Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/02—Details
  • A61N1/04—Electrodes
  • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
  • A61N1/0526—Head electrodes
  • A61N1/0541—Cochlear electrodes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F11/00—Methods or devices for treatment of the ears or hearing sense; Non-electric hearing aids; Methods or devices for enabling ear patients to achieve auditory perception through physiological senses other than hearing sense; Protective devices for the ears, carried on the body or in the hand
  • A61F11/20—Ear surgery

Definitions

• This invention relates to an insertion tool for a cochlear implant, and a method for using that tool to insert a cochlear electrode lead into a patient's ear.
• the stimulating electrode assembly of a cochlear implant is placed inside the cochlear partition, commonly into the scala tympani.
• a major problem with conventional electrode leads is in inserting them into the cochlea without irreversibly damaging the auditory nerve fibers, and the electrodes and lead wires of the electrode lead.
• electrode leads are surgically inserted along the line of sight through the round window and along the basal turn of the cochlea, either with an alligator forceps or with Y-shaped claws.
• the alligator forceps adequately control the force and direction of the electrode insertion, but risk of damage to the electrodes is high.
• the forceps also must be periodically removed and replaced to correctly orient the electrode array in the cochlea, since it can grip the electrode lead only through a limited angle of rotation.
• the Y-shaped claws minimize damage to the electrode, but it cannot be used to apply insertion force in the optimum direction, along the line of sight. Since it cannot grip the electrode lead, it also cannot be used to rotate the electrode to correctly place it in the cochlea.
• An object of my invention is to provide an insertion tool and a technique for insertion of the electrode lead which both protects the electrode assembly and allows successful manipulation of the electrode lead into the cochlea.
• the electrode lead is provided with a collar, preferably made of silicone rubber.
• the collar is affixed to the rear of the electrode lead at a predetermined point above the electrode assembly.
• the collar is expanded in Freon or
• Glue preferable silastic A
• the insertion or gripping tool has a rounded end, configured like a thumbnail at the tip, designed to fit between the collar and the lead.
• a major advantage of my invention is that the squeeze or friction fit of the gripping tool to the electrode lead (through the collar) completely prohibits possible damage to the electrode array as may occur with use of alligator forceps. This mode of attachment also permits optimum application of the insertion force directly along the axis. Further, the surgeon can use the gripping tool to rotate the electrode lead without fear that the tool will slip off the lead and damage the electrode assembly or the delicate tissues of the patient's ear. This contrasts with the prior art Y-shaped claws which cannot be used to apply force along the line of sight or to grip and rotate the electrode lead.
• My invention can also be used with both symmetric and non-symmetric electrodes.
• the gripping tool is placed under the collar so that 0 '
• the active electrodes e.g. 180 degrees away
• a mark is placed on the front of the handle of the gripping tool so that when the surgeon inserts the electrode lead into the cochlea and the electrode assembly is no longer visible, the surgeon is able to determine he orienta ⁇ tion of the active electrodes and to rotate the electrode lead to correctly place the active electrode assembly in the cochlea.
• the placement of the tool with respect to the array is not important.
• the gripping tool is removed by sliding it along the axis of the lead; the lead can be held steady (so that removal of the tool does not remove the lead) by temporary placement of the Y-shaped claws on the collar.
• FIG. 1A is an illustration of a prior art non- symmetric electrode lead
• FIG. IB is an illustration of a prior art symmetric electrode lead
• FIG. 2 illustrates the prior art method of inserting the electrode lead into the cochlea
• FIGS. 3A-C illustrate the preferred method of
• FIG. 4A is an illustration of the gripping tool
• FIG. 4B is an enlarged view of the tip of the gripping tool
• FIG. 5A-C illustrate the preferred method of u ⁇ in ⁇ the insertion tool with the electrode lead.
• Fig. 1A is an illustration of a prior art non- symmetric or localized electrode lead 2, with active electrodes 4 and electrode lead wires 6.
• Fig. IB shows a prior art symmetric or banded electrode lead 8, with active electrodes 10 and electrode lead wires 12.
• the prior art method of inserting an electrode lead into the cochlea is shown in Fig. 2. To achieve insertion, force must be - 4 -
• a collar is placed on the electrode lead to the rear of the electrode assembly.
• Figs. 3A-3C the preferred method of placing collar 20 around electrode lead 8 is illustrated.
• a 5-6mm length collar 20 made of silastic tubing, silicone rubber or other suitable material, is slipped over the front end of lead 8 to rest at a point approximately 26mm behind the last electrode.
• Collar 20 is expanded in Freon to produce an inner diameter of 0.6 mm, which is slightly larger than the outer diameter of electrode lead 8, so as to facilitate placement of collar 20 over lead 8 and to allow for a snug friction fit after evaporation of the Freon.
• Collar 20 has a wall thickness of
• Fig. 3B shows the placement of collar 20 on lead
• FIGs. 4A and 4B show gripping tool 24 which is adapted for use with collar 20.
• FIG. 4A is an illustration of gripping tool 24, with a 110 mm length handle 26 and a
• Fig. 4B is an enlarged view of the front of tip 28, with all sharp edges removed to form a rounded end
• rounded end 30 is placed gently under the rear end of collar 20, allowing the tip of the insertion tool to be attached to lead 8, removed - 5 -
• Fig. 5B is an enlarged view of the location of rounded groove 30 under collar 20.
• This technique of attachment permits the surgeon to apply force directly along the axis r in the optimum direction along the line of sight through the round window. Possible damage to the electrode lead is minimized, and the surgeon does not need to periodically remove and replace the gripping tool to push the lead forward.
• the friction fit of the gripping tool to the lead also permits the surgeon to rotate the lead and correctly orient it in- the cochlea without fear that the tool may slip off the lead.
• the gripping tool is placed 180 degrees from active electrodes 4, and a mark is placed on the front of handle 26, indicated the direction of the active elec ⁇ trodes. This enables the surgeon to determine the location of active electrodes 4 when the lead has been inserted through the round window and the active electrodes are no longer visible, permitting the surgeon to correctly orient the active electrodes with respect to the cochlear nerves.
• the collar is located outside the round window. Removal of the gripping tool from the collar is accomplished by sliding the tool along the axis of the lead; the lead can be held steady (so that removal of the tool does not remove the electrode assembly from the cochlea) by the temporary placement of prior art Y-shaped claws on the collar.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Veterinary Medicine (AREA)
• Heart & Thoracic Surgery (AREA)
• Public Health (AREA)
• General Health & Medical Sciences (AREA)
• Otolaryngology (AREA)
• Animal Behavior & Ethology (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Vascular Medicine (AREA)
• Physics & Mathematics (AREA)
• Psychology (AREA)
• Biophysics (AREA)
• Acoustics & Sound (AREA)
• Surgery (AREA)
• Cardiology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Radiology & Medical Imaging (AREA)
• Electrotherapy Devices (AREA)
• Prostheses (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=22138097

Family Applications (1)

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Cited By (7)

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Citations (2)

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• 1988
  • 1988-07-22 WO PCT/AU1988/000265 patent/WO1989000870A1/en not_active Application Discontinuation
  • 1988-07-22 EP EP19880907147 patent/EP0328597A4/en not_active Withdrawn
  • 1988-07-22 AU AU20893/88A patent/AU605343B2/en not_active Ceased
  • 1988-07-22 JP JP63506160A patent/JPH02500814A/ja active Pending

Patent Citations (2)

Non-Patent Citations (1)

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