Contact impedance measuring circuit, method and device, chip and electronic equipment

Abstract

The invention provides a contact impedance measuring circuit, method and device, a chip and electronic equipment. The contact impedance measuring circuit provided by the invention comprises an excitation signal control port group which is used for being connected to a first group of electrodes and outputting or receiving an excitation signal through the first group of electrodes; wherein the first group of electrodes comprises any two electrodes in the plurality of electrodes; the voltage signal measuring port group is used for being connected with the first group of electrodes connected with the excitation signal control port group and is used for acquiring voltage signals of the first group of electrodes; the switch module is used for controlling the connection state between each electrode and the excitation signal control port group and the connection state between each electrode and the voltage signal measurement port group; and the measurement module is used for obtaining the measurement impedance of the at least one first group of electrodes according to the excitation signal and the voltage signal, and obtaining the contact impedance of the at least one electrode according to the measurement impedance.

Description

Technical Field

[0001] The present application relates to the field of bioelectrical impedance technology, and in particular to a contact impedance measurement circuit, method, device, chip and electronic equipment. Background Art

[0002] Bioimpedance measurement is a non-destructive detection technology that uses the electrical properties of biological tissues and organs and their changing patterns to extract biomedical information related to the physiological and pathological conditions of the human body. In the measurement of bioimpedance, the contact impedance between the electrode and the organism will have a great impact on the accuracy and repeatability of the impedance measurement results of the object to be measured, resulting in large errors in the impedance measurement of the object to be measured.

[0003] Application Contents

[0004] The purpose of the present application is to provide a contact impedance measurement circuit, method, device, chip and electronic device to solve the technical problem of large errors in bioimpedance measurement in the prior art.

[0005] The technical solution of the present application is as follows, providing a contact impedance measurement circuit, comprising:

[0006] an excitation signal control port group, used to be connected to a first group of electrodes, and used to output or receive an excitation signal through the first group of electrodes; wherein the first group of electrodes includes any two electrodes from a plurality of electrodes;

[0007] A voltage signal measurement port group, used to be connected to the first group of electrodes connected to the excitation signal control port group, and used to obtain voltage signals of the first group of electrodes;

[0008] A switch module, used to control the connection status of each electrode with the excitation signal control port group and the voltage signal measurement port group respectively;

[0009] A measurement module is used to obtain a measurement impedance of at least one of the first group electrodes according to the excitation signal and the voltage signal, and to obtain a contact impedance of at least one of the electrodes according to the measurement impedance.

[0010] Another technical solution of the present application is as follows: a contact impedance measurement method is provided, and the contact impedance measurement method comprises:

[0011] Outputting or receiving the excitation signal through a first group of electrodes connected to the excitation signal control port group; wherein the first group of electrodes includes any two electrodes among the plurality of electrodes;

[0012] Acquiring voltage signals of the first group of electrodes through a voltage signal measurement port group;

[0013] A measured impedance of at least one of the first group of electrodes is acquired according to the excitation signal and the voltage signal, and is used to obtain a contact impedance of at least one of the electrodes according to the measured impedance.

[0014] Another technical solution of the present application is as follows: a contact impedance measurement device is provided, comprising the contact impedance measurement circuit described in any one of the above technical solutions and a plurality of electrodes, wherein the plurality of electrodes are connected to the contact impedance measurement circuit.

[0015] Another technical solution of the present application is as follows: a chip is provided, comprising any of the contact impedance measurement circuits described above.

[0016] Another technical solution of the present application is as follows: an electronic device is provided, comprising the contact impedance measurement circuit described in any one of the above technical solutions, or the contact impedance measurement device described in any one of the above technical solutions, or the chip described in the above technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 1 ;

[0018] Figure 2 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 2 ;

[0019] Figure 3 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 3 ;

[0020] Figure 4 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 4 ;

[0021] Figure 5 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 5 ;

[0022] Figure 6 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 6 ;

[0023] Figure 7 The structure frame of the contact impedance measurement circuit of the embodiment of the present application is Figure 7 ;

[0024] Figure 8 A first measurement schematic diagram of electrode contact impedance provided in an embodiment of the present application;

[0025] Fig. 9 A second measurement schematic diagram of electrode contact impedance provided in an embodiment of the present application;

[0026] Fig.10 A schematic diagram of a contact impedance measurement device provided in an embodiment of the present application Figure 1 ;

[0027] Fig.11 A schematic diagram of a contact impedance measurement device provided in an embodiment of the present application Figure 2 ;

[0028] Fig.12 A schematic diagram of the structure of a chip provided in an embodiment of the present application;

[0029] Fig.13 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application Figure 1 ;

[0030] Fig.14 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In the embodiments of the present application, at least one refers to one or more; multiple refers to two or more. In the description of the present application, the words "first", "second", "third", etc. are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.

[0034] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and 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 either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0035] Bioimpedance measurement is a non-destructive detection technology that uses the electrical properties of biological tissues and organs and their changing patterns to extract biomedical information related to the physiological and pathological conditions of the human body. It usually uses electrodes installed on electronic devices such as body fat scales or human body composition analyzers to apply an excitation electrical signal to the object to be measured, and measures the impedance data of the object to be measured based on the changes caused by the excitation electrical signal passing through the conductive circuit of the object to be measured. At present, the four-electrode or eight-electrode measurement method is commonly used in bioimpedance measurement. However, in this measurement method, contact impedance is generated due to the contact between the electrodes and the object to be measured, and the contact impedance will have a great impact on the results of the impedance measurement of the object to be measured, seriously affecting the accuracy of the impedance measurement results.

[0036] In order to alleviate the above problems, the present application embodiment provides a contact impedance measurement circuit 100, see Figure 1-3 The contact impedance measurement circuit 100 includes an excitation signal control port group 11, a voltage signal measurement port group 12, a switch module 14 and a measurement module 13. The excitation signal control port group 11 is used to connect to the first group of electrodes 201, and to output or receive an excitation signal through the first group of electrodes 201; wherein the first group of electrodes 201 includes any two electrodes of the plurality of electrodes 20. The voltage signal measurement port group 12 is used to connect to the first group of electrodes 201 connected to the excitation signal control port group 11, and to obtain a voltage signal of the first group of electrodes 201. The switch module 14 is used to control the connection state of each electrode with the excitation signal control port group 11 and the voltage signal measurement port group 12 respectively. The measurement module 13 is used to obtain the measurement impedance of at least one first group of electrodes 201 according to the excitation signal and the voltage signal, and to obtain the contact impedance of at least one electrode according to the measurement impedance.

[0037] In this embodiment, the excitation signal control port group and the voltage signal measurement port group are simultaneously connected to any two electrodes among the multiple electrodes, that is, in order to obtain the contact impedance of the electrode, the excitation signal control port group and the voltage signal measurement port group are simultaneously connected to the same group of electrodes (the first group of electrodes 201), the excitation signal control port group outputs or receives the excitation signal through the first group of electrodes 201, and the voltage signal measurement port group 12 connected to the first group of electrodes 201 measures the voltage of the first group of electrodes 201. In this way, all electrodes among the multiple electrodes 20 can be connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 in sequence through this combination of any two electrodes, and then the contact impedance of at least one electrode is obtained through the measurement module 13.

[0038] In order to better understand the present application, the conventional 4-electrode measurement method is described by taking the embodiment of the present application using the 4-electrode measurement method and the object to be measured as the human body as an example. Generally, when measuring the impedance of the human body with 4 electrodes, 2 electrodes of the 4 electrodes are used as excitation electrodes, and the other 2 electrodes are used as measuring electrodes, wherein the two excitation electrodes are respectively in contact with different parts of the human body, such as the left hand and the right hand, or the left foot and the right foot. In order to measure the voltage, the two measuring electrodes also correspond to the two excitation electrodes respectively. The excitation signal flows through the human body from one excitation electrode and is output from the other excitation electrode. Due to the existence of the human body impedance, the excitation signal has a voltage drop between the two measuring electrodes. After being collected and further processed by the measuring electrode, the human body impedance data can be calculated. In the present application, in order to obtain the contact impedance generated when at least one electrode contacts the human body, unlike the traditional technology in which the excitation electrode is only used to transmit the excitation signal and the measuring electrode is only used to measure the voltage signal, in the present application, the role and connection relationship of the excitation electrode and the measuring electrode are not limited, and the roles of the two types of electrodes can be mixed, without making a special distinction. That is, the excitation electrode can be used to transmit the excitation signal or to measure the voltage, and the measuring electrode can be used to measure the voltage or to transmit the excitation signal. That is to say, any two electrodes in the multiple electrodes can both be excitation electrodes, one can be an excitation electrode and the other can be a measuring electrode, or both can be measuring electrodes, and they can be combined at will.

[0039] In order to measure the contact impedance of each electrode, it is necessary to control the connection state of each electrode with the contact impedance measurement circuit 100. The contact impedance measurement circuit 100 includes a switch module 14, which is used to control the connection state of each electrode with the excitation signal control port group 11 and the voltage signal measurement port group 12. The switch module 14 is connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 respectively, and in order to control multiple electrodes 20, it is also connected to multiple electrodes 20. Then, the electrodes can be connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 respectively through the switch module 12. The specific structure of the switch module 14 is not limited here, as long as it can control the connection state of each electrode with the excitation signal control port group 11 and the voltage signal measurement port group 12 respectively.

[0040] In some embodiments, see Figure 3The switch module 14 is used to control the first group of electrodes 201 to be connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 respectively, and to control the second group of electrodes 202 to be disconnected from the excitation signal control port group 11 and the voltage signal measurement port group 12; wherein the second group of electrodes 202 includes electrodes in the plurality of electrodes 20 except the first group of electrodes 201. When the first group of electrodes 201 are respectively connected to the excitation signal control port group 11 and the voltage signal measurement port group 12, in order to avoid the remaining electrodes from being connected to the excitation signal control port group 11 and the voltage signal measurement port group 12, the second group of electrodes 202 can be controlled by the switch module 12, that is, the electrodes except the first group of electrodes 201 in the multiple electrodes 20 are disconnected from the excitation signal control port group 11 and the voltage signal measurement port group 12. In this way, it can be ensured that when a combination of any two electrodes in the multiple electrodes 20 are connected to the excitation signal control port group 11 and the voltage signal measurement port group 12, the other electrodes are in a disconnected state from the excitation signal control port group 11 and the voltage signal measurement port group 12, which does not affect the measurement of the electrodes respectively connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 at this time.

[0041] In this embodiment, at least one group of electrodes can be connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 at the same time by any combination of multiple electrodes in pairs, and then the measurement impedance of at least the first group of electrodes is obtained through the measurement module, thereby obtaining the contact impedance of at least one electrode; the contact impedance of at least one electrode is measured, the accuracy of the contact impedance measurement is improved, the influence of the contact impedance on the bioimpedance measurement in the actual measurement is reduced, and the accuracy of the bioimpedance measurement is improved.

[0042] In some embodiments, see Figure 4 The excitation signal control port group 11 includes a first excitation signal control port 111 and a second excitation signal control port 112. The first excitation signal control port 111 is used to connect to the first electrode in the first group of electrodes 201, and is used to output the excitation signal through the first electrode; the second excitation signal control port 112 is used to connect to the second electrode in the first group of electrodes 201, and is used to receive the excitation signal through the second electrode.

[0043] In this embodiment, the excitation signal control port group 11 may include a first excitation signal control port 111 and a second excitation signal control port 112, and the first group of electrodes 201 may also include a first electrode and a second electrode. The first electrode may be connected to the first excitation signal control port 111, and the second electrode may be connected to the second excitation signal control port 112, wherein the first electrode may be connected to the first excitation signal control port 111 through a switch module 14, and the second electrode may also be connected to the second excitation signal control port 112 through a switch module 14. The excitation signal control port 11 may output an excitation signal to the first electrode through the first excitation signal control port 111, and receive an excitation signal from the second electrode through the second excitation signal control port 112.

[0044] In some embodiments, see Figure 5 The voltage signal measurement port group 12 includes a first voltage signal measurement port 121 and a second voltage signal measurement port 122. The first voltage signal measurement port 121 is used to connect to a first electrode in the first group of electrodes 201 connected to the first excitation signal control port 11, and is used to obtain a first voltage signal of the first electrode; the second voltage signal measurement port 122 is used to connect to a second electrode in the first group of electrodes 201 connected to the second excitation signal control port 112, and is used to obtain a second voltage signal of the second electrode.

[0045] In this embodiment, the voltage signal measurement port group 12 may include a first voltage signal measurement port 121 and a second voltage signal measurement port 122. In addition to being connected to the first excitation signal control port 111, the first electrode may also be connected to the first voltage signal measurement port 121; in addition to being connected to the second excitation signal control port 112, the second electrode may also be connected to the second voltage signal measurement port 122, wherein the first electrode may be connected to the first voltage signal measurement port 121 through the switch module 14, and the second electrode may also be connected to the second voltage signal measurement port 122 through the switch module 14. The voltage signal measurement port group 12 may obtain the first voltage signal of the first electrode through the first voltage signal measurement port 121, and obtain the second voltage signal of the second electrode through the second voltage signal measurement port 122, and input the first voltage signal and the second voltage signal into the measurement module 13 so that the measurement module 13 processes them.

[0046] In some embodiments, the measurement module 13 is also used to obtain a third voltage signal between the first electrode and the second electrode based on the first voltage signal and the second voltage signal; and to obtain the measurement impedance of at least one first group of electrodes 201 based on the excitation signal and the third voltage signal, and to obtain the contact impedance of at least one electrode based on the measurement impedance.

[0047] After obtaining the first voltage signal and the second voltage signal, the measurement module 13 obtains the third voltage signal, that is, the voltage drop between the first electrode and the second electrode, according to the first voltage signal and the second voltage signal, and can obtain the measurement impedance corresponding to the first group of electrodes 201 according to the excitation signal and the third voltage signal. Since the first group of electrodes 201 can have multiple combinations, the measurement module 13 can obtain the measurement impedance of at least one first group of electrodes 201, and obtain the contact impedance of one or more electrodes based on the measurement impedance.

[0048] For example, see Figure 8 Similarly, taking the case where the plurality of electrodes include two excitation electrodes ISIN0 and ISIN1, two measurement electrodes VSEN0 and VSEN1, and the object to be measured is a human body as an example, if the first group of electrodes 201 includes the excitation electrode ISIN0 and the measurement electrode VSEN0, the excitation electrode ISIN0 may be the aforementioned first electrode, the measurement electrode VSEN0 may be the aforementioned second electrode, the excitation electrode ISIN0 may be simultaneously connected to the first excitation signal control port 111 and the first voltage signal measurement port 121, and the measurement electrode VSEN0 may be simultaneously connected to the second excitation signal control port 112 and the second voltage signal measurement port 122. The excitation signal may be output to the excitation electrode ISIN0 via the first excitation signal control port 111, and then received from the measurement electrode VSEN0 via the second excitation signal control port 112. Correspondingly, the first voltage signal measurement port 121 obtains the first voltage signal of the excitation electrode ISIN0, and the second voltage signal measurement port 122 obtains the second voltage signal of the measuring electrode VSEN0. The third voltage signal is the voltage drop between the excitation electrode ISIN0 and the measuring electrode VSEN0. The measurement module 13 can obtain the corresponding first measurement impedance through the third voltage signal and the excitation signal.

[0049] Correspondingly, the switch module 14 can also control the measuring electrode VSEN0 and the excitation electrode ISIN1 as the first group of electrodes 201, and can also control the measuring electrode VSENI and the excitation electrode ISIN0 as the first group of electrodes 201, and can also control the measuring electrode VSEN0 and the measuring electrode VSENI as the first group of electrodes 201. Accordingly, the second measurement impedance corresponding to the measuring electrode VSEN0 and the excitation electrode ISIN1, the third measurement impedance corresponding to the measuring electrode VSENI and the excitation electrode ISIN0, and the fourth measurement impedance corresponding to the measuring electrode VSEN0 and the measuring electrode VSENI can be obtained.

[0050] When any two electrodes among the plurality of electrodes are connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 as the first group of electrodes 201, the contact positions of the two connected electrodes with the object to be measured are different before, so some of the corresponding measured impedances may include human body impedance, and some may not include human body impedance. For example, if the excitation electrodes ISIN0 and ISIN1 are set to contact the left foot and the right foot of the human body respectively, the measuring electrodes VSEN0 and VSEN1 correspond to the excitation electrodes ISIN0 and ISIN1 respectively. If the first group of electrodes 201 includes the excitation electrode ISIN0 and the measuring electrode VSEN0, since the excitation electrode ISIN0 and the measuring electrode VSEN0 are both in contact with the left foot of the human body, they will not pass through the human body, and the corresponding first measured impedance does not include human body impedance. If the first group of electrodes 201 includes the measuring electrodes VSEN0 and VSENI, since the measuring electrodes VSEN0 and VSENI are in contact with the left foot and the right foot of the human body respectively, and pass through the human body to form a loop, the corresponding second measured impedance will include human body impedance. Accordingly, the contact impedance of some electrodes among the multiple electrodes is independent of the human body impedance, while the contact impedance of some electrodes is related to the human body impedance.

[0051] In some embodiments, in order to obtain the impedance of the object to be measured, the voltage signal measurement port group 12 is also used to connect to two measuring electrodes when the first group of electrodes 201 includes two excitation electrodes; and obtain the measurement voltage of the two measuring electrodes; wherein the measuring electrodes include electrodes corresponding to the excitation electrodes in the plurality of electrodes 20.

[0052] In this embodiment, in order to obtain the impedance of the object to be measured, when the first group of electrodes 201 includes two excitation electrodes, the voltage signal measurement port group 12 is connected to the two measurement electrodes, wherein the measurement electrodes include electrodes corresponding to the excitation electrodes in the plurality of electrodes 20. For example, see Figure 8 When the first group of electrodes 201 includes excitation electrodes ISIN0 and ISIN1, at this time, the excitation electrodes ISIN0 and ISIN1 are respectively connected to the excitation signal control port group 11. In order to obtain the impedance of the object to be measured, the measurement electrodes VSEN0 and VSEN1 can be controlled to be respectively connected to the voltage signal measurement port group 12. Then, the voltage signal measurement port group 12 can take the corresponding measurement voltage and input it into the measurement module 13.

[0053] In some embodiments, the measurement circuit 13 is further used to obtain the impedance of the object to be measured according to the excitation signal and the measurement voltage, and obtain the contact impedance of at least one electrode according to the measurement impedance and the impedance of the object to be measured. The measurement circuit 13 can receive the impedance of the object to be measured according to the excitation signal and the obtained measurement voltage, and obtain the contact impedance of at least one electrode according to the previously obtained measurement impedance combined with the impedance of the object to be measured.

[0054] In some embodiments, see Figure 6 The contact impedance measurement circuit also includes an excitation module 15, which is connected to the excitation signal control port group 11 and is used to generate a current signal, use the current signal as an excitation signal, and pass the first group of electrodes 201 via the excitation signal control port group 11.

[0055] As an implementation, see Figure 7 The excitation module 15 may include a direct digital frequency synthesizer 151 (Direct Digital Synthesizer, DDS), a digital analog converter 152 (Digital Analog Converter, DAC), a low pass filter 153 (Low Pass Filter, LPF) and a signal processing module 154, wherein the DDS is used to generate a preset digital signal, the DDS is used to convert the digital signal into an analog signal, the LPF is used to perform low pass filtering on the analog signal to obtain a sine wave signal, and the signal processing module 154 is used to process the sine wave signal to obtain a current signal, i.e., the excitation signal in the present application. A stable current signal is generated by the direct digital frequency synthesizer, the digital analog converter, the low pass filter and the signal processing module to improve the accuracy of measuring the biological contact impedance.

[0056] In some embodiments, the multiple electrodes may include a first excitation electrode, a second excitation electrode, a first measuring electrode, and a second measuring electrode, and the measurement module is used to: obtain a first measurement impedance between the first measuring electrode and the first excitation electrode; obtain a second measurement impedance between the first measuring electrode and the second excitation electrode; obtain a third measurement impedance between the second measuring electrode and the first excitation electrode; obtain a fourth measurement impedance between the first measuring electrode and the second measuring electrode; and obtain the contact impedance of at least one electrode based on the first measurement impedance, the second measurement impedance, the third measurement impedance, and the fourth measurement impedance.

[0057] In order to better understand the present application, as an example, the measurement of the contact impedance of at least one electrode in the present application is described by taking the multiple electrodes as 4 electrodes. Figure 8As mentioned above, the contact impedances of the first measuring electrode VSEN0, the second measuring electrode VSEN1, the first excitation electrode ISIN0 and the second excitation electrode ISIN1 are R1, R2, R3, and R4 respectively, the first measuring impedance corresponding to the first excitation electrode ISIN0 and the first measuring electrode VSEN0 is Z0, the second measuring impedance corresponding to the first measuring electrode VSEN0 and the second excitation electrode ISIN1 is Z1, the third measuring impedance corresponding to the second measuring electrode VSENI and the first excitation electrode ISIN0 is Z2, the fourth measuring impedance corresponding to the first measuring electrode VSEN0 and the second measuring electrode VSENI is Z3, and the impedance of the object to be measured is RB. By combining different electrodes, the measuring impedances of the first group of electrodes 201 can be obtained:

[0058] The first measurement impedance Z0 between the first measurement electrode VSEN0 and the first excitation electrode ISIN0 is:

[0059] Z0=R1+R3

[0060] The second measurement impedance Z1 between the first measurement electrode VSEN0 and the second excitation electrode ISIN1 is:

[0061] Z1=R1+R4+RB

[0062] The third measurement impedance Z2 between the second measurement electrode VSENI and the first excitation electrode ISIN0 is:

[0063] Z2=R2+R3+RB

[0064] The fourth measurement impedance Z3 between the first measurement electrode VSEN0 and the second measurement electrode VSENI is:

[0065] Z3=R1+R2+RB

[0066] The above formula can be used to obtain the values ​​of contact impedances R1, R2, R3, and R4:

[0067] R1=(Z0-Z2+Z3) / 2

[0068] R2=(Z2+Z3-Z0) / 2-RB

[0069] R3=(Z0+Z2-Z3) / 2

[0070] R4=Z1-(Z0-Z2+Z3) / 2-RB

[0071] It can be seen from the above-mentioned contact impedance acquisition formulas that, in the implementation method taking four electrodes as an example, the calculation of some contact impedances such as R1, R2 and R3 does not require obtaining all the measurement impedances, and some contact impedance values ​​are irrelevant to the human body impedance, such as R1 and R3. Therefore, the contact impedance of certain electrodes can be obtained without obtaining all the measurement impedances or human body impedances.

[0072] In some embodiments, when all contact impedances need to be measured in one measurement, a fifth measurement impedance Z4 between the second measurement electrode VSENI and the second measurement electrode VSENI is measured based on the above four measurement impedances, where Z4=R2+R4. The values ​​of each contact impedance R1, R2, R3, and R4 can be calculated based on the first measurement impedance Z0, the second measurement impedance Z1, the third measurement impedance Z2, the fourth measurement impedance Z3, and the fifth measurement impedance Z4.

[0073] As another example, the contact impedance measurement circuit 100 can also be used for contact impedance measurement of multiple electrodes such as 6 electrodes or 8 electrodes. Fig. 9 , you can also Figure 8 On the basis of , two electrodes are added. The newly added two electrodes can be electrode VSEN2 and electrode VSEN3, and their corresponding contact impedances are R5 and R6. Then VSEN0, VSEN1, ISIN0, and ISIN1 can form four electrodes, and the corresponding measured impedance of the object to be measured is RB0; VSEN2, VSEN3, ISIN0, and ISIN1 can form four new electrodes, and the corresponding measured impedance of the object to be measured is RB1; the measurement of its contact impedance is consistent with the above, which will not be repeated here.

[0074] In this embodiment, at least one group of electrodes can be connected to the excitation signal control port group 11 and the voltage signal measurement port group 12 at the same time by any combination of multiple electrodes in pairs, and then the measurement impedance of at least the first group of electrodes is obtained through the measurement module, thereby obtaining the contact impedance of at least one electrode; the contact impedance of at least one electrode is measured, the accuracy of the contact impedance measurement is improved, the influence of the contact impedance on the bioimpedance measurement in the actual measurement is reduced, and the accuracy of the bioimpedance measurement is improved.

[0075] The present application embodiment provides a contact impedance measurement method, which can be applied to the contact impedance measurement circuit in the above embodiment. The contact impedance measurement method includes:

[0076] Outputting or receiving the excitation signal through a first group of electrodes connected to the excitation signal control port group; wherein the first group of electrodes includes any two electrodes among the plurality of electrodes;

[0077] Acquiring voltage signals of the first group of electrodes through the voltage signal measurement port group;

[0078] A measured impedance of at least one first group of electrodes is acquired according to the excitation signal and the voltage signal, and is used to obtain a contact impedance of at least one electrode according to the measured impedance.

[0079] In some embodiments, the contact impedance measurement method further includes: when the first group of electrodes includes two excitation electrodes, obtaining the measurement voltage of the two measurement electrodes through the voltage signal measurement port group; wherein the measurement electrodes include electrodes corresponding to the excitation electrodes among the plurality of electrodes. The impedance of the object to be measured is obtained according to the excitation signal and the measurement voltage, and the contact impedance of at least one electrode is obtained according to the measurement impedance and the impedance of the object to be measured.

[0080] In some embodiments, the contact impedance measurement method further includes: controlling the connection state of each electrode with the excitation signal control port group and the voltage signal measurement port group respectively.

[0081] For a detailed description of this method, please refer to the detailed description of the aforementioned embodiment, which will not be described in detail in this embodiment.

[0082] The contact impedance measurement method provided in the embodiment of the present application outputs or receives an excitation signal through a first group of electrodes connected to an excitation signal control port group; wherein the first group of electrodes includes any two electrodes from a plurality of electrodes; a voltage signal of the first group of electrodes is obtained through a voltage signal measurement port group; a measurement impedance of at least one of the first group of electrodes is obtained according to the excitation signal and the voltage signal, and is used to obtain the contact impedance of at least one electrode according to the measurement impedance; at least one group of electrodes can be simultaneously connected to the excitation signal control port group and the voltage signal measurement port group by any combination of multiple electrodes in pairs, and then the measurement impedance of at least the first group of electrodes is obtained through a measurement module, thereby obtaining the contact impedance of at least one electrode; the contact impedance of at least one electrode is measured, the accuracy of the contact impedance measurement is improved, the influence of the contact impedance on the bioimpedance measurement in the actual measurement is reduced, and the accuracy of the bioimpedance measurement is improved.

[0083] The present application provides a contact impedance measurement device. Fig.10 The contact impedance measurement device 300 includes a contact impedance measurement circuit 100 and a plurality of electrodes 20 , wherein the plurality of electrodes are connected to the contact impedance measurement circuit 100 .

[0084] In some embodiments, see Fig.11The contact impedance measurement device further includes a switch module 14, which is used to control the connection state of each electrode with the excitation signal control port group 11 and the voltage signal measurement port group 12. In addition to being arranged in the contact impedance measurement circuit 100, the switch module can also be arranged outside the contact impedance measurement circuit 100, as long as it can control the connection state of multiple electrodes 20 with the excitation signal control port group 11 and the voltage signal measurement port group 12.

[0085] The present application embodiment provides a chip, see Fig.12 , the chip 400 includes a contact impedance measurement circuit 100 .

[0086] The embodiment of the present application provides an electronic device, the electronic device 500 includes a device body and a contact impedance measuring device 300, and a plurality of electrodes 20 are arranged on the device body. Fig.13 and Fig.14 , the electronic device 500 may also include a chip 400, or a contact impedance measurement circuit 100. The electronic device 400 may be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a stylus, a true wireless headset, a car, a smart wearable device, or a mobile terminal. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal) machines.

[0087] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above embodiments only express the preferred implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A contact impedance measurement circuit, characterized in that: include: an excitation signal control port group, used to be connected to a first group of electrodes, and used to output or receive an excitation signal through the first group of electrodes; wherein the first group of electrodes includes any two electrodes from a plurality of electrodes; A voltage signal measurement port group, used to be connected to the first group of electrodes connected to the excitation signal control port group, and used to obtain voltage signals of the first group of electrodes; The switch module is used to control the connection status of each electrode with the excitation signal control port group and the voltage signal measurement port group respectively. A measurement module is used to obtain a measurement impedance of at least one of the first group electrodes according to the excitation signal and the voltage signal, and to obtain a contact impedance of at least one of the electrodes according to the measurement impedance.

2. The contact impedance measurement circuit according to claim 1, characterized in that: The excitation signal control port group includes a first excitation signal control port and a second excitation signal control port; The first excitation signal control port is used to connect to a first electrode in the first group of electrodes, and is used to output the excitation signal through the first electrode; The second excitation signal control port is used to be connected to a second electrode in the first group of electrodes, and is used to receive the excitation signal through the second electrode.

3. The contact impedance measurement circuit according to claim 2, characterized in that: The voltage signal measurement port group includes a first voltage signal measurement port and a second voltage signal measurement port; The first voltage signal measurement port is used to be connected to the first electrode in the first group of electrodes connected to the first excitation signal control port, and is used to obtain a first voltage signal of the first electrode; The second voltage signal measurement port is used to be connected to the second electrode in the first group of electrodes connected to the second excitation signal control port, and is used to obtain a second voltage signal of the second electrode.

4. The contact impedance measurement circuit according to claim 3, characterized in that: The measuring module is also used for: Acquire a third voltage signal between the first electrode and the second electrode according to the first voltage signal and the second voltage signal; Acquire a measured impedance of at least one of the first group of electrodes according to the excitation signal and the third voltage signal; The contact impedance of at least one of the electrodes is obtained based on the measured impedance.

5. The contact impedance measurement circuit according to claim 4, characterized in that: The plurality of electrodes include a first excitation electrode, a second excitation electrode, a first measurement electrode, and a second measurement electrode, and the measurement module is used for: Acquire a first measurement impedance between the first measurement electrode and the first excitation electrode; Acquire a second measurement impedance between the first measurement electrode and the second excitation electrode; Acquire a third measurement impedance between the second measurement electrode and the first excitation electrode; acquiring a fourth measurement impedance between the first measurement electrode and the second measurement electrode; A contact impedance of at least one electrode is obtained according to the first measurement impedance, the second measurement impedance, the third measurement impedance, and the fourth measurement impedance.

6. The contact impedance measurement circuit according to claim 1, characterized in that: The voltage signal measurement port group is also used for: When the first group of electrodes includes two excitation electrodes, connected to two measurement electrodes; The measurement voltages of the two measurement electrodes are obtained; wherein the measurement electrodes include electrodes corresponding to the excitation electrodes among the plurality of electrodes.

7. The contact impedance measurement circuit according to any one of claims 1 to 6, characterized in that: The switch module is used to: control the first group of electrodes to be connected to the excitation signal control port group and the voltage signal measurement port group respectively, and control the second group of electrodes to be disconnected from the excitation signal control port group and the voltage signal measurement port group; wherein the second group of electrodes includes electrodes in the plurality of electrodes except the first group of electrodes.

8. A contact impedance measurement method, characterized in that: The contact impedance measurement method comprises: Outputting or receiving the excitation signal through a first group of electrodes connected to the excitation signal control port group; wherein the first group of electrodes includes any two electrodes among the plurality of electrodes; Acquiring voltage signals of the first group of electrodes through a voltage signal measurement port group; A measured impedance of at least one of the first group of electrodes is acquired according to the excitation signal and the voltage signal, and is used to obtain a contact impedance of at least one of the electrodes according to the measured impedance.

9. The contact impedance measurement method according to claim 8, characterized in that: The contact impedance measurement method further comprises: When the first group of electrodes includes two excitation electrodes, the measurement voltages of the two measurement electrodes are acquired through the voltage signal measurement port group; wherein the measurement electrodes include electrodes corresponding to the excitation electrodes among the plurality of electrodes. The impedance of the object to be measured is acquired according to the excitation signal and the measurement voltage, and the contact impedance of at least one of the electrodes is obtained according to the measurement impedance and the impedance of the object to be measured.

10. The contact impedance measurement method according to claim 9, characterized in that: The contact impedance measurement method further comprises: Controlling the connection state of each electrode with the excitation signal control port group and the voltage signal measurement port group respectively.

11. A contact impedance measuring device, characterized in that: It comprises the contact impedance measurement circuit according to any one of claims 1 to 7 and a plurality of electrodes, wherein the plurality of electrodes are connected to the contact impedance measurement circuit.

12. The contact impedance measuring device according to claim 11, characterized in that: Also includes: The switch module is used to control the connection status of each electrode with the excitation signal control port group and the voltage signal measurement port group respectively.

13. A chip, characterized in that: The invention comprises the contact impedance measurement circuit as described in any one of claims 1 to 7.

14. An electronic device, characterized in that: It comprises the contact impedance measurement circuit according to any one of claims 1 to 7, or the contact impedance measurement device according to any one of claims 11 to 12, or the chip according to claim 13.

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