COCHLEAR IMPLANT ASSEMBLY

• US 20090165921A1
• Filed: 12/06/2006
• Published: 07/02/2009
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Kaiser, Thomas
• Granted Patent: US 8,460,562 B2
• Time in Patent Office: Days
• US Class Current: 156/65
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

A method of forming electrode structures comprising a plurality of electrode pads and a plurality of electrically conducting wires extending from the electrode pads. The method comprises coating an electrode structure with a relatively electrically insulating material, arranging each of the electrode pads in a first arrangement; arranging the wires relative to each other to provide a sufficient gap of separation between neighboring wires; securing the wires to a remotely positioned anchor member to preserve a gap of separation between neighbouring wires, and applying a coating of relatively electrically insulating material to the electrode structure.

Claims

1-83. -83. (canceled)

84. A method of coating an electrode structure with an electrically insulating material, the electrode structure comprising a plurality of electrode pads and a plurality of electrically conducting wires, at least one wire extending from at least one of the electrode pads, the method comprising:

arranging each of the electrode pads in a first arrangement;

arranging the wires relative to each other to provide a gap of separation between neighboring wires;

securing the wires to a frame member to preserve said gap of separation between neighboring wires; and

applying a coating of electrically insulating material to said electrode structure,

wherein said gap is sufficient to enable said application of said coating of electrically insulating material to all surfaces of said wires without webbing between adjacent wires.

85. The method of claim 84, wherein each of the electrode pads are arranged in an array.

86. The method of claim 85, wherein said array comprises a single row or column of electrode pads.

87. The method of claim 85, wherein said array comprises a plurality of rows or columns of electrode pads.

88. The method of claim 86, wherein each of said rows and/or columns of electrode pads is arranged such that the electrode pads are aligned with respect to each other.

89. The method of claim 86, wherein said rows or columns of electrode pads are arranged such that at least some of the respective electrode pads are unaligned with respect to each other.

90. The method of claim 84, wherein the electrode pads are substantially rectangular in shape.

91. The method of claim 84, wherein said electrode pads comprise a pair of diametrically opposed ends connected by a pair of diametrically opposed sides.

92. The method of claim 91, wherein said diametrically opposed ends are shorter in length than said diametrically opposed sides of said electrode pads.

93. The method of claim 92, wherein said pads are arranged in a row such that said diametrically opposed ends of each electrode pad are aligned with respective diametrically opposed ends of other electrode pads in said row.

94. The method of claim 93, wherein at least one electrically conducting wire extends from at least one of said diametrically opposed ends of at least one of the electrode pads.

95. The method of claim 84, wherein at least one of said electrode pads is substantially circular or oval in shape.

96. The method of claim 95, wherein at least one electrically conducting wire is arranged to extend from a peripheral edge of at least one of the electrode pads.

97. The method of claim 84, wherein said electrode structure is formed from a single sheet of relatively electrically conducting material.

98. The method of claim 97, wherein said single sheet of electrically conducting material is applied to a carrier or substrate to facilitate handling of said electrically conductive material to form said electrode structure.

99. The method of claim 98, wherein said electrically conductive material is a foil of relatively electrically conductive material.

100. The method of claim 99, wherein said electrically conductive material comprises one or more of platinum or gold.

101. The method of claim 98, wherein said substrate comprises a sheet of copper.

102. The method of claim 84, wherein said electrode structure is formed by selectively removing selected parts of said electrically conductive material and said substrate.

103. The method of claim 102, wherein said electrode pads and associated wires are formed integral with each other.

104. The method of claim 103, wherein each said wire has a proximal end and a distal end.

105. The method of claim 104, wherein said proximal end of each wire is connected to said electrode pad, and said distal end of each wire is secured to said frame member.

106. The method of claim 105, wherein said connection of said proximal end of said wire with said electrode pad is an integral connection.

107. The method of claim 102, wherein said selected parts of said electrically conductive material and said substrate are removed by one or more of either electrical discharge machining, etching and cutting.

108. The method of claim 107, wherein a portion of said substrate acts as an electrode support upon which said electrode pads are arranged.

109. The method of claim 108, wherein the step of arranging said electrode pads in a first arrangement comprises:

removing selected parts of said electrically conductive material to form said electrode pads; and

retaining a portion of said substrate as a support for said electrode pads.

110. The method of claim 109, wherein said wires are formed such that they are free from said substrate.

111. The method of claim 92, wherein the step of arranging said wires relative to each other to provide a gap of separation between neighboring wires comprises:

extending each of said wires from said electrode pads at an angle to said diametrically opposed ends of said electrode pads.

112. The method of claim 96, wherein the step of arranging said wires relative to each other to provide a gap of separation between neighboring wires comprises:

extending said wires tangentially from said edge of said electrode pads.

113. The method of claim 111, wherein said electrode pads are arranged in a row and said wires extend from alternate opposing ends or edges of adjacent electrode pads in said row.

114. The method of claim 113, wherein said gap of separation between neighboring wires is a gap between said wires that enables said coating of electrically insulating material to fully coat said wires without causing webbing between said wires.

115. The method of claim 84, wherein the step of securing said wires to a frame member comprises:

forming said electrode structure such that said distal end of each wire is integrally formed with said frame member.

116. The method of claim 115, wherein said frame member comprises:

a portion of said sheet of electrically conductive material and substrate.

117. The method of claim 116, wherein said frame member is in the form of a frame portion comprising a peripheral region of said sheet of electrically conductive material and substrate.

118. The method of claim 117, wherein said frame portion comprises a rectangular frame portion.

119. The method of claim 117, wherein said frame portion comprises a substantially circular or oval frame portion.

120. The method of claim 84, wherein said wires are arranged such that they extend from said electrode pads in planes substantially parallel to a plane in which said electrode pads are arranged.

121. The method of claim 120, wherein said wires extending from adjacent pads in said row, extend from opposing ends or edges of said electrode pads.

122. The method of claim 121, wherein said electrode pads are arranged on a central plane and said wires extend along parallel planes on either side of said central plane.

123. The method of claim 120, wherein arranging the wires relative to each other to provide a gap of separation between neighboring wires comprises:

elevating adjacent wires such that they are secured to said frame member at different heights.

124. The method of claim 123, wherein securing said wires to said frame member comprises:

individually clamping the distal ends of each said wire.

125. The method of claim 84, wherein said electrode pads and associated wires are each formed separately.

126. The method of claim 125, wherein said electrode pads are formed from a sheet of conductive material.

127. The method of claim 126, wherein said sheet of conductive material is worked to create a desired shape of said electrode pads.

128. The method of claim 127, wherein said sheet of conductive material is punched, or cut or otherwise abraded to create said electrode pads.

129. The method of claim 125, wherein said proximal end of said wires are attached to said respective electrode pad by welding.

130. The method of claim 129, wherein arranging the electrode pads in a first arrangement comprises:

forming said electrode pads such that they are each arranged in a row and connected by a portion of conductive material.

131. The method of claim 130, further comprising:

following said step of applying a coating of electrically insulating material to said electrode structure, removing that portion of conductive material connecting each of said electrode pads, thereby separating each of the electrode pads.

132. The method of claim 131, wherein said wires are arranged by extending each wire from its respective electrode pad at an angle to said plane at which said electrode pad is arranged.

133. The method of claim 131, wherein said wires are arranged such that they extend laterally from said electrode pads.

134. The method of claim 132, wherein securing the electrically conducting wires to said frame member comprises:

connecting the distal end of each wire to one or more sacrificial members.

135. The method of claim 134, wherein said distal end of said wires are welded to said one or more sacrificial members in a spaced apart arrangement to form said gap between adjacent wires.

136. The method of claim 135, wherein said one or more sacrificial members are in the form of a plate.

137. The method of claim 136, wherein each plate is made from a suitable material to facilitate welding of the distal end of the wire thereto.

138. The method of claim 84, wherein prior to applying the coating of electrically insulating material to the electrode structure, portions of the electrode structure are masked to prevent coating of the masked portions.

139. The method of claim 138, wherein what are to become the stimulating surfaces of the electrode pads are masked to prevent them from being coated with the electrically insulating material.

140. The method of claim 139, wherein the masking is performed by applying a suitable tape or laminar material to the surface of the electrode structure, which is later removed following the coating step.

141. The method of claim 84, wherein the step of applying the coat of relatively electrically insulating material to the electrode structure comprises:

employing vacuum deposition techniques to coat the electrode structure.

142. The method of claim 141, wherein the electrically insulating material is parylene.

143. The method of claim 142, wherein the parylene is coated on said electrode structure by vapour-phase deposition.

144. The method of claim 84, wherein said step of applying said coat of electrically insulating material to said electrode structure comprises one of either dip coating and spray coating.

145. An electrode structure formed using the method of claim 84.

146. A method of forming an electrode structure comprising a plurality of electrode pads and a plurality of electrically conducting wires extending from the electrode pads, for use in an electrode array of an implantable medical device, the method comprising:

attaching a sheet of conductive material to a sheet of carrier material;

working said sheet to remove predetermined portions thereof to form a plurality of electrode pads of conductive material supported on an electrode support of carrier material, a frame member; and

a plurality of wires of relatively electrically conductive material, at least one wire connecting an electrode pad to the frame member;

coating said worked sheet with an electrically insulating material; and

removing said electrode support.

147. The method of claim 146, further comprising the step of:

removing said frame member.

148. The method of claim 146, wherein the step of attaching the sheet of conductive material to the sheet of carrier material is performed by roll bonding.

149. The method of claim 146, wherein the step of attaching the sheet of conductive material to the sheet of carrier material is performed by an adhesive.

150. The method of claim 146, wherein the sheet of conductive material is a sheet of platinum, iridium, gold, tungsten, tantalum, niobium, or an alloy with at least one of these metals.

151. The method of claim 146, wherein the sheet of carrier material is a sheet of metal or alloy, such as copper or iron or their alloys.

152. The method of claim 146, wherein the sheet of carrier material is a plastics material.

153. The method of claim 146, wherein the sheet is worked via electrical discharge machining (EDM), etching or cutting, to remove portions of the sheet of electrical conductive material and/or the sheet of carrier material as desired.

154. The method of claim 153, wherein the frame member extends along an edge or edges of the sheet.

155. The method of claim 154, wherein the electrode support of carrier material extends between two sides of the frame member to provide structural integrity to the worked sheet.

156. The method of claim 155, wherein the electrode pads are formed along the surface of the electrode support of carrier material.

157. The method of claim 156, wherein each pad is equally spaced from its adjacent pad along the surface of the electrode support.

158. The method of claim 146, wherein each wire connecting each pad to said frame member is formed integral with the conductive material of said electrode pads and said frame member.

159. The method of claim 146, wherein the step of coating the worked sheet with said electrically insulating material comprises:

placing said worked sheet in a vapor deposition chamber; and

depositing said electrically insulating material onto the worked sheet.

160. The method of claim 159, wherein the relatively electrically insulative material is parylene

161. The method of claim 160, wherein the parylene is coated on the worked sheet via a vapour deposition polymerisation process.

162. The method of to claim 146, wherein the step of coating the worked sheet with said electrically insulating material comprises:

spraying the relatively electrically insulative material over the worked sheet.

163. The method of claim 146, wherein the step of coating the worked sheet with said electrically insulating material comprises:

dipping the worked sheet into the relatively electrically insulative material.

164. The method of claim 146, wherein prior to the coating step, portions of the worked sheet are masked to prevent coating the portions with said electrically insulative material.

165. The method of claim 164, wherein the masking is performed by applying a suitable tape or other suitable laminar material to the surface of the worked sheet.

166. The method of claim 146, wherein the step of removing said electrode support and said frame member comprises etching said carrier material from the conductive material and cutting the wires adjacent frame member.

167. An electrode structure formed using the method of claim 146.