Method and apparatus for recommending electrode stimulation frequency

Abstract

The present application relates to a method and device for recommending electrode stimulation frequency. The electrode is at least one selected from a plurality of electrodes implanted into a human body for electrical stimulation, and the method comprises: obtaining impedance of each of the electrodes at different frequencies; calculating standard deviation and mean value of the impedance of the electrodes at each frequency; evaluating health of each of the electrodes at different frequencies according to the proportion of the value of the impedance deviating from the mean value to the standard deviation; calculating the number of the electrodes with optimal health at each frequency; and determining the frequency corresponding to the maximum number as the recommended frequency. The present application uses electrode impedance to represent the conductivity of the electrode, and by analyzing the measured electrode impedance at different frequencies, the medical personnel can be recommended the stimulation frequency of the electrode, so as to solve the problem that the current stimulation frequency of the electrode is inappropriate due to the change of the conductivity of the electrode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of implantable nerve stimulation, and in particular to a method and device for recommending electrode stimulation frequency. BACKGROUND

[0002] Implantable nerve stimulation is a method of stimulating target nerves with certain degree of electric pulse to adjust or restore the function of brain, nerves or muscles, so as to relieve symptoms. At present, an implantable nerve stimulation system mainly comprises a stimulator arranged in the body and a controller arranged outside the body, wherein the stimulator and the controller can perform radio frequency communication and energy transmission, and the controller provides radio frequency electric energy to the stimulator, on the basis of which, the controller provides stimulation pulse instructions in real time to drive the electrodes of the stimulator, so that the electrodes apply electric current to the treatment site of the patient. The frequency of the electric current (i.e. the stimulation frequency of the electrode) can be set by medical personnel.

[0003] However, electrolysis reaction may occur to the electrode under the action of electric current and tissue fluid, or due to the existence of tissue fluid and ions in the tissue where the electrode is located, in addition to electrolysis reaction, galvanic cell reaction may also occur. Due to the long-term effect of the in-vivo environment and electrochemical reaction (which is mainly electrolysis reaction), the conductive performance of the electrode will change. With the change of the conductive performance of the electrode, the stimulation frequency of the electrode needs to be dynamically adjusted.

[0004] The above statements of background art are only for the convenience of deep understanding of the technical solutions of the present application (the technical means used, the technical problems solved and the technical effects generated, etc.), and should not be regarded as acknowledging or in any form implying that the message constitutes the prior art known to those skilled in the art. SUMMARY

[0005] The purpose of the present application is to provide a method and device for recommending electrode stimulation frequency, which can recommend the stimulation frequency of the electrode to medical personnel to solve the problem of inappropriate current stimulation frequency of the electrode caused by the change of the conductive performance of the electrode.

[0006] According to an embodiment of the present application, a method for recommending electrode stimulation frequency is provided, the electrode being at least one selected from a plurality of electrodes implanted into the human body for electric stimulation, the method comprising: obtaining the impedance of each of the electrodes at different frequencies; calculating the standard deviation and the average value of the impedance of the electrodes at each frequency; evaluating the health degree of each of the electrodes at different frequencies according to the proportional relationship between the value of the impedance deviating from the average value and the standard deviation; calculating the number of electrodes with optimal health degree at each frequency; and determining the frequency corresponding to the maximum number as the recommended frequency.

[0007] The method for recommending the electrode stimulation frequency further comprises: when the recommended frequencies are two or more, calculating the variance of the impedance of the electrode at each recommended frequency; comparing the calculated variances, and determining the recommended frequency corresponding to the smallest variance as the final recommended frequency.

[0008] The step of evaluating the health of each of the electrodes at different frequencies according to the proportional relationship between the value of the impedance deviating from the average value and the standard deviation comprises: when the proportion is greater than 2, evaluating the health of the electrode at the corresponding frequency as poor; when the proportion is less than or equal to 2 and greater than 1, evaluating the health of the electrode at the corresponding frequency as general; when the proportion is less than or equal to 1, evaluating the health of the electrode at the corresponding frequency as good, and the electrode with the health evaluated as good is the electrode with the optimal health.

[0009] The step of obtaining the impedance of each of the electrodes at different frequencies comprises: transmitting a current with a specific frequency between a target electrode and all other electrodes except the target electrode, wherein the target electrode is any one of the electrodes; measuring the voltage at the target electrode caused by the current with the specific frequency; calculating the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode; calculating the impedance of each of the electrodes at the specific frequency by taking each of the electrodes as the target electrode one by one; changing the frequency of the current to calculate the impedance of each of the electrodes at different frequencies.

[0010] The step of changing the frequency of the current comprises: setting a frequency range in advance; dividing the frequency range into equal parts with corresponding values according to the size of the set frequency range, so as to obtain different values of the frequency in the frequency range; changing the frequency of the current according to the obtained different values of the frequency.

[0011] The step of dividing the frequency range into equal parts with corresponding values according to the size of the set frequency range comprises: when the frequency range is less than or equal to 100 Hz, dividing the frequency range into 10 equal parts; when the frequency range is greater than 100 Hz and less than or equal to 1000 Hz, dividing the frequency range into 20 equal parts; and when the frequency range is greater than 1000 Hz, dividing the frequency range into 50 equal parts.

[0012] According to another embodiment of the present application, there is provided a device for recommending an electrode stimulation frequency, comprising: at least one data processor; and at least one memory storing instructions which, when executed by the at least one data processor, cause the execution of the above-mentioned method for recommending an electrode stimulation frequency.

[0013] The present application has the following beneficial effects: the present application uses electrode impedance to represent the conductivity of the electrode, and by analyzing the measured electrode impedance at different frequencies, the electrode stimulation frequency can be recommended to medical personnel to solve the problem of inappropriate current electrode stimulation frequency caused by the change of electrode conductivity. BRIEF DESCRIPTION OF DRAWINGS

[0014] Exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. For the purpose of clarity, the same components in different drawings are denoted by the same reference numerals. It should be noted that the drawings are merely schematic and not necessarily drawn to scale. In these drawings:

[0015] Figure 1 is a schematic diagram of a plurality of electrodes implanted into a human body for electrical stimulation.

[0016] Figure 2 is a flowchart of a method of recommending an electrode stimulation frequency according to an embodiment of the present application.

[0017] Figure 3 is a schematic diagram of evaluating electrode health according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0018] The embodiments of the present application will be described in detail below, which are implemented on the premise of the technical solutions of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.

[0019] Figure 1 is a schematic diagram of a plurality of electrodes implanted into a human body for electrical stimulation. As shown in Figure 1 , a plurality of electrodes E1, E2, …, E8 are implanted into a human body for electrical stimulation. In Figure 1 the specific embodiment shown, the plurality of electrodes E1, E2, …, E8 can be arranged at a plurality of points of a nerve 10 to be stimulated. Due to the long-term effects of the in-vivo environment and electrochemical reactions (mainly electrolytic reactions), the conductivity of the electrode will change, and the stimulation frequency of the electrode needs to be dynamically adjusted. At this time, at least one electrode that needs to adjust the stimulation frequency can be selected from the plurality of electrodes E1, E2, …, E8.

[0020] Figure 2 is a flowchart of a method of recommending an electrode stimulation frequency according to an embodiment of the present application. As described above, the electrode is at least one selected from a plurality of electrodes implanted into a human body for electrical stimulation. As shown in Figure 2As shown, the method of recommending the electrode stimulation frequency includes the steps of: obtaining the impedance of each of the electrodes at different frequencies (S21); calculating the standard deviation and the mean of the impedance of the electrodes at each frequency (S22); evaluating the health of each of the electrodes at different frequencies according to the proportion of the value of the impedance deviating from the mean to the standard deviation (S23); calculating the number of the electrodes with the optimal health at each frequency (S24); determining the frequency corresponding to the maximum number as the recommended frequency (S25).

[0021] Hereinafter, the steps S21 to S25 are described in detail.

[0022] Since the impedance of the electrode can represent the conductivity thereof, at step S21, the impedance of each of the electrodes at different frequencies is obtained. Specifically, the step of obtaining the impedance of each of the electrodes at different frequencies (S21) can include: transmitting a current with a specific frequency between a target electrode and all other electrodes except the target electrode, wherein the target electrode is any one of the electrodes; measuring the voltage at the target electrode caused by the current with the specific frequency; calculating the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode; calculating the impedance of each of the electrodes at the specific frequency by taking each of the electrodes as the target electrode one by one; and changing the frequency of the current to calculate the impedance of each of the electrodes at different frequencies.

[0023] Herein, the current with a specific frequency refers to an alternating current whose size and direction change periodically with time, and the frequency of the current refers to the number of times the current completes the periodic change within 1 second. For example, the current can be an alternating current that changes with time according to a sine law.

[0024] Returning to Figure 1When the electrode E1 is the target electrode, the current of the specific frequency is applied to the electrode E1, the current is output from the electrode E1, the "+" sign represents the current output, and the current output from the electrode E1 is input to all the electrodes other than the electrode E1, i.e. the current is input to each of the electrodes E2, E3, E4, E5, E6, E7, E8, the "-" sign represents the current input. When the current direction is changed, the current is output from each of the electrodes E2, E3, E4, E5, E6, E7, E8, and input to the electrode E1 as the target electrode. The same can be applied to the case when the other electrodes are the target electrodes. Subsequently, the voltage at the target electrode caused by the current of the specific frequency is extracted by using a known digital signal processing method. In some examples of the present application, the measured voltage can be processed by techniques including but not limited to digital filtering, discrete Fourier transform, fast Fourier transform, and / or a combination of Goertzel algorithm. After the voltage at the target electrode is obtained, the impedance of the target electrode can be derived from the voltage at the target electrode, for example, by using known gain / offset calibration coefficients for calculating impedance, etc.

[0025] In this way, the impedance of each of the electrodes at the specific frequency can be calculated one by one with each of the electrodes as the target electrode. In addition, the frequency of the current can be changed to calculate the impedance of each of the electrodes at different frequencies.

[0026] Specifically, the step of changing the frequency of the current can include pre-setting a frequency range. For example, the medical personnel can set a certain frequency range, for example, in order to stimulate the nerve 10 to be stimulated by electric stimulation to relieve pain, the pre-set frequency range can be 50 Hz to 1000 Hz.

[0027] The frequency range is equally divided into a corresponding number of equal parts according to the size of the pre-set frequency range, so as to obtain different values of the frequency in the frequency range.

[0028] In the example embodiment, when the frequency range is less than or equal to 100 Hz, the frequency range is equally divided into 10 parts, when the frequency range is greater than 100 Hz and less than or equal to 1000 Hz, the frequency range is equally divided into 20 parts, and when the frequency range is greater than 1000 Hz, the frequency range is divided into 50 parts. For example, when the preset frequency range is 50 Hz to 1000 Hz, the frequency range is 950 Hz, and since 100 Hz < 950 Hz < 1000 Hz, the frequency range is equally divided into 20 parts. Thus, 21 frequencies with different values can be obtained, which are 50 Hz, 97.5 Hz, 145 Hz, 192.5 Hz, 240 Hz, 287.5 Hz, 335 Hz, 382.5 Hz, 430 Hz, 477.5 Hz, 525 Hz, 572.5 Hz, 620 Hz, 667.5 Hz, 715 Hz, 762.5 Hz, 810 Hz, 857.5 Hz, 905 Hz, 952.5 Hz, and 1000 Hz, respectively.

[0029] Subsequently, the frequency of the current is changed according to the obtained frequencies with different values. In the above example, the frequency of the current is sequentially changed according to the above 21 frequencies.

[0030] The current with the changed frequency is transmitted between the target electrode and all other electrodes except the target electrode, and each of the electrodes is sequentially targeted, and thus the impedance of each of the electrodes at different frequencies can be calculated.

[0031] The selected four electrodes E1, E2, E3, and E4 and the obtained 11 frequencies f1 to f 11 As an example, Table 1 shows the impedance corresponding to the electrodes, frequencies obtained at step S21.

[0032] Table 1

[0033]

[0034]

[0035] At step S22, the standard deviation and the average of the impedance of the electrodes at each frequency are calculated. That is, the impedance measurement result of each frequency is an array, and the standard deviation σ z and the average μ z of the elements in the array are calculated.

[0036] As shown in Table 1, the standard deviation σ z and the average μ z of A1, A2, A3, and A4 at frequency f1 are calculated, the standard deviation σ z and the average μz And so on, calculate the frequency f. 11 The standard deviations σ of K1, K2, K3, and K4 under the following conditions z and average value μ z .

[0037] In step S23, the health of each electrode at different frequencies is evaluated based on the ratio of the impedance deviation from the average value to the standard deviation.

[0038] Figure 3 This is a schematic diagram illustrating the evaluation of electrode health according to an exemplary embodiment of the present invention. Figure 3 As shown, there exists a value μ on the number line representing the average value. z The point, relative to the average μ z The deviation can refer to the deviation along the positive direction of the number axis or the deviation along the negative direction of the number axis. In an exemplary embodiment of the present invention, the ratio of the deviation from the mean to the standard deviation can be 1 or 2, thereby determining a standard deviation (i.e., the difference μ between the mean and the standard deviation) on the number axis to represent the deviation from the mean. z -σ z The sum of the mean and standard deviation, μ z +σ z The points, and the value μ used to represent the difference between the mean and the standard deviation by two standard deviations (i.e., twice the mean and standard deviation). z -2σ z The sum of the mean and twice the standard deviation, μ z +2σ z ) point.

[0039] Specifically, when the ratio of the impedance deviation from the average value to the standard deviation is greater than 2, the health of the electrode at the corresponding frequency is assessed as poor.

[0040] For example, when B1 < μ z -2σ z Or B1 > μ z +2σ z When this happens, the health of electrode E1 (which corresponds to impedance B1) can be assessed as poor.

[0041] When the ratio of the impedance deviation from the average value to the standard deviation is less than or equal to 2 and greater than 1, the health of the electrode at the corresponding frequency is assessed as average.

[0042] For example, when μ z -2σ z ≤B2<μ z -σ z or μ z +σ z <B2≤μ z +2σz When μ - σ < B2 ≤ μ + σ, the health of the electrode E2 (which corresponds to the impedance B2) can be evaluated as good.

[0043] When the ratio of the value by which the impedance deviates from the average value to the standard deviation is less than or equal to 1, the health of the electrode at the corresponding frequency is evaluated as good.

[0044] For example, when μ - σ < B2 ≤ μ + σ, the health of the electrode E2 (which corresponds to the impedance B2) can be evaluated as good. z - σ < B3 ≤ μ + σ z z + σ < B3 ≤ μ + σ z When μ - σ < B3 ≤ μ + σ, the health of the electrode E3 (which corresponds to the impedance B3) can be evaluated as good.

[0045] Good is the best result among bad, general, and good. Therefore, the electrode whose health is evaluated as good is regarded as an electrode whose health is the best.

[0046] Table 2 shows an example of the evaluation results in step S23.

[0047] Table 2

[0048]

[0049] In steps S24 and S25, the number of electrodes whose health is the best at each frequency is calculated, and the frequency corresponding to the case where the number (i.e., the number of electrodes whose health is the best described above) is the largest is determined as the recommended frequency.

[0050] In the exemplary embodiment, the electrode whose health is evaluated as good is regarded as an electrode whose health is the best, and from Table 2, it can be seen that at frequencies f9, f 10 , f 11 , there are four electrodes whose health is evaluated as good, and at frequencies other than f9, f 10 , f 11 , there are only two or three electrodes whose health is evaluated as good. That is, the frequency corresponding to the case where the number of electrodes evaluated as good is the largest is frequencies f9, f 10 , f 11 . Therefore, frequencies f9, f 10 , f 11 can be determined as the recommended frequency.

[0051] When the recommended frequency is one, the recommended frequency is the final recommended frequency.

[0052] However, when the recommended frequency is two or more, for example, in the example described above, frequencies f9, f 10 , f 11 ​When all of the frequencies f9, f

[0053] That is, when the frequencies f9, f 10 11 are determined as the recommended frequencies, in combination with Table 1, the variances σ 2 I , σ 2 J , and σ 2 K of I1, I2, I3, and I4, J1, J2, J3, and J4, and K1, K2, K3, and K4 can be calculated. 2 I 2 J 2 K are compared in size. For example, when σ 2 I 2 J 2 K , σ 2 I is the smallest, the frequency f9 can be determined as the final recommended frequency.

[0054] According to another embodiment of the present application, there is also provided a device for recommending an electrode stimulation frequency, the device comprising at least one data processor and at least one memory. The at least one memory stores instructions which, when executed by the at least one data processor, cause the performance of the method for recommending an electrode stimulation frequency as described above in steps S21 to S24.

[0055] The method and device for recommending an electrode stimulation frequency according to the embodiments of the present application utilize the electrode impedance to characterize the conductivity of the electrode, and by analyzing the measured electrode impedance at different frequencies, the medical personnel can be recommended the stimulation frequency of the electrode to solve the problem that the current stimulation frequency of the electrode is inappropriate due to the change in the conductivity of the electrode.

[0056] The various embodiments of the present application are not an exhaustive list of all possible combinations, but are intended to describe representative aspects of the present application, and what is described in the various embodiments can be applied independently or in combination of two or more.

[0057] ​​​​​The above description presented in the exemplary embodiments is merely intended to illustrate the technical solutions of the present application, and is not intended to be complete, nor intended to limit the present application to the precise forms described. Obviously, many changes and modifications are possible according to the above teachings for those skilled in the art. The exemplary embodiments are selected and described in order to explain the specific principles of the present application and its practical applications, so that other skilled in the art can easily understand, implement and utilize various exemplary embodiments of the present application and various selected forms and modified forms thereof. The scope of protection of the present application is intended to be defined by the appended claims and their equivalents.

Claims

1. A method for recommending an electrode stimulation frequency, wherein the electrode is at least one selected from a plurality of electrodes implanted in the human body for electrical stimulation, the method comprising: Obtain the impedance of each electrode at different frequencies; Calculate the standard deviation and average value of the electrode impedance at each frequency; The health of each electrode at different frequencies is assessed based on the ratio of the impedance deviation from the average value to the standard deviation. Calculate the optimal number of electrodes for each frequency to determine the health status. The frequency corresponding to the maximum quantity is determined as the recommended frequency; The step of assessing the health of the electrode at different frequencies based on the ratio of the impedance deviation from the average value to the standard deviation includes: When the ratio of the impedance deviation from the average value to the standard deviation is greater than 2, the health of the electrode at the corresponding frequency is assessed as poor. When the ratio of the impedance deviation from the average value to the standard deviation is less than or equal to 2 and greater than 1, the health of the electrode at the corresponding frequency is assessed as average. When the ratio of the impedance deviation from the average value to the standard deviation is less than or equal to 1, the electrode is assessed as having good health at the corresponding frequency, and the electrode with good health is considered the electrode with optimal health.

2. The method for recommending electrode stimulation frequency according to claim 1, further comprising: When there are two or more recommended frequencies, calculate the variance of the electrode impedance at each recommended frequency; The calculated variances are compared, and the recommendation frequency corresponding to the smallest variance is determined as the final recommendation frequency.

3. The method for recommending electrode stimulation frequency according to claim 2, wherein, The steps for obtaining the impedance of each electrode at different frequencies include: A current with a specific frequency is transmitted between a target electrode and all other electrodes except the target electrode, wherein the target electrode is any one of the electrodes; Measure the voltage at the target electrode caused by a current of a specific frequency; The impedance of the target electrode at a specific frequency is calculated based on the measured voltage at the target electrode. Each electrode is treated as a target electrode, and the impedance of each electrode at a specific frequency is calculated. The impedance of each electrode at different frequencies is calculated by changing the frequency of the current.

4. The method for recommending electrode stimulation frequency according to claim 3, wherein, The steps to change the frequency of the current include: Preset frequency range; The frequency range is divided into equal parts according to the size of the preset frequency range, so as to obtain frequencies with different values ​​within the frequency range. The frequency of the current is changed based on the different frequency values ​​obtained.

5. The method for recommending electrode stimulation frequency according to claim 4, wherein, The steps of dividing a frequency range into equal parts based on a pre-set frequency range include: When the frequency range is less than or equal to 100 Hz, the frequency range is divided into 10 equal parts. When the frequency range is greater than 100 Hz and less than or equal to 1000 Hz, the frequency range is divided into 20 equal parts. When the frequency range is greater than 1000 Hz, the frequency range is divided into 50 equal parts.

6. A device for recommending electrode stimulation frequency, comprising: At least one data processor; as well as At least one memory storing instructions, when executed by the at least one data processor, to cause the method of performing the recommended electrode stimulation frequency according to any one of claims 1 to 5.

Images