CN113856050A

CN113856050A - Implantable medical device with loop antenna

Info

Publication number: CN113856050A
Application number: CN202111313516.8A
Authority: CN
Inventors: 刘伟; 李建星; 金华; 陈小龙; 张广雷; 翟建波
Original assignee: Lepu Medical Electronics Technology Co ltd
Current assignee: Lepu Medical Electronics Technology Co ltd
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2021-12-31

Abstract

The present application relates to the technical field of medical equipment, and in particular, to an implantable medical device with a loop antenna, including: a case, a circuit board disposed in the case, a case head disposed on the case, and a plurality of sets of electrode assemblies disposed in the case head; a loop antenna including a loop antenna body disposed in the housing header and an impedance matching network disposed on the circuit board. The space of shell head is utilized to this equipment, the reasonable setting in shell head of loop antenna body and electrode subassembly that will adopt, make the loop antenna body can satisfy antenna length requirement, combine impedance matching network, this loop antenna can reliably communicate with external controlling means at 2 meters within ranges under lower transmitted power, and its energy consumption is lower, thereby the effectual life who prolongs implanted medical equipment, the reasonable setting of loop antenna makes implanted medical equipment's volume less, it is internal to be convenient for implant human, the harm of high frequency radiation to human body has been reduced.

Description

Implantable medical device with loop antenna

Technical Field

The application relates to the technical field of medical equipment, in particular to implantable medical equipment with a loop antenna.

Background

Implantable medical systems typically include implantable neural electrical stimulation systems including Deep Brain Stimulation (DBS), implantable cortical brain stimulation (CNS), implantable spinal cord electrical stimulation (SCS), implantable sacral nerve electrical stimulation (SNS), implantable vagal nerve electrical stimulation (VNS), and the like, implantable cardiac electrical stimulation systems (colloquially referred to as cardiac pacemakers), implantable drug infusion systems (IDDS), and the like. Taking the implanted neural electrical stimulation system as an example, the system mainly comprises a pulse generator (i.e. an implanted neural stimulator) implanted in a body, an electrode and an in vitro controller. The pulse generator is connected with the electrode through the extension lead, so that pulses generated by the pulse generator are transmitted to the electrode, pulse signals generated by the pulse generator are transmitted to a specific nerve target point through the electrode to carry out electric stimulation, and therefore the function of a human body is restored to a normal operation state. The in vitro controller comprises a doctor program controller and a patient program controller.

In this case, the patient program control device is a device which the patient controls his switch or adjusts the output parameters of the internal pulse generator according to his own circumstances, and the patient can usually adjust himself only within the adjustment range set by the doctor. A physician programmer is a device used by a physician to monitor and adjust the output parameters of an in vivo pulse generator based on the patient's condition, and typically one physician programmer may be used to control multiple pulse generators. The patient and physician programmers may communicate with the pulse generator via a wireless communication mode, magnetic coils, or other communication means.

Carry out wireless communication through setting up wireless communication antenna and external control device among the implanted medical equipment among the prior art, the communication frequency of traditional implanted medical equipment and external controller is between 402 ~ 405MHz, consequently to monopole antenna, needs longer length can reach required communication distance and effect usually, and it is comparatively difficult to set up longer monopole antenna to the inside extremely limited space of implanted medical equipment. And the head of the implanted medical equipment is provided with a plurality of metal stoppers for connecting electrodes, and the metal stoppers can cause interference on antenna communication and influence the wireless communication quality. In addition, the helical antenna for the implantable medical device needs to be processed with high precision, the processing process is complex, the helical antenna is designed independently or only the influence of the antenna and the metal shell is considered, when the implantable medical device adopting the helical antenna works actually, the helical antenna is greatly influenced by other structures such as electrodes and the like, the antenna efficiency can be reduced, and the wireless communication quality is further influenced.

Disclosure of Invention

The application provides an implanted medical equipment with loop antenna to solve the problem that the antenna in the traditional implanted medical equipment is longer, the antenna efficiency is low, and then the wireless communication quality of the implanted medical equipment is influenced.

The technical scheme adopted by the application for solving the technical problems is as follows:

an implantable medical device having a loop antenna, comprising:

a case, a circuit board disposed in the case, a case head disposed on the case, and a plurality of sets of electrode assemblies disposed in the case head;

the loop antenna comprises a loop antenna body arranged in the shell head and an impedance matching network arranged on the circuit board, and the loop antenna body is connected with a loop antenna interface of the circuit board through a platinum yttrium metal wire.

Further, the impedance matching network comprises a first parallel capacitor, a series inductor, a second parallel capacitor and a series resistor;

one end of the first parallel capacitor is connected with a chip antenna interface arranged on the circuit board;

one end of the series inductor is connected with the other end of the first parallel capacitor;

one end of the second parallel capacitor is connected with the other end of the series inductor;

one end of the series resistor is connected with the other end of the second parallel capacitor, and the other end of the series resistor is connected with the feed end of the platinum yttrium metal wire.

Further, the capacitance value of first parallel capacitor is 2.2pF, the inductance value of series inductance is 3.4nH, the capacitance value of second parallel capacitor is 2.4pF, the resistance of series resistance is 0.

Further, the loop antenna body is in a hexagonal ring shape.

Further, the center frequency of the loop antenna is 2.45Hz, and the bandwidth is greater than or equal to 100 MHz.

Furthermore, the loop antenna body is fixedly arranged on the circuit board through a ceramic connector.

Further, the electrode assembly comprises an electrode, a metal stop block, a silica gel plug and an annular buckle;

the metal stop block and the annular buckle are respectively fixedly connected with the circuit board through metal connecting wires, the electrode is connected with the circuit board through the metal stop block and the annular buckle, and the electrode is fixedly connected with the metal stop block through a silica gel plug arranged on the metal stop block.

Furthermore, the shell is made of titanium, the head of the shell is made of ethylene oxide, and the electrode, the metal stop block and the annular buckle are made of copper.

The technical scheme provided by the application comprises the following beneficial technical effects:

an implantable medical device having a loop antenna is provided, comprising: a case, a circuit board disposed in the case, a case head disposed on the case, and a plurality of sets of electrode assemblies disposed in the case head; and the loop antenna comprises a loop antenna body arranged in the head part of the shell and an impedance matching network arranged on the circuit board, wherein the feed end of the loop antenna body is connected with the loop antenna interface of the circuit board through a platinum yttrium metal wire. The space of shell head is utilized to this equipment, the reasonable setting in shell head of loop antenna body and electrode subassembly that will adopt, make the loop antenna body can satisfy antenna length requirement, combine impedance matching network, this loop antenna can reliably communicate with external controlling means at 2 meters within ranges under lower transmitted power, and its energy consumption is lower, thereby the effectual life who prolongs implanted medical equipment, the reasonable setting of loop antenna makes implanted medical equipment's volume less, it is internal to be convenient for implant human, the harm of high frequency radiation to human body has been reduced.

Drawings

Fig. 1 is a schematic structural diagram of an implantable medical device provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of the periphery of a loop antenna of an implantable medical device provided in an embodiment of the present application;

fig. 3 is a schematic diagram illustrating a positional relationship between a loop antenna body, a metal stopper, and a ceramic connector of an implantable medical device according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an impedance matching network of a loop antenna of an implantable medical device according to an embodiment of the present application;

FIG. 5 is a diagram illustrating an S of a loop antenna circuit of an implantable medical device according to an embodiment of the present application₁₁A curve;

FIG. 6 is a graph illustrating the efficiency of a loop antenna of an implantable medical device according to an embodiment of the present application;

fig. 7 is a first directional diagram of a center frequency of a loop antenna of an implantable medical device provided in an embodiment of the present application;

fig. 8 is a second pattern of a center frequency of a loop antenna of an implantable medical device according to an embodiment of the present application.

Description of reference numerals: the antenna comprises a shell 1, a shell 2, a shell head 3, an electrode 4, a loop antenna body 5, a ceramic connector 6, a platinum yttrium metal wire 7, a circuit board 31, a metal stop block 32, a silica gel plug 33, a loop buckle 41, a chip antenna interface 42, a first parallel capacitor 43, a series inductor 44, a second parallel capacitor 45, a series resistor 46 and a feed end of the platinum yttrium metal wire.

Detailed Description

To facilitate the description and understanding of the technical solutions of the present application, some concepts related to the present application will be first explained below.

The embodiment of the application provides an implanted medical equipment with loop antenna, and the loop antenna that this equipment gathered simple structure, processing convenience and communication efficiency are high, and this loop antenna's frequency channel is 2.45 GHz's bluetooth frequency channel. The Bluetooth frequency band has the advantages of low power consumption, low time delay, small antenna size and the like. The structure and size parameters of the loop antenna are material parameters of a shell, an electrode, a metal block, a metal connecting wire, ethylene oxide, a dielectric substrate and the like of implantable medical equipment, and are calculated and optimized by adopting CST2021 time domain solver electromagnetic full-wave simulation. The loop antenna has higher efficiency, so the transmitting power is lower, the battery energy is saved, and the influence of radiation on the human body is reduced. In order to further improve the bandwidth of the loop antenna and improve the bandwidth margin, the impedance matching design of the loop antenna is carried out on the circuit board, and the matching circuit element has no resistance energy dissipation element, so that the energy from the chip is fed into the loop antenna without loss.

The technical solution of the present application will be further described below with reference to the accompanying drawings and examples.

Referring to fig. 1, a schematic structural diagram of an implantable medical device provided in an embodiment of the present application is shown. As shown in fig. 1, the implantable medical device comprises a housing 1, a circuit board 7 arranged in the inner cavity of the housing 1, a housing head 2 arranged at the upper part of the housing 1, and a plurality of electrodes 3 partially arranged in the housing head 2, wherein the material of the housing 1 is titanium metal, the material of the housing head 2 is ethylene oxide, the dielectric constant of the ethylene oxide is 3.3, the loss tangent is 0.002, and the material of the electrodes 3 is copper metal.

Referring to fig. 2, a schematic diagram of the periphery of a loop antenna of an implantable medical device provided in an embodiment of the present application is shown. As shown in fig. 2, three sets of electrode assemblies are disposed in the head portion 2 of the housing, each electrode assembly includes an electrode 3, a metal stopper 31 and an annular buckle 33 for disposing the electrode 3, the metal stopper 31 and the annular buckle 33 are fixedly connected to the circuit board 7 through metal connecting wires, respectively, the metal stopper 31 is disposed at the tail portion of the electrode 3, the annular buckle 33 is disposed at the middle position of the electrode 3, the head portion of the electrode 3 penetrates out of the head portion 2 of the housing to be connected to an implanted electrode, and a silicone plug 32 is disposed on the metal stopper 31, the electrode 3 and the metal stopper 31 are fixedly connected by using the silicone plug 32, wherein three electrodes 3 are disposed in parallel and the distance between two adjacent electrodes 3 is equal, that is, the three metal stoppers 31 are parallel and the distance between two adjacent electrodes is equal, and the three annular buckles 33 are parallel and the distance between two adjacent electrodes is equal, the metal stopper 31 and the annular buckle 33 are made of metal copper, the dielectric constant of the silicon plug 32 is 4.0, and the loss tangent is 0.002.

On the left side of the electrode assembly is a loop antenna body 4 of the loop antenna, and in particular, see fig. 3, it is a schematic diagram of a positional relationship between the loop antenna body of the implantable medical device provided in the embodiment of the present application, the metal stopper, and the ceramic connector. As shown in fig. 3, the shape of the loop antenna body 4 is a hexagonal loop, and the arrangement of the loop antenna body 4 in a hexagonal loop is a result of electromagnetic full-wave simulation and optimization by using a CST2021 time domain solver, taking into consideration all the structures and material parameters of the housing 1, the metal connection wire, the metal stopper 31, the platinum yttrium metal wire 6, the electrode 3, the ceramic connection body 5, the circuit substrate, and ethylene oxide. The right side of the loop antenna body 4 is firstly connected with one end of a platinum yttrium metal wire 6 through a sleeve, the electrode 3 and the metal stopper 31 are avoided through one-time bending, the perimeter of the loop antenna body 4 is expanded as much as possible by being parallel to the boundary of the shell head 2, and finally the loop antenna body is connected with one end of the platinum yttrium metal wire 6 on the left side in parallel along the shell wall through a sleeve. The two platinum yttrium metal wires 6 respectively penetrate through the two holes of the ceramic connector 5, so that the two platinum yttrium metal wires 6 are fixed on the circuit board 7, and the other ends of the two platinum yttrium metal wires 6 are connected with a circuit board antenna interface on the circuit board 7. The ceramic interconnector 5 has a dielectric constant of 10 and a loss tangent of 0.001, the platinum yttrium wire 6 is an ideal electric conductor, and the circuit board 7 has a dielectric constant of 4.3 and a loss tangent of 0.02. The loop antenna body 4 reasonably utilizes the space in the fixed packaging range of the shell head 2, so that the loop antenna body has enough length, thereby avoiding the problem that the size of the shell head 2 must be enlarged due to insufficient length of the antenna, namely ensuring that the implanted medical equipment has smaller volume.

In order to further increase the bandwidth and increase the design margin, an impedance matching network of a loop antenna composed of lumped elements is designed at the end of the circuit board 7. Referring to fig. 4, as shown in fig. 4, after a signal is sent from the chip antenna interface 41, the signal passes through a first parallel capacitor 42 with a capacitance of 2.2pF, a series inductor with an inductance of 3.4nH, a second parallel capacitor with a capacitance of 2.4pF, and a series resistor with a resistance of 0, that is, in practical application, the signal is fed into the feeding terminal 46 of the platinum yttrium wire connected to the loop antenna body 4 without the series resistor. The central frequency of the loop antenna is 2.45Hz, the bandwidth is at least 100MHz, wherein the type of the patch inductor and the type of the patch capacitor can be 0603, and the loop antenna can be adjusted according to the actual application condition. The impedance matching network has no resistance element, so that energy can be fed into the loop antenna body 4 without loss.

The following are test results for the performance of the loop antenna.

Referring to fig. 5, S of a loop antenna circuit of an implantable medical device provided in an embodiment of the present application₁₁Curve line. The loop antenna uses the chip radio frequency port on the circuit board 7 as a reference surface and the scattering parameter S thereof₁₁As shown in FIG. 5, the-6 dB bandwidth is 2395MHz-2495MHz, completely covering the Bluetooth communication band 2400MHz-2480 MHz.

Referring to fig. 6, an efficiency curve for a loop antenna of an implantable medical device provided in an embodiment of the present application is shown. Within the bandwidth range of the Bluetooth frequency band, the radiation efficiency of the loop antenna is more than 85 percent, and the efficiency is high.

Referring to fig. 7 and 8, a first directional diagram and a second directional diagram of a center frequency of a loop antenna of an implantable medical device provided by an embodiment of the present application are shown, respectively. As can be seen from fig. 7 and 8, the antenna gain of the loop antenna at the center frequency of 2.45GHz is 3.87dB, the 3dB beam width is 110 ° when θ is 90 °, and the loop antenna is an omni antenna when θ is 0 °. In that

The 3dB beam width is 120 DEG at

At time, the 3dB beamwidth is 116 °, so the main energy of the loop antenna radiates to the antenna head.

In the implantable medical device with the loop antenna provided by the embodiment of the application, if only the loop antenna body 4 is connected with the 2.45GHz transmitting end, the efficiency is low, all structures and material parameters of the implantable medical device are considered during design, and except for the loop antenna body 4, current distribution is formed on the metal connecting wire and the metal stopper 31. This annular antenna body 4's hexagon ring-shaped design has satisfied the length requirement of bluetooth frequency channel antenna, and set up the side at metal stop 31, reasonable utilization the space in head shell 2, combine impedance matching network to make loop antenna can be under lower transmitting power, for example power is less than 25uw, just can reliably communicate at 2 meters within ranges with external controlling means, the energy consumption is lower, thereby the effectual life who prolongs implanted medical equipment, and make implanted medical equipment have less volume, be convenient for implant human internal, the harm of high frequency radiation to human body has been reduced.

Claims

1. An implantable medical device having a loop antenna, comprising:

a case (1), a circuit board (7) disposed in the case (1), a case head (2) disposed on the case (1), a plurality of sets of electrode assemblies disposed in the case head (2);

the loop antenna comprises a loop antenna body (4) arranged in the shell head part (2) and an impedance matching network arranged on the circuit board (7), wherein the loop antenna body (4) is connected with a loop antenna interface of the circuit board (7) through a platinum yttrium metal wire (6).

2. The implantable medical device with a loop antenna of claim 1, wherein the impedance matching network comprises a first parallel capacitance (42), a series inductance (43), a second parallel capacitance (44), and a series resistance (45);

one end of the first parallel capacitor (42) is connected with a chip antenna interface (41) arranged on the circuit board (7);

one end of the series inductor (43) is connected with the other end of the first parallel capacitor (42);

one end of the second parallel capacitor (44) is connected with the other end of the series inductor (43);

one end of the series resistor (45) is connected with the other end of the second parallel capacitor (44), and the other end of the series resistor (45) is connected with a feed end (46) of the platinum yttrium metal wire.

3. The implantable medical device with a loop antenna according to claim 2, wherein the capacitance value of the first parallel capacitor (42) is 2.2pF, the inductance value of the series inductor (43) is 3.4nH, the capacitance value of the second parallel capacitor (44) is 2.4pF, and the resistance value of the series resistor (45) is 0.

4. The implantable medical device with loop antenna according to any of claims 1-3, characterized in that the loop antenna body (4) is hexagonal ring shaped.

5. The implantable medical device with a loop antenna of claim 4, wherein the loop antenna has a center frequency of 2.45Hz and a bandwidth greater than or equal to 100 MHz.

6. The implantable medical device with a loop antenna according to claim 5, characterized in that the loop antenna body (4) is fixedly arranged on the circuit board (7) by means of a ceramic connector (5).

7. The implantable medical device with loop antenna according to claim 6, wherein the electrode assembly comprises an electrode (3), a metal stopper (31), a silicone plug (32) and a loop snap (33);

the metal stop block (31) and the annular buckle (33) are respectively fixedly connected with the circuit board (7) through metal connecting wires, the electrode (3) is connected with the circuit board (7) through the metal stop block (31) and the annular buckle (33), and the electrode (3) is fixedly connected with the metal stop block (31) through a silica gel plug (32) arranged on the metal stop block (31).

8. The implantable medical device with loop antenna according to claim 7, wherein the material of the housing (1) is titanium, the material of the housing head (2) is ethylene oxide, and the materials of the electrode (3), the metal stopper (31) and the loop clasp (33) are all copper.