdia" library functions each receive arterial blood
pressure as input.
20. A medical monitoring system comprising: one or more biometric
monitors configured to collect data of a plurality of monitored
biometric parameters; an expression evaluator configured to
evaluate a user-defined expression incorporating at least one of
(i) the monitored biometric parameters, (ii) one or more
patient-specific inputs, or (iii) one or more user selected
clinical biometric parameters received via a network to generate
data for a user-defined biometric parameter; and a further
processing component configured to perform processing and display
of data of at least one parameter selected from the monitored
biometric parameters, the patient-specific inputs, the user
selected clinical biometric parameters and the user-defined
biometric parameter, the further processing component operating in
the same way regardless of whether the at least one parameter is
selected from the monitored biometric parameters, the
patient-specific inputs, the user selected clinical biometric
parameters, or the user-defined biometric parameter.
21. A medical monitoring system as set forth in claim 20, wherein
an input/output I/O portion provides the user-defined biometric
parameters throughout the monitoring system.
22. A medical monitoring method comprising: collecting samples of a
plurality of monitored biometric parameters from all available
sources; evaluating a user-defined expression incorporating one or
more of the monitored biometric parameters to generate samples of a
user-defined biometric parameter; and processing samples of at
least one of the monitored biometric parameters and the
user-defined biometric parameter, the processing being performed in
the same way for both the at least one monitored biometric
parameter and for the user-defined biometric parameter.
23. The medical monitoring method as set forth in claim 22, wherein
the processing comprises: trending the samples of both the at least
one biometric parameter and the user-derived biometric parameter
respective to time.
24. A computer device programmed to perform a method including: (i)
evaluating a user-defined expression incorporating one or more
monitored biometric parameters to generate samples of a
user-defined biometric parameter, (ii) processing samples of at
least one of the monitored biometric parameters, and (iii)
processing the user-defined biometric parameter, the processing
operations being performed in the same way both for the samples of
the at least one monitored biometric parameter and for the samples
of the user-defined biometric parameter.
Description
[0001] The following relates to the medical monitoring arts. It
finds particular application in bedside patient monitoring in
clinical settings such as hospitals, intensive care units (ICU),
cardiac care units (CCU), and so forth, and will be described with
particular reference thereto. However, it also finds more general
application in medical monitoring generally, including fetal
monitoring, neonatal monitoring, pediatric monitoring, surgical
patient monitoring, outpatient monitoring, home monitoring,
veterinary monitoring, monitoring during aerobic workouts, and so
forth.
[0002] Medical monitoring systems provide extensive information
about the patient. In some systems, rack-mounted modular monitoring
units can be selectively assembled to monitor selected medical
parameters such as temperature, electrocardiographic (ECG) data,
heart rate, oxygen saturation (SpO.sub.2), breathing rate, blood
pressure parameters, and so forth. The mounted modular monitoring
units feed data into a monitoring system that plots or trends
selected data, stores data for later review, or so forth.
[0003] Each monitored parameter typically includes a connection
with the patient. For example, ECG monitoring includes four or more
electrical contacts to the patient's skin, typically in the torso
region near the heart. In some cases, a single connection to the
patient may provide more than one monitored signal. For example, a
single finger-clip monitor may provide both heart rate and
SpO.sub.2 data. To reduce the number of patient connections, some
medical monitoring systems include derived parameters. For example,
various blood pressure parameters such as arterial blood pressure,
central venous pressure, and so forth, can be derived from a
continuous blood pressure monitor. This facilitates increasing the
number of monitored parameters without concomitant increase in the
number of modular monitoring units and without concomitant increase
in the number of patient probes.
[0004] The monitoring system typically also provides event
monitoring, in which an alarm is sounded if and when a parameter
exceeds a threshold. For example, an alarm may sound if and when
the heart rate decreases below a lower threshold value, or exceeds
an upper threshold value. Similarly, an alarm may sound if the
oxygen saturation drops below a threshold such as 90%. Such event
monitoring advantageously provides an efficient and immediate way
to alert medical personnel to potentially life-threatening patient
conditions.
[0005] Existing monitoring systems provide monitoring flexibility
through the use of modular monitoring units and derived parameters.
However, medical personnel are limited to those monitoring units
and derived parameters provided by the monitoring system. Medical
personnel often perform calculations and estimations using existing
monitoring data to provide desired additional information.
[0006] Shaya et al., U.S. Pat. No. 5,447,164, discloses a medical
monitoring system in which the user can set up user-defined events
for alarming. This can enable medical personnel to better configure
the medical monitoring system to alarm upon occurrence of
potentially life-threatening patient conditions. For example,
rather than alarming exclusively by thresholding the heart rate, an
alarm can be triggered based on a user-selectable combination of
heart rate and blood pressure thresholds. However, this approach
does not provide medical personnel with additional information
except upon occurrence of the selected alarm threshold.
[0007] According to one aspect, a medical monitoring system is
disclosed. One or more biometric monitors are configured to collect
samples of a plurality of monitored biometric parameters. An
expression evaluator is configured to evaluate a user-defined
expression incorporating one or more of the monitored biometric
parameters to generate samples of a user-defined biometric
parameter. A further processing component is configured to perform
processing of samples of at least one parameter selected from the
monitored biometric parameters and the user-defined biometric
parameter. The further processing component operates in the same
way regardless of whether the at least one parameter is selected
from the monitored biometric parameters or the user-defined
biometric parameter.
[0008] According to another aspect, a medical monitoring system is
disclosed. One or more biometric monitors are configured to collect
data of a plurality of monitored biometric parameters. An
expression evaluator is configured to evaluate a user-defined
expression incorporating one or more of the monitored biometric
parameters to generate data for a user-defined biometric parameter.
A further processing component is configured to perform processing
of data of at least one parameter selected from the monitored
biometric parameters and the user-defined biometric parameter. The
further processing component operates in the same way regardless of
whether the at least one parameter is selected from the monitored
biometric parameters or the user-defined biometric parameter.
[0009] According to another aspect, a medical monitoring method is
disclosed. Samples are collected of a plurality of monitored
biometric parameters. A user-defined expression incorporating one
or more of the monitored biometric parameters is evaluated to
generate samples of a user-defined biometric parameter. Samples of
at least one of the monitored biometric parameters and the
user-defined biometric parameter are processed. The processing is
performed in the same way for both the at least one monitored
biometric parameter and for the user-defined biometric
parameter.
[0010] According to another aspect, a computer device is programmed
to perform a method including: (i) evaluating a user-defined
expression incorporating one or more monitored biometric parameters
to generate samples of a user-defined biometric parameter, (ii)
processing samples of at least one of the monitored biometric
parameters, and (iii) processing the user-defined biometric
parameter. The processing operations are performed in the same way
both for the samples of the at least one monitored biometric
parameter and for the samples of the user-defined biometric
parameter.
[0011] One advantage resides in improved patient monitoring
flexibility.
[0012] Another advantage resides in improved appropriateness of
biometric parameters selected for monitoring.
[0013] Another advantage resides enhancing information provided to
medical personnel about a patient's medical condition.
[0014] Another advantage resides in providing enhanced information
at the patients' bedside as well as throughout the monitoring
system.
[0015] Numerous additional advantages and benefits will become
apparent to those of ordinary skill in the art upon reading the
following detailed description of the preferred embodiments.
[0016] The invention may take form in various components and
arrangements of components, and in various process operations and
arrangements of process operations. The drawings are only for the
purpose of illustrating preferred embodiments and are not to be
construed as limiting the invention.
[0017] FIG. 1 diagrammatically shows a medical monitoring
system.
[0018] FIG. 2 diagrammatically shows a user interface for user
input of a user-defined expression corresponding to a user-defined
biometric parameter.
[0019] With reference to FIG. 1, a medical monitoring system 10
includes a monitoring station 12 operatively connected with a
modular biometric monitor rack 14. The rack 14 includes an example
heart rate (HR) monitor module 20 configured to monitor patient
heart rate, an example blood pressure monitor module 21 configured
to monitor patient blood pressure, an example temperature monitor
module 22 configured to monitor patient temperature, an example
blood oxygen saturation (SpO.sub.2) monitor module 23 configured to
monitor patient blood oxygen saturation level, and an example
electrocardiographic (ECG) monitor module 24 configured to monitor
patient cardiac cycling. Additional, fewer, or other biometric
parameters can be monitored. In some embodiments, a single monitor,
which may or not be modular, is configured to monitor more than one
biometric parameter.
[0020] Each of the biometric monitors 20, 21, 22, 23, 24 collects
samples that are communicated to a monitoring inputs portion 26 of
the monitoring station 12 as analog or digital signals. The samples
are time-stamped, either by the biometric monitors 20, 21, 22, 23,
24 or by data pre-processing provided by the inputs portion 26 of
the monitoring station 12. For example, some biometric monitors may
include analog-to-digital capability so as to digitally communicate
the biometric data as digital biometric parameter samples with
associated digital time-stamps. Some biometric monitors may output
continuous analog biometric data, and the data pre-processing of
the monitoring inputs portion 26 of the monitoring station 12
suitably performs analog-to-digital conversion at a selected
digitizing rate to generate time-stamped samples. While in the
monitoring system 10 of FIG. 1 the biometric monitors 20, 21, 22,
23, 24 are physically separate from the monitoring station 12, in
other embodiments one, some, or all of the biometric monitors may
be integral with the monitoring station. Moreover, physically
separate biometric monitors can be used in configurations other
than the illustrated rack-mounted configuration.
[0021] A user-configurable station controller 30 controls operation
of the monitoring station 12, including controlling operation of
further processing components that are configured to perform
processing of time-stamped biometric parameter samples. For
example, the station controller 30 controls a data storage 32 that
stores collected time-stamped samples of each biometric parameter
using a common data storage format. The data storage 32 includes: a
bin, data partition, file, or other storage structure 40 for
storing time-stamped heart rate samples; a storage structure 41 for
storing time-stamped blood pressure samples; a storage structure 42
for storing time-stamped patient temperature samples; a storage
structure 43 for storing time-stamped blood oxygen saturation
(SpO.sub.2) samples; and a storage structure 44 for storing
time-stamped electrocardiographic samples. Again, other
physiological data or combinations of data can be stored. Further,
all data may be encoded as to type of data and stored in a common
data storage area.
[0022] A trending processor 50 also controlled by the station
controller 30 performs real-time trending of selected parameters
and displays this stored data via a graphical display 52. The
illustrated display 52 includes three display regions 54, 55, 56
for displaying real-time waveform data and/or trend data of
selected biometric parameters; however, other numbers of waveform
and trending display regions may also be provided. In the
illustrated example, the selected biometric parameters include
electrocardiography (ECG) and blood oxygen saturation (SpO.sub.2):
the display region 54 is showing the real-time electrocardiographic
data, while the display region 55 is trending blood oxygen
saturation (SpO.sub.2) data respective to time. The trending can be
performed in real-time, for example by plotting samples acquired in
the last five minutes respective to time, and scrolling older data
off the left-side of the display 52 as time progresses and the
display region becomes full. Alternatively or additionally, the
trending can be retrospective, by plotting time-stamped samples
recalled from the data storage 32 respective to time.
[0023] Other processing can be performed under the control of the
station controller 30. For example, the display 50 is configured to
display a real-time heart rate value (HR) in numeric area 57 and a
real-time blood oxygen saturation value (SpO.sub.2) in a numeric
area 58. It is to be appreciated that the term "real-time" as used
herein may denote a most-recently acquired time-stamped sample
which is not necessarily the value at the present instant. For
example, if a new SpO.sub.2 sample is acquired every two seconds,
then the real-time value shown in the numeric area 58 may have been
acquired up to two seconds prior to the present instant.
[0024] Optionally, the monitoring station 12 includes an alarm,
such as a visual alarm light 60, an audio alarm speaker 62, or so
forth. If one or more of the trended parameters exceeds a threshold
(such as a trended heart rate going below a lower threshold, or a
trended blood pressure going above an upper threshold), then the
alarm 60, 62 suitably activates to warn medical personnel of a
potential problem with specific alarm information being displayed
on display 52.
[0025] To enable user interfacing and the exchange of data, in
addition to the display 50 the monitoring station 12 also includes
an input/output (I/O) portion 66. In some embodiments, the I/O
portion 66 enables the monitoring station 12 to be interfaced with
a computer (not shown in FIG. 1), and the user can input
configuration parameters or so forth via the computer and the I/O
portion 66. In another embodiment, the I/O portion 66 enables the
monitoring station 12 to be interfaced with a network such as a
hospital local area network (HLAN) and to be able to receive
additional time-stamped clinical information (blood gas data, lab
results, etc., not shown in FIG. 1), which the user can utilize as
additional input configuration parameters or so forth via the HLAN
and the I/O portion 66. Alternatively, the monitoring station 12
optionally incorporates a keypad, keyboard, touch-sensitive screen,
or other user input device (not shown) to enable user input. It is
also contemplated to include in the I/O portion 66 the capability
of exporting time-stamped biometric parameter samples stored in the
data storage 32. For example, the I/O portion 66 optionally
includes a USB port, Ethernet connection, or other interface for
transferring time-stamped biometric parameter samples or other data
to or from a connected computer or any other device on the
HLAN.
[0026] The modular biometric monitors rack 14 enables the
monitoring system 10 to monitor a variety of monitored biometric
parameters, such as the example illustrated heart rate, blood
pressure, patient temperature, blood oxygen saturation, and
electrocardiographic data. However, medical personnel may want to
have real-time and/or continuous monitoring of biometric parameters
other than monitored biometric parameters provided by the installed
biometric monitors 20, 21, 22, 23, 24.
[0027] Accordingly, the user can construct one or more user-defined
biometric parameters that are stored in a user-defined biometric
parameters storage 70. Each user-defined biometric parameter is
defined by a user-defined expression incorporating one or more of
the monitored biometric parameters, or one or more of the clinical
biometric parameters received via the HLAN to generate time-stamped
samples of the user-defined biometric parameter. An expression
evaluator 72 receives the time-stamped monitored biometric
parameters as inputs 74, and evaluates the user-defined expression
75 to generate as output 76 time-stamped samples of the
user-defined biometric parameter. Optionally, the expression
evaluator 72 includes or has access to a library 78 of pre-defined
functions. The library 78 may include general mathematical,
statistical, or calculus functions such as logarithm, integral
"Into", or average "Avg( )". The library 78 may additionally or
alternatively include pre-defined biometric parameters such as
systolic arterial blood pressure (ABPsys) or diastolic arterial
blood pressure (ABPdia). Optionally, the user-defined expression
further incorporates one or more patient-specific inputs. For
example, the user-defined expression may incorporate patient
weight, patient age, patient gender, patient disease type, patient
disease severity, or so forth. These patient-specific inputs may be
entered manually, or may be read from an electronic patient
database stored on a server of the HLAN or on another digital
device connected with the monitoring station 12.
[0028] The generated time-stamped samples of the user-defined
biometric parameter are subsequently treated by further processing
components in the same way as the monitored biometric parameters,
and can be similarly stored, trended, displayed in real-time, or so
forth. For example, as representatively illustrated in FIG. 1, two
user-defined biometric parameters denoted "U1" and "U2" are stored
in the data storage 32 in the same way as the monitored biometric
parameters are stored and in the same way as the user selected
clinical biometric parameters received via the HLAN. A storage
structure 80 is provided for storing the user-defined biometric
parameter "U1" and a storage structure 82 is provided for storing
the user-defined biometric parameter "U2". The data storage 32
operates in the same way for both the monitored biometric
parameters (stored in storage structures 40, 41, 42, 43, 44) and
the user-defined biometric parameters (stored in storage structures
80, 82).
[0029] The user-defined biometric parameters and user selected
clinical biometric parameters received via the HLAN can also be
trended in the same way as the monitored biometric parameters. As
representatively illustrated in FIG. 1, the user-defined biometric
parameter "U1" is displayed as a real-time waveform in the third
display region 56 in the same way that the monitored
electrocardiographic (ECG) is displayed or is displayed as trend
data in the same way that the blood oxygen saturation (SpO.sub.2)
biometric parameters are trended in the display regions 54, 55,
respectively. Such trending of the user-defined biometric
parameters can be done in real-time or retrospectively, the latter
using data stored in the data storage 32. Additionally, the display
50 is configured to display a real-time value of the user-defined
biometric parameter "U1" in a numeric area 88 in the same way the
display 50 is configured to display a real-time value of the blood
oxygen saturation (SpO.sub.2) in the numeric area 58. Optionally,
the alarm 60, 62 can be configured to activate if the trended
user-defined biometric parameter "U1" exceeds a selected threshold
value. In a similar fashion, time-stamped samples of the
user-defined biometric parameters can be exported from the data
storage 32 via the I/O portion 66 of the monitoring station 12.
[0030] In summary, the expression evaluator 72 outputs time-stamped
samples of the user-defined biometric parameters having the same
format as the time-stamped user selected clinical biometric
parameters received via the HLAN and as the time-stamped samples of
the monitored biometric parameters output by the monitoring inputs
portion 26 of the monitoring station 12. The time-stamped samples
of the user-defined biometric parameters are stored in the data
storage 32 using the same data storage format as for storing the
user selected clinical biometric parameters received via the HLAN
and as for storing the time-stamped samples of the monitored
biometric parameters. Accordingly, the further processing
components 32, 50, 52, 58, 88, 60, 62, 66 can process either
monitored biometric parameters, user selected clinical biometric
parameters received via the HLAN, or user-defined biometric
parameters in the same way. These further processing components 32,
50, 52, 58, 88, 60, 62, 66 perform processing of time-stamped
samples biometric parameters by operating in the same way
regardless of whether the biometric parameter or parameters
undergoing processing are selected from the monitored biometric
parameters, the user selected clinical biometric parameters
received via the HLAN, or the user-defined biometric parameter.
[0031] With reference to FIG. 2, a suitable user interface 100 for
user input of a user-defined expression corresponding to a
user-defined biometric parameter is shown. In some embodiments, the
user interface 100 is displayed on the display 50, which in these
embodiments is a touch-sensitive display enabling a user to operate
user interface controls. Typical controls include keys 102 or a
pointer 104 used to select from a list 106 of the monitored
biometric parameters and of the user selected clinical biometric
parameters received via the HLAN, or used to select from a list 108
of the functions stored in the library 78 (including operating a
scroll-bar 110 to access listed functions that do not fit in the
window of the list 108), or optionally usable to operate the keys
102. In some embodiments, the user interface 100 is displayed on a
computer (not shown) connected with the monitoring station 12 by
the I/O portion 66, and the controls 102, 104, 106, 108, 110 are
suitably operated using a keyboard, mouse, touch-sensitive screen,
or other input of the connected computer. In some embodiments, the
user interface 100 is displayed on the display 50, which in these
embodiments may or may not be touch-sensitive, and the monitoring
station 12 includes a keyboard, trackball, or other input device
(not shown) by which the user operates the controls 102, 104, 106,
108, 110. The user interface 100 also includes a display region 114
in which the user-entered expression is displayed.
[0032] In the representative illustration of FIG. 2, the user
inputted expression is:
U1=(K1/MABP).times.(ABPsys-ABPdia).times.HR (1),
where "HR" represents the heart rate monitored biometric parameter
selected from the monitored biometric parameters list 106, "K1" can
be a constant factor that is a function of age or disease state,
"MABP" represents the mean arterial blood pressure library function
selected from the library functions list 108, "ABPsys" represents
the systolic arterial blood pressure library function selected from
the library functions list 108, "ABPdia" represents the diastolic
arterial blood pressure library function selected from the library
functions list 108, and "U1" represents the user-defined biometric
parameter whose expression is being input or edited. The expression
of Equation (1) provides an estimate of cardiac output, a parameter
whose measurement typically includes the surgical implantation of a
measuring device into the arteries. The user may alternatively
denote the user-defined biometric parameter, "U1", with an actual
name of what they are calculating. For example, "U1" of equation
(1) could be labeled "CO" for cardiac output or "CO.sub.c" for
calculated cardiac output or "CO.sub.u" for user defined cardiac
output. This can be a useful user-defined, non-invasively measured
biometric parameter for diagnosing or monitoring certain cardiac
conditions.
[0033] Another suitable candidate for implementation as
user-defined biometric parameters is the pulmonary and systemic
afterload opposing ventricular emptying of the right and left
ventricles, respectively. Although afterload is a combination of
several forces that oppose ventricular emptying, most of the
component forces of afterload are not readily or reliably measured
by bedside biometric monitors. However, as a major component of
afterload is the resistance to ventricular outflow, the systemic
vascular resistance (SVR) or pulmonary vascular resistance (PVR)
are suitably estimated by:
U2=(MABP-CVP)/((K1/MABP).times.(ABPsys-ABPdia).times.HR) (2),
U3=(MPAP-LAP)/((K1/MABP).times.(ABPsys-ABPdia).times.HR) (3),
where "MABP" represents the mean arterial blood pressure library
function selected from the library functions list 108, "CVP"
represents the central venous pressure library function selected
from the library functions list 108, "MPAP" represents the mean
pulmonary artery pressure library function selected from the
library functions list 108, and "LAP" represents the left-atrial
pressure library function selected from the library functions list
108. Equation (2) assigns an estimate of the SVR to the
user-defined biometric parameter "U2", while Equation (3) assigns
an estimate of the PVR to the user-defined biometric parameter
"U3".
[0034] While three user-defined biometric parameters "U1", "U2",
and "U3" are used in the illustrated representative monitoring
system 10, it will be appreciated that the number of user-defined
biometric parameters can be one, two, three, four, or more. In some
embodiments in which multiple user-defined biometric parameters are
provided, the value of one user-defined biometric parameter may be
incorporated into one of the other user-defined biometric
parameters. For example, if the user-defined biometric parameter
"U1" is defined by the expression of Equation (1), then the
expression of Equation (3) can be written as:
U3=(MPAP-LAP)/U1 (4).
[0035] The expression input via the user interface 100 can be
stored in the user-defined biometric parameters storage 70 and
processed by the expression evaluator 72 in various ways. For
example, in some embodiments, the expression defining the
user-defined biometric parameter is stored in a textual form,
optionally parsed, in the user-defined biometric parameters storage
70. The expression evaluator 72 then includes processing for
converting the textual expression into a compiled or otherwise
processed expression suitable for numeric evaluation to generate
time-stamped samples of the user-defined biometric parameter. In
other embodiments, the expression can be stored in the user-defined
biometric parameters storage 70 in the compiled or otherwise
processed format, which typically speeds computation of
user-defined biometric parameters by the expression evaluator
72.
[0036] The time-stamped samples acquired for the monitored
biometric parameters may or may not be in synch. In other words,
the time-stamped samples acquired for the monitored biometric
parameters may or may not have the same time-stamp. In some
embodiments, for example, the monitor inputs portion 26 may acquire
samples of each monitored biometric parameter at about the same
time, and repeat this acquisition at fixed time intervals such as
every two seconds. In this case, the expression evaluator 72 is
suitably applied every two seconds to generate user-defined
biometric parameter samples with the same time-stamp as the
monitored biometric parameters, incremented every two seconds. In
such an arrangement, the samples are optionally made
time-identifiable in the data storage 32 by including a single
common time-stamp value for each set of substantially
simultaneously acquired samples, such as in the following example
comma-delimited text format:
13:00:00, S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1),
S(U2)
13:00:02, S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1),
S(U2)
13:00:04, S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1),
S(U2)
where each comma-delimited line stores comma-delimited samples
having about the same time-stamp, the first value of each line is
the time-stamp (shown in this example in the form "HH:MM:SS" where
"HH" denotes hours, "MM" denote minutes, and "SS" denotes seconds),
and the notation "S( )" denotes a numeric sample value for the
biometric parameter indicated within the parentheses (for example,
"S(HR)" denotes a specific numeric sample value of the heart rate
biometric parameter). If the time increment for the samples is
constant, then the samples can be made time-identifiable by storing
the start time of acquisition, such as:
Time start=13:00:00 Time increment=00:00:02
S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1), S(U2)
S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1), S(U2)
S(HR), S(BP), S(Temp), S(SpO.sub.2), S(ECG), S(U1), S(U2)
[0037] On the other hand, in some embodiments the various monitored
biometric parameter samples may be acquired at different times, so
that each monitored biometric parameter should be stored in the
data storage 32 with its own time-stamp. In these embodiments, the
expression evaluator 72 suitably computes each time-stamped
user-defined biometric parameter sample using those monitored
biometric parameter samples or user selected clinical biometric
parameters received via the HLAN that have time-stamps closest to
or utilizes the last valid timed-stamped sample until a new valid
entry is received of the user-defined biometric parameter value.
Alternatively, interpolation can be used to generate monitored
biometric parameter sample values at the time-stamp of the
user-defined biometric parameter sample being generated.
[0038] Instead of storing the time-stamped biometric parameter
sample values in text format, a suitable numeric storage format can
be used, such as a floating point binary representation of the
time-stamp and sample values. Regardless of the particular type of
storage selected, the monitored biometric parameters and the
user-defined biometric parameters are stored in the same way (e.g.,
all as text values, or all as floating-point binary values, or so
forth) so that the further processing components 32, 50, 52, 58,
88, 60, 62, 66 can readily process both monitored biometric
parameters and user-defined biometric parameters in the same
way.
[0039] The illustrated monitoring system 10 is a general-purpose
monitoring system suitable for use at patient bedside, in an
intensive care unit (ICU), in a cardiac care unit (CCU), or so
forth. However, the disclosed features are applicable in medical
monitoring generally, and will find application in fetal
monitoring, neonatal monitoring, pediatric monitoring, surgical
patient monitoring, outpatient monitoring, home monitoring,
veterinary monitoring, monitoring during aerobic workouts, and so
forth. For example, the medical monitoring features disclosed
herein are readily integrated into medical monitoring systems that
are components of exercise equipment such as stationary bicycles,
treadmills, or so forth, are readily integrated into medical
monitoring systems that are integrated components of neonatal care
units, or integrated onto home monitoring systems, or so forth.
[0040] The invention has been described with reference to the
preferred embodiments. Obviously, modifications and alterations
will occur to others upon reading and understanding the preceding
detailed description. It is intended that the invention be
construed as including all such modifications and alterations
insofar as they come within the scope of the appended claims or the
equivalents thereof.
* * * * *