U.S. patent application number 13/330012 was filed with the patent office on 2012-04-12 for physiological measuring system comprising a garment in the form of a sleeve or glove and sensing apparatus incorporated in the garment.
This patent application is currently assigned to Commwell Research and Development Ltd. A Coporation. Invention is credited to Daniel David, Irving Levy.
Application Number | 20120088986 13/330012 |
Document ID | / |
Family ID | 46332491 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120088986 |
Kind Code |
A1 |
David; Daniel ; et
al. |
April 12, 2012 |
Physiological Measuring System Comprising a Garment in the Form of
a Sleeve or Glove and Sensing Apparatus Incorporated in the
Garment
Abstract
A measuring system for measuring electrocardiogram signals
comprises a diagnostic garment with ECG electrodes that may assume
the form of a sleeve or glove. A disposable version of the glove
can be inflated. By using an inflatable glove, the contour of the
body is automatically matched by the contour of the glove. Samples
from the ECG electrodes positioned on a diagnostic garment are
compensated so that the samples better approximate samples from ECG
electrodes that are positioned at classical locations. Also,
samples from ECG electrodes are compensated to reduce signal noise
resulting from positioning the ECG electrodes on the diagnostic
garment.
Inventors: |
David; Daniel; (Rananna,
IL) ; Levy; Irving; (Rishon Lezion, IL) |
Assignee: |
Commwell Research and Development
Ltd. A Coporation
Kfar Saba
IL
|
Family ID: |
46332491 |
Appl. No.: |
13/330012 |
Filed: |
December 19, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12898430 |
Oct 5, 2010 |
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13330012 |
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11742904 |
May 1, 2007 |
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12898430 |
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10899484 |
Jul 26, 2004 |
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11742904 |
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10324303 |
Dec 20, 2002 |
6842722 |
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10899484 |
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10117250 |
Apr 5, 2002 |
6516289 |
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10324303 |
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09359340 |
Jul 21, 1999 |
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10117250 |
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Current U.S.
Class: |
600/301 ;
600/364; 600/388 |
Current CPC
Class: |
A61B 5/02055 20130101;
A61B 5/282 20210101; A61B 5/4041 20130101; A61B 5/6826 20130101;
A61B 5/02241 20130101; A61B 5/252 20210101; A61B 5/259 20210101;
A61B 5/442 20130101; A61B 5/341 20210101; A61B 5/021 20130101; A61B
5/6806 20130101; A61B 5/1101 20130101; A61B 5/6825 20130101; A61B
5/225 20130101; A61B 7/04 20130101; A61B 5/0017 20130101; A61B 5/11
20130101; A61B 5/0006 20130101; A61B 5/6843 20130101; A61B 5/14542
20130101; A61B 5/6822 20130101; A61B 5/389 20210101; A61B 5/14551
20130101; A61B 5/1455 20130101; A61B 5/6804 20130101; A61B 5/0008
20130101; A61B 5/349 20210101; A61B 5/6838 20130101; A61B 5/6824
20130101; A61B 2562/168 20130101; A61B 5/0002 20130101; A61B
5/02416 20130101; A61B 5/0531 20130101 |
Class at
Publication: |
600/301 ;
600/388; 600/364 |
International
Class: |
A61B 5/0408 20060101
A61B005/0408; A61B 5/021 20060101 A61B005/021; A61B 5/11 20060101
A61B005/11; A61B 5/00 20060101 A61B005/00; A61B 5/01 20060101
A61B005/01; A61B 5/053 20060101 A61B005/053; A61B 5/145 20060101
A61B005/145; A61B 5/022 20060101 A61B005/022 |
Claims
1. A method for compensating human electrocardiogram (ECG) inputs
from electrodes located on a diagnostic garment when an LL
electrode is positioned on the diagnostic garment, being fitted to
a portion of a patient, the method comprising: (A) determining a
first mean QRS vector from a first plurality of QRS mean vectors,
each corresponding mean QRS vector obtained with standard ECG
leads; (B) determining a second mean QRS vector from a second
plurality of QRS mean vectors, each constituent mean QRS vector
obtained with the diagnostic garment; (C) in response to (A) and
(B), determining at least one compensation component; and (D)
applying the at least one compensation component to a subsequent
sample to compensate for positioning at least one ECG electrode on
the diagnostic garment.
2. The method of claim 1, further comprising: (E) applying the at
least one compensation component to the subsequent sample from at
least two leads.
3. The method of claim 1, wherein (A) comprises selecting one of
the first plurality of mean QRS vectors, each mean QRS vector
corresponding to a QRS complex.
4. The method of claim 1, wherein (B) comprises selecting one of
the second plurality of mean QRS vectors, each mean QRS vector
corresponding to a QRS complex.
5. The method of claim 3, wherein said one of the first plurality
of QRS mean vectors is characterized as being a closest mean QRS
vector to an average of the first plurality of QRS mean
vectors.
6. The method of claim 4, wherein said one of the second plurality
of QRS mean vectors is characterized as being a closest mean QRS
vector to an average of the second plurality of QRS mean
vectors.
7. The method of claim 1, wherein (C) comprises: (i) determining a
difference angle between the first mean QRS vector and the second
mean QRS vector; and (ii) calculating a compensation coefficient
(k1) from the difference angle.
8. The method of claim 7, wherein the compensation coefficient is
determined by: k 1 = cos .PHI. cos ( .PHI. - .alpha. ) ,
##EQU00005## wherein .alpha. corresponds to the difference angle
and wherein .PHI.-.alpha. corresponds to a corresponding angle
between the first mean QRS vector and an ECG lead reference.
9. The method of claim 1, further comprising: (E) if the patient is
diagnosed with a bundle branch block, circumventing compensation of
the ECG inputs.
10. The method for reducing signal noise on an electrocardiogram
(ECG) waveform, the ECG waveform obtained from a plurality of
electrodes positioned on a diagnostic garment, the method
comprising: (A) determining a modified first lead value for each
sample associated with one of a plurality of QRS complexes; (B)
obtaining a first lead value for each sample associated with said
one of the plurality of QRS complexes; (C) determining a peak
modified first lead value and peak first lead value for said one of
the plurality of QRS complexes; (D) repeating (A)-(C) for each QRS
complex of the plurality of QRS complexes; (E) determining a
compensation coefficient (k2) from an average peak modified first
lead value and an average peak first lead value; and (F) applying
the compensation coefficient to a subsequent sample to compensate
for positioning at least one ECG electrode on the diagnostic
garment.
11. The method of claim 10, further comprising: (G) applying the
compensation coefficient to the subsequent sample from at least two
leads.
12. The method of claim 11, further comprising: (H) determining
another lead from the subsequent sample.
13. The method of claim 11, wherein (G) comprises: (i) determining
a lead potential (VL) from the at least two leads; and (ii)
compensating the at least two leads in accordance with the
compensation coefficient and the lead potential.
14. The method of claim 13, wherein (i) comprises: (1) determining
the lead potential (VL) by: VL=(Lead I+2*Lead III)/3.
15. The method of claim 14, wherein (ii) comprises: (1) determining
a first lead voltage by: Lead I.sub.NEW=k2*(V6-V1); and (2)
determining a second lead voltage by: Lead
III.sub.NEW=-k2*(V6-V1)/2+1.5 VL.
16. A method for compensating human electrocardiogram (ECG) inputs
from electrodes located on a diagnostic garment when an LL
electrode is positioned on the diagnostic garment, the method
comprising: (A) selecting a first mean QRS vector from a first
plurality of QRS mean vectors, each corresponding mean QRS vector
obtained with standard ECG leads; (B) selecting a second mean QRS
vector from a second plurality of QRS mean vectors, each
constituent mean QRS vector obtained with the diagnostic garment;
(C) in response to (A) and (B), determining a first compensation
coefficient; (D) determining a modified first lead value for each
sample associated with one of a plurality of QRS complexes; (E)
obtaining a first lead value for each sample associated with said
one of the plurality of QRS complexes; (F) determining a peak
modified first lead value and peak first lead value for said one of
the plurality of QRS complexes; (G) repeating (D)-(F) for each QRS
complex of the plurality of QRS complexes; (H) determining a second
compensation coefficient (k2) from an average peak modified first
lead value and an average peak first lead value; and (I) applying
the first compensation coefficient and the second compensation
coefficient to a subsequent sample to compensate for positioning at
least one ECG electrode on the diagnostic garment.
17. The method of claim 16, further comprising: (J) applying the
first compensation coefficient and the second compensation
coefficient to the subsequent sample from at least two leads.
18. An apparatus that processes ECG measurements from a diagnostic
garment, the apparatus comprising in combination: an interface
module that obtains the ECG measurements from a plurality of ECG
electrodes positioned on the diagnostic garment; and a processor
that is coupled to the interface module and that processes the ECG
measurements to compensate for the plurality of ECG electrodes
being positioned on the diagnostic garment, the processor
configured to perform: (A) selecting a first mean QRS vector from a
first plurality of QRS mean vectors, each corresponding mean QRS
vector obtained with standard ECG leads; (B) selecting a second
mean QRS vector from a second plurality of QRS mean vectors, each
constituent mean QRS vector obtained with the diagnostic garment;
(C) in response to (A) and (B), determining at least one
compensation component; and (D) applying the at least one
compensation component to a subsequent sample to compensate for
positioning at least one ECG electrode on the diagnostic
garment.
19. The apparatus of claim 18, wherein the processor is configured
to perform: (E) applying the at least one compensation component to
the subsequent sample from at least two leads.
20. The apparatus of claim 18, wherein the processor is configured
to perform: (E) selecting one of the first plurality of mean QRS
vectors, each mean QRS vector corresponding to a QRS complex.
21. The apparatus of claim 18, wherein the processor is configured
to perform: (E) selecting one of the second plurality of mean QRS
vectors, each mean QRS vector corresponding to a QRS complex.
22. The apparatus of claim 18, wherein the interface module
comprises a measurement module that is coupled to the plurality of
ECG electrodes positioned on the diagnostic garment.
23. The apparatus of claim 18, wherein the interface module
comprises a communications module that receives the ECG
measurements from a signal, the signal being received over a
communications channel.
24. An apparatus that processes ECG measurements from a diagnostic
garment, the apparatus comprising in combination: an interface
module that obtains the ECG measurements from a plurality of ECG
electrodes positioned on the diagnostic garment; and a processor
that is coupled to the interface module and that processes the ECG
measurements to compensate for the plurality of ECG electrodes
being positioned on the diagnostic garment, the processor
configured to perform: (A) determining a modified first lead value
for each sample associated with one of a plurality of QRS
complexes; (B) obtaining a first lead value for each sample
associated with said one of the plurality of QRS complexes; (C)
determining a peak modified first lead value and peak first lead
value for said one of the plurality of QRS complexes; (D) repeating
(A)-(C) for each QRS complex of the plurality of QRS complexes; and
(E) determining a compensation coefficient (k2) from an average
peak modified first lead value and an average peak first lead
value; and (F) applying the compensation coefficient to a
subsequent sample to compensate for positioning at least one ECG
electrode on the diagnostic garment.
25. The apparatus of claim 24, wherein the processor is configured
to perform: (G) applying the compensation coefficient to the
subsequent sample from at least two leads.
26. The apparatus of claim 24, wherein the interface module
comprises a measurement module that is coupled to the plurality of
ECG electrodes positioned on the diagnostic garment.
27. The apparatus of claim 24, wherein the interface module
comprises a communications module that receives the ECG
measurements from a signal, the signal being received over a
communications channel.
28. The apparatus of claim 18, wherein the apparatus is
incorporated in the diagnostic garment.
29. The apparatus of claim 28, wherein the diagnostic garment
comprises an inflatable glove.
30. The apparatus of claim 18, further comprising at least one
measuring sensor.
31. The apparatus of claim 30, wherein the at least one measuring
sensor comprises an oxygen sensor configured to measure a level of
oxygen in blood.
32. The apparatus of claim 30, wherein the at least one measuring
sensor comprises a finger plethysmograph configured to perform a
noninvasive arterial blood pressure measurement.
33. The apparatus of claim 30, wherein the at least one measuring
sensor comprises a cuff configured to measure at least one of a
brachial radial pressure and a finger blood pressure.
34. The apparatus of claim 30, wherein the at least one measuring
sensor comprises a temperature sensor placed in the diagnostic
garment and configured to measure body temperature.
35. The apparatus of claim 30, wherein the at least one measuring
sensor comprises a built-in measuring device configured to
determine at least one of nerve conduction, and muscle force hand
movement.
36. The apparatus of claim 30, wherein the at least one measuring
sensor comprises a built-in measuring device configured to assess
at least one of a tremor, a normal form of finger movement, and a
neurological form of finger movement.
37. The apparatus of claim 18, further comprising: a control unit
configured to acquire at least one bio-signal from the diagnostic
garment.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation utility application based upon,
incorporation by reference and claiming priority to U.S.
application Ser. No. 12/898,430, filed Oct. 5, 2010 entitled
"Physiological Measuring System Comprising a Garment in the Form of
a Sleeve or Glove and Sensing Apparatus Incorporated in the
Garment" which is a continuation-in-part of co-pending application
Ser. No. 11/742,904, filed May 1, 2007 entitled "Physiological
Measuring System Comprising a Garment in the Form of a Sleeve or
Glove and Sensing Apparatus Incorporated in the Garment" which is a
divisional of co-pending application Ser. No. 10/899,484 (now
abandoned), filed Jul. 26, 2004 entitled "Physiological Measuring
System Comprising a Garment in the Form of a Sleeve or Glove and
Sensing Apparatus Incorporated in the Garment", which is a
continuation-in-part of co-pending application Ser. No. 10/324,303,
filed on Dec. 20, 2002 entitled "Physiological Measuring System
Comprising a Garment in the Form of a Sleeve or Glove and Sensing
Apparatus Incorporated in the Garment" and granted as U.S. Pat. No.
6,842,722 on Jan. 11, 2005. Application Ser. No. 10/324,303 is a
continuation application of application Ser. No. 10/117,250 filed
Apr. 5, 2002 entitled "Physiological Measuring System Comprising a
Garment and Sensing Apparatus Incorporated in the Garment" and
granted as U.S. Pat. No. 6,516,289 on Feb. 4, 2003. Application
Ser. No. 10/117,250 is a continuation of application Ser. No.
09/359,340 (expressly abandoned), filed Jul. 21, 1999 entitled
"Physiological Measuring System Comprising a Garment in the Form of
a Sleeve or Glove and Sensing Apparatus Incorporated in the
Garment". Application Ser. Nos. 11/742,904; 10/899,484; 10/324,303;
10/117,250, and 09/359,340 are incorporated herewith by reference
and for which priority is claimed.
BACKGROUND OF THE INVENTION
[0002] The field of the invention is in the design of devices for
the acquisition, storage and transmission of multiple physiological
parameters from human subjects to be monitored in hospitals,
clinics, doctor's offices as well as in remote locations (home
environment, work place, recreational activity, etc.) or unnatural
environments (under-water, outer space, etc.).
[0003] The conventional acquisition of a human electrocardiogram
(ECG) requires the recording of the time dependent fluctuations in
the cardiac electrical activation from 12 different angles on the
human torso (6 in the frontal plane and 6 in the horizontal plane)
the so-called 12 lead ECG. Classically, this procedure involves the
placement on the human body of at least 10 electrodes at various
predefined anatomical locations.
[0004] Deviation from the predefined, worldwide, conventional
localization of these electrodes may result in the acquisition of
false data, possibly leading to misinterpretation and misdiagnosis.
Even in the hospital or clinic environment, the correct and stable
placement of the ECG electrodes, specifically the "chest leads" or
"V leads" is often problematic, unless one applies six adhesive
electrodes on the patient's chest. This is an impractical method in
many circumstances due mainly to financial and patient
inconvenience considerations. This problem is amplified in the
attempts to record a full diagnostic 12 lead ECG in a remote
location since the correct positioning of the electrodes by the
examinee himself or by available laymen bystanders (family members,
friends, etc.) is usually difficult and unreliable and therefore
impractical.
[0005] To overcome this problem and to allow for the accurate
acquisition of a 12 lead ECG in the ambulatory environment, various
devices were conceived. Such devices include various forms of
vests, girdles, adhesive and non-adhesive patches and other devices
with incorporated electrodes allowing for the placement of the ECG
electrodes on the patient's chest. However, most of these devices
are cumbersome to use and have therefore not been universally
accepted. Moreover, these devices do not lend themselves to the
integration of other sensors and instrumentation for the
simultaneous acquisition of other important physiological data
(blood pressure, Sp02, etc.), such data being very useful for the
purpose of ambulatory telemedical follow-up of patients in their
own environment (home, workplace, recreational activity, etc).
SUMMARY OF THE INVENTION
[0006] The invention proposes to integrate a multitude of sensors
and measuring devices in a diagnostic garment in the form of a
glove or sleeve for repeated continuous and simultaneous assessment
of various physiological data such as ECG, noninvasive blood
pressure (NIBP), blood oxygen saturation (Sp02), skin resistance,
motion analysis, an electronic stethoscope, etc. An important
advantage of the glove or sleeve is that it provides accurate,
repeatable and conventional placement or localization of the ECG
electrodes (specifically for the recording of the chest or V leads)
by positioning the left arm of patient in a natural and very
comfortable manner on the chest. Moreover, the glove or sleeve
provides a means for simultaneous recording, storage and
transmission of a multitude of other physiological data without the
need for difficult manipulations. Furthermore, the incorporation of
various measuring tools or instruments into one device, i.e. glove
or sleeve, allows for the reciprocal calibration and easy
acquisition of important, integrated, physiological data, a feature
presently almost unavailable in the ambulatory environment (e.g.
beat to beat NIBP changes, integration of: heart rate, blood
pressure, skin resistance and other parameters for the assessment
of autonomic balance, etc.).
[0007] With one aspect of the invention, samples from the ECG
electrodes positioned on a diagnostic garment (e.g., a glove or
sleeve) are compensated so that the samples better approximate
samples from ECG electrodes that are positioned at classical
locations. With an embodiment of the invention, a first mean QRS
vector is selected from a first plurality of mean QRS vectors
associated with standard electrodes and second mean QRS vector is
selected from a second plurality of mean QRS vectors associated
with the diagnostic garment.
[0008] With another aspect of the invention, samples from ECG
electrodes are compensated to reduce signal noise that may result
by positioning the ECG electrodes on the diagnostic garment.
[0009] With another aspect of the invention, a disposable version
of the glove can be inflated. By using an inflatable glove, the
contour of the body is automatically matched by the contour of the
glove. The matching contours will allow for a close fit between the
electrodes and the skin.
[0010] A further aspect of the invention relates to the inflatable
glove which is capable of assuming the contour of the body and
which is also disposable. The contoured glove incorporates
electrodes and thereby may enable appropriate positioning of ECG
electrodes.
[0011] Another aspect of the invention is the design of the
inflatable glove which may be incorporated with a sling or a
similar device such as a sleeve or holder will be separable from
and capable of appropriately positioning and holding the inflatable
glove.
[0012] These and other objects, advantages, features and aspects of
the invention will be set forth in the detailed description which
follows.
BRIEF DESCRIPTION OF THE DRAWING
[0013] In the detailed description which follows, reference will be
made to the drawing comprised of the following figures:
[0014] FIG. 1 depicts the classic locations for the placement of
ECG electrodes on a human body for recording of a conventional
12-lead electrocardiogram.
[0015] FIG. 2 depicts the central unit that includes all of the
control functions for the various devices incorporated in the glove
or sleeve device of the invention as well as on-line storage,
analog to digital conversion and transmission capabilities of all
acquired data; two blood-pressure cuffs (wrist and arm); and Sp02
and plethysmographic sensors (fingers).
[0016] FIG. 3 depicts the ventral aspect of the glove or sleeve
device illustrating the suggested location of the various ECG
electrodes to permit easy placement of the ECG electrodes at
predefined locations on a patient's body for recording a diagnostic
12 Lead ECG. Furthermore, two small microphones are depicted on the
ventral side of the glove to be connected with the electronic
stethoscope located in the central control unit.
[0017] FIG. 4 depicts the ventral aspect of the glove or sleeve
device depicting mainly the suggested location of other possible
sensors for the determination of other physiological data such as
temperature, skin resistance, etc.
[0018] FIG. 5 depicts the advised positioning of the patient's left
arm with the glove or sleeve device on the patient's chest to
ensure proper localization of the 12 lead ECG electrodes for
accurate and reproducible 12 lead ECG recordings, as well as the
proper positioning of an electronic stethoscope. This arm position,
aided by a neck sling which may also contain an additional ECG
electrode, is natural and comfortable and therefore allows for
prolonged, stable and continuous monitoring of all desired
physiological parameters.
[0019] FIG. 6 is a schematic circuit diagram of sensor inputs for
the system.
[0020] FIG. 7 is a schematic mechanical system diagram of the ECG
inputs and blood pressure inputs.
[0021] FIG. 8 is a schematic circuit diagram of the input circuitry
for the ECG measurements.
[0022] FIG. 9 is a schematic circuit diagram for the overall
system.
[0023] FIG. 10 shows a simplified representation of an exemplary
ECG waveform that is obtained from an ECG lead in accordance with
an embodiment of the invention.
[0024] FIG. 11 shows an ECG waveform and an associated vector
representation in accordance with an embodiment of the
invention.
[0025] FIG. 12 shows an Einthoven's triangle representing ECG leads
in accordance with an embodiment of the invention.
[0026] FIG. 13 shows a vector diagram for determining compensation
parameters in accordance with an embodiment of the invention.
[0027] FIG. 14A shows a flow diagram for compensating for the
positioning of ECG electrodes on a diagnostic garment in accordance
with an embodiment of the invention.
[0028] FIG. 14B shows a continuation of the flow diagram shown in
FIG. 14A.
[0029] FIG. 15A shows a flow diagram for compensating for signal
noise resulting from the positioning of ECG electrodes on a
diagnostic garment in accordance with an embodiment of the
invention.
[0030] FIG. 15B shows a continuation of the flow diagram shown in
FIG. 15A.
[0031] FIG. 16 shows apparatus for obtaining, transforming, and
communicating ECG measurements from electrodes that are positioned
on a diagnostic garment in accordance with an embodiment of the
invention.
[0032] FIG. 17 shows apparatus of a remote surveillance center for
receiving and processing ECG measurements in accordance with an
embodiment of the invention.
[0033] FIG. 18 is a plan view of an inflatable sensor carrying
device or glove or sleeve designed to be placed upon the left hand
and forearm of an individual with appropriate electrodes positioned
in accord with the teachings of the invention.
[0034] FIG. 19 is a plan view of the inflatable glove of FIG. 18 as
viewed from the opposite side thereof.
[0035] FIG. 20 is a side view of the glove of FIGS. 18 and 19.
[0036] FIG. 21 is an opposite side perspective view of the glove of
FIG. 18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] As depicted in FIGS. 2-5, the garment of the invention is
preferably in the form of a glove or sleeve or combined glove and
sleeve 10 and is fabricated from flexible material such as a nylon
fabric that can fit snugly, without causing discomfort, on a human
hand, forearm and arm. The glove or sleeve 10 is sized to fit or
conform to patient arm size and shape. A neck sling 12 is attached
to the glove or sleeve 10. The neck sling 12 is also adaptable and
adjustable to the individual patient to ensure accurate positioning
or elevation of the left arm on the chest of the patient for the
proper placement of the ECG electrodes. Moreover, the neck sling 12
may include an additional ECG electrode 14 (FIG. 5).
[0038] Two blood-pressure cuffs 16, 18 are incorporated in the
glove or sleeve 10. One cuff 16 is positioned on the arm in the
conventional blood-pressure measuring location, the second cuff 18
is placed on the forearm. Special restraining straps 20 mounted on
the outside of the glove are wrapped around the blood-pressure
cuffs 16, 18 to allow proper restrainment during cuff inflation.
The blood-pressure cuffs 16, 18 are connected by a flexible tube
22, 23 to a central control unit or device 24 for inflation,
deflation, and measurement of blood pressure by conventional
methodology and used in the automatic determination of NIBP.
[0039] At least ten ECG electrodes 30 are attached to the glove or
sleeve 10 as depicted in FIG. 3. All of the ECG electrodes 30
except the LA electrode face the patient's chest whereas the LA
electrode 30 is in contact with the skin of the left upper arm. The
RA electrode 30 or its equivalent is placed either on the index
finger of the glove 10 in the neck sling 12, or in another suitable
position. All of the electrodes 30 are wire connected to the ECG
recording device located in the central control unit 24 retained in
the sleeve 10.
[0040] The ECG electrodes 30 included the following features:
[0041] (a) An automatic electrolyte solution application device. In
the course of the recording of a conventional ECG, it is the
routine to manually apply an electrolyte solution or cream to the
contact surface between the skin and the recording electrodes to
cause a reduction of skin resistance and to improve the conduction
of the electrical current between the skin and the according
electrode. In the described glove or sleeve 10, each electrode 30
includes means for automatic injection of an electrolyte solution
into each electrode 30 prior to the acquisition of the ECG. This is
achieved by connection of each electrode to an electrolyte
reservoir by means of connecting tubes 32. Prior to the acquisition
of the ECG recording, the electrolyte solution will be
automatically sprayed into the electrodes 30 by pressure provided
by a pump located in the central control unit 24. [0042] (b) A
suction device for better electrode-skin contact: The ECG
electrodes 30 will be configured as suction electrodes 30 and will
be connected via suction tubes 34 to a pump located in the central
control unit 24. Once the glove or sleeve 10 is placed on the chest
in the proper position, an external signal will activate the pump
to create the needed negative pressure and suction to maintain the
proper electrode-skin contact. Following the termination of the ECG
recording, the negative pressure will be abolished allowing
detachment of the electrodes from the patient's chest. The same or
separate pumps may be utilized to effect electrolyte application
and the creation of electrode suction.
[0043] A conventional IR SpO2 measuring device 36 is incorporated
in the glove or sleeve 10 and placed on one of the glove finger
tips 38 to fit the patient's finger. Blood SpO2 is determined using
the conventional methods applied for this measurement and the
results will be stored in the central control unit 24.
[0044] A conventional finger Plethysmographic-measuring device 38
is incorporated in one of the glove fingertips 40 to fit on the
patient's finger. An external restraining device 42 ensures
continuous snug contact with the finger to provide continuous beat
to beat changes in finger blood volume variation. The finger
plethysmograph is wire connected to the central control unit 24.
The signal is periodically calibrated using the conventional cuff
blood pressure measurements thereby allowing for continuous beat to
beat blood pressure monitoring.
[0045] A thermistor 44 is incorporated in the glove or sleeve 10
and located on the ventral surface of the arm in direct contact
with the skin to allow the determination of skin temperature. The
thermistor 44 is wire connected to the central control unit 24.
[0046] A conventional sensor 46 for the determination of skin
resistance is incorporated in the glove or sleeve 10 and wire
connected to the central control unit 24.
[0047] Two special microphones 50, 52 are attached to the ventral
aspect of the glove or sleeve 10, one located over the base of the
left lung and the second on one of the fingers for the simultaneous
auscultation of both lungs. Furthermore, the finger microphones 50,
52 can also be moved to enable auscultation of the heart and other
organs. The microphones 50, 52 will be connected to the central
control unit 24 for recording and transmission of the auscultatory
findings.
[0048] Motion and force assessment devices 60, 80, 82 are
incorporated in the glove or sleeve 10 mainly for the early
detection of neurological and neuromuscular dysfunction. Sensors 60
assess passive and active functions such as: [0049] (a) Force of
muscular contraction (e.g., handgrip, arm flexion and extension,
etc.) [0050] (b) Passive pathological arm and finger motion
(Parkinsonian tremor, flapping tremor, etc.). [0051] (c) Assessment
of active finger, hand or arm motion (rapid hand pronation and
supination, rapid finger motion, etc.).
[0052] The glove or sleeve 10 is equipped with a central control
unit 24 attached to the dorsal aspect of the glove or sleeve 10
(FIG. 2). The general function of this unit 24 is the collection,
transformation, storage and transmission of all of the
physiological data collected from the various devices incorporated
in the glove 10. Moreover, the central control unit 24 includes
mechanical and other devices such as pumps, injectors, etc., needed
for the proper functioning of the incorporated devices as described
herein.
[0053] Specifically, the central control unit 24 includes the
appropriate measuring element for each sensor. The measured data is
digitized, stored and upon demand, made available for transmission
by RF or IR or any other form of wireless telemetric transmission
to a remote surveillance center. Conversely, the central control
unit 24 has the ability to receive signals from a remote
surveillance center for the activation or deactivation and other
control functions of the various measuring devices incorporated in
the glove 10.
[0054] In review, the glove 10 provides an unobtrusive stable
platform for self-application of numerous physiological sensors
using a glove and/or sleeve 10 and an optional neck support sling
12 to perform various simultaneous non-invasive on invasive
health-care related measurements for use in the home, workplace,
recreational, clinic or hospital environment. The invention has the
advantage over other methods of sensor applications in that no
prior knowledge of proper sensor placement is required and that
proper placement of the sensors on the patient is assured. The
sensor position is stable and reproducible. The invention improves
the repeatability of measurements by insuring that the placement
and distances between the various sensors remain constant.
Moreover, the interplay between the various sensors can result in
the combination of data acquisition integration and analysis adding
major sophistication and improvement as compared to the individual
use of each measuring devices.
[0055] In further review, the glove/sleeve 10 together with the
optional neck support sling 12 contains one or more of the
following measuring elements: [0056] (a) An optical emitter and
detector 36 attached to the index finger of the glove 10 for the
purpose of measuring the level of oxygen saturation in the blood,
and peripheral pulse (FIG. 2). [0057] (b) A finger plethysmograph
device 38 for continuous, beat to beat, noninvasive arterial blood
pressure measurement (calibrated by the mean of the arterial blood
pressure determinations derived from both the wrist and arm NIBP
devices) (FIG. 2). [0058] (c) Inflatable cuff and pressure cuffs or
sensor 16, 18 located in various locations on the arm and hand to
measure brachial radial or finger blood pressure for periodic
(automatic or manual) noninvasive blood pressure measurements
(NIBP). These NIBP measuring devices are also used to calibrating
the optical system used to measure continuous, beat to beat
arterial blood pressure as above mentioned (FIG. 2). [0059] (d) A
central control unit 24 for the acquisition and transmission of the
various bio-signals derived from the glove sensors. This central
control unit 24 which can be activated locally by the patient or
remotely by a monitoring center allows for automatic or manual
activation of any or all of the sensors. The central control unit
24 provides amongst other: the initial and repeated sensor
calibration procedures, activation of a built-in miniature pump for
the creation of positive and negative pressures, the reception of
commands from the remote control center, analog to digital
conversion of measured data and their transmission to the control
center as well as any other needed control functions (FIG. 2).
[0060] (e) A set of electrodes 30 (V1, V2, RA, RL) placed on the
palmar aspect of the glove 10 and/or the neck support sling 12 for
the purpose of simultaneous recording of a twelve-lead
electrocardiogram (FIG. 3). [0061] (f) A method for automatic
administration of an electric conductor solution/cream to the
electrodes 30 to reduce skin resistance and improve ECG relating
quality. [0062] (g) A method of producing and maintaining a
sufficient negative pressure (suction) inside the ECG electrodes 30
to insure proper contact between the ECG electrode and the skin
(FIG. 3). [0063] (h) A method of insuring proper contact between
the ECG electrodes 30 and the skin by the application of an air
cushion or a gel cushion around areas of the glove that are in
contact with the skin. The cushion is used to provide a body
contour fit (FIG. 3). [0064] (i) A method such as a buckle
connection 15 to adjust the sling 12 to ensure that the arm is held
at the proper level for accurate placement of the ECG electrodes 30
on the patients body. [0065] (j) A temperature sensor 40 placed in
appropriate areas of the glove/sleeve 10 for the purpose of
measuring body temperature (FIG. 4). [0066] (k) An electrode or set
of electrodes 46 placed in the palm area of the glove for the
purpose of measuring skin resistance (FIG. 4). [0067] (l) An
electronic stethoscope for the auscultation of lungs, heart and
other organs. [0068] (m) Built-in measuring devices 80 in FIG. 4 in
the glove fingers for the accurate assessment of tremor and other
normal or neurological forms of finger motions. [0069] (n) Built in
measuring devices 80 in the glove 10 for the determination of EMG.
[0070] (o) Built-in measuring devices 80 in the glove 10 for the
determination of nerve conduction. [0071] (p) Built-in measuring
device 82 for the determination of muscle force (hand grip,
extension, flexion, etc.). [0072] (q) Built-in device 82 for the
assessment of rapid/accurate voluntary hand movement. [0073] (r)
The advised positioning of the patient's left arm on the chest to
ensure proper localization of the 12 lead ECG electrodes of the
glove for accurate and reproducible 12 lead ECG recording is shown
in FIG. 5. This arm position, aided by the adjustable neck support
sling 12, is natural and comfortable and therefore allows for
prolonged, stable and continuous monitoring of all available
parameters (FIG. 5).
[0074] FIGS. 6, 7, 8 and 9 are schematic drawings depicting the
basic elements described above. FIG. 6 depicts the various sensors
including the SpO2 sensor 36, the plethysmography sensor 38, the
temperature sensor 44, skin resistance probes 46, strain gauges 48,
and stethoscope sensors 50, 52. As depicted in FIG. 6, each of the
inputs in amplified and, if necessary, filtered prior to being
converted to a 24 bit analog to digital converter. The output of
the analog to digital converter goes via a control ASIC depicted in
FIG. 9 to a dual port ram also in FIG. 9 where it is processed and
transmitted by a microprocessor and an infrared communications to a
stationary unit.
[0075] FIG. 7 depicts the various mechanical elements and
connections for the ECG electrodes and the blood pressure
mechanical and electronic portion of the system. Each ECG electrode
comprises a container that holds a saline solution or another
lubricant. This solution is drawn into the electrode via a vacuum
system. A bleed valve closes the system and then releases the
vacuum. The release of the vacuum will then release the lubricant
or solution. Digital input output drivers control the vacuum pump
and the bleed valve in response to signals that are provided from
the ASIC control lines. In the embodiment disclosed, there are two
blood pressure cuffs, one associated with the wrist and one with
the upper arm. A blood pressure pump (NIBP pump) pumps each cuff. A
pressure sensor then measures the pressure in each cuff. The values
from the pressure sensor are amplified, filtered and converted to
digital values in the 24-bit analog to digital converter. The
output of the analog to digital converter also passes through the
control ASIC in FIG. 9 to the dual port random access memory unit
where it is processed and transmitted by the microprocessor and IR
communications, for example, to a stationary unit.
[0076] FIG. 8 depicts the ECG analog input circuitry. Each
electrode input is separately amplified and ban passed filtered
prior to conversion by a 24-bit analog to digital converter. The
analog to digital converter signal passes through the control ASIC
in FIG. 9 to the dual port RAM where it is processed and
transmitted again by the microprocessor and IR communications to a
stationary unit.
[0077] FIG. 9 depicts the digital circuitry in the system. The
circuitry includes the ASIC which has logic for the timing signals
and for transmitting or passing the digitized analog signals from
the various analog to digital converters to the dual port RAM which
sits on the microprocessor. The microprocessor runs the software
provided from the flash memory, collects data samples, performs
basic analysis, controls the various valves and pumps and sends
data to the central data collector via IR communication. The
described circuitry is but one way to accomplish the goals and
objectives of the use of the glove and/or sleeve of the
invention.
Electrode Compensation
[0078] Embodiments of the invention enhance a vector representation
of the ECG waveforms. As will be discussed, methods and apparatuses
provide for adjusting a vector representation of ECG signals to
compensate for positioning ECG electrodes on a diagnostic garment
(e.g., the glove/sleeve as discussed above) rather than classically
positioning the electrodes on a patient's limbs as with standard
ECG electrodes. Also, an embodiment of the invention compensates
for additional signal noise that may be imposed on the ECG signals
resulting from the positioning of the ECG electrodes on the
diagnostic garment.
[0079] Cardiac activity generates a measurable amount of electric
current. The current is recorded through an electrocardiograph and
displayed as an ECG waveform, the shape of which is governed by
both the magnitude and direction of the current flow. The ECG
waveforms may be displayed as vectors whose trajectories also
depict the magnitude and direction of the heart's impulses as will
be discussed with FIG. 11. The average of these vectors for a
particular heart cycle is called the mean QRS vector and is
displayed on a vector image as a solid arrow whose length is the
average magnitude and whose angle is the average direction.
[0080] FIG. 10 shows a simplified representation 1000 of an
exemplary ECG waveform that is obtained from an ECG lead in
accordance with an embodiment of the invention. In normal sinus
rhythm, each P wave 1001 is followed by a QRS complex (comprising Q
wave 1003, R wave 1005, and S wave 1007). The QRS complex
represents the time it takes for depolarization of the ventricles.
Activation of the anterioseptal region of the ventricular
myocardium corresponds to the negative Q wave 1003. However, Q wave
1003 is not always present. Activation of the rest of the
ventricular muscle from the endocardial surface corresponds to the
remainder of the QRS complex. The R wave 1005 is a point when half
of the ventricular myocardium has been depolarized. Activation of
the posteriobasal portion of the ventricles give an RS line. The
normal QRS duration is approximately from 0.04 seconds to 0.12
seconds measured from the initial deflection of the QRS complex
from the isoelectric line to the end of the QRS complex. The QRS
complex precedes ventricular contraction.
[0081] FIG. 11 shows an ECG waveform and an associated vector
representation in accordance with an embodiment of the invention.
FIG. 11 shows QRS complex 1101 being represented as vectors 1003
(in relation to Einthoven's triangle 1107 as will be discussed)
whose trajectories also depict the magnitude and direction of the
heart's impulses. The average of these vectors for a particular
heart cycle is called mean QRS vector 1105 and is displayed on the
vector image as a solid arrow whose length is the average magnitude
and whose angle is the average direction. QRS complex 1109
corresponds to a subsequent heart cycle that can be presented by
another set of vectors.
[0082] Experimental studies involving hundreds of patients compare
12-lead ECG recordings with both standard electrodes and with
electrodes positioned on a diagnostic garment. The diagnostic
garment may assume a garment that fits on a portion of a patient's
body and may assume a form of a glove/sleeve as shown in FIGS. 2
and 3. An exemplary embodiment of the invention utilizes
PhysioGlove.TM., which is a glove/sleeve that fits over a patient's
left arm and left hand.
[0083] The standard "12 lead ECG" utilizes the three standard limb
bipolar leads (lead I, lead II, and lead III), three augmented limb
leads, and six precordial unipolar leads. The augmented leads are
the same as the standard leads, except that the augmented leads are
compared to a hypothetical null value that corresponds to a central
point over the heart where no fluctuations in potential can be
measured. The null point is actually mathematically determined
using the electrical potentials generated by the other 2 leads. The
lead on the left arm is known as an aVL lead, the lead on the right
arm as an aVR lead, and the lead on the left leg as an aVF lead.
Precordial leads are leads fanning across the chest. Precordial
leads (V1, V2, V3, V4, V5, and V6) give more specific information
about electrical conduction in the heart than the limb leads.
[0084] Comparing the locations of ECG electrodes 30 on diagnostic
garment 10 shown in FIG. 3 and the classic positioning of ECG
electrodes as shown in FIG. 1, one observes that the locations of
the corresponding ECG electrodes are different. In order to better
approximate the signals from the classic positioning of ECG
electrodes, the ECG signals from the ECG electrodes on diagnostic
garment 10 may be compensated as will be discussed. In particular,
experimental studies indicate variations in the ECG waveform are
caused by positioning the LL electrode on diagnostic garment 10
rather than on the left leg.
[0085] FIG. 12 shows an Einthoven's triangle 1200 representing
(modeling) ECG leads 1207, 1209, and 1211 in accordance with an
embodiment of the invention. Lead I 1207 represents the electrical
potential between LA (left leg) electrode 1203 and RA (right arm)
electrode 1201. Lead II 1209 represents the electrical potential
between LL (left leg) electrode 1205 and LA electrode 1203. Lead
III 1211 represents the electrical potential between LL electrode
1205 and RA electrode 1201. (RA electrode 1201, LA electrode 1203,
and LL electrode 1205 correspond to RA, LA, and LL electrodes 30
shown in FIG. 3.) From Einthoven's triangle 1200, one can determine
one lead from the other two leads by the following
relationships:
Lead I=Lead II-Lead III (EQ. 1A)
Lead II=Lead I+Lead III (EQ. 1B)
Lead III=Lead II-Lead I (EQ. 1C)
[0086] Null point 1219 is a hypothetical "null" value that exits at
a central point over the heart where no fluctuations in potential
can be measured. The "null point" is actually mathematically
determined using the electrical potentials generated by leads 1207,
1209, and 1211. Augmented leads aVR 1213 (corresponding to the
right arm), aVL 1215 (corresponding to the left arm), and aVF 1217
(corresponding to the left leg) are measured with respect to null
point 1219. Augmented leads 1213, 1215, and 1217 can be expressed
in terms of standard leads 1207, 1209, and 1211. For example, aVF
can be expressed as:
aVF=0.5*Lead I+Lead III (EQ. 1D)
[0087] Experimental results suggest that the mean QRS vector
representing the QRS complex obtained from the patients using the
diagnostic garment varies when compared with the mean QRS vector
obtained from patients using standard electrodes. Experimental
results also suggest that when these differences are compensated
for, one can obtain an ECG waveform analogous to the one obtained
using the standard electrode configuration.
[0088] FIG. 13 shows a vector diagram 1303 for determining
compensation parameters in accordance with an embodiment of the
invention. Analyzing a plurality of QRS complexes, vector 1301 is
the selected mean QRS vector with standard electrodes
(corresponding to the ECG electrodes shown in FIG. 1) and vector
1303 is the selected mean QRS vector with electrodes positioned on
the diagnostic garment (e.g., glove/sleeve 10 as shown in FIG. 2).
The selection of mean QRS vectors will be discussed. Angle 1351
(.PHI.-.alpha.) and angle 1353 (.alpha.) are used to determine a
compensation factor as will be discussed.
[0089] An analysis of the mean vector of the QRS complex is made
from any two of the three standard leads. In the embodiment, leads
I and III are used. However, other embodiments of the invention can
use lead II and lead III or lead I and lead II. The compensation
process is a two-stage procedure with each stage involving a series
of steps:
[0090] Stage I--Determine Compensation Parameters: [0091] Select an
ECG time interval with several QRS complexes. [0092] Find the
average vector angle for these QRS complexes. Each QRS complex is
associated with a mean QRS vector (e.g., vector 1105 as shown in
FIG. 11). A first plurality of mean QRS vectors is associated with
the standard electrode configuration (as shown in FIG. 1) and a
second plurality of mean QRS vectors is associated with the garment
electrode configuration (as shown in FIG. 3). [0093] Select the QRS
complex with the angle closest to the average. A first selected
mean QRS vector is selected that is closest to the average of the
first plurality of mean QRS vectors and a second mean QRS vector is
selected that is closest to the average of the second plurality of
mean QRS vectors. [0094] Find the compensation coefficient (k1),
where
[0094] k1=Cos .PHI./Cos(.PHI.-.alpha.) (EQ. 2) [0095] This
coefficient will be used in Stage II for performing the
compensation. The angles .PHI. and .PHI.-.alpha. correspond to the
angles shown in FIG. 13.
[0096] Stage II--Apply the Compensating Algorithm: [0097] The glove
is a DSP device transmitting N samples per second to the receiver
where N is the sample rate. [0098] Each sample contains Lead I and
Lead III voltages. [0099] The other limb leads are combinations of
these two leads.
[0100] During Stage 2, the limb lead values are compensated using
the following matrix formula:
( Lead I New Lead III New ) = k A - 1 BA ( Lead I Lead III ) ( EQ .
3 ) ##EQU00001## [0101] where
[0101] ( Lead I Lead III ) and ( Lead I New Lead III New )
##EQU00002##
are the columns of lead voltages before and after the compensation,
respectively. The compensation associated with Equation 3 uses the
following matrix values:
A = ( 1 0 0.5 1 ) ( EQ . 4 ) B = ( cos .alpha. - sin .alpha. sin
.alpha. cos .alpha. ) ( EQ . 5 ) k 1 = cos .PHI. / cos ( .PHI. -
.alpha. ) ( EQ . 6 ) ##EQU00003## [0102] Matrix A has an
inverse
[0102] A - 1 = ( 1 0 - 0.5 1 ) . ##EQU00004##
The compensation coefficient k1 is defined in Equation 2. The
determined compensation is applied to every ECG sample provided by
the diagnostic garment. The compensated waveforms/reports are hence
obtained.
[0103] While the exemplary embodiment selects one of the mean QRS
vectors closest to an average of a plurality of mean QRS vectors,
another embodiment can select a resulting mean QRS vector with
another criterion. Also, another embodiment may determine a
resulting mean QRS vector that corresponds to an average of the
plurality of mean QRS vectors even though the resulting mean QRS
vector does not correspond to actual measurement data.
[0104] The electrical signal from the heart's natural pace maker
starts in what is called the SA (sinoatrial) node located in the
right atrium travels through the right atrium to the ventricles
(i.e. the lower chambers of the heart). The electrical signals
cross a junction called the AV (atrialventricular) node going from
the atrium to the ventricles. From the AV node the electrical
signal travels through a path called the bundle of His that splits
into two paths one on the left lower chamber and one on the right
lower chamber. Each path is called a bundle branch. The electrical
signals from the bundle branches causes the ventricles to contract.
Normally both ventricles contract simultaneously. If one of the
bundle branches is damaged then the blockage blocks or slows the
electrical signal on one of the paths. The blockage of the
electrical signal is called a bundle branch block. A left bundle
branch block (LBBB) blocks the signal on the left side while a
right bundle branch block (RBBB) blocks the signal on the right
side. Patients that have a bundle branch block do not require
compensation as described above. Thus, a separate algorithm may be
used to detect those patients so that their ECG waveforms are not
compensated.
[0105] ECG waveform noise reduction is performed in two stages, in
which the signal noise results from positioning the ECG electrodes
on the diagnostic garment.
[0106] Stage I--Determine the Parameter for the Compensation Filter
[0107] Select an ECG time interval with several QRS complexes.
[0108] Calculate Mod_Lead I=V6-V1 values. Electrodes V6 and V1 are
positioned on the diagnostic garment as shown in FIG. 3. [0109]
Define the AVG (R(Lead I)) and AVG (R(Mod_Lead I)) for the selected
time interval. R is a parameter representing the height of the QRS
complex peak over the isoelectric line. R is a parameter
representing the height of the QRS complex peak over the
isoelectric line. In the embodiment, R corresponds to the height of
the R wave 1005 as shown in FIG. 10. [0110] Determine the
compensation coefficient k2, where
[0110] k2=AVG(R(Lead I))/AVG(R(Mod_Lead I)) (EQ. 7) [0111] The
compensation coefficient k2 will be used in Stage II for performing
the compensation.
[0112] Stage II--Apply the Compensating Algorithm
[0113] The glove transmits Lead I, Lead III, and V1 to V6 voltages.
Lead potential VL, which is a voltage between the LL electrode and
the center of Einthoven's triangle, is given by.
VL=LL-(LL+LA+RA)/3 (EQ. 8)
[0114] VL voltage may also be obtained from the combination of the
existing leads:
VL=(Lead I+2*Lead III)/3 (EQ. 9)
[0115] The compensated values for Lead I and Lead III are
determined by:
Lead I.sub.New=k2*(V6-V1) (EQ. 10)
Lead III.sub.New=-k2*(V6-V1)/2+3/2(VL) (EQ. 11)
[0116] where Lead I.sub.New and Lead III.sub.New are values after
compensation, VL is the previously defined voltage, and k2 is the
compensation coefficient.
[0117] FIG. 14A shows a flow diagram 1400 for compensating for the
positioning of ECG electrodes on a diagnostic garment in accordance
with an embodiment of the invention. If step 1401 determines that a
patient is diagnosed with a bundle branch block (as previously
discussed), then compensation of the ECG inputs is circumvented
through step 1413. If not, step 1403 selects a first mean QRS
vector that is closest to a first plurality of mean QRS vectors,
each corresponding to a QRS complex with a standard electrode
configuration. Step 1405 selects a second mean QRS vector that is
closest to a second plurality of mean QRS vectors, each
corresponding to a QRS complex with a garment electrode
configuration. In step 1407, an angle .alpha. between the two
selected mean QRS vectors is determined as shown in FIG. 13. In
step 1409, an angle .PHI.-.alpha. between the first selected mean
QRS vector and a reference axis corresponding to Lead I is
determined. In step 1411, a compensation coefficient k1 (as given
by EQ. 2) is determined. Procedure 1400 continues to step 1413 in
order to process subsequent samples.
[0118] FIG. 14B shows a continuation of flow diagram 1400, in which
the compensation coefficient k1 is used to compensate subsequent
ECG samples obtained from the electrodes positioned on the
diagnostic garment. (ECG samples are acquired every 1/N seconds,
i.e., N samples per second. A sample comprises ECG measurements
from a plurality of ECG electrodes as shown in FIG. 3.) Step 1415
determines if a new sample is available for Lead I (corresponding
to LA 1203 minus RA 1201 as shown in FIG. 12) and for Lead III
(corresponding to LL 1205 minus LA 1203 as shown in FIG. 12). If so
the voltages for Lead I and Lead III are compensated using
Equations 3-6 in step 1417. In Step 1419, the voltage for Lead II
is determined using EQ. 1B. Steps 1415-1419 are repeated for each
subsequent ECG sample.
[0119] FIG. 15A shows a flow diagram 1500 for compensating for
signal noise resulting from the positioning of ECG electrodes on a
diagnostic garment in accordance with an embodiment of the
invention. Process 1500 determines compensation coefficient k2 in
order to reduce signal noise induced by positioning ECG electrodes
on the diagnostic garment, e.g., glove/sleeve 10. Step 1501
determines if all QRS complexes have been processed. If so, step
1509 determines compensation coefficient k2 using Equation 7. If
not, step 1503 processes the next QRS complex.
[0120] In step 1505, a modified Lead I value is determined. With
step 1507 the height of the R wave 1005 (as shown in FIG. 10) is
determined for both Lead I and the modified Lead I (Mod_Lead I).
Process 1500 is repeated until all QRS complexes are processed. In
step 1511, once compensation coefficient k2 is determined, process
1500 continues to process subsequent ECG samples as shown in FIG.
15B.
[0121] FIG. 15B shows a continuation of flow diagram 1500. If step
1513 determines that a new ECG sample is available for processing,
lead potential VL is calculated with Equation 9 using Lead I and
Lead III potentials in step 1515. In step 1517, compensated lead
values are determined using Equations 10 and 11. Even though
Equations 10 and 11 compensate for two of the three leads, the
third lead can be compensated in accordance with Equations 1A-1C.
Steps 1513-1517 are repeated for subsequent ECG samples.
[0122] With another embodiment of the invention, the methods shown
in FIGS. 14A, 14B, 15A, and 15B can be combined so that both
compensation for electrode positioning and signal noise can be
performed on ECG signals received from a diagnostic garment.
[0123] The embodiments shown in FIGS. 14A, 14B, 15A, and 15B
exemplify compensating ECG samples from ECG electrodes that are
positioned on a diagnostic garment. However, other embodiments of
the invention support other algorithms to compensate for the ECG
electrodes being positioned differently from the classical
locations as shown in FIG. 1. Other embodiments of the invention
may position ECG electrodes at different non-classical locations
and correspondingly compensate for shifts in ECG electrode
positioning.
[0124] FIG. 16 shows an apparatus 1600 for obtaining, transforming,
and communicating ECG measurements from electrodes that are
positioned on a diagnostic garment in accordance with an embodiment
of the invention. Measurement module 1601 obtains ECG inputs
(samples) 1651 from ECG electrodes positioned on the diagnostic
garment. In the embodiment, measurement module 1601 includes a
buffer to appropriately interface to the voltage levels of the ECG
electrodes and a multiplexer to interface with a plurality of ECG
electrodes. Because ECG inputs typically have analog
characteristics, analog to digital converter (ADC) 1603 converts
analog ECG inputs into a digital format in order to process the ECG
samples.
[0125] Processor 1607 may compensate the ECG samples (in accordance
with processes 1400 and 1500) or may transmit the uncompensated ECG
samples to a remote apparatus (e.g., apparatus 1700) over
communications channel 1653 through communications module 1605. The
embodiment supports different types of communications channels
including wireline channels (e.g., telephone, cable and Internet
channels) and wireless channels (e.g., cellular radio channels,
point-to-point radio channels, and infrared point-to-point
channels).
[0126] FIG. 17 shows an apparatus 1700 of a remote surveillance
center for receiving and processing ECG measurements in accordance
with an embodiment of the invention. In the embodiment apparatus
1700 receives uncompensated samples over communications channel
1653 through communications module 1701. However, with another
embodiment of the invention, apparatus 1600 may compensate ECG
samples and send the compensated samples to apparatus 1700.
[0127] Apparatus 1700 receives ECG samples, in which each ECG
sample comprises ECG measurements from ECG electrodes positioned on
a diagnostic garment. Demultiplexer 1703 separates the ECG
measurements and passes them to processor 1707 through buffer 1705.
Processor 1707 processes the ECG samples. If the ECG samples are
uncompensated, processor 1707 compensates the ECG samples in
accordance with Equations 2-11.
[0128] The processed ECG samples may be stored in storage device
1709 for later retrieval or may be displayed on display module 1711
for a clinician to view. The clinician configures apparatus 1700
through input module 1713 for processing, storing, and displaying
processed ECG samples.
[0129] As can be appreciated by one skilled in the art, a computer
system with an associated computer-readable medium containing
instructions for controlling the computer system can be utilized to
implement the exemplary embodiments that are disclosed herein. The
computer system may include at least one computer such as a
microprocessor, digital signal processor, and associated peripheral
electronic circuitry.
Disposable Diagnostic Garment Option
[0130] An embodiment of the invention provides a disposable version
of the glove by making the glove out of a plastic material that can
be inflated. By using an inflatable glove, the contour of the body
(e.g., chest and torso) is automatically matched by the contour of
the glove. The matching contours will allow for a close fit between
the electrodes and the skin.
[0131] The inflation of the glove may be done automatically upon
opening a package containing the glove by use of a one-way valve.
The lower pressure within the glove will cause it to take in enough
air to inflate the glove.
[0132] The electrode may be painted or printed on the plastic of
the glove allowing for a low cost method of producing the
glove.
[0133] The glove may be either two dimensional (i.e. a single seam)
or three dimensional (i.e. multiple seams). The two dimensional
reduces cost while the three dimensional version allows more
flexibility in adapting the glove to the contour of the body.
[0134] FIGS. 18-21 illustrate a version of an inflatable glove. The
inflatable glove is in the form of a hollow rod 1802 having affixed
thereto a preformed series of hollow, molded, elongate, flexible
pillow members 1804. The pillow members 1804 are separated one from
the other by a seam such as seam 1806 but connected by a gas flow
passage. ECG electrodes such as electrodes 1830 are provided on the
various inflated pillow members 1804. Electrodes 1830 are also
positioned on opposite ends of the carrier rod or stick 1802. As
shown in FIG. 18, the separate electrodes 1830 may include leads or
lead wires 1832 connected thereto. The electrodes 1830 are spaced
by virtue of their positioning on the discrete pillow members 1804
to accommodate a desired physical positioning or spacing such as
would be accomplished by the sleeve and glove depicted in FIG.
3.
[0135] A valve 1834 is provided in hollow rod or tube member to
effect inflation of the pillow members 1804 of the glove. The
opposite side of the glove including the rod 1802 as well as the
pillow members 1804, may include an appropriate adhesive for
maintaining placement of the inflatable glove on the hand of an
individual such as illustrated in phantom in FIG. 18.
[0136] The uninflated pillow member 1804 of the glove of the type
depicted in FIG. 18 may then be folded over the rod when it is
originally packaged and upon unpackaging and inflation will assume
the configuration such as shown in FIGS. 18-21. The glove may then
be placed upon the hand and lower arm of an individual. The glove
is typically placed upon the left hand and lower arm or forearm in
the manner depicted for example with respect to the glove and
sleeve of FIGS. 3, 4 and 5. The pillow members 1804 may then be
inflated by inserting air or a non-toxic gas through the valve
mechanism 1834 into the rod 1802 and connected pillow members
1804.
[0137] The device is manufacturable in various sizes. Thus the
number of pillow members or elements 1804, the length of the rod
1802, the size of the pillow elements 1804 and other dimensional
characteristics of the disclosed glove may be altered in order to
accommodate persons having different physiology. Additionally, the
glove may be disposed following use. Further, the electrodes 1830
may be affixed to the various pillow segments 1804 by deposition of
a conductive material on the inflatable plastic which is utilized
to make the pillow. Likewise the leads 1832 may also be affixed by
such deposition techniques and connected to a socket assembly 1835
mounted on the rod 1802. Socket assembly 1835 may then receive a
plug (not shown) which connects to a central control unit 24.
[0138] Alternative aspects and features of the embodiment of FIGS.
18-21 include the capability of folding the uninflated pillow
members around the rod or stick 1802. Thus the assembly can then be
conveniently packaged in a small box or sealed package for
subsequent removal and inflation. The pillow members 1804 may be
formed of heat sealed sheets of plastic material with an air flow
channel provided between the pillow member 1804. The conductive
electrodes and leads may be printed on the surface of the
preinflated pillow members 1804 are affixed or molded into the
material forming the pillow members 1804. The pillow members 1804
may have distinct sizes and shapes. The pillow members 1804 may
also be sectioned so that only discrete portions thereof inflate.
The rod 1802 is typically hollow but generally rigid to facilitate
manual gripping and proper positioning.
[0139] While the invention has been described with respect to
specific examples including multiple modes of carrying out the
invention, those skilled in the art will appreciate that there are
numerous variations and permutations of the above described systems
and techniques that fall within the spirit and scope of the
invention as set forth in the appended claims.
* * * * *