LIGHT DIFFUSER AND PROCESS FOR PRODUCING THE SAME

• US 20090318912A1
• Filed: 06/18/2009
• Published: 12/24/2009
• Est. Priority Date: 05/03/2004
• Status: Active Grant

• Current Assignee: Woodwelding AG
• Original Assignee: Woodwelding AG
• Inventors: Walt, Heinrich, Torriani, Laurent, Aeschlimann, Marcel, Mayer, Jörg
• Granted Patent: US 8,568,395 B2
• Time in Patent Office: Days
• US Class Current: 606/14
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 2018/2261 with scattering, diffusion or dispersion of light

Abstract

A light diffuser (10), which is particularly suitable for introducing diffuse light into a tissue, is produced by interpenetration of a diffuser material in a liquid state into a boundary layer (4) of a porous shaping material, by which process a diffuser surface is formed having a surface structure which represents essentially a negative of the pore structure of the shaping material and includes undercut structures induced by a surface tension. The light diffuser (10) is e.g. produced by introducing a diffuser blank (1) including material which is liquefiable through mechanical vibration into the shaping material and simultaneously stimulating it with mechanical vibrations, such that the liquefiable material liquefies at least there where it is in contact with the shaping material and is pressed into the shaping material. An in situ production of the diffuser is particularly advantageous for photodynamic therapy in bone tissue (20).

Claims

1. A light diffuser consisting of an at least partly transparent diffuser material, the light diffuser comprising:

a proximal end suitable for coupling light supplied by a light conductor into the light diffuser, and

the light diffuser further comprising light scattering surface areas through which the light coupled into the light diffuser is deflected diffusely out of the light diffuser,

wherein the light scattering surface areas comprise structures which are produced by interpenetration of the diffuser material in a liquid state in a boundary layer of a porous shaping material and which therefore comprise undercut forms induced by a surface tension.

2. The light diffuser according to claim 1, being pin-shaped and the light scattering surface areas being situated upon its circumferential surface and/or at its distal end.

3. The light diffuser according to claim 1, wherein the diffuser material is a thermoplastic material, a material which is thermosetting through a chemical reaction, or a gel.

4. The light diffuser according to claim 1, and further comprising a diffuser core equipped for a further function.

5. The light diffuser according to claim 4, wherein the diffuser core consists of a non-transparent material and is equipped for a non-optical function.

6. The light diffuser according to claim 4, wherein the diffuser core consists at least partly of a transparent material and is equipped for a further optical function.

7. The light diffuser according to claim 1 being implanted in bone tissue, which constitutes the shaping material.

8. The light diffuser according to claim 1, and further comprising a diffuser cap of the porous shaping material, wherein the porous shaping material of the diffuser cap is interpenetrated in a boundary layer by the diffuser material.

9. The light diffuser according to claim 8, wherein the diffuser cap is designed as an instrument or part of an instrument.

10. The light diffuser according to claim 8, wherein the diffuser cap comprises a non-homogenous porosity.

11. A method for producing a light diffuser according to claim 1, the method comprising the steps of pressing the diffuser material, in a liquid state, into pores of a boundary region of the porous shaping material and then bringing it into a solid or gel-like state.

12. The method according to claim 11, wherein the porous shaping material is left on the diffuser as a diffuser cap.

13. The method according to claim 11, wherein the porous shaping material is re-moved from the diffuser.

14. The method according to claim 11, wherein the porous shaping material comprises a porosity with a pore size ranging between 0.005 and 1.0 mm.

15. The method according to claim 11, wherein a diffuser blank consisting of a thermoplastic diffuser material and comprising a distal end and a proximal end, which is equipped for coupling the supplied light into the light diffuser, is positioned in or on the porous shaping material and that mechanical vibration is applied to the proximal end and the diffuser blank is simultaneously pressed against the porous shaping material, so that the thermoplastic diffuser material liquefies in those regions of the surface area in contact with the porous shaping material and is pressed into the porous shaping material.

16. The method according to claim 11, wherein a diffuser blank consisting of a thermoplastic diffuser material and comprising a distal end and a proximal end, which is equipped for coupling the supplied light into the light diffuser, is positioned in or on the porous shaping material, wherein the diffuser material and/or the shaping material are equipped for absorbing light coupled into the diffuser material, and that light is coupled into the proximal end, and the diffuser blank is simultaneously pressed against the porous shaping material, so that the thermoplastic diffuser material liquefies at least partly through heat produced by the light absorption and is pressed into the porous shaping material.

17. The method according to claim 15, wherein an opening is provided in the porous shaping material and wherein the diffuser blank is positioned in the opening such that its distal end is not brought in contact with the bottom of the opening, neither when it is positioned nor when it is pressed and the mechanical vibration is applied.

18. The method according to claim 15, wherein an opening is provided in the porous shaping material and the diffuser blank is driven into a bottom of the opening, the distal end facing forward or wherein no opening is provided in the porous shaping material and the diffuser blank is driven into the porous shaping material with the distal end facing forward.

19. A diffuser blank suitable for being used in the method according to claim 11, the diffuser blank being pin-shaped, consisting at least partly of a transparent, thermoplastic diffuser material, comprising a distal end and a proximal end, wherein the proximal end is suitable for coupling light into the diffuser blank and for mechanical vibrations to be applied to the diffuser blank, and further comprising surface areas on its circumferential surface and/or on its distal end, where the diffuser material is to be liquefied for the generation of a light scattering surface structure and to be pressed into the porous shaping material, and which to this purpose protrude beyond further surface areas or are furnished with protruding energy directors and are situated on the diffuser blank in such a manner that they are able to be brought into contact with the porous shaping material.

20. The diffuser blank according to claim 19, wherein the further surface areas are polished or coated.

21. The diffuser blank according to claim 19, being suitable as an illuminative implant and comprising a clinically applicable, thermoplastic polymer.

22. The diffuser blank according to claim 21, wherein the polymer is biologically resorbable.

23. The diffuser blank according to claim 19, and further comprising a diffuser core equipped for further functions, and wherein the diffuser material is situated at the periphery of the diffuser core or the diffuser material is provided inside the diffuser core and the diffuser core comprises openings, through which the diffuser material can be pressed to the surface of the diffuser core.

24. A method for introducing diffuse light into an area in a tissue to be treated with light, which is supplied to the tissue area by means of a light conductor with a distal light conductor end, wherein a diffuser blank according to claim 21 is implanted in the tissue such that its proximal end remains accessible and its distal end reaches to, or into the tissue area to be treated, wherein, for implantation, mechanical vibrations are applied to the diffuser blank through its proximal end and the diffuser blank is pressed into the tissue such that the thermoplastic diffuser material is liquefied in the surface areas protruding or equipped with energy directors and is pressed into the tissue, and wherein the distal light conductor end is then coupled to the proximal end and light is coupled into the diffuser.

25. The method according to claim 24, wherein the diffuser blank is pin-shaped and is implanted in bone tissue.

26. The method according to claim 24, wherein a cortical bone layer is opened for the implantation of the diffuser blank, and wherein the diffuser blank is driven into cancellous bone without providing an opening therein.

27. The method according to claim 24, wherein the diffuser blank comprises towards its proximal end a surface range without energy directors or with a recessed surface and that the axial length of this surface range is adjusted to the depth of a bone region to be treated.

28. The method according to claim 26, wherein the diffuser blank comprises towards its distal end a surface range with energy directors or with a protruding surface and that the axial length of this surface range is adjusted to the size of the bone tissue area to be treated.

29. A method for introducing diffuse light into an area in a tissue to be treated, comprising the steps of:

supplying light to the tissue area by means of a light conductor with a distal light conductor end,

implanting a diffuser blank comprising a thermoplastic material and a light-scattering/light-absorbing agent in the tissue such that its proximal end remains accessible and its distal end reaches to, or into the tissue area to be treated,

for implantation, coupling light which is predominantly absorbed by the light-scattering/light-absorbing agent into the diffuser blank through its proximal end and

pressing the diffuser blank into the tissue such that the thermoplastic diffuser material is liquefied at least partly and is pressed into the tissue, and wherein light, which is pre-dominantly scattered by the light-scattering/light-absorbing agent is then coupled into the diffuser.

30. A pin-shaped implant suitable for implantation in bone tissue, the implant comprising:

a distal end,

a proximal end suitable for light being coupled into the implant,

the implant comprising a thermoplastic material, which in a pure state is light-transparent, and

further comprising a light-scattering/light-absorbing agent.

31. The implant according to claim 30, wherein the light-scattering/light-absorbing agent comprises at least one of titanium oxide, mica, calcium phosphate, sodium phosphate, calcium carbonate, saturated fatty acid, polysaccharide and glucose.