Transcutaneous medical device with variable stiffness

• US 20060015024A1
• Filed: 03/10/2005
• Published: 01/19/2006
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brister, Mark, Brauker, James
• Granted Patent: US 7,783,333 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• 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 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/6833 Adhesive patches

Abstract

The present invention relates generally to variable stiffness transcutaneous medical devices including a distal portion designed to be more flexible than a proximal portion. The variable stiffness can be provided by a variable pitch in one or more wires of the device, a variable cross-section in one or more wires of the device, and/or a variable hardening and/or softening in one or more wires of the device.

Claims

1. A transcutaneous analyte sensor, the sensor comprising an elongated flexible portion, wherein the elongated flexible portion has a variable stiffness along at least a portion of its length.

2. The sensor of claim 1, wherein the sensor comprises at least one wire in a helical configuration, and wherein the variable stiffness is provided by a variable pitch of the helical configuration.

3. The sensor of claim 1, wherein the sensor comprises at least one wire in a helical configuration, and wherein the variable stiffness is provided by a variable cross-section of the wire.

4. The sensor of claim 1, wherein the sensor comprises at least one wire, and wherein the variable stiffness is provided by a variable hardness of the wire.

5. The sensor of claim 4, wherein the variable stiffness of the elongated flexible portion is produced by subjecting the wire to an annealing process.

6. The sensor of claim 1, wherein the sensor comprises at least one wire, the wire having a variable diameter.

7. The sensor of claim 1, wherein a distal portion of the sensor is more flexible than a proximal portion of the sensor.

8. The sensor of claim 1, wherein an intermediate portion of the sensor is more flexible than at least one of a distal portion of the sensor and a proximal portion of the sensor.

9. The sensor of claim 1, wherein a distal tip of the sensor is stiffer than at least one of an intermediate portion of the sensor and a proximal portion of the sensor.

10. A transcutaneous analyte sensor, the sensor comprising a distal portion, an intermediate portion, and a proximal portion, wherein the distal portion is adapted to be inserted through a skin of a host, wherein the proximal portion is adapted to remain substantially external to the host when the distal portion is inserted in the host, and wherein a stiffness of the sensor is variable along a length of the sensor.

11. The sensor of claim 10, wherein the proximal portion is stiffer than the distal portion.

12. The sensor of claim 11, wherein the sensor comprises at least one wire in a helical configuration, and wherein a difference in stiffness of the distal portion and the proximal portion is provided by varying a pitch of the helical configuration.

13. The sensor of claim 11, wherein the sensor comprises at least one wire in a helical configuration, and wherein a difference in flexibility of the distal portion and the proximal portion is provided by a varying a cross-section of the wire.

14. The sensor of claim 11, wherein the sensor comprises at least one wire, and wherein a difference in flexibility of the distal portion and the proximal portion is provided by a varying a hardness of the wire.

16. The sensor of claim 11, wherein the intermediate portion is more flexible than at least one of the distal portion and the proximal portion.

17. The sensor of claim 16, wherein the distal portion comprises a distal tip on an end of the sensor that is stiffer a substantial portion of the sensor.

18. The sensor of claim 10, wherein the intermediate portion is more flexible than at least one of the distal portion and the proximal portion.

19. The sensor of claim 18, wherein the distal portion comprises a distal tip on an end of the sensor that is stiffer a substantial portion of the sensor.

15. The sensor of 14, wherein a variation in stiffness of the elongated flexible portion is produced by subjecting the wire to an annealing process.

20. A transcutaneous analyte sensor, the sensor comprising an in vivo portion adapted for insertion into a host and an ex vivo portion adapted for operable connection to a device that remains external to the host, wherein the sensor is configured to absorb a relative movement between the ex vivo portion of the sensor and the in vivo portion of the sensor.

21. The sensor of claim 20, wherein the sensor is configured to absorb a relative movement by a flexibility of at least an intermediate portion located between the in vivo portion and the ex vivo portion.

22. The sensor of claim 20, wherein the device comprises a housing adapted for mounting on a skin of a host, wherein the housing comprises electrical contacts operably connected to the sensor.

23. The sensor of claim 21, wherein the ex vivo portion of the sensor is has a preselected stiffness to maintain a stable connection between the sensor and the electrical contacts.

24. The sensor of claim 20, wherein the in vivo portion of the sensor has a preselected flexibility to minimize mechanical stresses caused by motion of the host.

25. The sensor of claim 20, wherein a stiffness of the ex vivo portion of the sensor is greater than a stiffness of the in vivo portion of the sensor.