Flexible light guides and heat sinks for endoscopy systems

Abstract

A flexible electronic light guide (18) for an endoscope (10) that acts as a heat sink for a light emitting diode (LED). A flexible tube (126) within the light guide extends from the LED to divert heat away from the LED. The flexible tube can be a solid metal tube that is perforated to make it flexible. The flexible tube can also be a braided wire sheath and can enclose a series of metal balls that are in contact with each other. The flexible tube can also be made of a variety of different metals. The flexible tube can also be a hollow tube and support an air or liquid cooling system, or be filled with metal balls that can be as small as grains of sand. The flexible tube can also be a connector formed by a series of metal parts held in close contact by springs.

Description

Background Art 1. Technical Field

[0002] The present invention relates to an endoscope light guide, and more particularly to an endoscope light guide having a flexible heat sink for a light emitting diode.

[0003] 2. Description of related technologies

[0004] In the field of endoscopic surgery, it is necessary to direct visible light into the human body to illuminate various surgical sites. Traditionally, this is achieved by attaching the distal end of a fiber optic light guide to the fiber optic light column of an endoscope. The opposite proximal end of the light guide is connected to an electronic light source. Typically, the light source is an AC voltage powered electronics housing that houses a high output lamp with a fiber optic cable that is coupled to the endoscope's light column for optimizing the transmission of light. One of the features of existing fiber optic light guides is that they are flexible and can be easily manipulated by the surgeon when adjusting or rotating the endoscope to view different surgical sites in the body.

[0005] Existing fiber optic light guides are limited in that their performance deteriorates during use due to the nature of the materials used in their construction. The light guide is composed of many individual glass optical fiber strands that form an array bundle. An outer sheath surrounds the glass strand bundle to protect the glass strand bundle from environmental influences when the device undergoes cleaning and reprocessing (sterilization) during use. The individual fiber strands are made of drawn glass, which is susceptible to breaking during use. When an individual optical fiber breaks at any position along its length, it is no longer able to transmit light, and therefore, the total light transmission emitted from the light source output will be reduced by a percentage. Conventional attempts to overcome these problems involve the use of battery-powered LED light sources that are attached to the light column of the endoscope. However, these devices are limited by the available battery life and therefore have a short usage time between charging operations and / or battery replacement. Therefore, there is a need in the art for a method that can provide illumination to the optical port of an endoscope for a longer period of time while maintaining the desired cable flexibility. Summary of the invention

[0006] The present invention comprises a flexible electronic light guide for an endoscope, the flexible electronic light guide comprising a heat sink for a light emitting diode module of the light guide. The heat sink is designed to enable the electronic light guide to maintain the flexible form factor desired by the surgeon, while shunting heat from the light source so that components that the surgeon will touch do not overheat. The electronic light guide does not use glass optical fibers, but instead relies on a calibrated fixed lighting output that does not degrade over the life of the product. The electronic light guide also reduces the number of connecting optical surfaces present when using traditional fiber optic light guides. When using an electronic light guide, the connection at the light source at the proximal end of the light guide is eliminated because the LED is positioned directly on the mirror post. By eliminating this optical connection, the associated surface losses are also eliminated, thereby increasing light output.

[0007] More specifically, the present invention is a flexible electronic light guide having a light emitting diode module within a housing, the light emitting diode module having a light emitting diode (LED). A power cable is coupled to the LED to provide power to the LED. A flexible tube adjacent to the light emitting diode module extends from the LED and surrounds the power cable to shunt heat away from the light emitting diode module.

[0008] In one embodiment, the flexible tube may include a solid metal tube that is perforated according to a predetermined pattern to allow the solid tube to be flexible. In another embodiment, the flexible tube may include a braided wire sheath. The braided wire sheath may enclose a series of metal balls that are in contact with each other. The flexible tube may also include a variety of metals. In another embodiment, the flexible tube may include a hollow tube, one end of which is connected to a fan, and the other end of which is connected to a manifold, which is positioned around the light emitting diode module. The manifold may have a front face that defines a series of openings. The fan may be positioned in a base unit to which the flexible tube is attached. In another embodiment, the flexible tube may include a hollow tube that is connected to a fluid reservoir. The hollow tube may include at least one valve that is configured to allow only fluid to flow in a predetermined direction. In yet another embodiment, the flexible tube may include a connector formed by a series of components that are held in contact with each other by a spring. In yet another embodiment, the flexible tube may include a hollow tube filled with a plurality of metal balls. The diameter of the plurality of metal balls may be between .0625 mm and 2.00 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be more fully understood and appreciated by reading the following detailed description in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a perspective view of an endoscope having a flexible light guide according to the present invention;

[0011] Figure 2is a cross-sectional view of a flexible light guide according to the present invention;

[0012] Figure 3 According to the present invention Figure 2 An exploded view of a flexible light guide;

[0013] Figure 4 is an exemplary pattern according to the present invention that may be etched into a solid metal tube to allow the tube to be flexible;

[0014] Figure 5 is a schematic diagram of a flexible heat sink according to the present invention, the flexible heat sink being formed by a plurality of metal sheets coupled together;

[0015] Figure 6 is a flexible heat sink according to the invention formed by a woven wire mesh heat sink for a flexible light guide.

[0016] Figure 7 is a flexible heat sink according to the present invention, said flexible heat sink being formed by a braided wire sheath enclosing a series of metal balls;

[0017] Figure 8 is a flexible heat sink according to the present invention, the flexible heat sink being formed by a braided wire sheath enclosing a series of metal balls; and

[0018] Fig. 9 A flexible heat sink according to the present invention is formed of a hollow tube enclosing a plurality of metal balls. DETAILED DESCRIPTION

[0019] Referring to the accompanying drawings, wherein like numerals refer to like parts throughout, Figure 1 As can be seen in FIG, endoscope 10 has an insertion tube 12 that allows an imaging component within a handpiece 14 to capture an optical image of the field of view at the opposite end of the insertion tube 12. A flexible shaft 16 extends from the handpiece 14 to transmit the image captured by the imaging component within the handpiece 14 to a remotely located display, such as a viewing screen or monitor. An electronic light guide 18 is laterally coupled to the insertion tube 12 at an optical input port 20 of the endoscope 10.

[0020] See also Figure 2 and 3, the electronic light guide 18 includes a body 112 that houses a lens 114 and an LED 116 mounted on a printed circuit board and positioned behind the lens 114. A window 144 is positioned in front of the lens 114 to protect the lens 114 and allow light from the LED 116 to be emitted from the electronic light guide 18 to the light port of the endoscope 10. It should be appreciated that the LED 116, lens 114, and window 140 can be packaged into a unit 146 to form a discrete module that can be integrated into the electronic light guide 18 in the manner described herein. A solid heat sink 118 is positioned adjacent to the LED 116 for removing heat generated when the LED 116 is enabled and extends rearwardly out of the body 112. The solid heat sink 118 can be a copper body and can include fins for improving the distribution of accumulated heat. The solid heat sink 118 can be adhered to the LED 116 using a metal epoxy (such as silver epoxy) to promote the transfer of heat from the LED 116. A flexible heat sink 120, such as a braided copper mesh, is attached directly to the rigid heat sink 118 by one of a plurality of band clamps 122 and 124. A cable 126 extends within the flexible heat sink 120 and includes a pair of wires 128 and 130 for powering the LED 116. The wires 128 and 130 extend through the solid heat sink 118 and are insulated from the solid heat sink by a pair of corresponding insulating sleeves 132 and 134, respectively. A heat shrink 136 may be positioned on a mid-portion of the flexible heat sink 120 to maintain the braided mesh in a compressed state. A shield 138 for providing stress relief is positioned over the component and at least a portion of the body 112 and is held in place by a ring 140 attached to the front end of the body 112 so as to engage the shield 138. A fitting 142 may be positioned inside the front end of the body 112 to selectively couple and decouple the electronic light guide 18 with the optical port 20 of the endoscope 10. O-rings 148 may be included in various locations to seal the internal components of the electron light guide 18 from ingress during use and to allow sterilization of the electron light guide 18 after use.

[0021] Although the flexible heat sink 120 is preferably a woven wire mesh, the present invention includes other methods that provide the necessary flexibility and transfer heat down a portion of the length of the electronic light guide 18. Figure 4 For example, the flexible heat sink 150 may include a flexible shaft 152 coupled to the rigid heat sink 118. The flexible shaft 152 may be formed by laser cutting a solid tube formed of a thermally conductive material, such as a metal, to remove material from the shaft 152 according to a predetermined pattern 154 that will allow the shaft 152 to flex in three dimensions. One end of the shaft 152 is coupled to the rigid heat sink 118 to draw heat away from the LED 116 while allowing movement of the endoscope 10 via flexure of the shaft 152.

[0022] See also Figure 5 , a flexible heat sink 200 according to the present invention may include a central cable 202 surrounded by a plurality of thermally conductive materials 204 that are placed in contact with the rigid heat sink 118 .

[0023] See also Figure 6 , a flexible heat sink 500 according to the present invention may include a braided sheath 502 surrounding an electrical line 504 for a rigid heat sink 118. The braided sheath 502 is formed of one or more thermally conductive materials. The braided sheath 502 is placed in contact with the rigid heat sink 118 to remove heat therefrom.

[0024] See also Figure 7 , a flexible heat sink 600 according to the present invention may include a braided sheath 602 surrounding electrical wiring for a rigid heat sink 118. A series of balls 604 are densely packed within the braided sheath 602. The braided sheath 602 and the balls 604 are formed of one or more thermally conductive materials, such as metal. The braided sheath 602 is placed in contact with the rigid heat sink 118 to remove heat therefrom using the balls 604 that provide additional heat collectors.

[0025] See also Figure 8 , a flexible heat sink 700 according to the present invention may include a connector 702 formed by a series of components 704 that are tightly compressed together by a biasing element 706 (such as a spring). When an endoscope including the heat sink 700 and the rigid heat sink 118 is used, the tight compression of the components 704 allows rapid transfer of heat and flexible movement.

[0026] See also Fig. 9 , a flexible heat sink 800 according to the present invention may include a flexible sheath 802 surrounding electrical wiring for a rigid heat sink 118. A series of balls 804 are densely packed within the flexible sheath 802. The flexible sheath 802 and the balls 804 are formed of one or more thermally conductive materials. The flexible sheath 602 is placed so that the balls 604 are in contact with the rigid heat sink 118 to remove heat therefrom. The balls 804 can be as small as a grain of sand (between .0625 mm and 2.00 mm) or larger, such as a ball bearing.

Claims

1. A flexible electronic light guide for an endoscope, the flexible electronic light guide comprising: a housing supporting a light emitting diode, wherein the light emitting diode is positioned behind a lens and a window is positioned in front of the lens within the housing to form a discrete module; a power cable coupled to the light emitting diode; and a solid heat sink positioned adjacent to and behind the LEDs and attached to a flexible tube extending around the power cable to shunt heat away from the LEDs, Wherein, the flexible electronic light guide is capable of selectively coupling and decoupling with the optical port of the endoscope.

2. The flexible electronic light guide of claim 1, wherein the flexible tube comprises a solid metal tube that is perforated according to a predetermined pattern to allow the solid metal tube to be flexible.

3. The flexible electronic light guide of claim 1, wherein the flexible tube comprises a braided wire sheath.

4. The flexible electronic light guide of claim 3, wherein the braided wire sheath encapsulates a plurality of metal balls in contact with each other.

5. The flexible electronic light guide of claim 3, wherein the flexible tube comprises a plurality of metals.

6. The flexible electronic light guide of claim 1, wherein the flexible tube comprises a hollow tube, and the flexible electronic light guide further comprises: a fan coupled to one end of the tube; and a manifold coupled to the other end of the tube and positioned around the light emitting diode module.

7. The flexible electronic light guide of claim 6, wherein the manifold comprises a front face defining a series of openings.

8. The flexible electronic light guide of claim 7, wherein the fan is positioned within a base unit to which the flexible tube is attached.

9. The flexible electronic light guide of claim 1, wherein the flexible tube comprises a hollow tube coupled to a fluid reservoir.

10. The flexible electronic light guide of claim 9, wherein the hollow tube comprises at least one valve configured to allow fluid flow only in one predetermined direction.

11. The flexible electronic light guide of claim 1 , wherein the flexible tube comprises a connector formed from a series of components held in contact with each other by springs.

12. The flexible electronic light guide of claim 1, wherein the flexible tube comprises a hollow tube filled with a plurality of metal balls.

13. The flexible electronic light guide of claim 12, wherein the plurality of metal balls have a diameter between .0625 mm and 2.00 mm.

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