Polymer membranes for continuous analyte sensors
Devices and methods are described for providing continuous measurement of an analyte concentration. In some embodiments, the device has a sensing mechanism and a sensing membrane that includes at least one surface-active group-containing polymer and that is located over the sensing mechanism. The sensing membrane may have a bioprotective layer configured to substantially block the effect and/or influence of non-constant noise-causing species.
1. A device for continuous measurement of an analyte concentration, the device comprising:
an implantable sensor configured to continuously measure in vivo a signal associated with an analyte concentration in a host; and
a membrane located over the sensor;
wherein the device is configured to provide, at analyte concentrations of from 40 mg/dL to 80 mg/dL, a level of accuracy corresponding to a mean absolute relative difference of no more than 10% over a sensor session of at least 3 days, wherein one or more reference measurements associated with calculation of the mean absolute relative difference are determined by analysis of blood.
2. The device of claim 1 , wherein the membrane comprises an enzyme configured to react with the analyte.
3. The device of claim 1 , wherein the membrane comprises a copolymer and a hydrophilic portion.
4. The device of claim 1 , wherein the copolymer comprises a polyurethane.
5. The device of claim 4 , wherein the copolymer further comprises a silicone segment.
6. The device of claim 5 , wherein the copolymer further comprises a polycarbonate segment.
7. The device of claim 1 , wherein the device is configured to provide, at analyte concentrations of from 40 mg/dL to 400 mg/dL, a level of accuracy of a mean absolute relative difference of no more than 10% over the sensor session, wherein one or more reference measurements associated with calculation of the mean absolute relative difference are determined by analysis of blood.
8. The device of claim 7 , wherein the mean absolute relative difference corresponding to measurements at analyte concentrations of from 40 mg/dL to 80 mg/dL is from 6% to 10%.
9. The device of claim 1 , wherein the mean absolute relative difference corresponding to measurements at analyte concentrations of from 40 mg/dL to 80 mg/dL is from 4.9% to 10%.
10. The device of claim 1 , wherein the membrane comprises a material that is a polymer produced by a reaction of an isocyanate.
11. The device of claim 10 , wherein the isocyanate is a polyisocyanate.
12. The device of claim 11 , wherein the polyisocyanate is a diisocyanate.
13. The device of claim 1 , wherein the sensor comprises an electrode configured to oxidize a measured species that is a product of an enzyme-catalyzed reaction with the analyte, whereby the signal is generated.
14. A system for continuous measurement of an analyte concentration, the system comprising:
an implantable sensor comprising a sensing region configured to continuously produce in vivo sensor data associated with an analyte concentration in a host, wherein the sensor further comprises a membrane located over the sensing region;
a processor configured to process continuous sensor data; and
a user interface configured to display information associated with continuous sensor data;
wherein the sensor is configured to provide, at analyte concentrations of from 40 mg/dL and 400 mg/dL, a level of accuracy of a mean absolute relative difference of no more than 10% over a sensor session of at least 3 days, wherein one or more reference measurements associated with calculation of the mean absolute relative difference are determined by analysis of blood.
15. The system of claim 14 , wherein the membrane comprises an enzyme configured to react with the analyte.
16. The device of claim 14 , wherein the membrane comprises a copolymer and a hydrophilic portion.
17. The device of claim 14 , wherein the copolymer comprises a polyurethane.
18. The device of claim 17 , wherein the copolymer further comprises a silicone segment.
19. The device of claim 18 , wherein the copolymer further comprises a polycarbonate segment.
20. The system of claim 14 , wherein the sensor is configured to provide, at analyte concentrations of from 40 mg/dL to 80 mg/dL, a level of accuracy of a mean absolute relative difference of no more than 10% over a sensor session of at least 3 days, wherein one or more reference measurements associated with calculation of the mean absolute relative difference are determined by analysis of blood.
21. The system of claim 20 , wherein the mean absolute relative difference corresponding to measurements at analyte concentrations of from 40 mg/dL to 80 mg/dL is from 6% to 10%.
22. The system of claim 14 , wherein the mean absolute relative difference corresponding to measurements at analyte concentrations of from 40 mg/dL to 400 mg/dL is from 6.8% to 10%.
23. The system of claim 14 , wherein the membrane comprises a material that is a polymer produced by a reaction of an isocyanate.
24. The system of claim 23 , wherein the isocyanate is a polyisocyanate.
25. The system of claim 24 , wherein the polyisocyanate is a diisocyanate.
26. The system of claim 14 , wherein the sensor comprises an electrode configured to oxidize a measured species that is a product of an enzyme-catalyzed reaction with the analyte, whereby the signal is generated.
27. A device for continuous measurement of an analyte concentration, the device comprising:
an implantable sensor configured to continuously measure in vivo a signal associated with an analyte concentration in a host; and
a membrane located over the sensor;
wherein, over a sensor session of at least 3 days, the device is configured to:
provide a level of accuracy corresponding to a first mean absolute relative difference value at analyte concentrations of from 40 mg/dL to 80 mg/dL, wherein one or more reference measurements associated with calculation of the first mean absolute relative difference are determined by analysis of blood; and
provide a level of accuracy corresponding to a second mean absolute relative difference value at analyte concentrations of from 40 mg/dL to 400 mg/dL, wherein one or more reference measurements associated with calculation of the second mean absolute relative difference are determined by analysis of blood; and
wherein the first mean absolute relative difference value is less than or equal to the second mean absolute relative difference value.
28. The device of claim 27 , wherein the membrane comprises an enzyme configured to react with the analyte.
29. The device of claim 27 , wherein the membrane comprises a copolymer and a hydrophilic portion.
30. The device of claim 27 , wherein the copolymer comprises a polyurethane.
31. The device of claim 30 , wherein the copolymer further comprises a silicone segment.
32. The device of claim 31 , wherein the copolymer further comprises a polycarbonate segment.
33. The device of claim 27 , wherein the first mean absolute relative difference value is from 4.9% to 10%.
34. The device of claim 27 , wherein the membrane comprises a material that is a polymer produced by a reaction of an isocyanate.
35. The device of claim 34 , wherein the isocyanate is a polyisocyanate.
36. The device of claim 35 , wherein the polyisocyanate is a diisocyanate.
37. The device of claim 27 , wherein the sensor comprises an electrode configured to oxidize a measured species that is a product of an enzyme-catalyzed reaction with the analyte, whereby the signal is generated.
38. A system for continuous measurement of an analyte concentration, the system comprising:
an implantable sensor configured to continuously measure in vivo a signal associated with an analyte concentration in a host, wherein the sensor further comprises a membrane located over the sensor;
a processor configured to process continuous sensor data; and
a user interface configured to display information associated with continuous sensor data;
wherein, over a sensor session of at least 3 days, the system is configured to:
provide a level of accuracy corresponding to a first mean absolute relative difference value at analyte concentrations of from 40 mg/dL to 80 mg/dL, wherein one or more reference measurements associated with calculation of the first mean absolute relative difference are determined by analysis of blood; and
provide a level of accuracy corresponding to a second mean absolute relative difference value at analyte concentrations of from 40 mg/dL to 400 mg/dL, wherein one or more reference measurements associated with calculation of the second mean absolute relative difference are determined by analysis of blood; and
wherein the first mean absolute relative difference value is less than or equal to the second mean absolute relative difference value.
39. The system of claim 38 , wherein the membrane comprises an enzyme configured to react with the analyte.
40. The device of claim 38 , wherein the membrane comprises a copolymer and a hydrophilic portion.
41. The device of claim 38 , wherein the copolymer comprises.
42. The device of claim 41 , wherein the copolymer further comprises a silicone segment.
43. The device of claim 42 , wherein the copolymer further comprises a polycarbonate segment.
44. The system of claim 38 , wherein the first mean absolute relative difference value is from 4.9% to 10%.
45. The system of claim 38 , wherein the membrane comprises a material that is a polymer produced by a reaction of an isocyanate.
46. The system of claim 45 , wherein the isocyanate is a polyisocyanate.
47. The system of claim 46 , wherein the polyisocyanate is a diisocyanate.
48. The system of claim 38 , wherein the sensor comprises an electrode configured to oxidize a measured species that is a product of an enzyme-catalyzed reaction with the analyte, whereby the signal is generated.