Full-duplex wireless simultaneous information and energy transfer system and implantable medical device

Abstract

According to the full duplex wireless simultaneous information and energy transfer system and the implantable medical device, an upper computer part comprises a level switching module which is responsible for controlling level switching according to a baseband signal; the class-D power amplifier converts a direct-current power supply into an alternating-current square wave signal; the radio frequency receiver receives an uplink radio frequency signal of the lower computer. The upper computer adds downlink data to an energy link in an ASK envelope mode through cooperative work of the level switching module and the class D power amplifier, and transmits the downlink data to the lower computer in a near field coupling mode. The lower computer part comprises an ASK (Amplitude Shift Keying) demodulation circuit for demodulating data from a downlink; the rectifying circuit converts the received alternating current signal into a direct current signal to supply power; and the radio frequency transmitter modulates the uplink data to a radio frequency signal and sends the radio frequency signal to the radio frequency receiver of the upper computer. According to the system design, the separation of data and energy links is optimized, the transmission efficiency is improved, the complexity, the power consumption and the cost are reduced, full-duplex communication is supported, the performance of the implantable medical device is improved, and the application range of the implantable medical device is widened.

Description

Technical Field

[0001] The invention relates to data and energy transmission technology for implantable medical equipment, and in particular to a full-duplex wireless signal and energy simultaneous transmission system and implantable medical equipment. Background Art

[0002] Implantable medical devices are a type of technology widely used in the medical field. They are implanted in patients to diagnose, monitor or treat various diseases and health conditions. In modern implantable medical devices, in order to reduce problems such as movement obstruction and infection risk, it is necessary to avoid direct connection of wires between external devices and implantable devices, which requires solving the problems of power supply and wireless data transmission in actual application scenarios. Among them, how to ensure high-efficiency energy and bidirectional data transmission of internal and external devices, and minimize the energy required for each bit of signal transmission has become a key research object in academia and industry.

[0003] Nowadays, the more common wireless energy and data transmission adopts a solution that completely separates the energy link from the data link. For the energy link, in order to improve efficiency, a Class D or Class E power amplifier combined with a series inductor and capacitor network is used to achieve the conversion from DC to AC. In the selection of capacitors and inductors, it is necessary to ensure that the series resonant frequency of the two is consistent with the output frequency of the power amplifier to maximize the energy output. In the selection of data links, the commonly used structures include additional coils, LED infrared transceivers, and far-field RF transceivers. The additional coil solution works at a higher frequency band, often using OOK or FSK modulation methods, requiring higher-frequency capacitor and inductor coils, which significantly increases the power consumption and area of ​​the circuit. The LED infrared transceiver solution is to transmit the signal in an optical form. The infrared transmitting tube is responsible for emitting infrared light of a certain wavelength, while the infrared receiving tube is responsible for receiving the infrared light and converting it into an electrical signal. However, this solution requires high-precision alignment in actual application, and has limited skin penetration ability, and only supports one-way transmission from the body to the outside. The far-field RF transceiver solution is to modulate the electrical information source with a high-frequency signal and transmit the data in the form of electromagnetic waves through the antenna. This solution often requires a local oscillator signal generator with high power consumption, combined with a mixer and a linear PA, resulting in a high power consumption of the energy transmission link, low single-bit energy efficiency, and causing a large amount of heat to the chip in the body under high-throughput data transmission conditions.

[0004] The above transmission schemes can achieve simultaneous transmission of data and energy, but they have certain limitations in terms of system complexity, robustness and energy efficiency, and they only support one-way data transmission at the same time, thus limiting the performance improvement and further application of implantable medical devices. Therefore, the current schemes still need to be optimized and improved.

[0005] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0006] The main purpose of the present invention is to solve the problems existing in the above-mentioned background technology and to provide a full-duplex wireless signal transmission system and an implantable medical device.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect of the present invention, a full-duplex wireless signal transmission system for an implantable medical device comprises:

[0009] The host computer part includes:

[0010] A level switching module, used for controlling level switching according to a baseband signal;

[0011] Class D power amplifier, used to convert DC power into AC square wave signal;

[0012] A radio frequency receiver, used for receiving an uplink radio frequency signal from a lower computer;

[0013] Among them, the class D power amplifier and level switching module of the upper computer are used together to attach the downlink data to the energy link in the form of ASK envelope and transmit it to the lower computer through near-field coupling;

[0014] The lower computer part includes:

[0015] ASK demodulation circuit, used to demodulate data from the downlink;

[0016] A rectifier circuit, used for converting a received AC signal into a DC signal;

[0017] A radio frequency transmitter, used for modulating uplink data into a radio frequency signal and sending the signal;

[0018] Among them, the ASK demodulation circuit and the rectifier circuit of the lower computer are used together to receive the downlink data and energy from the upper computer, and convert the AC signal into a DC signal to power the device;

[0019] The RF transmitter of the lower computer modulates the uplink data onto the RF signal through a far-field RF transmission method and sends it to the RF receiver of the upper computer.

[0020] In a second aspect of the present invention, an implantable medical device includes the full-duplex wireless signal transmission system.

[0021] The present invention has the following beneficial effects:

[0022] The present invention proposes a transmission scheme for separating uplink and downlink data, using a radio frequency transmitter as an uplink data link, and a Class D power amplifier combined with a level switching module as a downlink data link and an energy link, to achieve full-duplex transmission of energy and data for implantable medical devices, while improving system efficiency and reducing the complexity of data transmission, power consumption, circuit volume and cost.

[0023] Existing wireless energy and data transmission solutions often completely separate the two, resulting in half-duplex transmission in the data link, and at the same time, there are disadvantages in the selection of data links, such as high power consumption, poor robustness, and large occupied area. The solution proposed in the present invention integrates downlink data into the energy link for transmission, and designs a low-power transmitter for uplink data transmission, realizing full-duplex data transmission and greatly reducing the power consumption of the lower computer.

[0024] Compared with the existing solutions, the present invention proposes an efficient full-duplex signal and energy transmission solution suitable for implantable medical devices, and optimizes and improves the design in the division of data and energy links and the circuit structure of the transmitter.

[0025] First, in terms of the division of the data link, the existing solution is to completely separate it from the energy link, using dual coils, infrared LED pairs, far-field RF transmission and other solutions, resulting in a single link that only supports half-duplex data transmission. In the present invention, the downlink data is attached to the energy link in the form of an ASK envelope through a level switching module and a Class D power amplifier, and the uplink data is transmitted through an independent far-field RF transceiver, thereby separating the uplink and downlink data and realizing full-duplex transmission of the system.

[0026] Secondly, the existing scheme has high power consumption and low robustness for the design of the lower-level transmitter, which limits the application scope of implantable medical devices. The present invention adopts a low-power transmitter design with low-frequency oscillation edge synthesis in the design of the lower-level transmitter, so that the energy efficiency of uplink data is improved. Compared with the existing scheme, the present invention proposes a more efficient wireless signal transmission scheme, which broadens the application scenarios of implantable medical devices.

[0027] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is an overall block diagram of a full-duplex wireless signal transmission system according to an embodiment of the present invention.

[0029] Figure 2 This is a specific implementation circuit of the level switching module in the embodiment of the present invention.

[0030] Figure 3This is a specific implementation circuit of the transmitter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing as well as for coupling or communication.

[0033] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] The schemes for simultaneous transmission of data and energy in implantable medical devices can be roughly divided into single-link and dual-link structures, but both have certain defects. The system module of the single-link scheme is relatively simple, but because the data transmission rate is limited by the carrier frequency, its data rate is low. In addition, this scheme usually adopts load shift keying technology, which affects the energy transmission efficiency to a certain extent. The single-coil structure can only provide a unidirectional data link and does not support full-duplex data transmission. The dual-link structure includes high-frequency coils, far-field infrared transmission, and far-field radio frequency transmission in the selection of the second link. However, this type of scheme is more complex in design, especially in the design of the carrier generator, and has the disadvantages of high power consumption and large volume. At the same time, the existing dual-link scheme completely separates the energy link from the data link, and there are also half-duplex limitations in the transmission of energy and data.

[0036] See also Figure 1The embodiment of the present invention provides a full-duplex wireless signal and energy transmission system for implantable medical devices, including a host computer part and a slave computer part. The host computer part includes: a level switching module for controlling the level switching according to the baseband signal; a class D power amplifier for converting the DC power supply into an AC square wave signal; and a radio frequency receiver for receiving an uplink radio frequency signal from the slave computer; wherein the class D power amplifier and the level switching module of the host computer are used together to attach the downlink data to the energy link in the form of an ASK envelope, and transmit it to the slave computer through near-field coupling. The lower computer part includes: an ASK demodulation circuit, which is used to demodulate data from the downlink; a rectifier circuit, which is used to convert the received AC signal into a DC signal; and an RF transmitter, which is used to modulate the uplink data into an RF signal and send it. Among them, the ASK demodulation circuit and the rectifier circuit of the lower computer are used together to receive the downlink data and energy from the upper computer, and convert the AC signal into a DC signal to power the device; the RF transmitter of the lower computer modulates the uplink data into an RF signal through a far-field RF transmission method, and sends it to the RF receiver of the upper computer.

[0037] See also Figure 1 In some embodiments, the Class D power amplifier converts the DC power into an AC square wave signal whose frequency is equal to the input CLK signal.

[0038] See also Figure 1 In a preferred embodiment, the near-field coupling resonant circuit includes a first inductor L1 and a first capacitor C1 connected in series at the upper computer part, and a second inductor L2 and a second capacitor C2 connected in parallel at the lower computer part, and the resonant frequency matches the signal frequency generated by the power amplifier, satisfying the expression:

[0039]

[0040] The second inductor L2 receives energy from the host computer through mutual inductance, and the second capacitor C2 outputs the received AC energy signal to the rectifier circuit to achieve conversion from AC to DC.

[0041] See also Figure 2In a preferred embodiment, the level switching module includes: a transmission gate control logic, which is used to control the transmission gate TG connecting VINH and VINL to open according to the "0" and "1" states of the baseband signal BB, and selectively close the transmission gate connected to VINL according to the comparison result of the comparator to prevent circuit backflow; a high power level terminal VINH, which is used to provide a high level signal when the corresponding transmission gate is opened; a low power level terminal VINL, which is used to provide a low level signal when the corresponding transmission gate is closed; a power amplifier VDDPA, which is used to receive the level signal from the transmission gate and convert it into an amplitude modulation signal of the energy link; a comparator, which is used to compare the levels of VDDPA and VINL to prevent current from backflowing from the power amplifier to the power supply.

[0042] In some embodiments, the ASK demodulation module includes: a filter for extracting an envelope signal from a received modulated signal; and a demodulation circuit for converting the envelope signal extracted by the filter into a baseband signal.

[0043] By using the level switching module in conjunction with the ASK demodulation module, the downlink data can be attached to the energy transmission link in the form of an ASK envelope and can be effectively demodulated by the lower computer.

[0044] See also Figure 3 In a preferred embodiment, the RF transmitter includes: a crystal oscillator unit, which can be used to provide a 45MHz clock signal; a pulse generator, which is used to convert the clock signal generated by the crystal oscillator into a pulse signal; an injection locking mechanism, which is used to inject the pulse signal into the ring oscillator to improve the phase noise; a multi-phase signal generator, which is used to generate signals with multiple phases; the multi-phase signal generator is preferably a ring oscillator with a 9-level structure, which can generate 9 signals with different phases; a phase selection array, which is used to select the corresponding phase signal according to the baseband signal; an edge synthesis multiplication power amplifier, which is used to synthesize the edges of multiple signals with different phases and complete signal multiplication, such as 9 times; a resonant cavity, which is used for impedance matching and outputting the amplified signal to the antenna.

[0045] In one embodiment, the frequency band of the RF transmitter for far-field RF transmission is 405 MHz.

[0046] In some embodiments, the RF receiver uses a direct conversion receiver to move the received RF data to the baseband for demodulation, process the signal received from the RF receiver through a demodulation circuit, and recover the baseband signal.

[0047] In the above embodiment, the crystal oscillator unit, pulse generator, ring oscillator, multi-phase signal generator, phase selection array and edge synthesis multiplication power amplifier of the RF transmitter work together to achieve low-power data transmission; and the RF receiver cooperates with the RF transmitter to achieve effective reception and demodulation of uplink data.

[0048] An embodiment of the present invention further provides an implantable medical device, comprising the full-duplex wireless signal transmission system of any of the aforementioned embodiments.

[0049] The full-duplex wireless signal-energy simultaneous transmission system of the present invention provides an innovative solution for implantable medical devices, which realizes efficient full-duplex transmission of energy and data, while significantly reducing the power consumption and complexity of the system. By integrating the downlink data into the energy link in the form of an ASK envelope for transmission, the present invention optimizes the integration of the data link and the energy link, breaking the half-duplex transmission limitation caused by the separation of the two in the traditional solution. In addition, the system adopts a low-power transmitter design and is specially optimized for uplink data transmission, which not only improves energy efficiency but also enhances the robustness of the device.

[0050] Compared with the traditional single-link and dual-link structures, the present invention achieves an increase in data transmission rate and a reduction in energy consumption through the coordinated work of the level switching module and the Class D power amplifier. This design avoids the high power consumption and large volume problems commonly seen in additional coils, infrared LED pairs or far-field RF transmission solutions, and solves the limitation that a single link only supports one-way data transmission.

[0051] In addition, the system design of the present invention takes into account the specific application scenarios of implantable medical devices. By optimizing the circuit structure of the transmitter, it is helpful to reduce the energy required for each bit of signal transmission, thereby reducing the heating problem of the chip in the body under high-throughput data transmission. This design not only improves the safety and reliability of the equipment, but also broadens the application scope of implantable medical devices.

[0052] In general, the present invention, through its unique system design, achieves full-duplex data communication while ensuring efficient energy transmission, bringing lower power consumption, smaller size and better performance to implantable medical devices.

[0053] The specific embodiments of the present invention are further described below.

[0054] A solution for efficient energy transmission and full-duplex data transmission for implantable medical devices, the overall framework of the system is as follows Figure 1As shown. The upper computer of the system consists of a level switching module, a Class D power amplifier, a series inductor and capacitor, and a radio frequency receiver; the lower computer includes an ASK demodulation circuit, a rectifier circuit, and a radio frequency transmitter. Among them, the inductors L1 and L2 form a downlink in the form of mutual inductance, which can transmit energy and downlink data through the coupling of the two. Antennas A1 and A2 form an uplink in the form of electromagnetic waves. The radio frequency transmitter can transmit to the receiver outside the body at a higher data rate to meet the needs of multi-channel data acquisition in the body. The two branches complete data exchange in the near field and far field respectively, and will not generate crosstalk with each other, thereby achieving the purpose of full-duplex wireless signal transmission.

[0055] The main modules of the downlink energy link include a Class D power amplifier, capacitors C1, C2, inductors L1, L2 and a rectifier circuit. The Class D power amplifier converts the DC power supply into an AC square wave signal, whose frequency is equal to the input CLK signal. The values ​​of the inductor and capacitor must ensure that the resonant frequency of the loop is equal to the signal frequency generated by the power amplifier, that is, satisfying the expression:

[0056]

[0057] L2 receives energy from the host computer through mutual inductance, and outputs the signal to the rectifier circuit through the parallel C2 network to achieve the recovery from AC to DC, thus completing the energy link transmission. Compared with Class A and Class B power amplifiers, Class D amplifiers are nonlinear amplifiers with an ideal efficiency of 100%, so they can improve the efficiency of energy transmission.

[0058] On this basis, the introduction of the level switching module and the ASK demodulation module enables the downlink data to be attached to the energy transmission link in the form of an envelope. The circuit diagram of the level switching module is shown in Figure 2 As shown in the figure, the "0" and "1" of the baseband signal BB control the two transmission gates respectively, so that the VDDPA of the power amplifier is connected to the high power level VINH and the low power level VINL respectively, thereby modulating the amplitude of the energy link. In order to avoid the current from the power amplifier to the power supply backflow, the comparator will compare the values ​​of VDDPA and VINL at any time. Once VINL is lower than VDDPA, the transmission gate of the VINL branch will be turned off to protect the circuit. The ASK demodulation circuit uses a filter to restore the envelope signal, thereby demodulating the signal.

[0059] The uplink energy link adopts far-field radio frequency transmission, and the selected frequency band is 405MHz. Higher frequency can reduce the chip area. How to optimize the energy efficiency of high-throughput data links becomes a key issue. The power consumption of traditional transmitter circuits is proportional to the operating frequency, so high-frequency carriers will reduce system efficiency. The embodiment of the present invention makes a low-power design on the transmitter, and the specific circuit adopted is as follows: Figure 3 As shown. The circuit can be mainly divided into the following parts: crystal oscillator, pulse generator, multiphase signal generator, phase selection array and edge synthesis multiplier power amplifier. The crystal oscillator provides a 45MHz clock signal for the circuit, and the pulse generator converts it into a pulse signal to inject lock the ring oscillator, thereby improving the phase noise of the ring oscillator. The ring oscillator adopts a 9-level structure and can generate 9 different phase signals, while the phase selection array uploads the baseband signal to the carrier frequency band. Finally, the PA synthesizes the edges of the 9 different phase signals to complete the 9-fold frequency of the signal, and outputs it to the antenna through the resonant cavity to complete the data transmission. This circuit structure enables the transmitter to operate at a lower frequency except for the power amplifier, thereby greatly reducing the system power consumption. Since the energy allocation of the host computer is relatively ample, the receiver uses a direct conversion receiver to move the RF data to the baseband for demodulation. Thus, the transmission of uplink data is completed.

[0060] Existing wireless energy and data transmission solutions often completely separate the two, resulting in half-duplex transmission in the data link, and at the same time, there are disadvantages in the selection of data links, such as high power consumption, poor robustness, and large occupied area. The solution proposed in the present invention integrates downlink data into the energy link for transmission, and designs a low-power transmitter for uplink data transmission, realizing full-duplex data transmission and greatly reducing the power consumption of the lower computer.

[0061] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A full-duplex wireless signal transmission system for implantable medical devices, characterized in that: include: The host computer part includes: A level switching module, used for controlling level switching according to a baseband signal; Class D power amplifier, used to convert DC power into AC square wave signal; A radio frequency receiver, used for receiving an uplink radio frequency signal from a lower computer; Among them, the class D power amplifier and level switching module of the upper computer are used together to attach the downlink data to the energy link in the form of ASK envelope and transmit it to the lower computer through near-field coupling; The lower computer part includes: ASK demodulation circuit, used to demodulate data from the downlink; A rectifier circuit, used for converting a received AC signal into a DC signal; A radio frequency transmitter, used for modulating uplink data into a radio frequency signal and sending the signal; Among them, the ASK demodulation circuit and the rectifier circuit of the lower computer are used together to receive the downlink data and energy from the upper computer, and convert the AC signal into a DC signal to power the device; The RF transmitter of the lower computer modulates the uplink data onto the RF signal through a far-field RF transmission method and sends it to the RF receiver of the upper computer.

2. The full-duplex wireless signal transmission system as claimed in claim 1, characterized in that: The class D power amplifier converts the DC power supply into an AC square wave signal, the frequency of which is equal to the input CLK signal.

3. The full-duplex wireless signal transmission system as claimed in claim 1 or 2, characterized in that: The near-field coupling resonant circuit includes a first inductor L1 and a first capacitor C1 connected in series at the upper computer part, and a second inductor L2 and a second capacitor C2 connected in parallel at the lower computer part. The resonant frequency matches the signal frequency generated by the power amplifier and satisfies the expression: The second inductor L2 receives energy from the host computer through mutual inductance, and the second capacitor C2 outputs the received AC energy signal to the rectifier circuit to achieve conversion from AC to DC.

4. The full-duplex wireless signal transmission system according to any one of claims 1 to 3, characterized in that: The level switching module comprises: The transmission gate control logic is used to control the transmission gates connected to VINH and VINL to open according to the "0" and "1" states of the baseband signal BB, and selectively close the transmission gate connected to VINL according to the comparison result of the comparator; A high power level terminal VINH is used to provide a high level signal when a corresponding transmission gate is opened; A low power level terminal VINL is used to provide a low level signal when a corresponding transmission gate is closed; A power amplifier VDDPA, used for receiving the level signal from the transmission gate and converting it into an amplitude modulation signal of the energy link; A comparator is used to compare the levels of VDDPA and VINL to prevent current from flowing back from the power amplifier to the power supply; The ASK demodulation module comprises: A filter for extracting an envelope signal from a received modulated signal; The demodulation circuit is used to convert the envelope signal extracted by the filter into a baseband signal.

5. The full-duplex wireless signal transmission system according to any one of claims 1 to 4, characterized in that: The radio frequency transmitter comprises: A crystal oscillator unit, used for providing a clock signal; A pulse generator, used for converting a clock signal generated by a crystal oscillator into a pulse signal; Injection locking mechanism, used to inject pulse signals into the ring oscillator to improve phase noise; A multi-phase signal generator, used to generate signals with multiple phases; A phase selection array, used for selecting a corresponding phase signal according to a baseband signal; Edge synthesis frequency multiplication power amplifier, used to synthesize the edges of multiple signals with different phases and complete the multiple frequency multiplication of the signal; A resonant cavity, which is used for impedance matching and outputting the amplified signal to the antenna; The radio frequency receiver adopts a direct frequency conversion receiver, which is used to move the received radio frequency data to the baseband for demodulation, process the signal received from the radio frequency receiver through the demodulation circuit, and restore the baseband signal.

6. The full-duplex wireless signal transmission system as claimed in claim 5, characterized in that: The crystal oscillator provides a 45 MHz clock signal for the circuit.

7. The full-duplex wireless signal transmission system as claimed in claim 5, characterized in that: The multi-phase signal generator is a ring oscillator. The ring oscillator adopts a 9-level structure and is used to generate 9 signals with different phases.

8. The full-duplex wireless signal transmission system according to any one of claims 1 to 7, characterized in that: The frequency band of the radio frequency transmitter for far-field radio frequency transmission is 405 MHz.

9. An implantable medical device, characterized in that: It comprises a full-duplex wireless signal transmission system as described in any one of claims 1 to 7.

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