Source: http://www.freepatentsonline.com/y2002/0042629.html
Timestamp: 2019-09-18 09:14:02
Document Index: 65114389

Matched Legal Cases: ['art.\n12', 'art.\n60', 'art.\n61', 'art.\n62', 'art.\n63', 'art.\n64', 'art.\n102', 'art.\n103', 'art.\n104', 'art.\n105', 'art.\n106', 'art.\n133', 'art.\n134', 'art.\n135', 'art.\n136', 'art.\n137', 'art.\n144', 'art.\n145', 'art.\n146', 'art.\n147', 'art.\n148', 'art.\n176', 'art.\n177', 'art.\n178', 'art.\n179', 'art.\n180', 'art.\n187', 'art.\n188', 'art.\n189', 'art.\n190', 'art.\n191', 'art.\n216', 'art.\n217', 'art.\n218', 'art.\n219']

Cardioverter-defibrillator having a focused shocking area and orientation thereof - Cameron Health, Inc.
United States Patent Application 20020042629
09/940273
Download PDF 20020042629 PDF help
20090226015 METHODS, DEVICES AND SYSTEMS USING SIGNAL PROCESSING ALGORITHMS TO IMPROVE SPEECH INTELLIGIBILITY AND LISTENING COMFORT September, 2009 Zeng et al.
20090099633 SINGLE USE ICE PACK April, 2009 Bowen et al.
1. An implantable cardioverter defibrillator for subcutaneous positioning between the third rib and the twelfth rib within a patient, the implantable cardioverter-defibrillator comprising: a housing; an electrical circuit located within the housing; a first electrode coupled to the electrical circuit and located on the housing; and a second electrode coupled to the electrical circuit.
2. The implantable cardioverter-defibrillator of claim 1, wherein at least a portion of the housing is non-planar.
6. The implantable cardioverter-defibrillator of claim 1, wherein the housing further comprises a depth, wherein the depth of the housing is less than approximately 15 millimeters.
11. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode can emit an effective field strength for shocking the patient's heart.
12. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 25 J to approximately 50 J.
13. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 50 J to approximately 75 J.
14. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 75 J to approximately 100 J.
15. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 100 J to approximately 125 J.
16. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 125 J to approximately 150 J.
17. The implantable cardioverter-defibrillator of claim 11, wherein the effective field strength for shocking the patient's heart is approximately 150 J.
18. The implantable cardioverter-defibrillator of claim 11, wherein the first electrode can further receive physiological information.
19. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode can receive physiological information.
20. The implantable cardioverter-defibrillator of claim 1, wherein at least a portion of the first electrode is non-planar.
21. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially ellipsoidal in shape.
22. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially thumbnail shaped.
23. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially circular in shape.
24. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially square in shape.
25. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially rectangular in shape.
26. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is substantially spade shaped.
27. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is less than approximately 2000 square millimeters in area.
28. The implantable cardioverter-defibrillator of claim 27, wherein the first electrode is between approximately 750 square millimeters to approximately 1000 square millimeters in area.
29. The implantable cardioverter-defibrillator of claim 27, wherein the first electrode is between approximately 500 square millimeters to approximately 750 square millimeters in area.
30. The implantable cardioverter-defibrillator of claim 27, wherein the first electrode is between approximately 250 square millimeters to approximately 500 square millimeters in area.
31. The implantable cardioverter-defibrillator of claim 27, wherein the first electrode is between approximately 100 square millimeters to approximately 250 square millimeters in area.
32. The implantable cardioverter-defibrillator of claim 1, wherein at least a portion of the housing surrounding the electrode is ceramic.
33. The implantable cardioverter-defibrillator of claim 1, wherein the second electrode is located on the housing.
34. The implantable cardioverter-defibrillator of claim 1, wherein the housing further comprises a first end and a second end, wherein the first electrode is located on the first end of the housing and the second electrode is located on the second end of the housing.
35. The implantable cardioverter-defibrillator of claim 1, wherein the second electrode is disposed on a lead.
36. The implantable cardioverter-defibrillator of claim 35, wherein the lead is approximately 5 centimeters to approximately 55 centimeters in length.
37. The implantable cardioverter-defibrillator of claim 36, wherein the lead is approximately 5 centimeters to approximately 15 centimeters in length.
38. The implantable cardioverter-defibrillator of claim 36, wherein the lead is approximately 15 centimeters to approximately 25 centimeters in length.
39. The implantable cardioverter-defibrillator of claim wherein the lead is approximately 25 centimeters to approximately 35 centimeters in length.
40. The implantable cardioverter-defibrillator of claim 36, wherein the lead is approximately 35 centimeters to approximately 45 centimeters in length.
41. The implantable cardioverter-defibrillator of claim 36, wherein the lead is approximately 45 centimeters to approximately 55 centimeters in length.
42. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is positioned approximately in the anterior portion of a patient's ribcage.
43. The implantable cardioverter-defibrillator of claim 1, wherein the first electrode is positioned approximately in a parasternal region of the patient.
44. The implantable cardioverter-defibrillator of claim 43, wherein the first electrode is positioned approximately in a left parasternal region of the patient.
45. The implantable cardioverter-defibrillator of claim 1, wherein the second electrode is positioned approximately in a posterior region of a patient's ribcage.
46. The implantable cardioverter-defibrillator of claim 1, wherein the second electrode is positioned approximately in a paraspinal region of the patient.
47. The implantable cardioverter-defibrillator of claim 1, wherein the second electrode is positioned approximately in a parascapular region of the patient.
48. The implantable cardioverter-defibrillator of claim 1, wherein the implantable cardioverter-defibrillator further comprises: a first vector end point defining the position of the first electrode; a second vector end point defining the position of the second electrode; an origin defining a position approximately within the patent's heart and between the first vector end point and the second vector end point; and a depolarization vector, wherein the depolarization vector defines an angle of separation between the first vector end point and the second vector end point with respect to the origin.
49. The implantable cardioverter-defibrillator of claim 48, wherein the angle of separation is between approximately 30 degrees and approximately 90 degrees.
50. The implantable cardioverter-defibrillator of claim 48, wherein the angle of separation is between approximately 90 degrees and approximately 120 degrees.
51. The implantable cardioverter-defibrillator of claim 48, wherein the angle of the separation is between approximately 120 degrees and approximately 150 degrees.
52. The implantable cardioverter-defibrillator of claim 48, wherein the angle of the separation is between approximately 150 degrees and approximately 180 degrees.
53. An implantable cardioverter-defibrillator for subcutaneous positioning between the third rib and the twelfth rib within a patient, the implantable cardioverter-defibrillator comprising: a housing; an electrical circuit located within the housing; a first electrode coupled to the electrical circuit, wherein the first electrode is positioned at a first point with respect to the patient's heart; and a second electrode coupled to the electrical circuit, wherein the second electrode is positioned at a second point that is substantially on the opposite side of the patient's heart from the first point.
54. The implantable cardioverter-defibrillator of claim 53, wherein at least a portion of the housing is non-planar.
55. The implantable cardioverter-defibrillator of claim 53, wherein the housing has a length of approximately 3 centimeters to approximately 30 centimeters.
56. The implantable cardioverter-defibrillator of claim 53 , wherein the housing has a length of approximately 5 centimeters to approximately 20 centimeters.
57. The implantable cardioverter-defibrillator of claim 53, wherein the housing has a length of approximately 5 centimeters to approximately 12 centimeters.
58. The implantable cardioverter-defibrillator of claim 53, wherein the housing further comprises a depth, wherein the cardioverter-defibrillator is less than approximately 15 millimeters.
59. The implantable cardioverter-defibrillator of claim 53, wherein the electrical circuit can provide monophasic waveform cardioversion-defibrillation for a patient's heart.
60. The implantable cardioverter-defibrillator of claim 53, wherein the electrical circuit can provide multiphasic waveform cardioversion-defibrillation for a patient's heart.
61. The implantable cardioverter-defibrillator of claim 60, wherein the electrical circuit can provide biphasic waveform cardioversion-defibrillation for a patient's heart.
62. The implantable cardioverter-defibrillator of claim 60, wherein the electrical circuit can provide triphasic waveform cardioversion-defibrillation for a patient's heart.
63. The implantable cardioverter-defibrillator of claim 53, wherein the first electrode can emit an effective field strength for shocking the patient's heart.
64. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 25 J to approximately 50 J.
65. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 50 J to approximately 75 J.
66. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 75 J to approximately 100 J.
67. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 100 J to approximately 125 J.
68. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 125 J to approximately 150 J.
69. The implantable cardioverter-defibrillator of claim 63, wherein the effective field strength for shocking the patient's heart is approximately 150 J.
70. The implantable cardioverter-defibrillator of claim 63, wherein the first electrode can further receive sensory information.
71. The implantable cardioverter-defibrillator of claim 53, wherein the first electrode can receive sensory information.
72. The implantable cardioverter-defibrillator of claim 53, wherein at least a portion of the first electrode is non-planar.
73. The implantable cardioverter-defibrillator of claim 53, wherein the first electrode is less than approximately 1000 square millimeters in area.
74. The implantable cardioverter-defibrillator of claim 53, wherein at least a portion of the housing surrounding the electrode is ceramic.
75. The implantable cardioverter-defibrillator of claim 53, wherein the second electrode is located on the housing.
76. The implantable cardioverter-defibrillator of claim 53, wherein the housing further comprises a first end and a second end, wherein the first electrode is located on the first end of the housing and the second electrode is located on the second end of the housing.
77. The implantable cardioverter-defibrillator of claim 53, wherein the second electrode is disposed on a lead.
78. The implantable cardioverter-defibrillator of claim 77, wherein the lead is approximately 5 centimeters to approximately 55 centimeters in length.
79. The implantable cardioverter-defibrillator of claim 78, wherein the lead is approximately 5 centimeters to approximately 15 centimeters in length.
80. The implantable cardioverter-defibrillator of claim 78, wherein the lead is approximately 15 centimeters to approximately 25 centimeters in length.
81. The implantable cardioverter-defibrillator of claim 78, wherein the lead is approximately 25 centimeters to approximately 35 centimeters in length.
82. The implantable cardioverter-defibrillator of claim 78, wherein the lead is approximately 35 centimeters to approximately 45 centimeters in length.
83. The implantable cardioverter-defibrillator of claim 78, wherein the lead is approximately 45 centimeters to approximately 55 centimeters in length.
84. The implantable cardioverter-defibrillator of claim 53, wherein the first point is approximately in the anterior portion of a patient's ribcage.
85. The implantable cardioverter-defibrillator of claim 53, wherein the first point is approximately in a parasternal region of the patient.
86. The implantable cardioverter-defibrillator of claim 85, wherein the first point is approximately in a left parasternal region of the patient.
87. The implantable cardioverter-defibrillator of claim 53, wherein the second point is approximately in a posterior region of a patient's ribcage.
88. The implantable cardioverter-defibrillator of claim 53, wherein the second point is approximately in a paraspinal region of the patient.
89. The implantable cardioverter-defibrillator of claim 53, wherein the second point is approximately in a parascapular region of the patient.
90. The implantable cardioverter-defibrillator of claim 53, wherein the implantable cardioverter-defibrillator further comprises: a first vector end point defining the position of the first electrode; a second vector end point defining the position of the second electrode; an origin defining a position approximately within the patient's heart and between the first vector end point and the second vector end point; and a depolarization vector, wherein the depolarization vector defines an angle of separation between the first vector end point and the second vector end point with respect to the origin.
91. The implantable cardioverter-defibrillator of claim 90, wherein the angle of separation is between approximately 30 degrees and approximately 90 degrees.
92. The implantable cardioverter-defibrillator of claim 90, wherein the angle of separation is between approximately 90 degrees and approximately 120 degrees.
93. The implantable cardioverter-defibrillator of claim 90, wherein the angle of separation is between approximately 120 degrees and approximately 150 degrees.
94. The implantable cardioverter-defibrillator of claim 90, wherein the angle of separation is between approximately 150 degrees and approximately 180 degrees.
95. An implantable cardioverter defibrillator for subcutaneous positioning between the third rib and the twelfth rib within a patient, the implantable cardioverter-defibrillator comprising: a housing; an electrical circuit located within the housing; a first electrode coupled to the electrical circuit; and a second electrode coupled to the electrical circuit, wherein the second electrode is positioned approximately 30 degrees to approximately 180 degrees, with respect to the patient's heart, apart from the first electrode.
96. The implantable cardioverter-defibrillator of claim 95, wherein at least a portion of the housing is non-planar.
97. The implantable cardioverter-defibrillator of claim 95, wherein the housing has a length of approximately 3 centimeters to approximately 30 centimeters.
98. The implantable cardioverter-defibrillator of claim 95, wherein the housing has a length of approximately 5 centimeters to approximately 20 centimeters.
99. The implantable cardioverter-defibrillator of claim 95, wherein the housing has a length of approximately 5 centimeters to approximately 12 centimeters.
100. The implantable cardioverter-defibrillator of claim 95, wherein the housing further comprises a depth, wherein the cardioverter-defibrillator is less than approximately 15 millimeters.
101. The implantable cardioverter-defibrillator of claim 95, wherein the electrical circuit can provide monophasic waveform cardioversion-defibrillation for a patient's heart.
102. The implantable cardioverter-defibrillator of claim 95, wherein the electrical circuit can provide multiphasic waveform cardioversion-defibrillation for a patient's heart.
103. The implantable cardioverter-defibrillator of claim 102, wherein the electrical circuit can provide biphasic waveform cardioversion-defibrillation for a patient's heart.
104. The implantable cardioverter-defibrillator of claim 102, wherein the electrical circuit can provide triphasic waveform cardioversion-defibrillation for a patient's heart.
105. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode can emit an effective field strength for shocking the patient's heart.
106. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 25 J to approximately 50 J.
107. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 50 J to approximately 75 J.
108. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 75 J to approximately 100 J.
109. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 100 J to approximately 125 J.
110. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 125 J to approximately 150 J.
111. The implantable cardioverter-defibrillator of claim 105, wherein the effective field strength for shocking the patient's heart is approximately 150 J.
112. The implantable cardioverter-defibrillator of claim 105, wherein the first electrode can further receive sensory information.
113. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode can receive sensory information.
114. The implantable cardioverter-defibrillator of claim 95, wherein at least a portion of the first electrode is non-planar.
115. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is less than approximately 2000 square millimeters in area.
116. The implantable cardioverter-defibrillator of claim 95, wherein at least a portion of the housing surrounding the electrode is ceramic.
117. The implantable cardioverter-defibrillator of claim 95, wherein the second electrode is located on the housing.
118. The implantable cardioverter-defibrillator of claim 95, wherein the housing further comprises a first end and a second end, wherein the first electrode is located on the first end of the housing and the second electrode is located on the second end of the housing.
119. The implantable cardioverter-defibrillator of claim 95, wherein the second electrode is disposed on a lead.
120. The implantable cardioverter-defibrillator of claim 119, wherein the lead is approximately 5 centimeters to approximately 55 centimeters in length.
121. The implantable cardioverter-defibrillator of claim wherein the lead is approximately 5 centimeters to approximately 15 centimeters in length.
122. The implantable cardioverter-defibrillator of claim 120, wherein the lead is approximately 15 centimeters to approximately 25 centimeters in length.
123. The implantable cardioverter-defibrillator of claim 120, wherein the lead is approximately 25 centimeters to approximately 35 centimeters in length.
124. The implantable cardioverter-defibrillator of claim 120, wherein the lead is approximately 35 centimeters to approximately 45 centimeters in length.
125. The implantable cardioverter-defibrillator of claim 120, wherein the lead is approximately 45 centimeters to approximately 55 centimeters in length.
126. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is positioned approximately in the anterior portion of a patient's ribcage.
127. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is positioned approximately in a parasternal region of the patient.
128. The implantable cardioverter-defibrillator of claim 127, wherein the first electrode is positioned approximately in a left parasternal region of the patient.
129. The implantable cardioverter-defibrillator of claim 95, wherein the second electrode is positioned approximately in a posterior region of a patient's ribcage.
130. The implantable cardioverter-defibrillator of claim 95, wherein the second electrode is positioned approximately in a paraspinal region of the patient.
131. The implantable cardioverter-defibrillator of claim 95, wherein the second electrode is positioned approximately in a parascapular region of the patient.
132. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is approximately 30 degrees to approximately 60 degrees apart from the second electrode, with respect to the patent's heart.
133. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is approximately 60 degrees to approximately 90 degrees apart from the second electrode, with respect to the patent's heart.
134. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is approximately 90 degrees to approximately 120 degrees apart from the second electrode, with respect to the patent's heart.
135. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is approximately 120 degrees to approximately 150 degrees apart from the second electrode, with respect to the patent's heart.
136. The implantable cardioverter-defibrillator of claim 95, wherein the first electrode is approximately 150 degrees to approximately 180 degrees apart from the second electrode, with respect to the patent's heart.
137. A method of inserting an implantable cardioverter-defibrillator within a patient, the method comprising the steps of: providing a cardioverter-defibrillator comprising a housing, an electrical circuit located within the housing, a first electrode located on the housing, and a second electrode; making a single incision into the patient; advancing the cardioverter-defibrillator through the single incision and subcutaneously over approximately the anterior portion of a patient's ribcage; and orienting the second electrode on substantially the opposite side of a patient's heart from the first electrode.
138. The method of claim 137, wherein at least a portion of the cardioverter-defibrillator is non-planar.
139. The method of claim 137, wherein the cardioverter-defibrillator has a length of approximately 3 centimeters to approximately 30 centimeters.
140. The method of claim 137, wherein the cardioverter-defibrillator has a length of approximately 5 centimeters to approximately 20 centimeters.
141. The method of claim 137, wherein the cardioverter-defibrillator has a length of approximately 5 centimeters to approximately 12 centimeters.
142. The method of claim 137, wherein the cardioverter-defibrillator further comprises a depth, wherein the cardioverter-defibrillator is less than approximately 15 millimeters.
143. The method of claim 137, wherein the electrical circuit can provide monophasic waveform cardioversion-defibrillation for a patient's heart.
144. The method of claim 137, wherein the electrical circuit can provide multiphasic waveform cardioversion-defibrillation for a patient's heart.
145. The method of claim 144, wherein the electrical circuit can provide biphasic waveform cardioversion-defibrillation for a patient's heart.
146. The method of claim 144, wherein the electrical circuit can provide triphasic waveform cardioversion-defibrillation for a patient's heart.
147. The method of claim 137, wherein the first electrode can emit an effective field strength for shocking the patient's heart.
148. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 25 J to approximately 50 J.
149. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 50 J to approximately 75 J.
150. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 75 J to approximately 100 J.
151. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 100 J to approximately 125 J.
152. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 125 J to approximately 150 J.
153. The method of claim 147, wherein the effective field strength for shocking the patient's heart is approximately 150 J.
154. The method of claim 147, wherein the first electrode can further receive sensory information.
155. The method of claim 137, wherein the first electrode can receive sensory information.
156. The method of claim 137, wherein at least a portion of the first electrode is non-planar.
157. The method of claim 137, wherein the first electrode is less than approximately 2000 square millimeters in area.
158. The method of claim 137, wherein at least a portion of the housing surrounding the electrode is ceramic.
159. The method of claim 137, wherein the second electrode is located on the housing.
160. The method of claim 137, wherein the housing further comprises a first end and a second end, wherein the first electrode is located on the first end of the housing and the second electrode is located on the second end of the housing.
161. The method of claim 137, wherein the second electrode is disposed on a lead.
162. The method of claim 161, wherein the lead is approximately 5 centimeters to approximately 55 centimeters in length.
163. The method of claim 161, wherein the lead is approximately 5 centimeters to approximately 15 centimeters in length.
164. The method of claim 161, wherein the lead is approximately 15 centimeters to approximately 25 centimeters in length.
165. The method of claim 161, wherein the lead is approximately 25 centimeters to approximately 35 centimeters in length.
166. The method of claim 161, wherein the lead is approximately 35 centimeters to approximately 45 centimeters in length.
167. The method of claim 161, wherein the lead is approximately 45 centimeters to approximately 55 centimeters in length.
168. The method of claim 137, wherein the single incision is made approximately at the level of the cardiac apex.
169. The method of claim 137, wherein the single incision is made approximately in the left anterior axillary line.
170. The method of claim 137, wherein the first electrode is advanced approximately in a parasternal region of the patient.
171. The method of claim 170, wherein the first electrode is advanced approximately in a left parasternal region of the patient.
172. The method of claim 137, wherein the second electrode is oriented approximately in a posterior region of a patient's ribcage.
173. The method of claim 137, wherein the second electrode is oriented approximately in a paraspinal region of the patient.
174. The method of claim 137, wherein the second electrode is oriented approximately in a parascapular region of the patient.
175. The method of claim 137, wherein the first electrode is approximately 30 degrees to approximately 60 degrees apart from the second electrode, with respect to the patent's heart.
176. The method of claim 137, wherein the first electrode is approximately 60 degrees to approximately 90 degrees apart from the second electrode, with respect to the patent's heart.
177. The method of claim 137, wherein the first electrode is approximately 90 degrees to approximately 120 degrees apart from the second electrode, with respect to the patent's heart.
178. The method of claim 137, wherein the first electrode is approximately 120 degrees to approximately 150 degrees apart from the second electrode, with respect to the patent's heart.
179. The method of claim 137, wherein the first electrode is approximately 150 degrees to approximately 180 degrees apart from the second electrode, with respect to the patent's heart.
180. A method of inserting an implantable cardioverter-defibrillator within a patient, the method comprising the steps of: providing a cardioverter-defibrillator comprising a housing, an electrical circuit located within the housing, a first electrode located on the housing, and a second electrode; making a single incision into the patient; advancing the cardioverter-defibrillator through the single incision and subcutaneously over approximately the posterior portion of a patient's ribcage; and orienting the second electrode on substantially the opposite side of a patient's heart from the first electrode.
181. The method of claim 180, wherein at least a portion of the cardioverter-defibrillator is non-planar.
182. The method of claim 180, wherein the cardioverter-defibrillator has a length of approximately 3 centimeters to approximately 30 centimeters.
183. The method of claim 180, wherein the cardioverter-defibrillator has a length of approximately 5 centimeters to approximately 20 centimeters.
184. The method of claim 180, wherein the cardioverter-defibrillator has a length of approximately 5 centimeters to approximately 12 centimeters.
185. The method of claim 180, wherein the cardioverter-defibrillator further comprises a depth, wherein the cardioverter-defibrillator is less than approximately 15 millimeters.
186. The method of claim 180, wherein the electrical circuit can provide monophasic waveform cardioversion-defibrillation for a patient's heart.
187. The method of claim 180, wherein the electrical circuit can provide multiphasic waveform cardioversion-defibrillation for a patient's heart.
188. The method of claim 187, wherein the electrical circuit can provide biphasic waveform cardioversion-defibrillation for a patient's heart.
189. The method of claim 187, wherein the electrical circuit can provide triphasic waveform cardioversion-defibrillation for a patient's heart.
190. The method of claim 180, wherein the first electrode can emit an effective field strength for shocking the patient's heart.
191. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 25 J to approximately 50 J.
192. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 50 J to approximately 75 J.
193. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 75 J to approximately 100 J.
194. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 100 J to approximately 125 J.
195. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 125 J to approximately 150 J.
196. The method of claim 190, wherein the effective field strength for shocking the patient's heart is approximately 150 J.
197. The method of claim 190, wherein the first electrode can further receive sensory information.
198. The method of claim 180, wherein the first electrode can receive sensory information.
199. The method of claim 180, wherein at least a portion of the first electrode is non-planar.
200. The method of claim 180, wherein the first electrode is less than approximately 100 square millimeters in area.
201. The method of claim 180, wherein at least a portion of the housing surrounding the electrode is ceramic.
202. The method of claim 180, wherein the second electrode is located on the housing.
203. The method of claim 180, wherein the housing further comprises a first end and a second end, wherein the first electrode is located on the first end of the housing and the second electrode is located on the second end of the housing.
204. The method of claim 180, wherein the second electrode is disposed on a lead.
205. The method of claim 204, wherein the lead is approximately 5 centimeters to approximately 55 centimeters in length.
206. The method of claim 204, wherein the lead is approximately 5 centimeters to approximately 15 centimeters in length.
207. The method of claim 204, wherein the lead is approximately 15 centimeters to approximately 25 centimeters in length.
208. The method of claim 204, wherein the lead is approximately 25 centimeters to approximately 35 centimeters in length.
209. The method of claim 204, wherein the lead is approximately 35 centimeters to approximately 45 centimeters in length.
210. The method of claim 204, wherein the lead is approximately 45 centimeters to approximately 55 centimeters in length.
211. The method of claim 180, wherein the first electrode is advanced approximately in a paraspinal region of the patient.
212. The method of claim 180, wherein the first electrode is advanced approximately in a parascapular region of the patient.
213. The method of claim 180, wherein the second electrode is oriented approximately in a parasternal region of the patient.
214. The method of claim 213, wherein the second electrode is oriented approximately in a left parasternal region of the patient.
215. The method of claim 180, wherein the first electrode is approximately 30 degrees to approximately 60 degrees apart from the second electrode, with respect to the patent's heart.
216. The method of claim 180, wherein the first electrode is approximately 60 degrees to approximately 90 degrees apart from the second electrode, with respect to the patent's heart.
217. The method of claim 180, wherein the first electrode is approximately 90 degrees to approximately 120 degrees apart from the second electrode, with respect to the patent's heart.
218. The method of claim 180, wherein the first electrode is approximately 120 degrees to approximately 150 degrees apart from the second electrode, with respect to the patent's heart.
219. The method of claim 180, wherein the first electrode is approximately 150 degrees to approximately 180 degrees apart from the second electrode, with respect to the patent's heart.
[0001] Defibrillation/cardioversion is a technique employed to counter arrhythmia heart conditions including some tachycardias in the atria and/or ventricles. Typically, electrodes are employed to stimulate the heart with electrical impulses or shocks, of a magnitude substantially greater than pulses used in cardiac pacing.
[0010] One embodiment of the present invention provides an implantable cardioverter defibrillator for subcutaneous positioning between the third rib and the twelfth rib within a patient, the implantable cardioverter-defibrillator including a housing; an electrical circuit located within the housing; a first electrode coupled to the electrical circuit and located on the housing; and a second electrode coupled to the electrical circuit.
[0044] Turning now to FIG. 1, the S-ICD of the present invention is illustrated. The S-ICD consists of an electrically active canister 11 and a subcutaneous electrode 13 attached to the canister. The canister has an electrically active surface 15 that is electrically insulated from the electrode connector block 17 and the canister housing 16 via insulating area 14. The canister can be similar to numerous electrically active canisters commercially available in that the canister will contain a battery supply, capacitor and operational circuitry. Alternatively, the canister can be thin and elongated to conform to the intercostal space. The circuitry will be able to monitor cardiac rhythms for tachycardia and fibrillation, and if detected, will initiate charging the capacitor and then delivering cardioversion /defibrillation energy through the active surface of the housing and to the subcutaneous electrode. Examples of such circuitry are described in U.S. Pat. Nos. 4,693,253 and 5,105,810, the entire disclosures of which are herein incorporated by reference. The canister circuitry can provide cardioversion/defibrillation energy in different types of waveforms. In the preferred embodiment, a 100 uF biphasic waveform is used of approximately 10-20 ms total duration and with the initial phase containing approximately ⅔ of the energy, however, any type of waveform can be utilized such as monophasic, biphasic, multiphasic or alternative waveforms as is known in the art.
[0045] In addition to providing cardioversion/defibrillation energy, the circuitry can also provide transthoracic cardiac pacing energy. The optional circuitry will be able to monitor the heart for bradycardia and/or tachycardia rhythms. Once a bradycardia or tachycardia rhythm is detected, the circuitry can then deliver appropriate pacing energy at appropriate intervals through the active surface and the subcutaneous electrode. Pacing stimuli will be biphasic in the preferred embodiment and similar in pulse amplitude to that used for conventional transthoracic pacing.
[0049] In addition to use of the sense circuitry for detection of V-Fib or V-Tach by examining the QRS waves, the sense circuitry can check for the presence or the absence of respiration. The respiration rate can be detected by monitoring the impedance across the thorax using subthreshold currents delivered across the active can and the high voltage subcutaneous lead electrode and monitoring the frequency in undulation in the waveform that results from the undulations of transthoracic impedance during the respiratory cycle. If there is no undulation, then the patent is not respiring and this lack of respiration can be used to confirm the QRS findings of cardiac arrest. The same technique can be used to provide information about the respiratory rate or estimate cardiac output as described in U.S. Pat. Nos. 6,095,987, 5,423,326, 4,450,527, the entire disclosures of which are incorporated herein by reference.
[0052] The most distal electrode on the composite subcutaneous electrode is a coil electrode 27 that is used for delivering the high voltage cardioversion/defibrillation energy across the heart. The coil cardioversion/defibrillation electrode is about 5-10 cm in length. Proximal to the coil electrode are two sense electrodes, a first sense electrode 25 is located proximally to the coil electrode and a second sense electrode 23 is located proximally to the first sense electrode. The sense electrodes are spaced far enough apart to be able to have good QRS detection. This spacing can range from 1 to 10 cm with 4 cm being presently preferred. The electrodes may or may not be circumferential with the preferred embodiment. Having the electrodes non-circumferential and positioned outward, toward the skin surface, is a means to minimize muscle artifact and enhance QRS signal quality. The sensing electrodes are electrically isolated from the cardioversion/defibrillation electrode via insulating areas 29. Similar types of cardioversion/defibrillation electrodes are currently commercially available in a transvenous configuration. For example, U.S. Pat. No. 5,534,022, the entire disclosure of which is herein incorporated by reference, disclosures a composite electrode with a coil cardioversion/defibrillation electrode and sense electrodes. Modifications to this arrangement is contemplated within the scope of the invention. One such modification is illustrated in FIG. 2 where the two sensing electrodes 25 and 23 are non-circumferential sensing electrodes and one is located at the distal end, the other is located proximal thereto with the coil electrode located in between the two sensing electrodes. In this embodiment the sense electrodes are spaced about 6 to about 12 cm apart depending on the length of the coil electrode used. FIG. 3 illustrates yet a further embodiment where the two sensing electrodes are located at the distal end to the composite electrode with the coil electrode located proximally thereto. Other possibilities exist and are contemplated within the present invention. For example, having only one sensing electrode, either proximal or distal to the coil cardioversion/defibrillation electrode with the coil serving as both a sensing electrode and a cardioversion/defibrillation electrode.
[0053] It is also contemplated within the scope of the invention that the sensing of QRS waves (and transthoracic impedance) can be carried out via sense electrodes on the canister housing or in combination with the cardioversion/defibrillation coil electrode and/or the subcutaneous lead sensing electrode(s). In this way, sensing could be performed via the one coil electrode located on the subcutaneous electrode and the active surface on the canister housing. Another possibility would be to have only one sense electrode located on the subcutaneous electrode and the sensing would be performed by that one electrode and either the coil electrode on the subcutaneous electrode or by the active surface of the canister. The use of sensing electrodes on the canister would eliminate the need for sensing electrodes on the subcutaneous electrode. It is also contemplated that the subcutaneous electrode would be provided with at least one sense electrode, the canister with at least one sense electrode, and if multiple sense electrodes are used on either the subcutaneous electrode and/or the canister, that the best QRS wave detection combination will be identified when the S-ICD is implanted and this combination can be selected, activating the best sensing arrangement from all the existing sensing possibilities. Turning again to FIG. 2, two sensing electrodes 26 and 28 are located on the electrically active surface 15 with electrical insulator rings 30 placed between the sense electrodes and the active surface. These canister sense electrodes could be switched off and electrically insulated during and shortly after defibrillation/cardioversion shock delivery. The canister sense electrodes may also be placed on the electrically inactive surface of the canister. In the embodiment of FIG. 2, there are actually four sensing electrodes, two on the subcutaneous lead and two on the canister. In the preferred embodiment, the ability to change which electrodes are used for sensing would be a programmable feature of the S-ICD to adapt to changes in the patient physiology and size (in the case of children) over time. The programming could be done via the use of physical switches on the canister, or as presently preferred, via the use of a programming wand or via a wireless connection to program the circuitry within the canister.
[0062] FIGS. 10 and 11 illustrate another embodiment of the present S-ICD invention. In this embodiment there are two subcutaneous electrodes 13 and 13′ of opposite polarity to the canister. The additional subcutaneous electrode 13′ is essentially identical to the previously described electrode. In this embodiment the cardioversion/defibrillation energy is delivered between the active surface of the canister and the two coil electrodes 27 and 27′. Additionally, provided in the canister is means for selecting the optimum sensing arrangement between the four sense electrodes 23, 23′, 25, and 25′. The two electrodes are subcutaneously placed on the same side of the heart. As illustrated in FIG. 6, one subcutaneous electrode 13 is placed inferiorly and the other electrode 13′ is placed superiorly. It is also contemplated with this dual subcutaneous electrode system that the canister and one subcutaneous electrode are the same polarity and the other subcutaneous electrode is the opposite polarity.
[0068] Turning now to FIG. 14, the US-ICD of the present invention is illustrated. The US-ICD consists of a curved housing 1211 with a first and second end. The first end 1413 is thicker than the second end 1215. This thicker area houses a battery supply, capacitor and operational circuitry for the US-ICD. The circuitry will be able to monitor cardiac rhythms for tachycardia and fibrillation, and if detected, will initiate charging the capacitor and then delivering cardioversion/defibrillation energy through the two cardioversion/defibrillating electrodes 1417 and 1219 located on the outer surface of the two ends of the housing. The circuitry can provide cardioversion/defibrillation energy in different types of waveforms. In the preferred embodiment, a 100 uF biphasic waveform is used of approximately 10-20 ms total duration and with the initial phase containing approximately ⅔ of the energy, however, any type of waveform can be utilized such as monophasic, biphasic, multiphasic or alternative waveforms as is known in the art.
[0074] As described previously, the US-ICDs of the present invention vary in length and curvature. The US-ICDs are provided in incremental sizes for subcutaneous implantation in different sized patients. Turning now to FIG. 18, a different embodiment is schematically illustrated in exploded view which provides different sized US-ICDs that are easier to manufacture.
[0075] The different sized US-ICDs will all have the same sized and shaped thick end 1413. The thick end is hollow inside allowing for the insertion of a core operational member 1853. The core member comprises a housing 1857 which contains the battery supply, capacitor and operational circuitry for the US-ICD. The proximal end of the core member has a plurality of electronic plug connectors. Plug connectors 1861 and 1863 are electronically connected to the sense electrodes via pressure fit connectors (not illustrated) inside the thick end which are standard in the art. Plug connectors 1865 and 1867 are also electronically connected to the cardioverter/defibrillator electrodes via pressure fit connectors inside the thick end. The distal end of the core member comprises an end cap 1855, and a ribbed fitting 1859 which creates a water-tight seal when the core member is inserted into opening 1851 of the thick end of the US-ICD.
[0076] The core member of the different sized and shaped US-ICD will all be the same size and shape. That way, during an implantation procedures, multiple sized US-ICDs can be available for implantation, each one without a core member. Once the implantation procedure is being performed, then the correct sized US-ICD can be selected and the core member can be inserted into the US-ICD and then programmed as described above. Another advantage of this configuration is when the battery within the core member needs replacing it can be done without removing the entire US-ICD.
[0077] FIGS. 19-26 refer generally to alternative S-ICD/US-ICD canister embodiments. Although the following canister designs, various material constructions, dimensions and curvatures, discussed in detail below, may be incorporated into either S-ICD or US-ICD canister embodimens, hereinafter, these attributes will be discussed solely with respect to S-ICDs.
[0078] The canisters illustrated in these Figures possess a configuration that may 1) aid in the initial canister implantation; 2) restrict canister displacement once properly positioned; 3) create a consistently focused array of energy delivered toward the recipient's heart with less disbursement to other areas of the thorax; 4) allow for good signal reception from the heart by an S-ICD system; or 5) provide significant comfort and long-term wearability in a broad spectrum of patients with differing thoracic sizes and shapes. More particularly, FIGS. 19-26 detail various material constructions, dimensions and curvatures that are incorporated within the numerous S-ICD canister designs detailed in FIGS. 19-26C.
[0079] Referring now to the particular embodiments, FIG. 19 depicts an S-ICD canister 190 of an embodiment of the present invention. The shell of the S-ICD canister 190 comprises a hermetically sealed housing 192 that encases the electronics for the S-ICD canister 190. As with the previously described S-ICD devices, the electronics of the present embodiment include, at a minimum, a battery supply, a capacitor and operational circuitry. FIG. 19 further depicts a lead electrode 191 coupled to the shell of the canister through a lead 193. A dorsal fin 197 may be disposed on the lead electrode 191 to facilitate the positioning of the lead electrode.
[0080] The S-ICD devices of the present invention provide an energy (electric field strength (V/cm), current density (A/cm2), voltage gradient (V/cm) or other measured unit of energy) to a patient's heart. S-ICD devices of the present invention will generally use voltages in the range of 700 V to 3150 V, requiring energies of approximately 40 J to 210 J. These energy requirements will vary, however, depending upon the form of treatment, the proximity of the canister from the patient's heart, the relative relationship of the S-ICD canister's electrode to the lead electrode, the nature of the patient's underlying heart disease, the specific cardiac disorder being treated, and the ability to overcome diversion of the S-ICD electrical output into other thoracic tissues.
[0081] Ideally, the emitted energy from the S-ICD device will be directed into the patient's anterior mediastinum, through the majority of the heart, and out to the coupled lead electrode positioned in the posterior, posterolateral and/or lateral thoracic locations. Furthermore, it is desirable that the S-ICD canister 190 be capable of delivering this directed energy, as a general rule, at an adequate effective field strength of about 3-5 V/cm to approximately 90 percent of a patient's ventricular myocardium using a biphasic waveform. This delivered effective field strength should be adequate for defibrillation of the patient's heart—an intended application of an embodiment of the present invention.
[0082] Increased energy requirements necessitate larger, or alternatively, additional batteries and capacitors. The latter of these two options is often more desirable in order to reduce the overall depth of the resulting S-ICD canister 190. Increasing the number of batteries and capacitors, however, will increase the length and possibly the depth of the S-ICD canister 190. Therefore, numerous S-ICD devices of varying depth, widths and lengths are manufactured to accommodate the particular energy needs of a variety of patient recipients. For example, an overweight adult male may require a larger and bulkier S-ICD canister 190 than a young child. In particular, the young child is generally smaller, has a relatively lower resistance to current flow, and contains less current diverting body mass than the overweight adult male. As a result, the energy required to deliver an effective therapy to the young child's heart may be considerably less than for the overweight adult male, and therefore, the young child may utilize a smaller and more compact S-ICD canister 190. In addition, one may find that individuals, despite equivalent body size, may have different therapy requirements because of differences in their underlying heart disease. This may allow some patients to receive a smaller canister compared to another patient of equal body size but with a different type of heart disease.
[0083] The spatial requirements of a resulting S-ICD canister 190 are additionally dependent upon the type of operational circuitry used within the device. The S-ICD canister 190 may be programmed to monitor cardiac rhythms for tachycardia and fibrillation, and if detected, will initiate charging the capacitor(s) to deliver the appropriate cardioversion/defibrillation energy. Examples of such circuitry are described in U.S. Pat. Nos. 4,693,253 and 5,105,810, and are incorporated herein by reference. The S-ICD canister 190 may additionally be provided with operational circuitry for transthoracic cardiac pacing. This optional circuitry monitors the heart for bradycardia and/or tachycardia rhythms. In the event a bradycardia or tachycardia rhythm is detected, the operational circuitry delivers the appropriate pacing energy at the appropriate intervals to treat the disorder.
[0084] In additional embodiments, the operational circuitry may be: 1) programmed to deliver low amplitude shocks on the T-wave for induction of ventricular fibrillation for testing the S-ICD canister's performance; 2) programmed for rapid ventricular pacing to either induce a tachyarrhythmia or to terminate one; 3) programmed to detect the presence of atrial fibrillation; and/or 4) programmed to detect ventricular fibrillation or ventricular tachycardia by examining QRS waves, all of which are described in detail above. Additional operational circuitry, being known in the art for sensing, shocking and pacing the heart, are additionally incorporated herein as being within the spirit and scope of the present invention.
[0085] The primary function of the canister housing 192 is to provide a protective barrier between the electrical components held within its confines and the surrounding environment. The canister housing 192, therefore, must possess sufficient hardness to protect its contents. Materials possessing this hardness may include numerous suitable biocompatible materials such as medical grade plastics, ceramics, metals and alloys. Although the materials possessing such hardnesses are generally rigid, in particular embodiments, it is desirable to utilize materials that are pliable or compliant. More specifically, it is desirable that the canister housing 192 be capable of partially yielding in its overall form without fracturing.
[0086] Compliant canister housings 192 often provide increased comfort when implanted in patient recipients. S-ICD canisters 190 formed from such materials permit limited, but significant, deflection of the canister housing 192 with certain thoracic motions. Examples of permitted deflections are ones that are applied to the canister housing 192 by surrounding muscle tissue. The use of a compliant canister housing is particularly beneficial in canister housing embodiments that extend over a significant portion of a patient's thorax. The compliant material in these embodiment may comprise a portion of the canister housing, or alternatively, may comprise the canister housing in its entirety. The correct material selection (or combination thereof), therefore, is helpful in eliminating patient awareness of the device and in improving the long-term wearability of the implanted device.
[0087] Materials selected for the canister housing 192 should further be capable of being sterilized. Often commercial sterilization processes involve exposure to elevated temperatures, pressures or chemical treatments. It is important, therefore, that the materials used in forming the canister housing be capable of withstanding such exposures without degrading or otherwise compromising their overall integrity.
[0088] Polymeric materials suitable for the canister housing 192 of the present invention include polyurethanes, polyamides, polyetheretherketones (PEEK), polyether block amides (PEBA), polytetrafluoroethylene (PTFE), silicones, and mixtures thereof. Ceramic materials suitable for the canister housing 192 of the present invention include zirconium ceramics and aluminum-based ceramics. Metallic materials suitable for the canister housing 192 of the present invention include stainless steel, and titanium. Alloys suitable for the canister housing 192 of the present invention include stainless steel alloys and titanium alloys such as nickel titanium. In certain embodiments of the present invention, classes of materials may be combined in forming the canister housing 192. For example, a nonconductive polymeric coating, such as parylene, may be selectively applied over a titanium alloy canister housing 192 surface in order to allow only a specific surface area, such as that at the undersurface of the duckbill distal end, to receive signals and/or apply therapy.
[0089] In general, it is desirable to maintain the size of the S-ICD canister housing 192 under a total volume of approximately 50 cubic centimeters. In alternative embodiments of the present invention, it is desirable to maintain the size of the S-ICD canister housing 192 under a total volume of approximately 100 cubic centimeters. In yet alternative embodiments of the present invention, it is desirable to maintain the size of the S-ICD canister housing 192 under a total volume of approximately 120 cubic centimeters.
[0090] Moreover, it is additionally desirable to maintain the total weight of the S-ICD canister 190, as a whole (including the canister housing, operational circuitry, capacitors and batteries), under approximately 50 grams. In alternative embodiments of the present invention, it is desirable to maintain the total weight of the S-ICD canister 190 under approximately 100 grams. In yet alternative embodiments of the present invention, it is desirable to maintain the total weight of the S-ICD canister 190 under approximately 150 grams.
[0091] Maintaining the weight and size within the above identified parameters is primarily for patient comfort depending upon the shape of the device. The implantation of a S-ICD canister 190 is a long-term solution to heart dysfunction, and as such, will ideally remain in the patient until the device's batteries need replacement or an alternative therapy eventually leads to its removal. Accordingly, a considerable amount of engineering is devoted to minimizing discomfort associated with the installed device.
[0092] Weight and size considerations are particularly important to younger patient recipients. Children possessing ICDs are more likely to be cognitive of any additional weight or bulkiness associated with heavier and/or larger devices. The present invention overcomes these problems by designing a S-ICD canister 190 that takes into consideration the concerns of these smaller sized patient recipients. For example, lighter materials may be utilized to minimize discomfort associated with heavier materials. Furthermore, the S-ICD canister 190 (length, width and depth) in its entirety, or only a portion thereof, may be modified in order to accommodate a variety of sized patient recipients. For example, the shape of the S-ICD canister housing 192 may also be manufactured in a variety of anatomical configurations to better insure comfort and performance in younger children or smaller adults, throughout the life of their S-ICD canisters 190. In order to accommodate certain patients, a physician may place the canister 190 posteriorly with the lead electrode positioned anteriorly with the patient's body, the reverse of the canister's 190 usual positioning. This canister 190 placement is particularly useful when implanted in very small children. Such canister 190 placement generally optimizes comfort for these smaller stature recipients. Moreover, the shape of the canister 190 may be altered specifically to conform to a female's thorax, where breast tissue may alter comfort and performance requirements.
[0093] Referring now to specific portions of the canister housing 192, FIG. 19 depicts a canister housing 192 in accordance with one embodiment of the present invention having a top surface 194, a bottom surface 196 and surrounding sides 198 connecting these two surfaces. The S-ICD canister housing 192 depicted in FIG. 19 further includes a distal end 200 and a proximal end 202. In particular canister housing embodiments, the canister housing 192 may lack a proximal end and a distal end.
[0094] The top surface 194 of the canister housing 192 is generally smooth and void of appendages and apertures. The smooth top surface 194 enables the S-ICD canister 190 to advance effortlessly through the subcutaneous tissues during an implantation procedure. Smoothing the top surface 194 reduces the coefficient of friction of the S-ICD canister 190. Such measures reduce abrasion, and concurrently, also reduce inflammation associated with the device's insertion and advancement. The benefits of a reduction in surface friction also continues on long after implantation through a significant reduction in inflammation and soreness, lending to an overall heightened feeling of wearability and comfort.
[0095] In alternative embodiments, the top surface 194 of the canister housing 192 may include one or more apertures, sensors, electrodes, appendages, or a combination thereof. Apertures on the top surface 194 of the canister housing 192 are generally in the form of a connection port 203, or multiple connection ports, for coupling ancillary devices to the canister itself. More specifically, the connection ports 203 couple the operational circuitry housed within the canister to these ancillary devices, as well as to a lead electrode 191. Connection ports 203 may be positioned anywhere along the canister housing 192, however, in particular embodiments, the connection ports 203 are located at the distal end 200 or proximal end 202 of the canister housing 192. The connection ports 203 may additionally be positioned along the canister housing's sides 198 and bottom surface 196.
[0096] In yet another embodiment, connection ports 203 are located at both the distal end 200 and the proximal end 202 of the canister housing 192. Positioning connection ports 203 at both the canister's distal end 200 and the proximal end 202 may enhance the care provided by the S-ICD canister 190. In particular, this canister arrangement allows the operational circuitry in the S-ICD canister 190 to utilize multiple electrodes and sensors to best regulate and treat the particular condition experienced by the patient recipient. Examples of ancillary devices suitable for attachment include a lead 193, such as a lead for sensing, shocking and pacing. Additional ancillary devices suitable for attachment to the S-ICD canister 190, being known in the art, (e.g., heart failure monitoring sensors) are additionally incorporated as being within the spirit and scope of the present invention.
[0097] The top surface 194 of the canister housing 192 may additionally include particular appendages. Appendages are especially useful in anchoring the canister housing 192 in a fixed relative position, or alternatively, in advancing the canister housing 192 within the patient recipient. An example of an appendage that may be incorporated into the top surface 194 of the canister housing 192 is an extending fin. A fin-like appendage may extend from the canister housing 192 in order to better direct the S-ICD canister 190 during the implantation procedure. In this capacity, the extended fin acts as a rudder preventing the advancing S-ICD canister 190 from deviating from its desired path. The extended fin may additionally aid in preventing the S-ICD canister 190 from displacing from its original position after implantation—particularly in the direction perpendicular to the fin's length. Extending fins suitable for the present invention may extend the entire length of the canister housing 192, or alternatively, a segment of the length. Additionally, extending fins may be disposed on the bottom surface 196 of the canister housing 192 in order to provide similar functions.
[0098] Appendages may also aid physicians in advancing the S-ICD canister 190 to a desired location within the patient. Motility-enhancing appendages enable the physician to push, pull or otherwise direct the S-ICD canister 190 in a particular fashion throughout the patient's body. During the procedure, a physician generally attaches a medical instrument to the motility-enhancing appendage. This attachment step may occur either before or after the S-ICD canister 190 has been inserted within the patient. An example of one medical instrument capable of attaching to the motility-enhancing appendage is a hemostat. Other similar medical instruments, known to those skilled in the art, may also be utilized in this attachment step. The physician then advances the hemostat in a desired direction to properly seat the S-ICD canister 190 within the patient's body.
[0099] The surrounding sides 198 of the canister housing 192 are generally smooth and substantially rounded between the top surface 194 and the bottom surface 196 of the canister housing 192. Smoothing the side surfaces 198 aids in the insertion of the S-ICD canister 190 during the implantation procedure. More specifically, smoother side surfaces 198 permit the S-ICD canister 190, as a whole, to slide easily through the surrounding bodily tissue while minimizing abrasion. In addition, rounded, smooth transition surfaces allow the surrounding tissues to better conform to the presence of the device making the device more comfortable to the patient during chronic implantation.
[0100] In contrast, sharp edge formations may have the tendency to ablate, or at a minimum, irritate the surrounding tissue during the implantation process. Subsequent tissue irritation may also occur long after the implantation process. Minor fluctuations in the positioning of a sharp edged canister may cause an inflammatory response in the surrounding tissue. These minor fluctuations are often the result of simple day-to-day movements. Movement of the arms, bending at the waist and rotation of the torso are all daily activities that may cause surrounding bodily tissue to chafe against the installed canister. Smoothing these edges, however, would greatly reduce tissue abrasion, and thereby, reduce the soreness and discomfort associated with the implanted S-ICD canister 190.
[0101] Referring now to FIG. 20, the bottom surface 196 of the S-ICD canister 190 of FIG. 19 is shown. In particular, an electrode 204 possessing an electrically conductive surface is depicted within the confines of, and hermetically sealed within, the S-ICD canister housing 192. Although an electrode 204 is specifically illustrated, any sensor capable of receiving physiological information and/or emitting an energy may be similarly situated on the canister housing 192. For example, a sensor may be located on the canister housing 192 that may monitor a patient's blood glucose level, respiration, blood oxygen content, blood pressure and/or cardiac output.
[0102] Specifically with reference to FIG. 20, the exposed electrode 204 is electrically coupled to the operational circuitry encased within the canister housing 192. The electrode 204, therefore, performs many of the functions defined by the operational circuitry's programming. More specifically, the electrode 204 is the vehicle that actually receives the signals being monitored, and/or emits the energy required to pace, shock or otherwise stimulate the heart. Although only a single electrode 204 is shown for illustrative purposes, certain S-ICD canister embodiments 190 may be manufactured with multiple electrodes. For these embodiments, the multiple electrodes are often task specific, wherein each electrode 204 performs a single function. In alternate embodiments, a single electrode 204 may perform both monitoring and shocking functions.
[0103] The electrodes 204 are generally positioned at the ends 200 and 202 of the canister housing 192. In the S-ICD canister 190 depicted in FIG. 20, the electrode 204 is placed at the distal end 200 of the canister housing 192. Although the electrode 204 is positioned in close proximity to the distal end 200, the side 198 of the canister housing 192 nearest the distal end 200 should generally refrain from exposing any portion of the electrically conductive surface of the electrode 204. Additionally, although the electrode is generally planar, in particular embodiments, the electrode may possess a curved shape.
[0104] The size of the electrically conductive surface of an electrode 204, in one particular embodiment, is approximately 500 square millimeters in area. In alternate embodiments, it is desirable to maintain the size of the electrically conductive surface between approximately 100 square millimeters and approximately 2000 square millimeters in area. As with the size of the canister housing 192, the size of the electrically conductive surface may vary to accommodate the particular patient recipient. Furthermore, the shape and size of an electrode 204 may vary to accommodate the placement of the electrode 204 on the canister housing 192. The shape and size of an electrode may also be varied to adapt to specified diagnostic and therapeutic functions performed by the canister 190. For example, the electrode's 204 size and shape may be altered to minimize energy loss to surrounding bodily tissues, or for minimizing the diversion of current away from the heart.
[0105] One factor in minimizing current diversion is in maintaining an equal current density distribution throughout an electrode's 204 conductive surface. A controlling factor in an electrode's 204 current density distribution is the electrode's 204 overall shape. Certain electrode 204 shapes draw current to particular areas on the electrode's 204 conductive surface (e.g., sharp angles). As a result, these electrodes 204 create an unequal current density distribution. Electrodes 204 possessing sharp corners, for example, may have higher current densities in the regions defined by the sharp corner. This unequal current density distribution results in confined “hot spots”. The formation of hot spots may be desirable and intentional, such as when attempting to increase current density adjacent to the sternum. On the other hand, hot spots may be undesirable as these high current density locations may scorch or singe surrounding tissue during the electrode's 204 emission of electrical energy. Moreover, electrodes 204 possessing numerous hot spots on the electrode's 204 conductive surface consequently generate areas of low current density—or “cold spots”. This unequal distribution may render the electrode 204, as a whole, highly ineffective.
[0106] Electrode 204 embodiments of the present invention, in contrast, are substantially rounded. In particular, regions of the electrode 204 traditionally possessing sharp corners are rounded to prevent extreme hot spots. Nevertheless, the distal most segment of the electrode 200 is slightly angulated in order to modestly concentrate current at the tip, and therefore, direct current more through the mediastinum and into the patient's heart.
[0107] Another controlling factor in an electrode's 204 current density distribution is the electrode's 204 overall size. The relatively small conductive surfaces of electrodes 204 of the present invention, as discussed above, minimize the likelihood of forming either hot or cold spots. Larger electrodes, in contrast, possess large surface areas that may be more prone to generate more regions of unequal current distribution.
[0108] As discussed above, electrodes 204 may vary in shape and size to accommodate an assortment of canister housing 192 designs For illustrative purposes, FIG. 20 and FIGS. 23A-25A show various electrode shapes disposed upon various canister housings 192. The canister housings 192 depicted in these figures, however, are not limited to the electrode shape specifically illustrated.
[0109] The electrode 204 depicted in FIG. 20 is “thumbnail” shaped. The distal end margin 206 of this shaped electrode 204 generally follows the outline of the rounded distal end 200 of the canister housing 192. As the electrode 204 moves proximally along the length of the canister housing 192, the conductive surface terminates. In the thumbnail embodiment, the electrode's conductive surface is generally contained within the rounded portions of the distal end 200 of the canister housing 192. In alternate embodiments, the electrode's conductive surface may extend proximally further within the canister housing 192. In yet another thumbnail shaped electrode embodiment, the margins of the electrode's conductive surface refrain from following the exact rounded contour of the canister housing 192.
[0110] A “spade” shaped electrode 236 is depicted in FIG. 23A. The distal end of the spade shaped electrode also generally follows the outline of the rounded distal end 234 of the canister housing 220. As the spade shaped electrode 236 moves proximally along the length of the canister housing 220, the conductive surface terminates in a rounded proximal end. Similar to the thumbnail embodiment described above, the spade shaped electrode's conductive surface is generally contained within the distal end 234 of the canister housing 220. In alternate embodiments, the spade shape electrode's conductive surface may extend proximally further within the canister housing 220. In yet another spade shaped electrode 234 embodiment, the margins of the spade shaped electrode's conductive surface refrain from following the exact rounded contour of the canister housing 220, but substantially form a spade shaped configuration.
[0111] A circular shaped electrode 238 is illustrated in FIG. 23B.
[0112] A rectangular shaped electrode 246 is shown in FIG. 24A. Rectangular shaped electrodes 246 also incorporate electrodes that are substantially rectangular in shape. In particular to FIG. 24A, the corners of the rectangular shaped electrode 246 are rounded. Moreover, one margin of the rectangular shaped electrode's conductive surface generally follows the rounding of the distal end 246 of the canister housing 241.
[0113] A triangular shaped electrode 254 is depicted in FIG. 24B. Triangular shaped electrodes 254 also incorporate electrodes that are substantially triangular in shape. In particular to FIG. 24B, the corners of the triangular shaped electrode 254 are rounded.
[0114] A square shaped electrode 257 is depicted in FIG. 24C. Square shaped electrodes 257 also incorporate electrodes that are substantially square in shape. In particular to FIG. 24C, the corners of the square shaped electrode 257 are rounded. An ellipsoidal shaped electrode 268 is depicted in FIG. 25A. The distal end of the ellipsoidal shaped electrode 268 generally follows the outline of the rounded distal end 264 of the canister housing 260. As the ellipsoidal shaped electrode 268 moves proximally along the length of the canister housing 260, the conductive surface elongates and then again reduces in length to form a rounded proximal end. Similar to the thumbnail and spade shaped embodiments described above, the ellipsoidal shaped electrode's conductive surface is generally contained within the distal end 264 of the canister housing 260. In alternate embodiments, the ellipsoidal shape electrode's conductive surface may extend proximally further within the canister housing 260. In yet another ellipsoidal shaped electrode 264 embodiment, the margins of the ellipsoidal shaped electrode's conductive surface refrain from following the exact rounded contour of the canister housing 260, but substantially form an ellipsoidal shaped configuration.
[0115] Energy emissions from any of the above described electrodes 204 generally follow a path of least resistance. The intended pathway of the emission, therefore, may not necessarily be the pathway that the emission ultimately travels. This is particularly a problem with emissions made within the human anatomy where tissue conductivities are highly variable. Obstructing, or low conductivity tissues like bone material, fat, and aerated lung may all redirect released energy away from the heart. Alternatively, surrounding non-cardiac or striated muscle tissue, being generally a high conductivity tissue, may divert energy emissions away from the heart. This is a particular concern for the pectoralis, intercostal, and latissimus dorsus musculature, as well as other thoracic, noncardiac musculature found between the treating electrodes of the S-ICD. Since the S-ICD canister 190 of the present invention does not directly contact the heart muscle itself, such low and high conductivity tissues will impede and/or shunt a percentage of the emissions from the present invention's electrode 204—permitting the heart to receive a fraction of the total emitted energy.
[0120] Referring back to the embodiment depicted in FIG. 21, the curvatures between the top surface 194 and the bottom surface 196 are shown differing toward the distal end 200 of the canister housing 192. At the S-ICD canister's distal end 200, the canister housing's top surface 194 curvature tapers downwardly toward the canister's bottom surface 196. This tapering causes the distal end 200 of the canister housing 192 to be narrower (of a decreased depth) than the canister's proximal end 202. In certain embodiments, this tapering in depth may be gradual throughout the length of the canister's housing 192, or alternatively, the tapering may be confined to a particular area.
[0123] The depth of the canister housing 192 is shown as being very narrow as to the canister housing's length 207. The canister's housing depth is less than approximately 15 millimeters. In alternate embodiments, the depth of the canister's housing depth is approximately 5 millimeters to approximately 10 millimeters. At the tapered distal end 200, the canister housing may have a depth of approximately 1-4 millimeters.
[0136] In alternative embodiments, the origin 199 of the curvature vector θ may originate at a point other than the center of the S-ICD canister 190. Origins 199 shifted from the center of the S-ICD canister 190 produce regions of greater curvature, as well as areas of lesser curvature, in the same S-ICD canister 190. Similarly, a S-ICD canister 190 may possess multiple curvature vectors θ having origins 199 throughout the length of the S-ICD canister 190. Multiple curvature vectors θ produce various nonlinear or nonsymmetrical curves that, in certain circumstances, remain generally arc-shaped. Canister housings possessing multiple curvature vectors θ are particularly suitable for S-ICD canister 190 placement near the patient's sides (generally in the area under the patient's arms where the thorax has a more marked degree of curvature). Canister housings 192 incorporating a nonsymmetrical curvature are generally longer S-ICD canisters 190 that span over the front and sides of the patient's ribcage. In particular, these S-ICD canisters 190 span areas of the ribcage 216 that are generally planar (around the patient's sternum 212), as well as areas that are highly curved (generally in the area under the patient's arms).
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