JPH0246824A - Device for judging abnormality of pulse wave detecting device - Google Patents

Abstract

PURPOSE:To improve the accuracy of pulse wave detection by including the impedance pulse wave detecting means of the portion on which an electrode is attached and the judging means of abnormality of pulse wave detection by means of a pressure pulse wave detecting device. CONSTITUTION:A pulse wave detecting probe 10 is fastened to a wrist so as to be positioned on the artery 12 by means of a supporting band 14 and, as a pressure pulse wave is detected, the detected pressure pulse wave and the pressure P in a housing 16 are stored by a RAM, to determine and store the actual highest blood pressure value H and the lowest blood pressure value L. Then, the maximum pulse wave Mmax is determined, the pressure Pmax is obtained and switched over to a pressure maintaining condition, a pressure pulse wave MP1 which is detected by a pulse wave sensor 18 is read to determine and store the highest value MP1<max> and the lowest value MP1<min> and then a pressure pulse wave MP2 which is detected next is read and, after determining and storing the highest value MP2<max> and the lowest value MP2<max>, the highest blood pressure value and the lowest blood pressure value are determined. When there is little change or change in the negative direction of the amplitude value of an impedance pulse wave, an abnormality signal is outputted. Hence, a pulse wave detecting accuracy can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pressure pulse wave detection device that detects a pressure pulse wave generated in an artery when the artery is pressed against the artery of a living body. The present invention relates to an abnormality determination device for determining an abnormality.

Conventional technology and its problems For example, the pulse wave sensor is equipped with a pulse wave sensor equipped with a semiconductor pressure-sensitive element, etc., and the pulse wave sensor is fixed in contact with the epidermis directly above the artery of the living body, and the pulse wave sensor is developed using pressurized fluid or the like. A pressure pulse wave detection device has been proposed that detects a pressure oscillation wave, that is, a pressure pulse wave, generated as the artery expands and contracts in synchronization with the heartbeat by pressing the pressure pulse wave against the artery.

However, in such a device, when detecting a pressure pulse wave, the pressure pulse wave may be affected by displacement of the pressing position of the pulse wave sensor due to body movement of the living body, or changes in peripheral vascular resistance. In some cases, the accuracy of continuous pulse wave detection was not necessarily sufficient.

Means for Solving the Problems Against the background of the above circumstances, the present invention has been made with the aim of improving the accuracy of pulse wave detection by determining abnormalities in pressure pulse wave detection. This is a device that determines abnormalities in pressure pulse wave detection in a pressure pulse wave detection device that outputs a pressure pulse wave signal representing a pressure pulse wave generated in an artery of a living body when pressed against that artery. (a) comprising an electrode affixed to the epidermis of the living body;
impedance pulse wave detection means that continuously detects the impedance at the portion where the electrodes 1 to 1 are pasted and outputs an impedance pulse wave signal representing the impedance; (b) the pressure pulse wave signal and the impedance pulse wave signal; determining means for determining an abnormality in pulse wave detection by the pressure pulse wave detection device when a predetermined relationship between the pressure pulse wave signal and the impedance pulse wave signal no longer holds; It is to include.

Operation and Effect of the Invention In this way, the pressure pulse wave signal representing the arterial pressure pulse wave detected by the pressure pulse wave detection device and the impedance pulse wave signal representing the impedance pulse wave detected by the impedance pulse wave detection device can be obtained. When the predetermined relationship between the pressure pulse wave signal and the impedance pulse wave signal no longer holds true by comparing the signals with the pressure pulse wave signal in the determination means, it is determined that the pulse wave detection by the pressure pulse wave detection device is abnormal. It is determined that there is. Therefore, according to the present invention, the predetermined difference between the pressure pulse wave and the impedance pulse wave may be caused by, for example, shifting the pressing position of the pulse wave sensor due to body movements of the living body, or changes in peripheral vascular resistance. If the above relationship no longer holds true, it is determined that the pulse wave detection is abnormal, and the abnormality can be appropriately corrected, thereby stably achieving pulse wave detection accuracy.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram illustrating the configuration of a blood pressure monitoring device equipped with a pressure pulse wave detection device employing the abnormality determination device of this embodiment. A pressure pulse wave detection probe 10, shown in detail in FIG. 2, is fastened to the wrist of the living body by a support band 14 so as to be positioned above the artery 12 on the radius. Pulse wave detection probe 1
0 includes a relatively rigid rectangular container-shaped housing 16 and a pulse wave sensor 18 housed within the housing 16.
and 1. It consists of a rubber annular diaphragm 20 that is inserted between the pulse wave sensor 18 and the housing 16 and supports the pulse wave sensor 18 directly above the artery 12 so as to be in contact with the epidermis of the living body. .

Pressure fluid is supplied into the housing 16 through a piping 19 from an electric pump 22 via a pressure regulating valve 24 . The pressure regulating valve 24 regulates the pressure of the pressure fluid from the electric pump 22, and maintains the pressure in the housing 16 until it reaches a predetermined target pressure P1 of about 4Q mml 1 g, which is expected to be lower than the diastolic blood pressure value of a living body. P
In a rapid pressure increase state in which the target pressure P is increased rapidly, the pressure P is set at a predetermined distance of 5 to 6 mm suitable for pulse wave detection.
The pressure is switched to a rate-limited pressure increase state in which the pressure is gradually increased at a predetermined rate of about 11 g/sec, a pressure maintenance state in which the pressure inside the housing 16 is maintained at a constant level, and a rapid pressure discharge state. Additionally, a pipe 19 is provided between the housing 16 and the pressure regulating valve 24.
A pressure sensor 26 is connected to the housing 16, and a pressure P inside the housing 16 is detected, and a pressure signal SP representing the pressure P is sent to a CPU (to be described later) via an A/D converter 31.
28.

The pulse wave sensor 18 is equipped with a semiconductor strain sensor or a piezoelectric element for converting the pulsation of the artery 12 into an electrical signal, and when pressure fluid is supplied into the housing 16, the diaphragm 20 expands. The pressure pulse wave of the artery 12 is detected by being pressed against the artery 12 along with the pressure pulse wave, and the pressure pulse wave signal SM representing the pressure pulse wave is transmitted via the band pass filter 25 and the A/D converter 27. Te CP
Output to U28.

CP[J2B constitutes a so-called microcomputer together with RAM30 and ROM32.
While utilizing the memory function of the ROM 32, the human power signal is processed according to a program stored in advance in the ROM 32, and a series of blood pressure measurement operations are executed.

That is, the CPU 2B controls the electric pump 22 by supplying the 0N10FF signal to the drive circuit 34 connected to the electric pump 22 via the output interface 36 and controlling the power supply from the drive circuit 34 to the electric pump 22. By controlling the start and stop, and supplying a command signal to the pressure regulating valve 24 via the output interface 36, the pressure P in the housing 16 can be controlled as shown in FIGS. 3(a) and 3(b), respectively. After increasing the target pressure P at a rate of 2, the pressure is gradually increased at the predetermined rate, and within the rate-limiting pressure increase period, the pressure pulse wave represented by the pressure pulse wave signal SM and the pressure P represented by the pressure signal SP are R.A.
M30 is sequentially stored, and the systolic blood pressure value H and the diastolic blood pressure value are respectively determined from the pressure P based on the changes in the magnitude of the pressure pulse waves.

Further, the CPU 2B determines the maximum pressure pulse wave M Ill a After the pressure P□8 in the housing 16 at the time when X occurs and the blood pressure values H and L are determined as described above, the pressure P in the housing 16 is adjusted to Maintain in vaax.

Then, the pulse wave sensor 18 detects the pressure P. The relationship between the upper peak value (highest value) and lower peak value (lowest value) of the pulse wave detected by being pressed against the artery 12 by X and the highest and lowest blood pressure values H and L, respectively. Once calculated, the systolic and diastolic blood pressure values are continuously determined from the relationship based on the actual pulse wave and are displayed on the blood pressure display 38. As shown in FIG. 4, the blood pressure display 38 has a horizontal axis 33 and a vertical axis 35 representing time and blood pressure, respectively, according to the display signal supplied from the CPU 2B.
) A bar graph 37 whose upper end A and lower end B represent the systolic blood pressure value and the diastolic blood pressure value, respectively, is successively displayed on a cathode ray tube provided with a two-dimensional chart representing the blood pressure. Incidentally, a pulse signal CK of a predetermined frequency is supplied to the CPO 28 from a clock signal source 39.

A pair of electrodes 40 and 42 are respectively fixed at two predetermined positions separated by an appropriate distance M on the epidermis of the living body, such as on the forearm near the elbow and near the hand lamp, and are connected to a differential amplifier 43.

Electrodes 46 and 48, each connected to an alternating current constant current power source 44, are fixed adjacent to these electrodes 40 and 42, respectively. Therefore, a constant weak current is passed between the electrodes 46 and 48, voltages are supplied from the electrodes 40 and 42 to the differential amplifier 43, and the differential amplifier 43 converts the voltage at the electrode 42 into the electrode 4.
By reducing the voltage at 0, the voltage at electrode 40.4
The impedance generated between the two is detected.

Then, the differential amplifier 43 outputs an impedance pulse wave signal SM representing the impedance between the electrodes 40 and 42 to the bandpass filter 50, and the impedance pulse wave signal SM that is filtered by the bandpass filter 50. The signal S M + is supplied to the CPU 2B via the A/D converter 52. Therefore, in this embodiment, the differential amplifier 43 functions as impedance pulse wave detection means.

In the CPU 28, the amplitude value (peak-peak value) MP of the pressure pulse wave detected by the pulse wave sensor 18 and the amplitude value M of the impedance pulse wave are calculated, and
Compare the difference ΔM obtained by removing the amplitude value M of the immediately preceding pressure pulse wave from the amplitude value M, and the difference ΔM1 obtained by subtracting the amplitude value M+ of the immediately preceding impedance pulse wave from the amplitude value M. By this, it is determined whether a predetermined relationship between the pressure pulse wave and the impedance pulse wave is established, in other words, whether the pressure pulse wave is normally detected by the pulse wave sensor 18. Ru. If it is determined that the pressure pulse wave is not detected normally, the relationship between the pressure pulse wave and the blood pressure value as described above is corrected, and the blood pressure value is recalculated based on that relationship. be. This is because the pressure pulse wave obtained when the pulse wave sensor 18 is pressed against the artery 12 is relatively easily influenced by noise caused by body movements of the living body, changes in peripheral vascular resistance, etc. Since the blood pressure values obtained from the relationship determined based on the pressure pulse wave influenced by noise etc. lack reliability, the impedance pulse wave and the impedance pulse wave, which are not easily affected by noise or changes in peripheral vascular resistance, etc. This is to determine whether or not an abnormality has occurred during pressure pulse wave detection by comparing the pressure pulse wave with the pressure pulse wave. Therefore, in this embodiment, the CPU 28. RAM30. The ROM 32 constitutes a determining means.

The operation of the blood pressure monitoring device configured as described above will be explained below according to the flowchart shown in FIG.

First, when the power (not shown) is turned on, step Sl is executed, and it is determined whether a start/stop push button (not shown) has been pressed, that is, whether a start/stop signal is being supplied to the CPU 28.

When the activation stop signal is supplied after the pulse wave detection probe IO is attached to the wrist of the living body, step S2 is executed next, the count content T of the timer is reset to zero, and then the count content T from the clock signal source 39 is restarted. Start counting pulse signals CK. Subsequently, step S3 is executed, and the electric pump 2
At the same time as the operation of 2 starts, the pressure regulating valve 24 opens 2. The pressure P inside the housing 16 is changed to a rapid pressure increase state,
At the same time, in the following step S4, it is determined whether the pressure P has reached the target pressure P1. If it is determined that the distance has not been reached yet, step S3 is executed again, but if it is determined that the distance has been reached, step S5 is executed.

In step S5, the pressure regulating valve 24 is switched to a rate-limiting pressure increase state, and rate-limiting pressure increase in the housing 16 is started. In such a state, step S6 is executed to determine whether or not a pressure pulse wave has been detected. If it is determined that a pressure pulse wave has not been detected yet, the process is made to wait until it is detected. If it is determined that this is the case, step S7 is executed. In step S7, the pressure pulse wave detected in step S6 and the pressure P in the housing 16 at the time when the pressure pulse wave was generated are stored in the RAM 30.

In the blood pressure measurement routine of step S8, RAM3
The actual systolic blood pressure value H and the diastolic blood pressure value are determined from the pressure P in the housing 16 based on the magnitude of the pulse waves sequentially stored in 0.
and L are stored in RAM 30. This step S
For example, the blood pressure determination algorithm in step 8 determines the pressure P at the time when the amplitude of the sequentially obtained pulse wave train suddenly changes, or the pressure P at the time when the maximum value of the difference between these amplitudes occurs.
is determined, and based on the pressure P, the systolic blood pressure value I and the diastolic blood pressure value are determined from the relationship between the pressure P and the blood pressure value determined in advance. Subsequently, step S9 is executed, and in step S8, it is determined whether the systolic and diastolic blood pressure values are both determined and the measurement is completed. Initially, the pulse wave number required for blood pressure measurement is not obtained, so steps 86 and subsequent steps are executed again, but when it is determined in step S9 that the measurement of the blood pressure value is completed, the subsequent step S10 is executed. In step SlO, housing 1
6, the maximum pulse wave M @ a
is determined, and the pressure P in the housing 16 when the maximum pulse wave M IRa N occurs. X is required. In the next step Sll, the pressure regulating valve 24 is brought into a rapid pressure discharging state and then feedback-controlled and switched to a pressure maintaining state so that the pressure P in the housing 16 becomes the pressure P max determined in step S10. .

Subsequently, in step 312, the pressure pulse wave M p (detected by the pulse wave sensor 18 while the inside of the housing 16 is maintained at P□8 as described above is read, and the pressure pulse wave M The maximum value MPI'''0 and the minimum value M□'''' of , , are respectively determined and stored in the RAM 30, and the maximum value M
, ``'n, respectively, to determine the systolic blood pressure value SYS and the diastolic blood pressure value DIA: % formula % (1) D IA = -M, , '' +a - .
- The constant and a in (2) are determined. That is, the constants and a are calculated by substituting the actual blood pressure values H and L determined in step S8 into the systolic blood pressure values SYS and DIA. here,
These (Equations 11 and (2)) show that there is a proportional relationship between the maximum and diastolic blood pressure values determined based on changes in the magnitude of the pressure pulse wave and the maximum and minimum values of the pressure pulse wave, respectively. Therefore, the constants and a represent the slope and the intercept of the Y-axis, respectively, when the Y-axis is the blood pressure value and the X-axis is the magnitude of the pressure pulse wave. Note that even when the magnitude of the pressure pulse wave is zero, the blood pressure value is not necessarily zero, so the Y-intercept a
By adding , the relationship between the blood pressure value and the pressure pulse wave becomes accurate.

Next, in step S13, it is determined whether or not a pressure pulse wave has been detected following the pressure pulse wave MpH. If it is determined that the pressure pulse wave has been detected, the subsequent step S14 is executed, and the pressure pulse wave is detected. The detected pressure pulse waves M, 2 are read, and the highest value MPffi''''1 and lowest value M P2 ''''0 of the pulse wave M pz are determined and written in the RAM 30. Then, in step S15,
Since K and a have already been determined in step 312, their maximum value M.

By substituting ′″1
YS and the diastolic blood pressure value DIA are determined.

In the subsequent step S16, it is determined whether or not an abnormality signal indicating that an abnormality has occurred during pressure pulse wave detection is generated in an interrupt routine to be described later. If it is determined that an abnormal signal has occurred, steps from step 32 onwards are executed again, but if it is determined that no abnormal signal has occurred, step S
17 is executed, and the systolic blood pressure value SYS and the diastolic blood pressure value DIA determined in step 315 are displayed on the blood pressure display 38. In step 31B,
It is determined whether the start/stop push button has been operated again. If it is determined that the operation has been performed again, the process returns to step S1, but if it is determined that the operation has not been performed again,
Step S19 is executed and the count content T of the timer is the predetermined count content T. It is determined whether or not it has been reached.

This counting content T. corresponds to the time interval for re-determining K and a in order to correct the correspondence determined in step S12, for example, from 5 to IO.
It is set to approximately 1 minute. Therefore, when the count content T reaches To, steps 82 and subsequent steps will be executed again, but the count content T is still T at this stage. Since,M,2,is not reached, steps 313 and below are executed.
The systolic blood pressure value SYS and the diastolic blood pressure value DIA are determined every time a series of pulse waves M, .

In the process of repeatedly executing the main routine as described above, at each predetermined relatively short period,
The interrupt routine shown in FIG. 6 is executed sequentially. In steps S and Sl, it is determined whether or not an impedance pulse wave has been detected, and if it is determined that it has not been detected, the operation is returned to the main routine, but it is determined that an impedance pulse wave has been detected. Then, the following step SS2 is executed, and the amplitude value of the detected impedance pulse wave M11 is determined. Next, step SS3
, the impedance pulse wave M11 detected this time
The difference 6M1 is calculated by subtracting the amplitude value of the immediately preceding impedance pulse wave M+□ from the amplitude value of . In step S54, i,
The amplitude value of the pressure pulse wave MP2 is determined from the highest value M I'z'''''8 and the lowest value M,2'''' of the α-scaled pressure pulse wave M,2, and the pressure pulse wave MP2 The highest value M p 1 '''ax and the lowest value M of the pressure pulse wave Mp immediately before,
, m i , the amplitude value of the pressure pulse wave M is determined, and the immediately preceding pressure pulse wave M p is determined from the amplitude value of the pressure pulse wave M, t.
ΔM, which is the difference obtained by subtracting the amplitude value of 1, is calculated. Then, by executing the pulse wave detection abnormality determination routine in step SS5, it is determined whether the pressure pulse wave is normally detected by the pulse wave sensor 18.

That is, in the pulse wave detection abnormality determination routine, the seventh
As shown in the figure, step SRI is first executed, and the amplitude value difference Δ of the pressure pulse wave calculated in step SS4 is
It is determined whether M2 is within a predetermined tolerance range. If it is determined that ΔM is smaller than a small predetermined value α and larger than the predetermined value −α, then the amplitude value of the pressure pulse wave M, □ is the previous pressure pulse wave M, If it is determined that ΔMp has hardly changed from the amplitude value, step SR2 is executed, and if it is determined that ΔMp exceeds the predetermined value α, step SR3 is executed.
If it is determined that F is less than the predetermined value -α, step SR4 is executed. In steps SR2, SR3, and SR4, it is determined in advance whether the amplitude value difference ΔM of the impedance pulse wave calculated in step SS3 is smaller than a predetermined value β and larger than a predetermined value −β. It is determined whether the value exceeds a small predetermined value β or falls below a predetermined value −β, and it is determined whether or not the direction of change of ΔM+ matches the direction of change of ΔMp.

That is, if it is determined in step SR2 that 6M1 is between the predetermined value β and −β, the amplitude value of the pressure pulse wave and the amplitude value of the impedance pulse wave are both almost unchanged. Therefore, it is determined that pressure pulse wave detection is not affected by noise contamination or changes in peripheral vascular resistance, and the pulse wave detection abnormality determination routine ends, but if ΔM is less than the predetermined value β. If the value is large or smaller than the predetermined value - β, it is determined that there was an influence such as a shift in the pressing position of the pulse wave sensor 18 or peripheral vascular resistance when detecting the pressure pulse wave, and an abnormal signal is generated in step SR5. is output.

Further, if it is determined in step SR3 that 6M1 exceeds the predetermined value β and that the amplitude value of the pressure pulse wave and the amplitude i1α of the impedance pulse wave are both changing in the positive direction, the pressure pulse wave It is determined that the pressure pulse wave has been detected normally, but if the amplitude value hardly changes or changes in the negative direction, it is determined that the pressure pulse wave detection is abnormal and an abnormal signal is output in step SR6. Ru. Further, in step SR4, if it is determined that ΔM is less than the predetermined value −β and both the amplitude value of the pressure pulse wave and the amplitude value of the impedance pulse wave are changing in the negative direction, the pressure pulse wave It is determined that the wave has been detected normally, but if the amplitude value hardly changes or is changing in the positive direction, it is determined that the pressure pulse wave detection is abnormal, and an abnormal signal is detected in step SR7. It is output.

When the pulse wave detection abnormality determination routine of step SS5 is executed as described above, the interrupt routine of FIG. 6 is completed and the operation is returned to the main routine of FIG. 5. Then, while steps 813 and subsequent steps of the main routine are repeatedly executed, if it is determined in step S16 that an abnormal signal has been output in the pulse wave detection abnormality determination routine of the interrupt routine, steps S2 and subsequent steps are executed again. Based on the newly detected pressure pulse wave, the correspondence between the pressure pulse wave and the blood pressure value is corrected in step S12.

Further, in the process of repeatedly executing steps 313 and subsequent steps, the determination in step S16 is denied, and
In step S19, the count content T of the timer is T. When it is determined that the systolic blood pressure has been reached, the steps from step 32 onwards are executed again, so that the actual systolic blood pressure values H and L newly determined in step S8 and the maximum value of the pressure pulse wave read in step 312 are determined. and the lowest value, the constants of correspondence equations (1) and (2) and 5
is determined again, and the blood pressure value is determined based on the new correspondence.

As described above, in the abnormality determination device of this embodiment, the amplitude value of the impedance pulse wave, which is not easily influenced by noise and peripheral vascular resistance, and the amplitude value of the pressure pulse wave, which is relatively easy to be influenced by these influences, are determined. If the directions of change in the amplitude values match, it is determined that the pressure pulse wave has been detected normally without being affected by noise or peripheral vascular resistance. If the pressure pulse wave is affected by a shift in the pressing position of the wave sensor, the detection of the pressure pulse wave is determined to be abnormal because the directions of change do not match. Therefore, by using the abnormality determination device of this embodiment, it is possible to appropriately deal with abnormalities in pulse wave detection.
This stabilizes the accuracy of pulse wave detection by the pressure pulse wave detection device.

As a result, when such a pressure pulse wave detection device is adopted as a blood pressure monitoring device, the correspondence between the blood pressure value and the pressure pulse wave is corrected according to the determination of pulse wave detection abnormality, so that the blood pressure measurement results may be affected. This has the effect of increasing credibility.

Although one embodiment of the present invention has been described above based on the drawings,
The present invention can also be suitably implemented in other embodiments.

In the above-mentioned embodiment, in the pulse wave detection abnormality determination routine shown in FIG. Although it has been determined that there is an abnormality in wave detection, for example, a step for determining an abnormality in the impedance pulse wave may be provided following step SSI in the interrupt routine shown in FIG. That is, a value T that is considerably larger than the predetermined value β, which is a very small value, and a value -γ that is considerably smaller than the predetermined value −β are set, respectively, so that the amplitude value of the impedance pulse wave is smaller than the predetermined value γ. When the impedance pulse wave is larger than the predetermined value -T, it is determined that the impedance pulse wave is normal, but when it is larger than the predetermined value γ, it is determined that one or both of the electrodes 40 and 42 has come off the living body and noise has been mixed in. If the value is smaller than the predetermined value, it is determined that one or both of the electrodes 46 and 4 has come off the living body and the impedance pulse wave is no longer detected, and an abnormality in the impedance pulse wave is detected, and the interrupt routine The operation is returned to step SSI, and impedance pulse wave detection is performed again. In this case, if it is determined that the impedance pulse wave is abnormal, an alarm or the like may be generated from an alarm device connected to the CPU 28.

In addition, in the above embodiment, when an abnormality in pressure pulse wave detection is determined, the pressure pulse wave is detected again to determine the blood pressure value, and the pressure pulse wave and the blood pressure value are determined based on the detected blood pressure value. Instead of or in addition to this, it is possible to display an alarm to notify of an abnormality from an alarm device, or to perform noise removal processing on the detected pressure pulse wave. You can also

In addition, in the above embodiment, the pressure pulse wave was collected from the artery 12, which is the radial artery located on the radial bone near the wrist of the living body, but since it is located relatively close to the epidermis of the living body, Pulse waves may also be collected from other arteries where it is easy to collect, such as the carotid artery or the 2nd leg artery.

Further, in the above embodiment, the actual blood pressure is determined based on the change in the magnitude of the pressure pulse wave obtained by gradually increasing the pressing force of the pulse wave sensor 18 from the target pressure P of about 40 mmHg at a predetermined speed. Value H and! - was set as δIl +, but instead of this, a part of the living body that is not on the upstream side of the artery 12 that the pulse wave sensor 18 presses, for example, the upper arm of the arm on the opposite side to the side where the pulse wave sensor 18 is attached. The actual blood pressure value is determined based on the pulse wave obtained by wrapping a cuff around the body and changing the compression pressure within the cuff, and the pulse wave sensor is determined based on the correspondence obtained from the actual blood pressure value. The blood pressure value may be determined using the pressure pulse wave detected from 18.

Further, the electrodes 40, 42, 46, 48 may be attached to the arm on the opposite side of the pulse wave detection probe 10.

Furthermore, in the above embodiment, the abnormality determination device was used in a pressure pulse wave detection device adopted in a blood pressure monitor device, but the pressure pulse wave detection device only detects a pressure pulse wave and displays its waveform. It may also be used in other devices that utilize pressure pulse waves.

The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a blood pressure monitoring device employing a pressure pulse wave detection device equipped with an abnormality determining device according to an embodiment of the present invention. FIG. 2 is a front sectional view showing the configuration of the pulse wave sensor shown in FIG. 1 in detail. FIGS. 3(a) and 3(b) are time charts showing changes in the pressure inside the housing shown in FIG. 1 and changes in the magnitude of the pressure pulse wave detected by the pulse wave sensor over time, respectively. FIG. 4 is a diagram showing an example of the trend of blood pressure values displayed on the blood pressure display in FIG. 1. Figure 5 is the first
3 is a flowchart illustrating the operation of the device shown in the figure. 6th
The figure is a flowchart showing an interrupt routine that is executed periodically in the operation of FIG. FIG. 7 is a flowchart illustrating the operation of the pulse wave detection abnormality determination routine of FIG. 12: Artery 18: Pulse wave sensor 28: CPU 30: RAM 32: ROM 40, 42: Electrode 43: Differential amplifier (impedance pulse wave detection means) output I
Tojin Korin Electronics Co., Ltd. Figure 2 Figure 4

Claims (1)

[Scope of Claims] A pressure pulse wave detection device that detects a pressure pulse wave generated in an artery of a living body by being pressed against the artery, and outputs a pressure pulse wave signal representing the pressure pulse wave. A device for determining an abnormality in wave detection, comprising an electrode attached to the epidermis of the living body, continuously detecting impedance at a portion where the electrode is attached,
an impedance pulse wave detection means that outputs an impedance pulse wave signal representing the impedance; and comparing the pressure pulse wave signal and the impedance pulse wave signal,
A determining means for determining an abnormality in pulse wave detection by the pressure pulse wave detection device when a predetermined relationship between the pressure pulse wave signal and the impedance pulse wave signal no longer holds true. An abnormality determination device for a pressure pulse wave detection device.