JPS6020012B2 - heart rate monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to cardiac monitoring and, more particularly, to apparatus for sensing cardiac signals and providing cardiac signals to signal processing circuitry.

In the prior art, there are many devices suitable for use in measuring a patient's heart rate.

These devices range from complex, computer-controlled instruments that can monitor multiple patients simultaneously, to small, patient-individual units designed to monitor only heart rate. This latter device, for the most part, performs the task of measuring heart rate by measuring pulse rate, and is supplied as a device in the form of a wristband to which a pressure-sensitive or acoustically sensitive transducer is attached. It is placed on the wrist close to the wrist.
In addition to pulse monitoring devices, some small personal devices measure electrical pulse signals detected from the patient's skin.

This is accomplished by leads from the device to electrodes attached by conventional means to the patient's chest area. In this manner, electrical cardiac signals are sensed from the electrodes and provided to the device via the conductor. This device is suitable for use by a patient at several different locations on his or her body. For example, the device may be a box-like structure suitable for being worn on a patient's belt, or it may be in the form of a wristband that may be worn around the wrist. However, even with this device in place, the leads leading from the thoracic area to the device tend to break or break as the patient moves, causing the device to cease monitoring capabilities. There is a problem.
In the past, leads were used to measure electrical cardiac activity because each was considered necessary for continuous patient monitoring.

However, in many cases it is only necessary when making instantaneous measurements of heart rate. For example, a patient may have had a previous coronary attack and has not recovered sufficiently to lead a normal or near-normal life, with the exception of having to limit the heart rate to a certain maximum value. If the patient's heart rate is measured only during periods of heavy activity, such as exercise, continuous monitoring of the patient's heart activity would be a waste of the power source (batteries) powering the device. Of course, prior art devices could be modified to activate the device only when desired by the patient by attaching a simple switch to the device. However, the problem of conductors running from the patient's thoracic area to the location of the device remains.According to one preferred embodiment of the invention, each conductor runs from a different limb of a ) and a band of electrically conductive material selected to be capable of detecting electrical signals on the skin of a single person. The body is attached to the flute body and has a size that allows the combination of the shell body and the band body to firmly contact one of the limbs.

Here, (limb) is a general term for limbs, wrists, arms, etc. This band is in electrical communication with the above circuit device.
cation), as one of the pair of signals,
Provides the signal for one of the limbs mentioned above. Furthermore, a receiving means is provided which is mechanically fixed to the combination of the bulge and the band in an electrically insulated manner. The receiving means is in electrical communication with the circuit device, receives an electrical signal from the other limb upon contact, and supplies the received electrical signal to the circuit device as the other signal of the pair of signals. ing. Preferred embodiments of the present invention will be explained with reference to the drawings.

Referring to FIG. 1, a pair of IJ straps 10 and 12 are shown suitable for being worn on different wrists of a patient.

Wristband 10 includes a cliff body 14, a contact body 16, and an integral flexible telescoping metal body 18 and 20 that provides a cliff body 14 and a contact body 16. The cliff body 1W has a built-in electronic circuit used to process a pair of signals representing the yield signal of the electric heartbeat of the lead. This circuit is shown in Figure 4a and Figure 4b.
The figure will be described later. As is well known, the lead 1 electrical signals are derived from the patient's left and right wrists and are generally in a plane running parallel to the ground when the patient is in an upright position. It measures the electrical activity of the heart along the The contact body 16 has a conductive portion 22 and an insulating portion 24, which are arranged such that the conductive portion 22 is not in electrical communication with the elastic body 18 or 20. A wire 26 or other electrical conductor connects the conductive portion 22 and the circuitry within the enclosure 14. The elastics 18 and 20 may be similar to ordinary metal watch bands.

However, the elastics 18 and 20' must be made of a material capable of detecting the electrical signals that appear on the skin when the elastics 18 and 20' are brought into firm contact with the skin. The telescoping bodies 18 and 28 must be transversely connected to conduct the sensed electrical signal to circuitry within the weight body 14 that is in electrical communication with the telescoping bodies 18 and 20. The elastics 18 and 20 are also configured to be adjustable by removing or adding links thereof and are sized to tightly fit the entire wristband 10 around the patient's wrist and between the bands 8 and 20 and the skin. The structure must be such that the skin signal can be detected well by contact and pressure of the skin. moreover,
Band ends 8 and 20' must be of suitable width to provide sufficient surface area to obtain good contact.Band 12 must be free of electrical circuitry and insulating portions such as portion 24 must be suitable for contact. It is the same as Bando 0, except that it is not in Bando 28.

More specifically, the bandeau 2 is composed of a contact body 28 and a malleable metal elastic body 30 of a similar design to the flexible metal bodies 18 and 20. If desired, the telescoping body 30 could be split into two parts and the bandeau OG link 14 could be attached to insert and mount an ordinary wristwatch in a similar manner. Band 12 is a band! It is worn on the opposite wrist of 0.

When it is desired to measure the patient's heart rate, the contact body 28
to firmly contact the contact body 16. In this way, the elastic body 30
The thus detected galvanic skin signal is electrically applied to the conductive portion 22 of the contact 16 via the contact 28 .
From the conductive portion 22, the electrical signal is provided to electronic circuitry in the cliff body 14 via a conductive wire 26. In this case, contact body 1
Note that the exposed surface areas at 6 and 28 are designed to provide a good electrical connection at the location of physical contact. Such a design has similar dimensions and non-planar surfaces that are mirror images of each other. The housing 14 has a pair of switches 32 and 34.

Each switch 32 and 34 has a pair of push buttons, one of which is more prominent than the other. To change the state of either switch 32 or 34, the protruding button is depressed. Switch 32 is an on/off switch when measuring heart rate.
Only this switch is turned on. switch 34 is 6
/6 sand selection switch, that is, when measuring heart rate, count R waves for 6 seconds and report it as 1 minute pulse, or count R waves between 6 seconds and report it as 1 minute spurt. This is a switch that selects whether to directly report this as a 1-minute spurt. Both switches 32 and 34 control the electronic circuitry within the lotus body 14 as described for item 4a. For the on/off switch 32, the contact body 16 of FIG.
The pressure sensitive switches in or in contacts 40 and 42 of FIG. 3 perform the same function and thus have the advantage that the patient does not forget to turn on or turn off the device. Please be careful.

Referring to FIG. 2, the surface of the weight 14 is shown and is provided with a three-digit display 36, each digit consisting of seven luminescent segments.

The selected one of each segment is made to emit light, and any number from 0 to 9 is displayed on each number on the display 36. Display 36
can use an ordinary numeric display. FIG. 3 will be explained.

The figure shows a display board 38 which constitutes a different embodiment from the apparatus shown in FIG. The only difference between the ridge 38 of FIG. 3 and the ridge 14 of FIGS. 1 and 2 is the addition of contacts 40 and 42. Contact bodies 40 and 42
is arranged around the bonito body 38 at a position approximately 90 degrees from the wisteria line passing through the naked bodies 18 and 20. When using the shell body 38, the second watch band 12 shown in FIG.
equipment is omitted. Rather, the rope finger and one of the fingers of the limb (limb) farthest from the limb (limb) on which the monitoring device is attached is placed in firm contact with the contact bodies 40 and 42. In this way, the electrocardiac signal (electrocardiac signal female 1) present on the skin of the fingertip is transmitted to the circuit within the weight body 38 via the contacts 40 and 42.
A word of caution regarding the use of the specific example shown in FIG.
Second, signals may not be transmitted properly in some cases. FIG. 4 is a diagram showing the arrangement of FIGS. 4a and 4b.

FIGS. 4a and 4b are block diagrams of a circuit device 50 built into the chain 14. FIG.

Two signals from the wrist of a patient wearing either the device shown in FIG. 1 or FIG. 3 are sent to terminals 52 and 5, respectively.
given to 4.

Terminal 54 is connected to a reference potential point of the system, such as earth, and terminal 52 is connected to the amplification input of amplifier 56. The signal amplified from the amplifier 56 passes through a low frequency wave generator 58,
This reactor waver blocks all signals with frequencies above 20 hertz, for example, and eliminates 60 cycles and muscle noise. The output of the attenuator 58 is connected to the input of a voltage threshold sensing circuit 60, such as a Schmitt trigger.

The circuit 60' generates a pulse signal every time the voltage applied thereto exceeds a set threshold voltage. The dark value voltage of circuit 60 is adjusted to respond only to electrical cardiac signal R-waves to deliver a pulse on every R-wave occurrence. Note that the R wave of the electrocardiac signal is a positive deviation of the point of maximum amplitude of the signal. The R wave is preceded by a smaller positive excursion known as the P wave, and
A small positive shift known as a T-wave follows. Although not shown in the drawing, a potentiometer adjustment for the Schmitt trigger 60' is provided on the mass body 14, and for each person using this speed monitoring device, the Schmitt trigger 60 does not respond to P waves and T waves. It can be adjusted to be triggered only by R waves. The output pulse from the Schmitt trigger 60 is applied to a "one shot" or monostable multipipelator 62, which receives a controlled pulse signal each time an R wave is detected by the Schmitt trigger 60. occurs.

The output from "one shot" 62 is returned to the inhibit input of Schmitt trigger 60 via response prevention circuit 64. This response prevention circuit 64 prohibits the generation of another pulse for a certain period of time (i.e., the time width of the pulse to be generated from now on) after detecting the first R wave. Can be easily configured. This response prevention circuit 64 is provided to prevent a large amplitude T wave from being detected as the next R wave, but on the other hand, when a P wave is detected as an R wave, this response prevention circuit 64 This prevents an R wave that approaches and connects to this P wave from being detected as the next R wave. Additionally, a potentiometer adjustment (not shown) may be provided within body 14 to adjust the anti-response time based on the patient's normal heart rate and the maximum rate allowed by the patient. The signal processing circuitry consisting of amplifier 56, wave generator 58, Schmitt trigger 60, one-shot 62, and anti-response circuit 64 are all under executable control of power supply 66.

For the sake of clarity, the application of power +V to each of the brush components is not shown. Note also that the same applies to the power supplied to each of the other components described with respect to the block diagrams shown in Figures 4a and 4b. As previously mentioned, the output of power supply 66 is controlled by switch 32 such that power +V is provided when switch 32 is closed. However, when switch 32 is open, power is cut off to each component of circuit arrangement 50 and these components do not operate. The output from the one shot 62 is a pulse that substantially coincides in time with the R wave of the electrical cardiac signal.

This pulse is processed by other logic circuits as described below. The heart of this logic circuit is a 6 second timer 68 that generates one pulse every 6 seconds.

The 6/60 switch 34 is actually switches 34a and 34b.
and 34c, each of the switches 34a, 34b, 34c has one switch arm for each switch and a pair of output holes shown schematically at the upper and lower positions where the switch arms are arranged. and has.

The switch arms of switches 34a and 34b are both connected to the output of a 6 second timer 68. switch 34a
The upper contacts of switch 34b and the lower contacts of switch 34b are not connected to any of the components of the device. The lower contact of switch 34a is a conventional divided-by-ten circuit which generates one output pulse after one fixed input pulse is applied, i.e. every 60 seconds in the case of circuit arrangement 50. 70 connections are made. The upper terminal of switch 34b is connected to the output of the divide-by-10 circuit 70 mentioned above. When switch 34 is in the "top" position, the 10-divider circuit 7 is bypassed and the 10-divider circuit 70 outputs 6
One pulse appears every second, and with switch 34 in the "lower" position, one pulse appears at the output of the sand U circuit 70 every six sands. The upper terminal of switch 34c is connected to a voltage of 10V.

This voltage is here equivalent to a logic "1" signal. A reference or earth voltage is connected to the lower terminal of switch 34c, which in this case is equivalent to a logic "0".
When the switch 34 is in the lower position, the 1-divider circuit 70
timing pulse from the output of or switch 34
When is in the upper position, a timing pulse from the upper terminal of switch 34b is provided as an input to one-shot circuit 72, which produces a pulse of the desired width.

As shown in FIG. 4b, the output pulse of the one-shot 72 is used to conduct each of the 21 AND gates 72 (eMble
) given to the input. 21 AND gates 74 each have 7
It is divided into three groups of gates.

The output from one-shot 72 is also connected to each reset input of three decimal counters 76, 78 and 80. The IG Hayabusa counter 76 constitutes the lowest digit, and the counter 8 constitutes the highest digit. counter 76,7
8 and 80 are designed to respond green after the pulse from one shot 72 and reset their counts to zero. If the switch 34c is located directly on the upper part, a voltage of 10V is applied to the conduction (eMble) input device of the AND gate 2, and appears at the output end of the one-shot 72 in response to the R wave of the detected electrical D-signal. The pulse is an AND gate 82
The signal is applied to the input terminal of the 1st load counter 78 through the .

When the switch 34c is in the lower position, the earth voltage is applied through the inverter 86, which outputs the voltage to the AND gate 84 as a 10V voltage or a "1" signal.
The pulse corresponding to the detected R-wave is applied to the conduction (eMble) input of the
It is applied to the input terminal of the 0-base counter 76. The four outputs from each stage of 1G ship counters 76, 78 and 80 are:
4-bit to seven segment (4/7) converter circuits 88, 90 and 92, respectively.

This 4-bit to 7-segment (4/7) converter is
It converts a 4-wire binary coded decimal (BCD) signal into a suitable 7-wire signal that causes a 7-segment display to display the value of the BCD signal. The seven outputs of each converter circuit 88, 90 and 92 pass through a cooperating AND gate 74 to a seven latch circuit 9 in the block diagram when these gates are enabled by a pulse from one shot 72.
6, 98 and 100. Additionally, a pulse signal from the divider circuit 70 or the upper terminal of switch 34b is applied to the reset input of each latch of latch circuits 96, 98 and 100. The output signal of each latch 96, 98, and 100 is displayed on a 7-segment display 102, respectively.
, 104 and 106. Next, the circuit device 50
Explain the operation. First, assuming that switch 34 is in the "up" or 6 second position as shown in FIG. 4a, a pulse is generated that triggers one shot 72 every 6 seconds. Each latch of latch circuits 96, 98 and 100 is reset simultaneously and after one shot 72 is triggered, IG Hayabusa counters 76, 78 and 80 are reset green after the one shot 72 pulse. When switch 34 is in the "up" position, a ten volt voltage or logic "1" is used to enable AND gate 82.
e) Applied to the input terminal, also a negative voltage or logic “0”
is used for conducting the AND gate 82 through the inverter 86 (
enable) input terminal. Therefore, AND gate 82 passes the detected R-wave pulse from one shot 62 and provides it to second stage IG counter 78. Each time a pulse is applied to the IG Hayabusa counter 78, its count value increases by one. After 6 seconds, one pulse is applied and the latch circuits 96, 98 and 100
clears the latch and generates one pulse from one shot 72.

With this pulse, each gate of AND gate 74 becomes conductive, and the signals stored in counters 76, 78 and 80' are converted by converter circuits 88, 90 and 100 and provided to latches 96, 98 and 1001. switch arm 3
Note that when 4c is in the upper position, the lowest number stage 1G ship counter 76 is bypassed and maintains a zero count. In this state, 7 in the latch circuit 96
The latches cause the display 102 to display the number zero as the least significant digit on the display 36 (FIG. 2), in which case the displayed velocity is one digit of the number of pulses counted during the six second period. It's a needle sound. Thus, if six pulses are generated from one shot 62 during a six second period, display 104 will display a six and displays 102 and 106 will each display a zero. In other words, heart rate 60 is displayed. On the other hand, if 12 pulses are counted in 6 seconds, then 1G
The boat counter 78 counts 2, and the 1G boat counter 80 counts 1. As previously mentioned, this is indicated by indicators 104 and 106.
, the display 102 is 0 and a count of 120 is displayed. Then, after the pulse from one-shot 72 the green resets each of counters 76, 78 and 80, and another pulse appears at the input of one-shot 72, clearing the latches of latch circuits 96, 98 and 100; The above process is repeated again until one shot 72 generates a pulse that makes gate 74 conductive. With switch 34 in the "lower" or 6-way position, one solid pulse is required from six-second timer 68 to apply one pulse to one-shot 72 via divide-by-ten circuit 70. It is.

During the pulses of one shot 72, the pulses generated from the output of one shot 62 are applied to one-shot counter 76 via AND gate 84, which is conductive. In this case, the earth voltage from the switch 34c is inverted by the inverter 86 and applied to the AND gate 84 to make it conductive, the lowest number counter 76 is not bypassed, and the count value here is the same as described above. is displayed on the display 102 as follows. As described above, according to the present invention, since the signal processing means includes a response prevention circuit for preventing a large-amplitude T wave from being detected as the next R wave,
It has the advantage of being able to monitor heart rate. Further, since the switch that continues the power supply for driving the signal processing means is arranged on the surface of the lotus body, there is an advantage that power can be easily saved.

Furthermore, since the signal processing means has an adjustment means for outputting an output signal corresponding to the occurrence of a cardiac potential according to the magnitude of the amplitude of the QRS wave of the cardiac potential, the heart rate can be monitored and measured with precision according to the measurement target. .

[Brief explanation of the drawing]

FIG. 1 shows a pair of wristband detectors suitable for use with a circuit bag layer coupled to one wristband;
Figure 2 shows the surface of the lotus body that houses a circuit device that processes the signal detected by the detector in Figure 1. For example, the fourth
The Figures show the arrangement of Figures 4a and 4b, which are block diagrams of circuit arrangements for processing signals detected by the instruments shown in Figures 1 or 3. 10,12...wristband, 14,38...bonito body, 1
6, 28, 40, 42... contact body, 18, 20, 3
0...Stretchable body, 22...Conductive part, 24...
...Insulated part, 26... Conductor, 32, 34
...(34a, 34b, 34c)...switch, 36...
...Indicator, 60...Schmitt trigger circuit "62,
72... One shot, 102, 104, 106...
...Numeric display. Figl Fig. 2 Fi. 3 Fi9mu S Kozan 8 Kishan

Claims (1)

[Claims] 1. A band structure consisting of a housing and an arm band to be worn on the wrist of one hand, the band structure including an inner sensing element that can make direct electrical contact with the wrist. an electrocardiogram derived from an electrode, an outer sensing electrode provided on the band structure and configured to be selectively contacted by a finger of another hand of the wearer; and an electrocardiogram derived from the inner electrode and the outer electrode. an electric circuit means for sensing a PRT wave; a filter for passing an electric signal having a desired frequency from the output signal from the electric circuit means; and a response prevention means for suppressing an electric signal consisting of a T wave that has passed through the filter. A heart rate monitoring device comprising a circuit, wherein the outer electrode is adapted to contact at least one finger. 2. The heart rate according to claim 1, wherein a switch for continuing the power supply for driving the electric circuit means, the filter, and the response prevention circuit is disposed on the surface of the casing. Monitoring equipment.