Remote imaging system for medical endoscopic system for viewing a target

Abstract

The invention relates to an imaging system comprising: - a medical endoscopic system (1) comprising an insertion instrument (2) provided with at least one multicore optical fibre, the distal end of which is located on the distal head of the insertion instrument, the proximal end of the multicore optical fibre being provided with an optical connector (13); - an image acquisition and processing apparatus (15) comprising: * at least one first illumination source configured to deliver a light beam, according to at least one first wavelength spectrum, to the multicore optical fibre via the optical connector; *at least one imaging sensor configured to receive a light beam at least from the proximal end of the multicore optical fibre; *an imaging processor connected to the imaging sensor and configured to form images of the target.

Description

Description Title of the invention: Remote imaging system for a medical endoscopic system for viewing a target Technical Field

[0001] The present invention relates to the technical field of imaging systems implemented within the framework of medical endoscopic systems in the general sense allowing access to the interior of a body such as a cavity or a canal for example and it aims more specifically as medical endoscopic systems, medical catheters and medical endoscopes.

[0002] The medical endoscopic system implemented within the framework of the present invention finds particularly advantageous applications for allowing access to the internal surface of a hollow organ, a cavity or a natural or artificial conduit of the human body in order to carry out various operations for therapeutic, surgical or diagnostic purposes, and can be used in the field of the urinary tract, the gastrointestinal tract, the respiratory system, the cardiovascular system, the trachea, the sinus cavity, the female reproductive system, the abdominal cavity or any other part of the human body to be explored by a natural or artificial route. Prior art

[0003] Conventionally, a medical endoscopic system of the medical catheter or medical endoscope type comprises a control handle to which is attached an insertion tube having, opposite its part attached to the control handle, a distal head. This insertion tube has a greater or lesser length and flexibility so that it can be introduced into a natural or artificial access route in order to carry out various operations or functions for therapeutic, surgical or diagnostic purposes. It should be noted that such an endoscopic system is designed to have the smallest possible section in order to be able to access access routes having a limited passage section.

[0004] For a medical endoscopic system of the endoscope type, the distal head is equipped in particular with a vision system allowing the examination of the organ, cavity or duct of the human body. Upstream of this distal head, the insertion tube comprises a flexion structure or crutching part formed of articulated vertebrae allowing the orientation of the distal head. This medical endoscope is intended to be connected to a medical electronic device comprising a unit for processing the image signals delivered by the vision system of the endoscope. The images taken are viewed on a screen of this device or on a remote screen connected to this device.

[0005] The vision system mounted at the distal part of the tube comprises a camera which may or may not be associated with one or more light sources such as light-emitting diodes. The camera, or even the light sources, are electrically connected to electrical components located in the handle or in the medical device. According to the exemplary embodiment described by patent application US 2022 / 0160218, the camera and the light sources located at the distal part of the insertion tube are connected to the electrical components located in the handle. It should be noted that a medical endoscopic system is generally used in an environment in which various electrical equipment such as electric scalpels, X-ray radiography devices, scanners or screens operate, which may affect the operation of the camera and / or the signal delivered by the camera.Furthermore, in the case of a disposable endoscopic system, the light sources and the camera are discarded. In addition, these electronic components are electronic waste requiring recycling, increasing the cost of such a system.

[0006] It is also known from US patent 11,061,185, a medical endoscopic system comprising a multi-core optical fiber composed of a multitude of cores separated by a matrix and housed in a common sheath. This multi-core optical fiber receives the radiation from a target at its distal end and transmits the radiation along its entire length to deliver the radiation to an imaging sensor at its proximal part. The medical endoscopic system also comprises a lighting source delivering to the proximal end of an optical illumination fiber, a light beam exiting the distal end of the illumination fiber to illuminate the target.

[0007] Such a medical endoscopic system has a sensitivity to electromagnetic disturbances, which is zero compared to other medical endoscopic systems. However, this medical endoscope requires the use of a multi-core optical fiber and illumination in order to obtain a quality image of the target. It follows that such an endoscopic system does not have a section allowing it to access access routes having a limited passage section. Furthermore, the illumination is offset relative to the distal end of the multi-core optical fiber so that the area of ​​the target observed by the sensor may be poorly illuminated. Statement of the invention

[0008] The object of the invention aims to remedy the drawbacks of the state of the art by proposing an imaging system comprising a medical endoscopic system insensitive to electromagnetic disturbances and having a limited passage section while obtaining optimized image quality of the target.

[0009] Another object of the invention is to propose an imaging system comprising a medical endoscopic system having the lowest possible ratio between its passage section and the resolution of the images in order to obtain optimized image quality of the target for a reduced passage section.

[0010] Another object of the invention is to provide an imaging system designed to have a reduced manufacturing cost by limiting waste in the case of a disposable endoscopic system.

[0011] To achieve these objectives, the imaging system for a medical endoscopic system for visualizing a target comprises: - a medical endoscopic system comprising an insertion instrument terminating opposite a proximal part, by a distal head, this instrument insertion instrument being provided with at least one multi-core optical fiber having a distal end and a proximal end, the distal end of the multi-core optical fiber being located at the distal head of the insertion instrument while the multi-core optical fiber is provided with an optical connector at its proximal end and extends at least to the proximal portion of the insertion instrument; - an image acquisition and processing device comprising: * at least one first lighting source configured to deliver a light beam according to at least one first wavelength spectrum, to the multi-core optical fiber via the optical connector; * at least one imaging sensor configured to receive a light beam coming from at least the proximal end of the multi-core optical fiber; *an imaging processor connected to the imaging sensor and configured to form images of the target.

[0012] According to an example of implementation, the medical endoscopic system comprises a single multi-core optical fiber while the image acquisition and processing device comprises: * a lighting source configured to deliver a light beam according to at least a first wavelength spectrum, to the single multi-core optical fiber via the optical connector; * a single imaging sensor configured to receive a light beam from the proximal end of the single multi-core optical fiber.

[0013] According to another example of implementation: * the endoscopic system includes: - a first multi-core optical fiber and a second multi-core optical fiber, * the image acquisition and processing device includes: - a lighting source configured to deliver a light beam to the first multi-core optical fiber, - a single imaging sensor configured to have a first zone for receiving a light beam coming from the proximal end of the first multi-core optical fiber and a second receiving area separate from the first receiving area, for receiving a light beam from the proximal end of the second multi-core optical fiber.

[0014] According to another example of implementation: * the endoscopic system includes: - a first multi-core optical fiber and a second multi-core optical fiber, * the image acquisition and processing device includes: - a first lighting source configured to deliver a light beam to the first multi-core optical fiber, - a second lighting source configured to deliver a light beam to the second multi-core optical fiber, - a single imaging sensor configured to have a first reception area for a light beam coming from the proximal end of the first multi-core optical fiber and a second reception area separate from the first reception area for receiving a light beam coming from the proximal end of the second multi-core optical fiber.

[0015] According to another example of implementation: * the endoscopic system includes: - a first multi-core optical fiber and a second multi-core optical fiber, * the image acquisition and processing device includes: - a lighting source configured to deliver a light beam to the first multi-core optical fiber, - a first imaging sensor configured to receive a light beam from the proximal end of the first multi-core optical fiber, - a second imaging sensor configured to receive a light beam from the proximal end of the second multi-core optical fiber.

[0016] According to another example of implementation: * the endoscopic system includes: - a first multi-core optical fiber and a second optical fiber multi-core, * the image acquisition and processing device includes: - a first lighting source configured to deliver a light beam to the first multi-core optical fiber, - at least one second lighting source configured to deliver a light beam to the second multi-core optical fiber, - a first imaging sensor configured to receive a light beam from the proximal end of the first multi-core optical fiber, - a second imaging sensor configured to receive a light beam from the proximal end of the second multi-core optical fiber.

[0017] Advantageously: - the lighting source(s) are configured to deliver light beams according to different wavelength spectra, - the imaging sensor(s) are configured to acquire images of spectra of different wavelengths, - the imaging processor processes images of spectra of different wavelengths to obtain a spectral overresolution image.

[0018] According to one example, the one or more imaging sensors are configured to acquire images of spectra of different wavelengths using colored filters whose colors correspond to the spectra of different wavelengths of the light beams.

[0019] For example: - the lighting source(s) are configured to deliver light beams according to wavelength spectra of red, green and blue; - the imaging sensor(s) are configured to acquire images of red, green and blue wavelength spectra; - the imaging processor processes the images of wavelength spectra to obtain a contrasted or colored image.

[0020] For this example, to obtain a spectral overresolution image, for information purposes, the sensors are configured to acquire images of red, green and blue wavelength spectra using filters (for example example arranged in a Bayer matrix) filtering certain wavelengths arriving at each individual pixel (an individual pixel has a photosite). These filters can be micro-lenses. Also, these filters can be on optics or on the sensor itself.

[0021] It appears that each individual pixel (sometimes called sub-pixels) has a color assigned to it: red, green, or blue. By using illumination based on wavelength spectra of red, green, and blue, we therefore have individual pixels in the sensor that can be used according to the spectrum used for illumination, which allows us to precisely locate the perceived variations. By recombining the images obtained using the different spectra, we have an over-resolution. Furthermore, chromatic aberrations or the different absorbance of tissues can reveal new details in this example, depending on the spectra used.

[0022] According to another example: - the imaging processor drives the imaging sensor(s) to acquire time-shifted images, - the imaging processor processes the time-shifted images to obtain a temporal over-resolution image.

[0023] In this example, movements of the patient into whom the insertion instrument is inserted are taken into account, which may result from the patient's breathing. The time-shifted images therefore also have a spatial shift, allowing for over-resolution to be obtained through processing, for example by image recombination.

[0024] In this example, there are no actuators used to move the insertion instrument.

[0025] Advantageously, in this example, the acquisition speed of the over-resolution images is greater than 24 images per second, which implies an acquisition speed of the individual images which is greater than a multiple of 24, i.e. 24 times n with n the number of images shifted in time which make it possible to obtain an image.

[0026] Alternatively, the acquisition speed can be greater than 24 images per second, which makes it possible to implement a temporal overresolution at least for some of the images, or even by reusing certain images. For this alternative, augmentation techniques can be used to add images obtained by duplication of images or by combination of images obtained by acquisition.

[0027] Advantageously, the insertion instrument is static.

[0028] By static, we mean that the insertion instrument does not include automatic means capable of moving one or more elements of the insertion instrument, for example, it does not include actuators.

[0029] We thus have a simple device, which uses the patient's respiratory movements for temporal overresolution.

[0030] According to another advantageous example: - the imaging processor drives the imaging sensor(s) to acquire spatially offset images with an overlapping area, - the imaging processor processes the spatially shifted images to obtain a spatially over-resolution image.

[0031] For example, obtaining spatially shifted images with an overlapping area can be achieved by using two gratings in the fiber or multi-core fibers, these two gratings being shifted relative to each other.

[0032] This offset is implemented so that the two networks do not overlap, that is to say so that they do not receive the same light information for two elements of the multicore fiber belonging to two different networks. However, there is an overlapping zone within the images obtained by the imaging sensors.

[0033] Preferably, for information purposes, spatially shifted images of a fiber half-core are acquired along at least one axis of the image plane (generally designated as the X, Y plane, here, each fiber half-core belongs to a different one of said networks). An image is obtained for each fiber half-core. Preferably, the pixels of the image sensor are small dimensions, with at least 3 pixels of each color to obtain precise colorimetric information. Due to the shift, we obtain an over-resolution.

[0034] It has been observed that images may appear discontinuous (dotted), and it is possible to use artificial intelligence techniques, such as machine learning, to achieve over-resolution that makes the dotted lines disappear.

[0035] For information purposes, artificial intelligence techniques and in particular automated learning techniques can be used in the following documents: - ESRGAN: Enhanced Super-Resolution Generative Adversarial Networks (Xintao Wang et al., arXiv: 1809.00219); - Accelerating the Super-Resolution Convolutional Neural Network (Chao Dong et al., arXiv: 1608.00367).

[0036] According to an alternative embodiment, the medical endoscopic system comprises an optical lighting fiber having a distal end and a proximal end, the distal end of the optical lighting fiber being located at the distal head of the insertion instrument while the proximal end of the optical lighting fiber being located at the proximal part of the insertion instrument and being provided with an optical connector through which an illumination light beam provided by a lighting source is conveyed.

[0037] Advantageously, the image acquisition and processing device comprises an optical separation system arranged on the optical path between the proximal end of a multi-core optical fiber and an imaging sensor and reflecting in the direction of the proximal end of a multi-core optical fiber, the light beam coming from a lighting source.

[0038] According to one embodiment, the medical endoscopic system comprises, as an insertion instrument, an insertion tube ending in a distal head and held at its opposite end by a control handle, the multi-core optical fiber(s) being mounted inside the insertion tube.

[0039] According to another embodiment, the medical endoscopic system comprises, as an insertion instrument, a catheter comprising the multi-core optical fiber(s). Brief description of the drawings

[0040] [Fig. 1] Figure 1 is a general view of an example application of a remote imaging system for an endoscope as a medical endoscopic system for viewing a target.

[0041] [Fig. 2] Figure 2 is a general view of another example of application of a remote imaging system for an endoscope as a medical endoscopic system for visualizing a target.

[0042] [Fig. 3] Figure 3 is a general view of another example of application of a remote imaging system for a catheter as a medical endoscopic system for visualizing a target.

[0043] [Fig. 4] Figure 4 schematically represents a first example of the realization of a remote imaging system for a medical endoscopic system using a single multi-core optical fiber, a light source and an imaging sensor.

[0044] [Fig. 5] Figure 5 schematically represents another example of the embodiment of a remote imaging system for a medical endoscopic system using two multi-core optical fibers, a light source and an imaging sensor.

[0045] [Fig. 6] Figure 6 schematically represents another example of the embodiment of a remote imaging system for a medical endoscopic system using two multi-core optical fibers, two light sources and an imaging sensor.

[0046] [Fig. 7] Figure 7 schematically represents another example of the embodiment of a remote imaging system for a medical endoscopic system using two multi-core optical fibers, a light source and two imaging sensors.

[0047] [Fig. 8] Figure 8 schematically represents another example of the embodiment of a remote imaging system for a medical endoscopic system using two multi-core optical fibers, two light sources and two imaging sensors.

[0048] [Fig. 9] Figure 9 schematically represents the distal head of a medical endoscope comprising two multi-core optical fibers and showing a detail of a multi-core optical fiber.

[0049] [Fig. 10] Figure 10 is a functional block diagram of an exemplary embodiment of a remote imaging system for a medical endoscopic system.

[0050] [Fig. 11] Figure 11 schematically represents another example of the realization of a remote imaging system for a medical endoscopic system using two multi-core optical fibers, a light source and two imaging sensors as well as an additional illumination fiber. Description of the embodiments

[0051] As can be seen from the figures, the subject of the invention relates to an imaging system I for a medical endoscopic system 1 of the endoscope or catheter type in the general sense designed to access the interior of a body such as a cavity or a canal for example. Conventionally, an endoscopic system 1 of the endoscope or catheter type comprises an insertion instrument 2 having a proximal part 2a and, opposite, a distal part forming a free end. The insertion instrument 2 thus ends at its free end, with a distal head 2b from which a target C in the general sense is visualized.

[0052] According to an embodiment for which the medical endoscopic system 1 is an endoscope (figures 1, 2 and 9), the medical endoscopic system comprises, as insertion instrument 2, an insertion tube 3 having a free end forming the distal head 2b and held at its opposite end by a control handle 4, all or part of which forms the proximal part 2a of the insertion instrument. The insertion tube 3 is fixed temporarily or permanently to the control handle 4. In the example illustrated in figures 1 and 2, the insertion tube 3 is engaged by its end opposite its free end, in a housing of a tip 3a intended to be fixed to the distal part of the control handle 4. This insertion tube 3 which has a more or less significant length and flexibility is intended to be introduced into a natural or artificial access route in order to carry out various operations or functions for therapeutic, surgical or diagnostic purposes.

[0053] The insertion tube 3 is made of a semi-rigid material such as, for example, thermoplastic elastomer (TPE). The insertion tube 3 has a length adapted to the length of the conduit to be inspected and can be between 5 cm and 3 m. The insertion tube 3 has various cross-sectional shapes such as square, oval or circular. This insertion tube 3, which is in contact with tissues, human organs or medical devices (trocars or probes), is essentially intended for single or multiple use by a patient or even for reusable use after decontamination, disinfection or sterilization.

[0054] the endoscopic system 1 of the endoscope type also comprises, inside the insertion tube 3, a tubular conduit 6 forming an operating or working channel extending from the control handle 4 to the distal head 2b to allow, at the level of this distal head, the supply of various tools and / or fluids and / or the suction of fluids (figure 9). The tubular conduit 6 is surrounded by the insertion tube 3 over its entire length between the distal head 2b and the control handle 4. Conventionally, the tubular conduit 6 extends beyond the tip 3a inside the control handle 4.

[0055] Conventionally, the endoscopic system 1 of the endoscope type also comprises a control mechanism 8 for orienting the distal head 2b relative to the longitudinal axis of the insertion tube 3. For this purpose, the insertion tube 3 comprises, upstream of the distal head 2b, a flexion, folding or deflection structure 9 allowing the orientation of the distal head 2b relative to the longitudinal axis of the insertion tube 3. The control mechanism 8 can be produced in any suitable manner so that the distal head 2b can be moved between a rest position in which the insertion tube 3 is straight and a bent position in which the bent portion 9 is curved. For example, the control mechanism 8 may comprise a manual control lever rotating a pulley on which is fixed at least one actuating cable mounted to be fixed at the distal head 2b.

[0056] According to another mode of application for which the medical endoscopic system 1 is a catheter (figure 3), the medical endoscopic system comprises as insertion instrument 2, a catheter ending opposite a proximal part 2a, by a distal head 2b. Said catheter can be of conventional design without an actuation system allowing the distal part to be moved along one or more axes. It can also be equipped with a deflection system with a position return by a shape memory structure, such as for example a blade or a nithinol wire. Another device for actuation of the distal part can be produced by means of cables, deformable parts by playing on the elasticity of the materials.

[0057] According to the invention, the insertion instrument 2 is provided with at least one multi-core optical fiber 11 as in the variant illustrated in FIG. 4 and a first multi-core optical fiber 11 and a second multi-core optical fiber 12 as in the variants illustrated in FIGS. 5 to 8. Each multi-core optical fiber 11, 12 has respectively a distal end 11a, 12a and a proximal end 11b, 12b. The distal end 11a, 12a of the multi-core optical fibers is located at the distal head 2b of the insertion instrument 2 so as to visualize the target C. It should be noted that an optical structure can be placed at the distal end 11a, 12a of the multi-core optical fibers. Each multi-core optical fiber 11, 12 extends at least to the proximal portion 2a of the insertion instrument and is provided with at least one optical connector 13 at its proximal end 11b, 12b.

[0058] Of course, the optical connector 13 equipping the proximal end 11b, 12b of the multi-core optical fibers 11, 12 is intended to cooperate with a complementary male or female optical connector depending on the female type. or male of the optical connector 13. Advantageously, a focusing lens is mounted in the complementary connector to improve the optical connection, by offering a wider positioning tolerance. Indeed, the optical connector 13 may be intended to be discarded with the insertion instrument. In this case, the optical connector 13 can be produced economically with significant tolerance differences.

[0059] In a known manner, a multi-core optical fiber 11, 12 is an optical fiber comprising a multitude of cores 11c (figure 9), for example at least 10,000 cores separated by a common coating or a separation structure lld such as a matrix. These cores 11c coated with the separation structure lld are mounted inside a common protective sheath lle. This separation structure lld of the cores between them has, depending on the section of the multi-core optical fiber, a honeycomb shape. For example, optical fibers marketed under the trade name ESKA by the company Mitsubishi Rayon Co., MBI by the company Asahi Kasei or FIGP by the company Fujikura can be used as multi-core optical fibers 11, 12.

[0060] The imaging system I also comprises an image acquisition and processing apparatus 15 comprising either a single lighting source 16 as in the variants illustrated in FIGS. 4, 5, 7 or a first lighting source 16 and a second lighting source 17 as in the variants illustrated in FIGS. 6 and 8. Each lighting source 16, 17 is configured to deliver a light beam according to at least a first wavelength spectrum, to a multi-core optical fiber 11, 12 via the optical connector 13. Each lighting source 16, 17 is produced in any suitable manner to allow the multi-core optical fiber 11, 12, to deliver at its distal end 11a, 12a, a light beam suitable for illuminating the target C to be imaged. For example, the lighting sources 16, 17 can be produced by light-emitting diodes, halogen lamps, infrared or ultraviolet light sources.

[0061] The image acquisition and processing apparatus 15 also comprises either at least one imaging sensor 18 as in the embodiments illustrated in FIGS. 4, 5, 6 or a first imaging sensor 18 and a second imaging sensor 19 as in the embodiments illustrated in FIGS. 7 and 8. Each imaging sensor 18, 19 is configured to receive a light beam from the proximal end of a multi-core optical fiber 11, 12, each equipped with the optical connector 13.

[0062] As is apparent from the various embodiment variants, it should be noted that the lighting sources 16, 17 and the imaging sensors 18, 19 are part of the image acquisition and processing apparatus 15 and are thus remote from the medical endoscopic system 1. It follows that in the case where the medical endoscopic system 1 is of the disposable type, the lighting sources 16, 17 and the imaging sensors 18, 19 can be reused with another medical endoscopic system 1, thus reducing electronic waste. Furthermore, in the case where the medical endoscopic system 1 requires a decontamination operation, the image acquisition and processing device 15 is not concerned by such an operation so that the lighting sources 16, 17 and the imaging sensors 18, 19 which are part of this device are not likely to be damaged by this decontamination operation.

[0063] It should be noted that in the application example illustrated in Figure 1 for which an endoscope is used as a medical endoscopic system 1, the proximal end of the multi-core optical fiber(s), provided with the optical connector 13 is located at the proximal part 2a of the insertion instrument, i.e. at the level of the control handle 4. The multi-core optical fiber(s) 11, 12 are mounted inside the insertion tube 3 but outside the tubular conduit 6. The multi-core optical fiber(s) 11, 12 thus extend from the distal head of the insertion tube, inserting themselves along the entire length of the insertion tube 3, between the latter and the tubular conduit 6. The multi-core optical fiber(s) 11, 12 extend inside the control handle 4 to one or more optical connectors 13 mounted at the proximal part of the control handle 4.

[0064] According to this example, an optical cable 21 provides an optical connection between the optical connector(s) 13 and the image acquisition and processing apparatus 15 to ensure the routing of the light beams between, on the one hand, the multi-core optical fiber(s) 11, 12 and, on the other hand, the lighting source(s) 16, 17 and the imaging sensor(s) 18, 19. The optical cable 21 may be produced in any suitable manner in the form of one or more optical fibers. Typically, the optical cable 21 is provided, opposite its portion connected to the optical connector 13, with an optical connector 13a fixed to the image acquisition and processing apparatus 15. [0065JII It should be noted that in the application example illustrated in Figure 2 for which an endoscope is used as a medical endoscopic system 1, the proximal end of the multi-core optical fiber(s), provided with the optical connector 13, is connected directly to the image acquisition and processing device 15. According to this example, the proximal end of the multi-core optical fiber(s), provided with the optical connector 13, is fixed directly to the image acquisition and processing device 15. Thus, the multi-core optical fiber(s) 11, 12 extend from the distal head of the insertion tube, inserting themselves over the entire length of the insertion tube 3, between the latter and the tubular conduit 6.The multi-core optical fiber(s) 11, 12 extend inside the control handle 4 to exit the proximal portion of the control handle so as to be connected to the optical connector 13 fixed to the image acquisition and processing device 15. [0066JII It should be noted that in the application example illustrated in Figure 3 for which a catheter is used as a medical endoscopic system 1, this catheter is formed at least by the multi-core optical fiber(s) 11, 12 whose distal end 11a, 12a forms the distal head 2b of the insertion instrument 2. In the case where a single multi-core optical fiber is used, the insertion instrument 2 is formed by this multi-core optical fiber which can be integrated or surrounded in a protective sleeve. In the case where the two multi-core optical fibers 11, 12 are used, the insertion instrument 2 is formed by a protective sleeve in which the two optical fibers are mounted multi-cores 11, 12. It should be noted that the proximal end of the multi-core optical fiber(s) 11, 12 is connected via the optical connector 13, directly to the image acquisition and processing device 15 (as illustrated in FIG. 3) or indirectly using the optical cable 21 (as explained in relation to FIG. 1).

[0067] According to a first exemplary embodiment illustrated in figure 4, the medical endoscopic system 1 comprises a single multi-core optical fiber 11 while the image acquisition and processing device 15 comprises: - a lighting source 16 configured to deliver a light beam according to at least a first wavelength spectrum, to the single multi-core optical fiber 11 via the optical connector 13; - a single imaging sensor 18 configured to receive a light beam from the proximal end of the single multi-core optical fiber 11.

[0068] The image acquisition and processing apparatus 15 comprises an optical separation system 22 arranged on the optical path between the proximal end of the multi-core optical fiber 11 and the imaging sensor 18 and reflecting in the direction of the proximal end of the multi-core optical fiber 11, the light beam coming from the lighting source 16. This optical separation system 22 can be produced by any suitable means such as a semi-reflecting plate, a beam splitter or a prism optical system.

[0069] An advantage of this embodiment is that it can precisely illuminate the target area observed by the imaging sensor and minimize the diameter of the insertion instrument while reducing the waste generated by using a single multi-core optical fiber.

[0070] According to a second exemplary embodiment illustrated in Figure 5, the endoscopic system 1 comprises a first multi-core optical fiber 11 and a second multi-core optical fiber 12. The image acquisition and processing device 15 comprises: - a lighting source 16 configured to deliver a light beam to the first multi-core optical fiber 11, - a single imaging sensor 16 configured to present a first zone for receiving a light beam from the proximal end of the first multi-core optical fiber 11 and a second receiving zone separate from the first receiving zone, for receiving a light beam from the proximal end of the second multi-core optical fiber 12.

[0071] The image acquisition and processing apparatus 15 comprises an optical separation system 22 arranged on the optical path between the proximal end of the multi-core optical fiber 11 and the imaging sensor 18 and reflecting in the direction of the proximal end of the multi-core optical fiber 11, the light beam coming from the lighting source 16.

[0072] This exemplary embodiment has the advantage of being able to obtain two images simultaneously which can be processed at the same time to achieve over-resolution as will be described in the rest of the description.

[0073] According to a third exemplary embodiment illustrated in Figure 6, the endoscopic system 1 comprises a first multi-core optical fiber 11 and a second multi-core optical fiber 12. The image acquisition and processing device 15 comprises: - a first lighting source 16 configured to deliver a light beam to the first multi-core optical fiber 11, - a second lighting source 17 configured to deliver a light beam to the second multi-core optical fiber 12, - a single imaging sensor 18 configured to have a first reception zone for a light beam coming from the proximal end of the first multi-core optical fiber 11 and a second reception zone separate from the first reception zone, for receiving a light beam coming from the proximal end of the second multi-core optical fiber 12.

[0074] The image acquisition and processing apparatus 15 comprises an optical separation system 22 arranged on the optical path between the proximal end of each multi-core optical fiber 11, 12 and the imaging sensor 18 and reflecting in the direction of the proximal end of each multi-core optical fiber 11, 12, the light beam coming from the lighting sources 16.

[0075] This embodiment allows the target to be illuminated with light beams having different wavelength spectra in order to obtain a spectral overresolution image. This solution offers the advantage of being able to visualize tumors. Indeed, by choosing a specific wavelength spectrum, the vascularization of the tissues can be highlighted. However, since a tumor corresponds to a highly vascularized area, a tumor can be more easily observed using this technique.

[0076] According to a fourth exemplary embodiment illustrated in Figure 7, the endoscopic system 1 comprises a first multi-core optical fiber 11 and a second multi-core optical fiber 12. The image acquisition and processing device 15 comprises: - a lighting source 16 configured to deliver a light beam to the first multi-core optical fiber 11, - a first imaging sensor 18 configured to receive a light beam coming from the proximal end of the first multi-core optical fiber H, - a second imaging sensor 19 configured to receive a light beam from the proximal end of the second multi-core optical fiber 12.

[0077] The image acquisition and processing apparatus 15 comprises an optical separation system 22 arranged on the optical path between the proximal end of the multi-core optical fiber 11 and the imaging sensor 18 and reflecting in the direction of the proximal end of the multi-core optical fiber 11, the light beam coming from the lighting source 16.

[0078] This example allows for over-resolution since it is possible to acquire two images on two imaging sensors. It is also possible to acquire the images one after the other with different wavelengths.

[0079] According to a fifth exemplary embodiment illustrated in Figure 8, the endoscopic system 1 comprises a first multi-core optical fiber 11 and a second multi-core optical fiber 12. The acquisition and processing device of images 15 includes: - a first lighting source 16 configured to deliver a light beam to the first multi-core optical fiber 11, - a second lighting source 17 configured to deliver a light beam to the second multi-core optical fiber 12, - a first imaging sensor 18 configured to receive a light beam coming from the proximal end of the first multi-core optical fiber H, - a second imaging sensor 19 configured to receive a light beam from the proximal end of the second multi-core optical fiber 12.

[0080] The image acquisition and processing apparatus 15 comprises an optical separation system 22 arranged on the optical path between the proximal end of each multi-core optical fiber 11, 12 and the imaging sensor 18, 19 and reflecting in the direction of the proximal end of each multi-core optical fiber 11, 12, the light beam coming from the lighting sources 16, 17.

[0081] In this example, it is possible to obtain images with twice the resolution. One advantage of this solution is that it can visualize tumors.

[0082] It should be noted that in Figures 4 to 8, the proximal end of the multi-core optical fiber(s), provided with the optical connector 13, is shown diagrammatically as being connected directly to the image acquisition and processing device 15. Of course, the proximal end of the multi-core optical fiber(s) 11, 12, provided with the optical connector 13, may be located at the proximal part 2a of the insertion instrument so that an optical cable 21 provides the optical connection between the optical connector 13 fixed to the control handle 4 and the image acquisition and processing device 15.

[0083] In the same sense, it must be considered that the image acquisition and processing apparatus 15 is configured so as to ensure the routing of light between the imaging sensors 18, 19 and the optical connectors 13, 13a fixed to the image acquisition and processing apparatus 15. Similarly, the apparatus image acquisition and processing device 15 is configured so as to ensure, by any appropriate means, the routing of light between the lighting sources 16, 17 and the optical connectors 13, 13a fixed to the image acquisition and processing device 15.

[0084] It should be noted that according to figures 4 to 8, the multi-core optical fibers 11, 12 ensure in particular the routing of the light flux from the lighting sources to the distal head 2b of the insertion instrument. It should be noted, as illustrated in figure 11, that it can be envisaged that the medical endoscopic system 1 comprises a lighting optical fiber 28 allowing the supply of an additional light flux. This lighting optical fiber 28 has a distal end 28a and a proximal end 28b recovering the light flux from a light source 29. The distal end 28a of the lighting optical fiber 28 is located at the distal head 2b of the insertion instrument while the proximal end of the lighting optical fiber is located at the proximal part 2a of the insertion instrument and is provided with an optical connector through which an illumination light beam provided by the light source 29 is routed.This lighting optical fiber 28 can be implemented in all the embodiments described in the present application.

[0085] The image acquisition and processing apparatus 15 also comprises, as illustrated in FIG. 10, an imaging processor 25 connected to the imaging sensors 18, 19 and configured to form images of the target C, from the signals delivered by the imaging sensors 18, 19. The imaging processor 25 controls the imaging sensors 18, 19 in order to acquire the images of the target at determined times. The imaging processor 25 also controls the lighting sources 16, 17 to control the lighting emitted in particular during the acquisition of the images by the imaging sensors 18, 19 as described in the remainder of the description. The imaging processor 25 is connected to a display screen 26 for displaying the images of the target C. This display screen 26 may be part of the image acquisition and processing apparatus 15 or be remote from this apparatus. Of course, the imaging processor 25 may be connected to a memory for recording images.

[0086] The image acquisition and processing device 15 can be presented in different ways. Conventionally, the image acquisition and processing device 15 can be presented in the form of an electronic tablet provided with the display screen 26 and a human / machine interface allowing a user to enter data or to control this device. This human / machine interface can be a keyboard, a mouse, or the screen for example produced by a touch screen. The image acquisition and processing device 15 also comprises a communication unit configured to communicate with a generally remote database, forming part of a computer system.

[0087] The imaging system I according to the invention can be implemented in different ways which follow directly from the preceding description.

[0088] According to an exemplary implementation, the lighting source(s) 16, 17 are configured to deliver light beams according to different wavelength spectra and the imaging sensor(s) 18, 19 are adapted to acquire images of different wavelength spectra. Typically, it may be envisaged to acquire images with different acquisition times before reconstructing them.

[0089] Advantageously, the imaging processor 25 processes the images of spectra of different wavelengths to obtain a spectral overresolution image. In other words, the resulting image has a resolution greater than the resolution of the images taken.

[0090] According to an advantageous embodiment, the lighting source(s) 16, 17 are configured to deliver light beams according to wavelength spectra of red, green and blue and the imaging sensor(s) 18, 19 are configured to acquire images of wavelength spectra of red Ir, green Iv and blue Ib. In the example illustrated in FIG. 10, the first lighting source 16 is controlled to deliver a light beam according to a red wavelength spectrum and the first imaging sensor 18 is configured to acquire images of the red Ir wavelength spectrum. The second illumination source 17 is configured to successively deliver light beams according to green and blue wavelength spectra and the second imaging sensor 19 is configured to acquire images of green Iv and blue Ib wavelength spectra.

[0091] Furthermore, the imaging processor 25 processes the wavelength spectra images to obtain a contrasted or colored image which may be a white image. In the illustrated example, the imaging processor 25 processes the wavelength spectra images of red Ir, green Iv and blue Ib to obtain a white image Ic. Typically, for an imaging sensor 18, 19 CMOS type with a BAYER matrix, each image of wavelengths of red Ir, green Iv or blue Ib has for example a resolution of 40,000 pixels. Taking these images into account makes it possible to obtain a white image with a resolution of 120,000 pixels.

[0092] According to another advantageous exemplary embodiment, the lighting source(s) 16, 17 are configured to successively deliver light beams according to different wavelength spectra such as infrared light radiation and ultraviolet light radiation.

[0093] According to another exemplary implementation, the imaging processor 25 controls the imaging sensor(s) 18, 19 to acquire time-shifted images. The imaging processor 25 processes the time-shifted images to obtain a temporal over-resolution image. Thus, the imaging processor 25 processes a series of images taken successively in time so as to obtain a resulting image with an improved resolution compared to the resolution of each image taken.

[0094] According to another exemplary implementation, the imaging processor 25 controls the imaging sensor(s) 18, 19 to acquire images that are offset in space while presenting an overlapping zone. These images are offset in space following the movement of the insertion instrument 2 or taking into account the offset of the two multi-core optical fibers at the head. distal 2b. The imaging processor 25 processes the images shifted in space but also in time to obtain a spatial over-resolution image. Thus, the imaging processor 25 processes a series of images taken successively for different spatial positions of the distal head so as to obtain a resulting image with an improved resolution compared to the resolution of each image taken.

[0095] Spatial, temporal and spectral overresolution images are achieved using image processing algorithms based on multi-image super-resolution methods. These methods are based on three different approaches known as: Interpolation Based approaches; Frequency domain-based approaches; Reconstruction based approaches. These methods are briefly described in the following publications: 1 - S. Borman and R. Stevenson, Super-Resolution from Image Sequences: A Review, in Midwest Symposium on Circuits and Systems, Notre Dame, IN, USA, 8 1998, pp. 374-378. SC Park, MK Park, and MG Kang. 2-Super-Resolution Image Reconstruction: A Technical Overview, IEEE Signal Processing Magazine, vol. 20, no. 3, pp. 21-36, 5 200. 3-C. Mancas-Thillou and M. Mirmehdi, An Introduction to Super-Resolution Text, in Digital Document Processing, ser. Advances in Pattern Recognition. Springer London, 2007, pp. 305-327.4- Tian and K.-K. Ma, A survey on super-resolution imaging, Signal, Image and Video Processing (SIViP), vol. 5, no. 3, pp. 329-342, 2011.

Claims

Claims

1. Imaging system for a medical endoscopic system for viewing a target comprising: - a medical endoscopic system (1) comprising an insertion instrument (2) ending opposite a proximal part (2a), by a distal head (2b), this insertion instrument being provided with at least one multi-core optical fiber (11), (12) having a distal end and a proximal end, the distal end of the multi-core optical fiber being located at the distal head of the insertion instrument while the multi-core optical fiber is provided with an optical connector at its proximal end and extends at least to the proximal part of the insertion instrument; - an image acquisition and processing device (15) comprising: * at least one first lighting source (16), (17) configured to deliver a light beam according to at least one first wavelength spectrum, to the multi-core optical fiber via the optical connector; * at least one imaging sensor (18), (19) configured to receive a light beam coming at least from the proximal end of the multi-core optical fiber; *an imaging processor (25) connected to the imaging sensor and configured to form images of the target.

2. Imaging system according to claim 1 according to which the medical endoscopic system comprises a single multi-core optical fiber (11) while the image acquisition and processing apparatus (15) comprises: * a lighting source (16) configured to deliver a light beam according to at least a first wavelength spectrum, to the single multi-core optical fiber via the optical connector; * a single imaging sensor (18) configured to receive a light beam from the proximal end of the single multi-core optical fiber.

3. An imaging system according to claim 1 wherein: * the endoscopic system includes: - a first multi-core optical fiber (11) and a second multi-core optical fiber (12), * the image acquisition and processing device (15) comprises: - a lighting source (16) configured to deliver a light beam to the first multi-core optical fiber, - a single imaging sensor (18) configured to have a first reception zone for a light beam coming from the proximal end of the first multi-core optical fiber and a second reception zone separate from the first reception zone, for receiving a light beam coming from the proximal end of the second multi-core optical fiber.

4. An imaging system according to claim 1 wherein: * the endoscopic system includes: - a first multi-core optical fiber (11) and a second multi-core optical fiber (12), * the image acquisition and processing device (15) comprises: - a first lighting source (16) configured to deliver a light beam to the first multi-core optical fiber, - a second lighting source (17) configured to deliver a light beam to the second multi-core optical fiber, - a single imaging sensor (18) configured to have a first reception zone for a light beam coming from the proximal end of the first multi-core optical fiber and a second reception zone separate from the first reception zone for receiving a light beam coming from the proximal end of the second multi-core optical fiber.

5. An imaging system according to claim 1 wherein: * the endoscopic system includes: - a first multi-core optical fiber (11) and a second multi-core optical fiber (12), * the image acquisition and processing device (15) comprises: - a lighting source (16) configured to deliver a light beam to the first multi-core optical fiber, - a first imaging sensor (18) configured to receive a light beam from the proximal end of the first multi-core optical fiber, - a second imaging sensor (19) configured to receive a light beam from the proximal end of the second multi-core optical fiber.

6. An imaging system according to claim 1 wherein: * the endoscopic system includes: - a first multi-core optical fiber (11) and a second multi-core optical fiber (12), * the image acquisition and processing device (15) comprises: - a first lighting source (16) configured to deliver a light beam to the first multi-core optical fiber, - at least one second lighting source (17) configured to deliver a light beam to the second multi-core optical fiber, - a first imaging sensor (18) configured to receive a light beam from the proximal end of the first multi-core optical fiber, - a second imaging sensor (19) configured to receive a light beam from the proximal end of the second multi-core optical fiber.

7. Imaging system according to one of the preceding claims, wherein: - the lighting source(s) (16), (17) are configured to deliver light beams according to different wavelength spectra, - the imaging sensor(s) (18), (19) are configured to acquire images of spectra of different wavelengths, - the imaging processor (25) processes the images of spectra of different wavelengths to obtain a spectral overresolution image.

8. An imaging system according to claim 7, wherein the imaging sensor(s) (18), (19) are configured to acquire images of spectra of different wavelengths by means of colored filters whose colors correspond to the spectra of different wavelengths of the light beams.

9. Imaging system according to the preceding claim wherein: - the lighting source(s) (16), (17) are configured to deliver light beams according to wavelength spectra of red, green and blue; - the imaging sensor(s) (18), (19) are configured to acquire images of red, green and blue wavelength spectra; - the imaging processor (25) processes the images of wavelength spectra to obtain a contrasted or colored image.

10. Imaging system according to one of the preceding claims wherein: - the imaging processor (25) controls the imaging sensor(s) (18), (19) to acquire images shifted in time, - the imaging processor (25) processes the time-shifted images to obtain a temporal over-resolution image.

11. The imaging system of claim 10, wherein the insertion instrument is static.

12. Imaging system according to one of the preceding claims wherein: - the imaging processor (25) controls the imaging sensor(s) (18), (19) to acquire images offset in space by presenting an overlap zone, - the imaging processor (25) processes the spatially shifted images to obtain a spatially over-resolution image.

13. The system of claim 12, wherein obtaining the spatially shifted images with an overlapping area is obtained by using two networks in the fiber or multicore fibers, these two networks being offset from each other.

14. Imaging system according to one of the preceding claims, wherein the medical endoscopic system (1) comprises an illumination optical fiber having a distal end and a proximal end, the distal end of the illumination optical fiber being located at the distal head of the insertion instrument while the proximal end of the illumination optical fiber being located at the proximal part of the insertion instrument and being provided with an optical connector through which an illumination light beam provided by a lighting source is conveyed.

15. Imaging system according to one of the preceding claims, wherein the image acquisition and processing apparatus (15) comprises an optical separation system (22) arranged on the optical path between the proximal end of a multi-core optical fiber (11), (12) and an imaging sensor (18), (19) and reflecting in the direction of the proximal end of a multi-core optical fiber (11), (12), the light beam coming from a lighting source (16), (17).

16. Imaging system according to one of the preceding claims, wherein the medical endoscopic system (1) comprises, as insertion instrument (2), an insertion tube (3) ending in a distal head (2b) and held at its opposite end by a control handle (4), the multi-core optical fiber(s) (11), (12) being mounted inside the insertion tube.

17. Imaging system according to one of claims 1 to 13, according to which the medical endoscopic system (1) comprises, as insertion instrument (2), a catheter comprising the multi-core optical fiber(s) (11), (12).

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