Human body impedance detection circuit, method, equipment and storage medium

Abstract

This application relates to the field of human body embedded device detection technology, and particularly to a human body impedance detection circuit, method, device, and storage medium to solve the problem of low accuracy in human body impedance detection. The human body impedance detection circuit includes: a power conversion module, a current control module, a main control chip, and an impedance detection module; the power conversion module realizes static detection of the impedance to be measured; the current control module acts as a constant current source to realize dynamic detection of the impedance to be measured; the output terminal of the impedance detection module is connected to the first input terminal of the main control chip. The impedance detection module is used to obtain the equivalent current between the two current signals output by the current control module, and to obtain the detected value of the impedance to be measured through the voltage across the impedance to be measured. By combining static and dynamic detection, the resistance value of the impedance to be measured is detected, thereby improving the detection accuracy. Thus, the technical effects of impedance detection and improved detection accuracy can be achieved.

Description

Technical Field

[0001] This application relates to the technical field of human body embedded device detection, and in particular to a human body impedance detection circuit, method, device and storage medium. Background Technology

[0002] With the continuous advancement of medical technology, tiny detection devices or auxiliary instruments can be embedded in the human body to treat or detect diseases. Examples include pacemakers, minimally invasive needles, or simulators. Embedded simulators can mimic human vital functions or alleviate pain associated with illnesses.

[0003] For devices embedded in the human body, the instability caused by human movement necessitates the use of human body impedance detection to determine whether the device is functioning correctly within the body. However, the unpredictable factors associated with human movement complicate dynamic impedance detection. For instance, changes in the contact surface of the device within the body during movement can alter the detection results, reducing the accuracy of disease treatment.

[0004] Therefore, improving the accuracy and precision of human body impedance detection has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of this application provide a human body impedance detection circuit, method, device, and storage medium to solve the problem of low accuracy in human body impedance detection.

[0006] In a first aspect, one embodiment of this application provides a human body impedance detection circuit, including:

[0007] Power conversion module, current control module, main control chip and impedance detection module;

[0008] The output terminal of the power conversion module is connected to the first input terminal of the current control module, and the power conversion module is used to provide the operating voltage for the current control module.

[0009] The second input terminal of the current control module is connected to the first output terminal of the main control chip, the third input terminal of the current control module is connected to the second output terminal of the main control chip, the first output terminal of the current control module is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured, and the second output terminal of the current control module is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured. The current control module is used to provide a stable current signal to the impedance detection module under the control of the main control chip.

[0010] The output terminal of the impedance detection module is connected to the first input terminal of the main control chip. The impedance detection module is used to obtain the equivalent current between the two current signals output by the current control module, and to obtain the detection value of the impedance under test through the voltage across the impedance under test.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the main control chip is used to transmit a sinusoidal current signal to the current control module, and transmit a stable current signal to the impedance detection module through the current control module. The impedance detection module is also used to analyze the detection value of the impedance to be measured based on the current signal, and feed back the detection value of the impedance to be measured to the main control chip.

[0012] The main control chip is also used to change the input electrical signal of the power conversion module so that the output voltage signal of the power conversion module is adjusted. The main control chip is also used to change the input electrical signal of the current control module so that the current control module outputs an adjustment current signal. The adjustment voltage signal and the adjustment current signal are input to the impedance detection module, and the adjustment detection value of the impedance to be measured is detected by the impedance detection module.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the power conversion module includes: a power battery, a first inductor, a first transistor, a first diode, and a first capacitor;

[0014] The positive output terminal of the power battery is connected to one end of the first inductor, and the negative input terminal of the power battery is connected to the first terminal of the first transistor and one end of the first capacitor to the first ground terminal. The power battery provides the turn-on voltage for the main control chip and the current control module.

[0015] The other end of the first inductor is connected to the second end of the first transistor and the inverting input of the first diode;

[0016] The positive output terminal of the first diode and the other end of the first capacitor are connected to the first input terminal of the current control module as the output terminal of the power conversion module.

[0017] The control terminal of the first transistor is connected to the third output terminal of the main control chip.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, the current control module includes:

[0019] First operational amplifier, second operational amplifier, first switching transistor, second switching transistor, third switching transistor, fourth switching transistor, fifth switching transistor, sixth switching transistor, seventh switching transistor, eighth switching transistor, second capacitor, third capacitor, first impedance and second impedance;

[0020] The positive input terminal of the first operational amplifier is connected to the first output terminal of the main control chip as the second input terminal of the current control module. The inverting input terminal of the first operational amplifier is connected to one end of the first impedance and the second end of the first switching transistor. The output terminal of the first operational amplifier is connected to the control terminal of the first switching transistor.

[0021] The first terminal of the first switch is connected to the first terminal of the second switch, the control terminal of the second switch, and the control terminal of the third switch.

[0022] The other end of the first impedance is connected to the second ground terminal;

[0023] The second terminal of the second switch is connected to the output terminal of the power conversion module, along with the second terminals of the third, fourth, and fifth switches.

[0024] The first terminal of the third switch is connected to the first terminal of the sixth switch and one terminal of the second capacitor;

[0025] The second terminal of the sixth switch is connected to the third ground terminal, and the control terminal of the sixth switch is connected to the fourth output terminal of the main control chip.

[0026] The first terminal of the fourth switch is connected to the first terminal of the seventh switch and one terminal of the third capacitor, and the control terminal of the fourth switch is connected to the control terminal of the fifth switch, the first terminal of the fifth switch, and the first terminal of the eighth switch.

[0027] The second terminal of the seventh switch is connected to the fourth ground terminal, and the control terminal of the seventh switch is connected to the fifth output terminal of the main control chip.

[0028] The second terminal of the eighth switch is connected to one end of the second impedance and the inverting input terminal of the second operational amplifier, and the control terminal of the eighth switch is connected to the output terminal of the second operational amplifier.

[0029] The positive input terminal of the second operational amplifier is connected to the second output terminal of the main control chip as the third input terminal of the current control module.

[0030] The other end of the second impedance is connected to the fifth ground terminal;

[0031] The other end of the second capacitor serves as the first output terminal of the current control module, and is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured.

[0032] The other end of the third capacitor serves as the second output terminal of the current control module, and is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured.

[0033] In conjunction with the first aspect, in some implementations of the first aspect, the current control module includes:

[0034] The third operational amplifier, the fourth operational amplifier, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, the sixteenth switch, the seventeenth switch, the third impedance, the fourth impedance, the fifth impedance, the sixth impedance, the seventh impedance, the eighth impedance, the fourth capacitor, and the fifth capacitor;

[0035] The positive input terminal of the third operational amplifier is connected to the first output terminal of the main control chip as the second input terminal of the current control module. The inverting input terminal of the third operational amplifier is connected to the second terminal of the ninth switch and one end of the third impedance. The output terminal of the third operational amplifier is connected to the control terminal of the ninth switch.

[0036] The first terminal of the ninth switch is connected to the first terminal of the tenth switch, the control terminal of the tenth switch, and the control terminal of the eleventh switch.

[0037] The other end of the third impedance is connected to the sixth ground terminal;

[0038] The second terminal of the tenth switch is connected to the second terminals of the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, and one end of the fourth impedance;

[0039] The first terminal of the eleventh switch and the first terminal of the fourteenth switch are connected to the first input terminal of the impedance detection module as the first output terminal of the current control module.

[0040] The control terminal of the twelfth switch is connected to the other end of the fourth impedance and one end of the fifth impedance. The first end of the twelfth switch and the first end of the fifteenth switch serve as the second output terminal of the current control module and are connected to the second input terminal of the impedance detection module.

[0041] The other end of the fifth impedance is connected to the first end of the sixteenth switching transistor;

[0042] The first terminal of the thirteenth switch is connected to the control terminal of the thirteenth switch, the control terminal of the fourteenth switch, and the first terminal of the seventeenth switch.

[0043] The control terminal of the fifteenth switch is connected to one end of the sixth impedance and one end of the fourth capacitor, and the second terminal of the fifteenth switch and the other end of the fourth capacitor are connected to the seventh ground terminal.

[0044] The other end of the sixth impedance is connected to the first output terminal of the main control chip;

[0045] The control terminal of the sixteenth switch is connected to one end of the seventh impedance and one end of the fifth capacitor, and the second terminal of the sixteenth switch and the other end of the fifth capacitor are connected to the eighth ground terminal.

[0046] The other end of the seventh impedance is connected to the second output terminal of the main control chip;

[0047] The control terminal of the seventeenth switch is connected to the output terminal of the fourth operational amplifier, and the second terminal of the seventeenth switch is connected to one end of the eighth impedance and the inverting input terminal of the fourth operational amplifier.

[0048] The other end of the eighth impedance is connected to the ninth ground terminal;

[0049] The positive input terminal of the fourth operational amplifier is connected to the second output terminal of the main control chip.

[0050] In conjunction with the first aspect, in some implementations of the first aspect, the impedance detection module includes:

[0051] Protection unit and impedance detection unit;

[0052] The first input terminal of the protection unit is connected to the first output terminal of the current control module as the first input terminal of the impedance detection module, and the second input terminal of the protection unit is connected to the second output terminal of the current control module as the second input terminal of the impedance detection module. The first output terminal of the protection unit is connected to the first input terminal of the impedance detection unit, and the second output terminal of the protection unit is connected to the second input terminal of the impedance detection unit. The protection unit is used to block the current input to the impedance detection unit when the input current is too large.

[0053] The output terminal of the impedance detection unit is connected to the first input terminal of the main control chip as the output terminal of the impedance detection module. The impedance detection unit is used to detect the detection value of the impedance to be measured.

[0054] In conjunction with the first aspect, in some implementations of the first aspect, the protection unit includes: a first relay switch;

[0055] The first input terminal of the first relay switch is connected to the first output terminal of the current control module as the first input terminal of the protection unit. The second input terminal of the first relay switch is connected to the second output terminal of the current control module as the second input terminal of the protection unit. The first output terminal of the first relay switch is connected to the first input terminal of the impedance detection unit as the first output terminal of the protection unit. The second output terminal of the first relay switch is connected to the second input terminal of the impedance detection unit as the second output terminal of the protection unit. The first relay switch is used to block the flow of high current to the impedance detection unit when the received current is too high.

[0056] In conjunction with the first aspect, in some implementations of the first aspect, the impedance detection unit includes: a ninth impedance, a tenth impedance, an eleventh impedance, a twelfth impedance, a thirteenth impedance, a sixth capacitor, and a fifth operational amplifier;

[0057] One end of the ninth impedance is connected as the first input terminal of the impedance detection unit, and the other end of the ninth impedance is connected to one end of the tenth impedance and the positive input terminal of the fifth operational amplifier.

[0058] The other end of the tenth impedance is connected to the tenth ground terminal;

[0059] One end of the eleventh impedance is connected to the second output terminal of the protection unit as the second input terminal of the impedance detection unit, and the other end of the eleventh impedance is connected to one end of the twelfth impedance and the inverting input terminal of the fifth operational amplifier.

[0060] The other end of the twelfth impedance is connected to the output terminal of the fifth operational amplifier and one end of the thirteenth impedance;

[0061] The other end of the thirteenth impedance and one end of the sixth capacitor are connected to the first input terminal of the main control chip as the output terminal of the impedance detection unit.

[0062] The other end of the sixth capacitor is connected to the eleventh ground terminal.

[0063] In conjunction with the first aspect, in some implementations of the first aspect, the circuit further includes: an electrode selection module and a fine-tuning module;

[0064] The electrode selection module and the fine-tuning module are connected between the current control module and the impedance detection module. The first input terminal of the electrode selection module is connected to the first output terminal of the current control module, and the second input terminal of the electrode selection module is connected to the second output terminal of the current control module. The first output terminal of the electrode selection module is connected to the first input terminal of the fine-tuning module and one end of the impedance to be measured, and the second output terminal of the electrode selection module is connected to the second input terminal of the fine-tuning module and the other end of the impedance to be measured. The electrode selection module is used to select electrodes at different locations within the human body to change the detected value of the impedance to be measured. The fine-tuning module is used to change the branch current of the parallel-connected impedance to be measured so that the impedance detection module operates in the working current environment.

[0065] In conjunction with the first aspect, in some implementations of the first aspect, the electrode selection module includes: a switch selection chip, a first electrode rod and a second electrode rod, and the fine-tuning module includes multiple fine-tuning branches connected in parallel, wherein the fine-tuning branches are composed of impedance and switches connected in series;

[0066] The first input terminal of the switch selection chip is connected to the first output terminal of the current control module, the second input terminal of the switch selection chip is connected to the second output terminal of the current control module, and the third input terminal of the switch selection chip is connected to the fourth output terminal of the main control chip. The switch selection chip is used to receive the switch control signal output by the main control chip. The first output terminal of the switch selection chip is connected to the first contact of the first electrode rod and the second electrode rod, the second output terminal of the switch selection chip is connected to the second contact of the first electrode rod and the second electrode rod, and the third output terminal of the switch selection chip is connected to the second input terminal of the main control chip. The switch selection chip is also used to provide feedback on the switch status to the main control chip.

[0067] The first contact point of the first electrode rod and the second electrode rod is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured;

[0068] The second contact of the first electrode rod and the second electrode rod is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured.

[0069] Secondly, one embodiment of this application provides a human body impedance detection method, applied to any of the human body impedance detection circuits described in the first aspect, comprising:

[0070] Obtain the initial impedance value of the impedance to be measured;

[0071] The operating current of the current control module is adjusted to obtain the corresponding adjustment impedance value;

[0072] Based on the initial impedance value and the adjusted impedance value, the target detection value of the impedance to be measured is determined.

[0073] In conjunction with the second aspect, in some implementations of the second aspect, obtaining the initial impedance value of the impedance to be measured includes:

[0074] The first transistor is kept off to determine the initial supply voltage value corresponding to the voltage conversion module.

[0075] The initial current value output by the current control module is determined based on the initial power supply voltage value;

[0076] The initial impedance value of the impedance to be measured is determined based on the initial current value and the initial supply voltage value.

[0077] In conjunction with the second aspect, in some implementations of the second aspect, the adjustment of the operating current of the current control module to obtain the corresponding adjustment impedance value includes:

[0078] The main control chip controls the first transistor to remain closed, thereby determining the regulated voltage value output by the voltage conversion module.

[0079] Adjust the input signal of the current control module to obtain the adjusted operating current output by the current control module;

[0080] The adjusted impedance value corresponding to the impedance detection unit is obtained based on the adjusted voltage value and the operating current.

[0081] In conjunction with the second aspect, in some implementations of the second aspect, determining the target detection value of the impedance to be measured based on the initial impedance value and the adjusted impedance value includes:

[0082] Obtain the difference between the adjusted impedance value and the initial impedance value;

[0083] When the difference meets the preset threshold condition, the current adjusted impedance value is used as the target detection value of the impedance to be measured.

[0084] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes:

[0085] When the operating current of the current control module exceeds the set current threshold, the control protection unit remains disconnected, or the conduction state of the fine-tuning module is adjusted to activate the overcurrent protection of the impedance detection unit.

[0086] Thirdly, one embodiment of this application provides a detection device, including a processor and a memory, wherein the processor is configured to execute a control program for human body impedance detection stored in the memory to implement the human body impedance detection method described in any one of the second aspects.

[0087] Fourthly, one embodiment of this application provides a storage medium storing one or more programs that can be executed by one or more processors to implement the human body impedance detection method described in any of the second aspects.

[0088] The human body impedance detection circuit provided in this application embodiment comprises a power conversion module, a current control module, a main control chip, and an impedance detection module. The output terminal of the power conversion module is connected to the first input terminal of the current control module, and the power conversion module provides the operating voltage to the current control module. The second input terminal of the current control module is connected to the first output terminal of the main control chip, and the third input terminal of the current control module is connected to the second output terminal of the main control chip. The first output terminal of the current control module is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured, and the second output terminal of the current control module is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured. Next, the current control module is used to provide a stable current signal to the impedance detection module under the control of the main control chip; the output terminal of the impedance detection module is connected to the first input terminal of the main control chip, and the impedance detection module is used to obtain the equivalent current between the two current signals output by the current control module, and to obtain the detection value of the impedance under test through the voltage across the impedance under test; by adjusting the square wave signal in the current control module, the current magnitude is changed to obtain multiple impedance values, which are compared with the previously detected impedance values. Through fine-tuning, the purpose of dynamically detecting human body impedance is achieved, and the detection accuracy is improved through multiple tests; thus, the technical effect of improving the accuracy of human body impedance detection can be achieved. Attached Figure Description

[0089] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0090] Figure 1 The diagram shown is a schematic diagram of a human body impedance detection circuit provided in Embodiment 1 of this application;

[0091] Figure 2The diagram shown is a schematic diagram of a human body impedance detection circuit provided in Embodiment 2 of this application;

[0092] Figure 3 The diagram shown is a structural schematic of another human body impedance detection circuit provided in Embodiment 2 of this application;

[0093] Figure 4 The diagram shown is a structural schematic of a human body impedance detection circuit provided in Embodiment 3 of this application;

[0094] Figure 5 The diagram shown is a structural schematic of another human body impedance detection circuit provided in Embodiment 3 of this application;

[0095] Figure 6 The diagram shown is a flowchart of a human body impedance detection method provided in Embodiment 4 of this application;

[0096] Figure 7 The diagram shown is a flowchart of another human body impedance detection method provided in Embodiment 4 of this application.

[0097] Figure 8 The diagram shown is a structural schematic of a testing device provided in Embodiment 5 of this application.

[0098] Figure label:

[0099] 10. Power conversion module; 20. Current control module; 30. Impedance detection module; 40. Polar selection module; 50. Fine-tuning module; By: Power supply battery; L1: First inductor; Q1: First transistor; D1: First diode; C1: First capacitor; Rb: Impedance to be measured; MCU: Main control chip; U1A: First operational amplifier; U1B: Second operational amplifier; T1: First switching transistor; T2: Second switching transistor; T3: Third switching transistor; T4: Fourth switching transistor; T5: Fifth switching transistor; T6: Sixth switching transistor; T7: Seventh switching transistor; T8: Eighth switching transistor; C2: Second capacitor; C3: Third capacitor; R1: First impedance; R2: Second impedance; U2A: Third operational amplifier; U2B: Fourth operational amplifier; T9: Ninth switching transistor; T10: Tenth switching transistor; T1 1. Eleventh switch transistor; T12. Twelfth switch transistor; T13. Thirteenth switch transistor; T14. Fourteenth switch transistor; T15. Fifteenth switch transistor; T16. Sixteenth switch transistor; T17. Seventeenth switch transistor; R3. Third impedance; R4. Fourth impedance; R5. Fifth impedance; R6. Sixth impedance; R7. Seventh impedance; R8. Eighth impedance; C4. Fourth capacitor; C5. Fifth capacitor; 31. Protection unit; 32. Impedance detection unit; S1. First relay switch; R9. Ninth impedance; R10. Tenth impedance; R11. Eleventh impedance; R12. Twelfth impedance; R13. Thirteenth impedance; C6. Sixth capacitor; U3A. Fifth operational amplifier; 41. Switch selection chip; 42. First electrode rod; 43. Second electrode rod; R, impedance; K, switch. Detailed Implementation

[0100] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0101] With technological advancements, various methods exist for detecting human body impedance. These methods aim to clarify the proper functioning of therapeutic or detection devices within the human body, providing more accurate information for subsequent disease treatment and detection. However, in devices embedded in the human body, voltage or current is collected at a designated location via electrode rods, and the human body impedance at the detection location is calculated by detecting the equivalent voltage between two electrodes. As the body moves, the contact points of the electrode rods change, potentially affecting the measured impedance results.

[0102] To address the inaccuracy of human body impedance detection results caused by changes in the position of the embedded electrode rod, this application proposes a human body impedance detection circuit. This circuit utilizes a power conversion module to acquire the initial impedance value, a current control module to adjust the square wave signal within it for dynamic detection, and multiple sets of human body impedance values. A main control chip and an impedance detection module are then used to analyze the detected values ​​and select the closest possible human body impedance value, thereby improving the accuracy of human body impedance detection. The human body impedance detection circuit is described in detail below with reference to the accompanying drawings.

[0103] Example 1

[0104] Figure 1 The diagram shown is a structural schematic of a human body impedance detection circuit provided in Embodiment 1 of this application. Figure 1 As shown, the structure of the human body impedance detection circuit specifically includes:

[0105] The power conversion module 10, the current control module 20, the main control chip MCU, and the impedance detection module 30 are included.

[0106] The output terminal of the power conversion module 10 is connected to the first input terminal of the current control module 20. The power conversion module 10 is used to provide the operating voltage Vcc to the current control module 20.

[0107] The second input terminal of the current control module 20 is connected to the first output terminal of the main control chip MCU, the third input terminal of the current control module 20 is connected to the second output terminal of the main control chip MCU, the first output terminal of the current control module 20 is connected to the first input terminal of the impedance detection module 30 and one end of the impedance to be measured Rb, and the second output terminal of the current control module 20 is connected to the second input terminal of the impedance detection module 30 and the other end of the impedance to be measured Rb. The current control module 20 is used to provide a stable current signal to the impedance detection module 30 under the control of the main control chip MCU.

[0108] The output terminal of the impedance detection module 30 is connected to the first input terminal of the main control chip MCU. The impedance detection module 30 is used to obtain the equivalent current between the two current signals output by the current control module 20, and to obtain the detection value of the impedance Rb under test through the voltage across the impedance Rb under test.

[0109] For example, the main control chip MCU is used to transmit a sinusoidal current signal to the current control module 20, and transmit a stable current signal to the impedance detection module 30 through the current control module 20. The impedance detection module 30 is also used to analyze the detection value of the impedance Rb to be measured based on the current signal, and feed back the detection value of the impedance Rb to be measured to the main control chip MCU.

[0110] The main control chip MCU is also used to change the input electrical signal of the power conversion module 10 so that the output voltage signal of the power conversion module 10 is adjusted. The main control chip MCU is also used to change the input electrical signal of the current control module 20 so that the current control module 20 outputs an adjustment current signal. The adjustment voltage signal and the adjustment current signal are input to the impedance detection module 30, and the adjustment detection value of the impedance Rb to be measured is detected by the impedance detection module 30.

[0111] For example, the power conversion module 10 provides the operating voltage to the current control module 20 after converting the mains power into the operating voltage of the detection circuit. The current control module 20 acts as a constant current source and generates a current signal based on the square wave signal output by the main control chip MCU. The impedance detection module 30 feeds back the voltage and current signals across the impedance to be measured to the main control chip MCU for calculation to determine the detected value of the impedance to be measured, Rb. By comparing it with the previously detected impedance value, a more accurate detection value is selected. The main control chip MCU adjusts the strength of the output square wave signal based on the detection result, thereby changing the magnitude of the current signal generated by the current control module 20 to obtain different detection values. The main control chip MCU compares the detection values ​​corresponding to the impedance to be measured and filters out the detection value with higher accuracy time and time again.

[0112] This application provides a human body impedance detection circuit that provides operating voltage to the detection circuit through a power conversion module. By changing the frequency or amplitude of the square wave signal through the main control chip, the current signal of the current control module is changed, thereby affecting the detection result of the impedance detection module and obtaining multiple detection values ​​of the impedance to be measured. Through directional selection, a detection value closer to the accurate value is obtained, thus improving the detection accuracy of human body impedance.

[0113] Example 2

[0114] Figure 2 The diagram shown is a schematic diagram of a human body impedance detection circuit provided in Embodiment 2 of this application.

[0115] Figure 3 The diagram shown is a structural schematic of another human body impedance detection circuit provided in Embodiment 2 of this application. Figure 2 and Figure 3 This is based on the previous embodiment. Figure 2 and Figure 3 The provided diagram shows the specific structure of the human body impedance detection circuit, including:

[0116] The power conversion module 10, the current control module 20, the main control chip MCU, and the impedance detection module 30 are included.

[0117] For example, according to Figure 2and Figure 3 The provided diagram shows that the power conversion module 10 in the human body impedance detection circuit includes:

[0118] Power supply battery By, first inductor L1, first transistor Q1, first diode D1 and first capacitor C1.

[0119] The positive output terminal of the power battery By is connected to one end of the first inductor L1, and the negative input terminal of the power battery By is connected to the first end of the first transistor Q1 and one end of the first capacitor C1 to the first ground terminal. The power battery By provides the turn-on voltage Vcc to the main control chip MCU and the current control module 20.

[0120] The other end of the first inductor L1 is connected to the second end of the first transistor Q1 and the inverting input of the first diode D1.

[0121] The positive output terminal of the first diode D1 and the other end of the first capacitor C1 are connected to the first input terminal of the current control module 20 as the output terminal of the power conversion module 10.

[0122] The control terminal of the first transistor Q1 is connected to the third output terminal of the main control chip MCU.

[0123] For example, the first transistor Q1 can be understood as a MOSFET, IGBT, or transistor that functions as a switch. This application uses a MOSFET as the first transistor for illustration.

[0124] In one possible scenario, powered by a battery By, the main control chip (MCU) first controls the first transistor Q1 to turn off. At this time, the battery By stores energy through a circuit consisting of the first inductor and the first capacitor, providing the supply voltage Vcc to the subsequent current control module. Simultaneously, the MCU changes the square wave output signal, altering the conduction time of the first transistor while simultaneously closing it, thereby changing the output voltage and thus regulating the supply voltage Vcc.

[0125] For example, the static supply voltage value is obtained by disconnecting the first transistor Q1, which serves as the initial reference value for adjusting the voltage value.

[0126] For example, according to Figure 2 The provided diagram shows that the current control module 20 in the human body impedance detection circuit includes:

[0127] First operational amplifier U1A, second operational amplifier U1B, first switch T1, second switch T2, third switch T3, fourth switch T4, fifth switch T5, sixth switch T6, seventh switch T7, eighth switch T8, second capacitor C2, third capacitor C3, first impedance R1 and second impedance R2.

[0128] The positive input terminal of the first operational amplifier U1A is connected to the first output terminal of the main control chip MCU as the second input terminal of the current control module 20. The inverting input terminal of the first operational amplifier U1A is connected to one end of the first impedance R1 and the second end of the first switching transistor T1. The output terminal of the first operational amplifier U1A is connected to the control terminal of the first switching transistor T1.

[0129] The first terminal of the first switch T1 is connected to the first terminal of the second switch T2, the control terminal of the second switch T2, and the control terminal of the third switch T3.

[0130] The other end of the first impedance R1 is connected to the second ground terminal.

[0131] The second terminal of the second switch T2 serves as the first input terminal of the current control module 20, and is connected to the output terminal of the power conversion module 20 along with the second terminals of the third switch T3, the fourth switch T4, and the fifth switch T5.

[0132] The first terminal of the third switch T3 is connected to the first terminal of the sixth switch T6 and one terminal of the second capacitor C2.

[0133] The second terminal of the sixth switch T6 is connected to the third ground terminal, and the control terminal of the sixth switch T6 is connected to the fourth output terminal of the main control chip MCU.

[0134] The first terminal of the fourth switch transistor T4 is connected to the first terminal of the seventh switch transistor T7 and one terminal of the third capacitor C3. The control terminal of the fourth switch transistor T4 is connected to the control terminal of the fifth switch transistor T5, the first terminal of the fifth switch transistor T5 and the first terminal of the eighth switch transistor T8.

[0135] The second terminal of the seventh switch T7 is connected to the fourth ground terminal, and the control terminal of the seventh switch T7 is connected to the fifth output terminal of the main control chip MCU.

[0136] The second terminal of the eighth switch transistor Y8 is connected to one end of the second impedance R2 and the inverting input terminal of the second operational amplifier U1B. The control terminal of the eighth switch transistor T8 is connected to the output terminal of the second operational amplifier U1B.

[0137] The positive input terminal of the second operational amplifier U1B is connected to the second output terminal of the main control chip MCU as the third input terminal of the current control module 20.

[0138] The other end of the second impedance R2 is connected to the fifth ground terminal.

[0139] The other end of the second capacitor C2 is connected as the first output terminal of the current control module 20, the first input terminal of the impedance detection module 30, and one end of the impedance to be measured Rb.

[0140] The other end of the third capacitor C3 serves as the second output terminal of the current control module 20, connected to the second input terminal of the impedance detection module 30 and the other end of the impedance to be measured Rb.

[0141] For example, the purpose of the switching transistor is to turn on or off; in this solution, a bipolar transistor is used as the switching transistor. Alternatively, transistors with switching functions, such as MOSFETs (including PMOS and / or NMOS transistors) or IGBTs, can also be used.

[0142] For example, a square wave signal is provided to the current control module through the PWM interface in the main control chip.

[0143] In one possible scenario, the power conversion module 10 provides power (Vcc) to the current control module 20. After the main control chip MCU inputs a set DAC AC / DC signal to the first operational amplifier U1A and the second operational amplifier U1B in the current control module, it controls either the first operational amplifier U1A or the second operational amplifier U1B to output a high-level signal when the DAC signal is high and a low-level signal when the DAC signal is low. After the first operational amplifier U1A outputs a high level, the second switch T2 and the third switch T3 are turned on under the action of the power supply Vcc, forming a charging circuit with the second capacitor C2, the impedance under test Rb, the third capacitor C3, and the fifth switch T5. When the second operational amplifier U1B outputs a high-level signal, the fourth switch T4 and the fifth switch T5 are turned on under the action of the power supply Vcc, forming a power supply circuit with the third capacitor T3, the impedance under test Rb, the second capacitor C2, and the sixth switch T6. This forms a constant current source through the current control module, providing a stable current to the impedance under test Rb through the equivalent constant current source.

[0144] Furthermore, when the power supply Vcc needs adjustment, the square wave signal output by the main control chip MCU is changed, thereby controlling the on-time of the internal switch of the power conversion module 10 to change the output power. Simultaneously, by changing the square wave signal output by the main control chip MCU to the first operational amplifier U1A and the second operational amplifier U1B, the output signal of either the first operational amplifier U1A or the second operational amplifier U1B is changed, thereby changing the switching state of the first switching transistor T1 or the eighth switching transistor T8, and thus changing the current magnitude of the equivalent constant current source to adjust the current. By changing the current magnitude of the constant current source, the voltage across the impedance Rb under test changes. After the impedance detection module 30 detects the voltage and current of the impedance Rb under test and feeds them back to the main control chip MCU, the main control chip MCU calculates a detected value for the impedance Rb under test. This detected value is compared with the previously detected value to select the value closest to the true value for the next detection comparison, thereby improving the accuracy of the detection results.

[0145] For example, according to Figure 3The provided diagram shows that the current control module 20 in the human body impedance detection circuit includes:

[0146] The third operational amplifier U2A, the fourth operational amplifier U2B, the ninth switch T9, the tenth switch T10, the eleventh switch T11, the twelfth switch T12, the thirteenth switch T13, the fourteenth switch T14, the fifteenth switch T15, the sixteenth switch T16, the seventeenth switch T17, the third impedance R3, the fourth impedance R4, the fifth impedance R5, the sixth impedance R6, the seventh impedance R7, the eighth impedance R8, the fourth capacitor C4, and the fifth capacitor C5.

[0147] The positive input terminal of the third operational amplifier U2A is connected to the first output terminal of the main control chip MCU as the second input terminal of the current control module 20. The inverting input terminal of the third operational amplifier U2A is connected to the second terminal of the ninth switch T9 and one end of the third impedance R3. The output terminal of the third operational amplifier U2A is connected to the control terminal of the ninth switch T9.

[0148] The first terminal of the ninth switch T9 is connected to the first terminal of the tenth switch T10, the control terminal of the tenth switch T10, and the control terminal of the eleventh switch T11.

[0149] The other end of the third impedance R3 is connected to the sixth ground terminal.

[0150] The second terminal of the tenth switch transistor T10 is connected to the second terminals of the eleventh switch transistor T11, the twelfth switch transistor T12, the thirteenth switch transistor T13, the fourteenth switch transistor T14, and one end of the fourth impedance R4.

[0151] The first terminal of the eleventh switch T11 and the first terminal of the fourteenth switch T14 are connected to the first input terminal of the impedance detection module 30 as the first output terminal of the current control module 20.

[0152] The control terminal of the twelfth switch T12 is connected to the other end of the fourth impedance R4 and one end of the fifth impedance R5. The first end of the twelfth switch T12 and the first end of the fifteenth switch T15 are connected to the second input terminal of the impedance detection module 30 as the second output terminal of the current control module 20.

[0153] The other end of the fifth impedance R5 is connected to the first end of the sixteenth switch T16.

[0154] The first terminal of the thirteenth switch T13 is connected to the control terminal of the thirteenth switch T13, the control terminal of the fourteenth switch T14, and the first terminal of the seventeenth switch T17.

[0155] The control terminal of the fifteenth switch T15 is connected to one end of the sixth impedance R6 and one end of the fourth capacitor C4, and the second terminal of the fifteenth switch T15 and the other end of the fourth capacitor C4 are connected to the seventh ground terminal.

[0156] The other end of the sixth impedance R6 is connected to the first output terminal of the main control chip MCU.

[0157] The control terminal of the sixteenth switch transistor T16 is connected to one end of the seventh impedance R7 and one end of the fifth capacitor C5. The second terminal of the sixteenth switch transistor T16 and the other end of the fifth capacitor C5 are connected to the eighth ground terminal.

[0158] The other end of the seventh impedance R7 is connected to the second output terminal of the main control chip MCU.

[0159] The control terminal of the seventeenth switch transistor T17 is connected to the output terminal of the fourth operational amplifier U2B, and the second terminal of the seventeenth switch transistor T17 is connected to one end of the eighth impedance R8 and the inverting input terminal of the fourth operational amplifier U2B.

[0160] The other end of the eighth impedance R8 is connected to the ninth ground terminal.

[0161] The positive input of the fourth operational amplifier U2B is connected to the second output of the main control chip MCU.

[0162] In one possible example scenario, the current control module could be structured like this: Figure 2 In addition to the structure shown, it can also be arranged according to Figure 3 By configuring the structure within, it can also achieve the function of a constant current source, similarly, with... Figure 2 Compared to the internal structure of the current control module in [the text], Figure 3 The internal structure of the provided current control module is also designed to provide a stable current to the impedance under test.

[0163] The impedance mentioned here refers to resistive devices. The switching transistor mentioned here refers to devices with switching functions, such as MOSFETs, transistors, and ICBTs.

[0164] For example, according to Figure 3The provided diagram shows that after the power conversion module provides power Vcc, the main control chip MCU inputs square wave signals to the third operational amplifier U2A and the fourth operational amplifier U2B, controlling the conduction state of the ninth switch T9 and the seventeenth switch T17, thus forming a new circuit, equivalent to a new constant current source. The main control chip MCU alternately outputs AC square wave signals to provide AC current to the impedance under test Rb. By adjusting the magnitude of the square wave signals input to the seventh impedance R7 and the sixth impedance R6, the conduction state of the circuit is adjusted, and the magnitude of the square wave input to the third operational amplifier U2A and the fourth operational amplifier U2B is controlled to adjust the current magnitude. The impedance detection module 30 obtains multiple sets of different current data and corresponding voltage values ​​of the impedance under test, and then calculates the detected value of the impedance under test Rb.

[0165] Similarly, using Figure 3 The current control module provides a constant current signal to the impedance under test. By changing the square wave size of the signal output by the main control chip to the third and fourth operational amplifiers, the size of the constant current source is changed, thereby changing the voltage detection value of the impedance under test. The estimated value of the impedance under test is calculated from the voltage detection value and the current value. By comparing multiple sets of estimated values ​​with the previously detected data, a detection value closer to the true value is obtained, thus improving the detection accuracy.

[0166] For example, according to Figure 2 and Figure 3 The provided diagram shows that the impedance detection module 30 in the human body impedance detection circuit includes:

[0167] Protection unit 31 and impedance detection unit 32.

[0168] The first input terminal of the protection unit 31 is connected to the first output terminal of the current control module 20 as the first input terminal of the impedance detection module 30. The second input terminal of the protection unit 31 is connected to the second output terminal of the current control module 20 as the second input terminal of the impedance detection module 30. The first output terminal of the protection unit 31 is connected to the first input terminal of the impedance detection unit 32. The second output terminal of the protection unit 31 is connected to the second input terminal of the impedance detection unit 32. The protection unit 31 is used to block the current input to the impedance detection unit 32 when the input current is too large.

[0169] The output of the impedance detection unit 32 is connected to the first input of the main control chip MCU as the output of the impedance detection module 30. The impedance detection unit 32 is used to detect the value of the impedance Rb to be measured.

[0170] For example, the protection unit 31 is used for switch control. When the current output by the current control module is too high, in order to prevent damage to the internal components of the impedance detection unit 32, the protection unit 31 is disconnected internally to block the excessive current from flowing to the impedance detection unit 32.

[0171] Furthermore, after the current control module outputs a stable current, the current is input to the impedance detection unit 32 through the protection unit 31. The impedance detection unit 32 obtains the equivalent current and voltage across the impedance to be measured and feeds back the detected results to the main control chip MCU. The main control chip MCU calculates the detected value of the impedance to be measured.

[0172] In one possible scenario, the impedance detection module 30 is connected via the GPIO interface in the main control chip. After receiving and transmitting the current and voltage data detected by the impedance detection unit 32, the detection value of the impedance to be measured Rb is obtained through calculation, and the detection value is fed back to the impedance detection unit 32 through the GPIO port.

[0173] For example, according to Figure 2 and Figure 3 The provided diagram shows that the protection unit 31 in the human body impedance detection circuit includes: a first relay switch S1.

[0174] The first input terminal of the first relay switch S1 is connected to the first output terminal of the current control module 20 as the first input terminal of the protection unit 31. The second input terminal of the first relay switch S1 is connected to the second output terminal of the current control module 20 as the second input terminal of the protection unit 31. The first output terminal of the first relay switch S1 is connected to the first input terminal of the impedance detection unit 32 as the first output terminal of the protection unit 31. The second output terminal of the first relay switch S1 is connected to the second input terminal of the impedance detection unit 30 as the second output terminal of the protection unit 31. The first relay switch S1 is used to block the flow of high current to the impedance detection unit 32 when the received current is too high.

[0175] For example, the internal structure of the protection unit 31 is implemented using a relay. When the current control module outputs an excessively high current, the main control chip MCU controls the first relay switch S1 to open, preventing the excessively high current from damaging the impedance detection unit 32.

[0176] Optionally, the protection unit 31 may also include switching devices such as IGBTs or MOSFETs, which disconnect the internal connection when an excessively high current or an excessively low current is detected, thereby blocking the current.

[0177] For example, according to Figure 2 and Figure 3 The provided diagram shows that the impedance detection unit 32 in the human body impedance detection circuit includes: a ninth impedance R9, a tenth impedance R10, an eleventh impedance R11, a twelfth impedance R12, a thirteenth impedance R13, a sixth capacitor C6, and a fifth operational amplifier U3A.

[0178] One end of the ninth impedance R9 is connected as the first input terminal of the impedance detection unit 32, and the other end of the ninth impedance R9 is connected to one end of the tenth impedance R10 and the positive input terminal of the fifth operational amplifier U3A.

[0179] The other end of the tenth impedance R10 is connected to the tenth ground terminal.

[0180] One end of the eleventh impedance R11 is connected to the second output terminal of the protection unit 31 as the second input terminal of the impedance detection unit 32, and the other end of the eleventh impedance R11 is connected to one end of the twelfth impedance R12 and the inverting input terminal of the fifth operational amplifier U3A.

[0181] The other end of the twelfth impedance R12 is connected to the output of the fifth operational amplifier U3A and one end of the thirteenth impedance R13.

[0182] The other end of the thirteenth impedance R13 and one end of the sixth capacitor C6 are connected to the first input terminal of the main control chip MCU as the output terminal of the impedance detection unit 32.

[0183] The other end of the sixth capacitor C6 is connected to the eleventh ground terminal.

[0184] For example, the ninth and eleventh impedances act as voltage divider resistors to protect the impedance detection unit. The tenth impedance acts as a pull-up resistor. The RC circuit formed by the thirteenth impedance and the sixth capacitor performs filtering for the subsequent circuit.

[0185] In one possible scenario, the current control module 20 outputs a stable current signal, which is input to the fifth operational amplifier U3A through the protection unit 31. The two input terminals of the fifth operational amplifier U3A are indirectly connected to the two ends of the impedance to be measured Rb. The voltage difference across the impedance to be measured Rb is obtained by comparing the voltage difference at the input terminals, and then fed back to the processing unit of the main control chip MCU through filtering. The impedance value across the impedance to be measured Rb is calculated by the current value and voltage value obtained by the processing unit and storage unit of the main control chip MCU.

[0186] according to Figure 2 and Figure 3The provided diagram illustrates that after the main control chip provides the set square wave signal, when the first transistor is turned off, the power conversion module outputs an initial voltage value. Based on this initial voltage value, the current control module, acting as a constant current source, outputs a stable current to the first relay switch. When the current is within a safe range, the voltage difference across the impedance under test is obtained through the voltage difference across the fifth operational amplifier. The obtained voltage and current values ​​are stored in the main control chip's storage unit, and the static detection value of the impedance under test is calculated by the main control chip's processing unit. By changing the frequency or amplitude of the square wave output by the main control chip, the voltage value output by the power conversion module and the current value of the current control module are changed. The main control chip then recalculates a new detection value corresponding to the impedance under test. By comparing this new value with the value obtained from the previous detection, a more accurate impedance value is selected as the reference value for the next comparison. Through multiple dynamic detections, the accurate resistance value of the impedance under test is finally obtained, thus improving the detection accuracy.

[0187] Example 3

[0188] Figure 4 The diagram shown is a structural schematic of a human body impedance detection circuit provided in Embodiment 3 of this application.

[0189] Figure 5 The diagram shown is a structural schematic of another human body impedance detection circuit provided in Embodiment 3 of this application. Figure 4 and Figure 5 This description is based on the above embodiments. Figure 4 and Figure 5 The provided diagram shows the specific structure of the human body impedance detection circuit, including:

[0190] The power conversion module 10, the current control module 20, the main control chip MCU, and the impedance detection module 30 are included.

[0191] according to Figure 4 The diagram provided shows that the structure of the human body impedance detection circuit also includes: an electrode selection module 40 and a fine-tuning module 50.

[0192] Electrode selection module 40 and fine-tuning module 50 are connected between current control module 20 and impedance detection module 30. The first input terminal of electrode selection module 40 is connected to the first output terminal of current control module 20, and the second input terminal of electrode selection module 40 is connected to the second output terminal of current control module 20. The first output terminal of electrode selection module 40 is connected to the first input terminal of fine-tuning module 50 and one end of the impedance to be measured Rb. The second output terminal of electrode selection module 40 is connected to the second input terminal of fine-tuning module 50 and the other end of the impedance to be measured Rb. Electrode selection module 40 is used to select electrodes at different locations in the human body to change the detection value of the impedance to be measured Rb. Fine-tuning module 50 is used to change the branch current of the parallel-connected impedance to be measured Rb so that impedance detection module 30 operates in the working current environment.

[0193] For example, the electrodes are used to contact the human body. When two different electrodes come into contact with the human body, two potential energies are generated. The difference between the two potential energies is the electrical energy between the two electrodes, which is the electrical energy of the equivalent impedance.

[0194] An electrode selection module 40 is positioned between the current control module and the impedance to be measured. This module selects the equivalent impedance at different locations embedded in the human body. By changing the internal switch of the electrode selection module 40, different electrodes can be connected, thus enabling the detection of the equivalent impedance corresponding to different electrodes. A fine-tuning module is used to adjust the input current of the impedance detection module, preventing excessively high current from damaging the internal components and affecting the detection results.

[0195] In one possible scenario, multiple electrodes are selected via the electrode selection module 40 to obtain multiple equivalent impedances corresponding to these electrodes. The current control module 20 provides a stable current to the impedance under test (Rb), and the power conversion module 10 provides a voltage to Rb. These voltage and current signals are applied to the selected electrodes. The electrode selection module 40 selects two electrodes, and the voltage difference between these two electrodes is equated to the voltage difference of the impedance under test (Rb). The impedance detection module 30 acquires the voltage and current readings between the two electrodes and feeds them back to the main control chip (MCU) for processing. The equivalent impedance between the two electrodes is calculated (one of which is the impedance under test), and the impedance value of Rb is then detected. By changing the frequency or amplitude of the PWM wave output by the MCU and by adjusting the branch current and voltage using the fine-tuning module, multiple detection values ​​of the impedance under test (Rb) are calculated. Compared with the previous detection value, the impedance value closest to the true value is selected first, improving the accuracy of the detection. By switching to two other electrodes via the electrode selection module 40, the equivalent impedance between the other electrodes is detected. By changing the connection relationship of the electrodes, the equivalent impedance of the electrodes embedded in the human body can be detected.

[0196] according to Figure 5 The provided diagram shows the structure of the human body impedance detection circuit. The electrode selection module 40 includes: a switch selection chip 41, a first electrode rod 42, and a second electrode rod 43. The fine-tuning module 50 includes multiple fine-tuning branches connected in parallel, which are composed of impedance R and switch K connected in series.

[0197] The first input terminal of the switch selection chip 41 is connected to the first output terminal of the current control module 20, the second input terminal of the switch selection chip 41 is connected to the second output terminal of the current control module 20, and the third input terminal of the switch selection chip 41 is connected to the fourth output terminal of the main control chip MCU. The switch selection chip 41 is used to receive the switch control signal output by the main control chip MCU. The first output terminal of the switch selection chip 41 is connected to the first contact in the first electrode rod 42 and the second electrode rod 43. The second output terminal of the switch selection chip 41 is connected to the second contact in the first electrode rod 42 and the second electrode rod 43. The third output terminal of the switch selection chip 41 is connected to the second input terminal of the main control chip MCU. The switch selection chip 41 is also used to feed back the switch status to the main control chip MCU.

[0198] The first contact points of the first electrode rod 42 and the second electrode rod 43 are connected to the first input terminal of the fine-tuning module 50 and one end of the impedance to be measured Rb, respectively, to the first input terminal of the impedance detection module 30.

[0199] The second contact of the first electrode rod 42 and the second electrode rod 43 is connected to the second input terminal of the impedance detection module 30, the second input terminal of the fine-tuning module 50, and the other end of the impedance to be measured Rb.

[0200] Optionally, the electrode selection module 40 further includes a seventh capacitor C7 and an eighth capacitor C8. The seventh capacitor C7 is connected between the switch selection chip 41 and the first electrode rod 42, and the eighth capacitor C8 is connected between the switch selection chip 41 and the second electrode rod 43. The seventh capacitor C7 and the eighth capacitor C8 filter the current signal output by the switch selection chip 41 to provide a stable signal for the first electrode rod 42 and the second electrode rod 43.

[0201] For example, the electrode selection switch 41 typically consists of a register, multiple D flip-flops, multiple level shifters, etc., forming a selection network to achieve connection and selection of corresponding acquisition points on the first and second electrode rods. For example Figure 5 In the example, SWIN1 and SWIN2 are two input terminals, and SWOUT1 and SWOUT are a set of output terminals, transmitting the two selected input signals to the first electrode rod and the second electrode rod.

[0202] For example, the first and second electrode rods are provided with multiple contacts for collecting the electric field at a designated location on the human body after contact. The contact arrangement can be configured as an array or a circular patch shape as needed, and is not limited here. The two locations collected by the two electrode rods are used to obtain two sampling points, and the voltage difference between the two sampling points is equivalent to the voltage across the impedance to be measured.

[0203] In one possible scenario, after the first and second electrode rods are embedded in the designated location on the human body, the electrode selection switch 41 selects the first and second electrode rods at the contact point on the human body to collect two contact electrodes. The current input from the current control module is input to the fine-tuning module 50. The fine-tuning module 50 adjusts the impedance and the on / off state and number of closed switches in multiple fine-tuning branches according to the current magnitude. Under the condition of ensuring current safety, the current signal and voltage signal are input to the impedance detection module 30.

[0204] In one possible scenario, the first transistor is initially kept off, outputting an initial power supply. Under the control of the current control module, a stable current is output. A set of electrodes is selected by the electrode selection unit, and the current input to the fifth operational amplifier is controlled within a safe range by the fine-tuning module. The detected voltage and current are fed back to the main control chip to calculate the initial detection value of the impedance to be measured. Then, the first transistor is periodically closed, outputting a changed voltage to the impedance to be measured. By adjusting the amplitude or frequency of the PWM wave of the main control chip, the current output by the current control module is changed, and the impedance detection module obtains new current and voltage values. After processing by the main control chip again, a second detection value of the impedance to be measured is calculated. Compared with the initial detection value in the previous static state, the detection value that is closer to the true value is selected for use in the next dynamic detection comparison process. After multiple detections, a more accurate detection value is obtained. Using the same method, other electrode contacts in the electrode selection module are changed to perform the human body impedance detection process of the equivalent impedance between other electrodes.

[0205] Example 4

[0206] Figure 6 The diagram shown is a schematic flowchart of a human body impedance detection method provided in Embodiment 4 of this application. It is applied in a human body impedance detection circuit. According to... Figure 6 The provided diagram illustrates the specific methods for human body impedance detection, including:

[0207] S601. Obtain the initial impedance value of the impedance to be measured.

[0208] The initial impedance value mentioned here can be understood as the detected value of the impedance to be measured for the first time.

[0209] For example, based on the structure of the human body impedance detection circuit, the impedance of the human body can be detected, improving the detection accuracy. This helps to assist in medical research and development, further optimize the therapeutic effect of micro-detection devices or micro-treatment devices (such as artificial heart devices) implanted in the human body, and is of great help to medical research.

[0210] In one possible scenario, after the human body impedance detection circuit is activated, the main control chip acquires the voltage and current of the detected circuit, and then calculates the voltage and current on both sides of the branch where the impedance to be measured is located. The initial impedance value of the impedance to be measured in the initial state is then calculated and stored as a static detection value to provide a reference value for subsequent dynamic detection values.

[0211] S602. Adjust the operating current of the current control module to obtain the corresponding adjustment impedance value.

[0212] The adjustment process mentioned here can be understood as adjusting the amplitude or output frequency of the current, or adjusting the amplitude or frequency of the received PWM wave signal, thereby indirectly changing the operating current.

[0213] For example, after obtaining the initial impedance value, in order to improve the detection accuracy, the amplitude or frequency of the PWM wave and other square wave signals (such as DC-to-AC square wave signals or AC-to-DC square wave signals) output by the main control chip can be adjusted, and the changed signal can be fed back to the power conversion module to output the adjusted voltage signal; the changed current signal can be output by the current control module, and then the adjusted impedance value of the impedance to be measured can be calculated based on the new voltage and current obtained after the adjustment process.

[0214] S603. Based on the initial impedance value and the adjusted impedance value, determine the target detection value of the impedance to be measured.

[0215] The target detection value mentioned here can be understood as the detection value determined after static and dynamic detection, which is closer to the true value.

[0216] For example, by comparing the initial impedance value obtained in the static state with the adjusted impedance value obtained in the dynamic state, the impedance value that is closer to the true value is selected as the target detection value of the impedance to be measured, thereby achieving the purpose of combining static detection with dynamic detection to improve the accuracy of human body impedance detection.

[0217] Figure 7 The diagram shown is a flowchart of another human body impedance detection method provided in Embodiment 4 of this application. Figure 7 This is based on the previous embodiment. Figure 7 The provided diagram illustrates the steps of the human body impedance detection method, including:

[0218] S701: Control the first transistor to remain in the off state and determine the initial power supply voltage value corresponding to the voltage conversion module.

[0219] S702. Determine the initial current value output by the current control module based on the initial power supply voltage value.

[0220] S703. Determine the initial impedance value of the impedance to be measured based on the initial current value and the initial supply voltage value.

[0221] In one possible scenario, by turning off the first transistor, the battery stores energy in the first capacitor, and the resulting voltage is used as the initial supply voltage. When the main control chip provides the set PWM wave signal to the current control module, the current control module outputs a stable current signal as a constant current source. Based on the initial supply voltage value, the initial current value output by the current control module is determined. The impedance detection module feeds back the received initial supply voltage value and initial current value to the storage unit of the main control chip for storage. At the same time, the main control chip calculates the voltage and current values ​​of the impedance to be measured, and then calculates the initial impedance value in the static state.

[0222] S704: The main control chip controls the first transistor to remain closed, thereby determining the regulated voltage value output by the voltage conversion module.

[0223] S705: Adjust the input signal of the current control module to obtain the adjusted operating current output by the current control module.

[0224] S706. The adjusted impedance value corresponding to the impedance detection unit is obtained based on the adjusted voltage value and the operating current.

[0225] For example, after obtaining the initial impedance value in the static state, the main control chip changes the output square wave signal to control the conduction time of the first transistor, thereby changing the output voltage value of the power conversion module. The voltage value output after changing the square wave signal is used as the adjustment voltage value and input to the fifth operational amplifier. Simultaneously, the main control chip changes the frequency or amplitude of the output PWM wave to change the output current of the current control module, obtaining the changed operating current. The adjusted operating current is then input to the fifth operational amplifier, which feeds back the operating current and adjustment voltage to the main control chip for processing and storage. The main control chip calculates the impedance value of the impedance under test in a dynamic environment and stores the dynamically detected impedance value as the adjustment impedance value.

[0226] S707, Obtain the difference between the adjusted impedance value and the initial impedance value.

[0227] S708. When the difference meets the preset threshold condition, the current adjusted impedance value is used as the target detection value of the impedance to be measured.

[0228] S709. When the operating current of the current control module exceeds the set current threshold, the control protection unit remains open, or the conduction state of the fine-tuning module is adjusted to activate the overcurrent protection of the impedance detection unit.

[0229] For example, the main control chip obtains the initial impedance value under static conditions and the adjusted impedance value under dynamic adjustment. By comparing the difference between the two, it is determined whether the difference between the detection results before and after exceeds the set range. The set difference range is used as a threshold condition. When the difference is within the difference range, it indicates that the difference meets the threshold condition. Then, the adjusted impedance value can be changed. The adjusted impedance value is used as the initial impedance value and as the reference value for the next dynamic detection. After multiple comparisons, the target detection value is obtained.

[0230] Furthermore, after the main control chip changes the square wave signal, the operating current output of the current control module changes. When the changed operating current exceeds the set safe current threshold, if the operating current is directly input to the fifth operational amplifier, the fifth operational amplifier will burn out due to the large current. To protect the normal operation of the device, the switch in the protection unit is opened to block the large current input, thus protecting the safety of the subsequent circuits. Alternatively, the current can be diverted by closing multiple fine-tuning branches in the fine-tuning module, reducing the current input to the fifth operational amplifier and achieving overcurrent protection.

[0231] Example 5

[0232] Figure 8 The diagram shown is a structural schematic of a testing device provided in Embodiment 5 of this application. Figure 8 The detection device 800 shown includes at least one processor 801, a memory 802, at least one network interface 804, and other user interfaces 803. The various components in the detection device 800 are coupled together via a bus system 805. It is understood that the bus system 805 is used to implement communication between these components. In addition to a data bus, the bus system 805 also includes a power bus, a control bus, and a status signal bus. However, for clarity, ... Figure 8 The general labeled all buses as Bus System 805.

[0233] The user interface 803 may include a display, keyboard, or clicking device (e.g., mouse, trackball, touchpad, or touchscreen).

[0234] It is understood that the memory 802 in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 802 described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0235] In some implementations, memory 802 stores elements, executable units or data structures, or subsets thereof, or extended sets thereof: operating system 8021 and application programs 8022.

[0236] The operating system 8021 includes various system programs, such as the framework layer, core library layer, and driver layer, used to implement various basic business functions and handle hardware-based tasks. The application program 8022 includes various applications, such as a media player and a browser, used to implement various application functions. The program implementing the method of this application embodiment can be included in the application program 8022.

[0237] In this embodiment, by calling a program or instruction stored in memory 802, specifically a program or instruction stored in application program 8022, processor 801 executes the method steps provided in each method embodiment, including, for example:

[0238] Obtain the initial impedance value of the impedance to be measured; adjust the operating current of the current control module to obtain the corresponding adjusted impedance value; based on the initial impedance value and the adjusted impedance value, determine the target detection value of the impedance to be measured.

[0239] The methods disclosed in the embodiments of this application can be applied to or implemented by processor 801. Processor 801 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in processor 801 or by instructions in the form of software. The processor 801 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software units in the decoding processor. The software units may be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 802. Processor 801 reads the information in memory 802 and, in conjunction with its hardware, completes the steps of the above method.

[0240] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0241] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0242] The detection equipment provided in this embodiment can be as follows: Figure 8 The detection device shown can perform the following: Figure 6-7 All steps of the method for detecting human body impedance, thereby achieving Figure 6-7 For details on the technical effectiveness of the human body impedance detection method shown, please refer to [link / reference needed]. Figure 6-7 The relevant descriptions are presented concisely and will not be elaborated upon here.

[0243] This application also provides a storage medium (computer-readable storage medium). This storage medium stores one or more programs. The storage medium may include volatile memory, such as random access memory; it may also include non-volatile memory, such as read-only memory, flash memory, hard disk, or solid-state drive; and it may also include combinations of the above types of memory.

[0244] One or more programs in the storage medium can be executed by one or more processors to implement the human body impedance detection method described above, which is executed on the detection device side.

[0245] The processor is used to execute the human body impedance detection control program stored in the memory to implement the following steps of the human body impedance detection method executed on the human body impedance detection device side:

[0246] Obtain the initial impedance value of the impedance to be measured; adjust the operating current of the current control module to obtain the corresponding adjusted impedance value; based on the initial impedance value and the adjusted impedance value, determine the target detection value of the impedance to be measured.

[0247] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0248] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented in hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0249] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0250] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0251] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0252] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0253] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A human body impedance detection circuit, characterized in that, include: Power conversion module, current control module, main control chip and impedance detection module; The output terminal of the power conversion module is connected to the first input terminal of the current control module, and the power conversion module is used to provide the operating voltage for the current control module. The second input terminal of the current control module is connected to the first output terminal of the main control chip, the third input terminal of the current control module is connected to the second output terminal of the main control chip, the first output terminal of the current control module is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured, and the second output terminal of the current control module is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured. The current control module is used to provide a stable current signal to the impedance detection module under the control of the main control chip. The output terminal of the impedance detection module is connected to the first input terminal of the main control chip. The impedance detection module is used to obtain the equivalent current between the two current signals output by the current control module, and to obtain the detection value of the impedance under test through the voltage across the impedance under test. The main control chip is used to transmit a sinusoidal current signal to the current control module, and transmit a stable current signal to the impedance detection module through the current control module. The impedance detection module is also used to analyze the detection value of the impedance to be measured based on the current signal, and feed back the detection value of the impedance to be measured to the main control chip. The main control chip is also used to change the input electrical signal of the power conversion module so that the output voltage signal of the power conversion module is adjusted. The main control chip is also used to change the input electrical signal of the current control module so that the current control module outputs an adjusted current signal. The adjusted voltage signal and the adjusted current signal are input to the impedance detection module, and the impedance detection module detects the detection value of the impedance to be measured. The main control chip is also used to obtain the difference between the detected value and the initial impedance value; When the difference is within the range, the detected value is used as the new initial impedance value and as the reference value for the next dynamic detection.

2. The circuit according to claim 1, characterized in that, The power conversion module includes: a power battery, a first inductor, a first transistor, a first diode, and a first capacitor; The positive output terminal of the power battery is connected to one end of the first inductor, and the negative input terminal of the power battery is connected to the first terminal of the first transistor and one end of the first capacitor to the first ground terminal. The power battery provides the turn-on voltage for the main control chip and the current control module. The other end of the first inductor is connected to the second end of the first transistor and the inverting input of the first diode; The positive output terminal of the first diode and the other end of the first capacitor are connected to the first input terminal of the current control module as the output terminal of the power conversion module. The control terminal of the first transistor is connected to the third output terminal of the main control chip.

3. The circuit according to claim 1, characterized in that, The current control module includes: First operational amplifier, second operational amplifier, first switching transistor, second switching transistor, third switching transistor, fourth switching transistor, fifth switching transistor, sixth switching transistor, seventh switching transistor, eighth switching transistor, second capacitor, third capacitor, first impedance and second impedance; The positive input terminal of the first operational amplifier is connected to the first output terminal of the main control chip as the second input terminal of the current control module. The inverting input terminal of the first operational amplifier is connected to one end of the first impedance and the second end of the first switching transistor. The output terminal of the first operational amplifier is connected to the control terminal of the first switching transistor. The first terminal of the first switch is connected to the first terminal of the second switch, the control terminal of the second switch, and the control terminal of the third switch. The other end of the first impedance is connected to the second ground terminal; The second terminal of the second switch is connected to the output terminal of the power conversion module, along with the second terminals of the third, fourth, and fifth switches. The first terminal of the third switch is connected to the first terminal of the sixth switch and one terminal of the second capacitor; The second terminal of the sixth switch is connected to the third ground terminal, and the control terminal of the sixth switch is connected to the fourth output terminal of the main control chip. The first terminal of the fourth switch is connected to the first terminal of the seventh switch and one terminal of the third capacitor, and the control terminal of the fourth switch is connected to the control terminal of the fifth switch, the first terminal of the fifth switch, and the first terminal of the eighth switch. The second terminal of the seventh switch is connected to the fourth ground terminal, and the control terminal of the seventh switch is connected to the fifth output terminal of the main control chip. The second terminal of the eighth switch is connected to one end of the second impedance and the inverting input terminal of the second operational amplifier, and the control terminal of the eighth switch is connected to the output terminal of the second operational amplifier. The positive input terminal of the second operational amplifier is connected to the second output terminal of the main control chip as the third input terminal of the current control module. The other end of the second impedance is connected to the fifth ground terminal; The other end of the second capacitor serves as the first output terminal of the current control module, and is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured. The other end of the third capacitor serves as the second output terminal of the current control module, and is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured.

4. The circuit according to claim 1, characterized in that, The current control module includes: The third operational amplifier, the fourth operational amplifier, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch, the sixteenth switch, the seventeenth switch, the third impedance, the fourth impedance, the fifth impedance, the sixth impedance, the seventh impedance, the eighth impedance, the fourth capacitor, and the fifth capacitor; The positive input terminal of the third operational amplifier is connected to the first output terminal of the main control chip as the second input terminal of the current control module. The inverting input terminal of the third operational amplifier is connected to the second terminal of the ninth switch and one end of the third impedance. The output terminal of the third operational amplifier is connected to the control terminal of the ninth switch. The first terminal of the ninth switch is connected to the first terminal of the tenth switch, the control terminal of the tenth switch, and the control terminal of the eleventh switch. The other end of the third impedance is connected to the sixth ground terminal; The second terminal of the tenth switch is connected to the second terminals of the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, and one end of the fourth impedance; The first terminal of the eleventh switch and the first terminal of the fourteenth switch are connected to the first input terminal of the impedance detection module as the first output terminal of the current control module. The control terminal of the twelfth switch is connected to the other end of the fourth impedance and one end of the fifth impedance. The first end of the twelfth switch and the first end of the fifteenth switch serve as the second output terminal of the current control module and are connected to the second input terminal of the impedance detection module. The other end of the fifth impedance is connected to the first end of the sixteenth switching transistor; The first terminal of the thirteenth switch is connected to the control terminal of the thirteenth switch, the control terminal of the fourteenth switch, and the first terminal of the seventeenth switch. The control terminal of the fifteenth switch is connected to one end of the sixth impedance and one end of the fourth capacitor, and the second terminal of the fifteenth switch and the other end of the fourth capacitor are connected to the seventh ground terminal. The other end of the sixth impedance is connected to the first output terminal of the main control chip; The control terminal of the sixteenth switch is connected to one end of the seventh impedance and one end of the fifth capacitor, and the second terminal of the sixteenth switch and the other end of the fifth capacitor are connected to the eighth ground terminal. The other end of the seventh impedance is connected to the second output terminal of the main control chip; The control terminal of the seventeenth switch is connected to the output terminal of the fourth operational amplifier, and the second terminal of the seventeenth switch is connected to one end of the eighth impedance and the inverting input terminal of the fourth operational amplifier. The other end of the eighth impedance is connected to the ninth ground terminal; The positive input terminal of the fourth operational amplifier is connected to the second output terminal of the main control chip.

5. The circuit according to claim 1, characterized in that, The impedance detection module includes: Protection unit and impedance detection unit; The first input terminal of the protection unit is connected to the first output terminal of the current control module as the first input terminal of the impedance detection module. The second input terminal of the protection unit is connected to the second output terminal of the current control module as the second input terminal of the impedance detection module. The first output terminal of the protection unit is connected to the first input terminal of the impedance detection unit. The second output terminal of the protection unit is connected to the second input terminal of the impedance detection unit. The protection unit is used to block the current input to the impedance detection unit when the input current is too large. The output terminal of the impedance detection unit is connected to the first input terminal of the main control chip as the output terminal of the impedance detection module. The impedance detection unit is used to detect the detection value of the impedance to be measured.

6. The circuit according to claim 5, characterized in that, The protection unit includes: a first relay switch; The first input terminal of the first relay switch is connected to the first output terminal of the current control module as the first input terminal of the protection unit. The second input terminal of the first relay switch is connected to the second output terminal of the current control module as the second input terminal of the protection unit. The first output terminal of the first relay switch is connected to the first input terminal of the impedance detection unit as the first output terminal of the protection unit. The second output terminal of the first relay switch is connected to the second input terminal of the impedance detection unit as the second output terminal of the protection unit. The first relay switch is used to block the flow of high current to the impedance detection unit when the received current is too high.

7. The circuit according to claim 5, characterized in that, The impedance detection unit includes: a ninth impedance, a tenth impedance, an eleventh impedance, a twelfth impedance, a thirteenth impedance, a sixth capacitor, and a fifth operational amplifier; One end of the ninth impedance is connected as the first input terminal of the impedance detection unit, and the other end of the ninth impedance is connected to one end of the tenth impedance and the positive input terminal of the fifth operational amplifier. The other end of the tenth impedance is connected to the tenth ground terminal; One end of the eleventh impedance is connected to the second output terminal of the protection unit as the second input terminal of the impedance detection unit, and the other end of the eleventh impedance is connected to one end of the twelfth impedance and the inverting input terminal of the fifth operational amplifier. The other end of the twelfth impedance is connected to the output terminal of the fifth operational amplifier and one end of the thirteenth impedance; The other end of the thirteenth impedance and one end of the sixth capacitor are connected to the first input terminal of the main control chip as the output terminal of the impedance detection unit. The other end of the sixth capacitor is connected to the eleventh ground terminal.

8. The circuit according to claim 1, characterized in that, The circuit also includes: an electrode selection module and a fine-tuning module; The electrode selection module and the fine-tuning module are connected between the current control module and the impedance detection module. The first input terminal of the electrode selection module is connected to the first output terminal of the current control module, and the second input terminal of the electrode selection module is connected to the second output terminal of the current control module. The first output terminal of the electrode selection module is connected to the first input terminal of the fine-tuning module and one end of the impedance to be measured, and the second output terminal of the electrode selection module is connected to the second input terminal of the fine-tuning module and the other end of the impedance to be measured. The electrode selection module is used to select electrodes at different locations within the human body to change the detected value of the impedance to be measured. The fine-tuning module is used to change the branch current of the parallel-connected impedance to be measured so that the impedance detection module operates in the working current environment.

9. The circuit according to claim 8, characterized in that, The electrode selection module includes: a switch selection chip, a first electrode rod and a second electrode rod; the fine-tuning module includes multiple fine-tuning branches connected in parallel, and the fine-tuning branches are composed of impedance and switches connected in series. The first input terminal of the switch selection chip is connected to the first output terminal of the current control module, the second input terminal of the switch selection chip is connected to the second output terminal of the current control module, and the third input terminal of the switch selection chip is connected to the fourth output terminal of the main control chip. The switch selection chip is used to receive the switch control signal output by the main control chip. The first output terminal of the switch selection chip is connected to the first contact of the first electrode rod and the second electrode rod, the second output terminal of the switch selection chip is connected to the second contact of the first electrode rod and the second electrode rod, and the third output terminal of the switch selection chip is connected to the second input terminal of the main control chip. The switch selection chip is also used to provide feedback on the switch status to the main control chip. The first contact point of the first electrode rod and the second electrode rod is connected to the first input terminal of the impedance detection module and one end of the impedance to be measured; The second contact of the first electrode rod and the second electrode rod is connected to the second input terminal of the impedance detection module and the other end of the impedance to be measured.

10. A method for detecting human body impedance, applied to the human body impedance detection circuit as described in any one of claims 1 to 9, characterized in that, include: Obtain the initial impedance value of the impedance to be measured; The operating current of the current control module is adjusted to obtain the corresponding detection value; Based on the initial impedance value and the detected value, the target detected value of the impedance to be measured is determined.

11. The method according to claim 10, characterized in that, The process of obtaining the initial impedance value of the impedance to be measured includes: The first transistor is kept off to determine the initial supply voltage value corresponding to the voltage conversion module. The initial current value output by the current control module is determined based on the initial power supply voltage value; The initial impedance value of the impedance to be measured is determined based on the initial current value and the initial supply voltage value.

12. The method according to claim 10, characterized in that, The process of adjusting the operating current of the current control module to obtain the corresponding detection value includes: The main control chip controls the first transistor to remain closed, thereby determining the regulated voltage value output by the voltage conversion module. Adjust the input signal of the current control module to obtain the adjusted operating current output by the current control module; The impedance detection unit obtains its detection value based on the adjusted voltage value and the operating current.

13. The method according to claim 11 or 12, characterized in that, Determining the target detection value of the impedance to be measured based on the initial impedance value and the detected value includes: Obtain the difference between the detected value and the initial impedance value; When the difference meets a preset threshold condition, the detected value is used as the target detected value of the impedance to be measured.

14. The method according to claim 10, characterized in that, The method further includes: When the operating current of the current control module exceeds the set current threshold, the control protection unit remains disconnected, or the conduction state of the fine-tuning module is adjusted to activate the overcurrent protection of the impedance detection unit.

15. A testing device, characterized in that, include: A processor and a memory, the processor being configured to execute a control program for human body impedance detection stored in the memory to implement the human body impedance detection method according to any one of claims 10 to 14.

16. A storage medium, characterized in that, The storage medium stores one or more programs, which can be executed by one or more processors to implement the human body impedance detection method according to any one of claims 10 to 14.

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