Abstract
A fiberscope for stereoscopic imaging has at least one wavefront manipulator which, for creating a sample beam, is configured to pre-shape a wavefront of the light from a light source such that the pre-shaped light is focusable substantially on an object point in an object region and raster-deflectable to a multiplicity of object points. The fiberscope also includes an illumination fiber for supplying the pre-shaped sample beam to the object region, and a detector fiber for supplying scattered light reflected and/or scattered at the respective object point to a detector which captures the scattered light and is connected to a computer unit. The computer unit is configured to compose the stereoscopic image from the captured scattered light. A method is for acquiring stereoscopic image data from a fiberscope.
Claims
1. A fiberscope for stereoscopic imaging, the fiberscope comprising: at least one wavefront manipulator which, for creating a sample beam, is configured to pre-shape a wavefront of light from a light source such that the pre-shaped light is focusable on an object point in an object region and raster-deflectable to a multiplicity of object points; an illumination fiber for supplying a pre-shaped sample beam to the object region; a detector fiber for supplying scattered light at least one of reflected and scattered at a respective object point to a detector configured to capture the scattered light and being connected to a computer unit; wherein: i) the wavefront manipulator further is configured to create at least one of temporally separated sample beams and spectrally separated sample beams, which make a fixed stereo angle with each other, or ii) the wavefront manipulator, the illumination fiber and the detector fiber are each provided twice, with the wavefront manipulators further being configured to create at least one of the temporally separated sample beams and the spectrally separated sample beams; and, the computer unit being configured to form the stereoscopic image from at least one of the captured temporally separated scattered light and the captured spectrally separated scattered light.
2. A fiberscope for stereoscopic imaging, the fiberscope comprising: at least one wavefront manipulator which, for creating a sample beam, is configured to pre-shape a wavefront of light from a light source such that the pre-shaped light is focusable on an object point in an object region and raster-deflectable to a multiplicity of object points; an illumination fiber for supplying a pre-shaped sample beam to the object region; at least two detector fibers for supplying scattered light at least one of reflected and scattered at a corresponding object point to a corresponding detector configured to capture the scattered light and being connected to a computer unit; and, the computer unit being configured to compose the stereoscopic image from the captured scattered light.
3. The fiberscope of claim 2, wherein the at least two detector fibers have a fixed lateral spacing from one another.
4. The fiberscope of claim 3, wherein the fixed lateral spacing between the at least two detector fibers lies between 50 m and 500 m.
5. The fiberscope of claim 3, wherein the fixed lateral spacing between the at least two detector fibers lies between 100 m and 400 m.
6. The fiberscope of claim 3, wherein the fixed lateral spacing between the at least two detector fibers lies between 150 m and 300 m.
7. The fiberscope of claim 3, wherein the fixed lateral spacing between the at least two detector fibers is 200 m.
8. The fiberscope of claim 1, wherein the at least two detector fibers are arranged such that a same detection region is observable.
9. The fiberscope of claim 1, wherein a size of the object region able to be scanned is variable.
10. The fiberscope of claim 1, wherein the wavefront manipulator is configured to vary a size of the object region when a working distance is changed.
11. The fiberscope of claim 2, wherein the wavefront manipulator is configured to vary a size of the object region when a working distance is changed.
12. The fiberscope of claim 1, wherein the light source is provided twice.
13. The fiberscope of claim 2, wherein at least two of the illumination fiber and the at least two detector fibers are arranged immediately adjacent to one another.
14. The fiberscope of claim 1, wherein the illumination fiber and the detector fiber are arranged immediately adjacent to each other.
15. The fiberscope of claim 2, wherein at least two of the illumination fiber and the at least two detector fibers are arranged immediately adjacent to each other.
16. The fiberscope of claim 1 further comprising a display apparatus for displaying the stereoscopic image.
17. The fiberscope of claim 2 further comprising a display apparatus for displaying the stereoscopic image.
18. A method for acquiring stereoscopic image data from a fiberscope, the method comprising: a) pre-shaping a wavefront of light from at least one light source via at least one wavefront manipulator such that, for creating a sample beam, pre-shaped light is focusable on an object point in an object region and can be raster-deflected to a multiplicity of object points; b) supplying a pre-shaped sample beam to an object region via at least one illumination fiber; c) focusing supplied light on the object point in the object region by way of the at least one wavefront manipulator; d) supplying scattered light at least one of reflected and scattered at the object point to a detector via a detector fiber; e) repeating steps c) and d) for at least a subset of the object points in the object region; and, f) extracting a stereoscopic image from the acquired data of the detector.
19. The method of claim 18, wherein said focusing in step c) is preceded by a determination of a working distance between a distal end of the at least one illumination fiber and the object region.
20. The method of claim 19, wherein the working distance between the distal end of the at least one illumination fiber and the object region is used to adjust a size of the object region.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0051] The invention will now be described with reference to the drawings wherein:
[0052] FIG. 1 shows a schematic view of a first embodiment of a fiberscope according to the disclosure;
[0053] FIG. 2 shows a detail view of the first embodiment of the fiberscope;
[0054] FIG. 3 shows a schematic illustration of the overlapping object regions of the fiberscope;
[0055] FIG. 4 shows a schematic view of a second embodiment of the fiberscope according to the disclosure;
[0056] FIG. 5 shows a detail view of the second embodiment of the fiberscope with a small working distance;
[0057] FIG. 6 shows a detail view of the second embodiment of the fiberscope with a larger working distance;
[0058] FIG. 7 shows a schematic view of a third embodiment of the fiberscope according to the disclosure;
[0059] FIG. 8 shows a detail view of the second embodiment of the fiberscope with a middling working distance;
[0060] FIG. 9 shows a detail view of the distal end of a fourth embodiment of the fiberscope in cross section; and,
[0061] FIG. 10 shows a flowchart of a method for capturing stereoscopic images.
DETAILED DESCRIPTION
[0062] FIG. 1 shows a schematic view of a first embodiment of a fiberscope 1 according to the disclosure, which is configured for stereoscopic imaging. In the embodiment shown, the fiber endoscope 1 includes two light sources 2, each embodied as a laser light source 2 with different wavelengths. The two light sources 2 each emit light at a wavefront manipulator 3, which is formed as a micromirror actuator 4 in the embodiment shown. In this case, the micromirror actuator 4 is actuatable by a controller 5 for the purpose of pre-shaping the wavefront reflected by the micromirror actuator 4. In the embodiment shown, the light which was pre-shaped by the micromirror actuator 4 is in each case coupled into a proximal end 6 of an illumination fiber 7, the latter embodied as a multimode fiber whose distal ends 8 are directed at an examination object 9, an eye 10 of a patient in the embodiment shown. Suitable pre-shaping of the wavefront makes it possible to focus the light emitted by the illumination fiber 7 as a sample beam 23 on an object point 11 within an object region 12 formed on the examination object 9 and modify the position of the focus within this object region 12 in a targeted manner in order to ultimately illuminate the individual object points 11 on the object region 12 by the focused sample beam 23 and ultimately use the latter to scan the object region. As will still be explained in detail below with reference to FIG. 3, there is significant overlap of the object regions 12 of the two illumination fibers 7 in order to ensure that the scanned frames represent the same regions at least in part. The scattered light 13 reflected and/or scattered at each object point 11 in the respective object region 12 is input coupled into a distal end 8 of a detector fiber 14 and output coupled again at a proximal end 6 of the detector fiber 14, from where it is supplied to a detector 15. The detector 15 acquires the signals of the scattered light 13 reflected and/or scattered at the respective object point 11. In the embodiment shown, a total of two detector fibers 14 and two detectors 15 are provided. The acquired signals are subsequently composed to form a stereoscopic image 24 by a computer unit 16 and are displayed on a display device 17, a 3-D monitor in the present case. As will still be explained in detail below with reference to the detail view depicted in FIG. 2, the two light sources 2 emit spectrally separated light and ultimately have different wavelengths. Moreover, filter elements 18 are provided and configured such that only the reflected and/or scattered light 13 which is reflected and/or scattered by the object points 11 illuminated by the corresponding illumination fiber 7 at the appropriate wavelength is supplied to the corresponding detector 15. However, a time-offset raster scan can also be implemented in an alternative, with the result that the respective detector 15 only acquires the signals actually originating from the corresponding illumination fiber 7. In other words, each sample beam 23 ultimately has a dedicatedly assigned detector 15.
[0063] FIG. 2 shows a detail view of the distal ends 8 of the illumination fibers 7 and detector fibers 14 of the fiberscope 1 according to the first embodiment depicted in FIG. 1. As already explained above, the light sources 2 emit light at different wavelengths. Thus, as indicated by the dashed lines in FIG. 2, the light output coupled as sample beam 23 from the distal ends 8 of the illumination fibers 7 also has different wavelengths. The filter elements 18 assigned to the detector fibers 14 or the detectors 15 themselves in this case also ensure that only the scattered light 13 originating from the corresponding light source 2 is captured by the respective detector 15.
[0064] FIG. 3 shows, by way of example and also only by way of a simplified representation, the overlap of the two object regions 12, that is, the regions of the examination object 9 whose object points 11 can be raster-scanned by the respective sample beams 23 as a result of the suitable pre-shaping of the respective wavefront by the wavefront manipulator 3. Moreover, FIG. 3 also depicts the capturing regions 19 of the two detector fibers 14, that is, ultimately the regions from where reflected and/or scattered light 13 can be input coupled into the detector fiber 14 and supplied to the corresponding detector 15. In the embodiment shown, these capturing regions 19 are arranged concentrically with the object regions 12. In this case, the respective capturing region 19 of the detector fiber 14 is larger than the object region 12 of the illumination fiber 7. The overlap region 20 of the two illumination fibers 7 depicted by hatching in this case represents the region which can ultimately be depicted stereoscopically. The overlap of the two capturing regions 19 of the detector fibers 14 elucidates the necessity of temporally and/or spectrally separating the sample beams 23 from one another. Without this separation, the detectors 15 would each capture scattered light 13 from both sample beams 23.
[0065] FIG. 4 shows a particularly preferred embodiment of the fiberscope 1. In this case, only one wavefront manipulator 3 is provided; it is irradiated by a light source 2 and the light pre-shaped thereby is then ultimately input coupled into the proximal end 6 of an illumination fiber 7. The light is supplied to the examination object 9, the eye 10 of a patient in the present case, through the illumination fiber 7 and emerges from the distal end 8 of the illumination fiber 7 as sample beam 23. The sample beam is focused on an object point 11 within the object region 12 as a result of the pre-shaping of the wavefront. The scattered light 13 which was scattered and/or reflected by this object point 11 is input coupled into the two detector fibers 14 which are arranged immediately adjacent to the illumination fiber 7 and have longitudinal axes that are spaced apart from one another at a fixed lateral spacing 21.
[0066] As may be gathered from the detail view depicted in FIG. 5 and FIG. 6 only, this embodiment includes not only the two first detector fibers 14.1, whose distal ends 8 have a fixed first spacing 21.1 from one another and which are arranged immediately adjacent to the illumination fiber 7, but also two second detector fibers 14.2, which also have a fixed second spacing 21.2 from one another. In this case, the first spacing 21.1 is less than the second spacing 21.2. As already described above, the spacing 21 between the two detector fibers 14 used for the signal capture ultimately forms the stereo basis. In this case, the ratio of the stereo basis to the working distance 22 is a measure for the quality of the stereo impression, wherein a value of approximately 1:10 was found to be particularly advantageous in this context. As the working distance 22 is chosen to be larger, the stereo basis must also be chosen to be larger here. In the case of a small working distance 22 of for example 2 mm, as depicted in FIG. 5, it is possible to use the two first detector fibers 14.1, whose first spacing 21.1 is approximately 200 m, for signal acquisition. By contrast, if the working distance 22 is increased to 10 mm, as indicated in FIG. 6, then it is possible to use the two second detector fibers 14.2 which have a second spacing 21.2 of approximately 1 mm from one another. In this case, suitable signal acquisition can ensure that the contribution of the first detector fibers 14.1 to the signal acquisition is suppressed in the case of a relatively large working distance 22, for example by virtue of possible scattered light 13 not being output coupled from the proximal ends 6 of the first detector fibers 14.1. For example, the working distance 22 can be detected here via OCT measurements in each case, the latter being performed through the illumination fiber 7. In the embodiment shown, it is also important to observe that the size of the raster-scannable object region 12 is variable, and the size of the object region 12 is adjusted automatically when the working distance 22 is changed in order to always obtain an unchanging image.
[0067] FIG. 8 shows a further detail view of the embodiment depicted in FIGS. 5 and 6. In this case, it is not the two first detector fibers 14.11 and 14.12 or the two second detector fibers 14.21 and 14.22 that are used for the signal acquisition; instead, a first detector fiber 14.11 and a second detector fiber 14.22 can be used together in each case. These have a fixed third spacing 21.3 which lies between the fixed first spacing 21.1 and the fixed second spacing 21.2.
[0068] As already described above, the spacing 21 between the two detector fibers 14 used for the signal capture ultimately forms the stereo basis. In this case, the ratio of the stereo basis to the working distance 22 is a measure for the quality of the stereo impression, wherein a value of approximately 1:10 was found to be particularly advantageous in this context. As the working distance 22 is chosen to be larger, the stereo basis must also be chosen to be larger here. If the fixed spacing 21.1 between the detector fibers 14.11 and 14.12 is approximately 200 m and the fixed spacing 21.2 between the detector fibers 14.21 and 14.22 is approximately 1 mm, then the fixed spacing 21.3 between the detector fibers 14.11 and 14.22 or between the detector fibers 14.12 and 14.21 is approximately 600 m, and so this combination of detector fibers can be used particularly well in the case of a working distance of approximately 6 mm. In a manner analogous thereto, the detection fibers 14.11 and 14.21 or 14.12 and 14.22 could also be used to realize a fourth fixed spacing. By preference, on account of the pre-shaping of the wavefront, the sample beam 23 emerging from the distal end 8 of the illumination fiber 7 is configured to raster-scan object points 11 which are located in a joint capturing region of the respectively used combination of fiber pairs. In an alternative or in addition, it would also be possible to use the capturing regions of the fiber pairs 14.11, 14.22 and 14.12 and 14.21 for signal acquisition and suitably combine, for example, join together or fuse, the respectively captured regions or acquired data.
[0069] FIG. 7 shows a third embodiment of the fiberscope 1. As an alternative to the embodiments depicted in FIG. 1 and FIG. 4, it is possible in this case to also realize a stereoscopic fiberscope 1 which has only one illumination fiber 7 and only one detector fiber 14. In this case, the wavefront manipulator 3 is actuated such that all scanned object points 11 are always scanned by two sample beams 23 which make a defined stereo angle with each other, wherein this case also requires a temporal and/or spectral separation of the signal acquisition. However, in the case of spectral separation, it is then advantageous to use a second light source 2 with a second detector fiber 14, wherein the two light sources 2 emit light at different wavelengths. Suitable filter elements 18 prevent scattered light 13 from being guided to a non-corresponding detector 15.
[0070] FIG. 9 shows a detail view of the distal end 8 of a fourth embodiment of the fiberscope in cross section and can be considered to be a development of the aforementioned first to third embodiments, and hence can be combined in part or as a whole with these embodiments without restrictions. The distal ends of a plurality of fibers are depicted as concentric circles, with the fibers being arranged as a fiber bundle by way of example and the detector fibers 14.1-14.4 and an illumination fiber 7 being labelled by way of example. There is a fixed or unchanging spatial spacing between all fibers, especially the detector fibers, as depicted by way of example between some of the detector fibers 14.1-14.4, and this spacing is depicted by way of example as spacing 21.1-21.4 and can essentially depend on the dimensions of the individual fibers. In particular, it may be possible for detector fiber and illumination fiber to have a different diameter. In particular, a plurality of detector fibers and/or illumination fibers may also be arranged in a row.
[0071] In this case, the spacings between the individual distal ends of the detector fibers, shown by way of example as spacings 21.1-21.4 between the detector fibers 14.1-14.4, are different and ultimately form the stereo basis usable for the signal acquisition. The detector fibers 14.1-14.4 can be used in dynamic pairwise fashion for signal acquisition, especially depending on the working distance. Expressed differently, the stereo basis, and hence the pairs of detector fibers used for the signal acquisition, can be chosen on the basis of the working distance such that the ratio between the stereo basis and the working distance, which is a measure for the quality of the stereo impression, advantageously has a value of approximately 1:10. As the working distance is chosen to be larger, the stereo basis can also be chosen to be larger here. As a result of the arrangement of the detector fibers and the plurality of the detector fibers, the stereo basis can be set granularly, that is, with fine gradations, on the basis of the working distance, and so the preferred ratio between stereo basis and working distance of approximately 1:10 is kept substantially constant.
[0072] As an alternative or in addition, provision can also be made for a plurality of illumination fibers in the fiber bundle shown in FIG. 9 such that the illumination region can be increased in size and flexibly adjusted. The number of fibers shown in the fiber bundle shown in FIG. 9 should also only be understood to be by way of example; the number can be increased or reduced.
[0073] Furthermore, the signals recorded in particular also as a result of the multiplicity of possible combinations of fiber pairs can be used to make a 3-D reconstruction of the object region in order to provide the user of the fiberscope with a virtual 3-D image of the object region. This virtual image can inter alia also be augmented with other information, especially presurgical information or information from other imaging modalities.
[0074] In an alternative or in addition, provision can be made for detector fibers to also be used as illumination fibers and for illumination fibers to also be used as detector fibers. As a result of the use as illumination and/or detector fiber depending not on the configuration at the distal end but only on the configuration at the proximal end, the distal end of the endoscope can be kept small in terms of its dimensions and nevertheless be configured flexibly and dynamically and hence adjusted to the required or advantageous signal acquisition.
[0075] In an alternative or in addition, stereoscopic parameters of a user can also be used in the aforementioned embodiments to influence the ratio between stereo basis and working distance. For example, it may be advantageous to increase or reduce the size of the stereo basis as a result of specifications, inputs or requirements of a user. As a result, the stereo basis can be adjusted flexibly to the situational or user-specific requirements. In this context, stereoscopic parameters of a user may also include the eye spacing of the user. Furthermore, stereoscopic parameters of a user may also include values for the ratio of stereo basis to working distance used in the past, especially regularly recurring deviations from the ratio of 1:10, which was found to be sensible or advantageous, and averaged values or values calculated differently, and/or also situationally dependent values, advantageously also based on values used in the past, for example depending on the operation phase, the type of operation, the size of the object to be examined and/or the patient.
[0076] FIG. 10 shows a flowchart of a method S100 for acquiring stereoscopic image data from a fiberscope 1. In the method S100, a wavefront of the light from a light source 2 is initially pre-shaped via a wavefront manipulator 3 in a first step S101. In a further step S102, this pre-shaped wavefront is then supplied as a sample beam 23 to an object region 12, which ultimately represents the part of the examination object 9 illuminable by the fiber endoscope 1, via an illumination fiber 7. In so doing, the sample beam 23 is focused on an object point 11 in the object region 12 in a step S103. In a step S104, the scattered light 13 scattered and/or reflected by the respective object point 11 is supplied via a detector fiber 14 to a detector 15 which acquires the signal from the scattered light 13 and transmits this to a computer unit 16. Steps S103 and S104 are repeated S105 in this case for at least some of the object points 11 which form the object region. In a final step S106, the computer unit 16 ultimately acquires a stereoscopic image 24 from the scattered light 13 captured by the detector 15. As already explained above with reference to FIGS. 1 to 7, different combinations of illumination fibers 7 and detector fiber 14 can be used in the process. For example, if only one illumination fiber 7 and also only one detector fiber 14 are used, then it is necessary to always scan each object point 11 in the object region 12 by two sample beams 23 which make a defined stereo angle with each other. In this case, the capture of the scattered and/or reflected scattered light 13 is implemented in temporally and/or spectrally separated fashion by the detector 15 coupled to the detector fiber 14. Then, the stereoscopic image 24 can be extracted and composed, for example via the computer unit 16, from this temporally and/or spectrally separately captured scattered light 13. In a further embodiment, use is made of one illumination fiber 7 in combination with two detector fibers 14. In this case, the distal ends 8 of the two detector fibers 14 have a defined spacing 21 and ultimately form the stereo basis and thus input couple the scattered light 13 into the detector fibers 14 from different angles. In a further embodiment, each fiberscope 1 includes two illumination fibers 7 and two detector fibers 14. Here, too, the two detector fibers 14 have a fixed spacing 21 from one another, which ultimately forms the stereo basis. In this embodiment there is a temporal or spectral separation of the two detector fibers 14, as has already been described in detail above.
[0077] In a further embodiment, the fiberscope 1 includes one or more illumination fibers 7 and a plurality of detector fibers 14. Here, too, the detector fibers 14 have a fixed spacing 21 from one another, which ultimately forms the stereo basis. There may be dynamic pairing of detector fibers 14 and a temporal and/or spectral separation of detector fibers 14, as already described in detail above.
[0078] During the focusing in step S103, the working distance 22 between a distal end 8 of the illumination fiber 7 and the object region 12 is determined first; for example, this can be implemented via OCT measurements. The working distance 22 determined thus between the distal end 8 of the illumination fiber 7 and the object region 12 is then used to adjust the size of the object region 12.
[0079] In an alternative or in addition, the working distance determined thus can be used to select a combination of one or more detection fiber pairs and/or illumination fibers.
[0080] It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
LIST OF REFERENCE SIGNS
[0081] 1 Fiberscope [0082] 2 Light source [0083] 3 Wavefront manipulator [0084] 4 Micromirror actuator [0085] 5 Controller [0086] 6 Proximal end [0087] 7 Illumination fiber [0088] 8 Distal end [0089] 9 Examination object [0090] 10 Eye [0091] 11 Object point [0092] 12 Object region [0093] 13 Scattered light [0094] 14 Detector fiber [0095] 15 Detector [0096] 16 Computer unit [0097] 17 Display device [0098] 18 Filter element [0099] 19 Capturing region [0100] 20 Overlap region [0101] 21 Spacing [0102] 22 Working distance [0103] 23 Sample beam [0104] 24 Stereoscopic image [0105] S100-S106 Method steps
