Tissue support structure

• US 20060249875A1
• Filed: 02/14/2006
• Published: 11/09/2006
• Est. Priority Date: 02/14/2005
• Status: Active Grant

• Current Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Original Assignee: Mayo Foundation For Medical Education And Research (Mayo Clinic)
• Inventors: Rajagopalan, Srinivasan, Robb, Richard A.
• Granted Patent: US 7,718,109 B2
• Time in Patent Office: Days
• US Class Current: 264/239
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

Techniques for generating tissue support structure are presented. A curved minimal surface shape is determined as a template for generating a tissue support structure. The determined curved minimal surface shape is numerically or functionally defined to create data representing the shape. The data is exported to a rapid prototyping system to generate a plurality of tissue support structures having a curved minimal surface. The tissue support structure can have a pore sub-section and a non-pore sub-section divided by a non-intersecting two-sided surface. A number of characteristics of the tissue support structure can be modulated including porosity and mechanical strength.

Claims

1. A method of generating a tissue support structure, the method comprises:

determining a curved minimal surface shape as a template for the tissue support structure;

obtaining data indicative of the determined curved minimal surface shape; and

generating the tissue support structure based on the data.

2. The method of claim 1, further comprises generating a plurality of tissue support structures using a rapid prototyping technique.

3. The method of claim 2, wherein the rapid prototyping technique is solid freeform fabrication.

4. The method of claim 1, wherein generating the tissue support structure comprises creating a pore sub-space and a non-pore sub-space divided by a non-intersecting two-sided surface.

5. The method of claim 1, wherein determining a curved minimal surface shape comprises:

selecting a fundamental region; and

deforming for surface minimality a plane in the fundamental region to obtain a patch.

6. The method of claim 5, wherein obtaining data comprises defining the curved minimal surface shape using a numerical or a functional representation.

7. The method of claim 6, wherein generating the tissue support structure comprises:

tessellating the patch to generate a unit cell having a curved minimal surface; and

tessellating the unit cell to generate a monolithic scaffold comprising repeated unit cells having a curved minimal surface.

8. The method of claim 7, wherein the curved minimal surface is a triply periodic Schwartz minimal surface.

9. The method of claim 7, wherein the patch is a discrete patch represented by a variable number of triangles.

10. The method of claim 1, further comprises modulating a porosity of the tissue support structure based on a scaling factor.

11. The method of claim 10, wherein the porosity is greater than fifty percent.

12. The method of claim 1, further comprises modulating a mechanical strength of the tissue support structure based on a non-zero constant mean curvature.

13. The method of claim 1, further comprises creating parallel seeding and feeding networks by embedding a constant mean curvature version of a Schwartz unit-cell within an optimally evolved Schwartz unit-cell.

14. A machine readable medium storing instructions operable to cause data processing apparatus to:

determine a curved minimal surface shape as a template for the tissue support structure;

obtain data indicative of the determined curved minimal surface shape; and

export the data to a rapid prototyping system to generate the tissue support structure based on the data.

15. The machine readable medium of claim 14, wherein the rapid prototyping technique is solid freeform fabrication.

16. The machine readable medium of claim 14, wherein generating the tissue support structure comprises creating a pore sub-space and a non-pore sub-space divided by a non-intersecting two-sided surface.

17. The machine readable medium of claim 14, wherein determining a curved minimal surface shape comprises:

selecting a fundamental region; and

deforming for surface minimality a plane in the fundamental region to obtain a patch.

18. The machine readable medium of claim 17, wherein obtaining data comprises defining the curved minimal surface shape using a numerical or a functional representation.

19. The machine readable medium of claim 18, wherein generating the tissue support structure comprises:

tessellating the patch to generate a unit cell having a curved minimal surface; and

tessellating the unit cell to generate a monolithic scaffold comprising repeated unit cells having a curved minimal surface.

20. The machine readable medium of claim 19, wherein the curved minimal surface is a triply periodic Schwartz minimal surface.

21. The machine readable medium of claim 19, wherein the patch is a discrete patch represented by a variable number of triangles.

22. The machine readable medium of claim 14, wherein the instructions are further operable to cause data processing apparatus to modulate a porosity of the tissue support structure based on a scaling factor.

23. The machine readable medium of claim 22, wherein the porosity is modulated to a value greater than fifty percent.

24. The machine readable medium of claim 14, wherein the instructions are further operable to cause data processing apparatus to modulating a mechanical strength of the tissue support structure based on a constant mean curvature.

25. The machine readable medium of claim 14, wherein the instructions are further operable to cause data processing apparatus to create parallel seeding and feeding networks by embedding a constant mean curvature version of a Schwartz unit-cell within an optimally evolved Schwartz unit-cell.

26. A system for generating a tissue support structure, the system comprising:

a computer system operable to;

determine a curved minimal surface shape as

a template for the tissue support structure;

obtain data indicative of the determined

curved minimal surface shape; and

an automated fabrication system operable to receive the data and generate the tissue support structure based on the data.

27. The system of claim 26, wherein the automated fabrication system is a solid freeform fabrication system operable to generate a plurality of tissue support structures.

28. The system of claim 26, wherein generating the tissue support structure comprises creating a pore sub-space and a non-pore sub-space divided by a non-intersecting two-sided surface.

29. The system of claim 26, wherein determining a curved minimal surface shape comprises:

selecting a fundamental region; and

deforming for surface minimality a plane in the fundamental region to obtain a patch.

30. The system of claim 29, wherein obtaining data comprises defining the curved minimal surface shape using a numerical or a functional representation.

31. The system of claim 30, wherein generating the tissue support structure comprises:

tessellating the patch to generate a unit cell having a curved minimal surface; and

tessellating the unit cell to generate a monolithic scaffold comprising repeated unit cells having a curved minimal surface.

32. The system of claim 31, wherein the curved minimal surface is a triply periodic Schwartz minimal surface.

33. The system of claim 31, wherein the patch is a discrete patch represented by a variable number of triangles.

34. The system of claim 26, wherein the computer system is further operable to modulate a porosity of the tissue support structure based on a scale factor.

35. The system of claim 26, wherein the computer system is further operable to modulate a mechanical strength of the tissue support structure based on a constant mean curvature.

36. The system of claim 26, wherein the computer system is further operable to provide parallel seeding and feeding of the tissue support structure by embedding a constant mean curvature version of a Schwartz unit-cell within an optimally evolved Schwartz unit-cell.