Multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device and measurement method

Abstract

The present invention relates to the field of physiological information acquisition, and provides a multi-frequency multiplexing bioimpedance and neural transmission delay measurement device and measurement method. The device includes a signal generator, two end electrodes, a middle electrode and an MCU, wherein the signal generator is connected to the two end electrodes, the two end electrodes are connected to the middle electrode, and the MCU is connected to the signal generator and the middle electrode; the two end electrodes and the middle electrode are both attached to the surface of human skin; the signal generator is used to send two pulse signals of different frequencies under the control of the MCU; the two end electrodes are used to send one pulse signal to the middle electrode respectively; the middle electrode is used to receive the pulse signal sent by the two end electrodes and return it to the MCU; the MCU is used to perform bioimpedance measurement and neural delay measurement according to the electrical signal returned by the middle electrode.

Description

Technical Field

[0001] The present invention relates to the field of physiological information acquisition, and in particular to a multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device and a measurement method. Background Art

[0002] Bioimpedance is a measurement technology that uses the electrical properties of biological tissues and organs and their patterns of change to extract biomedical information related to human physiological and pathological conditions. Current bioimpedance devices use electrodes placed on the body surface to deliver a tiny AC current or voltage to the subject, detecting the resulting electrical impedance and its changes. However, no device currently measures impedance while also taking into account information about neural transmission delays. Summary of the Invention

[0003] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a multi-frequency multiplexed bioimpedance and nerve transmission delay measurement device and measurement method. The present invention proposes that a bidirectional dual-frequency stimulation current is sent to the detection object, and a common ground electrode is used. While measuring the impedance, the nerve transmission delay information can be measured by using an adding amplifier and a Schmitt trigger.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A first aspect of the present invention provides a multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device.

[0006] A multi-frequency multiplexing bioimpedance and nerve transfer delay measurement device includes: a signal generator, two end electrodes, a middle electrode, and an MCU, wherein the signal generator is connected to the two end electrodes, the two end electrodes are connected to the middle electrode, and the MCU is connected to the signal generator and the middle electrode; the two end electrodes and the middle electrode are both attached to the surface of human skin;

[0007] The signal generator is used to send two pulse signals of different frequencies under the control of the MCU;

[0008] The two end electrodes are used to respectively send a pulse signal to the middle electrode;

[0009] The middle electrode is used to receive the pulse signals sent by the electrodes at both ends and return them to the MCU;

[0010] The MCU is used to perform bioimpedance measurement and neural delay measurement based on the electrical signal returned by the intermediate electrode.

[0011] Furthermore, a voltage-controlled current source and a filter are sequentially provided between the MCU and the signal generator. The voltage-controlled current source is used to convert the pulse voltage signal emitted by the signal generator into a pulse current signal.

[0012] Furthermore, a plurality of electrodes are provided between the two end electrodes and the middle electrode, and the distances between adjacent electrodes are equal.

[0013] Furthermore, two electrodes are provided between one end electrode and the middle electrode, and two electrodes are also provided between the other end electrode and the middle electrode.

[0014] Furthermore, the bioimpedance measurement includes: the pulse signals sent by the electrodes at both ends pass through the two electrodes, reach the middle electrode, and return at the middle electrode; the impedance between one end electrode and the middle electrode, and the impedance between the other end electrode and the middle electrode, are amplified by the amplifier, filtered by the bandpass filter, and then converted into a digital signal by the analog-to-digital conversion circuit and input into the MCU.

[0015] Furthermore, the neural delay measurement includes: according to the direction of pulse signal transmission: an amplifier, a filter, an adding amplifier and a Schmitt trigger connected in sequence are provided between two adjacent electrodes, and the Schmitt trigger is connected to the MCU.

[0016] A second aspect of the present invention provides a multi-frequency multiplexing bioimpedance and nerve transmission delay measurement method.

[0017] A multi-frequency multiplexing bioimpedance and nerve transmission delay measurement method adopts the multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device described in the first aspect, comprising:

[0018] Attach the electrodes at both ends and the middle electrode to the surface of human skin;

[0019] Turn on the power supply;

[0020] Turn on the signal generator;

[0021] The MCU performs bioimpedance measurement and neural delay measurement based on the received signals.

[0022] Furthermore, the process of the MCU performing bioimpedance measurement according to the received signal includes:

[0023] Calculate the cosine value of the voltage from one end electrode to the middle electrode;

[0024] Calculate the sine value of the voltage from one end electrode to the middle electrode;

[0025] A first impedance signal is obtained by multiplying the arithmetic square root of the sum of the squares of the voltage cosine value and the voltage sine value by half of the pulse voltage amplitude;

[0026] Similarly, a second impedance signal between the other end electrode and the middle electrode is obtained.

[0027] Furthermore, performing the neural delay measurement includes:

[0028] The MCU records the time it takes for the pulse signal to reach the remaining electrodes from the electrodes at both ends;

[0029] According to the time it takes for the pulse signal to reach the remaining electrodes from the electrodes at both ends, the transmission time between two adjacent electrodes is calculated;

[0030] The delay time between two adjacent pulse signals is calculated based on the transmission time between two adjacent electrodes.

[0031] Furthermore, the calculation process of the time for the pulse signal to reach the remaining electrodes from the two end electrodes includes:

[0032] The electrical signals at two adjacent electrodes are added together to obtain a fused electrical signal;

[0033] If it is determined that the fused electrical signal is greater than the Schmitt trigger threshold, the MCU records the current time.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention uses a bioimpedance device to send a tiny AC measurement current to the test subject, while simultaneously measuring the transmission delay of the neural electrical signal. This makes it possible to locate the site of damage in nerve damage, amyotrophic lateral sclerosis, and other conditions.

[0036] Conventional bioimpedance uses a single-frequency unidirectional current to send to the detection object, which undoubtedly leads to a waste of ground electrode / negative electrode resources. The present invention proposes to send a bidirectional dual-frequency stimulation current to the detection object, using a common ground electrode. While measuring the impedance, the summing amplifier and Schmitt trigger can be used to measure the nerve transmission delay information. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0038] Figure 1 1 is a structural diagram of an electrode shown in the present invention;

[0039] Figure 2 1 is a diagram showing a circuit structure for performing neural delay measurement according to the present invention;

[0040] Figure 3 1 is a circuit diagram related to bioimpedance measurement according to the present invention;

[0041] Figure 4 4 is a circuit diagram of a multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device according to the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Example 1

[0046] like Figure 4 As shown, this embodiment provides a multi-frequency multiplexing bioimpedance and neural transmission delay measurement device, including an MCU, a current input module, seven electrodes, an impedance module and a neural delay module.

[0047] Electrode position and number Figure 1 As shown, electrodes 1 through 7 are standard patch electrodes, and 8 represents the surface of human skin. The arrows indicate the direction of current flow. Neural signal delay is proportional to the distance between adjacent electrodes, and the time difference between them for current to travel the same distance is the neural delay.

[0048] Current input module:

[0049] The MCU sends instructions to the signal generator to generate two frequency voltage signals. The voltage-controlled current source converts the voltage signal into a current source, which is filtered by the filter 8 and input into the f1 frequency current of the first electrode 1 and the f2 frequency current of the electrode 7 respectively. The f1 frequency current passes through the first electrode 1, the second electrode 2, the third electrode 3 to the fourth electrode 4, and the f2 frequency current passes through the seventh electrode 7, the sixth electrode 6, the fifth electrode 5 to the fourth electrode 4, forming a loop.

[0050] The bioimpedance measurement module and the neural delay measurement module share a current input module.

[0051] Bioimpedance measurement module such as Figure 3As shown, the MCU sends a command to the signal generator to generate the first frequency pulse voltage f1 and the second frequency pulse voltage f2. The voltage-controlled current source converts the voltage signal into a current source to filter 8 for filtering. The first electrode 1 and the seventh electrode 7 respectively input the first frequency pulse voltage f1 and the second frequency pulse voltage f2 into the detection object position, and return through the fourth electrode 4 to form a closed loop. The impedance from electrode 2 to electrode 3 and the impedance from electrode 6 to electrode 5 are amplified by amplifier 7.

[0052] The impedance from electrode 2 to electrode 3 is calculated as follows:

[0053]

[0054] Wherein, Z1 is the impedance signal, A1 is the amplitude of the pulse voltage f1, V1 is the cosine of the voltage from electrode 2 to electrode 3, and V2 is the sine of the voltage from electrode 2 to electrode 3.

[0055] The impedance from electrode 6 to electrode 5 is calculated as follows:

[0056]

[0057] Wherein, Z2 is the impedance signal, A2 is the amplitude of the pulse voltage f2, V3 is the cosine of the voltage from electrode 6 to electrode 5, and V4 is the sine of the voltage from electrode 6 to electrode 5.

[0058] After being filtered by the bandpass filter 7, the analog signal is converted into a digital signal by the analog-to-digital conversion circuit and input into the MCU.

[0059] The neural delay measurement module is composed of Figure 2 As shown, the first electrode 1 and the seventh electrode 7 input the first frequency current f1 and the second frequency current f2 respectively.

[0060] Signal transmission process: The amplifier amplifies the electrical signal measured by the electrodes, transmits it to the filter for filtering, and the summing amplifier sums the two input signals and outputs them to the Schmitt trigger. If the sum is greater than the threshold, the MCU records the current time.

[0061] 1. The frequency direction of the first frequency current f1 used by the first electrode 1 to the fourth electrode 4 is:

[0062] A current with a frequency of f1 is input through the first electrode 1 , passes through the second electrode 2 and the third electrode 3 , and reaches the fourth electrode 4 , which is a ground electrode.

[0063] (1) Input moment: When the first electrode 1 inputs the current of frequency f1, the electrical signal at the first electrode 1 is EMG1. The electrical signal at the second electrode 2 is amplified by amplifier 1 and filtered by filter 1 to obtain EMG2. EMG1 and EMG2 are input to summing amplifier 1, and the sum is output as EMG12. If it is greater than the threshold T1 of Schmitt trigger 1, the MCU records the current time t1.

[0064] (2) When the signal reaches the second electrode 2: the electrical signal at the third electrode 3 is amplified by the amplifier 2 and filtered by the filter 2 to obtain EMG3. EMG2 and EMG3 are input to the summing amplifier 2, and the sum is output as EMG23. If it is greater than the threshold T1 of the Schmitt trigger 2, the MCU records the time t2.

[0065] (3) When the signal reaches the third electrode 3: the electrical signal at the fourth electrode 4 is amplified by the amplifier 3 and filtered by the filter 3 to obtain EMG4. EMG3 and EMG4 are input to the summing amplifier 3, and the sum is output as EMG34. If it is greater than the threshold T1 of the Schmitt trigger 3, the MCU records the time t3.

[0066] 2. The frequency direction of the second frequency current f2 used from the seventh electrode 7 to the fourth electrode 4 is:

[0067] A current with a frequency of f2 is input through the seventh electrode 7 , passes through the sixth electrode 6 and the fifth electrode 5 , and reaches the fourth electrode 4 .

[0068] (1) Input moment: When the f2 frequency current is input to the seventh electrode 7, the electrical signal at the seventh electrode 7 is EMG7. EMG6 is used as the input of the summing amplifier 6, and the summed output is EMG76. If it is greater than the threshold T1 of the Schmitt trigger 6, the MCU records the time t7.

[0069] (2) When the signal reaches the sixth electrode 6: the electrical signal at the fifth electrode 5 is amplified by the amplifier 5 and filtered by the filter 5 to obtain EMG5. EMG6 and EMG5 are input to the summing amplifier 5, and the sum is output as EMG65. If it is greater than the threshold T1 of the Schmitt trigger 5, the MCU records the time t6.

[0070] (3) When the signal reaches the third electrode 3: the electrical signal at the fourth electrode 4 is amplified by the amplifier 4 and filtered by the filter 4 to obtain EMG4. EMG5 and EMG4 are input to the summing amplifier 4, and the sum is output as EMG54. If it is greater than the threshold T1 of the Schmitt trigger 4, the MCU records the time t5.

[0071] 3. Delivery time:

[0072] Transfer time from the first electrode 1 to the second electrode 2: t12=t2-t1;

[0073] Transfer time from the second electrode 2 to the third electrode 3: t23=t3-t2;

[0074] Transfer time from the seventh electrode 7 to the sixth electrode 6: t76 = t6 - t7;

[0075] Transfer time from the sixth electrode 6 to the fifth electrode 5 is: t65=t5-t6.

[0076] 4. Delay time:

[0077] f1 frequency direction: tf1=t23-t12;

[0078] F2 frequency direction: tf2=t65-t76.

[0079] Example 2

[0080] This embodiment provides a multi-frequency multiplexing bioimpedance and nerve transmission delay measurement method.

[0081] A multi-frequency multiplexing bioimpedance and nerve transmission delay measurement method adopts the multi-frequency multiplexing bioimpedance and nerve transmission delay measurement device described in the first aspect, comprising:

[0082] Attach the electrodes at both ends and the middle electrode to the surface of human skin;

[0083] Turn on the power supply;

[0084] Turn on the signal generator;

[0085] The MCU performs bioimpedance measurement and neural delay measurement based on the received signals.

[0086] The process of bioimpedance measurement includes: the MCU sends a command to the signal generator to generate a first frequency pulse voltage f1 and a second frequency pulse voltage f2; the voltage-controlled current source converts the voltage signal into a current source and filters it to the filter 8; the first electrode 1 and the seventh electrode 7 respectively input the first frequency pulse voltage f1 and the second frequency pulse voltage f2 into the detection object position, and return through the fourth electrode 4 to form a closed loop. The impedance from electrode 2 to electrode 3 and the impedance from electrode 6 to electrode 5 are amplified by the amplifier 7.

[0087] The impedance from electrode 2 to electrode 3 and the impedance from electrode 6 to electrode 5 are amplified by amplifier 7.

[0088] The impedance from electrode 2 to electrode 3 is calculated as follows:

[0089]

[0090] Wherein, Z1 is the impedance signal, A1 is the amplitude of the pulse voltage f1, V1 is the cosine of the voltage from electrode 2 to electrode 3, and V2 is the sine of the voltage from electrode 2 to electrode 3.

[0091] The impedance from electrode 6 to electrode 5 is calculated as follows:

[0092]

[0093] Wherein, Z2 is the impedance signal, A2 is the amplitude of the pulse voltage f2, V3 is the cosine of the voltage from electrode 6 to electrode 5, and V4 is the sine of the voltage from electrode 6 to electrode 5.

[0094] After being filtered by the bandpass filter 7, the analog signal is converted into a digital signal by the analog-to-digital conversion circuit and input into the MCU.

[0095] The process of performing neural latency measurements involves:

[0096] 1. The frequency direction of the first frequency current f1 used by the first electrode 1 to the fourth electrode 4 is:

[0097] A current with a frequency of f1 is input through the first electrode 1 , passes through the second electrode 2 and the third electrode 3 , and reaches the fourth electrode 4 , which is a ground electrode.

[0098] (1) Input moment: When the first electrode 1 inputs the current of frequency f1, the electrical signal at the first electrode 1 is EMG1. The electrical signal at the second electrode 2 is amplified by amplifier 1 and filtered by filter 1 to obtain EMG2. EMG1 and EMG2 are input to summing amplifier 1, and the sum is output as EMG12. If it is greater than the threshold T1 of Schmitt trigger 1, the MCU records the current time t1.

[0099] (2) When the signal reaches the second electrode 2: the electrical signal at the third electrode 3 is amplified by the amplifier 2 and filtered by the filter 2 to obtain EMG3. EMG2 and EMG3 are input to the summing amplifier 2, and the sum is output as EMG23. If it is greater than the threshold T1 of the Schmitt trigger 2, the MCU records the time t2.

[0100] (3) When the signal reaches the third electrode 3: the electrical signal at the fourth electrode 4 is amplified by the amplifier 3 and filtered by the filter 3 to obtain EMG4. EMG3 and EMG4 are input to the summing amplifier 3, and the sum is output as EMG34. If it is greater than the threshold T1 of the Schmitt trigger 3, the MCU records the time t3.

[0101] 2. The frequency direction of the second frequency current f2 used from the seventh electrode 7 to the fourth electrode 4 is:

[0102] A current with a frequency of f2 is input through the seventh electrode 7 , passes through the sixth electrode 6 and the fifth electrode 5 , and reaches the fourth electrode 4 .

[0103] (1) Input moment: When the f2 frequency current is input to the seventh electrode 7, the electrical signal at the seventh electrode 7 is EMG7. EMG6 is used as the input of the summing amplifier 6, and the summed output is EMG76. If it is greater than the threshold T1 of the Schmitt trigger 6, the MCU records the time t7.

[0104] (2) When the signal reaches the sixth electrode 6: the electrical signal at the fifth electrode 5 is amplified by the amplifier 5 and filtered by the filter 5 to obtain EMG5. EMG6 and EMG5 are input to the summing amplifier 5, and the sum is output as EMG65. If it is greater than the threshold T1 of the Schmitt trigger 5, the MCU records the time t6.

[0105] (3) When the signal reaches the third electrode 3: the electrical signal at the fourth electrode 4 is amplified by the amplifier 4 and filtered by the filter 4 to obtain EMG4. EMG5 and EMG4 are input to the summing amplifier 4, and the sum is output as EMG54. If it is greater than the threshold T1 of the Schmitt trigger 4, the MCU records the time t5.

[0106] 3. Delivery time:

[0107] Transfer time from the first electrode 1 to the second electrode 2: t12=t2-t1;

[0108] Transfer time from the second electrode 2 to the third electrode 3: t23=t3-t2;

[0109] Transfer time from the seventh electrode 7 to the sixth electrode 6: t76 = t6 - t7;

[0110] Transfer time from the sixth electrode 6 to the fifth electrode 5 is: t65=t5-t6.

[0111] 4. Delay time:

[0112] f1 frequency direction: tf1=t23-t12;

[0113] F2 frequency direction: tf2=t65-t76.

[0114] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A multi-frequency multiplexing bioimpedance and neural transmission delay measurement device, characterized in that: include: A signal generator, electrodes at both ends, a middle electrode and an MCU, wherein the signal generator is connected to the electrodes at both ends, the electrodes at both ends are connected to the middle electrode, and the MCU is connected to the signal generator and the middle electrode; the electrodes at both ends and the middle electrode are attached to the surface of human skin; The signal generator is used to send two pulse signals of different frequencies under the control of the MCU; The two end electrodes are used to send a pulse signal to the middle electrode respectively; The middle electrode is used to receive the pulse signal sent by the electrodes at both ends and return it to the MCU; The MCU is used to perform bioimpedance measurement and nerve transmission delay measurement based on the electrical signal returned by the middle electrode; A plurality of electrodes are provided between the two end electrodes and the middle electrode, and the distances between adjacent electrodes are equal; Two electrodes are provided between one of the two end electrodes and the middle electrode, and two electrodes are also provided between the other end electrode and the middle electrode; The bioimpedance measurement comprises: the pulse signals sent by the electrodes at both ends pass through the two electrodes, reach the middle electrode, and return at the middle electrode; the impedance between the electrode at one end and the middle electrode, and the impedance between the electrode at the other end and the middle electrode are amplified by an amplifier, filtered by a bandpass filter, and then converted into a digital signal by an analog-to-digital conversion circuit and input into an MCU; The nerve transmission delay measurement includes: according to the direction of pulse signal transmission: an amplifier, a filter, an adding amplifier and a Schmitt trigger connected in sequence are arranged between two adjacent electrodes, and the Schmitt trigger is connected to the MCU.

2. The multi-frequency multiplexing bioimpedance and neural transmission delay measurement device according to claim 1, characterized in that: A voltage-controlled current source and a filter are arranged in sequence between the MCU and the signal generator. The voltage-controlled current source is used to convert the pulse voltage signal emitted by the signal generator into a pulse current signal.

3. A multi-frequency multiplexing bioimpedance and nerve transmission delay measurement method, characterized in that: The multi-frequency multiplexing bioimpedance and nerve transmission delay measuring device according to claim 1 or 2 comprises: Attach the electrodes at both ends and the middle electrode to the surface of human skin; Connect the power supply. Turn on the signal generator; The MCU performs bioimpedance measurement and nerve transmission delay measurement based on the received signals.

4. The multi-frequency multiplexing bioimpedance and neural transmission delay measurement method according to claim 3, characterized in that: The process of the MCU performing bioimpedance measurement according to the received signal includes: Calculate the voltage cosine value and voltage sine value from one end electrode to the middle electrode; The first impedance signal is obtained by multiplying the arithmetic square root of the sum of the squares of the voltage cosine value and the voltage sine value by two times the pulse voltage amplitude; Similarly, a second impedance signal between the other end electrode and the middle electrode is obtained.

5. The multi-frequency multiplexing bioimpedance and neural transmission delay measurement method according to claim 3, characterized in that: The nerve transmission delay measurement includes: The MCU records the time it takes for the pulse signal to reach the remaining electrodes from the electrodes at both ends; According to the time it takes for the pulse signal to reach the remaining electrodes from the electrodes at both ends, the transmission time between two adjacent electrodes is calculated; According to the transmission time between two adjacent electrodes, the delay time between two pulse signals is calculated.

6. The multi-frequency multiplexing bioimpedance and neural transmission delay measurement method according to claim 5, characterized in that: The calculation process of the time taken for the pulse signal to reach the remaining electrodes from the electrodes at both ends includes: The electrical signals at two adjacent electrodes are added to obtain a fused electrical signal; If it is determined that the fused electrical signal is greater than the Schmitt trigger threshold, the MCU records the current time.

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