Biocompatible, human implantable apparatus and method for fully encasing a circuit within a polymer housing

• US 9,717,413 B2
• Filed: 06/29/2011
• Issued: 08/01/2017
• Est. Priority Date: 04/16/2004
• Status: Active Grant

• Current Assignee: Senseonics, Incorporated (Senseonics Holdings, Inc.)
• Original Assignee: Senseonics, Incorporated (Senseonics Holdings, Inc.)
• Inventors: Colvin, Arthur Earl, Lorenz, Carrie R., O'Connor, Casey J., Walters, Steven J.
• Primary Examiner(s): Dinh, Tuan T
• Application Number:
  US13/171,711
• Publication Number:
  US 20110255255A1
• Time in Patent Office: 2,225 Days
• Field of Search: 361782-784, 361752-753, 174 505, 174501, 174504, 174521
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: H05K 5/065 sealed by encapsulation, e.g. waterproof resin forming an integral casing, injection moulding

Abstract

A biocompatible, human implantable apparatus and a method for fully encasing a circuit within a polymer housing. The method may include placing the circuit in a mold, injecting a formulation into the mold, and polymerizing the formulation. The formulation may include monomers and polymers. The apparatus may include a circuit in a polymerized formulation of monomers and polymers.

Claims

1. A method for fully encasing a circuit within a polymer housing, comprising:

at least partially covering the circuit with an epoxy, wherein a sufficient amount of epoxy is used to cover the circuit so that the resulting surface topology is substantially smooth, some or all of the epoxy comprises a light blocking pigment, and the light blocking pigment is black;

placing the epoxy-covered circuit in a mold;

injecting a formulation comprising monomers and polymers into the mold; and

polymerizing the formulation to form a fully-enclosed housing for the circuit;

wherein the epoxy is located between the circuit and the polymerized formulation.

2. 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.

3. The method of claim 1, wherein the monomers are MMA monomers.

4. The method of claim 1, wherein the polymers are pre-polymerized PMMA.

5. The method of claim 1, wherein the monomers are MMA monomers, and the polymers are pre-polymerized PMMA.

6. The method of claim 1, wherein the formulation comprises between 60% and 80% pre-polymerized PMMA by volume.

7. The method of claim 1, wherein the formulation is injected into the mold so that the formulation surrounds the circuit.

8. The method of claim 4, wherein the formulation comprises between 60% and 80% pre-polymerized PMMA by volume.

9. The method of claim 6, 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.

10. The method of claim 7, wherein the formulation completely surrounds the circuit.

11. A biocompatible, human implantable apparatus, comprising:

a fully enclosed housing formed by a polymerized formulation of monomers and polymers;

a circuit encased within the fully enclosed housing formed by the polymerized formulation of monomers and polymers, and

an epoxy that at least partially covers the circuit in such a way that the epoxy-covered circuit has a surface topology that is substantially smooth, wherein some or all of the epoxy comprises a light blocking pigment, the light blocking pigment is black, and the epoxy is located between the circuit and the polymerized formulation.

12. The apparatus of claim 11, wherein the monomers are MMA monomers.

13. The apparatus of claim 11, wherein the polymers are pre-polymerized PMMA.

14. The apparatus of claim 11, wherein the monomers are MMA monomers, the polymers are pre-polymerized PMMA, and the formulation comprises between 60% and 80% pre-polymerized PMMA by volume.

15. The apparatus of claim 11, wherein the polymerized formulation surrounds the circuit.

16. The apparatus of claim 13, wherein the formulation comprises between 60% and 80% pre-polymerized PMMA by volume.

17. The apparatus of claim 14, 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.

18. The apparatus of claim 15, wherein the polymerized formulation completely surrounds the circuit.