Illumination unit and medical imaging system for fluorescence imaging in open surgery

Abstract

An illumination unit for illuminating an area of operation during open surgery. The illumination unit including: a body; a fiber bundle configured to guide light towards a distal end of the body, and a reflector body arranged at the distal end of the body. Where at least a part of the fiber bundle is guided inside the body along a longitudinal direction, the fiber bundle is split up into a plurality of optical fibers which form a fiber layer on an inner surface of the body, end faces of the plurality of optical fibers are arranged at the distal end of the body, the reflector body encloses the end faces of the plurality of optical fibers in a radial direction and extends distally beyond the distal end of the body in the longitudinal direction, and an inner surface of the reflector body is a reflective surface.

Claims

1. An illumination unit for illuminating an area of operation during open surgery, the illumination unit comprising: a body; a fiber bundle configured to guide light towards a distal end of the body, and a reflector body arranged at the distal end of the body; wherein at least a part of the fiber bundle is guided inside the body along a longitudinal direction, the fiber bundle is split up into a plurality of optical fibers which form a fiber layer on an inner surface of the body, end faces of the plurality of optical fibers are arranged at the distal end of the body, the reflector body is arranged radially outside from the end faces of the plurality of optical fibers relative to a central axis of the body to reflect a radially outer portion of the light emitted from the plurality of optical fibers towards the central axis, the reflector body extending distally beyond the distal end of the body in the longitudinal direction, and an inner surface of the reflector body is a reflective surface.

2. The illumination unit according to claim 1, wherein the plurality of optical fibers are arranged in an annular shape in the body.

3. The illumination unit according to claim 1, wherein the end faces of the plurality of optical fibers form a ring shaped exit face.

4. The illumination unit according to claim 1, wherein the body comprises a cylindrical opening, wherein the cylindrical opening is configured to receive at least one component of an optical imaging unit.

5. The illumination unit according to claim 1, wherein the illumination unit is one of a part of an exoscope tip or a fluorescence imaging adapter configured to be connected with a camera head.

6. The illumination unit according to claim 1, wherein the reflective surface of the reflector body has one of a convex, a concave or a parabolic shape.

7. The illumination unit according to claim 1, wherein the reflector body is cone shaped.

8. The illumination unit according to claim 1, wherein the reflective surface of the reflector body is made of aluminum or comprises aluminum.

9. The illumination unit according to claim 1, wherein the reflective surface comprises a protective coating.

10. The illumination unit according to claim 1, further comprising an ocular cone forming a rear part of a hull of the illumination unit.

11. The illumination unit according to claim 10, wherein the ocular cone is configured to be connected to an adapter of a camera head.

12. A medical imaging system for fluorescence imaging in open surgery, the medical imaging system comprising: an optical imaging unit; and an illumination unit according to claim 1 arranged concentrically around the optical imaging unit.

13. An exoscope comprising the illumination unit according to claim 1.

14. A fluorescence imaging adapter comprising the illumination unit according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics will become apparent from the description of the embodiments together with the claims and the included drawings. Embodiments can fulfill individual characteristics or a combination of several characteristics.

(2) The embodiments are described below, without restricting the general intent of the invention, based on exemplary embodiments, wherein reference is made expressly to the drawings with regard to the disclosure of all details that are not explained in greater detail in the text. In the drawings:

(3) FIG. 1 illustrates a schematic simplified representation of an exoscope arranged to illuminate and record an area of operation,

(4) FIG. 2 illustrates a schematic simplified representation of a camera head with a fluorescence imaging adapter,

(5) FIG. 3 illustrates a schematic simplified perspective representation of an illumination unit with a reflector body,

(6) FIG. 4 illustrates a schematic simplified cross sectional representation of a fluorescence imaging adapter with a reflector body,

(7) FIG. 5 illustrates a schematic simplified cross sectional representation of an illumination unit without a reflector body, and

(8) FIG. 6 illustrates a schematic simplified cross sectional representation of an illumination unit with a reflector body, showing the change in the light path of the emitted light rays.

(9) In the drawings, the same or similar types of elements or respectively corresponding parts are provided with the same reference numbers in order to prevent the item from needing to be reintroduced.

DETAILED DESCRIPTION

(10) FIG. 1 shows a schematic simplified representation of a medical imaging device, namely an exoscope 2 configured to observe and illuminate an area of operation 8. The exoscope 2 comprises an optical imaging unit 5 and an illumination unit arranged inside the exoscope 2. The optical imaging unit 5 records an image of the area of operation 8 within a field of view 4, which is indicated with dashed lines. The illumination unit comprises a fiber bundle 12 to guide light from a light source, which is not shown in FIG. 1, to an exoscope tip 10 at a distal end 3 of the exoscope 2 in order to illuminate an illuminated area 6. When the light is emitted at a distal end 11 of the exoscope tip 10 from the fiber bundle 12, the illuminated area 6 is usually larger than the field of view 4. Thus, the light intensity is comparatively low inside the field of view 4, as a lot of the emitted light intensity is wasted in areas outside the field of view 4.

(11) FIG. 2 illustrates a schematic representation of another medical imaging device, namely a combination of a camera head 100 and a fluorescence imaging adapter 110. The camera head 100 is configured for white light imaging as well as fluorescence imaging. It is handheld and has control buttons 102 on the top of its housing, an adapter 104 for attachment of various optics systems at its front surface and a connecting cable 106 for power and signal transmission leading to a central control unit (not shown). Since the camera head 100 is configured to receive telescope type endoscopes with eyepieces (ocular cones), its adapter 104 may be configured to receive such eyepieces. The imaging optics of the camera head 100 is configured to have its focus at a location where the typically attached endoscopes project a virtual image to be viewed with the naked eye through the eyepiece. The eyepieces of endoscopes are usually adjusted so that the virtual image is about one meter in front of the eyepiece (1 diopter). The exit pupil of the endoscopes is configured to approximately match the entrance pupil of the camera head and is located about 7 mm behind the edge of the eyepiece funnel, which is typically inside adapter 104 in the attached state.

(12) The fluorescence imaging adapter 110 differs from endoscopes and exoscopes in that it does not have imaging optics, i.e., it does not produce a virtual image. Instead, it provides a head lens or attachment lens in the form of a head lens system 112 having one or more individual lenses whose function it is to change the properties of the imaging optics of camera head 100, rendering the camera head 100 capable of viewing the operating field. This can be done, e.g., by decreasing the focal length of the camera head 100 and thereby enlarging its field of view. Although the head lens system 112 itself does not provide a virtual image to be viewed with the naked eye, the fluorescence imaging adapter has a standardized ocular cone 114 on its rear side for the purpose of connecting to the adapter 104 of camera head 100.

(13) Furthermore, the fluorescence imaging adapter 110 is equipped with a light guide cable 116 leading towards its front surface 111. The other end of the light guide cable 116 may be connected to an illumination light generating unit (not shown).

(14) FIG. 3 shows a perspective drawing of an illumination unit 80 configured to increase the light intensity inside the field of view 4. The illumination unit 80 comprises an ocular cone 50, a body 20 in the shape of a tube and a reflector body 30. The illumination unit 80 is part of a medical imaging system 82, which may also comprise a component 40 of the optical imaging unit 5, for example a lens unit. The illumination unit 80 may be arranged at the exoscope tip 10 of an exoscope as shown in FIG. 1 or may form a part of fluorescence imaging unit 110 as shown in FIG. 2.

(15) In the body 20, the fiber bundle 12 is split up and arranged on an inner surface 22 of the body 20 in an annular shape. At a distal end 26 of the body 20, the fiber bundle 12 forms an exit face 18 in the form of a ring. The reflector body 30 comprises a reflective surface 32 surrounding the exit face 18 of the fiber bundle 12 in a radial direction 72. When light is emitted from the exit face 18, the outer part of the emitted rays is reflected by the reflective surface 32 back towards a central axis 71.

(16) The body 20 also comprises a central opening 24 configured to receive the component 40 of the optical imaging unit 5. In FIG. 3, the component 40 is arranged outside of the opening 24. However, during assembly of the exoscope 2, the component 40 will be put inside the opening 24. In this arrangement, the exit face 18 of the illumination unit is arranged around the component 40 of the optical imaging unit 5, so that the area of operation 8 can be recorded and illuminated at the same time and with a symmetrical illumination.

(17) The fiber bundle 12 may extend along a longitudinal direction 70 on the inner surface 22 of the body 20. In the embodiment shown in FIG. 3, the outer surface 23 of the body 20 forms a hull 19 of the illumination unit 80 together with the ocular cone 50 and the reflector body 30.

(18) FIG. 4 shows another exemplary embodiment of an illumination unit 80 with a reflector body 30. A reflective surface 32 of the reflector body 30 has a convex shape. In this embodiment, the illumination unit 80 is part of a fluorescence imaging adapter 110. The body 20 of the illumination unit 80 comprises an outer hull element 90, a fiber guiding element 92 and a tubular element 94. The outer hull element 90 forms the outer hull of the body 20 and comprises an opening 98, which is configured to receive the fiber bundle 12. For sake of clarity, the fiber bundle 12 is not shown in FIG. 4. The fiber guiding element 92 is arranged concentrically inside the outer hull element 90 and comprises one or more guiding slots 96, which are configured to guide the optical fibers of the fiber layer once the fiber bundle 12 has been split up. The guiding slots 96 guide the optical fibers in the longitudinal direction such that the optical fibers are not bent at the distal end 26 of the body 20. The fiber guiding element 92 concentrically surrounds the tubular element 94, which comprises the opening 24 to receive the component 40. The optical fibers of the split up fiber bundle 12 are arranged surrounding the outer surface of the tubular element 96.

(19) In FIGS. 5 and 6, the effect of the reflector body 30 on the size and shape of the illuminated area 7 is demonstrated. FIGS. 5 and 6 both show cross sectional representations of different embodiments of an illumination unit 80. In FIG. 6, the illumination unit 80 comprises a reflector body 30 with a convex reflective surface 32, while in FIG. 5 there is no reflector body 30. As can be seen in the cross sectional views of FIGS. 4 and 5, the optical fibers 13, 14 of the fiber bundle 12 form a fiber layer 15 on the inner surface 22 of the body 20. At the end faces 17, 18 of the optical fibers 13, 14, light rays 60 are emitted. However, for the sake of clarity, only the light rays 60 emitted from the upper optical fiber 13 are shown in FIGS. 5 and 6. When comparing the light rays 60 in FIG. 5 with the light rays 60 in FIG. 6, it is evident that an outer part 62 of the light rays 60 in FIG. 6 is reflected back towards the central axis 71 by the reflective surface 32 of the reflector body 30 in FIG. 6. Thus, the reflector body 30 achieves a narrower illuminated area 6 and thus increases the light intensity inside the field of view 4. Due to the reflector body 30, the irradiance distribution is narrower and there is less light in the area outside the field of view 4. In addition, the maximum irradiance in the center of the illuminated area 6 is higher in the embodiment shown in FIG. 6 than in the embodiment shown in FIG. 5 without the reflector body 30.

(20) The reflective surface 32 or the entire reflector body 30 may comprise aluminum or may be made entirely out of aluminum. In addition, the reflective surface 32 may comprise a protective coating 34, which is indicated by vertical lines in FIGS. 4 and 6. This protective coating protects the reflective surface 32 from damage to provide a good illumination quality.

(21) While there has been shown and described what is considered to be 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.

LIST OF REFERENCES

(22) 2 exoscope 3 distal end 4 field of view 5 optical imaging unit 6 illuminated area 8 area of operation 10 exoscope tip 11 distal end 12 fiber bundle 13, 14 optical fiber 15 fiber layer 16, 17 end face 18 exit face 19 hull 20 tubular body 22 inner surface 23 outer surface 24 opening 26 distal end 30 reflector body 32 reflective surface 34 coating 40 component 50 ocular cone 60 light rays 62 outer part 70 longitudinal direction 71 central axis 72 radial direction 80 illumination unit 82 medical imaging system 90 outer hull element 92 fiber guiding element 94 tubular element 96 guiding slot 98 opening 100 camera head 102 control buttons 104 adapter for attachment devices 106 connecting cable 110 fluorescence imaging adapter 112 head lens system 114 ocular cone 116 light guide cable