AU2006202583A1 - Method and apparatus for intraocular retinal tack inserter - Google Patents

Description

S&F Ref: 563804D2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Second Sight Medical Products, Inc., of 12744 San Fernando Road Building Sylmar, California, 91342, United States of America Robert J Greenberg Joseph H Schulman Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Method and apparatus for intraocular retinal tack inserter The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c METHOD AND APPARATUS FOR INTRAOCULAR RETINAL TACK

SINSERTER

Field of the Invention 00 This invention relates to implanting retinal tacks and to the securing of a retinal 0 electrode element to the back of an eyeball.

0 Background An example of a preexisting tool for implanting retinal tacks is Sinnett, U.S. Pat.

No. 4,784,138; and No. 4,712,550. Actual laboratory experience with the Sinnett tool found that an apparatus like Sinnett's applied too much force to the retina. Consequently, this tool has a restricted functional ability to tack devices to the back of the eye.

Summary In accordance with one aspect of the present disclosure, there is provided a method for securing a retinal electrode element to the back of the eyeball comprising the steps of: a. holding and steadying the retinal electrode element; b. applying a vibrating forward and back motion to the retinal electrode element; c. forcing the electrode element's spike electrodes, real or dummy, and into materials to be secured to the back of the eyeball and into the retina, in any order; d. forcing the electrode element's spike electrodes, real or dummy, into the back of the eyeball.

Desirably the method further comprises the step of originating the vibrating back and forth motion with a piezoelectric crystal.

R:\LIBPP]0365 I d2.doc:EAA -2- In accordance with another aspect of the present disclosure, there is provided an apparatus for securing a retinal electrode element to the back of the eyeball, the apparatus comprising: a. means for holding and steadying the retinal electrode element; b. means to vibrate the retinal electrode element in a forward and back direction; c. means to force the retinal electrode element's spike electrodes, real or dummy into the retina and into other material that is to be secured to the interior back surface of the eyeball, in any order; d. means to force the retinal electrode element's spike electrodes, real or dummy, into the back of the eyeball.

The apparatus may further comprise a piezoelectric crystal as a source of vibrating forward and back motion.

Other aspects are also provided.

In one implementation, a tack suitable for insertion into the retina is driven into the retina by the repeated minute blows from the rapid contractions and expansions of the piezoelectric crystal.

In another implementation, a single, short impulse is used to drive the tack home.

With this mode of tack driving, a remotely placed driver couples its motion to the tack using an elongated tube filled with a suitable hydraulic fluid.

Similar method and apparatus is used for implanting a retinal implant having spike-like electrodes. In another implementation, a retinal implant with spike-like electrodes is driven into the retina (or other suitable tissue which can hold the implant) by the repeated minute blows from the rapid contractions and expansions of the piezoelectric [R:\LIBPP]0365 Id2.doc:EAA -3- O crystal. The spiked electrodes may have a barbed point so as to facilitate their remaining imbedded in the interior wall of the back of the eye.

In a different implementation, a single, short impulse is used to drive the retinal implant with spiked-electrodes home. With this mode of driving the spiked electrode 5 retinal implant, a remotely placed driver couples its motion to the implant using an 00

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elongated tube filled with a suitable hydraulic fluid. The spiked electrodes are driven into tissue suitable to hold it in place. The spike electrodes may have a type of barb point on Sthem so as to facilitate their remaining imbedded in the interior wall of the back of the eye. A plurality of spike electrodes may be dummy electrodes in that they function only io as mechanical anchors, and do not function as electrodes. Thus, four comer dummy electrodes may anchor the retinal electrode element, which may even have the rest of its electrodes shorter than the dummy electrodes or have the rest of the electrodes as flat electrodes.

Brief Description of the Drawings At least one embodiment of the invention will now be described with reference to the drawings in which: FIG. 1 shows a retinal tacker that uses an electronically driven piezoelectric crystal; FIG. 2 shows a retinal tacker that uses a remote impulse driver connected by a tube filled with hydraulic fluid; FIG. 3 shows a retinal implant tacker, for an implant with spiked electrodes, that uses an electronically driven piezoelectric crystal; FIG. 4 shows a retinal implant tacker, for an implant with spiked electrodes, which uses a remote impulse driver connected by a tube filled with hydraulic fluid; FIG. 5a shows a barb similar to a retinal tack for use with the spiked electrodes; [R:\LIBPP]0365 Id2.doc:EAA -4- O FIG. 5b shows a barb similar to a fishhook for use with the spiked electrodes; FIG. 6a shows a plurality of dummy non-working electrodes that extend beyond the lengths of the electrodes and anchor the retinal electrode element to the back of the eyeball; and FIG. 6b shows a plurality of dummy non-working electrodes that extend 00 sufficiently beyond the relevant lengths of the electrodes which are proportioned to the curvature of the retinal and anchor the retinal electrode element to the back of the eyeball.

Detailed Description (-i The following description is of the best mode presently contemplated for 1o carrying out the invention. This description is not to be taken in a limiting sense, but is merely made for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.

This invention is a method and apparatus for implanting retinal tacks and into the retina, as well as for doing the same for retinal implants with spike electrodes. FIG. 1 shows a retinal tacker that uses a piezoelectric crystal electrically driven by electrical source which may be a battery. The electrical or electronics unit also contains required resonant elements. The piezoelectric crystal undergoes a constriction-relaxation cycle under the application of an alternating current via wires Thus, the piezoelectric crystal is set into a vibrating motion that is mechanically coupled, by the tack holder to the retinal tack A mechanical system, in FIG. 1 or FIG. 2, holds a retinal tack The tack is made from titanium or from a similarly sufficiently biologically non-reactive material.

The material used must be sufficiently non-reactive with the back of the eyeball (sclera) where the tack is implanted, as well as the retina itself, and the vitreous humor fluid of the eye.

[R:\LIBPP]O365 I-d2.doc:EAA O The tack is inserted into the eye with the holder and placed against the retinal surface. As shown, in FIG. 1, when the tack is touching the retinal surface the electronic drive circuitry is turned on which causes the piezoelectric crystal to vibrate. The vibrating crystal is mechanically coupled to the tack and allows the 5 surgeon to insert the tack into the retina with less force. The vibrations allow the 00 ,I hard tack to enter the soft tissue of the retina instead of pushing it out of the way.

Advantageously, the vibrations make it easier to insert the tack into the sclera, Ssince the relaxation time of the organic tissues is shorter for breaking and longer for bending. Each vibration imparts a quick cutting effect to the leading point of the tack.

io Although each vibration is a short movement, the high rate of vibration results in effectively a longer, but individually for each vibration, a quick cutting action. The longer time comprises the sum of the individual forward vibration times and the nonforward part of the vibration stroke.

FIG. 3 illustrates the piezo-electric driver (FIG. 1) for a retinal tack (FIG. 1, applied to the retinal implant (20) with spike electrodes In this embodiment the head (21) of a retinal tack is mounted on or near the center of the retinal implant The holder fits the head-of-tack fitting (21) and the operation is similar to driving a single tack. A plurality of arms (22) emanating and anchored to the holder act to steady the implantable electrode element One embodiment of this invention uses four arms (22) to steady the four comers of a rectangular shaped back surface of the electrode element In FIGS. 1, 2, 3 and 4, the electrode element (20) is shown with a curvature so as to conform to the curvature of the retina However, the large number of spike electrodes (23) can require a larger voltage input into the piezo-electric crystal so as to produce a proportionally larger force (approximately). In another aspect of the invention, a plurality of spike electrodes may be dummy electrodes in that they function [R:\LIBPP]0365 Id2.doc:EAA -6- O only as mechanical anchors, and do not function as electrodes. Thus, four comer dummy electrodes may anchor the retinal electrode element, which may even have the rest of its electrodes shorter than the dummy electrodes or have the rest of the electrodes as flat electrodes.

FIG. 2 shows a retinal tacker that uses a piston electrically driven by 00 electrical source which may be a battery. In this alternative embodiment, the electronic circuitry (12) is turned on causing a piston to impact hydraulic fluid (10) in Sa thin tube The sudden impulse of the piston is transmitted to the tack being held in its tack holder This sudden impulse drives the tack into the retinal wall Advantageously, the sudden impulse is such that a large amount of force is transmitted in a very short time. Consequently the tack is forced into the desired organic tissue and does not just push it back or bend it.

FIG. 4 illustrates the hydraulic driver (FIG. 2) for a retinal tack (FIG. 2, applied to the retinal implant (20) with spike electrodes In this embodiment the head (21) of a retinal tack (FIG. 2, is mounted on or near the centre of the retinal implant The holder fits the head-of-tack fitting (21) and the operation is similar to driving a single tack (FIG. 2, However, the large number of spike electrodes (23) can require either a larger voltage input into the piston driving circuitry or a larger fluid driving piston so as to produce an approximate proportionally larger force. A plurality of arms (22) emanating and anchored to the holder act to steady the implantable electrode element One embodiment of this invention uses four arms (22) to steady the four comers of a rectangular shaped back surface of the electrode element In FIGS. 1, 2, 3 and 4, the electrode element (20) is shown with a curvature so as to conform to the curvature of the retina R:\LIBPP]0365 I_d2.doc: EAA -7- O Two types of barbs for the retinal element's spike electrodes are shown in FIG. FIG. 5a shows a barb (51) similar to a retinal tack. The tack-type barb (51) is formed as part of the spike electrode FIG. 5b shows a barb (53) similar to a fishhook barb. The fishhook-type barb (53) is formed as part of the retinal element's spike electrodes (52).

O 5 The barb help the electrode stay anchored in the tissue in which it has been driven by one 00 of the embodiments of this retinal tacker invention. A plurality of spike electrodes may be dummy electrodes in that they function only as mechanical anchors (FIGS. 6a and b), Sand do not function as electrodes. Thus (FIG. 6a), four comer dummy electrodes (611) may anchor the retinal electrode element which may even have the rest of its 1o electrodes (612) shorter than the dummy electrodes (611) or have the rest of the electrodes (FIG. 6b) as retina matching curved envelope electrodes (613). The head-oftack fitting (21) is also shown with the retina The retinal tack or the spike electrode with its barb may attach a retinal electrode element in an epiretinal or subretinal position. It may attach other items and the retina as well as a retinal electrode element or other eye implantable element to the back of the interior of the eyeball, in any order, impaled on the tack or the barbed spike electrode, dummy or real. The practical limitation is placed by the length of the tack or barbed spike electrode, real or dummy and by the holding power of the imbedded tack or barbed spike electrode, real or dummy.

While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.

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Claims (4)

1. A method for securing a retinal electrode element to the back of the eyeball comprising the steps of: S 5 a. holding and steadying the retinal electrode element; 00 b. applying a vibrating forward and back motion to the retinal electrode element; c. forcing the electrode element's spike electrodes, real or dummy, and (,1 into materials to be secured to the back of the eyeball and into the retina, in any order; d. forcing the electrode element's spike electrodes, real or dummy, into the back of the eyeball.

2. The method of claim 1 further comprising the step of originating the vibrating back and forth motion with a piezoelectric crystal.

3. An apparatus for securing a retinal electrode element to the back of the eyeball comprising: a. means for holding and steadying the retinal electrode element; b. means to vibrate the retinal electrode element in a forward and back direction; c. means to force the retinal electrode element's spike electrodes, real or dummy into the retina and into other material that is to be secured to the interior back surface of the eyeball, in any order; d. means to force the retinal electrode element's spike electrodes, real or dummy, into the back of the eyeball. [R:\LIBPP]03651 _d2.doc:EAA

4. The apparatus of claim 3 further comprising a piezoelectric crystal as a source of IN vibrating forward and back motion. 00 Dated this Sixteenth Day of June, 2006 C' Second Sight Medical Products, Inc. Patent Attorneys for the Applicant 0SPRUSON FERGUSON [R:\LIBPfIO36SI-d2.doc:EAA