Bioelectrical impedance measurement methods, circuits, chips and electronic devices

Abstract

This application provides a bioelectrical impedance measurement method, circuit, chip, and electronic device. The method includes: obtaining a first contact impedance value corresponding to a first excitation electrode and a second contact impedance value corresponding to a second excitation electrode through a preset method; determining the transmission direction of an excitation current between the first and second excitation electrodes based on the first and second contact impedance values; controlling the excitation current to transmit between the first and second excitation electrodes according to the transmission direction; determining a target voltage value between a first and second measuring electrode, and calculating the impedance of the measured object based on the target voltage value; wherein the first and second contact impedance values ​​are different. This application can reduce the influence of contact impedance on the bioelectrical impedance measurement results, reduce the measurement error of bioelectrical impedance, and improve the accuracy of bioelectrical impedance measurement.

Description

Technical Field

[0001] This application relates to the field of impedance measurement technology, and in particular to a bioelectrical impedance measurement method, circuit, chip and electronic device. Background Technology

[0002] Bioelectrical Impedance Analysis (BIA) is a detection technique that utilizes the electrical properties and changes in biological tissues and organs to extract biomedical information related to human physiological and pathological conditions. It typically involves applying a small excitation current to the object being measured using an electrode system placed on the body surface, detecting the corresponding impedance and its changes, and then obtaining relevant physiological and pathological information depending on the specific application.

[0003] In bioelectrical impedance analysis (BIA), the contact impedance between the electrode and the measurement object (such as the human body) has a significant impact on the accuracy and repeatability of the measurement. Insufficient contact or dry skin can lead to poor contact impedance, resulting in large measurement errors or even measurement failure. Therefore, it is necessary to provide a method to improve the accuracy of bioelectrical impedance analysis. Summary of the Invention

[0004] This application provides a bioelectrical impedance measurement method, circuit, chip, and electronic device to solve the technical problem that the contact impedance between the electrode and the object being measured causes a large error in the bioelectrical impedance measurement results.

[0005] In a first aspect, this application provides a bioelectrical impedance measurement method applied to an electronic device, the electronic device including a first excitation electrode and a first measurement electrode for contacting a first portion of the object being measured, and a second excitation electrode and a second measurement electrode for contacting a second portion of the object being measured, the method comprising:

[0006] The first contact impedance value corresponding to the first excitation electrode and the second contact impedance value corresponding to the second excitation electrode are obtained by a preset method.

[0007] The transmission direction of the excitation current between the first excitation electrode and the second excitation electrode is determined based on the first contact impedance value and the second contact impedance value.

[0008] The excitation current is controlled to propagate between the first excitation electrode and the second excitation electrode in the transmission direction;

[0009] A target voltage value is determined between the first measuring electrode and the second measuring electrode, so as to calculate the impedance of the object being measured based on the target voltage value;

[0010] The first contact impedance value and the second contact impedance value are different.

[0011] Secondly, this application also provides a bioelectrical impedance measurement circuit, the circuit being applied to an electronic device, the electronic device including a first excitation electrode and a first measurement electrode for contacting a first portion of the object being measured, and a second excitation electrode and a second measurement electrode for contacting a second portion of the object being measured, the circuit comprising:

[0012] The acquisition module is used to acquire the first contact impedance value corresponding to the first excitation electrode and the second contact impedance value corresponding to the second excitation electrode through a preset method;

[0013] A switching module is used to control the transmission of excitation current between the first excitation electrode and the second excitation electrode in a transmission direction; wherein the transmission direction is that the excitation current is output from the excitation electrode corresponding to the smaller value of the contact impedance and input from the excitation electrode corresponding to the larger value of the contact impedance.

[0014] A voltage determination module is used to determine a target voltage value between a first measuring electrode and a second measuring electrode, so as to calculate the impedance value of the object being measured based on the target voltage value.

[0015] Thirdly, this application also provides a chip, the chip including the bioelectrical impedance measurement circuit described in any of the second aspects above.

[0016] Fourthly, this application also provides an electronic device, including a device body and a chip disposed on the device body as described in the third aspect above.

[0017] The bioelectrical impedance measurement method, circuit, chip, and electronic device provided in this application obtain the first contact impedance corresponding to the first excitation electrode and the second contact impedance corresponding to the second excitation electrode through a preset method. The transmission direction of the excitation current between the first and second excitation electrodes is determined based on the first and second contact impedance values. The excitation current is controlled to transmit between the first and second excitation electrodes according to the transmission direction. Then, a target voltage value between the first and second measuring electrodes is determined to calculate the impedance to be measured of the object being measured. The first and second contact impedance values ​​are different. By directly determining the transmission direction of the excitation current based on the magnitude of the contact impedance, excessive contact impedance is avoided in the measurement results. This solves the technical problem in the prior art where the contact impedance between the electrode and the object being measured leads to large errors in the bioelectrical impedance measurement results. It reduces the influence of contact impedance on the bioelectrical impedance measurement results, lowers the measurement error, and improves the accuracy of bioelectrical impedance measurement.

[0018] These or other aspects of this application will become more apparent in the following description of the embodiments. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram illustrating the application of the bioelectrical impedance measurement method provided in this application;

[0021] Figure 2 A schematic flowchart of the bioelectrical impedance measurement method provided in this application;

[0022] Figure 3 A flowchart for determining the direction of turbulent current transmission provided in an embodiment of this application;

[0023] Figure 4 A flowchart for obtaining a first voltage value and a second voltage value is provided for embodiments of this application;

[0024] Figure 5 This is one of the flowcharts for determining the target voltage value provided in the embodiments of this application;

[0025] Figure 6 This is the second flowchart for determining the target voltage value provided in the embodiments of this application;

[0026] Figure 7 The third flowchart for determining the target voltage value provided in the embodiments of this application;

[0027] Figure 8 A block diagram of the bioelectrical impedance measurement circuit provided in the embodiments of this application;

[0028] Figure 9 A circuit diagram of a bioelectrical impedance measurement circuit provided in an embodiment of this application;

[0029] Figure 10 A circuit diagram of a bioelectrical impedance measurement circuit provided in another embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions 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, 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.

[0031] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be exchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0032] References such as “one embodiment” or “some embodiments” as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the terms “comprising,” “including,” “having,” and variations thereof, as used in this specification, mean “including, but not limited to,” unless otherwise specifically emphasized.

[0033] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0034] Many factors influence bioelectrical impedance analysis (BIA) measurements, including electrode configuration, the distance between electrodes, human movement, and body posture. In practical applications, contact impedance is a crucial factor affecting measurement results. Throughout the electrode signal transmission path, human tissue is a good conductor, with its impedance varying from hundreds to tens of ohms depending on the frequency. The contact impedance between the electrode and skin, however, varies from tens of thousands to hundreds of ohms. Therefore, the contact impedance between the electrode and skin directly affects the quality of the electrode signal.

[0035] The bioelectrical impedance measurement method and circuit provided in this application can be applied to biological impedance measurement devices, such as body fat scales, body composition analyzers, or wearable devices such as watches and bracelets with body fat measurement functions. To facilitate a better understanding of the bioelectrical impedance measurement method, circuit, chip, and electronic device provided in the embodiments of this application, the application scenarios applicable to the embodiments of this application are described below.

[0036] Please see Figure 1 , Figure 1This diagram illustrates the application of the bioelectrical impedance measurement method provided in this embodiment. Both the bioelectrical impedance measurement method and the bioelectrical impedance measurement circuit provided in this embodiment can be applied to applications such as… Figure 1 The body fat scale shown includes a housing and a bioelectrical impedance measurement circuit within the housing, which may include a current generation module and a voltage determination module.

[0037] The housing has a first contact area 101, a second contact area 102, and a display area 103. The first contact area 101 is provided with an excitation electrode and a measuring electrode for contacting a first part of the object being measured. The second contact area 102 is provided with an excitation electrode and a measuring electrode for contacting a second part of the object being measured. The display area 103 is used to display measurement information, such as weight, body fat percentage, heart rate, etc.

[0038] For example, a sinusoidal voltage wave of a preset frequency is generated by a sinusoidal signal generator. This sinusoidal voltage wave is input to a current generation module, which outputs an excitation current. This excitation current is an alternating constant current. This excitation current can be sent into the human body through the excitation electrodes and transmitted within the human body to form a current loop.

[0039] For example, the voltage determination module inputs the voltage signals obtained from the measuring electrode that contacts the first part of the object being measured and the measuring electrode that contacts the second part to the operational amplifier circuit. After the voltage signals are amplified, they are converted from analog to digital by the analog-to-digital converter circuit to obtain the corresponding voltage value.

[0040] For example, a first excitation electrode 104 and a first measurement electrode 105 are provided in the first contact area 101, and a second excitation electrode 106 and a second measurement electrode 107 are provided in the second contact area 102. The first excitation electrode 104 and the second excitation electrode 106 are connected to a current generating module within the housing, and the first measurement electrode 105 and the second measurement electrode 107 are connected to a voltage determining module within the housing.

[0041] When measuring the impedance of an object using a body fat scale, the excitation current generated by the current generation module inside the housing can flow into the object being measured (e.g., the human body) through the first excitation electrode 104 and be received from the second excitation electrode 106, forming a current transmission loop. This excitation current is transmitted to the object being measured through the first excitation electrode 104 and then to the second excitation electrode 106, generating a voltage difference between the first measuring electrode 105 and the second measuring electrode 107. The voltage determination module can obtain the voltage value corresponding to this voltage difference between the first measuring electrode 105 and the second measuring electrode 107, and then calculate the impedance value of the object being measured (e.g., the human body impedance value), thereby realizing the impedance measurement of the object being measured.

[0042] also, Figure 1 While this application is intended for use in body fat scales, the bioelectrical impedance measurement method and circuit described in this application can also be applied to other devices that require bioelectrical impedance measurement, which will not be elaborated here.

[0043] However, in the existing technology, in the entire transmission path of the electrode signal, human tissue is a good conductor, and its impedance varies from hundreds of ohms to tens of ohms depending on the frequency. The contact impedance between the electrode and the skin varies from tens of thousands of ohms to hundreds of ohms, which will directly affect the quality of the electrode signal. Therefore, contact impedance has become an important factor affecting the accuracy of biological impedance measurement results.

[0044] Because the electrodes themselves differ in position, size, material, and contact state with the object being measured (e.g., the first part, the second part), the contact impedances generated by the electrodes, including the first excitation electrode 104, the second excitation electrode 106, the first measurement electrode 105, and the second measurement electrode 107, are not constant, and the contact impedances of each electrode may even differ significantly.

[0045] Through theoretical analysis and experimental verification, the applicant discovered that, from the current-side perspective, because the contact impedance of the first excitation electrode 104 differs from that of the second excitation electrode 106, the voltage across the measured object is different when the excitation current flows into the first excitation electrode 104 and out of the second excitation electrode 106, versus when it flows in reverse. Similarly, because the first measuring electrode 105 differs from the second measuring electrode 107, swapping the connection positions of the first measuring electrode 105 and the second measuring electrode 107 also results in different voltages across the measured object. Through multiple experimental verifications, the applicant also found that when the excitation current flows into the excitation electrode with the smaller contact impedance, the error in the measured impedance value of the measured object is smaller.

[0046] Therefore, to address the technical problem of significant errors in bioelectrical impedance measurement results caused by the contact impedance between the electrodes and the object being measured, this application provides a bioelectrical impedance measurement method, circuit, chip, and electronic device. The method involves obtaining a first contact impedance corresponding to a first excitation electrode and a second contact impedance corresponding to a second excitation electrode through a preset method. The transmission direction of the excitation current between the first and second excitation electrodes is determined based on the first and second contact impedance values. The excitation current is controlled to propagate between the first and second excitation electrodes according to the transmission direction. Then, a target voltage value between the first and second measuring electrodes is determined to calculate the impedance to be measured of the object being measured. The first and second contact impedance values ​​are different. By directly determining the transmission direction of the excitation current based on the magnitude of the contact impedance, excessive contact impedance is avoided in the measurement results. This solves the technical problem of significant errors in bioelectrical impedance measurement results caused by the contact impedance between the electrodes and the object being measured in the prior art. It reduces the influence of contact impedance on bioelectrical impedance measurement results, lowers the measurement error, and improves the accuracy of bioelectrical impedance measurement.

[0047] The following is combined with Figures 2-10 This application describes the bioelectrical impedance measurement method, circuit, chip, and electronic device provided in the embodiments of this application.

[0048] In some embodiments, please refer to Figure 2 , Figure 2 This is a schematic flowchart of the bioelectrical impedance measurement method provided in this application. An embodiment of this application provides a bioelectrical impedance measurement method applied to an electronic device. The electronic device includes a first excitation electrode and a first measurement electrode for contacting a first portion of the object being measured, and a second excitation electrode and a second measurement electrode for contacting a second portion of the object being measured. The method includes:

[0049] Step 201: Obtain the first contact impedance value corresponding to the first excitation electrode and the second contact impedance value corresponding to the second excitation electrode through a preset method.

[0050] For example, the arrangement of the first excitation electrode 104, the first measurement electrode 105, the second excitation electrode 106, and the second measurement electrode 107 can be referred to the above description. Figure 1 As shown, the first excitation electrode 104 and the first measurement electrode 105 are arranged in the first contact area 101 that contacts the first part of the object being measured, and the second excitation electrode 106 and the second measurement electrode 107 are arranged in the second contact area 102 that contacts the second part of the object being measured.

[0051] The first excitation electrode 104 contacts a first part of the object being measured (human body) and has a first contact impedance value, while the second excitation electrode 106 contacts a second part of the object being measured (human body) and has a second contact impedance value. Because the electrodes differ in their position, size, material, and contact state with the object being measured, the first contact impedance value and the second contact impedance value are different.

[0052] In some implementations, the preset method for obtaining the first contact impedance value and the second contact impedance value can be obtained through existing detection equipment or detection circuits.

[0053] For example, a preset method for measuring contact impedance could be as follows:

[0054] When measuring human body impedance using a four-electrode method, two electrodes are used as excitation electrodes, and the other two as measurement electrodes. The two excitation electrodes are in contact with different parts of the body, such as the left and right hands, or the left and right feet. The two measurement electrodes, used to measure voltage, are also corresponding to the two excitation electrodes. The excitation signal flows through the body from one excitation electrode and is output from the other. Due to the body's impedance, a voltage drop exists between the two measurement electrodes. After being collected and further processed by the measurement electrodes, the human body impedance data can be calculated.

[0055] In this scheme, to obtain the contact impedance generated when at least one electrode comes into contact with the human body, the functions and connection relationships of the excitation electrode and the measuring electrode are not limited; the functions of the two types of electrodes can be used interchangeably without specific distinction. That is, the excitation electrode can be used to transmit excitation signals as well as to measure voltage, and the measuring electrode can be used to measure voltage as well as to transmit excitation signals. In other words, any two electrodes in multiple electrodes can be excitation electrodes, one can be an excitation electrode and the other a measuring electrode, or both can be measuring electrodes; they can be combined arbitrarily.

[0056] By arbitrarily combining multiple electrodes in pairs, at least one set of electrodes is simultaneously connected to the excitation port (e.g., the first excitation port and the second excitation port) in the current generation circuit and the voltage measurement port (e.g., the first voltage measurement port and the second voltage measurement port) in the voltage determination circuit. The measurement impedance of at least one set of electrodes is then obtained through a measurement module (not shown), thereby obtaining the contact impedance of at least one electrode. Specifically, to obtain the contact impedance of an electrode, two excitation ports and two voltage measurement ports are simultaneously connected to the same set of electrodes. The two excitation ports output or receive excitation signals through this set of electrodes, and the two voltage measurement ports connected to this set of electrodes measure the voltage of this set of electrodes. All electrodes can be connected sequentially to two excitation ports and two voltage measurement ports using this arbitrary pairing method, and the contact impedance of at least one electrode can be obtained through a preset measurement module.

[0057] Step 202: Determine the transmission direction of the excitation current between the first excitation electrode and the second excitation electrode based on the first contact impedance value and the second contact impedance value.

[0058] Step 203: Control the excitation current to be transmitted between the first excitation electrode and the second excitation electrode in the transmission direction.

[0059] For example, the direction of the excitation current can be controlled by a preset switching module. For instance, if the first contact impedance value is small, the excitation current can be output from the first excitation electrode and received from the second excitation electrode by the preset switching module; if the second contact impedance value is small, the excitation current can also be output from the second excitation electrode and received from the first excitation electrode by the preset switching module.

[0060] Step 204: Determine the target voltage value between the first measuring electrode and the second measuring electrode, so as to calculate the impedance of the object being measured based on the target voltage value.

[0061] Once the direction of the excitation current is determined, the excitation current will create a voltage drop at the inlet and outlet of the object being measured. This voltage drop can be obtained by measuring the voltage difference between the first and second measuring electrodes and can be used as the target voltage value to calculate the impedance of the object being measured.

[0062] The following examples will provide a detailed description of steps 202 to 204.

[0063] In some implementations, such as Figure 3 As shown, in step 202 above, determining the transmission direction of the excitation current between the first excitation electrode and the second excitation electrode based on the first contact impedance value and the second contact impedance value includes:

[0064] Step 301: Compare the magnitudes of the first contact impedance value and the second contact impedance value.

[0065] Step 302: Determine that the transmission direction is such that the excitation current is output from the excitation electrode corresponding to the smaller value of the contact impedance and input from the excitation electrode corresponding to the larger value of the contact impedance.

[0066] Due to the influence of electrode contact impedance, as mentioned above, the measured impedance value of the object being measured has a smaller error when the excitation current flows in from the excitation electrode with lower contact impedance. Therefore, after obtaining the contact impedance corresponding to the excitation electrode, the direction of excitation current transmission can be determined directly by comparing the magnitudes of the first and second contact impedance values. This ensures that the excitation current is transmitted from the excitation electrode with lower contact impedance to the excitation electrode with higher contact impedance, thereby reducing measurement error.

[0067] In some embodiments, step 203 above, controlling the excitation current to propagate between the first excitation electrode and the second excitation electrode according to the propagation direction, includes:

[0068] If the first contact impedance value is less than the second contact impedance value, the induced current is controlled to be output from the first excitation electrode and the induced current is controlled to be input from the second excitation electrode.

[0069] If the first contact impedance value is greater than the second contact impedance value, the induced current is controlled to be output from the second excitation electrode and the induced current is controlled to be input from the first excitation electrode.

[0070] It is understandable that the transmission direction of the excitation current can be controlled by setting the first set of switches. The specific implementation will be described in detail in the description of the corresponding circuit implementation, and will not be repeated here.

[0071] In this embodiment, the excitation current is output from the excitation electrode with a small contact impedance value, passes through the object being measured, and is input from the excitation electrode with a large contact impedance value. In this current loop, since the contact impedance value in the direction of the excitation current output is small, the corresponding voltage value will also be relatively small, which is closer to the actual voltage value of the object being measured, thereby obtaining a more accurate biological impedance and reducing the measurement error of biological impedance.

[0072] The following embodiments will describe how, based on the determined transmission direction of the excitation circuit, two voltage values ​​(i.e., the first voltage value and the second voltage value) are measured by exchanging the connection positions of the first and second measuring electrodes with the two ports of the voltage determination module, and these voltage values ​​are processed accordingly. This can further reduce measurement errors caused by other non-ideal factors and improve the anti-interference capability of impedance measurement, making the impedance measurement results more accurate.

[0073] In some implementations, such as Figure 4 As shown, step 204, determining the target voltage value between the first measuring electrode and the second measuring electrode, includes:

[0074] Step 401: Obtain the first voltage value of the first measuring electrode and the second measuring electrode under the first circuit connection method.

[0075] Step 402: Obtain the second voltage values ​​of the first measuring electrode and the second measuring electrode under the second circuit connection method.

[0076] Step 403: Determine the target voltage value based on the first voltage value and the second voltage value.

[0077] The first circuit connection method differs from the second circuit connection method. For example, the first current connection method may refer to a connection method in which the connection positions of the first measuring electrode and the second measuring electrode are not swapped. Conversely, the second circuit connection method may refer to a connection method in which the connection positions of the first measuring electrode and the second measuring electrode are swapped.

[0078] For example, if the first contact impedance is less than the second contact impedance, the direction of excitation current transmission is from the first excitation electrode to the second excitation electrode. In this case, the connection method without exchanging the connection positions of the first and second measuring electrodes means that the first excitation electrode and the first measuring electrode are still considered as one electrode pair, and the second excitation electrode and the second measuring electrode are also considered as one electrode pair. That is, the first excitation electrode and the first measuring electrode measure the same location (first location), and the second excitation electrode and the second measuring electrode also measure the same location (second location). The connection method with exchanging the connection positions of the first and second measuring electrodes means that the first excitation electrode and the second measuring electrode are considered as one electrode pair, and the second excitation electrode and the first measuring electrode are also considered as one electrode pair. That is, the first excitation electrode and the second measuring electrode measure the same location (first location), and the second excitation electrode and the first measuring electrode measure the same location (second location).

[0079] In some implementations, the first voltage value and the second voltage value can be obtained by controlling the first measuring electrode and the second measuring electrode in different circuit connection methods through the second switch group. The specific implementation will be described in detail in the description of the corresponding circuit implementation, and will not be repeated here.

[0080] As mentioned earlier, different measuring electrodes have different contact impedances. By swapping the connection positions of the first and second measuring electrodes with the voltage measuring module under the same current transmission direction of the excitation current, the first voltage value and the second voltage value can be obtained. The measuring electrode with the smaller contact impedance can be distinguished, and the target voltage value can be determined accordingly.

[0081] For step 403, this application provides three different calculation methods to determine the target voltage value.

[0082] In some implementations, such as Figure 5 As shown, step 403, which involves determining the target voltage value based on the first voltage value and the second voltage value, includes:

[0083] Step 501: Compare the magnitudes of the first voltage value and the second voltage value.

[0084] Step 502: Take the smaller voltage value between the first voltage value and the second voltage value as the target voltage value.

[0085] Due to the influence of electrode contact impedance, if the voltage value obtained by one of the connection methods is smaller, it indicates that the contact impedance of the measuring electrode corresponding to the excitation electrode of the output excitation current is smaller under that connection method. If the voltage value under this connection method is used, the influence on the biological impedance measurement result can be reduced due to the smaller contact impedance. Therefore, the smaller voltage value can be used as the target voltage value to reduce measurement error.

[0086] For example, assuming that the first voltage value is less than the second voltage value, the first voltage value is taken as the target voltage value, thereby determining the first voltage corresponding to the smaller contact impedance to calculate the impedance of the object being measured.

[0087] In some implementations, such as Figure 6 As shown, for step 403, the step of determining the target voltage value based on the first voltage value and the second voltage value includes:

[0088] Step 601: Obtain the difference between the first voltage value and the second voltage value.

[0089] It should be noted that all differences mentioned in this application refer to the absolute value of the difference.

[0090] Step 602: If the absolute value of the difference between the first voltage value and the second voltage value is less than or equal to a preset threshold, then the average value of the first voltage value and the second voltage value is taken as the target voltage value.

[0091] In other words, if the first voltage value and the second voltage value are within the preset threshold range, it means that the difference between the first voltage value and the second voltage value is not large, indicating that the contact impedance of the first measuring electrode and the second measuring electrode is not significantly different. In this case, the measurement error caused by the contact impedance of the measuring electrode is not the main factor causing the impedance measurement result error. Therefore, the impedance of the object being measured can be calculated by calculating the average value of the first voltage value and the second voltage value and using this average value as the target voltage value.

[0092] The preset threshold can be set according to actual application needs; it can be an absolute value or a percentage, and there is no limitation here.

[0093] Step 603: If the absolute value of the difference between the first voltage value and the second voltage value is greater than a preset threshold, then the smaller voltage value among the first voltage value and the second voltage value is taken as the target voltage value.

[0094] In other words, if the difference between the first voltage value and the second voltage value is large, it means that the contact impedance of the first measuring electrode and the second measuring electrode differs significantly. In this case, the contact impedance of the measuring electrode will cause a large error. Therefore, it is necessary to select the voltage measurement result corresponding to the smaller contact impedance, that is, to use the smaller voltage value as the target voltage value to calculate the impedance of the measured object, so as to reduce the influence of contact impedance on the impedance measurement results of the biological body.

[0095] For example, when the first contact impedance is less than the second contact impedance, and the direction of the excitation current transmission is from the first excitation electrode to the second excitation electrode, if the absolute value of the difference between the first voltage value and the second voltage value is greater than a preset threshold, and the first voltage value is smaller than the second voltage value, it indicates that the voltage value measured under the first circuit connection method is small, that is, the contact impedance value of the first measuring electrode is small, and the corresponding bioelectrical impedance measurement error will be smaller. Then the first voltage value can be used as the target voltage value to calculate the impedance of the measured object.

[0096] In some implementations, such as Figure 7 As shown, for step 403, the step of determining the target voltage value based on the first voltage value and the second voltage value includes:

[0097] Step 700: Calculate the first voltage value and the second voltage value according to the first ratio and the second ratio respectively to obtain the target voltage value.

[0098] The first ratio and the second ratio are both related to a preset threshold and the absolute value of the difference between the first voltage value and the second voltage value.

[0099] For example, step 700 includes:

[0100] Step 701: Compare the magnitudes of the first voltage value and the second voltage value.

[0101] Step 702: Calculate the first target voltage value by using the smaller voltage value according to the first ratio, and calculate the second target voltage value by using the larger voltage value according to the second ratio. The target voltage value is the sum of the first target voltage value and the second target voltage value.

[0102] The first ratio corresponds to the absolute value of the difference between the first voltage value and the second voltage value, and the second ratio corresponds to a preset threshold.

[0103] Specifically, the target voltage value can be calculated according to the following formula:

[0104] U = k1 * minimum voltage + k2 * maximum voltage;

[0105] Where, U represents the target voltage value, k1 represents the first ratio, k2 represents the second ratio, k1 = B / (A + B), k2 = A / (A + B), A represents the preset threshold, B represents the absolute value of the difference between the first voltage value and the second voltage value, the minimum voltage refers to the smaller one of the first voltage value and the second voltage value, the maximum voltage refers to the larger one of the first voltage value and the second voltage value, then k1 * minimum voltage represents the first target voltage value, and k2 * maximum voltage represents the second target voltage value.

[0106] For example, assume that the first voltage value U1 is the smaller value and the second voltage value U2 is the larger value, that is, U1 < U2, then U = U = k1 * U1 + k2 * U2.

[0107] In this way, when the difference between the first voltage value and the second voltage value is small, that is, when the contact impedance of the measurement electrode is not the main factor causing the measurement error, the target voltage value can be close to or equal to the average value of the first voltage value and the second voltage value. When the difference between the first voltage value and the second voltage value is large, that is, when the contact impedance of the measurement electrode can be the main factor causing the measurement error, the target voltage value can be mainly based on the smaller one of the first voltage and the second voltage value.

[0108] In summary, in the embodiment of the present application, by obtaining the first contact impedance corresponding to the first excitation electrode and the second contact impedance corresponding to the second excitation electrode, controlling the current to input from the end with the smaller contact impedance, and changing the circuit connection mode of the first measurement electrode and the second measurement electrode to measure the corresponding first voltage value and second voltage value, and determining the target voltage value for calculating the impedance of the measurement object according to the first voltage value and the second voltage value, it can solve the problem in the prior art that due to factors such as the position, material, size of the electrode itself and the contact state with the skin, different electrodes will have different contact impedances, so the contact impedances generated by different electrodes are not equal or even have large differences, resulting in large errors in the measurement results of bioelectrical impedance.

[0109] Next, the bioelectrical impedance measurement circuit provided by the present application will be described. The bioelectrical impedance measurement circuit described below can be correspondingly referred to the bioelectrical impedance measurement method described above.

[0110] Please refer to Figure 8 , Figure 8This is a block diagram of a bioelectrical impedance measurement circuit provided in this application. An embodiment of this application provides a bioelectrical impedance measurement circuit 800, which is applied to an electronic device. The electronic device includes a first excitation electrode and a first measurement electrode for contacting a first part of the object being measured, and a second excitation electrode and a second measurement electrode for contacting a second part of the object being measured. The circuit shown includes an acquisition module 810, a switching module 820, and a voltage determination module 830.

[0111] The acquisition module 810 is used to acquire the first contact impedance value corresponding to the first excitation electrode and the second contact impedance value corresponding to the second excitation electrode through a preset method.

[0112] The switching module 820 is used to control the transmission of excitation current between the first excitation electrode and the second excitation electrode in a transmission direction; wherein the transmission direction is that the excitation current is output from the excitation electrode corresponding to the smaller value of the contact impedance and input from the excitation electrode corresponding to the larger value of the contact impedance.

[0113] The voltage determination module 830 is used to determine a target voltage value between the first measuring electrode and the second measuring electrode, so as to calculate the impedance value of the object being measured based on the target voltage value.

[0114] In this embodiment, the contact impedance corresponding to each excitation electrode is obtained by the acquisition module 810. The switching module 820 can realize the transmission of the excitation current on the first and second excitation electrodes in a determined transmission direction according to the magnitude of the contact impedance. Then, the voltage determination module 830 obtains the voltage value between the corresponding measurement electrodes. Since the reduction of contact impedance is beneficial to the reduction of impedance measurement error, the transmission direction of the corresponding excitation current is determined according to the magnitude of the determined contact impedance, which can reduce the influence of contact impedance on the impedance measurement results of biological organisms and improve the accuracy of impedance measurement.

[0115] It should be noted that the bioelectrical impedance measurement circuit provided in this application embodiment can implement all the steps of the methods implemented in the above method embodiments and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail.

[0116] The above-described bioelectrical impedance measurement circuit is described below through specific embodiments.

[0117] Please refer to Figure 9 , Figure 9 This is one of the application schematic diagrams of the bioelectrical impedance measurement circuit provided in this application. A bioelectrical impedance measurement circuit 800 includes an acquisition module 810 (not shown in the figure), a switching module 820, and a voltage determination module 830.

[0118] In some embodiments, the bioelectrical impedance measurement circuit 800 further includes a current generation module 850 for outputting an excitation current to a first excitation electrode or a second excitation electrode. The current generation module 850 is connected to a switching module 820 and is used to output an excitation current to the first excitation electrode or the second excitation electrode via the switching module 820.

[0119] The bioelectrical impedance measurement circuit 800 is also equipped with a sine wave generator connected to the current generation module 850. It can generate a sine voltage wave, that is, the sine wave generator can output a voltage signal to the current generation module 850, and after passing through the current generation module 850, it outputs an excitation current.

[0120] In one implementation, the current generation module 850 includes a capacitor C0, a resistor R0, and an operational amplifier OPA1. One end of the capacitor C0 is connected to a sine wave generator, and the other end is connected to the resistor R0. The first input terminal of the operational amplifier OPA1 is connected to the resistor R0, the second input terminal is used to receive a common-mode voltage signal (VCM), and the output terminal is connected to the switching module 820. The sinusoidal voltage wave generated by the sine wave generator is DC blocked by the capacitor C0 to prevent DC current from flowing into the measurement object. This voltage signal is then input to the operational amplifier OPA1 through the resistor R0 via the first input terminal, which can be a negative input terminal. The operational amplifier OPA1 converts the voltage signal into a current signal and outputs the current signal, which is the excitation current mentioned above.

[0121] To measure the impedance of an object, at least two sets of electrode pairs are typically placed outside the bioelectrical impedance measurement circuit. Each electrode pair includes an excitation electrode and a measurement electrode. As one implementation, two sets of electrode pairs can be provided. These electrode pairs can be connected to the switching module 820 and voltage determination module 830 in the bioelectrical impedance measurement circuit to measure the biological impedance. Figures 9 to 10One electrode pair may include a first excitation electrode E1 (corresponding to the first excitation electrode 104 mentioned above) and a first measurement electrode E3 (corresponding to the first measurement electrode 105 mentioned above), and another electrode pair may include a second excitation electrode E2 (corresponding to the second excitation electrode 106 mentioned above) and a second measurement electrode E4 (corresponding to the second measurement electrode 107 mentioned above). Correspondingly, the bioelectrical impedance measurement circuit 800 also includes a contact module 840, which is disposed between the switch module 820 and the voltage determination module 830. The contact module 840 may include the electrode pairs and the measurement objects that contact each electrode pair. Zb represents the impedance of the measurement object, while Ze1 to Ze4 represent the contact impedance between each electrode and the measurement object (such as the human body). Among them, Ze1 represents the contact impedance of the first excitation electrode E1, Ze2 represents the contact impedance of the second excitation electrode E2, Ze3 represents the contact impedance of the first measurement electrode E3, and Ze4 represents the contact impedance of the second measurement electrode E4.

[0122] In some embodiments, the switching module 820 includes a first switch group 821, which is used to control the transmission direction of the excitation current between the first excitation electrode E1 and the second excitation electrode E2, that is, to control the excitation current to be output from the excitation electrode corresponding to the smaller value of the contact impedance and input from the excitation electrode corresponding to the larger value of the contact impedance.

[0123] In some embodiments, the first switch group 821 includes a first switch SW1 and a second switch SW2. Both the first switch SW1 and the second switch SW2 have a first terminal and a second terminal. The first terminal of the first switch SW1 is electrically connected to the first port N1 of the current generating module 850, and the second terminal of the first switch SW2 is selectively connected to either the first excitation electrode E1 or the second excitation electrode E2. The first terminal of the second switch SW2 is electrically connected to the second port N2 of the current generating module 850, and the second terminal of the second switch SW2 is selectively connected to either the second excitation electrode E2 or the first excitation electrode E1.

[0124] In one implementation, the first port N1 of the current generating module 850 can be a current transmitting port, and the second port N2 can be a current receiving port. Specifically, the first port N1 can be the first excitation port in the above embodiment, and the second port N2 can be the second excitation port in the above embodiment.

[0125] The direction of the excitation current transmission between the first excitation electrode E1 and the second excitation electrode E2 can be controlled by the first switch SW1 and the second switch SW2. Figure 9Specifically, the N1 port is connected to one of the first excitation electrodes E1 and the second excitation electrode E2 via the first switch SW1, while the N2 port is connected to the other of the first excitation electrode E1 and the second excitation electrode E2 via the second switch SW2.

[0126] Assuming the first contact impedance is less than the second contact impedance, the corresponding direction of the excitation current transmission should be from the first excitation electrode E1 to the second excitation electrode E2. Therefore, the second terminal of the first switch SW1 is connected to the first excitation electrode E1, and the second terminal of the second switch SW1 is connected to the second excitation electrode E2, so that the excitation current is output from the first excitation electrode E1 and the direction of the excitation current input from the second excitation electrode E2 is controlled. In other words, to ensure the excitation current transmission direction is from the first excitation electrode E1 to the second excitation electrode E2, the first switch SW1 is connected to the first excitation electrode E1, and the second switch is connected to the second excitation electrode E2. Therefore, the current direction is N1 → E1 → the object being measured → E2 → N2.

[0127] Assuming the first contact impedance is greater than the second contact impedance, the corresponding direction of the excitation current transmission should be from the second excitation electrode E2 to the first excitation electrode E1. Therefore, the second terminal of the first switch SW1 is connected to the second excitation electrode E2, and the second terminal of the second switch SW2 is connected to the first excitation electrode E1, so that the excitation current is output from the second excitation electrode E2 and the direction of the excitation current transmission is controlled to be from the first excitation electrode E1. In other words, to ensure the excitation current transmission direction is from the second excitation electrode E2 to the first excitation electrode E1, the first switch SW1 is connected to the second excitation electrode E2, and the second switch is connected to the first excitation electrode E1. Therefore, the current direction is N1 → E2 → the object being measured → E1 → N2.

[0128] It is understood that the implementation of the first switch SW1 and the second switch SW2 described above can be controlled by the level signals generated by the control module. For example, when the control module outputs a high-level signal to the first switch SW1 and a low-level signal to the second switch SW2, the first switch SW1 selects the first excitation electrode E1, and the second switch SW2 selects the second excitation electrode E2. Of course, the first switch SW1 and the second switch SW2 can also be controlled in other ways, which will not be elaborated here.

[0129] Based on the implementation of the above circuit, the direction of current transmission between the first and second excitation electrodes can be determined according to the magnitude of the contact impedance corresponding to each excitation electrode. Accordingly, to obtain the impedance of the object to be measured with small error, the excitation current can be output from the excitation electrode corresponding to the smaller value of the contact impedance and input from the excitation electrode corresponding to the larger value of the contact impedance. Then, the voltage between the first measuring electrode E3 and the second measuring electrode E4 is detected to obtain the target voltage value.

[0130] Therefore, based on the control of the excitation current output from the excitation electrode corresponding to the smaller of the first and second contact impedance values ​​and input from the excitation electrode corresponding to the larger of the contact impedance values, by using different circuit connection methods for the first measuring electrode E3 and the second measuring electrode E4 to obtain the corresponding first and second voltage values, and determining an appropriate voltage value as the target voltage value for calculating bioelectrical impedance according to the magnitude of the voltage value, the influence of contact impedance on the measurement results can be reduced, thus solving the technical problem that the electrode contact impedance causes a large error in the measurement results of bioelectrical impedance.

[0131] In some implementations, such as Figure 10 As shown, the switch module 820 further includes a second switch group 822. The second switch group 822 is used to control the connection mode of the first measuring electrode Z3 and the second measuring electrode Z4 with the voltage determination module 830. This connection mode includes a first circuit connection mode and a second circuit connection mode. That is, it controls whether the first measuring electrode Z3 and the second measuring electrode Z4 are connected to the voltage determination module 830 according to the first circuit connection mode or the second circuit connection mode. In this embodiment, the first circuit connection mode and the second circuit connection mode are different.

[0132] In some embodiments, the second switch group 822 includes a third switch SW3 and a fourth switch SW4. The third switch SW3 has a first terminal and a second terminal. The first terminal of the third switch SW3 is used to selectively connect to the first measuring electrode E3 or the second measuring electrode E4, and the second terminal of the third switch SW3 is connected to the first port N3 of the voltage determination module 830.

[0133] The fourth switch SW4 has a first terminal and a second terminal. The first terminal of the fourth switch SW4 is selectively connected to either the first measuring electrode E3 or the second measuring electrode E4. The second terminal of the fourth switch SW4 is connected to the second port N4 of the voltage determination module 830. The first port N3 can be the first voltage measuring port in the above embodiment, and the second port N4 can be the second voltage measuring port in the above embodiment.

[0134] When the connection method is the first circuit connection method, the first end of the third switch SW3 is used to connect to the first measuring electrode E3, and the first end of the fourth switch SW4 is used to connect to the second measuring electrode E4; that is, at this time, the first measuring electrode E3 is connected to the first port N3 of the voltage determination module 830, and the second measuring electrode E4 is connected to the second port N4 of the voltage determination module 830. When the connection method is the second circuit connection method, the first end of the third switch SW3 is used to connect to the second measuring electrode E4, and the first end of the fourth switch is used to connect to the first measuring electrode E3. That is, at this time, the first measuring electrode E3 is connected to the second port N4 of the voltage determination module 830, and the second measuring electrode E4 is connected to the first port N3 of the voltage determination module 830.

[0135] The voltage determination module 830 includes an operational amplifier OPA2, whose first input terminal can be a first port N3 and its second input terminal can be a second port N4.

[0136] By selecting different circuit connection methods to change the connection between the first measuring electrode E3 and the second measuring electrode E4 and the voltage determination module 830, that is, to change the connection relationship between the first measuring electrode E3 and the second measuring electrode E4 and the first port N3 and the second port N4 of the voltage determination module 830, two voltage values ​​can be measured under the same current transmission mode. This can further reduce the measurement error caused by other non-ideal factors and improve the anti-interference ability of impedance measurement, making the impedance measurement more accurate.

[0137] This measurement method yields two voltage measurement results, as follows:

[0138] Assuming that the first contact impedance value corresponding to the first excitation electrode is small, the excitation current is controlled to be output from the first excitation electrode E1 and input from the second excitation electrode E2. That is, the transmission direction of the excitation current is E1 → E2.

[0139] In the transmission direction of E1→E2, if the first circuit connection method is selected, that is, the first measuring electrode E3 is connected to the first port N3 of the voltage determination module 830 and the second measuring electrode E4 is connected to the second port N4 of the voltage determination module 830, the first voltage value is obtained.

[0140] In the transmission direction of E1→E2, if the second circuit connection method is selected, that is, the second measuring electrode E4 is connected to the first port N3 of the voltage determination module 830, and the first measuring electrode E3 is connected to the second port N4 of the voltage determination module 830, the second voltage value is obtained.

[0141] The method for determining the target voltage value in the voltage determination module 830 can be referred to the above. Figures 5-7 This will not be elaborated upon here.

[0142] In summary, by adopting the above method for calculating the target voltage value, it is beneficial to further reduce measurement errors caused by other non-ideal factors and improve the anti-interference capability of impedance measurement, thus making impedance measurement more accurate.

[0143] This application also provides a chip that includes the aforementioned bioelectrical impedance measurement circuit. The chip (Integrated Circuit, IC) can be, but is not limited to, a System on Chip (SOC) chip or a System in Package (SIP) chip. This chip, through the provided bioelectrical impedance measurement circuit technology, can solve the technical problem of significant errors in bioelectrical impedance measurement results caused by the contact impedance between the electrode and the object being measured.

[0144] This application also provides an electronic device, which includes a device body and a chip as described above disposed within the device body. The electronic device may be, but is not limited to, a weight scale, body fat scale, nutrition scale, infrared electronic thermometer, pulse oximeter, body composition analyzer, power bank, wireless charger, fast charger, car charger, adapter, display, USB (Universal Serial Bus) docking station, stylus, true wireless earphones, car infotainment screen, automobile, smart wearable device, mobile terminal, and smart home device. Smart wearable devices include, but are not limited to, smartwatches, smart bracelets, and neck massagers. Mobile terminals include, but are not limited to, smartphones, laptops, and tablets. This electronic device, through the aforementioned bioelectrical impedance measurement circuit technology, can solve the technical problem of large errors in bioelectrical impedance measurement results caused by contact impedance between the electrodes and the measured object.

[0145] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A bioelectrical impedance measurement method, characterized by, The method is applied to an electronic device, the electronic device comprising a first excitation electrode and a first measurement electrode for contacting a first part of a measurement object, and a second excitation electrode and a second measurement electrode for contacting a second part of the measurement object, the method comprising: obtaining a first contact impedance value corresponding to the first excitation electrode and a second contact impedance value corresponding to the second excitation electrode by a preset manner; comparing the first contact impedance value and the second contact impedance value; determining a transmission direction as the excitation current being output from the excitation electrode corresponding to the smaller one of the contact impedance values and being input from the excitation electrode corresponding to the larger one of the contact impedance values; controlling the excitation current to be transmitted between the first excitation electrode and the second excitation electrode in the transmission direction; determining a target voltage value between the first measurement electrode and the second measurement electrode, so as to calculate an impedance of the measurement object according to the target voltage value; wherein the first contact impedance value and the second contact impedance value are different.

2. The bioelectrical impedance measurement method according to claim 1, characterized in that, The step of controlling the excitation current to be transmitted between the first excitation electrode and the second excitation electrode in the transmission direction comprises: if the first contact impedance value is smaller than the second contact impedance value, controlling the excitation current to be output from the first excitation electrode and controlling the excitation current to be input from the second excitation electrode; if the first contact impedance value is larger than the second contact impedance value, controlling the excitation current to be output from the second excitation electrode and controlling the excitation current to be input from the first excitation electrode.

3. The bioelectrical impedance measurement method according to claim 1 or 2, characterized by, The step of determining the target voltage value between the first measurement electrode and the second measurement electrode comprises: obtaining a first voltage value of the first measurement electrode and the second measurement electrode in a first circuit connection mode, the first circuit connection mode being a connection mode in which the connection positions of the first measurement electrode and the second measurement electrode are not exchanged; obtaining a second voltage value of the first measurement electrode and the second measurement electrode in a second circuit connection mode, the second circuit connection mode being a connection mode in which the connection positions of the first measurement electrode and the second measurement electrode are exchanged; determining the target voltage value according to the first voltage value and the second voltage value; wherein the first circuit connection mode and the second circuit connection mode are different.

4. The bioelectrical impedance measurement method according to claim 3, characterized in that, The step of determining the target voltage value according to the first voltage value and the second voltage value comprises: comparing the first voltage value and the second voltage value, and taking the smaller one of the voltage values as the target voltage value.

5. The bioelectrical impedance measurement method according to claim 3, wherein, The step of determining the target voltage value according to the first voltage value and the second voltage value comprises: obtaining a difference value of the first voltage value and the second voltage value; if an absolute value of the difference value of the first voltage value and the second voltage value is smaller than or equal to a preset threshold value, taking an average value of the first voltage value and the second voltage value as the target voltage value; if the absolute value of the difference value of the first voltage value and the second voltage value is larger than the preset threshold value, taking the smaller one of the first voltage value and the second voltage value as the target voltage value.

6. The bioelectrical impedance measurement method according to claim 3, wherein, The step of determining the target voltage value according to the first voltage value and the second voltage value comprises: The first voltage value and the second voltage value are calculated according to a first proportion and a second proportion respectively to obtain the target voltage value; The first proportion and the second proportion are both related to a preset threshold and an absolute value of a difference between the first voltage value and the second voltage value.

7. The bioelectrical impedance measurement method according to claim 6, characterized in that, The step of calculating the first voltage value and the second voltage value according to a first proportion and a second proportion respectively to obtain the target voltage value comprises: The first voltage value and the second voltage value are compared, and the voltage value smaller one is calculated according to the first proportion to obtain a first target voltage value, and the voltage value larger one is calculated according to the second proportion to obtain a second target voltage value, and the target voltage value is a sum of the first target voltage value and the second target voltage value; The first proportion corresponds to an absolute value of a difference between the first voltage value and the second voltage value, and the second proportion corresponds to the preset threshold.

8. A bioelectrical impedance measurement circuit, characterized by The circuit is applied to an electronic device, the electronic device comprising a first excitation electrode and a first measurement electrode for contacting a first part of a measurement object, and a second excitation electrode and a second measurement electrode for contacting a second part of the measurement object, and the circuit comprising: An acquisition module is configured to acquire a first contact impedance value corresponding to the first excitation electrode and a second contact impedance value corresponding to the second excitation electrode by a preset manner; A switch module is configured to control an excitation current to be transmitted between the first excitation electrode and the second excitation electrode in a transmission direction, wherein the transmission direction is that the excitation current is output from the excitation electrode corresponding to the smaller contact impedance value and is input from the excitation electrode corresponding to the larger contact impedance value; A voltage determination module is configured to determine a target voltage value between the first measurement electrode and the second measurement electrode, so as to calculate an impedance value of the measurement object according to the target voltage value.

9. The bioelectrical impedance measurement circuit of claim 8, wherein, The circuit further comprises a current generation module, and the switch module comprises a first switch group. The current generation module is configured to output the excitation current to the first excitation electrode or the second excitation electrode. The first switch group is configured to control the transmission direction of the excitation current between the first excitation electrode and the second excitation electrode.

10. The bioelectrical impedance measurement circuit of claim 9, wherein, The first switch group comprises: A first switch having a first end and a second end, the first end of the first switch being connected to a first port of the current generation module, and the second end of the first switch being configured to be selectively connected to the first excitation electrode or the second excitation electrode; A second switch having a first end and a second end, the first end of the second switch being connected to a second port of the current generation module, and the second end of the second switch being configured to be selectively connected to the second excitation electrode or the first excitation electrode.

11. The bioelectrical impedance measurement circuit of claim 9, wherein, The switch module further comprises a second switch group. The second switch group is configured to control connection modes of the first measurement electrode and the second measurement electrode to the voltage determination module, wherein the connection modes comprise a first circuit connection mode and a second circuit connection mode.

12. The bioelectrical impedance measurement circuit of claim 11, wherein, The second switch group comprises: a third switch having a first end and a second end, the first end of the third switch being configured to selectively connect to the first measurement electrode or the second measurement electrode, the second end of the third switch being connected to the first port of the voltage determination module; a fourth switch having a first end and a second end, the first end of the fourth switch being configured to selectively connect to the second measurement electrode or the first measurement electrode, the second end of the fourth switch being connected to the second port of the voltage determination module.

13. The bioelectrical impedance measurement circuit of claim 12, wherein, The bioelectrical impedance measurement circuit comprises: when the connection mode is the first circuit connection mode, the first end of the third switch is configured to connect to the first measurement electrode, and the first end of the fourth switch is configured to connect to the second measurement electrode; when the connection mode is the second circuit connection mode, the first end of the third switch is configured to connect to the second measurement electrode, and the first end of the fourth switch is configured to connect to the first measurement electrode.

14. A chip, characterized by The chip comprises the bioelectrical impedance measurement circuit according to any one of claims 8-13.

15. An electronic device, comprising: The device comprises a device body and a chip according to claim 14 disposed on the device body.

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