Abstract:
Some configurations of the present invention provide a method for reducing eye fatigue that includes adjusting an intensity of an essentially white light source behind a display device to set an ambient light level in a room behind the display device, and adjusting an intensity of a blue light source disposed beside the display device to dilate pupils of the eyes of a viewer of the display device.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates generally to methods and apparatus for reducing eye fatigue, and more particularly to methods and apparatus for adjusting ambient lighting around various types of monitors, including LCD and CRT monitors, to reduce eye fatigue. 
   Liquid crystal displays (LCD) and cathode ray tube (CRT), displays well are known. (In this context as used herein, the terms “monitor” and “display” are considered synonymous. A “screen” is that part of the monitor or display upon which an image appears.) However, conditions in radiology reading rooms for reading these or other types of displays are not optimal for reducing eye fatigue or increasing accuracy of radiological studies. For example, many doctors turn off all lights to reduce screen glare on monitors. Studies indicate that radiologists experience eye fatigue under these conditions due to the increased contrast of the darkened room and a fully illuminated monitor screen (e.g., a CRT or LCD display screen). In addition, studies have also shown that the introduction of blue light into an environment results in dilation of the pupils of the eyes. When the pupils are dilated, the eyes are more focused and observational accuracy improves. Studies conducted with black-and-white images that were tinted using shade of blue to increase observational accuracy have found that radiologist found the blue-tinted images disturbing and out-of-sync with the black-and-white films they were trained to read. 
   Luminance variance between various types of images also contributes to eye fatigue. For example, radiologists studying breast mammograms must wait until their eyes have become acclimated before studying a CT or MR spine examination due to the greater average luminance of breast mammograms. 
   The use of separate lighting fixtures for ambient and environmental lighting is known. However, it can be inconvenient to adjust these separate fixtures for optimum lighting. Lighting attached to, or that attaches to a computer or display is also known, as is lighting that is powered by computer ports such as USB ports. However, known USB lighting is simple task lighting that does not adjust its intensity in accordance with information displayed on an associated computer screen. In addition, default display protocols (DDP) for medical images are known, but known protocols do not indicate or control optimal lighting parameters associated with examination types. 
   BRIEF DESCRIPTION OF THE INVENTION 
   There is therefore provided, in some configurations of the present invention, a method for reducing eye fatigue. The method includes adjusting an intensity of an essentially white light source behind a display device to set an ambient light level in a room behind the display device, and adjusting an intensity of a blue light source disposed beside the display device to dilate pupils of the eyes of a viewer of the display device. 
   Also in some configurations, the present invention provides a method for reducing eye fatigue that includes adjusting an intensity of an essentially white light source behind a display device to set an ambient light level in a room behind the display device. An intensity of a blue light source disposed beside the display device is adjusted to dilate pupils of the eyes of a viewer of the display device. The method also includes displaying a medical image on the display device. Adjusting an intensity of the white light source in these configurations includes adjusting an intensity of the white light source in accordance with a type of medical image displayed. Adjusting an intensity of the blue light source includes adjusting an intensity of the blue light source in accordance with the type of medical image displayed. 
   Moreover, some configurations of the present invention provide an apparatus for reducing eye fatigue. The apparatus includes a first light fixture and a second light fixture, a mount mechanically coupled to the first light fixture and the second light fixture and configured to attach to a rear portion of a display device so that the first light fixture is behind the display device and the second light fixture is beside the display device. The apparatus further includes a dimmer configured to separately control an intensity of lighting from the first light fixture and the second light fixture when the dimmer is powered and light sources are provided at the first light fixture and at the second light fixture. 
   Still other configurations of the present invention provide an apparatus for reducing eye fatigue that includes a stationary arm having a first light fixture, an arm mechanically coupled to the stationary arm and having a second light fixture, and a mount. The mount is mechanically coupled to the stationary arm and configured to attach the stationary arm to a rear portion of a display device so that the first light fixture is behind the display device and the second light fixture is beside the display device. The apparatus further includes a dimmer configured to separately control an intensity of lighting from the first light fixture and the second light fixture when the dimmer is powered and light sources are provided at the first light fixture and at the second light fixture. 
   Still other configurations of the present invention provide a display apparatus for reducing eye fatigue that includes a computer display, a first light fixture mechanically coupled to and behind the computer display and a second light fixture mechanically coupled to and at a side of the computer display. The apparatus further includes a dimmer configured to separately control an intensity of lighting from the first light fixture and the second light fixture, when the dimmer is powered and light sources are provided for the first light fixture and the second light fixture. 
   It will thus be observed that various configurations of the present invention reduce eye stress by providing an ambient light source and indirect blue lighting in rooms in which a display is read. Furthermore, various configurations of the present invention provide a reduction in eye stress and an increase in accuracy for reading of medical images. Some of these configurations advantageously adjust to reduce eye strain and increase accuracy automatically in accordance with the type of medical images being presented. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a drawing showing a top view representative of configurations of the present invention utilizing (or attached to) a liquid crystal display (LCD). 
       FIG. 2  is a drawing showing a top view representative of configurations of the present invention utilizing (or attached to) a cathode ray tube (CRT) display. 
       FIG. 3  is a drawing of a front view representative of the various configurations represented in  FIGS. 1 and 2 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In some configurations of the present invention and referring to  FIG. 1  and  FIG. 2 , a lighting apparatus  10  is provided that attaches to a display  12 . Display  12  can be any type of lighted monitor, such as a lighted liquid crystal display (LCD) monitor as shown in  FIG. 1  or a cathode ray tube (CRT) monitor as shown in  FIG. 2  (both of which are denoted as display  12 ). Lighting apparatus  10  includes a first fixture  14  that can receive and power a light source. In an operating lighting apparatus  10 , an essentially white light source  16 , e.g., a white or off-white incandescent lamp, one or more white fluorescent lights, one or more solid state light sources such as white LEDs, or some combination thereof is inserted in first fixture  14  and receives power therefrom. It will be appreciated that first fixture  14  can include one or more sockets for one or more light sources, and that the light sources can be individual white lights or colored lights that combine to produce an essentially white light. Light source or sources  16  produce ambient light behind display  12  to illuminate a room in which display  12  is located. 
   It is to be understood that light emitted by white light sources vary in color temperature. For example, a glowing incandescent light bulb appears slightly yellowish or reddish when compared to most white fluorescent lights. Furthermore, light emitted by a glowing incandescent bulb may become more reddish when a dimmer reduces the intensity of the bulb. However, “essentially white,” as that term is used herein, is intended to encompass all of these lighting cases. 
   Apparatus  10  includes a mount  20  mechanically coupled to first light fixture  14  and a second light fixture  18 . In some configurations, a third light fixture  22  is also mechanically coupled to mount  20 . Mount  20  is configured to attach to a rear portion of display  12  so that first light fixture  14  is behind display  12  (i.e., not visible by a person in front of monitor  12  who is viewing screen  24 ) when apparatus  10  is attached to display  12 . Mount  20  is further configured (e.g., by its position on apparatus  10 ) so that second light fixture  18  is beside display  12 . In some configurations, mount  20  is configured so that second light fixture  18  is beside and to the left of display  12  and third light fixture  22  is beside and to the right of display  12 . (“Beside,” as used herein, does not necessarily imply immediately adjacent to, but is intended to include configurations in which either of both second light fixture  18  and third light fixture  22  are spaced from the sides of display  12 .) 
   In an operating lighting apparatus  10 , a blue light source  26 , e.g., a blue incandescent lamp, one or more blue fluorescent lights, one or more solid state light sources such as blue LEDs, or some combination thereof is inserted in second light fixture  18  and receives power therefrom. Another blue light source  28  is inserted in third light fixture  22  in configurations having a third light fixture. In some configurations, second light fixture  18  and/or third light fixture  22  are on telescoping and/or pivoting arms  30  and  32  mechanically coupled to a stationary arm  34  on which first light fixture  14  resides. Thus, light fixtures  14 ,  18  and  22  are all mechanically coupled to mount  20 . Arms  30  and  32  permit blue light sources  26  and  28  to be positioned at selected and/or adjustable positions beside opposite sides of display  12 . In some configurations, first light fixture  14  is mounted on a stationary arm  34 . Stationary arm  34  in some configurations also has hinged attachment points  36  and  38  that attach to arms  30  and  32  respectively. 
   In some configurations, light sources  26  and/or  28  are positioned sufficiently in front of a plane of viewing screen  24  of display  12  to be just outside of the peripheral view of a person a viewing distance away (e.g., about 18 inches) from viewing screen  24 . However, to provide indirect lighting rather than direct lighting, some configurations of the present invention include a shade  27  configured to prevent direct light from blue light source  26  from directly impinging into the eye of a viewer viewing screen  24 . In various configurations having an additional blue light source  28 , an additional shade  29  is also provided. The effect of shades  27  and  29  can be appreciated by reference to  FIG. 3 , in which shades  27  and  29  are shown in partial cut-away view to reveal light sources  26  and  28  behind them. 
   In some configurations of the present invention and referring again to  FIGS. 1 and 2 , lighting parameters (i.e., intensity combinations including blue light intensity and white light intensity) corresponding to various specific types of examinations (e.g., breast MG, CT spine, CR PA and lateral, etc.) are preset in a dimmer  40 . The preset lighting parameters are selected to provide a favorable contrast and/or pupil dilation for each of the specific types of examinations and may take into account the average luminance of images in each type of examination. These lighting parameters are determined, in some configurations, from tests conducted on an appropriate population, for example, radiologists. Dimmer  40 , in some configurations, includes an interface  42  that is configured to couple to a computer  44  that controls display device  12 . Computer  44  controls display device  12  via interconnection  41  and also communicates a signal via wired or wireless interconnection  43  to dimmer  40 . This signal is indicative of the type of medical image displayed on display  12 , and dimmer  40  utilizes this signal to select one of the preset intensity combinations via interconnection  45  to device  10 . Dimmer  40  dims or brightens light sources  16  and  26  (and  28 , if present in the configuration) in accordance with the predetermined settings. In some configurations, computer  44  communicates signals indicative of actual intensity settings for light sources  16 ,  26  and  28  to dimmer  40  via interface  42 , and dimmer  40  sets these intensities. 
   In some configurations, dimmer  40  is also (or alternatively) provided with a manual control  46  to set intensities (including intensities relative to one another) of light sources  16  and  26  (and  28 , if present in the configuration) according to a viewer&#39;s own preferences. In some configurations, manual control  46  comprises independent controls for each light source  16 ,  26 , and  28 , or independent white and blue intensity controls, wherein, for example, the blue intensity control may control the intensity of more than one blue light source. Although not required by the invention, manual control  46  may additionally or alternatively provide a menu or selection switch from which a user can manually select one of the preset intensity combinations. 
   For the convenience of individuals installing or purchasing displays  12 , some configurations of the present invention include display  12 . For example, display  12  includes light sources (and, in some configurations, other features described above) pre-attached so that a user or installer of the display need not himself physically modify or attach additional components to display  12 . 
   It will thus be appreciated that configurations of the present invention introduce ambient light in darkened reading rooms, and thus decrease eye fatigue that users, and particularly radiologists, experience from reading monitor displays in high contrast environments. Additionally, the introduction of blue light results in a dilation of the eyes, allowing increased reading accuracy of the monitor display. Furthermore, lag time associated with acclimation to various degrees of ambient and examination luminance is reduced in configurations having automatic control of lighting conditions. 
   While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.