Method and device for recommending electrode stimulation frequency

Abstract

The invention relates to a method and a device for recommending electrode stimulation frequency. The electrodes are at least one selected from a plurality of electrodes implanted into a human body for electrical stimulation, the method comprising: obtaining impedance of each of the electrodes at different frequencies; calculating the standard deviation and the average value of the impedance of the electrode under each frequency; the health degree of each electrode at different frequencies is evaluated according to the proportional relation between the value of the impedance deviation average value and the standard deviation; the number of the electrodes with the optimal health degree under each frequency is calculated; and determining the frequency corresponding to the maximum number as the recommended frequency. The electrical conductivity of the electrode is represented by the electrode impedance, and the stimulation frequency of the electrode can be recommended to medical personnel by analyzing the measured electrode impedance under different frequencies, so that the problem that the current stimulation frequency of the electrode is inappropriate due to the change of the electrical conductivity of the electrode is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of implantable nerve stimulation, and particularly to a method and device for recommending the stimulation frequency of electrodes. Background Art

[0002] Implantable nerve stimulation is a method of stimulating target nerves with a certain degree of electrical pulses to adjust or restore the functions of the brain, nerves or muscles, so as to relieve symptoms. At present, the implantable nerve stimulation system mainly includes a stimulator disposed in the body and a controller disposed outside the body. Among them, the stimulator and the controller can perform radio frequency communication and energy transmission, and the controller provides radio frequency electrical energy to the stimulator. On this basis, the controller provides a stimulation pulse command in real time to drive the electrodes of the stimulator, so that the electrodes apply current to the treatment site of the patient. The frequency of the current (i.e., the stimulation frequency of the electrodes) can be set by medical personnel.

[0003] However, the electrodes will undergo electrolytic reactions under the action of current and tissue fluid, or due to the presence of tissue fluid and ions in the tissues where the electrodes are located, in addition to electrolytic reactions, galvanic cell reactions may also occur. Due to the long-term action of the internal environment and electrochemical reactions (mainly electrolytic reactions), the conductivity of the electrodes will change. As the conductivity of the electrodes changes, the stimulation frequency of the electrodes needs to be dynamically adjusted.

[0004] The above statement of the background art is only for the convenience of in-depth understanding of the technical solution of the present invention (such as the technical means used, the technical problems solved, and the technical effects produced), and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for recommending the stimulation frequency of electrodes, which can recommend the stimulation frequency of the electrodes to medical personnel to solve the problem that the current stimulation frequency of the electrodes is inappropriate due to the change of the conductivity of the electrodes.

[0006] According to an embodiment of the present invention, there is provided a method for recommending the stimulation frequency of electrodes, where the electrodes are at least one selected from multiple electrodes implanted into the human body for electrical stimulation. The method includes: 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 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 the optimal health 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 includes: when there are two or more recommended frequencies, 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 minimum variance as the final recommended frequency.

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

[0009] The step of obtaining the impedance of each electrode at different frequencies includes: causing a current with a specific frequency to be transmitted between the target electrode and all other electrodes outside the target electrode, where 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 electrode 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 electrode at different frequencies.

[0010] The step of changing the frequency of the current includes: presetting a frequency range; equally dividing the frequency range into corresponding numerical equal parts according to the size of the preset frequency range to obtain frequencies with different values within the frequency range; changing the frequency of the current according to the obtained frequencies with different values.

[0011] The step of equally dividing the frequency range into corresponding numerical equal parts according to the size of the preset frequency range includes: when the frequency range is less than or equal to 100 Hz, equally 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, equally dividing the frequency range into 20 equal parts; 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 invention, there is provided a device for recommending an electrode stimulation frequency, which includes: at least one data processor; and at least one memory that stores instructions, and when the instructions are executed by the at least one data processor, the method for recommending the electrode stimulation frequency described above is executed.

[0013] The present invention adopts the above technical solutions and has the following beneficial effects: The present invention uses electrode impedance to characterize the conductivity of the electrode. By analyzing the measured electrode impedance at different frequencies, it is possible to recommend the stimulation frequency of the electrode to medical personnel to solve the problem that the current stimulation frequency of the electrode is inappropriate due to the change in the conductive performance of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0017] Figure 3 is a schematic diagram for evaluating the health of the electrode according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

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

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

[0021] In the following, steps S21 to S25 will be described in detail.

[0022] Since the impedance of the electrode can characterize its conductivity, in step S21, the impedance of each electrode at different frequencies is obtained. Specifically, the step of obtaining the impedance of each electrode at different frequencies (S21) may include: causing a current with a specific frequency to be transmitted between the target electrode and all other electrodes except the target electrode, where the target electrode is any one of the electrodes; measuring the voltage at the target electrode caused by the current with a 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 electrode at the specific frequency by taking each electrode as the target electrode one by one; and changing the frequency of the current to calculate the impedance of each electrode at different frequencies.

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

[0024] Back to Figure 1, when the electrode E1 is used as the target electrode, a current of a specific frequency is applied to the electrode E1, and the current is output from the electrode E1. The "+" sign indicates the current output, and the current output from the electrode E1 is input to all other electrodes outside the electrode E1, that is, the current is input to each of the electrodes E2, E3, E4, E5, E6, E7, and E8. The "-" sign indicates the current input. When the current direction changes, the current is output from each of the electrodes E2, E3, E4, E5, E6, E7, and E8 and input to the electrode E1 used as the target electrode. And so on for the cases when other electrodes are used as the target electrode. Subsequently, a known digital signal processing method is used to extract the voltage at the target electrode caused by the current of the specific frequency. In some examples of the present invention, the measured voltage can be processed by the following techniques, which include but are not limited to a combination of digital filtering, discrete Fourier transform, fast Fourier transform, and / or Goertzel algorithm. When the voltage at the target electrode is obtained, the impedance of the target electrode can be derived based on the voltage at the target electrode, for example, by using known gain / offset calibration coefficients for calculating impedance, etc.

[0025] Thus, each of the electrodes can be used as the target electrode one by one to calculate the impedance of each of the electrodes at a specific frequency. 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 may include: presetting a frequency range. For example, medical personnel can set a certain frequency range. For example, in order to electrically stimulate the nerve 10 to be stimulated to relieve pain, the preset frequency range can be 50 Hz to 1000 Hz.

[0027] The frequency range is evenly divided into corresponding equal parts according to the size of the preset frequency range to obtain frequencies with different values within the frequency range.

[0028] In an exemplary embodiment, when the frequency range is less than or equal to 100 Hz, the frequency range is evenly 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 evenly divided into 20 equal parts; when the frequency range is greater than 1000 Hz, the frequency range is divided into 50 equal parts. For example, when the preset frequency range is from 50 Hz to 1000 Hz, the frequency range is 950 Hz. Since 100 Hz < 950 Hz ≤ 1000 Hz, the frequency range is evenly divided into 20 equal parts. Thus, 21 frequencies with different values can be obtained, and these frequencies 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, 1000 Hz respectively.

[0029] Subsequently, according to the obtained frequencies with different values, the frequency of the current is changed. In the above example, the frequency of the current is changed sequentially 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 electrode is taken as the target electrode one by one, and thus the impedance of each electrode at different frequencies can be calculated.

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

[0032] Table 1

[0033]

[0034]

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

[0036] As shown in Table 1, the standard deviation σ 1 and the average value μ z of A1, A2, A3, A4 at the frequency f z are calculated, and the standard deviation σ 2The standard deviation σ of B1, B2, B3, B4 and the mean value μ under z And the mean value μ z , and so on, calculate the frequency f 11 The standard deviation σ of K1, K2, K3, K4 and the mean value μ under z And the mean value μ z .

[0037] In step S23, according to the proportional relationship between the value of the impedance deviating from the mean value and the standard deviation, the health of each electrode at different frequencies is evaluated.

[0038] Figure 3 Is a schematic diagram for evaluating the health of an electrode according to an exemplary embodiment of the present invention. As Figure 3 Shown, there is a point representing the mean value μ on the number axis z , the deviation relative to the mean value μ z Can refer to the deviation in the positive direction of the number axis or the deviation in the negative direction of the number axis. In the exemplary embodiment of the present invention, the ratio of the value of the deviation from the mean value to the standard deviation can be 1 or 2. Thus, on the number axis, a point representing one standard deviation of the deviation from the mean value (that is, the difference between the mean value and the standard deviation μ z -σ z , the sum of the mean value and the standard deviation μ z +σ z ) can be determined, and a point representing two standard deviations of the deviation from the mean value (that is, the difference between the mean value and twice the standard deviation μ z -2σ z , the sum of the mean value and twice the standard deviation μ z +2σ z ) can be determined.

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

[0040] For example, when B1 < μ z -2σ z Or B1 > μ z +2σ z , the health of the electrode E1 (corresponding to the impedance B1) can be evaluated as poor.

[0041] When the ratio of the value of the impedance deviating from the mean 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 evaluated as average.

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

[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 z -σ z ≤B3≤μ z +σ z When this occurs, the health of electrode E3 (which corresponds to impedance B3) can be evaluated as good.

[0045] Since good is the optimal result among poor, average, and good, the electrode with a health evaluation of good is taken as the electrode with the optimal health.

[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 with the optimal health at each frequency is calculated, and the frequency corresponding to the maximum value of this number (i.e., the number of electrodes with the optimal health as described above) is determined as the recommended frequency.

[0050] In an exemplary embodiment, the electrode with a health evaluation of good is taken as the electrode with the optimal health. From Table 2, it can be seen that at frequencies f 9 、f 10 、f 11 there are four electrodes with a health evaluation of good, and at frequencies other than f 9 、f 10 、f 11 there are only two or three electrodes with a health evaluation of good. That is to say, the frequencies corresponding to the maximum number of electrodes evaluated as good are frequencies f 9 、f 10 、f 11 . Therefore, frequencies f 9 、f 10 、f 11 can be determined as the recommended frequencies.

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

[0052] However, when the recommended frequencies are two or more, for example, in the above example, frequencies f 9 、f 10 、f 11 are all determined as recommended frequencies, the variance of the impedance of the electrodes at each recommended frequency can be calculated, and comparisons are made among the calculated variances, and the recommended frequency corresponding to the smallest variance is determined as the final recommended frequency.

[0053] That is to say, when frequencies f 9 、f 10 、f 11 are all determined as recommended frequencies, referring to Table 1, the variances σ 2 I of I1, I2, I3, I4, the variances σ 2 J of J1, J2, J3, J4, and the variances σ 2 K of K1, K2, K3, K4 can be calculated. Comparisons of the magnitudes of σ 2 I , σ 2 J , and σ 2 K are made. For example, when σ 2 I <σ 2 J <σ 2 K , since the variance σ 9 2 I of the impedance of the electrodes at the recommended frequency f 9 is the smallest, the frequency f 9 can be determined as the final recommended frequency.

[0054] According to another embodiment of the present invention, there is also provided a device for recommending the electrode stimulation frequency, which device includes at least one data processor and at least one memory. The at least one memory stores instructions that, when executed by the at least one data processor, cause the method for recommending the electrode stimulation frequency of the above steps S21 to S24 to be executed.

[0055] The method and device for recommending the electrode stimulation frequency according to the embodiments of the present invention use the electrode impedance to characterize the conductivity of the electrode. By analyzing the measured electrode impedance at different frequencies, the medical staff 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 conductive performance of the electrode.

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

[0057] The description presented in the above exemplary embodiments is only for illustrating the technical solutions of the present invention, and is not intended to be exhaustive or to limit the present invention to the precise forms described. Obviously, many changes and variations are possible for those of ordinary skill in the art according to the above teachings. The selection of the exemplary embodiments and the description are for explaining the specific principles of the present invention and its practical applications, so that other technical personnel in the art can understand, implement and utilize the various exemplary embodiments of the present invention and their various alternative forms and modifications. The scope of protection of the present invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A method for recommending a stimulation frequency of an electrode, wherein the electrode is at least one selected from a plurality of electrodes implanted in a human body for electrical stimulation, the method comprising: Obtaining the impedance of each of the electrodes at different frequencies; Calculate the standard deviation and mean of the impedance of the electrodes at each frequency; The health of each electrode at different frequencies is evaluated based on the ratio of the impedance deviation from the mean value to the standard deviation; Calculate the number of electrodes with optimal health at each frequency; The frequency corresponding to when the number is the maximum is determined as the recommended frequency.

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

3. The method for recommending electrode stimulation frequency according to claim 2, wherein: The steps for evaluating the health of each electrode at different frequencies based on the ratio of the impedance deviation from the mean to the standard deviation include: When the ratio of the impedance deviation from the mean to the standard deviation was greater than 2, the health of the electrode at the corresponding frequency was evaluated as poor; When the ratio of the value of the impedance deviation from the mean 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 evaluated as fair; When the ratio of the value of the impedance deviation 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, and the electrode whose health is evaluated as good is regarded as the electrode with the best health.

4. The method for recommending electrode stimulation frequency according to claim 3, wherein: The steps of obtaining the impedance of each electrode at different frequencies include: transmitting a current having 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 of a specific frequency; calculating the impedance of the target electrode at a specific frequency based on the measured voltage at the target electrode; Each of the electrodes is taken as a target electrode one by one to calculate the impedance of each of the electrodes at a specific frequency; The frequency of the current is varied to calculate the impedance of each of the electrodes at different frequencies.

5. The method for recommending electrode stimulation frequency according to claim 4, wherein: The steps for changing the frequency of the current include: Preset frequency range; Dividing the frequency range into equal parts of corresponding values ​​according to the size of the preset frequency range, so as to obtain frequencies of different values ​​within the frequency range; According to the frequencies of different values ​​obtained, the frequency of the current is changed.

6. The method for recommending electrode stimulation frequency according to claim 5, wherein: The step of dividing the frequency range into equal parts of corresponding values ​​according to the size of the preset frequency range includes: When the frequency range is less than or equal to 100 Hz, divide the frequency range into 10 equal parts; When the frequency range is greater than 100 Hz and less than or equal to 1000 Hz, divide the frequency range into 20 equal parts; When the frequency range is greater than 1000 Hz, divide the frequency range into 50 equal parts.

7. A device for recommending an electrode stimulation frequency, comprising: at least one data processor; as well as At least one memory storing instructions, which, when executed by the at least one data processor, enable the method of recommending electrode stimulation frequency according to any one of claims 1 to 6 to be performed.

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