Low Profile Apparatus and Method for Phototherapy

• US 20130345687A1
• Filed: 08/13/2013
• Published: 12/26/2013
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: Gradiant Research, LLC
• Original Assignee: Gradiant Research, LLC
• Inventors: McMillan, Kathleen, Gupta, Anurag, McGuire, James Patrick Jr.
• Granted Patent: US 9,554,856 B2
• Time in Patent Office: Days
• US Class Current: 606/18
• CPC Class Codes: A61B 18/22 the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
• CPC Class Codes: A61B 2018/2222 Fibre material or composition
• CPC Class Codes: A61B 2018/2253 characterised by additional functions, e.g. surface cooling or detecting pathological tissue
• CPC Class Codes: A61N 5/06 using light
• CPC Class Codes: A61N 5/067 using laser light

Abstract

Disclosed herein are optical assemblies having thin, low profile shapes. These optical assemblies may be used with fiber coupled lasers and other light sources, including high power sources, to irradiate tissue at a wavelength suitable for inducing ablation or coagulation to a target depth, denaturation, thermal modification of a tissue, and/or preferential injury to a target tissue structure. Example optical assemblies can produce substantially uniform illumination patterns that are useful for treating superficial tissue, including the internal or luminal (e.g., esophageal) tissue. Some examples may have capability for cooling superficial tissue or skin, such as a detachable, reusable heat sink for active cooling without consumables, fluid pumps, or other cooling equipment.

Claims

1. An apparatus for irradiating a tissue surface, comprising:

a plurality of reflecting elements configured to direct light onto respective segment areas of a window element, the window element having a light-transmitting contact surface configured to irradiate the tissue surface.

2. The apparatus of claim 1, further including:

a cooling layer configured to remove heat from the plurality of reflecting elements via a cooling fluid.

3. The apparatus of claim 1, wherein the plurality of reflecting elements includes at least one partially reflecting prism or mirror disposed in the path of an optical beam.

4. A method of irradiating a tissue surface, comprising:

directing light onto a window element with a plurality of reflecting elements, each of which reflects light onto a respective segment area of the window element; and

irradiating the tissue surface with the reflected light via a light-transmitting contact surface of the window element.

5. The method of claim 4, further including:

removing heat from the plurality of reflecting elements via a cooling fluid.

6. The method of claim 5, wherein removing heat includes placing the cooling fluid in contact with optical surfaces of the plurality of reflecting elements.

7. The method of claim 4, wherein directing light onto at least one of the respective segment areas of the window element including reflecting light off a partially reflecting prism or mirror.

8. An apparatus for irradiating a tissue surface, said apparatus comprising an optical assembly, said assembly coupled by an optical transmission device to a light source, wherein the optical assembly comprises:

a) a light-transmitting contact surface configured to transmit light to the tissue surface;

b) a light guide plate having a light input surface at a lateral surface, said light guide plate adapted to receive light from the optical transmission device, the light propagating through the light guide plate;

c) a reflecting plate separated from the proximal surface of the light guide plate;

d) an extraction space defined by the proximal surface of the light guide plate and the reflecting plate;

e) extraction features within the extraction space, the extraction features formed by application of material to the proximal surface of the light guide plate, such that light reflected from the extraction features is transmitted to the tissue surface through the light-transmitting contact surface in a substantially uniform distribution, the extraction features being in direct physical contact with the reflecting plate;

f) a housing enclosing at least a portion of the light guide plate and the reflecting plate and having an opening at the lateral input surface of the light guide plate; and

g) a detachable heat sink in thermal contact with the housing and the light-transmitting contact surface, the detachable heat sink being disposed on a top surface of the housing, such that heat is conducted from the light-transmitting contact surface through the extraction features to the detachable heat sink.

9. The apparatus of claim 8, further including:

a cooling layer configured to remove heat from the light transmitting contact surface via a cooling fluid.

10. The apparatus of claim 8, wherein the extraction space comprises a heat transfer fluid having a refractive index lower than that of the light guide plate.

11. The apparatus of claim 8, wherein the housing has a thickness of about 6 mm or less.

12. The apparatus of claim 8, wherein the light-transmitting contact surface includes focusing features.

13. The apparatus of claim 8, further including:

a light source operably coupled to the light guide plate.

14. A method of irradiating a tissue surface comprising:

a) guiding light via an optical assembly, said assembly configured to produce a substantially uniform distribution of light and coupled by an optical transmission device to a light source, wherein the optical assembly comprises;

i) a light-transmitting contact surface configured to transmit light to the tissue surface;

ii) a light guide plate having a light input surface at a lateral surface, said light guide plate adapted to receive light from the optical transmission device, the light propagating through the light guide plate;

iii) a reflecting plate separated from the proximal surface of the light guide plate;

iv) an extraction space defined by the proximal surface of the light guide plate and the reflecting plate; and

v) extraction features within the extraction space, the extraction features formed by application of material to the proximal surface of the light guide plate, such that light reflected from the extraction features is transmitted to the tissue surface through the light-transmitting contact surface in a substantially uniform distribution, the extraction features being in direct physical contact with the reflecting plate;

vi) a housing enclosing at least a portion of the light guide plate and the reflecting plate and having an opening at the lateral input surface of the light guide plate; and

vii) a detachable heat sink in thermal contact with the housing and the light-transmitting contact surface, the detachable heat sink being disposed on a top surface of the housing, such that heat is conducted from the light-transmitting contact surface through the extraction features to the detachable heat sink; and

b) irradiating the tissue surface with light guided by the optical assembly.

15. The method of claim 14, further including:

generating the light with a light source operably coupled to the lateral input surface of the light guide plate.

16. The method of claim 14, further including:

removing heat from the light-transmitting contact surface via a cooling fluid.

17. The method of claim 16, wherein the cooling fluid has an index of refraction higher than that of the light guide plate.

18. The method of claim 14, wherein the light-transmitting contact surface has a contact surface area of at least about 30 mm2.

19. The method of claim 14, wherein the light-transmitting contact surface includes focusing features.

20. The method of claim 14, wherein the housing has a thickness of about 6 mm or less.