Circuit for a pulse generator, pulse generator and deep brain stimulation system

Abstract

The application discloses a kind of circuit for pulse generator, pulse generator and brain deep electrical stimulation system, low frequency resonant circuit is connected in series with ASK modulation circuit, the effective series connection of two circuits, both can utilize low frequency resonant circuit charging, and can be realized communication sending by ASK modulation circuit.In addition, charging coil and communication coil are combined into one, under the condition of equivalent communication success rate, charging function and communication function are realized on the same coil, the coil transmits charging energy and transmits communication information.The scheme provided by the application can combine charging coil and communication coil into one, and a very large volume can be saved in the limited space of implantable rechargeable computer deep brain stimulator, thereby simplifying the structural design and component assembly process of implantable pulse generator, and reducing the production cost of coil.Under the condition of equivalent communication success rate, the problems of large volume, large weight and low efficiency of the pulse generator in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of implantable medical instruments, and in particular relates to a circuit for a pulse generator, a pulse generator, and a deep brain electrical stimulation system. Background Art

[0002] With the advancement of brain surgery and neuroelectronics, deep brain stimulation (DBS) has become the preferred treatment for advanced Parkinson's disease worldwide, thanks to its superior clinical results compared to invasive surgery, minimally invasive procedure that does not damage brain tissue, and reversible treatment options. Existing DBS systems primarily consist of an implantable pulse generator (IPG), stimulation electrodes (leads), internal extension leads (extensions), an external programmer and remote, and surgical tools.

[0003] In DBS systems, long-distance communication with the implanted pulse generator (IPG) is the only means of monitoring the device's operating status. The success rate of communication is crucial for ensuring optimal therapeutic efficacy and reliability. Companies licensed to sell deep brain stimulation devices are diligently developing communication circuits with longer distances and higher success rates. To this end, most manufacturers utilize independent near-field communication coils, resulting in two coils within a single IPG: a charging coil and a communication coil. These products suffer from large size, heavy weight, and low efficiency.

[0004] For example, Medtronic and Boston Scientific use low-frequency communication to achieve wireless communication between active implantable medical devices and external programming devices, but the wireless communication coil and the charging coil are set separately. This increases the size of the active implantable medical devices and makes the circuits more complex, and also places higher requirements on production and assembly.

[0005] In existing DBS systems, the charging and communication functions are designed separately. This increases the size of the active implantable medical device, complicates the circuitry, and places higher demands on production and assembly. Therefore, a solution is needed to address the issues of large size, heavy weight, and low efficiency of pulse generators. Summary of the Invention

[0006] The object of the present invention is to provide a circuit for a pulse generator, a pulse generator, and a deep brain stimulation system, so as to solve the problem that the charging coil and the communication coil of the DBS system in the prior art are designed separately, which results in an increase in the size of the active implantable medical device and a complex circuit, and also puts higher requirements on production and assembly.

[0007] In order to solve the above technical problems, the first aspect of the present invention provides a circuit for a pulse generator, which is used to realize charging and communication of an IPG, including a low-frequency resonant circuit and an ASK modulation circuit;

[0008] Wherein, the low-frequency resonance circuit is connected in series with the ASK modulation circuit;

[0009] The low-frequency resonant circuit is used to provide a charging signal to charge the IPG, and to transmit a carrier signal and a first signal to the ASK modulation circuit;

[0010] The ASK modulation circuit is used to modulate the first signal according to the carrier signal to communicate with the IPG.

[0011] Optionally, the low-frequency resonant circuit includes a power supply, a charging module connected to the power supply, and a communication module. The carrier signal and the first signal are transmitted to the charging module via the communication module, and are transmitted to the ASK modulation circuit via the charging module.

[0012] Optionally, the communication module includes a first field effect transistor and a second field effect transistor, and the charging module includes a first capacitor, a second capacitor, a first coil, and a second coil;

[0013] The positive electrode of the power supply is connected to one end of the first coil, the other end of the first coil is connected to the drain of the first field-effect transistor, the source of the first field-effect transistor is connected to the drain of the second field-effect transistor, and the gate of the first field-effect transistor is used to transmit the carrier signal;

[0014] The source of the second field effect transistor is connected to the negative electrode of the power supply and is grounded, and the gate of the second field effect transistor is used to transmit the first signal;

[0015] The first capacitor is connected in parallel to both ends of the first coil, and the first coil and the second coil are coupled to each other;

[0016] The second capacitor is connected in parallel to both ends of the second coil, and the second coil is connected in series with the ASK modulation circuit.

[0017] Optionally, the first coil and the first capacitor have a first resonant frequency, and the first resonant frequency is equal to the frequency of the carrier signal.

[0018] Optionally, the second coil and the second capacitor have a second resonant frequency, and the second resonant frequency is equal to the frequency of the carrier signal.

[0019] Optionally, the first coil is a charging coil, the first capacitor is a charging capacitor, the second coil is a receiving coil, and the second capacitor is a receiving capacitor.

[0020] Optionally, the ASK modulation circuit includes a rectifier circuit, a first resistor and a third field effect transistor;

[0021] Wherein, one end of the first resistor is connected to one end of the second coil, and the rectifier circuit is connected between one end of the second coil and one end of the first resistor;

[0022] The other end of the first resistor is connected to the drain of the third field effect transistor, and the source of the third field effect transistor is connected to the other end of the second coil;

[0023] The drain of the third field effect transistor is connected to the output end of the ASK modulation circuit.

[0024] Optionally, the rectifier circuit includes a diode and a third capacitor;

[0025] The anode of the diode is connected to one end of the second coil and the source of the third field effect transistor respectively, and the cathode of the diode is connected to one end of the third capacitor and one end of the first resistor respectively;

[0026] The other end of the third capacitor is connected to the source of the third field effect transistor.

[0027] Based on the same inventive concept, the present invention proposes a pulse generator, comprising a circuit for a pulse generator as described in any one of the above feature descriptions.

[0028] Based on the same inventive concept, the present invention also proposes a deep brain electrical stimulation system, including a pulse generator as described in the above feature description.

[0029] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0030] The present invention provides a circuit for a pulse generator, a pulse generator, and a deep brain stimulation system. The low-frequency resonant circuit and the ASK modulation circuit are connected in series. The effective series connection of the two circuits enables both charging using the low-frequency resonant circuit and communication transmission via the ASK modulation circuit. This addresses the gap in the prior art for integrated charging and communication circuits.

[0031] In addition, the charging coil and the communication coil are combined into one, the charging function and the communication function are realized on the same coil in the case of the same communication success rate, the coil transmits charging energy and communication information, the charging coil and the communication coil are combined into one by the scheme, and a very large volume can be saved in the limited space of the implantable rechargeable computer deep stimulator. Therefore, the structure design and the component assembly process of the implantable pulse generator are simplified, and the coil production cost is reduced. In the case of the same communication success rate, the problems of large volume, large weight and low efficiency of the pulse generator in the prior art are solved. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A circuit structure schematic diagram for a pulse generator is provided for the embodiment of the present application.

[0033] Figure 2 A circuit logic schematic diagram for a pulse generator is provided for the embodiment of the present application.

[0034] 100-low frequency resonance circuit, 200-ASK modulation circuit, DC-power supply, V1-first field effect tube, V2-second field effect tube, C1-first capacitor, C2-second capacitor, L1-first coil, L2-second coil, R-first resistor, V3-third field effect tube, D-diode, C3-third capacitor. DETAILED DESCRIPTION

[0035] The specific embodiments of the present application will be described in more detail below with reference to the accompanying drawings. The advantages and features of the present application will be more apparent from the following description. It should be noted that the drawings are very simplified and use non-precise proportions, only to facilitate, clarify the purpose of assisting the description of the embodiments of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0037] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0038] Please refer to Figure 1 and Figure 2 An embodiment of the present invention provides a circuit for a pulse generator, which is used to achieve charging and communication with an IPG, including a low-frequency resonant circuit 100 and an ASK modulation circuit 200. The low-frequency resonant circuit 100 is connected in series with the ASK modulation circuit 200. The low-frequency resonant circuit 100 is used to provide a charging signal to charge the IPG and to transmit a carrier signal and a first signal to the ASK modulation circuit 200. The ASK modulation circuit 200 is used to modulate the first signal according to the carrier signal to communicate with the IPG. The output terminal Vsrx of the ASK modulation circuit 200 is used as a communication port for communicating with the IPG.

[0039] The difference from the prior art is that the low-frequency resonant circuit 100 is connected in series with the ASK modulation circuit 200. The low-frequency resonant circuit 100 can provide a charging signal to charge the IPG. In addition, the low-frequency resonant circuit 100 is also loaded with the carrier signal and the first signal. The first signal is actually a signal or instruction that needs to be transmitted to the IPG for communication. For example, the first signal can be an instruction for the IPG to emit a pulse current. The carrier signal and the first signal are transmitted to the ASK modulation circuit 200 through the low-frequency resonant circuit 100. The ASK modulation circuit 200 modulates the first signal according to the carrier signal and generates a modulated signal. The modulated signal is the modulated signal or instruction that needs to be transmitted to the IPG for communication. The modulated signal is transmitted to the IPG to achieve communication with the IPG. It should be noted that after the ASK modulation circuit 200 modulates the first signal, it needs to demodulate the modulated signal before transmitting it to the IPG. The demodulated modulated signal is the signal or instruction that is ultimately transmitted to the IPG. In addition, according to the principle of signal modulation and demodulation, it can be understood that the demodulation process of the modulated signal by the ASK modulation circuit 200 can be ASK demodulation. In the embodiment of the present invention, the specific method of ASK demodulation utilizes the envelope detection method (incoherent demodulation). In other embodiments, the specific method of ASK demodulation can also be implemented using the synchronous detection method (coherent demodulation). The specific method can be selected according to actual needs and is not limited here. For ease of understanding, the following embodiments of the present invention are specifically described using the envelope detection method as an example. The synchronous detection method is similar to the envelope detection method and will not be described here one by one. Through the effective series connection of the low-frequency resonant circuit 100 and the ASK modulation circuit 200, the low-frequency resonant circuit 100 can be used for charging, and the ASK modulation circuit 200 can be used for communication transmission. It fills the gap in the charging and communication integrated circuit in the prior art.

[0040] Specifically, please refer to Figure 2 The low-frequency resonance circuit 100 may include a power supply DC, a charging module connected to the power supply DC, and a communication module. The carrier signal and the first signal are transmitted to the charging module through the communication module, and then transmitted to the ASK modulation circuit 200 through the charging module. Preferably, please refer to Figure 1 The communication module includes a first field-effect transistor (FET) V1 and a second field-effect transistor (FET) V2, and the charging module includes a first capacitor C1, a second capacitor C2, a first coil L1, and a second coil L2. The positive electrode of the DC power supply is connected to one end of the first coil L1, the other end of the first coil L1 is connected to the drain of the first field-effect transistor (FET) V1, and the source of the first field-effect transistor (FET) V1 is connected to the drain of the second field-effect transistor (FET) V2. The gate of the first field-effect transistor (FET) V1 is used to transmit the carrier signal, and the frequency of the carrier signal can be controlled by turning the first field-effect transistor (FET) V1 on and off. The source of the second field-effect transistor (FET) V2 is connected to the negative electrode of the DC power supply and grounded, and the gate of the second field-effect transistor (FET) V2 is used to transmit the first signal, and the frequency of the carrier signal can be controlled by turning the second field-effect transistor (FET) V2 on and off. The first capacitor C1 is connected in parallel across the first coil L1, and the first coil L1 and the second coil L2 are coupled to each other. The second capacitor C2 is connected in parallel across the second coil L2, and the second coil L2 is connected in series with the ASK modulation circuit 200.

[0041] The first coil L1 and the second coil L2 are inductors. The first coil L1 functions as a charging coil, the first capacitor C1 functions as a charging capacitor, the second coil L2 functions as a receiving coil, and the second capacitor C2 functions as a receiving capacitor. When the low-frequency resonant circuit 100 is switched on, the first coil L1 generates an electromagnetic field, which is transmitted to the second coil L2. The second coil L2 generates a resonant electromagnetic field, which is then converted into electrical energy by the second coil L2 to achieve the charging function. In addition to achieving the charging function, the first coil L1 and the second coil L2 are also used to transmit communication signals. The low-frequency resonant circuit 100 also transmits the carrier signal and the first signal. The first signal is loaded onto the carrier signal. The ASK modulation circuit 200 modulates the first signal according to the carrier signal to generate a modulated signal. The modulated signal is demodulated and transmitted to the IPG. Changes in the load within the IPG cause changes in the resonant voltage of the low-frequency resonant circuit 100, enabling communication with the IPG.

[0042] It should be noted that there is no restriction on the sizes of the first coil L1, the second coil L2, the first capacitor C1, and the second capacitor C2. Preferably, the first coil L1 and the first capacitor C1 have a first resonant frequency, which is equal to the frequency of the carrier signal; the second coil L2 and the second capacitor C2 have a second resonant frequency, which is equal to the frequency of the carrier signal. For example, in an embodiment of the present invention, the frequency of the carrier signal is set to 7.12 kHz, the inductance of the first coil L1 is L1, the inductance of the second coil L2 is L2, the capacitance of the first capacitor C1 is C1, the capacitance of the second capacitor C2 is C2, the calculation formula of the first resonant frequency F1 is: F1 = 1 / (2π(L1×C1)^0.5), and the calculation formula of the second resonant frequency F2 is: F2 = 1 / (2π(L2×C2)^0.5). Therefore, L1, L2, C1, and C2 only need to satisfy: 1 / (2π(L1×C1)^0.5) = 1 / (2π(L2×C2)^0.5) = 7.12 kHz. For ease of explanation, in an embodiment of the present invention, the inductance of the first coil L1 is set to 1mH, the capacitance of the first capacitor C1 is set to 500nf, the inductance of the second coil L2 is set to 4mH, and the capacitance of the second capacitor C2 is set to 125nf. It should be noted that in this embodiment, the frequency of the carrier signal is set to 7.12kHz. It is understandable that in other embodiments, the frequency of the carrier signal can also be set to other values, for example, 6kHz or 8kHz. The specific value of the frequency of the carrier signal can be selected according to actual needs and is not limited here. In addition, the inventors found that when the frequency of the carrier signal exceeds 10kHz, the transmission efficiency of the carrier signal is very low. Therefore, setting the frequency of the carrier signal to less than 10kHz can be implemented as a preferred solution.

[0043] The charging coil and the communication coil are combined into one. Under the condition of the same communication success rate, the charging function and the communication function are realized on the same coil, and the coil transmits both charging energy and communication information. The solution provided by the present invention can combine the charging coil and the communication coil into one, which can save a lot of volume in the limited space of the implantable rechargeable deep brain stimulator. This simplifies the structural design of the implantable pulse generator and the component assembly process, and reduces the coil production cost. Under the condition of the same communication success rate, the problems of large size, heavy weight and low efficiency of the pulse generator in the prior art are solved.

[0044] Preferably, the power supply DC is configured as a direct current power supply.

[0045] Preferably, the ASK modulation circuit 200 includes a rectifier circuit, a first resistor R, and a third field-effect transistor V3. One end of the first resistor R is connected to one end of the second coil L2, and the rectifier circuit is connected between one end of the second coil L2 and one end of the first resistor R. The other end of the first resistor R is connected to the drain of the third field-effect transistor V3, the source of the third field-effect transistor V3 is connected to the other end of the second coil L2, and the drain of the third field-effect transistor V3 is connected to one end of the second coil L2. The drain of the third field-effect transistor V3 is also connected to the output terminal Vsrx of the ASK modulation circuit. The first resistor R is used to prevent excessive current from flowing during amplitude modulation of the ASK modulation circuit 200. The first resistor R serves as a current-limiting resistor in the ASK modulation circuit 200 to limit the current in the circuit containing the first resistor R, preventing excessive current from damaging circuit components connected in series with the first resistor R. The third field-effect transistor V3 changes the IPG load by turning it on and off.

[0046] Optionally, the rectifier circuit includes a diode D and a third capacitor C3. The anode of the diode D is connected to one end of the second coil L2 and the source of the third field-effect transistor V3, respectively. The cathode of the diode D is connected to one end of the third capacitor C3 and one end of the first resistor R, respectively. The other end of the third capacitor C3 is connected to the source of the third field-effect transistor V3.

[0047] For the convenience of explanation, a specific solution is given in the embodiment of the present invention. Please continue to refer to Figure 1 , including a carrier signal Vcarry with a frequency of 7.12kHz, a first signal Vstx with a frequency of 1.2kHz, the power supply DC is set to a 5V DC power supply, the models of the first field effect transistor V1, the second field effect transistor V2, and the second field effect transistor V2 are all set to AO3400, the first coil is a 1mH charging coil L1, the first capacitor is a 500nf charging capacitor C1, the second coil is a 4mH receiving coil L2, the second capacitor is a 125nf receiving capacitor C1, the diode D model is 1N5819, the third capacitor is a 10uf filter capacitor C3, and the resistance of the first resistor is 1KΩ. Wherein:

[0048] The 1mH charging coil L1 is connected in parallel with the 500nf charging capacitor C1; the positive pole of the 5V DC power supply is connected to one end of the 1mH charging coil L1; the negative pole of the 5V DC power supply is connected to the source of the AO3400 field-effect transistor V2 and is grounded; the other end of the 1mH charging coil L1 is connected to the drain of the AO3400 field-effect transistor V1; the source of the AO3400 field-effect transistor V1 is connected to the drain of the AO3400 field-effect transistor V2; the gate of the AO3400 field-effect transistor V1 is connected to the 7.12kHz carrier signal Vcarry; the gate of the AO3400 field-effect transistor V2 is connected to the 1.2kHz first signal Vstx.

[0049] A 4mH receiving coil L2 is connected in parallel with a 125nf receiving capacitor C2; one end of the 4mH receiving coil L2 is connected to the anode of a 1N5819 diode D and the drain of an AO3400 field-effect transistor V3; the other end of the 4mH receiving coil L2 is connected to the source of the AO3400 field-effect transistor V3, one end of a 10uf filter capacitor C3, and ground; the cathode of the 1N5819 diode D is connected to the other end of the 10uf filter capacitor C3 and one end of a 1K resistor R1; the other end of the 1K resistor R1 is connected to the drain of the AO3400 field-effect transistor V3; the drain of the AO3400 field-effect transistor V3 is also connected to an output terminal Vsrx for outputting demodulated information to achieve communication with the IPG. The transmission rate of information output from the output terminal Vsrx is 100 bits per second.

[0050] When the low-frequency resonant circuit 100 on the left side of L1 is open, the low-frequency first signal Vstx is superimposed on the carrier signal Vcarry. Since Vcarry is a 7.12kHz signal, the resonant frequency of the charging coil and charging capacitor must also be 7.12kHz, and the resonant frequency of the receiving coil and receiving capacitor must also be 7.12kHz. In this case, in addition to charging the circuit on the right side of L2, the carrier signal is transmitted to the circuit on the right side of L2 through the resonant electromagnetic field of the charging coil and receiving coil, and then enters the ASK modulation circuit 200 to transmit the communication signal.

[0051] An embodiment of the present invention further provides a pulse generator, comprising the circuit for a pulse generator described in any one of the above-mentioned feature descriptions.

[0052] An embodiment of the present invention further provides a deep brain electrical stimulation system, comprising the pulse generator described in the above feature description.

[0053] In summary, the present invention provides a circuit for a pulse generator, a pulse generator, and a deep brain stimulation system. These differ from prior art in that the low-frequency resonant circuit and the ASK modulation circuit are connected in series. This effective series connection of the two circuits enables both charging using the low-frequency resonant circuit and communication transmission via the ASK modulation circuit. This addresses the gap in prior art circuits for integrated charging and communication.

[0054] Furthermore, by combining the charging and communication coils into one, with the same communication success rate, both charging and communication functions are implemented on the same coil, allowing the coil to transmit both charging energy and communication information. The solution provided by this invention allows the charging and communication coils to be combined into one, significantly reducing the volume within the limited space of an implantable rechargeable deep brain stimulator. This simplifies the structural design of the implantable pulse generator and the component assembly process, reducing coil production costs.

[0055] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "example," or "specific example" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments. Furthermore, those skilled in the art may combine and reconcile different embodiments or examples described in this specification.

[0056] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other changes to the technical solution and technical content disclosed in the present invention shall be deemed to be within the scope of the present invention and still fall within the scope of protection of the present invention.

Claims

1. A circuit for a pulse generator, characterized in that Used to realize charging and communication with IPG, including low-frequency resonance circuit and ASK modulation circuit; Wherein, the low-frequency resonance circuit is connected in series with the ASK modulation circuit; The low-frequency resonant circuit is used to provide a charging signal to charge the IPG, and to transmit a carrier signal and a first signal to the ASK modulation circuit; The ASK modulation circuit is used to modulate the first signal according to the carrier signal to communicate with the IPG; The low-frequency resonant circuit includes a power supply, a charging module connected to the power supply, and a communication module. The carrier signal and the first signal are transmitted to the charging module via the communication module, and then transmitted to the ASK modulation circuit via the charging module. The communication module includes a first field effect transistor and a second field effect transistor, and the charging module includes a first capacitor, a second capacitor, a first coil and a second coil; The positive electrode of the power supply is connected to one end of the first coil, the other end of the first coil is connected to the drain of the first field-effect transistor, the source of the first field-effect transistor is connected to the drain of the second field-effect transistor, and the gate of the first field-effect transistor is used to transmit the carrier signal; The source of the second field effect transistor is connected to the negative electrode of the power supply and is grounded, and the gate of the second field effect transistor is used to transmit the first signal; The first capacitor is connected in parallel to both ends of the first coil, and the first coil and the second coil are coupled to each other; The second capacitor is connected in parallel to both ends of the second coil, and the second coil is connected in series with the ASK modulation circuit.

2. The circuit for a pulse generator according to claim 1, wherein The first coil and the first capacitor have a first resonant frequency, and the first resonant frequency is equal to the frequency of the carrier signal.

3. The circuit for a pulse generator according to claim 1, wherein The second coil and the second capacitor have a second resonant frequency, and the second resonant frequency is equal to the frequency of the carrier signal.

4. The circuit for a pulse generator according to claim 1, wherein The first coil is a charging coil, the first capacitor is a charging capacitor, the second coil is a receiving coil, and the second capacitor is a receiving capacitor.

5. The circuit for a pulse generator according to claim 1, wherein The ASK modulation circuit includes a rectifier circuit, a first resistor and a third field effect transistor; Wherein, one end of the first resistor is connected to one end of the second coil, and the rectifier circuit is connected between one end of the second coil and one end of the first resistor; The other end of the first resistor is connected to the drain of the third field effect transistor, and the source of the third field effect transistor is connected to the other end of the second coil; The drain of the third field effect transistor is connected to the output end of the ASK modulation circuit.

6. The circuit for a pulse generator according to claim 5, wherein: The rectifier circuit includes a diode and a third capacitor; The anode of the diode is connected to one end of the second coil and the source of the third field effect transistor respectively, and the cathode of the diode is connected to one end of the third capacitor and one end of the first resistor respectively; The other end of the third capacitor is connected to the source of the third field effect transistor.

7. A pulse generator, characterized in that: A circuit for a pulse generator comprising the circuit according to any one of claims 1 to 6.

8. A deep brain stimulation system, characterized in that: A pulse generator comprising the pulse generator described in claim 7.

Images