CN112120679A

CN112120679A - Pulse detection equipment and manufacturing method thereof

Info

Publication number: CN112120679A
Application number: CN201910547904.9A
Authority: CN
Inventors: 方鹏; 彭雨辉; 林宛华; 李光林
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2020-12-25

Abstract

The invention provides pulse detection equipment and a manufacturing method thereof. The pulse detection equipment comprises a sensing unit, a supporting structure and a data processing unit, wherein the sensing unit comprises a flexible piezoelectric electret film, two metal electrodes which are respectively arranged on the upper surface and the lower surface of the flexible piezoelectric electret film, and a packaging protective layer which is wrapped with the flexible piezoelectric electret film with the two metal electrodes; the sensing unit is arranged on the supporting structure; the data processing unit is connected with the two metal electrodes arranged on the flexible piezoelectric electret film and used for receiving the electric charge quantity variation output by the two metal electrodes, determining the electric potential variation according to the electric charge quantity variation and sending the electric potential variation to the data receiving terminal. The pulse detection equipment can accurately measure the pulse wave, is convenient to embed into daily supplies, and realizes real-time measurement.

Description

Pulse detection equipment and manufacturing method thereof

Technical Field

The invention relates to the technical field of medical instruments, in particular to pulse detection equipment and a manufacturing method thereof.

Background

Blood flows into the aorta via systole, where it is then transmitted to the systemic arteries. The artery is a conduit formed by elastic connective tissue and muscle, when a large amount of blood enters the artery, the pressure of the artery is increased to expand the caliber, and the artery at a shallow part of the body surface can feel the expansion, namely the pulse. As an information carrier closely related to cardiovascular activities, the pulse waves store abundant pathological and physiological information of the cardiovascular system, and the understanding of the information is helpful for diagnosing the state of an illness and provides great convenience for diagnosing the physiological health.

The detection structure for measuring the pulse wave based on the piezoelectric electret flexible sensing can provide original data, and can also obtain the physical quantity related to the pulse and the information related to the human physiological health through the information, thereby being more beneficial to clinical research and analysis application. These quantities of information typically include: elasticity of the artery; the size of the lumen; density and viscosity of blood; pulse Wave Velocity (PWV), which is the pressure wave velocity propagated along the wall of the aorta generated by the ejection of blood from the heart each time, is a simple, effective and economical non-invasive index for evaluating the stiffness of the artery blood vessel, can comprehensively reflect the damage of various risk factors to the blood vessel, and is an independent prediction factor of cardiovascular events; chronic stress; aging of blood vessels; impaired cardiac stability; a pulse wave pressure index; a pulse wave viscosity index; pulse beating index and pulse perfusion variability index.

The research on the pulse wave information is widely applied to various fields, such as biomechanics, medical clinics, rehabilitation engineering, engineering analysis, physical training, wearable equipment and the like, and has important scientific significance and application value. In order to make the pulse wave detection structure not only be used for research, but also be put into practical application (such as wearing on the person, measuring in real time, etc.), certain conditions must be met: the sensor has high sensitivity and can detect the weak signal of pulse; the sensor has stable performance, good repeatability and durability; the anti-interference capability is strong, the thermal stability is high, and the hysteresis effect is small; the capacity of resisting external interference is strong, and external noise and interference of human body movement to signals are prevented; the requirement on the use condition is not high, the measurement structure is simple and easy to use, and the result is accurate; the manufacturing cost is low, and the large-scale production and manufacturing can be realized.

The pulse wave signal is used as an important vital sign signal, and at present, the two measurement technical schemes are mainly adopted as follows: 1) the method comprises the steps of detecting a pulse signal by a projection or correlation type photoelectric method by means of a photoelectric means through volume pulse waves, emitting a beam of light by using an emitting tube, receiving the projected or correlation signal by a photosensitive diode through an artery, generating weak pulse current, and converting and amplifying the weak pulse current through a subsequent signal to obtain a pulse wave waveform. 2) The piezoresistive pulse sensor adopts piezoresistive material as a sensing unit, a probe of the sensor is attached to a place where arterial pulsation is stronger, resistance value of the piezoresistive material changes after deformation of the piezoresistive material caused by the pulse pulsation, and a resistance value change curve is drawn to obtain pulse waveform.

In the existing pulse wave detection technology, for a photoelectric pulse detection method, the detection process is easily influenced by ambient light, so that the detection result is inaccurate, the detection principle is that the change of light transmittance is detected when blood flows through, the signal is very weak, the body hair and the blood vessel hardness influence the detection process, the movement of bones, muscles and skin of a wrist can greatly influence the detection result, and the application field of the photoelectric pulse detection method has great limitation. For the piezoresistive pulse sensor, the sensing material is a pressure-sensitive material, the output response nonlinearity is difficult to obtain accurate data, the final output result is influenced by the close degree of the fit in the use process, the resistance value of the piezoresistive pulse sensor is influenced by the temperature, the sensing unit is seriously influenced by the ambient temperature and the skin surface temperature, the defects seriously influence the accuracy of the detection result, and in addition, the piezoresistive pulse sensor is generally used for detecting the magnitude of static force due to the poor dynamic performance of the piezoresistive pulse sensor and is not suitable for detecting the dynamic signal of pulse waves.

In recent years, a piezoelectric electret (Piezoelectret), a new flexible piezoelectric material, has attracted much attention. Piezoelectric electrets are a class of non-polar polymers that have some of the following characteristics: light in weight (tens to hundreds of milligrams), thin in thickness (tens to hundreds of microns); the material is soft, bendable and strong in processability; the sensitivity is high, and the piezoelectric coefficient can reach 600 pC/N; basically has no pyroelectric effect, and the piezoelectric coefficient of the piezoelectric ceramic is less influenced by temperature within the working temperature range; the force sensor is sensitive to force in the vertical direction and insensitive to shearing force in the horizontal direction, and is very suitable for detecting front pressure without being influenced by material bending; the linearity of piezoelectric response is good; the material cost is low.

In summary, the sensing technology based on the piezoelectric electret can make up for the defects of the existing sensing method to a certain extent, and the invention aims to improve the existing technology and provide pulse detection equipment based on the piezoelectric electret.

Disclosure of Invention

The present invention is directed to overcome the above-mentioned drawbacks of the prior art and to provide a novel pulse detection device and a method for manufacturing the same.

According to a first aspect of the invention, a pulse detection device is provided. This pulse detection equipment includes sensing unit, bearing structure, data processing unit, wherein: the sensing unit comprises a flexible piezoelectric electret film, two metal electrodes and a packaging protective layer, wherein the two metal electrodes are respectively arranged on the upper surface and the lower surface of the flexible piezoelectric electret film, the packaging protective layer wraps the flexible piezoelectric electret film with the two metal electrodes, the packaging protective layer transmits a pulse signal to the flexible piezoelectric electret film from a monitoring point, and the two metal electrodes output charge variation when the flexible piezoelectric electret film deforms; the sensing unit is arranged on the supporting structure to provide a bonding force between a monitoring point and the sensing unit; the data processing unit is connected with the two metal electrodes arranged on the flexible piezoelectric electret film and used for receiving the electric charge quantity variation output by the two metal electrodes, determining the electric potential variation according to the electric charge quantity variation and sending the electric potential variation to the data receiving terminal.

In one embodiment, the supporting structure is a flexible silicone wrist pad, a hard gasket with one flat surface and the other surface provided with a cambered protrusion is embedded in the wrist pad, and the sensing unit is arranged on the cambered protrusion surface.

In one embodiment, the support structure to which the sensing unit is attached is embedded in a mouse pad, a chair armrest or a wearable device.

In one embodiment, two metal electrodes on the upper and lower surfaces of the flexible piezoelectric electret film are respectively provided with a lead, and the data processing unit and the sensing unit are connected through the leads.

In one embodiment, the flexible piezoelectric electret film is a single-layer porous film or a stack of multiple porous films in parallel or in series.

In one embodiment, the flexible piezoelectric electret film is circular or elliptical.

In one embodiment, the packaging protective layer comprises a first packaging protective layer and a second packaging protective layer which are respectively wrapped on the upper surface and the lower surface of the piezoelectric electret film with the metal electrodes, and the first packaging protective layer and the second packaging protective layer are made of flexible polymer materials.

In one embodiment, the flexible piezoelectric electret film is polypropylene, polyethylene terephthalate, polyethylene naphthalate.

According to a second aspect of the invention, a method of manufacturing a pulse detection device is provided. The method comprises the following steps:

the method comprises the steps of obtaining a flexible piezoelectric electret film with a preset shape, arranging metal electrodes on the upper surface and the lower surface of the flexible piezoelectric electret film respectively, outputting the quantity of charge change generated when the flexible piezoelectric electret film deforms through the metal electrodes, and wrapping the flexible piezoelectric electret film attached with the two metal electrodes by a packaging protective layer;

acquiring a support structure with a preset shape and attaching a sensing unit on the support structure;

and connecting the metal electrode with a data processing unit so that the data processing unit receives the electric charge quantity variation generated when the flexible piezoelectric electret film deforms from the metal electrode, determines the potential variation according to the electric charge quantity variation, and sends the potential variation to a data receiving terminal.

In one embodiment, the manufacturing method of the pulse detection device further includes obtaining a support structure with a preset shape, wherein the support structure is a flexible silica gel wrist pad, a plastic hard gasket with one flat surface and the other surface provided with a cambered protrusion is embedded in the wrist pad, and the sensing unit is arranged on the surface provided with the cambered protrusion.

Compared with the prior art, the invention has the advantages that: the pulse wave is detected by adopting a piezoelectric sensing principle, so that the pulse wave detector is more suitable for detecting dynamic pressure change, is not influenced by ambient light, and can be used in an environment with a complex light environment; by designing the wrist-supporting type supporting structure, the pulse can be measured in real time in daily life and work, and no additional detection equipment is needed to be worn; the sensing material used by the invention is easy for mass production and has low cost; in addition, the pulse detection equipment has wide application scenes and can be embedded into various wrist support structures to realize continuous pulse wave measurement.

Drawings

The invention is illustrated and described only by way of example and not by way of limitation in the scope of the invention as set forth in the following drawings, in which:

fig. 1 is a schematic view of a sensing unit in a pulse detection device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a support structure for a sensor in a pulse detection device according to an embodiment of the present invention;

fig. 3 shows a flow chart of a method of manufacturing a pulse detection device according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions, design methods, and advantages of the present invention more apparent, the present invention will be further described in detail by specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

According to an embodiment of the present invention, there is provided a pulse detecting device measuring a pulse wave based on a piezoelectric electret, including a sensing unit for sensing a pressure of a pulse measurement point, a support structure, and a data processing unit; the support structure is used for providing a supporting force for the sensing unit, so that the wrist and the sensing unit are attached more tightly, and pulse wave signals are transmitted to the sensing unit better; the data processing unit is connected with the sensing unit, provides functions of trapping and signal amplification, and further transmits the processed signals to the data receiving terminal for subsequent development and utilization.

Referring to fig. 1, a sensing unit in a pulse detection device according to an embodiment of the present invention includes a detection layer 200 (or piezoelectric sensing layer), a package protection layer 100, and a package protection layer 300.

Specifically, the detection layer 200 includes a flexible piezoelectric electret film 201 and two

metal electrodes

202 and 203 respectively disposed on the upper and lower surfaces of the flexible piezoelectric electret film 201, and one ends of the

metal electrodes

202 and 203 are respectively connected to

leads

204 and 205.

In one embodiment, the piezoelectric electret film 201 is a flexible material, including but not limited to various polymers such as Polypropylene (PP), Polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), and the like.

In one embodiment, the flexible piezoelectric electret film 201 is a closed film made of a piezoelectric electret and having a plurality of holes inside, and a large amount of positive and negative charges are deposited on the upper and lower surfaces of the holes, respectively.

In another embodiment, the flexible piezoelectric electret 201 is formed by stacking multiple porous films in a folding manner to enhance the overall piezoelectric coefficient and improve the signal-to-noise ratio.

The upper and lower surfaces of the flexible piezoelectric electret film 201 are provided with

metal electrodes

202 and 203 to obtain the charge variation generated when the flexible piezoelectric electret film 201 deforms, in order to better measure the charge variation generated when the flexible piezoelectric electret film of the piezoelectric sensing layer deforms, the two metal electrodes of the embodiment are both provided with

leads

204 and 205, and the metal electrodes on the upper and lower surfaces can be further connected with a charge amplifier (the charge amplifier can be arranged in the data processing unit) to convert the charge variation generated when the electret deforms into the voltage variation (or called potential variation). Under the action of pressure, the internal holes of the piezoelectric electret are compressed, the internal electric dipole moment density changes, the upper surface compensation charges and the lower surface compensation charges change, the surface electrodes lead out the changes of the surface charges, and force signals are converted into electric signals, namely, the flexible piezoelectric electret film 201, the

metal electrodes

202 and 203 on the upper surface and the lower surface of the flexible piezoelectric electret film, and the

leads

204 and 205 of the two metal electrodes form a piezoelectric sensor, so that force-electricity conversion is realized.

In the above embodiment, on one hand, the metal electrode can lead out a surface charge signal to a subsequent data processing unit, and on the other hand, the electrode on the surface of the flexible piezoelectric electret film material can form electromagnetic shielding for the interior of the material, so that the anti-electromagnetic interference capability of the material is enhanced. Furthermore, the piezoelectric electret film with the metal electrode attached to the surface is packaged and wrapped by a flexible polymer material through a thermoplastic method, so that the damage to the film material and the falling-off of the metal electrode in the use process are prevented.

Alternatively, the flexible piezoelectric electret film 201 may be cut into a circular or elliptical shape, which shape facilitates the flexible piezoelectric electret film to conform.

The packaging protective layer 100 and the packaging protective layer 300 are used for wrapping the sensing unit, and the protective layer material includes, but is not limited to, waterproof flexible material such as Polyvinyl chloride (pvc).

In the embodiment of the invention, the provided pulse detection device further comprises two protective layers made of flexible filler, the two protective layers are respectively arranged on the upper surface and the lower surface of the detection layer and wrap the whole detection layer, and the packaging protective layer is used for transmitting pulse signals to the piezoelectric sensing layer from the surface of the skin of a human body and realizing impedance matching between a pulse signal transmission path and the piezoelectric sensing layer.

The packaged sensing unit can be arranged in a sensor support structure, see the wrist-supported support structure shown in fig. 2, the wrist-supported structure 400 is filled with silica gel, and is embedded with a hard gasket 500 with one flat surface and a protruding radian on the other surface, and then the sensing unit 600 is attached to the gasket. When the wrist support is placed at a proper position of the wrist support, the pulse wave signals formed by the propagation of the heart pulsation to the periphery along arterial blood vessels and blood flow can be detected, and the wrist and the sensing unit can be attached more tightly by a certain radian structure, so that the pulse wave signals are better transmitted to the sensing unit.

The data processing unit (not shown in the figure) is connected with the sensing unit through a lead, provides trapping and signal amplification functions, and transmits the processed signals to a terminal for subsequent development and utilization.

In one embodiment, the data processing unit comprises a flexible circuit board and a battery connected with the flexible circuit board, the flexible circuit board is connected with leads of the two metal electrodes to receive the charge quantity variation generated by the two metal electrodes when the flexible piezoelectric electret film deforms, and the potential variation is determined according to the charge quantity variation.

Further, the data processing unit can send the potential variation to a data receiving terminal in a wired or wireless communication mode, and the data receiving terminal can be a special pulse data receiving device and can also be an intelligent device such as a mobile phone. The specific connection mode between the data processing unit and the data receiving terminal belongs to the prior art, and is not described herein again.

The pulse detection equipment provided by the embodiment of the invention can be placed at the radial artery of the wrist when working, and is used for detecting pulse wave signals formed by the propagation of the pulsation (vibration) of the heart to the periphery along arterial blood vessels and blood flow, and the pulse wave signals are specifically as follows: with this pulse check out test set be fixed in wrist radial artery department, the pulse is when beating, make the encapsulation protective layer with skin contact produce the vibration, and then make the detection layer of parcel in the protective layer produce the vibration, when the detection layer vibrates, the porous structure of flexible piezoelectricity electret film is compressed, inside electric dipole moment density changes, arouse it, compensation charge in the lower surface metal electrode changes, two metal electrodes are connected to the data processing unit, and obtain the electric charge amount variation that flexible piezoelectricity electret film produced when deformation through two metal electrodes, and confirm the electric potential variation according to this electric charge amount variation, and then send the electric potential variation to data receiving terminal, data receiving terminal confirms pulse vibration signal according to the electric potential variation.

It should be noted that the pulse detection device of the present embodiment can be placed in the radial artery, brachial artery, carotid artery, dorsalis pedis artery, femoral artery, and the like. The different pulse measuring points have different pressure energy caused by pulse beating, the corresponding pulse detecting equipment has different fitting tightness degrees with different measuring points, and the signal to noise ratios of the collected signals are different, so that the pulse measuring points can be selected according to specific application scenes during actual pulse detection. Generally, the radial artery of the wrist of a human body is used as a pulse detection position. Besides the signal detection of the human body pulse wave, the sensing unit provided by the invention can be used for other purposes such as heart sound measurement, voice acquisition and the like.

In summary, according to the pulse detection device provided by the present invention, the piezoelectric electret film is structurally designed and packaged according to the material characteristics of the piezoelectric electret, and is made into an effective sensing unit, the sensing unit is attached to the wrist-support-type support structure, the sensing unit is used to collect pulse wave signals, and finally the signals are sent to the terminal device through the data processing unit. Through the design of the wrist support structure, the sensing unit can be embedded into daily living goods (a mouse pad, a seat armrest and the like), and the sensing unit is packaged by flexible materials, so that the service life of the sensing unit is remarkably prolonged while the sensing performance is ensured.

Correspondingly, the invention also provides a manufacturing method of the pulse detection device, which is shown in fig. 3 and comprises the following steps:

step S310, obtaining a flexible piezoelectric electret film in a preset shape, respectively arranging metal electrodes on the upper surface and the lower surface of the flexible piezoelectric electret film, and wrapping the flexible piezoelectric electret film attached with the metal electrodes with a packaging protective layer to form a sensing unit.

For example, metal electrodes are respectively arranged on the upper surface and the lower surface of the flexible piezoelectric electret film, and the flexible piezoelectric electret film attached with the two metal electrodes is wrapped by a packaging protective layer, wherein the packaging protective layer comprises a first protective layer and a second protective layer, and the upper surface and the lower surface of the flexible piezoelectric electret film attached with the metal electrodes are respectively arranged, so that the flexible piezoelectric electret film, the two metal electrodes and the packaging protective layer form a piezoelectric sensing unit to realize force-electricity conversion.

And step S320, connecting the metal electrode on the flexible piezoelectric electret film with a data processing unit.

Furthermore, a wire is attached to the metal electrode on the flexible piezoelectric electret film and is connected with the data processing unit through the wire.

Step S330, obtaining a support structure with a preset shape, and attaching the sensing unit to the support structure.

For example, the support structure with the preset shape is a wrist support type support structure and is filled with silica gel, one side of the support structure is embedded to be flat, the other side of the support structure is provided with a hard gasket protruding in a certain radian, a sensing unit is attached to the gasket, the wrist and the sensing unit can be attached more tightly by arranging the certain radian structure, and the wrist support type structure design facilitates embedding of the pulse detection equipment into daily supplies to realize real-time measurement.

Experiments prove that the pulse detection equipment can obtain high-quality pulse wave signals, and has the advantages of simple measurement method and stable signals. The pulse wave measurement method can be particularly applied to the following fields:

1) biomechanical study: although the term biomechanics was developed in the 60's of the 20 th century, some of the concerns remain an ancient topic. For example, galileo obtained a quantitative relationship between the pulse length and the period before and after 1582 years, measured the pulse rate of a person using the pulse, and expressed the pulse rate by the pulse length in time with the pulse.

2) Clinical research and application: there are many clinical diseases, especially heart diseases, which can cause pulse changes, so measuring pulse is an indispensable examination item for patients. In the cardiac cycle, the vessels are cyclically dilated and returned to the heart by alternating contraction and relaxation of the ventricles. The critical condition, especially the number of pulses before the end and the pulse rate, will change significantly. The pulse variation is also one of the basis for the doctor to diagnose the patient.

3) And rehabilitation medicine: the physiological sign information of the patient is detected, and the rehabilitation training is carried out more scientifically and meticulously.

4) And statistical analysis: through statistical analysis, the relationship between the pulse wave characteristic parameters and various physiological factors influencing the parameters is analyzed.

5) And physical training: various physiological and pathological information of the human body can be extracted by checking the pressure and waveform changes of the pulse wave. The use of pulse wave shapes and characteristics (such as amplitude, period, and wave velocity) to assess the pathophysiological state of the cardiovascular system of the human body is a leading field of cardiovascular disease diagnosis. By analyzing cardiovascular multi-parameters of fitness people, a more effective scientific fitness guidance scheme is explored, pulse waves are used as important indexes for fitness evaluation, and the pulse wave acquisition, processing and analysis technology in a motion state is adopted, so that the automatic identification and fitness guidance system of the pulse waves is completed on the basis.

6) And the wearable device: a wearable device is a portable device that is worn directly on the body or integrated into the clothing or accessories of the user. The built-in pulse wave sensor detects pulse wave, and then transmits data to terminal equipment such as a mobile phone through wireless communication. The vital sign information of the user is obtained in real time by acquiring the pulse waveform and carrying out subsequent processing and analysis.

It should be noted that, although the steps are described in a specific order, the steps are not necessarily performed in the specific order, and in fact, some of the steps may be performed concurrently or even in a changed order as long as the required functions are achieved.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A pulse detection device, comprising a sensing unit, a support structure, a data processing unit, wherein:

the sensing unit comprises a flexible piezoelectric electret film, two metal electrodes and a packaging protective layer, wherein the two metal electrodes are respectively arranged on the upper surface and the lower surface of the flexible piezoelectric electret film, the packaging protective layer wraps the flexible piezoelectric electret film with the two metal electrodes, the packaging protective layer transmits a pulse signal to the flexible piezoelectric electret film from a monitoring point, and the two metal electrodes output charge variation when the flexible piezoelectric electret film deforms;

the sensing unit is arranged on the supporting structure to provide a bonding force between a monitoring point and the sensing unit;

the data processing unit is connected with the two metal electrodes arranged on the flexible piezoelectric electret film and used for receiving the electric charge quantity variation output by the two metal electrodes, determining the electric potential variation according to the electric charge quantity variation and sending the electric potential variation to the data receiving terminal.

2. The pulse detection device according to claim 1, wherein the support structure is a flexible silicone wrist pad, a hard pad having a flat surface and a curved protrusion is embedded in the wrist pad, and the sensing unit is disposed on the curved protrusion.

3. The pulse detection device according to claim 2, wherein the support structure to which the sensing unit is attached is embedded in a mouse pad, a seat armrest, or a wearable device.

4. The pulse detection device according to claim 1, wherein wires are provided on the two metal electrodes on the upper and lower surfaces of the flexible piezoelectric electret film, respectively, and the data processing unit and the sensing unit are connected via the wires.

5. The pulse detection device of claim 1, wherein the flexible piezoelectric electret film is a single-layer porous film or a stack of multiple porous films in parallel or in series.

6. The pulse detection device of claim 1, wherein the flexible piezoelectric electret film is circular or elliptical.

7. The pulse detection device according to claim 1, wherein the encapsulation protection layer includes a first encapsulation protection layer and a second encapsulation protection layer respectively wrapping upper and lower surfaces of the metal electrode piezoelectric electret film, and the first encapsulation protection layer and the second encapsulation protection layer are made of flexible polymer materials.

8. The pulse detection device of claim 1, wherein the flexible piezoelectric electret film is polypropylene, polyethylene terephthalate, polyethylene naphthalate.

9. A method of manufacturing a pulse detection device according to any one of claims 1 to 8, comprising the steps of:

10. The method of claim 9, further comprising obtaining a support structure of a predetermined shape, wherein the support structure is a flexible silicone wrist pad, and wherein a rigid plastic pad having a flat surface and a curved protrusion is embedded in the wrist pad, and the sensing unit is disposed on the curved protrusion.