Drug-loaded cochlear implant electrode

Abstract

The present invention discloses a drug-loaded cochlear implant electrode. A flexible electrode head is arranged at the forefront, n electrode contacts and m air bags are both arranged on a silica gel body. The air bags are V-shaped, and the m air bags are arranged at several electrode contacts among the n electrode contacts close to the flexible electrode head, and the air bags and the electrode contacts are arranged at intervals; a second catheter is connected to a first catheter through a check valve, the second catheter is connected to a drug reservoir through a pressure regulating valve, a spring part is arranged in the drug reservoir, and by pressing the spring part, the drug in the drug reservoir enters the air bags through the second catheter, the check valve and the first catheter. In the present invention, V-shaped air bags are arranged in the electrode part of the cochlear implant. When filled, the electrode part of the cochlear implant is in a bent shape consistent with the shape of the cochlea, which can make the implanted electrode better fit the inner wall of the cochlea. Moreover, the water gel with ear drugs is filled into the air bags, achieving a better hearing and treatment effect.

Description

Technical Field

[0001] The present invention relates to the field of electronic medicine, and particularly to a drug-loaded cochlear electrode. Background Art

[0002] Data from the World Health Organization shows that approximately 280 million people worldwide currently suffer from disabling hearing loss. There are currently 27.8 million hearing-impaired people in China, of which 8 million are severely deaf. In addition to infectious causes such as meningitis, measles, mumps, and chronic ear infections, hearing impairment is usually caused by exposure to excessive noise, head and ear injuries, aging, and the use of ototoxic drugs.

[0003] Since the sensory cells of the inner ear of mammals develop only during embryogenesis and cannot regenerate postnatally, in cases where drug treatment is ineffective, hearing can currently only be restored by implanting a cochlear implant. The cochlear implant system is an implantable electronic device that can provide functional hearing for patients with severe and profound sensorineural deafness, and is also the only effective treatment for sensorineural deafness in current clinical practice. Cochlear implant technology provides hearing for patients with severe to profound sensorineural hearing loss by stimulating spiral ganglion neurons (SGNs) through electrodes implanted in the cochlea. The cochlear implant bypasses the outer ear, middle ear, and inner ear of the human body, and directly stimulates the auditory nerve with electrical pulses carrying sound information to generate hearing. It usually consists of an external device and an implantable internal device.

[0004] The external device is called the cochlear implant speech processor (abbreviation: speech processor). The main principle is that the microphone on the speech processor picks up the sound signal, processes and encodes the collected sound signal, and then transmits it wirelessly to the implant body. The internal device is called the cochlear implant (abbreviation: implant). Its principle is to receive the sound signal processed by the speech processor in the form of radio frequency, convert it into an electrical current pulse after decoding; the electrical current pulse stimulates the remaining auditory nerve in the cochlea through the electrode array, so that the brains of patients with severe and profound sensorineural deafness can perceive sound.

[0005] After cochlear implantation, residual hearing and the hearing generated by the cochlear implant are often affected by the growth of fibrocyte in the cochlea and the delayed degeneration of neuronal tissue after the operation. Histological evaluation of the temporal bones of cochlear implant patients shows that fibrous tissue hyperplasia has formed in nearly 60% of the cases examined. The formation of fibrous tissue hyperplasia is considered to be caused by mechanical damage to the fine structure of the cochlea due to electrode insertion and the body's rejection reaction to the implant. The formation of fibrous tissue between the electrode and the cochlea leads to damage to hair cells and spiral ganglion cells. At the same time, the fibrous tissue hyperplasia around the electrode increases the electrode impedance, which affects the effectiveness of electrical stimulation of the auditory nerve in the cochlea, reduces the dynamic range of the threshold, and decreases the speech perception effect and the function of the cochlear implant itself. Fibrous tissue hyperplasia mainly occurs in the first 4 weeks after implantation, and clinically, it can be judged from the increase in the electrode impedance of the cochlear implant.

[0006] In the prior art, the drug delivery cochlear electrode mainly doped drugs in the silicone body or hydrogel body of the electrode. Since doping will affect the quality of the silicone, the surface of the silicone is damaged after the drug dissolves, affecting the functionality and long-term reliability of the electrode. And doping drugs in the silicone or hydrogel body belongs to physical adsorption, and the release of the drug is affected by free diffusion and cannot be controlled. Summary of the Invention

[0007] In order to achieve the above object, the technical solution of the present invention is as follows: A drug delivery cochlear electrode includes a flexible electrode head, n electrode contacts, m air bags, a silicone body, a first booster ring, a second booster ring, a check valve, a first spiral part, a second spiral part, a loop electrode, a first catheter, a second catheter, a stimulating lead wire, a loop lead wire, a pressure regulating valve, a drug reservoir, a spring part and an injection port. Among them, the flexible electrode head is arranged at the front end, n electrode contacts and m air bags are arranged on the silicone body. The air bags are V-shaped, and m air bags are arranged at several electrode contacts close to the flexible electrode head among the n electrode contacts. The air bags and the electrode contacts are arranged at intervals; a first booster ring and a second booster ring are arranged behind the n electrode contacts relative to the flexible electrode head. The first catheter is connected to the m air bags, the second catheter is connected to the first catheter through the check valve, and the second catheter is connected to the drug reservoir through the pressure regulating valve. The spring part is arranged in the drug reservoir. Pressing the spring part injects the drug in the drug reservoir into the air bags through the second catheter, the check valve and the first catheter;

[0008] The loop electrode is arranged at the end of the silicone body. The electrode contacts are connected to the stimulating lead wire, and the drug film loop electrode is connected to the loop lead wire. The stimulating lead wire forms a first spiral part and a second spiral part in the silicone body.

[0009] Preferably, the drug in the drug reservoir is a glucocorticoid receptor agonist, laminin, insulin-like growth factor or a stem cell growth factor-containing substance.

[0010] Preferably, the V-shaped of the airbag is 0° in the un-inflated state and 15° when fully inflated.

[0011] Preferably, the glucocorticoid receptor agonist is dexamethasone.

[0012] Preferably, the carrier of the drug is hydrogel.

[0013] Preferably, the electrode contact is in a B-shaped-like form, with the two ends buckling inward and the middle part welding the stimulation lead wire.

[0014] Preferably, the electrode contact is oval-shaped, with the stimulation lead wire welded inside one long side of the oval, and the middle part of the other long side is hollowed out.

[0015] Preferably, 16 - 32 electrode contacts are provided.

[0016] Preferably, 7 - 12 airbags are provided.

[0017] Preferably, the tip angle of the flexible electrode head is 16° - 25°.

[0018] The present invention has at least the following beneficial effects: Currently, all existing cochlear curved electrodes need special tools for implantation, and the operation during implantation is relatively difficult, which is the fundamental reason why the current curved electrodes cannot be popularized; the electrode of the present invention embeds a V-shaped airbag on the back of the electrode, evacuates the air before implantation to keep the electrode in the shape of a straight electrode, and fills the drug after implantation to make the V-shaped airbag expand, so that the straight electrode is converted into the shape of a curved electrode in the cochlea, achieving the purpose of near-cochlear-axis stimulation; this invention is easy to operate, has little damage to the cochlea, and at the same time utilizes the V-shaped airbag to fill the drug and slowly release high-concentration cell growth factors, increasing the survival amount of inner hair cells in the cochlea, thereby achieving a better hearing rehabilitation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the drug-loaded cochlear electrode according to an embodiment of the present invention;

[0020] Figure 2 It is a schematic structural diagram of the drug-loaded cochlear electrode according to an embodiment of the present invention after the airbag is fully inflated after implantation;

[0021] Figure 3 It is a schematic structural diagram of the drug-loaded cochlear electrode according to an embodiment of the present invention with the airbag un-inflated and fully inflated;

[0022] Figure 4 It is a schematic structural diagram of the B-shaped-like electrode contact of the drug-loaded cochlear electrode according to an embodiment of the present invention;

[0023] Figure 5 It is a schematic structural diagram of the B-shaped-like electrode contact of the drug-loaded cochlear electrode according to an embodiment of the present invention welding the stimulation lead wire;

[0024] Figure 6 Schematic diagram of the elliptical electrode contact structure of the drug-loaded cochlear electrode according to an embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the welding stimulation lead structure of the elliptical electrode contact of the drug-loaded cochlear electrode according to an embodiment of the present invention. Detailed implementation manners

[0026] Embodiment 1

[0027] Referring to Figure 1 as shown, a drug-loaded cochlear electrode includes a flexible electrode head 1, n electrode contacts 4, m air bags 3, a silica gel body 2, a first boosting ring 5, a second boosting ring 6, a check valve 8, a first spiral part 9, a second spiral part 10, a loop electrode 11, a first catheter 7, a second catheter 14, a stimulation lead 13, a loop lead 12, a pressure regulating valve 15, a drug reservoir 16, a spring part 18 and an injection port. Among them, the flexible electrode head 1 is arranged at the forefront, the n electrode contacts 4 and the m air bags 3 are both arranged on the silica gel body 2. The air bags 3 are in a V shape, and the m air bags 3 are arranged at several electrode contacts 4 close to the flexible electrode head 1 among the n electrode contacts 4, and the air bags 3 and the electrode contacts 4 are arranged at intervals; a first boosting ring 5 and a second boosting ring 6 are arranged at the relative rear of the n electrode contacts 4 with respect to the flexible electrode head 1. The first catheter 7 is connected to the m air bags 3, the second catheter 14 is connected to the first catheter 7 through the check valve 8, and the second catheter 14 is connected to the drug reservoir 16 through the pressure regulating valve 15. The spring part 18 is arranged in the drug reservoir 16. Pressing the spring part 18 causes the drug 17 in the drug reservoir 16 to enter the air bags 3 through the second catheter 14, the check valve 8 and the first catheter 7;

[0028] The loop electrode 11 is arranged at the end of the silica gel body 2. The electrode contacts 4 are connected to the stimulation lead 13, and the drug 17 thin film loop electrode 11 is connected to the loop lead 12. The stimulation lead 13 forms a first spiral part 9 and a second spiral part 10 in the silica gel body 2. The first spiral part 9 is wavy and the second spiral part 10 is spiral.

[0029] The check valve 8 enables the hydrogel with the drug 17 to be only filled into the air bags 3 from the second catheter 14 to the first catheter 7. Before the cochlear electrode is implanted, the air bags 3 are evacuated through the second catheter 14, the check valve 8 and the first catheter 7. After the electrode is implanted, the drug 17 is filled, so that the V-shaped air bags 3 open, thereby converting the straight electrode into a bent electrode shape in the cochlea. Referring to Figure 2 to achieve the purpose of near-cochlear axis stimulation; this invention is easy to operate, has little damage to the cochlea, and at the same time utilizes the V-shaped air bags 3 to fill the drug 17 to slowly release high-concentration cell growth factors and increase the survival amount of inner hair cells in the cochlea.

[0030] The pressure regulating valve 15 can adjust the flow rate of the gas filled into the airbag 3. The spring part 18 in the medicine reservoir 16 is provided with a piston, which is similar to the structure of a syringe. The medicine 17 is added through the injection port 19.

[0031] The medicine 17 in the medicine reservoir 16 is a glucocorticoid receptor agonist, laminin, insulin-like growth factor or a stem cell growth factor-containing agent.

[0032] See Figure 3 , for the V-shaped airbag 3, the angle is 0° (A2) in the unfilled state and 15° (A1) when fully filled. The middle fold 24 enables the airbag 3 to contract regularly during pre-implantation evacuation, and the shape of the airbag 3 is also unified when fully filled, improving the overall reliability and effectiveness of the electrode.

[0033] The glucocorticoid receptor agonist is dexamethasone. The carrier of the medicine 17 is hydrogel or silk fibroin gel.

[0034] See Figure 4 , Figure 5 , the electrode contact 4 is in a B-shaped class, with the two ends buckled inward, and the middle part is welded to the stimulating lead 13. Most of the electrode contacts 4 in the prior art are C-shaped or semi-circular, and there is a certain possibility of falling off from the silica gel body 2. The buckled shape makes the electrode contact 4 not easy to fall off in the silica gel body 2, improving the adhesion firmness.

[0035] See Figure 6 , Figure 7 , the electrode contact 4 is oval-shaped, with the stimulating lead 13 welded to the inner side of one long side of the oval, and the center of the other long side is hollowed out. The welding situation can be observed from the hollowed-out center during welding. The oval shape and the hollowed-out belt setting make the electrode contact 4 not easy to fall off in the silica gel body 2, improving the adhesion firmness. The silica gel body 2 passes through the oval electrode contact 4, and the electrode contact 4 hardly has the possibility of falling off from the silica gel body 2.

[0036] 16 - 32 electrode contacts 4 are provided, and 7 - 12 airbags 3 are provided, which are arranged between 7 - 12 electrode contacts 4 starting from the flexible electrode head 1 side.

[0037] The tip angle of the flexible electrode head 1 is 16° - 25°, and the fillet radius of the tip is 0.15 mm - 0.25 mm, which reduces the damage to the inner wall of the cochlea during implantation and maximally preserves the residual hearing.

[0038] Previous studies have shown that dexamethasone is effective at a concentration of 0.2 - 0.7 μM. Around this local concentration, a significant reduction in the inflammatory tissue response can be seen around the nerve implant. The present invention can release 0.0823 μg / cm of dexamethasone after each cyclic voltammetry scan cycle, and release a total of nearly 23 μg / cm after 300 cyclic voltammetry scan cycles. 2 of dexamethasone, and release a total of nearly 23 μg / cm after 300 cyclic voltammetry scan cycles.2 According to most histological studies, the reactive area represented by enhanced glial fibrillary acidic protein (GFAP), which is a key intermediate filament, has an activity radius of less than 500 μm around the cochlear nerve electrode array, and the release of 0.0823 μg / cm 2 of dexamethasone will result in an average dexamethasone concentration of 0.67 μM within a 500-μm radius of the electrode. Therefore, the dose triggered by 1 cycle voltammetry scan period can achieve an effective concentration around the electrode array sufficient to reduce inflammation.

[0039] Laminin, insulin-like growth factor, or stem cell growth factor-containing are all effective in repairing the inner cochlear nerve tissue.

[0040] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A drug-loaded cochlear implant electrode, characterized in that, It includes a flexible electrode head, n electrode contacts, m airbags, a silica gel body, a first booster ring, a second booster ring, a check valve, a first spiral part, a second spiral part, a loop electrode, a first catheter, a second catheter, a stimulation lead wire, a loop lead wire, a pressure regulating valve, a drug reservoir, a spring part and an injection port. Among them, the flexible electrode head is arranged at the forefront, the n electrode contacts and the m airbags are both arranged on the silica gel body. The airbags are V-shaped, and the m airbags are arranged at several electrode contacts among the n electrode contacts that are close to the flexible electrode head, and the airbags and the electrode contacts are arranged at intervals; the first booster ring and the second booster ring are arranged at the relative rear of the n electrode contacts with respect to the flexible electrode head. The first catheter is connected to the m airbags, the second catheter is connected to the first catheter through the check valve, and the second catheter is connected to the drug reservoir through the pressure regulating valve. The spring part is arranged in the drug reservoir, and pressing the spring part causes the drug in the drug reservoir to enter the airbags through the second catheter, the check valve and the first catheter. The loop electrode is arranged at the end of the silica gel body. The electrode contacts are connected to the stimulation lead wire, and the loop electrode is connected to the loop lead wire. The stimulation lead wire forms a first spiral part and a second spiral part in the silica gel body.

2. The drug-loaded cochlear electrode according to claim 1, wherein: The drugs in the drug reservoir are glucocorticoid receptor agonists, laminin, insulin-like growth factor or contain stem cell growth factor.

3. The drug-loaded cochlear electrode according to claim 1, wherein: The V-shaped of the airbag is 0° in the non-inflated state and 15° when fully inflated.

4. The drug-loaded cochlear electrode according to claim 2, characterized in that: The glucocorticoid receptor agonist is dexamethasone.

5. The drug-loaded cochlear implant electrode according to claim 2, characterized in that: The carrier of the drug is hydrogel.

6. The drug-loaded cochlear implant electrode according to claim 1, wherein: The electrode contacts are in a B-like shape, with the two ends buckling inward and the middle welded with the stimulation lead wire.

7. The drug-loaded cochlear implant electrode according to claim 1, wherein: The electrode contacts are oval, with the stimulation lead wire welded to the inner side of one long side of the oval, and the middle of the other long side is hollowed out.

8. The drug-loaded cochlear electrode according to claim 1, wherein: 16 - 32 electrode contacts are provided.

9. The drug-loaded cochlear electrode according to claim 1, characterized in that: 7 - 12 airbags are provided.

10. The drug-loaded cochlear electrode according to claim 1, wherein: The tip angle of the flexible electrode head is 16° - 25°.

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