Implantable microstimulator having a separate battery unit and methods of use thereof

1. An implantable microstimulator arrangement, comprising:

a plurality of implantable microstimulator units, each of the plurality of microstimulator units individually comprising

a first implantable housing,

at least two electrodes disposed on, or as part of, the first implantable housing, and

an electronic subassembly disposed in the first implantable housing and coupled to the at least two electrodes, the electronic subassembly configured and arranged to generate electrical pulses at the at least two electrodes to stimulate adjacent tissue when implanted, the electronic subassembly comprising a processor configured and arranged to control characteristics of the generated electrical pulses;

an implantable battery unit comprising

a second implantable housing, and

a power source disposed in the second implantable housing,

wherein the implantable battery unit is separate from the plurality of implantable microstimulator units; and

a plurality of leads coupling the plurality of microstimulator units to the battery unit.

2. The implantable microstimulator arrangement of claim 1 , wherein the power source of the implantable battery unit comprises a primary battery.

3. The implantable microstimulator arrangement of claim 1 , wherein the power source of the implantable battery unit comprises a rechargeable battery.

4. The implantable microstimulator arrangement of claim 1 , wherein the implantable battery unit further comprises a DC/AC converter.

5. The implantable microstimulator arrangement of claim 1 , wherein the implantable battery unit further comprises an antenna.

6. The implantable microstimulator arrangement of claim 5 , wherein the processor is coupled to a receiver in communication with the antenna.

7. The implantable microstimulator arrangement of claim 1 , wherein the implantable microstimulator arrangement comprises at least three implantable microstimulator units, wherein each microstimulator unit is configured and arranged to stimulate the tissue adjacent that microstimulator unit using the electrical pulses generated by the electronic subassembly of that microstimulator unit.

8. The implantable microstimulator arrangement of claim 7 , further comprising at least one lead connector disposed between the implantable battery unit and at least one of the implantable microstimulator units and configured and arranged to receive and electrically couple at least two of the plurality of leads to allow electrical signals from one lead to be transmitted to another lead.

9. The implantable microstimulator arrangement of claim 8 , wherein the implantable microstimulator arrangement comprises a plurality of lead connectors, wherein each lead connector is configured and arranged to receive and electrically couple at least two of the plurality of leads to allow electrical signals from one lead to be transmitted to another lead.

10. The implantable microstimulator of claim 8 , wherein the plurality of leads comprises at least three leads and wherein the at least one lead connector is configured and arranged to receive and electrically couple the at least three leads to allow electrical signals from one lead to be transmitted to another lead.

11. The implantable microstimulator arrangement of claim 1 , wherein the implantable microstimulator arrangement comprises a plurality of battery units and a plurality of leads, wherein each of the battery units is coupled to a remainder of the microstimulator arrangement using a different lead.

12. The implantable microstimulator arrangement of claim 1 , wherein a one of the plurality of implantable microstimulator units further comprises an antenna disposed in the first implantable housing.

13. The implantable microstimulator arrangement of claim 1 , wherein a one of the plurality of leads is removably coupled to the battery unit.

14. The implantable microstimulator arrangement of claim 1 , wherein a one of the plurality of leads is removably coupled to a one of the plurality of microstimulator units.

15. The implantable microstimulator arrangement of claim 1 , wherein the processor is configured to control timing of the electrical pulse.

16. The implantable microstimulator arrangement of claim 1 , wherein the processor is configured to produce a signal to begin charging the battery.

17. An implantable microstimulator arrangement, comprising:

at least one implantable battery unit comprising

a first implantable housing, and

a power source disposed in the first implantable housing;

a plurality of implantable microstimulator units, wherein each implantable microstimulator unit comprises

a second implantable housing,

at least two electrodes disposed on, or as part of, the second implantable housing, and

an electronic subassembly disposed in the second implantable housing and coupled to the at least two electrodes, the electronic subassembly configured and arranged to generate electrical pulses at the at least two electrodes to stimulate adjacent tissue when implanted, the electronic subassembly comprising a processor configured and arranged to control characteristics of the generated electrical pulses;

a plurality of lead connectors; and

a plurality of leads that couple the microstimulator units to the at least one battery unit using the lead connectors

wherein the at least one implantable battery unit is separate from the plurality of implantable microstimulator units.

18. A method of treating body tissue, the method comprising:

implanting at least one microstimulator unit into a body in the proximity of the body tissue to be treated, each microstimulator unit comprising a first housing, at least two electrodes disposed on, or as part of, the first housing, and an electronic subassembly disposed in the first housing and coupled to the at least two electrodes, the electronic subassembly configured and arranged to generate electrical pulses at the at least two electrodes to stimulate the body tissue, the electronic subassembly comprising a processor configured and arranged to control characteristics of the generated electrical pulses;

implanting a separate battery unit into the body, the battery unit comprising a second implantable housing and a power source disposed in the second implantable housing;

coupling the battery unit to the microstimulator unit using at least one lead prior to implanting the at least one microstimulator unit; and

operating the microstimulator unit to treat the body tissue.

19. The method of claim 18 , wherein implanting at least one microstimulator unit comprises implanting a plurality of microstimulator units.

20. The method claim 19 , wherein implanting a plurality of microstimulator units comprises implanting a plurality of microstimulator units to treat a plurality of body tissue regions.

21. The method of claim 19 , wherein coupling the battery unit to the microstimulator unit comprises coupling the battery unit to the plurality of microstimulator units using a plurality of leads and at least one lead connector that receives and electrically couples at least two of the plurality of leads to allow electrical signals from one lead to be transmitted to another lead.

22. The method of claim 15 , further comprising replacing the battery unit without removing the at least one microstimulator unit.