Patent Description:
In recent years, dozens of kinds of therapeutic electrical nerve stimulation devices have been developed, and tens of thousands of people needing electrical stimulation devices undergo implant surgery every year. Due to developments in precision manufacturing technology, medical instruments such as implantable electrical stimulation devices have been shrunk so that they can be implanted into the human body.

A conventional electrical stimulation device generally performs electrical stimulation <NUM> hours a day, until there is no electricity remaining. When it is necessary to change the electrical stimulation parameters of the electrical stimulation signal, only the pulse width of the electrical stimulation signal and the amplitude of the signal (that is, the magnitude of the voltage or current) can be adjusted. There is no specific relationship between the pulse width and the electrical stimulation parameters such as voltage and current. Therefore, setting the electrical stimulation parameters is usually left to the doctor's choice, based on personal and professional experience.

<CIT> relates to a medical electrical lead systems for detecting and isolating lead-related conditions including the features of the preamble of independent claim <NUM>.

<CIT> relates to management of tissue charge safety limits in a neurostimulation system.

<CIT> and <CIT> relate to further implantable electrical stimulators.

In view of the problems of the prior art described above, an electrical stimulation method, an electrical stimulation device, and a computer-readable storage medium are provided in the embodiments of the present disclosure, wherein all embodiments relating to an electrical stimulation method are provided for exemplary purpose only and do not form part of the invention as claimed.

An embodiment of the present disclosure provides an electrical stimulation method. The electrical stimulation method is applied to an electrical stimulation device. The steps of the electrical stimulation method comprise: obtaining a target energy value; providing an electrical stimulation signal to a target area; calculating a total energy value according to an energy value transmitted from the electrical stimulation signal to the target area; and determining whether the total energy value has reached the target energy value.

In one or more embodiments, the electrical stimulation signal may comprise a plurality of pulse signals.

In one or more embodiments, the electrical stimulation device may sample at least one of the plurality of pulse signals to calculate the total energy value corresponding to the plurality of pulse signals.

In one or more embodiments, the electrical stimulation method may further comprise obtaining a voltage value of the electrical stimulation signal; obtaining a current value of the electrical stimulation signal; and calculating the energy value of the electrical stimulation signal according to the voltage value and the current value of the electrical stimulation signal.

In one or more embodiments, the electrical stimulation method may further comprise obtaining a current value of the electrical stimulation signal; and calculating the energy value of the electrical stimulation signal according to the current value of the electrical stimulation signal and further according to a tissue impedance value corresponding to the electrical stimulation signal and a time parameter.

In one or more embodiments, the time parameter may comprise a pulse width and a pulse frequency.

In one or more embodiments, the electrical stimulation method may further comprise stopping providing the electrical stimulation signal to the target area when the total energy value has reached the target energy value.

In one or more embodiments, the electrical stimulation method may further comprise obtaining the target energy value, a pulse width, and a pulse frequency from an external control device through the electrical stimulation device.

In one or more embodiments, the electrical stimulation method may further comprise obtaining the target energy value, a pulse width, and a pulse frequency from the electrical stimulation device.

In one or more embodiments, an intra-pulse frequency of the electrical stimulation signal may in a range from <NUM> to <NUM>.

In one or more embodiments, an intra-pulse frequency of the electrical stimulation signal is in a range from <NUM> to <NUM>.

In one or more embodiments, a pulse frequency of the electrical stimulation signal is in a range of <NUM>~<NUM>.

An embodiment of the present disclosure provides an electrical stimulation device. The above-mentioned electrical stimulation device comprises an electrical stimulation signal generation circuit and a calculation module. The electrical stimulation signal generation circuit provides an electrical stimulation signal to a target area. The calculation module obtains a target energy value, calculates a total energy value according to an energy value of the electrical stimulation signal transmitted to the target area, and determines whether the total energy value has reached the target energy value.

In one or more embodiments, the electrical stimulation signal may comprise a plurality of pulse signals, and the electrical stimulation device may samples at least one of the plurality of pulse signals to calculate the total energy value corresponding to the plurality of pulse signals.

In one or more embodiments, the calculation module may be further configured to obtain a voltage value of the electrical stimulation signal, obtain a current value of the electrical stimulation signal, and calculate the energy value of the electrical stimulation signal according to the voltage value and the current value of the electrical stimulation signal.

In one or more embodiments, the calculation module may be further configured to obtain a current value of the electrical stimulation signal and calculate the energy value of the electrical stimulation signal according to the current value of the electrical stimulation signal and further according to a tissue impedance value corresponding to the electrical stimulation signal and a time parameter.

In one or more embodiments, when the total energy value has reached the target energy value, the electrical stimulation signal generation circuit may stop providing the electrical stimulation signal to the target area.

In one or more embodiments, the electrical stimulation device may comprising a communication circuit.

In one or more embodiments, the communication circuit may obtain the target energy value, a pulse width, and a pulse frequency from an external control device.

In one or more embodiments, the electrical stimulation device may comprising a storage unit.

In one or more embodiments, the storage unit may store a lookup table.

In one or more embodiments, the calculation module may be configured to obtain the target energy value, a pulse width, and a pulse frequency from the storage unit.

In one or more embodiments, an intra-pulse frequency of the electrical stimulation signal may be in a range from <NUM> to <NUM>.

In one or more embodiments, a pulse frequency of the above electrical stimulation signal may be in a range of <NUM>~<NUM>.

An embodiment of the present disclosure provides a computer-readable storage medium. The computer-readable storage medium stores one or more instructions and cooperates with an electrical stimulation device. When the one or more instructions are executed by the electrical stimulation device, the electrical stimulation device executes a plurality of steps, comprising: obtaining a target energy value; providing an electrical stimulation signal to a target area; calculating a total energy value according to an energy value of the electrical stimulation signal transmitted to the target area; and determining whether the total energy value has reached the target energy value.

In one or more embodiments, the electrical stimulation signal may comprise a plurality of pulse signals, and the electrical stimulation device may sample at least one of the plurality of pulse signals to calculate the total energy value corresponding to the plurality of pulse signals.

In one or more embodiments, the plurality of steps executed by the electrical stimulation device may further comprise: obtaining a voltage value of the electrical stimulation signal; obtaining a current value of the electrical stimulation signal; and calculating the energy value of the electrical stimulation signal according to the voltage value and the current value of the electrical stimulation signal.

In one or more embodiments, the plurality of steps executed by the electrical stimulation device may further comprise: obtaining a current value of the electrical stimulation signal; and calculating the energy value of the electrical stimulation signal according to the current value of the electrical stimulation signal and further according to a tissue impedance value corresponding to the electrical stimulation signal and a time parameter.

In one or more embodiments, the plurality of steps executed by the electrical stimulation device may further comprise stopping providing the electrical stimulation signal to the target area when the total energy value has reached the target energy value.

In one or more embodiments, the plurality of steps executed by the electrical stimulation device may further comprise obtaining the target energy value, a pulse width, and a pulse frequency from the electrical stimulation device.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure, without departing from the spirit and scope of the present disclosure.

The present disclosure can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:.

The following description is a preferred embodiment of the invention, which is intended to describe the invention, but is not intended to limit the invention. For the actual inventive content, reference must be made to the scope of the claims.

<FIG> is a block diagram of an electrical stimulation device <NUM>, according to an embodiment of the present disclosure. As shown in <FIG>, the electrical stimulation device <NUM> at least includes a power management circuit <NUM>, an electrical stimulation signal generation circuit <NUM>, a measurement circuit <NUM>, a control unit <NUM>, a communication circuit <NUM>, and a storage unit <NUM>. It should be appreciated that the block diagram shown in <FIG> is only for the convenience of explaining the embodiments of the present disclosure, the present disclosure is not limited thereto. The electrical stimulation device <NUM> may also include other elements.

According to an embodiment of the present disclosure, the electrical stimulation device <NUM> may be electrically coupled to an external control device <NUM>. The external control device <NUM> may be provided with an operation interface. According to user's operation on the operation interface, the external control device <NUM> may generate instructions or signals to be transmitted to the electrical stimulation device <NUM>, and transmits the instructions or signals to the electrical stimulation device <NUM> via a wire communication (e.g., a transmission line).

In addition, according to another embodiment of the present disclosure, the external control device <NUM> may transmit the instructions or signals to the electrical stimulation device <NUM> via a wireless communication, such as Bluetooth, Wi-Fi, or NFC (near field communication).

According to the embodiment of the present disclosure, the electrical stimulation device <NUM> may be an implantable electrical stimulation device, an external electrical stimulation device with a lead implanted into human body, or a transcutaneous electrical stimulation device (TENS). According to an embodiment of the present disclosure, when the electrical stimulation device <NUM> is a non-implantable electrical stimulation device (e.g., an external electrical stimulation device or a transcutaneous electrical stimulation device), the electrical stimulation device <NUM> may be integrated with the external control device into a device. According to an embodiment of the present disclosure, the electrical stimulation device <NUM> may be an electrical stimulation device with batteries, or an electrical stimulation device of which power is transmitted wirelessly by the external control device <NUM>. According to an embodiment of the present disclosure, in a trial phase, the electrical stimulation device <NUM> is an external electrical stimulation device with a lead implanted into human body. There are electrodes on the lead, so that the external electrical stimulation device may send the electrical stimulation signal to the corresponding target area via the electrodes on the lead. In the trial phase, after the terminal of the lead with an electrode has been implanted into the human body, the other terminal is thereby linked to the external control device <NUM>, and the external stimulation device may send an electrical stimulation signal to evaluate the effectiveness of the therapy, and to confirm if the functions of the lead are normal, and if the position into which the lead is implanted is correct. In the trial phase, the external control device <NUM> may first pair with the external electrical stimulation device (i.e., a non-implantable electrical stimulation device). After the lead is implanted into the human body, the external electrical stimulation device may be connected to the lead. The external electrical stimulation device may be wirelessly controlled by the external control device <NUM> to perform electrical stimulation of the human body. According to an embodiment of the present disclosure, if the evaluation in the trial phase is effective, a permanent implantation phase may be entered. In the permanent implantation phase, the electrical stimulation device <NUM> is implanted into the human body together with the lead. The electrical stimulation device <NUM> sends the electrical signal to the corresponding target area via the electrodes on the lead. While the external control device <NUM> is entering the permanent implantation phase, a user or a doctor must let the external control device <NUM> detect a phase change card, so as to change the state of the external control device <NUM> from the trial phase to the permanent implantation phase via near field wireless communication. In addition, the external control device <NUM> may select a target energy upper bound and a target energy lower bound from the first target energy set according to a predetermined electrical stimulation level. Then, the external control device <NUM> may generate the second target energy set according to the target energy upper bound and the target energy lower bound (further explanation will be provided). Moreover, before the permanent implantation phase or during the permanent implantation phase, the external control device <NUM> may pair with the implantable electrical stimulation device first, and the external electrical stimulation device (i.e., a non-implantable electrical stimulation device) may be removed, and the electrical stimulation device <NUM> (i.e., an implantable electrical stimulation device) connects to the lead and is implanted into the human body.

According to the embodiment of the present disclosure, the power management circuit <NUM> is used for providing power to the elements and circuit in the electrical stimulation device <NUM>. The power provided by the power management circuit <NUM> may be from a built-in rechargeable battery, or the external control device <NUM>, but the present disclosure is not limited thereto. The external control device <NUM> may provide power to the power management circuit <NUM> using a wireless power technology. The power management circuit <NUM> may be activated or deactivated according to the instructions of the external control device <NUM>. According to an embodiment of the present disclosure, the power management circuit <NUM> may include a switch circuit (not shown in the figure). The switch circuit may be switched on or off according to the instructions of the external control device <NUM>, so as to activate or deactivate the power management circuit <NUM>.

According to the embodiment of the present disclosure, the electrical stimulation signal generation circuit <NUM> is used for generating the electrical stimulation signal. The electrical stimulation device <NUM> may transmit the generated electrical stimulation signal to the electrodes on the lead via at least a lead, so as to perform electrical stimulation on the target area of the body of a user (human or animal) or a patient. The target area may be, for example, spine, spinal nerve, vagus nerve, trigeminal nerve, lateral recess, or peripheral nerve, but the present disclosure is not limited thereto. The detailed structure regarding the electrical stimulation signal generation circuit <NUM> will be explained in <FIG>.

<FIG> is the schematic diagram of an electrical stimulation device <NUM>, according to an embodiment of the present disclosure. As shown in <FIG>, the electrical stimulation signal may be output to the lead <NUM>, so that the electrical stimulation signal may be transmitted via a terminal <NUM> of the lead <NUM> to the other terminal <NUM> of the lead <NUM>. In an embodiment of the present disclosure, the electrical stimulation device <NUM> and the lead <NUM> may be separately electrically connected to each other, but the present disclosure is not limited thereto. For example, the electrical stimulation device <NUM> and the lead <NUM> may be a monolithic device.

<FIG> is the schematic diagram of an electrical stimulation device <NUM>, according to another embodiment of the present disclosure. As shown in <FIG>, the electrode <NUM> and the electrode <NUM> may be directly installed on one side of the electrical stimulation device <NUM>. The electrical stimulation signal may be transmitted to the electrode <NUM> or the electrode <NUM>, so as to perform electrical stimulation on the target area. In other words, in this embodiment, the electrical stimulation device <NUM> does not need to transmit the electrical stimulation signal to the electrode <NUM> and the electrode <NUM> via the lead.

<FIG> is the waveform diagram of the electrical stimulation signals of the electrical stimulation device, according to an embodiment of the present disclosure. As shown in <FIG>, according to an embodiment of the present disclosure, the electrical stimulation signal may be a pulsed radiofrequency (PRF) signal (also referred to as a pulse signal, for short), a continuous sinusoidal waveform, or a continuous triangle waveform, but the present disclosure is not limited thereto. Besides, when the electrical stimulation signal is a pulse AC (alternating current) signal, a pulse cycle time Tp includes a pulse signal and at least an idle period, and the pulse cycle time Tp is the inverse of the pulse repetition frequency. For example, the pulse repetition frequency (also referred to as the pulse frequency, for short) may ranges from <NUM> Hertz to <NUM> Hertz, preferably range from <NUM> Hertz to <NUM> Hertz. In this embodiment, the exemplary pulse repetition frequency of the electrical stimulation signal is <NUM> Hertz. Besides, the duration time Td (i.e., the pulse width) of a pulse in a pulse cycle time may be at <NUM>-<NUM> milliseconds, preferably at <NUM>-<NUM> milliseconds. In this embodiment, the exemplary duration time Td is <NUM> milliseconds. In this embodiment, the frequency of the electrical stimulation signal is <NUM> Hertz. In other words, the electrical stimulation signal cycle time Ts is approximately <NUM> microseconds(µs). In addition, the frequency of the electrical stimulation signal is the intra-pulse frequency in each pulse AC signal of <FIG>. In some embodiments, the intra-pulse frequency of the electrical stimulation signal may, for example, range from <NUM> Hertz to <NUM> Hertz. It should be appreciated that in each embodiment of the present disclosure, the frequency of the electrical stimulation signal refers to the intra-pulse frequency of the electrical stimulation signal. Furthermore, the intra-pulse frequency of the electrical stimulation signal may, for example, range from <NUM> Hertz to <NUM> Hertz. Furthermore, the intra-pulse frequency of the electrical stimulation signal may, for example, range from <NUM> Hertz to <NUM> Hertz. Furthermore, the intra-pulse frequency of the electrical stimulation signal may be, for example, <NUM> Hertz. The voltage of the electrical stimulation signal may range from -25V ~ +25V. Furthermore, the voltage of the electrical stimulation signal may range from -20V ~ +20V. The current of the electrical stimulation signal may range from <NUM>-<NUM> mA. Furthermore, the current of the electrical stimulation signal may range from <NUM>-<NUM> mA.

According to an embodiment of the present disclosure, a user may operate the electrical stimulation device <NUM> to perform electrical stimulation only when in need (e.g., the symptom becomes more serious or does not alleviate). After the electrical stimulation device <NUM> has performed electrical stimulation on the target area once, the electrical stimulation device <NUM> must wait for a limited period before performing electrical stimulation on the target area again. For example, after the electrical stimulation device <NUM> has performed electrical stimulation on the target area once, the electrical stimulation device <NUM> must wait for <NUM> minutes (i.e., the limited period) before performing electrical stimulation on the target area again, but the present disclosure is not limited thereto. The limited period may be <NUM> minutes, <NUM> hour, <NUM> hours, or any time period within <NUM> hours.

According to the embodiment of the present disclosure, the measurement circuit <NUM> may measure the voltage value and the current value of the electrical stimulation signal according to the electrical stimulation signal generated by the electrical stimulation signal generation circuit <NUM>. In addition, the measurement circuit <NUM> may measure the voltage value and the current value on the tissues in the target area of the body of the user or the patient. According to an embodiment of the present disclosure, the measurement circuit <NUM> may adjust the current and the voltage of the electrical stimulation signal according to the instructions of the control unit <NUM>. The detailed structure regarding the measurement circuit <NUM> will be explained in <FIG>.

According to the embodiment of the present disclosure, the control unit <NUM> may be a controller, a microcontroller, or a processor, but the present disclosure is not limited thereto. The control unit <NUM> may be used for controlling the electrical stimulation signal generation circuit <NUM> and the measurement circuit <NUM>. The operations regarding the control unit <NUM> will be explained in <FIG>.

According to the embodiment of the present disclosure, the communication circuit <NUM> may be used for communicating with the external control device <NUM>. The communication circuit <NUM> may transmit the instructions or signals received by the external control device <NUM> to the control unit <NUM>, and transmit the data measured by the electrical stimulation device <NUM> to the external control device <NUM>. According to the embodiment of the present disclosure, the communication circuit <NUM> may be a wireless communication or a wire communication for communicating with the external control device <NUM>.

According to an embodiment of the present disclosure, all the electrodes of the electrical stimulation device <NUM> may be activated during the electrical stimulation. Therefore, users do not need to select which electrodes to be activated, and do not need to select which activated electrodes are negative polarity or positive polarity. For example, if the electrical stimulation device <NUM> is equipped with <NUM> electrodes, these <NUM> electrodes can be <NUM> positive polarities and <NUM> negative polarities staggeringly arranged.

A pulse signal that is lower (e.g., <NUM> Hertz) than conventional electrical stimulation may be prone to cause discomfort such as the feeling of stabbing pain, or paresthesia to the user. In an embodiment of the present disclosure, the electrical stimulation signal is a high frequency (e.g., <NUM> Hertz) pulse signal, so it will not cause paresthesia to users, or just cause extremely slight paresthesia to users.

According to the embodiment of the present disclosure, the storage unit <NUM> may be a volatile memory (e.g., a random access memory (RAM)), or a non-volatile memory (e.g., flash memory), a read only memory (ROM), a hard drive, or any combination thereof. The storage unit <NUM> may be used for storing the files and data required for performing the electrical stimulation. According to an embodiment of the present disclosure, the storage unit <NUM> may be used for storing related information of the lookup table provided by the external control device <NUM>.

<FIG> is a schematic diagram of an electrical stimulation device <NUM>, according to an embodiment of the present disclosure. As shown in <FIG>, the electrical stimulation signal generation circuit <NUM> may include a variable resistor <NUM>, a waveform generator <NUM>, a differential amplifier <NUM>, a channel switch circuit <NUM>, a first resistor <NUM>, and a second resistor <NUM>. The measurement circuit <NUM> may include a current measurement circuit <NUM> and a voltage measurement circuit <NUM>. It should be appreciated that the schematic diagram shown in <FIG> is only for the convenience to explain the embodiments of the present disclosure, but the present disclosure is not limited to <FIG>. The electrical stimulation device <NUM> may also include other elements, or other equivalent circuits.

As shown in <FIG>, according to the embodiment of the present disclosure, the variable resistor <NUM> may be coupled to a serial peripheral interface (SPI) (not shown in the figure) of the control unit <NUM>. The control unit <NUM> may transmit instructions to the variable resistor <NUM> via the SPI to adjust the resistance of the resistor <NUM>, so as to adjust the amplitude of the electrical stimulation signal to be output. The waveform generator <NUM> may be coupled to a pulse width modulation (PWM) signal generator (not shown in the figure) of the control unit <NUM>. The PWM signal generator may generate a square wave signal, and transmit the square wave signal to the waveform generator <NUM>. After receiving the square wave signal generated by the PWM signal generator, the waveform generator <NUM> will convert the square wave signal into a sinusoidal wave signal, and transmit the sinusoidal wave signal to the differential amplifier <NUM>. The differential amplifier <NUM> may convert the sinusoidal wave signal into a differential signal (i.e., the electrical stimulation signal output), and transmit the differential signal to the channel switch circuit <NUM> via the first resistor <NUM> and the second resistor <NUM>. The channel switch circuit <NUM> may transmit the differential signal (i.e., the electrical stimulation signal output) to the electrode corresponding to each channel via the lead L in turn according to the instructions of the control unit <NUM>.

As shown in <FIG>, according to the embodiment of the present disclosure, the current measurement circuit <NUM> and the voltage measurement circuit <NUM> may be coupled to the differential amplifier <NUM>, so as to obtain the current value and the voltage value of the differential signal (i.e., the electrical stimulation signal output). Besides, the current measurement circuit <NUM> and the voltage measurement circuit <NUM> may be used for measuring the voltage value and the current value on the tissues in the target area of the body of the user or the patient. In addition, the current measurement circuit <NUM> and the voltage measurement circuit <NUM> may be coupled to the input/output (I/O) interface (not shown in the figure) of the control unit <NUM>, so as to receive the instructions from the control unit <NUM>. According to the instructions of the control unit <NUM>, the current measurement circuit <NUM> and the voltage measurement circuit <NUM> may adjust the current and the voltage of the electrical stimulation signal into a current value and a voltage value suitable for the control unit <NUM>. For example, if the voltage value measured by the voltage measurement circuit <NUM> is ±10V, and the control unit <NUM> is suitable for processing a voltage value with <NUM>-<NUM> Volts, then the voltage measurement circuit <NUM> may decrease the voltage value to ±<NUM>. 5V, and then increase the voltage value to <NUM>-3V.

After adjusting the current value and the voltage value, the current measurement circuit <NUM> and the voltage measurement circuit <NUM> may transmit the adjusted electrical stimulation signal to the analog-to-digital convertor (ADC) (not shown in the figure) of the control unit <NUM>. The ADC may take samples from the electrical stimulation signal for the control unit to perform follow-up computation and analysis.

According to an embodiment of the present disclosure, when performing electrical stimulation on the target area of the body of a patient, the user (medical personnel or the patient himself) may select an electrical stimulation level from among a plurality of electrical stimulation levels on the operation interface of the external control device <NUM>. In the embodiment of the present disclosure, different electrical stimulation levels may correspond to different target energies. The target energy may be a set of default energy. When the user selects an electrical stimulation level, the electrical stimulation device <NUM> may find out how many millijoules of energy must be provided to the target area in order to perform the electrical stimulation, according to the target energy corresponding to the electrical stimulation level selected by the doctor or the user. According to the embodiment of the present disclosure, in the trial phase, a plurality of target energies corresponding to a plurality of electrical stimulation levels may be regarded as a first set of default target energy. According to the embodiment of the present disclosure, the first set of the default target energy (i.e., the target energies) may be a linear sequence, an arithmetic sequence, or a geometric sequence, but the present disclosure is not limited thereto.

According to an embodiment of the present disclosure, in the trial phase, the external control device <NUM> may be provided with a lookup table. In this embodiment, the first lookup table may record each of the electrical stimulation levels and the corresponding target energy. Therefore, according to the electrical stimulation level selected by the user, the external control device <NUM> may look up the lookup table, and obtain the target energy corresponding to the electrical stimulation level selected by the user from the first target energy set. After obtaining the target energy corresponding to the electrical stimulation level selected by the user, the external control device <NUM> will transmit the target energy to the electrical stimulation device <NUM>. Thus, the electrical stimulation device <NUM> may perform electrical stimulation on the target area according to the target energy.

According to another embodiment of the present disclosure, the electrical stimulation device <NUM> may be provided with a built-in first lookup table (e.g., a first lookup table stored in the storage unit <NUM>). In this embodiment, the first lookup table may record each of the electrical stimulation levels and the corresponding target energy. After the user has selected an electrical stimulation level from the external control device, the external control device <NUM> will transmit an instruction to inform the control unit <NUM> of the electrical stimulation device <NUM> what electrical stimulation level was selected by the user. Then, the control unit <NUM> may select the target energy that corresponds to the electrical stimulation level selected by the user from the first target energy set according to the built-in first lookup table. After obtaining the target energy, the electrical stimulation device <NUM> may perform electrical stimulation on the target area according to the selected target energy, until the corresponding first target energy value is transmitted to the target area and the time for the electrical stimulation ends. One round of electrical stimulation is thus completed.

According to another embodiment of the present disclosure, the communication circuit <NUM> may first obtain the electrical stimulation level selected by the user, and the first lookup table, from the external control device <NUM>. In this embodiment, the first lookup table may record the electrical stimulation level and the corresponding target energy. Then, the control unit <NUM> selects the target energy that corresponds to the electrical stimulation level selected by the user from the first target energy set, according to the electrical stimulation level selected by the user and the first lookup table that are obtained from the external control device <NUM>. After obtaining the target energy, the electrical stimulation device <NUM> may thus perform electrical stimulation on the target area according to the target energy.

According to the embodiment of the present disclosure, the users may select the electrical stimulation level from the lowest level (the lowest level of electrical stimulation corresponds to the lowest target energy in the first target energy set). After the electrical stimulation ends and the limited period passes, the next target energy may be selected from the first target energy set. Once the user finds the target energy that he/she prefers or that is more therapeutically effective, then the target energy may be regarded as a predetermined target energy, and the electrical stimulation level corresponding to the predetermined target energy may be regarded as a predetermined electrical stimulation level.

According to an embodiment of the present disclosure, in the permanent implantation phase, the external control device <NUM> (e.g., a controller of the external control device <NUM>) may select a target energy upper bound and a target energy lower bound from the first target energy set according to the predetermined electrical stimulation level. Then, the external control device <NUM> (e.g., a controller of the external control device <NUM>) may generate a second target energy set according to the target energy upper bound and the target energy lower bound. In this embodiment, the external control device <NUM> (e.g., a controller of the external control device <NUM>) may generate a second lookup table according to the electrical stimulation level corresponding to each of the target energies in the second target energy set. The external control device <NUM> may transmit the second lookup table and the related parameter information to the electrical stimulation device <NUM>. When the user is operating the external control device <NUM>, the electrical stimulation device <NUM> may perform electrical stimulation according to the second lookup table and the related parameter information. According to an embodiment of the present disclosure, in the trial phase, an external electrical stimulation device (i.e., a non-implantable electrical stimulation device) is used to perform electrical stimulation according to the first target energy set in the first lookup table selected by the user. In the permanent phase, the electrical stimulation device <NUM> (i.e., an implantable electrical stimulation device) is used to perform electrical stimulation according to the second target energy set in the second lookup table selected by the user. In an embodiment of the present disclosure, the electrical stimulation device <NUM> performs electrical stimulation on the target area, until the corresponding second target energy value is transmitted to the target area and this round of electrical stimulation ends. One round of electrical stimulation is thus completed.

According to another embodiment of the present disclosure, in the permanent implantation phase, the electrical stimulation device <NUM> may select a target energy upper bound and a target energy lower bound from the first target energy set according to the predetermined electrical stimulation level. Then, the electrical stimulation device <NUM> may generate the second target energy set according to the target energy upper bound and the target energy lower bound. In this embodiment, the electrical stimulation device <NUM> may generate a second lookup table according to the second target energy set and the electrical stimulation level corresponding to each of the target energies in the second target energy set. The electrical stimulation device <NUM> may transmit the second lookup table and the related parameter information to the external control device <NUM>. When the user is operating the external control device <NUM>, the electrical stimulation device <NUM> may perform electrical stimulation according to the second lookup table and the related parameter information.

According to the embodiment of the present disclosure, the second target energy set may be a linear sequence, an arithmetic sequence, or a geometric sequence, but the present disclosure is not limited thereto. According to an embodiment of the present disclosure, the number of the target energies included by the first target energy set may be the same as the number of the target energies included by the second target energy set. According to another embodiment of the present disclosure, the number of the target energies included by the first target energy set may be different to the number of the target energies included by the second target energy set.

<FIG> illustrates the first target energy set, according to an embodiment of the present disclosure. <FIG> illustrates the second target energy set, according to an embodiment of the present disclosure. It should be appreciated that <FIG> are only for depicting an embodiment of the present disclosure, but the present disclosure is not limited to the first target energy set and the second target energy set in <FIG>.

As shown in <FIG>, the first lookup table may store the correspondence between electrical stimulation levels and the first target energies. The first target energy set may include the target energy X1-X10. The electrical stimulation levels Level <NUM>(L1)-Level <NUM>(L10) correspond to the target energies X1-X10, respectively, and the unit of the target energy is millijoule. In addition to the target energies, the electrical stimulation levels L1-L10 may further correspond to different current values or voltage values. In this embodiment, in the trial phase, when the predetermined electrical stimulation level selected by the user is L6 (the predetermined target energy is X6, accordingly), the predefined target energy upper bound is X8 and the target energy lower bound is X5. There is a target energy between the target energy upper bound X8 and the predetermined target energy X6, while there is no target energy between the target energy lower bound X5 and the predetermined target energy X6.

In the permanent implantation phase, after obtaining the target energy upper bound X8 and the target energy lower bound X5, the electrical stimulation device <NUM> or the external control device <NUM> may generate the second target energy set according to the target energy upper bound X8 and the target energy lower bound X5. As shown in <FIG>, the second target energy set may include target energies Y1-Y8, which correspond to the electrical stimulation levels L1-L8 of the external control device <NUM> respectively. Besides, in this embodiment, the lowest target energy Y1 of the second target energy set corresponds to the target energy lower bound X5, and the highest target energy Y8 corresponds to the target energy upper bound X8. In the permanent implantation phase, the electrical stimulation device <NUM> and the external control device <NUM> may perform operations of electrical stimulation according to the second target energy set.

According to the embodiment of the present disclosure, when corresponding to a predetermined electrical stimulation level in the trial phase, the first target energy set may include a target energy upper bound and a target energy lower bound. The target energy upper bound and the target energy lower bound will be brought into the permanent implantation phase. The target energy upper bound will be the highest target energy in the second target energy set, and the target energy lower bound will be the lowest target energy in the second target energy set (as shown in <FIG>). As such, the user may perform the electrical stimulation in the permanent implantation phase using an energy intensity near the predetermined electrical stimulation level selected, thus the safety of the electrical stimulation is further assured.

According to an embodiment of the present disclosure, there is a first number of target energies between the target energy upper bound and the predetermined target energy, and there is a second number of target energies between the target energy lower bound and the predetermined target energy. According to an embodiment of the present disclosure, the first number (e.g., <NUM>) is larger than the second number (e.g., <NUM>) (as shown in <FIG>). According to another embodiment of the present disclosure, the first number may be equivalent to the second number.

According to an embodiment of the present disclosure, the predetermined target energy is not included in the second target energy set (as shown in <FIG>). According to another embodiment of the present disclosure, the predetermined target energy may be included in the second target energy set.

According to an embodiment of the present disclosure, the trial phase and the permanent implantation phase may both be further divided into a non-electrically-stimulating phase and an electrically-stimulating phase. In other words, the trial phase may include the non-electrically-stimulating phase and the electrically-stimulating phase, and the permanent implantation phase may also include the non-electrically-stimulating phase and the electrically-stimulating phase. The non-electrically-stimulating phase refers to when the electrical stimulation device <NUM> and the external control device <NUM> have just been turned on, or after the electrical stimulation device <NUM> and the external control device <NUM> have been connected, but the user has not yet initiated electrical stimulation. The electrical-stimulating phase refers to when the electrical stimulation device <NUM> has started providing electrical stimulation treatment. It should be noted that a method of how to calculate the tissue impedance value is applicable to the trial stage or the permanent implantation stage.

According to an embodiment of the present invention, before the electrical stimulation device <NUM> performs electrical stimulation on the target area, the control unit <NUM> of the electrical stimulation device <NUM> determines whether the signal quality of the electrical stimulation signal generated by the electrical stimulation signal generation circuit <NUM> meets a threshold standard. There are more detailed instructions below.

<FIG> is a block diagram of the control unit <NUM> according to an embodiment of the present invention. As shown in <FIG>, the control unit <NUM> may comprise a sampling module <NUM>, a Fast Fourier transform operation module <NUM>, a determination module <NUM>, and a calculation module <NUM>. It should be noted that the block diagram shown in <FIG> is only for the convenience of explaining the embodiment of the present invention, but the present invention is not limited to <FIG>. The control unit <NUM> may also comprise other elements. In the embodiment of the present invention, the sampling module <NUM>, the fast Fourier transform operation module <NUM>, the determination module <NUM> and the calculation module <NUM> may be implemented by hardware or software. Moreover, according to another embodiment of the present invention, the sampling module <NUM>, the fast Fourier transform operation module <NUM>, the determination module <NUM>, and the calculation module <NUM> may also be independent from the control unit <NUM>.

According to an embodiment of the present invention, when the control unit <NUM> of the electrical stimulation device <NUM> determines whether the signal quality of the electrical stimulation signal generated by the electrical stimulation signal generation circuit <NUM> meets the threshold standard, the sampling module <NUM> will first sample the electrical stimulation signal generated by the stimulation signal generating circuit <NUM> and sent it to the fast Fourier transform operation module <NUM> to perform a fast Fourier transform operation. More specifically, the sampling module <NUM> samples the voltage signal of the electrical stimulation signal, and the fast Fourier transform operation module <NUM> performs a fast Fourier transform operation on the sampled voltage signal. In addition, the sampling module <NUM> samples the current signal of the electrical stimulation signal, and the fast Fourier transform operation module <NUM> performs a fast Fourier transform operation on the sampled current signal. In the embodiment of the present invention, the sampling module <NUM> samples the electrical stimulation signal in a sampling period, and the sampling period indicates that the voltage signal and the current signal in a period of time in the pulses included in each duration Td are sampled, that is, sampling the electrical stimulation signal means sampling the pulse signal. According to an embodiment of the present invention, the sampling module <NUM> first samples the voltage signal of the electrical stimulation signal (for example, by taking <NUM> points), and then samples the current signal of the electrical stimulation signal (for example, by taking <NUM> points). However, the invention is not limited to the above sampling number or sampling order.

In an embodiment of the present invention, the sampling module <NUM> samples each pulse signal of the plurality of pulse signals. In another embodiment of the present invention, the sampling module <NUM> samples at least one of the plurality of pulse signals. For example, the sampling module <NUM> only samples one pulse signal among every two pulse signals, or the sampling module <NUM> samples only one pulse signal among every three pulse signals. In one embodiment of the present invention, the data of the adjacent sampled pulse signals may be applied to the unsampled pulse signal, however the present invention is not limited thereto. In other words, in an embodiment of the present invention, in one around of electrical stimulation (i.e., the transmission of the first target energy value or the second target energy value to the target area is completed), the sampling module <NUM> may sample at least one of a plurality of pulse signals at one or more times to obtain a corresponding tissue impedance value or tissue impedance values.

The determination module <NUM> will determine whether the signal quality of the electrical stimulation signal which has been processed by the fast Fourier transform operation meets the threshold standard. More specifically, the determination module <NUM> will determine whether a first frequency of the voltage signal that has been processed by the fast Fourier transform operation and a second frequency of the current signal which has been processed by the fast Fourier transform operation conform to a predetermined frequency, so as to determine whether the signal quality of the electrical stimulation signal meets the threshold standard. In other words, when the first frequency of the voltage signal that has been processed by the fast Fourier transform operation and the second frequency of the current signal which has been processed by the Fast Fourier transform operation conform to the predetermined frequency, the determination module <NUM> will determine that the signal quality of the electrical stimulation signal meets the threshold standard. When the first frequency of the voltage signal that has been processed by the fast Fourier transform operation and the second frequency of the current signal which has been processed by the fast Fourier transform operation do not conform to the predetermined frequency, the determination module <NUM> will determine that the signal quality of the electrical stimulation signal does not meet the threshold standard. According to one embodiment of the present invention, the predetermined frequency may be between <NUM> and <NUM> Hz. According to another embodiment of the present invention, the predetermined frequency may be between <NUM> and <NUM> Hz.

According to an embodiment of the present invention, when at least one of the first frequency and the second frequency does not conform to the predetermined frequency during the non-electrically-stimulating phase, the determination module <NUM> will determine whether a voltage value corresponding to the electrical stimulation signal is greater than or equal to a first predetermined voltage value (for example: <NUM> volts). If the voltage value is less than the first predetermined voltage value, the determination module <NUM> increases the voltage value of the electrical stimulation signal by a set value, and then the electrical stimulation signal is re-sampled. If the voltage value is greater than or equal to the first predetermined voltage value, the determination module <NUM> will report to the external control device <NUM> that the tissue impedance value cannot be calculated. According to an embodiment of the present invention, the set value may be a certain value between <NUM> and <NUM> volts, and the first predetermined voltage value may be a certain value between <NUM> and <NUM> volts, however the invention is not limited thereto. According to an embodiment of the present invention, an initial voltage value of the electrical stimulation signal is also a certain value between <NUM> and <NUM> volts. In this embodiment, when the first frequency or the second frequency does not conform to the predetermined frequency, the determination module <NUM> may first increase a value of a counter by one and determine whether the value of the counter is equal to a predetermined count value. When the value of the counter is equal to the predetermined count value, the determination module <NUM> will report to the external control device <NUM> that the tissue impedance value cannot by calculated. When the value of the counter is less than the predetermined count value, the determination module <NUM> determines whether a voltage value corresponding to the electrical stimulation signal is greater than or equal to a first predetermined voltage value. If the first frequency and the second frequency both conform to the predetermined frequency once before the value of the counter reaches the predetermined count value, the counter is reset to zero. According to an embodiment of the present invention, the predetermined count value may be any value between <NUM> and <NUM>.

According to an embodiment of the present invention, in the non-electrically-stimulating phase, when the first frequency or the second frequency does not conform to the predetermined frequency, the determination module <NUM> will determine whether an average current value corresponding to the sampled electric stimulation signal is greater than or equal to a predetermined current value (for example: 2mA). If the average current value is less than the predetermined current value, the determination module <NUM> increases the voltage value of the electrical stimulation signal by a set value. If the average current value is greater than or equal to the predetermined current value, the determination module <NUM> will perform the subsequent calculation of the electrical stimulation signal. According to an embodiment of the present invention, the set value may be a certain value between <NUM> and <NUM> volts, and the first predetermined voltage value may be a certain value between <NUM> and <NUM> volts, however the invention is not limited thereto. According to an embodiment of the present invention, an initial voltage value of the electrical stimulation signal is also a certain value between <NUM> and <NUM> volts.

According to an embodiment of the present invention, during the electrically-stimulating phase, when at least one of the first frequency and the second frequency does not conform to the predetermined frequency, the determination module <NUM> will re-sample the electrical stimulation signal and does not use the electrical stimulation signal which is sampled this time, or the external control device <NUM> can recognize that the electrical stimulation signal sampled this time is not used according to the determination result of the determination module <NUM>. In the embodiment, when at least one of the first frequency and the second frequency does not conform to the predetermined frequency, the determination module <NUM> can use the electrical stimulation signal that met the threshold standard in the previous iteration to perform subsequent operations in the electrical stimulation. Alternatively, the external control device <NUM> can use the electrical stimulation signal that met the threshold standard in the previous iteration to perform subsequent operations in the electrical stimulation, according to the determination result of the determination module <NUM>.

According to an embodiment of the present invention, when the determination module <NUM> determines that the signal quality of the electrical stimulation signal meets the threshold standard, the calculating module <NUM> will calculate an impedance value (i.e., a tissue impedance) corresponding to the sampled electrical stimulation signal value) to electrically stimulate a target area. There is a more detailed description provided below.

According to an embodiment of the present invention, when the determination module <NUM> determines that the signal quality of the electrical stimulation signal meets the threshold standard, the calculation module <NUM> extracts a first voltage sampling point corresponding to a maximum voltage value in each sampling period and a second voltage sampling point corresponding to a minimum voltage value, and subtracts the minimum voltage value from the maximum voltage value and divides the difference by <NUM> to generate an average voltage value, which can eliminate the background value. It should be noted that, as described above, the voltage measuring circuit <NUM> can increase the voltage value to a positive value according to the command of the control unit <NUM> , so as to facilitate the processing by the control unit <NUM>. Moreover, when the determination module <NUM> determines that the signal quality of the electrical stimulation signal meets the threshold standard, the calculation module <NUM> will extract a first current sampling point corresponding to a maximum current value and a second current sampling point corresponding a minimum current value in each sampling period value one of the s, and subtracts the minimum current value from the maximum current value and divides the difference by <NUM> to generate an average current value for eliminating background values. After obtaining the average voltage value and the average current value, the calculation module <NUM> obtains a total impedance value according to the average voltage value and the average current value and calculates the tissue impedance value according to the total impedance value. How to calculate the tissue impedance value based on the total impedance value is described below in detail. According to another embodiment of the present invention, if the background value is <NUM>, the calculation module <NUM> may add the maximum voltage value and the minimum voltage value and then divide the sum by <NUM> to generate an average voltage value, and further add the maximum current value and the minimum current value and then divide the sum by <NUM> to generate the average voltage value.

According to another embodiment of the present invention, when the determination module <NUM> determines that the signal quality of the electrical stimulation signal meets the threshold standard, the sampling module <NUM> will sample all the peaks and valleys of the voltage signal of the electrical stimulation signal, and the calculation module <NUM> generates an average voltage value according to the values of all the voltage sampling points. For example, the calculation module <NUM> may average the peaks and valleys included in the <NUM> sampling points of the voltage signal sampled in each sampling period to generate the average voltage value. Moreover, the sampling module <NUM> samples all the peaks and valleys of the current signal of the electrical stimulation signal, and the calculation module <NUM> generates an average current value according to the values of all the current sampling points. For example, the calculation module <NUM> may average the peaks and valleys included in the <NUM> sampling points of the current signal sampled in each sampling period to generate the average current value. Then, the calculation module <NUM> obtains a total impedance value according to the average voltage value and the average current value and calculates the tissue impedance value according to the total impedance value. How to calculate the tissue impedance value based on the total impedance value is described below in detail.

According to an embodiment of the present invention, before the electrical stimulation device <NUM> performs electrical stimulation on the target area, e.g., in the non-electrically-stimulating phase, the electrical stimulation apparatus <NUM> calculates a tissue impedance value of the target area. According to an embodiment of the present invention, the electrical stimulation device <NUM> (such as the electrical stimulation device <NUM> shown in <FIG>) can calculate the tissue impedance value according to the impedance value of the lead and the impedance value of the electrical stimulation device <NUM> itself. According to another embodiment of the present invention, the electrical stimulation device <NUM> (such as the electrical stimulation device <NUM> shown in <FIG>) can calculate the tissue impedance value according to the impedance value of the electrical stimulation device <NUM> itself. There is a more detailed description provided below.

<FIG> is a block diagram showing an impedance compensation device <NUM> according to an embodiment of the present invention. As shown in <FIG>, the impedance compensation device <NUM> may comprise a measurement circuit <NUM>, however the invention is not limited thereto. The measurement circuit <NUM> can be used to measure an impedance value ZInner of the electrical stimulation device <NUM> and an impedance value Zlead of the lead. According to an embodiment of the present invention, the impedance compensation device <NUM> (or the measurement circuit <NUM> ) may also comprise the related circuit structure shown in <FIG>.

According to an embodiment of the present invention, when the measurement circuit <NUM> is to measure the electrical stimulation device <NUM> as shown in <FIG>, the measurement circuit <NUM> first provides a high-frequency environment. This frequency is the same as the frequency of the electrical stimulation signal which is provided for the electrical stimulation on the target area, for example <NUM>. Then, the measurement circuit <NUM> measures a resistance value RLead, a capacitance value CLead, and an inductance value LLead of the lead, and calculates the impedance value ZLead of the lead under the high frequency signal according to at least one of the measured resistance value RLead, capacitance value CLead, and inductance value LLead. Moreover, the measurement circuit <NUM> measures a resistance value RInner, a capacitance value CInner, and an inductance value LInner of the electrical stimulation device <NUM>, and calculates the impedance value ZInner of the electrical stimulation device <NUM> according to at least one of the measured resistance value RInner, capacitance value CInner, and inductance value LInner. In an embodiment of the present invention, the inductance value LInner of the electrical stimulation device <NUM> may not be measured. The measurement circuit <NUM> writes the calculated impedance value ZLead of the lead, and the impedance value ZInner of the electrical stimulation device <NUM> into the firmware of the electrical stimulation device <NUM>.

When the electrical stimulation device <NUM> wants to calculate the tissue impedance value ZLoad of the target area, the electrical stimulation device <NUM> deducts the impedance value ZLead of the lead and the impedance value ZInner of the electrical stimulation device <NUM> from the measured total impedance value ZTotal to obtain the tissue impedance value ZLoad of the target area, such as the impedance compensation model ZLoad=ZTotal-ZInner-ZLead shown in <FIG>, however the present invention is not limited thereto. In the embodiment of the present invention, the total impedance value ZTotal can be calculated by the calculation module <NUM> according to the current measured by the current measurement circuit <NUM> and the voltage measured by the voltage measuring circuit <NUM> (i.e., R=V/I). Since the calculation manner of the impedance value ZLead of the lead and the impedance value ZInner of the electrical stimulation device <NUM> can refer to Z=R+j (XL-XC), wherein R is resistance, XL is inductive reactance, and XC is capacitive reactance. They are well known to those skilled in the art, so the related description is omitted.

According to another embodiment of the present invention, when the measurement circuit <NUM> is to measure the electrical stimulation device <NUM> as shown in <FIG>, the measurement circuit <NUM> first provides a high-frequency environment. The measurement circuit <NUM> measures a resistance value RInner, a capacitance value CInner, and an inductance value LInner of the electrical stimulation device <NUM>, and calculates the impedance value ZInner of the electrical stimulation device <NUM> according to at least one of the measured resistance value RInner, the capacitance value CInner, and the inductance value LInner. In an embodiment of the present invention, the inductance value LInner of the electrical stimulation device <NUM> may not be measured. The measurement circuit <NUM> writes the calculated impedance value ZInner of the electrical stimulation device <NUM> into the firmware of the electrical stimulation device <NUM>. When the electrical stimulation device <NUM> is to calculate the tissue impedance value ZLoad of the target area, the electrical stimulation device <NUM> deducts the impedance value ZInner of the electrical stimulation device <NUM> from the measured total impedance value ZTotal to obtain the tissue impedance value ZLoad of the target area, such as the impedance compensation model ZLoad=ZTotal-ZInner shown in <FIG>, however the present invention is not limited thereto.

According to an embodiment of the present invention, the measurement circuit <NUM> can simulate a high-frequency environment according to an electrical stimulation frequency used by the electrical stimulation device <NUM>. According to an embodiment of the present invention, the pulse frequency range of the high-frequency environment provided by the measurement circuit <NUM> can be in the range of <NUM> to <NUM>. According to an embodiment of the present invention, the pulse frequency of the high-frequency environment provided by the measurement circuit <NUM> is the same as that of the electrical stimulation signal.

According to an embodiment of the present invention, the impedance compensation device <NUM> may be disposed in the external control device <NUM>. According to another embodiment of the present invention, the impedance compensation device <NUM> may be disposed in the electrical stimulation device <NUM>. That is, the high-frequency environment may be provided by the electrical stimulation device <NUM> or the external control device <NUM>. Moreover, according to another embodiment of the present invention, the impedance compensation device <NUM> can also be an independent device (e.g., an impedance analyzer).

According to an embodiment of the present invention, the impedance compensation device <NUM> may be applied in a trial phase (i.e., the electrical stimulation device <NUM> is an external electrical stimulation device with a lead implanted in the body). According to an embodiment of the present invention, the impedance compensation device <NUM> can be applied in the permanent implantation stage (i.e., the electrical stimulation device <NUM> is an implantable electrical stimulation device, and the electrical stimulation device <NUM> can be implanted into the human body together with the lead).

According to an embodiment of the present invention, the impedance compensation device <NUM> can be applied before the production of the electrical stimulation device <NUM> (e.g., in the laboratory or factory terminal). In one embodiment, before the electrical stimulation device <NUM> is produced, the impedance compensation device <NUM> may first calculate the impedance value ZLead of the lead and the impedance value ZInner of the electrical stimulation device <NUM> and write the calculated impedance value ZLead of the lead and the calculated impedance value ZInner of the electrical stimulation device <NUM> into the firmware of the electrical stimulation device <NUM>. In another embodiment, before the electrical stimulation device <NUM> is produced, the impedance compensation device <NUM> may first calculate the impedance value ZInner of the electrical stimulation device <NUM> and write the calculated impedance value ZInner of the electrical stimulation device <NUM> into the firmware of the electrical stimulation device <NUM>. According to an embodiment of the present invention, the impedance compensation device <NUM> may also performs real-time compensation during the electrically-stimulating phase and the non-electrically-stimulating phase, that is, ZInner and ZLead can be measured each time an electrical stimulation signal is sent.

According to one embodiment of the present invention, after the electrical stimulation device <NUM> obtains the tissue impedance value ZLoad, the electrical stimulation device <NUM> transmits the tissue impedance value ZLoad to the external control device <NUM>. The external control device <NUM> will determine whether the tissue impedance value ZLoad is within a predetermined range. During the electrically-stimulating phase, when the tissue impedance value ZLoad is outside the predetermined range, the external control device <NUM> may indicate the electrical stimulation device <NUM> to terminate the electrical stimulation. In the electrically-stimulating phase, when the tissue impedance value ZLoad is within the predetermined range, the external control device <NUM> may indicate the electrical stimulation device <NUM> to continue the electrical stimulation. According to another embodiment of the present invention, the electrical stimulation device <NUM> may also determine by itself whether the tissue impedance value ZLoad is within a predetermined range. During the electrically-stimulating phase, when the tissue impedance value ZLoad is outside the predetermined range, the electrical stimulation device <NUM> may terminate the electrical stimulation. In the electrically-stimulating phase, when the tissue impedance value ZLoad is within the predetermined range, the electrical stimulation device <NUM> may continue the electrical stimulation. According to an embodiment of the present invention, the case in which the tissue impedance value is outside the predetermined range means that the electrical stimulation device <NUM> and the lead <NUM> are in an open circuit, and the case in which the tissue impedance value is within the predetermined range means that the electrical stimulation device <NUM> and the lead <NUM> are in normal electrical connection.

According to an embodiment of the present invention, an upper limit values of the predetermined range for the tissue impedance may be <NUM> ohms, and a lower limit value of the predetermined range for the tissue impedance may be <NUM> ohms.

According to an embodiment of the present invention, after the electrical stimulation device <NUM> obtains a plurality of tissue impedance values ZLoad (for example: three tissue impedance values ZLoad), the calculation module <NUM> will calculate the average tissue impedance value of the plurality of tissue impedance values and transmits the average tissue impedance value to the external control device <NUM>. According to an embodiment of the present invention, the electrical stimulation device <NUM> may determine whether the average tissue impedance value is greater than the previous average tissue impedance value and whether the absolute value of the difference (i.e. absolute difference) between the average tissue impedance value and the previous average tissue impedance value is greater than a first predetermined percentage (for example: <NUM>%, <NUM>%, or <NUM>%). When the average tissue impedance value is greater than the previous average tissue impedance value and the difference between the average tissue impedance value and the previous average tissue impedance value is greater than the first predetermined percentage, the electrical stimulation device <NUM> averages the average tissue impedance value and the previous average tissue impedance value to generate an average value and updates an output average tissue impedance value as this average value. When the average tissue impedance value is not greater than (i.e., equal to or less than) the previous average tissue impedance value or the difference between the average tissue impedance value and the previous average tissue impedance value is not greater than the first predetermined percentage, the electrical stimulation device <NUM> updates a tissue impedance temporarily stored for output as the average tissue impedance value.

Moreover, according to an embodiment of the present invention, the electrical stimulation device <NUM> may determine whether the absolute value of the difference between the output average tissue impedance value and the previous output average tissue impedance value is greater than a second predetermined percentage (for example: <NUM>% , <NUM>% or <NUM>%). When the difference between the output average tissue impedance value and the previous output average tissue impedance vale is not greater than the second predetermined percentage, the external control device <NUM> indicates the electrical stimulation device <NUM> not to adjust an output current, wherein the output current refers to the current of the electrical stimulation signal generated by the electrical stimulation device <NUM>. It should be noted that different output average tissue impedance values correspond to different output currents. When the output average tissue impedance value is greater, the output current is greater. In an embodiment of the present invention, the corresponding relationship between the output average tissue impedance value and the output current may be stored in a first look-up table or a second look-up table (not shown). When the difference between the output average tissue impedance value and the previous output average tissue impedance value is greater than the second predetermined percentage, the electrical stimulation device <NUM> determines whether the output average tissue impedance value is less than a predetermined impedance value (e.g., <NUM> ohms). If the output average tissue impedance value is not less than (i.e., greater than or equal to) the predetermined impedance value, the electrical stimulation device <NUM> may determine not to adjust the output current. If the output average tissue impedance value is less than the predetermined impedance value, the electrical stimulation device <NUM> adjusts the output current according to the output average tissue impedance value.

For example, when the tissue impedance values obtained by the electrical stimulation device <NUM> for the first to third times are <NUM>, <NUM>, and <NUM> ohms, the electrical-stimulation device <NUM> may calculate the average tissue impedance value as <NUM> ohms; when the tissue impedance values obtained by the electrical stimulation device <NUM> for the fourth to sixth times are of <NUM>, <NUM>, <NUM> ohms, the (new) average tissue impedance value is <NUM> ohms. The average tissue impedance value at this time (<NUM> ohms) is less than the previous average tissue impedance value (<NUM> ohms), and the electrical stimulation device <NUM> updates the output average tissue impedance value as <NUM> ohms. When the tissue impedance values obtained by the electrical stimulation device <NUM> for the seventh to ninth times are obtains <NUM>, <NUM>, and <NUM> ohms, the average tissue impedance value is <NUM> ohms. The average tissue impedance value (<NUM> ohms) at this time is greater than the previous average tissue impedance value (<NUM> ohms), and the absolute value of the difference is greater than the first predetermined percentage (for example, <NUM>%). Then, the electrical stimulation device <NUM> averages the current average tissue impedance value (<NUM> ohms) and the previous average tissue impedance value (<NUM> ohms) to generate an average value (<NUM> ohms) and updates the output average tissue impedance value as the average value. Next, when the electrical stimulation device <NUM> determines that the absolute value of the difference between the output average tissue impedance value (<NUM> ohms) and the previous output average tissue impedance value (<NUM> ohms) is greater than the second predetermined percentage (for example: <NUM>%), the electrical stimulation device <NUM> determines that the output average tissue impedance value (<NUM> ohms) is less than the predetermined impedance value (e.g., <NUM> ohms). The electrical stimulation device <NUM> adjusts the output current according to the current output average tissue impedance value (<NUM> ohms).

In an embodiment of the present invention, the tissue impedance values, the average tissue impedance values, and the output average tissue impedance values can all be stored in the buffer region of the control unit <NUM> or the buffer region of the storage unit <NUM>, however the present invention is not limited thereto.

According to an embodiment of the present invention, in the electrically-stimulating phase (i.e., when the electrical stimulation device <NUM> has provided electrical stimulation treatment), in order to make the measurement circuit <NUM> operate successfully, if the voltage of the electrical stimulation signal is greater than a second predetermined voltage value (for example, <NUM> volts), the electrical stimulation device <NUM> generates electrical stimulation signals of a first predetermined number (for example: <NUM>) and performs a voltage reduction operation on electrical stimulation signals of a second predetermined number among the electrical stimulation signals of the first predetermined number. That is, the reducing voltages to the second predetermined voltage value is performed, and the electrical stimulation signals of the second predetermined number suffering the voltage reduction operation are used for the calculation of the subsequent tissue impedance value. The electrical stimulation signals, which do not suffer the voltage reduction operation, will not be used for the calculation of the subsequent tissue impedance. This operation is repeated. That is, after electrical stimulation signals of the first predetermined number are generated, electrical stimulation signals of the second predetermined number are generated, and the voltages are reduced to the second predetermined voltage value. Then, electrical stimulation signals of the first predetermined number are generated. For example, in the electrically-stimulating phase, if all the voltages of the electrical stimulation signals of front N times (for example, N=<NUM>, i.e. the 1st to 10th times) among the first predetermined number (for example: <NUM>) are greater than the second predetermined voltage value (for example, <NUM> volts), these N electrical stimulation signals will not be used for the calculation of the subsequent tissue impedance value. The electrical stimulation device <NUM> performs the voltage reduction operation (for example, to <NUM> volts) only on electrical stimulation signals of the second predetermined number (for example: the 11th to 13th times) and the calculation of the subsequent tissue impedance is performed using the specific electrical stimulation signals which have suffered the voltage reduction operation.

In an embodiment of the present invention, the tissue impedance value is used to calculate the energy value of the electrical stimulation signal transmitted to the target area, and the calculation equation of the energy value transmitted by the electrical stimulation signal can be E=<NUM>*I<NUM>*ZLoad* PW*rate*t, wherein E is the energy value, and the unit is Joule; <NUM> is a constant; I is the current, and the unit is ampere; PW is the pulse duration Td (that is, the duration Td in <FIG>), and the unit is seconds; ZLoad is the tissue impedance value, and the unit is ohm; rate is the pulse repetition frequency of the electrical stimulation signal, and the unit in Hertz; and t is the time for electrical stimulation, and the unit is seconds. In an embodiment of the present invention, the pulse width and the pulse frequency can be recorded in a look-up table stored in the storage unit <NUM> of the electrical stimulation device <NUM> and correspond to respective electrical stimulation levels. In another embodiment, the pulse width and pulse frequency can be recorded in a look-up table stored in the external control device <NUM> and correspond to the respective electrical stimulation levels, and the communication circuit <NUM> of the electrical stimulation device <NUM> can obtain the pulse width and pulse frequency from the external control device <NUM>.

Since the tissue impedance value ZLoad corresponding to the electrical stimulation signal sampled each time may vary, the energy value of the electrical stimulation signal sampled each time may vary accordingly. According to an embodiment of the present invention, in the electrically-stimulating phase, the calculation module <NUM> can calculate the energy value generated by the electrical stimulation signal to the target area to generate a total energy value and determine whether the total energy value has reached a target energy value. It should be noted that, if the sampling module <NUM> does not sample each pulse signal of a plurality of pulse signals, the total energy value still refers to the energy value generated by all the pulse signals to the target area. For example, in every two pulse signals, the sampling module <NUM> samples only one pulse signal, and the total energy value may be obtained by multiplying the energy value calculated for all the sampled pulse signals by <NUM>.

When the total energy value has reached the target energy value, the electrical stimulation signal generation circuit <NUM> will stop providing any electrical stimulation signal to the target area, which means that the electrical stimulation device <NUM> will terminate the electrical stimulation. For example, assume the target energy value is <NUM> millijoules (mJ). If the energy value of the electrical stimulation signal output by the electrical stimulation device <NUM> is <NUM> mJ when the electrical stimulation signal corresponds to a first tissue impedance value ZLoad and the energy value of the electrical stimulation signal output by the device <NUM> is <NUM> mJ when the next electrical stimulation signal corresponds to a second tissue impedance value ZLoad, the calculation module <NUM> can accumulate the energy value of the electrical stimulation signal to generate the total energy value (i.e., <NUM>+<NUM>=150mJ) and determines whether the total energy value has reached the target energy value (<NUM><<NUM>, the target energy value has not been reached). When the total energy value has reached the target energy value, the electrical stimulation signal generation circuit <NUM> will stop providing any electrical stimulation signal to the target area.

<FIG> is a flowchart <NUM> of an electrical stimulation method according to an embodiment of the present invention. The flow diagram <NUM> of the electrical stimulation method is applicable to the electrical stimulation device <NUM>. As shown in <FIG>, in Step S910, the electrical stimulation device <NUM> obtains a target energy value.

In Step S920, the electrical stimulation device <NUM> provides an electrical stimulation signal to a target area.

In Step S930, the electrical stimulation device <NUM> calculates a total energy value according to the energy value transmitted by the electrical stimulation signal to the target area.

In Step S940, the electrical stimulation device <NUM> determines whether the total energy value has reached the target energy value.

If the total energy value has reached the target energy value, the method proceeds to Step S950. In Step S950, the electrical stimulation of the electrical stimulation device <NUM> is terminated.

If the accumulated energy value has not reached the target energy value yet, the method proceeds to Step S960. In Step S960, the electrical stimulation device <NUM> continues to perform the electrical stimulation.

According to an embodiment of the present invention, in step S940 of the electrical stimulation method, the electrical stimulation device <NUM> can calculate energy value of each electrical stimulation signal according to the current value of the electrical stimulation signal, the corresponding tissue impedance value, and a time parameter.

According to the electrical stimulation method proposed in the present invention, the electrical stimulation device <NUM> can calculate the energy value of the electrical stimulation signal according to the change of the tissue impedance value. When the total energy value of the electrical stimulation signal transmitted to the target area has reached the target energy value, the electrical stimulation is terminated. Therefore, the user can be prevented from suffering electrical stimulation for a long time, and the electrical stimulation can be more efficiently performed on the user according to the energy level.

Ordinal terms used in the claims, such as "first," "second," "third," etc., are only for convenience of explanation, and do not imply any precedence relation between one another.

The steps of the methods and algorithms provided in the present disclosure may be directly applied to a hardware and a software module or the combination thereof by executing a processor. A software module (including executing instructions and related data) and other data may be stored in a data memory, such as random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), registers, hard drives, portable drives, CD-ROM, DVD, or any other computer-readable storage media format in the art. For example, a storage media may be coupled to a machine device, such as a computer/processor (denoted by "processor" in the present disclosure, for the convenience of explanation). The processor may read information (such as codes) from and write information to a storage media. A storage media may integrate a processor. An application-specific integrated circuit (ASIC) includes the processor and the storage media. A user apparatus includes an ASIC. In other words, the processor and the storage media are included in the user apparatus without directly connecting to the user apparatus. Besides, in some embodiments, any product suitable for computer programs includes a readable storage media, wherein the storage media includes codes related to one or more disclosed embodiments. In some embodiments, the computer program product may include packaging materials.

The above paragraphs are described with multiple aspects. Obviously, the teachings of the specification may be performed in multiple ways. Any specific structure or function disclosed in examples is only a representative situation. According to the teachings of the specification, it should be noted by those skilled in the art that any aspect disclosed may be performed individually, or that more than two aspects could be combined and performed.

Claim 1:
An electrical stimulation device (<NUM>) comprising:
an electrical stimulation signal generation circuit (<NUM>) configured for providing an electrical stimulation signal to a target area; and
a calculation module (<NUM>) configured to obtain a target energy value, calculate a total energy value according to an energy value of the electrical stimulation signal transmitted to the target area, and determine whether the total energy value has reached the target energy value,
characterized in that
the calculation module (<NUM>) is configured to obtain a value of the current of the electrical stimulation signal and calculate the energy value of the electrical stimulation signal according to the value of the current of the electrical stimulation signal and further according to a tissue impedance value corresponding to the electrical stimulation signal and a time parameter.