An antenna and an implantable medical device for wireless communication through the antenna

Abstract

The present invention discloses an antenna and an implantable medical device for wireless communication by means of the antenna. The medical device includes: a device housing, a hybrid circuit, an antenna, and a feedthrough component. The antenna is designed in a three-dimensional shape, which maximally increases the radiation aperture of the antenna and reduces the two-dimensional area of the antenna. By means of coupling, the conductive housing is changed into a partial radiation component to achieve data transmission, improving the energy transmission efficiency and the data transmission distance.

Description

Technical Field

[0001] The invention relates to an antenna which can be packaged in an implantable medical device and connected to a hybrid circuit of the implantable medical device through a feed-through component to achieve far-field communication between the implantable medical device and an in vitro remote device, and is suitable for medical instruments and clinical fields. Background Art

[0002] Implantable medical devices (implants) are widely available to provide diagnostic or therapeutic capabilities. There are three types of active implantable products, including implantable cardioverter defibrillators (ICDs), implantable cardiac monitors (ICMs), implantable pacemakers (Cardiac Pacemakers), leadless implantable pacemakers, subcutaneous implantable cardioverter defibrillators (SICDs), and various tissue, organ, and nerve stimulators or sensors. Doctors or professionals are generally required to use an external programmer to achieve wireless communication with the implant stimulator to complete data transmission, implant software upgrades, emergency stop and other possible functions. The purpose of the present invention is to solve the efficiency and quality of wireless communication, improve the efficiency of wireless transmission, and avoid communication problems or failures.

[0003] The traditional communication method uses inductive near-field coupling to perform wireless communication at a distance of several centimeters. The disadvantages of this method are: the communication distance is too short, the usage is limited and the data rate is low, which is generally thousands or tens of kilobits.

[0004] With the advancement of technology, remote communication between implant circuits and external programmers and other remote control devices has become possible, and is increasingly being used in equipment control, data transmission, and real-time monitoring. Implants and external devices can communicate at a distance of several meters. As one of the hardware foundations for communication, the implant antenna is placed in the connector outside the shell, which ensures that the energy radiated by the antenna is not absorbed by the metal shell and is conducted to the maximum extent. As circuits and structures become more integrated and miniaturized, the physical space for antennas is restricted. Generally speaking, the communication distance is related to the radiation efficiency / gain of the antenna, the transmitting power of the transmitting antenna, and the sensitivity of the receiving antenna. There is a positive correlation between the efficiency / gain of the antenna and its size. To maximize the antenna efficiency and increase the maximum transmission distance, designers have proposed various solutions. For example, modifying the communication frequency and decoding method to make the system more sensitive to signals under the same hardware conditions; or attempting to design an antenna with better directivity to achieve better efficiency in a certain direction; or adding a matching network to achieve smaller return loss and better radiation efficiency, enabling a longer transmission distance at a specific frequency. These methods are usually not advisable because they either deviate from the communication frequency bands allowed by the implant in regulations in actual situations, or require additional requirements during the surgery, or it is difficult to maintain communication stability in a changing environment, and they also increase the components to be used.

[0005] Generally speaking, to achieve an ideal antenna efficiency, the total length of the antenna needs to be at least one-quarter to one-half

[0006] of a wavelength. Reducing the antenna length will reduce the radiation impedance of the antenna, making it more difficult to match the antenna with the source and couple with the air impedance, thus significantly reducing the antenna efficiency. This example proposes a solution to increase the effective radiation efficiency of the antenna. The antenna is bent multiple times in three-dimensional space and coupled with the housing to obtain better radiation ability. Summary of the Invention

[0007] The present invention provides an antenna, which includes three parts. The first part includes two L-shaped segments ABC and DEF and an arc segment CD connecting the short sides of the two L-shaped segments. The planes where the two L-shaped segments ABC and DEF are located are perpendicular to each other. The lengths of the two sides AB and EF of the two L-shaped segments are different, and they are on the same side of the plane where the two short sides BC and DE are located. The second part is a bent segment GH in the same plane, and the plane where the bent segment is located is perpendicular to the planes where the two L-shaped segments in the first part are located. The third part is an arc segment FG, which connects the longest side EF of the L-shaped segment in the first part and the bent segment GH in the second part.

[0008] The antenna is for MICS microwave communication, and the operating frequency is from 402 MHz to 405 MHz of MICS.

[0009] The antenna is a monopole antenna without a corresponding dual structure.

[0010] The bent segment of the antenna includes a vertical Z-shaped, multiple consecutive vertical Z-shaped, horizontal Z-shaped, multiple consecutive horizontal Z-shaped,

[0011] Horizontal trapezoid, multiple consecutive horizontal trapezoids, vertical trapezoid, multiple consecutive vertical trapezoids, horizontal W shape, multiple consecutive horizontal W shapes, vertical W shape, multiple consecutive vertical W shapes.

[0012] The arc segment CD of the first part of the antenna is perpendicular to the plane where the arc segment FG of the third part is located, and the arc segment FG of the third part is parallel to the plane where the L-shaped segment with the shorter long side in the first part is located.

[0013] The present invention provides an implantable medical device, which is composed of four parts: a device housing (equipment housing), a hybrid circuit, an antenna, and a feedthrough component. The antenna includes three parts. The first part includes two L-shaped segments ABC and DEF and an arc segment CD connecting the short sides of the two L-shaped segments. The planes where the two L-shaped segments ABC and DEF are located are perpendicular to each other. The lengths of the two sides AB and EF of the two L-shaped segments are different and are on the same side of the plane where the two short sides BC and DE are located. The second part is a bent segment GH in the same plane, and the plane where the bent segment is located is perpendicular to the planes where the two L-shaped segments in the first part are located. The third part is an arc segment FG, which connects the longest side EF of the L-shaped segment in the first part and the bent segment GH in the second part.

[0014] The antenna is connected to the main body of the medical device through a feedthrough component and is encapsulated within the feedthrough component.

[0015] The radiation part of the implantable medical device is jointly constituted by the antenna body and the implant housing.

[0016] The implantable medical device and the external programmer respectively have a set of hardware configurations, including a radio frequency antenna, a radio frequency chip, and corresponding software for configuration.

[0017] The antenna is connected to the main body of the medical device through a section formed by connecting an arc segment and a planar segment.

[0018] The edge line of the medical device is parallel to the plane where the L-shaped segment with the shorter long side in the first part of the antenna is located.

[0019] The antenna makes a final fold below and parallel to the housing, and the parallel part can turn the housing into a partial radiation component through coupling, improving the signal transmission efficiency.

[0020] The present invention discloses and describes an implantable medical device capable of signal transmission with an external remote device through an antenna. In some examples, the implantable medical device can automatically trigger the sensing of electrocardiogram signal parameters inside the heart. For example, without a trigger input initiated from an external source, such as a request initiated by the patient or by a doctor from an external device, and at least partially based on one or more physiological parameters of the patient, the sensed physiological parameters are transmitted to an exogenous far-field device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional structural schematic diagram of an antenna.

[0022] Figure 2 Viewed from Figure 1 the direction of the R arrow in, it is a three-dimensional structural schematic diagram of the antenna.

[0023] Figure 3 It is another three-dimensional structural schematic diagram of an antenna.

[0024] Figure 4 It is a schematic diagram of the external structure of the implantable medical device and the relative positions of each part component in the heart when it is implanted inside the heart.

[0025] Figure 5 For Figure 1 the antenna shown, it is an antenna structural schematic diagram of a fixing method.

[0026] Figure 6 For Figure 1 the antenna shown, it is a position structural schematic diagram of the antenna installed on the implantable medical device ICD.

[0027] Figure 7 Viewed from Figure 6 the arrow T direction in, it is a position structural schematic diagram of the antenna installed on the implantable medical device ICD. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Figure 1 It is a three-dimensional structural schematic diagram of an antenna. Taking the antenna shown in Figure 1 as an example, the specific operation process of the antenna in the implantable medical device is described. For the convenience of description and illustration, Figure 1 the respective nodes of the antenna are marked with letters A, B, C, D, E, F, G, H, I, J from one end of the antenna to the other end. The antenna includes three parts. The first part is the part marked from letter A to F, which includes two L-shaped segments ABC and DEF and an arc segment CD connecting the short sides of the two L-shaped segments. Combining Figure 6It can be seen that the planes where the two L-shaped segments ABC and DEF are located, namely plane II and plane III, are perpendicular to each other. The lengths of the two sides AB and EF of the two L-shaped segments are different, and they are located on the same side of the plane formed by the two short sides BC and DE, namely plane I. The second part is the part from letter G to J, including a bent segment GH in the same plane. The third part is an arc segment FG that connects the end point F of the longest side of the L-shaped segment in the first part to the starting point G of the bent segment in the second part. The plane I where the arc segment CD in the first part of the antenna is located is perpendicular to the plane II where the arc segment FG in the third part is located. The third part of the arc segment FG is parallel to the plane III where the L-shaped segment DEF with the shorter long side in the first part is located. The whole antenna forms a monopole antenna without a reflector part. The biggest feature of the monopole antenna is that it can provide satisfactory radiation characteristics in a very wide frequency band, and at the same time has many advantages such as simple structure, light weight, simple feeding structure, easy analysis, and good omnidirectional characteristics. The raw material of the antenna can be selected as copper plate or tin-plated steel plate. The working principle of the antenna is for MICS microwave communication, and the working frequency of the antenna is from MICS 402 MHz to MICS 405 MHz. The effective radiation efficiency of the antenna is increased by high frequency, and better radiation ability is obtained by bending multiple times in three-dimensional space. This antenna can be encapsulated in implantable cardiac defibrillators, implantable cardiac monitors, implantable cardiac pacemakers, leadless implantable cardiac pacemakers, subcutaneous implantable cardiac defibrillators, and various implantable medical devices such as tissue, organ, and nerve stimulators or sensors. The schematic structural diagram of the antenna installed in the subcutaneous implantable cardiac defibrillator is shown in Figure 5 and Figure 6 . The antenna is connected to the internal circuit board of the implantable medical device for communication to achieve far-field communication between the implantable medical device and the external remote device. The width of the antenna can be adjusted according to the implantable medical device used, and it can be achieved by Figure 1 widening any section of the antenna main body structure and fixing it in an appropriate way. The fixing methods include: mechanical structure fixing by drilling holes, glue bonding, bolt connection, welding, riveting, interference fit of shaft and hole, transitional fit of shaft and hole, clearance fit, and key connection followed by thread pressing, etc. The antenna should be encapsulated inside the implantable medical device and the length of the antenna should be as long as possible to enhance the signal transmission sensitivity of the antenna.

[0029] Figure 2 From Figure 1 is the schematic three-dimensional structure diagram of the antenna viewed from the direction indicated by the R arrow in Figure 2 . The second part of the antenna is a bent segment GH, and this bent segment is in the same plane. Figure 2In addition to the vertical trapezoid shown, it can also be designed as one or a combination of several of a vertical Z-shape, a continuous plurality of vertical Z-shapes, a horizontal Z-shape, a continuous plurality of horizontal Z-shapes, a horizontal trapezoid, a continuous plurality of horizontal trapezoids, a continuous plurality of vertical trapezoids, a horizontal W-shape, a continuous plurality of horizontal W-shapes, a vertical W-shape, and a continuous plurality of vertical W-shapes. However, it is necessary to ensure that the plane Ⅰ where the bending segments of the various shapes are located is perpendicular to the planes Ⅱ and Ⅲ where the two L-shaped segments ABC and DEF are located in the first part. Figure 3 It is a schematic three-dimensional structure diagram of another antenna. For the convenience of explanation and description, Figure 3 Starting from one end of the antenna to the other end, the respective nodes of the antenna are marked with letters a, b, c, d, e, f. The antenna includes three parts. The first part is the part marked from letter a to b, which is an S-shaped segment. Figure 3 And Figure 1 The difference lies only in the first part of the antenna. Figure 3 The second part is the part from letter b to c, including a bending segment cd in the same plane. The third part is an arc segment bc that connects the S-shaped segment of the first part to the bending segment of the second part. The plane Ⅰ where the S-shaped segment ab of the first part of the antenna is located is perpendicular to the plane Ⅱ where the arc segment bc of the third part is located. The antenna is connected to the device hybrid circuit through an overall structure composed of an arc segment de and a planar segment ef.

[0030] Implanted medical devices (implants) generally have the ability to provide diagnosis or treatment. Three types of active implant products such as implantable cardioverter-defibrillators, implantable cardiac monitors, implantable cardiac pacemakers, leadless implantable cardiac pacemakers, subcutaneous implantable cardioverter-defibrillators, and various tissue, organ, and nerve stimulators or sensors generally require doctors or professionals to achieve wireless communication between an external programmer and the implant stimulator to complete functions such as data transmission, implant software upgrade, and emergency stop. In this embodiment, taking an ICD as an example, the working scheme of the antenna in the implanted medical device is described.

[0031] Figure 4 It is a schematic diagram of the external structure of the ICD100 and the relative positions of the various components in the heart when it is implanted inside the heart. The ICD is composed of four parts: a device housing 105, a hybrid circuit in the device housing, an antenna, and a feedthrough component. The antenna is encapsulated in the feedthrough component of the ICD head structure 107. Inside the feedthrough component, not only the antenna feedthrough is encapsulated, but also the wire feedthrough is encapsulated. The wire feedthrough is shown in Figure 5In the ICD head structure, the lead feedthrough is connected to the lead 115, and the ICD main circuit board is connected to the heart through the antenna to sense the electrocardiogram signal parameters or perform treatment by pacing. Inside the device housing, there are usually a power supply, a capacitor, and a hybrid circuit, which is usually implemented by a chip through program coding. The ICD function can be achieved in two ways. One is the automatic regulation inside the ICD body, which does not require manual triggering and control and can be automatically achieved. The other is achieved by the communication signal 185 sent by the external programming device 190. The external programming device of the ICD is generally a programmer, a patient assistant, or other devices that can issue commands to it or sense its internal signals. The communication method between the ICD and the external programming device 190 can be one or more of wired communication, Bluetooth, WIFI, LTE, or CDMA wireless communication networks. Figure 1 The shown ICD lead 115 is a single lead. During clinical use, it may also be a double lead, a triple lead, or a quadruple lead. The basic structure of the lead is similar to that of the lead 115. The lead 115 is composed of a coil 118, an electrode 120A, and an electrode 120B. The coil 118 is connected to the ICD body through a connector 107. The function of the coil is to achieve sensing or treatment through discharging. The electrodes 120A and 120B sense the signal parameters of the cardiac event. The electrode 120B is also called the helix head and contains a helical coil inside. The electrode 120A on the lead is screwed into the insulating material outside the lead before use and can be screwed out from the other end of the lead before implanting into the human heart, so that the 120A electrode end of the lead is fixed to the myocardial tissue inside the heart. The electrode lead needs to be coated with insulating materials such as silicone, polyurethane, or epoxy resin.

[0032] Figure 5 is Figure 1 Schematic diagram of the antenna structure of a fixing method of the shown antenna. Figure 5 The dotted line in it represents the antenna part enclosed by the dotted line and does not represent a plane. Figure 5 and Figure 1 The difference between the antenna in it and the antenna lies in the part 208 enclosed by the dotted line. Figure 4 The antenna Figure 1 The long side EF part of the first part L section DEF of the shown antenna has been further processed. Figure 4 The antenna 202 Figure 2 The width of the long side EF section of the L section DEF in the antenna is widened, and holes 206 are drilled on the widened section 204. The number of holes is from 0 to 10, and the size of the holes can be adjusted according to the size of the specific medical device. The holes in the antenna are used to fix the antenna inside the ICD head. The fixing method can be selected as bonding with glue, bolt connection, welding, riveting, interference fit of the shaft and the hole, transition fit or clearance fit of the shaft and the hole, and key connection followed by tightening with a thread, etc.

[0033] Figure 6 The Figure 1 schematic diagram of the position structure where the shown antenna is installed on an implantable medical device (ICD). 316 is the device housing of the medical device. Inside the device housing, there is a hybrid circuit that completes the functions of sensing and communicating electrocardiogram parameters for the implant device. A feedthrough component is encapsulated in the head of the ICD, and the feedthrough component includes an antenna feedthrough and a wire feedthrough. The antenna feedthrough is a component that connects the antenna and the device body. One end of the antenna 320 is connected to the internal circuit board of the device body through the antenna feedthrough via part 312, and the other end is open or connected to the internal circuit of the stimulator to form a loop. The wire feedthrough is connected to the hybrid circuit inside the device housing 316 through 1 to 5 wires 308. The position where the wires are connected to the hybrid circuit is designed within a range area, and the area shown in this figure for connection is 310. The wire feedthrough component contains four silicone insulators 318 that separate three conductors 302 to prevent short circuits caused by electrical connection between the conductors. The antenna is connected to the hybrid circuit of the medical device through an overall structure composed of an arc segment HI and a planar segment IJ. 314 is the ground wire that grounds the internal circuit board of the device to form a loop for wireless signal transmission. The ICD and the external programmer each have a set of hardware configurations, including a radio frequency antenna, a radio frequency chip, and corresponding software configurations. 304 on the wire feedthrough is a fixing structure, and the fixing methods include: glue bonding, mechanical structure fixing, bolt connection, welding, and riveting. At the same time, the fixing structure 304 must be a conductor with conductive function to connect the antenna 320 to the internal circuit board of the implantable medical device, so that the antenna is connected to the internal circuit of the device and the wireless communication function is exerted.

[0034] Figure 7 viewed from Figure 6 the direction of arrow T in the schematic diagram of the position structure where the antenna is installed on an implantable medical device (ICD). Figure 7 The dotted lines in the figure represent the planes where the dotted boxes are located. Every four dotted lines enclose a dotted box, and one dotted box is located in one plane. The three dotted boxes in the figure represent the three planes where the three dotted boxes are respectively located, and these three planes are perpendicular to each other in pairs. The antenna 320 makes a final fold below and parallel to the ICD housing. And the plane Ⅲ where the L-shaped segment DEF with a shorter long side in the first part of the antenna 320 is located is parallel to the edge line of the antenna housing. The material of the device housing 316 in direct contact with the human tissue is electrically conductive metal titanium. The parallel part AB can make the device housing 316 become a partial radiation component through coupling, so that the antenna body 320 and the device housing 316 together constitute the radiation part of the implantable medical device, improving the signal transmission efficiency. There are four silicone insulators 318 on the wire feedthrough of the ICD head. The label 306 is installed on Figure 3The fixed part on the 304 fixing structure in the middle fixes the wire feedthrough to the head of the implantable medical device ICD through fixation. The fixing methods of the fixing part 306 include: mechanical structure fixing, glue bonding, bolt connection, welding, riveting, interference fit of the shaft and hole, transitional fit and clearance fit of the shaft and hole, and key connection followed by tightening with threads, etc.

[0035] The present invention discloses a special-shaped antenna for wireless communication applicable to implantable medical devices. The antenna of the present invention is designed in a three-dimensional shape. The antenna of the medical device makes a final fold below and parallel to the housing. The parallel part can increase the capacitance between the antenna and the housing, and the housing can be changed into a partial radiation component through coupling, maximizing the radiation aperture of the antenna, reducing the two-dimensional area of the antenna, improving the radiation efficiency, the energy transmission efficiency, and the data transmission distance.

Claims

1. An antenna, characterized in that, the antenna comprises three parts. The first part includes two L-shaped segments and an arc segment (CD) connecting the short sides of the two L-shaped segments. The planes where the two L-shaped segments are located are perpendicular to each other. The lengths of the two sides of the two L-shaped segments are different, and they are on the same side of the plane formed by the two short sides. The second part is a bent segment in the same plane, and the plane where the bent segment is located is perpendicular to the planes where the two L-shaped segments in the first part are located. The third part is an arc segment (FG) that connects the longest side of the L-shaped segment in the first part to the starting point of the bent segment in the second part. The plane where the arc segment (CD) in the first part of the antenna is located is perpendicular to the plane where the arc segment (FG) in the third part is located, and the plane where the arc segment (FG) in the third part is parallel to the plane where the L-shaped segment with the shorter long side in the first part is located; the antenna is used for an implantable medical device, and the implantable medical device includes a housing. The end of the second part of the antenna is connected to the internal circuit board of the housing; the long side of the L-shaped segment with the shorter long side in the first part of the antenna is coupled with the housing to make the housing become a partial radiation component, and the plane where the L-shaped segment with the shorter long side in the first part of the antenna is located is parallel to the edge line of the antenna housing.

2. An antenna according to claim 1, characterized in that, the antenna is for MICS microwave communication, and the operating frequency is from 402 MHz to 405 MHz of MICS.

3. An antenna according to claim 2, characterized in that, the antenna is a monopole antenna, without a dual structure, and is a single-feed point structure.

4. An antenna according to claim 3, characterized in that, the bent segment of the antenna includes a vertical Z-shaped, a continuous plurality of vertical Z-shaped, a horizontal Z-shaped, a continuous plurality of horizontal Z-shaped, a horizontal trapezoid, a continuous plurality of horizontal trapezoids, a vertical trapezoid, a continuous plurality of vertical trapezoids, a horizontal W-shaped, a continuous plurality of horizontal W-shaped, a vertical W-shaped, and a continuous plurality of vertical W-shaped.

5. An antenna according to claim 4, characterized in that, the end of the bent segment of the antenna is connected to the housing through an overall structure formed by an arc segment (HI) and a planar segment (IJ).

6. An implantable medical device, characterized in that, the medical device is composed of four parts: a device housing, a hybrid circuit, an antenna, and a feedthrough component. The antenna includes three parts. The first part includes two L-shaped segments and an arc segment (CD) connecting the short sides of the two L-shaped segments. The planes where the two L-shaped segments are located are perpendicular to each other. The lengths of the two sides of the two L-shaped segments are different, and they are on the same side of the plane formed by the two short sides. The second part is a bent segment in the same plane, and the plane where the bent segment is located is perpendicular to the planes where the two L-shaped segments in the first part are located. The third part is an arc segment (FG) that connects the longest side of the L-shaped segment in the first part to the starting point of the bent segment in the second part. The end of the second part of the antenna is connected to the internal circuit board of the housing. The long side of the L-shaped segment with the shorter long side in the first part of the antenna is coupled with the housing to make the housing become a partial radiation component. The edge line of the medical device is parallel to the plane where the L-shaped segment with the shorter long side in the first part of the antenna is located.

7. An implantable medical device according to claim 6, wherein, the antenna is connected to the medical device body through a feedthrough component and is encapsulated within the feedthrough component.

8. An implantable medical device according to claim 7, wherein, the radiation part of the implantable medical device is the antenna body and the implant housing.

9. An implantable medical device according to claim 8, wherein, the implantable medical device includes a hybrid circuit module, the hybrid circuit module includes a radio frequency antenna, a radio frequency chip and corresponding software configuration, wherein the implant radio frequency part includes an antenna debugging chip.

10. An implantable medical device according to claim 6, wherein, the antenna is connected to the medical device body through a cross-section formed by connecting an arc segment and a planar segment.

11. An implantable medical device according to claim 10, wherein, the antenna is finally folded below and parallel to the housing.

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