CN103622693A - Portable bio-electrical impedance measurement device - Google Patents

Abstract

Translated fromChinese

一种便携式生物电阻抗测量装置，包括主控模块及与主控模块电连接的激励模块、阻抗测量模块、液晶显示模块、电极脱落检测模块和电量检测模块，主控模块发出指令使激励模块产生恒定的激励电流通过一对与待测目标接触的激励电极注入目标，同时阻抗测量模块通过另一对与待测目标接触的测量电极采集目标的电压信号并处理后送至主控模块计算出相应的阻抗值。本发明的使用灵活，结构简单，功耗低，便于外出携带和使用。

A portable bioelectrical impedance measurement device, comprising a main control module and an excitation module electrically connected to the main control module, an impedance measurement module, a liquid crystal display module, an electrode shedding detection module and a power detection module, and the main control module sends instructions to make the excitation module generate A constant excitation current is injected into the target through a pair of excitation electrodes in contact with the target to be measured, and at the same time, the impedance measurement module collects the voltage signal of the target through another pair of measurement electrodes in contact with the target to be measured and sends it to the main control module to calculate the corresponding the impedance value. The invention has flexible use, simple structure, low power consumption, and is convenient to carry and use when going out.

Description

A kind of portable bio-electrical impedance measuring apparatus

Technical field

the present invention relates to Electrical Bioimpedance Measurement Technology field, specifically relate to a kind of portable bio-electrical impedance measuring apparatus.

Background technology

In organism, cell is wrapped up by cell membrane, and inside is full of Cytoplasm, is extracellular fluid between cell.Physiologic Studies shows, when direct current or low-frequency current put on biological tissue, electric current will be walked around cell in any one possible mode, Main Current is through extracellular fluid: when putting on the frequency of biological tissue's electric current, increase, the capacitive reactance of cell membrane electric capacity reduces, one part of current will be through the cell membrane intracellular fluid of flowing through, and this makes biological tissue's impedance present to external world certain Dispersion.

Bio-electrical impedance technology is called again medical science electrical impedance or is called for short impedance, is a kind of electrical characteristics of utilizing biological tissue and organ and Changing Pattern extraction thereof and Human Physiology, the detection technique of biomedical information that pathological condition is relevant.It applies with small AC measurment curtage to detected object by means of the electrode system of body surface conventionally, detects corresponding electrical impedance and situation of change thereof, then according to different application purposes, obtains relevant physiology and pathological information.There is noinvasive, harmless, the feature such as cheap, safe, simple to operate, reproducible and function information is abundant.

While carrying out impedance bioelectrical measurement in traditional impedance bioelectrical measurement technology, generally by pair of exciting, target is applied to sinusoidal current pumping signal, recycle the voltage signal of a pair of measurement electrode measurement target, and use high speed analog-digital converter (ADC) to carry out high-speed sampling to voltage signal, then use the method for phase demodulation, demodulate real part and the imaginary part of the electrical impedance of target.In this traditional bio-electrical impedance measuring circuit, need to use the higher chips of power consumption such as FPGA, high-speed ADC; And in demodulating process, need to carry out more multiplying, cause the operand of microcontroller large, power consumption is large; In addition, after also needing to be connected with computer, could realize impedance information and show and store when carrying out data analysis processing, volume is large, and power consumption is large, be not easy to carry and use, thereby the apparatus and method of this traditional bio-electrical impedance measuring cannot be popularized outside institute.

Summary of the invention

The object of the invention is to for above-mentioned existing problems and deficiency, a kind of portable bio-electrical impedance measuring apparatus is provided, it by two pairs can plug electrode pair complete current excitation and voltage measurement, can Measurement accuracy and the resistance value of display-object, and can store or wireless transmission measurement data, this device is used flexibly, simple in structure, low in energy consumption, be convenient to go out to carry and use.

Technical scheme of the present invention is achieved in that

Portable bio-electrical impedance measuring apparatus of the present invention, is characterized in comprising main control module and the stimulating module being electrically connected to main control module, impedance measurement module, LCD MODULE, electrode come off detection module and electric weight detection module, wherein:

Stimulating module produces constant exciting current and exciting current is injected in target to be measured by exciting electrode a pair of and that target to be measured contacts under the control between main control module and impedance measurement module and at main control module, and simultaneously impedance measurement module is gathered and delivers to main control module after the voltage signal of target to be measured processing and calculate corresponding resistance value measurement electrode contact with target to be measured by another;

Electrode comes off detection module for monitoring the situation of laying of electrode, when electrode is loosening or come off, will report to the police by LED lamp and buzzer;

Electric weight detection module, for monitoring the residual electric quantity of this device, will be reported to the police by LED lamp and buzzer when electric weight is not enough;

LCD MODULE is for showing in real time the resistance value of target to be measured and the residual electric quantity of this device.

Above-mentioned stimulating module comprises Direct Digital frequency synthesis (DDS) chip, voltage/current conversion circuit and a pair of exciting electrode that can plug.

Above-mentioned impedance measurement module comprises a reference resistance, a pair of measurement electrode, two differential amplifier circuits, a high-pass filtering circuit and a demodulation chip that can plug, the target to be measured of wherein said measurement electrode collection and the voltage signal of reference resistance demodulate the voltage relationship of target to be measured and reference resistance after by differential amplifier circuit and high-pass filtering circuit, and above-mentioned main control module can calculate the resistance value of target to be measured by the voltage relationship of target to be measured and reference resistance.

The computing formula of above-mentioned resistance value is as follows:

This formula is an once linear equation, wherein,

with

be respectively the voltage input signal amplitude of target to be measured and reference resistance,be the comparison Output rusults of two groups of signal amplitudes,

represent a fixing slope,

represent a fixing intercept,

with

become once linear relationship, due to identical by the electric current of target to be measured and reference resistance, so this formula can be done as down conversion:

So, as long as collect

just can go out according to the computing the resistor value of reference resistance the resistance value of target to be measured.

Above-mentioned main control module comprises main control chip and peripheral circuit module thereof, described main control chip can be controlled the sine wave signal that stimulating module produces characteristic frequency by sending instruction, and described main control chip can also gather impedance signals and complete impedance signal and calculates by 14 built-in high accurate A/D acquisition modules.

The peripheral circuit module of above-mentioned main control chip includes data storage circuitry module and wireless transceiver circuit module, described data storage circuitry module can directly be stored the impedance data measuring, and described wireless transceiver circuit module can send the data to by the mode of wireless transmission terminal and do further research use.

Operation principle of the present invention is as follows:

When the present invention uses, main control module sends pumping signal control instruction to stimulating module, stimulating module injects exciting current by exciting electrode to target to be measured, impedance measurement module gathers the voltage signal of target to be measured and reference resistance by measurement electrode, the resistance value that voltage signal is demodulated after by one-level differential amplifier circuit and high-pass filtering circuit, calculate target to be measured, main control chip gathers resistance value by built-in ADC and shows and store.

Compared with prior art, tool has the following advantages in the present invention:

1, the present invention is simple in structure, and the necessary module of integrated bio impedance bioelectrical measurement device and miscellaneous function can be used alone without connecting computer, can arrive in the various environment of indoor and outdoor and complete surveying work;

2, measuring range of the present invention is large, strong adaptability, and certainty of measurement <1%, can well solve the measurement error producing due to individual variation, meets the demand of clinical measurement;

3, the invention provides a kind of new impedance computation method, can accurately calculate the resistance value of target, there is very high accuracy and versatility;

4, the present invention adopts portable, low power dissipation design, and electrode system can plug carry and take care of, and chip adopts single power supply more, has reduced the power consumption of device as far as possible, and single battery stream time can reach 10 hours, meets indoor and outdoor job requirement.

Below in conjunction with accompanying drawing, the present invention is further illustrated.

Accompanying drawing explanation

Fig. 1 is structural representation of the present invention.

Fig. 2 is overhaul flow chart of the present invention.

The specific embodiment

As shown in Figure 1, portable bio-electrical impedance measuring apparatus of the present invention, comprises main control module, stimulating module, impedance measurement module, LCD MODULE, electrode come off detection module and electric weight detection module.Wherein, main control module sends instruction makes stimulating module produce constant exciting current to stimulating module, exciting current is injected in target to be measured by exciting electrode a pair of and that target to be measured contacts, impedance measurement module by another, measurement electrode contacting with target to be measured is gathered to the voltage signal of target to be measured and process after deliver to main control module and calculate corresponding resistance value.

Stimulating module comprises Direct Digital frequency synthesis (DDS) chip, voltage/current conversion circuit and a pair of exciting electrode that can plug.

Impedance measurement module comprises a reference resistance, a pair of measurement electrode, two differential amplifier circuits, a high-pass filtering circuit and a demodulation chip that can plug.The target to be measured of measurement electrode collection and the voltage signal of reference resistance demodulate the voltage relationship of target to be measured and reference resistance after by differential amplifier circuit and high-pass filtering circuit.

Especially, resistance value computing formula provided by the invention is:

This formula is an once linear equation, wherein,with

be respectively the voltage input signal amplitude of target to be measured and reference resistance,

be the comparison Output rusults of two groups of signal amplitudes,

represent a fixing slope,

represent a fixing intercept,

with

become once linear relationship, due to identical by the electric current of target to be measured and reference resistance, so this formula can be done as down conversion:

So, as long as collect

just can go out according to the computing the resistor value of reference resistance the resistance value of target to be measured.

The resistance value of target to be measured will be gathered by built-in ADC by main control module

after calculate, show and store.

As shown in Figure 1, main control module comprises main control chip and peripheral circuit module thereof.Wherein, the peripheral circuit module of main control chip includes data storage circuitry module, wireless transceiver circuit module, excitation control circuit module and AD acquisition module.Main control module can send instruction by excitation control circuit module and control the sine wave signal that stimulating module produces characteristic frequency, and main control module can also and complete impedance signal by 14 high accurate A/D acquisition module acquired signal and calculate.Data storage circuitry module can directly be stored the impedance data measuring, and wireless transceiver circuit module can send the data to by the mode of wireless transmission terminal and do further research use.In addition, main control module also has electrode and comes off that signal detection, electric weight detection signal detect and the function of LCDs interface circuit.

The electrode detection module that comes off can continue to monitor the situation of laying of electrode, when electrode is loosening or come off, will report to the police by LED lamp and buzzer.

Electric weight detection module can be monitored the residual electric quantity of this device, when electric weight is not enough, will report to the police by LED lamp and buzzer.

In addition, LCD MODULE is 128*64 matrix liquid-crystal display screen, for showing in real time the resistance value of target to be measured and the residual electric quantity of this device.

As shown in Fig. 2, the concrete measuring process during work of this device is as follows:

S1: load battery, in order electrode insertion line;

S2: electrode is connected with electrode wires, and is pasted on target surface to be measured;

S3: measurement parameter is set, as measuring frequency and electric current, starts to measure;

S4: the voltage signal that gathers target to be measured and reference resistance;

S5: calculate target impedance value to be measured;

S6: resistance value storage, demonstration.

The key performance of portable bio-electrical impedance measuring apparatus of the present invention is as follows:

1) measure signal to noise ratio: >75dB;

2) system works frequency band: 10kHz-500kHz;

3) impedance measurement precision: <1%;

4) impedance measurement rate respectively: 0.01 Ω;

5) constant-current source output impedance: >500K Ω;

6) continuous power-on time: about 10 hours.

The above is the preferred embodiment of the present invention, should be understood that, for those skilled in the art, can also make some improvement and change under the premise without departing from the principles of the invention, these improvement and change all should be encompassed in the middle of claim scope of the present invention.

Claims (6)

Translated fromChinese

1.一种便携式生物电阻抗测量装置，其特征在于包括主控模块及与主控模块电连接的激励模块、阻抗测量模块、液晶显示模块、电极脱落检测模块和电量检测模块，其中：1. A portable bioelectrical impedance measurement device, characterized in that it comprises a main control module and an excitation module electrically connected with the main control module, an impedance measurement module, a liquid crystal display module, an electrode shedding detection module and an electric quantity detection module, wherein:激励模块位于主控模块和阻抗测量模块之间且在主控模块的控制下产生恒定的激励电流并通过一对与待测目标接触的激励电极将激励电流注入到待测目标中，同时阻抗测量模块通过另一对与待测目标接触的测量电极采集待测目标的电压信号并处理后送至主控模块计算出相应的阻抗值；The excitation module is located between the main control module and the impedance measurement module, and generates a constant excitation current under the control of the main control module, and injects the excitation current into the target to be measured through a pair of excitation electrodes that are in contact with the target to be measured. Simultaneously, the impedance measurement The module collects the voltage signal of the target to be measured through another pair of measuring electrodes that are in contact with the target to be measured and sends it to the main control module to calculate the corresponding impedance value after processing;电极脱落检测模块用于监测电极的安放情况，当电极松动或者脱落时将通过LED灯和蜂鸣器进行报警；The electrode drop detection module is used to monitor the placement of the electrode, and when the electrode is loose or falls off, it will give an alarm through the LED light and the buzzer;电量检测模块用于监测本装置的剩余电量值，当电量不足时将通过LED灯和蜂鸣器进行报警；The power detection module is used to monitor the remaining power value of the device, and when the power is insufficient, it will give an alarm through the LED light and the buzzer;液晶显示模块用于实时显示待测目标的阻抗值以及本装置的剩余电量值。The liquid crystal display module is used to display the impedance value of the target to be measured and the remaining power value of the device in real time.2.根据权利要求1所述的便携式生物电阻抗测量装置，其特征在于上述激励模块包括直接数字频率合成(DDS)芯片、电压/电流转换电路和一对可拔插的激励电极。2. The portable bioelectrical impedance measuring device according to claim 1, characterized in that said excitation module comprises a direct digital frequency synthesis (DDS) chip, a voltage/current conversion circuit and a pair of pluggable excitation electrodes.3.根据权利要求1所述的便携式生物电阻抗测量装置，其特征在于上述阻抗测量模块包括一个参考电阻、一对可拔插的测量电极、二个差分放大电路、一个高通滤波电路和一个解调芯片，其中所述测量电极采集的待测目标和参考电阻的电压信号通过差分放大电路和高通滤波电路后解调出待测目标和参考电阻的电压关系，上述主控模块通过待测目标和参考电阻的电压关系可计算出待测目标的阻抗值。3. The portable bioelectrical impedance measuring device according to claim 1, wherein said impedance measuring module comprises a reference resistor, a pair of pluggable measuring electrodes, two differential amplifier circuits, a high-pass filter circuit and a solution Adjusting the chip, wherein the voltage signals of the target to be measured and the reference resistor collected by the measuring electrodes are demodulated to obtain the voltage relationship between the target to be measured and the reference resistor through a differential amplifier circuit and a high-pass filter circuit. The voltage relationship of the reference resistor can be used to calculate the impedance value of the target to be measured.4.根据权利要求1或3所述的便携式生物阻抗测量装置，其特征在于上述阻抗值的计算公式如下：4. The portable bio-impedance measuring device according to claim 1 or 3, wherein the calculation formula of the above-mentioned impedance value is as follows:

 

 该公式是一个一次线性方程，其中，

和

分别为待测目标和参考电阻的电压输入信号幅值，

为两组信号幅值的比较输出结果，

代表一个固定的斜率，

代表一个固定的截距，和

成一次线性关系，由于通过待测目标和参考电阻的电流相同，因此该公式可作如下变换：The formula is a linear equation where,

and

are the voltage input signal amplitudes of the target to be measured and the reference resistor, respectively,

is the comparison output result of two groups of signal amplitudes,

represents a constant slope,

represents a fixed intercept, and

As a linear relationship, since the current through the target to be measured and the reference resistance are the same, the formula can be transformed as follows: 

 

所以，只要采集到

就可以根据参考电阻的阻值计算出待测目标的阻抗值。Therefore, as long as the collected

Then the impedance value of the target to be measured can be calculated according to the resistance value of the reference resistor.5.根据权利要求1所述的便携式生物电阻抗测量装置，其特征在于上述主控模块包括主控芯片及其外围电路模块，所述主控芯片可通过发送指令控制激励模块产生特定频率的正弦波信号，且所述主控芯片还可以通过内置的14位高精度AD采集模块采集阻抗信号并完成阻抗信号计算。5. The portable bioelectrical impedance measuring device according to claim 1, characterized in that the above-mentioned main control module includes a main control chip and its peripheral circuit modules, and the main control chip can control the excitation module to generate a sine wave of a specific frequency by sending instructions. Wave signals, and the main control chip can also collect impedance signals and complete impedance signal calculations through the built-in 14-bit high-precision AD acquisition module.6.根据权利要求5所述的便携式生物电阻抗测量装置，其特征在于上述主控芯片的外围电路模块包括有数据存储电路模块和无线收发电路模块，所述数据存储电路模块可以直接存储测量得到的阻抗数据，所述无线收发电路模块可以通过无线发送的方式将数据发送给计算机终端作进一步的研究使用。6. The portable bioelectrical impedance measuring device according to claim 5, wherein the peripheral circuit module of the above-mentioned main control chip includes a data storage circuit module and a wireless transceiver circuit module, and the data storage circuit module can directly store and measure the obtained Impedance data, the wireless transceiver circuit module can send the data to the computer terminal by wireless transmission for further research and use.

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