CN211243337U

CN211243337U - Blood pressure flexible sensor with measuring point position fault-tolerant performance

Info

Publication number: CN211243337U
Application number: CN201920962995.8U
Authority: CN
Inventors: 刘伟庭; 马立新; 杨潮; 陈智鹏
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2020-08-14
Anticipated expiration: 2029-06-25

Abstract

The utility model discloses a blood pressure flexible sensor who possesses measuring point position fault-tolerant capability. The flexible bulge structure film layer is in close contact with the bottom of the rigid base, the flexible bulge structure film layer is provided with two independent film cavities which are not communicated with each other, and the film cavities are used as pressure transmission medium cavities; the two pressure sensitive units are arranged in the rigid base, two pressure guide holes are formed in the rigid base, the two pressure sensitive units are respectively arranged at one ends of the two pressure guide holes and are in sealed connection, the other ends of the two pressure guide holes are communicated with the two film cavities of the film layer with the flexible bulge structure, and pressure transmission silicone oil is filled in the film cavities and the pressure guide holes; the rigid base is also provided with two liquid injection holes and two air holes. The utility model is used for monitor wrist radial artery blood pressure in succession, guaranteed that the blood pressure beats the signal and spreads into the sensor high efficiency into, can obtain reliable and stable blood pressure signal, improved measurement accuracy, greatly improve and dress and experience, be applicable to continuous long-time blood pressure control.

Description

Blood pressure flexible sensor with measuring point position fault-tolerant performance

Technical Field

The utility model belongs to the technical field of the physiology monitoring sensor and specifically relates to a flexible interface blood pressure measurement sensor based on hydraulic pressure conduction has been designed, possesses measuring point position fault-tolerant ability, is particularly useful for wrist wearable blood pressure measuring device, can be used for monitoring wrist radial artery blood pressure in succession.

Background

Modern high and new technology is changing day by day, and the rapid development of the internet is facing the big data era of healthy life and national medical treatment. The nation also duly puts forward a national health medical promotion plan, and strongly supports the development of health care career. The development of the national medical treatment inevitably promotes the high-efficiency integration of medical resources, promotes the change of medical modes and reduces the huge burden of medical expenses. In this trend, the development of portable mobile data terminal acquisition devices (such as wearable real-time acquisition devices for basic physiological parameters) has become a hot spot due to the promotion of the demand of medical big data. Compared with the mature network technology, the lack of such physiological data terminals can be said to become a serious bottleneck restricting the medical development of big data. Although the commercialized health bracelet with fashionable appearance exists, the daily exercise condition of people can be recorded, and the sleep condition of people can be indirectly inferred through the motion monitoring of hands. Medical Holter systems (ambulatory ECG monitoring systems) exist for professional continuous ECG monitoring as well. It should be noted that no commercialized mobile data terminal which has good wearing comfort, does not influence the daily activities of people and is suitable for monitoring the human body physiological parameters continuously and in real time for a long time is available so far.

The blood pressure is one of basic physiological parameters of a human body, widely comprises various information of a circulatory system of the human body, can reflect the functional conditions of the heart and blood vessels of the human body, and moreover, the traditional Chinese medicine can treat patients by feeling pulse conditions, so that the arterial blood pressure is an important basis for clinically diagnosing diseases, observing treatment effects and carrying out prognosis judgment. The blood pressure of the human body changes along with the physiological cycle, the individual mood, the external and internal various stimuli, and has obvious fluctuation.

Because the blood pressure parameters are influenced by a plurality of factors such as physical conditions, environmental conditions, physiological rhythm and the like, the results of single measurement or intermittent measurement have larger difference, and the continuous measurement method can measure the blood pressure in each cardiac cycle, thereby having more important significance in clinical and medical research. Changes in blood pressure are associated with changes in sympathetic activity parallel to the normal sleep-wake cycle. For paroxysmal cardiovascular and cerebrovascular diseases, early morning blood pressure has very important significance. Pathophysiological and epidemiological studies have shown that: sudden cardiac death, acute myocardial infarction, cerebrovascular disease and stroke occur with increased probability in the morning. By continuous blood pressure monitoring, the premonitory symptoms can be found in time, and valuable time is won for patients and doctors to foresee the development of the disease.

Continuous blood pressure measurements can provide corresponding blood pressure fluctuation information, thereby providing a basis for the inference of sleep information and the diagnosis of sleep quality, stage and sleep disorders.

The existing mainstream noninvasive continuous blood pressure measuring method mainly comprises a volume compensation method, a photoplethysmography method, a pulse wave measuring method and the like. However, the above methods have their limitations, which severely limit the development of blood pressure measuring devices based on the above methods, and this is also the reason why no portable wearable blood pressure measuring wristwatch is marketed so far. Although the volume compensation method is mature in technology, the comfort is poor, and due to the existence of a servo operation system, a measuring device becomes bulky and extremely complex and can only be used for clinical recumbent use. Although the related device of the photoplethysmography solves the problems of volume and wearing comfort, and related products exist in the market, the method has low blood pressure detection precision, and the accuracy of the measurement result is difficult to ensure, so the method is not recommended to be used by professional medical institutions. The pulse wave measurement method is also an existing relatively hot method, but the pulse wave measurement method excessively depends on a complex algorithm and an accurate physical model, the adaptability is not high, the equipment is complex, and the measurement precision can be seriously influenced by limb signals. The arterial tension method adopted by us is a blood pressure measuring method which is concerned and widely researched by more scholars, but a perfect sensor structure based on the method has no unified view.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem existing in the background art, the utility model aims to provide a movable non-invasive continuous blood pressure monitoring and sensing device based on liquid pressure conduction.

The utility model discloses based on hydraulic pressure force conduction, used a novel flexible film protruding structure who encapsulates liquid silicone oil, adopted the artery tension method with absolute blood pressure of direct measurement, innovated blood pressure measuring device, improved blood pressure transducer position fault-tolerant capability, solved the difficult problem of blood vessel location; the flexible sensitive unit parallel array is added to endow the sensing device with the capability of determining the position of a blood vessel, a blood pressure correction algorithm is developed, not only can the radial artery blood pressure signal be directly obtained, but also a pulse wave propagation speed signal can be obtained; in the measurement, the light compression state of the artery is kept by adopting low external pressure with a fixed value, the pressure adjusting device is cancelled, the bloated structure is simplified, the wearing is more comfortable, the accuracy of the blood pressure output of the sensing device is ensured by a secondary correction algorithm, and the real-time continuous blood pressure measurement of the wrist strap type becomes possible.

As shown in fig. 1, the utility model adopts the technical scheme that:

the utility model comprises a flexible bulge structure film layer, a rigid base used for fixing the flexible film and reliably contacting with the flexible film, pressure transmission silicone oil with good temperature stability and low viscosity used for filling the tube cavity of the film, and a pressure sensitive unit arranged right above a pressure guide hole; the flexible bulge structure film layer is in close contact with the bottom of the rigid base, the flexible bulge structure film layer is provided with two independent film cavities which are not communicated with each other, and the film cavities are used as pressure transmission medium cavities; the two pressure sensitive units are arranged in the rigid base, two pressure guide holes are formed in the rigid base, the two pressure sensitive units are respectively arranged at one ends of the two pressure guide holes and are in sealed connection, the other ends of the two pressure guide holes are communicated with the two film cavities of the film layer with the flexible bulge structure, and pressure transmission silicone oil is filled in the film cavities and the pressure guide holes; the rigid base is also provided with two liquid injection holes and two air holes, one ends of the two liquid injection holes are communicated with an external liquid injection source from the top end of the rigid base, and the other ends of the two liquid injection holes are respectively communicated with the middle parts of the two pressure guide holes through respective internal channels of the rigid base; one end of each air hole extends out of the rigid base and is communicated with an external vacuum pump, and the other end of each air hole is communicated with the middle part of each pressure guide hole through the internal channel of the rigid base.

The bottom surface of the flexible convex structure film layer is a convex surface and is in contact with the skin of a human body.

The blood pressure detection flexible sensor is assembled on the watch body, the connecting line direction of the two pressure sensitive units is parallel to the trend of the radial artery of the wrist, the bulge structure of the flexible bulge structure film layer in the blood pressure detection flexible sensor is enabled to be attached to the surface layer of the skin under the action of the wrist strap of the watch, and the radial artery keeps a light compression state.

The utility model discloses the sensor whole set up two short distances, parallel arrangement's independent sensor unit of each other altogether, the medium that is formed by flexible film layer two parallels promptly holds the chamber, and two pressure sensitive units (4a) and (4b), two sensor units are unanimous along the trend of direction of arranging and wrist radial during the use for the flexible sensor of blood pressure can directly ingest radial artery blood pressure signal, can acquire pulse wave propagation velocity signal again.

The two pressure sensitive units (4a) and (4b) have the same structural composition, and signals of the two pressure sensitive units are processed according to a difference principle, so that the sensor becomes insensitive to pseudo signals brought by wrist muscle tissue movement, and the fault tolerance of the position of a measuring point is realized.

The whole blood pressure sensor can slightly press the bulge structure under the action of the wrist strap to keep the light pressing state of the artery, so that the radial artery blood pressure information is taken by utilizing an artery tension method and a blood pressure secondary correction algorithm, meanwhile, the pulse wave signal quality can be enhanced by paying attention to proper pressing force, the measurement result precision is improved, for example, the situation is best when the artery wall is just in a flat state due to the pressure, but the state can not be kept due to the fact that the pressure value applied by the wrist strap is not fixed and the individual and environment difference causes, and the state can bring great discomfort, so that the accurate blood pressure value can be obtained by slightly pressing and then correcting through the blood pressure secondary correction algorithm.

The wrist strap ensures that the bulge structure is pressed downwards, so that the radial artery is in a light compression state, a larger pulse wave signal amplitude is obtained, a signal is processed by an artery tension method to capture a blood pressure value, and the pressure value of the pressurizing device is fixed in a normal state.

A signal conditioning circuit module is arranged on the top of the rigid base and connected to the pressure sensitive unit, and signals collected by the pressure sensitive unit are directly output to the signal conditioning circuit module.

The pressure-sensitive sensor comprises a signal acquisition circuit module which is used for being connected with a pressure-sensitive unit and leading out signals acquired by the pressure-sensitive unit, wherein two ends of the signal acquisition circuit module are connected between the pressure-sensitive unit and a signal conditioning circuit module, and the signals acquired by the pressure-sensitive unit are output to the signal conditioning circuit module after being acquired by the signal acquisition circuit module.

The signal acquisition circuit module is connected with the pressure sensitive unit through an ultrasonic bonding technology by using a gold wire, so that the transmission efficiency and the reliability can be improved.

The utility model discloses be provided with on the rigid base of sensor and lead the pressure hole and be used for annotating liquid and pressure conduction, the base bottom can tightly laminate with the film simultaneously, and bottom surface machining roughness requires comparatively high.

The contact surfaces of the flexible protruding structure film layer and the rigid base are designed into groove structures in a semicircular groove shape, and the two groove structures are butted to form a complete circular channel groove to serve as a film cavity.

The bottom surface of the rigid base is provided with a groove structure in a semicircular groove shape, the flexible protruding structure film layer is in a flexible circular film pipe shape, the upper portion of the flexible circular film pipe and the groove structure in the semicircular groove shape of the rigid base are bonded through glue in a seamless attaching mode, and the lower portion of the flexible circular film pipe extends out of the groove structure of the rigid base, so that the semicircular flexible film protruding structure is formed.

The groove structure can be used as a part of the medium cavity, or the groove structure is attached to and wraps a part of the pipe wall, one side of the thin film pipe wall is exposed in a protruding mode, and the cross section of the groove can be semicircular, semi-elliptical or rectangular.

The flexible film layer with the protruding structure is used as a pressure transmission interface for blood pressure measurement, the outer side (bottom surface side) of the film is in contact with the skin, the inner side (top surface side) of the film is provided with a pressure transmission medium containing cavity, the protruding structure can be in a trapezoid shape, a semicircular shape or a tubular shape, and pulse signals are sensed and acquired through the contact of the flexible film protrusion and the skin above the radial artery.

The thickness of the flexible film layer is 100-500 mu m, and the flexible film layer is bent at any angle and is attached to the bottom surface of the rigid base.

The pressure transmission medium accommodating cavity is filled with the pressure transmission medium subjected to degassing purification treatment through the liquid injection hole in the rigid base, the pressure transmission medium is pressure transmission silicone oil with good temperature stability, low viscosity and no toxicity, the liquid incompressible characteristic of the pressure transmission medium and the good compliance performance of the flexible film layer and the liquid in the cavity ensure that the pressure applied to the flexible interface can be efficiently transmitted into the pressure transmission silicone oil, and the measurement error caused by the pressure application position deviation on the flexible film layer is weakened. And the characteristics of the liquid pressure transmission overcome the characteristics of elastic body stress attenuation and stress distribution nonuniformity, the fault-tolerant performance of the positioning deviation of the central position of the flexible sensor and the radial artery position is improved, the measurement accuracy is greatly enhanced, and the operation difficulty of wearing and mounting is weakened.

The rigid base is provided with a pressure guide hole and an air hole. The pressure guide hole is used for guiding pressure, and pressure change in the pressure transmission silicone oil is transmitted to the detection end of the pressure sensitive unit arranged above the base through the hole, so that a pulse pressure signal is obtained.

The air holes are mainly used for exhausting the cavity in the liquid injection process, so that the deformation and shrinkage of the film cavity in the vacuum liquid injection process are prevented, the cavity can be completely filled with silicon oil, gas residues in the cavity are prevented from being dissolved in the silicon oil, or bubbles are prevented from being attached to the bottom of the pressure sensitive unit, and the phenomenon that the measurement result of the pulse signal has large errors and the error causes are difficult to be checked is avoided.

Injecting liquid before starting to work, wherein the liquid injection hole and the air vent are not sealed by a sealing plug at the moment, the air vent is connected with a vacuum pump, the liquid injection hole is connected with a liquid source of silicon oil, the vacuum pump works to pump air, the silicon oil enters the pressure guide hole from the liquid injection hole and is filled with the pressure guide hole and the thin film cavity, then the vacuum pump and the liquid source are removed, and the liquid injection hole and the air vent are sealed by the sealing plug.

The film layer with the flexible convex structure is uniform in thickness and free of defects, and the preparation component of the film layer is a polymer material with good chemical inertness and biocompatibility, is non-toxic and tasteless, and does not cause any damage to the surface of an organism.

The sealing plug of the liquid injection hole and the air vent is made of a high-elasticity silica gel ball made of PDMS (polydimethylsiloxane) material, and the silica gel ball is sealed by glue after being placed in the hole.

The signal conditioning circuit module adopts a low-power consumption amplification chip, a low-voltage constant current source chip and a silicon-based pressure chip as a pressure sensitive unit.

Four strain gauges in the chip of the pressure sensitive unit form a resistor of a full-bridge circuit, so that the measurement sensitivity is improved, and the temperature drift effect is reduced.

The rigid base can be internally provided with a cavity, the signal acquisition circuit module is fixedly arranged in the cavity, or a circuit board of the signal acquisition circuit module is directly placed on the top of the base to reduce the height of the base.

The utility model discloses a basic operating principle is:

in a cardiac cycle, the side pressure of blood to an artery wall is correspondingly changed due to the change of the periodic blood flow generated by blood circulation, when a ventricle contracts, the blood flow rises, the pressure applied by the blood on the artery wall rises, and when the pressure reaches the highest value, the pressure is called systolic pressure; when the ventricles relax, the heart stops shooting blood, the artery wall retracts due to the elastic action, and the pressure applied to the artery wall by the blood is gradually reduced and is called the diastolic pressure when the pressure drops to the lowest value.

When the convex structure formed by the flexible film layer is contacted with the radial artery of the wrist, pressure change generated in the artery can penetrate through the artery wall, subcutaneous tissues and skin, so that pulse beating is formed, and the corresponding deformation of the film convex structure can be generated; because the medium containing cavity that the film formed is filled with incompressible conduction fluid, the transmission fluid can be extruded to the cavity film of deformation, according to pascal's theorem, the inside hydraulic pressure that forms of conduction fluid, is measured by the perception of silicon-based pressure sensing unit, and silicon-based pressure sensing unit turns into the mechanical wave signal of pulse and passes through inside gold thread, signal acquisition circuit module, FPCB transmission to subsequent conditioning circuit module.

When the relative position of the blood pressure sensor and the radial artery of the wrist generates deviation due to the movement of a user or the blood pressure sensor is not accurately positioned when the blood pressure sensor is initially worn by the user, but the length of the bulge structure is far greater than the diameter of the radial artery, a part of bulge still contacts with the artery under the condition of generating deviation, and according to the basic principle that pressure change of any part of static fluid in a closed container in the Pascal principle is transmitted to all directions without weakening, a blood pressure signal can still be accurately sensed and measured by a silicon-based sensitive unit to obtain a corresponding electric signal, so that the position fault tolerance performance of the blood pressure sensor is ensured.

The utility model is suitable for a wrist blood pressure flexible transducer is not created to wearing formula under the general daily activity intensity of human body.

The utility model has the advantages that:

the utility model discloses an its signal acquisition mode is based on the fluid pressure conduction, and above-mentioned sensor absorbs radial artery blood pressure information above being fixed in the radial artery between radial arch and the wrist tendon under wrist strap packing force effect during the use.

The utility model discloses the compliance of flexible interface has guaranteed that blood pressure beats the signal and has spread into the sensor high efficiency into, even receive and also can obtain reliable and stable blood pressure signal under the condition that operation deviation appears in artery and sensor central point position, improved measurement accuracy, flexible material can also guarantee contact site's safety and travelling comfort, greatly improves and dresses experience, is applicable to continuous long-time blood pressure monitoring.

The utility model adopts the flexible film bulge structure with the liquid filling cavity to enlarge the measuring range of the blood pressure monitoring device and effectively enhance the position fault tolerance when the blood pressure monitoring device is worn; the position and the attaching force information are collected by the flexible sensitive unit parallel array and the attaching pressure sensitive element, and the accuracy of blood pressure measurement can be greatly improved by combining the stored correction data; the external pressure applied by the fixed wrist strap is adopted, the pressure adjusting device is omitted, the equipment structure is simplified, the cost is reduced, and the real-time continuous blood pressure accurate measurement of the wrist strap type becomes possible.

The pressure sensitive unit adopted by the utility model is a silicon-based pressure sensitive chip, which has high sensitivity, high precision, stable and reliable performance, mature manufacturing process and low cost; due to the adoption of the liquid conduction principle, the silicon-based pressure sensitive unit is far away from a direct pressure area and is not easy to damage.

The whole structure of sensor is compact, the miniaturized design of being convenient for adopts flexible film and wrist contact simultaneously, very big improvement people's wearing experience, this provides new power for wearing formula blood pressure measurement equipment's popularization.

Drawings

Fig. 1 is a schematic view of the cross-sectional three-dimensional structure of the present invention;

fig. 2(a) is a schematic perspective view of a trapezoidal protrusion structure in example 1 of the present invention;

fig. 2(b) is a schematic perspective view of a semicircular convex structure in example 1 of the present invention;

fig. 3 is a schematic perspective view of embodiment 2 of the present invention;

fig. 4 is a schematic perspective view of embodiment 3 of the present invention;

fig. 5 is a schematic view of the split structure of the present invention;

FIG. 6 is a schematic cross-sectional view of a trapezoidal membrane chamber of the present invention;

fig. 7 is a schematic diagram of the working principle.

FIG. 8 is a diagram showing the structure of a membrane in example 2.

FIG. 9 is a diagram showing the structure of a membrane in example 3.

In the figure: 1. the sensor comprises a rigid base, 2, a flexible bulge structure thin film layer, 3, a liquid injection hole, 4, a pressure sensitive unit, 5, a pressure guide hole, 6, an air hole, 7, pressure transmission silicon oil, 8, a signal conditioning circuit module, 9, a sealing plug, 10, a groove structure, 11, a flexible circular film tube, 12 and a signal acquisition circuit module.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

Example 1

As shown in fig. 1 and fig. 2, the present embodiment includes a pressure transmission film 2 with a flexible convex structure, a rigid base 1 for fixing the flexible film and making reliable contact with the film, pressure transmission silicone oil 7 with good temperature stability and low viscosity for filling a film layer medium cavity, a pressure sensitive unit 4, a signal acquisition circuit module 12, and a pulse signal conditioning circuit module 8.

The flexible bulge structure film layer 2 is closely contacted with the bottom of the rigid base 1, glue is uniformly coated on the bottom of the rigid base 1 in advance, and the fixed connection and sealing of the flexible bulge structure film layer and the rigid base are ensured; the flexible bulge structure film layer 2 is provided with two independent film cavities which are not communicated with each other, and the film cavities are used as pressure transmission medium cavities.

The two pressure sensitive units 4 are arranged in the rigid base 1, two pressure guide holes 5 are formed in the rigid base 1, the two pressure sensitive units 4 are respectively arranged at one ends of the two pressure guide holes 5 and are connected in a sealing mode, particularly, the connection part of the pressure sensitive units 4 and the pressure guide holes 5 is sealed on the periphery on the premise that the pressure sensitive units 4 are not affected, the other ends of the two pressure guide holes 5 are communicated with the two film cavities of the flexible bulge structure film layer 2, and pressure transmission silicone oil 7 is filled in the film cavities and the pressure guide holes 5; the specific implementation is that a through groove is arranged on the surface of the flexible convex structure film layer 2 contacted with the bottom of the base 1, and the film cavity is communicated with the pressure guide hole 5 through the through groove.

The rigid base 1 is provided with a pressure guide hole 5, a liquid injection hole 3 and an air vent 6 for conducting pressure and vacuum liquid injection. One end of each of the two liquid injection holes 3 is communicated with an external liquid injection source from the top end of the rigid base 1, and the other end of each of the two liquid injection holes 3 is communicated with the middle parts of the two pressure guide holes 5 through respective internal channels of the rigid base 1; one end of each of the two air holes 6 extends out of the rigid base 1 and is communicated with an external vacuum pump, and the other end of each of the two air holes 6 is communicated with the middle parts of the two pressure guide holes 5 through respective internal channels of the rigid base 1.

The bottom surface of the flexible convex structure film layer 2 is a convex surface, and the flexible convex structure film layer 2 is higher than the surface of the rigid base 1 in a convex mode and is in contact with the skin of a human body. The protrusions of the flexible film 2 may be formed in a trapezoidal shape or a semicircular shape, as shown in fig. 2(a) and 2(b), respectively.

The film cavity formed by the film layer 2 with the flexible protruding structure is used as a pressure transmission medium cavity and is communicated with the pressure guide hole 5, as shown in fig. 6, pressure transmission oil 7 is filled in the film cavity, the film layer 2 and liquid oil medium sense pulse pressure, the pressure change of the liquid oil medium is transmitted to the pressure sensitive unit 4 through the pressure guide hole 5, and finally the pulse pressure change is collected by the sensitive unit 4.

The liquid injection hole 3 and the air holes 6 are sealed by a sealing plug 9 after the liquid injection of the pressure conduction oil liquid 7 is finished, the pressure sensitive unit 4 is placed right above the pressure guide hole 5, and the periphery of the pressure sensitive unit 4 is sealed on the premise of not influencing the pressure sensitive unit 4.

A cavity is arranged in the rigid base 1, and the signal acquisition circuit module 12 is fixedly arranged in the cavity. A signal conditioning circuit module 8 for processing pulse signals is arranged at the top of the rigid base 1, the signal conditioning circuit module 8 is connected to the pressure sensitive unit 4 through a signal acquisition circuit module 12, and signals sensed by the pressure sensitive unit 4 are output to the signal conditioning circuit module 8 through a circuit board of the signal acquisition circuit module 12. The bonding pad of the signal acquisition circuit module 12 is connected with the electrode of the pressure sensitive unit 4 by a gold wire through an ultrasonic bonding technology, and the signal acquisition circuit module 12 is connected with the signal conditioning module 8 through the FPBC.

Example 2

As shown in fig. 1 and fig. 3, the present embodiment includes a pressure transmission film 2 with a flexible convex structure, a rigid base 1 for fixing the flexible film and making reliable contact with the film, a pressure transmission silicone oil 7 with good temperature stability and low viscosity for filling a dielectric cavity of the film layer, a pressure sensitive unit 4 and a pulse signal acquisition circuit module 12.

The flexible protruding structure thin film layer 2 is processed into a semi-tubular shape, the flexible protruding structure thin film layer 2 is in close contact with the bottom of the rigid base 1, the contact surfaces of the flexible protruding structure thin film layer 2 and the rigid base 1 are provided with groove structures 10 in a semi-circular groove shape, and the two groove structures 10 are in butt joint to form a complete circular channel groove serving as a film cavity and a medium accommodating cavity. Glue is uniformly coated on the bottom of the rigid base 1 in advance, so that the rigid base 1 and the flexible raised structure film layer 2 are fixedly connected and sealed.

The two pressure sensitive units 4 are arranged at the top of the rigid base 1, two pressure guide holes 5 are formed in the rigid base 1, the two pressure sensitive units 4 are respectively arranged at one ends of the two pressure guide holes 5 and are connected in a sealing mode, particularly, the connection part of the pressure sensitive units 4 and the pressure guide holes 5 is sealed on the periphery of the pressure sensitive units 4 on the premise that the pressure sensitive units 4 are not affected, the other ends of the two pressure guide holes 5 are communicated with the two film cavities of the flexible bulge structure film layer 2, and pressure transmission silicone oil 7 is filled in the film cavities and the pressure guide holes 5; the specific implementation is that the cavity formed by the film layer 2 with the flexible raised structure and the base 1 is directly communicated with the pressure guide hole 5 without any structure.

The film cavity formed between the flexible protruding structure film layer 2 and the bottom of the rigid base 1 serves as a pressure transmission medium containing cavity and is communicated with the pressure guide hole 5, as shown in fig. 6, based on the same principle of the trapezoidal protruding structure, pressure transmission oil 7 fills the film cavity, the film layer 2 and liquid oil medium sense pulse pressure, the pressure change of the liquid oil medium is transmitted to the pressure sensitive unit 4 through the pressure guide hole 5, and finally the pulse pressure change is collected by the sensitive unit 4.

A signal acquisition circuit module 12 for acquiring and transmitting pulse current signals is arranged at the top of the rigid base 1, the signal acquisition circuit module 12 is connected to the pressure sensitive unit 4 through a gold wire, and current signals induced by the pressure sensitive unit 4 are output to the signal conditioning circuit module 8 through the acquisition circuit module 12.

Example 3

As shown in fig. 1 and 4, the present embodiment includes a flexible circular membrane tube 11 evolved from a flexible convex structure pressure transmission membrane 2 with a certain convex shape, a rigid base 1 for fixing the flexible membrane and reliably contacting with the membrane, pressure transmission silicone oil 7 with good temperature stability and low viscosity for filling a membrane layer medium cavity, a pressure sensitive unit 4 and a pulse signal acquisition circuit module 12.

The groove structure 10 of semicircle groove form is seted up to the bottom surface of rigid base 1, and flexible protruding structure thin layer 2 is flexible circular membrane pipe 11 form and as the film chamber, and the groove structure 10 of the semicircle groove form of flexible circular membrane pipe 11 upper portion and rigid base 1 passes through the seamless laminating of glue and bonds, and flexible circular membrane pipe 11 lower part extends the groove structure 10 of rigid base 1 to form the protruding structure of flexible membrane of semicircle form. Thin glue is uniformly coated on the inner surface of the groove structure 10, the outer surface of the upper part of the flexible circular membrane tube 11, which is formed with a medium accommodating cavity by the flexible circular membrane tube, is just in close contact with the groove wall of the groove structure 10 and is in seamless joint with the groove wall, and the lower part of the flexible circular membrane tube 11 protrudes out of the bottom surface of the rigid base 1, so that a semicircular flexible membrane protruding structure is formed.

The two pressure sensitive units 4 are arranged at the top of the rigid base 1, two pressure guide holes 5 are formed in the rigid base 1, the two pressure sensitive units 4 are respectively arranged at one ends of the two pressure guide holes 5 and are connected in a sealing mode, particularly, the connection part of the pressure sensitive units 4 and the pressure guide holes 5 is sealed on the periphery of the pressure sensitive units 4 on the premise that the pressure sensitive units 4 are not affected, the other ends of the two pressure guide holes 5 are respectively communicated with one end of a flexible circular membrane tube 11, and pressure transmission silicone oil 7 is filled in a membrane cavity and the pressure guide holes 5; the two flexible circular membrane tubes 11 are respectively and specifically implemented to form a medium containing cavity and are filled with pressure transmission silicone oil 7, no structure is needed, and the pressure guide hole 5 is directly communicated with the containing cavities.

The film cavity directly formed by the flexible circular film tube 11 is used as a pressure transmission medium containing cavity and is communicated with the pressure guide hole 5, as shown in fig. 6, based on the principle that the trapezoidal protrusion structures are the same, the pressure transmission oil 7 fills the film cavity, the film layer 2 evolves into the circular film tube 11, the pulse pressure is sensed by the flexible film tube wall and the medium, the medium pressure change is uploaded to the pressure sensing unit 4 through the pressure guide hole 5, and finally the sensing pulse pressure change is collected by the sensing unit 4.

Examples 2 and 3 can effectively reduce the height of the sensor structure, and have better practicability for the wearable blood pressure wristwatch with higher requirement on size, but example 1 is more suitable for research and analysis of the arterial tension method, and the structural schematic diagrams of examples 2 and 3 do not have the signal conditioning circuit module 8, because the module is placed outside the blood pressure sensor module in the two implementations, but is still connected with the signal acquisition circuit module 12 through the longer FPBC.

As shown in fig. 5, the sensor module in embodiment 1 is taken as an example for disassembly, which shows the approximate positional relationship among the components, and includes, from top to bottom, a signal conditioning circuit module 8, a signal acquisition circuit module 12, a sealing plug 9, a pressure sensitive unit 4, a rigid base 1, and a flexible film layer 2 with a convex structure.

As shown in fig. 7, a schematic diagram of the blood pressure sensor in a working state is shown, specifically, the flexible blood pressure sensor can be assembled on a watch body, a connection line direction of two pressure sensitive units 4 is parallel to a direction of a radial artery of a wrist, a protrusion structure of a flexible protrusion structure film layer 2 in the flexible blood pressure sensor is made to be attached to a skin surface layer under the action of a wrist strap of the watch, and the radial artery is kept in a light compression state. When the sensor is used, the two sensor units are consistent with the trend of the radial artery of the wrist along the arrangement direction, so that the blood pressure flexible sensor can directly pick up the blood pressure signal of the radial artery and can also acquire the pulse wave propagation speed signal.

Fig. 8 and 9 show the difference in the structure of two membranes in examples 2 and 3, one being semi-tubular and the other tubular.

The utility model discloses a preparation and working process as follows:

the sealing plug is designed into a rubber ball with the size matched with that of the hole and is made of PDMS material.

The rigid base 1 is manufactured by a 3D printing method because it has a complicated internal structure and is not suitable for general machining because of the provision of the liquid injection hole 3, the pressure guide hole 5, and the air vent 6.

The pressure sensitive unit 4 is placed right above the pressure guide hole 5, fixed and bonded with the rigid base 1 by adopting specific glue to ensure the sealing performance of the pressure sensitive unit, and the signal acquisition circuit module is connected with the electrode of the silicon-based sensitive element by gold thread by adopting a wire bonder and utilizing an ultrasonic welding technology.

The flexible thin film layer 2 is made of PDMS materials, the shape is prepared through a mold injection molding process, and the flexibility degree of the surface of the flexible thin film layer 2 of the sensor is adjusted by adjusting the proportion of the PDMS main agent and the auxiliary agent.

Adhere the flexible thin film layer 2 that step 4 obtained and the sensor subassembly that step 3 obtained, guarantee the sealing between thin film layer 2 and the rigid substrate 1, form the medium and hold the chamber, whole vacuum chamber of putting into carries out evacuation processing, annotate liquid hole 3 and let in pressure transmission silicon oil 7, make the cavity in be full of silicon oil, the injection of assurance silicon oil that the existence of bleeder vent 6 can be better, annotate the liquid and accomplish the back and take out the subassembly, seal liquid hole 3 and bleeder vent 6 with sealing plug 9 and seal, guarantee the leakproofness of final cavity and can not contain the bubble, finally accomplish the utility model discloses position fault-tolerant blood pressure sensor's preparation.

When the device works, when the convex structure formed by the flexible film layer 2 is contacted with the radial artery of the wrist, pressure change generated in the artery can penetrate through the artery wall, subcutaneous tissues and skin, so that what we say, pulse beat is formed, and the corresponding deformation of the convex structure of the film can be generated; because the medium that thin layer 2 formed holds the chamber and is filled with incompressible conduction fluid 7, the transmission fluid 7 can be extruded to the cavity thin layer 2 of deformation, according to pascal's theorem, the inside hydraulic pressure that forms of conduction fluid, by the perception measurement of silicon-based pressure sensing unit 4, silicon-based pressure sensing unit 4 turns into the mechanical wave signal of pulse and passes through inside gold thread with the signal of telecommunication, signal acquisition circuit module 12, transmit to subsequent conditioning circuit module 8 by the FPCB, follow-up correlation between pulse signal and the blood pressure value of utilizing, adopt outside third party software can obtain human blood pressure value.

When the relative position of blood pressure sensor and wrist radial artery produce the deviation because user's motion, perhaps the user does not pinpoint when wearing initially, nevertheless because protruding structure length is greater than the diameter of radial artery far away, still can be contacted with the artery by partial arch under the circumstances that produces the deviation, according to the pressure variation that any part of static fluid in the closed container takes place in the pascal principle, will not weaken this basic principle of ground to each direction transmission, blood pressure signal still can be accurate still be measured by the perception of silica-based sensitive unit 4, obtain corresponding signal of telecommunication, thereby fine assurance this utility model blood pressure sensor's position fault tolerance performance.

Therefore, the implementation is visible, the utility model discloses position fault tolerance when blood pressure monitoring device wears can effectively have been strengthened, blood pressure measurement's accuracy can be improved, equipment structure is simplified, reduce cost is suitable for extensively.

The above-mentioned specific embodiments are provided for explaining the present invention, and are not intended to limit the present invention, and any modifications and changes made by the present invention are within the spirit and scope of the claims of the present invention.

Claims

1. The utility model provides a flexible sensor of blood pressure that possesses fault-tolerant performance in measuring point position which characterized in that: the pressure sensitive device comprises a flexible bulge structure film layer (2), a rigid base (1) used for fixing a flexible film and reliably contacting the flexible film, pressure transmission silicone oil (7) used for filling a film tube cavity, good in temperature stability and low in viscosity, and a pressure sensitive unit (4) placed right above a pressure guide hole (5); the flexible bulge structure film layer (2) is in close contact with the bottom of the rigid base (1), the flexible bulge structure film layer (2) is provided with two independent film cavities which are not communicated with each other, and the film cavities are used as pressure transmission medium cavities; the two pressure sensitive units (4) are arranged in the rigid base (1), two pressure guide holes (5) are formed in the rigid base (1), the two pressure sensitive units (4) are respectively arranged at one ends of the two pressure guide holes (5) and are connected in a sealing manner, the other ends of the two pressure guide holes (5) are communicated with two film cavities of the flexible raised structure film layer (2), and pressure transmission silicone oil (7) is filled in the film cavities and the pressure guide holes (5); the rigid base (1) is also provided with two liquid injection holes (3) and two air holes (6), one ends of the two liquid injection holes (3) are communicated to an external liquid injection source from the top end of the rigid base (1), and the other ends of the two liquid injection holes (3) are respectively communicated to the middle parts of the two pressure guide holes (5) through respective internal channels of the rigid base (1); one end of each of the two air holes (6) extends out of the rigid base (1) and is communicated with an external vacuum pump, and the other end of each of the two air holes (6) is communicated with the middle parts of the two pressure guide holes (5) through the internal channel of the rigid base (1).

2. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the bottom surface of the flexible convex structure film layer (2) is a surface with a convex shape and is contacted with the skin of a human body.

3. The blood pressure flexible sensor with fault tolerance for measuring point positions according to claim 2, wherein: the blood pressure flexible sensor is assembled on a watch body, the connecting line direction of the two pressure sensitive units (4) is parallel to the trend of the radial artery of the wrist, the bulge structure of the flexible bulge structure film layer (2) in the blood pressure flexible sensor is tightly attached to the skin surface layer under the action of the wrist strap of the watch, and the radial artery keeps a compression state.

4. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: a signal conditioning circuit module (8) is arranged at the top of the rigid base (1), the signal conditioning circuit module (8) is connected to the pressure sensitive unit (4), and signals collected by the pressure sensitive unit (4) are directly output to the signal conditioning circuit module (8).

5. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the pressure-sensitive sensor comprises a signal acquisition circuit module (12) which is used for being connected with a pressure-sensitive unit (4) and leading out signals acquired by the pressure-sensitive unit (4), wherein two ends of the signal acquisition circuit module (12) are connected between the pressure-sensitive unit (4) and a signal conditioning circuit module (8), and the signals acquired by the pressure-sensitive unit (4) are output to the signal conditioning circuit module (8) after being acquired by the signal acquisition circuit module (12).

6. The blood pressure flexible sensor with fault tolerance for measuring point positions according to claim 5, wherein: the signal acquisition circuit module (12) is connected with the pressure sensitive unit (4) by a gold thread.

7. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the contact surface of the flexible protruding structure film layer (2) and the rigid base (1) is designed into a groove structure (10) in a semicircular groove shape, and the two groove structures (10) are butted to form a complete circular channel groove serving as a film cavity.

8. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the bottom surface of rigid base (1) set up groove structure (10) of half slot form, flexible protruding structure thin layer (2) are flexible circle membrane pipe (11) form, the groove structure (10) of the half slot form of flexible circle membrane pipe (11) upper portion and rigid base (1) bond through the seamless laminating of glue, the groove structure (10) of rigid base (1) are stretched out to flexible circle membrane pipe (11) lower part to form the protruding structure of flexible membrane of semicircle form.

9. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the thickness of the flexible bulge structure film layer (2) is 100-500 mu m, and the flexible bulge structure film layer is bent at any angle and is attached to the bottom surface of the rigid base (1).

10. The flexible blood pressure sensor with fault tolerance for the measurement point according to claim 1, wherein: the rigid base (1) is internally provided with a cavity, the signal acquisition circuit module (12) is fixedly arranged in the cavity, or a circuit board of the signal acquisition circuit module (12) is directly placed on the top of the base.