Methods for obtaining blood from a subject
Provided herein are methods for extracting blood from a subject's digit, such as a finger. Methods provided herein may release relatively large quantities of blood from a pierced finger. Pressure can be applied at selected locations on the subject's digit to increase blood flow released from the subject.
1. A method by a technician for releasing blood from a subject, comprising:
gripping only one digit of the subject using a multi-pressure zone technique, wherein gripping applies grip pressure simultaneously to i) a proximal phalanx of the digit between two digits of a hand of the technician at first zone and ii) one or both of an intermediate phalanx and a distal phalanx of the digit between another two digits of said hand of the technician at a second zone, and,
while pressure is maintained on the proximal phalanx and said one or both of the intermediate phalanx and the distal phalanx, piercing a site on the distal phalanx, wherein blood is released from the site pierced on the distal phalanx;
contacting released blood with a blood collection device;
after the distal phalanx has been pierced, releasing all of said pressure from the proximal phalanx and said one or both of the intermediate phalanx and distal phalanx,
reapplying and maintaining pressure to the proximal phalanx, and
while pressure is maintained on the proximal phalanx, reapplying and maintaining pressure to one or both of the intermediate phalanx and the distal phalanx, wherein blood is released from the site pierced on the distal phalanx and is contacted again by the blood collection device.
2. The method of claim 1 , wherein pressure on the proximal phalanx is maintained without using a sliding or translational motion to apply pressure against the digit.
3. The method of claim 1 , wherein pressure on said one or both of the intermediate phalanx and the distal phalanx is maintained without using a sliding or translational motion to apply pressure against the digit.
4. The method of claim 1 , wherein pressure is applied to the digit of the subject in a sequential manner, wherein pressure is first applied to the proximal phalanx and then pressure is applied to said one or both of the intermediate phalanx and the distal phalanx.
5. The method of claim 1 , wherein at least one of i) the applying and maintaining of pressure to the proximal phalanx or ii) the applying and maintaining of pressure to said one or both of the intermediate phalanx and distal phalanx, is performed by one or more fingers of a hand of a human technician.
6. The method of claim 5 , wherein both i) the applying and maintaining of pressure to the proximal phalanx and ii) the applying and maintaining of pressure to said one or both intermediate phalanx and distal phalanx, is performed by one or more fingers of a hand of a human technician.
7. The method of claim 5 , wherein the fingers are selected from a thumb, an index finger, a middle finger, a ring finger, and a small finger, and wherein the applying and maintaining pressure to the proximal phalanx is performed by fingers comprising the thumb and index finger.
8. The method of claim 5 , wherein the applying and maintaining pressure to said one or both intermediate phalanx and distal phalanx is performed by one or more fingers comprising the middle finger.
9. The method of claim 1 , further comprising warming the digit before the applying pressure to or piercing the digit.
10. The method of claim 1 , wherein during the method a total of at least 50 microliters blood is released from the digit of the subject.
11. The method of claim 10 , wherein during the method a total of at least 100 microliters blood is released from the digit of the subject.
12. The method of claim 1 , wherein during the majority of the duration of the method, the distal phalanx is maintained at a lower elevation than the elevation of the proximal phalanx.
13. The method of claim 1 , wherein the digit is pierced with a needle having an outer diameter of 1.1 mm or smaller.
14. The method of claim 1 , further comprising contacting the released blood with a channel of the blood collection device.
15. The method of claim 14 , wherein the channel of the blood collection device has a perimeter of no greater than 15 millimeters.
16. A method of teaching a technician to obtain blood from a subject's digit, the method comprising providing the technician with instructions for releasing blood from a subject's digit according to the method of claim 1 .
17. A kit for releasing blood from a subject, the kit comprising instructions for releasing blood from a subject's digit according to the method of claim 1 , wherein the instructions are written on paper or stored on a portable data storage device and at least one blood collection device.
18. The kit of claim 17 , wherein the kit further comprises a piercing device.