Systems and methods for the analysis of mechanical properties of materials

• US 8,095,706 B2
• Filed: 09/02/2008
• Issued: 01/10/2012
• Est. Priority Date: 08/30/2007
• Status: Expired due to Fees

• Current Assignee: McGill University, Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Sprigle, Stephen, Kong, Linghua, Wang, Qi, Hayward, Vincent, Caspall, Jayme
• Primary Examiner(s): Khuu, Cindy H
• Application Number:
  US12/202,821
• Publication Number:
  US 20090076732A1
• Time in Patent Office: 1,225 Days
• Field of Search: 702/42
• US Class Current: 710/42
• CPC Class Codes: A61B 5/0051 by applying vibrations
• CPC Class Codes: A61B 5/442 Evaluating skin mechanical properties, e.g. elasticity, hardness, texture, wrinkle assessment
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore

Abstract

The various embodiments of the present invention relate generally to the analysis of the mechanical properties of materials. More particularly, the various embodiments of the present invention relates to systems and methods of deriving the static and dynamic mechanical properties of deformative materials, for example, but not limited to, biological surfaces. The systems and methods of the present invention can be used to derive and evaluate the mechanical properties of many biological surfaces and subsurfaces, including but not limited to the skin.

Claims

1. A system for deriving at least one mechanical property of a skin and tissue, the system comprising:

(a) an excitation generator configured to generate a predetermined excitation at a predetermined time;

(b) a first elongated member having a first distal end configured to contact the skin at a first position;

(c) a second elongated member that has a second distal end configured to contact the skin at a second position spaced apart from the first position, the second elongated member including a flexion element that is constrained in two different spaced apart places and that is configured to apply a first strain tangentially to the skin in a first direction in response to the predetermined excitation;

(d) a detection element configured to measure a parameter of the first flexion element in response to the predetermined excitation; and

(e) a processing system to calculate the at least one mechanical property of the skin and tissue based on the parameter measured by the detection element.

2. The system of claim 1, wherein the mechanical property is selected from a list of properties consisting of:

elasticity, viscosity, surface stiffness, surface thickness, relaxation, creep, hysteresis, and combinations thereof.

3. The system of claim 1, wherein the excitation generator comprises an electronic circuit configured to generate an electrical excitation.

4. The system of claim 1, wherein the flexion element comprises:

(a) a metal strip; and

(b) a piezoelectric strip affixed to the metal strip and configured to change length in response to an electrical excitation.

5. The system of claim 1, wherein the first elongated member comprises a flexion element that is constrained in two different spaced apart places and that is configured to apply a force tangentially to the skin in a second direction, different from the first direction, in response to the excitation.

6. The system of claim 5, wherein the flexion element comprises:

(a) a metal strip; and

(b) a piezoelectric strip affixed to the metal strip and configured to change length in response to an electrical excitation.

7. The system of claim 1, further comprising a first set of pins that is configured to constrain the flexion element in a first place and a second set of pins spaced apart at a distance from the first set of pins and that is configured to constrain the flexion element in a second place, different from the first place.

8. The system of claim 7, wherein at least one of the first set of pins and the second set of pins is adjustable so as to be configured to adjust the distance between the first place and the second place.

9. The system of claim 7, further comprising a pair insulating elements disposed on the first elongated member and the second elongated member so as to electrically isolate the first elongated member and the second elongated member from the skin.

10. A method for measuring a mechanical property of a surface, comprising the steps of:

(a) placing a first elongated member against the surface;

(b) applying an excitation to a first flexion element, a portion of which is in contact with the surface at a position that is spaced apart from the first elongated member, thereby causing the first flexion element to apply a strain tangentially to the surface;

(c) measuring a deflection of the first flexion element when the excitation is being applied thereto; and

(d) calculating, using a digital processor, the mechanical property of the surface based on the strain and the deflection.

11. The method of claim 10, wherein the mechanical property is selected from a list of mechanical properties consisting of:

elasticity, viscosity, surface stiffness surface thickness, relaxation, creep, hysteresis, and combinations thereof.

12. The method of claim 10, wherein the surface comprises a skin.

13. The method of claim 10, wherein the excitation comprises an electrical excitation.

14. The method of claim 10, wherein the flexion element comprises:

(a) a metal strip; and

(b) a piezoelectric strip affixed to the metal strip, and

wherein the excitation comprise and electrical excitation applied to the piezoelectric strip thereby causing the piezoelectric strip to change in length.

15. The method of claim 10, further comprising the step of constraining the first flexion element in two spaced apart places.

16. The method of claim 10, wherein the first elongated member comprises a flexion element, the method further comprising the step of applying an excitation to the first elongated element.