Vein Identification Technique

• US 20090124925A1
• Filed: 11/13/2007
• Published: 05/14/2009
• Est. Priority Date: 11/13/2007
• Status: Active Grant

• Current Assignee: Avent Incorporated (Avanos Medical, Inc.)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Kim, JungMo, Kim, Jaeho, Yang, Kaiyuan, MacDonald, J. Gavin
• Granted Patent: US 8,287,461 B2
• Time in Patent Office: Days
• US Class Current: 600/549
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/489 Blood vessels

Abstract

A technique for identifying a vein in a patient is disclosed. The technique involves the application of a thermochromic ink to a venous area on the skin of a patient (e.g., human or animal). The thermochromic ink comprises thermosensitive color-changing microcapsules that contain a proton-accepting chromogen and a desensitizer. The desensitizer possesses a melting point above which the chromogen is capable of becoming protonated, thereby resulting in a color change. Thereafter, the venous area is observed for the color change.

Claims

1. A method for identifying a vein in a patient, the method comprising:

applying a thermochromic ink to a venous area on the skin of a patient, wherein the thermochromic ink comprises thermosensitive color-changing microcapsules that contain a proton-accepting chromogen and a desensitizer, wherein the desensitizer possesses a melting point above which the chromogen is capable of becoming protonated, thereby resulting in a color change; and

thereafter, observing the venous area for the color change.

2. The method of claim 1, wherein the proton-accepting chromogen is a leuco dye.

3. The method of claim 2, wherein the leuco dye includes a phthalide, phthalene, acyl-leucomethylene, fluorane, spiropyrane, cumarin, or a combination thereof.

4. The method of claim 1, wherein proton-accepting chromogens constitute from about 0.1 wt. % to about 20 wt. % of the microcapsules.

5. The method of claim 1, wherein the desensitizer has a boiling point of about 150°

C. or higher.

6. The method of claim 1, wherein the desensitizer has a melting point of about from about 26°

C. to about 34°

C.

7. The method of claim 1, wherein the desensitizer includes a saturated or unsaturated alcohol, an ester of a saturated or unsaturated alcohol, an amide, or a combination thereof.

8. The method of claim 1, wherein desensitizers constitute from about 10 wt. % to about 70 wt. % of the microcapsules.

9. The method of claim 1, wherein the microcapsules further comprises a proton-donating agent.

10. The method of claim 9, wherein proton-donating agents constitute from about 0.5 wt. % to about 30 wt. % of the microcapsules.

11. The method of claim 1, wherein the microcapsules are formed from a polymer resin.

12. The method of claim 11, wherein polymer resins constitute from about 20 wt. % to about 80 wt. % of the microcapsules.

13. The method of claim 1, wherein the microcapsules having a mean particle size of from 10 nanometers to about 10 micrometers.

14. The method of claim 1, wherein the chromogen undergoes a color change at a temperature of from about 26°

C. to about 34°

C.

15. The method of claim 1, wherein the chromogen undergoes a color change at a temperature of from about 28°

C. to about 33°

C.

16. The method of claim 1, wherein the thermochromic ink further comprises a cooling agent.

17. The method of claim 16, wherein the cooling agent has an enthalpy of vaporization of about 40 kilojoules per mole or less.

18. The method of claim 16, wherein the cooling agent is an alcohol.

19. The method of claim 16, wherein cooling agents constitute from about 50 wt. % to about 99.9 wt. % of the ink and the microcapsules constitute from about 0.1 wt. % to about 50 wt. % of the ink.

20. The method of claim 16, wherein cooling agents constitute from about 30 wt. % to about 99 wt. % of the ink and the microcapsules constitute from about 1 wt. % to about 70 wt. % of the ink.

21. The method of claim 1, wherein the thermochromic ink is disposed on a substrate.

22. The method of claim 21, wherein the substrate contains a nonwoven web.

23. A kit for puncturing the vein of a patient, the kit comprising:

a thermochromic ink capable of locating the vein through a change in color, wherein the ink contains thermosensitive color-changing microcapsules that contain a proton-accepting chromogen and a desensitizer, the desensitizer possessing a melting point above which the chromogen is capable of becoming protonated; and

a syringe associated with a needle for puncturing the vein located by the thermochromic ink.

24. The kit of claim 23, wherein the thermochromic ink further comprises a cooling agent.

25. The kit of claim 23, further comprising a wipe for spreading the thermochromic ink onto a venous area of the skin.