Systems and methods for making and using an electrical stimulation system with a case-neutral battery
A control module for an electrical stimulation system includes a sealed electronics housing; an electronic subassembly disposed within the electronics housing; one or more connector assemblies coupled to the electronic subassembly; and a rechargeable battery disposed external to the electronics housing. The one or more connector assemblies are configured to receive a lead. The rechargeable battery includes a positive electrode, a negative electrode, and a single battery case attached directly to the sealed electronics housing and forming a sealed cavity that encapsulates both the positive electrode and the negative electrode. The battery case is electrically isolated from each of the positive electrode and the battery electrode.
1. A method of charging a rechargeable battery of a control module of an electrical stimulation system implanted along a patient's skull, the method comprising:
providing a control module comprising
a sealed electronics housing,
an electronic subassembly disposed within the sealed electronics housing,
one or more connector assemblies coupled to the electronic subassembly, the one or more connector assemblies configured and arranged to receive a lead, and
a rechargeable battery disposed external to the sealed electronics housing, the rechargeable battery comprising
a positive electrode,
a negative electrode, and
a single battery case attached directly to the sealed electronics housing and forming a sealed cavity that encapsulates both the positive electrode and the negative electrode, the single battery case electrically isolated from each of the positive electrode and the negative electrode;
forming a recess along an outer surface of the skull;
placing the control module along the skull with the rechargeable battery of the control module inserted into the recess, thereby surrounding portions of the rechargeable battery extending from the control module with bone cells, the bone cells having a heat tolerance;
attaching the control module to the skull; and
inductively charging the rechargeable battery at a charging rate limited by the heat tolerance of the bone cells surrounding the rechargeable battery.
2. The method of claim 1 , wherein the control module further comprises a positive terminal coupled to the positive electrode and a negative terminal coupled to the negative electrode.
3. The method of claim 2 , wherein the positive terminal is formed from different material than the positive electrode, or the negative terminal is formed from different material than the negative electrode, or both.
4. The method of claim 1 , wherein the single battery case comprises a cap attached to the sealed electronics housing and electrically isolating the positive and negative electrodes.
5. The method of claim 4 , wherein the positive electrode and the negative electrode extend through the cap.
6. The method of claim 1 , wherein the single battery case forms a hermetic seal around the positive electrode and the negative electrode.
7. The method of claim 1 , wherein the single battery case is attached to the sealed electronics housing via at least one of a weld or adhesive.
8. The method of claim 1 , wherein the control module further comprises a first feedthrough and a second feedthrough extending through the sealed electronics housing, the first feedthrough electrically coupled to the positive electrode and the second feedthrough electrically coupled to the negative electrode.
9. The method of claim 1 , wherein the single battery case is configured and arranged to directly contact patient tissue when implanted into a patient.
10. The method of claim 1 , wherein the single battery case is configured and arranged to directly contact a bony structure when implanted into a patient.
11. The method of claim 1 , wherein the control module further comprises a covering disposed over at least a portion of each of the sealed electronics housing and the one or more connector assemblies.
12. The method of claim 1 , wherein each of the one or more connector assemblies comprises:
a connector lumen configured and arranged to receive a lead, and
a plurality of connector contacts arranged along the connector lumen and in electrical communication with the electronic subassembly.
13. The method of claim 1 , wherein providing the control module comprises providing the control module with the single battery case coated with at least one of parylene or silicone.
14. The method of claim 1 , further comprising coating the rechargeable battery with silicone prior to attaching the control module to the skull.
15. The method of claim 1 , wherein placing the control module along the skull with the rechargeable battery of the control module inserted into the recess comprises placing the control module along the skull with at least a portion of the sealed electronics housing extending from the recess.
16. The method of claim 1 , wherein attaching the control module to the skull comprises at least one of adhering the control module to the skull using bone cement or fastening the control module to the skull using one or more fasteners.