Transcutaneous analyte sensors, applicators therefor, and associated methods
The present embodiments relate generally to applicators of on-skin sensor assemblies for measuring an analyte in a host, as well as their method of use and manufacture. In some aspects, an applicator for applying an on-skin sensor assembly to a skin of a host is provided. The applicator includes an applicator housing, a needle carrier assembly comprising an insertion element configured to insert a sensor of the on-skin sensor assembly into the skin of the host, a holder releasably coupled to the needle carrier assembly and configured to guide the on-skin sensor assembly while coupled to the needle carrier assembly, and a drive assembly configured to drive the insertion element from a proximal starting position to a distal insertion position, and from the distal insertion position to a proximal retraction position.
1. An applicator for applying an on-skin sensor assembly to a skin of a host, the applicator comprising:
an on-skin sensor assembly including a housing;
a first body releasably coupled to an insertion element;
a second body releasably coupled to the first body by a frictional engagement;
a spring configured to provide a first force to the second body, the first force driving the first body, the second body, and the on-skin sensor assembly in a distal direction; and
wherein the frictional engagement is configured to be decoupled by a counter force applied to the on-skin sensor assembly in an opposite direction of the first force.
2. The applicator of claim 1 , further comprising at least one retention element configured to frictionally couple the second body to the first body.
3. The applicator of claim 2 , wherein the at least one retention element is formed integral with the second body.
4. The applicator of claim 3 , wherein the at least one retention element is frictionally engaged against a wall of the first body.
5. The applicator of claim 4 , wherein the counter force decouples the frictional engagement by displacing the at least one retention element from the wall of the first body.
6. The applicator of claim 5 , wherein the wall is a backstop.
7. The applicator of claim 5 , wherein the wall is configured to prevent the at least one retention element from deflecting.
8. The applicator of claim 2 , wherein the frictional engagement is decoupled by the counter force exceeding a force threshold.
9. The applicator of claim 8 , wherein the force threshold is determined by the frictional force between the at least one retention element and the first body.
10. The applicator of claim 9 , wherein the threshold is at least 0.5 lbf.
11. The applicator of claim 9 , wherein the threshold is at least 1 lbf.
12. The applicator of claim 1 , wherein the first body is configured to retract in a proximal direction upon decoupling of the frictional engagement.
13. The applicator of claim 12 , further comprising a second spring, the second spring configured to drive the first body in a proximal direction.
14. The applicator of claim 13 , wherein the second spring is retained from release by at least one retention element of the second body.
15. The applicator of claim 1 , wherein the decoupling of the frictional engagement is configured to be independent of a distance between the on-skin sensor assembly and a distal end of the applicator.
16. The applicator of claim 15 , wherein the first body is configured to retract independent of the distance between the on-skin sensor assembly and the distal end of the applicator.
17. The applicator of claim 1 , wherein the counter force applied to the on-skin sensor assembly is configured to be provided by the skin of the host opposing the first force.
18. The applicator of claim 17 , wherein an interior of the applicator is configured to allow the skin of the host to reside within the interior.
19. The applicator of claim 1 , wherein the insertion element is configured to be inserted into the skin a predetermined depth.
20. The applicator of claim 1 , wherein the frictional engagement is configured to decouple at a range of distances between the on-skin sensor assembly and a distal end of the applicator.