HOUSING FOR A CIRCUIT THAT IS TO BE IMPLANTED IN-VIVO AND PROCESS OF MAKING THE SAME
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.
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.