U.S. patent application number 10/906315 was filed with the patent office on 2005-10-13 for patch sensor for measuring blood pressure without a cuff.
This patent application is currently assigned to TRIAGE WIRELESS, INC.. Invention is credited to Banet, Matthew John.
Application Number | 20050228299 10/906315 |
Document ID | / |
Family ID | 35061470 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050228299 |
Kind Code |
A1 |
Banet, Matthew John |
October 13, 2005 |
PATCH SENSOR FOR MEASURING BLOOD PRESSURE WITHOUT A CUFF
Abstract
A monitoring device, method and system for monitoring vital
signs of a patient over a wireless network are disclosed herein.
The monitoring device includes an adhesive patch sensor, typically
mounted on a patient's head, and a processing component. The
adhesive patch sensor typically includes an optical system that
generates an optical waveform, and an electrode that generates an
electrical waveform. The processing component processes the optical
and electrical waveforms, along with a calibration table, to
determine the patient's vital signs.
Inventors: |
Banet, Matthew John; (Del
Mar, CA) |
Correspondence
Address: |
MATTHEW J. BANET
6540 LUSK BLVD., C200
SAN DIEGO
CA
92121
US
|
Assignee: |
TRIAGE WIRELESS, INC.
11622 El Camino Real Suite100
San Diego
CA
|
Family ID: |
35061470 |
Appl. No.: |
10/906315 |
Filed: |
February 14, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10906315 |
Feb 14, 2005 |
|
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10709014 |
Apr 7, 2004 |
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Current U.S.
Class: |
600/485 ;
128/903; 600/323 |
Current CPC
Class: |
A61B 2562/06 20130101;
A61B 5/02438 20130101; A61B 5/1455 20130101; A61B 5/25 20210101;
A61B 5/14532 20130101; A61B 5/02125 20130101; A61B 5/021 20130101;
A61B 5/0022 20130101; A61B 5/1112 20130101; A61B 2560/0412
20130101; A61B 5/0205 20130101; A61B 5/002 20130101; A61B 5/14552
20130101; A61B 5/6814 20130101 |
Class at
Publication: |
600/485 ;
128/903; 600/323 |
International
Class: |
A61B 005/02; A61B
005/00 |
Claims
What is claimed is:
1. A system for monitoring blood pressure, the system comprising: a
monitoring device comprising an adhesive patch sensor component
that generates an optical signal and a processing component for
processing the optical signal with calibration information to
obtain blood pressure information; and a computer system configured
to receive and display the blood-pressure information.
2. The system of claim 1, wherein the optical system comprises at
least one LED and a photodiode.
3. The system of claim 2, wherein the processing component
comprises a microprocessor that processes the optical waveform
along with the calibration information to determine the
blood-pressure information.
4. The system of claim 1, wherein the adhesive patch sensor
component further comprises an electrode that measures an
electrical waveform.
5. The system of claim 4, wherein the processing component further
comprises a microprocessor that processes both the optical and
electrical waveforms to determine the blood-pressure
information.
6. The system of claim 1, wherein the adhesive patch sensor further
comprises a short-range wireless transmitter.
7. The system of claim 6, wherein the short-range wireless
transmitter is a transmitter that operates a protocol based on
Bluetooth.TM., 802.11a, 802.11b, 802.1g, or 802.15.4.
8. The system of claim 1, wherein the monitoring device further
comprises a short-range wireless component that operates a wireless
protocol based on Bluetooth.TM., 802.11a, 802.11b, 802.1g, or
802.15.4.
9. The system of claim 1, wherein the processing component further
comprises a wireless transmitter that wirelessly transmits the
blood pressure information over a terrestrial wireless network.
10. The system of claim 1, wherein the processing component further
analyzes the optical signal to determine pulse oximetry and heart
rate.
11. The system of claim 1, where in adhesive patch sensor component
comprises and adhesive component configured to attach to a
patient's head.
12. A monitoring device for monitoring a patient's blood pressure,
the monitoring device comprising: a head-mounted component
comprising a body and an optical device positioned within the body
for measuring blood pressure from the patient's artery, the body
having an adhesive on an exterior surface for adhesively securing
the body to the patient's head; and, means for wirelessly
transmitting a signal representative of the patient's blood
pressure.
13. The monitoring device according to claim 12, further comprising
means for transmitting the signal to a network.
14. The monitoring device according to claim 12, wherein the
optical device comprises a first LED capable of radiating light at
a wavelength of approximately 600-800 nanometers, a second LED
capable of radiating light at a wavelength of approximately
900-1200 nanometers, and a photodetector capable of detecting
reflected light originating from the first LED and the second
LED.
15. A method for measuring blood pressure from a patient, the
method comprising: attaching a head-mounted component of a
monitoring device to the head of a patient; generating light from a
light source within the head-mounted component, the light directed
at an artery of the patient; absorbing reflected light originating
from the light source with a photodetector positioned within the
head-mounted component; sending a signal representative of the
absorption rate of the reflected light, the signal sent from the
photodetector to a processing component; and processing the signal
with the processing component to determine a blood pressure value
for the patient.
16. The method according to claim 15 wherein sending the signal
comprises transmitting a wireless signal from the head-mounted
component to a wireless transceiver within the processing
component.
17. The method according to claim 15 further comprising wirelessly
sending blood pressure information over a wireless network.
18. The method according to claim 15 wherein the head-mounted
monitoring component comprises a polymer body with adhesive on an
exterior surface for adhesively attaching the head-mounted
monitoring component to the patient's head, the light source and
the photodetector positioned within the polymer body.
Description
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 10/709,014, filed on Apr. 7,
2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a device, method and system
for measuring vital signs, particularly blood pressure.
[0005] 2. Description of Related Art
[0006] Pulse oximeters are medical devices featuring an optical
module, typically worn on a patient's finger or ear lobe, and a
processing module that analyzes data generated by the optical
module. The optical module typically includes first and second
light sources (e.g., light-emitting diodes, or LEDs) that transmit
optical radiation at, respectively, red (X 630-670 nm) and infrared
(.lambda..about.800-1200 nm) wavelengths. The optical module also
features a photodetector that detects radiation transmitted or
reflected by an underlying artery. Typically the red and infrared
LEDs sequentially emit radiation that is partially absorbed by
blood flowing in the artery. The photodetector is synchronized with
the LEDs to detect transmitted or reflected radiation. In response,
the photodetector generates a separate radiation-induced signal for
each wavelength. The signal, called a plethysmograph, varies in a
time-dependent manner as each heartbeat varies the volume of
arterial blood and hence the amount of transmitted or reflected
radiation. A microprocessor in the pulse oximeter processes the
relative absorption of red and infrared radiation to determine the
oxygen saturation in the patient's blood. A number between 94%-100%
is considered normal, while a value below 85% typically indicates
the patient requires hospitalization. In addition, the
microprocessor analyzes time-dependent features in the
plethysmograph to determine the patient's heart rate.
[0007] Pulse oximeters work best when the appendage they attach to
(e.g., a finger) is at rest. If the finger is moving, for example,
the light source and photodetector within the optical module
typically move relative to the underlying artery. This generates
`noise` in the plethysmograph, which in turn can lead to
motion-related artifacts in data describing pulse oximetry and
heart rate. Ultimately this reduces the accuracy of the
measurement. Another medical device, called a sphygmomanometer,
measures a patient's blood pressure using an inflatable cuff and a
sensor (e.g., a stethoscope) that detects blood flow by listening
for sounds called the Korotkoff sounds. During a measurement, a
medical professional typically places the cuff around the patient's
arm and inflates it to a pressure that exceeds the systolic blood
pressure. The medical professional then incrementally reduces
pressure in the cuff while listening for flowing blood with the
stethoscope. The pressure value at which blood first begins to flow
past the deflating cuff, indicated by a Korotkoff sound, is the
systolic pressure. The stethoscope monitors this pressure by
detecting strong, periodic acoustic `beats` or `taps` indicating
that the blood is flowing past the cuff (i.e., the systolic
pressure barely exceeds the cuff pressure). The minimum pressure in
the cuff that restricts blood flow, as detected by the stethoscope,
is the diastolic pressure. The stethoscope monitors this pressure
by detecting another Korotkoff sound, in this case a `leveling off`
or disappearance in the acoustic magnitude of the periodic beats,
indicating that the cuff no longer restricts blood flow (i.e., the
diastolic pressure barely exceeds the cuff pressure).
[0008] Low-cost, automated devices measure blood pressure using an
inflatable cuff and an automated acoustic or pressure sensor that
measures blood flow. These devices typically feature cuffs fitted
to measure blood pressure in a patient's wrist, arm or finger.
During a measurement, the cuff automatically inflates and then
incrementally deflates while the automated sensor monitors blood
flow. A microcontroller in the automated device then calculates
blood pressure. Cuff-based blood-pressure measurements such as
these typically only determine the systolic and diastolic blood
pressures; they do not measure dynamic, time-dependent blood
pressure.
[0009] Data indicating blood pressure are most accurately measured
during a patient's appointment with a medical professional, such as
a doctor or a nurse. Once measured, the medical professional can
manually record these data in either a written or electronic file.
Appointments typically take place a few times each year.
Unfortunately, in some cases, patients experience `white coat
syndrome` where anxiety during the appointment affects the blood
pressure that is measured. For example, white coat syndrome can
elevate a patient's heart rate and blood pressure; this, in turn,
can lead to an inaccurate diagnoses.
[0010] Various methods have been disclosed for using pulse
oximeters to obtain arterial blood pressure. One such method is
disclosed in U.S. Pat. No. 5,140,990 to Jones et al., for a `Method
Of Measuring Blood Pressure With a Photoplethysmograph`. The '990
Patent discloses using a pulse oximeter with a calibrated auxiliary
blood pressure to generate a constant that is specific to a
patient's blood pressure. Another method for using a pulse oximeter
to measure blood pressure is disclosed in U.S. Pat. No. 6,616,613
to Goodman for a `Physiological Signal Monitoring System`. The '613
Patent discloses processing a pulse oximetry signal in combination
with information from a calibrating device to determine a patient's
blood pressure.
[0011] Chen et al, U.S. Pat. No. 6,599,251, discloses a system and
method for monitoring blood pressure by detecting pulse signals at
two different locations on a subject's body, preferably on the
subject's finger and earlobe. The pulse signals are preferably
detected using pulse oximetry devices, and then processed to
determine blood pressure.
[0012] Schulze et al., U.S. Pat. No. 6,556,852, discloses an
earpiece having an embedded pulse oximetry device and thermopile to
monitor and measure physiological variables of a user.
[0013] Jobsis et al., U.S. Pat. No. 4,380,240, discloses an optical
probe featuring a light source and a light detector incorporated
into channels within a deformable mounting structure which is
adhered to a strap. The light source and the light detector are
secured to the patient's body by adhesive tapes and pressure
induced by closing the strap around a portion of the body.
[0014] Tan et al., U.S. Pat. No. 4,825,879, discloses an optical
probe with a T-shaped wrap having a vertical stem and a horizontal
cross bar, which is utilized to secure a light source and an
optical sensor in optical contact with a finger. A metallic
material is utilized to reflect heat back to the patient's body and
to provide opacity to interfering ambient light. The sensor is
secured to the patient's body using an adhesive or hook-and-loop
material.
[0015] Modgil et al., U.S. Pat. No. 6,681,454, discloses a strap
composed of an elastic material that wraps around the outside of a
pulse oximeter probe and is secured to the oximeter probe by
attachment mechanisms such as Velcro.
[0016] Diab et al., U.S. Pat. Nos. 6,813,511 and 6,678,543,
discloses a disposable optical probe that reduces noise during a
measurement. The probe is adhesively secured to a patient's finger,
toe, forehead, earlobe or lip, and can include reusable and
disposable portions.
BRIEF SUMMARY OF THE INVENTION
[0017] The present invention provides a cuffless, blood-pressure
monitor, featuring an adhesive patch. The patch is disposable and
is typically used for 24-72 hours. The blood pressure monitor makes
a transdermal, optical measurement of the time-dependent dynamics
of blood flowing in an underlying artery. A processor analyzes this
information, typically with a calibration table, to determine blood
pressure. Once determined, the processor sends it to a hand-held
wireless component (e.g., a cellular phone or wireless PDA). The
processing component preferably features an embedded, short-range
wireless transceiver and a software platform that displays,
analyzes, and then transmits the information through a wireless
network to an Internet-based system. With this system a medical
professional can continuously monitor a patient's blood pressure
during their day-to-day activities. Monitoring patients in this
manner minimizes erroneous measurements due to `white coat
syndrome` and increases the accuracy of a blood-pressure
measurement.
[0018] The invention has many advantages. In particular, one aspect
of the invention provides a system that continuously monitors a
patient's blood pressure using a cuffless blood pressure monitor
and an off-the-shelf mobile communication device. Information
describing the blood pressure can be viewed using an Internet-based
website, using a personal computer, or simply by viewing a display
on the mobile device. Blood-pressure information measured
continuously throughout the day provides a relatively comprehensive
data set compared to that measured during isolated medical
appointments. This approach identifies trends in a patient's blood
pressure, such as a gradual increase or decrease, which may
indicate a medical condition that requires treatment. The invention
also minimizes effects of `white coat syndrome` since the monitor
automatically and continuously makes measurements away from a
medical office with basically no discomfort to the patient.
Real-time, automatic blood pressure measurements, followed by
wireless transmission of the data, are only practical with a
non-invasive, cuffless monitor like that of the present invention.
Measurements can be made completely unobtrusive to the patient.
[0019] The monitor can also characterize the patient's heart rate
and blood oxygen saturation using the same optical system for the
blood-pressure measurement. This information can be wirelessly
transmitted along with blood-pressure information and used to
further diagnose the patient's cardiac condition.
[0020] The monitor is small, easily worn by the patient during
periods of exercise or day-to-day activities, and makes a
non-invasive blood-pressure measurement in a matter of seconds. The
resulting information has many uses for patients, medical
professional, insurance companies, pharmaceutical agencies
conducting clinical trials, and organizations for home-health
monitoring.
[0021] Having briefly described the present invention, the above
and further objects, features and advantages thereof will be
recognized by those skilled in the pertinent art from the following
detailed description of the invention when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0022] FIG. 1A is a schematic top view of an adhesive patch sensor
that measures blood pressure according to the invention;
[0023] FIG. 1B is a schematic, cross-sectional view of the patch
sensor of FIG. 1A;
[0024] FIG. 2 is a graph of time-dependent optical and electrical
waveforms generated by the patch sensor of FIG. 1A;
[0025] FIG. 3 is a schematic diagram of the electrical components
of a processing module connected to the patch sensor of FIG.
1A;
[0026] FIGS. 4A and 4B are schematic diagrams of the patch sensor
of FIG. 1A attached to, respectively, a patient's forehead and
ear;
[0027] FIG. 5 is a schematic diagram of a head-mounted sensor
similar to that shown in FIG. 4A connected to a belt-mounted
processing module using a wireless link;
[0028] FIG. 6 is a schematic view of an Internet-based system used
to send vital-sign information from a patient to an
Internet-accessible website.
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIGS. 1A and 1B show an adhesive patch sensor 20 according
to the invention that features a pair of LEDs 10, 12 and
photodetector 14 that, when attached to a patient, generate an
optical waveform (31 in FIG. 2). A horseshoe-shaped metal electrode
17 surrounds these optical components and generates an electrical
waveform (32 in FIG. 2). The electrical and optical waveforms, once
generated, pass through a cable 18 to a processing module, which
analyzes them as described in detail below to measure a patient's
systolic and diastolic blood pressure, heart rate, and pulse
oximetry. The patch sensor 20 features an adhesive component 19
that adheres to the patient's skin and secures the LEDs 10, 12,
photodetector 14, and electrode 17 in place to minimize the effects
of motion. During operation, the cable 18 snaps into a plastic
header 16 disposed on a top portion of the patch sensor 20. Both
the cable 18 and header 16 include matched electrical leads that
supply power and ground to the LEDs 10, 12, photodetector 14, and
electrode 19. The cable 18 and header 16 additionally supply a
high-frequency electrical signal to the electrode that helps
generate the electrical waveform. When the patch sensor 20 is not
measuring optical and electrical waveforms (e.g., when the patient
is sleeping), the cable 18 unsnaps from the header 16, while the
sensor 20 remains adhered to the patient's skin. In this way a
single sensor can be used for several days. After use, the patient
removes and then discards the sensor 20.
[0030] To measure blood pressure, heart rate, and pulse oximetry,
the LEDs 10, 12 generate, respectively, red and infrared radiation
that irradiates an underlying artery. Blood volume increases and
then decreases as the heart pumps blood through the patient's
artery. Blood cells within the blood absorb and transmit varying
amounts of the red and infrared radiation depending the on the
blood volume and how much oxygen binds to the cells' hemoglobin.
The photodetector 14 detects a portion of the radiation that
reflects off an underlying artery, and in response sends a
radiation-induced photocurrent to an analog-to-digital converter
embedded within the processing module. The analog-to-digital
converter digitizes the photocurrent to generate a time-dependent
optical waveform for each wavelength. In addition, the
microprocessor analyzes waveforms generated at both red and
infrared wavelengths, and compares a ratio of the relative
absorption to a calibration table coded in its firmware to
determine pulse oximetry. The microprocessor additionally analyzes
the time-dependent properties of one of the optical waveforms to
determine the patient's heart rate.
[0031] Concurrent with measurement of the optical waveform, the
electrode 19 detects an electrical impulse from the patient's skin
that the microprocessor processes to generate an electrical
waveform. The electrical impulse is generated each time the
patient's heart beats.
[0032] The patch sensor 20 preferably has a diameter, `D`, ranging
from 0.5 centimeter (`cm`) to 10 cm, more preferably from 1.5 cm to
3.0 cm, and most preferably 2.5 cm. The patch sensor 20 preferably
has a thickness, `T`, ranging from 1.0 millimeter ("mm") to 3 mm,
more preferably from 1.0 mm to 1.5 mm, and most preferably 1.25 mm.
The patch sensor 20 preferably includes a body composed of a
polymeric material such as a neoprene rubber. The body is
preferably colored to match a patient's skin color, and is
preferably opaque to reduce the affects of ambient light. The body
is preferably circular in shape, but can also be non-circular, e.g.
an oval, square, rectangular, triangular or other shape.
[0033] FIG. 2 shows both optical 31 and electrical 32 waveforms
generated by the patch sensor of FIGS. 1A and 1B. Following a
heartbeat, the electrical impulse travels essentially
instantaneously from the patient's heart to the patch sensor, where
the electrode detects it to generate the electrical waveform 32. At
a later time, a pressure wave induced by the same heartbeat
propagates through the patient's arteries and arrives at the
sensor, where the LEDs and photodetector detect it as described
above to generate the optical waveform 31. The propagation time of
the electrical impulse is independent of blood pressure pressure,
whereas the propagation time of the pressure wave depends strongly
on pressure, as well as mechanical properties of the patient's
arteries (e.g., arterial size, stiffness). The microprocessor runs
an algorithm that analyzes the time difference AT between the
arrivals of these signals, i.e. the relative occurrence of the
optical 31 and electrical 32 waveforms as measured by the patch
sensor. Calibrating the measurement (e.g., with a conventional
blood pressure cuff) accounts for patient-to-patient variations in
arterial properties, and correlates .DELTA.T to both systolic and
diastolic blood pressure. This results in a calibration table.
During an actual measurement, the calibration source is removed,
and the microprocessor analyzes .DELTA.T along with other
properties of the optical and electrical waveforms and the
calibration table to calculate the patient's real-time blood
pressure.
[0034] The microprocessor can analyze other properties of the
optical waveform 31 to augment the above-mentioned measurement of
blood pressure. For example, the waveform can be `fit` using a
mathematical function that accurately describes the waveform's
features, and an algorithm (e.g., the Marquardt-Levenberg
algorithm) that iteratively varies the parameters of the function
until it best matches the time-dependent features of the waveform.
In this way, blood pressure-dependent properties of the waveform,
such as its width, rise time, fall time, and area, can be
calibrated as described above. After the calibration source is
removed, the patch sensor measures these properties along with
.DELTA.T to determine the patient's blood pressure.
[0035] Methods for processing the optical and electrical waveform
to determine blood pressure are described in the following
co-pending patent applications, the entire contents of which are
incorporated by reference: 1) CUFFLESS BLOOD-PRESSURE MONITOR AND
ACCOMPANYING WIRELESS, INTERNET-BASED SYSTEM (U.S. Ser. No.
10/709,015; filed Apr. 7, 2004); 2) CUFFLESS SYSTEM FOR MEASURING
BLOOD PRESSURE (U.S. Ser. No. 10/709,014; filed Apr. 7, 2004); 3)
CUFFLESS BLOOD PRESSURE MONITOR AND ACCOMPANYING WEB SERVICES
INTERFACE (U.S. Ser. No. 10/810,237; filed Mar. 26, 2004); 4)
VITAL-SIGN MONITOR FOR ATHLETIC APPLICATIONS (U.S. Ser. No.; filed
Sep. 13, 2004); 5) CUFFLESS BLOOD PRESSURE MONITOR AND ACCOMPANYING
WIRELESS MOBILE DEVICE (U.S. Ser. No. 10/967,511; filed Oct. 18,
2004); and 6) BLOOD PRESSURE MONITORING DEVICE FEATURING A
CALIBRATION-BASED ANALYSIS (U.S. Ser. No. 10/967,610; filed Oct.
18, 2004).
[0036] FIG. 3 shows a preferred configuration of electronic
components featured within the processing module 50. A
data-processing circuit 17 connects to an optical signal processing
circuit 35 that powers both the LEDs and the photodetector, and
additionally processes radiation-induced photocurrent generated by
the photodetector. The data-processing circuit 17 typically
includes a microprocessor 45, which in turn includes an embedded
analog-to-digital converter 46 that digitizes signals to generate
both the electrical and optical waveforms. In a similar manner, the
data-processing circuit 17 controls an RF source 18 for the
electrode. To receive inputs from wireless devices, the processing
module 50 includes a Bluetooth.TM. wireless transceiver 38 that
receives information through an antenna 26 from a matched
transceiver embedded within an external component. The processing
module 50 can also include a liquid crystal display (`LCD`) 42 that
displays blood-pressure information for the user or patient. In
another embodiment, the data-processing circuit 17 avails
calculated information through a serial port 40 to an external
personal computer, which then displays and analyzes the information
using a client-side software application. A battery 37 powers all
the electrical components within the processing module, and is
preferably a metal hydride battery (generating 3-7V) that can be
recharged through a battery-recharge interface 44.
[0037] Referring to FIGS. 4A and 4B, in embodiments the patch
sensor 20 is head-mounted and attaches through a cable 18 to a
processing module 50 worn on the patient's belt. Preferably the
sensor attaches to the patent's forehead 52, underneath the
patient's ear, on the back of the patient's neck, or to any other
location on the patient's head that is on or near an artery.
Typically the patient's head undergoes relatively little motion
compared to other parts of the patient's body (e.g., the hands),
and thus attaching the sensor to this region reduces the negative
affects of motion-related artifacts.
[0038] In another embodiment, shown in FIG. 5, the sensor 20
includes a wireless transceiver 70 (e.g., a Bluetooth transceiver)
that communicates with a matched wireless transceiver 71 in the
processing module 50 through a wireless link 24. In this embodiment
the sensor 20 additionally includes a battery 73 that powers the
wireless transceiver 70 and all the sensing components therein.
During operation, the battery-powered sensor 20 collects the
optical and electrical waveforms as described above, and transmits
these with the wireless transceiver 70 to the transceiver 71 in the
processing component 50. The processing module 50 then processes
the waveforms as described above to determine the patient's vital
signs.
[0039] FIG. 6 shows a preferred embodiment of an Internet-based
system 53 that operates in concert with the adhesive patch sensor
20 and processing module 50 to send information from a patient to a
hand-held wireless device 15. The wireless device 15 then sends the
information through a wireless network 54 to a web site 66 hosted
on an Internet-based host computer system 57. A secondary computer
system 69 accesses the website 66 through the Internet 67. The
system 53 functions in a bidirectional manner, i.e. the processing
module 50 can both send and receive data. Most data flows from the
processing module 20 to the website 66; using the same network,
however, the device can also receive data (e.g., `requests` to
measure data or text messages) and software upgrades.
[0040] A wireless gateway 55 connects to the wireless network 54
and receives data from one or more wireless devices 15, as
discussed below. The wireless gateway 55 additionally connects to a
host computer system 57 that includes a database 63 and a
data-processing component 68 for, respectively, storing and
analyzing the data. The host computer system 57, for example, may
include multiple computers, software pieces, and other
signal-processing and switching equipment, such as routers and
digital signal processors. The wireless gateway 55 preferably
connects to the wireless network 54 using a TCP/IP-based
connection, or with a dedicated, digital leased line (e.g., a
frame-relay circuit or a digital line running an X.25 or other
protocols). The host computer system 57 also hosts the web site 66
using conventional computer hardware (e.g. computer servers for
both a database and the web site) and software (e.g., web server
and database software).
[0041] During typical operation, the patient continuously wears the
patch sensor 20 for a period of time ranging from a 1-2 days to
weeks. Alternatively, the patient may wear the sensor 20 for
shorter periods of time, e.g. just a few hours. For example, the
patient may wear the sensor during a brief hospital stay, or during
a medical checkup. To view information sent from the processing
module, the patient or medical professional accesses a user
interface hosted on the web site 66 through the Internet 67 from
the secondary computer system 69. The system 53 may also include a
call center, typically staffed with medical professionals such as
doctors, nurses, or nurse practioners, whom access a care-provider
interface hosted on the same website 66.
[0042] In an alternate embodiment, the host computer system 57
includes a web services interface 70 that sends information using
an XML-based web services link to a secondary, web-based computer
application 71. This application 71, for example, could be a
data-management system operating at a hospital.
[0043] The processing module 50 can optionally be used to determine
the patient's location using embedded position-location technology
(e.g., GPS, network-assisted GPS, or 802.11-based location system).
In situations requiring immediate medical assistance, the patient's
location, along with relevant medical data collected by the blood
pressure monitoring system, can be relayed to emergency response
personnel.
[0044] In a related embodiment, the processing module 50 and
wireless device may use a `store and forward` protocol wherein the
processing module 50 stores information when the wireless device is
out of wireless coverage, and then sends this information to the
wireless device when it roams back into wireless coverage.
[0045] In an alternate embodiment of the invention, the processing
module and patch sensor are used within a hospital, and the
processing module includes a short-range wireless link (e.g., a
module operating Bluetooth.TM., 802.11a, 802.11b, 802.1g, or
802.15.4 wireless protocols) that sends vital-sign information to
an in-hospital network. In this embodiment, a nurse working at a
central nursing station can quickly view the vital signs of the
patient using a simple computer interface.
[0046] Still other embodiments are within the scope of the
following claims.
* * * * *