CA1077652A - Implantable structure - Google Patents
Implantable structureInfo
- Publication number
- CA1077652A CA1077652A CA258,631A CA258631A CA1077652A CA 1077652 A CA1077652 A CA 1077652A CA 258631 A CA258631 A CA 258631A CA 1077652 A CA1077652 A CA 1077652A
- Authority
- CA
- Canada
- Prior art keywords
- stem
- structure according
- implanted
- electric current
- porous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
-
- 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
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/18—Internal ear or nose parts, e.g. ear-drums
-
- 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
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/18—Internal ear or nose parts, e.g. ear-drums
- A61F2002/183—Ear parts
Abstract
ABSTRACT
The structure for in vivo implantation comprises a porous element defining a pad and a stem extending from the central portion of the pad. At least a substantial portion of the pad and at least a portion of the stem are of a porous material which promotes living tissue to grow into the pores of the material when implanted to secure the structure in the implanted position. The structure is adapted to be implanted in place of at least a portion of the bony chain of the middle ear, to serve as a plug for a tube, or to serve as an implant electrode.
The structure for in vivo implantation comprises a porous element defining a pad and a stem extending from the central portion of the pad. At least a substantial portion of the pad and at least a portion of the stem are of a porous material which promotes living tissue to grow into the pores of the material when implanted to secure the structure in the implanted position. The structure is adapted to be implanted in place of at least a portion of the bony chain of the middle ear, to serve as a plug for a tube, or to serve as an implant electrode.
Description
~0~7765Z
IMPLANTABLE STRUCTURE
One of the reasons for deafness is the failure of the bony chain, i.e., the hammer, the anvil and the stirrup to transmit the vibrations of the ear drum to the inner ear.
Efforts have been made to repair the elements of the bony chain and to substitute components therefor. With the substitution of components, one difficulty encountered is the securing of such components in the desired organic position. One example of a suitable implant structure is described in our German Offenlegungsschrift 2,458,932 which provides an implant structure having a biocompatible columella and a biocompatible porous pad secured to at least one of the ends of the columella.
The present invention is an improvement over such structure in that the biocompaptible porous material can be used to form the columella as well as each of its ends. The tissue ingrowth at the ends as well as along the columella can ensure the securing of the implant in the desired position. The structure of the present invention offers an improved structure, for example, for the transmission of sound vibrations in the ear because it can be made from a continuous, single block of material throughout which tissue may grow.
Also, during recent years, many efforts have been made to provide a simple, reversible, birth control method devoid j 1 / - 1 --107765~
of side effects. The use of the pill for birth control has such undesirable side effects. A positive method of sterili~
zation for women involves closing the fallopian tubes. This method is not reversible. The improved structure of the pre-sent invention, however, is especially adapted for implanta-tion in the end of the fallopian tubes opening into the uterus. Accordingly, a birth control method using the im-plant structure of this invention provides for reversibility when desired.
Also, certain physiological processes, such as fracture healing, heartbeat pacing, pain modulation, etc., can be con-trollably modified by passing electric current into a selected tissue of a living organism. A common means o~
passing electric current is to insert a noble metal electrode into the organism. Using such metal electrodes, it was found that the current density distribution to the selected tissue cannot be easily controlled.
A~cording to the present invention, there is provided a structure for in vivo implantation, the str~cture being an integral elongated body made of a resilient and distensible material an end of which body is enlarged whereby the remainder of the body forms a stem extending ~rom said enlarged end, said enlarged end and said stem being biocompatible, and at least a substantial portion of the material of which said enlarged end is made and at least a portion of the material of which said stem is made being a porous material which promotes living tissue to ~row into the pores of the material when implanted to secure the -structure in the implanted position.
The enlarged end and the stem are bicompatible and promote the ingrowth of living tissue. For most applications, the stem can have transverse dimensions between 0.25 and 3 millimeters, and the pad's largest dimension can be between 0.5 and 8 millimeters.
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.
The improved structure is adapted to be implanted in place of at least a portion of the bony chain of the middle ear. The stem is made sufficiently long to approximate the dimensions of the bony chain which it replaces, and, preferably, the surface pores of the center portion of the stem are closed.
Also, it is preferred that the surface pores of nearly the entire stem be closed when the structure is used as a plug for the fallopian tubes opening into the uterus. The pad has a dimension to allow sufficient tissue ingrowth to secure the structure in its implanted position. Added securing by ridges along the stem can be provided to resist movement of the structure from its implanted position.
A fluoroethylene propylene tube can be heat shrunk onto the stem for closing its surface pores. The end of the stem which extends beyond the tube can have one or more leaves, or the end can be enlarged in one dimension to form a flat, bulbous end portion with sufficient flexibility to bend at a substantially right angle to the longitudinal axis of the stem. A wire can be connected to an end of the stem. Also, a disc of porous ingrowth-promoting material can be bonded to one end of the stem.
In general, the pad will be frusto-conical in shape with its larger end facing outwardly. When the pad defines a shallow recess for receiving a portion of the bony chain jl/ _3~
.
therein, the improved structure can serve as a stapes replacement.
The porous material of the element forming the structure can have the property of conducting electric current. Therefore, such structure can serve as an improved in-vivo electrode, which is totally biocompatible. By virtue of having a substantial tissue ingrowth within its pores, such electrode offers a relatively-large contact area for current distribution between the electrode and the ingrown and thereto contiguous tissue.
In this manner, better control of electric current distribution between the electrode and the contiguous tissue can be achieved. -~
The objects and advantages of the invention will become better understood from the following description when taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a side elevational view of one shape of the improved structure of the present invention;
Pig. 2 is a sectional view taken along line 2-2 in Fig. l;
Fig. 3 is a side elevational view partly in section of the improved structure used for replacement of the stapes of the ear;
Fig. 3a is an end view taken along line 3a-3a on Fig. 3;
Fig. 4 is an elevational view, partly in section, of another form of implantable structure of the present invention;
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Fig. 5 is a sectional view taken along line 5-5 on Fig. 4;
Fi8. 6 is a side elevational view of another form of improved structure of the present invention;
Fig. 7 is an end view taken along line 7-7 in Fig. 6;
Fig. 8 is a side elevational view of another form of improved structure for use as a bony chain replacement in the ear;
Fig. 9 is a side elevational view of another form of implantable structure of the present invention;
Fig. 10 is side elevational view, partly in section, of another form of implantable structure of the present invention; and Fig. 11 is a side elevational view of still another modified form of implantable structure of the present invention.
In Fig. 1 is shown an implantable structure, generally designated as 10, which may be used either as a tube plug or as a bony chain substitute. Structure 10 includes an enlarged end 12, the preferred form of which is generally frusto-conlcal.
A stem 14 is integral with and extends from the central portion 13 of enlarged end 12. For most applications, the enlarged end's largest dimension is between 0.5 and 8 millimeters. Stem 14 has transverse dimensiQn6 between 0.25 and 3 millimeters.
At least a substantial por-jl/ -5-; :- ~ . ' :
~07~S'Z
ion of the surface of enlarged end 12 and the end of stem 14 away from enlarged end 12 are porous and of a material which promotes the ingrowth of tissue when the structure is used as a bony chain substitute. Only the surface of enlarged end 12 need be porous when the structure is used as a tube plug.
In applications in which structure 10 is to be used as a substitute for at least a portion of the bony chain of the ear, it is preferred that the outer surface of the center part of stem 14 be either compressed or otherwise treated to have limited porosity to avoid the ingrowth of tissue in and around its surface. When so compressed, the structure will have a non-uniform density distribution along its longitudinal axis.
Theimproved structure of the present invention is made of a body of material at least a portion of which is porous and which readily promotes the growth of living tissues into the pores and voids within the material. Our British Patent 1,390,445 describes a porous material of carbon fibers bonded by polytetrafluorethylene which can be used as the growth-promoting material. Other suitable growth-promoting materials are also disclosed in said British patent. The present invention also has application to other biocompatible growth-promoting materials which may be implanted and cause living tissues to ingrow.
-jl/ -6-107765~
The structure 16 illustrated in Fig. 3 is suitable as a stapes replacement for implantation in the ear. Such structure includes a frusto-conical enlarged end 18 and a stem 20. The structure 16 is similar to structure 10 except that the outer end 21 of enlarged end 18 now defines a concave recess 22 shaped to receive a portion of the bony chain therein when implanted.
The center portion 15 of the stem 20 has its surface pores at least partially closed as indicated by the shaded area 24.
Structure 10 can be cut out from a block of the ingrowth-promoting material and is completely porous, as shown. On theother hand, structure 16 can be developed from a cylindrical bloc~ of such material and the stem 20, except for its outer end 25, can be compressed to the shape illustrated in Fig. 3 to obtain the surface 24 with the pores closed or sufficiently restricted to prevent growth of tissue in and through such external surface 24. The end 25 of stem 20 may be trimmed to size, if desired. Preferably, the end 25 should not exceed the diameter of the recess of the vestibule to the inner ear but form a close fit therein. An unexpected advantage of structure ~ -16 formed by compression along the central portion 15 of the stem 20 is that such portion exhibits substantially no mechanical hysteresis. This mechanical characteristic can be advantageous in allowing the surgeon to more precisely shape the geometry of structure 16 relative to the middle ear architecture. -.
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The closing of the pores, as represented by the shaded area 24 in Fig. 3, can be accomplished by pressure, pressure and heat, or any other suitable process, mechanical or chemical to ensure that the surface porosity is reduced sufficiently so that tissue growth cannot take place in and through the surface.
In addition to surface treatments, mechanical means such as shrink sleeves or pore-occluding coatings of medical grade materials, such as silicone rubber, polymeric dispersions, etc., can also be used as the pore~closing means, as hereinafter described.
In structure 26 shown in Figs. 4 and 5, the enlarged end 28 is frusto-conical in shape and has the stem 30 integral there-with and extending therefrom. The stem 30 is surrounded by a mechanical pore-closing means for closing the pores around its ~ -exterior, such as a tubular sleeve 32 which surrounds the exterior of stem 30 except for the outer end 33 thereof.
Tubular sleeve 32 is a biocompatible plastic tube which has been shrunk into its position surrounding stem 30, as shown.
Sleeve 32 and all materials used for in-vivo implants are to be completely biocompatible so that they do not cause any adverse reaction by the local tissues in and around the implantation site. An example of a suitable material for sleeve 32 is a fluorinated ethylene propylene tube which may be shrunk onto stem 30 at temperatures between 400F to 450F without damaging the porous material of structure 26. These sleeves are characterized as being good electrical insulators. -jl/ -8-.. : , ~ - . . , 107~76SZ
The structure 34 shown in Figs. 6 and 7 is similar to the structure 26 of Fig. 4, but has an enlarged flat end 36 into which a wire 38 is fixed. A sleeve 40 is shrunk about the central portion 41 of stem 42. The opposite ends 36 and 44 of the stem extend outwardly of sleeve 40. Structure 34 can be used either as a stapes replacement or as an electrode, as will be hereinafter set forth.
The structure 46 shown in Fig. 8 is substantially similar to structure 34, except that structure 46 is longer and is designed to be a replacement for the entire bony chain of the ear. Structure 46 includes an elongated flat end 48 integral with stem 50 about which a sleeve 52 is shrunk, leaving opposite ends 48 and 54 extending therefrom. End 48 is sufficiently thin to be flexible. End 48 can be easily bent so that it may be positioned at a substantially right angle to stem 50 and rest flat on the ear drum. With such geometric configuration, a large area of the porous material is exposed to the ear drum to ensure positive fixation by the growth of tissues in and through the pores of the material from which structure 46 is made.
The shrink fitting of the sleeves is done by any process well known in the art. For example, the shrink fitting can be accomplished by passing heated air over an expanded tubular sleeve 52 which has been placed in surrounding relation to the central part 51 of stem 50 for a relatively short period i 11 _9_ 1~7765Z
f time, for example, a few seconds. In such case, sufficient heat should be provided to exceed the setting temperature of the sleeve and the material of the sleeve remembers its original size and returns thereto, squeezing the central portion 51 of stem 50 as shown. The shrink sleeves are of a material which prevents living tissue from growing and attaching thereto.
The material also should be selected so that it does not cause appreciable dampening of the vibration transmission from the ear drum to the oval window of the inner ear.
A modified structure 56 is shown in Fig. 9. Stem 57 is provided with a shrink fit sleeve 58. One end of the stem 57 -~
projecting outwardly from sleeve 58 has been separated into a plurality of leaves 60. The leaves make an improved connection to the ear drum as compared to a single ended stem. The other projecting end 62 is as described in relation to end 44 of structure 34.
Another modified structure 63 is shown in Fig. 10. The stem 64 is surrounded by a shrink fit sleeve 66 over the central portion thereof. Only one end 68 of the stem projects outwardly of one end of the sleeve. The other end of the sleeve is flush with the stem and is covered by a disc 70 of a biocompatible porous material that promotes the ingrowth of tissue. A film 72, such as fluorinated ethylene propylene, bonds disc 70 to the end of sleeve 66 and to stem 64. Structure 63 can be made, if desired, without an end 68 projecting outwardly of sleeve 66.
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A modified structure 74 is shown in Fig. 11 designed to be used as a Fallopian tube closure plug. It includes an enlarged end 76 and a stem 78 provided with external ridges 80 facing toward enlarged end 76. Ridges 80 are preferably formed in such a manner that their external surfaces have their pores closed, as represented by the shaded area 84, so as to prevent the ingrowth of tissue. Such ridges 80 can be formed by compressing or molding of stem 78 so long as the external pores on the ridges 80 are sufficiently closed to prevent tissue ingrowth.
When structure 74 is used as a plug for a tube, ridges 80 will provide sufficient resistance to the traveling contractions of the tube so that the plug will not be displaced from its desired position before the ingrowth of tissue has progressed sufficiently within the enlarged end 76 to secure the structure in place. Hence, ridges 80 serve to impede the displacement of the plug within the tube.
Thus, the structures of the present invention for implant-ation in the ear are characterized as having an elongate porous element with pore-closing means over a central part of the element with one or both ends of the element extending beyond the pore-closing means.
The porous material as described in said British patent No. 1,390,445 is a fairly good electric conductor and, therefore, electric current density would be distributed over the entire structure of this invention and would flow into the ingrown tissue. Therefore, each of the structures shown in j 1/ -11-. . - . .
Figs, l-ll can also serve as an implant current-carrying electrode. In its simplest form shown in Fig. 6, wire 38 would carry an electric current to the tissues in the pores of structure 34, while sleeve 40 would serve to insulate the tissues adjoining the sleeve, thereby providing selective current density distribution.
In a modified form, a wire 37 can be attached to end 33 of stem 30 (Fig. 4) with the aid of a thin biocompatible layer or film 35 of a noble metal such as gold or platinum. Wire 37 can also be mechanically secured to end 33. Similarly, each of the shown embodiments of the implant structure can be adapted -~
to serve as an implant electrode.
From the foregoing it will be appreciated that the present invention provides an improved structure for in-vivo implantation, such as a Fallopian tube plug, or in place of all or part of the bony chain between the ear drum and the inner ear, or as an implant electrode with selective current density distribution;
the structure is relatively simple to make and involves the use of a porous biocompatible material and relatively simple ~ 20 manufacturing proceclures.
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.. . . . . . .
IMPLANTABLE STRUCTURE
One of the reasons for deafness is the failure of the bony chain, i.e., the hammer, the anvil and the stirrup to transmit the vibrations of the ear drum to the inner ear.
Efforts have been made to repair the elements of the bony chain and to substitute components therefor. With the substitution of components, one difficulty encountered is the securing of such components in the desired organic position. One example of a suitable implant structure is described in our German Offenlegungsschrift 2,458,932 which provides an implant structure having a biocompatible columella and a biocompatible porous pad secured to at least one of the ends of the columella.
The present invention is an improvement over such structure in that the biocompaptible porous material can be used to form the columella as well as each of its ends. The tissue ingrowth at the ends as well as along the columella can ensure the securing of the implant in the desired position. The structure of the present invention offers an improved structure, for example, for the transmission of sound vibrations in the ear because it can be made from a continuous, single block of material throughout which tissue may grow.
Also, during recent years, many efforts have been made to provide a simple, reversible, birth control method devoid j 1 / - 1 --107765~
of side effects. The use of the pill for birth control has such undesirable side effects. A positive method of sterili~
zation for women involves closing the fallopian tubes. This method is not reversible. The improved structure of the pre-sent invention, however, is especially adapted for implanta-tion in the end of the fallopian tubes opening into the uterus. Accordingly, a birth control method using the im-plant structure of this invention provides for reversibility when desired.
Also, certain physiological processes, such as fracture healing, heartbeat pacing, pain modulation, etc., can be con-trollably modified by passing electric current into a selected tissue of a living organism. A common means o~
passing electric current is to insert a noble metal electrode into the organism. Using such metal electrodes, it was found that the current density distribution to the selected tissue cannot be easily controlled.
A~cording to the present invention, there is provided a structure for in vivo implantation, the str~cture being an integral elongated body made of a resilient and distensible material an end of which body is enlarged whereby the remainder of the body forms a stem extending ~rom said enlarged end, said enlarged end and said stem being biocompatible, and at least a substantial portion of the material of which said enlarged end is made and at least a portion of the material of which said stem is made being a porous material which promotes living tissue to ~row into the pores of the material when implanted to secure the -structure in the implanted position.
The enlarged end and the stem are bicompatible and promote the ingrowth of living tissue. For most applications, the stem can have transverse dimensions between 0.25 and 3 millimeters, and the pad's largest dimension can be between 0.5 and 8 millimeters.
rw/
- . , ., . - . . , - . . .
.
The improved structure is adapted to be implanted in place of at least a portion of the bony chain of the middle ear. The stem is made sufficiently long to approximate the dimensions of the bony chain which it replaces, and, preferably, the surface pores of the center portion of the stem are closed.
Also, it is preferred that the surface pores of nearly the entire stem be closed when the structure is used as a plug for the fallopian tubes opening into the uterus. The pad has a dimension to allow sufficient tissue ingrowth to secure the structure in its implanted position. Added securing by ridges along the stem can be provided to resist movement of the structure from its implanted position.
A fluoroethylene propylene tube can be heat shrunk onto the stem for closing its surface pores. The end of the stem which extends beyond the tube can have one or more leaves, or the end can be enlarged in one dimension to form a flat, bulbous end portion with sufficient flexibility to bend at a substantially right angle to the longitudinal axis of the stem. A wire can be connected to an end of the stem. Also, a disc of porous ingrowth-promoting material can be bonded to one end of the stem.
In general, the pad will be frusto-conical in shape with its larger end facing outwardly. When the pad defines a shallow recess for receiving a portion of the bony chain jl/ _3~
.
therein, the improved structure can serve as a stapes replacement.
The porous material of the element forming the structure can have the property of conducting electric current. Therefore, such structure can serve as an improved in-vivo electrode, which is totally biocompatible. By virtue of having a substantial tissue ingrowth within its pores, such electrode offers a relatively-large contact area for current distribution between the electrode and the ingrown and thereto contiguous tissue.
In this manner, better control of electric current distribution between the electrode and the contiguous tissue can be achieved. -~
The objects and advantages of the invention will become better understood from the following description when taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a side elevational view of one shape of the improved structure of the present invention;
Pig. 2 is a sectional view taken along line 2-2 in Fig. l;
Fig. 3 is a side elevational view partly in section of the improved structure used for replacement of the stapes of the ear;
Fig. 3a is an end view taken along line 3a-3a on Fig. 3;
Fig. 4 is an elevational view, partly in section, of another form of implantable structure of the present invention;
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Fig. 5 is a sectional view taken along line 5-5 on Fig. 4;
Fi8. 6 is a side elevational view of another form of improved structure of the present invention;
Fig. 7 is an end view taken along line 7-7 in Fig. 6;
Fig. 8 is a side elevational view of another form of improved structure for use as a bony chain replacement in the ear;
Fig. 9 is a side elevational view of another form of implantable structure of the present invention;
Fig. 10 is side elevational view, partly in section, of another form of implantable structure of the present invention; and Fig. 11 is a side elevational view of still another modified form of implantable structure of the present invention.
In Fig. 1 is shown an implantable structure, generally designated as 10, which may be used either as a tube plug or as a bony chain substitute. Structure 10 includes an enlarged end 12, the preferred form of which is generally frusto-conlcal.
A stem 14 is integral with and extends from the central portion 13 of enlarged end 12. For most applications, the enlarged end's largest dimension is between 0.5 and 8 millimeters. Stem 14 has transverse dimensiQn6 between 0.25 and 3 millimeters.
At least a substantial por-jl/ -5-; :- ~ . ' :
~07~S'Z
ion of the surface of enlarged end 12 and the end of stem 14 away from enlarged end 12 are porous and of a material which promotes the ingrowth of tissue when the structure is used as a bony chain substitute. Only the surface of enlarged end 12 need be porous when the structure is used as a tube plug.
In applications in which structure 10 is to be used as a substitute for at least a portion of the bony chain of the ear, it is preferred that the outer surface of the center part of stem 14 be either compressed or otherwise treated to have limited porosity to avoid the ingrowth of tissue in and around its surface. When so compressed, the structure will have a non-uniform density distribution along its longitudinal axis.
Theimproved structure of the present invention is made of a body of material at least a portion of which is porous and which readily promotes the growth of living tissues into the pores and voids within the material. Our British Patent 1,390,445 describes a porous material of carbon fibers bonded by polytetrafluorethylene which can be used as the growth-promoting material. Other suitable growth-promoting materials are also disclosed in said British patent. The present invention also has application to other biocompatible growth-promoting materials which may be implanted and cause living tissues to ingrow.
-jl/ -6-107765~
The structure 16 illustrated in Fig. 3 is suitable as a stapes replacement for implantation in the ear. Such structure includes a frusto-conical enlarged end 18 and a stem 20. The structure 16 is similar to structure 10 except that the outer end 21 of enlarged end 18 now defines a concave recess 22 shaped to receive a portion of the bony chain therein when implanted.
The center portion 15 of the stem 20 has its surface pores at least partially closed as indicated by the shaded area 24.
Structure 10 can be cut out from a block of the ingrowth-promoting material and is completely porous, as shown. On theother hand, structure 16 can be developed from a cylindrical bloc~ of such material and the stem 20, except for its outer end 25, can be compressed to the shape illustrated in Fig. 3 to obtain the surface 24 with the pores closed or sufficiently restricted to prevent growth of tissue in and through such external surface 24. The end 25 of stem 20 may be trimmed to size, if desired. Preferably, the end 25 should not exceed the diameter of the recess of the vestibule to the inner ear but form a close fit therein. An unexpected advantage of structure ~ -16 formed by compression along the central portion 15 of the stem 20 is that such portion exhibits substantially no mechanical hysteresis. This mechanical characteristic can be advantageous in allowing the surgeon to more precisely shape the geometry of structure 16 relative to the middle ear architecture. -.
~'. ' jl/ -7-.~ ~ ' - ' ~ ' :10776S2 `
The closing of the pores, as represented by the shaded area 24 in Fig. 3, can be accomplished by pressure, pressure and heat, or any other suitable process, mechanical or chemical to ensure that the surface porosity is reduced sufficiently so that tissue growth cannot take place in and through the surface.
In addition to surface treatments, mechanical means such as shrink sleeves or pore-occluding coatings of medical grade materials, such as silicone rubber, polymeric dispersions, etc., can also be used as the pore~closing means, as hereinafter described.
In structure 26 shown in Figs. 4 and 5, the enlarged end 28 is frusto-conical in shape and has the stem 30 integral there-with and extending therefrom. The stem 30 is surrounded by a mechanical pore-closing means for closing the pores around its ~ -exterior, such as a tubular sleeve 32 which surrounds the exterior of stem 30 except for the outer end 33 thereof.
Tubular sleeve 32 is a biocompatible plastic tube which has been shrunk into its position surrounding stem 30, as shown.
Sleeve 32 and all materials used for in-vivo implants are to be completely biocompatible so that they do not cause any adverse reaction by the local tissues in and around the implantation site. An example of a suitable material for sleeve 32 is a fluorinated ethylene propylene tube which may be shrunk onto stem 30 at temperatures between 400F to 450F without damaging the porous material of structure 26. These sleeves are characterized as being good electrical insulators. -jl/ -8-.. : , ~ - . . , 107~76SZ
The structure 34 shown in Figs. 6 and 7 is similar to the structure 26 of Fig. 4, but has an enlarged flat end 36 into which a wire 38 is fixed. A sleeve 40 is shrunk about the central portion 41 of stem 42. The opposite ends 36 and 44 of the stem extend outwardly of sleeve 40. Structure 34 can be used either as a stapes replacement or as an electrode, as will be hereinafter set forth.
The structure 46 shown in Fig. 8 is substantially similar to structure 34, except that structure 46 is longer and is designed to be a replacement for the entire bony chain of the ear. Structure 46 includes an elongated flat end 48 integral with stem 50 about which a sleeve 52 is shrunk, leaving opposite ends 48 and 54 extending therefrom. End 48 is sufficiently thin to be flexible. End 48 can be easily bent so that it may be positioned at a substantially right angle to stem 50 and rest flat on the ear drum. With such geometric configuration, a large area of the porous material is exposed to the ear drum to ensure positive fixation by the growth of tissues in and through the pores of the material from which structure 46 is made.
The shrink fitting of the sleeves is done by any process well known in the art. For example, the shrink fitting can be accomplished by passing heated air over an expanded tubular sleeve 52 which has been placed in surrounding relation to the central part 51 of stem 50 for a relatively short period i 11 _9_ 1~7765Z
f time, for example, a few seconds. In such case, sufficient heat should be provided to exceed the setting temperature of the sleeve and the material of the sleeve remembers its original size and returns thereto, squeezing the central portion 51 of stem 50 as shown. The shrink sleeves are of a material which prevents living tissue from growing and attaching thereto.
The material also should be selected so that it does not cause appreciable dampening of the vibration transmission from the ear drum to the oval window of the inner ear.
A modified structure 56 is shown in Fig. 9. Stem 57 is provided with a shrink fit sleeve 58. One end of the stem 57 -~
projecting outwardly from sleeve 58 has been separated into a plurality of leaves 60. The leaves make an improved connection to the ear drum as compared to a single ended stem. The other projecting end 62 is as described in relation to end 44 of structure 34.
Another modified structure 63 is shown in Fig. 10. The stem 64 is surrounded by a shrink fit sleeve 66 over the central portion thereof. Only one end 68 of the stem projects outwardly of one end of the sleeve. The other end of the sleeve is flush with the stem and is covered by a disc 70 of a biocompatible porous material that promotes the ingrowth of tissue. A film 72, such as fluorinated ethylene propylene, bonds disc 70 to the end of sleeve 66 and to stem 64. Structure 63 can be made, if desired, without an end 68 projecting outwardly of sleeve 66.
j 1/ -10-1077~
A modified structure 74 is shown in Fig. 11 designed to be used as a Fallopian tube closure plug. It includes an enlarged end 76 and a stem 78 provided with external ridges 80 facing toward enlarged end 76. Ridges 80 are preferably formed in such a manner that their external surfaces have their pores closed, as represented by the shaded area 84, so as to prevent the ingrowth of tissue. Such ridges 80 can be formed by compressing or molding of stem 78 so long as the external pores on the ridges 80 are sufficiently closed to prevent tissue ingrowth.
When structure 74 is used as a plug for a tube, ridges 80 will provide sufficient resistance to the traveling contractions of the tube so that the plug will not be displaced from its desired position before the ingrowth of tissue has progressed sufficiently within the enlarged end 76 to secure the structure in place. Hence, ridges 80 serve to impede the displacement of the plug within the tube.
Thus, the structures of the present invention for implant-ation in the ear are characterized as having an elongate porous element with pore-closing means over a central part of the element with one or both ends of the element extending beyond the pore-closing means.
The porous material as described in said British patent No. 1,390,445 is a fairly good electric conductor and, therefore, electric current density would be distributed over the entire structure of this invention and would flow into the ingrown tissue. Therefore, each of the structures shown in j 1/ -11-. . - . .
Figs, l-ll can also serve as an implant current-carrying electrode. In its simplest form shown in Fig. 6, wire 38 would carry an electric current to the tissues in the pores of structure 34, while sleeve 40 would serve to insulate the tissues adjoining the sleeve, thereby providing selective current density distribution.
In a modified form, a wire 37 can be attached to end 33 of stem 30 (Fig. 4) with the aid of a thin biocompatible layer or film 35 of a noble metal such as gold or platinum. Wire 37 can also be mechanically secured to end 33. Similarly, each of the shown embodiments of the implant structure can be adapted -~
to serve as an implant electrode.
From the foregoing it will be appreciated that the present invention provides an improved structure for in-vivo implantation, such as a Fallopian tube plug, or in place of all or part of the bony chain between the ear drum and the inner ear, or as an implant electrode with selective current density distribution;
the structure is relatively simple to make and involves the use of a porous biocompatible material and relatively simple ~ 20 manufacturing proceclures.
., '~ ' .
jl/ -12-, :
.. . . . . . .
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A structure for in vivo implantation, the structure being an integral elongated body made of a resilient and distensible material an end of which body is enlarged whereby the remainder of the body forms a stem extending from said enlarged end, said enlarged end and said stem being bicompatible, and at least a substantial portion of the material of which said enlarged end is made and at least a portion of the material of which said stem is made being a porous material which promotes living tissue to grow into the pores of the material when implanted to secure the structure in the implanted position.
2. A structure according to claim 1, characterized in that said stem has transverse dimensions between 0.25 and 3 millimetres, and said enlarged end's largest dimension is between 0.5 and 8 millimetres.
3. A structure according to claim 1, characterized in that said structure is for implantation in place of of at least a portion of the bony chain of the middle ear, and said stem is sufficiently long to approximate the dimensions of the bony chain which it replaces.
4. A structure according to claim 1, characterized in that some of the surfaces pores of the stem are closed.
5. A structure according to Claim 1, characterized in that said structure is for implantation into the end of the Fallopian tubes opening into the uterus, and said stem has a length dimension sufficient to guide said structure in its implanted position.
6. A structure according to Claim 5, characterized in that the exterior of said stem comprises ridges to resist movement from its implanted position.
7. A structure according to Claim 4 characterized in that a sleeve is heat shrunk onto a portion of said stem for closing said surface pores, and a porous end of said stem projects from said tube.
8. A structure according to Claim 4 characterized in that a portion of said stem is coated with an occlusive coating thereby closing said surface pores.
9. A structure according to Claim 7 wherein said porous end of said stem a plurality of leaves.
10. A structure according to Claim 7 characterized in that said porous end of said stem has an enlarged dimension to form a flat, bulbous end portion with sufficient flexi-bility to bend at a substantially right angle to the longi-tudinal axis of said stem.
11. A structure according to claim 7, characterized in that a wire is connected to and extends from said porous end of said stem.
12. A structure according to claim 4, characterized in that a disc of porous ingrowth-promoting material is bonded to the other end of said stem.
13. A structure according to claim 1, characterized in that said enlarged end is frusto-conical in shape with the larger end thereof facing outwardly of said stem.
14. A structure according to claim 4, characterized in that said stem has a non-uniform density along its longi-tudinal axis.
15. A structure according to claim 13, characterized in that the outer end of said enlarged end defines a recess for receiving a portion of a bony chain therein when implanted.
16. A structure according to claim l, 2 or 3, characterized in that said material has the property of conducting electric current, and means are connected to said material for feeding electric current to said structure when it is implanted as an electrode.
17. A structure according to claim 4, 5 or 6 characterized in that said material has the property of conducting electric current, and means are connected to said material for feeding electric current to said structure when it is implanted as an electrode.
18. A structure according to claim 7, 8 or 9 characterized in that said material has the property of conducting electric current, and means are connected to said material for feeding electric current to said structure when it is implanted as an electrode.
19. A structure according to claim 10, 12 or 13 characterized in that said material has the property of conducting electric current, and means are connected to said material for feeding electric current to said structure when it is implanted as an electrode.
20. A structure according to claim 14 or 15 characterized in that said material has the property of conducting electric current, and means are connected to said material for feeding electric current to said structure when it is implanted as an electrode.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US60462475A | 1975-08-14 | 1975-08-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1077652A true CA1077652A (en) | 1980-05-20 |
Family
ID=24420356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA258,631A Expired CA1077652A (en) | 1975-08-14 | 1976-08-06 | Implantable structure |
Country Status (10)
| Country | Link |
|---|---|
| JP (2) | JPS5223892A (en) |
| AU (1) | AU509186B2 (en) |
| BR (1) | BR7605154A (en) |
| CA (1) | CA1077652A (en) |
| CH (1) | CH597845A5 (en) |
| DE (1) | DE2635863A1 (en) |
| FR (1) | FR2320724A1 (en) |
| GB (1) | GB1546107A (en) |
| NL (1) | NL182533C (en) |
| SE (1) | SE7608829L (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2378529A1 (en) * | 1975-10-28 | 1978-08-25 | Univ Case Western Reserve | Implantable electrical terminal for organic tissue - is porous to intermesh with tissue without formation of fibrous tissue encapsulation |
| US4301815A (en) * | 1980-01-23 | 1981-11-24 | Telectronics Pty. Limited | Trailing tine electrode lead |
| JPS5769855A (en) * | 1980-10-18 | 1982-04-28 | Kazuhiko Murata | Inserting tool in deferent duct |
| US4407302A (en) * | 1981-04-06 | 1983-10-04 | Telectronics Pty., Ltd. | Cardiac pacemaker electrode tip structure |
| US4408604A (en) * | 1981-04-06 | 1983-10-11 | Teletronics Pty, Limited | Porous pacemaker electrode tip |
| DE3211209A1 (en) * | 1982-03-26 | 1983-11-17 | Ernst Leitz Wetzlar Gmbh, 6330 Wetzlar | OWN BONE PROSTHESIS AND METHOD FOR THE PRODUCTION THEREOF |
| FR2565111B1 (en) * | 1984-05-29 | 1986-09-12 | Celsa Composants Electr Sa | ELECTRODE FOR HEART STIMULATION PROBE |
| DE3901796A1 (en) * | 1989-01-21 | 1990-07-26 | Heinz Kurz | OWN BONE PROSTHESIS |
| JPH02191450A (en) * | 1989-01-27 | 1990-07-27 | Kazuhiko Murata | Insert jig for body lumen |
| US6705323B1 (en) | 1995-06-07 | 2004-03-16 | Conceptus, Inc. | Contraceptive transcervical fallopian tube occlusion devices and methods |
| US6176240B1 (en) | 1995-06-07 | 2001-01-23 | Conceptus, Inc. | Contraceptive transcervical fallopian tube occlusion devices and their delivery |
| KR20200048824A (en) * | 2018-10-30 | 2020-05-08 | 부산대학교 산학협력단 | Eustachian tube plug device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE493526A (en) * | 1949-04-25 | |||
| US3314420A (en) * | 1961-10-23 | 1967-04-18 | Haeger Potteries Inc | Prosthetic parts and methods of making the same |
| US3473170A (en) * | 1967-07-05 | 1969-10-21 | Dow Corning | Middle ear prosthesis |
| FR1583971A (en) * | 1968-06-13 | 1969-12-12 | ||
| US3711869A (en) * | 1970-08-27 | 1973-01-23 | Richards Mfg Co | Prosthesis for the inner ear |
| US3909852A (en) * | 1973-12-17 | 1975-10-07 | Charles A Homsy | Implantable substitute structure for at least part of the middle ear bony chain |
-
1976
- 1976-07-19 AU AU16005/76A patent/AU509186B2/en not_active Expired
- 1976-07-23 GB GB30931/76A patent/GB1546107A/en not_active Expired
- 1976-08-06 BR BR7605154A patent/BR7605154A/en unknown
- 1976-08-06 SE SE7608829A patent/SE7608829L/en unknown
- 1976-08-06 CA CA258,631A patent/CA1077652A/en not_active Expired
- 1976-08-09 NL NLAANVRAGE7608857,A patent/NL182533C/en not_active IP Right Cessation
- 1976-08-09 CH CH1013076A patent/CH597845A5/xx not_active IP Right Cessation
- 1976-08-10 DE DE19762635863 patent/DE2635863A1/en active Granted
- 1976-08-13 FR FR7624768A patent/FR2320724A1/en active Granted
- 1976-08-13 JP JP51096182A patent/JPS5223892A/en active Pending
-
1985
- 1985-06-17 JP JP1985090203U patent/JPS6116108U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6228972Y2 (en) | 1987-07-25 |
| CH597845A5 (en) | 1978-04-14 |
| JPS5223892A (en) | 1977-02-23 |
| FR2320724B1 (en) | 1982-07-02 |
| AU509186B2 (en) | 1980-04-24 |
| GB1546107A (en) | 1979-05-16 |
| NL182533C (en) | 1988-04-05 |
| AU1600576A (en) | 1978-01-26 |
| BR7605154A (en) | 1977-08-02 |
| DE2635863A1 (en) | 1977-02-24 |
| DE2635863C2 (en) | 1987-11-19 |
| JPS6116108U (en) | 1986-01-30 |
| SE7608829L (en) | 1977-02-15 |
| NL7608857A (en) | 1977-02-16 |
| NL182533B (en) | 1987-11-02 |
| FR2320724A1 (en) | 1977-03-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |