Device and method for determining analyte levels

• US 20050124873A1
• Filed: 01/19/2005
• Published: 06/09/2005
• Est. Priority Date: 03/04/1997
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Updike, Stuart J., Tapsak, Mark A., Rhodes, Rathbun K., Gilligan, Barbara J.
• Granted Patent: US 7,136,689 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• 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 5/14558 by polarisation
• 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 1/006 for glucose

Abstract

Devices and methods for determining analyte levels are described. The devices and methods allow for the implantation of analyte-monitoring devices, such as glucose monitoring devices that result in the delivery of a dependable flow of blood to deliver sample to the implanted device. The devices include unique architectural arrangement in the sensor region that slows accurate date to be obtained over long periods of time.

Claims

1. An implantable device for measuring an analyte in a biological fluid, the device comprising:

a sensor body comprising a sensor and electronics configured to measure the analyte; and

an angiogenic layer disposed on at least a portion of the sensor,

wherein the sensor comprises an optical sensing mechanism or an acoustic sensing mechanism.

2. The implantable device of claim 1, wherein the optical sensing mechanism or acoustic sensing mechanism is selected from the group consisting of a surface plasmon resonance sensor, a surface acoustic wave sensor, an optical absorbance sensor, a polarized light optical rotation sensor, and a fluorescence sensor.

3. The implantable device of claim 1, wherein the angiogenic layer comprises a biostable material selected from the group consisting of hydrophilic polyvinylidene fluoride, mixed cellulose esters, ePTFE, polyester, polyvinyl chloride, polypropylene, polyethylene, polysulfone, polyethersulfone, cellulose acetate, nylon, polycarbonate, and polymethylmethacrylate.

4. The implantable device of claim 1, further comprising a bioprotective layer located more proximal to the sensor than the angiogenic layer.

5. The implantable device of claim 4, wherein the bioprotective layer comprises a biostable material selected from the group consisting of polyurethane, polytetrafluoroethylene, polypropylene, polyethylene, and polysulfone.

6. The implantable device of claim 4, wherein the angiogenic layer and the bioprotective layer together comprise a composite membrane.

7. The implantable device of claim 1, further comprising a member for securing the sensor body to a host tissue.

8. The implantable device of claim 5, wherein the securing member comprises a material selected from the group consisting of woven polyester, velour, expanded polytetrafluoroethylene, polytetrafluoroethylene felts, polypropylene cloth, porous silicone, and non-woven polyester fibers.

9. The implantable device of claim 1, further comprising a sensing membrane.

10. The implantable device of claim 9, wherein the sensing membrane comprises a resistance layer configured to control a rate of delivery of the analyte through the sensing membrane.

11. The implantable device of claim 9, wherein the sensing membrane comprises an enzyme layer configured to catalyze the analyte with a cofactor.

12. The implantable device of claim 9, wherein the sensing membrane comprises an interference layer configured to allow the analyte to pass through, while preventing passage of an interfering substance.

17. The implantable device of claim 1, further comprising a member for securing the sensor body to a host tissue.

18. The implantable device of claim 17, wherein the securing member comprises a material selected from the group consisting of woven polyester, velour, expanded polytetrafluoroethylene, polytetrafluoroethylene felts, polypropylene cloth, porous silicone, and non-woven polyester fibers.

13. An implantable device for measuring an analyte in a biological fluid, the device comprising:

a sensor body comprising a sensor and electronics configured to measure the analyte; and

an angiogenic layer disposed on at least a portion of the sensor, wherein the angiogenic layer comprises a biostable material selected from the group consisting of hydrophilic polyvinylidene fluoride, mixed cellulose esters, ePTFE, polyester, polyvinyl chloride, polypropylene, polyethylene, polysulfone, polyethersulfone, cellulose acetate, nylon, polycarbonate, and polymethylmethacrylate.

14. The implantable device of claim 13, further comprising a bioprotective layer located more proximal to the sensor than the angiogenic layer.

15. The implantable device according to claim 14, wherein the bioprotective layer comprises a biostable material selected from the group consisting of polyurethane, polytetrafluoroethylene, polypropylene, polyethylene and polysulfone.

16. The implantable device of claim 14, wherein the angiogenic layer and the bioprotective layer together comprise a composite membrane.

19. The implantable device of claim 13, wherein the sensor is an electrochemical sensor.

20. The implantable device of claim 13, further comprising a sensing membrane.

21. The implantable device of claim 20, wherein the sensing membrane comprises a resistance layer configured to control a rate of delivery of the analyte through the sensing membrane.

22. The implantable device of claim 20, wherein the sensing membrane comprises an enzyme layer configured to catalyze the analyte with a cofactor.

23. The implantable device of claim 20, wherein the sensing membrane comprises an interference layer configured to allow the analyte to pass through, while preventing passage of an interfering substance.

24. The implantable device of claim 20, wherein the sensing membrane comprises an electrolyte layer configured maintain a hydrophilic environment at the sensor.

25. The implantable device of claim 13, further comprising an electrolyte phase, the electrolyte phase comprising a free-fluid phase comprising a solution comprising at least one compound that conducts an electric current.