Device and method for imaging moving targets

Abstract

The embodiments of the invention provide an imaging device (100) of a target (200), the device (100) may include: a first unit (10) comprising: a localization module (12) configured to determine several motion parameters of the target (200); an optical contact module (11) configured to collect optical signals generated in an area of ​​interest of the target (200), comprising a free end (111) in contact with the area of ​​interest, a captive end (112) and a plurality of optical fibers (110); a second unit (20) comprising: an optical processing module (21) associated with an optical axis (211); a rotating module (22) configured to rotate the captive end (112) around the optical axis (211) by means of a motor (26); a computing module (25) configured to determine control instructions for the motor (26). Figure for the abridged version: Fig. 1

Description

Title of the invention: Device and method for imaging moving targets Prior art

[0001] The present invention generally relates to the field of imaging and in particular to a device and a method for imaging moving targets.

[0002] Major technological advances have been made in recent years in the field of neuroscience, which encompasses the scientific studies of the nervous system. Neuroscience has a transdisciplinary character, drawing on many disciplines such as biology, chemistry, optics, mathematics, etc. Various approaches have been proposed to study the dynamics of nervous system activity, such as functional brain imaging, which allows the brain to be observed and analyzed during the execution of a cognitive task.

[0003] Functional brain imaging generally consists of measuring a signal resulting from neuronal activity in a living being. There are a multitude of functional brain imaging techniques which differ from each other in the nature of the signals measured and in the methodology implemented to acquire such signals.

[0004] Some functional brain imaging techniques, known to be non-invasive and suitable for human experimentation, rely on reading signals related to vascular or metabolic events that arise from neuronal activation. Such techniques include magnetic resonance imaging, magnetoencephalography, and positron emission tomography. These techniques offer only an indirect reading of neuronal activity and are therefore very limited in terms of temporal resolution. In addition, they require heavy and bulky equipment that significantly limits the subjects' repertoire of actions and movements, making them poorly suited to the study of complex behavioral tasks.

[0005] Other functional brain imaging techniques manipulating optical signals, and based on the use of fluorescent probes sensitive to variations in membrane potential and / or variations in intracellular calcium concentration, allow a more direct reading of neuronal activity. Such techniques therefore offer better temporal resolution and are therefore more suited to fundamental research aimed at characterizing the neuronal bases of behavior in non-human subjects.

[0006] Among the optical functional brain imaging techniques, there is fluorescence imaging which exploits the optical fluorescence properties of proteins or chemical species chosen for their capacity to emit photons in response to excitation, in a proportion depending on the local activity of the nervous tissues. The recording and analysis of sequences of images of tissues under excitation make it possible to monitor neuronal activity with a temporal resolution of the order of tens of milliseconds and with a spatial resolution ranging from a single neuron to hundreds of micrometers. Furthermore, there are fluorescent protein probes making it possible to target expression in neuronal populations chosen by means of genetic manipulations. These tools are increasingly developed, particularly in mouse models, because they allow a functional dissection of the neuronal circuitry.Mice have thus become essential models in integrative neuroscience, because they lend themselves easily to genetic manipulation while offering relatively rich behavior.

[0007] The implementation of optical functional imaging techniques requires the use of numerous optical components to collect small variations in the quantity of light. Such optical components are often heavy and bulky, so the coupling of optical recordings with the accomplishment of more or less complex behavioral tasks in mice is one of the main methodological challenges encountered by neuroscientists at present.

[0008] To perform optical functional imaging of the brain activity of a moving target moving freely for a long observation period, typically several tens of minutes, it is known to use a miniaturized microscope and a suitable lens in combination, and to fix the assembly thus formed on the skull of the moving target. However, it is difficult to reconcile miniaturization and performance of optical acquisition devices. In addition, such a solution has drawbacks related to the autonomy and the significant weight of the microscope and the lens which strongly impact the behavior of the moving target.

[0009] It is also known to immobilize the target under a conventional imaging system, and to place it in a virtual environment which can be interactive. Such a solution makes it possible to simulate a natural behavior of the moving target. However, it is complex to implement and it has a very high deployment cost.

[0010] Another known solution is to transport the optical signals from an area of ​​interest of a moving target to a conventional static imaging system, via a flexible interface consisting of a set of optical fibers. However, the fiber interface imposes constraints on the movement of the moving target, particularly in terms of rotation, thus limiting the behavioral repertoire that can be studied. In addition, the mechanical constraints linked to the rotations of the moving target can lead to rapid deterioration of the interface, which is made up of fragile optical fibers.

[0011] There is thus a need for an improved device and method for imaging moving targets. General definition of invention

[0012] To this end, the present invention provides a device for imaging a moving target moving on a given plane of motion. The imaging device comprises: - a first unit arranged on the moving target, the first unit comprising a localization module configured to determine one or more movement parameters of the moving target; and an optical contact module configured to collect optical signals generated in an area of ​​interest of the moving target, the optical contact module comprising a free end in contact with the area of ​​interest, a captive end having a first given planar geometric shape and a plurality of optical fibers connecting the two ends; - a second unit comprising an optical processing module associated with an optical axis and an active area having a second given planar geometric shape, the optical processing module being configured to process the collected optical signals; a rotating module configured to pivot the captive end around the optical axis by means of a motor provided in the imaging device; and a calculation module configured to determine, as a function of the one or more movement parameters, control instructions intended for the motor.

[0013] In one embodiment, the optical processing module may be configured to acquire, during acquisition time windows, a plurality of optical images, each of the optical images being representative of a plurality of optical signals collected via the plurality of optical fibers and simultaneously acquired from the area of ​​interest.

[0014] In another embodiment, the calculation module can be configured to determine the control instructions so as to block the pivoting of the captive end during the acquisition time windows, according to an optimal pivoting angle between the first and the second geometric shape.

[0015] Advantageously, the optimal pivot angle may correspond to a maximum overlap between the first and second geometric shape.

[0016] Alternatively, the calculation module can be configured to determine, outside the acquisition time windows, the control instructions in a manner to compensate for the torsion undergone by the plurality of optical fibers and induced by rotational movements of the moving target.

[0017] In one embodiment, the calculation module can be configured to determine the control instructions so as to compensate for the torsion undergone by the plurality of optical fibers and induced by rotational movements of the moving target, during and outside the acquisition time windows.

[0018] In another embodiment, the second unit may further comprise a backup module configured to backup each of the acquired optical images associated with a corresponding pivot angle between the first and second geometric shapes.

[0019] Advantageously, the optical processing module can further be configured to emit, during emission time windows, a plurality of optical excitation signals towards the area of ​​interest.

[0020] Alternatively, the second unit may further comprise a relay module comprising a rotating element and a static element, the relay module being configured to receive, via a first wired connection connected to the rotating element, the one or more movement parameters from the location module, and to transmit, via a second wired connection connected to the static element, the one or more received movement parameters to the calculation module.

[0021] Optionally, the first unit may further comprise a wireless transmission module configured to transmit the one or more motion parameters, and the second unit may further comprise a wireless reception module configured to receive the one or more motion parameters.

[0022] In one embodiment, the one or more motion parameters may include an angle defining the orientation of the moving target relative to a predefined direction and collinear with the plane of motion.

[0023] In another embodiment, the location module may comprise an inertial unit comprising a magnetometer.

[0024] There is further provided a method for imaging a moving target moving on a given plane of motion, implemented in an imaging device comprising an optical contact module, the optical contact module comprising a free end in contact with an area of ​​interest of the moving target, a captive end and a plurality of optical fibers connecting the two ends, and an optical processing module associated with an optical axis and an active area, the method comprises the steps of: - determine one or more movement parameters of the moving target; - determine, based on one or more movement parameters, control instructions intended for a motor provided in the device imaging so as to compensate for a twist experienced by the plurality of optical fibers, at least outside of acquisition time windows; - rotate the captive end around the optical axis by means of the motor, at least outside the acquisition time windows; - acquire, during the acquisition time windows, one or more optical images.

[0025] Advantageously, the step of determining control instructions can be implemented so as to block the pivoting of the captive end around the optical axis, during the acquisition time windows. Brief description of the figures

[0026] Other characteristics and advantages of the present invention will appear better on reading the description which follows in relation to the following appended drawings:

[0027] [Fig-1] represents a device for imaging moving targets, according to a mode of realization of the invention;

[0028] [Fig.2] represents an optical contact module, according to an embodiment of the invention;

[0029] [Fig.3-A]

[0030] and

[0031] [Fig.3-B] illustrate the pivoting of the captive end relative to the active zone, according to embodiments of the invention;

[0032] [Fig.4] represents a method of imaging moving targets, according to one embodiment of the invention. Detailed description

[0033] [Fig.l] represents an imaging device 100 of a moving target 200 moving on a given plane of movement, according to an embodiment of the invention.

[0034] The imaging device 100 may be used in neuroscience applications to study the nervous system of a subject. The subject may be any living being. For example, the imaging device 100 may be used to study the neural bases of behavior in a small animal (such as a mouse, for example), when the animal behaves freely, i.e. without being subjected to any external constraint likely to affect its behavior. The imaging device 100 according to the invention is advantageously compatible with various optical imaging techniques used in neuroscience, such as, for example and by way of non-limiting examples, photon / multi-photon fiber imaging, confocal microscopy, uniform or patterned optogenetic stimulation, etc. More generally, the imaging device 100, according to the embodiments of the invention, may be used to perform imaging of any moving target 200 whose behavior cannot be predicted and may include rotational movements.

[0035] The moving target 200 can move on a plane of movement provided with a measurement reference in which the instantaneous position of the moving target 200 can be defined by two coordinates according to the coordinate system used, the coordinate system being able to be the Cartesian coordinate system or the polar coordinate system, for example. The plane of movement can be fixed in the terrestrial reference frame and its orientation in such a reference frame can be known exactly beforehand. In general, the moving target 200 can move in a three-dimensional (3D) evolution space provided with a measurement reference in which the instantaneous position of the moving target 200 can be identified by three coordinates, the Cartesian, cylindrical or spherical coordinates being able to be used.

[0036] The moving target 200 can move freely on the plane of movement without being subjected to any external constraint likely to act on its behavior. Alternatively, the moving target 200 can be subjected to external constraints which may consist of modifying the characteristics of the environment in which the moving target 200 evolves. Such characteristics of the environment of the target may include, for example and by way of non-limiting example, physical obstacles, the intensity and orientation of the electromagnetic field, the level of brightness, and / or the chemical properties. In both embodiments with or without constraints, the movement of the moving target 200, as described by a trajectory and a speed of movement, cannot be predicted and may be random, that is to say that the trajectory traveled by the target 200 may be arbitrary and its speed of movement may vary over time.

[0037] The moving target 200 may be a laboratory mouse moving on a given plane of motion. In this case, the imaging device 100 of [Fig.l] may be configured to image an area of ​​interest of the mouse using a suitable optical imaging technique. For example, the area of ​​interest may be the cerebral cortex of the laboratory mouse and the optical imaging technique may be two-photon excitation imaging which exploits the process of fluorescence to image living tissue.

[0038] The imaging device 100 comprises a first unit 10 rigidly arranged on the moving target 200. The first unit 10 comprises a location module 12 configured to determine one or more movement parameters of the moving target 200 such as the instantaneous position of the moving target 200 in the plane of movement. Such movement parameters can make it possible to determine accurately and in real time the trajectory and the speed of movement of the target. mobile 200. The location module 12 may not be in direct contact with the mobile target 200.

[0039] The first unit 10 further comprises an optical contact module 11 comprising a plurality of optical fibers 110 and two ends: a first end, called free end 111 (EL), and a second end, called captive end 112 (EC), the two free and captive ends being connected via the plurality of optical fibers 110. Advantageously, the free end 111 can be rigidly fixed to an area of ​​interest of the moving target 200. In the example of a moving target 200 of the laboratory mouse type, the area of ​​interest can be the cerebral cortex of the mouse. The free end 111 of the optical contact module 11 can be configured to collect, by means of the optical fibers 110 used, optical signals, i.e. photons, generated spontaneously or stimulated in the area of ​​interest.Indeed, each of the optical fibers 110 forming the optical contact module 11 can have at its free end 111 an acceptor cone (numerical aperture) defining the light rays which will be guided, that is to say transmitted, through the optical fiber. In this case, the optical signals collected by the free end 111 of the optical contact module 11 are recovered at the captive end 112 after propagation through the optical fibers 110 used.

[0040] [Fig. 2] illustrates an example of an optical contact module 11. The optical fibers 110 forming the optical contact module 11 may be identical in terms of opto-geometric characteristics and their number may be chosen according to the resolution of the optical images to be acquired by the imaging device 100 and according to the surface of the area of ​​interest. The optical fibers 110 may be sufficiently long so as to allow the moving target 200 to move freely on the plane of movement. Furthermore, the ends of the optical fibers 110 may be distributed regularly at each of the two free and captive ends of the optical contact module 11 according to a first given planar geometric shape. The first planar geometric shape may be obtained by connecting the ends of the outer optical fibers 110 into one of the two ends of the optical contact module 11 and may be rectangular, circular or other.Furthermore, both the free and captive ends of the optical contact module 11 may be compact so as to maintain the distribution of the ends of the optical fibers 110 which must be the same in the free and captive ends of the optical contact module 11.

[0041] As shown in [Fig.l], the imaging device 100 further comprises a second unit 20 separate from the first unit 10, i.e. the second unit 20 is not arranged on the moving target 200 and may be fixed relative to the plane of movement on which the moving target 200 moves. The second unit 20 comprises an optical processing module 21 associated with an optical axis 211 and an active zone 212 having a second given planar geometric shape which may be different from the first planar geometric shape described above, the optical axis 211 being perpendicular to the active zone 212. The active zone 212 corresponds for example to the zone where the photographic sensors which represent the photosensitive elements are grouped. Advantageously, the optical processing module 21 can be arranged opposite the captive end 112 of the optical contact module 11 so as to optimize the optical coupling between the two elements.Optimization of the optical coupling can be achieved by making the optical axis 211 coincide with the center of the captive end 112 and arranging the active area 212 and the captive end 112 in parallel, which creates an overlap between the first and second planar geometric shapes while projecting the captive end 112 onto the active area 212. Such an adjustment can be performed only once before putting the imaging device 100 into operation.

[0042] In embodiments of the invention, the optical processing module 21 may be configured to acquire, during acquisition time windows, one or more optical images, each of the optical images being representative of the optical signals simultaneously acquired from the area of ​​interest and reaching the optical processing module 21 by means of the optical contact module 11. For example, each constituent element of the optical image, each pixel for example, may be obtained by detecting an optical signal reached by means of one of the optical fibers 110 forming the optical contact module.

[0043] In other embodiments of the invention, the optical processing module 21 may be configured to emit, during emission time windows, optical excitation signals towards the area of ​​interest by means of the optical contact module 11. For example, two optical excitation signals simultaneously emitted by the optical processing module 21 may have identical or different characteristics in terms of intensity, wavelength and polarization state.

[0044] Advantageously, the second unit 20 comprises a rotating module 22 to which the captive end 112 of the optical contact module 11 is fixed so as to allow rotation of the captive end 112 about the optical axis 211 of the optical processing module 21. The rotating module 22 may be configured to pivot about the optical axis 211 of the optical processing module 21 by means of a motor 26 provided in the imaging device 100. For example, the rotating module 22 may have the shape of a hollow cylinder having as its axis of revolution the optical axis 211 of the optical processing module 21. In this case, the optical fibers 110 may pass vertically through the interior of the rotating module 22, and the captive end 112 may be placed so as to block the rotating module 22. In addition, a A belt 23 and a transmission pulley 24 may be used to transmit rotational motion from the motor 26 to the rotating module 22. A pivot angle may be defined to quantify the rotation of the captive end 112 relative to the active area 212 of the optical processing module 21.

[0045] The second unit 20 further comprises a calculation module 25 configured to receive the movement parameters of the moving target 200 as determined by the location module 12 arranged on the moving target 200. Furthermore, the calculation module 25 is configured to determine, as a function of the movement parameters received, control instructions intended for the motor 26 acting on the rotation of the rotating module 22. Advantageously, the calculation module 25 can be configured to determine such control instructions so as to reduce the torsion undergone by the optical fibers 110 forming the optical contact module 11 and induced by the rotational movements of the moving target 200. It should be noted that the level of torsion undergone by the optical fibers 110 can be low or high.While a low level of twist does not impact the quality of the optical signals or the behavior of the moving target 200, a high level of twist impacts the behavior of the moving target 200 and degrades the quality of the optical signals and can damage the optical fibers 110. In embodiments of the invention, the calculation module 25 can be configured to compensate only for high levels of twist experienced by the optical fibers 110 used.

[0046] In embodiments of the invention, the calculation module 25 is configured to operate according to a first operating mode, in which control instructions intended for the motor 26 are determined so as to block, during each acquisition time window, the pivoting of the rotating module 22, that is to say to block the pivoting of the captive end 112, relative to the active zone 212 of the optical processing module 21. Advantageously, the pivoting can be blocked at an optimal pivoting angle between the captive end 112 and the active zone 212 which maximizes their overlap. Such embodiments are advantageous for short acquisition time windows, typically less than one second, during which the moving target 200 can remain stationary or its movement generates a low level of torsion without consequences on the quality of the optical signals and on the behavior of the moving target 200.Thus, the optical images acquired during the same acquisition time window are superimposable and can be interpreted without difficulty. Furthermore, outside the acquisition time windows, the calculation module 25 can be configured to determine control instructions intended for the motor 26 so as to compensate for the torsion undergone by the optical fibers 110.

[0047] Advantageously, the first operating mode implemented in relation to an acquisition of optical images can be adapted to emit, during emission time windows, optical excitation signals towards the area of ​​interest. In this case, during each of the emission time windows, the calculation module 25 can be configured to block the pivoting of the captive end 112 relative to the active area 212 of the optical processing module 21.

[0048] In other embodiments of the invention, the calculation module 25 is configured to operate according to a second operating mode, in which control instructions intended for the motor 26 are determined so as to compensate for the torsion undergone by the optical fibers 110 and induced by the rotational movements of the moving target 200, during and outside the acquisition time windows. In such embodiments, the second unit 20 may further comprise a backup module (not shown in [Fig.l]) configured to save, temporarily or permanently, each optical image acquired by the optical processing module 21 in association with the corresponding pivot angle between the captive end 112 and the active zone 212.Advantageously, digital processing can be implemented in real time or a posteriori by the backup module, for example, for each set of optical images acquired during the same acquisition time window, in order to rotate each optical image according to the corresponding pivot angle so as to align all the optical images according to the same pivot angle. This makes it possible in particular to simplify the interpretation of the information contained in the acquired optical images. Such embodiments are particularly advantageous for long acquisition time windows, typically greater than a few seconds, during which the moving target 200 can perform rotational movements.

[0049] Similarly, the second operating mode described in relation to an acquisition of optical images can be adapted to emit, during emission time windows, optical excitation signals towards the area of ​​interest. In this case, the calculation module 25 can be configured to determine control instructions intended for the motor 26 so as to compensate for the torsion undergone by the optical fibers 110 and induced by the rotational movements of the moving target 200, during and outside the emission time windows. The backup module can then be configured to save the pivot angle at which each plurality of excitation signals is simultaneously emitted.

[0050] In embodiments of the invention, the optical processing module 21 may be configured to perform the emission of excitation signals and the acquisition of optical images in a parallel manner in time. In such embodiments embodiment, the calculation module 25 is configured to determine an operating mode from among the first and second operating modes as a function of the duration of the acquisition and transmission time windows.

[0051] In other embodiments of the invention, the optical processing module 21 may be configured to perform the emission of excitation signals and the acquisition of optical images sequentially over time. The calculation module 25 is then configured to determine an operating mode for performing the acquisition of optical images or the emission of excitation signals according to the duration of the corresponding time window. In particular, the acquisition of optical images may be performed in an operating mode different from that of the emission of excitation signals.

[0052] As shown in [Fig. 1], the second unit 20 may further comprise a “slip ring” type relay module 27 configured to convey, in the form of electrical signals, via a wired connection (i.e. using very light electrical cables), the movement parameters determined by the location module 12 to the calculation module 25. The relay module 27 comprises a freely rotating element and a static element configured to reliably exchange electrical signals. In such an embodiment, the freely rotating element of the relay module 27 is connected to the location module 12 via a first plurality of electrical cables, and the static element of the relay module 27 is connected to the calculation module 25 via a second plurality of electrical cables.Such a configuration makes it possible to simply compensate for the torsion undergone by the first plurality of electrical cables and induced by the rotational movements of the moving target 200. Advantageously, the rotational movement of the freely rotating element of the relay module 27 can be carried out by the motor 26, via a belt 23 for example, in a similar manner to the rotational movement of the rotating module 22.

[0053] Alternatively, instead of using a relay module 27 and electrical cables, the routing of the movement parameters determined by the location module 12 to the calculation module 25 can be carried out via a wireless connection between the two modules. In such an alternative embodiment, the first unit 10 may further comprise a wireless transmission module configured to transmit, in the form of radio frequency signals, the movement parameters determined by the location module 12. The second unit 20 may further comprise a wireless reception module configured to receive and decode the radio frequency signals carrying the movement parameters. The wireless reception module may also be configured to transmit the received movement parameters to the calculation module 25. Such an embodiment presents the advantage of allowing the moving target 200 to move with less constraints, only optical fibers 110 connecting the moving target 200 to the second unit 20.

[0054] In embodiments of the invention, the location module 12 may be configured to determine and transmit, via a wired or wireless connection, the movement parameters periodically over time, for example every second. More generally, the time period may be determined based on the behavior of the moving target 200.

[0055] In other embodiments of the invention, the localization module 12 is further configured to compare the current motion parameters, associated with the current instant, with the previous motion parameters, associated with the previous instant, and to transmit the current motion parameters only when they are different from the previous motion parameters. Thus, the localization module 12 is configured not to transmit motion parameters when the moving target 200 is stationary over time, which makes it possible to reduce the computational load in the computation module 25.

[0056] In one embodiment of the invention, the location module 12 may comprise an inertial unit. Advantageously, the inertial unit may be of the microelectromechanical system (MEMS) type of reduced size, typically less than 1 cm3. Generally, an inertial unit is capable of determining movement parameters of a moving object relative to the starting point of the moving object. Such movement parameters include the instantaneous position, the speed of movement and the orientation (roll, pitch and heading angles). For a moving target 200 moving on a plane of movement or evolving in a 3D space, the location module 12 may be configured to determine and to transmit to the calculation module 25 at least the roll angle which governs the rotational movements of the moving target 200 and which induces twists in the optical fibers 110.Alternatively, the location module 12 can be configured to determine and transmit to the calculation module 25 at least the instantaneous position of the moving target 200.

[0057] In another embodiment of the invention, the location module 12 may further comprise a magnetometer integrated in the inertial unit and configured to determine the direction pointed by the moving target 200 in the terrestrial reference frame. The implementation of an inertial unit comprising a magnetometer in the location module 12 makes it possible to remedy the measurement errors accumulated in the inertial unit. Optionally, the location module 12 may be configured to transmit, according to regular or irregular transmission times in time, to the calculation module 25 movement parameters comprising at least one movement parameter determined by the inertial unit which may be the angle roll and / or instantaneous position, i.e. the motion parameter determined by the magnetometer may not be transmitted at every transmission instant.

[0058] Advantageously, the calculation module 25 can be configured to implement a data fusion algorithm which receives input parameters comprising: - movement parameters of the moving target 200 as provided by the location module 12; - mechanical and geometric parameters associated with the motor 26 and the rotating module 22; - time parameters such as reception and transmission time windows; - one operating mode from among the first and second operating modes described above.

[0059] Furthermore, the calculation module 25 can be configured to determine control instructions intended for the motor 26 as a function of one or more parameters among the input parameters.

[0060] Optionally, the second unit 20 may further comprise one or more fixing modules 28 configured to rigidly fix the other modules of the second unit 20.

[0061] Figures 3-A and 3-B illustrate the rotational movement of the captive end 112 relative to the active area 212 of the optical processing module 21, according to two embodiments of the invention. In relation to [Fig.3-A], the spacing between the captive end 112 and the active area 212 of the optical processing module 21 is optimized so that the circle 300 described by the rotation of the captive end 112 is completely included in the active area 212 of the optical processing module 21. Such an embodiment makes it possible, for example, to detect the optical signals coming from the captive end 112, and is particularly advantageous when the calculation module 25 operates according to the second operating mode described above.

[0062] With reference to [Fig. 3-B], the spacing between the captive end 112 and the active area 212 of the optical processing module 21 can be optimized by providing at least one optimal pivot angle maximizing the overlap between the captive end 112 and the active area 212 of the optical contact module 11. In the example of [Fig. 3-B] where the active area 212 and the captive end 112 have a rectangular shape, there are two optimal pivot angles (0 degrees and 180 degrees). This embodiment makes it possible to efficiently exploit the active area 212 of the optical processing module 21. Such an embodiment is particularly advantageous when the computing module 25 is configured to operate according to the first operating mode in which the pivoting of the captive end 112 is blocked during the acquisition or transmission time windows.

[0063] In one embodiment of the invention, the computing module 25 is configured to operate according to the first operating mode. In the presence of several optimal pivot angles allowing a maximum overlap between the captive end 112 and the active zone 212 of the optical processing module 21, the computing module 25 can be configured to choose an optimal pivot angle to perform the acquisition of optical images and / or the emission of excitation signals, this angle being chosen according to the current position of the captive end 112. For example, the optimal pivot angle chosen can be the angle closest to the current position of the captive end 112.

[0064] [Fig. 4] represents a method for imaging moving targets implemented by the imaging device 100 described in relation to [Fig. 1], according to one embodiment of the invention.

[0065] In step 401, one or more movement parameters of the moving target 200 are determined, using a location module 12 comprising, for example, an inertial unit integrating a magnetometer. Such movement parameters may comprise the instantaneous position of the moving target 200.

[0066] In step 402, control instructions for the motor 26 governing the pivoting of the captive end 112 relative to the active zone 212 of the optical processing module 21 are determined. Such control instructions may be determined as a function of several input parameters including the received movement parameters and mechanical and geometric parameters associated with the motor 26 and the rotating module 22 to which the captive end 112 is attached. More specifically, outside of the acquisition time windows, step 402 may comprise the determination of control instructions for the motor 26 so as to compensate for the torsion experienced by the optical fibers 110 and induced by the rotational movement of the moving target 200.

[0067] In step 403, the pivoting of the captive end 112 around the optical axis 211, i.e. relative to the active zone 212, of the optical processing module 21 is implemented, at least outside the acquisition time windows.

[0068] In step 404, one or more optical images are acquired by means of the optical processing module 21, during the acquisition time windows. Optionally, step 404 may comprise saving in a saving module each of the acquired optical images in association with the corresponding pivot angle between the captive end 112 and the active zone 212 of the optical processing module 21.

[0069] Advantageously, steps 401 to 404 can be repeated regularly or irregularly over time over an observation period which can range from a few seconds to several days.

[0070] In embodiments of the invention, step 402 described above may further consist, during acquisition time windows, in determining control instructions intended for the motor 26 so as to block the pivoting of the captive end 112 relative to the active zone 212 of the optical processing module 21, according to an optimal pivoting angle.

[0071] In other embodiments of the invention, step 402 may consist of determining control instructions intended for the motor 26 so as to compensate for the torsion undergone by the optical fibers 110, similarly during and outside the acquisition time windows.

[0072] Those skilled in the art will understand that the imaging method described above in relation to the acquisition of optical images can be used, in an identical manner, to emit, during emission time windows, optical excitation signals towards an area of ​​interest of the moving target 200.

[0073] The embodiments of the invention thus provide a device 100 for imaging moving targets making it possible to image an area of ​​interest of a moving target 200 while allowing the moving target 200 to move freely.

[0074] The invention is not limited to the embodiments described above by way of non-limiting example. It encompasses all the variant embodiments which may be envisaged by those skilled in the art.

Claims

1. Claims Imaging device (100) of a moving target (200) moving on a given plane of movement, characterized in that it comprises: - a first unit (10) arranged on said moving target (200), said first unit (10) comprising: • a location module (12) configured to determine one or more movement parameters of said moving target (200), said location module (12) comprising an inertial unit comprising a magnetometer; • an optical contact module (11) configured to emit and collect optical signals generated in an area of ​​interest of said moving target (200), said optical contact module (11) comprising a free end (111) in contact with said area of ​​interest, a captive end (112) having a first given planar geometric shape and a plurality of optical fibers (110) connecting the two ends (111, 112); - a second unit (20) fixed relative to said plane of movement on which the moving target 200 moves, said second unit (20) comprising: • an optical processing module (21) associated with an optical axis (211) and with an active zone (212) having a second given planar geometric shape, said optical processing module (21) being configured to process said collected optical signals and to acquire, during acquisition time windows, a plurality of optical images, each of said optical images being representative of a plurality of optical signals collected via said plurality of optical fibers (110) and simultaneously acquired from said zone of interest; • a rotating module (22) configured to pivot said captive end (112) around said optical axis (211) by means of a motor (26) provided in said imaging device (100); • a calculation module (25) configured to determine, as a function of said one or more movement parameters, control instructions intended for said motor (26) so as to compensate, at least outside of said acquisition time windows, the torsion undergone by said plurality of optical fibers (110) and induced by rotational movements of said moving target (200).

2. Imaging device (100) according to claim 1, characterized in that said calculation module (25) is configured to determine said control instructions so as to block the pivoting of said captive end (112) during said acquisition time windows, according to an optimal pivoting angle between said first and said second geometric shape.

3. Imaging device (100) according to claim 2, characterized in that said optimal pivot angle corresponds to a maximum overlap between said first and said second geometric shape.

4. An imaging device (100) according to any preceding claim, characterized in that said second unit (20) further comprises a backup module configured to backup each of said acquired optical images associated with a corresponding pivot angle between said first and said second geometric shape.

5. Imaging device (100) according to any one of the preceding claims, characterized in that said optical processing module (21) is further configured to emit, during emission time windows, a plurality of optical excitation signals towards said area of ​​interest.

6. An imaging device (100) according to any preceding claim, characterized in that said second unit (20) further comprises a relay module (27) comprising a rotary element and a static element, said relay module (27) being configured to receive, via a first connection wired connection connected to said rotating element, said one or more movement parameters from said localization module (12), and to transmit, via a second wired connection connected to said static element, said one or more movement parameters received to said calculation module (25).

7. An imaging device (100) according to any one of claims 1 to 5, characterized in that said first unit (10) further comprises a wireless transmission module configured to transmit said one or more motion parameters, and in that said second unit (20) further comprises a wireless reception module configured to receive said one or more motion parameters.

8. Imaging device (100) according to any one of the preceding claims, characterized in that said one or more movement parameters comprise an angle defining the orientation of said moving target (200) relative to a predefined direction and collinear with said plane of movement.

9. A method for imaging a moving target (200) moving on a given plane of motion, implemented in an imaging device (100) comprising a location module (12) and an optical contact module (11), said location module (12) comprising an inertial unit comprising a magnetometer, said optical contact module (11) comprising a free end (111) in contact with an area of ​​interest of said moving target (200), a captive end (112) and a plurality of optical fibers (110) connecting the two ends, and an optical processing module (21) associated with an optical axis (211) and an active area (212), the method comprising the steps of: - determining (401) one or more motion parameters of said moving target (200);• determine (402), as a function of said one or more movement parameters, control instructions intended for a motor (26) provided in said imaging device (100) so as to compensate for a torsion undergone by said plurality of optical fibers (110), at least outside of acquisition time windows; - rotating (403) said captive end (112) around said optical axis (211) by means of said motor (26), at least outside said acquisition time windows; - acquiring (404), during said acquisition time windows, one or more optical images.

10. Imaging method according to claim 9, characterized in that said step of determining (402) control instructions is implemented so as to block the pivoting of said captive end (112) around said optical axis (211), during said acquisition time windows.

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