Implantable microstimulator with plastic housing and methods of manufacture and use

Abstract

An implantable microstimulator includes a plastic housing having a first end and a second end; an electronic subassembly disposed within the housing; a first electrode disposed at the first end of the plastic housing and in electrical communication with the electronic subassembly; and a second electrode disposed at the second end of the plastic housing and in electrical communication with the electronic subassembly. The plastic housing, first electrode, and second electrode form a hermetically sealed structure around the electronic subassembly.

1 . An implantable microstimulator comprising:
 an elongate plastic housing having a first end and a second end, wherein the first end includes a first plastic threaded region and an interior of the housing;   an electronic subassembly disposed within the interior of the housing;   a first end cap comprising a second plastic threaded region and a first electrode, wherein the first electrode is in electrical communication with the electronic subassembly, wherein the first and second plastic threaded regions are coupled together to form a seal therebetween, the seal blocking the access to the interior of the housing; and   a second electrode disposed at the second end of the plastic housing and in electrical communication with the electronic subassembly.   
   
   
       2 . The implantable microstimulator of  claim 1 , wherein the first and second ends are opposing ends of the plastic housing. 
   
   
       3 . The implantable microstimulator of  claim 1 , wherein the first electrode defines at least one cut-out configured and arranged for facilitating coupling together the first threaded region and the second threaded region. 
   
   
       4 . The implantable microstimulator of  claim 1 , further comprising a second end cap comprising a third threaded region. 
   
   
       5 . The implantable microstimulator of  claim 4 , wherein the third threaded region is formed from plastic. 
   
   
       6 . The implantable microstimulator of  claim 4 , wherein the second electrode is disposed on the second end cap. 
   
   
       7 . The implantable microstimulator of  claim 6 , wherein the second electrode is formed from a conductive coating coated over at least a portion of the second end cap. 
   
   
       8 . The implantable microstimulator of  claim 1 , wherein the first electrode is formed from a conductive coating coated over at least a portion of the first end cap. 
   
   
       9 . The implantable microstimulator of  claim 1 , further comprising a coating disposed over the plastic housing. 
   
   
       10 . The implantable microstimulator of  claim 9 , wherein the coating disposed over the plastic housing is configured and arranged to improve biocompatibility of the microstimulator. 
   
   
       11 . The implantable microstimulator of  claim 9 , wherein the coating disposed over the plastic housing comprises at least one compound that releases over time when the microstimulator is implanted in a patient. 
   
   
       12 . The implantable microstimulator of  claim 9 , wherein the coating disposed over the plastic housing comprises two or more layers. 
   
   
       13 . The implantable microstimulator of  claim 9 , wherein the coating disposed over the plastic housing is non-conductive. 
   
   
       14 . The implantable microstimulator of  claim 1 , wherein the plastic housing is cylindrical. 
   
   
       15 . The implantable microstimulator of  claim 1 , further comprising a solvent weld of a plastic material of the plastic body of the first end cap directly to a plastic material of the plastic housing. 
   
   
       16 . The implantable microstimulator of  claim 1 , wherein the first and second plastic threaded regions are solvent welded directly to each other. 
   
   
       17 . The implantable microstimulator of  claim 1 , further comprising a melt seal of a plastic material of the plastic housing directly to a plastic material of the plastic body of the first end cap. 
   
   
       18 . The implantable microstimulator of  claim 1 , wherein the first and second plastic threaded regions are melted directly to each other. 
   
   
       19 . The implantable microstimulator of  claim 1 , wherein the first electrode defines a hole through which a lead is disposed, and wherein the lead is coupled to the electronic subassembly and the first electrode. 
   
   
       20 . A stimulation system comprising:
 the implantable microstimulator of  claim 1 ; and   an external control unit configured and arranged to communicate with the electronic subassembly of the implantable microstimulator to provide signals to the implantable microstimulator, wherein the external control unit comprises a programming unit comprising an interface for entering information to be provided to the microstimulator.