Combination stylet and sheath for an electrode array

• US 20070073371A1
• Filed: 11/27/2006
• Published: 03/29/2007
• Est. Priority Date: 10/04/2000
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Gibson, Peter, Treaba, Claudiu, Parker, John, Dadd, Fysh, Darley, Ian
• Granted Patent: US 7,822,487 B2
• Time in Patent Office: Days
• US Class Current: 607/137
• CPC Class Codes: A61F 11/20 Ear surgery
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

A cochlear implant electrode assembly device (10) comprising an elongate electrode carrier member (11), a stiffening element (15), and a stiffening sheath (16) that at least partially envelops the elongate member (11). The member (11) is made of a resiliently flexible first material and has a plurality of electrodes (12) mounted thereon. The member (11) has a first configuration that allows it to be inserted into an implantee'"'"'s cochlea (30). The member (11) also has a second configuration wherein the member is curved to match an inside surface of the cochlea (30), and at least one intermediate configuration between the first and second configurations. Both the stiffening element (15) and sheath (16) are made of a material that is relatively stiffer than the member (11). The stiffening element (15) and the stiffening sheath (16) in combination bias the elongate member (11) into the first configuration. If either the stiffening element (15) or the stiffening sheath (16) is removed or deactivated, the elongate member (11) adopts an intermediate configuration.

Claims

1-27. -27. (canceled)

28. A method for inserting an electrode array into a cochlea comprising the steps of:

stiffening an elongate member in a first configuration using a first and second biasing means, wherein the elongate member has a plurality of electrodes mounted thereon and the elongated member is made from a memory material capable of a second configuration;

modifying the first biasing means while inserting the elongate member into the cochlea; and

removing the second biasing means from the elongate member such that the elongate member assumes the second configuration when insertion into the cochlea is completed.

29. The method of claim 28, further comprising the step of positioning the elongate member during insertion to apply preselected tissue stimulation with the plurality of electrodes.

30. The method of claim 28, wherein the first configuration is substantially straight.

31. The method of claim 28, wherein the second configuration is curved.

32. The method of claim 28, wherein the first biasing means is least partially envelopes the elongate member.

33. The method of claim 32, wherein the first biasing means is a sheath.

34. The method of claim 28, wherein modifying the first biasing means comprises dissolving the first biasing means.

35. The method of claim 28, wherein modifying the first biasing means comprises deactivating the first biasing means.

36. The method of claim 28, wherein modifying the first biasing means comprises bending the first biasing means using heat.

37. The method of claim 36, wherein the first biasing means is made from a heat sensitive material.

38. The method of claim 28, wherein the second biasing means is a stylet partially in a lumen of the elongate member.

39. The method of claim 28, wherein the first biasing means is modified before the second biasing means is removed.

40. The method of claim 28, further comprising the step of inserting the elongated member into the cochlea when the elongated member is in the first configuration.

41. The method of claim 28, wherein the elongated member may be partially outside the cochlea when insertion into the cochlea is completed.

42. An electrode array for an implantable hearing prosthesis comprising:

an elongate member having a plurality of electrodes mounted thereon made from a resiliently flexible material;

a tip region mounted on a distal end of the elongate member, the tip region made from one or more materials that collectively are relatively less stiff than the elongate member; and

a stiffening sheath that surrounds the tip region, wherein the stiffening sheath is a material that is relatively stiffer than the tip region.

43. The electrode array of claim 42, wherein the stiffening sheath dissolves upon insertion into a cochlea.

44. The electrode array of claim 42, wherein the tip region comprises metallic particles.

45. The electrode array of claim 44, wherein the metallic particles are denser towards a proximal end of the tip region than the distal end of the tip region.

46. The electrode array of claim 44, wherein the metallic particles vary throughout the tip region.

47. The electrode array of claim 42, wherein the tip region is detachable from the elongate member.

48. The electrode array of claim 42, wherein the tip region tapers towards a distal end.

49. The electrode array of claim 42, further comprising a stiffening element inserted into a lumen of the elongate member.

50. An electrode array for an implantable hearing prosthesis comprising:

an elongate member having a plurality of electrodes mounted thereon and having a first configuration that allows the elongate member to be inserted into an implantee'"'"'s body, a second configuration wherein the elongate member is adapted to apply preselected tissue stimulation with the electrodes, and at least one intermediate configuration between the first and second configurations;

a stiffening element at least partially inserted in a lumen of the elongate member; and

a stiffening sheath at least partially enveloping the elongate member;

wherein the stiffening element and the stiffening sheath in combination bias the elongate member into the first configuration and further wherein either the stiffening element or the stiffening sheath is used alone to bias the elongate member into the at least one intermediate configuration.

51. The electrode array of claim 50, wherein the second configuration is curved.

52. The electrode array of claim 50, wherein the first configuration is substantially straight.

53. The electrode array of claim 50, wherein the stiffening element is removed from the lumen thereby allowing the stiffening sheath to bias the elongate member into the at least one intermediate configuration.

54. The electrode array of claim 53, wherein the stiffening sheath is removed to allow the elongate member to adopt the second configuration when inserted in the cochlea.

55. The electrode array of claim 53, wherein the stiffening sheath dissolves to allow the elongate member to adopt the second configuration when inserted in the cochlea.

56. The electrode array of claim 53, wherein the stiffening sheath bends to allow the elongate member to adopt the second configuration when inserted in the cochlea.

57. The electrode array of claim 50, wherein the stiffening element dissolves in the lumen thereby allowing the stiffening sheath to bias the elongate member into the at least one intermediate configuration.

58. The electrode array of claim 57, wherein the stiffening sheath is removed to allow the elongate member to adopt the second configuration when inserted in the cochlea.

59. The electrode array of claim 57, wherein the stiffening sheath dissolves to allow the elongate member to adopt the second configuration when inserted in the cochlea.

60. The electrode array of claim 57, wherein the stiffening sheath bends to allow the elongate member to adopt the second configuration when inserted in the cochlea.

61. The electrode array of claim 50, wherein the stiffening element bends in the lumen thereby allowing the stiffening sheath to bias the elongate member into the at least one intermediate configuration.

62. The electrode array of claim 61, wherein the stiffening sheath is removed to allow the elongate member to adopt the second configuration when inserted in the cochlea.

63. The electrode array of claim 61, wherein the stiffening sheath dissolves to allow the elongate member to adopt the second configuration when inserted in the cochlea.

64. The electrode array of claim 61, wherein the stiffening sheath bends to allow the elongate member to adopt the second configuration when inserted in the cochlea.

65. The electrode array of claim 50, wherein the stiffening sheath is removed from the elongate member thereby allowing the stiffening element to bias the elongate member into the at least one intermediate configuration.

66. The electrode array of claim 65, wherein the stiffening element is removed from the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

67. The electrode array of claim 65, wherein the stiffening element dissolves in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

68. The electrode array of claim 65, wherein the stiffening element bends in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

69. The electrode array of claim 50, wherein the stiffening sheath dissolves thereby allowing the stiffening sheath to bias the elongate member into the at least one intermediate configuration.

70. The electrode array of claim 69, wherein the stiffening element is removed from the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

71. The electrode array of claim 69, wherein the stiffening element dissolves in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

72. The electrode array of claim 69, wherein the stiffening element bends in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

73. The electrode array of claim 50, wherein the stiffening sheath bends thereby allowing the stiffening sheath to bias the elongate member into the at least one intermediate configuration.

74. The electrode array of claim 73, wherein the stiffening element is removed from the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

75. The electrode array of claim 73, wherein the stiffening element dissolves in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

76. The electrode array of claim 73, wherein the stiffening element bends in the lumen to allow the elongate member to adopt the second configuration when inserted in the cochlea.

77. The electrode array of claim 50, wherein the elongate member is made from a material having a memory shape of the second configuration.