Surgical headlamp

A surgical headlamp containing lamp housings, each containing multiple LED light sources is featured wherein the LEDs cooperate together to produce a light engine. The lamp housings may be adjusted so that light beams emitted by each LED be selectively converged through a focusing lens at a spot a predetermined distance in front of the lamp housings. Each lamp housing typically contains in addition to the LEDs, one or more focusing lenses to gather and direct the light generated by the LEDs forward to an illuminated work area. Batteries, preferably rechargeable, are mounted in a waist pack external to the headband, and are used to poser the LEDs. A cooling system for cooling the heat generated by the LED's is provided which utilizes a swirling effect of fluid adjacent a heat sink to transfer the heat to the swirling fluid.

I. BACKGROUND OF THE INVENTION

A. Field of Invention

The present invention pertains to lights that can be worn on a user's head to provide illumination in an area of work, and, more particularly, to a headlight for surgeons, dentists or other medical personnel or craftsmen. The light uses two independent lamp housings working cooperatively to converge light beams at a predetermined distance from the LED light sources.

It is essential in certain medical procedures that the physician, surgeon, or Dentist has his or her hands free for manipulating various surgical diagnostic or therapeutic instruments. At the same time, the particular part of the patient's body that the physician or surgeon is treating must be adequately illuminated. For these purposes, doctors and surgeons have heretofore utilized surgical head lights, some of which require the user to remain attached by via fiber optics to a free-standing light source, and/or to a power outlet or an energy source.

Battery powered head-mounted lamps utilizing an incandescent lamp as a light have also been used. Typically, the high power consumption, relatively low light output, high weight, and short battery life of each device of the prior art have made their use difficult, uncomfortable, or otherwise unsatisfactory.

Even with such configurations, however, the amount of light illuminating upon the work area can be inadequate. There have been attempts to increase the light pinching upon the work area by utilizing xenon or halide lamps, which require high power and have a relatively short bulb life and generate substantial amounts of heat.

Some of the problems associated with such xenon and halide lights may be overcome by utilizing light-emitting diodes (LEDs).

Some prior art apparatus have used relatively high-powered LEDs to generate sufficient light output. Such LEDs typically generate so much heat that a heat sink is required; heretofore the prior art has not been able to satisfy the repairment of a heat sink or cooling system for LED light generation.

B. Discussion of the Related Art

Several attempts to solve the problems described herein above have been made in the prior art. For example, published U.S. Pat. No. 6,055,444, published Jun. 2, 2005, and issued as a patent on Oct. 18, 2005 for Surgical Headlight by Suhil Gupta, teaches a head-mounted lamp assembly with at least two LEDs mounted side by side and focused utilizing a rear reflector. Such rear reflector use greatly diminishes the efficiency of the projection of the light generated by the LEDs and thus is unsatisfactory for providing a high intensity, focused light beam of the apparatus of the present invention.

U.S. Pat. No. 7,108,400 entitled Light Source Unit and Projector, by inventor Shuhei Yamada and Takeshi Seto, teaches the use of a LED light source for illumination of high luminants, which includes a cooling system for the illumination of high ruminants, which generates substantial heat. This design utilizes two liquid heat source absorbers and is very complex and is much more difficult to implement than that cooling system taught by the present invention.

U.S. Published Patent Application No. 2005/0243539 teaches a cooled light emitting apparatus comprising a light source including a close-packed array of light emitting diodes and a cooling system for cooling the light source. The cooling system is a thermoelectric cooling device in the form of a peltier device connected by a heat spreader to the light source and a heat exchange system for removing heat from the peltier device. The heat exchange system utilizes a liquid coolant to cool the peltier device in this instance the invention utilizes a heat pipe configuration or arrangement, and this is far less satisfactory than the liquid cooling system taught by the present invention.

II. SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a surgical headlight that overcomes the problems of head-mounted surgical headlamps of the prior art. A plurality of LED's are mounted in a circular arrangement on a printed circuit board that includes a metal substrate heat sink associated therewith that is in contact with a coolant chamber and a belt-mounted cooling liquid is pumped through the cooling chamber to control the heat output from the LED array mounted under and focused by a focus lens that is a single lens that focuses all of the diodes into a coherent focused pattern at a particular point of desired focus and intensity.

It is, therefore, an object of the invention to provide a head-mounted LED based headlamp for use by surgeons or other medical personnel, etc. It is another object of the invention to provide a head-mounted LED based headlamp comprised of a pair of individual lamp housings, each incorporating a plurality of LED cells and each unit mounted with associated with a focus lens that provides a 6″ focus angle for an effective 200 mm circle of light at 440 mm.

It is a further object of the invention to provide a head-mounted LED-based headlamp powered by rechargeable batteries.

It is a further object of the invention to provide a head-mounted LED-based headlamp which has a bulb life of at least 50 times that of a xenon/halide bulb while operating at a less than ⅙ the wattage requirement of such xenon/halide bulbs.

It is a further object of the invention to provide a head-mounted LED-based headlamp which is very reasonable in cost and provides a significant solid-state semi-coherent light for passage through a focus lens at a 6°focus angle for an effective 200 mm circle of light at 440 mm.

For purposes of brevity and clarity, components and elements of the apparatus of this invention will bear the same designations or numbering throughout the Figures.

IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a surgical headlight which may be used by surgeons, physicians, dentists, etc., who require a reliable, portable, high density, battery-power light source. For the sake of brevity, the term surgeon is used hereinafter to refer to any user of the head-mounted headlamp of the invention.

Referring first toFIG. 1of the drawings,10indicates generally the head-mounted headlamp of the invention which comprises a basic band12to go around the head and forehead of the user, and this band12is normally adjustable to be able to therefore fit the size of the wearer of the unit. A top strap14is shown, which goes over the top of the head of the user and stabilized the whole assembly to fit comfortably and securely onto the user's head, in much the typical way of any of these devices.

The band12mounts then to a mounting plate16which attaches itself to a further forehead plate18and plate18operates through a ratcheting swivel20to provide an actual mounting plate22which carries the improved head-mounted headlamp24of the invention. The basic headlamp24is composed of two separate lamps24, as best seen inFIG. 6. The basic headlamp is comprised of a rearward housing26which carries the actual LED configuration and cooling, to be described later, and a front protective cover for the focusing lenses as described in conjunction withFIG. 4.

The auxiliary package is indicated generally by30and this is remotely mounted, normally on the waist or the back, through a belt arrangement typically suitable for the user. This auxiliary package incorporates a LED power supply32is a conventional rechargeable battery typically used for this type of system and is conveniently located for replacement or recharging in the box assembly30. The box30also incorporates a coolant reservoir34, again shown in dotted line, and coolant reservoir incorporates a coolant pump36, again shown in dotted line and the pump36transmits coolant through a coolant tube38, also indicated by dotted line within the box30and then there is a quick connect or disconnect unit40located between the flexible tubing that constitutes the tubing42that sends the coolant fluid up and into its appropriate use for cooling in the headlamp assembly24.

Referring now to the headlamp assembly24shown inFIG. 2of the drawings, the headlamp includes a plurality of LED's indicated by44. The LEDs are mounted in a hexagonally-shaped focusing lens28that comprises a plurality of independent lenses46associated with each LED. The lens28is preferably a solid polymer molding to incorporate six individual lenses46, all physically connected to a central hexagon piece47, all as one overall piece by a separate mold that locates the lenses as shown inFIG. 5so as to focus at a point approximately 18 inches from the lenses46. This will be explained in more detail with respect to the drawings shown inFIGS. 3 and 4.

The LEDs44are wired in series to the power supply, as shown inFIG. 7, with an with an on-off switch33, and this switch33also simultaneously turns on the fluid pump36. The solid-state, semi-coherent light passes through the focusing lens46at a 6° focus angle for an effective 200 mm circle of light at 440 mm. The alignment of the LEDs44and the focusing lenses46is best seen inFIG. 4where it shows that the LEDs actually put out an approximately 80° cone of semi-coherent light, which is condensed into a much narrower approximately 6° of conical light with each respective LED focused at the same point, as shown inFIG. 5. These actual distances and relationships can be varied depending upon the particular focus characteristics of the focus lenses46. It is important to the proper functioning of the LEDs that the LEDs draw no more than about 50 watts of battery power and preferable the battery32will be between 12 and 24 volts to produce a load of 1 amp to power each of the 12 LEDs in the two-unit headlamp24.

Referring again toFIG. 7of the drawing, the battery32is connected through the closing of switch33to provide 1 amp in power to the LED array. The LEDs are each preferable of 5 watt power output. The LEDs44working together form a light engine for each of the headlamps24ofFIG. 6. The LEDs44are activated and emit bright semi-coherent light through the focus lenses46now probably best seen in bothFIGS. 3 and 4. This light is then emitted to the focus lenses46, as best seen inFIG. 4. It is important to note, also, that the semi-coherent light emitted by the LEDs is in a lamberton distribution.

The heat generated from the LEDs is drawn out through an aluminum heat sink layer50. With the coolant flowing in the coolant chamber52, excess heat is carried away from the assembly via the coolant output54and coolant input56, which brings the coolant into the chamber52. Coolant input56and output54are connected to a coolant reservoir and pump with flexible tubing, as already described with respect toFIG. 1. The coolant can be water, and it has been found that the flow rate of 400 ml per minutes works very well.

Referring toFIGS. 8 and 9, these represent perspective views of a single headlamp design that is reduced in size and weight and still puts out a very large condensed beam through the focused lenses and appears to be more operable and a better more modern design to the headlamp. It is designed in this instance to be a 20 mm surgical headlamp. Referring toFIGS. 10 and 11, and particularly atFIG. 11, numeral70indicates the general headlamp, which comprises a mounting bracket72, a main casing74, a front cap76, an aluminum heat sink78, an optical focus lens80, light emitting diode aluminum substrate printed circuit board82, an insert84to the printed circuit board82which provides a cover for electrical conductors100from the LED printed circuit board82. The cooling chamber is identified by numeral86, and the tubing cap by numeral88. A cooling chamber input-output lumen is identified by numeral90. A mounting flange for the main casing is identified by numeral72, and O-rings and sealing gaskets94isolate the cooling chamber from the LEDs and any other constituents in the headlamp70.

Cooling fluid and electrical power enter into the tubing cap104, where the fluid flows into the cooling chamber86, and the electricity is conducted to two copper inserts molded inside the conductor insert at102. The power is then transferred to the LED printed circuit board82through the connector102and the connector100protected under the insert84, The coolant flows into the cooling chamber86and carries away heat generated by the LED printed circuit board82. The coolant is isolated using the seals and gaskets94. The light generated by the LED passes through the optical focus lens, where it is focused into a 100 mm circular pattern 440 mm in front of the lens. The main casing of light70, is secured to a mounting bracket74using a fastener and the mounting flange72.

An important feature of this design because of the reduced size of the headlamp itself being a diameter across the covering lens100, of about 20 mm, there is less space for the coolant to flow, and therefore the design incorporates a means to swirl and/or create a funnel configuration with the water entering the cooling chamber so that there is a swirling motion of the water to act as a better transfer agent for heat from the LEDs. This is achieved by the swirling obstruction112, seen inFIG. 12and this creates the swirling effect of the cooling fluid and the cooling chamber. The cooling chamber is sealed from the rest of the housing by the O-rings shown inFIG. 13.

Since other modifications and changes vary to fit particular operating requirements and environments, it will be apparent to those skilled in the art that the invention is not limited to the examples chosen for purposes of disclosure and covers all changes and modifications which do not constitute departures from the true spirit and scope of the invention.