Abstract:
A medical luminaire for photodynamic diagnosis. The medical luminaire including: a broad-band lamp for generating broad-band background light; a semiconductor lamp for generating short-wave excitation light, wherein the semiconductor lamp comprises a laser diode, the light from which is fed alternatively or additionally into a light path of the broad-band lamp, and a light fibre bundle for transporting the light, wherein the excitation light is transported in a partial bundle.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is based upon and claims the benefit of priority from PCT/EP2010/004798 filed on Aug. 5, 2010, which claims benefit to DE 10 2009 040 093.1 filed on Sep. 4, 2009, the entire contents of each of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention generally relates to a medical luminaire, and particularly to a medical luminaire of the type described in claim  1 . 
         [0004]    2. Prior Art 
         [0005]    Photodynamic Diagnosis (PDD) is primarily used for recognition of tumours which for example fluoresce after administration of certain substances. For this purpose, luminaires are required which emit short-wave excitation light onto the area to be observed, by which the fluorescent areas are stimulated to fluoresce tin the long-wave range. Observation is usually accomplished by means of a long-pass filter to suppress the short-wave excitation light. Details on this state of the art can be seen for example in DE 19902184 C1 or DE 19639653 A1. 
         [0006]    A luminaire of this class is described in DE 10200601 1749 A1. The broad-band lamp used here is an arrangement consisting of several light emitting diodes, which together generate white light and one of which, which generates blue light, serves as the semiconductor lamp for generating the excitation light. Thus the semiconductor lamp serves both to generate the excitation light and to generate the corresponding spectral range of the broad-band light. 
         [0007]    However, this also results in disadvantages, primarily because the semiconductor lamp in this type of design must be relatively broad-band. It therefore generates a very intense blue, outshining all other frequencies, wherein only a narrow frequency range, usable for excitation, actually excites the fluorescence. The intensive blue must be filtered out with a highly effective long-pass filter in order not to outshine the entire image, including the fluorescent effects, during observation. 
         [0008]    Luminaires of similar class are known from DE 101 36 191 A1 and DE 93 17 984 U1 in which both the light of the broad-band lamp and the excitation light are transported together into a light guide fibre bundle. A laser diode is used as the semiconductor lamp. Thus a very simple design results. 
         [0009]    A drawback in these designs on the other hand is that both the long-wave light and the short excitation light travel through the same glass fibres, thus through the same glass. This causes disadvantages, since the glass types are not optimally adapted to the wavelengths. 
       SUMMARY 
       [0010]    The goal of the present invention consists of creating a simple and cost-effective solution to this illumination problem. 
         [0011]    According to the invention the excitation light is transported in a separate partial bundle. This can therefore be optimized for the wavelength of the excitation light, for example may consist of quartz glass, while the remainder of the partial bundle is optimized for white light in the usual way. 
         [0012]    A superimposed feed of the excitation light onto the broad-band light is possible in many ways, but advantageously according to claim  2  [is done] with a mirror, which for example because of the angle of incidence or the different light frequencies is penetrated by the one light, while the other is reflected from it. 
         [0013]    The selection property of the mirror in terms of one light or the other can in tum be achieved in various ways, but advantageously according to claim  3 , in that the light that passes through penetrates the mirror in a hole. This is a particularly simple design possibility. 
         [0014]    The partial bundle can also be integrated in the light fibre bundle or advantageously, according to claim  4 , be formed outside of the light fibre bundle, e.g., completely separated from it. This can offer advantages in assembly and cross-sectional utilization. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    In the drawing, the invention is shown schematically by way of example, in which: 
           [0016]      FIG. 1  illustrates a schematic front view of an endoscope with a luminaire according to the invention, 
           [0017]      FIG. 2  illustrates an enlarged section along line  2 - 2  in  FIG. 1 , and 
           [0018]      FIG. 3  illustrates a section through the luminaire of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIG. 1  shows an endoscope  1  in the shaft region  2  of which an image guide  3  and a fibre light guide  4  are arranged in parallel. A commonly present outer tube surrounding the image guide  3  and the fibre light guide  4 , possibly also containing additional channels, has been left out of the drawing for the sake of simplicity. 
         [0020]    The image guide  3 , which for example may be designed as an image guide fibre bundle or a relay lens arrangement, at its distal end has an objective  5  and at its proximal end an eyepiece  6 . Instead of the eyepiece  6  a camera may also be provided, which may also be arranged distally in the image guide  3 . 
         [0021]    The fibre light guide  4  consists of a light guide bundle, which emits light from its distal front end  7  and is supplied with light at its proximal end via a luminaire  8 . The fibre light guide  4  and/or the image guide  3  can be made flexible. 
         [0022]    The shaft region  2  of the endoscope  1  is directed against the tissue surface  9 , which is shown as a cutaway in  FIG. 1 . On the visualized cutaway of the tissue surface  9  is a tumour  10  which is irradiated with the light from the fibre light guide  4  and viewed from the objective  5  of the image guide  3 . 
         [0023]    In the exemplified embodiment shown, the fibre light guide  4 , as presented in  FIG. 2 , is equipped in a particular way for the transport of various light types. In the usual way, the light guide fibre bundle  12  that forms the fibre light guide  4  is positioned in a protective sleeve  11 . In the light guide fibre bundle  12  a separate partial bundle  13  is shown, which is arranged centrally in the exemplified embodiment. 
         [0024]    The partial bundle  13  can in turn be formed as a bundle of light guide fibres or consist of a single fibre. It is optimized in particular for short wave light, thus for example can consist of quartz, while the remaining bundle  12  consists of glass. 
         [0025]    In contrast to what is shown here, the partial bundle  13  can also be formed outside of the light guide fibre bundle  12 , e.g., alongside it, or located completely separately. 
         [0026]    The interior of the luminaire  8  is shown in section in  FIG. 3 . The proximal end of the fibre light guide  4  is fastened in a hole in a housing  14 . Through a condenser  15 , which is shown schematically as a lens, the proximal face of the fibre light guide  4  is illuminated by a broad-band lamp  16  over a mirror  17  arranged at a 45° angle to the axis of the proximal end section of the fibre light guide  4 . In the center, the mirror  17  has a hole  18  through with a laser diode  19  shines a narrow light bundle directly on the area of the partial bundle  13 . 
         [0027]    The laser diode  19  is designed for short wave light in the blue or ultraviolet spectrum, and in its narrow band emission spectrum, matches the absorption spectrum of a fluorescent substance administered to the tissue  9  of  FIG. 1  in order to make the tumour  10  fluoresce. 
         [0028]    In the arrangement of  FIG. 3  the light generated by the laser diode  19  is transported in the partial bundle  13  separately from the light of the lamp  16 , which is transported in the other cross-sectional region of the fibre light guide  4 . 
         [0029]    In a modification of the design, the fibre light guide  4  can also be made entirely of fibres of the same type, which jointly transport both types of light, thus the light of the lamp  16  and the light of the laser diode  19 . 
         [0030]    In addition the superimposition of the two light types from the lamp  16  and the laser diode  19  can be achieved in a different way than is shown, for example in that the mirror  18  is formed without a hole, but for example is permeable to the light of the laser diode  19 , while it reflects the light of the lamp  16 . 
         [0031]    The lamp  16  is shown with a reflector  20 . It can be a conventional broad-band lamp, e.g., a xenon lamp, or also as a semiconductor lamp, for example, it can consist of several lighted diodes which together generate broad-band, e.g., white light. 
         [0032]    Instead of superimposing the light of the laser diode  19  on that of the broad-band lamp  16  as shown, it is also possible to work with alternating light. Instead of the mirror  17 , for example, a movable mirror may be provided, which alternately allows one light or the other to pass through in the direction of the fibre image guide  4 . 
         [0033]    If a planar broad-band lamp is used, which is designed for example as a flat chip with LEDs arranged on it, it is possible to dispense with the mirror  17  and the light of the laser diode  19  may pass through a hole in the chip of the broad-band lamp. 
         [0034]    While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.