ANALYTE SENSOR

• US 20090287074A1
• Filed: 08/04/2009
• Published: 11/19/2009
• Est. Priority Date: 10/04/2006
• Status: Abandoned Application

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brister, Mark, Kamath, Apurv U., Shults, Mark, Wong, David K.
• Application Number:
  US12/535,620
• Publication Number:
  US 20090287074A1
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

Systems and methods of use for continuous analyte measurement of a host'"'"'s vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host'"'"'s circulatory system.

Claims

1. A system for monitoring analyte concentration in a biological fluid of a host, the system comprising:

an analyte sensor configured to produce a data signal indicative of an analyte concentration in a host during exposure of the sensor to a biological fluid;

a vascular access device configured for communication with a circulatory system of a host, wherein the vascular access device comprises a catheter configured for insertion into the host'"'"'s circulatory system and tubing;

a high oxygen solubility material that has at least about 3×

higher oxygen solubility than aqueous media;

a infusion solution, wherein the oxygen concentration of the infusion solution is greater than the oxygen concentration of the biological fluid; and

a flow control device configured to intermittently expose the sensor to the biological fluid and to the infusion solution, wherein the flow control device is configured to draw back the biological fluid into the catheter but not substantially into the tubing during a first phase, and to infuse the infusion solution through the catheter into the host during a second phase.

2. The system of claim 1, wherein oxygen is absorbed during the second phase and released during the first phase.

3. The system of claim 1, wherein the sensor is located within the catheter.

4. The system of claim 1, wherein the vascular access device further comprises a fluid coupler connectable to the catheter.

5. The system of claim 4, wherein the sensor is located within the fluid coupler.

6. The system of claim 4, wherein the flow control device is configured to draw back the sample volume into the fluid coupler, but substantially no farther than the fluid coupler.

7. The system of claim 4, wherein the sensor is held by the fluid coupler.

8. The system of claim 1, wherein the catheter is at least one of a venous catheter or an arterial catheter.

9. The system of claim 1, wherein the catheter is a Swan-Ganz catheter.

10. The system of claim 1, wherein the infusion solution comprises saline.

11. The system of claim 1, wherein the sensor comprises the high oxygen solubility material.

12. The system of claim 1, wherein the flow control device is configured to draw back a sample volume of from about 15 μ

L to about 2 mL of the biological fluid during a first phase.

13. The system of claim 12, wherein the sample volume is from about 20 μ

l to about 1 ml.

14. The system of claim 13, wherein the sample volume is from about 20 μ

l to about 500 μ

l.

15. The system of claim 14, wherein the sample volume is from about 25 μ

l to about 150 μ

l.

16. The system of claim 1, wherein the analyte comprises at least one analyte selected from the group consisting of glucose, O₂, CO₂, PCO₂, PO₂, potassium, sodium, pH, lactate, urea, bilirubin, creatinine, hematocrit, and combinations thereof.

17. The system of claim 1, wherein the analyte is glucose.

18. The system of claim 1, wherein second phase is longer than the first phase.

19. The system of claim 1, wherein a volume of the infusion solution moved during the second phase is greater than a volume of the biological fluid moved during the first phase.

20. The system of claim 1, wherein the high oxygen solubility material comprises a polymer selected from the group consisting of a hydrocarbonaceous polymer, an oxyhydrocarbon polymer, and combinations thereof.

21. The system of claim 1, wherein the high oxygen solubility material comprises a polymer selected from the group consisting of silicone, fluorocarbon and perfluorocarbons.

22. The system of claim 1, wherein the high oxygen solubility material has an oxygen permeability of from about 1 Barrer to about 1000 Barrers.