Skin Modeling Methods And Systems

• US 20100256966A1
• Filed: 03/30/2010
• Published: 10/07/2010
• Est. Priority Date: 04/02/2009
• Status: Active Grant

• Current Assignee: The Gillette Company LLC (The Procter & Gamble Company)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: O'Callaghan, David John, Cowley, Kevin David
• Granted Patent: US 8,306,753 B2
• Time in Patent Office: Days
• US Class Current: 703/11
• CPC Class Codes: G09B 23/30 Anatomical models G09B23/281 - G09B23/288 take precedence

Abstract

A system and method for generating a numerical skin model. The skin model may be used to predict the interaction of the skin to various devices, such as shaving devices and absorbent articles, for example. The computer-based numerical skin material model of the simulated skin may comprise a mechanical behavior model of a surface epidermis, a mechanical behavior model of a dermis, a mechanical behavior model of a hypodermis, and a van der Waals hyperelastic formulation to represent the behavior of the simulated skin. A strain stiffening viscoelasticty of the simulated human skin may be determined by a Prony time series expansion.

Claims

1. A method comprising:

determining the interaction of a simulated human skin with a simulated load delivered by a simulated device to the simulated human skin, wherein a behavior of the simulated human skin is represented by a van der Waals hyperelastic formula implemented by a computer system.

2. The method of claim 1, wherein the simulated device is a shaving device.

3. The method of claim 2, comprising generating a computer simulation of the shaving device.

4. The method of claim 2, wherein the shaving device is selected from the group consisting of a razor cartridge, a foil shaver, and a rotary shaver.

5. The method of claim 3, comprising generating a computer simulation of human skin.

6. The method of claim 1, wherein the simulated device is an absorbent article.

7. The method of claim 6, comprising generating a computer simulation of the absorbent article.

8. The method of claim 1, wherein the van der Waals hyperelastic formula represents the behavior of the simulated skin in accordance with any of an epidermis, a dermis, and a hypodermis layer of skin.

9. The method of claim 8, comprising determining a first response of at least the hypodermis layer of skin using a probe indent test.

10. The method of claim 9, comprising determining a second response of at least the dermis layer of skin using a skin bulge test.

11. The method of claim 10, comprising determining a third response of at least the epidermis layer of skin using an extensometry test.

12. The method of claim 11, comprising comparing with a computer system a simulated skin response generated by the van der Waals hyperelastic formula to any of the first response, the second response, and the third response.

13. The method of claim 12, comprising determining a difference between the simulated skin response and any one of the first, second, and third skin responses, and changing at least one parameter of the van der Waals hyperelastic formula based on the comparison when there is a predetermined difference between the simulated response and any one of the first, second, and third skin layer responses.

14. The method of claim 1, comprising determining a strain stiffening viscoelasticity of the simulated human skin by a Prony time series expansion.

15. The method of claim 14, wherein the Prony time series expansion is expressed as:

16. The method of claim 1, comprising characterizing the simulated human skin using a first site and a second site.

17. The method of claim 16, wherein the first site is a cheek site and the second site is a cheekbone site.

18. The method of claim 1, comprising characterizing the simulated human skin using at least one site selected from the group consisting of face, neck, legs, groin, and axilla.

19. The method of claim 1, wherein the van der Waals formulation is defined in terms of its strain potential as:

20. A shaving device designed according to the method of claim 1.

21. An absorbent article designed according to the method of claim 1.

22. A system for modeling the response of human skin to a shaving device, the system comprising:

a processor to determine the interaction of a simulated human skin with a simulated shaving load delivered by a simulated shaving device to the simulated human skin, wherein a behavior of the simulated human skin is represented by a van der Waals hyperelastic formula.

23. The system of claim 22, wherein the processor is to generate a computer simulation of a shaving device.

24. The system of claim 23, wherein the processor is to generate a computer simulation of a human skin.

25. The system of claim 24, wherein a first response of at least the hypodermis layer of skin is determined using a probe indent test.

26. The method of claim 25, wherein a second response of at least the dermis layer of skin is determined using a skin bulge test.

27. The method of claim 26, wherein a third response of at least the epidermis layer of skin is determined using an extensometry test.

28. The method of claim 27, wherein the processor is to compare the simulated skin response generated by the van der Waals hyperelastic formula to any of the first response, the second response, and the third response.

29. The method of claim 28, wherein the processor is to determine a difference between the simulated skin response and any one of the first, second, and third skin responses, and change at least one parameter of the van der Waals hyperelastic formula based on the comparison when there is a predetermined difference between the simulated response and any one of the first, second, and third responses.

30. The system of claim 22, wherein the van der Waals hyperelastic formula represents the behavior of the simulated skin in accordance with any of a surface epidermis, a dermis, and a hypodermis.

31. The system of claim 22, wherein the processor is to determine a strain stiffening viscoelasticty of the simulated human skin by a Prony time series.

32. The system of claim 31, wherein the Prony time series expansion μ

^R(t) is expressed as;

33. The system of claim 22, wherein the human skin is characterized using a first site and a second site.

34. The system of claim 33, wherein the first site is a cheek site and the second site is a cheekbone site.

35. The method of claim 22, comprising characterizing the simulated human skin using at least one site selected from the group consisting of face, neck, legs, groin, and axilla.

36. The system of claim 22, wherein the van der Waals formulation is defined in terms of its strain potential as:

37. A method comprising:

determining with a computer system the interaction of a simulated human skin with a simulated shaving load delivered by a simulated shaving device to the simulated human skin, the simulated human skin comprising a tri-layered skin model implemented by a hyperelastic formula.

38. The method of claim 37, wherein the tri-layered skin model comprises a first layer representing an epidermis, a second layer representing a dermis, and a third layer representing a hypodermis.

39. The method of claim 38, comprising determining a first response of at least the hypodermis layer of skin using a probe indent test.

40. The method of claim 39, comprising determining a second response of at least the dermis layer of skin using a skin bulge test.

41. The method of claim 40, comprising determining a third response of at least the epidermis layer of skin using an extensometry test.

42. The method of claim 41, wherein a van der Waals hyperelastic formula represents the behavior of the tri-layered skin model.

43. The method of claim 42, comprising comparing a simulated response generated by the van der Waals hyperelastic formula to any of the first response, the second response, and the third response.

44. The method of claim 43, comprising determining a difference between the simulated skin response and any of the first, second, and third responses, and changing at least one parameter of the van der Waals hyperelastic formula based on the comparison when there is a predetermined difference between the simulated response and any of the first, second, and third skin layer responses.

45. A method for generating a hyperelastic material skin model, comprising:

generating a computer simulation of a shaving device;

determining an actual skin response according to a predetermined test;

generating an initial computer simulation of human skin using a numerical formula;

generating a simulated skin response based on the numerical formula;

determining the interaction of the simulated skin with the simulated shaving device;

comparing with a computer system the results of the simulated skin response and the actual skin response;

determining a difference between the simulated response and any one of the first, second, and third skin responses;

changing at least one parameter of the numerical formula based on the comparison when the difference exceeds a predetermined difference to generate a revised numerical formula; and

generating a hyperelastic material model of skin based on numerical formula.

46. The method of claim 45, wherein the numerical formula is a van der Waals hyperelastic formula.

47. The method of claim 46, wherein the predetermined test is any of a probe indent test, a skin bulge test, and an extensometry test.

48. The method of claim 45, wherein the actual skin response is determined at least one site selected from the group consisting of face, neck, legs, groin, and axilla.