Cortical visual prosthesis implantable antenna based on water-based medium resonance

Abstract

The invention discloses a cortical visual prosthesis implantable antenna based on water-based medium resonance, and belongs to the technical field of medical instruments, the cortical visual prosthesis implantable antenna comprises an annular outer shell, an annular inner shell is arranged in the annular outer shell, a through groove is formed in the side wall of the annular inner shell, and the through groove is communicated with the inner space of the annular outer shell and the inner space of the annular inner shell to form a water cavity; a water body is arranged in the water cavity, a metal floor is fixedly connected to the bottom ends of the annular outer shell and the annular inner shell, a top shell is fixedly connected to the top ends of the annular outer shell and the annular inner shell, coaxial feeder lines are embedded in the annular inner shell and the top shell, and outer conductors of the coaxial feeder lines are connected with the metal floor; the water-based medium resonant antenna is arranged, so that the use of a metal structure can be reduced, the size is reduced, the heat damage risk increased by ohmic loss generated by current on irregular metal can be avoided, the effective heat protection performance is ensured, and the strict requirement of human brain tissues on heat protection is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of medical devices, and particularly relates to a cortex visual prosthesis implantable antenna based on water-based medium resonance. BACKGROUND

[0002] Nearly 300 million people worldwide are affected by severe visual impairment, and the number of visually impaired people is likely to continue to increase in the future.

[0003] Cortex visual prosthesis technology can directly stimulate the visual cortex through a medical implant implanted on the surface of the brain cortex to induce visual perception, completely solving the problem of blindness, and has been widely used in related fields.

[0004] In the application process of cortex visual prosthesis technology, in order to avoid the risk of infection caused by retaining the cranial incision, the device working in the brain generally communicates with the external device in a wireless manner, therefore, the quality of implant wireless communication directly determines the basic performance of the overall device, that is, the pros and cons of the implant wireless communication carrier are crucial.

[0005] The existing cortex visual prosthesis system implant generally uses an implantable antenna for wireless communication, but the implantable antenna currently applied to the cortex visual prosthesis system generally adopts a patch antenna form, the current on the irregular metal generates ohmic loss, which increases the risk of thermal damage, and it is difficult to meet the stringent requirements of human brain tissue for heat protection.

[0006] In view of this, a cortex visual prosthesis implantable antenna based on water-based medium resonance is designed to solve the above problems. SUMMARY

[0007] To solve the problems raised in the background art, the application provides a cortex visual prosthesis implantable antenna based on water-based medium resonance, which has the characteristics of high biocompatibility, high electromagnetic compatibility, strong anti-interference ability, low cost and simple structure and is easy to produce.

[0008] To achieve the above purpose, the application provides the following technical scheme: a cortex visual prosthesis implantable antenna based on water-based medium resonance, comprising: a ring-shaped shell, a ring-shaped inner shell is arranged inside the ring-shaped shell, a through slot is formed in the side wall of the ring-shaped inner shell, the through slot communicates the internal space of the ring-shaped shell and the internal space of the ring-shaped inner shell to form a water cavity, a water body is arranged inside the water cavity, a metal floor is fixedly connected to the bottom end of the ring-shaped shell and the ring-shaped inner shell, a top shell is fixedly connected to the top end of the ring-shaped shell and the ring-shaped inner shell, a coaxial feeder is embedded in the ring-shaped inner shell and the top shell, the outer conductor of the coaxial feeder is connected to the metal floor, an assembly groove is formed in the top end of the top shell, a slotted ring-shaped metal microstrip is embedded in the assembly groove, and the inner conductor of the coaxial feeder is embedded in the ring-shaped inner shell and the top shell and connected to the slotted ring-shaped metal microstrip.

[0009] Further, the annular shell, the annular inner shell and the top shell are all made of a cured 3D printing material 405 nm photosensitive resin.

[0010] Further, the through slot is arranged in a vertical structure, and the through slot and the position of the coaxial feed line are symmetrical about the y-axis with respect to the center of the annular inner shell as the origin, and the included angle between the line connecting the center of the annular inner shell and the positive and negative half axes of the x-axis is the same.

[0011] Further, the water body is distilled water.

[0012] Further, the water-based medium resonance-based cortical visual prosthesis implantable antenna is applied in cerebrospinal fluid tissue between the brain tissue surface and the arachnoid membrane.

[0013] Compared with the prior art, the beneficial effects of the present application are:

[0014] 1. The water-based medium resonance antenna can reduce the use of metal structures, reduce the volume, avoid the increase of ohmic loss and the risk of thermal damage caused by current on irregular metal, ensure effective thermal protection performance, and meet the strict requirements of human brain tissue on thermal protection.

[0015] 2. The annular shell and the annular inner shell with the through slot form a water cavity, the water body is arranged in the water cavity, and the annular shell and the annular inner shell play the role of a resonance cavity under the wrapping action of the water body, and two mutually orthogonal modes are excited, realizing circularly polarized radiation waves directly above, avoiding stray radiation, and widening the impedance bandwidth to improve the working stability.

[0016] 3. The present application has the advantages of high biological compatibility, high electromagnetic compatibility, strong anti-interference ability, low cost and simple structure, and is easy to produce. DETAILED DESCRIPTION

[0017] Figure 1 is a structural schematic diagram of the present application, wherein (a) is a structural explosion schematic diagram, (b) is a cavity section top view, (c) is a general top view, and (d) is a front view;

[0018] Figure 2 is a curve diagram of the scattering parameter and the target frequency band, and the axial ratio value changes with frequency in the target direction;

[0019] Figure 3 is an actual gain pattern at the working frequency point of the present application;

[0020] Figure 4 is a working flowchart of the present application;

[0021] In the figure: 1, slotted annular metal microstrip; 2, assembly slot; 3, top shell; 4, water body; 5, coaxial feeder; 6, through slot; 7, annular inner shell; 8, annular outer shell; 9, metal floor. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Reference is made to the accompanying Figure 1 (a):

[0024] A cortical visual prosthesis implantable antenna based on water-based medium resonance, comprising: an annular outer shell 8, an annular inner shell 7 is arranged inside the annular outer shell 8, a through slot 6 is arranged on the side wall of the annular inner shell 7, the through slot 6 communicates the inner space of the annular outer shell 8 and the inner space of the annular inner shell 7 to form a water cavity, a water body 4 is arranged inside the water cavity, a metal floor 9 is fixedly connected to the bottom end of the annular outer shell 8 and the annular inner shell 7, a top shell 3 is fixedly connected to the top end of the annular outer shell 8 and the annular inner shell 7, a coaxial feeder 5 is embedded in the annular inner shell 7 and the top shell 3, the outer conductor of the coaxial feeder 5 is connected with the metal floor 9, an assembly slot 2 is arranged on the top end of the top shell 3, a slotted annular metal microstrip 1 is embedded in the assembly slot 2, and the inner conductor of the coaxial feeder 5 is embedded in the annular inner shell 7 and the top shell 3 and connected with the slotted annular metal microstrip 1.

[0025] The annular outer shell 8 and the annular inner shell 7 play the role of a resonance cavity under the wrapping action of the water body 4, and are respectively excited to two mutually orthogonal modes, which can realize circularly polarized radiation wave in the directly above, while reducing ohmic loss and widening impedance bandwidth.

[0026] Specifically, the annular outer shell 8, the annular inner shell 7 and the top shell 3 are all made of cured 3D printing material 405nm photosensitive resin.

[0027] Specifically, the through slot 6 is arranged in a vertical structure, the center of the annular inner shell 7 is taken as the origin, the through slot 6 and the coaxial feeder 5 are symmetrical about the y-axis, and the included angle between the line connecting the through slot 6 and the coaxial feeder 5 and the x-axis positive and negative half-axes is the same.

[0028] The included angle value varies according to actual use, and the variation of the included angle value can change the distribution of the water body 4 and adjust the performance of the implantable antenna.

[0029] Specifically, the water body 4 is distilled water.

[0030] Specifically, a cortical visual prosthesis implantable antenna based on water-based dielectric resonance is applied within the cerebrospinal fluid tissue between the brain tissue surface and the arachnoid membrane.

[0031] Example

[0032] See attached Figure 1 (b), (c) and (d):

[0033] The height H of the annular housing 8 w is 2.2 mm, width W2 is 0.6 mm and radius R o The thickness is 6.0 mm, the dielectric constant is 2.7, and the loss tangent is 0.02;

[0034] The height H of the annular inner shell 7 w is 2.2 mm, width W4 is 0.6 mm and radius R f The thickness is 4.3 mm, the dielectric constant is 2.7, and the loss tangent is 0.02;

[0035] The width W3 of the water cavity between the annular outer shell 8 and the annular inner shell 7 is 0.8 mm;

[0036] The width W of the through slot 6 g 0.3mm;

[0037] The angle θ between the line connecting the through slot 6 and the center of the annular inner shell 7 and the positive and negative half axes of the x-axis is 20 degrees;

[0038] The dielectric constant of water 4 is 81, and the loss tangent is 0.001;

[0039] Height H of the metal floor 9 sub 0.3mm;

[0040] Height H of top case 3 sup is 0.5 mm and the inclined surface thickness R e The thickness is 0.5 mm, the dielectric constant is 2.7, and the loss tangent is 0.02;

[0041] The width W of the slotted annular metal microstrip 1 s The width W1 from the edge of the inclined surface is 0.2 mm and 1.1 mm;

[0042] The annular inner shell 7 is divided into two sector-shaped ring parts, one long and one short, by the through slot 6 and the coaxial feed line 5. Two resonances are generated at low and high frequencies near the target frequency band, respectively. This introduces two extreme points in the scattering parameter curve, resulting in a wide impedance bandwidth covering the target frequency band. At the same time, circular polarization performance is achieved in the target frequency band.

[0043] The implantable antenna is implanted near the human brain. The human body tissue is complexly distributed. The electrical characteristics of different tissues are greatly different. The frequency offset, multipath effect and polarization mismatch are easily caused. The relatively wide impedance bandwidth covering the target frequency band can resist the frequency offset;

[0044] Due to the clinical operation error in the implantation process, the complex structure of the human brain, the electrical characteristic difference of different human tissues and the movement of the human body, the polarization mismatch and multipath fading problems may occur in the working environment of the implantable antenna. The circular polarization performance is obtained at the target frequency band, that is, the circular polarization radiation can well resist these uncertain factors and improve the working stability.

[0045] Referring to the accompanying drawings Figure 2 and 3 :

[0046] The -10dB |S 11 | impedance bandwidth of the implantable antenna based on water-based medium resonance is at least 2-4GHz frequency band. The 3dB axial ratio bandwidth covers at least 2.4-2.485GHz frequency band.

[0047] The half-power beam of the implantable antenna based on water-based medium resonance covers at least the directly above of the axial line of the ring-shaped shell 8 and the top shell 3. In this direction, the axial ratio at the frequency point of 2450MHz is lower than 3dB.

[0048] Referring to the accompanying drawings Figure 4 :

[0049] The integrated system of the implantable antenna includes the implantable antenna, the implantable processor and the electrode array.

[0050] The implantable antenna is applied to the cerebrospinal fluid tissue between the brain tissue surface and the arachnoid membrane.

[0051] After the external device captures and processes the visual information, the signal is transmitted to the implantable antenna through the wireless link. The implantable antenna transmits the signal to the implantable processor. After the implantable processor demodulates, the signal is used to control the electrode array directly contacting the cerebral cortex to discharge according to the requirement, stimulate the cerebral cortex to induce visual perception, and achieve the purpose of restoring vision.

[0052] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A cortical visual prosthesis implantable antenna based on water-based dielectric resonance, characterized in that: include: An annular outer shell (8) is provided inside the annular outer shell (8), a through groove (6) is provided on the side wall of the annular inner shell (7), the through groove (6) connects the internal space of the annular outer shell (8) and the internal space of the annular inner shell (7) to form a water cavity, a water body (4) is provided inside the water cavity, a metal floor (9) is fixedly connected to the bottom ends of the annular outer shell (8) and the annular inner shell (7), a top shell (3) is fixedly connected to the top ends of the annular outer shell (8) and the annular inner shell (7), a coaxial feeder (5) is embedded in the annular inner shell (7) and the top shell (3), the outer conductor of the coaxial feeder (5) is connected to the metal floor (9), an assembly groove (2) is provided at the top end of the top shell (3), a slotted annular metal microstrip (1) is embedded in the assembly groove (2), and the inner conductor of the coaxial feeder (5) is embedded in the annular inner shell (7) and the top shell (3) and connected to the slotted annular metal microstrip (1).

2. The cortical visual prosthesis implantable antenna based on water-based dielectric resonance according to claim 1, characterized in that: The annular outer shell (8), the annular inner shell (7) and the top shell (3) are all made of a solidified 3D printing material 405nm photosensitive resin.

3. The implantable antenna for cortical visual prosthesis based on water-based dielectric resonance according to claim 2, characterized in that: The through slot (6) is arranged in a vertical structure, with the center of the annular inner shell (7) as the origin. The positions of the through slot (6) and the coaxial feed line (5) are symmetrical about the y-axis, and the angles between the line connecting the center of the annular inner shell (7) and the positive and negative half axes of the x-axis are the same.

4. The implantable antenna for cortical visual prosthesis based on water-based dielectric resonance according to claim 3, characterized in that: The water body (4) is distilled water.

5. The implantable antenna for cortical visual prosthesis based on water-based dielectric resonance according to claim 4, characterized in that: The cortical visual prosthesis implantable antenna based on water-based dielectric resonance is applied in the cerebrospinal fluid tissue between the brain tissue surface and the arachnoid membrane.

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