CN202036215U - Noninvasive artery pulse wave detection apparatus based on MEMS sensor technology - Google Patents

Abstract

Translated fromChinese

本实用新型涉及一种基于MEMS传感器技术的无创动脉脉搏波检测装置。本实用新型的目的是提供一种同步触发、实时记录并实现远传的基于MEMS传感器技术的无创动脉脉搏波检测装置，旨在提高临床诊断的准确性；可高速、实时记录数据而不用受计算机主机物理位置的限制；同步精度高、数据远传速率高、使用方便，费用合理。本实用新型的技术方案是：基于MEMS传感器技术的无创动脉脉搏波检测装置，其特征在于：该检测装置包括控制单元，以及分别与该控制单元电连接的传感器单元、数据记录单元、温度采集单元和通讯接口单元。本实用新型适用于检测人体浅表动脉（踝、桡、肱、颈、颞等）的脉搏波信号。

The utility model relates to a noninvasive arterial pulse wave detection device based on MEMS sensor technology. The purpose of this utility model is to provide a non-invasive arterial pulse wave detection device based on MEMS sensor technology that is triggered synchronously, records in real time and realizes remote transmission. The physical location of the host is limited; the synchronization accuracy is high, the data remote transmission rate is high, the use is convenient, and the cost is reasonable. The technical solution of the utility model is: a non-invasive arterial pulse wave detection device based on MEMS sensor technology, characterized in that: the detection device includes a control unit, and a sensor unit, a data recording unit, and a temperature acquisition unit electrically connected to the control unit respectively and communication interface unit. The utility model is suitable for detecting pulse wave signals of human superficial arteries (ankle, radial, brachial, cervical, temporal, etc.).

Description

A kind of noinvasive arterial pulse wave checkout gear based on the MEMS sensor technology

Technical field

This utility model relates to a kind of based on the MEMS(MEMS) the noinvasive arterial pulse wave checkout gear of sensor technology.Be applicable to the pulse wave signal of the shallow table tremulous pulse of human body (ankle, oar, the upper arm, neck, temporo etc.).

Background technology

The detection of the physical quantitys such as amplitude, waveform, the rhythm and pace of moving things and spread speed of the pulse signal that blood flow is produced when the arteries be noinvasive obtain important channel with the analyzing cardiovascular hemodynamic parameter.During blood flow intravascular that heart contraction pumps, the pressure that oppose side wall produces causes the blood vessel elasticity expansion.Under blood total capacity and the relatively stable situation of cardiac output of stroke volume, signature waveform and velocity of wave that skin displacement brief acceleration that shallow table arteriopalmus causes changes have directly reflected the indexs such as pulse pressure, dilatancy, compliance, stiffness index, elastic modelling quantity of blood vessel.

Current pick off that announced, that be used for the detection of the shallow table arterial pulse wave of human body signal noinvasive has piezoelectric type, pressure resistance type, photoelectricity positive displacement, laser position to detect formula, electret acoustic sensor formula.

The medium that is used for the signal transmission of pulse wave has air, rubber, water, rigid body etc.; Be used for pulse--the material of electrical signal energy conversion has pressure resistance type semi-conducting material, piezoquartz, PVDF(Kynoar) thin film, light-sensitive material etc.Be used for detecting the technology of pulse, with being most widely used of pressure resistance type pressure detecting method and photoelectricity volumetric method.

The operation principle of photoelectricity volumetric method is: under normal circumstances, acral tissue (soft tissues such as skeleton, muscle) is very little to specific optical transmission/reflection short term variations rate, and with acral biological tissue medium vessels net in the variation of the total blood volume that comprises can cause that optical transmission/reflectance changes synchronously.Because the rhythm and pace of moving things that total blood volume changes is consistent with aortal pulsation, therefore reflect some parameters of tremulous pulse with light Power Capacity method.And it has following some weak point, and at first it has directly reflected the arterial property of the detected scope of sensor light, with large artery trunks some difference is arranged still; Secondly factors such as ethanol, medicine, limb temperature also have considerable influence to the output result; Use (above 3 hours) to bring significant discomfort continuously to patient.

The operation principle of pressure resistance type pressure detecting method is: the electric bridge that adopts strain resistor to form, deformation cause the voltage signal and the proportional variation of pressure of exporting.Multiple factor is bonded in the adhesive properties of using on the flexible member such as sensing element, and the angle of pick off and contact point, admittedly the form of propping up, temperature coefficient all can cause the bigger distortion of output waveform.

Summary of the invention

The technical problems to be solved in the utility model is: a kind of synchronous triggering, real time record are provided and realize the noinvasive arterial pulse wave checkout gear based on the MEMS sensor technology of teletransmission, be intended to improve the accuracy of clinical diagnosis; Can be at a high speed, real-time recorded data and need not be subjected to the restriction of main frame physical location; Synchronization accuracy height, data remote speed height, easy to use, expense is reasonable.

The technical scheme that this utility model adopted is: based on the noinvasive arterial pulse wave checkout gear of MEMS sensor technology, it is characterized in that: this checkout gear comprises control unit, and the sensor unit, data record unit, temperature collecting cell and the communication interface unit that are electrically connected with this control unit respectively, wherein:

Sensor unit comprises a pair of 3-axis acceleration sensor chip, and one of them is as measuring transducer, and another is as reference sensor, and sensor unit is used for detected fluctuating signal is transferred to control unit;

Data record unit is a slice TF card, and by the SPI serial communication interface transmission data of 4 line systems, data record unit is used to preserve data or is uploaded to computer with 485 communication modes between TF card and the control unit;

Temperature collecting cell is a slice digital temperature sensor chip, is used for ambient temperature measurement;

Communication interface unit is used for the synchronous data sampling between many table apparatus.

Described control unit also is connected to one group of working station indicator, one group of button and power supply.

The beneficial effects of the utility model are: (1) has adopted the senser element of 3 shaft speed sensors of current state-of-the-art MEMS technology production, high sensitivity, high linearity as shallow table arterial elasticity expansionary force and displacement, can directly measure the physical characteristic of tremulous pulse, do not need through calculating, reduced the influence of ambient parameter significantly, improved the accuracy of clinical diagnosis the result.This device uses the pick off of a same model as reference sensor, be fixed on measuring transducer near, away from the path of passing through of tremulous pulse, be used to eliminate the baseline drift that the measurement point human motion causes simultaneously.

(2) adopt high capacity mobile memory medium TF card, can be at a high speed, real-time recorded data and be not subjected to the restriction of main frame physical location, can factor during record during according to teletransmission communication failure cause data-bag lost and and the restriction of the data communication rates upper limit.

(3) synchronization accuracy height, under the clock driving frequency of 4MHz, hardware timer can be differentiated the time difference that reaches 0.25 microsecond, and the conduction time measurement error of calculating pulse wave is little, thereby can realize short-range arterial property measurement, more can reflect the blood vessel elasticity feature of tested artery segment.

(4) data remote speed height when needing on-line measurement, is pressed the pattern switching button, and 485 communication chips promptly are converted to normal operating conditions from the stand-by operation state.This utility model message transmission rate surpasses general wireless mode transmission, and price has only the part of wireless mode, even 1/tens.

Description of drawings

Fig. 1 is a circuit block diagram of the present utility model.

Fig. 2 is the electrical schematic diagram of control unit in this utility model, sensor unit, temperature collecting cell, working station indicator and button.

Fig. 3 is the electrical schematic diagram of data record unit in this utility model, communication interface unit and power supply.

The specific embodiment

As shown in Figure 1, the present embodiment checkout gear hascontrol unit 5, and the sensor unit 1 that is electrically connected with this control unit respectively,data record unit 2,temperature collecting cell 4 andcommunication interface unit 7.

Describedcontrol unit 5 mainly comprises single-chip microcomputer U1(model MSP430F5438), 16 products that single-chip microcomputer is an American TI Company of MSP430 series, leading low-power consumption, integrated level height.

Described sensor unit 1 is made of a pair of 3-axis acceleration sensor chip (model ADXL345), substrate, fixed mechanism, attached electrical fitting.One of them sensor chip is as measuring transducer 1-1, and another sensor chip is as reference sensor 1-2.Adopt the SPI serial communication interface of 4 line systems to link to each other between sensor unit 1 and thecontrol unit 5, wherein: thefoot 8,9,12,13,14 of measuring transducer 1-1 connects 31,32,35,34,36 of single-chip microcomputer U1 respectively, and thefoot 7 of measuring transducer 1-1 connects the foot 39 of single-chip microcomputer U1; Thefoot 8,9,12,13,14 of reference sensor 1-2 connects the foot 74,75,78,77,79 of single-chip microcomputer U1 respectively, and thefoot 7 of reference sensor 1-2 connects the foot 80 of single-chip microcomputer U1.During use, measuring transducer is fixed near on the skin of the shallow table tremulous pulse of human body, reference sensor is fixed near on the skeleton outer skin of the shallow table tremulous pulse of human body.

Describeddata record unit 2 has a slice TF card, can be inserted in constituent components on the TF deck.SPI serial communication interface by 4 line systems betweendata record unit 2 and thecontrol unit 5 transmits data.Wherein: theoutput pin 1,2,3,5,7,8,9 of TF card (by connector J2) connects thefoot 54,53,42,52,51,50,49 of single-chip microcomputer U1 respectively.This example adopts the TF card of the common 2G capacity in market, and self-built file management system is FAT16.From preserving in real time on the quantity of data, when a record took 32 bytes, a card can be stored nearly more than 6,000 ten thousand data; From can be on the continuous recording time, the acquisition speed of setting in this example be under the situation of 200 record/seconds, can continuous record more than 80 hours; On writing speed, the record of this exampleactual measurement 32 byte lengths, the writing speed of record reaches more than 3600 each second at full speed.

Describedtemperature collecting cell 4 is a slice one line digital temperature sensor chip T1(model DS18B20), itsoutput pin 2 connects thefoot 100 of single-chip microcomputer U1.This temperature sensor chip T1 is in-55 ℃～+ 125 ℃ temperature ranges, and accuracy is ± 0.5 ℃, is used for ambient temperature measurement, carries out temperature correction for system.

Describedcommunication interface unit 7 comprises communication interface chip U3(model SN65HVD12), communication baud rate is 115200bps, and 8 line external interface U5.Comprise external power source and synchronous triggering signal line in the RJ45 socket that plate carries, be used for the synchronous data sampling between many table apparatus.Wherein, thefoot 1,2,3,4 of U3 connects the foot 73,71,70,72 of single-chip microcomputer U1 respectively; Thefoot 2 and 3 of U5 connects the foot 25 and 26 of single-chip microcomputer U1 respectively.

Except that said units part,control unit 5 also is connected to 2 working station indicator 3(D1, D2), D1 be green, when system's (device) when switching to line model to serve as 1 second flicker at interval, do not glimmer when working offline, when starting working, glimmer 3 times; D2 is a red light, crosses low or during the TF card failure running into cell voltage, the prompting malfunction, and cell voltage is crossed low flicker, and the TF card failure is bright often.Control unit 5 also connects 2 button 8(SW1, SW2), button SW1 is the logging mode switch key, system will switch at off-line record and online uploading between two kinds of mode of operations; Button SW2 is the start and stop key, and system will switch between work and stopmode.Power supply 6 is mainly a mu balanced circuit U4 (SPX5205) and a Schottky diode IN5819, and it is a power supply that externally automaticallyes switch between power supply and the battery, and the regulated power supply by a low pressure reduction becomes 3.3V voltage with outside 5W voltage transitions.

Operation principle of the present utility model is: after machine power is opened, acceleration transducer ADXL345 passes to the MSP430F5438 single-chip microcomputer with the signal that records, single-chip microcomputer is preserved data get off with the TF card according to the mode of operation at place, perhaps is uploaded to computer with 485 communication modes.

Because this device has been selected the MSP430 series monolithic of super low-power consumption, 0.1 microampere of its standby current, 250 microamperes in full speed operation electric current for use.What pick off was selected for use is the ADXL345 3-axis acceleration sensor, is under the situation of 200Hz in output speed, and power is 60 microamperes, and the standby current of TF card is 0.4 milliampere, 3 milliamperes of operating currents.1 microampere of the standby current of SN65HVD12 differential transceiver, 9 milliamperes of operating currents.The standby current of temperature sensor DS18B20 is 0.75 microampere, operating current 1mA.Therefore the power consumption of complete machine is very low, when common capacity isAAA battery 2 joints of 600 MAHs on using market, can work more than 120 hours.

Claims (2)

Translated fromChinese

1.一种基于MEMS传感器技术的无创动脉脉搏波检测装置，其特征在于：该检测装置包括控制单元（5），以及分别与该控制单元电连接的传感器单元（1）、数据记录单元（2）、温度采集单元（4）和通讯接口单元（7），其中：1. A non-invasive arterial pulse wave detection device based on MEMS sensor technology, characterized in that: the detection device includes a control unit (5), and a sensor unit (1) and a data recording unit (2) electrically connected to the control unit respectively ), temperature acquisition unit (4) and communication interface unit (7), wherein:传感器单元（1）包括一对三轴加速度传感器芯片，其中一个作为测量传感器（1-1），另一个作为参比传感器（1-2），传感器单元用于将检测到的脉动信号传输给控制单元（5）；The sensor unit (1) includes a pair of three-axis acceleration sensor chips, one of which is used as a measurement sensor (1-1), and the other is used as a reference sensor (1-2), and the sensor unit is used to transmit the detected pulsation signal to the control unit(5);数据记录单元（2）为一片TF卡，TF卡与控制单元（5）之间通过4线制的SPI串行通信接口传输数据，数据记录单元用于保存数据或用485通信方式上传给计算机；The data recording unit (2) is a TF card, and the data is transmitted between the TF card and the control unit (5) through a 4-wire SPI serial communication interface. The data recording unit is used to save the data or upload it to the computer by 485 communication;温度采集单元（4）为一片数字式温度传感器芯片，用于环境温度测量；The temperature acquisition unit (4) is a digital temperature sensor chip for ambient temperature measurement;通讯接口单元（7），用于多台装置之间的数据同步采集。The communication interface unit (7) is used for synchronous data collection among multiple devices.2.根据权利要求1所述的基于MEMS传感器技术的无创动脉脉搏波检测装置，其特征在于：所述控制单元（5）还接有一组工作状态指示灯（3）、一组按键（8）及电源（6）。2. The non-invasive arterial pulse wave detection device based on MEMS sensor technology according to claim 1, characterized in that: the control unit (5) is also connected with a set of working status indicator lights (3) and a set of buttons (8) and power supply (6).

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