System and method for measuring electrode impedance and method for evaluating electrode health

Abstract

The invention relates to a system and a method for measuring electrode impedance and a method for evaluating electrode health. The system includes a plurality of electrodes, a current generator, and a controller. The plurality of electrodes are implanted into a human body for electrical stimulation. The current generator is electrically connected to each electrode and generates a current of a specific frequency that is transmitted between the plurality of electrodes. The controller is electrically connected with the current generator, so that the current with the specific frequency generated by the current generator is transmitted between the target electrode and all other electrodes except the target electrode, and the target electrode is any one of the multiple electrodes; measuring a voltage at the target electrode caused by the current of the particular frequency; calculating an impedance of the target electrode at a specific frequency from the measured voltage at the target electrode; the impedance of each electrode at a specific frequency is calculated using each electrode as a target electrode one by one. The measured electrode impedance may be subsequently processed in a unified manner for assessing the health of the electrode.

Description

Technical Field

[0001] The present invention relates to the technical field of implantable nerve stimulation, and particularly to a system and method for measuring electrode impedance and a method for evaluating electrode health. Background Art

[0002] Implantable nerve stimulation is a method of stimulating a target nerve 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 stimulation pulse commands in real time to drive the electrodes of the stimulator, so that the electrodes apply a stimulation current to the treatment site of the patient. However, the electrodes will undergo electrolytic reactions under the action of current and tissue fluid, or there is tissue fluid and ions in the tissue where the electrodes are located. In addition to electrolytic reactions, galvanic 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, and the electrodes may be corroded. For electrodes, conductivity is the most important indicator of their health. Usually, the impedance of the electrodes is used to characterize their conductivity, and then the health of the electrodes is evaluated.

[0003] Figure 1 is a paired measurement method of electrode impedance according to the prior art. As Figure 1 shown, two adjacent electrodes (for example, electrode E1 and electrode E2) are taken as a pair, and the current generated by the current generator can be transmitted between this pair of electrodes. Specifically, the current can be an alternating current. The current generator applies a current to one of the pair of electrodes (for example, electrode E1), and the current outputs from electrode E1, and the "+" sign indicates the current output, and then inputs to the other electrode (that is, electrode E2), and the "-" sign indicates the current input. When the current direction changes, the current outputs from electrode E2 and inputs to electrode E1. Thus, the impedance of electrode E1 can be determined by measuring the voltage at electrode E1, and the impedance of electrode E2 can be determined by measuring the voltage at electrode E2. Similarly, by forming multiple pairs of electrodes with electrode E2 and electrode E3, electrode E3 and electrode E4, electrode E5 and electrode E6, electrode E6 and electrode E7, electrode E7 and electrode E8, the impedance of each electrode in each pair of electrodes can be measured.

[0004] However, the disadvantage of the paired measurement method is that the electrodes at the edges (that is, electrode E1 and electrode E8) can only measure the impedance once, while the electrodes at non-edge positions (that is, electrodes E2 to E7) can measure the impedance twice, which will cause the impedance data to be unable to be uniformly processed subsequently.

[0005] The above statement of the background art is only for facilitating the 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 an implication in any form that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a system and method for measuring electrode impedance and a method for evaluating electrode health, and the measured electrode impedance can be uniformly processed subsequently for evaluating electrode health.

[0007] According to an embodiment of the present invention, a system for measuring electrode impedance is provided. The system includes: a plurality of electrodes configured to be implanted into a human body for electrical stimulation; a current generator electrically connected to each of the plurality of electrodes and configured to generate a current with a specific frequency for transmission between the plurality of electrodes; a controller electrically connected to the current generator and configured to: cause the current with the specific frequency generated by the current generator to be transmitted between a target electrode and all other electrodes other than the target electrode, where the target electrode is any one of the plurality of electrodes; measure the voltage at the target electrode caused by the current with the specific frequency; calculate the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode; and calculate the impedance of each of the plurality of electrodes at the specific frequency by taking each of the plurality of electrodes as the target electrode one by one.

[0008] The controller is further configured to: change the frequency of the current generated by the current generator to calculate the impedance of each of the plurality of electrodes at different frequencies.

[0009] The controller is configured to cause the frequency of the current generated by the current generator to conform to:

[0010] f = {0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n , f 2n+1 , … f m}

[0011] where f is the frequency of the current generated by the current generator, and f n is the preset frequency for electrical stimulation;

[0012] f 2n = 2f n ;

[0013] 0, f 1 , f2 ,…, f n-1 , f n , f n+1 ,…, f 2n-1 , f 2n The difference between two adjacent ones among them is the difference δ 1 , f 2n+1 ,… f m The difference between two adjacent ones among them is the difference δ 2 , the difference δ 1 and the difference δ 2 satisfy the relationship: δ 1 < δ 2 .

[0014] According to another embodiment of the present invention, there is provided a method for measuring the impedance of an electrode, wherein the electrode is provided as a plurality of electrodes implanted into the human body for electrical stimulation, and the method includes: transmitting a current of a specific frequency between a target electrode and all other electrodes except the target electrode, wherein the target electrode is any one of the plurality of electrodes; measuring the voltage at the target electrode caused by the current of the specific frequency; calculating the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode; and calculating the impedance of each of the plurality of electrodes at the specific frequency by taking each of the plurality of electrodes as the target electrode one by one.

[0015] The method for measuring the impedance of an electrode further includes: changing the frequency of the current to calculate the impedance of each of the plurality of electrodes at different frequencies.

[0016] The step of changing the frequency of the current includes making the frequency of the current conform to:[[]]

[0017] f = {0, f 1 , f 2 ,…, f n-1 , f n , f n+1 ,…, f 2n-1 , f 2n , f 2n+1 ,… f m}[[]]

[0018] wherein, f is the frequency of the current, and f n is a preset frequency for electrical stimulation;

[0019] f 2n = 2f n ;

[0020] 0, f 1 , f 2 ,…, f n-1 , f n , f n+1 ,…, f2n-1 , f 2n The difference between two adjacent ones among them is the difference δ 1 , f 2n+1 , … f m The difference between two adjacent ones among them is the difference δ 2 , the difference δ 1 and the difference δ 2 satisfy the relationship: δ 1 < δ 2 .

[0021] According to another embodiment of the present invention, a method for evaluating the health of electrodes is provided. The electrodes are provided as a plurality of electrodes implanted into a human body for electrical stimulation. The method includes the steps of: obtaining the impedance of each of the plurality of electrodes at different frequencies; calculating the variance of the impedance of the plurality of electrodes at each frequency according to the obtained impedance of each of the plurality of electrodes at different frequencies; comparing between the calculated variances, and determining the frequency corresponding to the smallest variance as the reference frequency; calculating the standard deviation and the average value of the impedance of the plurality of electrodes at the reference frequency; determining the difference between the average value and the standard deviation, the sum value of the average value and the standard deviation, the difference between the average value and twice the standard deviation, and the sum value of the average value and twice the standard deviation according to the calculated standard deviation and average value; comparing the impedance of each of the plurality of electrodes at the reference frequency with the difference between the average value and the standard deviation, the sum value of the average value and the standard deviation, the difference between the average value and twice the standard deviation, and the sum value of the average value and twice the standard deviation; and evaluating the health of each of the plurality of electrodes according to the comparison result.

[0022] The step of evaluating the health of each of the plurality of electrodes according to the comparison result includes: when the impedance of the electrode at the reference frequency is less than the difference between the average value and twice the standard deviation or greater than the sum value of the average value and twice the standard deviation, evaluating the health of the electrode as poor; when the impedance of the electrode at the reference frequency is greater than or equal to the difference between the average value and twice the standard deviation and less than the difference between the average value and the standard deviation, or when the impedance of the electrode at the reference frequency is greater than the sum value of the average value and the standard deviation and less than or equal to the sum value of the average value and twice the standard deviation, evaluating the health of the electrode as fair; and when the impedance of the electrode at the reference frequency is greater than or equal to the difference between the average value and the standard deviation and less than or equal to the sum value of the average value and the standard deviation, evaluating the health of the electrode as good.

[0023] The steps of obtaining the impedance of each of multiple electrodes at different frequencies include: transmitting a current of a specific frequency between a target electrode and all other electrodes other than the target electrode, where the target electrode is any one of the multiple electrodes; measuring the voltage at the target electrode caused by the current of the specific frequency; calculating the impedance of the target electrode at the specific frequency based on the measured voltage at the target electrode; calculating the impedance of each of the multiple electrodes at the specific frequency by taking each of the multiple electrodes as the target electrode one by one; and changing the frequency of the current to calculate the impedance of each of the multiple electrodes at different frequencies.

[0024] The step of changing the frequency of the current includes making the frequency of the current conform to:

[0025] f = {0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n , f 2n+1 , …f m}

[0026] where f is the frequency of the current, and f n is a preset frequency for electrical stimulation;

[0027] f 2n = 2f n ;

[0028] 0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n The difference between two adjacent ones among 0, f 1 , f 2n+1 , …f m is the difference δ 2 , and the difference between two adjacent ones among 1 f 2 , …f 1 is the difference δ 2 .

[0029] The present invention adopts the above technical solutions and has the following beneficial effects: The electrode impedance measured by the present invention can be uniformly processed subsequently for evaluating the health of the electrode. In addition, by causing current transmission between the electrode and all other electrodes other than the electrode itself, the inconsistency of the electrode itself caused by the manufacturing process in the paired measurement method according to the prior art can be eliminated in a stimulator including multiple electrodes, and the effectiveness and accuracy of the results can be further improved. In addition, the value compared with the electrode impedance is a value calculated using the electrode impedance, rather than a value that requires a large number of tests to determine. Different measured electrode impedances result in different values for comparison with the electrode impedance, which can adapt to the individual differences of patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] Figure 1 is a paired measurement method of electrode impedance according to the prior art.

[0032] Figure 2 is a schematic diagram of a system for measuring electrode impedance according to an embodiment of the present invention.

[0033] Figure 3 shows an example of the impedance spectrum of an electrode.

[0034] Figure 4 is a flowchart of a method for measuring electrode impedance according to an embodiment of the present invention.

[0035] Figure 5 is a flowchart of a method for evaluating the health of an electrode according to an embodiment of the present invention.

[0036] Figure 6 shows a schematic diagram for evaluating the health of an electrode according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The embodiments of the present invention will be described in detail below. The following 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.

[0038] Figure 2 is a schematic diagram of a system for measuring electrode impedance according to an embodiment of the present invention. As Figure 2As shown, a system for measuring electrode impedance according to an embodiment of the present invention includes a plurality of electrodes (e.g., electrode E1, electrode E2, …, electrode E8), a current generator 10, and a controller 20.

[0039] The plurality of electrodes are arranged to be implanted into the human body for electrical stimulation. In Figure 2 the specific embodiment shown, the plurality of electrodes E1, E2, …, E8 can be arranged at multiple points of the nerve 30 to be stimulated. Each of the plurality of electrodes has an impedance.

[0040] The current generator 10 is electrically connected to each of the plurality of electrodes and is configured to generate a current with a specific frequency for transmission between the plurality of electrodes. Herein, the 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 can be an alternating current that changes with time according to a sine law.

[0041] The controller 20 is electrically connected to the current generator 10 and is configured to: cause the current with a specific frequency generated by the current generator 10 to be transmitted between a target electrode and all other electrodes other than the target electrode. Wherein, the target electrode is any one of the plurality of electrodes.

[0042] As Figure 2 shown, when electrode E1 is used as the target electrode, the controller 20 causes the current with a specific frequency generated by the current generator 10 to be applied to electrode E1. The current outputs from electrode E1, and the “+” sign indicates the current output. And the current output from electrode E1 inputs to all other electrodes other than electrode E1, that is, the current inputs to each of electrodes E2, E3, E4, E5, E6, E7, E8, and the “-” sign indicates the current input. When the current direction changes, the current outputs from each of electrodes E2, E3, E4, E5, E6, E7, E8 and inputs to electrode E1 as the target electrode. And so on for the cases when other electrodes are used as the target electrode.

[0043] The controller 20 is configured to measure the voltage at the target electrode caused by the current with a specific frequency and calculate the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode.

[0044] Specifically, the controller 20 extracts the voltage at the target electrode caused by the current of a specific frequency using known digital signal processing methods. In some examples of the present invention, the controller 20 may process the measured voltage through 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. In the case where 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.

[0045] Thereby, the controller 20 can calculate the impedance of each of the plurality of electrodes at a specific frequency by taking each of the plurality of electrodes as the target electrode one by one.

[0046] According to an exemplary embodiment of the present invention, the controller 20 can change the frequency of the current generated by the current generator 10. Similar to the above operation of the controller 20, the controller 20 takes each of the plurality of electrodes as the target electrode one by one, transmits the current with the changed frequency between the target electrode and all other electrodes other than the target electrode, and thus can calculate the impedance of each of the plurality of electrodes at different frequencies.

[0047] Different from the paired measurement method according to the prior art, the electrode impedances measured using the embodiments of the present invention can be subsequently processed uniformly. In addition, by causing current transmission between an electrode and all other electrodes other than the electrode itself, the inconsistency of the electrode itself caused by the manufacturing process in the paired measurement method according to the prior art can be eliminated in a stimulator including multiple electrodes, and the effectiveness and accuracy of the results can be further improved.

[0048] For each electrode, the correspondence between impedance and frequency can be represented by an impedance spectrum. Figure 3 An example of the impedance spectrum of an electrode is shown. As Figure 3 shown, the ordinate of the impedance spectrum is impedance, and the abscissa is the frequency of the current generated by the current generator 10 under the control of the controller 20.

[0049] In an exemplary embodiment of the present invention, the controller 20 is configured to make the frequency of the current generated by the current generator 10 comply with:

[0050] f = {0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n , f 2n+1 , …f m}

[0051] Among them, f is the frequency of the current generated by the current generator 10, and f n is a preset frequency for electrical stimulation. In the Figure 2 specific embodiment shown, by arranging a plurality of electrodes E1, E2, …, E8 at multiple points of the nerve 30 to be stimulated, the electrical stimulation of the plurality of electrodes E1, E2, …, E8 can help the patient relieve pain. For example, medical staff can suggest setting the frequency for electrical stimulation to 100 Hz to achieve a good pain relief effect. That is to say, f n = 100 Hz.

[0052] In addition, f 2n = 2f n , and the difference between two adjacent ones among 0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n is the difference δ 1 , f 2n+1 , … f m is the difference δ 2 , and the difference δ 1 and the difference δ 2 satisfy the relationship: δ 1 < δ 2 .

[0053] That is to say, a smaller measurement step value is applied within the range of ±100% of the frequency 100 Hz for electrical stimulation recommended by medical staff (i.e., 0 to 200 Hz), while a larger measurement step value is applied outside the range of 0 to 200 Hz.

[0054] Since the frequency f of the current generated by the current generator 10 can be reflected in the value of the abscissa of the impedance spectrum, therefore, as shown in the impedance spectrum of Figure 3 , the frequency f of the current generated by the current generator 10 conforms to:

[0055] f = {0, 10, 20, …, 90, 100, 110, …, 190, 200, 300, … 2000}

[0056] Thus, f n = f 10 = 100 Hz, f 2n = f 20 = 200 Hz, f m = f 38 = 2000 Hz.

[0057] The difference δ between two adjacent values among 0, 10, 20, …, 90, 100, 110, …, 190, 200 1 = 10 Hz. That is to say, within the range of 0 to 200 Hz, the measurement step value is 10 Hz. The difference δ between two adjacent values among 200, 300, …, 2000 2 = 100 Hz, so δ 1 < δ 2 . That is to say, within the range of 200 Hz to 2000 Hz, the measurement step value is 100 Hz, which is greater than 10 Hz.

[0058] However, the present invention is not limited thereto. Depending on the different treatment sites and treatment functions of electrode implantation, the frequencies f n recommended by medical personnel for electrical stimulation may be different. In addition, preferably, a larger frequency range can be used. For example, f m can reach 20 kHz.

[0059] Figure 4 is a flowchart of a method for measuring electrode impedance according to an embodiment of the present invention. As Figure 4 shown, the method for measuring electrode impedance according to an embodiment of the present invention includes: transmitting a current of a specific frequency between a target electrode and all other electrodes except the target electrode (S11), where the target electrode is any one of a plurality of electrodes.

[0060] Next, measure the voltage at the target electrode caused by the current of the specific frequency (S12), and calculate the impedance of the target electrode at the specific frequency according to the measured voltage at the target electrode (S13).

[0061] Calculate the impedance of each of the plurality of electrodes at the specific frequency by taking each of the plurality of electrodes as the target electrode one by one (S14).

[0062] Next, change the frequency of the current to calculate the impedance of each of the plurality of electrodes at different frequencies (S15).

[0063] Specifically, the step of changing the frequency of the current may include making the frequency of the current conform to:

[0064] f = {0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n , f 2n+1 , … f m}

[0065] where f is the frequency of the current, fn is a preset frequency for electrical stimulation.

[0066] f 2n = 2f n , and between 0, f 1 , f 2 , …, f n-1 , f n , f n+1 , …, f 2n-1 , f 2n the difference between two adjacent ones among them is the difference δ 1 , f 2n+1 , …f m the difference between two adjacent ones among them is the difference δ 2 , the difference δ 1 and the difference δ 2 satisfy the relationship: δ 1 < δ 2 .

[0067] After obtaining the impedance of each of multiple electrodes at different frequencies, the impedance of each of the obtained multiple electrodes at different frequencies can be used to evaluate the health of each of the multiple electrodes.

[0068] In the prior art, electrode impedance is often calibrated through experiments. Specifically, when evaluating health, the electrode impedance is compared with a fixed nominal value. However, individual differences lead to different electrode impedances, and it is difficult to adapt to the individual differences of patients by comparing the electrode impedance with a fixed nominal value. At this time, medical staff need to conduct a large number of clinical tests to evaluate the health of the electrodes.

[0069] Figure 5 is a flowchart of a method for evaluating electrode health according to an embodiment of the present invention.

[0070] Obtain the impedance of each of multiple electrodes at different frequencies (S21). Specifically, step S21 may include steps S11 to S15 in the above method for measuring electrode impedance.

[0071] Taking four electrodes E1, E2, E3, E4 and three frequencies f of the current 1 , f 2 , f 3 as an example, Table 1 shows the impedance corresponding to the electrodes and frequencies.

[0072] Table 1

[0073] Impedance <![CDATA[Frequency f 1 > <![CDATA[Frequency f 2 > <![CDATA[Frequency f 3 > Electrode E1 a1 b1 c1 Electrode E2 a2 b2 c2 Electrode E3 a3 b3 c3 Electrode E4 a4 b4 c4

[0074] Calculate the variance (S22) of the impedances of multiple electrodes at each frequency based on the impedance of each of the multiple electrodes at different frequencies.

[0075] Taking Table 1 as an example, at frequency f 1 , the variance of the impedances of electrodes E1 to E4 refers to the variance σ of a1, a2, a3, a4 2 a . At frequency f 2 , the variance of the impedances of electrodes E1 to E4 refers to the variance σ of b1, b2, b3, b4 2 b . At frequency f 3 , the variance of the impedances of electrodes E1 to E4 refers to the variance σ of c1, c2, c3, c4 2 c .

[0076] Compare the calculated variances and determine the frequency corresponding to the smallest variance as the reference frequency (S23).

[0077] Compare the sizes of the variances of a1, a2, a3, a4, σ 2 a , b1, b2, b3, b4, σ 2 b and c1, c2, c3, c4, σ 2 c . For example, if the comparison result is that the variance σ of b1, b2, b3, b4 2 b is the smallest, then the reference frequency is f 2 .

[0078] Calculate the standard deviation and mean of the impedances of multiple electrodes at the reference frequency (S24).

[0079] When the reference frequency is f 2 , calculate the standard deviation σ of b1, b2, b3, b4 z and the mean μ z .

[0080] Based on the calculated standard deviation and mean, determine the difference between the mean and the standard deviation, the sum of the mean and the standard deviation, the difference between the mean and twice the standard deviation, and the sum of the mean and twice the standard deviation (S25).

[0081] That is, based on the standard deviation σ z and the mean μ z to determine the difference between the mean and the standard deviation μ z - σ z , the sum of the mean and the standard deviation μz +σ z 、 the difference μ between the average value and twice the standard deviation z -2σ z 、 and the sum value μ of the average value and twice the standard deviation z +2σ z 。

[0082] Compare the impedance of each of the multiple electrodes at the reference frequency with the difference between the average value and the standard deviation, the sum of the average value and the standard deviation, the difference between the average value and twice the standard deviation, and the sum of the average value and twice the standard deviation (S26). Finally, evaluate the health of each of the multiple electrodes based on the comparison result (S27).

[0083] Compare each of b1, b2, b3, b4 with μ z -σ z 、 μ z +σ z 、 μ z -2σ z 、 μ z +2σ z Make a comparison, determine the position of each of b1, b2, b3, b4 in the interval composed of μ z -σ z 、 μ z +σ z 、 μ z -2σ z 、 μ z +2σ z and evaluate the health of the electrode based on the determined position.

[0084] Therefore, different from comparing the electrode impedance with a fixed nominal value in the prior art, according to the embodiments of the present invention, the value compared with the electrode impedance is a value calculated using the electrode impedance, rather than a value that requires a large number of tests to determine. In addition, the measured electrode impedance is different, and the value used for comparison with the electrode impedance is also different, which can adapt to the individual differences of patients.

[0085] Figure 6 Shows a schematic diagram for evaluating the health of an electrode according to an exemplary embodiment of the present invention.

[0086] When the impedance of the electrode at the reference frequency is less than the difference between the average value and twice the standard deviation or greater than the sum of the average value and twice the standard deviation, evaluate the health of the electrode as poor.

[0087] As Figure 6 shown, for example, when b1 < μ z -2σ z or b1 > μ z +2σ zWhen the impedance of electrode E1 (which corresponds to impedance b1) is less than the difference between the average value and the standard deviation, the health of electrode E1 can be evaluated as poor.

[0088] When the impedance of an electrode at the reference frequency is greater than or equal to the difference between the average value and twice the standard deviation and less than the difference between the average value and the standard deviation, or when the impedance of the electrode at the reference frequency is greater than the sum of the average value and the standard deviation and less than or equal to twice the sum of the average value and the standard deviation, the health of the electrode is evaluated as fair.

[0089] For example, when μ z - 2σ z ≤ b2 < μ z - σ z or μ z + σ z < b2 ≤ μ z + 2σ z the health of electrode E2 (which corresponds to impedance b2) can be evaluated as fair.

[0090] When the impedance of an electrode at the reference frequency is greater than or equal to the difference between the average value and the standard deviation and less than or equal to the sum of the average value and the standard deviation, the health of the electrode is evaluated as good.

[0091] For example, when μ z - σ z ≤ b3 ≤ μ z + σ z the health of electrode E3 (which corresponds to impedance b3) can be evaluated as good.

[0092] According to the system and method for measuring electrode impedance and the method for evaluating electrode health according to the embodiments of the present invention, the electrode impedance data measured by using the present invention can be uniformly processed subsequently for evaluating the health of the electrode.

[0093] In addition, according to the system and method for measuring electrode impedance according to the embodiments of the present invention, by causing current transmission between an electrode and all other electrodes other than the electrode itself, the inconsistency of the electrode itself caused by the manufacturing process in the paired measurement method according to the prior art can be eliminated in a stimulator including multiple electrodes, and the effectiveness and accuracy of the results can be further improved.

[0094] In addition, according to the method for evaluating electrode health according to the embodiments of the present invention, the value compared with the electrode impedance is a value calculated by using the electrode impedance, rather than a value that requires a large number of tests to determine. Different measured electrode impedances result in different values for comparison with the electrode impedance, which can adapt to the individual differences of patients.

[0095] 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.

[0096] 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 technicians 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 system for measuring electrode impedance, the system comprising: a plurality of electrodes configured to be implanted into a human body for electrical stimulation; a current generator electrically connected to each of the plurality of electrodes and configured to: generate a current having a specific frequency for transmission between the plurality of electrodes; A controller is electrically connected to the current generator and is configured to: transmitting a current of a specific frequency generated by a current generator between a target electrode and all other electrodes other than the target electrode, wherein the target electrode is any one of the plurality of 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 plurality of electrodes is taken as a target electrode one by one to calculate the impedance of each of the plurality of electrodes at a specific frequency.

2. The system for measuring electrode impedance according to claim 1, wherein: The controller is further configured to: The frequency of the current generated by the current generator is varied to calculate the impedance of each of the plurality of electrodes at different frequencies.

3. The system for measuring electrode impedance according to claim 2, wherein: The controller is configured to make the frequency of the current generated by the current generator conform to: f={0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n ,f 2n+1 ,…f m } Where f is the frequency of the current generated by the current generator, f n It is the pre-set frequency used for electrical stimulation; in 2n =2f n ; 0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n The difference between two adjacent ones is the difference δ1, f 2n+1 ,…f m The difference between two adjacent values ​​is difference δ2, and the difference δ1 and the difference δ2 satisfy the relationship: δ1<δ2.

4. A method for measuring impedance of electrodes, the electrodes being arranged as a plurality of electrodes implanted into a human body for electrical stimulation, the method comprising: transmitting a current of a specific frequency between a target electrode and all other electrodes other than the target electrode, wherein the target electrode is any one of the plurality of 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 plurality of electrodes is taken as a target electrode one by one to calculate the impedance of each of the plurality of electrodes at a specific frequency.

5. The method for measuring electrode impedance according to claim 4, further comprising: The frequency of the current is varied to calculate the impedance of each of the plurality of electrodes at different frequencies.

6. The method for measuring electrode impedance according to claim 5, wherein: The step of changing the frequency of the current comprises changing the frequency of the current to conform to: f={0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n ,f 2n+1 ,…f m } Where f is the frequency of the current, f n It is the pre-set frequency used for electrical stimulation; in 2n =2f n ; 0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n The difference between two adjacent ones is the difference δ1, f 2n+1 ,…f m The difference between two adjacent values ​​is difference δ2, and the difference δ1 and the difference δ2 satisfy the relationship: δ1<δ2.

7. A method for evaluating the health of electrodes, the electrodes being arranged as a plurality of electrodes implanted into a human body for electrical stimulation, the method comprising the steps of: obtaining impedance of each of the plurality of electrodes at different frequencies; Calculate the variance of the impedance of the plurality of electrodes at each frequency based on the impedance of each of the plurality of electrodes at different frequencies; The calculated variances are compared, and the frequency corresponding to the smallest variance is determined as the reference frequency; Calculate the standard deviation and average of the impedance of multiple electrodes at the reference frequency; Based on the calculated standard deviation and mean, determine the difference between the mean and the standard deviation, the sum of the mean and the standard deviation, the difference between the mean and twice the standard deviation, and the sum of the mean and twice the standard deviation; comparing the impedance of each of the plurality of electrodes at a reference frequency to a difference between a mean and a standard deviation, a sum of the mean and the standard deviation, a difference between the mean and twice the standard deviation, and a sum of the mean and twice the standard deviation; The health of each of the plurality of electrodes is evaluated based on the results of the comparison.

8. The method for evaluating electrode health according to claim 7, wherein: The step of evaluating the health of each of the plurality of electrodes according to the comparison results includes: When the impedance of the electrode at the reference frequency is less than the difference between the mean and two times the standard deviation or greater than the sum of the mean and two times the standard deviation, the health of the electrode is evaluated as poor; When the impedance of the electrode at the reference frequency is greater than or equal to the difference between the mean and two times the standard deviation and less than the difference between the mean and the standard deviation, or when the impedance of the electrode at the reference frequency is greater than the sum of the mean and the standard deviation and less than or equal to the sum of the mean and two times the standard deviation, the health of the electrode is evaluated as fair; When the impedance of the electrode at the reference frequency is greater than or equal to the difference between the mean and the standard deviation and less than or equal to the sum of the mean and the standard deviation, the health of the electrode is evaluated as good.

9. The method for evaluating electrode health according to claim 7, wherein: The steps of obtaining the impedance of each of the plurality of electrodes at different frequencies include: transmitting a current of a specific frequency between a target electrode and all other electrodes other than the target electrode, wherein the target electrode is any one of the plurality of 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; calculating the impedance of each of the plurality of electrodes at a specific frequency by treating each of the plurality of electrodes as a target electrode one by one; The frequency of the current is varied to calculate the impedance of each of the plurality of electrodes at different frequencies.

10. The method for evaluating electrode health according to claim 9, wherein: The step of changing the frequency of the current comprises changing the frequency of the current to conform to: f={0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n ,f 2n+1 ,…f m } Where f is the frequency of the current, f n It is the pre-set frequency used for electrical stimulation; in 2n =2f n ; 0,f1,f2,…,f n-1 ,f n ,f n+1 ,…,f 2n-1 ,f 2n The difference between two adjacent ones is the difference δ1, f 2n+1 ,…f m The difference between two adjacent values ​​is difference δ2, and the difference δ1 and the difference δ2 satisfy the relationship: δ1<δ2.

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