Abstract:
An intelligent endoscopic light source system for controlling the intensity of a light source, including a light source emitting light at a first intensity, an attenuator positioned to receive light from the light source at a first intensity and movable to pass light from the light source at a second intensity, a sensor mounted to the attenuator for measuring the first intensity, and a controller for receiving the intensity measurement from the sensor and moving the attenuator to pass light at a desired second intensity.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to an intelligent endoscopic light source, and more particularly, to an endoscopic light source that detects lamp intensity at startup and adjusts the level of attenuation necessary for a desired light output intensity. 
       BACKGROUND OF THE INVENTION 
       [0002]    Conventional endoscopes are often supplied with illumination from an external light source. The light sources are generally coupled to the endoscope by means of a detachable waveguide or fiber optic light cable. 
         [0003]    Such light sources generally include high intensity lamps, such as an incandescent or arc lamps. However, one issue with the use of such lamps is that their intensity cannot effectively be controlled by conventional means, such as reducing the power to the lamp through an electronic dimmer control. Instead, high intensity lamps are generally operated at full power and an alternate system is provided to reduce the intensity of the light transmitted to an endoscope for illuminating a site. 
         [0004]    Another issue with high intensity lamps is that they produce a high amount of infrared energy, which if not properly reduced can cause damage. For example, light from a high intensity lamp can burn operating drapes, a patient&#39;s skin, or clothing. 
         [0005]    Still further, as a high intensity lamp ages, the intensity of the lamp reduces and the color temperature drifts. For example, once a lamp has aged to the point where the output intensity is approximately 20-25% of a new lamp, the color temperature of the lamp output begins to drift. The color temperature drift can be so dramatic that an endoscopic camera system used with the light source may no longer correctly white balance the image. Thus, all images acquired by the camera will be off color, which can have tragic results if a surgeon using the light source makes an incorrect diagnosis based upon inaccurate tissue color and/or appearance. 
         [0006]    Therefore, when using high intensity lamps in endoscopic light sources, it is desirable that both the intensity and infrared energy of the light transmitted to the endoscope is attenuated. It is also desirable that the color temperature of the lamp is monitored. 
         [0007]    The reduction of the transmitted intensity of a lamp using a mechanical attenuator is effective for use with endoscopic light sources. Such systems are disclosed in U.S. Pat. No. 5,006,965. However, this and other known devices do not effectively control the light output intensity as a lamp degrades or inform a user when a lamp needs to be replaced. Such devices also do not inform a user when the color temperature of the lamp drifts. Still further, such devices do not inform a user if the infrared energy emitted by the system is too high. Thus, with such devices disclosed in the prior art, it is difficult for a user to maintain a consistent light output intensity, for a user to know when the color temperature of the light source has drifted and for a user to determine if too much infrared energy is being output. 
         [0008]    It is therefore desired to provide an improved endoscopic light source that automatically detects the intensity of a lamp and reduces the intensity to a predetermined level. It is further desired, that the system will inform a user when the lamp&#39;s intensity falls below a predetermined level, the color temperature is no longer acceptable and if the infrared energy is above a predetermined value. 
       SUMMARY OF THE INVENTION 
       [0009]    Thus, it is an object of the invention to provide an endoscopic light source system having a light source emitting light at a first intensity, an attenuator positioned to receive light from the light source at the first intensity and movable to pass light from the light source at a second intensity, a sensor is mounted to the attenuator for measuring the first intensity, and a controller receives the first intensity measurement from the sensor and moves the attenuator into the proper position to pass light at a desired second intensity. 
         [0010]    It is a further object of the invention to measure the first intensity each time the system is turned on and adjusting the attenuator to obtain a consistent second intensity as the first intensity varies with time. 
         [0011]    It is still a further object of the invention to alert a user when the first intensity is below a predetermined value, informing the user that the light source needs to be replaced. 
         [0012]    It is another object of the invention that the sensor measures the color temperature of the light source and the system alerts a user when the color temperature of the light source has drifted outside a predetermined range, informing the user the light source needs to be replaced. 
         [0013]    It is still another object of the invention that the sensor measures the infrared energy of the light source and the system alerts a user when the infrared energy of the light source is above a predetermined value, informing the user to either troubleshoot the light source or the hot-mirrors may need adjusting or replacing. 
         [0014]    It is another object of the invention that the sensor includes a wireless transceiver allowing the sensor to communicate with the controller wirelessly. 
         [0015]    It is also an object of the invention that the sensor includes a photovoltaic cell that allowing the sensor to be powered by the light source. 
         [0016]    It is still another object of the invention that the attenuator can be either a rotary attenuator or a linear attenuator. 
         [0017]    These and other objects are achieved by providing an endoscopic light source system, including a light source emitting light at a first intensity and having a light output path, an attenuator having a control path for variably passing light from the light source at a second intensity and a sensor module having a light intensity sensor for measuring the first intensity. The control path and the sensor module are positionable in the light output path. A controller receives the first intensity measurement from the sensor module when the sensor module is in the light output path, and the controller positioning the attenuator to a location on the control path in the light output path in order to adjust the second intensity to a desired level. 
         [0018]    The sensor module further including a color temperature sensor on the sensor module for measuring the color temperature of the light source and transmitting the measurement to the controller in order to alert a user when the color temperature of the light source is outside a predetermined range. 
         [0019]    The sensor module can further include a photovoltaic cell to power the sensor module and a wireless a wireless transceiver for communicating with the controller. 
         [0020]    The sensor module also including an infrared sensor for measuring the infrared energy of the light source and transmitting the measurement to the controller in order to alert a user when the infrared energy of the light source is above a predetermined value. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of an endoscopic light system according to an embodiment of the present invention. 
           [0022]      FIG. 2  is a schematic diagram of the endoscopic light system shown in  FIG. 1   
           [0023]      FIG. 3A  is a front view one embodiment of the attenuator of  FIGS. 1 and 2 . 
           [0024]      FIG. 3B  is a schematic diagram of an embodiment of the sensor module affixed to the attenuator as shown in  FIGS. 2 and 3A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]      FIG. 1  shows a perspective view of an exemplary embodiment of an endoscopic light system  10  according to the invention. The system  10  includes an endoscopic light source  12  for providing visible light to a waveguide  14  that provides visible light to an endoscope  16 .  FIG. 1  includes a cutaway showing the internal components of the endoscopic light source  12  as shown in  FIG. 2 . 
         [0026]      FIG. 2  is a schematic view of the endoscopic light system  10  of  FIG. 1 .  FIG. 2  includes a lamp  40 , which provides visible light  41  having an optical axis  43 . The lamp  40  can be an incandescent lamp, arc lamp or any other suitable light source. A condenser lens  42  condenses the light beam  44  toward the input end  47  of a fiber optic bundle  48 . An attenuator  50  is placed in the path of the light beam  44 . The attenuator  50  is connected to the shaft  46  of a motor  45  for controlling the position of the attenuator  50 . The rotational axis of the shaft  46  is offset and substantially parallel to the optical axis  43 . The endoscopic light source  12  further includes a controller  30  connected to the lamp  40 , motor  46 , and front control panel  20 . The front control panel  20  of the endoscopic light source  12 , includes an on/off switch  18 , indicator light  22  and other display and connection features for use by an operator. 
         [0027]    The on/off switch  18  controls the power state of the endoscopic light source  12 . The controller  30  controls the lamp  40  and motor  45  for actuating the attenuator  50 . The controller  30  can communicate with the lamp  40  and motor  45  via either a direct connection or wirelessly. Thus, in certain embodiments the controller includes a processor  32  and a wireless transceiver  34 . The wireless transceiver  34  can be any suitable technology for wireless communication, including for instance, infrared(IR), radio frequency(RF), Wifi and Bluetooth. 
         [0028]    As shown in  FIG. 3A , the attenuator  50  is preferably an opaque rotary vane attenuator for mechanically regulating, throttling, or controlling the intensity output  49  of the lamp  40 . The light beam  44  forms a spot  52  on the outer portion of the attenuator  50 . An arcuate control area  53  extends circumferentially around the attenuator  50 . The control area  53  has a movement axis  54  that coincides with the optical axis  43  of the light beam  44 . In this embodiment, the movement axis  54  divides the control area into an outer band  55  lying on the outside of the movement axis  54  and an inner band  56  lying on the inside of the movement axis  54 . 
         [0029]    The outer band  55  has a substantial arcuate solid area  57  with the remainder of its active length an open area  58 . Thus, when the solid area  57  is in the path of the light beam  44 , approximately 50% of the light beam  44  is blocked by the attenuator  50 . When the open area  58  is in the path of the light beam  44 , then this 50% is restored to the transmitted portion  49  of the light beam  44 . 
         [0030]    When the solid area  57  is in the path of the light beam  44  the outer band  55  reduces the amount of fine control required to be accomplished by the attenuator  50 . Thus, the inner band  56  must attenuate only half of the light. Above the 50% attenuation level, open area  58  is used and the light transmitted by the outer band  55  is added to the light transmitted by the inner band  56 . 
         [0031]    The inner band  56  includes a progression of slots  61  combined with opaque bars  62 . The width of the slots and bars are selected to produce a desired light intensity transmission.  FIG. 3A  is only an example of one suitable arrangement to provide a smooth variation of transmitted light intensity. The gradual changes allows for fine control of the transmitted light intensity. 
         [0032]    For instance, slots  63  and  64  are relatively far apart, spaced by a wide bar  65 . The bars between the slots narrow as they approach slot  66 , but the slots remain about the same width. After this region, the bars remain about constant, but slots such as slot  67  become wider. Finally, slot  68  is very wide, and abuts the edge  80  of the outer band  55 , creating a cross-over point  81  where light becomes controlled along with light passed by the outer band  55 . Then bars  82  start to decrease while the slots are constant, followed by a region near slot  83  where the slots again increase in width. 
         [0033]    In use, as the attenuator  50  turns away from slots  63  and  64  the light transmitted by the inner band  56  increases while the outer band  55  blocks transmission. Then at the cross-over point  81 , the inner band  56  again has reduced throughput, which gradually increases that is now in addition to the light transmitted by the outer band  55 . 
         [0034]    The illustrated arrangement and sizes of the slots and bars are for purposes of providing an example. Many other patterns, slots, bars and portions of the outer band can be provided, which will produce a desired, but different dimming pattern. Furthermore, it should be understood that the attenuator may be linear instead of rotational. In such event, the control area would be linear and moved back and forth across the optical axis. 
         [0035]    The attenuator  50  also includes a sensor module  70  affixed to a solid portion of the attenuator  50  in the movement axis  54  of the light beam  44 . As shown in  FIG. 3B , the sensor module  70  includes a processor  71  and a visible light sensor  72  used to measure properties of the light beam  44 , including luminance intensity and color temperature. In certain embodiments the sensor module  70  can also include a photovoltaic cell  73  to power the sensor module, an infrared (“IR”) sensor  74  to measure the IR energy and a wireless transceiver  75  to communicate with the controller  30 . The wireless transceiver  75  can be any suitable technology for wireless communication, including for instance, infrared(IR), radio frequency(RF), Wifi and Bluetooth. Alternatively, the sensor module  70  can be directly wired to the controller  30 . 
         [0036]    In use, the attenuator  50  is rotated such that the sensor module  70  is positioned within the light beam  44 . If the sensor module  70  is equipped with a photovoltaic cell  73 , the light beam  44  will power the sensor module  70 . Once the sensor module  70  is energized, the processor  71  will detect the luminance intensity and color temperature using the visible light sensor  72  and communicate these values to the controller  30 . This communication can be via the wireless transceivers  34 ,  75  of the controller  30  and sensor module  70 . 
         [0037]    Once the controller receives the luminance intensity and of the lamp  40 , the controller  30  determines the percentage of attenuation required for the desired intensity output  49 . The controller  30  then communicates with the motor  45  moving the attenuator  50  into the proper position to provide the desired amount of intensity. As the lamp  40  reaches the end of its useful life, less and less attenuation is required to achieve the desired output. 
         [0038]    If the sensor module  70  is equipped with an IR sensor  74 , the sensor module  70  will detect the IR energy in the light beam  44 . By detecting the IR energy and communicating it to the controller  30 , the controller  30  can determine whether the IR energy is being properly blocked or redirected by the hot-mirrors (not shown). If the IR energy value is above a predetermined set-point, indicating inadequate hot-mirror performance, the operator will be notified. For instance, controller  30  may turn on the indicator light  18  on the control panel  20  indicating that the lamp  40  requires troubleshooting and the hot-mirrors may require replacement. 
         [0039]    Preferably, the endoscopic light source  12  will determine the output intensity of the lamp  40  each time the lamp  40  is turned on. Thus, the controller  30  can determine the intensity of the lamp  40  and properly adjust the attenuator  50  in order to maintain a consistent desired light source  12  intensity output. 
         [0040]    Generally once the lamp  40  has aged and the output intensity is approximately 20-25% of a new lamp  40 , the color temperature of the lamp output begins to drift. As previously described, the color temperature drift can be so dramatic that an endoscopic camera system used with the endoscopic light source  12  may no longer correctly white balance the image, causing all images acquired by the camera will be “off color”. Thus, once the output intensity of the lamp  40  is below a certain level and/or the color temperature value is outside a certain range, a user will be notified that the lamp  40  requires replacement. 
         [0041]    Since the controller  30  preferably checks the lamp  40  intensity and color temperature at each power-up, the controller  30  will detect when a new lamp  40  has been installed and automatically zero out the lamp  40  “hours on” counter displayed on the control panel  20 . Moreover at initialization, if the controller  30  determines a “hot lamp” or incorrect lamp  40  is installed (e.g. a lamp over the maximum wattage rating for the system), the user will be notified. 
         [0042]    Preferably the attenuator  50  is designed so at the normal intensity level of a new lamp  40 , the attenuator  50  is positioned at approximately 20% attenuation (i.e. “light blockage”) with the control panel  20  showing that the lamp  40  is at 100% intensity output. As the lamp  40  ages and its output intensity degrades, the controller  30  will introduce a correction/offset to the attenuator  50  position so that at the lamp&#39;s  40  maximum age (i.e. lowest acceptable intensity output) the attenuator  50  would be positioned completely out of the light output path (i.e. 0% attenuation). 
         [0043]    While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that various changes and modifications in form and details may be made thereto, and the scope of the appended claims should be construed as broadly as the prior art will permit. 
         [0044]    The description of the invention is merely exemplary in nature, and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.