KR20030035783A - Cochlear implant electrode and its fabricating method - Google Patents

Abstract

PURPOSE: Cochlear implant electrode and its fabricating method are provided which is better adhered to an inner wall of the cochlea using at least one shape memory alloy. CONSTITUTION: An electrode carrier(501) has a cochlea shape and is formed from a flexible material. An electrode site(502) is inserted into one side face in the electrode carrier and stimulates auditory cells in the cochlea. A wire(503) is located within the electrode carrier and connects the electrode site electrically and physically. At least one shape memory alloy(504) is formed within the electrode carrier at a predetermined interval in parallel to the electrode site. A lead wire(505) is connected to both ends of the shape memory alloy for applying a current.

Description

Cochlear implant electrode and its fabricating method

The present invention relates to an electrode structure for cochlear implants, and more particularly, to a cochlear electrode structure and a method for manufacturing the cochlear implant that can be more closely adhered to the inner wall of the cochlea using one or more shape memory alloys.

The ear is largely composed of the outer ear, middle ear, and inner ear. The outer ear is composed of the auricle and the ear canal. The auricle collects the sound and the ear canal amplifies the sound.

The middle ear is composed of the eardrum and the isola, and the sound waves coming through the ear canal vibrate the eardrum, and the vibrations are transmitted to the inner ear through three small isosceles connected to the eardrum: the vertebrae, the bones, and the spines. At this time, the sound is amplified more than simply transmitted, the amplification effect of the sound obtained through the middle ear is known as about 35dB. If there is a hole in the eardrum, or if the connection between the bone bone is intact, the hearing function is reduced.

The inner ear is composed of a cochlea (or cochlea), vestibular, and semi-gwan, and the vestibular and semi-gwan are mainly involved in the balance and dizziness of the body, and the hearing is handled by the cochlea, which has auditory cells called hair cells. The vibration of the sound transmitted through the isogol vibrates the perilymph and the endolymph of the liquid in the cochlea through the oval window. These oscillations cause waves to flow, like waves generated when a stone is thrown into a lake, which stimulates auditory cells in the endolymph, transforming the transmission of sound into electrical signals. The auditory nerve is connected to these auditory cells and transmits their signals to the brain, which the brain perceives as sound. That is, when the auditory cells in the cochlea are damaged or the hearing nerve is impaired, sound cannot be transmitted, which is called sensorineural hearing loss.

A cochlear implant is a device that provides hearing by electrical stimulation of the auditory nerve to a patient who has a high sensorineural hearing loss or a deafness due to damage to the inner ear. That is, the cochlear implant replaces the function of the auditory cells by directly stimulating spiral neurons or auditory nerve fibers when the auditory cells in the cochlea are innately or acquiredly damaged or lost.

The structure of the cochlear implant can be divided into the extracorporeal part and the internal part.

The external part installed outside the body is composed of a microphone (transmitter), a sound processor (language synthesizer), and a transmission antenna (transmitter). In this case, the microphone and the transmission antenna are collectively called a headset. The body that is implanted in the body consists of a receptor / stimulator (handset) and an electrode.

The process of listening to sound through a cochlear implant is as follows.

When the sound is detected by a small microphone installed in the headset behind the ear, i.e., a talker, the sound from the microphone is delivered to a speech processor, a powerful small computer, along a thin wire.

The speech processor filters the sound, analyzes it, and turns it into encoded digital signals. This signal is sent from the sound processor through the wire to the transmitting antenna.

The transmitting antenna sends a signal through the skin to a receiver / stimulator, i.e., a receiver, which is a cochlear implant in the skin. The acceptor / stimulator delivers the appropriate electrical energy to the electrodes with a constant arrangement inserted into the cochlea.

The electrode stimulates the living auditory nerve fibers in the cochlea by sending an appropriate level of current signal to the outside, and as a result, electrical sound information is transmitted to the cerebrum through the auditory nerve.

On the other hand, since the cochlear implant was first commercialized in 1972 for the first time in a single channel cochlear implant and was performed to a hearing impaired, tens of thousands of hearing impaired people have been transplanted.

The main part of the implantation of the cochlear implant may be to insert the electrode inside the cochlear implant within the cochlear implant and fix the body. Various methods have been proposed regarding the manufacture of the electrode and the insertion of the electrode.

An example will be described as follows.

US Patent No. 6,195,586 proposes a method of inserting an electrode carrier made of a polymer material into which an electrode site is inserted and repositioning the positioner behind the electrode carrier to closely adhere the electrode site to the cochlear inner wall.

In addition, US Patent No. 6,078,841 proposes a position controller having a tapered shape, which is intended to insert the tapered position controller together with the electrode carrier into the cochlear to closely adhere to the cochlear inner wall. have.

In addition, US Patent No. 6,119,044 proposes a method of inserting an electrode carrier using a conventional method, and then using the shape memory alloy to closely adhere the inserted electrode carrier to the cochlear inner wall.

However, the cochlear implant electrode according to the prior art has the following problems.

In order to stimulate the auditory cells in the cochlear inner wall, the cochlear electrode should be in close contact with the cochlear inner wall.

The present invention has been made to solve the above problems, it is possible to control the sequential shape memory alloy according to the method programmed at the time of insertion using a plurality of shape memory alloy, and also to shape the electrode structure after insertion It is an object of the present invention to provide a cochlear electrode structure and a method of manufacturing the cochlear electrode structure which can be closely adhered to the cochlear inner wall by enabling partial modification.

1 is a cross-sectional view of a cochlear electrode structure according to a first embodiment of the present invention.

2 is an enlarged view of a portion A of FIG. 1.

3A and 3B are views for explaining the storage form of the shape memory alloy and the processing form before insertion, which are applied to the first embodiment in the present invention;

Figure 4 is a graph for explaining the transition characteristics of the form according to the temperature of the shape memory alloy applied to the first embodiment of the present invention.

5A to 5C are cross-sectional views illustrating a method of manufacturing a cochlear electrode structure according to a first embodiment of the present invention.

6A to 6C are schematic diagrams for explaining a method for inserting a cochlear implant structure according to a first embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

501 electrode carrier 502 electrode site

503: wire 504: shape memory alloy

505: wire 506: polymer material

The electrode structure for a cochlear implant according to the first embodiment of the present invention for achieving the above object is an electrode carrier having a shape of a cochlea and made of a flexible material, and inserted into one side of the cochlear implant within the cochlea. An electrode site for stimulating auditory cells, a wire located in the electrode carrier to electrically and physically interconnect each electrode site, and inserted into the electrode carrier at regular intervals so as to be parallel to the electrode site; One or more position control shape memory alloys which are deformed to be easy to insert at temperatures above and electrically connected to each of the shape memory alloys, and wherein the shape memory alloys are inserted into the cochlea by selectively applying an arbitrary current. Including conductors leading to restoration to the cochlear shape And a gong.

The one or more position control shape memory alloys are manufactured to have an easy shape for insertion at a temperature of 40 ° C. to 45 ° C. above the body temperature in advance, and then connected to both ends of the shape memory alloy when the artificial cochlear electrode structure is inserted into the cochlea. When the current is applied to the electrical conductors, the straight line or the straight line close to the straight line is easily inserted into the electrode, and the supply of the current is sequentially stopped by the stored program. The cochlear electrode structure may be in close contact with the cochlear inner wall by elasticity.

The method for manufacturing a cochlear electrode structure according to the first embodiment of the present invention includes an electrode carrier inserted into a cochlear implant and including an electrode carrier having an electrode site that serves to stimulate auditory cells in the cochlear implant. A method for applying a current to each end of one or more shape memory alloys that has been processed to have an easy shape for electrode insertion at a specific temperature above body temperature, so that each shape memory alloy has a stored shape when inserted into the cochlea. Forming a conductive wire, wrapping at least one shape memory alloy to which the conductive wire is connected with a polymer material, and incorporating at least one shape memory alloy wrapped with the polymer material with the electrode carrier. do.

Here, the conductive wires connected to both ends of the one or more shape memory alloys may change shape to facilitate insertion by applying current to the shape memory alloy immediately before the artificial cochlear electrode structure of the present invention is inserted into the cochlear implant. It is characterized in that the electrode carrier is formed to have the shape of the cochlea by the elasticity of the elastomer that is the material forming the electrode carrier by controlling the current flowing through the conductive wire in turn.

The electrode structure for cochlear implant of the present invention has a shape memory alloy having a shape which is stored in advance in order to facilitate insertion by flowing a current to the shape memory alloy when inserted into the cochlear implant. By sequentially reducing the current flowing through the shape memory alloy has the characteristic of having a complete cochlear shape finally by the elasticity of the elastomer constituting the electrode carrier.

Hereinafter, with reference to the drawings will be described in detail the electrode structure for cochlear implant of the present invention and its manufacturing method.

1 is a cross-sectional view of a cochlear electrode structure according to a first embodiment of the present invention, Figure 2 is an enlarged view of a portion A of FIG.

As shown in FIG. 1, the cochlear electrode structure according to the first embodiment of the present invention includes the following components.

An electrode carrier 501 having an elongated shape and a shape of an entire cochlear electrode structure made of a flexible material is a basic component, and the electrode carrier 501 is inserted into one side of the electrode carrier 501. And an electrode site 502 for stimulating auditory cells in the cochlea, and a wire 503 positioned in the electrode carrier 501 to electrically and physically connect the electrode site 502. The electrode carrier 501 has a flexible characteristic, it may have a shape suitable for insertion into the cochlear wow. Here, the base material of the electrode carrier incorporating the electrode site and the wire is a high molecular material, and in general, an elastomer is mainly used.

In addition, at least one shape memory alloy 504 is formed at an upper end of the electrode carrier 501 at regular intervals so as to be parallel to the electrode site 502, and a current is formed at both ends of each of the shape memory alloys 504. The conductive wire 505 for applying the is connected (see FIG. 2).

Although not shown in the drawing, the wire is connected to the stimulator and the receiver, and the stimulator communicates with the outside through a predetermined coil, and determines the amount of current flowing through the at least one shape memory alloy through external control to form the electrode. Can be controlled.

The one or more shape memory alloys 504 are pre-machined to have a straight line or a similar shape to the straight line, each of which is easy to insert at a temperature higher than the body temperature. When the electrode carrier is changed into an easy-to-insert shape, and the shape memory alloy is below the shape memory temperature by adjusting the amount of current simultaneously with or after the insertion, the electrode carrier is bent in the cochlear shape by the force of the elastomer of the electrode carrier. It acts to ensure close contact with the cochlea.

3A and 3B show the shape of a cochlear implant due to the elasticity of the elastomer of the electrode carrier below the shape memory temperature of the shape memory alloy applied to the first embodiment of the present invention, and easy insertion at the shape memory temperature. FIG. 4 is a diagram for explaining a shape having a straight line or a shape close to a straight line, and FIG. 4 is a graph for explaining the transition characteristics of the shape memory alloy according to the temperature of the first embodiment of the present invention.

First, one or more shape memory alloys having a predetermined length are arranged to be molded at a high temperature so that the overall shape has an easy shape for insertion, and then the shape is stored at about 45 ° C., which is a temperature higher than a human body temperature (Fig. 3b).

Subsequently, at body temperature, the shape memory alloy loses the force to return to the stored form and is easily changed by external force. 3A shows a shape memory alloy when the electrode carrier has a shape similar to a cochlear implant due to elasticity of the electrode carrier. Here, as the shape memory alloy, nitinol composed of an alloy of nickel (Ni) and titanium (Ti) is mainly used.

Thus, the shape memorized in the shape memory alloy at a temperature of about 45 ° C. or more is inserted into the cochlear or close to the cochlear while being bent into the cochlear shape by the elasticity of the elastomer due to the decrease in the amount of current. Will be.

On the other hand, the shape memory alloy has a property of returning to a linear form at a temperature above the body temperature, that is, about 45 ° C. or higher, and at a temperature near the body temperature, there is no characteristic of returning to the stored remembered form (see FIG. 4). .

A method of manufacturing an electrode structure for cochlear implant using a shape memory alloy that stores a predetermined shape as described above is as follows.

5A to 5C are cross-sectional views illustrating a method for manufacturing a cochlear electrode structure according to a first embodiment of the present invention.

First, as shown in FIG. 5A, a conductive line 505 for applying a current is connected to both ends of one or more shape memory alloys 504 that have been previously processed to store shapes. Here, the shape memory alloy is stored to have a straight shape at a temperature higher than the body temperature.

The conductive wires 505 connected to both ends of the shape memory alloys 504 are formed by applying a current to the shape memory alloys 504 of the corresponding portions when the electrode structure for cochlear implant of the present invention is inserted into the cochlea. By generating resistance heat in the memory alloy 504, the shape memory alloy 504 serves to return to the shape previously stored.

Subsequently, the polymer material 506 is molded to sufficiently enclose one or more shape memory alloys 504 arranged in a straight line shape. Here, the polymer material is mainly used an elastomer having sufficient elasticity. In addition, the polymer material is also a basic constituent material of the electrode carrier to be described later.

Next, as shown in FIG. 5B, an electrode carrier 501 having an electrode site 502 for stimulating auditory cells in the cochlea and a wire 503 for electrically and physically connecting the electrode site 502 is provided. After the preparation, as shown in Figure 5c, when the electrode carrier 501 and the at least one shape memory alloy 504 wrapped with the polymer material 506 is coalesced to manufacture a cochlear electrode structure of the present invention Is complete. Here, the coalescing with the electrode carrier is easy to coalesce at a high temperature because the base material of the electrode carrier is also a thermoplastic material such as the polymer material.

The implantation mechanism in the actual cochlear implant of the cochlear implant structure of the present invention completed through the above process will be described below with reference to the drawings.

6A to 6C are schematic diagrams for explaining a method for inserting a cochlear implant structure according to a first embodiment of the present invention.

First, as shown in FIG. 6A, a cochlear electrode structure having one or more shape memory alloys 504 having a linear shape is inserted into a cochlear by flowing a current through the shape memory alloy to increase the temperature. . At this time, by reducing the current from the end of the electrode to the wires (not shown) of both ends of the shape memory alloy corresponding to the inserted portion, the shape memory alloy eliminates the property of storing the shape and is caused by the elasticity of the elastomer. The electrode structure has a wow shape. In this way, as shown in Figure 6b, in order to be inserted into the corresponding shape memory alloy in order to reduce the current to change to the shape of the cochlear implant cochlear electrode structure of the present invention finally It is in close contact with the inner wall (see FIG. 6C).

After inserting the cochlear electrode structure into the cochlear implant as described above, the electrode is in close contact with the cochlear wall in the absence of any current flowing through the shape memory alloy.

In the above-described method, the insertion of the electrode structure is corrected by adjusting the applied current of the shape memory alloy according to the position to be monitored by monitoring the insertion shape of the electrode structure by X-ray according to the insertion step. Can be.

Another embodiment of the present invention is as follows.

The core technology of the cochlear electrode structure according to the first embodiment of the present invention makes it easy to insert one or more shape memory alloys at a predetermined temperature or more, so that the current is applied to the shape memory alloy during the cochlear insertion of the entire electrode structure. Compared to the first embodiment of the present invention, the shape memory alloys store the shape of the cochlea, and the electrode carrier is different from the first embodiment of the present invention. The elastomer that forms the core is formed in the form of a straight line.

At room temperature, the electrode forms a linear electrode structure by inserting a straight line by the elasticity of the elastomer that forms the electrode carrier, thereby increasing the current flowing through the shape memory alloy. The electrode structure is shaped after insertion. The force of the memory alloy is in close contact with the cochlear axis.

After inserting and calibrating the cochlear electrode structure in the cochlear implant as described above, when a predetermined time passes, the cochlear phenomenon occurs in the cochlear cavity, that is, a phenomenon in which an empty space in the cochlear grows and fills the cochlear implant electrode. After the insertion of the structure, even if the current application is stopped, the shape is fixed semi-permanently by the osmosis phenomenon as described above does not change.

On the other hand, the cochlear implant structure using the memorized shape of the shape memory alloy as described above when the temperature of the shape memory alloy is lowered by a method of adding a saline cooled to 30 ℃ or less, the shape memory alloy Since the silver loses its power to remember its shape, it can be straightened to remove the inserted cochlear electrode structure.The electrode structure containing the shape-retaining alloy, ie, a polymer material (elastic polymer), can be formed into a cochlear shape. In addition, the shape memory alloy is stored in a straight line shape at a predetermined temperature or more.

That is, in the first and second embodiments of the present invention, the constituent materials constituting the cochlear electrode structure are the same, but the characteristics of the shape memory alloy and the polymer material, which play a key role, are changed according to temperature and molding properties. will be.

The shape memory alloy of the first embodiment of the present invention was pre-processed to have a straight shape when the temperature is increased by applying a current. The shape memory alloy of the second embodiment of the present invention has a wow shape when the temperature is increased by applying a current.

When the artificial cochlear electrode structure according to the first embodiment of the present invention having the shape memory alloy is inserted into the cochlear implant, a current is applied to the shape memory alloy that stores a straight shape at a predetermined temperature or more. In other words, the polymer material inherent, that is, the electrode carrier is straightened, and then the current is sequentially applied to each of the inserted shape memory alloys so that the polymer material formed to have a wow shape returns to its original shape. In this way, through the method of applying or stopping the current to each shape memory alloy, it is possible to perform the same intra-cochlear implant and modiolus-hugging as the second embodiment of the present invention.

As described above, the cochlear electrode structure of the present invention and its manufacturing method have the following effects.

Since the shape memory alloy is embedded in the cochlear electrode structure, the electrode structure manufactured to be in close contact with the inner wall of the cochlear implant can be deformed to facilitate insertion.

Likewise, the electrode structure fabricated in an easy-to-insert shape can be closely attached to the cochlear axis during insertion using a shape memory alloy, thereby actively stimulating auditory cells of the cochlea to facilitate auditory stimulation.

In addition, according to the insertion step within the cochlear implant, the insertion structure of the electrode structure is monitored by X-ray, and the insertion current of the shape memory alloy is adjusted by adjusting the applied current of the shape memory alloy according to a position to be corrected.

Claims (4)

An electrode carrier having a wow shape and made of a flexible material; An electrode site inserted into one side of the electrode carrier to stimulate auditory cells in the cochlea; A wire located within the electrode carrier to electrically and physically interconnect each of the electrode sites; At least one shape memory alloy inserted into the electrode carrier at a predetermined distance parallel to the electrode site and deformed into a wow shape at a specific temperature; And a conductive line electrically connected to each of the shape memory alloys, and selectively applying a predetermined current to induce the shape memory alloy inserted into the coch to be restored to a straight line or a shape similar to the straight line. Cochlear electrode structure, characterized in that made. In the manufacture of an electrode structure for cochlear implant comprising an electrode carrier which is embedded in the cochlear embedding the electrode site that serves to stimulate the auditory cells in the cochlea, Conductors for applying a current to each end of one or more shape memory alloys that have been processed to have a straight or similar shape for easy insertion at a specific temperature, so that each shape memory alloy has a stored shape when inserted into the cochlea Forming a; Wrapping at least one shape memory alloy to which the conductor is connected with a polymer material; And incorporating at least one shape memory alloy wrapped with the polymer material pre-formed into the cochlear shape with the electrode carrier. An electrode carrier made of a flexible material having a straight line or similar shape to a straight line for easy insertion; An electrode site inserted into one side of the electrode carrier to stimulate auditory cells in the cochlea; A wire located within the electrode carrier to electrically and physically interconnect each of the electrode sites; At least one shape memory alloy inserted into the electrode carrier at a predetermined distance parallel to the electrode site and deformed into a wow shape at a specific temperature; It is electrically connected to each of the shape memory alloys, and optionally applied to any of the cochlear implant comprising a conductive wire to guide the shape memory alloy inserted into the cochlear having a shape surrounding the cochlear inner wall Electrode structures. In the manufacture of an electrode structure for cochlear implant comprising an electrode carrier which is embedded in the cochlear embedding the electrode site that serves to stimulate the auditory cells in the cochlea, Conductors for applying a current to each end of one or more shape memory alloys which are processed to form a partial cochlear shape at a specific temperature to have a cochlear shape as a whole, so that each shape memory alloy has a memorized shape when inserted into the cochlear implant. Forming; Wrapping at least one shape memory alloy to which the conductor is connected with a polymer material; And incorporating the at least one shape memory alloy wrapped with the polymer material into the electrode carrier.