Housing for a circuit that is to be implanted in-vivo and process of making the same

Abstract

The present invention provides a biocompatible circuit assembly that includes a circuit encased within a housing. In some embodiments, the housing is a PMMA housing and before the circuit is enclosed within the housing the circuit is encased within a brick of epoxy.

What is claimed is: 
     
         1 . A method for fully encasing a circuit within a polymer housing, comprising:
 placing the circuit in a mold;   injecting a formulation comprising monomers and polymers into the mold; and   polymerizing the formulation.   
     
     
         2 . The method of  claim 1 , further comprising the step of at least partially covering the circuit with an epoxy prior to placing the circuit in the mold, wherein a sufficient amount of epoxy is used to cover the circuit so that the resulting surface topology is substantially smooth. 
     
     
         3 . The method of  claim 2 , wherein some or all of the epoxy comprises a light blocking pigment. 
     
     
         4 . The method of  claim 3 , wherein the light blocking pigment is black. 
     
     
         5 . The method of  claim 1 , wherein the polymerization step is performed in a pressure vessel where the pressure is increased to at least about 125 psi using inert gas. 
     
     
         6 . The method of  claim 1 , wherein the monomers are MMA monomers. 
     
     
         7 . The method of  claim 1 , wherein the polymers are pre-polymerized PMMA. 
     
     
         8 . The method of  claim 7 , wherein the formulation comprises between 60% and 80% pre-polymerized PMMA by volume. 
     
     
         9 . The method of  claim 1 , wherein the monomers are MMA monomers, and the polymers are pre-polymerized PMMA. 
     
     
         10 . The method of  claim 1 , wherein the formulation comprises between 60% and 80% pre-polymerized PMMA by volume. 
     
     
         11 . The method of  claim 10 , wherein the formulation comprises 70% pre-polymerized PMMA by volume and 30% un-reacted MMA monomer into which the 70% pre-polymerized PMMA has been dissolved. 
     
     
         12 . The method of  claim 1 , wherein the formulation is injected into the mold so that the formulation surrounds the circuit. 
     
     
         13 . The method of  claim 12 , wherein the formulation completely surrounds the circuit.