A human body implantable antenna system with high radiation efficiency

Abstract

The present invention discloses a human-implanted antenna system with high radiation efficiency, relating to the field of communications technology. The system comprises a substrate, a top copper layer, a bottom copper layer, and a lumped capacitor. The top of the substrate is provided with a top copper layer for radiation, and the bottom of the substrate is provided with a bottom copper layer for low-impedance transmission. The bottom-to-top electric field coupling structure designed in this application increases the antenna's input impedance and radiation efficiency. The antenna wirelessly receives and transmits signals within the body, establishing a communication connection between a leadless cardiac pacemaker and an external device. The antenna's miniaturized design reserves more space for key components such as the leadless cardiac pacemaker's battery, thereby supporting a larger battery capacity and extending the device's service life. This reduces the device's power consumption, thereby reducing the frequency of device replacements and lowering the risk of surgical procedures for patients. Due to its smaller size and higher efficiency, the implanted device places less strain on the patient's body.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a human body implantable antenna system with high radiation efficiency. Background Art

[0002] The research of wireless body area networks (WBAN) has attracted increasing attention from researchers in recent years. Based on the physiological data collected from different internal electro-invasive or non-invasive devices, it has great potential to improve health, provide auxiliary treatment and prolong patients' lives.

[0003] Implantable leadless cardiac pacemakers (LCPs) can monitor the status of various organs. Each implanted node can communicate with each other and send information to a subcutaneous implantable device or an external base station. This allows for coordinated operation between multiple implantable devices and transmits real-time cardiac data to the body. This allows for convenient and rapid diagnosis and treatment, improving patient survival and overall health. Therefore, designing reliable, low-power, and efficient communication links for these applications is crucial.

[0004] Cardiac pacemakers are currently the most important and widely used implantable devices. By implanting multiple (two to three) leadless pacemaker capsules into the heart, they can detect cardiac dysfunction and regulate normal cardiac synchronization. With traditional pacemakers, communication and synchronization between multiple implantable capsules are achieved by connecting several deeply implanted pacemaker capsules to a subcutaneous control unit via wires. After decades of advancements in pacing technology, wires are generally considered the weak point of traditional systems, potentially leading to complications such as breakage, infection, and venous blockage.

[0005] Leadless cardiac pacemakers (LCPs) replace wires with wireless transmission, minimizing the risk of infection and being less invasive for patients. They have been proven safe and effective in clinical practice. A highly reliable and efficient communication link is paramount for LCPs, requiring a low bit error rate and high radiation efficiency. To improve LCP communication performance, a miniaturized, highly efficient implantable antenna system is required.

[0006] This application designs a miniaturized, low-cost and high-radiation-efficiency implantable antenna system to optimize the communication link of a leadless cardiac pacemaker. This application adopts the design of a planar electrically coupled loop antenna, reduces costs by simplifying the manufacturing process, and utilizes its light and thin planar structure to be integrated into a leadless cardiac pacemaker, thereby improving the radiation efficiency and the overall performance of the communication system. Because the volume of the wireless cardiac pacemaker capsule is very small, reducing the volume occupied by the antenna in the wireless cardiac pacemaker capsule can provide as much space as possible for the electric field, thereby indirectly extending the working time of the wireless cardiac pacemaker capsule in the heart, thereby solving the above-mentioned technical problems in turn. Summary of the Invention

[0007] The present invention provides a human body implantable antenna system with high radiation efficiency. Through the design of a planar structure and lumped capacitance, the radiation efficiency of the antenna is enhanced, the space occupancy is reduced, and cost control is achieved by utilizing existing PCB manufacturing technology. The radiation efficiency of the implanted antenna is improved, the size of the antenna is reduced, and the manufacturing cost is reduced, thereby solving the problems in the background technology.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a human-implanted antenna system with high radiation efficiency, comprising a substrate, a top copper layer, and a bottom copper layer. The top of the substrate is provided with a top copper layer for radiation, and the bottom of the substrate is provided with a bottom copper layer for low-impedance transmission. The antenna receives and transmits signals wirelessly within the body, thereby establishing a communication connection between a leadless cardiac pacemaker and an external device.

[0009] Furthermore, it also includes a lumped capacitor, which is arranged on the substrate and is used to adjust the resonant frequency of the antenna and the imaginary part of the input impedance.

[0010] Furthermore, the top copper layer is provided with a ring structure, which is the main radiation unit to realize wireless communication and is responsible for radiating the signal.

[0011] Furthermore, the bottom copper layer is an open-circuit low-impedance transmission line, which transmits the signal to the top copper layer through electric field coupling for antenna feeding.

[0012] Furthermore, the substrate is a partition between the top copper layer and the bottom copper layer, and is a dielectric layer. The real part of the input impedance is adjusted by adjusting the size, thickness and dielectric constant of the top copper layer and the bottom copper layer.

[0013] Furthermore, the planar electrically coupled loop antenna is integrated into a leadless cardiac pacemaker to achieve wireless communication.

[0014] Furthermore, the annular structure of the top copper layer is the main radiation unit, which is a short-circuited high-impedance transmission line, connected to the negative pole of the coaxial cable, and fed through electric field coupling from the bottom copper layer to the top copper layer.

[0015] Furthermore, the feed line transfers energy to the top copper layer through electric field coupling. The coupling strength between the two layers is adjusted by the size of the overlapping area. The bottom copper layer is an open-circuit low-impedance transmission line, which is connected to the positive pole of the coaxial cable. The real part of the input impedance is adjusted by adjusting the size, thickness and dielectric constant of the top and bottom copper layers.

[0016] Furthermore, the antenna was made to resonate in various frequency bands, the impedance was adjusted by modifying the size of the feed head and the antenna, and the input impedance was adjusted to 50 ohms by adjusting the coupling between the top copper layer and the bottom copper layer. The antenna was manufactured using the same PCB process.

[0017] Compared with the prior art, the present invention provides a human body implantable antenna system with high radiation efficiency, which has the following beneficial effects:

[0018] This highly efficient, human-implanted antenna system features a miniaturized design that leaves more space for critical components like the leadless pacemaker's battery, allowing for larger batteries and extending the device's lifespan. This reduces the device's power consumption, leading to fewer device replacements and lowering the risk of surgical intervention for patients. Due to its smaller size and greater efficiency, implantation places less strain on the patient's body. The antenna's efficient design reduces the likelihood of communication failure, improves the reliability of the medical device, and reduces the need for subsequent maintenance and surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic structural diagram of a human body implantable antenna system with high radiation efficiency according to the present invention;

[0021] Figure 2 A side view of the top copper layer and the bottom copper layer of a human body implantable antenna system with high radiation efficiency according to the present invention;

[0022] Figure 3 The present invention is a high radiation efficiency human implant antenna system in the heart tissue measured reflection coefficient and input impedance diagram;

[0023] Figure 4The present invention is a high radiation efficiency human body implant antenna system radiation pattern, the left figure is the E plane, the right figure is the H plane;

[0024] Figure 5 The present invention provides a human body implant antenna system with high radiation efficiency, and a simulation diagram of the antenna's reflection coefficient and radiation performance in a human anatomical model.

[0025] Figure 6 This is a schematic diagram of a human body implantable antenna system with high radiation efficiency according to the present invention, in which antennas are placed in three pacemakers. DETAILED DESCRIPTION

[0026] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0027] In the description and claims of the embodiments of the present disclosure, as well as in the accompanying drawings, the terms "first," "second," and the like are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe the embodiments of the present disclosure herein. In addition, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to having a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0029] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0030] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0031] See also Figure 1-6 The present invention discloses a human body implantable antenna system with high radiation efficiency, comprising a substrate, a top copper layer and a bottom copper layer. Figure 1 The top layer is a top copper layer, and the bottom layer is a bottom copper layer. The top of the substrate is provided with a top copper layer for radiation, and the bottom of the substrate is provided with a bottom copper layer for low-impedance transmission. The antenna receives and transmits signals wirelessly in the body to establish a communication connection between the leadless pacemaker and the external device.

[0032] The top copper layer is provided with a ring structure, which is the main radiation unit for realizing wireless communication and responsible for radiating the signal. The ring structure of the top copper layer is the main radiation unit, which is a short-circuited high-impedance transmission line, connected to the negative pole of the coaxial cable, and fed through electric field coupling from the bottom copper layer to the top copper layer. The feed line transfers energy to the top copper layer through electric field coupling. The coupling strength between the two layers is adjusted by the size of the overlapping area. The bottom copper layer is an open-circuited low-impedance transmission line, connected to the positive pole of the coaxial cable. The real part of the input impedance is adjusted by adjusting the size, thickness and dielectric constant of the top and bottom copper layers.

[0033] This application discloses a novel planar electrically coupled loop antenna system for wireless body area networks (WBANs). Designed specifically for implantable medical devices such as leadless cardiac pacemakers (LCPs), it effectively improves both in-body and out-body communication efficiency, while also improving in-body communication efficiency. This system enables reliable, highly robust, and low-power communication links, thereby providing more reliable support for patient health monitoring and medical diagnosis.

[0034] This application proposes a new type of planar electrically coupled loop antenna and uses PCB technology to manufacture it to achieve the goals of miniaturization, low cost, and high radiation efficiency. In this application, an implantable antenna system is designed that can effectively improve the communication efficiency of leadless pacemakers and is easy to produce, install, and use.

[0035] The bottom copper layer is an open-circuit low-impedance transmission line, which transmits the signal to the top copper layer through electric field coupling for antenna feeding.

[0036] The substrate is a separator between the top copper layer and the bottom copper layer, and is a dielectric layer. The real part of the input impedance is adjusted by adjusting the size, thickness and dielectric constant of the top copper layer and the bottom copper layer, thereby optimizing the operating frequency and radiation efficiency of the antenna.

[0037] The antenna further comprises a lumped capacitor, which is arranged on the substrate and is used to adjust the resonant frequency of the antenna and the imaginary part of the input impedance.

[0038] This application designs a new antenna, resembling a small, planar loop, composed of two layers of copper plates that transmit signals through the coupling of the electric fields between the layers. This design makes the antenna more compact, easier to integrate into common leadless pacemaker devices, and reduces costs. Furthermore, the antenna's performance can be optimized by adjusting its size and thickness, resulting in higher radiation efficiency and more stable wireless transmission. Compared to traditional implantable antennas, the high-radiation-efficiency, planar electrically coupled loop antenna system of the present invention can significantly improve the communication efficiency of leadless pacemakers and reduce the device's power consumption.

[0039] The design structure of the planar electrically coupled loop antenna breaks the volume limitation of traditional antennas and achieves miniaturization.

[0040] Utilize PCB technology for manufacturing to reduce costs and improve production efficiency.

[0041] Efficient energy transmission is achieved through the interlayer electrical coupling mechanism. For implantable antennas, since human tissue is a high-loss medium, the radiation efficiency of the antenna of this application in this high-loss medium is higher than that of other antennas, thereby achieving the purpose of significantly improving the antenna radiation efficiency.

[0042] By optimizing parameters such as antenna size, thickness, and substrate material, communication performance can be further improved and power consumption requirements can be reduced.

[0043] Specifically, a planar electrically coupled loop antenna is integrated into a leadless cardiac pacemaker to achieve wireless communication.

[0044] Specifically, the antenna is enabled to resonate in various frequency bands, the impedance is adjusted by modifying the size of the feed head and the antenna, and the input impedance of the antenna manufactured using the same PCB process is adjusted to 50 ohms by adjusting the coupling between the top copper layer and the bottom copper layer.

[0045] This technology achieves high radiation efficiency by designing a two-layer metal ring structure, utilizing the ring radiating element on the top layer and the energy transmission path from the bottom layer to the top layer, and adjusting the coupling between the top and bottom layers to match the requirements of a 50-ohm system. Furthermore, the antenna's resonant frequency and input impedance are further optimized by adjusting the lumped capacitance, the size of the top and bottom layers, and the overlap, ensuring reliable and efficient operation in a variety of applications.

[0046] When in use, the antenna of the present invention is implanted in the patient's body and connected to the leadless cardiac pacemaker device to achieve data transmission. The antenna uses metal plates as radiation units and transfers energy through interlayer electrical coupling to achieve efficient wireless transmission. The details are as follows:

[0047] The external device transmits the signal to the base of the antenna via a coaxial cable.

[0048] The bottom copper layer acts as an open-circuit, low-impedance transmission line, passing the signal to the top antenna via electric field coupling.

[0049] The top copper layer acts as the main radiating element, radiating the signal into the surrounding space.

[0050] The transceiver receives the signal and processes it.

[0051] The antenna is fixed inside the human body and no additional movement is required.

[0052] In summary, the miniaturized design of this high-radiation-efficiency human implantable antenna system leaves more space for key components such as the leadless pacemaker's battery, allowing for a larger battery capacity and extending the device's lifespan. This reduces the device's power consumption, thus reducing the frequency of device replacements and lowering the risk of surgical procedures for patients. Because the device is more compact and efficient, implantation places less strain on the patient's body. The efficient antenna design reduces the likelihood of communication failure, improves the reliability of the medical device, and reduces the need for subsequent maintenance and surgery.

[0053] Compared to conventional electrically coupled loop antennas, the planar electrically coupled loop antenna proposed in this invention solves the manufacturing challenges of ECLAs with its planar structure. It also boasts a smaller size and is easier to integrate with implantable devices. Conventional electrically coupled loop antennas require micromachining equipment for fabrication, resulting in high costs, low yields, and low precision. The proposed planar electrically coupled loop antenna, based on conventional PCB technology, offers advantages such as low cost, high precision, and ease of mass production.

[0054] The planar structure of the antenna is easier to integrate with the leadless pacemaker and saves space. The electronic components in the leadless pacemaker are arranged in a stacked structure, so the planar antenna can be placed on the top or bottom of the capsule.

[0055] This application selects a substrate with a low loss tangent, adjusts the coupling strength between the top and bottom copper layers, and controls the parallel capacitance by adjusting the substrate thickness and overlap size, thereby achieving higher radiation efficiency and lower power consumption requirements.

[0056] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless expressly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A human body implantable antenna system with high radiation efficiency, characterized by: The device comprises a substrate, a top copper layer, and a bottom copper layer. The top copper layer is a short-circuited high-impedance transmission line, and the bottom copper layer is an open-circuited low-impedance transmission line. The bottom copper layer feeds electricity to the top copper layer through electric field coupling, and the coupling strength is adjusted by the size of the overlapping area of the two copper layers. The antenna receives and transmits signals wirelessly within the body, thereby establishing a communication connection between the leadless cardiac pacemaker and an external device. It also includes a lumped capacitor, which is arranged on the substrate and is used to adjust the resonant frequency of the antenna and the imaginary part of the input impedance; The top copper layer is connected to the negative side of the coaxial cable, and the bottom copper layer is connected to the positive side of the coaxial cable.

2. The human body implantable antenna system with high radiation efficiency according to claim 1, characterized in that: The top copper layer is provided with a ring structure, which is the main radiation unit, realizes wireless communication, and is responsible for radiating the signal.

3. The human body implantable antenna system with high radiation efficiency according to claim 1, characterized in that: The substrate is a partition between the top copper layer and the bottom copper layer and is a dielectric layer. The real part of the input impedance can be adjusted by adjusting the size, thickness and dielectric constant of the top copper layer and the bottom copper layer.

4. The human body implantable antenna system with high radiation efficiency according to claim 1, characterized in that: A planar electrically coupled loop antenna is integrated into a leadless cardiac pacemaker for wireless communication.

5. The human body implantable antenna system with high radiation efficiency according to claim 1, characterized in that: The antenna is made to resonate in various frequency bands, the impedance is adjusted by modifying the size of the feed head and the antenna, and the input impedance is adjusted to 50 ohms by adjusting the coupling between the top copper layer and the bottom copper layer. The antenna is manufactured using the same PCB process.

Images