Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a physiological monitoring
system.
Physiological monitoring systems are not newO Examples
of such systems are found in Canadian Patents Nos. 738,747, issued
to R.J. Preston on July 19, 1966; 801,875, issued to F.R. Anderholm
et al on December 17, 1968; 886,724, issued to N. Murata on
November 23, 1971; 940,433, issued to C.H. Fuller on December 23,
1975; 1,027,1~1, issued to R.A. Lewis on February 28, 1978;
1,043,425, issued to D.G. Noiles on November 28, 1978; 1,105,562,
issued to P. Schmidt-Andersen on July 21, 1981; 1,128,138, issued
to M. Toshimitsu et al on July 20, 1982, and U.S. Patents NosO
3,212,495, issued to R.J. Preston on October 19, 1965; 4,237,900,
issued to J.H. Schulman et al on December 9, 1980; 4,249,538,
issued to T. Musha et al on February 10, 1981; 4,321,933, issued
to L.R. Baessler on March 30, 1982; 4,456,825, issued to G.J.
Veith on November 2, 1982; 4,387,724, issued to D.L. Zartman
on June 14, 1983; 4,399,821, issued to D.L. Bowers on August 23,
1983 and 4,531,526, issued to L.J. Genest on July 30, 1985.
In general, physiological monitoring systems have been
2Q used for some time to provide management information for animal
operations. The principle objective has been to identify the
individual animals, and to provide some means for monitoring
temperature and heart rate. The systems employ a variety of
probes which may be subdermally implanted, located close to the
tympanic membrane, or mounted in the vagina for detecting temperature.
- 1 -
- ~b
,. . .
Some probes are not internally powered, so that they
must be actuated using an external source of power located close to
the probe. Such passive probes transmit data only when interrogated.
Even in cases where the probe constantly monitors a condition,
e.g. using batter~ operated probes, information is obtained only
upon actuating a transmitter/receiver. Thus, information not
gathered at the moment of transmission is lost. A problem common
to all such devices is that continuous remote monitoring is in
general not possible.
~he object of the present invention is to overcome the
drawbacks of existing àpparatuses by providing a relatively
simple physiological monitoring system, which is capable of
measuring physiological functions such as pulse rate and temperature
in a living creature, storing the data, and transmitting the data
complete with an identification code via a radio telemetry link.
Accordingly, the present invention relates to a physio-
logical monitoring system comprising remote telemetry means for
attachment to the subject to be monitored including sensor means
for detecting a condition of the subject, first microcomputer
means connected to said sensor means for storing data concerning
the sensed condition, and first transmitter/receiver means for
transmitting a signal representative of the condition and for
receiving command signals; and master t~lemetry means for
communicating with said remote telemetry system including second
computer means for storing data and for generating a command
- 2 -
6~`6`1~3
signal, and second transmitter/receiver means for transmitting
command signals to said remote telemetry unit, and for receiving
data from said first microcomputer.
The invention will now be described in greater detail
with reference to the accompanying drawings which illustrate
preferred embodiments of the invention, and wherein:
Figure l is a schematic block diagram o~ a remote
telemetry unit for use in the system of the present invention;
Figure 2 is a schematic block diagram of a master
telemetry unit for use in the system of the present invention;
and
Figure 3 is a schematic block diagram of another form
; of remote telemetry unit for use in the system of the present
invention.
With reference to Figs. l and 2, the basic elements
of the present invention include a remote telemetry unit (Fig. l)
and a master telemetry unit (Fig. 2). The remote telemetry unit
is externally or internally attached to the animal to be monitored.
The master telemetry unit functions as a base station for collecting
and processing data received from one or more remote telemetry units
during operation of the latter.
The remote telemetry unit includes a microcomputer l
for collecting data from one or more sensors 2. The sensors 2
are connected directly to the microcomputer l. ~lternatively,
the sensors can be connected to an analog to digital converter 3,
3 --
or to a multiplexer 5 which is connected directly to the micro-
computer 1 or through an analog to digital converter 6 to the
microcomputer 1. The microcomputer 1 is operated by a power
supply 7. A transmitter/receiver 8 carrying an antenna 9 is
connected to the microcomputer. The transmitter/receiver 8
receives command signals via the antenna 9 from the master
telemetry unit, and transmits data from the microcomputer 1 to
the master telemetry unit.
Examples of the microcomputer 1 include CPU, R~'s,
ROM's and EPROM's, which collect data from the sensors 2, stores
the data, performs monitoring routines, and controls transmission
of the data to the master telemetry unit. The sensors 2, which
are ~orms ~f transducers,measure the appropriate physiological
function such as pulse rate, temperature and respiration rate,
and transmit data to the microcomputer. The power supply 7 is
a compact power supply, e.g. a battery, so that the entire remote
telemetry unit can be attached internally, subcutaneously or
externally to the subject being monitored.
The entire remote telemetry unit is contained in a
sing~e package. Very large scale integration (FLSI) is used
to make the remote telemetry unit as small as possible, and to
keep manufacturing costs as low as possible. The manner of
attaching the remote telemetry unit to the subject depends on the
use or application. Mounting of the remote telemetry unit
subcutaneously possesses the advantage of utilizing the skin
- 4 -
6~
for mechanical protection of the remote telemetry unit. Alterna-
tively, the remote telemetry unit can be injected into the
digestive tract of the subject when the physiological functions
to be determined require such form of sensing. In cases where
relatively short term sensing, or when there is no need for
mechanical protection, the remote telemetry unit can be attached
to the surface o~ the skin using an adhesive. For internal or
subcutaneous use, the remote telemetry unit can be in the form
of a small cylinder (one inch by one-quarter inch). For surface
mounting on the skin, the remote telemetry unit can be a thin
disc with an adhesive backing. The antenna 9 can be integral with
; or external to the remote telemetry unit, and in the case of
subcutaneous use can extend through the skin of the subject.
With reference to Fig. 2, the master telemetry unit
includes a computer 10 connected to a ~ransmitter/receiver 12
on which is mounted an antenna 13. The transmitter/receiver
12 sends command signals to the transmitter/receiver 8 of the
remote telemetry unit, and receives stored data from the micro-
computer 1 via the transmitter/receiver 8. The usual auxillary
equipment, including an LED (light emitting diode) readout
device 14, a monitor 15, a printer 16 and a disc storage device
17 are attached to the computer 10.
Referring to Fig. 3, an alternative form of remote
telemetry unit includes a computer 40 connected to sensors 42
and 43 (one of each shown). The ~igital sensors 42 are connected
- 5 -
68
directly to the computer, while the analog sensors are
connected through an analog/digital converter 44 to the
computer 40. The microcomputer 40 is connected through a
grounded interface 46, a quad line receiver 47, operational
amplifiers 48 and 49, a voltage/frequency converter 50,
operational amplifier 52, relay 53 and an isolating
transformer 54 to the transmit circuit oE a communications
unit 56. Lines 58 and 59 bypass the amplifiers 48 and 49,
the converter 50 and the amplifier 52, connecting the quad
line receiver 47 directly to a universal asynchronous
receiver/transmitter (UART) 60 and a read only memory (ROM)
61, and connecting the latter to the relay 53. A rate
generator 64 is connected to the UART 60.
The computer 40 is also connected through the
interface 46, a quad line driver 65, a Schmidt trigger 66,
an operational amplifier 68, a frequency voltage converter
69, a Schmidt trigger 70, an operational amplifier 72, a
relay 73 and an isolating transformer 74 to the receive
circuit of the communications unit 56. As in other
embodiments, an antenna 57 is provided on the
communications unit 51. A line 77 connects the ROM 61 to
the relay 73.
While not illustrated, the master telemetry unit can
~e identical to the unit shown in Fig. 3, except that the
~5 computer 40, sensors 42 and 43, and the analog/digital
converter 44 are replaced by a computer with peripheral
devices, including a
6~
monitor, printer and data s-torage.
The quad line receiver 47 is a monolithic quad line
receiver designed to interface data terminal equipment with data
communications equipment in conformance with the specifications
of EIA Standard No. RS-232C (see Motorola Semiconductors Data
Sheet). The quad line driver 52 is a monolithic quad line
driver also designed to interface data terminal equipment with
data communications equipment in conformance with the specifications
of EIA Standard No. RS-232C. The voltage/frequency converter 48
accepts a variable analog input signal and generates an output
pulse train, thefrequencyof which is linearly proportional to the
input voltage. The samè device can be used as a frequency to
voltage converter 54, which accepts virtually any input frequency
wave form and provides a linearly proportional voltage output
(see Teledyne Semiconduc~or Data Sheet). The inverting Schmidt
triggers 66 and 70 are circuits having a high voltage output when
~ the input voltage is low. The output voltage remains high while
; the input voltage increases until the input voltage exceeds set
point. The output voltage then switches to its minimum value and
holds that value until the input voltage has decreased below set
point.
In operation, the computer of the master telemetry
unit identifies a remote telemetry unit to be interrogated, either
through its software or by operator request. A digital coded
signal is sent via the interface 46 to the quad line receiver
, .
47. The receiver 47 conditions the digital signal to a voltage
level acceptable to the digital input volta~e signal. The output
pulse train is then input to the communications unit 56 via the
amplifiers 48 and 49, the voltage/frequency converter 50, the
amplifier 52, the relay 53 and the isolating trans~ormer 54. The
operational amplifiers 48, 49 and 52, and the volta~e/frequency
converter 50 are used to condition the signal from the receiver
47 to the transformer 54. The isolating transformer 54 is used
to electrically isolate the communications unit from the remainder
of the circuit.
The signal from the output of the quad line receiver 47
also goes to the UART 60. The UART 60 receives the serial signal
and converts it to a parallel signal which is sent to the ROM 61.
The ROM 61 interprets the signal on its address ~us (not shown)
and if the signal is a command from the computer 40 to transmit,
it operates the transmit relay 53 which puts the telemetry unit
into the transmit mode of operation. If the transmit signal is
not received by the ROM 61, then the ROM operates the receive
; relay 73 to maintain the master telemetry unit in the receive
mode of operation.
The communications unit S6 of the master telemetry unit
is normally operated in the receive mode. When the communications
unit 56 senses an input to its transmission circuitry, the unit
automatically switches to transmit mode and transmits the input
data via the antenna 76. When the input data stops, the
- 8 -
:
communication unit 56 switches back to the recei~e mode. A
suitable communications unit is a Citizen ~and transmit/receiver,
Julian International Model JWT 603. The unit has voice activated
input, and operates at 49~876 megahertz.
When a signal is received by a communications unit of
the master telemetry unit via the antenna 76, the signal is
directed to the receive port through the isolating transformer 74
to the converter 69. The converter 69 converts the input pulse
train to a digital voltage ouput for the quad line driver 65. The
driver 65 converts the digital signal to a voltage level in
accordance with the standard of the interface 46. The Schmidt
triggers 66 and 70, and the ampliEiers 68 and 72 are used
to condition the signals from the driver 65 to the transformer
74. The signal is then passed to the computer for processing.
As mentioned above, the portion of the remote telemetry
unit which sends a signal to the communications unit 56 or
receives a signal is the same as the master telemetry unit. The
data acquisition portion of the remote telemetry unit functions
when the analog sensor 43 sends a signal to the analog-to-digital
converter 44. The signal is proportional to the phenomena being
sensedl e.g. temperature, pressure, voltage, etc. The analog-to-
digital converter 44 changes the input analog signal to a digital
signal, which is input to the computer 40 for processing. The
digital sensor 42 produces a digital signal, which is sent
directly to the computer ~0 for processing, and can be used with
$~3
the analog sensor 43 to act as a switch indicating that an event
has occured.
It will be appreciated that the master telemetry unit
is required to communicate with the remote telemetry unit.
Consequently the design of the master telemetry unit depends upon
whether the unit is portable or stationary, the ra~ge required
between the two units, the number of remote telemetry units
in the system and the type of display required. X'he transmitter/
receiver operates on the same frequency as the remote telemetry
unit. The master telemetry unit antenna would be designed to
make up for deficiencies in the remote telemetry unit antenna,
e.g. a parabolic antenna could be used to receive a weak signal
from a remote telemetry unit and to transmit a strong, omnidirectional
signal towards the remote telemetry unit.
The computers are referred to in the generic sense as
any of a multitude of commercially available computers having
a suitable inter~ace. Communications between the computers and
the transmitter/receiver are via the interface. One oE the
more important features of the invention is the use of a micro-
computer as part of the remote telemetry unit for attachment
to the subject to be monitored. The microcomputer control~
; measurement of physiological variables, stores the measurements,
identified transmissions from the master telemetry unit, and
controls radio transmission oE stored data to the master telemetry,
unit. There are various advantages to using a microcomputer in
" - 10 -
the remote telemetry lmit. Data transmission does not have
to be continuous, since the data can be collected and stored in
the microcomputer for transmission when instructions are received,
at predetermined time inter~als or if preset values of specific
d~ta are exceeded. Because transmission is controlled, power
drain on the battery used as the power supply is minimized or
conversely, a smaller battery can be used, and one standard
frequency can be used when more than one remote telemetry unit
is in operation for the same installation. For example, each
xemote telemetry unit could transmit for approximately two
seconds every twenty-four hours and the master telemetry unit
would provide continuous twenty-four hour surveillance. There is
no danger of losing data, since the microcomputer can have
sufficient storage capacity. ~ microprocessor complete with the
components listed hereinhefore can ~e sufficiently small for subcutan-
eous implantation in the subject to be monitored. Using very large
scale integration technology, it is~likelv that the battery used
for the power supply would constitute the largest component.
Using the communications link ~etween the remote and
master telemetry uni~s, it is possible to calibrate the remote
telemetry unit for the specific variables being monitored.
For example, in order to calibrate the temperature monitoring
system, the remote telemetry unit is immersed in a medium such
as water prior to attachmen~ to the subject. The water temperature
is measured using a thermometer, the temperature is input manually
.
into the master telemetry unit, which in turn transmits the
temperature to the remote telemetry unit. The microprocessor of
the remote telemetry unit is programmed to receive the data, compare
it to the measurement taken using the temperature tranducer(s),
and make the necessary changes to the temperature algorithm used in
the microcomputer. Following attachment of the remote telemetry
unit to the subject, the temperature, pulse rate, etc. of the
subject can be measured using traditional methods, and -the data
transmitted to the remote telemetry unit. The microprocessor
would have the capability of confirming or correcting the algorithm.
When using a microcomputer, each remote telemetry unit
can be given a unique digital name or code, which is used when
the remote telemetry unit is interrogated, for requesting data
transmission fxom the particular remote telemetry unit or to
identify data transmission from a remote telemetry unit.
~ he system described hereinbefore can be used,
inter a ia for artificial insemination, live stock performance
monitoring, health monitoring and wild animal monitoring. In
the livestock industry, data can be collected to determine the
estrous cycle in order to increase the probability of successful
impregnation. Livestock in test stations and feed lots can be
monitored to determine the health/ location, feeding habits and
weight gain. The monitoring of feeding habits and weight gain
would require sensors at feed bunks and load cells to identify
the animal. The calving period in commercial cattle operations is
- 12 -
notoriously labour intensive. The system can be usel to monitor
the cattle, and provide an alarm when physiological changes
occur to indicate that the cow is in labour or about to give birth.
Branding could be eliminated since each remote telemetry unit has
it~own unique code used to identify each individual animal.
When used in health monitoring, heart attack or stroke
patients can be monitored in intensive care units and/or during
recovery. The system allows a doctor to monitor a patient
in an environment away from the hospital. If necessary, a pocket
carried, rechargeable repeater station can be used to strengthen
transmission of the remote telemetry unit signal. By implanting
a remote telemetry unit in a bird or wild animal, the need
for banding or tagging is eliminated.
~ 13 -
~'
,
