Implantable medical device

Abstract

The application provides an implantable medical device, which comprises a metal shell, a circuit board, an antenna and at least one connecting structure. The connecting structure connects a radio frequency ground of the circuit board and a connecting point of the metal shell to change electromagnetic characteristics of the metal shell, the distance between the connecting point and an antenna hole is m, the extension path length of the connecting structure between the connecting point and the radio frequency ground is n, the working wavelength of the antenna is lambda, and m+n<=0.2lambda, so that the radiation frequency of the metal shell is far away from the working frequency of the antenna, the radiation of the metal shell to the antenna is reduced, the loss of the electromagnetic wave energy radiated by the metal shell to the antenna is reduced, and the radiation efficiency of the antenna is improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an implantable medical device. Background Technology

[0002] Implantable medical devices, including deep brain stimulation (DBS), implantable cortical stimulation (CNS), implantable spinal cord stimulation (SCS), implantable sacral nerve stimulation (SNS), implantable vagus nerve stimulation (VNS), implantable cardiac stimulation systems (commonly known as pacemakers), and implantable drug delivery systems (IDDS), can achieve data interaction with external devices via wireless communication.

[0003] Antennas are one of the key components in the wireless communication system of implantable medical devices. Since part of the antenna is inside a relatively enclosed metal shell, the electromagnetic waves radiated by the antenna part will be attenuated inside the metal shell, affecting the antenna's radiation efficiency. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an implantable medical device that increases the radiation frequency of the metal shell, reduces the energy loss of electromagnetic waves radiated by the antenna by the metal shell, and improves the radiation efficiency of the antenna.

[0005] In a first aspect, embodiments of the present invention provide an implantable medical device, comprising:

[0006] The metal casing has an antenna hole and a connection point with a distance of m from the antenna hole;

[0007] A circuit board is disposed inside the metal casing, and the circuit board is provided with a radio frequency ground.

[0008] An antenna, at least a portion of which extends from the antenna aperture into the metal housing to connect to the circuit board; and

[0009] At least one connecting structure, said connecting structure being located inside the metal shell;

[0010] The connection structure connects the connection point and the radio frequency ground. The extension path of the connection structure between the connection point and the radio frequency ground is n. The operating wavelength of the antenna is λ. Then m+n≤0.2λ, so that the radiation frequency of the metal shell is far away from the operating frequency of the antenna.

[0011] Furthermore, in some embodiments of the present invention, the connection structure is an electrical conductor or a circuit including at least one device such as a resistor, capacitor, and inductor.

[0012] Furthermore, in some embodiments of the present invention, the connection structure is a circuit, and in the operating frequency band of the antenna, the real part of the impedance of the connection structure is less than 20Ω, and the absolute value of the imaginary part of the impedance is less than 20Ω.

[0013] Furthermore, in some embodiments of the present invention, the antenna includes a main body and an extension connected to each other. The main body is located outside the metal shell, and the metal shell is provided with a plurality of antenna holes. The extension, which extends into the metal shell and is connected to the circuit board, passes through the plurality of antenna holes.

[0014] Furthermore, in some embodiments of the present invention, the metal shell and the circuit board are respectively provided with the connection structure corresponding to the plurality of antenna holes.

[0015] Furthermore, in some embodiments of the present invention, the circuit board is connected to the connection structure on both sides of the antenna, and the metal shell is provided with grounding points on opposite sides of the antenna hole.

[0016] Furthermore, in some embodiments of the present invention, the metal housing includes a feedthrough ring mounted in the antenna aperture, and the antenna passes through the annular hole of the feedthrough ring.

[0017] Furthermore, in some embodiments of the present invention, the connection point is located at the feedthrough loop;

[0018] The connection structure connects to the feed ring and is connected to the metal shell through the feed ring.

[0019] Furthermore, in some embodiments of the present invention, the circuit board includes a dielectric substrate and multiple metal layers, the dielectric substrate being used to separate adjacent metal layers, and the multiple metal layers including a metal layer serving as the radio frequency ground.

[0020] Furthermore, in some embodiments of the present invention, the metal casing has a first sidewall facing the board surface of the circuit board and a second sidewall adjacent to the first sidewall, and the first sidewall or the second sidewall is provided with the antenna hole.

[0021] This invention provides an implantable medical device, including a metal shell, an antenna circuit board, and a connection structure. A portion of the antenna extends into the metal shell through an antenna aperture and connects to the circuit board. The connection structure connects the connection point of the metal shell to the radio frequency ground of the circuit board, thereby altering the electromagnetic properties of the metal shell. The relationship between the connection point, the antenna aperture, the connection structure, and the antenna wavelength is m+n≤0.2λ, which makes the radiation frequency of the metal shell far away from the operating frequency of the antenna, thus reducing the radiation interference of the metal shell to the antenna. Therefore, it reduces the loss of electromagnetic wave energy radiated by the antenna due to the metal shell and improves the radiation efficiency of the antenna. Attached Figure Description

[0022] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0023] Figure 1 This is a schematic diagram of an implantable medical device provided in Embodiment 1 of the present invention;

[0024] Figure 2 This invention includes the markers n and m. Figure 1 Schematic diagram of a local structure in the middle;

[0025] Figure 3 This is the present invention. Figure 1 A schematic diagram of a partial cross-section of AA;

[0026] Figure 4 This is a three-dimensional structural diagram of an implantable medical device provided in Embodiment 1 of the present invention;

[0027] Figure 5 This is a schematic diagram of an implantable medical device provided in Embodiment 2 of the present invention;

[0028] Figure 6 This is a schematic diagram of an implantable medical device provided in Embodiment 3 of the present invention;

[0029] Figure 7 This is a schematic diagram of an implantable medical device provided in Embodiment 4 of the present invention;

[0030] Figure 8 This is a schematic diagram of an implantable medical device provided in Embodiment 5 of the present invention;

[0031] Figure 9 This is a schematic diagram of an implantable medical device provided in Embodiment Six of the present invention;

[0032] Figure 10 This is a schematic diagram of an implantable medical device provided in Embodiment 7 of the present invention;

[0033] Figure 11 This is a comparison chart of the actual test results of the antenna performance of the implantable medical device of Embodiment 1 of the present invention and existing medical devices;

[0034] Figure 12 This is a comparison chart of the actual test results of the antenna performance of the implantable medical devices of Embodiments 1 and 2 of the present invention and existing medical devices.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1-Metal shell; 11-First sidewall; 12-Second sidewall;

[0037] 2-Antenna; 3-Top cover; 4-Connection structure; 5-Circuit board;

[0038] 51 - Auxiliary structure; 511 - Conductive hole;

[0039] 521 - First metal layer; 522 - Second metal layer; 523 - Third metal layer; 524 - Fourth metal layer; 525 - Fifth metal layer;

[0040] 53-Dielectric substrate; 6-Antenna hole; 61-Feedthrough ring. Detailed Implementation

[0041] The present invention is described below based on embodiments, but the invention is not limited to these embodiments. In the detailed description of the invention below, certain specific details are described in detail. Those skilled in the art will fully understand the invention even without these details. To avoid obscuring the essence of the invention, well-known methods, processes, flows, elements, and circuits are not described in detail.

[0042] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0043] Unless the context explicitly requires it, words such as "including" or "contains" in the specification should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to".

[0044] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0045] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in the invention according to the specific circumstances.

[0046] In the description of this disclosure, it should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this disclosure can be combined with each other.

[0047] Implantable medical devices communicate with external devices via wireless communication, and the antenna is one of the key components in the wireless communication system of implantable medical devices. The antenna extends from the radio frequency signal output port located inside the metal shell, through an antenna hole on one side of the metal shell, and then to the outside of the metal shell. When the antenna is powered, the electromagnetic waves radiated by the antenna are attenuated inside the metal shell.

[0048] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0049] Figure 1 This is a schematic diagram of an implantable medical device provided in Embodiment 1 of the present invention. Figure 2 This invention includes the markers n and m. Figure 1 A schematic diagram of a local part of the structure.

[0050] This invention provides an implantable medical device, which includes a metal shell 1, a circuit board 5, an antenna 2, and at least one connecting structure 4. The metal shell 1 houses the circuit board 5, the connecting structure 4, and part of the antenna 2. The circuit board 5 is connected to the antenna 2, and the circuit board 5 provides radio frequency signals to the antenna 2.

[0051] In this invention, the metal shell 1 is made of titanium alloy. Compared with other materials, titanium alloy is not easily deformed, can achieve antenna design with maximum space utilization efficiency, and has better biocompatibility.

[0052] like Figure 1-2 The metal casing 1 has an antenna aperture 6, and a feedthrough ring 61 is installed in the antenna aperture 6. A portion of the antenna 2 extends into the interior of the metal casing 1 through the annular hole of the feedthrough ring 61 and connects to the circuit board 5 inside the metal casing 1. The other portion of the antenna 2 is located on the outside of the metal casing 1, which can enhance the radiation signal of the antenna 2. The radio frequency ground includes an auxiliary structure 51, which is made of metal, preferably copper. The auxiliary structure 51 can be disposed on the dielectric substrate in the form of a metal layer. A connecting structure 4 is provided, one side of which is connected to the auxiliary structure 51, and the other side of which is connected to the metal casing 1, thereby changing the electromagnetic characteristics of the metal casing 1 and thus changing the frequency of radiation from the metal casing 1. The position where the metal casing 1 and the connecting structure 4 are connected is defined as the connection point. The distance between the connection point and the antenna aperture 6 is m, the extension path length of the connecting structure 4 between the connection point and the radio frequency ground is n, the wavelength of the antenna 2 when it is working is λ, and m + n ≤ 0.2λ. The units of the variables in the formula are meters. Optionally, m = 0.1λ, n = 0.1λ. The radiation frequency of the metal shell 1 is far away from the radiation frequency of the antenna 2, which reduces the radiation interference of the metal shell 1 to the antenna 2, thereby reducing the energy loss of the radio frequency radiation electromagnetic waves of the antenna 2 and improving the radiation efficiency of the antenna 2.

[0053] Furthermore, one end of the connection structure 4 along its length can be connected to the radio frequency ground, and the other end of the connection structure 4 along its length can be connected to the metal shell 1. The extension length of the connection structure 4 from one end to the other along its length is n.

[0054] In this invention, the circuit board 5 includes a dielectric substrate 53 and multiple metal layers. The dielectric substrate 53 is used to separate adjacent metal layers, and the multiple metal layers include a metal layer used as a radio frequency ground.

[0055] Figure 3 This is the present invention. Figure 1 A schematic diagram of a partial cross-section of AA.

[0056] like Figure 3 The circuit board 5 includes five metal layers, namely, a first metal layer 521, a second metal layer 522, a third metal layer 523, a fourth metal layer 524, and a fifth metal layer 525. The circuit board 5 also includes a dielectric substrate 53 disposed between adjacent metal layers. In this embodiment, the dielectric substrate 53 includes an FR4 board. The antenna 2 is connected to the first metal layer 521, and the auxiliary structure 51 is located on the same dielectric substrate as the first metal layer 521. The radio frequency ground includes a conductive via 511 located on the second metal layer 522. The conductive via 511 is disposed on the dielectric substrate between the first metal layer 521 and the second metal layer 522. The auxiliary structure 51 is connected to the second metal layer 522 through the conductive via 511. The auxiliary structure 51 facilitates the connection between the connection structure 4 and the circuit board 5, avoiding layout conflicts between the first metal layer 521 and the radio frequency ground. Those skilled in the art can design circuits for the first metal layer 521, the second metal layer 522, the third metal layer 523, the fourth metal layer 524, and the fifth metal layer 525 according to design requirements.

[0057] In some embodiments, the radio frequency ground can be the top or bottom layer of a multilayer metal layer.

[0058] In some embodiments, when the circuit board 5 includes only two metal layers, one of the two metal layers can serve as a radio frequency ground, and the connection structure 4 is directly connected to the radio frequency ground. The other layer can serve as a radio frequency circuit layer and be connected to the antenna 2. The circuit board 5 is small in size, which can reduce the size of the implantable medical device.

[0059] In this invention, the connection structure 4 can be a circuit including at least one device such as a resistor, capacitor, and inductor. The circuit exhibits low impedance characteristics in the operating frequency band of the antenna 2 (impedance is defined as Z = R + jX, where R is the real part of the impedance and X is the imaginary part). Within the operating frequency range of the antenna 2, the real part R of the impedance needs to be less than 20Ω, and the absolute value of the imaginary part X needs to be less than 20. By adjusting the components in the circuit, the electromagnetic characteristics of the metal shell 1 are changed to achieve the effect of adjusting the radiation frequency of the metal shell 1.

[0060] The connecting structure 4 can also be an electrical conductor. One side of the connecting structure 4 is connected to the auxiliary structure 51, and the other side is connected to the connection point of the metal shell 1 near the antenna hole 6. Preferably, the connecting structure 4 is laser welded to the metal shell 1, and the connecting structure 4 is soldered to the auxiliary structure 51. The connecting structure 4 can be strip-shaped or column-shaped. The extension path of the connecting structure 4 between the connection point and the radio frequency ground is n. The length of the connecting structure 4 needs to be as short as possible, and n ≤ 0.1λ can be limited. This can optimize the internal space layout of the metal shell 1, avoid the connecting structure 4 occupying too much space and affecting the setting of other components, and also adjust the electromagnetic characteristics of the metal shell 1, change the frequency of radiation of the metal shell 1, reduce the loss of radio frequency electromagnetic wave energy of the antenna 2 by the metal shell 1, and improve the radiation efficiency of the antenna 2.

[0061] In this invention, the metal casing 1 has a first sidewall 11 facing the surface of the circuit board 5 and a second sidewall 12 adjacent to the first sidewall 11. Figure 1-8 In the example, antenna hole 6 is located on the second side wall 12.

[0062] Figure 4 This is a three-dimensional structural diagram of an implantable medical device provided in Embodiment 1 of the present invention.

[0063] like Figure 1 and Figure 4 The implantable medical device also includes a top cover 3 disposed outside the second sidewall 12, the top cover 3 having a receiving cavity. The top cover 3 is disposed on the side of the metal shell 1 with the antenna hole 6, and the antenna 2 extends from the metal shell 1, passes through the antenna hole 6, and is partially disposed in the receiving cavity.

[0064] Figure 5 This is a schematic diagram of an implantable medical device provided in Embodiment 2 of the present invention. The difference between Embodiment 2 and Embodiment 1 is that: connecting structures 4 are provided on both sides of the antenna hole 6.

[0065] like Figure 5 The implantable medical device is equipped with two connection structures 4, which are respectively set on the circuit boards on both sides of the antenna 2. The metal shell 1 is provided with grounding points on opposite sides of the antenna 2. Compared with embodiment 1, the current path is reduced by half the circumference of the antenna hole 6, which increases the radiation frequency of the metal shell 1 compared with embodiment 1 and moves it further away from the radiation frequency of the antenna 2. The metal shell 1 has less energy loss of electromagnetic waves radiated by the antenna 2.

[0066] In some embodiments, the connection structure 4 is positioned as close as possible to the connection point between the antenna 2 and the circuit board 5, based on the positions of other components within the metal casing 1. The location of the connection point should also ensure that the connection structure 4 has the shortest possible dimensions, reducing the value of m+n, further increasing the radiation frequency of the metal casing 1, and making the radiation frequency of the metal casing 1 far away from the radiation frequency of the antenna 2.

[0067] Figure 6 This is a schematic diagram of an implantable medical device provided in Embodiment 3 of the present invention. The difference between Embodiment 3 and Embodiment 1 is that the connecting structure 4 is connected to the feedthrough ring 61.

[0068] like Figure 6 The metal shell 1 has an antenna hole 6 and includes a feedthrough ring 61 mounted in the antenna hole 6. The antenna 2 passes through the annular hole of the feedthrough ring 61. A connection structure 4 is provided, with one side connected to the radio frequency ground and the other side connected to the feedthrough ring 61, and connected to the metal shell 1 through the feedthrough ring 61. In this case, the connection point is located on the feedthrough ring 61, and the distance between the connection point and the antenna hole 6 is negligible, i.e., m = 0. This design increases the range of possible lengths for the connection structure 4, requiring only that the length of the connection structure 4 be less than 0.2λ. The connection structure 4 is also simpler to design, even with its length remaining constant. Compared to Embodiment 1, the radiation frequency of the metal shell 1 is slightly increased, and the energy loss of the radiated electromagnetic waves from the metal shell 1 to the antenna 2 is reduced.

[0069] Figure 7 This is a schematic diagram of an implantable medical device provided in Embodiment 4 of the present invention. The difference between Embodiment 4 and Embodiment 1 is that: connecting structures 4 are provided on both sides of the antenna hole 6, and the connecting structures 4 are connected to the feedthrough ring 61.

[0070] like Figure 7 Two connecting structures 4 are provided on both sides of the antenna hole 6. Two connecting structures 4, two auxiliary structures 51, and two conductive holes 511 are provided. Compared with embodiment 1, the two connecting structures 4 are respectively connected to the feedthrough ring 61. The distance between the connection point and the antenna hole 6 can be ignored. The current flows from both sides of the antenna hole 6. The current flow path is less than half the circumference of the antenna hole, which can further reduce the current flow path on the metal shell 1. The metal shell 1 has less energy loss of electromagnetic waves radiated by the antenna 2.

[0071] Antenna 2 can be divided into a main body and an extension that are interconnected. The main body is located on the outside of the metal shell 1, and the extension is used to extend into the antenna hole 6 to connect to the circuit board 5. When multiple extensions are provided, multiple antenna holes 6 are provided accordingly. Connection structures 4 can be provided between the metal shell 1 and the circuit board 5 for each of the multiple antenna holes 6. In this invention, "multiple" includes two. In some embodiments, when three or more extensions are provided, the antenna 2 can be designed according to requirements, such as multiple feeds or multiple grounds.

[0072] Figure 8 This is a schematic diagram of an implantable medical device provided in Embodiment 5 of the present invention. The difference between Embodiment 5 and Embodiment 1 is that: the opposite ends of the antenna 2 are respectively connected to the circuit board 5, and there are two antenna holes 6, with a connection structure 4 on both sides of each antenna hole 6.

[0073] like Figure 8 The second sidewall 12 of the metal shell 1 is provided with two antenna holes 6 at intervals, and a feedthrough ring 61 is installed on the antenna hole 6. There are two extensions distributed on opposite sides of the main body. The extensions that extend into the metal shell 1 are inserted into the annular holes of the two feedthrough rings 61, and the two extensions are respectively connected to the circuit board 5.

[0074] The metal shell 1 has four connecting structures 4 corresponding to the two antenna holes 6, and the circuit board 5 has four conductive holes 511 and four auxiliary structures 51. There is a connecting structure 4 on each side of the extension, and the connection point is set on the metal shell 1. The connecting structure 4 is connected to the metal shell 1, and at the same time, it satisfies m+n≤0.2λ.

[0075] In this invention, one of the two extensions of the antenna 2 can be used for power feeding, and the other for grounding. Two connection structures are respectively provided on the periphery of the two antenna holes 6, which can further reduce the energy loss of the radiated electromagnetic waves of the antenna 2.

[0076] Figure 9 This is a schematic diagram of an implantable medical device provided in Embodiment Six of the present invention. The difference between Embodiment Six and Embodiment Five is that the connection point is located at the feedthrough ring 61.

[0077] like Figure 9 Four connection structures 4 are connected to the feedthrough ring 61. The connection structures 4 are connected to the metal shell 1 through the feedthrough ring 61. The distance between the connection point and the antenna hole 6 is negligible, i.e. m = 0. The range of selectable lengths of the connection structures 4 is expanded, which facilitates the structural layout inside the metal shell 1 and significantly reduces the current flow path inside the metal shell 1.

[0078] Figure 10 This is a schematic diagram of an implantable medical device provided in Embodiment 7 of the present invention.

[0079] like Figure 10 The metal layer has five layers, and adjacent metal layers are separated by a dielectric substrate. An antenna hole 6 is provided on the surface of the first sidewall 11 of the metal shell 1 facing the circuit board 5.

[0080] In some embodiments, the first sidewall 11 may also be provided with a plurality of antenna holes 6.

[0081] Antenna hole 6 is fitted with a feedthrough ring 61. Antenna 2 passes through the annular hole of feedthrough ring 61 and extends to the outside of metal shell 1. Connection structure 4 is connected to the second metal layer 522 via auxiliary structure 51. Connection structure 4 is located close to antenna 2 and extends from circuit board 5 to the first sidewall 11 of metal shell 1. Grounding point is located on the first sidewall 11 near antenna hole 6. Connection structure 4 is connected to the connection point on the first sidewall 11, satisfying m+n≤0.2λ.

[0082] In some embodiments, two or more connection structures 4 may be provided around the connection point between the antenna 2 and the circuit board 5 as needed. The material and size of each connection structure 4 may be the same or different depending on actual production requirements. The location of the connection structure 4 can be freely chosen as long as it is close to the antenna 2, providing high flexibility.

[0083] Figure 11 This is a comparison chart of the actual test results of the implantable medical device provided in Embodiment 1 of the present invention and existing implantable medical devices. Figure a shows the actual test curve of the existing implantable medical device without the connection structure 4, and figure b shows the actual test curve of the implantable medical device provided in Embodiment 1 of the present invention with the connection structure 4. Compared to existing implantable medical devices, the implantable medical device of the present invention shows a reduction in test link loss of more than 5dB in the 2.4GHz-3GHz frequency band, meaning a 5dB increase in gain in the test direction. This indicates that the implantable medical device of the present invention, by setting the connection structure 4, effectively reduces the signal loss of the metal shell 1 to the antenna 2 and improves the signal strength of the device.

[0084] Figure 12 This is a comparison chart of the actual test results of the antenna performance of the implantable medical devices of Embodiments 1 and 2 of the present invention and existing medical devices. c represents the test curve with two connection structures 4. Figure 12 As can be seen, in the 2.6GHz-3GHz range, the link loss of curve c is significantly reduced compared to curve b, which further reduces the signal loss of the metal shell 1 to the antenna 2 and improves the signal strength of the device.

[0085] This invention provides an implantable medical device, which may be a deep brain stimulator, an implantable cortical stimulator, an implantable spinal cord stimulator, an implantable sacral nerve stimulator, an implantable vagus nerve stimulator, an implantable pacemaker, or an implantable drug infusion device, etc.

[0086] The implantable medical device includes a metal shell 1, a circuit board 5, an antenna 2, and at least one connection structure 4. The metal shell 1 houses the circuit board 5 and the connection structure 4. A portion of the antenna 2 is located inside the metal shell 1 and connected to the circuit board 5. The two ends of the connection structure 4 are respectively connected to the radio frequency ground of the circuit board 5 and the connection point of the metal shell 1, thereby changing the electromagnetic characteristics of the metal shell 1 to alter the frequency of its radiation. The distance between the connection point and the antenna aperture 6, and the operating wavelength λ of the connection structure 4 and the antenna 2, satisfy m+n≤0.2λ, causing the radiation frequency of the metal shell 1 to be far away from the operating frequency of the antenna 2. This reduces the radiation interference of the metal shell 1 to the antenna 2, thus reducing the energy loss of the electromagnetic waves radiated by the antenna 2 and improving the radiation efficiency of the antenna 2.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. An implantable medical device, characterized in that, include: The metal casing has an antenna hole and a connection point with a distance of m from the antenna hole; The circuit board is disposed inside the metal casing; An antenna, in part, extends from the antenna hole into the metal housing to connect to the circuit board; as well as At least one connecting structure, said connecting structure being located inside the metal shell; The connection structure connects the connection point and the radio frequency ground of the circuit board. The extension path of the connection structure between the connection point and the radio frequency ground is n. The operating wavelength of the antenna is λ. Then m+n≤0.2λ, so that the radiation frequency of the metal shell is far away from the operating frequency of the antenna.

2. The implantable medical device according to claim 1, characterized in that, The connection structure is an electrical conductor or a circuit that includes at least one device: a resistor, a capacitor, and an inductor.

3. The implantable medical device according to claim 2, characterized in that, The connection structure is a circuit. In the operating frequency band of the antenna, the real part of the impedance of the connection structure is less than 20Ω, and the absolute value of the imaginary part of the impedance is less than 20Ω.

4. The implantable medical device according to claim 1, characterized in that, The antenna includes a main body and an extension that are connected to each other. The main body is located on the outside of the metal shell. The metal shell has a plurality of antenna holes, and an extension that extends into the metal shell and connects to the circuit board is inserted through the plurality of antenna holes.

5. The implantable medical device according to claim 4, characterized in that, The metal casing and the circuit board are respectively provided with the connection structure corresponding to the multiple antenna holes.

6. The implantable medical device according to claim 1, characterized in that, The circuit board is connected to the connection structure on both sides of the antenna, and the metal shell is provided with grounding points on opposite sides of the antenna hole.

7. The implantable medical device according to claim 1, characterized in that, The metal housing includes a feedthrough ring mounted in the antenna aperture, through which the antenna passes.

8. The implantable medical device according to claim 7, characterized in that, The connection point is located in the feedthrough loop; The connection structure connects to the feed ring and is connected to the metal shell through the feed ring.

9. The implantable medical device according to claim 1, characterized in that, The circuit board includes a dielectric substrate and multiple metal layers, wherein the dielectric substrate is used to separate adjacent metal layers, and the multiple metal layers include a metal layer used as the radio frequency ground.

10. The implantable medical device according to claim 1, characterized in that, The metal casing has a first sidewall facing the circuit board and a second sidewall adjacent to the first sidewall, and the first sidewall or the second sidewall is provided with the antenna hole.

Images