BACKGROUND

The present invention relates generally to a handheld lighting system that can be mechanically coupled to a variety of devices, such as medical and industrial endoscopes, to provide high intensity, low heat light.

Many devices that operate in small, closed areas, require a light source to operate. For example, laparoscopic and endoscopic procedures are conducted through small incisions in the skin or natural body orifices. In order to operate or view an internal area, medical professionals use endoscopes that have small, elongated distal portions that fit within these small openings but are long enough to reach the internal areas within the body. These instruments need to provide precise and accurate movement in order to reach areas within the body that are difficult to access. The distal working ends of the endoscopes usually contain a small camera that allows a medical professional to view an internal area within the body during the procedure. The camera and the working end of the endoscope must have adequate remotely controlled illumination to permit the medical professional to view the internal area. In some endoscopes, a camera positioned outside the patient's body can receive, via a light guide, radiation reflected from an illuminated internal area and form an image of that area for viewing by a medical professional.

Many conventional light sources are inefficient in converting electrical power to light, and must be connected to external power sources, limiting their range of motion. Light emitting diodes (LED) can produce light. without generating a large amount of heat, but they are not typically capable of generating enough illumination to be useful in a variety of applications, such as endoscopic systems. Even if multiple LEDs are employed, in many conventional systems, the inefficient coupling of the light generated by the LEDs into a light guide of a device can result in insufficient illumination intensity.

Accordingly, there is a need for enhanced lighting systems, and particularly a need for such systems that can be employed to provide light to a variety of medical and industrial devices.

SUMMARY

In one aspect, a handheld lighting system is disclosed, which comprises a handheld housing extending from a proximal end to a distal end, and a removable and replaceable light module disposed at least partially in the housing. The handheld lighting system further includes a power module that is coupled to the housing (e.g., it is at least partially disposed within the housing) and is electrically coupled to the light module, e.g., through a pair of electrical leads, for providing electrical power thereto.

The light module further includes an adapter disposed at the distal end of the housing for coupling the lighting system to a device having one or more light guides, e.g., one or more optical fibers, for providing light from the light module to those light guide(s), which can in turn transfer the light to a field of view for illumination thereof. In some embodiments, the adapter is removable and replaceable.

In some embodiments, the handheld housing includes at least a portion formed of a thermally conductive material, e.g., a metal such as aluminum. In some such embodiments, the thermally conductive portion includes a corrugated external surface for facilitating transfer of heat generated by the light module and/or the power module to an external environment. In some such embodiments, the corrugated external surface includes a plurality of fins that increase its surface area, thereby enhancing heat dissipation through that surface. In some such embodiments, the fins extend longitudinally and have a height in a range of about ⅛ inches to about ⅙ inches.

In some embodiments, the power module allows adjusting the intensity of the light generated by the light module. In some embodiments, the light module includes a pair of electrical connectors (leads) protruding through an internal wall of the housing for electrically connecting the light module to the power module.

In some embodiments, the housing includes a first enclosure extending from the distal end of the housing to an internal wall thereof for receiving the light module, and a second housing extending from the internal wall to a proximal end of the housing for receiving the power module.

In some embodiments, the housing includes a rotatable shell coupled to the power module such that the rotation of the rotatable shell adjusts the power supplied by the power module to the light module, thereby changing the intensity of the light generated by the light module. In some such embodiments, the housing includes a heat sink portion to which the rotatable shell is coupled. By way of example, the rotatable shell can include a spring-loaded ball that can engage within a retaining groove provided in an inner wall of the heat sink portion. By way of example, the power module can include an adjustable potentiometer electrically coupled to a light source of the light module and mechanically coupled to said rotatable shell such that a rotation of the shell results in a change of resistance of the potentiometer, thereby adjusting the intensity of the light generated by the light module.

In some embodiments, the light module includes a hollow chamber extending from a proximal end to a distal end, a lens positioned removably and replaceably in the hollow chamber, the lens having a lens body comprising an input surface for receiving light from the light source (e.g., an LED) and an output surface through which light exits the lens, said lens further comprising a collar encircling at least partially said lens body.

The light module can further include at least one sleeve disposed in the hollow chamber in contact with the lens collar for providing mechanical support to the lens, and an optical window disposed in the hollow chamber and optically coupled to said output surface of the lens such that the light exiting the lens passes through the optical window before exiting the light module. The light source can be coupled to the hollow chamber at a proximal end thereof for providing light to said input surface of the lens. The optical window can be formed of any suitable material, such as sapphire, quartz, glass, etc.

In some embodiments of the above light module, a retaining window can be coupled releasably to the distal end of the hollow chamber, e.g., via a plurality of threads engaging with respective threads at the distal end of the hollow chamber. The retaining window can have an opening for coupling to an adapter, which can in turn couple to a light guide so as to deliver the light from the light module to the light guide.

In some embodiments, a gasket can be disposed between the optical window and the retaining window.

The light module can further include a printed circuit (PC) board on which the light source is mounted. The PC board can include a plurality of electrical leads for applying electrical power to the light source and optionally controlling its operation.

A plate can be coupled to the distal end of the light module's housing, where the plate can have a plurality of openings through which the electrical leads of the light module can extend for coupling to the power module of the lighting system.

In some embodiments, the light module can include a shoulder for holding the lens within its housing. For example, the light module can include at least one sleeve supporting the lens above the PC board. In some embodiments, a pair of sleeves are disposed on opposite sides of the lens collar, where one sleeve supports the lens above the PC board and the other sleeve supports the optical window above the lens.

A plurality of different lenses can be employed in the light module. By way of example, the lens can include a lens body comprising a proximal section having said input surface and a distal section having said output surface. The proximal section can include a substantially elliptical peripheral surface receiving at least a portion of the light entering the lens body via said input surface and directing at least some of said received light via total internal reflection to said distal section such that at least a portion of the light directed to the distal section exits the lens body through said output surface. The peripheral elliptical surface is characterized by a proximal focal point and a distal focal point. In some embodiments, the peripheral surface is shaped such that the distal focal point is positioned external to the lens body, e.g. at a distance above the output surface of the lens. In other embodiments, the distal focal point can be positioned in the lens body, e.g., below the output surface or at the output surface. Further, in some embodiments, the proximal focal point is positioned substantially at or in proximity of the light source such that the elliptical surface transfers at least a portion of the light emitted by the light source from the proximal focal point to the distal focal point. In many embodiments, the focal points are disposed on an optical axis of the lens, e.g., an axis about which the lens body is rotationally symmetric.

In some embodiments, the input surface includes a central convex portion and a peripheral portion surrounding said convex portion. In such embodiments, the input surface can form a surface of a cavity configured to receive at least partially the light source. In some such embodiments, the proximal focal point can be positioned in the input cavity.

In some embodiments, the peripheral portion of the input surface can include a proximal concave segment and a distal convex segment.

In some embodiments, the peripheral portion of the input surface is shaped such that at least a portion of the light entering the lens body via said peripheral portion propagates to said peripheral elliptical surface to be reflected thereby. The peripheral portion of the input surface can be shaped such that at least about 80%, or at least about 90%, or at least about 95% (and preferably 100%) of the light entering the lens body via the peripheral portion propagates to the peripheral surface of the lens body to be reflected thereby.

In some embodiments, the convex portion of the input surface can exhibit a positive optical power in a range of about 50 D to about 300 D. In some such embodiments, at least a portion of the light entering the lens body via said convex portion propagates to the output surface without striking the peripheral surface.

In some embodiments, the input surface of the lens is configured to capture at least about 70%, or at least about 80%, or at least about 90%, or at least about 95% (and preferably 100%) of the light energy emitted by the light source. In some embodiments, the lens transfers the light energy emitted by the light source from the light source to its output surface with an efficiency of at least about 70%, or at least about 80%, or at least about 90% or at least about 95%.

In some embodiments, the light module of the lighting system couples the light emitted by the light source to a light guide of a device to which the lighting system is coupled with an efficiency of at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90%.

In some embodiments, the output surface of the lens is substantially flat and is orthogonal to an optical axis of the lens.

The lens can be formed of a variety of different materials, such as polymeric materials, or glass. Some examples of suitable materials include, without limitation, polymethymethacylate (PMMA), polycarbonate, and silicone.

In some embodiments, the power module of the lighting system can be battery operated, and in other embodiments, the power module can receive AC line voltage and convert that voltage to a DC voltage suitable for application to the light source.

In some embodiments, the handheld lighting system can include a light module, which includes a housing providing a hollow chamber extending from a proximal end to a distal end, a lens positioned in said hollow chamber, said lens having a lens body comprising an input surface for receiving light from a light source and an output surface through which light exits the lens body, said lens further comprising a collar at least partially encircling said lens body. The light module can further include at least one shoulder on which said collar is seated, a light source coupled to said hollow chamber at said distal end for providing light to said input surface of the lens. In some embodiments, the shoulder providing a seat for the lens can be in the form of a sleeve disposed in the hollow chamber. In other embodiments, the shoulder can be in the form of a protrusion extending from an inner wall of the chamber.

In the above light module, the lens can further include a peripheral surface for receiving at least a portion of the light entering the lens body via the input surface and for directing the received light via total internal reflection to the lens's output surface. In some such embodiments, the peripheral surface can have a truncated elliptical shape characterized by an input focus and an output focus.

In some embodiments, the housing of the lighting system can include a corrugated external surface for facilitating transfer of heat generated by at least one of the light module and the power module to an external environment. By way of example, the corrugated surface can include a plurality of fins disposed on the external surface of the housing for enhancing the surface area thereof, thereby facilitating the dissipation of heat to the surrounding environment.

In a related aspect, an endoscope system is disclosed, which includes a light guide configured to be at least partially inserted into a subject, and a handheld lighting system optically coupled to said light guide for providing light thereto. The handheld lighting system can include a handheld housing extending from a proximal end to a distal end, a light module disposed in said housing and having at least a light source for generating light, and a power module disposed within said housing and electrically coupled to said light module for providing electrical power thereto.

In some embodiments, the light module can be removably and replaceably disposed within the housing of the lighting system.

The lighting system, including the light module, of the above endoscope can be implemented in a manner discussed above.

In a related aspect, a device is disclosed, which includes a body housing at least one light guide, and a handheld lighting system that is mechanically coupled to the body to be in optical coupling with the light guide to provide light thereto. The handheld lighting system can include a removable and replaceable light module for generating light to be delivered to the light guide of the device. The handheld lighting system, including the light module, can be implemented in a manner discussed above. In some embodiments, the device can be any of an endoscope, a, illuminated surgical instrument, such as a surgical headlight, a video camera, a retractor, or a speculum.

Further understanding of various aspects of the invention can be obtained by reference to the following detailed description in conjunction with the drawings, which are described briefly below.

