Cantilever beam type piezoelectric ceramic microphone and preparation method thereof

Abstract

The invention provides a cantilever beam type piezoelectric ceramic microphone and a preparation method thereof, the cantilever beam type piezoelectric ceramic microphone comprises an acoustic bridge clamp, a titanium tube, a lead wire device, a platinum wire, a pre-amplifier and a piezoelectric ceramic bimorph, the acoustic bridge clamp is made of titanium metal and comprises an L-shaped cantilever beam and a titanium metal clamp, the titanium metal clamp is connected with a vertical arm of the L-shaped cantilever beam, and the piezoelectric ceramic bimorph is connected with the titanium tube. The titanium clamp is used for being attached to the long protrusion of the incus and close to the side of the stapes, a cross arm of the cantilever beam is parallel to the stapes and connected with the piezoelectric ceramic bimorph in the titanium tube, and the piezoelectric ceramic bimorph, the pre-amplifier, the platinum wire and the lead wire device are all implanted into the titanium tube and packaged through laser welding. The L-shaped cantilever drives the piezoelectric ceramic bimorph to vibrate in the vertical direction by taking the hammer bone as a fulcrum, so that the piezoelectric ceramic bimorph converts vibration into electric energy to the greatest extent, and the device is superior to a traditional gluing and grid wrapping attachment mode on the aspect of improving the efficiency of collecting conduction vibration of the ossicular chain, and is suitable for popularization and application. And the sound vibration acquisition sensitivity and the signal output strength are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cochlear implants, and in particular to a cantilever beam piezoelectric ceramic microphone and a preparation method thereof. Background Art

[0002] A cochlear implant is a medical device that uses functional electrical stimulation to directly excite residual spiral nerve cells to restore hearing in patients with profound or severe sensorineural hearing loss. In recent years, cochlear implants have become the standard treatment for patients with moderate to severe bilateral sensorineural hearing loss. After implantation, patients' speech recognition ability and quality of life have been significantly improved. The great success of cochlear implants has led to the rapid growth of the global hearing implant market. Despite the great success, there are still many problems with cochlear implant products at this stage: the traditional tympanic cavity implant technology uses direct gluing or wrapping with a mesh titanium shell. Since the blood supply of the ossicles only relies on the surface periosteum, it is necessary to minimize the contact area and pressure between the implant and the ossicles, and the tympanic cavity implant technology is not efficient in collecting vibrations transmitted by the ossicular chain in terms of structure. Summary of the invention

[0003] In response to the above technical problems, the present invention provides a cantilever beam piezoelectric ceramic microphone and a preparation method thereof, which is superior to traditional gluing and grid wrapping attachment methods in improving the efficiency of collecting vibrations conducted by the ossicular chain, and increases the sensitivity of sound vibration collection and the signal output intensity.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a cantilever beam piezoelectric ceramic microphone, comprising a sound bridge clip, a titanium tube, a guide wire device, a platinum wire, a preamplifier and a piezoelectric ceramic dual chip, wherein the sound bridge clip is made of titanium metal, and comprises an L-shaped cantilever beam and a titanium metal clip, wherein the titanium metal clip is connected to the vertical arm of the L-shaped cantilever beam, and the titanium metal clip is used to attach to the long process of the incus and close to the position of one side of the stapes, and the horizontal arm of the cantilever beam maintains a parallel relationship with the malleus and is connected to the piezoelectric ceramic dual crystal in the titanium tube, and the piezoelectric ceramic dual chip, the preamplifier, the platinum wire and the guide wire device are all implanted in the titanium tube and packaged by laser welding, and the L-shaped cantilever beam drives the titanium tube to vibrate in the vertical direction with the malleus as a fulcrum, so that the piezoelectric ceramic dual chip converts the vibration into electrical energy to the greatest extent.

[0005] Furthermore, the angle of the L-shaped cantilever beam at the corner is adjustable. When the cantilever beam has a corner of 90 degrees, the voltage signal generated by the piezoelectric ceramic dual crystal is maximum.

[0006] Furthermore, the piezoelectric ceramic bimorph is installed in a rectangular metal shell and packaged with medical silicone.

[0007] Furthermore, the preamplifier adopts LMV1032 chip, and the preamplifier is installed in a rectangular metal shell and encapsulated with medical silicone.

[0008] Furthermore, the preamplifier is fixed to one end of the piezoelectric ceramic dual chip by using medical silica gel, and the preamplifier is fixed to the L-shaped cantilever beam to form a fulcrum between the piezoelectric ceramic dual chip and the L-shaped cantilever beam.

[0009] Furthermore, the piezoelectric ceramic bimorph is point-connected to the preamplifier by micro-welding, and three platinum wires are led out of the preamplifier by welding, and the platinum wires are respectively a signal wire, a power wire and a ground wire.

[0010] Furthermore, the piezoelectric ceramic dual chip and the preamplifier are placed in a titanium tube, the platinum wire is led out of the titanium tube via a lead wire device, and the lead end of the wire is encapsulated in the titanium tube by medical silicone.

[0011] Furthermore, both ends of the titanium tube are packaged with a thin layer of medical silicone, and the outer layer of the titanium tube is packaged with a Parylene vapor deposition coating.

[0012] On the other hand, the present invention also provides a method for preparing a cantilever beam piezoelectric ceramic microphone, characterized in that it comprises the following steps:

[0013] Prepare a sound bridge clip, the sound bridge clip includes an L-shaped cantilever beam and a titanium metal clip, wherein the titanium metal clip is connected to the short axis of the L-shaped cantilever beam;

[0014] Prepare a tubular titanium shell, wherein the tubular titanium shell is used to place a piezoelectric ceramic bimorph and a preamplifier;

[0015] For internal connection, conductive epoxy resin is used to connect the points of the piezoelectric ceramic bimorph and the preamplifier, and three platinum wires are led out of the preamplifier by welding;

[0016] Prepare a pipeline lead wire device, the pipeline lead wire device includes a pipeline lead wire insulator with three holes and a pipeline lead wire flange for fixing the pipeline lead wire insulator, and the pipeline lead wire insulator, the platinum wire and the pipeline lead wire flange are all vacuum welded;

[0017] Titanium shell packaging, using laser welding to package the piezoelectric ceramic dual chip, preamplifier and lead wire device in the titanium shell, and the packaged titanium shell is welded to one end of the long axis of the L-shaped cantilever beam.

[0018] Furthermore, during installation, the titanium metal clip is attached to the long process of the incus and close to the side of the stapes. The long axis of the L-shaped cantilever beam is parallel to the malleus, and the malleus is used as a fulcrum to drive the titanium tube to vibrate in the vertical direction, so that the piezoelectric ceramic bimorph can convert the vibration into electrical energy to the greatest extent.

[0019] The present invention has the following beneficial effects and technical advances:

[0020] 1. The present invention adopts an L-shaped bridge arm structure to improve the efficiency of collecting ossicular chain conduction vibrations, thereby increasing the sensitivity of sound collection and the signal output intensity.

[0021] 2. The L-shaped cantilever beam structure allows for adjustment of the folding angle (defined as 90° by default). This allows for convenient adjustment of sensor performance during surgery, which is beneficial for improving the quality of use for patients.

[0022] 3. Since the blood supply of the ossicles depends only on the surface periosteum, it is necessary to reduce the contact area and pressure between the implant and the ossicles as much as possible. The fixation method of titanium clips used in the present invention is more conducive to the preservation of the function and structure of the ossicles than the prior art gluing and grid fixation methods. Titanium clips have been widely verified in vibrating sound bridges and artificial ossicles, and will not cause ischemic necrosis of the ossicles. They are a safe structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 The figure is a schematic structural diagram of a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention.

[0025] Figure 2 The figure is a side cross-sectional view of a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention.

[0026] Figure 3 The present invention is a flowchart of a method for preparing a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0029] Figure 1 FIG. 1 is a schematic diagram of the structure of a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention. Figure 1 As shown, a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention comprises a sound bridge clamp 1, a titanium tube 2, a guide wire device 3, a platinum wire 4, a preamplifier 6 and a piezoelectric ceramic dual chip 5.

[0030] Preferably, in this embodiment, in order to couple the microphone power consumption with the auditory ossicles, the sound bridge clamp 1 is made of extremely thin titanium metal, so that it can be attached to the long process of the incus close to the stapes. The titanium metal has plasticity and a certain elasticity, and can retain the complete ossicular chain structure after clamping the auditory ossicles.

[0031] like Figure 2 As shown, the sound bridge clamp 1 includes an L-shaped cantilever beam and a titanium metal clamp. The titanium metal clamp is connected to the vertical arm 7 of the L-shaped cantilever beam. The titanium metal clamp 1 is used to attach to the long process of the incus and close to one side of the stapes. The horizontal arm 8 of the cantilever beam maintains a parallel relationship with the malleus and is connected to the titanium tube.

[0032] The titanium tube 2 adopts a cylindrical structure to accommodate the piezoelectric ceramic bimorph 5, the preamplifier 6, the platinum wire 4 and the guide wire device 3. It should be noted that the titanium tube 2 used in this embodiment as a conductor for transmitting sound has light weight, low density, high strength, strong anti-damping performance, long self-vibration attenuation, good biocompatibility in the human body, non-toxic, and not rejected by the human body. At the same time, titanium is non-magnetic and can be subjected to magnetic resonance imaging examination.

[0033] Preferably, in this embodiment, the piezoelectric ceramic dual chip 5 includes two strip-shaped thin-layer piezoelectric ceramic chips with a length of 2.0 to 6.0 mm, a width of 1.0 to 2.0 mm, and a thickness of 0.3 mm, and the piezoelectric ceramic dual chip 5 is installed in a square cylindrical metal shell with a thickness of 0.1 mm and is encapsulated with medical silicone. While meeting the packaging requirements, it can take into account the saving of assembly space and the need for free vibration space of the piezoelectric ceramic piece.

[0034] Preferably, in this embodiment, the preamplifier chip 6 is an LMV1032 chip, which is 3.0-7.0 mm × 1.6 mm ~ 3.0 mm × 1.3 mm in size, and is installed in a metal square cylindrical copper shell with a cross-sectional inner diameter of 1.3 mm × 1.1 mm, and both ends of the copper shell are encapsulated with medical silicone. In the in vitro and cat ear verification tests, the above structure can sensitively pick up 100 Hz ~ 20000 Hz test pure tone signals, and has a highly consistent frequency response curve in vitro, and also has a good frequency response curve in the human body.

[0035] The preamplifier chip 6 is fixed to one end of the piezoelectric ceramic bimorph 5 by medical adhesive to form a part of a single-arm cantilever beam, and the three wires led out are directly micro-welded with the preamplifier chip 6, saving the device assembly space. In this embodiment, the preamplifier chip 6 occupies an area of ​​about 551.2mm×1.4mm of the piezoelectric ceramic bimorph after bonding. The piezoelectric ceramic bimorph 5 is connected to the preamplifier chip 6 by micro-welding, and then three platinum wires 4 with a diameter of 0.1mm are welded out from the preamplifier chip 6. The platinum wires are signal output, working power supply and ground wire, and each wire is 200mm long.

[0036] Finally, after gluing the connection between the chip and the wire 4 again, the fixed components are placed in the titanium tube 2, and the lead-out end of the wire is glued and fixed to form a single-arm cantilever structure to pick up the sound of the piezoelectric ceramic microphone. Both ends of the titanium tube 2 are encapsulated with a thin layer of medical silicone to complete the final encapsulation.

[0037] Figure 2 FIG. 1 is a flow chart of a method for preparing a cantilever beam piezoelectric ceramic microphone according to an embodiment of the present invention. Figure 2 As shown, a method for preparing a cantilever beam piezoelectric ceramic microphone of the present invention comprises the following steps:

[0038] Prepare a sound bridge clip, the sound bridge clip includes an L-shaped cantilever beam and a titanium metal clip, wherein the titanium metal clip is connected to the short axis of the L-shaped cantilever beam;

[0039] Prepare a tubular titanium shell, wherein the tubular titanium shell is used to place a piezoelectric ceramic bimorph and a preamplifier;

[0040] For internal connection, conductive epoxy resin is used to connect the points of the piezoelectric ceramic bimorph and the preamplifier, and three platinum wires are led out of the preamplifier by welding;

[0041] Prepare a pipeline lead wire device, the pipeline lead wire device includes a pipeline lead wire insulator with three holes and a pipeline lead wire flange for fixing the pipeline lead wire insulator, and the pipeline lead wire insulator, the platinum wire and the pipeline lead wire flange are all vacuum welded;

[0042] Titanium shell packaging, using laser welding to package the piezoelectric ceramic dual chip, preamplifier and lead wire device in the titanium shell, and the packaged titanium shell is welded to one end of the long axis of the L-shaped cantilever beam.

[0043] The L-shaped cantilever beam structure of the microphone of the present invention is parallel to the long axis of the malleus. The main vibration direction of the malleus is the swing with the malleus head as the fulcrum. The cantilever beam structure formed by this fixing method can effectively conduct vibration, so that the piezoelectric material can convert vibration into electrical energy to a greater extent. The piezoelectric performance of piezoelectric materials is mainly measured by parameters d33 and d31, 3 is the vertical direction (vertical arm) of the largest plane of the rectangular piezoelectric element, and 1 direction is the long arm direction. The vibration in the 3 direction has the largest force conversion, which can be calculated by the d33 value. The use of the 1 direction requires the cantilever beam as the basis (a boundary constraint condition in which one end is fixed and the other end is free to swing). In this swinging mode, the two sides of the piezoelectric sheet will form compressive stress and tensile stress due to bending, so as to generate charge movement through the deformation in the 1 direction. The results of the three-dimensional reconstruction finite element analysis confirmed that under the piezoelectric sensor of the same size, the coupling method of the cantilever beam structure with a 90-degree angle is better than adhesive fixation and mesh wrapping fixation. Further, the results of animal experiments are also consistent with the above conclusions.

[0044] Preferably, by changing the angle at the bend of the cantilever beam, the vector components in the 3 directions and 1 direction can change, and the voltage and signal generated at this time will become smaller (maximum only at 90 degrees), but the frequency response curve remains unchanged. By changing the angle, the performance of the sensor can be debugged without changing the piezoelectric sheet and the packaging structure. For individual patients, the more convenient the signal output debugging of the acoustic device, the more beneficial it is. During intraoperative implantation, the patient's acoustic stimulus input response is evaluated through EABR and other means, and the degree of the bend is changed synchronously to conveniently debug the sensor performance.

[0045] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cantilever beam piezoelectric ceramic microphone, characterized in that: The invention comprises a sound bridge clamp, a titanium tube, a guide wire device, a platinum wire, a preamplifier and a piezoelectric ceramic dual chip. The sound bridge clamp is made of titanium metal, and comprises an L-shaped cantilever beam and a titanium metal clamp. The titanium metal clamp is connected to the vertical arm of the L-shaped cantilever beam. The titanium metal clamp is used to attach to the long process of the incus and close to one side of the stapes. The horizontal arm axis of the cantilever beam keeps a parallel relationship with the malleus and is connected to the piezoelectric ceramic dual chip in the titanium tube. The piezoelectric ceramic dual chip, the preamplifier, the platinum wire and the guide wire device are all implanted in the titanium tube and packaged by laser welding. The L-shaped cantilever beam drives the titanium tube to vibrate in the vertical direction with the malleus as a fulcrum, so that the piezoelectric ceramic dual chip converts the vibration into electrical energy to the greatest extent.

2. A cantilever beam piezoelectric ceramic microphone as claimed in claim 1, characterized in that: The angle of the L-shaped cantilever beam at the folding angle is adjustable. When the folding angle of the cantilever beam is 90 degrees, the voltage signal generated by the piezoelectric ceramic bimorph is maximum.

3. The cantilever beam piezoelectric ceramic microphone according to claim 1, characterized in that: The piezoelectric ceramic bimorph is installed in a rectangular metal shell and is packaged with medical silica gel.

4. A cantilever beam piezoelectric ceramic microphone as claimed in claim 3, characterized in that: The preamplifier adopts LMV1032 chip, and the preamplifier is installed in a rectangular metal shell and is packaged with medical silica gel.

5. The cantilever beam piezoelectric ceramic microphone according to claim 4, characterized in that: The preamplifier is fixed to one end of the piezoelectric ceramic dual crystal by using medical silica gel, and the preamplifier is fixed to the L-shaped cantilever beam to form a fulcrum between the piezoelectric ceramic dual crystal and the L-shaped cantilever beam.

6. The cantilever beam piezoelectric ceramic microphone according to claim 5, characterized in that: The piezoelectric ceramic bimorph is point-connected to the preamplifier by micro-welding. Three platinum wires are led out of the preamplifier by welding. The platinum wires are respectively a signal wire, a power wire and a ground wire.

7. The cantilever beam piezoelectric ceramic microphone according to claim 6, characterized in that: The piezoelectric ceramic dual chip and the preamplifier are placed in the titanium tube, the platinum wire is led out of the titanium tube through a lead wire device, and the lead end of the wire is encapsulated in the titanium tube through medical silica gel.

8. The cantilever beam piezoelectric ceramic microphone according to claim 7, characterized in that: The two ends of the titanium tube are packaged with a thin layer of medical silica gel, and the outer layer of the titanium tube is packaged with a Parylene vapor deposition coating.

9. The method for preparing a cantilever beam piezoelectric ceramic microphone according to any one of claims 1 to 8, characterized in that: The following steps are involved: Prepare a sound bridge clip, the sound bridge clip includes an L-shaped cantilever beam and a titanium metal clip, wherein the titanium metal clip is connected to the short axis of the L-shaped cantilever beam; Prepare a tubular titanium shell, wherein the tubular titanium shell is used to place a piezoelectric ceramic bimorph and a preamplifier; For internal connection, conductive epoxy resin is used to connect the points of the piezoelectric ceramic bimorph and the preamplifier, and three platinum wires are led out of the preamplifier by welding; Prepare a pipeline lead wire device, the pipeline lead wire device includes a pipeline lead wire insulator with three holes and a pipeline lead wire flange for fixing the pipeline lead wire insulator, and the pipeline lead wire insulator, the platinum wire and the pipeline lead wire flange are all vacuum welded; Titanium shell packaging, using laser welding to package the piezoelectric ceramic dual chip, preamplifier and lead wire device in the titanium shell, and the packaged titanium shell is welded to one end of the long axis of the L-shaped cantilever beam.

10. The method for preparing a cantilever beam piezoelectric ceramic microphone according to claim 9, characterized in that: During installation, the titanium metal clip is attached to the long process of the incus and close to one side of the stapes. The long axis of the L-shaped cantilever beam remains parallel to the malleus, and the malleus is used as a fulcrum to drive the titanium tube to vibrate in the vertical direction, so that the piezoelectric ceramic bimorph converts vibration into electrical energy to the greatest extent.

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