WO2019010615A1

WO2019010615A1 - Pulse wave sensor, sensor array and pulse wave measurement method

Info

Publication number: WO2019010615A1
Application number: PCT/CN2017/092399
Authority: WO
Inventors: 刘苏; 张劭龙; 耿兴光; 张以涛; 张俊; 侯洁娜; 张海英
Original assignee: 中国科学院微电子研究所
Priority date: 2017-07-10
Filing date: 2017-07-10
Publication date: 2019-01-17

Abstract

Disclosed are a pulse wave sensor, sensor array and a pulse wave measurement method. The pulse wave sensor comprises a flexible piezoelectric sensor (2) and a static pressure sensor (4), wherein the flexible piezoelectric sensor (2) is used to sense a pulse wave and the static pressure sensor (4) is used to measure static pressure applied on the pulse wave sensor. The sensors separately measure static pressure signals and dynamic pulse wave pressure signals; a piezoelectric film is used to measure dynamic pressure fluctuations and a piezoresistive sensor is used to measure static pressures, thereby enabling dynamic sensitivity thereof to be free from the effect of the measurement range of static pressures, ensuring high sensitivity of pulse waves under a wide range of static pressures; the sensor employs a flexible frame (1), thereby enabling an assembled array thereof to conform to wrist features of different user types and realizing an excellent fit between the array and arm surfaces.

Description

Pulse wave sensor, sensor array and pulse wave measuring method

Technical field

The present disclosure belongs to the field of non-invasive detection technology for human health, and in particular relates to a device for collecting brachial artery pulse waves, and more particularly to a pulse wave sensor, a sensor array and a pulse wave measuring method.

Background technique

Pulse waveforms reflect human health and a variety of diseases. Pulse wave measurement methods are classified into invasive and non-invasive. The invasive pulse wave measurement method causes great damage to the patient, and the non-invasive type has little damage to the patient, such as a pressure sensor, an ultrasonic sensor, a photoelectric sensor, and the like. These sensors enable non-invasive measurement of pulse waves. However, the current mainstream method of measuring pulse waves is still a pressure sensor to measure pulse waves. Some devices use a piezoresistive pressure sensor to pulse multiple points on the wrist. Some devices use strain gauges as pulse wave sensors, and some devices use MEMS piezoresistive sensors to detect pulse. The dynamic range of the above sensor is limited by the material itself, and the sensitivity is limited by the range. Under the same power supply and sensitivity, the greater the power measurement range, the lower the resolution of the force, and the lower the output voltage. Subsequent amplification circuits are simply amplified, and the amplification is too high. The voltage output is easily saturated under large pressure. In addition, extracting dynamic pulse waves from static pressure increases the complexity of subsequent processing circuits and algorithms.

Pressure sensors with pure piezoelectric principle have high sensitivity and the output amplitude is not affected by static pressure, but piezoelectric sensors cannot measure static pressure. Therefore, the two sensors independently used for pulse wave measurement can not effectively reflect the physical condition of the person being tested. If you want to reflect the type of disease through the pulse wave, pulse waves must be acquired over a wide range of static pressures. However, the sensitivity of current piezoresistive sensors is determined by the range in which the force is applied. This results in a small-range pressure sensor range that does not meet the test requirements. The large-range sensor output voltage has a low resolution of force, and cannot output a morphological pulse wave at low pressure.

In addition, the existing sensor array has two problems. One problem is that the sensor array cannot meet the problem of arm shape fit of different people. The difference in array fit cannot guarantee the acquisition of pulse waves. The fidelity; another problem is the mutual interference between the sensors caused by the deformation of the sensor. This problem can superimpose the pulse waves collected by adjacent sensors and affect the accuracy of the pulse wave.

Therefore, it is necessary to study a pulse wave sensor that can measure large static pressure while maintaining high sensitivity and wide dynamic measurement range, and constitute a sensor that can reduce interference between sensors and fit the arm.

Summary of the invention

In view of this, the main object of the present disclosure is to provide a pulse wave sensor, a sensor array, and a pulse wave measuring apparatus using the same, to solve at least one of the above technical problems.

In order to achieve the above object, as one aspect of the present disclosure, the present disclosure provides a pulse wave sensor including a static pressure sensor and a flexible piezoelectric sensor, characterized in that:

The flexible piezoelectric sensor is configured to sense a pulse wave and generate an electrical signal;

The static pressure sensor is for sensing a static pressure applied to the pulse wave sensor.

As another aspect of the present disclosure, the present disclosure also provides a pulse wave sensor array including an elastic buffer material and a plurality of pulse wave sensors as described above, wherein a plurality of the pulse wave sensors are distributed at intervals in the elastic buffer On the material.

As still another aspect of the present disclosure, the present disclosure further provides a pulse wave measuring method, including the following steps:

Sensing a pulse wave by a flexible piezoelectric sensor and generating an electrical signal;

The static pressure exerted on the pulse wave sensor is sensed by a static pressure sensor over a large pressure range.

Based on the above technical solution, the pulse wave sensor of the present disclosure has the following beneficial effects: the sensor overcomes the problem that the pulse wave collecting device in the prior art cannot accurately and comprehensively reflect the pulse information of the human body, and the traditional piezoresistive sensor range and The sensitivity is inversely proportional. The pulse wave sensor needs to capture the weak pulse signal in a large range of range, while the conventional piezoresistive sensor has lower sensitivity in a large range of range, and the sensor of the present disclosure separately measures the static pressure signal and the dynamic pulse wave pressure signal, and utilizes Piezoelectric film measures dynamic pressure fluctuations, piezoresistive sensor Static pressure, so that the dynamic sensitivity is not affected by the static pressure range, can maintain high sensitivity to pulse wave under a wide range of static pressure; the sensor of the present disclosure uses a long curved surface skeleton and elastic buffer material as a support to constitute The array can meet the wrist characteristics of different groups of people, achieving a good fit on the arm surface.

DRAWINGS

1 is a schematic structural view of a pulse wave sensor of the present disclosure;

2 is a side elevational view of the pulse wave sensor array structure of the present disclosure;

3A-3C are schematic diagrams showing the positional relationship between the downwardly concave space on the sensor skeleton of the present disclosure and the flexible film of the flexible piezoelectric sensor, respectively;

4 is a schematic view showing the positional relationship between the pulse wave measuring device and the radial artery of the present disclosure;

Fig. 5 is a front elevational view showing the positional relationship between the pulse wave sensor array structure of the present disclosure and the radial artery.

In the above figure, the meanings of the reference symbols are as follows:

1, sensor skeleton

2. Flexible piezoelectric sensor 3. Contact of flexible piezoelectric sensor

4, static pressure sensor 5, static pressure sensor contacts

6, sensor unit

6-1, the first sensor unit

6-2, the second sensor unit

6-3, the third sensor unit

6-4, fourth sensor unit

6-5, fifth sensor unit

7, elastic cushioning material

8, the downward recessed space

9. Pressurizing device

10, radial artery 11, humerus

12, the skin

Detailed ways

The present disclosure will be further described in detail below with reference to the specific embodiments of the embodiments of the invention.

The present disclosure is to solve the problem that the pulse wave collecting device in the prior art cannot accurately and comprehensively reflect the pulse information of the human body. Traditional piezoresistive sensor ranges are inversely proportional to sensitivity. Pulse wave sensors need to capture weak pulse signals over a wide range of ranges, while conventional piezoresistive sensors have lower sensitivity over a wide range of ranges. In order to solve this problem, in the present disclosure, the static pressure signal is measured separately from the dynamic pulse wave pressure signal, the dynamic pressure fluctuation is measured by the piezoelectric film, and the static pressure is measured by the piezoresistive sensor, thereby improving the sensitivity of the piezoelectric thin film sensor and making the pulse The wave signal is sharper and the static pressure is accurately measured over a wide pressure range.

In addition, the present disclosure provides a structure for mitigating mutual interference between sensors and adapting to different groups of people's arms, in view of the problem of sensor state mutual influence and arm-fitting in existing sensor arrays.

Specifically, as an aspect of the present disclosure, the present disclosure discloses a pulse wave sensor including a flexible piezoelectric sensor and a static pressure sensor, wherein:

a flexible piezoelectric sensor for sensing a pulse wave;

A static pressure sensor is used to measure the static pressure exerted on the pulse wave sensor.

The static pressure sensor may be a piezoresistive sensor, such as but not limited to a MEMS sensor, a piezoresistive film sensor, and a strain gauge sensor.

The flexible piezoelectric sensor is a piezoelectric pressure sensor, and the piezoelectric material thereof includes, for example, but not limited to, PVDF (polyvinylidene fluoride), PZT (lead zirconate titanate piezoelectric ceramic), BaTiO3, and the like.

Wherein, the flexible piezoelectric sensor is further provided with a contact, and one side of the contact is connected with the skin to be tested, and is used for fitting the surface of the arm and conducting the pulse wave to be tested, and detecting the other side of the contact with the flexible piezoelectric sensor. The cells are connected or in contact, and the pulse wave to be measured is conducted to the detecting unit of the flexible piezoelectric sensor.

The static pressure sensor is also provided with a contact, and the contact of the static pressure sensor is used to conduct the static pressure to the detection unit of the static pressure sensor.

The materials of the contacts of the two sensors include, but are not limited to, materials such as silica gel, foam, sponge, etc., and the Shore A hardness of the contacts is, for example, between 1 and 80 degrees.

As another aspect of the present disclosure, the present disclosure also discloses a pulse wave sensor array including an elastic cushioning material and a plurality of the above-described pulse wave sensors, wherein the plurality of pulse wave sensors are distributed on the elastic cushioning material at intervals.

The elastic cushioning material includes, for example, but not limited to, a urethane sponge, a slow rebound memory foam, etc., and the pulse wave sensor array can be attached to the arms of different people.

The number of the pulse wave sensors is, for example, five, or three, four, six, seven, eight, nine, or ten, and are sequentially arranged at equal intervals along the measured wrist. Preferably, the first sensor is attached to the lateral side of the wrist to the side of the palm, and the remaining sensors are sequentially arranged in the direction of the elbow of the arm.

When the external pressure device applies pressure to the pulse wave sensor array, the static pressure sensor senses the static pressure transmitted from the elastic buffer material above the sensor array, and the flexible piezoelectric sensor is used to measure the radial artery pulse, which is finally realized at different pressures. Detection of brachial artery pulse signals by a lower pulse wave sensor array.

As still another aspect of the present disclosure, the present disclosure also discloses a pulse wave measuring method, including the following steps:

The static pressure sensor is a MEMS sensor, a piezoresistive film sensor or a strain gauge sensor; the flexible piezoelectric sensor is a piezoelectric pressure sensor, and the piezoelectric material is made of PVDF, PZT or BaTiO3; as a preferred, the flexible piezoelectric sensor is flexible. Thin film sensor.

In some embodiments, the pulse wave sensor of the present disclosure includes a sensor backbone, a flexible piezoelectric sensor, a flexible piezoelectric sensor contact, a static pressure sensor, a static pressure sensor contact. The concave side of the sensor frame is connected to the flexible piezoelectric sensor for supporting the flexible piezoelectric sensor; the other side of the sensor frame is connected to the static pressure sensor for supporting the static pressure sensor. The other side of the flexible piezoelectric sensor is connected to the flexible contact for sensing the pulse wave transmitted by the contact. The other side of the contact is attached to the skin for adhering to the arm surface and conducting pulse waves. The other side of the static pressure sensor is connected to a pressurizing device for detecting the overall pressure experienced by the sensor structure. The static pressure sensor is a piezoresistive sensor, including but not limited to a MEMS sensor, a piezoresistive film sensor, and a strain gauge sensor. The flexible piezoelectric sensor is a piezoelectric pressure sensor, and the piezoelectric material includes but is not limited to materials such as PVDF, PZT, and BaTiO ₃ . The material of the contacts includes but is not limited to materials such as silicone, foam and sponge.

In some embodiments, the pulse wave sensor array of the present disclosure comprises a porous elastic buffer material and five pulse wave sensors, the porous elastic buffer material is connected to five sensors, and the porous elastic buffer material is connected to one side of the static pressure sensor structure. It is used for absorption buffer and reduces vibration interference between sensors and external impact interference. In addition, the porous elastic cushioning material allows the sensor array to fit the arms of different people. The porous elastic cushioning material is not limited to a urethane sponge, a slow rebound memory foam, or the like.

Each sensor is sequentially spaced along the wrist at equal intervals. The first sensor is placed close to the palm side of the wrist, and the second to fifth sensors are sequentially arranged from the side of the wrist. This distribution can be applied to different groups of arm lengths, increasing the length of the radial artery fluctuation detection.

Several specific embodiments of the present disclosure will be further described below in conjunction with the accompanying drawings.

As shown in FIGS. 1-5, the pulse wave sensor of the present disclosure includes a sensor skeleton 1, a flexible piezoelectric sensor 2, a contact 3 of a flexible piezoelectric sensor, a static pressure sensor 4, and a contact 5 of a static pressure sensor. The contact 3 of the flexible piezoelectric sensor is in contact with the skin 12, the material property of the contact 3 of the flexible piezoelectric sensor enables it to fit the skin, and the contact 3 of the flexible piezoelectric sensor has a certain elastic deformation to make the arm radial artery 10 The pulse wave is transmitted to the flexible piezoelectric sensor 2. The flexible piezoelectric sensor is attached to the sensor frame 1 in a curved state, and converts the pulse wave fluctuations transmitted by the contacts 3 of the flexible piezoelectric sensor into electrical signals, and the converted electrical signals are output through the two poles of the flexible piezoelectric sensor 2. When the radial artery 10 beats to the skin 12 a force is received by the contact 3 of the flexible piezoelectric sensor and transmitted to the flexible piezoelectric sensor 2, the flexible piezoelectric sensor 2 can output an electrical signal.

As shown in FIGS. 4 and 5, the sensor frame 1 has a long curved surface shape, and one side is soft. The piezoelectric sensor 2 provides support. As shown in FIG. 3A, one side of the sensor frame 1 connected to the flexible piezoelectric sensor 2 includes a downwardly concave space 8, and the flexible piezoelectric sensor 2 is laid flat above the downwardly concave space 8. The edge is fixed to the periphery of the downwardly concave space 8, as shown in Fig. 3A, and is fixed around the periphery, and the flexible film above the downwardly concave space 8 is suspended. The suspended structure converts the forward pressure received by the flexible film of the flexible piezoelectric sensor 2 into a pulling force to the periphery, thereby greatly increasing the pressure of the flexible film, thereby causing a larger piezoelectric signal, thereby Increased sensor sensitivity. The other side of the sensor frame 1 is fixed with a static pressure sensor 4, and the other side of the static pressure sensor 4 is connected to a pressurizing device 9 for detecting the overall pressure experienced by the sensor structure. Wherein the pressing device 9 is, for example, an inflatable bandage, or an inflatable balloon, etc.

As shown in Figure 4, the sensor array comprises a porous elastic cushioning material 7 and five of the aforementioned pulse wave sensors 6-1, 6-2, 6-3, 6-4, 6-5. The sensor array is laid flat on the arm to be tested. Due to the characteristics of the elastic cushioning material 7, the five sensors 6-1, 6-2, 6-3, 6-4, 6-5 can be attached according to the measured hand type. Arm surface. When the pulse beats, the elastic buffer material 7 can also absorb the extra impact, reduce the influence of the pulse beat point under a certain sensor on the adjacent sensor, and reduce mutual interference between the sensors.

The sensor array is used to detect pulse beats of the iliac artery 10 near the tibia 11 at different pressures. Each sensor is sequentially spaced along the wrist at equal intervals. The first sensor 6-1 is adjacent to the palm side of the wrist, and the second to fifth sensors 6-2, 6-3, 6-4, 6-5 are sequentially arranged from the side of the wrist horizontal arm. This distribution can be applied to different groups of arm lengths, increasing the length of the radial artery 10 fluctuation detection. When the outside pressurizing device 9 applies pressure to the sensor array, the static pressure sensor 4 senses the static pressure transmitted from the elastic cushioning material 1 above the sensor, and the flexible piezoelectric sensor 2 is used to measure the radial artery pulse. Finally, the sensor array is used to detect the radial artery pulse signal under different pressures.

As a variation of the above embodiment, as shown in FIGS. 3B and 3C, the flexible film of the flexible piezoelectric sensor 2 may be fixed only on both sides (FIG. 3B); or three-sidedly fixed (FIG. 3C), in which the hatched portion indicates a downwardly concave space. 8 overlapping portion with the flexible film; or completely suspended above the downwardly concave space 8 by the projecting jig; these do not affect the realization of the technical effects of the present disclosure. Further, in order to prevent folding and deformation of the flexible film of the flexible piezoelectric sensor 2, Reinforcing ribs or guide strips may be provided on the flexible film to bend as far as possible in certain directions to avoid malfunction.

The specific embodiments of the present invention have been described in detail with reference to the preferred embodiments of the present disclosure. All modifications, equivalents, improvements, etc., made within the spirit and scope of the present disclosure are intended to be included within the scope of the present disclosure.

Claims

A pulse wave sensor comprising a static pressure sensor and a flexible piezoelectric sensor, characterized in that:

The flexible piezoelectric sensor is configured to sense a pulse wave and generate an electrical signal;

The static pressure sensor is for sensing a static pressure applied to the pulse wave sensor.
The pulse wave sensor according to claim 1, wherein the static pressure sensor is a MEMS sensor, a piezoresistive film sensor, or a strain gauge type sensor.
The pulse wave sensor according to claim 1, wherein said flexible piezoelectric sensor is a piezoelectric pressure sensor, and said piezoelectric material is made of PVDF, PZT or BaTiO 3 material.
The pulse wave sensor of claim 1 wherein said flexible piezoelectric sensor is a flexible film sensor.
The pulse wave sensor according to claim 1, wherein the flexible piezoelectric sensor and/or the static pressure sensor are provided with contacts.
The pulse wave sensor according to claim 1, wherein the contact is made of silica gel, foam or sponge.
The pulse wave sensor according to claim 1, wherein said sensor skeleton is a spherical body, a cylinder or an elongated body curved into a curved surface.
A pulse wave sensor array comprising an elastic cushioning material and a plurality of pulse wave sensors according to any one of claims 1 to 7, wherein a plurality of said pulse wave sensors are distributed over said elastic cushioning material at intervals.
The pulse wave sensor array according to claim 8, wherein the elastic cushioning material is a polyurethane sponge or a slow rebound memory foam.
The pulse wave sensor array according to claim 8, wherein the number of the pulse wave sensors is 3, 4, 5, 6, 7, 8, 9, or 10.
A pulse wave measurement method includes the following steps:

Sensing a pulse wave by a flexible piezoelectric sensor and generating an electrical signal;

The static pressure exerted on the pulse wave sensor is sensed by a static pressure sensor over a large pressure range.
The pulse wave measuring method according to claim 11, wherein the static pressure sensor is a MEMS sensor, a piezoresistive film sensor, or a strain gauge type sensor.
The pulse wave measuring method according to claim 11, wherein the flexible piezoelectric sensor is a piezoelectric pressure sensor, and the piezoelectric material is made of PVDF, PZT or BaTiO 3 material.
The pulse wave measuring method according to claim 11, wherein the flexible piezoelectric sensor is a flexible thin film sensor.