Oxygen enhancing membrane systems for implantable devices

• US 9,993,186 B2
• Filed: 02/09/2017
• Issued: 06/12/2018
• Est. Priority Date: 07/25/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Petisce, James R., Tapsak, Mark A., Simpson, Peter C., Carr-Brendel, Victoria, Brauker, James H.
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US15/429,022
• Publication Number:
  US 20170150910A1
• Time in Patent Office: 488 Days
• Field of Search: 600309, 600345-366
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

The present invention relates generally to systems and methods for increasing oxygen availability to implantable devices. The preferred embodiments provide a membrane system configured to provide protection of the device from the biological environment and/or a catalyst for enabling an enzymatic reaction, wherein the membrane system includes a polymer formed from a high oxygen soluble material. The high oxygen soluble polymer material is disposed adjacent to an oxygen-utilizing source on the implantable device so as to dynamically retain high oxygen availability to the oxygen-utilizing source during oxygen deficits. Membrane systems of the preferred embodiments are useful for implantable devices with oxygen-utilizing sources and/or that function in low oxygen environments, such as enzyme-based electrochemical sensors and cell transplantation devices.

Claims

1. A system for continuous in vivo measurement of a glucose concentration in a host, the system comprising:

an implantable sensor configured to generate in vivo a signal indicative of a concentration of glucose in a host;

a membrane located over the sensor, the membrane comprising;

a first domain comprising an enzyme configured to catalyze a reaction that has glucose as a reactant; and

a second domain configured to provide an interface with a biological fluid, wherein the second domain comprises a material having an oxygen solubility that is about 3-10 times higher than an oxygen solubility of water;

sensor electronics configured to operatively connect with the implantable sensor and to process the signal and determine a glucose concentration value.

2. The implantable device of claim 1, wherein the material of the second domain has an oxygen permeability of from about 5 Barrers to about 500 Barrers.

3. The implantable device of claim 1, wherein the material of the second domain has an oxygen permeability of from about 25 Barrers to about 250 Barrers.

4. The implantable device of claim 1, wherein the membrane has a thickness of from about 3 microns to about 100 microns.

5. The implantable device of claim 1, wherein the membrane further comprises a third domain configured to limit or block passage of an interfering species therethrough.

6. The implantable device of claim 1, wherein the material of the second domain comprises a copolymer comprising polyurethane and silicone.

7. The implantable device of claim 1, wherein the material has an oxygen solubility that is at least about four times greater than an oxygen solubility of water.

8. The implantable device of claim 1, wherein the material has an oxygen solubility that is about five times greater than an oxygen solubility of water.

9. The implantable device of claim 1, wherein the material has an oxygen solubility that is about six times greater than an oxygen solubility of water.

10. The implantable device of claim 1, wherein the material has an oxygen solubility that is about seven times greater than an oxygen solubility of water.

11. The implantable device of claim 1, wherein the material has an oxygen solubility that is about nine times greater than an oxygen solubility of water.

12. The implantable device of claim 1, wherein the material has an oxygen solubility that is about ten times greater than an oxygen solubility of water.