A brain bioelectrical impedance detection system and method for stroke identification

Abstract

The present application provides a cranial bioelectrical impedance detection system and method for stroke identification. The system includes a control device, a signal generating circuit, a current conversion control circuit, a differential receiving circuit, a processing circuit, a plurality of transmitting electrodes and a plurality of receiving electrodes. The control device is used to generate a plurality of electromagnetic wave signals according to the target frequency band indicating the signal generating circuit, and the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal indicates the current conversion control circuit to perform corresponding current regulation; during detection, the transmitting electrode and the receiving electrode are installed on both sides of the cranial brain, and the electromagnetic wave signal is sent to the cranial brain after current regulation. The electromagnetic wave signal to be detected sent by the cranial brain is sent to the control device after processing, and the bioelectrical impedance of the cranial brain to be detected is finally determined. In this way, the embodiment of the present application takes a short time to perform electrical impedance detection, and can detect the electrical impedance in time after the patient becomes ill, thereby identifying the type of stroke, and shortening the time interval from onset to treatment.

Description

Technical Field

[0001] The present application relates to the technical field of bioelectrical impedance detection, and in particular to a cranial bioelectrical impedance detection system and method for stroke identification. Background Art

[0002] Stroke, also known as cerebrovascular accident or stroke, is a disease caused by blood vessel blockage that prevents blood from flowing into the brain or sudden rupture of brain blood vessels, causing brain tissue damage. It includes two types: ischemic stroke and hemorrhagic stroke. Since the earlier the treatment of stroke begins, the better the prognosis, it is very important to study the early identification of stroke.

[0003] The early symptoms of ischemic stroke and hemorrhagic stroke are very similar, and it is difficult to effectively distinguish them by analyzing clinical symptoms. Currently, imaging technology is mainly used for identification, such as magnetic resonance imaging or Doppler ultrasound. This method requires a long time to obtain the identification results, resulting in a long time interval from onset to treatment, which may miss the golden treatment period for stroke.

[0004] In the process of seeking a better solution for identifying stroke, considering that the human body is a bioelectric conductor, each tissue and organ has a specific electrical impedance. The physiological change of the brain caused by ischemic stroke is edema, and the physiological change of the brain caused by hemorrhagic stroke is hematoma. Since the conductive function of the brain under these two physiological changes is quite different, stroke can be identified by detecting the bioelectrical impedance of the brain. Because the detection of bioelectrical impedance of the brain takes a short time, it can identify the type of stroke in time after the onset of the disease, and then give the corresponding treatment plan, which can greatly shorten the time interval from onset to treatment. Therefore, there is an urgent need for a bioelectrical impedance detection system for stroke identification.

[0005] Based on this, there is an urgent need for a cranial bioelectrical impedance detection system for stroke identification, which is used to solve the problem that the existing technology cannot promptly identify the type of stroke after the onset of the disease, thereby resulting in a long time interval from onset to treatment. Summary of the invention

[0006] The present application provides a cranial bioelectrical impedance detection system and method for stroke identification, which can be used to solve the technical problem that the existing technology cannot promptly identify the type of stroke after the onset of the disease, thereby resulting in a long time interval from onset to treatment.

[0007] In a first aspect, an embodiment of the present application provides a cranial bioelectrical impedance detection system for stroke identification, the system comprising a control device, a signal generating circuit, a current conversion control circuit, a differential receiving circuit, a processing circuit, a plurality of transmitting electrodes and a plurality of receiving electrodes; during detection, the transmitting electrodes and the receiving electrodes are both installed on both sides of the cranial brain to be detected;

[0008] The signal generating circuit comprises an oscillator and a signal generator, wherein the signal generator is electrically connected to the oscillator;

[0009] The current conversion control circuit is electrically connected to the signal generator, and the current conversion control circuit is electrically connected to each transmitting electrode respectively;

[0010] The differential receiving circuit is electrically connected to each receiving electrode respectively;

[0011] The processing circuit is electrically connected to the differential receiving circuit;

[0012] The control device is electrically connected to the oscillator, the signal generator, the current conversion control circuit and the processing circuit respectively;

[0013] Wherein, the control device is configured to perform the following steps:

[0014] Obtaining the initial frequency preset in the cranial bioelectrical impedance detection system;

[0015] Determine a target frequency according to the initial frequency, and determine a target frequency segment corresponding to the target frequency;

[0016] sending the target frequency segment to the oscillator, and sending a preset frequency adjustment value to the signal generator;

[0017] According to the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal, and the correspondence between the predetermined frequency band and the resistance value corresponding to the current conversion control circuit, determine the target resistance value corresponding to the current conversion control circuit, and send the target resistance value to the current conversion control circuit; the electromagnetic wave signal is generated by the signal generator according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator according to the target frequency band;

[0018] Receive the real part data and imaginary part data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit; the electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are sent by the transmitting electrode to the brain to be detected, and the differential receiving circuit performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode; the differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit performs current regulation and differential conversion processing on the electromagnetic wave signals according to the target resistance value;

[0019] The bioelectrical impedance of the brain to be detected is determined according to the real and imaginary data of the electrical impedance corresponding to all electromagnetic wave signals to be processed; the bioelectrical impedance is used to identify cerebral stroke.

[0020] In an implementation manner of the first aspect, before determining the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency segment corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency segment and the resistance value corresponding to the current conversion control circuit, the control device is further configured to perform the following steps:

[0021] Determine whether there is a target electromagnetic wave signal with a frequency exceeding the target frequency range, and if so, send a stop instruction to the signal generator, wherein the stop instruction is used to instruct the signal generator to stop generating the electromagnetic wave signal; and set the frequency of the target electromagnetic wave signal to the target frequency, and return to the step of determining the target frequency range corresponding to the target frequency;

[0022] If the frequency of the target electromagnetic wave signal exceeds the maximum frequency range preset in the cranial bioelectrical impedance detection system, a termination instruction is sent to the signal generator, and the termination instruction is used to instruct the signal generator to terminate operation.

[0023] In an implementation manner of the first aspect, the oscillator is configured to perform the following steps:

[0024] Receiving the target frequency segment;

[0025] generating the reference signal according to the target frequency segment;

[0026] The reference signal is sent to the signal generator.

[0027] In an implementation manner of the first aspect, the signal generator is configured to perform the following steps:

[0028] receiving the frequency adjustment value;

[0029] receiving the reference signal;

[0030] Generate a plurality of electromagnetic wave signals in sequence according to the reference signal and the frequency adjustment value;

[0031] Sending the plurality of electromagnetic wave signals to the control device and the current conversion control circuit in sequence;

[0032] After receiving the stop instruction, stop generating the electromagnetic wave signal;

[0033] After receiving the termination instruction, the operation is terminated.

[0034] In an implementable manner of the first aspect, sequentially generating a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value includes:

[0035] Generate a basic electromagnetic wave signal according to the reference signal;

[0036] Generate a plurality of adjustment electromagnetic wave signals in sequence according to the basic electromagnetic wave signal and the frequency adjustment value;

[0037] The basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals are collectively used as the multiple electromagnetic wave signals.

[0038] In an implementation manner of the first aspect, the corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is determined by the following method:

[0039] A plurality of frequency bands are pre-set in the cranial and cerebral bioelectrical impedance detection system; the plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequency;

[0040] Determine the resistance value of the current conversion control circuit corresponding to each frequency band according to the voltage of the electromagnetic wave signal to be used and the output current corresponding to each preset frequency band;

[0041] According to the resistance value corresponding to the current conversion control circuit corresponding to each frequency segment, a corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is established.

[0042] In a second aspect, an embodiment of the present application provides a method for detecting bioelectrical impedance of a cranial brain for identifying stroke, the method being applied to a bioelectrical impedance detection system for detecting stroke, the system comprising a control device, a signal generating circuit, a current conversion control circuit, a differential receiving circuit, a processing circuit, a plurality of transmitting electrodes and a plurality of receiving electrodes; during detection, the transmitting electrodes and the receiving electrodes are both installed on both sides of the cranial brain to be detected;

[0043] The signal generating circuit comprises an oscillator and a signal generator, wherein the signal generator is electrically connected to the oscillator;

[0044] The current conversion control circuit is electrically connected to the signal generator, and the current conversion control circuit is electrically connected to each transmitting electrode respectively;

[0045] The differential receiving circuit is electrically connected to each receiving electrode respectively;

[0046] The processing circuit is electrically connected to the differential receiving circuit;

[0047] The control device is electrically connected to the oscillator, the signal generator, the current conversion control circuit and the processing circuit respectively;

[0048] The method comprises:

[0049] The control device obtains the initial frequency preset in the cranial and cerebral bioelectrical impedance detection system;

[0050] The control device determines a target frequency according to the initial frequency, and determines a target frequency segment corresponding to the target frequency;

[0051] The control device sends the target frequency segment to the oscillator, and sends a preset frequency adjustment value to the signal generator;

[0052] The control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency range corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency range and the resistance value corresponding to the current conversion control circuit, and sends the target resistance value to the current conversion control circuit; the electromagnetic wave signal is generated by the signal generator according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator according to the target frequency range;

[0053] The control device receives the real part data and imaginary part data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit; the electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are transmitted by the transmitting electrode to the brain to be detected, and the differential receiving circuit performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode; the differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit performs current regulation and differential conversion processing on the electromagnetic wave signals according to the target resistance value;

[0054] The control device determines the bioelectrical impedance of the brain to be detected according to the real part data and imaginary part data of the electrical impedance corresponding to all electromagnetic wave signals to be processed; the bioelectrical impedance is used to identify cerebral stroke.

[0055] In an implementation manner of the second aspect, before the control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency segment corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency segment and the resistance value corresponding to the current conversion control circuit, the method further includes:

[0056] The control device determines whether there is a target electromagnetic wave signal whose frequency exceeds the target frequency range, and if so, sends a stop instruction to the signal generator, wherein the stop instruction is used to instruct the signal generator to stop generating the electromagnetic wave signal; and sets the frequency of the target electromagnetic wave signal to the target frequency, and returns to the step of determining the target frequency range corresponding to the target frequency;

[0057] If the frequency of the target electromagnetic wave signal exceeds the maximum frequency range preset in the cranial bioelectrical impedance detection system, the control device sends a termination instruction to the signal generator, and the termination instruction is used to instruct the signal generator to terminate operation.

[0058] In an implementation manner of the second aspect, the method further includes:

[0059] The oscillator receives the target frequency segment;

[0060] The oscillator generates the reference signal according to the target frequency band;

[0061] The oscillator sends the reference signal to the signal generator.

[0062] In an implementation manner of the second aspect, the corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is determined by the following method:

[0063] The control device pre-sets a plurality of frequency bands in the cranial bioelectrical impedance detection system; the plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequency;

[0064] The control device determines the resistance value corresponding to the current conversion control circuit corresponding to each frequency band according to the voltage of the electromagnetic wave signal to be used and the output current corresponding to each preset frequency band;

[0065] The control device establishes a corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit according to the resistance value corresponding to the current conversion control circuit corresponding to each frequency band.

[0066] In an implementation manner of the second aspect, the method further includes:

[0067] The signal generator receives the frequency adjustment value;

[0068] The signal generator receives the reference signal;

[0069] The signal generator sequentially generates a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value;

[0070] The signal generator sends the plurality of electromagnetic wave signals to the control device and the current conversion control circuit in sequence;

[0071] After receiving the stop instruction, the signal generator stops generating the electromagnetic wave signal;

[0072] The signal generator stops running after receiving the termination instruction.

[0073] In an implementable manner of the second aspect, the signal generator sequentially generates a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value, including:

[0074] The signal generator generates a basic electromagnetic wave signal according to the reference signal;

[0075] The signal generator sequentially generates a plurality of adjustment electromagnetic wave signals according to the basic electromagnetic wave signal and the frequency adjustment value;

[0076] The signal generator uses the basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals together as the multiple electromagnetic wave signals.

[0077] In this way, the brain bioimpedance detection system for stroke identification provided by the embodiment of the present application uses electromagnetic wave signals that can more comprehensively cover all frequencies applicable to brain bioimpedance detection; during detection, the control device sends different current adjustment instructions to the current conversion control circuit according to the different ranges of the frequency of the electromagnetic wave signal, so that the current conversion control circuit can emit currents of different powers at different electromagnetic wave frequencies, which is more in line with the different impedance characteristics of the brain at different electromagnetic wave frequencies. The entire system directly installs electrodes on both sides of the brain during detection, which is more convenient to use; the entire impedance detection process takes a short time, and can promptly identify the type of stroke after the patient becomes ill, shortening the time interval from onset to treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 A schematic diagram of the structure of a cranial bioelectrical impedance detection system for stroke identification provided in an embodiment of the present application;

[0079] Figure 2 A schematic diagram of a flow chart that a control device provided in an embodiment of the present application is configured to execute;

[0080] Figure 3 An overall flow chart for determining the target resistance value corresponding to the current conversion control circuit and the output corresponding current;

[0081] Figure 4 A circuit diagram of a current conversion control circuit provided in an embodiment of the present application;

[0082] Figure 5 A schematic diagram of the overall detection process corresponding to a cranial bioelectrical impedance detection system for stroke identification provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0084] In order to solve the problem, an embodiment of the present application provides a cranial bioelectrical impedance detection system for stroke identification, which is specifically used to solve the problem that the existing technology cannot promptly identify the type of stroke after the onset of the disease, thereby resulting in a long time interval from onset to treatment. Figure 1 The structural diagram of a cranial bioelectrical impedance detection system for stroke identification provided by an embodiment of the present application is exemplarily shown. Figure 1 As shown, the cranial brain bioelectrical impedance detection system has the function of realizing cranial brain bioelectrical impedance detection. The cranial brain bioelectrical impedance detection system provided in the embodiment of the present application includes a control device 100, a signal generating circuit 200, a current conversion control circuit 300, a differential receiving circuit 400, a processing circuit 500, a plurality of transmitting electrodes 600 and a plurality of receiving electrodes 700. During detection, the transmitting electrodes 600 and the receiving electrodes 700 are both installed on both sides of the cranial brain to be detected.

[0085] The signal generating circuit 200 includes an oscillator 210 and a signal generator 220 , and the signal generator 220 is electrically connected to the oscillator 210 .

[0086] The current conversion control circuit 300 is electrically connected to the signal generator 220 , and the current conversion control circuit 300 is electrically connected to each transmitting electrode 600 .

[0087] The differential receiving circuit 400 is electrically connected to each receiving electrode 700 .

[0088] The processing circuit 500 is electrically connected to the differential receiving circuit 400 .

[0089] The control device 100 is electrically connected to the oscillator 210 , the signal generator 220 , the current conversion control circuit 300 , and the processing circuit 500 , respectively.

[0090] Specifically, the number of transmitting electrodes 600 and the number of receiving electrodes 700 should be two or more, which can be determined based on experience and actual conditions, such as two transmitting electrodes 600 and two receiving electrodes 700, without specific limitation. During detection, the transmitting electrodes 600 and the receiving electrodes 700 can be pasted on both sides of the brain to be detected, or can be fixed by hand, without specific limitation. The current conversion control circuit 300 is electrically connected to each transmitting electrode 600 through a signal line, and the length of each signal line should be the same; the differential receiving circuit 400 is electrically connected to each receiving electrode 700 through a signal line, and the length of each signal line should be the same; the control device 100 is electrically connected to the oscillator 210, the signal generator 220, the current conversion control circuit 300 and the processing circuit 500 through a control line.

[0091] in, Figure 2 The control device 100 provided in the embodiment of the present application is configured to execute a flow chart. The control device 100 can use a microcontroller chip PIC18LF4455-I / PT to complete the execution of the control program. Specifically, the control device 100 is configured to execute the following steps:

[0092] Step 201, obtaining an initial frequency preset in a cranial bioelectrical impedance detection system.

[0093] Step 202: determine a target frequency according to the initial frequency, and determine a target frequency segment corresponding to the target frequency.

[0094] Step 203 , sending the target frequency segment to the oscillator 210 , and sending the preset frequency adjustment value to the signal generator 220 .

[0095] Step 204, determining the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency segment corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency segment and the resistance value corresponding to the current conversion control circuit, and sending the target resistance value to the current conversion control circuit 300.

[0096] Step 205 : receiving the real part data and imaginary part data of the electrical impedance corresponding to the plurality of electromagnetic wave signals to be processed sent by the processing circuit 500 .

[0097] Step 206, determining the bioelectrical impedance of the brain to be detected according to the real part data and imaginary part data of the electrical impedance corresponding to all the electromagnetic wave signals to be processed.

[0098] In the embodiment of the present application, the electromagnetic wave signal used can more comprehensively cover all frequencies applicable to the bioelectrical impedance detection of the brain; during detection, the control device sends different current adjustment instructions to the current conversion control circuit according to the different ranges of the frequency of the electromagnetic wave signal, so that the current conversion control circuit can emit currents of different powers at different electromagnetic wave frequencies, which is more in line with the different electrical impedance characteristics of the brain at different electromagnetic wave frequencies. The entire system directly installs electrodes on both sides of the brain during detection, which is more convenient to use; the entire electrical impedance detection process takes a short time, and can promptly identify the type of stroke after the patient becomes ill, shortening the time interval from onset to treatment.

[0099] Specifically, in step 201, the control device obtains the initial frequency pre-set in the cranial and cerebral bioelectrical impedance detection system from the host computer. The host computer will finally determine the initial frequency of the cranial and cerebral bioelectrical impedance detection through a series of experiments, that is, the detection frequency used at the beginning of the detection. The detection system starts from this initial frequency each time it starts detection. Since the frequency range of the electromagnetic wave signal to be used set by the cranial and cerebral bioelectrical impedance detection system provided in the embodiment of the present application is 50Hz to 300kHz, the initial frequency should also be within the range of 50Hz to 300kHz, generally 50Hz, and is not specifically limited. It should be noted that the lower the initial frequency, the more electromagnetic wave signals will be generated in the entire frequency range, and the higher the accuracy of the final analysis result will be.

[0100] In step 202, the initial frequency is set as the target frequency, and the target frequency is compared with a frequency segment preset in the cranial bioelectrical impedance detection system to determine the frequency segment to which the target frequency belongs, ie, the target frequency segment.

[0101] The frequency segments pre-set in the cranial bioelectrical impedance detection system are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large according to the frequency. In the embodiment of the present application, the frequency range of the electromagnetic wave signal to be used is 50Hz to 300kHz, and the pre-set frequency segments are 50Hz to 300kHz divided into multiple frequency segments from small to large. There are many ways to set the number of frequency segments and the range size of each frequency segment. In one example, it can be divided into four frequency segments, namely 50Hz~1kHz, 1k Hz~10kHz, 10k Hz~100kHz and 100k Hz~300kHz. In other possible examples, those skilled in the art can determine according to experience and actual conditions, such as divided into 50Hz~10kHz, 10kHz~100kHz and 100k Hz~300kHz, without specific limitation.

[0102] In step 203, the control device 100 sends the target frequency segment to the oscillator 210 and sends the preset frequency adjustment value to the signal generator 220. The control device 100 presets different frequency adjustment values ​​according to different target frequency segments. The oscillator 210 can be a high-precision adjustable oscillator. Corresponding to the control device 100, the oscillator 210 provided in the embodiment of the present application is configured to perform the following steps:

[0103] Receive the target frequency band.

[0104] Generate a reference signal according to the target frequency band. The oscillator 210 generates different reference signals according to different target frequency bands.

[0105] The reference signal is sent to the signal generator 220 .

[0106] The use of the above-mentioned high-precision adjustable oscillator can generate a sinusoidal reference signal with a wider frequency range and higher stability, which is more conducive to improving the accuracy of the entire cranial bioelectrical impedance detection system.

[0107] The signal generator 220 provided in the embodiment of the present application is configured to perform the following steps:

[0108] Receive frequency adjustment value.

[0109] Receive a reference signal.

[0110] According to the reference signal and the frequency adjustment value, a plurality of electromagnetic wave signals are generated in sequence. Since the reference signals and frequency adjustment values ​​corresponding to different target frequency bands are different, the frequencies of the electromagnetic wave signals generated by the signal generator 220 are also different in different target frequency bands.

[0111] The plurality of electromagnetic wave signals are sequentially sent to the control device 100 and the current conversion control circuit 300 .

[0112] Specifically, after the control device 100 sends the target frequency segment to the oscillator 210, the oscillator 210 receives the target frequency segment, generates a corresponding reference signal, and sends it to the signal generator 220; after the control device 100 sends the preset frequency adjustment value to the signal generator 220, the signal generator 220 receives the frequency adjustment value and the reference signal, and generates a plurality of electromagnetic wave signals in sequence, and feeds these electromagnetic wave signals back to the control device 100 in sequence, and sends them to the power conversion control circuit 300 in sequence.

[0113] The specific process of the signal generator 220 sequentially generating a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value is as follows:

[0114] A basic electromagnetic wave signal is generated according to the reference signal.

[0115] According to the basic electromagnetic wave signal and the frequency adjustment value, multiple adjustment electromagnetic wave signals are generated in sequence. Among them, the frequency of the first adjustment electromagnetic wave signal is the sum of the frequency of the basic electromagnetic wave signal and the frequency adjustment value; the frequency of each subsequent adjustment electromagnetic wave signal is the sum of the frequency of the previous adjustment electromagnetic wave signal corresponding to the adjustment electromagnetic wave signal and the frequency adjustment value.

[0116] The basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals are taken together as multiple electromagnetic wave signals. That is, the multiple electromagnetic wave signals are composed of the basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals, wherein each signal is taken as an electromagnetic wave signal.

[0117] Before executing step 204, the control device 100 is further configured to execute the following steps:

[0118] Determine whether there is a target electromagnetic wave signal whose frequency exceeds the target frequency band. If so, send a stop instruction to the signal generator 220, where the stop instruction is used to instruct the signal generator 220 to stop generating the electromagnetic wave signal; and set the frequency of the target electromagnetic wave signal to the target frequency, and return to the step of determining the target frequency band corresponding to the target frequency in step 302.

[0119] If the frequency of the target electromagnetic wave signal exceeds the maximum frequency band preset in the cranial bioelectrical impedance detection system, a termination instruction is sent to the signal generator 220, and the termination instruction is used to instruct the signal generator 220 to terminate the operation.

[0120] Corresponding to the control device 100, the signal generator 220 is further configured to perform the following steps:

[0121] After receiving the stop instruction, the generation of the electromagnetic wave signal is stopped.

[0122] After receiving the termination instruction, the operation is terminated.

[0123] In order to explain steps 201 to 203 more clearly, a specific example is given below.

[0124] Assuming that the frequency range of the electromagnetic wave signal to be used is divided into four frequency segments from small to large according to the frequency, namely 50Hz~1kHz (greater than or equal to 50Hz and less than 1kHz), 1kHz~10kHz (greater than or equal to 1kHz and less than 10kHz), 10kHz~100kHz (greater than or equal to 10kHz and less than 100kHz) and 100kHz~300kHz (greater than or equal to 100kHz and less than or equal to 300kHz), the initial frequency acquired by the control device 100 is assumed to be 50Hz, then 50Hz is set as the target frequency. By comparison, it can be seen that the target frequency segment corresponding to the target frequency is 50Hz~1kHz. The frequency adjustment value preset by the control device 100 for this frequency segment is assumed to be 500Hz, then the control device 100 sends the target frequency segment 50Hz~1kHz to the oscillator 210, and sends the frequency adjustment value 500Hz to the signal generator 220. The oscillator 210 generates a reference signal corresponding to the frequency band. Assuming the frequency is 15 MHz, the reference signal is sent to the signal generator 220. The signal generator 220 generates a reference electromagnetic wave signal and an adjustment electromagnetic wave signal in sequence at preset time intervals. Assuming the frequency of the reference electromagnetic wave signal is 50 Hz, the frequency of the first adjustment electromagnetic wave signal is 50+500=550 Hz, and the frequency of the second adjustment electromagnetic wave signal is 550+500=1.05 kHz. At this time, the control device 100 determines that the frequency of the second adjustment electromagnetic wave signal has exceeded the target frequency band of 50 Hz to 1 kHz, and sends a stop command to the signal generator 220.

[0125] The control device 100 uses the second adjusted electromagnetic wave signal as the target electromagnetic wave signal, and sets the frequency 1.05kHz as the target frequency. By comparison, it can be seen that the target frequency corresponding to the target frequency is 1kHz to 10kHz. The control device 100 assumes that the preset frequency adjustment value of the frequency segment is 2kHz, and the control device 100 sends the target frequency segment 1kHz to 10kHz to the oscillator 210, and sends the frequency adjustment value 2kHz to the signal generator 220. The oscillator 210 generates a reference signal corresponding to the frequency band. Assuming the frequency is 20 MHz, the reference signal is sent to the signal generator 220. The signal generator 220 generates a reference electromagnetic wave signal and an adjustment electromagnetic wave signal in sequence at preset time intervals. Assuming the frequency of the reference electromagnetic wave signal is 1 kHz, the frequency of the first adjustment electromagnetic wave signal is 1+2=3 kHz, the frequency of the second adjustment electromagnetic wave signal is 3+2=5 kHz, the frequency of the third adjustment electromagnetic wave signal is 5+2=7 kHz, the frequency of the fourth adjustment electromagnetic wave signal is 7+2=9 kHz, and the frequency of the fifth adjustment electromagnetic wave signal is 9+2=11 kHz. At this time, the control device 100 determines that the frequency of the fifth adjustment electromagnetic wave signal has exceeded the target frequency band of 1 kHz to 10 kHz, and sends a stop command to the signal generator 220.

[0126] The control device 100 uses the fifth adjusted electromagnetic wave signal as the target electromagnetic wave signal, and sets the frequency 11kHz as the target frequency. By comparison, it can be seen that the target frequency range corresponding to the target frequency is 10kHz to 100kHz. The control device 100 assumes that the preset frequency adjustment value of the frequency range is 10kHz, and the control device 100 sends the target frequency range 10kHz to 100kHz to the oscillator 210, and sends the frequency adjustment value 10kHz to the signal generator 220. The oscillator 210 generates a reference signal corresponding to the frequency band. Assuming the frequency is 25 MHz, the reference signal is sent to the signal generator 220. The signal generator 220 generates a reference electromagnetic wave signal and an adjustment electromagnetic wave signal in sequence at preset time intervals. Assuming the frequency of the reference electromagnetic wave signal is 10 kHz, the frequency of the first adjustment electromagnetic wave signal is 10+10=20 kHz, the frequency of the second adjustment electromagnetic wave signal is 20+10=30 kHz... and the frequency of the ninth adjustment electromagnetic wave signal is 90+10=100 kHz. At this time, the control device 100 determines that the frequency of the ninth adjustment electromagnetic wave signal has exceeded the target frequency band of 10 kHz to 100 kHz, and sends a stop command to the signal generator 220.

[0127] The control device 100 uses the ninth adjusted electromagnetic wave signal as the target electromagnetic wave signal, and sets the frequency 110kHz as the target frequency. By comparison, it can be seen that the target frequency corresponding to the target frequency is 100kHz to 300kHz. The control device 100 assumes that the preset frequency adjustment value of the frequency segment is 100kHz, and the control device 100 sends the target frequency segment 100kHz to 300kHz to the oscillator 210, and sends the frequency adjustment value 100kHz to the signal generator 220. The oscillator 210 generates a reference signal corresponding to the frequency band. Assuming the frequency is 30 MHz, the reference signal is sent to the signal generator 220. The signal generator 220 generates a reference electromagnetic wave signal and an adjustment electromagnetic wave signal in sequence at preset time intervals. Assuming the frequency of the reference electromagnetic wave signal is 100 kHz, the frequency of the first adjustment electromagnetic wave signal is 100+100=200 kHz, the frequency of the second adjustment electromagnetic wave signal is 200+100=300 kHz, and the frequency of the third adjustment electromagnetic wave signal is 300+100=400 kHz. At this time, the control device 100 determines that the frequency of the third adjustment electromagnetic wave signal has exceeded the target frequency band of 100 kHz to 300 kHz, that is, it has exceeded the preset maximum frequency band, and then sends a stop command to the signal generator 220.

[0128] In this way, the above method is used to control the signal generator 220 to send multiple electromagnetic wave signals with a wide frequency range, which can more comprehensively cover all frequencies applicable to cranial bioelectrical impedance detection and can more accurately distinguish various abnormal pathological conditions of cranial and brain tissues.

[0129] In step 204, the control device 100 determines which preset frequency band the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal belongs to, determines the target resistance value corresponding to the current conversion control circuit according to the corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit, and sends the target resistance value to the current conversion control circuit 300. The electromagnetic wave signal is generated by the signal generator 220 according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator 210 according to the target frequency band.

[0130] The corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit is determined by the following method:

[0131] A plurality of frequency bands are pre-set in the cranial brain bioelectrical impedance detection system, wherein the plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequency.

[0132] According to the voltage of the electromagnetic wave signal to be used and the preset output current corresponding to each frequency band, the resistance value corresponding to the current conversion control circuit corresponding to each frequency band is determined.

[0133] Specifically, according to the characteristics of the electrodes installed at the brain to be detected, and the different impedance characteristics of the brain to be detected itself at different frequencies of the electromagnetic wave signal, the corresponding output current is preset for each frequency band, and the voltage of the electromagnetic wave signal to be used is divided by the output current corresponding to each frequency band, and the corresponding resistance value of the current conversion control circuit corresponding to each frequency band can be obtained. It should be noted that the current conversion control circuit 300 has an electronic resistor built in, and the resistance value corresponding to the current conversion control circuit refers to the resistance value of the electronic resistor in the current conversion control circuit 300. Figure 3 An overall flow chart for determining a target resistance value corresponding to a current conversion control circuit and outputting a corresponding current is shown by way of example.

[0134] According to the resistance value corresponding to the current conversion control circuit corresponding to each frequency segment, a corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is established.

[0135] In this way, by adopting the above-mentioned current conversion method, according to the frequency of the electromagnetic wave signal, the current conversion control circuit 300 is controlled to perform different current adjustments on the signal, so that the current conversion control circuit 300 can emit currents of different powers at different electromagnetic wave frequencies, which is more in line with the different electrical impedance characteristics of the brain at different electromagnetic wave frequencies, and the detection results are more accurate.

[0136] In step 205, the control device 100 receives the real part data and imaginary part data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit 500. The electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are sent to the brain to be detected by the transmitting electrode 600, and the differential receiving circuit 400 performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode 700. The differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit 300 performs current regulation and differential conversion processing on the electromagnetic wave signals according to the target resistance value.

[0137] Specifically, Figure 4 The circuit diagram of the current conversion control circuit provided by the embodiment of the present application is exemplarily shown. Figure 4As shown, the signal SIG_VOUT is the voltage signal output by the signal generator 220, and the voltage signal SIG_VOUT is converted into the current signal SIGNAL_T+ through the operational amplifier U3A and its surrounding passive components. Among them, the operational amplifier chips U3 and U4 are OPA2192AIDR. The passive components around the operational amplifier U3A include sampling resistor R8, negative feedback sampling resistor R9, negative feedback sampling capacitor C13, positive feedback sampling resistors R12, R16, R14, resistors R13, R17, R18 connected to the electronic variable resistor IC2, and resistor R19 connected to the output signal SIGNAL_T+. +12VA and -12VA are the power supplies for the operational amplifier chips U3 and U4, and AGND is the reference ground for the signal and power supply. C15 is a +12VA decoupling capacitor, and C16 is a -12VA decoupling capacitor.

[0138] The current signal SIGNAL_T+ is transformed into a current signal SIGNAL_T- with the opposite polarity to SIGNAL_T+ through the in-phase follower operational amplifier U3B and its surrounding passive components, and the inverting operational amplifier U4A and its surrounding passive components. Among them, the surrounding passive components of the in-phase follower operational amplifier U3B include a negative feedback sampling resistor R11, and a resistor R15 connected to the inverting operational amplifier U4A. The surrounding passive components of the inverting operational amplifier U4A include a negative feedback sampling capacitor C14 and a negative feedback sampling resistor R10.

[0139] The electronic variable resistor IC2 completes the current control according to the resistance value of the electronic resistor between the control signal W1 and the control signal B1. Among them, the model of the electronic variable resistor chip IC2 is AD5293BRUZ-20-RL7. The control signal W1 and the control signal B1 are connected to the two ends of the electronic resistor, and are connected to the chip pins A and W, and the pin B. The signal RDY is the "select" function signal of the control signal, connected to the chip pin RDY. The signal SDO2 is the "data output" function signal of the control signal, connected to the chip pin SDO. The signal SYNC is the "data synchronization" function signal of the control signal, connected to the chip pin SYNC. The signal SCLK is the "clock" function signal of the control signal, connected to the chip pin SCLK. The signal DIN is the "data input" function signal of the control signal, connected to the chip pin DIN.

[0140] Among them, +12VA and -12VA are used to power the electronic variable resistor IC2, and are connected to the chip pins VDD and VSS respectively. DGND is the digital ground of the electronic variable resistor chip IC2, and is connected to the chip pin GND. The chip pin EXT_CAP is connected through capacitor C20 to meet the needs of external capacitors of the chip. +5V is connected to the chip pin VLOGIC to power the digital part of the chip. +5V is connected to the chip pin RESET to prevent the chip from resetting. Resistor R20 is a pull-up resistor for signal RDY, and resistor R21 is a pull-up resistor for signal SDO2. Capacitor C17 is used for pin decoupling of chip pins VLOGIC and RESET.

[0141] Specifically, the current conversion control circuit 300 is configured to perform the following steps:

[0142] Receive multiple target resistance values ​​in sequence.

[0143] A plurality of electromagnetic wave signals are received in sequence. Specifically, each electromagnetic wave signal corresponds to a target resistance value.

[0144] The electromagnetic wave signal is subjected to current regulation and differential conversion processing according to the target resistance value in turn to generate a plurality of differential electromagnetic wave signals to be transmitted. Specifically, if there are two transmitting electrodes 600, each differential electromagnetic wave signal to be transmitted refers to a pair of signals on the signal lines connected to the two transmitting electrodes 600 by the current conversion control circuit 300, and the two signals have the same amplitude and opposite phase.

[0145] A plurality of differential electromagnetic wave signals to be transmitted are sequentially sent to the transmitting electrode 600 .

[0146] The transmitting electrode 600 is configured to perform the following steps:

[0147] A plurality of differential electromagnetic wave signals to be transmitted are received in sequence.

[0148] A plurality of differential electromagnetic wave signals to be transmitted are sequentially sent to the brain to be detected.

[0149] The receiving electrode 700 is configured to perform the following steps:

[0150] A plurality of differential electromagnetic wave signals to be detected emitted from the brain to be detected are received in sequence. Specifically, each differential electromagnetic wave signal to be detected refers to a pair of differential electromagnetic wave signals to be detected, and the two signals have the same amplitude and opposite phase.

[0151] A plurality of differential electromagnetic wave signals to be detected are sent to the differential receiving circuit 400 in sequence.

[0152] The differential receiving circuit 400 may be a high input impedance differential receiving circuit. Specifically, the differential receiving circuit 400 is configured to perform the following steps:

[0153] A plurality of differential electromagnetic wave signals to be detected are received in sequence.

[0154] The plurality of differential electromagnetic wave signals to be detected are pre-amplified in sequence to generate a plurality of electromagnetic wave signals to be processed.

[0155] The plurality of electromagnetic wave signals to be processed are sent to the processing circuit 500 in sequence.

[0156] By selecting the high input impedance differential receiving circuit, the high input impedance can be used to pre-amplify the weak differential electromagnetic wave signal to be detected, thereby eliminating common mode noise and interference and ensuring the high accuracy of the hardware channel.

[0157] The processing circuit 500 includes a conditioning and filtering circuit, an analog-to-digital conversion circuit, and a fast Fourier transform circuit, which are used to perform conditioning and filtering, analog-to-digital conversion, and fast Fourier transform on the electromagnetic wave signal to be processed. Among them, the conditioning and filtering circuit is used to condition the gain bandwidth of the electromagnetic wave signal to be processed, and the analog-to-digital conversion circuit is used to digitize the electromagnetic wave signal to be processed after the gain bandwidth is conditioned to obtain a digital signal; the fast Fourier transform circuit is used to perform fast Fourier transform on the digital signal to obtain the real part data and imaginary part data of the electrical impedance corresponding to the electromagnetic wave signal to be processed. The analog-to-digital conversion circuit and the fast Fourier transform circuit can be set together with the signal generating circuit 200 in the same circuit board of a biochip, and the model of the biochip can be AD5933YRSZ. Specifically, the processing circuit 500 is configured to perform the following steps:

[0158] A plurality of electromagnetic wave signals to be processed are received in sequence.

[0159] The plurality of electromagnetic wave signals to be processed are sequentially conditioned and filtered, analog-to-digital converted, and fast Fourier transformed to obtain real and imaginary impedance data corresponding to the electromagnetic wave signals to be processed.

[0160] The real part data and imaginary part data of the electrical impedance corresponding to the plurality of electromagnetic wave signals to be processed are sent to the control device 100 in sequence.

[0161] In step 206, the control device 100 determines the bioimpedance of the brain to be detected according to the real part data and imaginary part data of the electrical impedance corresponding to all electromagnetic wave signals to be processed. The bioimpedance can be used to identify stroke.

[0162] Thus, the brain bioelectrical impedance detection system provided in the embodiment of the present application has a simple process for detecting electrical impedance, takes less time, and has higher accuracy. It can promptly identify the type of stroke after the onset of the disease, shorten the time interval from onset to treatment, and has high practicality.

[0163] To describe the above content more clearly, Figure 5The figure is a schematic diagram of the overall detection process corresponding to a cranial bioelectrical impedance detection system for stroke identification provided by an embodiment of the present application. Specifically, it includes the following steps:

[0164] Step 501: The control device 100 obtains an initial frequency preset in the cranial bioelectrical impedance detection system.

[0165] In step 502, the control device 100 determines a target frequency according to an initial frequency.

[0166] Step 503: The control device 100 determines a target frequency segment corresponding to the target frequency.

[0167] In step 504, the control device 100 sends the target frequency segment to the oscillator 210, and sends the preset frequency adjustment value to the signal generator 220. The oscillator 210 receives the target frequency segment, and the signal generator 220 receives the frequency adjustment value.

[0168] In step 505, the oscillator 210 generates a reference signal according to the target frequency segment, and sends the reference signal to the signal generator 220. The signal generator 220 receives the reference signal.

[0169] In step 506 , the signal generator 220 generates a plurality of electromagnetic wave signals in sequence according to the reference signal and the frequency adjustment value.

[0170] In step 507, the signal generator 220 sends the plurality of electromagnetic wave signals to the control device 100 and the current conversion control circuit 300 in sequence. The control device 100 and the current conversion control circuit 300 receive the plurality of electromagnetic wave signals in sequence respectively.

[0171] In step 508 , the control device 100 determines whether the frequency of the electromagnetic wave signal exceeds the target frequency range. If so, step 509 is executed; if not, step 510 is executed.

[0172] Step 509: The control device 100 sends a stop instruction to the signal generator 220, and sets the frequency of the target electromagnetic wave signal that exceeds the target frequency range as the target frequency. The signal generator 220 receives the stop instruction and stops generating the electromagnetic wave signal.

[0173] In step 510, the control device 100 determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency range corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency range and the resistance value corresponding to the current conversion control circuit, and sends the target resistance value to the current conversion control circuit 300. The current conversion control circuit 300 receives the target resistance value.

[0174] In step 511 , the control device 100 determines whether the target frequency exceeds the maximum frequency band preset in the cranial bioelectrical impedance detection system. If so, step 512 is executed; if not, the control device 100 returns to step 503 .

[0175] Step 512: Send a termination instruction to the signal generator 220. The signal generator 220 receives the termination instruction and terminates the operation.

[0176] In step 513 , the current conversion control circuit 300 performs current regulation and differential conversion processing on the electromagnetic wave signal according to the target resistance value in turn, and generates a plurality of differential electromagnetic wave signals to be transmitted.

[0177] In step 514, the current conversion control circuit 300 sequentially transmits the plurality of differential electromagnetic wave signals to be transmitted to the transmitting electrode 600. The transmitting electrode 600 sequentially receives the plurality of differential electromagnetic wave signals to be transmitted.

[0178] Step 515: The transmitting electrode 600 sequentially transmits a plurality of differential electromagnetic wave signals to be transmitted to the brain to be detected.

[0179] Step 516: The receiving electrode 700 sequentially receives a plurality of differential electromagnetic wave signals to be detected emitted from the brain to be detected.

[0180] In step 517, the receiving electrode 700 sequentially sends the plurality of differential electromagnetic wave signals to be detected to the differential receiving circuit 400. The differential receiving circuit 400 sequentially receives the plurality of differential electromagnetic wave signals to be detected.

[0181] In step 518 , the differential receiving circuit 400 sequentially performs pre-amplification on the plurality of differential electromagnetic wave signals to be detected to generate a plurality of electromagnetic wave signals to be processed.

[0182] In step 519, the differential receiving circuit 400 sequentially sends the plurality of electromagnetic wave signals to be processed to the processing circuit 500. The processing circuit 500 sequentially receives the plurality of electromagnetic wave signals to be processed.

[0183] In step 520, the processing circuit 500 sequentially performs conditioning filtering, analog-to-digital conversion, and fast Fourier transform on the plurality of electromagnetic wave signals to be processed, and obtains real part data and imaginary part data of electrical impedance corresponding to the electromagnetic wave signals to be processed.

[0184] In step 521, the processing circuit 500 sequentially sends the real part data and imaginary part data of the electrical impedance corresponding to the plurality of electromagnetic wave signals to be processed to the control device 100. The control device 100 sequentially receives the real part data and imaginary part data of the electrical impedance corresponding to the plurality of electromagnetic wave signals to be processed.

[0185] In step 522, the control device 100 determines the bioelectrical impedance of the brain to be detected according to the real part data and the imaginary part data of the electrical impedance corresponding to all the electromagnetic wave signals to be processed.

[0186] In this way, the brain bioimpedance detection system for stroke identification provided by the embodiment of the present application uses electromagnetic wave signals that can more comprehensively cover all frequencies applicable to brain bioimpedance detection; during detection, the control device sends different current adjustment instructions to the current conversion control circuit according to the different ranges of the frequency of the electromagnetic wave signal, so that the current conversion control circuit can emit currents of different powers at different electromagnetic wave frequencies, which is more in line with the different impedance characteristics of the brain at different electromagnetic wave frequencies. The entire system directly installs electrodes on both sides of the brain during detection, which is more convenient to use; the entire impedance detection process takes a short time, and can promptly identify the type of stroke after the patient becomes ill, shortening the time interval from onset to treatment.

[0187] The following is an embodiment of the method of the present application, which can be applied to the embodiment of the cranial bioelectrical impedance detection system for stroke identification of the present application. For details not disclosed in the embodiment of the method of the present application, please refer to the embodiment of the cranial bioelectrical impedance detection system for stroke identification of the present application.

[0188] An embodiment of the present application provides a cranial bioelectrical impedance detection method for stroke identification, which is applied to a cranial bioelectrical impedance detection system for stroke identification. A cranial bioelectrical impedance detection system for stroke identification includes a control device, a signal generating circuit, a current conversion control circuit, a differential receiving circuit, a processing circuit, multiple transmitting electrodes and multiple receiving electrodes; during detection, the transmitting electrodes and the receiving electrodes are installed on both sides of the cranial brain to be detected.

[0189] The signal generating circuit comprises an oscillator and a signal generator, and the signal generator is electrically connected to the oscillator.

[0190] The current conversion control circuit is electrically connected to the signal generator, and the current conversion control circuit is electrically connected to each sending electrode respectively.

[0191] The differential receiving circuit is electrically connected to each receiving electrode respectively.

[0192] The processing circuit is electrically connected to the differential receiving circuit.

[0193] The control device is electrically connected to the oscillator, the signal generator, the current conversion control circuit and the processing circuit respectively.

[0194] The method specifically comprises the following steps:

[0195] The control device obtains the initial frequency preset in the cranial and brain bioelectrical impedance detection system.

[0196] The control device determines the target frequency according to the initial frequency, and determines the target frequency segment corresponding to the target frequency.

[0197] The control device sends the target frequency band to the oscillator, and sends the preset frequency adjustment value to the signal generator.

[0198] The control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency band and the resistance value corresponding to the current conversion control circuit, and sends the target resistance value to the current conversion control circuit. The electromagnetic wave signal is generated by the signal generator according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator according to the target frequency band.

[0199] The control device receives the real and imaginary data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit. The electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are sent by the transmitting electrode to the brain to be detected, and the differential receiving circuit performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode; the differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit performs current regulation and differential conversion on the electromagnetic wave signals according to the target resistance value.

[0200] The control device determines the bioimpedance of the brain to be detected according to the real part data and imaginary part data of the electrical impedance corresponding to all electromagnetic wave signals to be processed. The bioimpedance is used to identify cerebral stroke.

[0201] In an implementable manner, before the control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency band and the resistance value corresponding to the current conversion control circuit, the method further includes:

[0202] The control device determines whether there is a target electromagnetic wave signal whose frequency exceeds the target frequency band. If so, a stop instruction is sent to the signal generator, where the stop instruction is used to instruct the signal generator to stop generating the electromagnetic wave signal; and the frequency of the target electromagnetic wave signal is set to the target frequency, and returns to the step of determining the target frequency band corresponding to the target frequency.

[0203] If the frequency of the target electromagnetic wave signal exceeds the maximum frequency band preset in the cranial bioelectrical impedance detection system, the control device sends a termination instruction to the signal generator, and the termination instruction is used to instruct the signal generator to terminate operation.

[0204] In one possible implementation, the method further includes:

[0205] The oscillator receives the target frequency band.

[0206] The oscillator generates a reference signal according to a target frequency band.

[0207] The oscillator sends the reference signal to the signal generator.

[0208] In one possible implementation, the corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is determined by the following method:

[0209] The control device pre-sets a plurality of frequency bands in the cranial bioelectrical impedance detection system. The plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequencies.

[0210] The control device determines the resistance value corresponding to the current conversion control circuit corresponding to each frequency band according to the voltage of the electromagnetic wave signal to be used and the output current corresponding to each preset frequency band.

[0211] The control device establishes a corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit according to the resistance value corresponding to the current conversion control circuit corresponding to each frequency band.

[0212] In one possible implementation, the method further includes:

[0213] The signal generator receives a frequency adjustment value.

[0214] The signal generator receives a reference signal.

[0215] The signal generator generates a plurality of electromagnetic wave signals in sequence according to the reference signal and the frequency adjustment value.

[0216] The signal generator sends a plurality of electromagnetic wave signals to the control device and the current conversion control circuit in sequence.

[0217] After receiving the stop instruction, the signal generator stops generating the electromagnetic wave signal.

[0218] The signal generator stops running after receiving the termination instruction.

[0219] In one possible implementation, the signal generator sequentially generates a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value, including:

[0220] The signal generator generates a basic electromagnetic wave signal according to the reference signal.

[0221] The signal generator generates a plurality of adjustment electromagnetic wave signals in sequence according to the basic electromagnetic wave signal and the frequency adjustment value.

[0222] The signal generator uses the basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals together as multiple electromagnetic wave signals.

[0223] In this way, the cranial bioelectrical impedance detection method for stroke identification provided by the embodiment of the present application is applied to the detection system, and the electromagnetic wave signal used can more comprehensively cover all frequencies applicable to cranial bioelectrical impedance detection; during detection, the control device sends different current adjustment instructions to the current conversion control circuit according to the different ranges of the frequency of the electromagnetic wave signal, so that the current conversion control circuit can emit currents of different powers at different electromagnetic wave frequencies, which is more in line with the different electrical impedance characteristics of the cranial brain at different electromagnetic wave frequencies. The entire system directly installs electrodes on both sides of the cranial brain during detection, which is more convenient to use; the entire electrical impedance detection process is time-consuming, and can promptly identify the type of stroke after the patient becomes ill, shortening the time interval from onset to treatment.

[0224] In an exemplary embodiment, a computer-readable storage medium is also provided, in which a computer program or a smart contract is stored, and the computer program or the smart contract is loaded and executed by the node to implement the transaction processing method provided in the above embodiment. Optionally, the above computer-readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0225] Those skilled in the art can clearly understand that the technology in the embodiments of the present application can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a disk, an optical disk, etc., including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application or some parts of the embodiments.

[0226] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0227] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A cranial bioelectrical impedance detection system for stroke identification, characterized in that: The system includes a control device, a signal generating circuit, a current conversion control circuit, a differential receiving circuit, a processing circuit, a plurality of transmitting electrodes and a plurality of receiving electrodes; during detection, the transmitting electrodes and the receiving electrodes are both installed on both sides of the brain to be detected; The signal generating circuit comprises an oscillator and a signal generator, wherein the signal generator is electrically connected to the oscillator; The current conversion control circuit is electrically connected to the signal generator, and the current conversion control circuit is electrically connected to each transmitting electrode respectively; The differential receiving circuit is electrically connected to each receiving electrode respectively; The processing circuit is electrically connected to the differential receiving circuit; The control device is electrically connected to the oscillator, the signal generator, the current conversion control circuit and the processing circuit respectively; Wherein, the control device is configured to perform the following steps: Obtaining the initial frequency preset in the cranial bioelectrical impedance detection system; Determine a target frequency according to the initial frequency, and determine a target frequency segment corresponding to the target frequency; sending the target frequency segment to the oscillator, and sending a preset frequency adjustment value to the signal generator; According to the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal, and the correspondence between the predetermined frequency band and the resistance value corresponding to the current conversion control circuit, determine the target resistance value corresponding to the current conversion control circuit, and send the target resistance value to the current conversion control circuit; the electromagnetic wave signal is generated by the signal generator according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator according to the target frequency band; Receive the real part data and imaginary part data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit; the electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are sent by the transmitting electrode to the brain to be detected, and the differential receiving circuit performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode; the differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit performs current regulation and differential conversion processing on the electromagnetic wave signals according to the target resistance value; The bioelectrical impedance of the brain to be detected is determined according to the real and imaginary data of the electrical impedance corresponding to all electromagnetic wave signals to be processed; the bioelectrical impedance is used to identify cerebral stroke.

2. The system according to claim 1, characterized in that Before determining the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency band corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency band and the resistance value corresponding to the current conversion control circuit, the control device is further configured to perform the following steps: Determine whether there is a target electromagnetic wave signal whose frequency exceeds the target frequency range, and if so, send a stop instruction to the signal generator, wherein the stop instruction is used to instruct the signal generator to stop generating the electromagnetic wave signal; and setting the frequency of the target electromagnetic wave signal as the target frequency, and returning to the step of determining a target frequency segment corresponding to the target frequency; If the frequency of the target electromagnetic wave signal exceeds the maximum frequency range preset in the cranial bioelectrical impedance detection system, a termination instruction is sent to the signal generator, and the termination instruction is used to instruct the signal generator to terminate operation.

3. The system according to claim 2, characterized in that The oscillator is configured to perform the following steps: Receiving the target frequency segment; generating the reference signal according to the target frequency segment; The reference signal is sent to the signal generator.

4. The system according to claim 3, characterized in that The signal generator is configured to perform the following steps: receiving the frequency adjustment value; receiving the reference signal; Generate a plurality of electromagnetic wave signals in sequence according to the reference signal and the frequency adjustment value; Sending the plurality of electromagnetic wave signals to the control device and the current conversion control circuit in sequence; After receiving the stop instruction, stop generating the electromagnetic wave signal; After receiving the termination instruction, the operation is terminated.

5. The system according to claim 4, characterized in that The step of sequentially generating a plurality of electromagnetic wave signals according to the reference signal and the frequency adjustment value comprises: Generate a basic electromagnetic wave signal according to the reference signal; Generate a plurality of adjustment electromagnetic wave signals in sequence according to the basic electromagnetic wave signal and the frequency adjustment value; The basic electromagnetic wave signal and the multiple adjusted electromagnetic wave signals are collectively used as the multiple electromagnetic wave signals.

6. The system according to claim 1, characterized in that The corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit is determined by the following method: A plurality of frequency bands are pre-set in the cranial and cerebral bioelectrical impedance detection system; the plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequency; Determine the resistance value of the current conversion control circuit corresponding to each frequency band according to the voltage of the electromagnetic wave signal to be used and the output current corresponding to each preset frequency band; According to the resistance value corresponding to the current conversion control circuit corresponding to each frequency segment, a corresponding relationship between the frequency segment and the resistance value corresponding to the current conversion control circuit is established.

7. A method for detecting brain bioelectrical impedance for stroke identification, characterized in that: The method is applied to the system according to any one of claims 1 to 6, and the method comprises: The control device obtains the initial frequency preset in the cranial and cerebral bioelectrical impedance detection system; The control device determines a target frequency according to the initial frequency, and determines a target frequency segment corresponding to the target frequency; The control device sends the target frequency segment to the oscillator, and sends a preset frequency adjustment value to the signal generator; The control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency range corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency range and the resistance value corresponding to the current conversion control circuit, and sends the target resistance value to the current conversion control circuit; the electromagnetic wave signal is generated by the signal generator according to the reference signal and the frequency adjustment value; the reference signal is generated by the oscillator according to the target frequency range; The control device receives the real part data and imaginary part data of the electrical impedance corresponding to the multiple electromagnetic wave signals to be processed sent by the processing circuit; the electromagnetic wave signals to be processed are obtained after the differential electromagnetic wave signals to be transmitted are transmitted by the transmitting electrode to the brain to be detected, and the differential receiving circuit performs pre-amplification on the differential electromagnetic wave signals to be detected received by the receiving electrode; the differential electromagnetic wave signals to be transmitted are obtained after the current conversion control circuit performs current regulation and differential conversion processing on the electromagnetic wave signals according to the target resistance value; The control device determines the bioelectrical impedance of the brain to be detected according to the real part data and imaginary part data of the electrical impedance corresponding to all electromagnetic wave signals to be processed; the bioelectrical impedance is used to identify cerebral stroke.

8. The method according to claim 7, characterized in that Before the control device determines the target resistance value corresponding to the current conversion control circuit according to the electromagnetic wave frequency range corresponding to the frequency of the electromagnetic wave signal and the correspondence between the predetermined frequency range and the resistance value corresponding to the current conversion control circuit, the method further includes: The control device determines whether there is a target electromagnetic wave signal whose frequency exceeds the target frequency range, and if so, sends a stop instruction to the signal generator, wherein the stop instruction is used to instruct the signal generator to stop generating the electromagnetic wave signal; and sets the frequency of the target electromagnetic wave signal to the target frequency, and returns to the step of determining the target frequency range corresponding to the target frequency; If the frequency of the target electromagnetic wave signal exceeds the maximum frequency range preset in the cranial bioelectrical impedance detection system, the control device sends a termination instruction to the signal generator, and the termination instruction is used to instruct the signal generator to terminate operation.

9. The method according to claim 8, characterized in that The method further comprises: The oscillator receives the target frequency segment; The oscillator generates the reference signal according to the target frequency band; The oscillator sends the reference signal to the signal generator.

10. The method according to claim 7, characterized in that The corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit is determined by the following method: The control device pre-sets a plurality of frequency bands in the cranial bioelectrical impedance detection system; the plurality of frequency bands are obtained by dividing the frequency range of the electromagnetic wave signal to be used from small to large frequency; The control device determines the resistance value corresponding to the current conversion control circuit corresponding to each frequency band according to the voltage of the electromagnetic wave signal to be used and the output current corresponding to each preset frequency band; The control device establishes a corresponding relationship between the frequency band and the resistance value corresponding to the current conversion control circuit according to the resistance value corresponding to the current conversion control circuit corresponding to each frequency band.

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