Electroactive polymer based artificial sphincters and artificial muscle patches
Provided are artificial muscle patches, which are adapted to be implanted adjacent a patient's heart, and artificial sphincter cuffs, which are adapted to be implanted around a body lumen, such as the urethra, the anal canal, or the lower esophagus. The devices of the present invention comprise: (a) one or more electroactive polymer actuators; and (b) a control unit for electrically controlling the one or more electroactive polymer actuators to expand or contract the devices.
1. A medical device, comprising: (a) a cuff that is adapted for placement around a body lumen, said cuff comprising a plurality of electroactive polymer actuators; (b) a control unit electrically controlling said electroactive polymer actuators to expand or contract said cuff; and (c) a sensing system in communication with said control unit for sensing the degree of contraction of said electroactive polymer actuators.
2. The medical device of claim 1 , wherein opposing ends of said cuff are provided with fasteners for securing said cuff around said body lumen.
3. The medical device of claim 1 , wherein said control unit comprises a power source and a switch.
4. The medical device of claim 1 , wherein said electroactive polymer actuators comprise an electroactive polymer selected from the group consisting of polyaniline, polypyrrole, and polyacetylene.
5. The medical device of claim 4 , wherein said electroactive polymer is polypyrrole.
6. The medical device of claim 1 , wherein said cuff is provided with a restoring force to bring it into an expanded or contracted state.
7. The medical device of claim 6 , further comprising at least one elastic structural element, wherein said restoring force is provided by the structural element.
8. The medical device of claim 7 , wherein said at least one elastic structural element is an elastic annular tube structure whose length increases upon a decrease in its cross-sectional diameter.
9. The medical device of claim 1 , wherein said sensing system comprises a plurality of strain gauges.
10. The medical device of claim 1 , wherein said control unit comprises a power source and a computer.
11. The medical device of claim 1 , wherein said plurality of electroactive polymer actuators comprise (i) a plurality of active members, (ii) a counter-electrode and (iii) an electrolyte disposed between said active member and said counter-electrode.
12. The medical device of claim 11 , wherein said one or more active members are disposed on at least one substrate layer.
13. The medical device of claim 12 , further comprising at least one barrier layer.
14. The medical device of claim 13 , further comprising an exterior mesh layer.
15. The medical device of claim 12 , wherein said one or more active members are provided in a non-linear configuration.
16. The medical device of claim 12 , wherein at least two of said substrate layers are provided.
17. The medical device of claim 12 , wherein said substrate layer is an insulating layer.
18. The medical device of claim 17 , wherein conductive lines are provided on said substrate layer to allow electrical communication between said one or more active members and said power source.
19. The medical device of claim 12 , wherein said substrate layer is a conductive layer.
20. The medical device of claim 11 , wherein said device is sealed to avoid release of electrolyte in vivo.