U.S. patent application number 10/890042 was filed with the patent office on 2004-12-23 for chair and ancillary apparatus with medical diagnostic features in a remote health monitoring system.
This patent application is currently assigned to Commwell, Inc.. Invention is credited to David, Daniel, David, Zipora, Halperson, Ziv, Levy, Irving.
Application Number | 20040260156 10/890042 |
Document ID | / |
Family ID | 29270343 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040260156 |
Kind Code |
A1 |
David, Daniel ; et
al. |
December 23, 2004 |
Chair and ancillary apparatus with medical diagnostic features in a
remote health monitoring system
Abstract
A medical examination chair includes a group of sensors
including electrodes in finger-tip sensors, various other types of
sensors incorporated in straps for the patient in the chair and
load cells supporting the chair, all of which provide data which is
partially processed in the electronics mounted in the chair and
then transmitted to a central station for patient diagnosis.
Inventors: |
David, Daniel; (Ranana,
IL) ; David, Zipora; (Wilmette, IL) ; Levy,
Irving; (Rishon Lezion, IL) ; Halperson, Ziv;
(Ramat Gan, IL) |
Correspondence
Address: |
BANNER & WITCOFF, LTD.
TEN SOUTH WACKER DRIVE
SUITE 3000
CHICAGO
IL
60606
US
|
Assignee: |
Commwell, Inc.
Evanston
IL
|
Family ID: |
29270343 |
Appl. No.: |
10/890042 |
Filed: |
July 13, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10890042 |
Jul 13, 2004 |
|
|
|
10276455 |
Nov 18, 2002 |
|
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Current U.S.
Class: |
600/300 ;
128/897; 297/463.2; 600/301 |
Current CPC
Class: |
A61B 5/0205 20130101;
A61B 5/1036 20130101; A61B 5/0002 20130101; A61B 5/14532 20130101;
A61B 5/14551 20130101; A61B 5/0531 20130101; A61B 5/087 20130101;
A61B 5/02241 20130101; A61B 5/282 20210101; A61B 5/6891 20130101;
A61B 5/225 20130101; A61B 7/04 20130101; A61B 5/7278 20130101; A61B
5/0026 20130101; A61B 5/1455 20130101; A61B 5/6887 20130101; A61B
5/0816 20130101 |
Class at
Publication: |
600/300 ;
600/301; 128/897; 297/463.2 |
International
Class: |
A61B 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2001 |
WO |
PCT/US01/16360 |
Claims
What is claimed is:
1. A medical examination diagnostic device comprising: a generally
horizontal seat; at least four support members for the seat, said
seat having a front edge and a back edge, two of said support
members generally aligned with the back edge and two of said
support members generally aligned with the front edge; an
independent load sensor device located under each of said support
members, each of said load sensors comprising an element for
detecting the load independently on each of the load sensors to
provide a set of four independent data signals for medical
diagnosis; means for collecting and comparing the four signals
thereby providing at least one of the following: a diagnostic ecg;
a diagnostic respiration rate; neurological disorders;
neuromuscular pathology; stroke; balance.
2. The device of claim 1 further including one or more of the
following supplemental sensor elements: blood pressure sensor;
pulse oximetry sensor; sound sensor; skin resistance sensor; manual
grip sensor; fluid flow rate sensor; glucometer.
3. The device of claim 1 further including a processor element for
providing a base reference signal for each of said load sensors; a
differential amplifier to amplify the changes in signal for each of
said load sensors; a high task filter to remove the DC component of
each of said signals from said amplifier and a low pass filter to
remove the AC component of each of said signals.
4. The device of claim 1 further including a sensor element to
sense the voltage associated with each of said load sensors
independently and a bandpass filter to filter out select
signals.
5. The device of claim 4 further including a signal processor for
processing the voltage signals from the independent load sensors to
measure the differential signal between at least two pairs of load
sensors.
6. The device of claim 1 further including a hand grip monitoring
device including: a blotter; a tube connected to the bladder; a
source of pressurized fluid for the bladder connected through the
tube; a check valve for monitoring the bladder and tube filled with
a volume of fluid; a pressure sensor connected to the bladder for
measuring the fluid pressure in the bladder and providing a first
signal representative of the absolute pressure in the bladder and a
second signal representative of the change in pressure over time in
the bladder; and a recorder for recording the first signal over a
measured increment of time and for recording the second signal over
said measured increment of time said first signal being integrated
and recorded, said second signal being recorded to provide
frequency and amplitude over the said increment of time.
7. The device of claim 1 further including means for historical
recording of like signals to provide a record and a comparator for
comparing the record with other recordings.
8. The device of claim 7 wherein the other recordings are derived
from the same patient.
9. The device of claim 8 wherein the recordings are derived at
least in part from a nonpatient source.
10. The device of claim 9 further including an alarm for denoting
the departure from a source of other recording.
11. The device of claim 1 in combination with a central station,
said device maintained at a remote station, said stations being
linked by two-way communications medium.
12. The device of claim 1 in combination with multiple remote
station devices and a single station and further including a
control system for monitoring each device.
13. The device of claim 1 wherein there is provided a control
system for monitoring a plurality of remote stations and further
including a switch for connecting a central station to each remote
stations individually and sequentially.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of utility application
Ser. No. 10/276,455 filed Nov. 18, 2002 which is based on
PCT/US01/16360 filed May 18, 2001, which is a utility application
based upon and incorporating by reference the following three
provisional applications: Ser. No. 60/232,708, filed Sep. 15, 2000,
Ser. No. 60/205,369 filed May 18, 2000, and Ser. No. 60/205,144
filed May 18, 2000, upon which we claim priority.
BACKGROUND OF THE INVENTION
[0002] In a principal aspect, the present invention relates to a
chair and ancillary apparatus incorporated with the chair for use
in the conduct of medical diagnostic tests in a diagnostic system
wherein the subject may be remotely located.
[0003] U.S. Pat. No. 5,544,649, incorporated herewith by reference,
discloses various techniques for interactive patient monitoring
from a central station, (e.g., a clinic) of patients located at a
remote site, (e.g., their home). The diagnostic techniques
disclosed in U.S. Pat. No. 5,544,649 rely, at least in part, upon
utilization of apparatus, such as a diagnostic chair incorporating
various sensor apparatus to facilitate the conduct of diagnostic
measurements. U.S. Pat. No. 5,544,649 discloses a chair which
includes sensors for measuring patient temperature, blood pressure
and the like, and for transmitting such data via alternative
transmission means to a central station for analysis and
diagnosis.
[0004] The diagnostic session involving a patient in a remote
location chair may be interactive. That is, the health care
professional at the central station and the patient at the remote
site are in real time, two-way audio and video communication and
diagnostic data sensed at the remote location is simultaneously
provided in real time to the central station. Such communication
enhances the validity and the scope of the diagnostic tests being
conducted.
[0005] The diagnostic information is analyzed by personnel at the
central station. This provides a convenient and low cost manner in
which to monitor patient condition without requiring the patient to
physically travel to a diagnostic clinic or hospital. This
technique and the associated apparatus also enable the health
practitioner to direct the patient through test protocols and to
diversify or revise the test protocols as necessary during the
interactive session.
[0006] The use of apparatus of this type disclosed, and, in
particular, a chair and various other ancillary equipment have
become the topic of continued research and development in order to
provided apparatus which senses the diagnostic parameters necessary
to provide immediate and appropriate patient health care or
monitoring in an inexpensive, yet highly reliable manner. Such
continued research and development has led to the discovery of the
apparatus disclosed hereinafter and also provides for the
combination of such apparatus in an interactive diagnostic
system.
SUMMARY OF THE INVENTION
[0007] Briefly, the present invention relates to the construction
and design of a chair or other support platform device used for
subject monitoring and medical examination and to the combination
of such a device with a system for remote monitoring from a central
station.
[0008] The device in the form of a chair or platform incorporates
numerous apparatus for the acquisition of physiological and other
diagnostic parameters from a subject who is sitting in or lying on
the device. In a preferred embodiment, a chair is utilized which
accepts commands for the acquisition and analysis of diagnostic
data and sends the results, either processed on site and/or as raw
data, by wireless communication to a relay system located at the
site. The relay system then transfers data received from
instrumentation incorporated in the chair to a central system by
means of a wide bandwidth public channel (e.g., wireless network,
telephone system, cable modem or other public utility).
Communication and sensor control is interactive. That is, the
transmissions are two-way transmissions. Additionally, two other
communication channels are simultaneously operative, i.e., audio
and video are interactive. Simultaneous, two-way transmission on
three channels results in the capacity to diagnose and, to a
limited extent, treat a patient at a remote site interactively. The
channels may also be integrated for example by modulation or
packing of a single channel signal.
[0009] By way of example and not limitation, the following medical
information and testing, protocols are enabled by the chair or
platform design: (1) finger-tip ECG, (2) "safety-belt" diagnostic
ECG, (3) non-invasive blood pressure, (4) weight, (5) balance, (6)
respiration rate, (7) saturated pulse oximetry (Sp02), (8) blood
glucose analysis, (9) lung sounds, (10) expiratory flow
(respiration exhale and/or inhale flow rates), (11) skin
resistance, and (12) hand grip strength. All of the instrumentation
required for the various measurements recited are an integral part
of the chair. No special knowledge, expertise, or physical
dexterity is required on the part of the patient or subject to
participate in the test procedures since all of the instruments are
an integral part of the chair or device. The chair also provides an
ergonomically safe support for the patient, an aesthetically
pleasant appearance and includes storage for the sensors and
instruments not in use.
[0010] Exemplary of the diagnostic capabilities of the system and
chair is measurement of hand grip strength of a patient. That is, a
hand grip instrument can detect whether the patient suffers from
tremors when gripping an object and thus can be relied upon as a
diagnostic tool to evaluate the health of a patient. Apparatus
which provide information of this general nature also allows
assessment of motor activity which is associated with neurological
features or capacity of a patient as well as strength which is
associated with the muscle characteristics of a patient. Such
monitoring is capable of projecting the likelihood or impact of
stroke, for example, and other patient abnormalities.
[0011] Thus, a hand grip monitoring device which, in one
embodiment, includes a bladder in the form of an elongated
ellipsoid may be provided. A source of pressurized fluid is
provided to the bladder with a check valve connected to the bladder
filled with a predetermined volume of fluid (e.g., gas or liquid).
A sensor is connected to the bladder for monitoring the fluid
pressure in the bladder and providing a first signal which
represents the absolute pressure therein and a second signal
representative of the change in pressure over time. A recorder is
provided for recording the first and second signals. Data
associated with the first and second signals is analyzed, the first
signal being representative of the total energy associated with
patient grip and the second signal associated with tremors or a
change in pressure with time. As indicated heretofore, tremors may
be indicative of neurological status, neuromuscular pathology or
stroke. The system may include historical recordings of like
signals or a library of data to compare with the measurement or
sensed signals in order to determine the change in patient health
with time. Alarms may be provided to alert the medical technician
at the central station of deviation beyond the general patient
specific norm.
[0012] Another example involves load cells mounted on the support
legs of the chair or device. The cells detect shifts in weight
which, in turn, can be relied upon to diagnose balance and other
physiological characteristics of a patient.
[0013] The chair and its associated diagnostic sensors may be
utilized in combination with a remote monitoring system or
infrastructure which operates from a central station by
communication techniques with multiple, remote sites.
[0014] It is an object of the invention to provide a diagnostic
chair or device and other ancillary apparatus used in combination
with the chair to provide sensors that reliable interact with a
patient for the measurement of respiration rate, pulmonary
condition, heart condition, muscle strength, blood pressure, and
other physiological parameters.
[0015] Yet a further object of the invention is to provide a highly
reliable, yet inexpensive diagnostic apparatus comprised of a chair
or furniture which may be utilized at a remote location yet easily
transported from one location to another and easily interfaced with
sensor transmission equipment and with a remote diagnostic system
of the type generally depicted in U.S. Pat. No. 5,544,649.
[0016] Another object of the invention is to provide a chair or
platform which maybe utilized to obtain diagnostic data from
subjects located at a remote site for transmission to and recordal
at a central station in order to obtain an historic record of the
subject indicative of the wellness or deterioration in wellness of
the subject or the status of recovery of the subject.
[0017] These and other objects, advantages and features of the
invention will be set forth in the detailed description which
follows.
BRIEF DESCRIPTION OF THE DRAWING
[0018] In the detailed description which follows, reference will be
made to the drawing comprised of the following figures:
[0019] FIG. 1 is a side elevation of an embodiment of a chair with
sensing apparatus;
[0020] FIG. 1a is an exploded sectional view of a portion of the
chair depicted in FIG. 1;
[0021] FIG. 2 is a front elevation of the chair and ancillary
apparatus of FIG. 1;
[0022] FIG. 3 is a schematic view of a hand grip sensor utilized in
combination with the chair of the invention and with the system
incorporating the chair;
[0023] FIG. 4 is a diagrammatic view of the diagnostic chair
incorporated in a remote monitoring system;
[0024] FIG. 5 is a block diagram of the signal processing protocol
for the load cells associated with measurement of weight, balance,
respiration rate and other physical characteristics of a
subject;
[0025] FIG. 6 is a series of graphs depicting the readings from
load cells on a time scale and further depicting readings which
represent the sum of various combinations of signals;
[0026] FIG. 7 is a series of graphs similar to FIG. 6 representing
a distinct physiological pattern;
[0027] FIG. 8 is another series of graphs similar to FIG. 6
representing a further distinct physiological pattern; and
[0028] FIG. 9 is another series of graphs similar to FIG. 6
representing a further distinct ogical pattern or event.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The apparatus of the invention comprises the combination of
a chair or equivalent subject support platform device such as a
bed, gurney or the like with various data, audio and visual
transmission components. Thus, the chair depicted in FIGS. I and 2,
involves data sensing, collection and transmission, as well as
control of sensors in the chair through the data transmission links
or channels. The chair typically comprises an element of an overall
system and has self-contained sensing and control elements. FIG. 4
illustrates the chair and home unit components of such a system and
the invention is described in the embodiment of a chair though
other platform devices may be substituted such as a bed.
[0030] Referring to the figures, an exemplary chair includes the
following elements: a seat 14, a back support 16 and an optional
moveable, cantilever leg support 18. The chair is mounted on four,
spaced legs 20 or the equivalent four mounting pads on the bottom
of a chair base. Each leg 20 or mounting pad is supported on a
separate load cell 22. A stable platform 23 supports the four load
cells 22. The load cells 22 on fixed support platform 23 are used
to measure or indicate weight, balance, and weight distribution at
any given time and as a function of time as described in more
detail below. The load cells 22 preferably are positioned on the
corners of a rectangle.
[0031] Back support 16 includes an array of straps 24, 26, 28 and a
non-invasive blood pressure cuff strap 33. Strap 26 is an
electronic stethoscope strap 26 used for assessment of heart and
lung sounds and includes a respirometer used for measuring
respiration data. A "safety belt" like strap 28 is used for
diagnostic ECG (electrocardiogram). The "safety belt" like strap 28
is similar to the design of a safety belt used in an automobile
with attached electrodes 29 to permit secure placement of the
electrodes 29 in the appropriate position on a human subject for
obtaining a diagnostic single, multiple or full 12 lead ECG
measurement. Ancillary electrodes 29 may be provided on the other
straps 24, 26.
[0032] Moveable, cantilever leg support 18 facilitates raising the
legs of a patient from resting on the floor when measuring patient
weight by load cells 22. A strain gage 19 in leg support 18 also
allows measurement of leg muscle strength. That is, a patient may
attempt to lower the support 18 by engagement with their legs. The
force imparted on support 18 by such activity may be sensed by a
strain gage 19 to thereby provide a measurement of leg strength,
muscle condition and muscle coordination.
[0033] Arm rests or supports 30 include "finger-tip" electrodes 32,
34 used for measuring a single lead ECG lead-I and skin resistance.
A hand-grip 36 is used to measure hand muscular strength and
control. A skin sensor 38 is used to measure blood glucose
measurements. An infra-red emitter and sensor 40 is used to measure
SpO2. An infra-red (IR) transmitter and receiver 42 is used for
wireless communication to a transmission device 44 located at the
patient or remote site. Communication device 44 is then linked to a
central station, for example, by a wireless transmission, switched
network cable line, telecommunication line or the like. An
electronics enclosure 50 is attached underneath the seat 14 and
contains the analog to digital conversion and microprocessor
electronics for the operation of the sensor instruments in the
chair.
[0034] The chair is designed so that the entire weight of the
person sitting in the chair is transferred solely to the load cells
22. Thus, rectangular platform or frame 23 holds four load cells 22
arranged at the corners of the rectangular platform 23 supporting
the chair. The frame 23 provides a means for physically locating
the load cells 22 for supporting the chair. The frame 23 allows the
load cells 22 to be fixed in each of the four corners of the
rectangle or in any other desired geometric pattern associated with
the legs 20 or chair support and the diagnostic protocol.
Electronics which provide a common reference voltage to all load
cells 22; differential amplifiers which amplify the temporal
changes due to the weight shift on each load cell 22; bandpass
filter for respiratory monitoring; low pass filter for human
balance monitoring and a microprocessor with a multi-channel analog
to digital converter are all housed in the enclosure 50. Software
which controls data collection and signal processing is also
incorporated in the hardware in the enclosure 50. Though the four
load cells 22 are in a rectangular array, additional load cells in
other arrays may be utilized to measure weight distribution as it
varies with time over the surface of the seat 14 to thereby permit
diagnostic measurements of the type discussed hereinafter. Each of
the cells 22 provide a separate, recordable signal to the
processing equipment described for ultimate transmission to a
central station.
Respiration Rate Measurement
[0035] As previously described, a recliner chair is preferably used
in order that support 18 will lift the feet of the patient from the
floor. This is done so that all of the body weight of the patient
is supported solely by the chair and the weight is directed in some
pattern of distribution to each of the four sensors or load cells
22 under the chair seat 14 during measurement of respiration and
other indices of patient health. That is, as a patient breathes,
there is a small shift of weight from the back to the front of the
chair or vice versa. This weight shift is transferred to the
appropriate front and back load cells 22 in response to the
shifting of patient weight due to respiration. The load cells 22
are thus arranged such that they can detect small changes in load
due to patient respiratory induced weight shift. In other words,
the load cells 22 are arranged so that they can detect load changes
in both the X and Y directions, i.e., side to side and front to
back of seat 14. As schematically depicted in FIG. 5, a high pass
filter may be used to remove the DC component of the weight signal
allowing only the AC changes in the signal to be passed. Since the
AC changes are very small compared with the DC component, AC
coupling allows the signal to be highly amplified. The signal to
noise response of the system is improved by the quadrature nature
of the signals. The quadrature nature of the signals arises from
the fact that any increase in weight in one direction in the X-Y
plane is compensated by an equal decrease in weight in the opposing
direction in the X-Y plane. Noise and non-body movement artifacts
thus can be removed from the signal. The front to back and side to
side signal change of a sitting or recumbent subject represents
respiration rate and many other physical parameters. In other
words, by appropriately positioning load cells 22 and processing
the AC component associated with changes in weight distribution,
the system enables a physician or diagnostician located at a remote
site to monitor respiration rate of the patient in real time
responsive, for example, to instructed as well as natural breathing
patterns. For example, the patient may have exercised before
sitting in the diagnostic chair thereby enabling the diagnostician
the opportunity to evaluate respiration rate following activity as
well as at rest. Many variable patterns of patient activity are
possible, all of which may be remotely monitored using the
described system.
Weight
[0036] The lower portion of the chair acts as a scale that allows
measurement of the gross weight of the patient sitting in the seat
14 of the chair. To measure total weight, the patient must raise
his or her feet from the floor allowing all of the body weight to
fall on the seat 14 of the chair. The DC component of the load
cells signal is indicative of weight. Note, the chair may not
include the cantilever leg support 18 in which event the patient
must lift his or her legs from the floor to provide a true DC
weight signal by the load cells 22. Also if the platform is a bed
on gurney, then positioning of cells 22 will be dependent on the
size of the platform and the platform will normally be supportive
of leg or limb weight.
Balance
[0037] Each individual who sits down in the chair or gets up from
the chair produces a characteristic response signature of time
dependent weight distribution on each of the four load cells 22.
The signature is used for historical reference to determine if
changes in this signature may indicate physiological or
pathological trauma as suggested, for example, by a change in
patient ability to balance and in the response time to the command
to change position (e.g., to rise from the chair) following
instructions.
[0038] The monitoring of balance is accomplished by recording, for
example, the transient response on the load cells 22 as a patient
rises from the chair. The transient response provides a
characteristic picture signature of the shifts of body weight as a
function of time when the patient rises. For example, the weight is
initially transferred from the back to the front of the chair and
then later to the arms 30 which provide support for the person
rising from the chair. Information from the four load cells 22 over
time provides a characteristic picture signature of temporal
balance changes as one rises from the chair. An example of data
provided for diagnostic analysis includes measurement of the
movement of the center of mass of a patient over seat 14 in the X
and Y directions as a function of time. Unlike respiration, the
weight signals relating to changes in balance and gross weight are
large signals containing the DC element. The system is designed so
that the characteristic frequency of the load cells 22 is well
above the upper frequency response required from the system.
[0039] Periodic monitoring of a person rising from the chair
produces data pattern signatures. These patterns are stored and
statistically compared to new data using multidimensional
statistical analysis. When the new data pattern signature is
significantly different than the stored data pattern, an alarm (not
shown) may be activated indicating the need for further diagnostic
investigation. That alarm may be in the chair, but more
appropriately is maintained at the diagnostic center.
[0040] In summary, the load cells 22 generate a myriad of data,
including weight or load change as a function of time for each cell
22 as well as gross load for each cell 22 as a function of time.
Preferably, this data is collected in its most basic form as analog
signals by sensors 22. The signals are then typically converted to
digital form by the software and hardware in the chair and
transmitted by a wireless transmitter 42 to a receiver 44 at the
remote site. There receiver 44 may store the data, compress the
data and otherwise preliminarily process the data and subsequently
forward the data via a preferred network, for example, to the
central station. The data transmission may be interspersed with
data or control signals to the transmitter 44. The data may thus be
downloaded periodically or continually and may be processed, in
part before transmission or transmitted in full.
[0041] The load cell 22 signals may be assigned to a single channel
for transmission to the central station separate from the other
diagnostic signals so that the interrelationship of the various
diagnostic protocols may be observed. For example, weight shift
data and gross weight data may interrelate with heart rate data to
provide diagnostic insight. Consequently, assigning weight or load
cell information to one data channel and heart rate and condition
to another data channel may be optionally desired and programmed.
Other diagnostic information may also be simultaneously recorded or
sensed and then correlated with heart, weight distribution data,
etc. Of course simultaneous audio and video interaction may also
occur to facilitate the diagnostic activity.
[0042] FIGS. 6 through 9 are graphical results derived from load
cell measurements of the direct current (weight parameter) of the
load cells 22 in an experiment conducted to evaluate the diagnostic
capacity of the device. The load cells were placed in a rectangular
array with left and right back sensors or load cells 22 attached to
the back legs or back edge of the chair and left and right sensors
or load cells 22 attached to with the left and right front legs or
front edge of the chair. Each figure depicts ten graphs which are
the result of the processing of the signals from the four load
cells 22. The first four graphs in the upper portion of each figure
comprise or specify the absolute weights sensed by each of the
sensors 22 taken during 2 second intervals. The next four graphs
show differences between the pairs of adjacent sensors as indicated
on the figure. The final two graphs show the summed differences of
the back, the front, and of the left to right sensors, and are
indicated as delta right to left and delta back to front.
[0043] Referring first to FIG. 6 there is depicted the results with
respect to a person in good general health without handicap arising
from a chair in a very normal fashion. The weight of a person
arising from the chair is initially shifted from the back (as
sensed by the change detected by the back sensors) to the front of
the chair (as detected by the front sensors) causing the rise in
signal and thus the rise in weight detected in the front sensors
and a corresponding decrease in the weight detected in the back
sensors. Once the person has risen from the chair, of course both
the front and the back sensors show a decrease and a steady state
with respect to weight. In FIG. 6 it is seen that the person is
risen from the chair at approximately one second. Also it is to be
noted that the differential weight shift from the front to the back
indicates very little difference between the left to the right
sides. This indicates that the person rose from the chair in a
symmetrical manner. This suggests that muscle strength and
coordination is balanced and that the person rose from the chair in
a normal balanced fashion relying upon the equal strength and
agility with respect to muscles on both sides of the body.
[0044] FIG. 7 includes graphs quite similar to those set forth in
FIG. 6. However, the events required a longer time. Approximately
two seconds are required to rise from a chair in the graphs
depicted in FIG. 7. Again there is little difference between the
left and right sensors during the event. Thus, though the person
took almost twice as long, the person arose from the chair in a
very symmetrical fashion. This indicates the balance of the person
is symmetrical although because of the prolonged time to rise from
the chair there may be an indication of weakness or diminished
strength or some other indicator of a physiological problems.
[0045] FIG. 8 indicates a person rising slowly from a chair and
then momentarily falling back into the chair before completely
rising. The fact that the person fell back into the chair is
indicated by the bimodal peaks in the graphs. However, in this
circumstance the difference between the left and right sensors is
still comparable indicating that the person rose in a symmetric
fashion. These charts may indicate a loss of balance, a diminution
or loss of muscle strength or other physiological problems, but in
any event, suggest further diagnosis is in order.
[0046] FIG. 9 includes graphs or tracings that indicate that the
person favors or leans to his or her left side. That is, the left
side measurements increase while the right side measurements
decrease. Otherwise, there is a shift from the back sensors to the
front sensors as the person rises. The time period or term in order
for the person to effect the movement is also somewhat prolonged.
The pathophysiological indications from these charts suggest a
weakness on the right side in muscle or muscle control or balance.
Again, further testing and analysis are indicated.
[0047] Maintaining a record of such charts for a particular patient
and comparing the charts over time will enable a practitioner to
understand whether the person is maintaining a certain level of
health, whether the patient is declining in health and whether, for
example, therapy is assisting the patient with respect to recovery.
Further charts along with norms associated with certain movements
will facilitate the practitioners analysis and diagnosis.
Finger-Tip/Arm Rest ECG
[0048] Another type of data collected via the chair sensors relates
to electrical sensing, most typically, ECG sensing. Thus, two
electrodes 34, one mounted on the left arm 30 of the chair and one
mounted in the right arm 30 of the chair, may be used to measure
tile standard lead one ECG vector. The use of two electrodes 34
without a reference electrode is made possible by using an analog
design incorporating a very high common mode rejection. The
placement of the electrodes 34 is such that the measurement is made
by the patient holding his or her arms and hands on both of the
arms 30 of the chair simultaneously.
[0049] A second use of the two electrodes 34 is to provide a
patient activated switch. Placing the fingers on the electrodes 34
provides one state of the switch, while removing the fingers from
the electrodes 34 provides the second state of the switch. For
example, the electrodes 34 of both arms 30 may require touching or
activation to initiate a sequence of sensor operation.
Consequently, initiation of the record of an ECG may not begin
until the patient properly places fingers from each hand on
separate sensors 34. Also, the patient may be required to operate
the switches 34 in a sequence or in response to an audio or video
signal to diagnose sight, sound, response time or memory or
attention deficit.
[0050] Alternatively, for ECG monitoring, two electrodes 34 are
placed on one arm 30 of the chair and a third electrode 34 (as a
ground) is placed on the other arm 30 of the chair. The input from
the two electrodes 34 on the same arm can then be monitored to
provide for the vector one ECG reading or signal.
[0051] Multiple other variations of electrode positioning on the
arms 30 and/or belts 24, 26, 28 are within the scope of the
invention. For example, the sensors may be placed in the back
support 16 of the chair. Such placement may incorporate redundancy
inasmuch as multiple sensors may be provided to sense the same
feature of patient health. For example, positioning of multiple
electrodes 34 on each arm for engagement by separate digits of each
hand can be utilized in combination with various prescribed video
and audio instructions (either preprogrammed or initiated by the
central station diagnostician). This may enable detection or
analysis of muscular control, memory, attention span, etc. which,
in turn, provide valuable diagnostic information for detection of
disease such as stroke, Alzheimer disease, etc.
Safety Belt Diagnostic ECG
[0052] The "safety belt" is a diagnostic element which, in a
preferred embodiment, consists of two portions, a chest strap 26
which crosses the patient's chest from the upper right to the lower
left, and a lap portion 28 which crosses the patient horizontally
above the abdomen from the right side to the left side where it
meets with the chest strap 26. The straps 28, 26 are made with an
elastic material allowing initial placement of electrode pads 29 to
accommodate a patient's anatomy. Electrode pods 29 are thus placed
in the standard chest predefined positions used for the limb
measurements of, LL and RL as well as the standard chest positions
used for C1, C2, C3, C4, C5, and C6 of an ECG. The leads LA and RA
are obtained from the finger-tip or arm rest electrodes 34. The
elasticity of the belt strap 28 insures good skin contact while the
measurement is made. When the measurement is completed the safety
belt strap 28 returns into a housing 31 mounted on the side of the
chair. A full 12 lead ECG consisting of leads 1, 11, 111, AVR, AVL,
AVF, V1, V2, V3, V4, V5, V6 is derived from the input electrodes
29.
[0053] Alternative placement of electrodes is, as suggested above,
possible. Thus, the number of electrodes, their placement, their
structure and construction are variable depending upon the
diagnostic protocol to be adapted.
Non-Invasive Blood Pressure
[0054] A cuff 33 is used to measure non-invasive blood pressure and
is stored on the side of the chair. Cuff 33 is designed for easy
placement on a patient's arm. The blood pressure measurement is
activated remotely after the patient slides his arm into cuff 33.
Electronics in the chair control enclosure or housing 50
automatically monitors inflation and deflation of the cuff. Sensors
in cuff 33 detect pressure and pressure change. Measurement of
blood pressure may be effected separately or simultaneously with
other tests described. Again, a separate data channel coordinated
with other channels may be utilized in the system. Also, the data
may be gathered, processed, transmitted and analyzed in the manner
described above for load cell data. Other alternatives for data
storage and coordination with other parameters are possible again
depending upon the diagnostic protocol adopted and typically
controlled from the central station.
Saturated Pulse Oximetry
[0055] Pulse oximetry is a means to confirm the amount of oxygen in
the blood. Standard instrumentation uses a comparison of absorption
of red and infra-red light by the body tissue to determine the
percentage of oxygenated blood cells by placing a finger clip
emitter/sensor 40 on patient's finger. The chair incorporates a
finger clip or socket 40 located in the arm 30 of the chair. The
measurement will be made by the patient placing his finger in the
finger clip or socket 40. A socket 40 may be provided in one or
both arms 30. Again, the data may be processed as described
above.
Blood Glucose Analysis
[0056] Blood glucose measurements are usually made by placing a
drop of blood on a chemically treated paper and recording the color
of the paper. The chair has an optical sensor 38 built into the arm
30 which can measure the color of the paper. In addition, a
sterilized finger prick 60 using disposable finger pricks is built
into the arm 30. A container 41 on the side of the chair is used to
store finger pricks and paper, while another container 62 is used
for disposing the used material. Alternatively, skin sensors can be
attached to the chair to noninvasively measure blood glucose
levels. The chair may also incorporate newer blood glucose
measuring devices that do not require the drawing of a blood
sample.
Heart and Lung Sounds
[0057] An electronic stethoscope is incorporated in strap 26 or may
be attached to the side or back support 16 of the chair to assess
heart and lung sounds. Alternatively, the stereoscope may be
incorporated in belt or strap 26.
Respiratory Flow Measurements
[0058] A respirometer 35 attached to the side of the chair and is
used to measure pulmonary inspiratory and expiratory flow
functions. Respirometer 35 may be incorporated in strap 26.
Skin Resistance
[0059] Skin resistance is measured by placing a high frequency
signal into the finger tip electrode 34 and measuring the
associated resistance between the electrodes 34.
Manual Strength Measurement
[0060] Hand grips 36 placed on one or both arms 30 with sensors are
used for early detection of neurological and neuromuscular
dysfunction. The grips 36 measure the active force caused by
muscular contraction as well as passive sensing of finger motion
associated with tremors. Similar technology is built into the leg
support 18 rest for the determination of leg muscle force.
[0061] Typically, referring to FIG. 3, one embodiment of a real
time hand grip monitoring device comprises a bladder 36 in the form
of an ellipsoid. However, other bladder shapes may be used which
are comfortable for a patient to hold or grip. The bladder 36 may
be positioned and incorporated in one arm 30 or two bladders 36 may
be provided, one in each arm 30, i.e., for left hand gripping and
for right hand gripping. A comparison of signals from both the left
and right hand arrangement of bladders 36 is considered important
when analyzing certain muscular and neuromuscular characteristics
of a patient.
[0062] The bladder 36 is connected by a tube 70 through a check
valve 72 to a fluid source 74. Typically, the fluid is air,
although other fluids may be utilized. The bladder 36 further
includes an internal pressure sensor 76 with sensing leads 77
connected thereto. The sensing leads 78 connect the sensor 76 with
a data recorder 78. The data recorder 78 is connected with a data
comparator 80.
[0063] Typically, the bladder 36 is maintained at atmospheric
pressure. When there is no manual pressure applied to the bladder
36, then there is no pressure differential with respect to
atmospheric pressure. Squeezing the bladder 36 increases the
pressure within the bladder 36. This pressure is sensed by the
pressure sensor 76. The pressure sensor 76 produces an electrical
voltage proportional to the pressure applied to the sensor which
varies in time, depending upon the patient's strength and grip. The
voltage contains two elements, a direct current element and an
alternating current element. The direct current element represents
the absolute pressure while the alternating current element
represents changes in pressure associated with physiological
change, for example, information relating to muscle or hand
tremors.
[0064] Thus, the signal from the sensor 76 is divided into two
parallel processing paths. The first path is for the direct current
signal. Typically, the path will have a filter that removes the AC
or alternating current portion of the signal. The second path is
for the alternating current portion of the signal. This path
removes the direct current portion. In each instance, after removal
of the appropriate portion of the signal, by virtue of an
appropriate filter, the signal is amplified. The signals Arill then
be converted into a digital format if desired and necessary by
hardware and software in housing 50. The digital signals then may
be transferred to a communication system as described above or
processed on site and then transmitted.
[0065] In practice, it is desirable to have a bladder 36 associated
with both the left hand and right hand of the patient so as to
compare data with respect to both channels for the left hand and
right hand side of the patient. The patient hand strength with
respect to each hand provides additional physiological information,
for example, associated with stroke and stroke patient
recovery.
[0066] In any event, the direct current signal typically will
increase to a steady state value upon manual gripping. The steady
state value represents maximum hand strength. The length of time at
that fixed value represents the time during which the patient can
maintain the maximum hand grip force on the bladder. Integration of
that fixed value represents the total energy exerted by the
patient. The data is typically recorded for future comparison.
[0067] The alternating current signals are converted to an
appropriate frequency where the data frequency and amplitude are
recorded. Historical comparisons can then be made for the
individual patient or by comparison to the standard formats or a
standard library of information. Over time, the change in the
readings on both channels can be determined. The differential
readings with respect to left and right hand signal processing can
also be determined. Thresholds can be set and an alarm can be
provided which will indicate the crossing of a signal threshold.
That may be indicative of a possible abnormality of the
patient.
[0068] An alternative embodiment of the hand grip sensor includes a
grip mechanism with load cell sensors in place of the bladder
construction described. Other mechanical or electro-mechanical
substitutes may be utilized to provide the AC and DC signals.
System Operation
[0069] Of course, the chair is capable of interactive use as part
of a remote station/central station system as generally described
in the aforementioned U.S. Pat. No. 5,544,649. However, the present
invention incorporates not only sensor specific features associated
with the chair, but also system features associated with the means
and protocol for collecting, analyzing, transmitting, and
processing data. Also, the interrelationship of the collected data
is made possible for diagnostic implication. That is, conducting
and measuring multiple physical parameters simultaneously at a
remote site provides a better diagnostic overview of a patient and
the described system permits such a diagnostic overview.
[0070] It is possible, however, to vary the function, elements and
construction of the diagnostic chair and system with the chair. For
example, the number of load cells 22 and their geometric array may
be varied in order to enhance the data representative of factors
such as weight, respiration, rate, balance, etc. Also, the chair or
device may be utilized in a hospital or clinic and is not
restricted to remote site use.
[0071] In operation, the patient is directed to sit in the chair
and to follow a series of steps in desired and specific sequence or
simultaneously. The directions are provided through the remote
monitoring audio and video transmission from the central station.
As depicted in FIG. 4, a video screen 51 and camera 53 are utilized
in combination with the chair. As each instrument, for example, the
straps 26, 28 are attached to the patient by the patient, a signal
is initiated and transmitted from the transmitter receiver 42 to
the transmission device 44 and then back to the central station.
The electronics and logic systems in the electronics enclosure 50
control all of the initial sensing and set up and the described
processing of the various signals from the patient. Thus, data
manipulation is accomplished in the software and hardware and
maintained in the chair or at the remote site as an initial first
step. The essential data is then transmitted from the transmitter
receiver to the transmission device and ultimately over some
network such as a switched network to the central station. Upon
completion of the examination, the patient will rise from the chair
and disconnect the chair from a power source.
[0072] The platform may be in the form of a chair as described on
in the form of a bed or gurney or other subject support device.
Repositioning the sensors on various platforms is viewed as within
the scope of the ability of a practitioner in the relevant field.
The platform is also useful for detection of physical change,
monitoring of subject wellness, emergency diagnosis, general health
care management, rehabilitation monitoring, recovery monitoring,
information collection, information dissemination, and interaction
with respect to health and wellness for geriatrics especially
Examples of the utility of the device include the following.
EXAMPLE 1
Congestive Heart Failure (CHF) Patients
[0073] Currently CHF patients present one of the biggest challenges
of medicine. The New England Journal of Medicine reports that heart
failure affects approximately 6 million Americans and is the
leading cause of hospitalization for adults over the age of 65.
Annual expenditures for heart failure related costs are estimated
as high as $38 billion, according to research conducted by the
Journal of the American College of Cardiologists, of which $23
billion is for hospitalizations.
[0074] Numerous studies suggest that comprehensive
heart-failure-managemen- t programs can improve patients' quality
of life, reduce hospital readmissions and emergency room visits and
save overall costs of treating this condition. Despite the improved
results, physicians are concerned about the low level of
compliance. The lack of compliance results in inaccurate data
received from patients with the consequence of inappropriate
treatment. The present system and device permits transmission of
data such as weight, ECG, balance and coordination information
etc., from the patient site to the monitoring center which will be
done automatically without the need of patient activity,
audio-visual verification of medication in-take, and visual contact
with a health practitioner to maintain human contact.
EXAMPLE 2
Diabetes
[0075] Diabetes affects 5.9% of the U.S. population, estimated to
be 15.7 million Americans. Approximately half of all diabetes
occurs in people older than 55. Of the 65 and older population
yearly 18.4% (6.8 million people have diabetes). Diabetes causes
many serious complications, including blindness, heart disease and
kidney failure. One in four patients with diabetes develops foot
problems which require treatment. Sixty thousand amputations are
performed on people with diabetes in the U.S. each year.
Complications from diabetes costs the U.S. economy $45 billion each
year, with an additional $47 billion attributed to indirect costs
from diabetes-related disabilities.
[0076] Diabetes requires daily self management. Education, frequent
monitoring and medication adjustments in the home setting with the
disclosed device will help patients achieve better glucose and
blood pressure control, thereby preventing or slowing the
progression of diabetes complications, provide psychological
support achieved by audio-visual interaction with a nurse, and
provide the capability of monitoring and retrieving various vital
signs (i.e., ECG, NIBP, weight) and clinical observations (i.e.,
wounds, swelling, etc.) and to prevent complications such as
cardiac problems and circulatory problems leading to amputation,
stroke, etc.
EXAMPLE 3
Parkinson's Disease
[0077] Parkinson's disease is a progressive disorder of the central
nervous system affecting approximately 2 out of 1,000 people, and
most often develops after age 50. It is one of the most common
neurological disorders of the elderly. Treatment begun early in the
disorder can slow progression of the disease.
[0078] The health care provider may be able to diagnose Parkinson's
disease based on the symptoms and physical examination. However,
the symptoms may be difficult to assess, particularly in the
elderly. Some of these symptoms are: muscle rigidity, stiffness,
difficult bending arms and legs, unstable, or slumped-over posture,
loss of balance, gait changes, shuffling walk slow movements,
difficulty beginning to walk, difficulty in initiating any
voluntary movement, small steps followed by he need to run to
maintain balance, freezing of movement when the movement is
stopped, inability to resume movement, shaking and tremor, changes
in facial expression.
[0079] Some of these symptoms are not specific to Parkinson and may
be confused with other disorders that cause similar symptoms. For
example, the posture changes may be similar to osteoporosis or
other changes associated with aging. Lack of facial expression may
be a sign of depression. The tremor may not appear when the person
is sitting quietly with arms in the lap.
[0080] Untreated, the disorder progresses to total disability,
often accompanied by general deterioration of all brain functions.
It may result in an early death if untreated.
[0081] Treated, the disorder impairs people in varying ways. Most
people respond (to some extent) to medications. The extent of
symptom relief, and how long this control of symptoms lasts, is
highly variable. The side effects of medications may be severe. The
device with its response time test and the ability to detect and
measure tremors will enable the early detection of the disease as
well as the follow up of the efficacy of the medications.
[0082] The type and number of tests which can be implemented
utilizing the chair or an alternative platform may be varied. All
of the tests described need not be performed. Various additional
tests may be incorporated into the chair using additional types of
sensors. Also, the chair (device) may be automatically controlled
from a remote (or near) station to automatically perform a series
of tests without a nurse or professional guiding the subject. The
system can therefore be programmed to conduct testing upon
initiation by the subject of a predefined protocol. The test
results will then be transmitted and/or recorded for later personal
review. Thus, the subject matter of the invention is to be limited
only by the following claims and equivalents thereof.
* * * * *