Illumination system adapted for surgical lighting

• US 6,513,962 B1
• Filed: 12/14/1999
• Issued: 02/04/2003
• Est. Priority Date: 12/17/1998
• Status: Expired due to Term

• Current Assignee: Maquet Incorporated (Getinge AB)
• Original Assignee: Getinge/Castle, Inc.
• Inventors: Brukilacchio, Thomas J., Elterman, Paul B., Mayshack, Alvin C., Noble, Lynn W., DiCarlo, Brain James, Pievsky, Arkady, Boulant, Benoit
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Ton, Anabel
• Application Number:
  US09/460,689
• Time in Patent Office: 1,148 Days
• Field of Search: 362/33, 362/807, 362/551, 362/552, 362/556, 362/555, 362/572, 362/295, 362/231, 362/230, 362/267, 362/573, 362/583, 362/804, 385/116, 356/406
• US Class Current: 362/583
• CPC Class Codes: F21V 21/28 adjustable in more than one plane
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21W 2131/205 for operating theatres
• CPC Class Codes: F21Y 2113/00 Combination of light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G02B 6/02033 Core or cladding made from organic material, e.g. polymeric material G02B1/04 takes precedence
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/2808 using a mixing element which evenly distributes an input signal over a number of outputs
• CPC Class Codes: G02B 6/2817 using reflective elements to split or combine optical signals
• CPC Class Codes: G02B 6/3814 with cooling or heat dissipation means
• CPC Class Codes: G02B 6/40 having fibre bundle mating means
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4296 coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: H05B 35/00 : Electric light sources using a combination of different types of light generation
• CPC Class Codes: Y10S 362/804 : Surgical or dental spotlight
• CPC Class Codes: Y10S 362/807 : Star

Abstract

An illumination system for illuminating an area within a room includes one or more light sources, preferably disposed outside the room, one or more lighting heads disposed within the room, one or more light pipes and/or fiber bundles to transmit light from the source(s) to the lighting head(s). The system includes means for controlling both the intensity and the color rendering index of the light emitted from the lighting head. In a preferred embodiment, the sources include an incandescent source extending across the visible spectrum and a light emitting diode source which emits essentially red light, and control of the color rendering index is effected by controlling the relative amounts of light from the two sources reaching the lighting head. Preferred forms of the invention also include special joints which permit all necessary translations and rotations of the lighting head while still permitting a continuous light path via fiber bundles and/or light pipes from the source to the lighting head.

Claims

1. An illumination system for illuminating an area within a room, the illumination system comprising:

at least one light source;

at least one lighting head disposed within the room and arranged to output light to the area to be illuminated;

at least one light pipe and/or fiber bundle arranged to transmit light from said at least one light source to said at least one lighting head; and

means for controlling the color rendering index of the light output from said at least one lighting head.

2. An illumination system according to claim 1 wherein said at least one light source is located outside said room.

3. An illumination system according to claim 1 comprising at least two light sources emitting light with differing spectral distributions, wherein said means for controlling the color rendering index of the light output comprises means for controlling the relative amounts of light from said at least two lighting sources reaching said at least one lighting head.

4. An illumination system according to claim 3 wherein said at least two light sources comprise an incandescent source, having an output extending across the visible spectrum, and a light emitting diode source having its maximum emission in the red portion of the visible spectrum.

5. An illumination system according to claim 1 further including means for controlling the intensity of the light output from said at least one lighting head.

6. An illumination system according to claim 5 wherein said means for controlling the intensity of the light output comprises at least one variable aperture.

7. An illumination system according to claim 3 further comprising means for mixing and homogenizing the output from said at least two light sources to produce a substantially uniform light output.

8. An illumination system according to claim 7 wherein said means for mixing and homogenizing comprises a multi-mode light pipe of polygonal cross-section.

9. An illumination system according to claim 7 further comprising at least one variable aperture arranged to control said substantially uniform light output from said mixing and homogenizing means.

10. An illumination system arranged to mix the output from two separate light sources, said system comprising:

first and second light sources;

a first fiber bundle having an input end arranged to receive light emitted by the first light source;

a second fiber bundle having an input end arranged to receive light emitted by the second light source

wherein the output ends of the fibers forming the first and second fiber bundles form a single fiber bundle arranged to transmit light from both the first and second light sources; and

an optical homogenizer having an input end arranged to receive light from said single fiber bundle and an output end which delivers a substantially uniform light output.

11. An illumination system according to claim 10 wherein said first and second light sources have different spectral distributions.

12. An illumination system according to claim 11 wherein the first and second light sources comprise an incandescent source, having an output extending across the visible spectrum, and a light emitting diode source having its maximum emission in the red portion of the visible spectrum.

13. An illumination system according to claim 10 wherein the output ends of the fibers forming the first and second fiber bundles are substantially intermingled in the single fiber bundle, whereby partial homogenization of the light from the first and second light sources is effected before the light enters the optical homogenizer.

14. An illumination system according to claim 10 wherein the optical homogenizer comprises a multi-mode light pipe.

15. An illumination system according to claim 14 wherein the multi-mode light pipe is of circular cross-section.

16. An illumination system according to claim 14 wherein the multi-mode light pipe is of polygonal cross-section.

17. An illumination system according to claim 10 further comprising sampling means for sampling the light output produced by the optical homogenizer.

18. An illumination system according to claim 17 wherein said first and second light sources have different spectral distributions and wherein said sampling means comprises a first sampling device which samples the entire light output of the optical homogenizer and a second sampling device arranged to be more sensitive to one of the first and second light sources than to the other.

19. An illumination system according to claim 10 further comprising control means for controlling the intensity of the light leaving the optical homogenizer.

20. An illumination system according to claim 19 wherein said control means comprises a variable aperture disposed adjacent the output end of the optical homogenizer.

21. An illumination system arranged to mix the output from two separate light sources and to control at least one parameter of the mixed output, said illumination system comprising:

a first light source arranged to emit light having a first characteristic value;

a second light source arranged to emit light having a second characteristic value differing from the first characteristic value;

a light mixing means arranged to receive light emitted from the first and second light sources and to produce a light output having a third characteristic value differing from the first and second characteristic values;

a light detector arranged to receive part of the light output from the light mixing means and to determine said third characteristic value of said light output; and

intensity control means arranged to vary the intensity of the light output from at least one of the first and second light sources and thereby to vary said third characteristic value of said light output from said light mixing means, said intensity control means being controlled by said light detector.

22. An illumination system according to claim 21 wherein said first and second light sources comprise an incandescent source, having an output extending across the visible spectrum, and a light emitting diode source having its maximum emission in the red portion of the visible spectrum.

23. An illumination system according to claim 21 wherein the light mixing means comprises a multi-mode light pipe.

24. An illumination system according to claim 23 wherein the multi-mode light pipe is of circular cross-section.

25. An illumination system according to claim 23 wherein the multi-mode light pipe is of polygonal cross-section.

26. An illumination system according to claim 23 further comprising first and second fiber bundles arranged to transmit light from the first and second sources respectively to the input end of the multi-mode light pipe.

27. An illumination system according to claim 26 wherein the output ends of the fibers forming the first and second fiber bundles are substantially intermingled to form a single fiber bundle adjacent the input end of the multi-mode light pipe, whereby partial mixing of the light from the first and second light sources occurs before the light enters the multi-mode light pipe.

28. An illumination system according to claim 23 wherein said light detector is arranged to receive light via the side wall of said light pipe, and a light reflector is disposed within said light pipe and arranged to divert a sample of the light passing along said light pipe through said wall thereof on to said light detector.

29. An illumination system according to claim 21 having first and second detectors each arranged to receive part of the light output from the light mixing means, said first detector being arranged to receive a sample of all the light output from the light mixing means and the second detector arranged to be more sensitive to light having one of said first and second characteristic values than to light having the other of said first and second characteristic values.

30. An illumination system according to claim 29 wherein said second detector is provided with a filter to reduce the amount of light in a predetermined wavelength range reaching said second detector.

31. An illumination system according to claim 29 further comprising a differential amplifier arranged to receive a first signal representative of the output of said first detector and a second signal representative of the output of said second detector, and to produce an output signal representative of the difference between said first and second signals and to supply said output signal to said intensity control means.

32. An illumination system according to claim 31 further comprising a variable gain amplifier arranged to receive the output from one of said first and second detectors, and to generate one of said first and second signals, and a fixed gain amplifier arranged to receive the output from the other of said first and second detectors, and to generate the other of said first and second signals.

33. An illumination system according to claim 21 wherein said intensity control means comprises at least one variable aperture arranged to vary the intensity of the light output from at least one of said first and second light sources.

34. A rotatable fiber joint for use in an illumination system, said joint comprising:

a first member having walls defining a first passage extending therethrough;

a second member disposed adjacent the first member and having walls defining a second passage extending therethrough, one end of said second passage being disposed adjacent one end of said first passage; and

a fiber optic bundle disposed within said first and second passages, the bundle being secured relative to the second member so that the bundle cannot rotate within said second passage, but not being secured to the first member so that the bundle can rotate freely within said first passage, whereby the first and second members can rotate relative to each other.

35. A rotatable fiber joint according to claim 34 wherein at least the adjacent portions of said first and second members have the form of hollow tubes, with the interiors of said tubes forming said first and second passages.

36. A rotatable fiber joint according to claim 35 wherein at least said adjacent portions of said first and second members are coaxial and are rotatable relative to one another about their common axis.

37. A rotatable fiber joint according to claim 34 further comprising a lighting head pivotally mounted on said second member, said fiber bundle extending into said lighting head.

38. A rotatable fiber joint according to claim 34 wherein said first member has a first section and a second section pivotally attached to said first section, said fiber bundle extending into said second section of said first member, and the adjacent portions of said first and second sections of said first member being of enlarged cross-section so as to permit pivoting of said first and second sections relative to one another without damage to said fiber bundle.

39. A rotatable fiber joint according to claim 34 further comprising a hub having a fixed section and a rotatable section, and an elongate third member having transmitting means for transmitting light therealong, wherein said first member is rotatably mounted on the third member at the end thereof remote from said hub.

40. A rotatable fiber joint according to claim 39 wherein said means for transmitting light along said third member comprises a second fiber optic bundle.

41. A rotatable fiber joint according to claim 39 wherein said first member has a first section and a second section pivotally attached to said first section, said fiber bundle extending into said second section of said first member, and the adjacent portions of said first and second sections of said first member being of enlarged cross-section so as to permit pivoting of said first and second sections relative to one another without damage to said fiber bundle, and wherein the end of said second section of said first member remote from said first section thereof is rotatably mounted on the third member at the end thereof remote from said hub, said fiber optical bundle extending through said first member to a point adjacent said third member, whereby said fiber optic bundle is arranged to receive light from said transmitting means.

42. A rotatable fiber joint according to claim 41 further comprising a lighting head pivotally mounted on said second member, said fiber bundle extending into said lighting head, so that said lighting head can be translated along three perpendicular axes, and rotated about at least two perpendicular axes, relative to said hub.

43. A lighting head for use in an illumination system, said lighting head having an optical axis and comprising:

input means for introducing light into the light head;

a first reflector positioned along said optical axis and arranged to receive light entering the lighting head through said input means and to reflect this light radially outward from said first reflector;

a second reflector having a plurality of facets facing said first reflector, the second reflector being arranged to receive said light reflected radially from the first reflector and to reflect this light to produce a substantially uniform illumination over a target area.

44. A lighting head according to claim 43 wherein said first reflector is substantially conical in at least one azimuth.

45. A lighting head according to claim 43 wherein said input means comprises a fiber optic bundle arranged to direct light passing along said bundle on to said first reflector.

46. A lighting head according to claim 45 wherein the output end of said fiber optic bundle has the form of an annulus surrounding the axis of said substantially conical first reflector, whereby said output end of said fiber optic bundle forms an off-axis, annularly distributed light source.

47. A lighting head according to claim 46 wherein said annular output end of said fiber optic bundle comprises at least two adjacent rows of fibers.

48. A lighting head according to claim 43 further comprising a handle extending substantially along the axis of the first reflector but on the side thereof remote from the second reflector, said handle permitting a user to move said light head.

49. A lighting head according to claim 43 having a transparent window covering the open face of said second reflector.

50. A lighting head according to claim 44 wherein said substantially conical first reflector has a central aspheric section and at least one peripheral conical section surrounding said aspheric section.

51. A lighting head according to claim 50 wherein said substantially conical first reflector has two peripheral conical sections differing in cone angle.

52. A lighting head according to claim 50 wherein said central aspheric section has a form given by:

$z<br><br>\left(r\right)=\frac{{\mathrm{cr}}^2}{1+{\left[1-\left(1+K\right)<br><br>c^2<br><br>r^2\right]}^{1/2}}+A<br><br>\text{\hspace{1em}<br><br>}<br><br>r^2+B<br><br>\text{\hspace{1em}<br><br>}<br><br>r^4+B<br><br>\text{\hspace{1em}<br><br>}<br><br>r^6+C<br><br>\text{\hspace{1em}<br><br>}<br><br>r^8+D<br><br>\text{\hspace{1em}<br><br>}<br><br>r^{10}+\mathrm{\cdots <br><br>}$

where;

z(r) is the sag,

c is the curvature at the apex of the surface,

r²=x²+y²,

K is the conic constant, and

A, B, C, D, . . . are the 4th, 6th, 8th, and 10th order deformation terms.

53. A lighting head for use in an illumination system, said lighting head comprising:

input means for introducing light into the lighting head;

a first reflector arranged to receive light entering the lighting head through said input means and to reflect this light, said first reflector being substantially frusto-pyramidal in shape, being provided around its periphery with a plurality of facets each of which is concave in both azimuths, said input means being arranged to produce a plurality of beams each directed at one of said facets; and

a second reflector having a plurality of facets, the second reflector being arranged to receive light reflected from the first reflector and to reflect this light to produce a substantially uniform illumination over a target area.

54. A lighting head according to claim 53 wherein said first reflector is provided with baffles extending between adjacent pair of said facets.

55. A lighting head according to claim 53 wherein said input means comprises a fiber optic bundle the output end of which is divided into a plurality of sub-bundles each of which produces one of said beams directed at said facets.

56. A lighting head according to claim 55 wherein said input means further comprises a framework and a plurality of tubes supported on said framework and directed towards the facets of said first reflector, said sub-bundles of optic fibers being disposed within said tubes.

57. A lighting head according to claim 56 wherein said framework and said tubes are movable axially relative to said first reflector.

58. A lighting head according to claim 56 further comprising a handle extending substantially along the axis of said first reflector but on the side thereof remote from said second reflector, said handle permitting a user to move said light head.

59. A lighting head according to claim 58 wherein said handle can be rotated and said framework and said tubes thereby moved axially relative to said first reflector.

60. A lighting head according to claim 53 wherein each of said plurality of facets is parabolic in both azimuths.

61. An illumination system in which a single input light flux is distributed among a plurality of output fiber bundles or light pipes, said illumination system comprising:

light input means arranged to supply a single beam of light;

at least first and second light output means each comprising a fiber optic bundle or light pipe, the first and second light output means being movable relative to one another and to the light input means; and

a light distribution means arranged to receive light from the light input means, to divert a first part of the received light into the first light output means and to divert a second part of the received light into the second light output means, said light distribution means comprising a substantially cylindrical fiber optic bundle, and said first and second light output means being arranged to rotate about the axis of said substantially cylindrical fiber optic bundle.

62. An illumination system according to claim 61 wherein said fiber optic bundle has a first section having a first diameter and a second section having a second diameter less than said first diameter, thereby leaving an annular shoulder at the junction of said first and second sections, the input end of said first light output means being disposed adjacent said annular shoulder and the input end of said second light output means being disposed adjacent the end of said second section remote from said first section.

63. An illumination system according to claim 61 further comprising control means disposed between, and arranged to control the amount of light passing from, said light input means to at least one of said first and second light output means.

64. An illumination system according to claim 63 wherein said control means comprises a variable aperture.

65. An illumination system according to claim 62 further comprising variable apertures disposed between, and arranged to control the amount of light passing from, said light input means to said first and second light output means.

66. An illumination system according to claim 61 further comprising a housing having a first section carrying said light distribution means, a second section rotatably mounted on said first section and carrying said first light output means, and a third section rotatably mounted on said second section and carrying said second light output means.

67. An illumination system according to claim 66 wherein said first, second and third sections of said housing are substantially cylindrical and all have substantially the same diameter.

68. An illumination system according to claim 61 further comprising clutch means arranged to frictionally retard the rotation of at least one of said first and second light output means relative to said light input means.

69. An illumination system according to claim 68 wherein said clutch means comprise first clutch means arranged to frictionally retard the rotation of said first light output means relative to said light input means, and second clutch means arranged to frictionally retard the rotation of said second light output means relative to said light input means.

70. An illumination system in which a single input light flux is distributed among a plurality of output fiber bundles or light pipes, said illumination system comprising:

light input means arranged to supply a single beam of light;

at least first and second light output means each comprising a fiber optic bundle or light pipe, the first and second light output means being movable relative to one another and to the light input means; and

a light distribution means arranged to receive light from the light input means, to divert a first part of the received light into the first light output means and to divert a second part of the received light into the second light output means,

wherein said light distribution means comprises;

a first light pipe rotatable relative to, and having an input end arranged to receive light from, said light input means, said first light pipe having an output end through which light leaves said first light pipe, said first light pipe also having a mirrored surface arranged to divert part of the light entering said input end through a side wall of said first light pipe into said first light output means, while permitting the remainder of the light to leave via said output end; and

a second light pipe rotatable relative to said first light pipe, said second light pipe having an input end arranged to receive light from said output end of said first light pipe and an output end arranged to direct light into said second light output means.

71. An illumination system according to claim 70 wherein said light input means comprises an input light pipe having an output end disposed adjacent said input end of said first light pipe, said first, second and input light pipes being substantially cylindrical and coaxial, said first and second light pipes being independently rotatable about their common axis relative to said input light pipe.

72. An illumination system according to claim 70 wherein said first light pipe is provided with a side arm extending substantially normally to the direction in which light passes from said input end to said output end of said first light pipe, said side arm having a substantially planar light output surface at its end from the main body of said first light pipe, and wherein said mirrored surface is arranged to divert part of the light passing through said first light pipe out through said substantially planar light output surface.

73. A light pipe comprising a substantially transparent rod having an axis, and a mirror surface disposed within the rod at an angle to the axis thereof, such that when light is passed axially along the rod, part of this light will be diverted by the mirror surface at an angle to the axis so as to emerge from a side surface of the rod, while the remaining light will continue axially along the rod, said light pipe being substantially cylindrical and wherein said mirror surface lies at substantially 45°

to the axis of said cylinder, so that part of the light is diverted by said mirror surface substantially normally to the axis of said cylinder.

74. A light pipe according to claim 73 which is substantially cylindrical and wherein said mirror surface lies at substantially 45°

to the axis of said cylinder, so that part of the light is diverted by the mirror surface substantially normally to the axis of said cylinder.

75. A light pipe according to claim 73 provided with a side arm extending substantially normally to said axis of said cylinder, said side arm having a substantially planar light output surface at its end from the main body of said light pipe, and wherein said mirrored surface is arranged to divert part of the light passing through said light pipe out through said substantially planar light output surface.

76. An illumination system comprising:

a first light transmission device selected from the group consisting of light pipes and fiber optic bundles, the first light transmission device having an input end and an output end;

a second light transmission device selected from the group consisting of light pipes and fiber optic bundles, the second light transmission device having an input end and an output end, the input end of the second light transmission device being disposed adjacent the output end of the first light transmission device; and

variable aperture means disposed between the output end of the first light transmission device and the input end of the second light transmission device, the variable aperture means being variable to block a varying portion of the light leaving the output end of the first light transmission device from reaching the input end of the second light transmission device, and thereby controlling the intensity of the light leaving the output end of the second light transmission device.

77. A coupling device for coupling light from a high intensity light source into optic fibers which can be damaged by heat, said coupling device comprising:

a window arranged to receive light from the light source, the window reflecting at least part of infra-red radiation received from the light source;

optic fibers having input ends disposed adjacent the window so as to receive light passing through the window; and

a heat dissipating means in heat conducting relationship with the input ends of the optic fibers, and thereby serving to remove from said input ends heat generated with said input ends as said input ends receive light passing through the window.

78. A coupling device according to claim 77 further comprising a control means disposed adjacent said window and arranged to control the amount of light entering said window.

79. A coupling device according to claim 78 wherein said control means comprises a variable aperture.

80. A coupling device according to claim 77 wherein said window is formed of sapphire.

81. A coupling device according to claim 80 wherein said sapphire window is provided, on its surface facing the light source with a dielectric coating reflective of ultraviolet and infrared radiation from said light source.

82. A coupling device according to claim 77 wherein said heat dissipating device comprises a metal ferrule in which said input ends of said fibers are secured.

83. A coupling device according to claim 82 wherein said heat dissipating device further comprises a hollow metal body within which are secured both said window and said ferrule.

84. A coupling device according to claim 83 wherein said hollow metal body is provided with cooling fins.

85. A coupling device according to claim 82 wherein said ferrule is in thermal contact with said window.

86. A coupling device according to claim 82 wherein said input ends of said optic fibers are secured in a plate, said coupling device further comprising a hollow body member within which both said plate and said window are secured, said window, said plate and said hollow body member having walls defining a chamber lying on the opposed side of said window from said light source, and wherein said heat dissipating means comprises a fluid within said chamber.

87. A coupling device according to claim 86 wherein said input ends of said optic fiber are secured in said plate at points spaced from the extreme ends of said optic fibers so that said fibers extend beyond the plate into the interior of the said fluid within said chamber.

88. A coupling device according to claim 86 wherein said heat dissipating means further comprises a heat exchanger and pump means for circulating fluid from said chamber to said heat exchanger and back to said chamber.

89. A coupling device according to claim 86 wherein the gaps between said input ends of said optical fibers are filled with a material which is not wetted by the fluid within said chamber.

90. An illumination system for illuminating an area within a room, said illumination system comprising:

at least one light source disposed outside the room;

at least one lighting device disposed within the room and arranged to output light to said area to be illuminated;

at least one light pipe and/or fiber bundle arranged to transmit light from said at least one light source to said at least one lighting device;

means for controlling the intensity of the light output from said at least one lighting device; and

means for controlling the color rendering index of the light output from said at least one lighting device.

91. The illumination system of claim 90 wherein said lighting device is selected from the group consisting of endoscopes and surgical head lamps.

92. The illumination system of claim 90 comprising at least two light sources emitting light with differing spectral distributions, wherein said means for controlling the color rendering index of the light output comprises means for controlling the relative amounts of light from said at least two lighting sources reaching said at least one lighting head.

93. The illumination system of claim 92 wherein said at least two light sources comprise an incandescent source, having an output extending across the visible spectrum, and a light emitting diode source having its maximum emission in the red portion of the visible spectrum.

94. The illumination system of claim 90 wherein said means for controlling the intensity of the light output comprises at least one variable aperture.

95. The illumination system of claim 92 further comprising means for mixing and homogenizing the output from said at least two light sources to produce a substantially uniform light output.

96. An illumination system according to claim 93 wherein said means for controlling the intensity of the light output comprises at least one variable aperture arranged to control said substantially uniform light output from said mixing and homogenizing means.