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Claims  |
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What is claimed is:
1. Apparatus for recording, controlling and early detecting of
cardiovascular diseases by detection, recording, and visual and audible
display of the heart beat frequency and rhythm from a digital pulse
recording picked up by a plethysmographic process at a finger of a hand of
a person, said apparatus comprising
at least two different transducer devices of different types, each in
operative proximity around said finger and each having a generator for
providing a signal of a determined frequency and an associated sensor for
sensing signals from said generator, said sensor providing an output
signal modulated in amplitude by expansion of the blood vessel walls in
said finger;
a multiplexing unit connected to said transducer devices and processing
output signals from said sensors of said transducer devices to select
signals from said transducer devices which are representative of
information about the heart beat frequency and rhythm;
at least one correlating circuit connected between the output of said
transducer devices and said multiplexing unit for predetermining the
oncome of a pulse from one of said transducer devices in accordance with
at least one of the pulses already detected by another of said transducer
devices; and
display means connected to said multiplexing unit for visually and audibly
displaying said information and recording said information so that said
information is always representative of the regularity of the heart beat
frequency and rhythm when the latter is regular or of the irregularity of
the heart beat frequency and rhythm when the latter is irregular.
2. Apparatus as claimed in claim 1, wherein one of said transducer devices
comprises a high frequency infrared generator and another of said
transducer devices comprises a high frequency oscillator having emitter
coupling, a very low level and an amplitude feedback loop.
3. Apparatus as claimed in claim 1, wherein one of said transducer devices
comprises a high frequency infrared generator and another of said
transducer devices comprises a high frequency ultrasonic generator.
4. Apparatus as claimed in claim 1, wherein one of said transducer devices
comprises a high frequency oscillator having emitter coupling, a very low
level and an amplitude feedback loop.
5. Apparatus as claimed in claim 4, wherein said high frequency oscillator
comprises an oscillating transistor having an emitter, a base, a
collector, an emitter circuit and a collector circuit, a first tuned
circuit connected in said collector circuit, a second tuned circuit
connected in said emitter circuit, a pick-up circuit connected to said
collector for deriving a small part of the high frequency signal from said
transistor to provide a picked-up signal, an amplifier connected to said
picked-up circuit for amplifying said picked-up signal to provide an
amplified signal, a differentiating network connected to said amplifier
for decoupling said amplified signal to provide a differentiated signal, a
detecting circuit connected to said differentiating network for detecting
the differentiated signal to provide a detected signal, and a control
circuit connected to said detecting circuit and coupled to the base of
said oscillating transistor.
6. Apparatus as claimed in claim 5, wherein said control circuit consists
of two transistors connected in a Darlington circuit.
7. Apparatus as claimed in claim 1, wherein said correlating circuit
comprises at least two capacitors, charge and discharge means for
substantially constant charging and discharging of said capacitors and at
least two threshold flip-flops associated with said capacitors.
8. Apparatus as claimed in claim 7, wherein said flip-flops are associated
with said transducer devices and selectively pass and block pulses emitted
from said transducer devices during a time predetermined by said
capacitors.
9. Apparatus for recording, controlling, and early detecting of
cardiovascular diseases by detection, recording, and visual and audible
display of the heart beat frequency and rhythm from a digital pulse
recording picked-up by a plethysmographic process at a finger of a hand of
a person, said apparatus comprising
at least two different transducer devices of different types, each in
operative proximity around said finger and each having a generator for
providing a signal of a determined frequency and an associated sensor for
sensing signals from said generator, said sensor providing an output
signal modulated in amplitude by expansion of the blood vessel walls in
said finger;
a multiplexing unit connected to said transducer devices and processing
output signals from said sensors of said transducer devices to select
signals from said transducer devices which are representative of
information about the heart beat frequency and rhythm;
at least one correlating circuit connected between the output of said
transducers and said multiplexing unit for predetermining the oncome of a
pulse from one of said transducer devices in accordance with at least one
of the pulses already detected by another of said transducer devices, said
correlating circuit comprising at least two capacitors, charge and
discharge means for substantially constant charging and discharging of
said capacitors and at least two threshold flip-flops associated with said
capacitors, said flip-flops being associated with said transducer devices
and selectively pass and block pulses emitted from said transducer devices
during a time predetermined by said capacitors; and
display means connected to said multiplexing unit for visually and audibly
displaying said information and recording said information so that said
information is always representative of the regularity of the heart beat
frequency and rhythm when the latter is regular or of the irregularity of
the heart beat frequency and rhythm when the latter is irregular.
10. Apparatus for recording, controlling and early detecting of
cardiovascular diseases by detection, recording, and visual and audible
display of the heart beat frequency and rhythm from a digital pulse
picked-up by a plethysmographic process at a finger of a hand of a person,
said apparatus comprising
at least two different transducer devices of different types, each in
operative proximity around said finger and each having a generator for
providing a signal of a determined frequency and an associated sensor for
sensing signals from said generator, said sensor providing an output
signal modulated in amplitude by expansion of the blood vessel walls in
said finger, one of said transducer devices comprising a high frequency
oscillator having emitter coupling, a very low level and an amplitude
feedback loop, said high frequency oscillator comprising an oscillating
transistor having an emitter, a base, a collector, an emitter circuit and
a collector circuit, a first tuned circuit connected in said collector
circuit, a second tuned circuit connected in said emitter circuit, a
pick-up circuit connected to said collector for deriving a small part of
the high frequency signal from said transistor to provide a picked-up
signal, an amplifier connected to said picked-up circuit for amplifying
said picked-up signal to provide an amplified signal, a differentiating
network connected to said amplifier for decoupling said amplified signal
to provide a differentiated signal, a detecting circuit connected to said
differentiating network for detecting the differentiated signal to provide
a detected signal, and a control circuit connected to said detecting
circuit and coupled to the base of said oscillating transistor, said
control circuit driving said transistor with said detected signal;
a multiplexing unit connected to said transducer devices and processing
output signals from said sensors of said transducer devices to select
signals from said transducer devices which are representative of
information about the heart beat frequency and rhythm; and
display means connected to said multiplexing unit for visually and audibly
displaying said information and recording said information so that said
information is always representative of the regularity of the heart beat
frequency and rhythm when the latter is regular or of the irregularity of
said beat frequency and rhythm when the latter is irregular. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
This is a Continuation-in-Part of application Ser. No. 170,574, filed July
21, 1980, for Apparatus for Recording, Control and Early Detection of
Cardiovascular Diseases, and now abandoned.
The present invention relates to apparatus for recording, control or
testing and early detection or tracking down or checkup of cardiovascular
diseases.
Many reports and statistical data regularly emphasize the continuously
growing increase of cardiovascular diseases, which are one of the primary
causes of mortality and increased death rate. Such diseases do not bypass
those persons who often erroneously consider themselves as being in good
health. The detection or tracking down of heart arrhythmia is essentially
based on the electrocardiogram; such a test or examination should however
in any case be carried out by a specialist in a doctor's consulting-room.
In most cases, such testing or examination is performed during the
presence of the disease. In other words, there is no early detection of
the disease, whereas statistical data show that an initial early detection
would be much beneficial.
It has therefore become indispensable for obvious reasons, to early detect
or track down to the utmost such cardiovascular diseases otherwise than
through the mere advice to proceed periodically with suitable tests,
controls, checkup and like examinations. Such an approach may not a priori
yield satisfactory results, because most people are reluctant and
unwilling to make tests as long as they deem their state of health to be
satisfactory.
SUMMARY OF THE INVENTION
The principal object of the invention is to provide apparatus for the early
detection and prevention of cardiovascular diseases.
An object of the invention is to provide apparatus which is simple in use
and is adapted to be made available to the general public at suitable
places.
Another object of the invention is to provide apparatus able to forthwith
show up, without the assistance of any specialist, any anomaly or
disturbance of the heart beat rhythm.
Still another object of the invention is to provide apparatus which,
although it does not supply an electrocardiogram, supplies simplified
information which sufficiently discloses, in particular, heart beat rhythm
characteristic periodical phenomena easily interpreted and handled or
analyzed.
Yet another object of the invention is to provide apparatus for detecting
heart beat frequency and rhythm, which apparatus is simple to use.
Another object of the invention is to provide apparatus for detecting heart
beat frequency and rhythm, which apparatus functions as a health guide.
Still another object of the invention is to provide apparatus for detecting
heart beat frequency and rhythm, which apparatus is automatic and does not
require either a skilled operator or a specialist for interpreting the
results.
The apparatus of the invention is accordingly adapted to record in
particular the heart beat frequency and rhythm from the recording of the
digital pulse picked up through any simple or complicated plethysmographic
process. With such a process, it is possible to show up the change in
volume of one or several organs under the influence of variations in the
vessels which are irrigating or feeding this or these organs.
More specifically, during the ventricular contraction, the heart would
eject a certain amount of blood which travels along the arterial vessels
and gives rise at some location of the arterial system to a displacement
of the walls of the artery. Such a displacement is sensed at at least one
selected spot of the body, such as the end of a finger of a hand, for
example. Thus is obtained a mechanical translation of the passing of a
certain amount of blood to a given place of the body.
This manner of proceeding does not record the pulse, because this would
require a special apparatus to obtain an analog curve of the displacement
of the artery walls (sphygmogram), but involves the sensing of the pulse
beats where physically elementary data is gathered or picked-up. Thus,
with such an apparatus, the mechanical phenomenon of the displacement of
the walls of an artery at a particular spot thereof is sensed and this
phenomenon will be repeated x times every minute (frequency per minute)
with a time period between each occurrence of the phenomenon which is
either constant or not (regularity or irregularity). Stated otherwise,
such an apparatus provides an artifacted plot or setting out consisting of
a series of like pulses, each pulse corresponding to a beat of the pulse
which is sensed by means of a suitable device.
The invention provides apparatus for recording, controlling or testing or
checking and for early detection or tracking down of cardiovascular
diseases through the sensing, recording and/or audible and/or visual
display of the heart beat frequency and rhythm from the recording of the
digital pulse picked-up through a plethysmographic process at a determined
spot of the body such as a finger of the hand, for example. The apparatus
comprises a digital pulse transducer device consisting of a generator for
producing a determined frequency or emission and of an associated sensor,
processing circuits, a recording and/or audible and/or visual display
device. In accordance with the invention, the apparatus comprises at least
two transducer devices of different physical natures, the output signals
of which are processed separately and/or together in order to yield more
accurate information about the heart beat frequency and rhythm.
Another feature of the invention is that the transducer devices used are
optical, infrared ray, ultrasonic devices, or devices using high frequency
oscillators having a very low level, ultrasonic devices using the
so-called "Howling" effect, etc. These devices are located at the same
place of the human body, or at different places, in particular, when the
transducer devices are of the same physical nature, so as to avoid as much
as possible interference phenomena.
Still another feature of the invention is the use of transducer devices
which use a high frequency oscillator of a very low level comprising an
oscillating circuit such as a transistor having an emitter coupling, with
oscillation amplitude control to constantly take-up or compensate for the
amplitude attenuation or weakening of the oscillations (power loss)
resulting from the increase in the volume of the artery due to the
oncoming rush or flow of blood.
Yet another feature of the invention is that the transducer devices, which
use ultrasonic Howling effect oscillators, comprise an amplifying loop and
a measuring loop to extract the pulses representative of the pulse beats.
A feature of the invention is the inclusion in the apparatus of at least
one correlating circuit in order to predetermine the oncome of a pulse
issuing from a transducer device in accordance with at least one of the
foregoing already sensed pulses.
Another feature of the invention is the use of at least two different type
transducer devices located around a finger of a hand of a person in
proximity with each other. These transducer devices avoid, as much as
possible, interference phenomena. In fact, the use of two identical
transducers such as infrared detection devices permits interference
phenomena to occur with output signals from the corresponding sensors.
This problem is resolved by the apparatus of the invention.
In accordance with the invention, apparatus for recording, controlling and
early detecting of cardiovascular diseases by detection, recording and
visual and audible display of the heart beat frequency and rhythm from a
digital pulse recording picked up by a plethysmographic process at a
finger of a hand of a person, comprises at least two transducer devices of
different types, each in operative proximity around the finger. Each of
the transducer devices has a generator for providing a signal of a
determined frequency and an associated sensor for sensing signals from the
generator. The sensor provides an output signal modulated in amplitude by
expansion of the blood vessel walls in the finger. A multiplexing unit is
connected to the transducer devices and processes output signals from the
sensors of the transducer devices to select signals from the transducer
devices which are representative of information about heart beat frequency
and rhythm. A display device connected to the multiplexing unit visibly
and audibly displays the information and records the information.
One of the transducer devices comprises a high frequency infrared generator
and another of the transducer devices comprises a high frequency
oscillator having emitter coupling, a very low level and an amplitude
feedback loop.
One of the transducer devices comprises a high frequency infrared generator
and another of the transducer devices comprises a high frequency
ultrasonic generator.
The transducer devices are positioned at two different places of the
finger.
One of the transducer devices comprises a high frequency oscillator having
emitter coupling, a very low level and an amplitude feedback loop.
At least one correlating circuit predetermines the oncome of a pulse from
one of the transducer devices in accordance with at least one of the
pulses already detected by another of the transducer devices.
The high frequency oscillator comprises an oscillating transistor having an
emitter, a base, a collector, an emitter circuit and a collector circuit.
A first tuned circuit is connected in the collector circuit. A second
tuned circuit is connected in the emitter circuit. A pickup circuit is
connected to the collector for deriving a small part of the high frequency
signal from the transistor to provide a picked-up signal. An amplifier is
connected to the pickup circuit for amplifying the picked-up signal to
provide an amplified signal. A differentiating network is connected to the
amplifier for decoupling the amplified signal to provide a differentiated
signal. A detecting circuit is connected to the differentiating network
for detecting the differentiated signal to provide a detected signal. A
control circuit is connected to the detecting circuit and coupled to the
base of the oscillating transistor. The control circuit drives the
transistor with the detected signal.
The correlating circuit comprises at least two capacitors, charge and
discharge devices for substantially constant charging and discharging of
the capacitors and at least two threshold flip-flops associated with the
capacitors.
The control circuit consists of two transistors connected in a Darlington
circuit.
The flip-flops are associated with the transducer devices and selectively
pass and block pulses emitted from the transducer devices during a time
predetermined by the capacitors.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the
following description, taken in connection with the accompanying drawings,
in which:
FIG. 1 is a block diagram of a system utilizing several devices for
detecting the digital pulse at one finger of a user of the apparatus of
the invention;
FIG. 2 is a block diagram of an embodiment of the main processing circuits
of the apparatus of the invention;
FIG. 3 is a circuit diagram of an embodiment of the first transducer device
of the apparatus of the invention;
FIG. 4 is a block diagram of an embodiment of the second transducer device
of the apparatus of the invention;
FIG. 5 is a graphic presentation of test results obtained by the apparatus
of the invention;
FIG. 6 is a block and circuit diagram showing an embodiment of a
correlating circuit of the apparatus of the invention with iterative
predetermination for determining in advance the oncome of a test pulse;
and
FIG. 7 is a graphic presentation of the principle of operation of the
circuit of FIG. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 diagrammatically shows three transducer devices 1, 2, 3 of the
apparatus of the invention. Each transducer device is adapted to sense the
digital pulse at, for example, a finger 4 of the hand of a user of said
apparatus. The finger 4 is placed on a support or rest 5.
The transducer device 1 is, for example, a conventional optical transducer
device comprising a light source or generator 6 emitting light or a light
beam 7 received by an associated light sensor 6a.
The transducer device 2 is, for example, a conventional ultrasonic
transducer device of acoustic type, or possibly of electromagnetic type
comprising an ultrasonic generator 8 emitting ultrasonic frequencies 9
received by an associated ultrasonic sensor 8b. The frequency of the
ultrasonic beam is, for example, several megaHertz.
The transducer device 3 is, for example, an infrared ray transducer device
comprising an infrared source or generator 10 providing an infrared beam
11 received by an associated infrared sensor lOc. The infrared rays may
have a wavelength of 900 nanometers, for example.
All of these transducer devices are shown as operating in the transmission
mode. That is, a generator and its associated sensor are located on
opposite sides of the finger 4. It is, however, possible to operate
according to the deep reflection mode. That is, a generator and its
associated sensor are positioned on the same side of the finger 4. This is
preferable, for example, in a device for optical detection in visible
light.
In FIG. 2, the outputs of the sensors 6a, 8b and lOc are connected to the
inputs of three detectors 12a, 12b and 12c, respectively. The outputs of
the three detectors 12a, 12b and 12c are connected to three amplifiers
13a, 13b and 13c, respectively. The outputs of the amplifiers, after
shaping by circuits 14a, 14b and 14c, are connected to the inputs of a
multiplexing unit 15 performing several functions. The functions performed
by the multiplexing unit 15 permit the following.
The visual presentation of the heart beat frequency and rhythm of the user
on a display device 16 or the translation of the heart beat frequency and
rhythm by an audible device 16a.
The recording of the heart beat frequency and rhythm in a recorder 17 with
printout, and, in particular, on a filigreed paper strip or tape 18
created to comply with the needs. The visual display device 16, the
audible device 16a and the recorder 17 are connected to outputs of the
multiplexing unit 15 via a data bus 19.
The possible selection of a particular sensor 6a, 8b or lOc in accordance
with the data gathered or collected by the multiplexing unit 15 from these
sensors. For this purpose, the apparatus comprises, for example, a
selector or switch 20, having a movable armature or yoke 21 automatically
controlled or actuated by a data bus 23 leading from the multiplexing unit
15. The switch 20 also has stationary contacts 22 which cooperate with the
movable armature or yoke 21 in order to select one or the other of the
sensors. The contacts 22 are connected through lead lines 24 to the
sensors 6a, 8b and 1Oc.
FIG. 3 shows a particular transducer device 30 which is a high frequency
oscillator having a very low level and servo-controlled as an amplitude
loop.
The transducer device 30 comprises an oscillating transistor 31 with
emitter coupling. The emitter of the transistor 31 is connected to a tuned
emitter circuit comprising a coil or winding B.sub.1, one end of which is
connected to said emitter of said transistor and the other end of which is
connected to ground. A capacitor C.sub.1 is possibly connected in parallel
with, or across, the winding B.sub.1 to improve the oscillation.
The collector of the oscillating transistor 31 is connected to a tuned
collector circuit comprising a coil or winding B.sub.2, one end of which
is connected to the collector of said transistor and the other end of
which is connected to a voltage supply (+V). A capacitor C.sub.2 is
connected in parallel with, or across, the winding B.sub.2.
The collector of the oscillating transistor 31 is preferably connected to a
RC network for taking the high frequency signal from the oscillator. The
RC network comprises a resistor R.sub.3 and a capacitor C.sub.3 connected
in series.
The terminal of the capacitor C.sub.3 farthest from the resistor R.sub.3 is
connected to the base of an amplifying transistor 32, the emitter of which
is grounded. A resistor R.sub.4 is connected between the collector and
base of the transistor 32 to provide the bias and the negative or reverse
feedback of said transistor. The collector of the amplifying transistor 32
is connected to the voltage source (+V) via a load resistor R.sub.5.
The collector of the amplifying transistor 32 is connected to a
differentiating decoupling circuit comprising a capacitor C.sub.6 and a
grounded resistor R.sub.6. The differentiating circuit R.sub.6, C.sub.6 is
connected to a detecting circuit consisting of twc diodes 33 and 34. The
connecting point between the resistor R.sub.6 and the capacitor C.sub.6 is
connected to the cathode of the diode 33. The anode of the diode 34 is
connected to the cathode of the diode 33 and its cathode is grounded. The
anode of the diode 33 is connected to a detection filter capacitor
C.sub.7.
The point of connection between the diode 33 and the capacitor C.sub.7 is
connected to two current-limiting resistors R.sub.7 and R.sub.8 connected
in series. The other end of the resistor R.sub.8 is connected to a sliding
contact of a potentiometer 35 for adjusting the amplitude of the
oscillations of the transistor 31 through the Darlington circuit,
hereinafter described.
The point of connection between the current-limiting resistors R.sub.7 and
R.sub.8 is connected to a drive circuit for controlling the base current
of the oscillating transistor 31 via an interposed filter capacitor
C.sub.8. The control or drive circuit consists of two transistors 36 and
37 arranged as a "Darlington" circuit. The emitter of the transistor 37 is
connected to one end of a resistor R.sub.9 for limiting the base current
of the oscillating transistor 31. The other end of the resistor R.sub.9 is
connected to the base of the transistor 31 and is also connected to ground
via a high frequency decoupling capacitor C.sub.9.
The output of the transducer device 30 is at the point of connection
between the detecting capacitor C7 and the current-limiting resistor
R.sub.7. This point of connection is connected to the base of a current
amplifying transistor 38 via a resistor R.sub.1O. The collector of the
transistor 38 is connected to a voltage supply source (+V) and the emitter
of said transistor is connected to ground via a load resistor R.sub.11.
The amplified signal is derived from the emitter of the impedance-matching
amplifying transistor 38 to drive a bandpass filter 39 and then a shaping
circuit 40 to obtain usable primary or elementary information.
FIG. 4 shows another type of transducer device of the invention. The
transducer device 45 of FIG. 4 is an ultrasonic device comprising an
ultrasonic generating circuit 46 and an ultrasonic receiver circuit 47 for
receiving the emitted ultrasonic frequencies, an oscillation loop and a
coupling loop. The oscillation loop comprises an amplifier 48, the input
of which is connected to the output of the receiver 47. The output of the
amplifier 48 is connected to the input of an attenuator 49, the output of
which is connected to the ultrasonic generator 46.
The coupling loop comprises an oscillation-taking circuit consisting of a
resistor R.sub.12 and a capacitor C.sub.1O connected in series, or any
other type of coupling system. The resistor R.sub.12 is connected to the
output of the ultrasonic receiver 47 and the capacitor C.sub.1O is
connected to a measuring amplifier 50. The output of the amplifier 50 is
connected to a detection stage 51 which provides AC to DC conversion of
the signals it receives. The DC, or continuous, signals at the output of
the detecting stage 51 make it possible to control or drive the attenuator
49, which is a DC-controlled unit, for example. The servo-control loop
take-up or hunting signals at the output of the detector 51 are also
processed and shaped by a shaper circuit 52 in order to obtain a signal
usable by the multiplexing unit 15, at the output S.
The apparatus also comprises at least one correlating circuit 55, shown in
FIG. 6. The correlating circuit permits the predetermination of the oncome
of a pulse output by a transducer device in accordance with at least one
of the foregoing pulses already sensed at another transducer device. The
correlating circuit 55 comprises a first circuit 56 essentially comprising
a circuit (voltage v, resistor R) for charging a capacitor C.sub.1 with a
constant current via an interposed switch I.sub.1, and a circuit for
discharging the capacitor C.sub.1 with a constant current resistor R.sub.1
via an interposed switch I'.sub.1 mechanically coupled to the switch
I.sub.1, for example. The discharge circuit is connected to the control or
drive inputs of two threshold flip-flops, or multivibrator, or toggle
circuits B.sub.1 and B.sub.2. The correlating circuit 55 further comprises
a second circuit 57 like the foregoing one and consisting of a circuit for
charging (voltage v, resistor R) a capacitor C.sub.2 with a constant
current via an interposed switch I.sub.2, and a circuit for discharging
the capacitor C.sub.2 with a constant current, consisting of a resistor
R.sub.2 via an interposed switch I'.sub.2, mechanically coupled to the
switch I.sub.2, for example. This discharge circuit is connected to the
control or drive inputs of the two threshold flip-flop, or multivibrator,
or toggle circuits B.sub.1 and B.sub.2.
The connections of the correlating circuit 55 is hereinafter described in
greater detail in the explanation of the operation of the apparatus.
The aforedescribed apparatus operates as follows.
The user who desires to effect a test begins at first to put the apparatus
into operation by any suitable means such as, for example, presence of the
finger, push-button, insertion of a coin into a slot of the apparatus. If
the apparatus includes conventional transducer devices 1, 2 and 3 (FIGS. 1
and 2), the gate voltage or switching on of the apparatus causes
energizing of the generators 6, 8 and 10. In the absence of a foreign
substance or body intercepting the frequencies or emissions 7, 9 and 11 of
the generators 6, 8 and 10, respectively, the sensors 6a, 8b and 1Oc,
respectively, associated with said generators receive the whole emissions.
The detectors 12a, 12b and 12c, associated with the sensors 6a, 8b and
1Oc, respectively, which are sensitive or responsive to amplitude
variations of the electric signals supplied by the sensors 6a, 8b and lOc,
respectively, deliver no output signal, since there is no disturbance of
the emissions 7, 9 and 11 of the generators 6, 8 and 10, respectively. The
multiplexing unit 15 receives no signal and only an indicating or monitor
lamp is energized in the visual display device 16, meaning that the
apparatus is switched on, that is, it is alive or has voltage applied to
it.
After switching on, the user properly positions one finger of his hand at a
place or spot clearly shown on the apparatus to disturb the different
emissions of all the generators of the transducer devices 1, 2 and 3.
The emission 7 of the light source or generator 6 is partly absorbed by the
finger 4 of the user, so that the light sensor 6a associated with said
light source delivers a signal of smaller amplitude. This amplitude
variation is detected by the detector 12a, which in turn generates a
signal amplified by the associated amplifier 13a and shaped by the
associated shaping circuit 14a. This signal is then received by the
multiplexing unit 15.
The emissions 9 and 11 of the ultrasonic generator 8 and the infrared
source 10, respectively, are also disturbed and the signals emitted by the
ultrasonic sensor 8b and the infrared sensor 1Oc processed like the signal
emitted by the light sensor 6a.
In the exemplary embodiment shown, the multiplexing unit 15 accordingly
receives three signals which in fact are not interesting for the test,
because they only show the presence of a foreign body or substance in the
paths of the emissions of the transducer devices 1, 2 and 3. If this
foreign body is inert, the multiplexing unit 15 no longer receives any
signal. If, on the contrary, the foreign body has a varying volume, the
energy absorbed by such body varies and this is reflected in amplitude
and/or frequency variations of the signals at the outputs of the sensors
6a, 8b and 1Oc. In the contemplated application, this change in volume
occurs at the vessel which expands at each oncoming flow or rush of blood.
In other words, there are amplitude variations in the signals emitted by
the sensors 6a, 8b and 10c. These amplitude variations therefore result in
signals which are received by the multiplexing unit 15.
The function of the multiplexing unit is to compare, mix, correlate,
interpolate, etc. these different signals received in order to analyze or
interpret them with a view to extract exhaustive information or data with
high reliability and very high probability of veracity or truthfulness on
the one hand, as well as secondary information or data which is indirect
or indirectly inferred on the other hand. This information or data, and in
particular, the digital pulse frequency, is then sent through the medium
of the data bus 19 to the visual display device 16 and/or to the audible
device 16a, and/or to the recording device 17 with printing on a filigreed
paper strip or tape 18.
FIG. 5 shows two artifacted plots a and b, respectively, which represent
two heart beat frequencies, respectively, recorded on the filigreed strip
or tape 18. The artifacted plot a shows a normal heart beat frequency and
the artifacted plot b shows an abnormal heart beat frequency. The analysis
or handling of these artifacted plots is obvious for the user, who will be
able to draw the necessary conclusions therefrom.
It is possible to control the switch 20 to select, for example, a
particular sensor which is likely to give the best results. As a matter of
fact, since the transducer devices are of different physical natures, they
may respond or react differently against the user.
The operation of the transducer device 30 of FIG. 3, which may
advantageously be substituted for one of the transducer devices 1, 2 and 3
of FIG. 1 is hereinafter described.
Once the transducer device 30 is switched on, or has a voltage applied
thereto, the oscillating transistor 31 generates oscillations at a very
low level, of about a hundred millivolts. If a foreign body or member, is
inserted between the two coils or windings B.sub.1 and B.sub.2 of the
emitter circuit and the tuned collector circuit, respectively, there is a
decrease in the amplitude of the oscillations due to the variation in the
coefficient of voltage surge or overvoltage of the tuned circuit, as well
as a change in the coupling between the emitter and the collector of the
oscillating transistor 31. As previously, the oncoming rushes or flows of
blood in the vessels of the finger 4 interposed between the windings
B.sub.1 and B.sub.2 change the amplitudes of the oscillations from the
transistor 31 each time.
A very small portion of the oscillations present at the collector of the
transistor 31 is transmitted via the resistor R.sub.3 and the capacitor
C.sub.3. It is necessary to transmit only a very weak signal in order to
avoid too large a weakening or attenuation which would make the
oscillations collapse. For this reason, the coupling is very weak and in
the case described the resistance R.sub.3 is relatively high.
The signal transmitted by the pickup circuit R.sub.3, C.sub.3 is then
amplified by the amplifying transistor 32. The amplified signal is
decoupled by the differentiating circuit consisting of the capacitor
C.sub.6 and the resistor R.sub.6. The positive pulses are then excluded
via the diode 34 in order to retain only the negative pulses, which would
pass through the diode 33. The negative signal is then subtracted from the
initial signal of adjustment of the oscillating transistor 31 provided by
the resistor R.sub.8 and the potentiometer 35. The voltage at the point of
connection of the resistors R.sub.7 and R.sub.8, that is the voltage at
the base of the transistor 36 decreases and the voltage at the base of the
oscillating transistor 31 is accordingly decreased. Under such
circumstances, the collector-base voltage of the transistor 31 increases,
whereby it is possible to compensate for the decrease of the oscillations
caused by the oncoming flow of blood in the finger 4. There is accordingly
provided a very high oscillator with a very low level which is
servo-controlled in follow-up or feedback relationship in an amplitude
loop. The negative pulses at the output of the diode 33 resulting from an
electronic hunting or taking-up of the feedback or servo-control loop are
taken and amplified by the amplifier transistor 38 and processed by the
processing circuits 39 and 40 in order to obtain at the output S pulses
workable by the multiplexing unit 15.
FIG. 4 shows another embodiment of a transducer device 45 of the invention.
The transducer device 45 is an ultrasonic device using the Howling effect.
The ultrasonic frequencies emitted by the ultrasonic generator 46 are
received by the ultrasonic detector or receiver 47. The oscillation pulses
at the output of the receiver 47 are amplified by the amplifier 48 and
then fed again to the generator 46 via a drivable or controllable
attenuator 49. Under such circumstances, one portion of the output energy
is fed again into the input to maintain the oscillations. As previously,
the interposition of the finger 4 of the user between the ultrasonic
generator 46 and the receiver 47, together with the oncoming flows or
rushes of blood in said finger, induces amplitude variations of the
oscillations at said receiver. A very small portion of the signal output
by the receiver 47 is taken via the resistor R.sub.12 and the capacitor
C.sub.10. This weak signal is amplified by the amplifier 50.
As in the transducer device described with reference to FIG. 3, only a weak
signal should be taken or picked up, in order not to disturb the
oscillations. The alternating signal picked up is then converted by the
detector 51 into a continuous or DC signal, which makes it possible to
drive or control the attenuator 49 in order to compensate for decreases in
oscillation induced by the oncoming flows or rushes of blood in the finger
4 of the user. The signal at the output of the detector 51 is processed by
the shaping circuits 52 in a conventional manner in order to provide
pulses workable by the multiplexing unit 15 at the output S.
The operation of the correlating circuit 55 in order to predetermine the
oncome of a pulse output by a transducer device in accordance with at
least one of the pulses previously sensed by another transducer device is
described with ref | | |
