Implantable analyte sensor

• US 8,277,713 B2
• Filed: 05/03/2004
• Issued: 10/02/2012
• Est. Priority Date: 05/03/2004
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Petisce, James R., Brister, Mark, Shults, Mark, Brauker, James H., Neale, Paul V.
• Primary Examiner(s): Johnson, Christina
• Assistant Examiner(s): PIERY, MICHAEL T
• Application Number:
  US10/838,658
• Publication Number:
  US 20050242479A1
• Time in Patent Office: 3,074 Days
• Field of Search: 264/216, 264/255, 264/650, 435/25, 600/347, 200/403.05
• US Class Current: 264/216
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors

Abstract

An implantable analyte sensor including a sensing region for measuring the analyte and a non-sensing region for immobilizing the sensor body in the host. The sensor is implanted in a precisely dimensioned pocket to stabilize the analyte sensor in vivo and enable measurement of the concentration of the analyte in the host before and after formation of a foreign body capsule around the sensor. The sensor further provides a transmitter for RF transmission through the sensor body, electronic circuitry, and a power source optimized for long-term use in the miniaturized sensor body.

Claims

1. A method for forming a membrane for use with an implantable electrochemical glucose sensor, the method comprising:

forming a membrane configured to provide in vivo an interface between an implantable electrochemical glucose sensor and a biological fluid, wherein forming the membrane comprises forming a domain configured to substantially reduce a flux of potentially electrochemically interfering substances through the membrane and control diffusion of glucose and oxygen through the membrane, wherein forming a domain comprises;

forming a sufficiently diluted solvent solution comprising a solvent and a polymer blend of a silicone-containing polyurethane polymer and a hydrophilic polymer, wherein the sufficiently diluted solvent solution comprises a ratio of polymer blend to solvent of about 1 to 10 wt. % polymer blend to about 90 to 99 wt. % solvent; and

applying the solvent solution to a surface at a speed sufficient to substantially avoid film thickness inhomogeneities due to evaporation of the sufficiently diluted solvent solution.

2. The method of claim 1, wherein the domain is configured to limit diffusion of hydrophilic species.

3. The method of claim 1, wherein the domain has a thickness of from about 0.1 microns to about 5 microns.

4. The method of claim 1, wherein the domain has a thickness of from about 0.5 microns to about 3 microns.

5. The method of claim 1, wherein the speed is from about 8 inches/second to about 15 inches/second.

6. The method of claim 1, wherein the speed is about 11.5 inches/second.

7. The method of claim 1, wherein forming a membrane comprises forming the membrane on a support.

8. The method of claim 1, wherein forming a membrane comprises forming the membrane on a sensing region of the sensor.

9. The method of claim 8, wherein forming the membrane on a sensing region of the sensor comprises spin-coating, spray-coating, or dip-coating to form the domain.