Abstract:
An illumination device used in dermoscopy for enhanced imaging and illumination of the skin for medical examination and treatment. An array of LEDs encircle a magnifying lens assembly. One set of surrounding LEDs provides cross-polarized white light to aid in canceling the reflected light from the skin and creating less glare. Another set of surrounding LEDs provides non-polarized white light for traditional immersion fluid dermoscopy or for non-polarized viewing of the skin. A third set of surrounding LEDs provides polarized colored light, wherein the wavelength color is selected at a color wavelength that maximizes the viewing of skin pigment regions which is important for early detection of skin cancers and other skin diseases. In one embodiment, the colored LEDs comprise orange light at a wavelength in the range of 581 nm to 600 nm wavelengths.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to an illumination device used in dermoscopy. More particularly, the invention comprises an improved apparatus for enhanced imaging and illumination of the skin for medical examination and treatment. 
     2. Background 
     When using surface illumination to view human skin in medical examination, a great deal of surface light is reflected from the top layer of skin. Hand held dermoscopy devices that use light along with magnification can utilize polarizers or liquid-glass interface to reduce surface reflection and see deeper in to the skin. Dermoscopy apparatuses that employ light polarization to aid in viewing human skin surfaces and deeper tissue and structures of the skin are known and described U.S. Pat. Nos. 7,006,223 and 7,167,243 both issued to Mullani, the substance of each of which is incorporated herein by reference. In addition, a dermoscopy device identified as Dermlite® DL3 device is manufactured and marketed by 3Gen, Inc. of San Juan Capistrano. In the Dermlite® DL3 hand held device, a series of light emitting diodes (“LEDs”) are concentrically positioned around a magnifying lens to assist in lighting of a magnified image. The device includes two sets of white light LEDs that can be activated independently; one set of twenty one (21) LEDs provides reduced glare cross-polarized light to aid in canceling the reflected light from the skin, whereas the other set of seven (7) LEDs provides non-polarized light for traditional immersion fluid dermoscopy or for simply employing non-polarized light. Both sets of LEDs can be operated independently or at the same time. Users of the Dermlite® DL3 can toggle between polarized and non-polarized light to provide an enhanced perspective of skin surface and lesions. 
     It is also well known that different colored light penetrates to different depths in human skin tissue. Specific color wavelengths are absorbed differently by different components of the skin tissue. Such use of colored LEDs in a dermatoscope is described in U.S. Pat. Nos. 7,027,153 and 7,167,244 both issued to Mullani, the substance of each of which is incorporated herein by reference. The previously identified references disclose the combined use of white LEDs, UV/blue LEDs (405 nm), green/yellow LEDs (565 nm) and orange/red (630 nm). Alternatively, the 7,027,153 and 7,167,244 references suggest the use of LEDs with 480 nm, 580 nm and 660 nm wavelengths. In addition, a dermoscopy device identified as Dermlite® II Multispectral dermoscopy device manufactured and marketed by 3Gen, Inc. of San Juan Capistrano, Calif. provides four sets LED&#39;s comprising white, blue light (470 nm) for surface pigmentation, yellow light (580 nm) for superficial vascularity viewing, and red light (660 nm) for viewing of pigmentation and vascularity with the deeper-penetrating red light frequency. 
     In related medical examination procedures, such as for viewing structures on the surface and beneath the skin, a further way to introduce more light in to the skin is to use side-transillumination techniques whereby the light source is caused to be in direct contact with the skin to transfer light directly into the skin. One such technique is known and taught in U.S. Pat. No. 5,146,923 issued to Dhawan, the substance of which is incorporated herein by reference. A combination of surface illumination, epiluminescence and transillumination apparatus and method is demonstrated in the Nevoscope™ product sold manufactured by Translite LLC. of Sugar Land, Tex. Another known apparatus and method of viewing vein structures beneath the skin employs the use of transillumination as described in U.S. Pat. No. 7,874,698 issued to Mullani the substance of which is incorporated herein by reference. U.S. Pat. No. 7,874,698 issued to Mullani describes the use of orange light between 580 and 620 nm for transillumination imaging of deeper blood vessels in skin tissue. However, the technology of transillumination is different than imaging skin with direct surface light. In transillumination, the light is directed into the skin by direct contact with the skin. 
     With respect to Dermatoscopes that use white light to image the skin, white light has a range of colors from Blue to Red. As such, the skin can be visualized up to 3 mm deep depending on the ‘color’ of the white light. White light used in known dermatoscopes are usually generated by white LEDs and unlike halogen bulb light, the light from these LEDs comprise a great deal of blue light in the spectrum of white light. This bluish tint to the white light makes the dermatoscope more sensitive to the top 1 mm of skin. When using the blue tinted white light in dermatoscopes, it is difficult to see the pigmentation structures in the deeply pigmented areas that are deep. For purposes of early skin cancer detection, viewing pigmentation structures is important for diagnosing cancerous lesions that may be hidden from view at a deeper depth when using blue tinted white light. 
     To aid in the early detection of skin cancers, the viewing of deeper structures of the skin in close proximity of the skin without the need to contact the skin directly with a light source, or penetrate the skin surface is beneficial for examination, diagnosis and treatment. As described above, polarized white light and colored lights for surface illumination is known. Also, the use of colors in the orange range spectrum is known with respect to translliumiation devices for viewing vein structures. However, there is a great need in the art for a dermoscopy device that can illuminate the skin with white light and/or light in a color range that is adapted to provide a more advantageous viewing of the skin and sub-surface skin structures to enable a more enhanced viewing of pigments and lesions found in the skin that will aid in a visual early detection of various types of skin cancer. 
     BRIEF SUMMARY 
     The present invention relates to an epiluminescence microscopy device designed to view skin lesions with high magnification and clarity with a plurality of sets of LEDs (light emitting diodes) that can be activated independently. An array of LEDs encircle a magnifying lens assembly. One set of surrounding LEDs provides cross-polarized light to aid in canceling the reflected light from the skin and creating less glare. Another set of surrounding LEDs provides non-polarized light for traditional immersion fluid dermoscopy or for non-polarized viewing of the skin. A third set of surrounding LEDs provides polarized colored light, wherein the wavelength color is selected at a color wavelength that maximizes the viewing of skin pigment regions which is important for early detection of skin cancers and other skin diseases. The present invention discloses the range of colored LEDs in the orange portion of the visible spectrum, namely at 581 nm to 600 nm wavelengths. 
     The device of the present invention includes, among other features, a high quality multi-element, 25 mm, 10× lens that provides color correction and reduced image distortion to produces an image rich surface detail. To facilitate the use of immersion fluids, and allow for fixed digital imaging, the unit is equipped with a retractable faceplate spacer. 
     The present invention demonstrates that the use of orange light in the specified range as described herein enhances the ability of white light LED based dermatoscopes for imaging deeper pigmentation or blood vessels. The present invention provides for the independent use of cross-polarized white light that can be enhanced with cross-polarized orange light. Alternatively the cross-polarized orange light or white light each can be used independently. The device of the present invention includes the ability to toggle between several modes of operation so that the viewer can toggle between images to provide an enhanced perspective of the skin to a doctor, researcher or healthcare professional. The device of the present invention also provides that the cross polarized orange light can also be used with non-polarized light to enhance the imaging of deeper pigmentation when using a glass-liquid interface and white light. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
         FIG. 1  is a is a top perspective view of the device of the present invention; 
         FIG. 2  is a bottom perspective view of the device of the present invention; 
         FIG. 3  is a composite view of the device of the present invention demonstrating the removable and retractable features of the device of the present invention; 
         FIG. 4  is an exploded view of device of the present invention demonstrating mechanical sub assembly of the present invention; 
         FIG. 5  is an exploded view of the components associated with the LED and lens sub-assemblies along with the PCB assembly of the device of the present invention; 
         FIG. 6  is an exploded view of the of the various components of the device of the present invention; 
         FIG. 7  is a cross sectional view of the device of the present invention; 
         FIG. 8  is an enlarged view of the arrangement of LEDs in the lighting array surrounding the lens structure and in connection with the switching device of the device of the present invention; 
         FIG. 9  is a side view of the LED array in combination with the switching circuit and lead lines; 
         FIG. 10  is a view of the arrangement of LEDs, switching component and tail printed circuit board for interfacing with a recharging jack of the device of the present invention; 
         FIG. 11  shows the device of the present invention in a charging assembly; and 
         FIG. 12  shows the device of the present invention being removed from the charging assembly. 
     
    
    
     DETAILED DESCRIPTION 
     It is generally known that light is highly absorbed by the pigmentation in skin lesions for the central part of the visible spectrum from 500 to 570 nm. This high absorption is a problem with visualizing deep pigmented areas because the light gets blocked or absorbed superficially. The absorption of light in pigmentation for the frequencies above 570 nm decreases and this light can be used to see into deeply pigmented areas better. 
     Surface light falling on human skin in the visible spectrum can include a range of colors with Blue light (450-500 nm) penetrating the shortest distance in skin tissue. Blue light is known to be highly absorbed in pigmentation and blood and as such its depth is limited to less than 1 mm. Green light (500-550 nm) penetrates slightly deeper than blue light and is highly absorbed by hemoglobin in the blood. Yellow-orange light (560-610 nm) light penetrates between 1 and 2 mm depth in skin tissue, while red color light (620-670 nm) penetrates deepest (between 2 and 3 mm). 
     The present invention demonstrates the use of orange light on skin, with the imaging depth into the skin is between 1 and 2 mm below the surface. Unlike blue light, which is more absorbed by pigmentation and blood up to a depth of 1 mm, the orange light is better for imaging pigmentation and blood vessels between 1 and 2 mm below skin. Pigmented lesions can vary in depth from very superficial to deeper than 2 mm. 
     The imaging of the deeply pigmented lesions and deeper blood vessels can be enhanced by the addition of an orange light (581 nm to 560 nm) when added to, or compared against the blue tinted white LED light in dermatoscopes. Also, the present invention demonstrates the polarization of the orange light so that it can penetrate deeper in tissue and include less reflected glare as compared to the conventional surface light. 
     The two major absorptions of light in human skin are from melanin and hemoglobin in the blood. Below is a chart (shown in Table 1) demonstrates the coefficient data for Melanin and Hemoglobin and the depth of penetration of light for the identified specific light wavelengths. These values are approximations of know data graphed in the following publications: 
     V. Venugopalan slides, http://www.osa.org/meetings/archives/2004/BIOMED/Program/#educ. The graphed data in Table 1 includes different values for oxygenated and deoxygenated blood, and the below chart takes the average of the two values. The light penetration depth was disclosed in the article: A Bashkatov et al. J PHys D Appl Phys 38:2543-2555 (2005). 
     
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 480 nm 
                 585 nm 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Melanin Absorption Coefficient/cm 
                 1000 
                 500 
               
               
                   
                 Hemoglobin Absorption Coefficient/cm 
                 100 
                 300 
               
               
                   
                 Light Penetration Depth (mm) 
                 0.75 
                 1.5 
               
               
                   
                   
               
             
          
         
       
     
     The data in the chart demonstrates that the melanin absorption data for white light has a peak at around 480 nm and a broad peak at around 525 nm. The broad peak can vary due to the types of chemicals used to convert the blue light to white light. The orange light supplied by the device of the present invention penetrates deeper than the blue color of the white light with the orange light being absorbed to a lesser degree than the blue color in melanin. 
     The present invention demonstrates that the use of orange light in the range of 581-600 nm used in dermatoscopes enhances the ability of the user to view deeper into the skin and into pigmentation and blood vessels. Visualizing pigmentation becomes more difficult at around 700 nm due to the fact that the pigmentation becomes almost transparent for deep red to near infrared light. As such, the optimum light frequency for detection of pigmentation and deeper penetration includes the range of 581 to 600 nm. 
     In this regard, the orange light enhancement is especially adapted for viewing pigmented skin, when used alone or combined with the white light of the other LEDs. Because many cancerous lesions involve pigmentation, the device of the present invention provides enhanced viewing of the pigmented regions along with enhanced viewing of the perimeter of the pigmented regions which can be revealing in examination and diagnosis. Another effect of the orange light is that it is absorbed by hemoglobin in the blood. Malignant lesions tend to have higher blood volume around them due to the growth of new blood vessels. As such, abnormal vein activity surrounding a lesion may be identified with increased viewing depth and interaction of the orange light with hemoglobin. 
     The present invention provides independent use of cross-polarized white light that can be enhanced with cross-polarized orange light. Alternatively the cross-polarized light can be used independently. As a further alternative, the device of the present invention includes the ability to toggle between several modes of operation so that the viewer can toggle between images for an enhanced perspective of the skin. The device of the present invention provides that the cross polarized orange light can also be used with non-polarized light to enhance the imaging of deeper pigmentation when using a glass-liquid interface and white light. Although the present invention demonstrates that the orange light is polarized, it is contemplated and within the scope of the present invention that the orange light can be non-polarized or simply polarized. 
     Also, although the present invention identifies specific ranges or specific wavelengths for the LEDs used in the invention, the exact color of the orange light may vary slightly depending on the commercial availability of the color of the LEDs. Also, a specific number of LEDs in various combinations are provided, the number of white and orange LEDs can be varied depending on the brightness of each of the LEDs or other factors. 
     Referring collectively to  FIGS. 1 and 2  the illumination device of the present invention  12  is shown with a housing  14  that is adapted to be hand held and to encase, among other things, a battery (not shown) lighting sources (not shown) and magnification lenses (not shown). While the disclosure of the present invention shows a hand held, battery powered device, it is contemplated by the present invention that the components of the invention that provide the beneficial illumination for skin examination could be could be incorporated into other types of diagnostic devices, such as fiber optic hand pieces or incorporated into surgical lighting or other types of examination lighting. Preferably, the housing  14 , and other internal sub-assembly pieces of the structure of the device of the present invention is formed of assembled pieces of injection molded polycarbonate and polyurethane. It will be recognized by one skilled in the art that the housing  14  can be formed form other suitable rigid lightweight material, including, but not limited to plastic, composite materials, fiberglass, aluminum, PVC, acetate and or lexan. The housing  14  of the device is adapted to be cleaned and disinfected as is necessary. 
     An eyepiece  16  is attached to the housing  14  to allow a user to view central lenses (not shown) that are incorporated into the housing  14 . The annular eyepiece  16  is in visual communication with a proximal viewing port  20 , that includes a glass faceplate  22  comprised attached to a spacer (not shown) and held in place by a capture  24 , creating a line of sight form the eyepiece  16  through the housing  14  to the viewing port  20 , through glass faceplate  22 . The view corridor through ports  16  and  20  allows a user to view with the skin with a naked eye to view subject skin placed below proximal viewing port  20 . The housing  14  includes a retaining ring  24  that when in a secured position holds a spacer  26  in place, and the spacer  26  face incorporations a glass faceplate  22 . A focus dial  28  is provided for adjusting position of spacer by extending or retracting the same to adjust the focal distance to the object or tissue to be viewed (not shown). 
     Referring particularly to  FIG. 3 , a composite drawing demonstrates the various removable components of the device of the present invention. The eyepiece  16  is optional. The eyepiece  16  is used in those instances where the user wishes to improve the contrast of the image and reduce internal reflections. The eyepiece  16  is selectively removable and is attached to the housing  14  by eyepiece threads  30 . The eyepiece threads  30  engage the eyepiece  16  by rotating internal threads of the eyepiece (not shown). The eyepiece threads  30  are 28 mm thread used in camera adaptors and serve the alternate purpose allowing the attaching of the device of the present invention to a camera. A simple ring adapter (such as a 28-37 mm stepping ring) may be employed to connect the device of present invention to a camera. 
     Also, the retainer ring  24  is threaded and may be rotated to be removed from the housing  14  to access the removal of the spacer  26 . Once the retainer ring  24  is removed, the focus dial  28  is rotated until the spacer  26  is unsecured from the housing  14 . To re-attach the spacer  26 , internal pins (not shown) are aligned on notches and the focus dial  28  is rotated until the spacer pulled back into the housing  14 . The retaining ring  24  can then be threaded back onto the housing  14  using retaining threads  34 . The selective placement of the spacer  26  allows the device  12  to be used as non-contact dermoscopy device without the spacer, or oil and glass dermoscopy with the spacer extended. With the spacer  26  retracted, the user can effect a dry examination of the skin. With spacer  26  in the extended position, a user can complete a direct contact skin examination, typically employing oil emersion. The sidewalls of the spacer  26  support a glass faceplate. The glass faceplate  22  also incorporates a scale  21  (shown in  FIG. 2 ) to provide the user with information regarding size of a lesion, blood vessel or other object to be viewed. 
     Referring particularly to  FIG. 4 , there is shown an exploded view of the components of the housing  14  of the present invention. The housing  14  is formed from bottom housing component  14   a  or which can be referred to as a grip, and top housing component  14   b  also referred to as the mechanical sub-assembly. The bottom housing component  14   a  interfaces and connects to the top housing component  14   a  to form the housing  14 . The grip  14   a  provides the primary interface for the user&#39;s hand to hold the device  12  during examination. A recess  36  is formed in the top housing component  14   b  to receive an instruction label  38  and battery  40 . The battery  40  nests within the recess  36  and is electrically connected to a power port connector  42  for charging the device  12  and the lighting array  44  for providing a lighting source for the device  12 . The battery  40  is selectively removable from the device  12  and the battery  40  provides power to the device  12 . The battery  40  is a Lithium rechargeable battery, however it is understood that any like battery power source could be used in relation to the present invention. 
     The lighting array  44  is housed within a core assembly  46 . The core assembly  46  comprises the lighting array  44 , a polarizer  50  and lens sub-assembly (not shown) enclosed by a core cover  48 . The core assembly  46  nests within the circular structure of the focus dial  28 . The lighting array  44  along with the polarizer  50  encircle the forward lens of the device  12  to transmit light upon tissue or object to be viewed. 
     Referring particularly to  FIG. 5 , there is shown an exploded view of the core assembly  46  along with a printed circuit board (“PCB”) assembly  52 . With respect to the core assembly  46 , as described above, the same comprises lighting array  44 , a polarizer  50  and lens sub-assembly enclosed by a core cover  48 . The lighting array  44  comprises a circular array of LEDs affixed to a circuit board  56 . The circuit board  48  is secured within the housing  14 . The LEDs are affixed to and in electrical communication with the circuit board  48  via a plurality of lead lines  58 . Each LED has at least two lead lines  58 . The LEDs are also supported on the circuit board by a fin  60  which provides support and additionally provides separation between LEDs. The fin  60  additionally provides support for the polarizer  50 , the function of which is described in more detail in relation to  FIGS. 8-10  below. As can be appreciated each of the components of the core assembly  46  are sized and positioned with a central aperture to permit unobstructed viewing of examined tissues or objects through the lens assembly  54 , through the PCB board  56 , lighting array  44  and fin  60 , polarizer  50  and core cover  48 . 
     The PCB assembly includes the PCB board  56  in electrical communication with the main PCB  62  which houses switching circuitry (not shown). The main PCB interconnects the power port  42  for charging the device  12  to the battery  40  (not shown). Switching circuits on board the main PCB permit the user to selectively activate various combinations of LEDs in the lighting array  44 . External switches, discussed more fully below, provide the mechanism for activating and deactivating sets of LEDs. Power lead lines  64  provide electrical connection between the tail PCB  66  and the main PCB  62 . The tail PCB  66  includes contacts  66  that interface with a charging station (not shown) for charging a battery (not shown). The power port connection  42  additionally provides a connection to leads  68  as a means for charging the device  12 . 
     Referring specifically to  FIG. 6 , there is shown an exploded view of the assembled parts of the device  12  of the present invention. The top housing  14   b  is shown in two assembled parts, the plate  70  and PCB cover  72 . Four screws  74  (three shown) provide the fastening means for the plate  72  and PCB cover and main PCB  62  and tail PCB  66 . 
     Lens sub-assembly  54  (shown exploded) comprises a lens tube  76  for enclosing the following: a center polarizer  78  and polarizer spacer  80 . The lenses  82  and  84  are dual achromat 25×50 mm lenses. Although the device of the present invention discloses dual achromat lenses other similar lens structures may be utilized such as an aspherical lens, a single convex lens or combination of two or more such lenses or such lenses in combination the double achromat lenses. In addition, the lens may incorporate Hastings lenses. The lenses may also include color tinting. Also included with lenses  82  and  84  is lens spacer  81 . The base of the lens sub-assembly  54  is attached to plate  70  by plate ring  88 . The focus dial  28  is adapted to engage the helix ring  90  to provide mechanical engagement between the spacer  26  and the focus dial  28  to extend and retract the spacer  26 . 
     Referring particularly to  FIG. 7 , there is shown a cross-sectional view of the device  12  of the present invention.  FIG. 7  is useful to demonstrate the cross-sectional view of the viewing corridor through the eyepiece  16  lenses  84  and  82 , to enable a user to view objects or tissues with the aid of the LED light.  FIG. 7  demonstrates where the spacer  26  is in the retracted position within the housing  14 . 
     The battery  40  is interconnected to the main PCB  62  to provide power to the light array  44 . Upon activation of a switch, the light array  44  provides selective lighting through filter  50  on a plurality of the LEDs and unfiltered on a number of other LEDs. The light travels through the glass faceplate  22  to direct light upon examined tissue or an object to be viewed. The lighting array  44  is interconnected to a LED PCB  56  via leads  58 . The PCB  56  is in electrical communication with the PCB boards  62  which provide selective activation of the lighting array  44 . An indicator LED  91  is interconnected to the main PCB  62  to provide a status indication through indicator LED lens  92  of the device  12  in operation. The LED lens  92  will illuminate to red to indicate that the device  12  is being charged. When the lithium battery  40  is fully charged the indicator LED lens  92  will be green and the device will allow up to two hours of continuous operation or enough power for imaging approximately 600 lesions at 30 seconds per examination. When the battery  40  life reaches less than 25% power remaining, the LED indicator lens  92  will turn orange. 
     Referring collectively to  FIGS. 8 through 10 , the lighting array  44  and corresponding electronics are shown in greater detail. Referring particularly to  FIG. 8 , the lighting array  44  is shown wherein 28 LEDs are circumferentially placed about the lens opening through which tissue is viewed for examination. The lens (not shown) is covered by a polarizer  78 . As such, all light reflected back from the object surface is filtered through the central polarizer to reach the eye with polarized light through the lenses. The central polarizer aids in diminishing glare from the surface of the skin. 
     With regard to the lighting array  44  there is shown 28 LEDs of both white LEDs and orange colored LEDs (588 nm). As shown in hatched marking, namely LEDs D03, D05, D08, D10, D14, D18, D21, D23, D26 and D28 represent the orange colored LEDs (588 nm). As such, ten of the LEDs of the LED array  44  are the orange colored (588 nm) LEDs, and the remaining LEDs are white LEDs. The white LEDs comprise D01, D02, D04, D06, D07, D09, D11, D12, D13, D15, D16, D17, D19, D20, D22, D24, D25 and D27. The orange LEDs are SuperBright RL3-Y4545 with the color wave length of 588 nm. Although the present invention discloses the use of an orange LED of 588 nm, it is contemplated by the present invention that such colored LED could range anywhere from 581 nm to 600 nm. The white LEDs of the LED array  44  are Nichia NSPW 310DS. 
     The LEDs are overlaid with a polarizer  50  which is cross-polarized relative to the central polarizer  78 . The polarizer  50  includes a series of openings to expose six of the white LEDs so that when such LEDs are in operation the white light emanating from such LEDs is not polarized by the polarizing filter  50 . As such, the light that reflects back from the object to the user&#39;s eye is polarized only once by the central polarizer  78 . When light emanates from any of the other LEDs of the lighting array  44  the light passes through the light polarizer  50  and such light is polarized 90 degrees opposite of the central polarizer  78 . As such, when light from the LEDs that are polarized by polarizer  50  is reflected back from the sample tissue, it is polarizes a second time by the central polarizer  78  causing the light to be crossed polarized when reaching the user&#39;s eye. As discussed above, the polarization and cross polarization aids greatly in reducing the glare from the skins surface and allows the user to see more deeply into the skin. Although the lighting array  44  of the device of the present invention  12  includes 28 LEDs, it is contemplated that such device may include any number of LEDs surrounding the central opening for the lens. Furthermore, although the lighting array  44  shows that the LEDs are formed concentrically around the opening, it is contemplated that the LEDs could be staggered or otherwise arranged, the only requirement being that the LEDs provides sufficient light onto the sample tissue, without obstructing the center viewing zone of the device  12 . Furthermore, although the device of the present invention discloses  12  filtered white LEDs, six unfiltered white LEDs and ten filtered orange LEDs, it should be understood and contemplated by the present invention that any number of ratios of the types of LEDs disclosed may be utilize and is contemplated by the present invention. Furthermore, the use of non-polarized or non-cross polarized orange LEDs is contemplated. 
     Referring again particularly to  FIGS. 8 through 10 , the lighting array  44  is an electrical communication with the main PCB  62  via electrical leads  96 . The electrical leads  96  travel from the main PCB  62  up the lens tube  76  to electrically connect to the LED PCB  56 . The leads  96  provide both power to the LED as well as on and off signals as directed by the PCB  62  and the device switches described more fully below. 
     In operation, the LED array  44  is aimed in the direction of the skin, object or lesion to be examined. It is expected that the device be placed approximately 1 inch (25 mm) from the skin. By pushing and holding the power button  98  for approximately one second, the cross-polarized mode will initiate. In this regard, LEDs D01, D02, D06, D07, D11, D12, D15, D16, D19, D20, D24 and D25 will all light providing cross-polarized white light for examination. A further pushing of the button  98  enables the non-polarized mode for viewing the subject tissue without polarize light or for conducting emersion fluid dermoscopy. In this case, non-polarized LEDs D03, D09, D13, D17, D22 and D27 will initiate. A further tap of the button  98  will revert the device back to cross-polarized mode. In either non-polarized or cross-polarized mode, additional illumination may be activated by button  100  which in turn initiates the orange light (588 nm) LEDs. As shown in  FIG. 8  that includes LEDs D03, D05, D08, D10, D14, D18, D21, D23, D26 and D28. For reasons discussed above, the orange LEDs provide enhanced viewing of pigmented skin. 
     For dermoscopy involving skin contact oil immersion or for camera use the focus dial  28  may be utilized for refined focusing by rotating the focus the dial to the left or to the right. 
     Referring particularly to  FIGS. 11-12  there is shown a charging base  200  adapted to receive the device  12 . The charging base  200  is connected to a power outlet (not shown) to provide power to charge the on-board battery (not shown) of the device  12 . The charging base  200  engages leads  68  (not shown) to provide power to the battery (not show) for charging. 
     The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including various ways of providing orange light in the range of 581 nm to 600 nm to be used in a skin examination lighting device. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.