Human body electrical impedance signal detection system and detection method with automatic electrode clamping

Abstract

The present invention discloses a human body impedance signal detection system with automatic electrode clamping and a detection method thereof, comprising a human body impedance signal detection device and a host, wherein the human body impedance signal detection device is connected to the host via a USB; the human body impedance signal detection device is used to collect human body impedance signals, including amplitude information and phase angle information of human body impedance, and transmit the human body impedance signals to the host; the host is used to control the collection process of human body impedance signals, receive the collected human body impedance signals, and store, display and analyze the human body impedance signals. The human body impedance signal detection device is equipped with an automatic finger clamping device, which can judge the size of the contact force between the electrode and the finger according to the real-time power consumption of its stepping motor, thereby realizing the control of the clamping force. The present invention can effectively solve the measurement error caused by excessive or insufficient electrode-skin contact force, and realize automatic clamping of the electrode.

Description

Technical Field

[0001] The present invention relates to the technical field of human body electrical impedance signal detection, in particular to a human body electrical impedance signal detection system with automatic electrode clamping and a detection method thereof. Background Art

[0002] Human body electrical impedance is an important electrical parameter in human biological signals, which contains rich physiological and pathological information of the human body. The measurement and analysis of human body electrical impedance signals are of great significance in the fields of medical diagnosis and health care.

[0003] The commonly used method for measuring human body impedance is to input a weak current of a certain frequency into the human body through electrodes attached to the body surface. Due to differences in muscle, fat and other components of different people, different human body impedances are generated. By switching the measurement site, the impedance characteristics of a certain section of the body can be obtained. By analyzing the impedance signal, the health status of the person can be known.

[0004] When measuring human body impedance, the selection of measurement sites is critical. The more measurement sites there are, the richer the impedance information obtained. Arranging measurement sites at specific locations can obtain impedance signals in a targeted manner.

[0005] The accuracy of the impedance measurement result is greatly affected by the contact state of the measuring electrode. Whether it is poor contact or contact overload, it will affect the impedance measurement result. Moreover, when the contact force between the electrode and the skin is large, it will increase the discomfort caused by the measurement. Therefore, a method for controlling the electrode-skin contact force during the human body impedance measurement process is needed to reduce the measurement error caused by the electrode contact and reduce the discomfort caused by the electrode contact. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and propose a human body electrical impedance signal detection system with automatic electrode clamping and a detection method thereof. The system adopts a design in which the electrode clamping force is flexible and controllable, which can not only realize the automatic clamping of finger electrodes, but also effectively solve the measurement errors caused by excessive or insufficient electrode-skin contact force.

[0007] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a human body electrical impedance signal detection system with automatic electrode clamping, comprising a human body electrical impedance signal detection device and a host, wherein the human body electrical impedance signal detection device is connected to the host via a USB; wherein:

[0008] The human body impedance signal detection device is used to collect human body impedance signals, including amplitude information and phase angle information of human body impedance, and transmit the human body impedance signals to the host;

[0009] The host is used to control the acquisition process of the human body electrical impedance signal, receive the acquired human body electrical impedance signal, and store, display and analyze the human body electrical impedance signal.

[0010] Further, the human body electrical impedance signal detection device includes a signal acquisition unit and a detection component;

[0011] The signal acquisition unit includes a forehead electrode unit, a finger electrode unit and a finger automatic clamping unit; the forehead electrode unit is a head-mounted structure, each of which is provided with a forehead excitation electrode and a forehead detection electrode; the finger electrode unit includes 10 pairs of finger electrode groups, which correspond to 10 fingers of the human body respectively, and each pair of finger electrode groups includes a finger side excitation electrode and a finger side detection electrode, which are distributed on the left and right sides of the finger, and the surfaces of the finger side excitation electrode and the finger side detection electrode are designed as concave arc surfaces according to the finger structure to fit the two sides of the finger; the forehead excitation electrode and the forehead detection electrode are connected to the fingers of each pair of finger electrode groups. The side excitation electrodes and the finger side detection electrodes constitute a four-electrode human body impedance detection path, the forehead excitation electrodes and the finger side excitation electrodes are responsible for generating and receiving currents of specific frequencies, and the forehead detection electrodes and the finger side detection electrodes are responsible for obtaining voltage values. Based on the four-electrode human body impedance detection path, the human body electrical impedance value between each finger and the forehead can be obtained; the finger automatic clamping unit includes 10 finger automatic clamping devices, which correspond to 10 pairs of finger electrode groups respectively. The finger automatic clamping devices are used to control the contact force between the electrodes in the finger electrode group and the fingers, so that the electrodes can be better attached to the finger surface, ensuring good contact between the electrodes and the fingers;

[0012] The detection component includes an integrated analog front end, a microcontroller, a multi-way switch, a USB module, a power supply and an LED display module; the forehead electrode unit and the finger electrode unit are connected to the integrated analog front end through the multi-way switch; the multi-way switch is controlled by the microcontroller and is used to switch a specific finger electrode group into a working state. The microcontroller controls the conduction of a specific channel in the multi-way switch to switch the acquisition channel of the integrated analog front end and traverse 10 fingers; the integrated analog front end is a chip for bioelectric measurement, which is responsible for generating an excitation current of a specific frequency and obtaining a voltage signal excited by the excitation current in the human body. The integrated analog front end can Perform preliminary processing to generate intermediate data, which is then processed by a microcontroller to generate electrical impedance data; the microcontroller communicates data with the host through a USB module; the power supply is used to power the integrated analog front end, the microcontroller, the multi-way switch, the USB module and the LED display module; the microcontroller is used to control the integrated analog front end, the multi-way switch, the USB module and the LED display module to achieve multi-channel and multi-frequency impedance detection, receive and execute the calibration and measurement instructions of the host, and send the calibration data and the detection data to the host; the LED display module is used to display the detection status of the system, including start, detection, pause, abnormality and end.

[0013] Furthermore, the automatic finger clamping device includes a stepper motor, an asymmetrical crank slider mechanism group and a mounting seat; the finger side excitation electrode and the finger side detection electrode of the finger electrode group are respectively installed on the asymmetrical crank slider mechanism group, and the stepper motor and the asymmetrical crank slider mechanism group are installed on the mounting seat. The asymmetrical crank slider mechanism group is driven by the stepper motor to operate, thereby driving the finger side excitation electrode and the finger side detection electrode to clamp or release the finger.

[0014] Furthermore, the finger electrode unit, the automatic finger clamping unit and the detection component are integrated in one box.

[0015] Furthermore, the forehead electrode unit includes a forehead excitation electrode, a forehead detection electrode, an electrode mounting shell and an elastic strap, the forehead excitation electrode and the forehead detection electrode are respectively mounted on the electrode mounting shell, and the electrode mounting shell is worn on the user's head through the elastic strap.

[0016] The present invention also provides a detection method for the human body impedance signal detection system with automatic electrode clamping, which is specifically: when starting the human body impedance signal detection, the user places 10 fingers in 10 finger electrode groups at the same time, and the stepper motor drives the asymmetrical crank slider mechanism group to make the finger side excitation electrodes and the finger side detection electrodes of the finger electrode group clamp the fingers; wherein, according to the real-time power consumption of the stepper motor, it is judged whether to clamp, and after clamping, the stepper motor enters a self-locking state and starts to collect human body impedance signals. After the collection is completed, the stepper motor is unlocked, and the finger side excitation electrodes and the finger side detection electrodes of the finger electrode group are released, thereby ending the human body impedance signal detection process, and the measurement results will be displayed on the host.

[0017] Furthermore, the method for judging whether the fingers are clamped is: based on the real-time value of the power consumption of the stepper motor and the change in the motor power consumption at two time nodes before and after. If the real-time value of the motor power consumption is greater than the set threshold, and the difference in the motor power consumption at two time nodes before and after is also greater than the set value, it is judged that the fingers have been clamped, otherwise they have not been clamped.

[0018] Furthermore, the process of collecting human body electrical impedance signals is as follows: first, the integrated analog front end generates an excitation current of a specific frequency that has been current-limited. The excitation current flows into the finger-side excitation electrode on the side of one finger of the user and flows out of the forehead excitation electrode. The integrated analog front end obtains a voltage signal through the finger-side detection electrode and the forehead detection electrode, and uses the voltage signal to perform parameter calculations in the integrated analog front end and the microcontroller to calculate the electrical impedance of half the body from the finger to the forehead. By switching the frequency of the excitation current, the human body electrical impedance signals at different frequencies can be obtained. Similarly, the electrical impedance from 10 fingers to the center of the forehead can be obtained through the above process. The specific measurement method is: the microcontroller controls the conduction of a specific channel in the multi-way switch to switch the acquisition channel of the integrated analog front end, traversing 10 fingers.

[0019] Furthermore, the frequency of the excitation current is 12 frequencies selected from the range of 5.86 kHz to 250 kHz.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] The present invention controls the contact force between the electrode and the finger through the finger automatic clamping device, so that the electrode is appropriately attached to the finger skin surface, reduces the human body impedance measurement error caused by the difference in electrode contact state, reduces the electrode contact impedance noise caused by the contact pressure change, enhances the quality of the human body impedance signal, reduces the discomfort caused by the electrode squeezing during the measurement process, and thus improves the comfort of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the installation diagram of the human body electrical impedance signal detection system.

[0023] Figure 2 This is a partial structural diagram of the human body electrical impedance signal detection system.

[0024] Figure 3 Schematic diagram of the structure of the forehead electrode unit.

[0025] Figure 4 This is a structural block diagram of the detection component.

[0026] Figure 5 This is one of the structural schematic diagrams of the finger automatic clamping device.

[0027] Figure 6 This is one of the structural schematic diagrams of the finger automatic clamping device. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0029] See also Figure 1 As shown, the human body electrical impedance signal detection system with automatic electrode clamping provided in this embodiment includes a human body electrical impedance signal detection device 1 and a host 2, wherein the human body electrical impedance signal detection device 1 is connected to the host 2 via a USB; wherein:

[0030] The human body impedance signal detection device 1 is used to collect the human body impedance signal, including the amplitude information and phase angle information of the human body impedance, and transmit the human body impedance signal to the host 2;

[0031] The host 2 is used to control the acquisition process of the human body electrical impedance signal, receive the acquired human body electrical impedance signal, and store, display and analyze the human body electrical impedance signal.

[0032] See also Figures 2 to 4 As shown, the human body electrical impedance signal detection device 1 includes a signal acquisition unit and a detection component;

[0033] The signal acquisition unit includes a forehead electrode unit, a finger electrode unit and a finger automatic clamping unit; the forehead electrode unit is a head-mounted structure, including a forehead excitation electrode 111, a forehead detection electrode 112, an electrode mounting shell 118 and an elastic strap 119, the forehead excitation electrode 111 and the forehead detection electrode 112 are respectively mounted on the electrode mounting shell 118, and the electrode mounting shell 118 is worn on the user's head through the elastic strap 119; the finger electrode unit includes 10 pairs of finger electrode groups, corresponding to 10 fingers of the human body, each pair of finger electrode groups includes a finger side excitation electrode 113 and a finger side detection electrode 114, which are distributed on the left and right sides of the finger, and the surfaces of the finger side excitation electrode 113 and the finger side detection electrode 114 are designed as concave arc surfaces according to the finger structure. to fit both sides of the finger; the forehead excitation electrode 111 and the forehead detection electrode 112 and the finger side excitation electrode 113 and the finger side detection electrode 114 of each pair of finger electrode groups constitute a four-electrode human body impedance detection path, the forehead excitation electrode 111 and the finger side excitation electrode 113 are responsible for generating and receiving current of a specific frequency, the forehead detection electrode 112 and the finger side detection electrode 114 are responsible for obtaining a voltage value, based on the four-electrode human body impedance detection path, the human body electrical impedance value between each finger and the forehead can be obtained; the finger automatic clamping unit includes 10 finger automatic clamping devices, which correspond to 10 pairs of finger electrode groups respectively, and the contact force between the electrodes in the finger electrode group and the fingers is controlled by the finger automatic clamping device, so that the electrodes can be better attached to the finger surface, ensuring good contact between the electrodes and the fingers;

[0034] The detection component includes an integrated analog front end 121, a microcontroller 122, a multi-way switch 123, a USB module 124, a power supply 125 and an LED display module 126; the forehead electrode unit and the finger electrode unit are connected to the integrated analog front end 121 through the multi-way switch 123; the multi-way switch 123 is controlled by the microcontroller 122 and is used to switch a specific finger electrode group into a working state. The microcontroller 122 controls the conduction of a specific channel in the multi-way switch 123 to switch the acquisition channel of the integrated analog front end 121, traversing 10 fingers; the integrated analog front end 121 is a chip for bioelectric measurement, which is responsible for generating an excitation current of a specific frequency and obtaining a voltage signal excited by the excitation current in the human body. The integrated analog front end 121 can perform The microcontroller 122 performs preliminary processing to generate intermediate data, which is then processed by the microcontroller 122 to generate electrical impedance data; the microcontroller 122 performs data communication with the host 2 through the USB module 124; the power supply 125 supplies power to the integrated analog front end 121, the microcontroller 122, the multi-way switch 123, the USB module 124 and the LED display module 126; the microcontroller 122 is used to control the integrated analog front end 121, the multi-way switch 123, the USB module 124 and the LED display module 126 to realize multi-channel and multi-frequency impedance detection, receive and execute the calibration and measurement instructions of the host 2, and send the calibration data and the detection data to the host 2; the LED display module 126 is used to display the detection status of the system, including start, detection, pause, abnormality and end.

[0035] See also Figure 5 and Figure 6 As shown, the automatic finger clamping device includes a stepper motor 115, an asymmetrical crank slider mechanism group 116 and a mounting base 117; the finger side excitation electrode 113 and the finger side detection electrode 114 of the finger electrode group are respectively mounted on the asymmetrical crank slider mechanism group 116, and the stepper motor 115 and the asymmetrical crank slider mechanism group 116 are mounted on the mounting base 117. The asymmetrical crank slider mechanism group 116 is driven by the stepper motor 115 to move, thereby driving the finger side excitation electrode 113 and the finger side detection electrode 114 to clamp or release the finger.

[0036] Optionally, the finger electrode unit, the automatic finger clamping unit and the detection component are integrated in a box 13 .

[0037] Optionally, the forehead excitation electrode 111 and the forehead detection electrode 112 are circular and flat, and are made of stainless steel. It is understood that the electrodes may also be of other shapes or materials, and this embodiment does not limit this.

[0038] Optionally, the finger-side excitation electrode 113 and the finger-side detection electrode 114 are made of stainless steel. It is understandable that the electrodes may also be of other shapes or materials, which is not limited in this embodiment.

[0039] Optionally, the integrated analog front end 121 may be an integrated analog front end chip such as AFE4300 of Texas Instruments (TI) or CS1256 of CoreSea Technology. It is understood that the integrated analog front end 121 may be other products of other companies, and this embodiment does not limit this.

[0040] In conjunction with the accompanying drawings, the operation mode of the human body electrical impedance signal detection system in this embodiment is as follows:

[0041] When starting the human body impedance signal detection, the user places 10 fingers in 10 finger electrode groups at the same time, and the stepper motor 115 drives the asymmetrical crank slider mechanism group 116 to make the finger side excitation electrode 113 and the finger side detection electrode 114 of the finger electrode group clamp the fingers; wherein, according to the real-time power consumption of the stepper motor 115, it is judged whether to clamp, and after clamping, the stepper motor 115 enters a self-locking state and starts to collect human body impedance signals. After the collection is completed, the stepper motor 115 is unlocked, and the finger side excitation electrode 113 and the finger side detection electrode 114 of the finger electrode group are released, ending the human body impedance signal detection process, and the measurement results will be displayed on the host 2.

[0042] To further explain, in this embodiment, the method for judging whether the finger is clamped is: judging based on the real-time value of the power consumption of the stepper motor 115 and the change in the motor power consumption at two previous time nodes; if the real-time value of the motor power consumption is greater than the set threshold, and the difference in the motor power consumption at two previous time nodes is also greater than the set value, then it is judged that the finger has been clamped, otherwise it has not been clamped.

[0043] The process of collecting human body electrical impedance signals is as follows: First, the integrated analog front end 121 generates an excitation current of a specific frequency that has been current-limited. The excitation current flows into the finger-side excitation electrode 113 on the side of one finger of the user and flows out of the forehead excitation electrode 111. The integrated analog front end 121 obtains a voltage signal through the finger-side detection electrode 114 and the forehead detection electrode 112. The voltage signal is used to perform parameter calculations in the integrated analog front end 121 and the microcontroller 122 to calculate the electrical impedance of half the body from the finger to the forehead. By switching the frequency of the excitation current, the human body electrical impedance signals at different frequencies can be obtained. Similarly, the electrical impedance from 10 fingers to the center of the forehead can be obtained through the above process. The specific measurement method is: the microcontroller 122 controls the conduction of a specific channel in the multi-way switch 123 to switch the acquisition channel of the integrated analog front end 121, traversing 10 fingers.

[0044] In this embodiment, the frequency of the excitation current may be 12 frequencies selected from the range of 5.86 kHz to 250 kHz. It is understood that the excitation current may also be other frequencies, which is not limited in this embodiment.

[0045] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A detection method for a human body electrical impedance signal detection system with automatic electrode clamping, the human body electrical impedance signal detection system comprising a human body electrical impedance signal detection device and a host, the human body electrical impedance signal detection device being connected to the host via a USB; wherein: The human body impedance signal detection device is used to collect human body impedance signals, including amplitude information and phase angle information of human body impedance, and transmit the human body impedance signals to the host; The host is used to control the acquisition process of the human body electrical impedance signal, receive the acquired human body electrical impedance signal, and store, display and analyze the human body electrical impedance signal; The human body electrical impedance signal detection device comprises a signal acquisition unit and a detection component; The signal acquisition unit includes a forehead electrode unit, a finger electrode unit and a finger automatic clamping unit; the forehead electrode unit is a head-mounted structure, each of which is provided with a forehead excitation electrode and a forehead detection electrode; the finger electrode unit includes 10 pairs of finger electrode groups, which correspond to 10 fingers of the human body respectively, and each pair of finger electrode groups includes a finger side excitation electrode and a finger side detection electrode, which are distributed on the left and right sides of the finger, and the surfaces of the finger side excitation electrode and the finger side detection electrode are designed as concave arc surfaces according to the finger structure to fit the two sides of the finger; the forehead excitation electrode and the forehead detection electrode are connected to the fingers of each pair of finger electrode groups. The side excitation electrodes and the finger side detection electrodes constitute a four-electrode human body impedance detection path, the forehead excitation electrodes and the finger side excitation electrodes are responsible for generating and receiving currents of specific frequencies, and the forehead detection electrodes and the finger side detection electrodes are responsible for obtaining voltage values. Based on the four-electrode human body impedance detection path, the human body electrical impedance value between each finger and the forehead can be obtained; the finger automatic clamping unit includes 10 finger automatic clamping devices, which correspond to 10 pairs of finger electrode groups respectively. The finger automatic clamping devices are used to control the contact force between the electrodes in the finger electrode group and the fingers, so that the electrodes can be better attached to the finger surface, ensuring good contact between the electrodes and the fingers; The detection component includes an integrated analog front end, a microcontroller, a multi-way switch, a USB module, a power supply and an LED display module; the forehead electrode unit and the finger electrode unit are connected to the integrated analog front end through the multi-way switch; the multi-way switch is controlled by the microcontroller and is used to switch a specific finger electrode group into a working state. The microcontroller controls the conduction of a specific channel in the multi-way switch to switch the acquisition channel of the integrated analog front end and traverse 10 fingers; the integrated analog front end is a chip for bioelectric measurement, which is responsible for generating an excitation current of a specific frequency and obtaining a voltage signal excited by the excitation current in the human body. The integrated analog front end can Perform preliminary processing to generate intermediate data, which is then processed by a microcontroller to generate electrical impedance data; the microcontroller communicates data with the host through a USB module; the power supply is used to power the integrated analog front end, the microcontroller, the multi-way switch, the USB module and the LED display module; the microcontroller is used to control the integrated analog front end, the multi-way switch, the USB module and the LED display module to achieve multi-channel multi-frequency impedance detection, receive and execute calibration and measurement instructions from the host, and send calibration data and detection data to the host; the LED display module is used to display the detection status of the system, including start, detection, pause, abnormality and end; The automatic finger clamping device comprises a stepping motor, an asymmetric crank slider mechanism group and a mounting seat; the finger-side excitation electrode and the finger-side detection electrode of the finger electrode group are respectively mounted on the asymmetric crank slider mechanism group, and the stepping motor and the asymmetric crank slider mechanism group are mounted on the mounting seat, and the asymmetric crank slider mechanism group is driven by the stepping motor to move, thereby driving the finger-side excitation electrode and the finger-side detection electrode to clamp or release the finger; The detection method is characterized in that: when starting the human body impedance signal detection, the user places 10 fingers in 10 finger electrode groups at the same time, and the stepper motor drives the asymmetrical crank slider mechanism group to make the finger side excitation electrodes and the finger side detection electrodes of the finger electrode group clamp the fingers; wherein, according to the real-time power consumption of the stepper motor, it is judged whether to clamp, and after clamping, the stepper motor enters a self-locking state and starts to collect the human body impedance signal, and after the collection is completed, the stepper motor is unlocked, the finger side excitation electrodes and the finger side detection electrodes of the finger electrode group are released, and the human body impedance signal detection process ends, and the measurement results will be displayed on the host.

2. The detection method of the human body electrical impedance signal detection system with automatic electrode clamping according to claim 1 is characterized in that: The finger electrode unit, the finger automatic clamping unit and the detection component are integrated in one box.

3. The detection method of the human body electrical impedance signal detection system with automatic electrode clamping according to claim 1, characterized in that: The forehead electrode unit comprises a forehead excitation electrode, a forehead detection electrode, an electrode mounting shell and an elastic strap. The forehead excitation electrode and the forehead detection electrode are respectively mounted on the electrode mounting shell, and the electrode mounting shell is worn on the user's head through the elastic strap.

4. The detection method of the human body electrical impedance signal detection system with automatic electrode clamping according to claim 1 is characterized in that: The method for judging whether the finger is clamped is: based on the real-time value of the power consumption of the stepper motor and the change in the motor power consumption at two time nodes before and after. If the real-time value of the motor power consumption is greater than the set threshold, and the difference in the motor power consumption at two time nodes before and after is also greater than the set value, it is judged that the finger has been clamped, otherwise it has not been clamped.

5. The detection method of the human body electrical impedance signal detection system with automatic electrode clamping according to claim 1, characterized in that: The process of collecting human body electrical impedance signals is as follows: first, the integrated analog front end generates an excitation current of a specific frequency that has been current-limited. The excitation current flows into the finger-side excitation electrode on the side of one finger of the user and flows out of the forehead excitation electrode. The integrated analog front end obtains a voltage signal through the finger-side detection electrode and the forehead detection electrode. The voltage signal is used to perform parameter calculations in the integrated analog front end and the microcontroller to calculate the electrical impedance of half the body from the finger to the forehead. By switching the frequency of the excitation current, the human body electrical impedance signals at different frequencies can be obtained. Similarly, the electrical impedance from 10 fingers to the center of the forehead can be obtained through the above process. The specific measurement method is: the microcontroller controls the conduction of a specific channel in the multi-way switch to switch the acquisition channel of the integrated analog front end, traversing 10 fingers.

6. The detection method of the human body electrical impedance signal detection system with automatic electrode clamping according to claim 5, characterized in that: The frequency of the excitation current is 12 frequencies selected from the range of 5.86kHz to 250kHz.

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