Catalysts for body fluid sample extraction
An arrangement for producing a sample of body fluid from a wound opening created in a skin surface at a sampling site includes at least one skin-penetration member having a first end configured to pierce the surface of the skin, and a inner lumen in communication with the first end; at least one actuator operatively associated with the at least one skin-penetration member; and at least one catalyst device configured to cause perfusion of body fluid at the sampling site; wherein the at least one actuator is configured to locate the at least one skin-penetration member so as to obstruct the wound opening while transporting body fluid through the inner lumen. Associated methods are also described.
1. A method for producing a sample of, and for calculating the presence and/or concentration of a target analyte in, body fluid from a wound opening created in a skin surface at a sampling site, the method comprising:
providing an arrangement comprising a plurality of skin-penetration members, the skin penetration members each having a first end configured to pierce the surface of the skin, and each skin-penetration member further comprising an inner lumen in communication with each first end;
actuating a first of the plurality skin-penetration members with a respective torsional spring actuator operatively associated with the first skin-penetration member; wherein the spring actuator has a neutral rest position, and obstructing the wound opening with the first end of the first skin-penetration member when the spring actuator is in the neutral rest position, and urging the first skin-penetration member along an arcuate path with the spring actuator;
applying at least one catalyst to facilitate perfusion of body fluid at the sampling site;
providing a plurality of signaling mechanisms, each signaling mechanism associated with a respective skin penetration member,
transporting a sample of body fluid from the first end of the first skin penetration member to a respective signaling mechanism, and generating a detectable signal indicative of the presence and/or concentration of the target analyte;
detecting the signal with at least one detector associated with the plurality of signaling mechanisms;
calculating the presence and/or concentration of the target analyte with electronics using the signal; and
retracting the first skin-penetration member after the calculation of the presence and/or concentration of the target analyte, wherein the arrangement performs the retracting.
2. The method of claim 1 , further comprising positioning a footprint over the sampling site prior to actuating the skin-piercing member.
3. The method of claim 2 , wherein the footprint has an opening, the opening having a diameter or major dimension of about 3-8 mm.
4. The method of claim 3 , wherein the footprint comprises an elastomeric seal.
5. The method of claim 1 , wherein the method is initiated by manually pressing a button.
6. The method of claim 1 , wherein the first skin-penetration member is actuated and driven into the surface of the skin without interference by a positive stop to limit a depth of penetration of the first skin-penetration member.
7. The method of claim 1 , wherein applying the catalyst comprises applying one or more of vacuum pressure, positive pressure, heat, vibration or topical drugs to the sampling site.
8. The method of claim 7 , wherein applying the catalyst comprises applying vacuum pressure to the sampling site with a pump.
9. The method of claim 7 , further comprising quantifying a volume of the body fluid sample.
10. The method of claim 9 , further comprising controlling the application of the catalyst based at least in part on a volume of body fluid extracted.
11. The method of claim 1 , further comprising providing the plurality of skin-penetration members and the plurality of actuators operatively arranged on a disposable cartridge, and initiating multiple testing sequences without replacing the cartridge.
12. The method of claim 11 , further comprising moving the cartridge to present a new skin-penetration member and actuator for use after the performance of a preceding testing sequence.
13. The method of claim 2 , further comprising sensing when the sampling site is located over the footprint.
14. The method of claim 13 , wherein once the sampling site has been sensed, automatically actuating the catalyst and the first skin penetration member.
15. The method of claim 1 , further comprising providing a plurality of hubs, wherein each skin-penetration member is attached to a respective hub, and wherein each hub is attached to a respective torsional spring actuator.
16. The method of claim 15 , wherein each hub comprises a respective signaling mechanism.
17. The method of claim 16 , wherein each signaling mechanism comprises a reagent pad.
18. The method of claim 1 , wherein the body fluid comprises blood.
19. The method of claim 1 , further comprising transporting body fluid through the inner lumen of the first skin-penetration member.