Replaceable light source and radiation generating device including the same

A replacement light apparatus includes a base plate a bearing member, and a light source. The bearing member extends from a portion of the base plate. The bearing member includes a bearing surface. The light source is coupled to the bearing surface of the bearing member and adapted to project a cone of light centered on an illumination axis that extends perpendicular to the bearing surface.

FIELD OF THE DISCLOSURE

The present disclosure is directed to a replaceable light source and, more particularly, to a replaceable light source for a field lamp projector and/or an optical distance indicator of a radiation generating device such as a linear accelerator for medical treatment applications.

BACKGROUND

Linear accelerators are typically used to generate radiation for use in medical treatment. To assist with calibration, these devices typically include a field lamp projector and/or an optical distance indicator. Field lamp projectors project a pattern of light through an optical assembly and onto the patient. The pattern of light estimates the pattern of radiation that is to be projected. Optical distance indicators project a light through an optical assembly that includes a lens having a plurality of numbers etched or printed thereon. This results in the projection of one or more numbers on the patient, which indicates to the technician a distance between the radiation generator and the patient. The light sources for these field lamp projectors and optical distance indicators conventionally include halogen bulbs, which create a large sphere of light. To try and focus the light toward the optical assemblies and to reduce reflections in the projectors, apertured plates are often arranged between the bulbs and the optical assemblies.

SUMMARY

One aspect of the present disclosure provides a replacement light apparatus including a base plate a bearing member, and a light source. The bearing member extends from a portion of the base plate. The bearing member includes a bearing surface. The light source is coupled to the bearing surface of the bearing member and adapted to project a cone of light centered on an illumination axis that extends perpendicular to the bearing surface.

Another aspect of the present disclosure provides a replacement light apparatus including a base plate, a grip plate, a bearing member, and a light source. The grip plate extends from a first portion of the base plate. The bearing member extends from a second portion of the base plate. The bearing member includes a bearing surface. The light source is coupled to the bearing surface of the bearing member and adapted to project a cone of light centered on an illumination axis that extends perpendicular to the bearing surface.

Yet another aspect of the present disclosure provides a radiation generating device including a linear particle accelerator, a collimator, and a light projector. The collimator is arranged in proximity to the linear particle accelerator for aligning the particles departing the accelerator and projecting a radiation field. The light projector includes a housing, an optical assembly, and a light fixture. The optical assembly is carried by the housing and has an optical axis. The light fixture is removably disposed in the housing and includes a bearing plate defining a bearing surface. The light source is coupled to the bearing surface and centered on the optical axis. The light source is adapted to project a cone of light centered on an illumination axis that is coaxial with the optical axis.

A still further aspect of the present disclosure includes a method of projecting a pattern of light on a target of a radiation generating device. The method includes emitting a cone of light to produce a pattern of light on the target, wherein the cone of light is emitted along an illumination axis with a light source, the light source being carried by and removably disposed in a projector housing of the radiation generating device.

DETAILED DESCRIPTION

The present disclosure is directed to replaceable light sources for radiation generating devices such as linear accelerators, radiation generating devices including such replaceable light sources, and related methods. The replaceable light sources of the disclosure include light-emitting-diodes (LEDs), as opposed to conventionally used halogen bulbs. As will be described, LEDs provide a more concentrated cone of light in the disclosed examples, which advantageously results in extended life expectancy and increased operational efficiency.

FIG. 1depicts one version of a radiation generating device10constructed in accordance with the principles of the present disclosure. The device10includes a stationary support structure12, a gantry14, and a bed22. In the conventional manner, the gantry14contains a linear accelerator16, a bending magnet18, and a collimator20for generating a radiation field24, as shown, to be projected on a patient25lying on the bed22. In addition to the foregoing, the radiation generating device10ofFIG. 1includes a field lamp projector26and an optical distance indicator28carried within the collimator20. The field lamp projector26is adapted to create a pattern of light on the patient25to estimate a pattern of radiation that falls on the patient24during operation of the radiation generating device10. The optical distance indicator28projects a light defining one or more numbers on the patient25, whereby the number(s) indicate a distance between the radiation generator10and the patient25.

Referring now toFIG. 2, the field lamp projector26of the present disclosure includes a projector housing30and a light fixture32. The projector housing30defines a socket34and an optical cavity36that intersects the socket34. The light fixture32is slidably and removably disposed in the socket34. The optical cavity36contains an optical assembly38. The optical assembly38can include one or more lenses40disposed along an optical axis Ao for focusing light emitted by the light fixture32onto the patient25. As shown, the light fixture32of the presently disclosed version of the disclosure includes a base plate42, a grip plate44, a bearing member46, and a light source47. In some versions, the base plate42, grip plate44, and bearing member46can be constructed from a single piece of material such as aluminum, for example, which may be anodized to reduce glare and reflections. In other versions, the base plate42, grip plate44, and bearing member46can be constructed of different pieces assembled together by welding, brazing, adhesive, or any other suitable means.

With continued reference toFIG. 2and additionally toFIG. 3, the base plate42of the bearing member46can include a generally flat plate having a first surface60and a second surface62that is opposite the first surface60. Similar to the base plate42, the grip plate44also can include a generally flat plate and, in the disclosed version, extends perpendicularly from the first surface60of the base plate42. The bearing member46extends from the second surface62of the base plate42. In the disclosed version, the bearing member46includes a bearing plate48and a body portion50. The bearing plate48can be a generally flat plate that defines a bearing surface64carrying the light source47. In the disclosed version, the bearing surface64is flat and disposed in a first plane P1that is perpendicular to a second plane P2, in which the base plate42resides. The body portion50can be a cylindrical form defining a through bore52that at least partially overlaps with an opening54in the base plate42for accommodating electrical connections57(shown inFIGS. 3 and 6) such as one or more wires for connecting the light source47to a power source58(shown inFIG. 6). The light source47of the presently disclosed version includes a light-emitting-diode (LED)66mounted on a circuit board68. In one version, the circuit board68can be a 10 mm by 10 mm square circuit board. In another version, the circuit board68can be a Southern Linac Universal Mounting Printed Circuit Board, which is a thin, 8 mm thick, FR4 board that utilizes vias and copper pours to enable maximum thermal transfer capabilities. In the depicted version, the light source47is mounted flush on the bearing surface64of the bearing member46and centered on the optical axis Ao of the optical assembly38. So configured, and as shown, the light source47is adapted to project a cone of light70that is disposed on an illumination axis Ai, which is coaxial with the optical axis Ao of the optical assembly38. The illumination axis Ai therefore also extends perpendicular to the first plane P1and the bearing surface64of the bearing member46. So configured, the light source47advantageously directs and concentrates its cone of light70in the desired direction along the optical axis Ao, which thereby reduces reflections inside the socket34and optical cavity36and optimizes the efficiency of the device.

In one version, the light source47of the present disclosure can include an LED having a color temperature of 5650 k, exhibiting 235 lumens when running at 700 mA, or 320 lumens when running at 1000 mA. In another version, the light source47of the present disclosure can include an LED (e.g., the XP-G2, manufactured by Cree) having a color temperature of 5600 k, exhibiting an output of 254 lumens when running at 700 mA or an output of 458 lumens when running at 1500 mA. LEDs having such characteristics work advantageously well with conventional diffusers used in connection with existing field lamp projectors and optical distance indicators. Additionally, LEDs having such characteristics illuminate well on patient skin. That is, even though such an LED results in a 2 lux reduction relative to conventional halogens, the color temperature of the LED appears brighter to the human eye when projected on skin. One example of an LED that has been tested and found to be suitable includes the Luxeon Rebel LED (Part No. LXML-PWC2) mounted on a 10 mm circuit board. Another example of an LED that has been tested and found to be suitable includes the Cree XP-G2, mounted on the Southern Linac Universal Mounting PCB described above. Yet another example of an LED that can be used is the Luxeon Rebel LED (Part No. LXML-PM01-0100), which emits light having a wavelength of between 520 and 540 nanometers (i.e., green light), and, preferably, a wavelength of approximately 530 nanometers, and which can be mounted on the Southern Linac Universal Mounting PCB described above. This LED has been tested and found to be particularly well-suited for the uses described herein (e.g., illuminating on patient skin). It will of course be appreciated that other LEDs, for example LEDs configured to emit green light having a different wavelength (e.g., a wavelength lower than 520 nm or higher than 540 nm) or LEDs configured to emit light of a different color (e.g., red), can be utilized.

Referring now toFIG. 4, and as mentioned above, the radiation generating device10of the present disclosure can also include the optical distance indicator28. The optical distance indicator28is constructed in a manner very similar to the field lamp projector26discussed above, but for the sake of completeness, will also be described herein.

As shown inFIG. 4, the optical distance indicator28of the present disclosure includes a projector housing80and a light fixture82. The projector housing80defines a socket84and an optical cavity86that intersects the socket84. The light fixture82is slidably and removably disposed in the socket84. The optical cavity86contains an optical assembly88. The optical assembly88can include one or more lenses90disposed along an optical axis Ao for focusing light emitted by the light fixture82onto the patient25. Additionally, in some versions, the optical assembly88of the optical distance indicator28can include a graduated lens 125 having a plurality of numbers etched, printed or otherwise carried thereon for projecting numbers onto the patient25, as discussed above. As shown, the light fixture82of the presently disclosed version of the disclosure includes a base plate92, a grip plate94, a bearing member96, and a light source97. In some versions, the base plate92, grip plate94, and bearing member96can be constructed from a single piece of material such as aluminum, for example, which may be anodized to reduce glare and reflections. In other versions, the base plate92, grip plate94, and bearing member96can be constructed of different pieces assembled together by welding, brazing, adhesive, or any other suitable means.

With continued reference toFIG. 4and additionally toFIG. 5, the base plate92can include a generally flat plate having a first surface100and a second surface102that is opposite the first surface100. Similar to the base plate92, the grip plate94also can include a generally flat plate and, in the disclosed version, extends from the first surface100of the base plate92. The bearing member96extends perpendicularly from the second surface102of the base plate92. In the disclosed version, the bearing member96includes a bearing plate98and a body portion104. The bearing plate98can be a generally flat plate that defines a bearing surface106carrying the light source97. In the disclosed version, the bearing surface106is flat and disposed in a first plane P1that is perpendicular to a second plane P2, in which the base plate92resides. The body portion104can be a cylindrical form defining a through bore108that at least partially overlaps with an opening110in the base plate92for accommodating electrical connections57(shown inFIGS. 5 and 6) such as one or more wires for connecting the light source97to a power source58(shown inFIG. 6). The light source97of the presently disclosed version includes a light-emitting-diode (LED)112mounted on a circuit board114. In one version, the circuit board114can be a 10 mm by 10 mm square. In another version, the circuit board114can be a Southern Linac Universal Mounting PCB, which is a thin, 8 mm thick, FR4 board that utilizes vias and copper pours to enable maximum thermal transfer capabilities. Thus, in some cases, the circuit board68and the circuit board114can be the same. In the depicted version, the light source97is mounted flush on the bearing surface106of the bearing member96and centered on the optical axis Ao of the optical assembly98. So configured, and as shown, the light source97is adapted to project a cone of light116that is disposed on an illumination axis Ai, which is coaxial with the optical axis Ao of the optical assembly98. The illumination axis Ai therefore also extends perpendicular to the first plane P1and the bearing surface106of the bearing member96. So configured, the light source97advantageously directs and concentrates its cone of light116in the desired direction along the optical axis Ao, which thereby reduces reflections and optimizes the efficiency of the device.

Identical to that described above with respect to the field lamp projector26, the light source97of the presently disclosed optical distance indicator28can include an LED having a color temperature of 5650 k, exhibiting 235 lumens when running at 700 mA, or 320 lumens when running at 1000 mA. Alternatively, the light source97can include an LED (e.g., the XP-G2, manufactured by Cree) having a color temperature of 5600 k, exhibiting an output of 254 lumens when running at 700 mA or an output of 458 lumens when running at 1500 mA. LEDs having such characteristics work advantageously well with conventional diffusers used in connection with existing field lamp projectors and optical distance indicators. Additionally, LEDs having such characteristics illuminate well on patient skin. That is, even though such an LED results in a 2 lux reduction relative to conventional halogens, the color temperature of the LED appears brighter to the human eye when projected on skin. One example of an LED that has been tested and found to be suitable includes the Luxeon Rebel LED (Part No. LXML-PWC2) mounted on a 10 mm circuit board. Another example of an LED is the Luxeon Rebel LED (Part No. LXML-PM01-0100), which emits light having a wavelength of between 520 and 540 nanometers, and, preferably, a wavelength of approximately 530 nanometers, and which can be mounted on the Southern Linac Universal Mounting PCB described above. This LED has been tested and found to be particularly well-suited for the uses described herein (e.g., illuminating on patient skin). It will of course be appreciated that other LEDs, for example LEDs configured to emit green light having a different wavelength (e.g., a wavelength lower than 520 nm or higher than 540 nm) or LEDs configured to emit light of a different color (e.g., red), can be utilized.

As mentioned above, and with reference toFIG. 6, the light source47of the field lamp projector26must be connected to a power source58in order to generate the desired cone of light70. As shown inFIG. 6, the light source97of the presently disclosed optical distance indicator can be connected to the same power source58as the field lamp projector26in order to generate the desired cone of light116. The power source58used in conventional devices includes AC power sources, but DC power sources can alternatively be employed. Therefore, because the power source58used in conventional devices includes AC power sources, the present disclosure further includes a pair of LED drivers72positioned between the power source58and the light sources47,97. As illustrated inFIG. 6, the LED drivers72can be connected in parallel between the power source58and the light sources47,97. In one version, the parallel drivers72can each include a 500 mA AC/DC LED driver such as the LuxDrive 7006 Buckbullet LED driver. Alternatively, as illustrated inFIG. 7, the LED drivers72need not be connected in parallel. In the depicted alternative version, one LED driver72(e.g., a 1.5 A LED driver such as the Southern Linac LED driver) can be mounted to the light fixture32(e.g., to a back74of the light fixture32), and the other LED driver72(e.g., a 500 mA AC/DC LED driver such as the LuxDriver 7006 Buckbullet LED driver) can be positioned in the harness that feeds power to the light source97. In any event, the present disclosure advantageously enables the use of the existing power supply.

From the foregoing disclosure, it can be seen that the LED light sources of the light fixtures32,82disclosed herein advantageously direct and concentrate the generated light along the optical axis Ao of the respective optical assemblies38,88. As mentioned, this reduces and/or eliminates reflections within the housing30,80. Additionally, because the light sources47,97are directed in this manner, the light fixtures32,82do not include aperture plates disposed between the light sources47,97and optical assemblies38,88, as are present in conventional assemblies using halogen bulbs.

From the foregoing disclosure, it can be seen that both the field lamp projector26and optical distance indicator28are configured to project a pattern of light on a target (i.e., the patient25). Specifically, this is achieved by energizing the respective LEDs66,112and emitting the respective cones of light70,116to produce a pattern of light on the patient25. The respective cone of light70,116is emitted along the respective illumination axis Ai with the respective light source47,97. Each light source47,97is carried by a projector housing30,80of the radiation generating device10and the illumination axis Ai is disposed coaxially with an optical axis Ao of the respective optical assembly38,88, which is also carried by the projector housing30,80. With the field lamp projector26of the present disclosure, emitting the cone of light70advantageously produces a pattern of light on the patient which comprises an estimation of a pattern of radiation on the patient25, which can also be more accurate than estimations provided by conventional halogen light. In contrast, with the optical distance indicator28, emitting the cone of light116includes emitting the cone of light116through the optical assembly88including the lens125carrying the plurality of numbers. So configured, the pattern of light that is projected onto the patient25includes one or more numbers indicating a distance between the radiation generating device10and the target25. Once a technician is suitably satisfied with the patterns projected by the field lamp projector26and/or optical distance indicator28, the radiation generating device10can be energized to project a radiation field onto the patient25in a targeted and specific manner.

Additionally, from the foregoing disclosure, it can be seen that either or both light fixtures32,82of the disclosed projectors26,28can easily be installed into an existing radiation generating device10as an upgrade over conventional light fixtures utilizing halogen bulbs. To initiate such an upgrade, a technician can first remove a cover101(shown inFIG. 1) from the collimator20of the radiation generating device10, to expose the internal hardware. Then, any existing light fixture can be disconnected from the power source58. Before or after such disconnection, the existing light fixture can be removed from the light fixture housing30,80by sliding the existing light fixture out along a linear axis Aa (as shown inFIGS. 2 and 4) of the housing socket64,84. With the existing light fixture disconnected and out of the way, the upgraded light fixture32,82can be connected to the power source58and installed. For installation, the upgraded light source47,97is centered on the optical axis Ao of an optical assembly38,88carried by the respective housing30,80. This is achieved by sliding the upgraded light fixture32,83into the respective socket64,84along the linear axis Aa. Once connected, the cover 101 m of the collimator20can be re-attached to the radiation generating device10and the upgrade process is complete.

The foregoing description is provided as one or more examples embodying the present invention but is not intended to limit the scope of the invention. The scope of the invention is defined by the following claims and includes all equivalents thereof that fall within the spirit and scope of the claims and the disclosure as a whole.