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BACKGROUND OF THE INVENTION
A. Field of the Invention
This invention relates to techniques for monitoring the medical condition
of a patient, and, more particularly, to a method and apparatus for
monitoring a patient at a remote site from a central station by means of
interactive visual communications techniques and devices. While the
invention is also suitable for use in any situation where a patient is to
be monitored at a site remote from a central station, it is especially
suitable to the monitoring and caring for the elderly in the home
environment. Thus, the invention can also be said to relate to the field
of geriatric care.
B. The Prior Art
1. General Considerations
Modern society with its improvement in living conditions and advanced
health care has brought about a marked prolongation of life expectancy.
This change has resulted in a dramatic and progressive increase in the
geriatric population. A large percentage of the geriatric population needs
continuous general, as well as medical, supervision and care. For example,
supervision of daily activities such as dressing, personal hygiene, eating
and safety as well as supervision of their health status is necessary.
Furthermore, the relief of loneliness and anxiety is a major, yet
unsolved, problem that has to be dealt with. These and other facets of the
management of the ever increasing geriatric population have yet to be
successfully addressed and solved.
The creation of retirement facilities and old age homes, as well as other
geriatric facilities, provide only a partial solution to the problems
facing the geriatric population. The geriatric population, a constantly
increasing fraction of society, has become increasingly dependent upon the
delivery of home health and general care, which has its own set of
challenges and drawbacks.
The notion of ambulatory (home environment) patient care is gaining
increased popularity and importance. According to some recently published
reports, the number of old aged people receiving home care services under
Medicare has shown a 13% annual growth rate and has tripled in 10 years
(1978-1988) from 769,000 to 2.59 million. This dramatic shift in patient
care from the "sheltered" institutional milieu to the patient's home, work
place, or recreational environment is due primarily to a radical change in
concepts. That is, specialists in geriatric care tend to keep the aged in
their own natural environment for as long as possible. Moreover, the
marked increase in the cost of institutional patient care, the important
technological advances and the development of medical equipment, and the
explosive development in the field of telecommunication are some of the
additional factors that may help in creating proper home care for the
aged.
Presently, geriatric home care is still in its first stages of development.
However, according to some recently published market research reports, the
market for home care services and products is booming. Annual spending on
home care services is expected to increase from $8.8 billion in 1988 to
$16 billion in 1995, while annual spending on home care products will
increase from $1.15 billion to $1.86 billion during the same period.
Except for scarce model organizations, home care is carried out either by
the patient's family or by nonprofessional help. The monitoring equipment
at home care facilities is usually minimal or nonexistent, and the patient
has to be transported to the doctor's office or other diagnostic facility
to allow proper evaluation and treatment.
Patient follow-up is done by means of home visits of nurses which are of
sporadic nature, time consuming and generally very expensive. A visiting
nurse can perform about 5-6 home visits per day. The visits have to be
short and can usually not be carried out on a daily basis. Moreover, a
visiting nurse program provides no facilities for continuous monitoring of
the patient and thus no care, except in fortuitous circumstances, in times
of emergency. The remainder of day after the visiting nurse has left is
often a period of isolation and loneliness for the elderly patient.
The existing home care nursing facilities divert skilled nurses, a scarce
commodity, from the hospital environment and uses them in a highly
inefficient manner due to the wide dispersion of the patients and the lack
of sophisticated diagnostic facilities in the patients'home. Clearly, the
practice of visiting nurses leaves much to be desired.
These considerations apply to the general population as well, as the
spiraling cost of hospital care has lead to a dramatic increase in the use
of outpatient care as a treatment modality.
2. Prior Art Models of Ambulatory Patient Monitoring
One of the areas in which ambulatory patient monitoring is most widely used
is out-of-the-hospital surveillance of the cardiac patient. Patients with
cardiovascular problems (diseases of the heart and blood vessels)
constitute the largest and most important diagnostic and therapeutic
challenge facing the authorities responsible for the deployment of health
care to the adult and specifically aging population in the U.S. About 15%
of the adult population of the industrialized world suffers from
hypertension, a major risk factor for atherosclerosis, heart disease, and
stroke. Other commonly accepted risk factors such as: elevated blood lipid
levels, obesity, diabetes, smoking, mental stress and others are also
abundant.
Every year more than 1.5 million people in the U.S. suffer a heart attack.
This together with stroke constitutes the number one cause of death in our
adult population. More importantly, the majority of cardiac related deaths
occur outside of the sophisticated and sheltered hospital environment.
Therefore the need for means for ambulatory monitoring of these patients
is obvious.
To date the electrocardiogram (ECG) and blood pressure are two main
parameters most commonly monitored in the out-of-the-hospital environment.
Holter monitoring (continuous 24 hour tape recording of the
electrocardiogram) and continuous recording of blood pressure are useful
modalities for the evaluation of changes in the cardiovascular system.
These, however, are short term monitoring systems that provide only off
line information that becomes available at best hours after their
recording. Moreover, the hook up should be done by a nurse or technician.
Lately, transtelephonic ECG surveillance has been gaining in importance.
This system uses small ECG transmitters which allow the transmission of
the patients ECG over any telephone line to a diagnostic center. This
on-line information system is operative 24 hours a day, 365 days a year.
The patient is in direct contact with a highly trained team that can
intervene at any time and make real time decisions. The drawback of this
system is its communication system, which does not lend itself to
prolonged monitoring sessions and does not allow for visual observation of
the subject.
A home medical surveillance system is described in U.S. Pat. No. 4,838,275,
issued to Lee. This system involves the generation and transmission of
health-parameter signals from a patient's home to a central station.
However, the described system envisions only two way voice communication
between the patient and the observer at the central station. This system
does not provide for interactive visual communications between the patient
and health care provider, and thus lacks a principal feature and advantage
of the present invention.
U.S. Pat. No. 4,524,243 discloses a personal alarm system in which a
warning signal is sent to a central monitoring station if the patient's
activity level becomes inactive, such as in the case of a medical
emergency. This technology is limited in its diagnostic and therapeutic
value, and does not, in and of itself, provide for interactive voice or
visual communication between the patient and the physician.
Other patents disclose techniques for the transmission of still medical
images over a communications line to a remote site. For example, U.S. Pat.
No. 4,860,112, issued to Nichols et al., discloses methods and apparatus
for scanning medical images such as x-ray images and transmitting the
scanned image to a remote location. U.S. Pat. No. 5,005,126, issued to
Haskin, discloses a system for picking off an internal analog video signal
from imaging diagnostic equipment such as a CAT scanner and transmitting
the image to a remotely located physician's station. U.S. Pat. No.
4,945,410, issued to Walling, discloses a satellite communications system
for transmission of still medical images from a remote satellite
transmission station to a central headquarters. These patents have their
own inherent limitations and lack the interactive audio and visual
capabilities provided by the present invention. An ambulatory home care
and patient monitoring system, combining a long-term monitoring facility,
the possibility of visual contact between the patient and health
practitioner, and on-line, real time intervention capability has eluded
those in the art.
3. Available Home Health Monitoring Devices
There exists, at present, home health care and monitoring products that
perform various functions. The simplest include, amongst others,
instruments such as self-operated blood pressure devices
(sphygmomanometers), blood glucose measuring instruments, automated
medication dispensers and others. While these products are designed to be
useable by a patient without any assistance, they have no inherent
capability of remote monitoring. Moreover, they are often difficult to use
by elderly or infirm patients.
The other end of the spectrum includes the development of computer
controlled robots that provide an integrated, highly sophisticated, home
based monitoring unit. An example of such a device is the HANC (Home
Automated Nursing Center) system described in U.S. Pat. No. 5,084,828,
issued to Kaufman et al. This patent includes a robot capable of
monitoring the patient's vital signs, reminding the patient of his or her
medications, dispensing them in due time, and contacting a control center
for routine follow-up as well as in emergency situations. This device is
generally an unsatisfactory solution to the problem of at-home patient
monitoring because it is extremely expensive, unfriendly, impersonal,
cumbersome, and lacks interactive communication capabilities between the
patient and their physician.
The complex robotic units and home computer are impressive in their
capacity, but lack the human contact which is so important in effective
geriatric care. The patient's interaction with a machine, as sophisticated
as it may be, will always be inferior to the direct human contact.
Moreover, these systems are very expensive and will in the foreseeable
future be available to only a very small number of patients who can afford
them. Moreover, the older population does not adjust easily to computers
and robots, and mistakes in their use are frequent. Maintenance and
problems and the difficulty in programs in the computerized system make
the upkeep more complex. Thus, the currently available techniques for
providing home patient monitoring, particularly of the elderly, leave much
to be desired.
4. Other Geriatric Health Risks
Additional facts support development of an improved home health care system
especially for a geriatric population. For example, falls are a major
health problem among the elderly, causing injury, disability and death.
One third (some studies suggest half) of those over the age of 65 suffer
at least one fall each year. The rate of falling increases to 40% among
those who exceed the age of 80. According to the National Safety Council,
falls accounted for one-third of the death total for the elderly. Those
who survive falls may have restricted activity, soft-tissue injuries, or
fractures. It is estimated that up to 5% of falls by elderly persons
result in fractures. A similar percent result in soft-tissue injury
requiring hospitalization or immobilization for an extended period. It is
estimated that hip fractures resulting from falls cost approximately $2
billion in the United States during 1980. Falls are mentioned as a
contributing factor to admissions to nursing homes.
The factors leading to falls can be divided into two main groups:
environmental factors and medical factors. In spite of the difficulty in
the surveillance of patient condition before a fall, almost all
researchers share the conclusion that environmental hazards are
decreasingly important in causing falls as age increases. A clear
correlation between clinical or medical problems and the incident of falls
by the elderly has been established. Many of these medical problems of the
elderly or infirm can be detected by simple clinical observation. For
example gait and balance abnormality may indicate difficulty with
neurologic and musculoskeletal functions that may contribute to physical
instability. Changes in gait can be identified by the following: slow
speed, short step length, narrow stride width, wide range of stepping
frequency, a large variability of step length, and increasing variability
with increasing frequency.
Thus, there are relatively straight forward techniques which enable
diagnosis of a predisposition or likelihood of falls among elderly.
However, there is no inexpensive procedure for undertaking such diagnosis
or investigating such predisposition in a large patient population wherein
the kinematic condition of the patient can be investigated or where the
appearance, and reflex activity of the patient can be investigated with
ease.
SUMMARY OF THE INVENTION
In a principal aspect, the present invention comprises an interactive
television and audio patient monitoring system connecting a patient
situated at home with a central monitoring station manned by health
practitioners (e.g., trained nurses or clinicians). The term "patient" as
used herein is to be interpreted broadly to include elderly persons,
persons actively being treated or monitored for specific medical ailments,
as well as persons who wish to have their general medical condition
monitored by health practitioners.
The present invention provides two-way interactive visual communications
between the patient and the central station. The invention also provides
for the monitoring by the central station of any of a number of possible
vital signs and diagnostic test data. By way of example and not
limitation, the vital signs to be monitored may include blood pressure,
temperature, weight, heart rate, respiratory rate, oximetry and so on. At
the present, two-way interactive cable television, with its widespread
network, provides a two-way communication network suitable for use in the
present invention. Its interactive nature provides the personal, visual
contact between the patient and the staff located at the monitoring
center. Moreover, this communication system provides almost unlimited
monitoring time. These attributes enable the collection of a multitude of
medical data for prolonged periods of time, as well as the human contact
that constitutes an important factor in the care of the population in need
for such services. The long-term storage of medical and visual information
helps in diagnosis and treatment. The transmission of the visual
information and the monitored medical data between the central station and
the patient's home may be made by satellite, radio transmission or through
telephone lines, instead of cable television lines.
The preferred embodiment of the present invention involves an interactive
system for monitoring a patient's condition by health practitioner. The
patient is located at a remote location from a central monitoring station
and the health practitioner is located at a central station. The system
comprises in combination a first audio-visual camera for generating a
first audio-visual signal of a patient at the remote location. The system
also includes a means for measuring a medical condition of a patient at
the remote location and for generating a signal representative of the
measured medical condition. The measured medical condition may be any
health parameter, such as heart rate, respiratory rate, pulse oximetry,
blood pressure, and so on, and will of course vary from patient to
patient. A communications network is used for transmission of the first
audio-visual signal to the central monitoring station. The medical signal
is transmitted simultaneously with the first audio-visual signal. The
central station includes a display for substantially simultaneous display
of the first audio-visual signal and the medical signal. The system
further includes a second audio-visual means for generating a second
audio-visual signal of the health practitioner originating from the
central station, and the transmission of the second audiovisual signal to
the remote location. The system further includes a means for display of
the second audio-visual signal at the remote location for observation by
the patient preferably simultaneously with the transmission of the first
audio-visual transmission, whereby the patient and the health practitioner
are capable of substantially simultaneous interactive audio-visual
communication concerning the measured medical condition. Typically, the
display of the second audio-visual signal at the remote location will be
made on a TV set at the patient's home. Preferably, the means for
generating the first and second audio-visual signals are conventional
cameras such as camcorder type cameras. Thus, the present invention is
readily adaptable to existing technology and can be implemented at
relatively low cost.
The new, integrative, highly sophisticated and cost-effective home
monitoring system combining modern sensors and measuring devices with
interactive television solves many of the problems facing an ever growing
fraction of society. The geriatric population, the chronically ill, the
handicapped, and patients discharged from hospitals but still in need of
monitoring are only some examples of those who benefit from the invention.
As a further aspect of the invention, the visual signal generated by the
audio visual means associated with the patient may be relied upon to
measure the medical condition of the patient directly. That is, patient
gait, mobility, appearance and other visual aspects of a patient, which
may be relied upon by medical practitioners to evaluate the patient, may
be designated, marked, specified or tagged electronically in the visual
signal from the patient and thereby serve as a time dependent measurement
of the medical condition of the patient. Such measurements are transmitted
to the central station and processed electronically or visually.
Electronically the information may be stored or compared to standard data
or previously stored base line data associated with the patient. This
technique may be conducted utilizing analytical software or by a trained
technician or physician. Diagnosis of a propensity to fall may, for
example, be derived. Other diagnosis may also be derived in this manner.
Thus, an objective of this invention is to provide a central, remote home
care surveillance system combining a relatively inexpensive patient
monitoring devices with a sophisticated central surveillance center using
available telecommunication systems. The present invention provides an
interactive and cost-effective system that will allow around- the-clock
supervision of the various aspects of the various aspects of the patient's
daily activities and health in the home environment.
Moreover, the invention provides the capability for a physician at a remote
location, such as the physician's office, to interact audially and
visually with the patient.
A further object is to provide an efficient and economical health care
system. Ambulatory patient care is by far more economical than
institutional care. More importantly, it allows diagnostic and therapeutic
assessments in the patient's natural environmental rather than in the
"sterile" setting of a hospital ward. The equipment involved is easy to
use and alleviates the problem of frequent mistakes common in other
systems. Some of the benefits of audio-visual interactive communication
features of the present invention include: 1) enhancement of diagnosis by
the physician; 2) facilitation of instruction of the patient in the use of
home-based medical equipment and the administration of medicines, as well
as avoidance of mistake or misuse; 3) observation of the patient in times
of medical emergency, particularly if the patient cannot speak; 4)
psychological benefits by having a nurse "visit" the patient
electronically, and the comfort of knowing that the patient can have this
"visit" any time a problem occurs; and 5) facilitation of group
:instruction of a large number of patients at the same time. Group
instruction in, for example, preventative medicine or general health
matters can take place with the patients being capable of asking
questions.
These and other advantages and features of the subject invention will
become apparent from the detailed description of preferred and alternative
embodiments which follows.
BRIEF DESCRIPTION OF THE DRAWING
In the detailed description of presently preferred embodiments of the
present invention which follows, reference will be made to the drawings
comprised of the following figures, wherein like reference numerals refer
to like elements in the various views and wherein:
FIG. 1 is a simplified, overall functional block diagram of the health
monitoring system of the present invention;
FIG. 2.is a more detailed functional block diagram of the system of FIG. 1,
showing a central station simultaneously monitoring a plurality of
patients in remote locations;
FIG.3 is a schematic diagram illustrating how an audio-visual signal of a
patient may be transmitted via cable television lines from a patient's
remote location to the central station of FIG. 1;
FIG. 4 is a more detailed functional block diagram of the data analysis and
display center of the central station of FIG. 2;
FIG. 5 an illustration of one possible arrangement of the health monitoring
and telecommunications equipment in the central stations;
FIG. 6 an illustration of one possible arrangement of the medical condition
measuring, sensing and telecommunications equipment in a patient's home
environment;
FIG. 7 is an illustration of a health monitoring apparatus which may be
used in the present invention in the patient's home environment;
FIG.8.is more detailed block diagram of the transmitter of FIG. 7;
FIG. 9.is a more detailed block diagram of the receiver of FIG. 7; and
FIG. 10 is a more detailed illustration of the modular medical condition
sensing and display unit of FIG. 6 which may be used in the patient's home
environment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Briefly, a method and apparatus are provided for monitoring a medical
condition of a patient by means of instrumentation maintained at the
patient's living quarters linked through a communications network to a
central surveillance station. The system is interactive since the patient
and personnel at the central station may engage in two-way audio and
visual communication.
General Description
The system uses or incorporates inexpensive home medical monitoring
equipment that includes sensors and measuring devices for the particular
medical parameters to be monitored. The patient's home equipment is simple
to use and modular to allow for the accommodation of the monitoring device
to the specific needs of each patient. To reduce production costs and to
avoid complex maintenance problems, the home unit includes only the sensor
part of the measuring device. The raw data is transmitted to the central
station, which includes all of the needed sophistication to allow for the
storage, transformation, display and interpretation of the data. The need
for expensive equipment in the home is thus avoided. Inexpensive sensors
are placed in the patients'homes, and the more costly analytic equipment
for all the patients is located at the central station.
The central station includes a computer-based multi-channel data analysis
and display unit that enables the interpretation, display, and storage of
the transmitted data. This central station is preferably equipped with
alarm mechanisms to alert the staff to any aberration from the expected.
The central station further includes apparatus for the communication of
data to all authorities involved in the wide spectrum of the patient's
needs,e.g., emergency care agencies, the patient's physician, nursing
services, social workers, etc.
The central station is preferably provided with the capability of
automatically scanning predesignated patient home units at predetermined
intervals to provide continuous supervision of specific parameters. In
some instances, the central station may monitor continuously one or more
parameters, e.g., ECG, blood pressure, respiration, etc., for hours or
even days, thereby creating a semi-intensive-care capability. The
embodiment disclosed enables one highly trained nurse or patient
monitoring personnel located at the control center to supervise and
monitor as many as 50 patients either seriatim or substantially
simultaneously. Whereas a visiting nurse may only be able to visit 5 or 6
homes per day in person, a nurse at the central station may be able to
visit 5 or 6 patients per hour by making electronic "home visits".
Cable television provides an already existing, widespread and ideal system
for interactive visual communication with most residential units in
densely populated urban areas. The ambulatory patient monitoring system
integrating the latest advances in biomedical technology with cable
television provide safe and accurate general and medical supervision for
the geriatric/homebound population in their own, natural environment.
Using such an interactive system, a direct visual uni- or bi-directional
contact between the elderly person monitored and the supervision is
established at any time, day or night. This contact can be initiated, at
will, by the patient monitor or by the patient. Moreover, this
communication system is used to transfer general data as well as medical
data from sensors to monitor the various medical and non-medical
parameters. Further, a health practitioner may be able to have "classes"
with many remotely located patients.
Cable television networks provide a useful mode of communication between
the patient's remote location and the central station at the present, and
is a presently preferred means for transmission of the audio-visual signal
from the patient to the central station and for transmission of the
audio-visual signal of a health practitioner to the patient's remote
location. Further, the measured medical data can be displayed in the
patient's remote location and the parameters picked up by the camera. The
transmission of the measured medical data may also be by cable television,
or may be through another communication network such as the telephone
system. The data transmission could also be by microwave, cable, or other
transmission means. It will be appreciated that as advances in
telecommunications develop, other techniques for transmission of video
signals between a central station and the home may be desirable and
economically feasible. For example, satellite and radio transmission of
the video signal and/or monitored medical data, or transmission via modem
through the telephone lines, may also prove satisfactory.
Communication between the patient's remote location and the central station
can be initiated by a variety of techniques. One method is by manually or
automatically placing a call on the telephone to the patient's home or to
the central station. When the call is received, a responsive switch is
thrown, turning on the camera in the patient's home or at the central
station. Alternatively, the patient and central station could agree on
times or time intervals in which communication would take place. Ideally,
a remote control button 220 on the patient's chair (FIG. 10) is installed
which, when activated, turns on the equipment in the home and alerts the
health practitioner at the central station.
Referring now to FIG. 1, a greatly simplified schematic diagram of the
ambulatory patient monitoring invention is shown. Ambulatory patients
located in a remote location 10, such as the home, are monitored from a
central surveillance station 20. Only one remote location 10 is shown, for
the sake of simplicity. Audio and visual signals of the patient, as well
as medical data measured in the home such as heart rate, blood pressure,
temperature, oximetry data, etc., are sent over a communications network
12 to the central station 20. The audio-visual information and the
measured medical data are displayed at the central station 20 on display
equipment such as television monitors. The audio-visual information of the
patient, as well as the medical data, is monitored by a health care worker
such as a nurse at the central station 20. The system of FIG. 1 also
includes the generation of a second audio-visual signal of the health care
practitioner at the central station 20 and the transmission of the
audio-visual signal over a communications network 12 to the patient's home
or remote location 10. The second audio-visual signal is displayed in the
patient's remote location 10 on a television set. The transmission of the
second audio-visual signal of the health practitioner to the patient's
remote location 10 is preferably substantially simultaneous with the
incoming audio-visual signal from the patient and permits the patient and
health practitioner to engage in interactive visual communication
concerning the patient's current medical condition. The term
"substantially simultaneous" is meant to include actual simultaneous
transfer, as well as the situation where the patient and central station
transmissions are separated in time but immediately follow each other, as
may be required by equipment limitations in some cable television systems.
The system of FIG. 1 also includes the capability of a physician at a
remote location 30 to engage, in interactive visual communication with the
patient. At location 30, the physician may gain access by a second
communications network 14 to access the patient's health data or
audio-visual signal at the central surveillance station 20. Also, the
invention provides the capability of the patient gaining access to an
audio-visual signal of the physician.
Should the patient be experiencing health symptoms requiring intervention
and immediate care, the health care practitioner at the central station 20
may summon help from an emergency services provider 40. The emergency
services provider may send an ambulance, fire department personnel, family
member, or other emergency personnel to the patient's remote location 10.
The emergency services provider 40 may, perhaps, be an ambulance facility,
a police station, the local fire department, or any suitable support
facility.
Referring now to FIG. 2, the ambulatory patient health monitoring invention
is shown in a more detailed functional block diagram. The present
invention provides for the capability of a health care practitioner at the
central station 20 to monitor any given number of patients at remote
sites. FIG. 2 shows remote sites 10A and 10B, but of course there may be
any number of subscriber patients which may be monitored by the central
station 20 and only two are shown for purposes of simplicity. At the
remote site 10A, the patient 16 has in the home sensing equipment 18 for
measurement of a medical condition of the patient 16, such as a blood
pressure gauge, a comprehensive non-invasive patient monitor device such
as the Criticare Systems, Inc. Model 507 monitor, a simple thermometer,
oximetry equipment, or other equipment depending on the patient's medical
status. Preferably, the sensing equipment 18 requires passive or only
minimal activity on the part of the patient. The patient 16 also has in
his home 10A a camera 22 suitable for generating an audio-visual signal of
the patient 16. The patient 16 also has in his home 10A a television set
24 or other suitable means for displaying a audio-visual image of a health
care practitioner located at the central station 20.
Special equipment may be used for measuring medical parameters of the
patient with only minimal involvement by the patient. For example, a chair
(not shown) may be provided which includes sensors for measuring the
patient's temperature and weight, a blood-pressure cuff for measuring the
patient's blood pressure, electrodes for monitoring the patient's ECG, and
sensors for measuring the patient's pulse. Preferably, most of these
sensors are placed directly on the arms of the chair so that the patient's
medical data can be derived with minimal participation by the patient. The
sensors can be wired directly to a signal conditioning and transmission
unit (not shown) for amplification, analog to digital conversion, data
storage and transmission to the central station 20 over the telephone
line. A preferred modular medical condition sensing and display unit is
discussed below in conjunction with FIG. 10.
In operation, the health monitoring and sensing equipment 18 measures the
medical condition of the patient and generates a signal representative of
the measured medical condition, and transmits the raw data directly to the
central station over a transmission line 26 such as the telephone, or
perhaps sends it by a radio frequency transmitter to the central station
20. The data can also be sent directly over the cable television line to
the central station. Techniques for transmission of medical information
over a transmission line such as a telephone line are well known in the
art. Alternatively, the camera 22 may have its lens focused on the display
of the health monitor equipment 18, such as the face of the Criticare
Systems monitor, or the dial of a blood pressure gauge, or the face of
digital thermometer. The camera 22 also is used to generate an
audio-visual signal of the patient 16. The audio-visual signal generated
by the camera 22 is then transmitted over the communications network 12 to
the central station 20. The communications network 12 can be a cable
television cable provided by a cable company to the patient's location 10A
(discussed in detail below), or may be a telephone line through which the
digitized audio-visual signal is transmitted from the patient 16 to the
central station 20. Alternatively, the communications network may be any
other suitable transmission network or means for transmitting the
audio-visual signals to the central station, such as satellite
transmission. The TV set 24 serves as a means for displaying in the
patient's location 10A the audio-visual signal of the health practitioner
at the central station that is interacting with the patient in the home.
In its simplest form, the invention can be practiced by transmitting the
measurements of the patient's medical condition to the central station 20
by using the camera 22 to record the displays of the sensing equipment 18.
However, better use and analysis of the measured medical data may be
afforded if the medical data is transmitted over a separate communications
line 26. However, the data transmission does not have to be a separate
line, as the signals can be superimposed on each other. For example, the
output from the sensors can be transmitted through the audio channel
together with speech.
The equipment used at a second remote site 10B is essentially the same as
10A. Of course, it will be appreciated that the patient 17 at location 10B
may have an entirely different set of medical conditions to be monitored,
and thus the medical condition measuring and sensing equipment 18 at
location 10B may be entirely different than the equipment 18 at location
10A.
The central station 20 includes a data analysis and display center 28, an
audio-visual signal generation station 32 and a switching center 34. The
data analysis and display center 28 receives the incoming data transmitted
by the health monitoring equipment 18 at the patient's remote location.
The data analysis and display station 28 also receives the incoming
audio-visual signals from the patients'cameras 22. The data analysis and
display station 28 includes equipment to process the health monitoring
data, and to store and retrieve the data. The data, including the
audio-visual signal of the patient 16, is retrieved and displayed as
desired by the health practitioner. For example, the health practitioner
at the central station 20 may wish to see the image of the patient
generated by the camera 22, or may wish to generate graphs or ECG maps of
cardiac activity, or review the history of the patient's heart rate over
the previous 24-hour period. These are just a few illustrative examples of
the use that can be made out of the transmitted medical information. The
central station 20 is also provided with a set of the patients'medical
records in order to compare the incoming; medical data and audio-visual
signal with the patients'history. If alarm conditions are present,
suitable action can be taken by the health practitioner.
The video generation station 32 includes at least one video camera (not
shown) for generating an audio-visual signal of a health practitioner and
transmission equipment to transmit the signal to the patients 16, 17 at
the remote sites 10A and 10B. The patient can therefore see the face of a
health care worker and interact in an audio-visual manner with the health
practitioner concerning his or her medical condition. If a staff or team
of patient monitors or health care workers at the central station are
employed, as when a large number of patients are being monitored, multiple
cameras or even small-scale studios may be used, one for each health
monitor or nurse, so that individual patients at the remote locations can
see their own particular health care worker that they are used to.
The switching center 34 serves to direct the incoming and outgoing signals
from the patients and the health care workers at the central station 20 to
orchestrate the proper channeling of the incoming and outgoing
audio-visual signals. The switching center 34 further has the capability
of permitting access by a physician at a remote site 30 to the medical
data or audio-visual signal of the patient 16.
The remote site 30, which may be the physician's office, his home, or a
hospital at a remote location, includes a camera 36 for generating an
audio-visual signal of the physician at the remote site 30. The
audio-visual signal of the physician is sent over a communications line 14
(such as cable television lines) to the switching center 34 and sent out
to the patients'remote locations 10A and 10B, thus permitting the
physician to interact in an audio-visual manner with the patients. The
remote site 30 also has a monitor 38 (such as the television set) for
display of the audio-visual signal of the patient 16. The physician at the
remote site 30 may also have a personal computer 42 to gain access via a
modem (not shown) and a telephone line 44 to the patient's medical
information stored in the data analy | | |
