WO2007094464A1

WO2007094464A1 - Cardiopulmonary function measuring instrument

Info

Publication number: WO2007094464A1
Application number: PCT/JP2007/052876
Authority: WO
Inventors: Zhongwei Jiang; Samjin Choi
Original assignee: Yamaguchi University
Priority date: 2006-02-16
Filing date: 2007-02-16
Publication date: 2007-08-23
Also published as: JPWO2007094464A1; JP4998896B2

Abstract

[PROBLEMS] A cardiopulmonary function measuring instrument by which a high precision signal can be obtained over a long time using a piezoelectric film and/or a conductive fiber sensor. [MEANS FOR SOLVING PROBLEMS] A cardiopulmonary function measuring instrument using a piezoelectric film has circuitry including a low-pass filter for cutting out noise due to a power supply, myoelectricity, static electricity, and the like, a band-pass filter for preventing baseline variation and high frequency noise, a comparator for canceling saturation state, and a short circuit. A cardiopulmonary function measuring instrument using a conductive fiber sensor has circuitry including a low-pass filter, a first band-pass filter for preventing baseline variation and high frequency noise, a notch filter for cutting out power supply noise, and a second band-pass filter. Some model can be attached to the body using a belt.

Description

Specification

Cardiorespiratory function measuring device

Technical field

[oooi] The present invention relates to a cardiopulmonary function measuring device, and in particular, includes a signal processing circuit and an algorithm that enables high-precision signals to be obtained over a long time using a piezoelectric film sensor and a Z or conductive fiber sensor. The present invention relates to a cardiopulmonary function measuring device.

Background art

[0002] Recently, many accidents have occurred due to driver's operation errors in airplanes, high-speed trains, long-distance express buses and the like. Many of these accidents are caused by the driver's high mental stress and drowsiness, some of which are diagnosed by sleep apnea syndrome. In addition, sudden death of infants and sleep apnea syndrome occur mostly during sleeping or in the unconscious state!

[0003] For these diseases, there is a need for an accurate, continuous observation method that will help identify if the patient is in good health or not when the doctor consults. In addition, methods for identifying whether or not in such a state of health have become a new demand for home health care, as the development of medical technology extends the life span of human beings. .

[0004] Patent Document 1 discloses that a first bioelectrode formed by sandwiching a first polymer piezoelectric film between two sheets of electrically conductive fabric, and a second polymer piezoelectric film as two sheets of electric conduction. A pressure fluctuation measuring unit receiving a signal of a biosignal measuring sensor force having a second biomedical electrode configured to be sandwiched between the elastic cloth and an electrical signal line configured to measure pressure fluctuation and bioelectricity, bioelectrical measurement A biosignal measuring apparatus comprising a biosignal processing unit is described.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-284697

When such a biosignal measurement sensor is attached to a human body to collect data, the sensor circuit can not have an absolute ground, and the body temperature and the living body weak current cause a charge in the piezoelectric film sensor. Noise is generated by the rise of the output voltage due to the buildup, and the movement of the body and myoelectricity. On the other hand, when measuring heart rate information and creating an electrocardiogram by using an electrically conductive fabric as an electrode, three electrodes are generally used, but in consideration of wearability etc., Patent Document 1 discloses two electrodes. Use the method. In addition, since the sensor using the electrically conductive cloth does not connect the reference electrode, the collected signal is weak, and at the same time noise due to the influence of the human body (for example, body temperature or static electricity) occurs.

Disclosure of the invention

Problem that invention tries to solve

As described above, a conventional measuring device for processing a signal obtained by a pressure fluctuation measuring sensor composed of a piezoelectric film and an electrically conductive fabric, and a bioelectric sensor composed of an electrically conductive fabric , The collected signal is weak and the sensor circuit is

It is inevitable that noise will be generated due to the rise of the output voltage due to the accumulation of electric charge in the piezoelectric film sensor due to the influence of the human body such as body temperature or static electricity, and the body movement or EMG. Because of this, it was not possible to improve the measurement accuracy. Therefore, it is required to suppress pressure fluctuations and noise generated in a measuring apparatus that processes signals from sensors that measure bioelectricity, and to obtain high-precision measurement signals over a long period of time. .

Means to solve the problem

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is a piezoelectric film sensor formed by sandwiching a polymer piezoelectric film between two thin layer biological electrodes. And a signal processing circuit for processing a signal obtained by the piezoelectric film sensor, wherein the signal processing circuit cuts low frequency noise to a signal indicating pressure fluctuation obtained by the piezoelectric film sensor. A pass filter, a band pass filter that cuts baseline variation and high frequency noise from the amplified signal after passing through the low pass filter, and a comparator circuit connected to eliminate a saturated state in the piezoelectric film sensor And a short circuit, and is a cardiopulmonary function measurement device using a piezoelectric film sensor.

In the invention according to claim 2 relating to the invention according to claim 1, the power off frequency of the low pass filter is 500 Hz or less, and the cut off frequency of the band pass filter is 0.10 H It is a cardiopulmonary function measurement device using a piezoelectric film sensor characterized by z to 30 Hz.

In the invention according to claim 3 citing the invention according to any one of claims 1 or 2, the signal indicating the pressure fluctuation obtained by the piezoelectric film sensor is a respiration signal and a heartbeat signal. It is a cardiopulmonary function measurement device using a piezoelectric film sensor characterized in that

[0011] The invention according to claim 4, which cites the invention according to claim 3, cuts low frequency components that affect baseline fluctuation and high frequency components that are not necessary for respiration signals, which are obtained by the piezoelectric film sensor. And a signal processing unit that performs processing for calculating a zero-crossing point, calculating an inspiratory interval and an expiratory interval, and extracting a respiration signal with a low-pass filter. This cardiopulmonary function measurement device is characterized in that it is possible to extract respiration information from the signal obtained by the sensor.

The invention according to claim 5 relating to the invention according to claim 3 is a band pass filter for cutting high frequency components unnecessary for the influence of a respiration signal and a heartbeat signal from the signal acquired by the piezoelectric film sensor. The signal processing unit is further provided with a signal processing unit that performs processing for extracting a heartbeat signal by a band pass filter, passing it through a low pass filter to detect a peak, and calculating a peak interval, and the signal strength obtained by the piezoelectric film sensor It is a cardiopulmonary function measurement device characterized in that information can be extracted.

The invention according to claim 6 is a conductive fiber sensor comprising a biological electrode consisting of two conductive fibers, and a signal processing circuit for processing a signal obtained by the conductive fiber sensor. The signal processing circuit comprises a low noise filter for cutting low frequency noise from the signal indicative of bioelectricity acquired by the conductive fiber sensor, and a signal amplified after passing through the low pass filter. Conductivity characterized by including a first band pass filter for cutting baseline fluctuation and high frequency noise, a notch filter for cutting power supply noise, and a second band pass filter. It is a cardiopulmonary function measurement device using a fiber sensor.

[0014] The invention according to claim 7 relating to the invention according to claim 6 is such that the power off frequency of the low pass filter is 500 Hz or less, and the cut off frequency of the first band pass filter is 0.1 Hz 150 Hz, The cutoff frequency of the second band pass filter is 0.10 Hz It is a cardiopulmonary function measurement device using a conductive fiber sensor characterized in that the frequency is 120 Hz.

The invention according to claim 8 citing the invention according to any one of claims 6 or 7 is characterized in that the signal indicating bioelectricity obtained by the conductive fiber sensor is an electrocardiogram signal and a heartbeat signal. It is a cardiopulmonary function measuring device using a conductive fiber sensor characterized by the above.

[0016] The invention according to claim 9 relating to the invention according to claim 8 is a band pass filter for cutting the signal obtained by the conductive fiber sensor from high frequency components unnecessary for the influence of the respiration signal and the heartbeat signal. A signal processing unit that passes through a notch filter that removes power supply noise, extracts a heartbeat signal with a non-pass filter, passes through a low pass filter to make it easier to detect peaks, and calculates peak intervals. Further, the present invention is a cardiopulmonary function measuring device characterized in that it is possible to extract the signal strength heartbeat information obtained by the conductive fiber sensor.

In the invention according to claim 10, a piezoelectric film sensor configured by sandwiching a polymer piezoelectric film between two thin-layered bioelectrodes, and a signal acquired by the piezoelectric film sensor are collected and processed. A conductive fiber sensor comprising a signal collecting circuit for a piezoelectric film sensor and a biological electrode consisting of two conductive fibers, and a conductive fiber sensor for collecting and processing signals obtained by the conductive fiber sensor And a signal acquisition circuit for a piezoelectric film sensor, the signal acquisition circuit for a piezoelectric film sensor comprising a low pass filter for cutting low frequency noise, and baseline fluctuation and high frequency noise for an amplified signal after passing through the low pass filter. A band pass filter, and a comparator circuit and a short circuit connected to eliminate saturation in the piezoelectric film sensor. And the signal collection circuit for the conductive fiber sensor is a low pass filter for cutting low frequency noise, and a baseline variation and high frequency noise for the amplified signal after passing through the low pass filter. A combined cardiopulmonary function measurement device characterized in that it comprises: 1 band pass filter, notch filter for cutting noise of power source, and second band pass filter.

The invention according to claim 11, which cites the invention according to any one of claims 1, 2, 3, 6, 7, 8, 10, is worn on the body so that the measurement of cardiopulmonary function can be performed. Equipped with mounting means for It is a cardiopulmonary function measuring device characterized by becoming.

Effect of the invention

According to the present invention, a cardiopulmonary function measuring device using a piezoelectric film sensor and Z or a conductive fiber sensor, a low pass filter, a band pass for signals acquired by the piezoelectric film sensor, and The filter cuts noise while the comparator and short circuit eliminate saturation in the sensor, and for the signal acquired by the conductive fiber sensor, low pass filter, first and second band pass filters, notch Since noise is cut by the filter, a high-accuracy signal can be obtained for a long time, and a cardiopulmonary function measuring device of a form that can be used by ordinary people in daily life such as sleep can be obtained. .

BEST MODE FOR CARRYING OUT THE INVENTION

In the cardiopulmonary function measurement according to the present invention, an embodiment using a piezoelectric film sensor for acquiring biological signals such as respiration and heart rate as a biological sensor, a conductive fiber sensor for measuring an electrocardiogram and heart rate information There is a form that uses a piezoelectric film sensor and a form that uses a piezoelectric film sensor and a conductive fiber sensor.

Therefore, first, a piezoelectric film sensor type cardiopulmonary function measuring device using a piezoelectric film sensor will be described. Figure 1 shows the configuration of a piezoelectric film sensor type cardiopulmonary function measuring device. The piezoelectric film sensor 1 is composed of a first thin-layered bioelectrode and a second thin-layered bioelectrode sandwiching a piezoelectric poly (vinyl fluoride) (PVDF) film, which is a piezoelectric body. The signal passes through the RC low pass filters 2 and 3, is amplified by the amplifier 4, is output through the band pass filter 5, and the short circuit 6 and the comparator 7 are provided in parallel. The piezoelectric film sensor type cardiopulmonary function detection device includes a piezoelectric film sensor type unit including a piezoelectric film sensor 1 as shown in FIG. 1, an RC low pass filter 2, an amplifier 4, a band pass filter 5, a short circuit 6 and a comparator 7 force. Be done.

Fig. 2 shows an example of an RC low-pass filter. This filter is provided to cut high-frequency noise that is always generated when measuring a biomedical signal and amplify it with a force amplifier, and to obtain a higher quality signal. It can. The cutoff frequency of the RC low pass filter may be 500 Hz or less. The short circuit 6 and the comparator 7 are for discharging the charges accumulated in the piezoelectric film sensor when measuring for a long time, and for preventing the overflow of the sensor. The band pass filter 5 is provided to output higher quality breathing signals and heartbeat signals. Taking respiration and heart rate signals as an example, the power off frequency of the bandpass filter may be between 0.01 and 30 Hz. The order of the band pass filter is preferably 2 or more.

FIG. 3 shows the signal force obtained by the piezoelectric film sensor and the extracted respiration information. Fig. 3 (a) shows the original signal obtained by the piezoelectric film sensor, and simultaneously contains respiration information and heart rate information. FIG. 3 (b) shows the signal obtained as a result extracted by the algorithm shown in FIG. 5 described later. For comparison, Fig. 3 (c) shows the signal obtained from a commercially available respiratory curve recording sensor. In each graph, the horizontal axis is time. In Fig. 3 (b), the time of the adjacent white circle time of the black circle = time interval of inhalation, time of the adjacent black circle time of white circle = time interval of exhalation.

FIG. 4 shows the heartbeat information extracted by the signal force obtained by the piezoelectric film sensor. Fig. 4 (a) shows the original signal obtained by the piezoelectric film sensor, and it simultaneously contains respiration information and heart rate information as in Fig. 3 (a). Figure 4 (b) shows the resulting signal extracted by the algorithm described later. For comparison, Fig. 4 (c) shows the signals obtained from a 3-electrode ECG (electrocardiogram). In Fig. 4 (b), the time interval between the white circles is the heart rate RR interval.

FIG. 5 shows an algorithm for extracting respiration information from the signal obtained by the piezoelectric film sensor as shown in FIG. 3 (a). The signal obtained by the piezoelectric film sensor is output as a sensor signal x (n) (step 1), and then it is necessary for low frequencies and respiration signals that affect baseline variations, such as wavelets and filters. Pass a software filter (0.01 to 4 Hz) to effectively remove high frequency components (step 2). Next, the respiration signal is extracted using a digital low pass filter (0.3 Hz) (step 3). After the time delay compensation (step 4), the zero close point is calculated (step 5). The results are as shown in Fig. 3 (b). The inspiratory interval and expiratory interval can be calculated by measuring the interval of the obtained zero close point (step 6). As described above, it is possible to extract respiration information from the signal obtained by the piezoelectric film sensor, and the cardiopulmonary function measuring apparatus may be provided with a signal processing circuit for performing the processes of steps 1 to 6. Although a dedicated circuit for that purpose may be provided, a signal processing may be carried out by a computer having software for that purpose.

FIG. 6 shows an algorithm for extracting heart rate information from the signal obtained by the piezoelectric film sensor as shown in FIG. 4 (a). The signal obtained by the piezoelectric film sensor is output as a sensor signal x (n) (step 1), and then the effect of the respiration signal and high frequency components unnecessary for the heart beat signal, such as a wavelet filter, are effectively used. Pass a software filter (8 to 120 Hz) to remove (step 2). Next, heart rate information is extracted using a digital band pass filter (13 to 25 Hz) (step 3). Then, in order to make it easy to detect the peak value, the absolute value of the data obtained in step 3 is taken, then it is passed through a single pass filter (5 Hz) (step 4), and the peak value is detected (step 5). The interval between the obtained peak values is the interval between heart beats R and R (step 6).

As described above, the cardiopulmonary function measuring apparatus capable of extracting heart rate information from the signal obtained by the piezoelectric film sensor may be provided with a signal processing circuit for performing the processes of steps 1 to 6. Although a dedicated circuit for that purpose may be provided, a signal processing may be carried out by a computer having software for that purpose.

Next, a conductive fiber sensor type cardiopulmonary function measuring apparatus will be described. Figure 7 shows the configuration of a conductive fiber sensor type cardiopulmonary measurement device. The conductive fiber sensor 11 is composed of a first biological electrode and a second biological electrode made of conductive fiber, and the signal from each electrode is a RC low-pass filter 12, which removes noise signals due to power supply, myoelectricity, static electricity, etc. 13, through the first band pass filter 15 to be amplified by the amplifier 14, through the first band pass filter 15 to prevent baseline fluctuation and high frequency noise, and through the notch filter 16 to cut the noise of the power supply, and then the second band pass filter Output after 17 The cutoff frequency of the RC low pass filters 12 and 13 may be 500 Hz or less. Further, it is preferable that the order of each of the band pass filters 15 and 17 is 2nd or higher. The first band pass filter 15 preferably has a cutoff frequency of 0.01-15 OHz, and the second band pass filter 17 preferably has a cutoff frequency of 0.01 to 120 Hz. AC noise at 60 Hz or 50 Hz is removed using notch filter 16 Be In order to obtain an appropriate output signal from the conductive fiber sensor 11, the first band pass filter 15, the notch filter 16, and the second band pass filter 17 are arranged in this order. This is very important. The conductive fiber sensor type cardiopulmonary function detection device is the conductive fiber sensor 11 as shown in FIG. 7, RC low pass filter 12, 13, amplifier 14, first band pass filter 15, notch filter 16, second band pass filter It comprises the conductive fiber sensor type unit which consists of seventeen.

[0031] Fig. 8 shows the heart rate information extracted by the conductive fiber sensor type cardiopulmonary function measuring device.

The graph on the left is the case where the signal was obtained normally, and the graph on the right is the case where muscle noise is introduced. The top row shows the original signal obtained by the conductive fiber sensor type cardiopulmonary function measuring device, and the middle row shows the extracted heartbeat information. For comparison, the lower part shows the signals obtained with a commercially available 3-electrode ECG.

FIG. 9 shows an algorithm for extracting heart beat information obtained by the conductive fiber sensor. The signal obtained by the conductive fiber sensor is output as a sensor signal x (n) (step 1), and then effectively removes the influence of the respiration signal and high frequency components unnecessary for the heartbeat signal, such as a wavelet 'filter. Pass the software filter (0. 03 to 125 Hz) for (step 2). Next, remove the power supply noise (60 Hz or 50 Hz) using a notch filter (Step 3). Next, heartbeat information is extracted using a digital band pass filter (13 to 25 Hz) (step 4). Then, in order to make it easy to detect the peak value, the absolute value of the data obtained in step 4 is taken and then passed through a single pass filter (5 Hz) (step 5) to detect the peak value (step 6). The interval between the obtained peak values is the heart rate RR interval (step 7).

The cardiopulmonary function measuring apparatus capable of extracting the heartbeat information obtained by the conductive fiber sensor should have a signal processing circuit for performing the processes of steps 1 to 7. Although a configuration may be provided in which dedicated circuits are provided for the purpose, a computer having software for the purpose may be used to perform signal processing.

Next, a combined-type cardiopulmonary measurement device in which a piezoelectric film sensor and a conductive fiber sensor are combined will be described. The conductive fiber sensor is more suitable for measuring the cardiac beat signal than the piezoelectric film sensor. However, under normal sleeping conditions and daily life In such cases, it may be considered that the situation where the conductive fiber sensor can not contact well with the body frequently occurs. In that case, the conductive fiber sensor can not measure the cardiac beat signal.

On the other hand, in the piezoelectric film sensor, even if the sensor itself does not make contact with the body, it can not detect the piezoelectric film sensor force if the movement due to breathing or heartbeat gives the piezoelectric film sensor expansion and contraction. It is possible. However, the signal strength of the conductive fiber sensor can more accurately extract the heartbeat information from the signal of the piezoelectric film sensor. Therefore, in the case of a more accurate cardiopulmonary function measuring device, a combined cardiopulmonary function measuring device provided with both a conductive fiber sensor and a piezoelectric film sensor can be provided. By using both sensors simultaneously and interpolating each other, a more sophisticated cardiopulmonary measurement device can be realized.

[0036] Fig. 10 shows the configuration of a combined cardiopulmonary function measurement device comprising a conductive fiber sensor and a piezoelectric film sensor. In this cardiopulmonary function measurement device, the signal from the conductive fiber sensor 21 is first. The conductive fiber sensor signal collecting circuit 23 configured to include the conductive fiber sensor type unit described above is collected and processed by the microcomputer 25 after AZD conversion. At the same time, the signal from the piezoelectric film sensor 22 is also collected through the piezoelectric film sensor signal collecting circuit 24 configured to include the above-described piezoelectric film sensor type unit, and processed by the microcomputer 25 after AZD conversion. Further, the collected signal or data obtained by processing the signal is fed to a computer 27 connected via, for example, the USB 26, and data display 'storage' analysis is performed.

As a form of a cardiopulmonary function measuring device provided with both a conductive fiber sensor and a piezoelectric film sensor, it can be considered to make the device form that can be worn on the body, such as a belt type. FIG. 11 shows an example of the configuration of a belt-type cardiopulmonary function measuring apparatus 31. The belt-type cardiopulmonary function measuring device 31 has a belt 33 attached to a sensor head 32 which is formed by attaching two conductive fiber sheets 34 and 35 and a piezoelectric film sensor 36 to a cushioning material or a flexible plate. It is attached and made to be worn around the waist. The sensor head 32 has a width of, for example, 90 mm and a length of 185.5 mm, and two conductive fiber sheets 34, 35 are used to measure the ECG for extracting heart rate information. Also, the piezoelectric film sensor 36 is It measures the cycle of breathing from up and down movement and also measures the heart rate.

[0038] FIG. 12 shows an output waveform and a heartbeat signal of the conductive fiber sensor. In the figure, (a) is a waveform measured when the conductive fiber sensor is in contact with the body poorly or is dry, and (b) is a heartbeat signal extracted by applying the algorithm of FIG. I understand that I could not do it.

FIG. 13 shows the output signal of the piezoelectric film sensor and the extracted heartbeat signal at the same time as the measurement of the conductive fiber sensor shown in FIG. In the figure, (c) is the output signal of the piezoelectric film sensor force, and (d) is the heartbeat signal obtained by applying the algorithm of FIG. 6, and it can be seen that the heartbeat information force S was successfully extracted.

When using a conductive fiber sensor, it is always in contact with the skin and the skin needs to be moist. In fact, as the skin becomes dry, significant noise is generated. In the example shown in FIG. 12, it is clear that the RR interval can not be measured accurately.

On the other hand, FIG. 13 (c) shows an output signal obtained from the piezoelectric film sensor at the same time as the measurement using the conductive fiber sensor. Figure 13 (d) shows the heartbeat signal extracted by the algorithm of Figure 6. It is obvious that the RR interval can be calculated from the output signal which can not be measured by the conductive fiber sensor, but the piezoelectric film sensor force is also obtained. Therefore, by using the conductive fiber sensor and the piezoelectric film sensor simultaneously and interpolating each other, a higher performance cardiopulmonary function sensor can be realized.

As described above, the piezoelectric film sensor and its signal processing algorithm can effectively extract respiration information, and have high potential for extraction of heart rate information. However, piezoelectric film sensors may not always be effective. For example, if the belt sensor is shifted or moved by the movement of the body, it may lose its function for a fixed time during sleep.

[0043] FIG. 14 shows the result when the piezoelectric film sensor did not operate well and the conductive fiber sensor operated well. (A) shows the heart rate signal extracted by the algorithm of FIG. 6 when the force signal which is the output signal from the piezoelectric film sensor is extremely small (b) shows extraction of heart rate information or respiration information . Meanwhile, at this time, as shown in (c), the conductive fiber sensor seems to be functioning properly, and it is clear that the heartbeat signal can be extracted. Therefore, by using the conductive fiber sensor and the piezoelectric film sensor simultaneously and interpolating each other, a higher performance cardiopulmonary function sensor can be realized.

Brief description of the drawings

FIG. 1 is a view showing a configuration of a piezoelectric film sensor type cardiopulmonary function measuring device as one embodiment of the present invention.

FIG. 2 is a diagram showing an example of an RC low pass filter.

[Fig. 3] Piezoelectric film sensor force Fig. 3 is a view showing extracted respiration information.

[FIG. 4] Piezoelectric film sensor force obtained signal force FIG.

FIG. 5 is a diagram showing an algorithm for extracting respiration information from a piezoelectric film sensor signal.

FIG. 6 is a diagram showing an algorithm for extracting signal information of the piezoelectric film sensor as well as heartbeat information.

FIG. 7 is a view showing the configuration of a conductive fiber sensor type cardiopulmonary function measuring apparatus according to another embodiment of the present invention.

[FIG. 8] A diagram showing two cases in which the conductive fiber sensor sensor and heart rate information are extracted,

The left column shows when the signal is obtained normally, and the right column shows the case where the noise of the muscle enters.

[Fig. 9] This is an algorithm for extracting heart rate information from conductive fiber sensor signals.

FIG. 10 is a view showing the configuration of a combined cardiopulmonary function measurement device provided with both a conductive fiber sensor and a piezoelectric film sensor according to still another embodiment of the present invention.

FIG. 11 is a view showing a belt type of the cardiopulmonary function measuring apparatus according to the present invention.

FIG. 12 is a view showing an output signal of a conductive fiber sensor and a heartbeat signal.

FIG. 13 is a diagram showing an output signal of a piezoelectric film sensor and a heartbeat signal extracted.

FIG. 14 is a diagram showing the results when the piezoelectric film sensor did not operate well and the conductive fiber sensor operated well.

Explanation of sign

1 Piezoelectric film sensor

2 RC low pass filter RC low pass filter

Amplifier

RC Rono Sufiinoleta

Short circuit

CONNORATOR

Conductive fiber sensor

RC low pass filter

Amplifier

First band pass filter Notch filter

Second band pass filter Conductive fiber sensor

Piezoelectric film sensor

Signal acquisition circuit for conductive fiber sensor Signal acquisition circuit for piezoelectric film sensor Microcomputer

Belt sensor

The sensor head

Benolet

5 Conductive fiber sheet

Piezoelectric film sensor

Claims

The scope of the claims

[1] A signal processing circuit comprising: a piezoelectric film sensor configured by sandwiching a piezoelectric polymer film between two thin layer bio-electrodes; and a signal processing circuit that processes a signal acquired by the piezoelectric film sensor. The circuit cuts a low noise noise to the signal indicating pressure fluctuation acquired by the piezoelectric film sensor, and a baseline fluctuation and high frequency noise to the amplified signal after passing through the low pass filter. What is claimed is: 1. A cardiopulmonary function measuring device using a piezoelectric film sensor, comprising: a bandpass filter; and a comparator circuit and a short circuit connected so as to eliminate a saturated state in the piezoelectric film sensor.

[2] The cardiopulmonary function measurement using the piezoelectric film sensor according to claim 1, characterized in that the cutoff frequency of the low pass filter is 500 Hz or less, and the cutoff frequency of the band pass filter is 0.1 Hz to 30 Hz. apparatus.

[3] The piezoelectric film sensor according to any one of claims 1 and 2, wherein the signal indicating pressure fluctuation acquired by the piezoelectric film sensor is a respiration signal and a heartbeat signal. Cardiorespiratory function measuring device.

[4] The cardiopulmonary function measurement device according to claim 3, wherein the signal obtained by the piezoelectric film sensor is used as a band pass filter for cutting low frequencies that affect baseline fluctuation and high frequency components that are not necessary for respiration signals. The signal processing unit is further provided with a signal processing unit that performs processing for extracting a respiration signal with a low pass filter, performing time delay compensation, calculating a zero crossing point, and calculating an inspiratory interval and an expiratory interval, obtained by the piezoelectric film sensor A cardiopulmonary function measuring device characterized in that respiration information can be extracted from a signal.

[5] In the cardiopulmonary function measuring device according to claim 3, the signal obtained by the piezoelectric film sensor is passed through a band pass filter for cutting high frequency components unnecessary for the influence of a respiration signal and a heartbeat signal, The signal processing unit is further provided with a signal processing unit that performs processing of extracting a heartbeat signal by a filter, passing it through a low pass filter to easily detect a peak, and calculating a peak interval, and signal heartbeat information obtained by the piezoelectric film sensor A cardiopulmonary function measuring device characterized by being able to extract

[6] A conductive fiber sensor comprising a biological electrode consisting of two conductive fibers, and the conductive property A signal processing circuit for processing a signal acquired by a fiber sensor, wherein the signal processing circuit is a low pass filter for cutting low frequency noise from a signal indicating bioelectricity acquired by the conductive fiber sensor; A first band pass filter that cuts baseline variation and high frequency noise from the amplified signal after passing through a low noise filter, a notch filter that cuts noise of the power supply, and a second band pass filter A cardiopulmonary function measuring device using a conductive fiber sensor characterized by including!

[7] The cut-off frequency of the low-pass filter is 500 Hz or less, the cut-off frequency of the first band-pass filter is 0.10 Hz, 150 Hz, and the cut-off frequency of the second band-pass filter is 0.10 Hz The cardiopulmonary function measuring apparatus using the conductive fiber sensor according to claim 6, characterized in that the frequency is 120 Hz.

[8] The conductive fiber sensor according to any one of claims 6 or 7, characterized in that the signal indicating bioelectricity acquired by the conductive fiber sensor is an electrocardiogram signal and a heartbeat signal. Cardiorespiratory function measuring device using.

[9] In the cardiopulmonary function measurement device according to claim 8, a signal obtained by the conductive fiber sensor is passed through a band pass filter for cutting high frequency components unnecessary for the influence of the respiration signal and the heartbeat signal, The conductive fiber sensor further includes a signal processing unit that passes a notch filter that removes noise, extracts a heartbeat signal by a band pass filter, passes a low pass filter to facilitate peak detection, and calculates a peak interval. A cardiopulmonary function measuring device characterized in that the heart rate information can also be extracted from the signal power obtained in the above.

[10] A piezoelectric film sensor configured by sandwiching a polymer piezoelectric film between two thin layer bio-electrodes, and a signal collecting circuit for a piezoelectric film sensor that collects and processes signals obtained by the piezoelectric film sensor. A conductive fiber sensor comprising a biological electrode consisting of two conductive fibers, and a signal collection circuit for a conductive fiber sensor for collecting and processing a signal acquired by the conductive fiber sensor, A signal acquisition circuit for a piezoelectric film sensor comprises: a low pass filter for cutting low frequency noise; a band pass filter for cutting a baseline fluctuation and high frequency noise from an amplified signal after passing through the low noise filter; The conductive system comprises a comparator circuit and a short circuit connected to eliminate saturation in the film sensor. Signal collection times for Wei sensor The path includes a low noise filter that cuts low frequency noise, a first band pass filter that cuts baseline variation and high frequency noise from the amplified signal after passing through the low pass filter, and noise from the power supply. A combined cardiopulmonary function measuring device comprising: a notch filter; and a second band pass filter.

The cardiopulmonary function according to any one of claims 1, 2, 3, 6, 7, 8 and 10, characterized in that it comprises an attachment means for attaching to a body so that the measurement of cardiopulmonary function can be performed. Measuring device