Voltage pulse type impedance measurement circuit and method suitable for implantable nerve stimulator

Abstract

The invention provides a voltage pulse type impedance measurement circuit and method suitable for an implantable nerve stimulator. The circuit comprises a charge pump module, a charge storage module, a pulse output module, a voltage acquisition module, a timing module, a controller module and a memory module. The controller module judges whether the nerve stimulator is in a pulse treatment process or not by monitoring the working state of the pulse output module; if yes, the charge pump module is controlled to charge the voltage on the charge storage module to the therapeutic electric pulse amplitude in the pulse gap; controlling the pulse output module to emit impedance measurement electric pulses with the same frequency and pulse width as the treatment electric pulses, and controlling the timing module to start timing; collecting the voltage of the charge storage module; when the voltage of the charge storage module is reduced to the reference voltage, the timing module is controlled to stop timing so as to obtain voltage decay time; and generating impedance data according to the voltage decay time and the impedance calibration data so as to solve the problem that the impedance in the electric pulse treatment process cannot be truly reflected.

Description

Technical Field

[0001] The present application relates to the technical field of impedance measurement circuits, and in particular to a voltage pulse impedance measurement circuit and method suitable for an implantable neural stimulator. Background Art

[0002] An implantable neurostimulator includes an implantable electrode wire and a pulse generator. The implantable electrode wire has electrode contacts. After the electrode contacts are connected to the pulse generator, the pulse generator can form electrical pulses between the electrode contacts to affect the neural functional groups of biological tissue around the electrode contacts by generating electrical pulses between the electrode contacts.

[0003] In order to evaluate whether the contact between the electrode contacts and the biological tissue is good, it is necessary to measure the impedance of the human biological tissue between the electrode contacts. The relevant impedance measurement methods mainly include constant current method, capacitor discharge method, fixed voltage pulse method and other methods. Among them, when using the constant current method for impedance measurement, the measured impedance range is too small, which is easy to cause large impedance measurement errors; when using the capacitor discharge method for impedance measurement, when measuring a large impedance load, it is impossible to distinguish between the two situations of large impedance and open circuit, and it cannot be directly used on implantable neurostimulators; for the fixed voltage pulse method measurement, there is a problem that the current passing through the load is too small when measuring a large impedance load, which places higher requirements on the current acquisition system of the device. It is easy to be interfered by environmental noise when collecting small signals, affecting the measurement. Moreover, in the impedance measurement method for implantable neurostimulators, when measuring impedance, if the pulse generator is issuing therapeutic electric pulses, it is necessary to stop the current pulse and convert it into an electric pulse dedicated to impedance measurement for measurement. The amplitude, pulse width and frequency of the impedance measurement pulse deviate greatly from the therapeutic electric pulse, resulting in the impedance value measured by it not being able to truly reflect the impedance during the electric pulse treatment process. Summary of the invention

[0004] The present application provides a voltage pulse impedance measurement circuit and method applicable to an implantable neurostimulator to solve the problem that the impedance cannot be truly reflected during electrical pulse therapy.

[0005] In a first aspect, the present application provides a voltage pulse impedance measurement circuit suitable for an implantable neurostimulator, comprising: a charge pump module, a charge storage module, a pulse output module, a voltage acquisition module, a timing module, a controller module, and a memory module;

[0006] The controller module is electrically connected to the charge pump module, the pulse output module, the voltage acquisition module, the timing module, and the memory module respectively; the charge pump module is electrically connected to the charge storage module; the charge storage module is electrically connected to the pulse output module; the controller module is configured as follows:

[0007] Determining whether the neurostimulator is in the pulse treatment process by monitoring the working state of the pulse output module;

[0008] If the neurostimulator is in a pulse therapy process, controlling the charge pump module to charge the voltage on the charge storage module to the therapeutic electrical pulse amplitude during the pulse interval;

[0009] Control the pulse output module to emit impedance measurement electric pulses with the same frequency and pulse width as the therapeutic electric pulses and control the timing module to start timing;

[0010] collecting the voltage of the charge storage module;

[0011] When the voltage of the charge storage module drops to the reference voltage, the timing module is controlled to stop timing to obtain the voltage decay time;

[0012] Impedance data is generated according to the voltage decay time and the impedance calibration data.

[0013] The circuit has the characteristic of evaluating impedance in real time during electric pulse stimulation, can reflect the actual change of impedance during electric pulse treatment, and provide more accurate clinical data; using electric pulses with parameters close to the treatment electric pulses to measure impedance during electric pulse treatment can reduce the discomfort of clinical patients during impedance measurement to a certain extent, and reduce the use of high-precision signal acquisition electronic components, thereby reducing costs and obtaining relatively accurate impedance values. In addition, the voltage of the charge storage module can be directly collected, and there is no need to collect voltage on the pulse waveform of the load, thereby avoiding the influence of the electric pulse shape fluctuating with the change of load on the impedance measurement, so as to solve the problem of not being able to truly reflect the impedance during electric pulse treatment.

[0014] Optionally, the controller module is further configured to:

[0015] If the neurostimulator is not in the pulse treatment process, controlling the charge pump module to charge the voltage on the charge storage module to a preset low-voltage electrical pulse amplitude;

[0016] Control the pulse output module to emit low-voltage electrical pulses with a specific frequency and pulse width and control the timing module to start timing;

[0017] collecting the voltage of the charge storage module;

[0018] When the voltage of the charge storage module drops to the reference voltage, the timing module is controlled to stop timing to obtain the voltage decay time;

[0019] Impedance data is generated according to the voltage decay time and the impedance calibration data.

[0020] The controller charges the voltage on the charge storage module to a preset low-voltage electric pulse amplitude and emits low-voltage electric pulses of specific frequency and pulse width. This not only helps to ensure that the neurostimulator does not cause unnecessary stimulation to human biological tissue in a non-therapeutic state, but also maintains low energy consumption and output, thereby extending the service life of the device and reducing unnecessary power consumption.

[0021] Optionally, the pulse output module is provided with electrode contacts, and the polarities of the electrode contacts include positive, negative, and invalid; and the controller module is configured as follows:

[0022] The pulse output module is controlled to emit electric pulses of preset frequency and pulse width through a load between the positive electrode contact and the negative electrode contact.

[0023] The pulse output module emits an electric pulse of preset frequency and pulse width through the load between the positive electrode contact and the negative electrode contact, so as to accurately measure the impedance data. Setting the electrode contact with invalid polarity can cut off the current in abnormal situation, protect the electrode from damage, and improve the safety of the circuit.

[0024] Optionally, the timing module includes a hardware clock and a hardware frequency divider; the clock frequency of the hardware clock is 32 MHz; the hardware frequency divider is electrically connected to the hardware clock to achieve microsecond timing and millisecond timing.

[0025] The clock frequency of the hardware clock is 32MHz, so that the timing module can perform very fine time measurement and improve the accuracy and resolution of timing. The hardware divider can divide the high-frequency clock signal into the required low-frequency signal according to actual needs for different timing requirements to achieve microsecond and millisecond timing.

[0026] Optionally, the memory module is a non-volatile memory for storing pre-measured impedance calibration data; the impedance calibration data includes initial voltage, pulse width, frequency, discharge time and standard resistance.

[0027] The non-volatile memory can retain data without power supply, thereby ensuring the security and integrity of the data. The impedance calibration data is used to find a standard resistance value consistent with the initial voltage, pulse width, frequency, and voltage decay time during the impedance measurement process to achieve impedance measurement.

[0028] Optionally, a human-computer interaction module is further included; the human-computer interaction module is communicatively connected with the controller module; the controller module is further configured as follows:

[0029] The impedance data is sent to the human-computer interaction module so that the human-computer interaction module displays the impedance data.

[0030] The human-machine interaction module and the controller module realize data exchange through wireless communication technology, and display the impedance data measured by the controller module to relevant personnel for review.

[0031] Optionally, the controller module is further configured to:

[0032] When the timing time of the timing module exceeds the preset threshold time, the timing module is controlled to stop timing and an impedance abnormality notification is generated;

[0033] The impedance abnormality notification is sent to the human-computer interaction module, so that the human-computer interaction module displays the impedance abnormality notification.

[0034] When an impedance anomaly is detected, the timing can be stopped immediately and an impedance anomaly notification can be generated to ensure that the problem is responded to quickly. The human-computer interaction module can provide an intuitive interface to display the impedance anomaly notification, so that the user can understand the situation and re-measure or adjust the electrode contact position.

[0035] Optionally, the controller module is further configured to:

[0036] If the neurostimulator is not in the pulse treatment process, the amplitude of the electric pulse emitted by the pulse output module is the same as the voltage amplitude on the charge storage module;

[0037] If the neurostimulator is in a pulse therapy process, the amplitude of the electric pulse emitted by the pulse output module and the voltage amplitude on the charge storage module are both the same as the amplitude of the therapeutic electric pulse.

[0038] The amplitude of the electrical pulses can be precisely controlled under different working conditions of the neurostimulator to ensure that the output electrical pulse amplitude meets the expected requirements. This can not only reduce unnecessary power consumption, but also ensure the effectiveness and reliability of treatment when measuring impedance data.

[0039] Optionally, the controller module is further configured to:

[0040] If the neurostimulator is not in the pulse treatment process, before controlling the timing module to start timing, the pulse output module is controlled to emit two low-voltage electrical pulses with specific frequency and pulse width.

[0041] By issuing two low-voltage electrical pulses with specific frequency and pulse width in advance, not only can the components reach thermal equilibrium and electrical stability, reducing measurement errors, but also transient noise or interference can be reduced, thereby improving the accuracy and reliability of the entire measurement process.

[0042] The second aspect of the present application provides a voltage pulse impedance measurement method applicable to an implantable neurostimulator, which is applied to the voltage pulse impedance measurement circuit applicable to the implantable neurostimulator described in the first aspect, and the method comprises:

[0043] By monitoring the working status of the pulse output module, it is determined whether the neurostimulator is in the pulse treatment process;

[0044] If the neurostimulator is in a pulse therapy process, controlling the charge pump module to charge the voltage on the charge storage module to the therapeutic electrical pulse amplitude during the pulse interval;

[0045] Control the pulse output module to emit impedance measurement electric pulses with the same frequency and pulse width as the therapeutic electric pulses and control the timing module to start timing;

[0046] collecting the voltage of the charge storage module;

[0047] When the voltage of the charge storage module drops to the reference voltage, the timing module is controlled to stop timing to obtain the voltage decay time;

[0048] Impedance data is generated according to the voltage decay time and the impedance calibration data.

[0049] The above method can reflect the real change of impedance during electric pulse therapy and provide more accurate clinical data; using electric pulses with parameters close to the treatment electric pulses to measure impedance during electric pulse therapy can reduce the discomfort of clinical patients during impedance measurement to a certain extent, and reduce the use of high-precision signal acquisition electronic components, thereby reducing costs and obtaining relatively accurate impedance values. In addition, the voltage of the charge storage module can be directly collected, and there is no need to collect voltage on the pulse waveform of the load, thereby avoiding the influence of the electric pulse shape on the impedance measurement when it fluctuates with the change of load, so as to solve the problem of not being able to truly reflect the impedance during electric pulse therapy.

[0050] It can be seen from the above technical scheme that the present application provides a voltage pulse impedance measurement circuit and method suitable for an implantable neural stimulator, the circuit comprising: a charge pump module, a charge storage module, a pulse output module, a voltage acquisition module, a timing module, a controller module and a memory module; the controller module is electrically connected to the charge pump module, the pulse output module, the voltage acquisition module, the timing module and the memory module respectively; the charge pump module is electrically connected to the charge storage module; the charge storage module is electrically connected to the pulse output module; the controller module determines the working state of the neural stimulator by monitoring the working state of the pulse output module Whether the stimulator is in the process of pulse therapy; if the neurostimulator is in the process of pulse therapy, control the charge pump module to charge the voltage on the charge storage module to the amplitude of the therapeutic electric pulse in the pulse interval; control the pulse output module to emit impedance measurement electric pulses with the same frequency and pulse width as the therapeutic electric pulses and control the timing module to start timing; collect the voltage of the charge storage module; when the voltage of the charge storage module drops to the reference voltage, control the timing module to stop timing to obtain the voltage decay time; generate impedance data according to the voltage decay time and impedance calibration data to solve the problem that the impedance cannot be truly reflected during the electric pulse therapy process. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0052] Figure 1 This is a block diagram of a voltage pulse impedance measurement circuit applicable to an implantable neural stimulator according to an embodiment of the present application;

[0053] Figure 2 A schematic diagram of the change in the voltage on the charge storage module and the amplitude of the electrical stimulation pulse when the voltage pulse impedance measurement circuit applicable to the implantable neurostimulator described in the embodiment of the present application performs impedance measurement during electrical pulse therapy;

[0054] Figure 3 This is a schematic diagram of the changes in the amplitude of the electrical stimulation pulse and the voltage on the charge storage module when the voltage pulse impedance measurement circuit suitable for the implantable neurostimulator described in an embodiment of the present application performs impedance measurement before electrical pulse therapy.

[0055] Illustration Description:

[0056] Among them, 100-charge pump module; 200-charge storage module; 300-pulse output module; 400-voltage acquisition module; 500-timing module; 600-controller module; 700-memory module; 800-human-computer interaction module. DETAILED DESCRIPTION

[0057] The embodiments will be described in detail below, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following embodiments do not represent all implementation methods consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application.

[0058] An implantable neurostimulator includes an implantable electrode wire and a pulse generator. It is an implantable medical device. The implantable electrode wire has electrode contacts. After the electrode contacts are connected to the pulse generator, the pulse generator can form electric pulses between the electrode contacts. After the electrode wire of the neurostimulator is implanted in the human body, the electrode contacts are in contact with the human biological tissue. By generating electric pulses between the electrode contacts, it can affect the nerve functional groups around the electrode contacts. This electric pulse can inhibit the conduction of neural pain to the central nervous system, thereby achieving the effect of suppressing pain.

[0059] During the clinical application of implantable neurostimulators, it is necessary to measure the impedance of human biological tissue between electrode contacts. The main purpose of the measurement is to evaluate whether the contact between the electrode contacts and the biological tissue is good. If there is a break in the circuit between the electrode contacts and the biological tissue, or a short circuit between the electrode contacts, the actual electric pulses will fail, affecting the clinical treatment effect. At the same time, the impedance between the electrode contacts can be obtained through impedance measurement, and the changing trend of electric pulse stimulation with different amplitudes can provide effective data support for subsequent clinical treatment.

[0060] During impedance measurement, if the pulse generator is emitting therapeutic electric pulses, it is necessary to stop the current pulse and convert it to an electric pulse dedicated to impedance measurement for measurement. The amplitude, pulse width and frequency of the impedance measurement pulse deviate greatly from the therapeutic electric pulse, resulting in the measured impedance value being unable to truly reflect the impedance during the electric pulse treatment process.

[0061] To solve the problem of not being able to truly reflect the impedance during electrical pulse therapy, see Figure 1Some embodiments of the present application provide a voltage pulse impedance measurement circuit suitable for an implantable neurostimulator, including: a charge pump module 100, a charge storage module 200, a pulse output module 300, a voltage acquisition module 400, a timing module 500, a controller module 600 and a memory module 700; the controller module 600 is electrically connected to the charge pump module 100, the pulse output module 300, the voltage acquisition module 400, the timing module 500 and the memory module 700 respectively; the charge pump module 100 is electrically connected to the charge storage module 200; the charge storage module 200 is electrically connected to the pulse output module 300.

[0062] It should be understood that the controller module 600 is mainly composed of a control device, which can be a microcontroller (MCU), a digital signal processor (DSP) or a programmable logic unit (FPGA). The controller module 600 can control the switches in the charge pump module 100 and the pulse output module 300. The controller module 600 reads the timing data from the timing module 500, reads the impedance calibration data from the memory module 700, reads the voltage data from the voltage acquisition module 400, and performs filtering on the continuously collected voltage data. The charge pump module 100 is used to provide charge to the charge storage module 200 so that the charge storage module 200 maintains a certain voltage. When the charge pump module 100 is working, it continuously provides charge to the charge storage module 200, and the voltage on the charge storage module 200 gradually rises over time. The controller module 600 can control the working time of the charge pump module 100 so that the voltage on the charge storage module 200 is just maintained at the voltage amplitude set by the controller module 600. The charge storage module 200 is composed of capacitors, which are used to store the charge provided by the charge pump module 100 and to generate discharge pulses to the load as an energy source of the voltage pulse. The pulse output module 300 is used to discharge the charge on the charge storage module 200 to the load in the form of a voltage pulse. The pulse output module 300 can select the electrode contact position for generating the discharge pulse and determine the polarity of the electrode contact. The voltage acquisition module 400 is used for voltage acquisition and provides the actual voltage of the charge storage module 200 to the controller module 600 in real time.

[0063] In some embodiments, the polarity of the electrode contacts includes positive, negative, and inactive; the controller module 600 is configured to:

[0064] The control pulse output module 300 issues an electrical pulse of a preset frequency and pulse width through a load between the positive electrode contact and the negative electrode contact.

[0065] It should be understood that when impedance measurement is performed during electric pulse therapy, the electric pulse with a preset frequency and pulse width is an impedance measurement electric pulse having the same frequency and pulse width as the treatment electric pulse; when impedance measurement is performed before electric pulse therapy, the electric pulse with a preset frequency and pulse width is a low-voltage electric pulse with a specific frequency and pulse width.

[0066] The pulse output module 300 emits an electric pulse of preset frequency and pulse width through the load between the positive electrode contact and the negative electrode contact, so as to accurately measure the impedance data. Setting the electrode contact with invalid polarity can cut off the current in an abnormal situation, protect the electrode from damage, and improve the safety of the circuit.

[0067] In some embodiments, the timing module 500 includes a hardware clock and a hardware frequency divider; the clock frequency of the hardware clock is 32 MHz; the hardware frequency divider is electrically connected to the hardware clock to achieve microsecond timing and millisecond timing.

[0068] It should be understood that the timing module 500 is used for timing, and the hardware clock can divide the clock through a hardware divider. Specifically, when configured for millisecond timing, the counter in the timing module 500 is incremented once every 1 millisecond. The controller module 600 can start and stop the timing module 500. When the timing module 500 is stopped, the current timing time is obtained by reading the accumulated times of the counter in the timing module 500.

[0069] The clock frequency of the hardware clock is 32MHz, so that the timing module 500 can perform very fine time measurement and improve the accuracy and resolution of timing. The high-frequency clock signal can be divided into the required low-frequency signal according to actual needs through the hardware divider for different timing requirements to achieve microsecond and millisecond timing.

[0070] In some embodiments, the memory module 700 is a non-volatile memory to store pre-measured impedance calibration data; the impedance calibration data includes initial voltage, pulse width, frequency, discharge time, and standard resistance.

[0071] It should be understood that the impedance calibration data is formed by performing electric pulse discharge on standard resistors of different resistance values ​​and recording the time consumed by the voltage on the charge storage module 200 to decrease from the initial voltage to the reference voltage. The reference voltage is determined by the initial voltage. When the initial voltage is different, the reference voltage is also different. The initial voltage, pulse width, frequency and discharge time corresponding to different standard resistors together constitute an impedance calibration table. In the impedance calibration table, the initial voltage, pulse width, frequency and discharge time constitute a set of query indexes, and a set of query indexes uniquely determines a standard resistance value. The controller module 600 can search the impedance calibration table for a standard resistance value that is consistent with the initial voltage, pulse width, frequency and discharge time during the impedance measurement process to achieve impedance measurement.

[0072] Non-volatile memory can retain data without power supply, thus ensuring data security and integrity. Impedance calibration data is used to find the standard resistance value consistent with the initial voltage, pulse width, frequency, and voltage decay time during the impedance measurement process to achieve impedance measurement.

[0073] The controller module 600 is configured to:

[0074] Determine whether the neurostimulator is in the pulse treatment process by monitoring the working state of the pulse output module 300;

[0075] If the neurostimulator is in the process of pulse therapy, the charge pump module 100 is controlled to charge the voltage on the charge storage module 200 to the amplitude of the therapeutic electrical pulse during the pulse interval;

[0076] Control the pulse output module 300 to emit impedance measurement electric pulses with the same frequency and pulse width as the therapeutic electric pulses and control the timing module 500 to start timing;

[0077] Collecting the voltage of the charge storage module 200;

[0078] When the voltage of the charge storage module 200 drops to the reference voltage, the timing module 500 is controlled to stop timing to obtain the voltage decay time;

[0079] Generate impedance data based on voltage decay time and impedance calibration data.

[0080] It should be understood that when impedance measurement is performed during electric pulse therapy, the controller module 600 controls the initial voltage of the charge storage module 200 to be the amplitude of the therapeutic electric pulse, and times the decay time of the charge storage module 200 from the initial voltage to the reference voltage while keeping the frequency and pulse width of the current therapeutic electric pulse unchanged, and finally realizes impedance measurement by acquiring the corresponding impedance data in the memory module 700.

[0081] See also Figure 2 When measuring impedance during electrical pulse therapy, the electrical stimulation pulse amplitude V am and the voltage V on the charge storage module 200 c The synchronous changes of the electrical stimulation pulse amplitude V during the treatment process am With V c The same value, where V c =V c0 , V c0 For the treatment electric pulse amplitude, at time t1, due to the release of the electric pulse, the charge on the charge storage module 200 begins to lose part of its charge, and the corresponding voltage increases from V c0The pulse starts to decay partially, and at time t2, the pulse stops and enters the pulse interval time. At this time, the charge pump module 100 recharges the charge storage module to the therapeutic electric pulse amplitude V set by the controller module 600. c0 , the pulse interval ends, and at time t3, the next stimulation pulse is issued to ensure that the amplitude of each therapeutic pulse remains the same. At time t4, impedance measurement begins, and the charge pump module 100 charges the voltage on the charge storage module 200 to V c0 After that, an impedance measurement electric pulse is issued. The frequency and pulse width of the impedance measurement electric pulse are the same as those of the treatment electric pulse. However, during the interval time of the impedance measurement electric pulse, the charge pump module 100 no longer charges the charge storage module 200. Therefore, the voltage on the charge storage module 200 increases from V c0 It starts to decrease continuously until t5, when V c The value is reduced to the reference voltage V c1 When the voltage decay time t from t4 to t5 is calculated, m , and finally by t m At time t6, the impedance measurement is completed, and the charge pump module 100 recharges the voltage on the charge storage module 200 to V c0 Then, therapeutic electrical pulses are delivered.

[0082] The circuit has the characteristic of evaluating impedance in real time during electric pulse stimulation, and can reflect the actual change of impedance during electric pulse treatment, providing more accurate clinical data. Using electric pulses close to the treatment electric pulse parameters for impedance measurement during electric pulse treatment can reduce the discomfort of clinical patients during impedance measurement to a certain extent, and reduce the use of high-precision signal acquisition electronic components, thereby reducing costs and obtaining relatively accurate impedance values. The voltage of the charge storage module 200 can be directly collected, and there is no need to collect voltage on the pulse waveform of the load, thereby avoiding the influence of the electric pulse shape on the impedance measurement when it fluctuates with the change of load, so as to solve the problem of not being able to truly reflect the impedance during electric pulse treatment.

[0083] In some embodiments, the controller module 600 is further configured to:

[0084] If the neurostimulator is not in the pulse treatment process, the charge pump module 100 is controlled to charge the voltage on the charge storage module 200 to a preset low-voltage electrical pulse amplitude;

[0085] Control the pulse output module 300 to emit low-voltage electrical pulses with a specific frequency and pulse width and control the timing module 500 to start timing;

[0086] Collecting the voltage of the charge storage module 200;

[0087] When the voltage of the charge storage module 200 drops to the reference voltage, the timing module 500 is controlled to stop timing to obtain the voltage decay time;

[0088] Generate impedance data based on voltage decay time and impedance calibration data.

[0089] It should be understood that when the impedance measurement is performed before the electric pulse treatment, the controller module 600 controls the initial voltage of the charge storage module 200 to be fixed to the preset low voltage electric pulse amplitude V T0 , and controls the pulse output module 300 to measure the specific frequency f of the electrical pulse with impedance T , pulse width W T The load under test is discharged with a pulse of 0.5V. T0 As a reference voltage, the charge storage module 200 is T0 to 0.5V T0 The decay time is timed, and finally the impedance measurement is achieved by acquiring the impedance data corresponding to the timing time in the memory module 700.

[0090] The controller charges the voltage on the charge storage module 200 to a preset low-voltage electric pulse amplitude and emits low-voltage electric pulses of specific frequency and pulse width. This not only helps to ensure that the neurostimulator does not cause unnecessary stimulation to human biological tissue in a non-therapeutic state, but also maintains low energy consumption and output, thereby extending the service life of the device and reducing unnecessary power consumption.

[0091] In some embodiments, the controller module 600 is further configured to:

[0092] If the neurostimulator is not in the pulse treatment process, before the timing module 500 starts timing, the pulse output module 300 is controlled to release two low-voltage electrical pulses with specific frequency and pulse width.

[0093] See also Figure 3 When impedance measurement is performed before electrical pulse therapy, the electrical stimulation pulse amplitude V am and the voltage V on the charge storage module 200 c The synchronous change of the electric pulse amplitude V during the measurement process am With V c The impedance measurement starts at time t1, the controller module 600 starts the charge pump module 100 to charge the charge storage module 200, and at time t2, the voltage of the charge storage module 200 is charged to the initial voltage V T0 At this time, the controller module 600 controls the pulse output module 300 to issue the first electric pulse to the load under test. Due to the issuance of the electric pulse, the charge on the charge storage module 200 begins to lose part of its charge, and the corresponding voltage changes from V T0At time t3, the first pulse stops and enters the pulse interval time. At this time, the charge pump module 100 recharges the charge storage module to the initial voltage V T0 , the pulse interval time ends, and at time t4, the controller module 600 controls the pulse output module 300 to issue a second electric pulse to the load under test. During the second electric pulse interval, the charge pump module 100 charges the charge energy storage module to the initial voltage V T0 Until time t5, after the discharge pulse is generated, the pulse interval time begins. At this time, the charge pump module 100 no longer charges the charge storage module 200, so the voltage on the charge storage module 200 increases from V T0 It starts to decrease continuously until t6, when V T0 The value is reduced to the reference voltage 0.5V T0 When the voltage decay time t from t5 to t6 is calculated, m , and finally by t m After the impedance measurement pulse is issued, the controller module 600 queries the memory module 700 for the initial voltage, pulse width, frequency and t m The standard resistance value with the same value is the equivalent load in the measurement process, that is, the impedance value.

[0094] In some embodiments, a human-computer interaction module 800 is further included; the human-computer interaction module 800 is in communication connection with the controller module 600; the controller module 600 is further configured as follows:

[0095] The impedance data is sent to the human-computer interaction module 800 so that the human-computer interaction module 800 displays the impedance data.

[0096] It should be understood that the human-computer interaction module 800 is a tablet computer that can display impedance information.

[0097] The human-machine interaction module 800 and the controller module 600 realize data interaction through wireless communication technology, and display the impedance data measured by the controller module 600 to relevant personnel for review.

[0098] In some embodiments, the controller module 600 is further configured to:

[0099] When the timing time of the timing module 500 exceeds the preset threshold time, the timing module 500 is controlled to stop timing and generate an impedance abnormality notification;

[0100] The impedance abnormality notification is sent to the human-computer interaction module 800 so that the human-computer interaction module 800 displays the impedance abnormality notification.

[0101] It should be understood that the preset threshold time is used to limit the maximum duration of the impedance measurement process. When the timing module 500 has counted more than the preset threshold time, it means that the voltage on the charge storage module 200 has not decayed to the reference voltage during this period of time.

[0102] When an impedance anomaly is detected, the timing can be stopped immediately and an impedance anomaly notification can be generated to ensure that the problem is responded to quickly. The human-computer interaction module 800 can provide an intuitive interface to display the impedance anomaly notification, so that the user can understand the situation and re-measure or adjust the electrode contact position.

[0103] In some embodiments, the controller module 600 is further configured to:

[0104] If the neurostimulator is not in the pulse treatment process, the amplitude of the electric pulse emitted by the pulse output module 300 is the same as the voltage amplitude on the charge storage module 200;

[0105] If the neurostimulator is in the process of pulse treatment, the amplitude of the electric pulse emitted by the pulse output module 300 and the voltage amplitude on the charge storage module 200 are both the same as the amplitude of the treatment electric pulse.

[0106] The amplitude of the electrical pulses can be precisely controlled under different working conditions of the neurostimulator to ensure that the output electrical pulse amplitude meets the expected requirements. This can not only reduce unnecessary power consumption, but also ensure the effectiveness and reliability of treatment when measuring impedance data.

[0107] Some embodiments of the present application also provide a voltage pulse impedance measurement method applicable to an implantable neurostimulator, which is applied to the voltage pulse impedance measurement circuit applicable to the implantable neurostimulator of the above embodiment, and the method includes:

[0108] Determine whether the neurostimulator is in the pulse treatment process by monitoring the working state of the pulse output module 300;

[0109] If the neurostimulator is in the process of pulse therapy, the charge pump module 100 is controlled to charge the voltage on the charge storage module 200 to the amplitude of the therapeutic electrical pulse during the pulse interval;

[0110] Control the pulse output module 300 to emit impedance measurement electric pulses with the same frequency and pulse width as the therapeutic electric pulses and control the timing module 500 to start timing;

[0111] Collecting the voltage of the charge storage module 200;

[0112] When the voltage of the charge storage module 200 drops to the reference voltage, the timing module 500 is controlled to stop timing to obtain the voltage decay time;

[0113] Generate impedance data based on voltage decay time and impedance calibration data.

[0114] The above method can reflect the real change of impedance during electric pulse therapy and provide more accurate clinical data. Using electric pulses with parameters close to the treatment electric pulses to measure impedance during electric pulse therapy can reduce the discomfort of clinical patients during impedance measurement to a certain extent, and reduce the use of high-precision signal acquisition electronic components, thereby reducing costs and obtaining relatively accurate impedance values. In addition, the voltage of the charge storage module 200 can be directly collected, and there is no need to collect voltage on the pulse waveform of the load, thereby avoiding the influence of the electric pulse shape on the impedance measurement when it fluctuates with the change of load, so as to solve the problem of not being able to truly reflect the impedance during electric pulse therapy.

[0115] It can be seen from the above technical scheme that the embodiment of the present application provides a voltage pulse impedance measurement circuit and method suitable for an implantable neural stimulator, the circuit comprising: a charge pump module 100, a charge storage module 200, a pulse output module 300, a voltage acquisition module 400, a timing module 500, a controller module 600 and a memory module 700; the controller module 600 is electrically connected to the charge pump module 100, the pulse output module 300, the voltage acquisition module 400, the timing module 500, and the memory module 700 respectively; the charge pump module 100 is electrically connected to the charge storage module 200; the charge storage module 200 is electrically connected to the pulse output module 300; the controller module 600 monitors the pulse output The working status of the output module 300 determines whether the neurostimulator is in the pulse therapy process; if the neurostimulator is in the pulse therapy process, the charge pump module 100 is controlled to charge the voltage on the charge storage module 200 to the amplitude of the therapeutic electric pulse during the pulse interval; the pulse output module 300 is controlled to emit an impedance measurement electric pulse with the same frequency and pulse width as the therapeutic electric pulse and the timing module 500 is controlled to start timing; the voltage of the charge storage module 200 is collected; when the voltage of the charge storage module 200 drops to the reference voltage, the timing module 500 is controlled to stop timing to obtain the voltage decay time; the impedance data is generated according to the voltage decay time and the impedance calibration data to solve the problem that the impedance cannot be truly reflected during the electric pulse therapy process.

[0116] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

1. A voltage pulse impedance measurement circuit suitable for an implantable neural stimulator, characterized in that: include: A charge pump module (100), a charge storage module (200), a pulse output module (300), a voltage acquisition module (400), a timing module (500), a controller module (600), and a memory module (700); The controller module (600) is electrically connected to the charge pump module (100), the pulse output module (300), the voltage acquisition module (400), the timing module (500), and the memory module (700); the charge pump module (100) is electrically connected to the charge storage module (200); the charge storage module (200) is electrically connected to the pulse output module (300); the controller module (600) is configured as follows: Determining whether the neurostimulator is in a pulse treatment process by monitoring the working state of the pulse output module (300); If the neurostimulator is in a pulse treatment process, the charge pump module (100) is controlled to charge the voltage on the charge storage module (200) to the amplitude of the therapeutic electrical pulse during the pulse interval; Controlling the pulse output module (300) to emit impedance measurement electric pulses having the same frequency and pulse width as the therapeutic electric pulses and controlling the timing module (500) to start timing; collecting the voltage of the charge storage module (200); When the voltage of the charge storage module (200) decreases to a reference voltage, the timing module (500) is controlled to stop timing to obtain a voltage decay time; Impedance data is generated according to the voltage decay time and the impedance calibration data.

2. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The controller module (600) is also configured to: If the neurostimulator is not in the pulse treatment process, controlling the charge pump module (100) to charge the voltage on the charge storage module (200) to a preset low-voltage electrical pulse amplitude; Controlling the pulse output module (300) to emit low-voltage electrical pulses with a specific frequency and pulse width and controlling the timing module (500) to start timing; collecting the voltage of the charge storage module (200); When the voltage of the charge storage module (200) decreases to a reference voltage, the timing module (500) is controlled to stop timing to obtain a voltage decay time; Impedance data is generated according to the voltage decay time and the impedance calibration data.

3. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The pulse output module (300) is provided with an electrode contact, and the polarity of the electrode contact includes positive, negative and invalid; the controller module (600) is configured as follows: The pulse output module (300) is controlled to emit electric pulses with a preset frequency and pulse width through a load between the positive electrode contact and the negative electrode contact.

4. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The timing module (500) comprises a hardware clock and a hardware frequency divider; the clock frequency of the hardware clock is 32 MHz; the hardware frequency divider is electrically connected to the hardware clock to achieve microsecond timing and millisecond timing.

5. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The memory module (700) is a non-volatile memory for storing pre-measured impedance calibration data; The impedance calibration data includes initial voltage, pulse width, frequency, discharge time and standard resistance.

6. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: Also includes a human-computer interaction module (800); The human-computer interaction module (800) is communicatively connected to the controller module (600); the controller module (600) is further configured to: The impedance data is sent to the human-computer interaction module (800) so that the human-computer interaction module (800) displays the impedance data.

7. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 6, characterized in that: The controller module (600) is also configured to: When the time measured by the timing module (500) exceeds a preset threshold time, the timing module (500) is controlled to stop measuring, and an impedance abnormality notification is generated; The impedance abnormality notification is sent to the human-computer interaction module (800), so that the human-computer interaction module (800) displays the impedance abnormality notification.

8. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The controller module (600) is also configured to: If the neurostimulator is not in the pulse treatment process, the amplitude of the electric pulse emitted by the pulse output module (300) is the same as the voltage amplitude on the charge storage module (200); If the neurostimulator is in a pulse treatment process, the amplitude of the electric pulse emitted by the pulse output module (300) and the voltage amplitude on the charge storage module (200) are both the same as the amplitude of the therapeutic electric pulse.

9. The voltage pulse impedance measurement circuit for an implantable neurostimulator according to claim 1, characterized in that: The controller module (600) is also configured to: If the neurostimulator is not in the pulse treatment process, before controlling the timing module (500) to start timing, the pulse output module (300) is controlled to emit two low-voltage electrical pulses with specific frequency and pulse width.

10. A voltage pulse impedance measurement method applicable to an implantable neurostimulator, characterized in that: The voltage pulse impedance measurement circuit for an implantable neural stimulator according to any one of claims 1 to 9, the method comprising: Determining whether the neurostimulator is in a pulse treatment process by monitoring the working state of the pulse output module (300); If the neurostimulator is in a pulse treatment process, the charge pump module (100) is controlled to charge the voltage on the charge storage module (200) to the amplitude of the treatment electrical pulse during the pulse interval; Controlling the pulse output module (300) to emit impedance measurement electric pulses having the same frequency and pulse width as the therapeutic electric pulses and controlling the timing module (500) to start timing; collecting the voltage of the charge storage module (200); When the voltage of the charge storage module (200) decreases to a reference voltage, the timing module (500) is controlled to stop timing to obtain a voltage decay time; Impedance data is generated according to the voltage decay time and the impedance calibration data.

Images