WO2018036209A1

WO2018036209A1 - Apparatus and method for multistage amplification of micro signals from biosensors

Info

Publication number: WO2018036209A1
Application number: PCT/CN2017/084227
Authority: WO
Inventors: 张贯京; 高伟明; 唐昭月
Original assignee: 深圳市前海安测信息技术有限公司
Priority date: 2016-08-26
Filing date: 2017-05-12
Publication date: 2018-03-01
Also published as: CN106374861A

Abstract

An apparatus (1) and a method for multistage amplification of micro signals from biosensors. The apparatus (1) comprises a first differential amplifier (11), a second differential amplifier (12), a third differential amplifier (13), an ADC amplification chip (14), and a single chip microcomputer (15). The first differential amplifier (11) obtains a first micro signal from a first biosensor (2), obtains a second micro signal from a second biosensor (3), and performs differential calculation and amplification to obtain a first differential signal. The second differential amplifier (12) obtains a third micro signal from a third biosensor (4), obtains a fourth micro signal from a fourth biosensor (5), and performs differential calculation and amplification to obtain a second differential signal. The third differential amplifier (13) performs differential operation and amplification on the first differential signal and the second differential signal to obtain a measurement feature signal. The ADC amplification chip (14) amplifies the measurement feature signal and then outputs the amplified measurement feature signal to the single chip microcomputer (15). The apparatus (1) and method are adaptive to multistage amplifiers having different amplification factors to perform multistage amplification on micro signals, thereby accurately measuring the micro signals.

Description

Micro-signal multi-stage amplification device and method for biosensor

[0001] The present invention relates to the technical field of signal amplification, and in particular, to a micro-signal multi-stage amplification apparatus and method for a biosensor.

Background technique

[0002] The amplification of micro signals is the basis of signal measurement and measurement. For small signals within 50mV, it cannot be directly used for chips such as AD sampling. The signal must be amplified by the amplifier circuit before it can be measured. Micro-signal measurement is often a difficult point in signal measurement, and small signals within 50mV are difficult to detect by signal measurement circuits. Generally, bioelectrical signals output by biosensors (such as blood glucose, body temperature, heart rate biosensors, etc. in vital signs monitoring biosensors) are relatively weak. Since the bioelectrical signals to be measured are weak, the bioelectricity to be measured must be measured by an amplifying circuit. The signal can only be measured after it has been amplified. However, the amplifying circuit in the existing signal measuring device cannot effectively match the multi-stage amplifier of different amplification factors to multi-stage the weak characteristic electric signal, thereby causing the measurement result of the weak bioelectric signal to be measured to be inaccurate.

[0003] A primary object of the present invention is to provide a micro-signal multi-stage amplifying apparatus and method for a biosensor, which aim to solve the problem of multi-stage amplification of a weak signal by a multi-stage amplifier that cannot effectively match different amplification factors.

Problem solution

Technical solution

[0004] In order to achieve the above object, the present invention provides a micro-signal multi-stage amplifying device for a biosensor, the micro-signal multi-stage amplifying device being connected with a first biosensor, a second biosensor, a third biosensor, and a fourth a biosensor, the micro signal multistage amplifying device includes a first differential amplifier, a second differential amplifier, a third differential amplifier, an ADC amplification chip, and a single chip, wherein the first differential amplifier and the second differential amplifier each include two first a resistor and two second resistors, the third differential amplifier comprising two third resistors and two fourth resistors, wherein: [0005] The first differential op amp is configured to acquire a first micro signal from a first biosensor and acquire a second micro signal from a second biosensor, and pass the first micro signal and the second micro signal through the first differential The amplification factor of the amplifier is differentially operated and amplified to obtain a first differential signal, and the amplification factor of the first differential amplifier is equal to a ratio of the resistance of the second resistor and the first resistor in the first differential amplifier;

[0006] the second differential amplifier is configured to acquire a third micro signal from a third biosensor and acquire a fourth micro signal from a fourth biosensor, and pass the third micro signal and the fourth micro signal through the second differential amplifier Amplifying the differential operation and amplifying the second differential signal, the amplification factor of the second differential amplifier being equal to the amplification factor of the first differential amplifier;

[0007] The third differential amplifier is configured to perform differential operation on the first differential signal and the second differential signal by using the amplification factor of the third differential amplifier, and obtain a measurement characteristic signal, where the amplification factor of the third differential amplifier is equal to a ratio of a resistance value of the fourth resistor and the third resistor in the third differential amplifier;

[0008] The ADC amplifying chip includes an amplifying circuit chip and an ADC circuit chip, and the amplifying circuit chip is configured to amplify the measured characteristic signal by amplifying a magnification of the amplifying circuit chip, and output the signal to the AD C circuit chip, where The amplification factor of the amplifying circuit chip is an inherently specific value of the amplifying circuit chip.

[0009] Further, the first input end of the first differential amplifier is connected to the first biosensor, the second input end of the first differential amplifier is connected to the second biosensor; the first input of the second differential amplifier Connected to the third biosensor, the second input of the second differential amplifier is connected to the fourth biosensor; the output of the first differential amplifier is connected to the first input of the third differential amplifier, the second differential amplifier The output end is connected to the second input end of the third differential amplifier; the output end of the third differential amplifier is connected to the input end of the amplifying circuit chip, and the output end of the amplifying circuit chip is connected to the input end of the ADC circuit chip The output of the ADC circuit chip is connected to the single chip microcomputer

[0010] Further, the first differential amplifier further includes a first transistor, one of the first resistors of the first differential amplifier is connected in series to the first input end of the first transistor, and the other of the first differential amplifier a resistor is connected in series to the second input end of the first transistor, one end of one of the second resistors of the first differential amplifier is connected to the first input end of the first transistor and the other end of the second resistor is connected to the first crystal An output end of the transistor, one end of the other second resistor of the first differential amplifier is connected to the second input end of the first transistor and the other end of the second resistor is connected to the ground line [0011] Further, the second differential amplifier further includes a first transistor, one of the first resistors of the second differential amplifier is connected in series to the first input end of the first transistor, and the other of the second differential amplifier a resistor is connected in series to the second input end of the first transistor, one end of one of the second resistors of the second differential amplifier is connected to the first input end of the first transistor and the other end of the second resistor is connected to the first crystal An output end of the transistor, one end of the other second resistor of the second differential amplifier is connected to the second input end of the first transistor and the other end of the second resistor is connected to the ground line

[0012] Further, the third differential amplifier further includes a second transistor, wherein a third resistor is connected in series to the first input end of the second transistor, and the other third resistor is connected in series to the second transistor a second input end, wherein one end of the fourth resistor is connected to the first input end of the second transistor and the other end of the fourth resistor is connected to the output end of the second transistor, wherein one end of the other fourth resistor is connected to The second input of the second transistor and the other end of the fourth resistor are connected to the ground line.

[0013] Further, the first biosensor is configured to sense a first micro signal generated by the first wavelength infrared light being irradiated on the target detection object, and the second biosensor is configured to sense the second wavelength infrared light to be irradiated on the target Detecting a second micro signal generated on the object, a third biosensor for sensing a third micro signal generated by the third wavelength infrared light on the target detection object, and a fourth biosensor for sensing the fourth wavelength infrared light irradiation A fourth microsignal generated on the target detection object.

[0014] Further, the ADC circuit chip is configured to perform digital-to-analog conversion on the amplified measurement characteristic signal and output the signal to the single-chip microcomputer for signal measurement and analysis.

[0015] In order to achieve the above object of the present invention, the present invention further provides a micro-signal multi-stage amplification method for a biosensor, which is applied to a micro-signal multi-stage amplification device, and the micro-signal multi-stage amplification device is connected with a first biosensor. a second biosensor, a third biosensor, and a fourth biosensor, the micro signal multistage amplifying device comprising a first differential amplifier, a second differential amplifier, a third differential amplifier, an ADC amplification chip, and a single chip, the first differential amplifier And the second differential amplifiers each include two first resistors and two second resistors, the third differential amplifier includes two third resistors and two fourth resistors, and the A DC amplification chip includes an amplification circuit chip and an ADC circuit chip. , wherein the micro signal multi-level amplification side The method includes the following steps:

[0016] the first differential op amp acquires a first micro signal from a first biosensor and a second micro signal from a second biosensor;

[0017] the first differential op amp performs differential operation on the first micro-signal and the second micro-signal through the amplification factor of the first differential op amp and amplifies the first differential signal, where the first differential amplifier The amplification factor is equal to a ratio of a resistance of the second resistor and the first resistor in the first differential amplifier;

[0018] the second differential amplifier acquires a third micro signal from a third biosensor and obtains a fourth micro signal from a fourth biosensor;

[0019] the second differential amplifier performs differential operation on the third micro signal and the fourth micro signal by the amplification factor of the second differential amplifier, and amplifies the second differential signal, where the amplification factor of the second differential amplifier is equal to a magnification of a differential amplifier;

[0020] The third differential amplifier performs differential operation on the first differential signal and the second differential signal by the amplification factor of the third differential amplifier, and amplifies the measurement characteristic signal, and the amplification factor of the third differential amplifier is equal to the third a ratio of a resistance value of a fourth resistor of the differential amplifier to a third resistor;

[0021] The amplifying circuit chip amplifies the measured characteristic signal by the amplification factor of the amplifying circuit chip, and outputs the signal to the ADC circuit chip. The amplification factor of the amplifying circuit chip is an inherent specific value of the amplifying circuit chip.

[0022] Further, the first micro signal is that the first biosensor senses the characteristic electric signal generated by the first wavelength infrared light on the target detection object, and the second micro signal is that the second biosensor senses the second The two-wavelength infrared light illuminates the characteristic electric signal generated on the target detection object, and the third micro-signal is that the third bio-sensor senses the characteristic electric signal generated by the third-wavelength infrared light irradiation on the target detection object, and the fourth micro-signal is The fourth biosensor senses the characteristic electric signal generated by the fourth wavelength infrared light on the target detection object.

[0023] Further, the ADC amplification chip further includes an ADC circuit chip, and the multi-signal multi-stage amplification method further includes the following steps:

[0024] The ADC circuit chip performs digital-to-analog conversion on the amplified measurement characteristic signal and outputs the signal to the single-chip microcomputer for signal measurement and analysis.

Advantageous effects of the invention Beneficial effect

Compared with the prior art, the micro-signal multi-stage amplifying apparatus and method for the biosensor of the present invention adopts the above technical solutions, and obtains the following technical effects: by acquiring four weak characteristic electric signals and passing multi-level difference The amplifier performs a differential operation and performs high-magnification amplification to obtain a measurement characteristic signal, thereby achieving the effect of measuring a weak characteristic electrical signal.

Brief description of the drawing

DRAWINGS

1 is a schematic diagram showing the circuit structure of a preferred embodiment of a micro-signal multi-stage amplifying device of a biosensor of the present invention.

2 is a flow chart of a method of a preferred embodiment of the micro-signal multi-stage amplification method of the biosensor of the present invention.

[0028] The implementation, functional features, and advantages of the present invention will be further described with reference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION

The specific embodiments, structures, features and utilities of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

1, FIG. 1 is a circuit diagram showing a preferred embodiment of a micro-signal multi-stage amplifying apparatus of a biosensor of the present invention. In this embodiment, the micro-signal multi-stage amplifying device 1 includes, but is not limited to, a first differential amplifier 11, a second differential amplifier 12, a third differential amplifier 13, an ADC (digital-to-analog conversion) amplifier chip 14, and a single chip microcomputer. 15. The first input of the first differential amplifier 11 is connected to the first biosensor 2, the second input of the first differential amplifier 11 is connected to the second biosensor 3, and the first input of the second differential amplifier 12 is connected to the third The biosensor 4, the second input of the second differential amplifier 12 is connected to the fourth biosensor 5. The output of the first differential amplifier 11 is connected to the first input of the third differential amplifier 13, and the output of the second differential amplifier 12 is connected to the second input of the third differential amplifier 13, the output of the third differential amplifier 13. Connected to the ADC amplifying chip 14, the ADC amplifying chip 14 is connected to the microcontroller 15.

[0031] the first biosensor 2 is configured to acquire a first micro signal from a target detection object, and the second biosensor 3 For acquiring the second micro signal from the target detection object, the third biosensor 4 is for acquiring the third micro signal from the target detection object, and the fourth biosensor 5 is for acquiring the fourth micro signal from the target detection object. In this embodiment, by using infrared light of four different wavelengths to respectively illuminate the target detection object, the first micro signal is that the first biosensor 2 senses that the first wavelength infrared light is generated on the target detection object. a characteristic electric signal, the second micro signal is that the second biosensor 3 senses a characteristic electric signal generated by the second wavelength infrared light on the target detection object, and the third micro signal is that the third biosensor 4 senses the third The wavelength infrared light illuminates the characteristic electrical signal generated on the target detection object, and the fourth micro signal is the fourth electrical sensor 5 senses the characteristic electric signal generated by the fourth wavelength infrared light irradiation on the target detection object. In this embodiment, four kinds of micro signals which are irradiated to the target detection object by infrared light of four different wavelengths are obtained, and the measurement characteristic signals of the target detection object are measured by performing multi-level differential operation on the four kinds of micro signals and amplifying. For example, it is necessary to measure the blood glucose concentration of the human body, and use four different wavelengths of infrared light to irradiate the blood glucose measurement site (target detection site), respectively, and then obtain four weak blood glucose concentration electrical signals through the four biosensors, and then pass The micro-signal multi-stage amplifying device 1 performs multi-stage differential operation and amplifies to obtain a blood glucose concentration signal of the human body, and outputs the signal to the single-chip microcomputer 5 for subsequent blood glucose concentration analysis. In this embodiment, the first differential amplifier 11 and the second differential amplifier 12 each include two first resistors R1, two second resistors R2, and a first transistor Q1. One of the first resistors R1 of the first differential amplifier 11 is connected in series to the first input terminal of the first transistor Q1, and the other one of the first resistors R1 of the first differential amplifier 11 is connected in series to the second input terminal of the first transistor Q1. One end of one of the second resistors R2 of the first differential amplifier 11 is connected to the first input end of the first transistor Q1 and the other end of the second resistor R2 is connected to the output end of the first transistor Q1, the first difference One of the other second resistors R2 of the amplifier 11 is connected to the second input terminal of the first transistor Q1 and the other end of the second resistor R2 is connected to the ground line. One of the first resistors R1 of the second differential amplifier 12 is connected in series to the first input terminal of the first transistor Q1, and the other one of the first resistors R1 of the second differential amplifier 12 is connected in series to the second input terminal of the first transistor Q1. One end of one of the second resistors R 2 of the second differential amplifier 12 is connected to the first input end of the first transistor Q1 and the other end of the second resistor R2 is connected to the output end of the first transistor Q1, the second One end of the other second resistor R2 of the differential amplifier 12 is connected to the second input terminal of the first transistor Q1 and the other end of the second resistor R2 is connected to the ground line. [0033] The first differential op amp 11 is configured to acquire a first micro signal from the first biosensor 2 and acquire a second micro signal from the second biosensor 3, and pass the first micro signal and the second micro signal through the first The amplification of a differential op amp 11 is differentially operated and amplified to obtain a first differential signal. The second differential amplifier 12 is configured to acquire a third micro signal from the third biosensor 4 and acquire a fourth micro signal from the fourth biosensor 5, and pass the third differential signal and the fourth micro signal through the second differential amplifier The amplification of 12 is differentially operated and amplified to obtain a second differential signal. The amplification factor of the first differential amplifier 11 is equal to the ratio of the resistance value of the second resistor R2 in the first differential amplifier 11 and the first resistor R1, and the amplification factor of the second differential amplifier 12 is equal to the amplification factor of the first differential amplifier 11.

In the present embodiment, the temperature coefficient K1 of the first differential amplifier 11 is determined by the temperature coefficient of the second resistor R2 and the first resistor R1 in the first differential amplifier 11. It can be understood that the temperature coefficient of the one resistor refers to the relative change value of the resistance value of the resistor when the temperature changes by 1 ° C, and the unit is ppm : . For example, the temperature coefficient of the first resistor R1 is expressed as QCR1=?R1

/R1??T, the temperature coefficient of the second resistor R2 is expressed as QCR2=?R2/R2??T, where QCR1 is the temperature coefficient of the first resistor R1, and QCR2 is the temperature coefficient of the second resistor R2, ? T is the temperature change value, ? R1 is the resistance change value of the first resistor R1 under temperature change, ? R2 is the resistance change value of the second resistor R2 under temperature change, / represents the division operation, ? Represents multiplication. In practical applications, the temperature coefficient usually uses the average temperature coefficient, and has a negative temperature coefficient, a positive temperature coefficient, and a critical temperature coefficient at which the resistance will only mutate at a certain temperature. The temperature coefficient K1 of the first differential amplifier 11 is equal to the ratio of the temperature coefficient QCR2 of the second resistor R 2 to the temperature coefficient QCR1 of the first resistor R1, that is, Kl = QCR2 / QCR1. The temperature coefficient of the second differential amplifier 12 is equal to the temperature coefficient of the first differential amplifier 11

[0035] In this embodiment, the third differential amplifier 13 includes two third resistors R3, two fourth resistors R4, and a second transistor Q2, wherein one third resistor R3 is connected in series to the second transistor Q2. a first input terminal, wherein the other third resistor R3 is connected in series to the second input end of the second transistor Q2; one end of the fourth resistor R4 is connected to the first input end of the second transistor Q2 and the fourth resistor The other end of R4 is connected to the output end of the second transistor Q2, wherein the other end of the fourth resistor R4 is connected to the second input terminal of the second transistor Q2 and the other end of the fourth resistor R4 is connected to the ground line. [0036] The third differential amplifier 13 is configured to perform differential operation on the first differential signal and the second differential signal by the amplification factor of the third differential amplifier 13 and amplify the measured characteristic signal. In this embodiment, the amplification factor of the third differential amplifier 13 is equal to the ratio of the resistance values of the fourth resistor R4 and the third resistor R3 in the third differential amplifier 13. The temperature coefficient K2 of the third differential amplifier 13 is determined by the temperature coefficient of the fourth resistor R4 and the third resistor R3 in the third differential amplifier 13. For example, the temperature coefficient of the third resistor R3 is expressed as QCR3=?R3/R3??T, and the temperature coefficient of the fourth resistor R4 is expressed as QCR4=?R4/R4??T, where QCR3 is the temperature of the third resistor R3. The coefficient, QCR4 is the temperature coefficient of the fourth resistor R4, ? T is the temperature change value, ? R3 is the resistance change value of the third resistor R3 under temperature change, ? R4 is the resistance change value of the fourth resistor R4 under temperature change, / represents the division operation, ? Represents multiplication. The temperature coefficient K2 of the third differential amplifier 13 is equal to the ratio of the temperature coefficient QCR4 of the fourth resistor R4 to the temperature coefficient QCR3 of the third resistor R3, that is, K2 = QCR4 / QCR3.

In the present embodiment, the ADC amplification chip 14 includes, but is not limited to, an amplification circuit chip 141 and an ADC circuit chip 142. The input end of the amplifying circuit chip 141 is connected to the output end of the third differential amplifier 13. The output end of the amplifying circuit chip 141 is connected to the input end of the ADC circuit chip 142, and the output end of the ADC circuit chip 142 is connected to The single chip microcomputer 15. The amplifying circuit chip 141 is configured to amplify the measured characteristic signal by the amplification factor of the amplifying circuit chip 141 and output the signal to the ADC circuit chip 142. The ADC circuit chip 142 is configured to count the amplified measured characteristic signals. The mode is converted and output to the microcontroller 15 for subsequent signal measurement analysis.

[0038] In the embodiment, the amplifying circuit chip 141 is composed of an amplifying circuit in the prior art, and the AD C circuit chip 142 is composed of a digital-to-analog converting circuit in the prior art. It can be understood by those skilled in the art that the amplification factor of the amplifying circuit chip 141 is an inherent specific value of the amplifying circuit chip 141, that is, an intrinsic amplification property of the amplifying circuit chip 141, but is subjected to the amplifying circuit chip during operation. The temperature coefficient K3 of 141 produces the effect of temperature drift. The temperature coefficient K3 of the amplifying circuit chip 141 is a temperature characteristic inherent to the amplifying circuit chip 141, which reflects the severity of temperature drift of the amplifying circuit chip 141 when the amplifying circuit chip 141 changes in operating temperature. The amplifying circuit chip 141 generates a temperature drift phenomenon as a function of the operating temperature, causing a signal interference with the measurement characteristic signal, thereby causing the measurement characteristic signal to be submerged in the interference signal, and thus the measurement characteristic signal cannot be accurately measured. In the present embodiment, by determining the first one of the first differential amplifier 11 and the second differential amplifier 12 The temperature coefficient of the resistor R1 and the second resistor R2, and the temperature coefficient K1 of the first differential amplifier 11 and the third differential amplifier 13 are determined by determining the temperature coefficients of the third resistor R3 and the fourth resistor R4 in the third differential amplifier 13. The product of the temperature coefficient K2 is equal in magnitude and opposite in sign to the temperature coefficient K3 of the amplifying circuit chip 141, thus causing the influence of the temperature drift generated by the first differential amplifier 11 and the third differential amplifier 13 on the signal interference and the amplifying circuit chip 141. The effects of the generated temperature drift on the signal interference cancel each other out, thereby eliminating the signal interference caused by the temperature drift of the weak signal in the signal amplification of the high-magnification amplifier circuit, and improving the accuracy of measuring the weak signal.

[0039]

[0040] In order to achieve the object of the present invention, the present invention also provides a micro-signal multi-stage amplification method for a biosensor, which is applied to the micro-signal multi-stage amplification device 1 shown in FIG. As shown in Fig. 2, Fig. 2 is a flow chart of a preferred embodiment of the micro-signal multi-stage amplification method of the biosensor of the present invention. In this embodiment, the micro-signal multi-stage amplification method includes steps S21 to S27.

[0041] Step S21, the first differential amplifier acquires the first micro signal from the first biosensor and acquires the second micro signal from the second biosensor; specifically, the first differential op amp 11 acquires the first biosensor 2 A microsignal and a second microsignal is obtained from the second biosensor 3. In this embodiment, the first micro signal is that the first biosensor 2 senses a characteristic electric signal generated by the first wavelength infrared light being irradiated on the target detection object, and the second micro signal is sensed by the second biosensor 3 The second wavelength infrared light is irradiated to illuminate the characteristic electrical signal generated on the target detection object.

[0042] Step S22, the first differential amplifier performs differential operation on the first micro signal and the second micro signal by using the amplification factor of the first differential op amp 11 to obtain a first differential signal. Specifically, the first differential op amp The first and second micro signals are differentially operated by the amplification of the first differential op amp 11 and amplified to obtain a first differential signal. The amplification factor of the first differential op amp 11 is equal to the ratio of the second resistor R2 of the first differential amplifier 11 and the resistance value of the first resistor R1, and is generated by the temperature coefficient K1 of the first differential op amp 11 The effect of temperature drift. In the present embodiment, the temperature coefficient K1 of the first differential amplifier 11 is determined by the temperature coefficient of the second resistor R2 and the first resistor R1 in the first differential amplifier 11. For example, the temperature coefficient of the first resistor R1 is expressed as QCR1=?R1/R1??T, and the temperature coefficient of the second resistor R2 is expressed as QCR2=?R2/R2??T, where QCR1 is the temperature of the first resistor R1. The coefficient, QCR2 is the temperature coefficient of the second resistor R2, ? T is the temperature change value, ? R1 refers to the first resistor R1 under temperature change Resistance change value, ? R2 is the resistance change value of the second resistor R2 under temperature change, / represents the division operation, ? Represents multiplication. In practical applications, the temperature coefficient usually uses the average temperature coefficient, and has a negative temperature coefficient, a positive temperature coefficient, and a critical temperature coefficient at which the resistance will only abrupt at a certain temperature. The temperature coefficient K1 of the first differential amplifier 11 is equal to the ratio of the temperature coefficient QCR2 of the second resistor R2 to the QCR1 of the temperature coefficient of the first resistor R1, that is, K1 = QCR2 / QCR1.

[0043] Step S23, the second differential amplifier acquires the third micro signal from the third biosensor and acquires the fourth micro signal from the fourth biosensor; specifically, the second differential amplifier 12 acquires the third micro from the third biosensor 4. The signal and the fourth micro-signal are acquired from the fourth biosensor 5. In this embodiment, the third micro signal is that the third biosensor 4 senses the characteristic electric signal generated by the third wavelength infrared light on the target detection object, and the fourth micro signal is sensed by the fourth biosensor 5 The fourth wavelength infrared light is irradiated to illuminate the characteristic electrical signal generated on the target detection object.

[0044] Step S24, the second differential amplifier performs differential operation on the third micro signal and the fourth micro signal by using the amplification factor of the second differential amplifier, and amplifies the second differential signal; specifically, the second differential amplifier 12 The third micro signal and the fourth micro signal are differentially operated by the amplification factor of the second differential amplifier 12 and amplified to obtain a second differential signal. In the present embodiment, the amplification factor of the second differential amplifier 12 is equal to the amplification factor of the first differential amplifier 11.

[0045] Step S25, the third differential amplifier performs differential operation on the first differential signal and the second differential signal through the second amplification factor of the third differential amplifier, and amplifies the measurement characteristic signal; specifically, the third differential amplifier 13 The first differential signal and the second differential signal are differentially operated by the amplification factor of the third differential amplifier 13 and amplified to obtain a measurement characteristic signal. The amplification factor of the third differential amplifier 13 is equal to the ratio of the resistance values of the fourth resistor R4 and the third resistor R3 in the third differential amplifier 13, and is affected by the temperature drift caused by the temperature coefficient K2 of the third differential amplifier 13. In the present embodiment, the temperature coefficient K2 of the third differential amplifier 13 is determined by the temperature coefficients of the fourth resistor R4 and the third resistor R3 in the third differential amplifier 13. For example, the temperature coefficient of the third resistor R3 is expressed as QCR3=?R3/R3??T, and the temperature coefficient of the fourth resistor R4 is expressed as QCR4=?R4/R4??T, where QCR3 is the temperature of the third resistor R3. The coefficient, QCR4 is the temperature coefficient of the fourth resistor R4, ? T is the temperature change value, ? R3 is the resistance change value of the third resistor R3 under temperature change, ? R4 is the resistance change value of the fourth resistor R4 under temperature change, / represents the division operation, ? Represents multiplication. The temperature coefficient K2 of the third differential amplifier 13 The ratio of the temperature coefficient QCR4 of the fourth resistor R4 to the temperature coefficient QCR3 of the third resistor R3, that is, K2 = QCR4 / QCR3.

[0046] Step S26, the amplification circuit chip amplifies the measurement characteristic signal by the amplification factor of the amplification circuit chip, and outputs the signal to the ADC circuit chip. Specifically, the amplification circuit chip 141 passes the measurement characteristic signal through the amplification circuit chip 141. The amplification factor is amplified by the signal and output to the ADC circuit chip 142. In the embodiment, the amplifying circuit chip 141 is composed of an amplifying circuit in the prior art, and the AD C circuit chip 142 is composed of a digital-to-analog converting circuit in the prior art. It can be understood by those skilled in the art that the amplification factor of the amplifying circuit chip 141 is an inherent specific value of the amplifying circuit chip 141, that is, the amplifying circuit chip 141 has an inherent amplification property, but is subjected to the amplifying circuit chip 141 during operation. The temperature coefficient K3 produces the effect of temperature drift. The temperature coefficient K3 of the amplifying circuit chip 141 is an inherent temperature characteristic of the amplifying circuit chip 141, which reflects the severity of the temperature drift of the amplifying circuit chip 141 caused by the amplifying circuit chip 141 in the case of a change in operating temperature. The amplifying circuit chip 141 generates a temperature drift phenomenon with a change in operating temperature to cause signal interference with the measured characteristic signal, thereby causing the measured characteristic signal to be submerged in the interfering signal, and thus the measured characteristic signal cannot be accurately measured. In the present embodiment, by determining the temperature coefficients of the first resistor R1 and the second resistor R2 in the first differential amplifier 11 and the second differential amplifier 12, and by determining the third resistor R3 and the third in the third differential amplifier 13 The temperature coefficient of the fourth resistor R4 is such that the product of the temperature coefficient K1 of the first differential amplifier 11 and the temperature coefficient K2 of the third differential amplifier 13 is equal in magnitude and opposite in sign to the temperature coefficient K3 of the amplifying circuit chip 141, thus making the first The influence of the temperature drift generated by the differential amplifier 11 and the third differential amplifier 13 on the weak signal interference and the influence of the temperature drift generated by the amplifying circuit chip 141 on the weak signal interference cancel each other, thereby eliminating the signal amplification of the weak signal in the high-magnification amplifier circuit.信号 Signal interference caused by temperature drift.

[0047] Step S27, the ADC circuit chip performs digital-to-analog conversion on the amplified measurement characteristic signal, and outputs the signal to the single-chip microcomputer for signal measurement and analysis. Specifically, the ADC circuit chip 142 performs digital-to-analog conversion on the amplified measurement characteristic signal and outputs the signal to the ADC. The single chip microcomputer 15 is used for subsequent signal measurement analysis.

[0048] The micro-signal multi-stage amplifying apparatus and method for the biosensor of the present invention can obtain a measured characteristic signal by acquiring four weak characteristic electric signals and performing differential operation through a multi-stage differential amplifier and performing high-magnification amplification, thereby achieving The effect of measuring weak characteristic electrical signals. In addition, the present invention also utilizes The effect of the temperature drift generated by the multi-stage differential amplifier on the weak signal interference cancels out the influence of the temperature drift generated by the amplifying circuit chip itself on the weak signal interference, thereby achieving the elimination of the weak signal in the high-magnification amplifier circuit for signal amplification. Signal interference caused by temperature drift improves the accuracy of measuring weak signals.

[0049]

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalent structure or equivalent function changes made by the description of the present invention and the contents of the drawings, or directly or indirectly applied to other related The technical field is equally included in the scope of patent protection of the present invention.

Industrial applicability

Claims

Claim

[Claim 1] A micro-signal multi-stage amplifying device of a biosensor, wherein the micro-signal multi-stage amplifying device is connected to a first biosensor, a second biosensor, a third biosensor, and a fourth biosensor, wherein The micro-signal multi-stage amplifying device includes a first differential amplifier

a second differential amplifier, a third differential amplifier, an ADC amplification chip, and a single chip microcomputer, wherein the first differential amplifier and the second differential amplifier each include two first resistors and two second resistors, and the third differential amplifier includes two a third resistor and two fourth resistors, wherein: the first differential op amp is configured to acquire a first micro signal from a first biosensor and to acquire a second micro signal from a second biosensor, The second micro signal is differentially operated by the amplification of the first differential op amp and amplified to obtain a first differential signal, and the amplification factor of the first differential amplifier is equal to the second resistance of the first differential amplifier and the first resistor a ratio of resistance values; the second differential amplifier is configured to acquire a third micro signal from the third biosensor and acquire a fourth micro signal from the fourth biosensor, and pass the third differential signal and the fourth micro signal through the second differential The amplification factor of the amplifier is differentially operated and amplified to obtain a second differential signal, and the amplification factor of the second differential amplifier is equal to a magnification of a differential amplifier; the third differential amplifier is configured to differentially calculate a first differential signal and a second differential signal by amplifying the third differential amplifier, and amplify the measured characteristic signal, the third differential amplifier The amplification factor is equal to a ratio of the resistance values of the fourth resistor and the third resistor in the third differential amplifier; the ADC amplification chip includes an amplification circuit chip and an ADC circuit chip, and the amplification circuit chip is configured to use the measurement characteristic signal The signal is amplified by the amplification factor of the amplifying circuit chip and output to the ADC circuit chip, and the amplification factor of the amplifying circuit chip is an inherently specific value of the amplifying circuit chip.

[Claim 2] The micro-signal multi-stage amplifying device of the biosensor according to claim 1, wherein

: a first input of the first differential amplifier is coupled to the first biosensor, a second input of the first differential amplifier is coupled to the second biosensor; and a first input of the second differential amplifier is coupled to the third a second sensor of the second differential amplifier is connected to the fourth biosensor; the output of the first differential amplifier is connected to the third difference a first input end of the sub-amplifier, an output of the second differential amplifier is coupled to a second input of the third differential amplifier; an output of the third differential amplifier is coupled to an input of the amplifying circuit chip, the amplifying An output of the circuit chip is coupled to an input of the ADC circuit chip, and an output of the ADC circuit chip is coupled to the microcontroller.

[Claim 3] The micro-signal multi-stage amplifying device of the biosensor according to claim 1, wherein

The first differential amplifier further includes a first transistor, one of the first resistors of the first differential amplifier is connected in series to the first input of the first transistor, and the other of the first resistors is connected in series to the first a second input end of a transistor, one end of one of the second resistors of the first differential amplifier is connected to the first input end of the first transistor and the other end of the second resistor is connected to the output end of the first transistor One of the other second resistors of the first differential amplifier is connected to the second input terminal of the first transistor and the other end of the second resistor is connected to the ground line.

[Claim 4] The micro-signal multi-stage amplifying device of the biosensor according to claim 1, wherein

The second differential amplifier further includes a first transistor, one of the first resistors of the second differential amplifier is connected in series to the first input of the first transistor, and the other of the second resistors is connected in series to the first a second input end of a transistor, one end of one of the second resistors of the second differential amplifier is connected to the first input end of the first transistor and the other end of the second resistor is connected to the output end of the first transistor One of the other second resistors of the second differential amplifier is connected to the second input terminal of the first transistor and the other end of the second resistor is connected to the ground line.

[Claim 5] The micro-signal multi-stage amplifying device of the biosensor according to claim 1, wherein

The third differential amplifier further includes a second transistor, wherein a third resistor is connected in series to the first input of the second transistor, and the other third resistor is connected in series to the second input of the second transistor, wherein One end of a fourth resistor is connected to the first input end of the second transistor and the other end of the fourth resistor is connected to the output end of the second transistor, wherein one end of the other fourth resistor is connected to the second transistor The second input and the other end of the fourth resistor are connected to the ground line.

[Claim 6] The micro-signal multi-stage amplifying device of the biosensor according to claim 1, wherein The ADC circuit chip is configured to perform digital-to-analog conversion on the amplified measurement characteristic signal and output the signal to the single-chip microcomputer for signal measurement analysis.

[Claim 7] The micro-signal multi-stage amplifying device of the biosensor according to any one of claims 1 to 6, wherein the first biosensor is configured to sense a first wavelength infrared light irradiation at a target detection a first micro signal generated on the object, a second biosensor for sensing a second micro signal generated by the second wavelength infrared light on the target detection object, and a third biosensor for sensing the third wavelength infrared light illumination The third micro-signal generated on the target detection object is used to sense the fourth micro-signal generated by the fourth-wavelength infrared light irradiation on the target detection object.

[Claim 8] A micro-signal multi-stage amplification method for a biosensor, which is applied to a micro-signal multi-stage amplification device, wherein the micro-signal multi-stage amplification device is connected with a first biosensor, a second biosensor, and a third biosensor And a fourth biosensor, wherein the micro signal multistage amplifying device comprises a first differential amplifier, a second differential amplifier, a third differential amplifier, an ADC amplification chip, and a single chip microcomputer, and the first differential amplifier and the second differential amplifier are both The first differential resistor includes two second resistors, and the second differential amplifier includes two third resistors and two fourth resistors. The ADC amplification chip includes an amplification circuit chip and an AD C circuit chip, where the micro The signal multi-stage amplification method includes the following steps: the first differential op amp acquires a first micro signal from a first biosensor and acquires a second micro signal from a second biosensor; the first differential op amp will be first The micro signal and the second micro signal are differentially operated by the amplification of the first differential op amp and amplified to obtain the first a sub-signal, the amplification factor of the first differential amplifier is equal to a ratio of a resistance of the second resistor and the first resistor in the first differential amplifier; the second differential amplifier acquires a third micro-signal from the third biosensor and The fourth biosensor acquires a fourth micro signal; the second differential amplifier performs differential operation on the third micro signal and the fourth micro signal by using a magnification of the second differential amplifier, and amplifies the second differential signal, the second The amplification factor of the differential amplifier is equal to the amplification factor of the first differential amplifier; the third differential amplifier performs differential operation on the first differential signal and the second differential signal by the amplification factor of the third differential amplifier, and amplifies the measured characteristic signal. The amplification factor of the third differential amplifier is equal to a ratio of a resistance value of the fourth resistor and the third resistor of the third differential amplifier; the amplifier circuit chip amplifies the measurement characteristic signal by the amplification factor of the amplifier circuit chip, and outputs the signal to the ADC circuit chip, where the amplification is performed. The amplification factor of the circuit chip is an inherently specific value of the amplifying circuit chip.

[Claim 9] The method of micro-signal multi-stage amplification of a biosensor according to claim 8, wherein

The first micro signal is that the first biosensor senses the characteristic electric signal generated by the first wavelength infrared light irradiation on the target detection object, and the second micro signal is that the second biosensor senses the second wavelength infrared light irradiation. a characteristic electrical signal generated on the target detection object, the third micro signal is that the third biosensor senses the characteristic electric signal generated by the third wavelength infrared light irradiation on the target detection object, and the fourth micro signal is the fourth biosensor sense The characteristic electric signal generated by the fourth wavelength infrared light on the target detection object is detected.

The micro-signal multi-stage amplification method of the biosensor according to claim 8 or 9, wherein the ADC amplification chip further comprises an ADC circuit chip, and the micro-signal multi-stage amplification method further comprises a step The ADC circuit chip performs digital-to-analog conversion on the amplified measurement characteristic signal and outputs the signal to the single-chip microcomputer for signal measurement analysis.