Sixteen-electrode biological impedance measuring circuit

CN119302639APending Publication Date: 2025-01-14GUANGDONG ICOMON TECH CO LTD
View PDF 5 Cites 0 Cited by

Patent Information

Application Number
CN202411174261.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-08-26
Publication Date
2025-01-14

AI Technical Summary

Technical Problem

The existing biological impedance measurement products have long measurement loops that cause signal attenuation, affecting the accuracy and accuracy of the data. They cannot directly test the trunk impedance, and need to be converted through multiple sets of measurement paths, which lacks accuracy.

Method used

A sixteen electrode biological impedance measurement circuit was designed, which contacted different positions of the human body through 16 electrodes. The analog switch circuit, sine wave generation circuit and impedance voltage acquisition circuit are used to control electrode communication and data acquisition, and the measurement circuit is optimized. , reduce signal attenuation and directly measure trunk impedance.

Benefits of technology

It improves the accuracy and stability of the test data, can directly and accurately measure the trunk impedance, and avoids data fluctuations caused by multiple sets of measurement path conversion.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN119302639A_ABST
    Figure CN119302639A_ABST
Patent Text Reader

Abstract

The invention discloses a sixteen-electrode biological impedance measuring circuit, which comprises sixteen electrode circuits, electrode ends of which are respectively in contact with different positions of a human body; the analog switch circuit is used for controlling different electrode circuits to be connected; the sine wave generation circuit is used for converting the square wave signal into a sine wave signal and sending the sine wave signal to the analog switch circuit; the impedance voltage acquisition circuit is used for acquiring data generated when different electrode circuits are connected; the main control circuit is used for sending square wave signals to the sine wave generation circuit, controlling the analog switch circuit to enable different electrode circuits to be connected, receiving data collected by the impedance voltage collection circuit for calculation processing, optimizing a measurement loop, reducing the signal attenuation problem and improving the accuracy and stability of test data. And meanwhile, the trunk impedance TR can be accurately, stably and directly tested, and the problem of data fluctuation caused by conversion of multiple groups of measurement paths is avoided.
Need to check novelty before this filing date? Find Prior Art

Description

[Technical field]

[0001] The invention relates to a sixteen-electrode bioimpedance measurement circuit. [Background Technology]

[0002] Among the bioimpedance measurement products currently on the market, body impedance testing is generally performed through 8 electrodes. The basic principle of the test is to perform impedance testing through the left and right hand loops, the left and right foot loops, the left hand and left foot loops, the left hand and right foot loops, the right hand and right foot loops, and the right hand and left foot loops. This type of loop test has the problem of attenuation of the test signal due to the long measurement loop, which affects the accuracy and precision of the measurement data. At the same time, due to the problem of the measurement path, the trunk impedance TR cannot be directly tested. Therefore, the trunk impedance TR is usually calculated through multiple sets of measurement paths and lacks accuracy. [Summary of the invention]

[0003] The present invention overcomes the shortcomings of the prior art and provides a sixteen-electrode bioimpedance measurement circuit.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A sixteen-electrode bioimpedance measurement circuit, characterized in that:

[0006] The electrode circuit is provided with 16 electrodes, and the electrode ends are in contact with different positions of the human body respectively;

[0007] The analog switch circuits are connected to the 16 electrode circuits respectively and are used to control the connectivity of different electrode circuits;

[0008] A sine wave generating circuit is connected to the analog switch circuit and is used to convert a square wave signal into a sine wave signal and send the signal to the analog switch circuit;

[0009] An impedance voltage acquisition circuit is connected to the analog switch circuit and is used to collect data generated when different electrode circuits are connected;

[0010] The main control circuit is respectively connected to the analog switch circuit, the sine wave generating circuit and the impedance voltage collecting circuit, and is used to send a square wave signal to the sine wave generating circuit, control the analog switch circuit to connect different electrode circuits, and receive data collected by the impedance voltage collecting circuit for calculation and processing.

[0011] A sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the main control circuit sends 20KHz and 100KHz square wave signals to the sine wave generating circuit; the sine wave generating circuit converts the 20KHz square wave signal and the 100KHz square wave signal into 20KHz sine wave signal and 100KHz sine wave signal and sends them to the analog switch circuit.

[0012] A sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the 16 electrode circuits are respectively HVL left hand voltage acquisition electrode circuit, HVR right hand voltage acquisition electrode circuit, FVL left foot voltage sampling electrode circuit, FVR right foot voltage sampling electrode circuit, HIL left hand current excitation electrode circuit, HIR right hand current excitation electrode circuit, FIL left foot current excitation electrode circuit, FIR current excitation electrode circuit, CVL left chest voltage sampling electrode circuit, CVR right chest voltage sampling electrode circuit, AVL left abdomen voltage sampling electrode circuit, AVR right abdomen voltage sampling electrode circuit, CIL left chest current excitation electrode circuit, CIR right chest current excitation electrode circuit, AIL left abdomen current excitation electrode circuit, AIR right abdomen current excitation electrode circuit.

[0013] A sixteen-electrode bioimpedance measurement circuit as described above, characterized in that: the HVR right-hand voltage acquisition electrode circuit includes a right-hand electrode PAD, which is connected to one end of a resistor R73, one end of a resistor R67, and one end of a resistor R79 respectively through a resistor R43, a resistor R55, and a capacitor C86, a capacitor C74 is connected in parallel with the resistor R43, the other end of the resistor R73 is connected to the power supply VA, the other end of the resistor R67 is grounded, the other end of the resistor R79 is connected to the pin 3 of the operational amplifier U10A, the pin 2 of the operational amplifier U10A is connected to the pin 1 of the operational amplifier U10A through a resistor E88 and a capacitor C92, the pin 4 of the operational amplifier U10A is connected to the power supply VCC, the pin 11 of the operational amplifier U10A is grounded, and the pin 1 of the operational amplifier U10A is connected to the analog switch circuit;

[0014] The circuit structures of the HVL left hand voltage sampling electrode circuit, the FVL left foot voltage sampling electrode circuit, the FVR right foot voltage sampling electrode circuit, the CVL left chest voltage sampling electrode circuit, the CVR right chest voltage sampling electrode circuit, the AVL left abdomen voltage sampling electrode circuit, and the AVR right abdomen voltage sampling electrode circuit are the same as the HVR right hand voltage sampling electrode circuit.

[0015] A sixteen-electrode bioimpedance measurement circuit as described above, characterized in that: the right-hand current excitation electrode circuit includes a left-hand electrode PAD, the left-hand electrode PAD is connected to the analog switch circuit through resistors R44 and R56 in sequence, and the capacitor C75 is connected in parallel with the resistor R44;

[0016] The circuit structures of the HIL left hand current excitation electrode circuit, FIL left foot current excitation electrode circuit, FIR current excitation electrode circuit, CIL left chest current excitation electrode circuit, CIR right chest current excitation electrode circuit, AIL left abdomen current excitation electrode circuit, and AIR right abdomen current excitation electrode circuit are uniform and the same as the HIR right hand current excitation electrode circuit.

[0017] The sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the analog switch circuit includes an analog switch chip U12, an analog switch chip U13, an analog switch chip U14 and an analog switch chip U15, the analog switch chip U12 pin 14 is connected to the HIR right hand current excitation electrode circuit, the analog switch chip U12 pin 12 is connected to the HIL left hand current excitation electrode circuit, the analog switch chip U12 pin 1 is connected to the CIL left chest current excitation electrode circuit, the analog switch chip U12 pin 15 is connected to the AIL left abdomen current excitation electrode circuit, the analog switch chip U12 pin 13 and pin 3 are respectively connected to the sine wave generating circuit, the analog switch chip U12 pin 11 is connected to the AIR right abdomen current excitation electrode circuit, the analog switch chip U12 pin 6 and pins 9-10 are respectively connected to the main control circuit, the analog switch chip U12 pin 16 is connected to the power supply VCC, the analog switch chip U12 pin 2 is connected to the FIL left foot current excitation electrode circuit, and the analog switch chip U12 pin 5 is connected to the CIR right chest current excitation electrode circuit , pin 4 of the analog switch chip U12 is connected to the FIR right foot current excitation electrode circuit, and pins 7-8 of the analog switch chip U12 are grounded; pin 14 of the analog switch chip U13 is connected to the AIR right abdomen current excitation electrode circuit, pin 12 of the analog switch chip U13 is connected to the AIL left abdomen current excitation electrode circuit, pin 1 of the analog switch chip U13 is connected to the CIR right chest current excitation electrode circuit, pin 13 and pin 3 of the analog switch chip U13 are respectively connected to the sine wave generating circuit, and pin 11 of the analog switch chip U13 is connected to the sine wave generating circuit through The resistor R127 is respectively connected to one end of the resistor R126 and the pin 11 of the analog switch chip U15, the pin 4 of the analog switch chip U13 is respectively connected to the other end of the resistor R126 and the pin 4 of the analog switch chip U15 through the resistor R125, the pin 6 and pins 9-10 of the analog switch chip U13 are respectively connected to the main control circuit, the pin 16 of the analog switch chip U13 is connected to the power supply VCC, the pin 5 of the analog switch chip U13 is connected to the CIL left chest current excitation electrode circuit, and the pins 7-8 of the analog switch chip U13 are respectively grounded;Pin 14 of the analog switch chip U14 is connected to the right-hand voltage collection electrode circuit of HVR, pin 12 of the analog switch chip U14 is connected to the left-hand voltage collection electrode circuit of HVL, pin 1 of the analog switch chip U14 is connected to the left chest voltage sampling electrode circuit of CVL, pin 15 of the analog switch chip U14 is connected to the left abdomen voltage sampling electrode circuit of AVL, pin 13 and pin 3 of the analog switch chip U14 are respectively connected to the impedance voltage collection circuit, pin 11 of the analog switch chip U14 is connected to the right abdomen voltage sampling electrode circuit of AVR, pin 6 and pins 9-10 of the analog switch chip U14 are respectively connected to the main control circuit, pin 16 of the analog switch chip U14 is connected to the power supply VCC, pin 2 of the analog switch chip U14 is connected to the left foot voltage sampling electrode circuit of FVL, and pin 5 of the analog switch chip U14 is connected to the right chest of CVR Front voltage sampling electrode circuit, analog switch chip U14 pin 4 is connected to FVR right foot voltage sampling electrode circuit, analog switch chip U14 pin 7-8 are grounded respectively; analog switch chip U15 pin 14 is connected to AVR right abdomen voltage sampling electrode circuit, analog switch chip U15 pin 12 is connected to AVL left abdomen voltage sampling electrode circuit, analog switch chip U15 pin 1 is connected to CVR right chest voltage sampling electrode circuit, analog switch chip U15 pin 13 and pin 3 are connected to impedance voltage acquisition circuit respectively, analog switch chip U15 pin 6 and pins 9-10 are connected to main control circuit respectively, analog switch chip U15 pin 16 is connected to power supply VCC, analog switch chip U15 pin 5 is connected to CVL left chest voltage sampling electrode circuit, analog switch chip U15 pin 7-8 are grounded respectively. ;

[0018] The sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the sine wave generating circuit includes an operational amplifier U6A, the operational amplifier U6A pin 1 is connected to one end of the capacitor C56 and one end of the resistor R87 through the resistor R68 and the resistor R88 in sequence, the other end of the resistor R87 is connected to one end of the capacitor C55 and one end of the resistor R86, the other end of the resistor R86 is connected to one end of the capacitor C54 and one end of the resistor R85, the other end of the resistor R85 is connected to one end of the resistor R84 and one end of the resistor R81, and the other end of the resistor R84 is connected to one end of the capacitor C54 and one end of the resistor R85. The pins 1 and 2 of the filter U8 and one end of the resistor R83 are connected respectively. The other end of the resistor R83 is connected to the other end of the resistor R81 and the main control circuit respectively. The pin 3 of the filter U8, the other end of the capacitor C54, the other end of the capacitor C55, and the other end of the capacitor C56 are grounded respectively. The pin 2 of the operational amplifier U6A is connected to one end of the capacitor C50 and one end of the resistor R74 through the resistor R75 respectively. The other end of the capacitor R74 is connected to one end of the capacitor C49 and one end of the resistor R73 respectively. The other end of the resistor R73 is connected to one end of the capacitor C48 and one end of the resistor R72 respectively. The other end of resistor R72 is connected to one end of resistor R69 and one end of resistor R71 respectively. The other end of resistor R71 is connected to pin 1 and pin 2 of filter U7 and one end of resistor R70 respectively. The other end of resistor R70 is connected to the other end of resistor R69 and the main control circuit respectively. Pin 3 of filter U7, the other end of capacitor C48, the other end of capacitor C49 and the other end of capacitor C50 are grounded respectively. Pin 3 of op amp U6A is connected to power supply VA, pin 4 of op amp U6A is connected to power supply VCC, pin 11 of op amp U6A is grounded, and op amp Pin 1 of U6A is connected to the analog switch circuit and pin 9 of op amp U6C through resistor R76 respectively. Pin 10 of op amp U6C is connected to one end of capacitor C53, one end of resistor R82 and pin 14 of op amp U6D respectively. Pin 12 of op amp U6D is connected to the power supply VA. Pin 13 of op amp U6D is connected to the other end of resistor R82, the other end of capacitor C53 and one end of resistor R79 respectively. The other end of resistor R79 is connected to one end of resistor R80 and pin 8 of op amp U6C respectively. The other end of resistor R80 is connected to the analog switch circuit.

[0019] The sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the impedance voltage acquisition circuit includes an operational amplifier U10A, pin 2 of the operational amplifier U10A is respectively connected to one end of a resistor R94 and one end of a resistor R102, the other end of the resistor R102 is respectively connected to one end of a resistor R99 and one end of a capacitor C64, the other end of the resistor R99 and the other end of the capacitor C64 are respectively connected to one end of a capacitor C65, one end of a capacitor C67, and an analog switch circuit, the other end of the capacitor C67 is grounded, pin 3 of the operational amplifier U10A is respectively connected to one end of a resistor R100 and one end of a resistor R105, the other end of the resistor R105 is respectively connected to one end of a resistor R98 and one end of a capacitor C66, the other end of the resistor R98 and the other end of the resistor R100 are respectively connected to the analog switch circuit. The power source VA is connected, the other end of the capacitor C66 is respectively connected to the other end of the capacitor C65, one end of the capacitor C68, and the analog switch circuit, the other end of the capacitor C68 is grounded, the pin 1 of the operational amplifier U10A is respectively connected to one end of the resistor R103, the other end of the resistor R94, and one end of the capacitor C59, the other end of the capacitor C59 is respectively connected to one end of the capacitor C60 and one end of the resistor R108, the other end of the capacitor C60 is respectively connected to one end of the resistor R90 and the pin 3 of the operational amplifier U9A, the other end of the resistor R90 is connected to the power supply VA, the pin 11 of the operational amplifier U9A is connected to the power supply VCC, the pin 4 of the operational amplifier U9A is grounded, the pin 2 of the operational amplifier U9A is respectively connected to one end of the resistor 106 and one end of the resistor R91, and the other end of the resistor R91 is connected to the power supply VA , the other end of resistor R106 is respectively connected to pin 1 of op amp U9A, the other end of resistor R108, and one end of capacitor C61, the other end of capacitor C61 is respectively connected to one end of resistor R109 and one end of capacitor C62, the other end of capacitor C62 is respectively connected to one end of resistor R92 and pin 5 of op amp U9B, the other end of resistor R92 is connected to power supply VA, pin 6 of op amp U9B is respectively connected to one end of resistor R107 and one end of resistor R93, the other end of resistor R93 is connected to power supply VA, the other end of resistor R107 is respectively connected to the other end of resistor R109, pin 7 of op amp U9B, and one end of resistor R97, the other end of resistor R97 is respectively connected to one end of capacitor C63 and pin 10 of op amp U9C, the other end of capacitor C63 Connected to the power supply VA, the operational amplifier U9C pin 9 is respectively connected to one end of the resistor R110 and one end of the resistor R96, the other end of the resistor R96 is connected to the power supply VA, the other end of the resistor R110 is respectively connected to the operational amplifier U9C pin 8 and one end of the resistor R101, the other end of the resistor R101 is respectively connected to the operational amplifier U9D pin 13, the rectifier diode D1 pin 1, and one end of the resistor R89, the operational amplifier U9D pin 12 is connected to the power supply VA through the end R104, the operational amplifier U9D pin 14 is connected to the rectifier diode D1 pin 3, the rectifier diode D1 pin 2 is respectively connected to the other end of the resistor R89, one end of the capacitor C57, and one end of the resistor R95, the other end of the resistor R95 is respectively connected to the other end of the capacitor C58 and the main control circuit,The other end of capacitor C57 and the other end of capacitor C58 are connected to the power supply VA respectively; the other end of resistor R103 is connected to one end of resistor R122 and one end of capacitor C69 respectively, the other end of resistor R122 is connected to one end of capacitor C75 and pin 10 of op amp U10C respectively, pin 9 of op amp U10C is connected to one end of resistor R111 and one end of resistor R118 respectively, the other end of resistor R118 and the other end of capacitor C75 are connected to the power supply VA respectively, pin 8 of op amp U10C is connected to the other end of capacitor C69 and resistor R11 1 and one end of resistor R119, the other end of resistor R119 is respectively connected to one end of resistor R120 and one end of capacitor C70, the other end of resistor R120 is respectively connected to one end of capacitor C74 and pin 5 of op amp U10B, pin 6 of op amp U10B is respectively connected to one end of resistor R112 and one end of resistor R117, the other end of resistor R117 and the other end of capacitor C74 are respectively connected to power supply VA, pin 7 of op amp U10B is respectively connected to the other end of capacitor C70, the other end of resistor R112 and one end of capacitor C73 , the other end of capacitor C73 is connected to one end of resistor R115 and pin 12 of op amp U10D respectively, the other end of resistor R115 is connected to power supply VA, pin 13 of op amp U10D is connected to one end of resistor R124 and one end of resistor R116 respectively, the other end of resistor R116 is connected to power supply VA, pin 14 of op amp U10D is connected to the other end of resistor 124 and one end of resistor R121 respectively, the other end of resistor R121 is connected to one end of resistor R113, pin 1 of rectifier diode D2 and pin 2 of op amp U11A respectively. The pin 3 of the op amp U11A is connected to the power supply VA through the resistor R123, the pin 4 of the op amp U11A is connected to the power supply VCC, the pin 11 of the op amp U11A is grounded, the pin 1 of the op amp U11A is connected to the pin 3 of the rectifier diode D2, the pin 2 of the rectifier diode D2 is respectively connected to the other end of the resistor R113, one end of the capacitor C71, and one end of the resistor R114, the other end of the resistor R114 is respectively connected to one end of the capacitor C72 and the main control circuit, and the other end of the capacitor C71 and the other end of the capacitor C72 are respectively connected to the power supply VA.

[0020] The sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: the main control circuit includes a Bluetooth chip U10, the pin 1 of the Bluetooth chip U10 is respectively connected to one end of the capacitor C32, the pin 4 of the crystal oscillator Y2, and one end of the capacitor C34 through the capacitor C31, the pin 2 of the Bluetooth chip U10 is respectively connected to the other end of the capacitor C32 and the pin 3 of the crystal oscillator Y2, the pin 3 of the Bluetooth chip U10 is respectively connected to the other end of the capacitor C34 and the pin 1 of the crystal oscillator Y2, the pin 2 and pin 4 of the crystal oscillator Y2 are respectively grounded, the pin 4 of the Bluetooth chip U10 is connected to the power supply VA, the pin 5 and pin 12 of the Bluetooth chip U10 are respectively connected to the impedance voltage acquisition circuit, the pins 6-7 of the Bluetooth chip U10 are respectively connected to the sine wave generating circuit, the pin 9 of the Bluetooth chip U10 is connected to one end of the crystal oscillator Y1, and the other end of the crystal oscillator Y1 is grounded, and the Bluetooth chip U10 is connected to the power supply VA. Pin 13 is respectively connected to one end of capacitor C41 and one end of capacitor C42, the other end of capacitor C42 is grounded, and the other end of capacitor C41 is connected to the power supply VDD3.3V. Pin 14 of Bluetooth chip U10 is grounded, and pin 15 of Bluetooth chip U10 is grounded through inductor L2 and capacitor C40 in turn. Pin 16 of Bluetooth chip U10 is respectively connected to one end of capacitor C38, capacitor C9 and power supply VDD3.3V, and the other end of capacitor C38 and the other end of capacitor C39 are grounded respectively. Capacitor C36 is respectively connected to pin 17 and pin 18 of Bluetooth chip U10, pin 19 of Bluetooth chip U10 is grounded through capacitor C3, pins 23-30 of Bluetooth chip U10 are respectively connected to the analog switch circuit, pin 31 of Bluetooth chip U10 is grounded through capacitor C24, and pin 33 of Bluetooth chip U10 is grounded.

[0021] A sixteen-electrode bioimpedance measurement circuit as described above is characterized in that: it also includes a power supply circuit for power supply and an antenna circuit connected to the main control circuit for sending and receiving signals, the power supply circuit includes an operational amplifier U6B, pin 5 of the operational amplifier U6B is respectively connected to one end of a resistor R78, one end of a capacitor C52, one end of a capacitor C51, and one end of a resistor R77, the other end of the resistor R78, the other end of the capacitor C52, and the other end of the capacitor C51 are respectively grounded, the other end of the resistor R77 is connected to a power supply VCC, pin 7 of the operational amplifier U6B is connected to pin 6 of the operational amplifier U6B, and Pin 7 of operational amplifier U6B outputs power supply VA; the antenna circuit includes antenna ANT1, pin 2 of antenna ANT1 is respectively connected to one end of capacitor C27 and one end of capacitor C25, the other end of capacitor C25 is respectively connected to one end of capacitor C30 and one end of capacitor C26, the other end of capacitor C26 is respectively connected to one end of capacitor C28 and one end of inductor L1, the other end of inductor L1 is respectively connected to one end of capacitor C29 and the main control circuit, pin 1 of antenna ANT1, the other end of capacitor C27, the other end of capacitor C30, the other end of capacitor C28 and the other end of capacitor C29 are respectively grounded.

[0022] The beneficial effects of the present invention are:

[0023] The present invention sets 16 electrode circuits to perform body impedance testing, controls the operation of the analog switch circuit through the main control circuit to form loops for different parts of the body, collects digital signal data of the loops of different body parts through the impedance voltage acquisition circuit, and finally processes the digital signal data of the loops of different body parts through the main control circuit to obtain body impedance information. This case belongs to a brand-new testing method, which reduces the attenuation problem of the signal and improves the accuracy and stability of the test data by optimizing the measurement loop, and can directly test the trunk impedance TR accurately and stably, avoiding the data fluctuation problem caused by the conversion of multiple groups of measurement paths. [Drawings]

[0024] Figure 1 It is the principle diagram of the present invention;

[0025] Figure 2 This is one of the schematic diagrams of the contact between some electrodes and the human body of the present invention;

[0026] Figure 3 This is the second schematic diagram of the contact between some electrodes and the human body of the present invention;

[0027] Figure 4 This is a schematic diagram of the circuit structure of 16 electrodes of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure of the analog switch circuit of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the sine wave generating circuit of the present invention;

[0030] Figure 7 This is a schematic diagram of the structure of the impedance voltage acquisition circuit of the present invention;

[0031] Figure 8 This is a schematic diagram of the main control circuit structure of the present invention;

[0032] Fig. 9 This is a schematic diagram of the power supply circuit structure of the present invention;

[0033] Fig.10 It is a schematic diagram of the structure of the antenna circuit of the present invention;

[0034] Fig.11 It is a schematic diagram of the output status of the analog switch chip pins corresponding to the impedance loops of various parts of the present invention. [Specific implementation method]

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings.

[0036] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the descriptions of "preferred", "sub-preferred", etc. in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "preferred" or "sub-preferred" may explicitly or implicitly include at least one such feature.

[0037] like Figure 1 As shown, a sixteen-electrode bioimpedance measurement circuit includes

[0038] The electrode circuit 1 is provided with 16 electrodes, and the electrode ends are in contact with different positions of the human body respectively;

[0039] The analog switch circuits 2 are respectively connected to the 16 electrode circuits 1 and are used to control the connectivity of different electrode circuits 1;

[0040] The sine wave generating circuit 3 is connected to the analog switch circuit 2 and is used for converting the square wave signal into a sine wave signal and sending it to the analog switch circuit 2;

[0041] The impedance voltage acquisition circuit 4 is connected to the analog switch circuit 2 and is used to collect impedance data generated when different electrode circuits 1 are connected;

[0042] The main control circuit 5 is connected to the analog switch circuit 2, the sine wave generating circuit 3 and the impedance voltage collecting circuit 4 respectively, and is used to send a square wave signal to the sine wave generating circuit 3, control the analog switch circuit 2 to connect different electrode circuits 1, and receive the impedance data collected by the impedance voltage collecting circuit 4 for calculation and processing;

[0043] A power supply circuit 6, used to supply power to each circuit;

[0044] The antenna circuit 7 is connected to the main control circuit 5 and is used for sending and receiving signals.

[0045] In this case, a 4-wire BIA bioimpedance measurement scheme is used. A high-precision AC voltage source is used to excite an AC voltage (F+, F-) to load the measurement object. The impedance is calculated by the current (I) flowing through the unknown impedance and the voltage V on the unknown impedance. The calculation method is as follows:

[0046] R(100kHz)=α*V(100kHz) / I;

[0047] R(200kHz)=α*V(20kHz) / I;

[0048] R(100kHz) is the impedance of the object measured at a frequency of 100kHz;

[0049] R(20kHz) is the impedance of the object measured at a frequency of 20kHz;

[0050] V(100kHz) is the effective value of the voltage on the object measured at a frequency of 100kHz;

[0051] V(100kHz) is the effective value of the voltage on the object measured at a frequency of 20kHz;

[0052] I is the current flowing through the measured object;

[0053] α is the system coefficient, which is calculated by connecting three objects with known impedances: low, medium and high.

[0054] In this case, the 16 electrode circuits 1 are respectively HVL left hand voltage collection electrode circuit, HVR right hand voltage collection electrode circuit, FVL left foot voltage sampling electrode circuit, FVR right foot voltage sampling electrode circuit, HIL left hand current excitation electrode circuit, HIR right hand current excitation electrode circuit, FIL left foot current excitation electrode circuit, FIR current excitation electrode circuit, CVL left chest voltage sampling electrode circuit, CVR right chest voltage sampling electrode circuit, AVL left abdomen voltage sampling electrode circuit, AVR right abdomen voltage sampling electrode circuit, CIL left chest current excitation electrode circuit, CIR right chest current excitation electrode circuit, AIL left abdomen current excitation electrode circuit, and AIR right abdomen current excitation electrode circuit.

[0055] Before the test, the electrodes of 16 different electrode circuits were Figure 2-3 As shown, the corresponding parts are pasted on the measured human body parts. During measurement, the main control circuit 5 sends 20KHz and 100KHz square wave signals to the sine wave generating circuit 3; the sine wave generating circuit 3 generates corresponding 20KHz and 100KHz sine wave signals and sends them to the analog switch circuit 2; then the main control circuit 5 controls the on and off of the analog switch in the analog switch circuit 2, so that different electrode circuits and different body parts form a loop for testing, and respectively measure the impedance test of LA left hand impedance, RA right hand impedance, TR trunk impedance, LF left foot impedance, and RF right foot impedance; the impedance voltage acquisition circuit 4 collects the impedance ADC of the loop test of different body parts and sends it to the main control circuit 5, and the main control circuit 5 calculates and processes according to the above calculation method to obtain TR trunk impedance data.

[0056] In this case, the specific circuit structure of the 16 electrode circuits 1 is as follows: Figure 4 As shown; the specific circuit structure of the analog switch circuit 2 is as follows Figure 5 As shown; the specific circuit structure of the sine wave generating circuit 3 is as follows Figure 6As shown; the specific circuit structure of the impedance voltage acquisition circuit 4 is as follows Figure 7 As shown; the specific circuit structure of the main control circuit 5 is as follows Figure 8 As shown; the specific circuit structure of the power supply circuit 6 is as shown Fig. 9 The specific circuit structure of the antenna circuit 7 is shown as follows: Fig.10 shown.

[0057] like Figure 5 and Fig.11 As shown, the main control circuit 5 controls the on and off of the analog switch in the analog switch circuit 2 to measure the impedance of the LA left hand, the RA right hand, the TR trunk, the LF left foot, and the RF right foot respectively. The impedance test method is as follows:

[0058] When measuring the LA left hand impedance, the Bluetooth chip U10 outputs low level, low level, and low level to pin 6 and pin 9-10 of the analog switch chip U12 of the analog switch circuit 2, and outputs low level, low level, and low level to pin 6 and pin 9-10 of the analog switch chip U14 of the analog switch circuit 2, so that an LA left hand impedance current test path is formed between the HIL left hand current excitation electrode circuit and the CIL left chest current excitation electrode circuit, and the electrodes of the HVL left hand voltage collection electrode circuit and the electrodes of the CVL left chest voltage sampling electrode circuit are used as the voltage detection point group of the LA left hand impedance.

[0059] When measuring the RA right hand impedance, the Bluetooth chip U10 outputs low level, low level, and high level to pin 6 and pin 9-10 of the analog switch chip U12 of the analog switch circuit 2, and outputs low level, low level, and high level to pin 6 and pin 9-10 of the analog switch chip U14 of the analog switch circuit 2, so that a RA right hand impedance current test path is formed between the HIR right hand current excitation electrode circuit and the CIR right chest current excitation electrode circuit, and the electrodes of the HVR right hand voltage collection electrode circuit and the electrodes of the CVR right chest voltage sampling electrode circuit are used as the voltage detection point group of the RA right hand impedance.

[0060] When measuring the LF left foot impedance, the Bluetooth chip U10 outputs low level, high level, and low level to pin 6 and pin 9-10 of the analog switch chip U12 of the analog switch circuit 2, and outputs low level, high level, and low level to pin 6 and pin 9-10 of the analog switch chip U14 of the analog switch circuit 2, so that a LF left foot impedance current test path is formed between the AIL left abdomen current excitation electrode circuit and the FIL left foot current excitation electrode circuit, and the electrodes of the AVL left abdomen voltage sampling electrode circuit and the electrodes of the FVL left foot voltage sampling electrode circuit are used as the voltage detection point group of the LF left foot impedance.

[0061] When measuring the RF right foot impedance, the Bluetooth chip U10 outputs low level, high level, and high level to pin 6 and pin 9-10 of the analog switch chip U12 of the analog switch circuit 2, and outputs low level, high level, and high level to pin 6 and pin 9-10 of the analog switch chip U14 of the analog switch circuit 2, so that an RF right foot impedance current test path is formed between the AIR right abdomen current excitation electrode circuit and the FIR current excitation electrode circuit, and the electrodes of the AVR right abdomen voltage sampling electrode circuit and the electrodes of the FVR right foot voltage sampling electrode circuit are used as the voltage detection point group of the RF right foot impedance.

[0062] When measuring the TR trunk impedance, first, the Bluetooth chip U10 outputs low level, low level, and low level to pin 6 and pin 9-10 of the analog switch chip U13 of the analog switch circuit 2, and outputs low level, low level, and low level to pin 6 and pin 9-10 of the analog switch chip U15 of the analog switch circuit 2, so that the first current test path of the TR trunk impedance is formed between the AIL left abdominal current excitation electrode circuit and the CIR right chest current excitation electrode circuit, and the electrode of the AVL left abdominal voltage sampling electrode circuit and the electrode of the CVR right chest voltage sampling electrode circuit are used as the first voltage test path of the TR trunk impedance. Detection point group; then the Bluetooth chip U10 outputs low level, low level, and high level to pin 6 and pin 9-10 of the analog switch chip U13 of the analog switch circuit 2, and outputs low level, low level, and high level to pin 6 and pin 9-10 of the analog switch chip U15 of the analog switch circuit 2, so that the TR trunk impedance second current test path is formed between the AIR right abdominal current excitation electrode circuit and the CIL left chest current excitation electrode circuit, and the electrode of the AVR right abdominal voltage sampling electrode circuit and the electrode of the CVL left chest voltage sampling electrode circuit are used as the TR trunk impedance second voltage detection point group.

[0063] When measuring TR trunk impedance, BIA biometric calibration is required. During calibration, the Bluetooth chip U10 outputs low level, high level, and high level to pin 6 and pin 9-10 of the analog switch chip U13 of the analog switch circuit 2, and outputs low level, high level, and high level to pin 6 and pin 9-10 of the analog switch chip U15 of the analog switch circuit 2, so that a BIA biometric calibration flow test path is formed between pin 11 and pin 4 of the analog switch chip U13, and pin 11 and pin 4 of the analog switch chip U15 are used as a BIA biometric calibration voltage detection point group.

[0064] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A sixteen-electrode bioimpedance measurement circuit, characterized in that: Included The electrode circuit (1) is provided with 16 electrodes, and the electrode ends are respectively in contact with different positions of the human body; The analog switch circuit (2) is connected to the 16 electrode circuits (1) respectively and is used to control the connection between different electrode circuits (1); A sine wave generating circuit (3) is connected to the analog switch circuit (2) and is used to convert a square wave signal into a sine wave signal and send the signal to the analog switch circuit (2); An impedance voltage acquisition circuit (4) is connected to the analog switch circuit (2) and is used to collect data generated when different electrode circuits (1) are connected; The main control circuit (5) is respectively connected to the analog switch circuit (2), the sine wave generating circuit (3) and the impedance voltage collecting circuit (4), and is used to send a square wave signal to the sine wave generating circuit (3), control the analog switch circuit (2) to connect different electrode circuits (1), and receive data collected by the impedance voltage collecting circuit (4) for calculation and processing.

2. A sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The main control circuit (5) sends 20KHz and 100KHz square wave signals to the sine wave generating circuit (3); the sine wave generating circuit (3) converts the 20KHz square wave signal and the 100KHz square wave signal into 20KHz sine wave signals and 100KHz sine wave signals and sends them to the analog switch circuit (2).

3. The sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The 16 electrode circuits (1) are HVL left hand voltage collection electrode circuit, HVR right hand voltage collection electrode circuit, FVL left foot voltage sampling electrode circuit, FVR right foot voltage sampling electrode circuit, HIL left hand current excitation electrode circuit, HIR right hand current excitation electrode circuit, FIL left foot current excitation electrode circuit, FIR current excitation electrode circuit, CVL left chest voltage sampling electrode circuit, CVR right chest voltage sampling electrode circuit, AVL left abdomen voltage sampling electrode circuit, AVR right abdomen voltage sampling electrode circuit, CIL left chest current excitation electrode circuit, CIR right chest current excitation electrode circuit, AIL left abdomen current excitation electrode circuit, AIR right abdomen current excitation electrode circuit.

4. The sixteen-electrode bioimpedance measurement circuit according to claim 3, characterized in that: The HVR right-hand voltage collection electrode circuit includes a right-hand electrode PAD, which is connected to one end of a resistor R73, one end of a resistor R67, and one end of a resistor R79 respectively through a resistor R43, a resistor R55, and a capacitor C86, a capacitor C74 is connected in parallel with the resistor R43, the other end of the resistor R73 is connected to the power supply VA, the other end of the resistor R67 is grounded, the other end of the resistor R79 is connected to the pin 3 of the operational amplifier U10A, the pin 2 of the operational amplifier U10A is connected to the pin 1 of the operational amplifier U10A through a resistor E88 and a capacitor C92, the pin 4 of the operational amplifier U10A is connected to the power supply VCC, the pin 11 of the operational amplifier U10A is grounded, and the pin 1 of the operational amplifier U10A is connected to the analog switch circuit (2); The circuit structures of the HVL left hand voltage sampling electrode circuit, the FVL left foot voltage sampling electrode circuit, the FVR right foot voltage sampling electrode circuit, the CVL left chest voltage sampling electrode circuit, the CVR right chest voltage sampling electrode circuit, the AVL left abdomen voltage sampling electrode circuit, and the AVR right abdomen voltage sampling electrode circuit are the same as the HVR right hand voltage sampling electrode circuit.

5. The sixteen-electrode bioimpedance measurement circuit according to claim 3, characterized in that: The right-hand current excitation electrode circuit includes a left-hand electrode PAD, which is connected to the analog switch circuit (2) via resistors R44 and R56 in sequence, and capacitor C75 is connected in parallel with resistor R44; The circuit structures of the HIL left hand current excitation electrode circuit, FIL left foot current excitation electrode circuit, FIR current excitation electrode circuit, CIL left chest current excitation electrode circuit, CIR right chest current excitation electrode circuit, AIL left abdomen current excitation electrode circuit, and AIR right abdomen current excitation electrode circuit are uniform and the same as the HIR right hand current excitation electrode circuit.

6. The sixteen-electrode bioimpedance measurement circuit according to claim 3, characterized in that: The analog switch circuit (2) includes an analog switch chip U12, an analog switch chip U13, an analog switch chip U14 and an analog switch chip U15. The pin 14 of the analog switch chip U12 is connected to the HIR right hand current excitation electrode circuit, the pin 12 of the analog switch chip U12 is connected to the HIL left hand current excitation electrode circuit, the pin 1 of the analog switch chip U12 is connected to the CIL left chest current excitation electrode circuit, the pin 15 of the analog switch chip U12 is connected to the AIL left abdomen current excitation electrode circuit, the pin 13 and pin 3 of the analog switch chip U12 are respectively connected to the sine wave generating circuit (3), the pin 11 of the analog switch chip U12 is connected to the AIR right abdomen current excitation electrode circuit, the pin 6 and pins 9-10 of the analog switch chip U12 are respectively connected to the main control circuit (5), the pin 16 of the analog switch chip U12 is connected to the power supply VCC, the pin 2 of the analog switch chip U12 is connected to the FIL left foot current excitation electrode circuit, the pin 5 of the analog switch chip U12 is connected to the CIR right chest current excitation electrode circuit, the pin 4 of the analog switch chip U12 is connected to the FIR right foot current excitation electrode circuit, and the pins 7-8 of the analog switch chip U12 are grounded; The pin 14 of the analog switch chip U13 is connected to the AIR right abdominal current excitation electrode circuit, the pin 12 of the analog switch chip U13 is connected to the AIL left abdominal current excitation electrode circuit, the pin 1 of the analog switch chip U13 is connected to the CIR right chest current excitation electrode circuit, the pin 13 and pin 3 of the analog switch chip U13 are respectively connected to the sine wave generating circuit (3), the pin 11 of the analog switch chip U13 is respectively connected to one end of the resistor R126 and the pin 11 of the analog switch chip U15 through the resistor R127, the pin 4 of the analog switch chip U13 is respectively connected to the other end of the resistor R126 and the pin 4 of the analog switch chip U15 through the resistor R125, the pin 6 and pins 9-10 of the analog switch chip U13 are respectively connected to the main control circuit (5), the pin 16 of the analog switch chip U13 is connected to the power supply VCC, the pin 5 of the analog switch chip U13 is connected to the CIL left chest current excitation electrode circuit, and the pins 7-8 of the analog switch chip U13 are respectively grounded; The pin 14 of the analog switch chip U14 is connected to the HVR right hand voltage collection electrode circuit, the pin 12 of the analog switch chip U14 is connected to the HVL left hand voltage collection electrode circuit, the pin 1 of the analog switch chip U14 is connected to the CVL left chest voltage sampling electrode circuit, the pin 15 of the analog switch chip U14 is connected to the AVL left abdomen voltage sampling electrode circuit, the pin 13 and pin 3 of the analog switch chip U14 are respectively connected to the impedance voltage collection circuit (4), the pin 11 of the analog switch chip U14 is connected to the AVR right abdomen voltage sampling electrode circuit, the pin 6 and pins 9-10 of the analog switch chip U14 are respectively connected to the main control circuit (5), the pin 16 of the analog switch chip U14 is connected to the power supply VCC, the pin 2 of the analog switch chip U14 is connected to the FVL left foot voltage sampling electrode circuit, the pin 5 of the analog switch chip U14 is connected to the CVR right chest voltage sampling electrode circuit, the pin 4 of the analog switch chip U14 is connected to the FVR right foot voltage sampling electrode circuit, and the pins 7-8 of the analog switch chip U14 are respectively grounded; Pin 14 of the analog switch chip U15 is connected to the AVR right abdomen voltage sampling electrode circuit, pin 12 of the analog switch chip U15 is connected to the AVL left abdomen voltage sampling electrode circuit, pin 1 of the analog switch chip U15 is connected to the CVR right chest voltage sampling electrode circuit, pin 13 and pin 3 of the analog switch chip U15 are respectively connected to the impedance voltage acquisition circuit (4), pin 6 and pins 9-10 of the analog switch chip U15 are respectively connected to the main control circuit (5), pin 16 of the analog switch chip U15 is connected to the power supply VCC, pin 5 of the analog switch chip U15 is connected to the CVL left chest voltage sampling electrode circuit, and pins 7-8 of the analog switch chip U15 are respectively grounded.

7. The sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The sine wave generating circuit (3) includes an operational amplifier U6A, wherein the pin 1 of the operational amplifier U6A is connected to one end of the capacitor C56 and one end of the resistor R87 through the resistor R68 and the resistor R88 in sequence, the other end of the resistor R87 is connected to one end of the capacitor C55 and one end of the resistor R86, the other end of the resistor R86 is connected to one end of the capacitor C54 and one end of the resistor R85, the other end of the resistor R85 is connected to one end of the resistor R84 and one end of the resistor R81, the other end of the resistor R84 is connected to the pins 1 and 2 of the filter U8, and the resistor R83 One end of the operational amplifier U6A is connected, the other end of the resistor R83 is connected to the other end of the resistor R81 and the main control circuit (5), the pin 3 of the filter U8, the other end of the capacitor C54, the other end of the capacitor C55, and the other end of the capacitor C56 are grounded respectively; the pin 2 of the operational amplifier U6A is connected to one end of the capacitor C50 and one end of the resistor R74 through the resistor R75, the other end of the capacitor R74 is connected to one end of the capacitor C49 and one end of the resistor R73, the other end of the resistor R73 is connected to one end of the capacitor C48 and one end of the resistor R72, and the other end of the resistor R72 is connected to the One end of resistor R69 and one end of resistor R71 are connected, the other end of resistor R71 is respectively connected to pin 1 and pin 2 of filter U7 and one end of resistor R70, the other end of resistor R70 is respectively connected to the other end of resistor R69 and main control circuit (5), pin 3 of filter U7, the other end of capacitor C48, the other end of capacitor C49 and the other end of capacitor C50 are respectively grounded; pin 3 of op amp U6A is connected to power supply VA, pin 4 of op amp U6A is connected to power supply VCC, pin 11 of op amp U6A is grounded, pin 1 of op amp U6A is connected to ground through power supply VA, pin 2 of op amp U6A is connected to ground through power supply VCC, pin 3 of op amp U6A is connected to power supply VA, pin 4 of op amp U6A is connected to power supply VCC, pin 11 of op amp U6A is connected to ground, pin 1 of op amp U6A is connected to ground through power supply VCC ...1 of op amp U6A is connected to ground through power supply VCC, pin 1 of op amp U6A is connected to ground through power supply VCC, pin 1 of op amp U Resistor R76 is respectively connected to the analog switch circuit (2) and pin 9 of the operational amplifier U6C; pin 10 of the operational amplifier U6C is respectively connected to one end of the capacitor C53, one end of the resistor R82 and pin 14 of the operational amplifier U6D; pin 12 of the operational amplifier U6D is connected to the power supply VA; pin 13 of the operational amplifier U6D is respectively connected to the other end of the resistor R82, the other end of the capacitor C53 and one end of the resistor R79; the other end of the resistor R79 is respectively connected to one end of the resistor R80 and pin 8 of the operational amplifier U6C; the other end of the resistor R80 is connected to the analog switch circuit (2).

8. The sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The impedance voltage acquisition circuit (4) includes an operational amplifier U10A, wherein pin 2 of the operational amplifier U10A is respectively connected to one end of a resistor R94 and one end of a resistor R102, the other end of the resistor R102 is respectively connected to one end of a resistor R99 and one end of a capacitor C64, the other end of the resistor R99 and the other end of the capacitor C64 are respectively connected to one end of a capacitor C65, one end of a capacitor C67, and an analog switch circuit (2), the other end of the capacitor C67 is grounded, pin 3 of the operational amplifier U10A is respectively connected to one end of a resistor R100 and one end of a resistor R105, the other end of the resistor R105 is respectively connected to one end of a resistor R98 and one end of a capacitor C66, the other end of the resistor R98 and the other end of the resistor R100 are respectively connected to a power supply VA, and the other end of the capacitor C66 is respectively connected to one end of a resistor R100 and one end of a resistor R105. The other end of the capacitor C65 is connected to one end of the capacitor C68, and the analog switch circuit (2). The other end of the capacitor C68 is grounded. The pin 1 of the operational amplifier U10A is respectively connected to one end of the resistor R103, the other end of the resistor R94, and one end of the capacitor C59. The other end of the capacitor C59 is respectively connected to one end of the capacitor C60 and one end of the resistor R108. The other end of the capacitor C60 is respectively connected to one end of the resistor R90 and the pin 3 of the operational amplifier U9A. The other end of the resistor R90 is connected to the power supply VA. The pin 11 of the operational amplifier U9A is connected to the power supply VCC. The pin 4 of the operational amplifier U9A is grounded. The pin 2 of the operational amplifier U9A is respectively connected to one end of the resistor 106 and one end of the resistor R91. The other end of the resistor R91 is connected to the power supply VA. The other end of the resistor R106 They are respectively connected to pin 1 of op amp U9A, the other end of resistor R108, and one end of capacitor C61. The other end of capacitor C61 is respectively connected to one end of resistor R109 and one end of capacitor C62. The other end of capacitor C62 is respectively connected to one end of resistor R92 and pin 5 of op amp U9B. The other end of resistor R92 is connected to power supply VA. Pin 6 of op amp U9B is respectively connected to one end of resistor R107 and one end of resistor R93. The other end of resistor R93 is connected to power supply VA. The other end of resistor R107 is respectively connected to the other end of resistor R109, pin 7 of op amp U9B, and one end of resistor R97. The other end of resistor R97 is respectively connected to one end of capacitor C63 and pin 10 of op amp U9C. The other end of capacitor C63 is connected to power supply VA. The operational amplifier U9C pin 9 is connected to one end of the resistor R110 and one end of the resistor R96 respectively, the other end of the resistor R96 is connected to the power supply VA, the other end of the resistor R110 is connected to the operational amplifier U9C pin 8 and one end of the resistor R101 respectively, the other end of the resistor R101 is connected to the operational amplifier U9D pin 13, the rectifier diode D1 pin 1, and one end of the resistor R89 ​​respectively, the operational amplifier U9D pin 12 is connected to the power supply VA through the terminal R104, the operational amplifier U9D pin 14 is connected to the rectifier diode D1 pin 3, the rectifier diode D1 pin 2 is connected to the other end of the resistor R89, one end of the capacitor C57, and one end of the resistor R95 respectively, the other end of the resistor R95 is connected to the other end of the capacitor C58 and the main control circuit (5) respectively,The other end of capacitor C57 and the other end of capacitor C58 are connected to the power supply VA respectively; the other end of resistor R103 is connected to one end of resistor R122 and one end of capacitor C69 respectively, the other end of resistor R122 is connected to one end of capacitor C75 and pin 10 of op amp U10C respectively, pin 9 of op amp U10C is connected to one end of resistor R111 and one end of resistor R118 respectively, the other end of resistor R118 and the other end of capacitor C75 are connected to the power supply VA respectively, pin 8 of op amp U10C is connected to the other end of capacitor C69 and resistor R111 respectively The other end of the resistor R119 is connected to one end of the resistor R120 and one end of the capacitor C70 respectively, the other end of the resistor R120 is connected to one end of the capacitor C74 and pin 5 of the op amp U10B respectively, pin 6 of the op amp U10B is connected to one end of the resistor R112 and one end of the resistor R117 respectively, the other end of the resistor R117 and the other end of the capacitor C74 are connected to the power supply VA respectively, pin 7 of the op amp U10B is connected to the other end of the capacitor C70, the other end of the resistor R112 and one end of the capacitor C73 respectively, The other end of capacitor C73 is connected to one end of resistor R115 and pin 12 of op amp U10D respectively, the other end of resistor R115 is connected to power supply VA, pin 13 of op amp U10D is connected to one end of resistor R124 and one end of resistor R116 respectively, the other end of resistor R116 is connected to power supply VA, pin 14 of op amp U10D is connected to the other end of resistor 124 and one end of resistor R121 respectively, the other end of resistor R121 is connected to one end of resistor R113, pin 1 of rectifier diode D2 and pin 2 of op amp U11A respectively, Pin 3 of the op amp U11A is connected to the power supply VA through the resistor R123, pin 4 of the op amp U11A is connected to the power supply VCC, pin 11 of the op amp U11A is grounded, pin 1 of the op amp U11A is connected to pin 3 of the rectifier diode D2, pin 2 of the rectifier diode D2 is respectively connected to the other end of the resistor R113, one end of the capacitor C71, and one end of the resistor R114, the other end of the resistor R114 is respectively connected to one end of the capacitor C72 and the main control circuit (5), the other end of the capacitor C71 and the other end of the capacitor C72 are respectively connected to the power supply VA.

9. The sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The main control circuit (5) includes a Bluetooth chip U10, wherein the pin 1 of the Bluetooth chip U10 is respectively connected to one end of a capacitor C32, the pin 4 of a crystal oscillator Y2, and one end of a capacitor C34 through a capacitor C31, the pin 2 of the Bluetooth chip U10 is respectively connected to the other end of the capacitor C32 and the pin 3 of the crystal oscillator Y2, the pin 3 of the Bluetooth chip U10 is respectively connected to the other end of the capacitor C34 and the pin 1 of the crystal oscillator Y2, the pin 2 and the pin 4 of the crystal oscillator Y2 are respectively grounded, the pin 4 of the Bluetooth chip U10 is connected to a power supply VA, the pin 5 and the pin 12 of the Bluetooth chip U10 are respectively connected to an impedance voltage acquisition circuit (4), the pins 6-7 of the Bluetooth chip U10 are respectively connected to a sine wave generating circuit (3), the pin 9 of the Bluetooth chip U10 is connected to one end of the crystal oscillator Y1, the other end of the crystal oscillator Y1 is grounded, and the pin 13 of the Bluetooth chip U10 is respectively connected to the capacitor C The first embodiment of the present invention is characterized in that the first embodiment of the present invention is connected to one end of the bluetooth chip U10 and one end of the capacitor C41, the other end of the capacitor C42 is grounded, the other end of the capacitor C42 is grounded, the other end of the capacitor C41 is connected to the power supply VDD3.3V, the pin 14 of the bluetooth chip U10 is grounded, the pin 15 of the bluetooth chip U10 is grounded in turn through the inductor L2 and the capacitor C40, the pin 16 of the bluetooth chip U10 is respectively connected to one end of the capacitor C38, the capacitor C9 and the power supply VDD3.3V, the other end of the capacitor C38 and the other end of the capacitor C39 are grounded respectively, the capacitor C36 is respectively connected to the pin 17 and pin 18 of the bluetooth chip U10, the pin 19 of the bluetooth chip U10 is grounded through the capacitor C3, the pins 23-30 of the bluetooth chip U10 are respectively connected to the analog switch circuit (2), the pin 31 of the bluetooth chip U10 is grounded through the capacitor C24, and the pin 33 of the bluetooth chip U10 is grounded.

10. The sixteen-electrode bioimpedance measurement circuit according to claim 1, characterized in that: The invention also includes a power supply circuit (6) for power supply and an antenna circuit (7) connected to the main control circuit (5) for transmitting and receiving signals. The power supply circuit (6) includes an operational amplifier U6B. Pin 5 of the operational amplifier U6B is respectively connected to one end of a resistor R78, one end of a capacitor C52, one end of a capacitor C51, and one end of a resistor R77. The other ends of the resistor R78, the other ends of the capacitor C52, and the other ends of the capacitor C51 are respectively grounded. The other end of the resistor R77 is connected to a power source VCC. Pin 7 of the operational amplifier U6B is connected to pin 6 of the operational amplifier U6B. The output of pin 7 of the operational amplifier U6B is connected to pin 6 of the operational amplifier U6B. The antenna circuit (7) includes an antenna ANT1, wherein a pin 2 of the antenna ANT1 is respectively connected to one end of a capacitor C27 and one end of a capacitor C25, the other end of the capacitor C25 is respectively connected to one end of a capacitor C30 and one end of a capacitor C26, the other end of the capacitor C26 is respectively connected to one end of a capacitor C28 and one end of an inductor L1, the other end of the inductor L1 is respectively connected to one end of a capacitor C29 and a main control circuit (5), and a pin 1 of the antenna ANT1, the other end of the capacitor C27, the other end of the capacitor C30, the other end of the capacitor C28, and the other end of the capacitor C29 are respectively grounded.

Citation Information

Patent Citations

  • Single-channel multi-signal acquisition circuit

    CN110955164A

  • Human electric impedance test appearance based on eight sections impedance models

    CN205795695U

  • Voltage data acquisition circuit for ERT system

    CN213149084U

  • Body composition measurement method and apparatus

    US20040059242A1

  • Methods of and apparatus for determining fluid volume presence in mammalian tissue

    US20060264775A1