DEVICE AND METHOD FOR ACQUIRING THE THREE-DIMENSIONAL GEOMETRIC SHAPE OF AN OBJECT

Abstract

TITLE OF THE INVENTION: DEVICE AND METHOD FOR ACQUIRING THE THREE-DIMENSIONAL GEOMETRIC SHAPE OF AN OBJECT. The device for acquiring and navigating and / or robotically targeting the geometric shape of an object (22) comprises: - a distance sensor (25) between the object and an acquisition unit, - a computer (12) for generating a three-dimensional geometric model of the object, - a navigation camera to determine the position and orientation of a first navigation reference fixed to the object, relative to the object resting on a mechanical reference; and - a computing unit to determine, during movements of the object captured by the navigation camera, the position and orientation of the mechanical reference and then the position and orientation of the object, and to position and orient the geometric model of the object in a virtual space in accordance with this position and orientation of the object. Figure for the abstract: Figure 2

Description

Title of the invention: DEVICE AND METHOD FOR ACQUIRING THE THREE-DIMENSIONAL GEOMETRIC SHAPE OF AN OBJECT Technical field of the invention

[0001] The present invention relates to a method for acquiring the three-dimensional geometric shape of an object and a device for acquiring and using the three-dimensional geometric shape of an object, particularly a surgical instrument and / or an implant, in a navigation system and / or a robotic aiming system. It is particularly applicable to the field of computer-assisted surgery and, more specifically, to the use of the geometric shape of a surgical instrument and / or an implant in a navigation system and / or a robotic aiming system. State of the art

[0002] The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section constitutes prior art simply because of its inclusion in this section.

[0003] During computer-assisted surgical procedures implementing a navigation system and / or a robotic aiming system, the surgical instruments and / or implants used are represented in real time on medical images by means of 3D models or their 2D cross-sectional representation.

[0004] Today, each robotic navigation and / or aiming system has its own set of instruments and implants. This forces medical facilities to adapt the range of instruments and / or implants associated with the navigation or aiming system they have chosen to use. This makes medical facilities dependent on the consumables from the manufacturers of these systems and increases the operating cost of these systems and, consequently, the cost of surgical procedures. Summary of the invention

[0005] The general concept of the invention consists of a device and a method for navigating, that is, virtually manipulating, any type of object within a captured image. This manipulation can be purely virtual, for example, by moving a digital model of the object within the captured image using a pointing device, such as a computer mouse. This virtual manipulation can also correspond to the movement of the object in the real world, movement captured by a camera and transmitted to the navigation software.

[0006] The captured image is, for example, an image of the patient's body based on medical images. The object may be a surgical instrument and / or an implant held by an instrument to be inserted into the patient's body.

[0007] To this end, a 3D acquisition device (for example, structured light, line laser, time-of-flight, or photogrammetry type) is used manually and / or robotically to create a three-dimensional geometric model of the instrument and / or implant to be navigated. This model is then used by a navigation system and / or a robotic aiming system to be displayed in real time on the medical images, thus allowing the surgeon to follow the evolution in space of the instrument and / or implant being manipulated in real time. Brief description of the figures

[0008] Other advantages, purposes and particular features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the device and method of the present invention, with reference to the accompanying drawings, in which: [Fig. 1] represents, schematically and in side view, a first particular embodiment of a modeling device, [Fig.2] schematically represents, in side view, a second particular embodiment of a modeling device, [Fig.3] schematically represents, in side view, a third particular embodiment of a modeling device, [Fig.4] schematically represents, in side view, a first particular embodiment of a calibration device, [Fig. 5] schematically represents, in side view, a second particular embodiment of a calibration device, [Fig. 6] schematically represents, in side view, a third particular embodiment of a calibration device, [Fig. 7] schematically represents three successive configurations of a surgical instrument or implant for acquiring its complete geometry, in the case of a geometry not exhibiting rotational symmetry and having at least one concavity, and [Fig.8] represents, in the form of a flowchart, the steps of a first particular embodiment of the process which is the subject of the invention. Description of the implementation methods

[0009] The present description is given by way of non-limiting grammar, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0010] It should be noted from the outset that the figures are not to scale.

[0011] As will be understood from the present description, various inventive concepts can be implemented by one or more of the methods or devices described below, several examples of which are provided herein. The actions or steps carried out in the implementation of the method or device can be ordered in any appropriate manner. Consequently, it is possible to construct embodiments in which the actions or steps are performed in a different order than that illustrated, which may include the simultaneous execution of certain acts, even if they are presented as sequential acts in the illustrated embodiments.

[0012] The indefinite articles "un" and "une", as used in the description, should be understood as meaning "at least one", unless clearly stated otherwise.

[0013] The expression "and / or", as used in this document, shall be understood as meaning "either or both" of the elements thus joined, that is, elements that are present conjunctively in some cases and disjunctively in others. Multiple elements listed with "and / or" shall be interpreted in the same way, that is, "one or more" of the elements thus joined. Other elements may also be present, other than those specifically identified by the "and / or" clause, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open language such as "including", may refer, in one embodiment, to A only (possibly including elements other than B); in another embodiment, to B only (possibly including elements other than A); in yet another embodiment, to A and B (possibly including other elements); etc.

[0014] As used herein in the description, "or" should be understood inclusively.

[0015] As used in this description, the expression "at least one," with reference to a list of one or more elements, should be understood as meaning at least one element chosen from among one or more elements in the list of elements, but not necessarily including at least one of each element specifically enumerated in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the expression "at least one" refers, whether or not they are related to those elements. specifically identified elements. Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, possibly including more than one, A, without B present (and possibly including elements other than B); in another embodiment, to at least one, possibly including more than one, B, without A present (and possibly including elements other than A); in yet another embodiment, to at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0016] In the description below, all transitive expressions such as "comprising", "including", "carrying", "having", "containing", "implying", "holding", "composed of", and others, should be understood as open, that is, as meaning including but not limited to. Only the transitive expressions "consisting of" and "consisting essentially of" should be understood as closed or semi-closed transitive expressions, respectively.

[0017] Throughout this description, the terms "upper" and "top" refer to what is at the top when the device of the present invention is in its operational configuration. The terms "lower" and "bottom" refer to what is at the bottom when the device of the present invention is in its operational configuration. The term "inside" refers to what is inside the device. The term "outside" refers to what is outside the device.

[0018] Throughout the description, a surgical instrument or surgical implant is called a "surgical object".

[0019] As briefly described above, the invention proposes to overcome the problems of the prior art by providing a device and a method enabling the use, by a surgical navigation system or a robotic aiming system, of a geometric model of any type of instrument and / or implant (the implants being held by instruments for insertion into the patient's body). To this end, at least one three-dimensional acquisition, for example, of the structured light, laser scanning, laser line projection, or time-of-flight type, is performed manually and / or robotically. Based on each acquisition, the three-dimensional geometric model is calculated and stored.This three-dimensional geometric model is then used by a navigation system and / or a robotic aiming system to be represented in real time on medical images, thus allowing the surgeon to follow in real time the evolution in space of the instrument and / or implant he is manipulating.

[0020] [Fig. 1] represents a first embodiment of a modeling device, i.e., a three-dimensional acquisition of points on the external surface of a surgical object 22.

[0021] The surgical instrument 12 is positioned on a support 14. In [Fig. 1], this support 14 is a table. Preferably, the support 14 allows the surgical instrument to be rotated around an axis and locked in a position. This type of support allows for multiple distance measurements of points on the instrument in different configurations, as shown opposite [Fig. 7]. A robot 11 includes a mobile trolley 15 equipped with wheels 16, and supporting an anthropomorphic robotic arm 17 having joints 18. The robotic arm 17 supports, at its free end, an acquisition unit 19 having a means for projecting 27 a laser line 21 formed on the object 22. It is noted that the laser line 21 can be obtained by implementing an optic placed in front of a laser source, having at least one cylindrical lens, or by scanning the line 21 with a moving linear laser beam.

[0022] The acquisition unit 19 is also equipped with a distance sensor 25 and a handle 24 with which an operator 23 can manipulate this acquisition unit 19. The laser line 21 is perpendicular to the direction of movement of the acquisition unit 19, this movement being, in [Fig.1], from left to right.

[0023] During this movement, the robotic arm operates in cooperative mode. This cooperative mode is implemented by means of at least one force sensor (not shown) located at the free end of the robotic arm 17, or directly in the joints 18 of the robotic arm 17, if it is an "active" arm. In this cooperative mode, the robotic arm 17 applies constraints to the movements of its end. For example, the only movements permitted, in cooperative mode, at the free end of the robotic arm 17 are in a plane roughly parallel to the upper surface of the support 14, or, preferably, along a straight line roughly parallel to a longitudinal axis of the support 14.

[0024] Alternatively, motors of the robotic arm 17 are actuated to make the acquisition unit 19 travel a path in relation to the surgical object 22. This path makes the laser line 21 travel over the entire surface of the surgical object 22 visible from the projection means 27. Alternatively, the surgical object is positioned on a conveyor belt which moves this object at a constant speed during the measurement of distances.

[0025] The distance sensor operates within a certain range of distances relative to the object to be modeled. This range of distances being known to the operator, the operator positions the distance sensor within this range of distances.

[0026] Alternatively, the acquisition unit 19 also includes a laser pointer 26. The laser pointer 26 provides a distance between the acquisition unit 19 and the surgical object 22. This laser pointer 26 thus constitutes a means of determining a geometric reference frame for the object within the field of view of the distance sensor 25. This distance between the acquisition unit 19 and the surgical instrument 22 is then adjusted automatically or manually by moving the acquisition unit 19. Typically, the adjusted distance is on the order of 10 to 40 centimeters for a surgical instrument.

[0027] It should be noted that the distance sensor 25 can also constitute a means of determining a geometric reference frame for the object within its field of view.

[0028] The distance sensor 25 comprises, for example, an image sensor 25 and a means of calculating the distances of the points of the object 22 illuminated by the laser line 21 projected by the projection means 27. This calculation is performed by triangulation, according to known techniques.

[0029] Alternatively, the three-dimensional acquisition of points on the surface of the surgical object 22 is of the structured light type or time-flight measurement type.

[0030] The second embodiment of the modeling device 20 shown in [Fig. 2] contains the same elements as the first embodiment. However, unlike the first embodiment, no robotic arm is used to follow the movement of the acquisition unit 19 in three dimensions.

[0031] A navigation camera 37 is carried by an articulated positioning arm 36, itself carried by a camera support trolley 35. To locate the acquisition unit 19 in space, at least one second navigation reference 34 is fixed to the acquisition unit 19.

[0032] A navigation reference is a set of at least four markers pre-mounted, in a fixed and predetermined manner, on a rigid support, itself fixed on the acquisition unit 19. An image of this second navigation reference 34, captured by the camera 37, thus makes it possible to locate the position (three coordinates in an orthonormal frame) and the orientation (three angular coordinates in this frame) of this second navigation reference 34 and, consequently, of the acquisition unit 19.

[0033] The optical field 39 of the camera 37 covers the different positions of the second navigation reference 34 during the movement of the acquisition unit 19.

[0034] Alternatively, so that the operator 23 does not have to hold the acquisition unit 19 at arm's length and so that the movement of the acquisition unit 19 is a translation parallel to the longitudinal axis of the support 14, a sliding support 28 is provided. This translation is preferably parallel to an axis of the support 14, for example, the axis of rotation of the support 14. For example, this support 28 has, in its upper part, two horizontal rails parallel to the longitudinal axis of the support 14 on either side of the object 22, rails on which the acquisition unit 19 slides or rolls on casters (not shown) in translation. This movement is imparted by the operator 23 and, possibly, braked at the level of the wheels so that the capture of points of the surface of interest is sufficiently dense.

[0035] In the third embodiment of the modeling device 40 shown in [Fig.3], this device includes a matrix camera 41 equipped with a lens 42 and a mat 44 supporting the surgical object 22. This surgical object is entirely within the optical field 43 of the camera 41.

[0036] The support mat 44 carries contrasting optical markers 45 on its upper surface facing the camera 41. These markers 45 are, for example, white or reflective circles or discs on a black background. These optical markers 45, arranged in positions known to image processing software, allow the dimensions of the surgical object 22 to be acquired. They can also be distributed non-uniformly. These markers 45 thus form visual references easily recognized by the image processing software for images acquired by the camera 41.

[0037] To create a model of the surgical object 22, it is placed on the mat 44 and an initial image acquisition is performed. The surgical object 22 is then rotated around its principal axis of inertia and a second image acquisition is performed, and so on, depending on the complexity of the surgical object 22, as described opposite [Fig. 7]. The images thus acquired are then processed by a computer 12 to generate a complete three-dimensional model of the surgical object 22, using a 3D pattern recognition modeling algorithm. The computer 12 can be located locally or remotely, for example, as a web server.

[0038] Once the three-dimensional model is generated by the computer 12, it is transferred into memory.

[0039] Once the three-dimensional model is defined by one of the modeling devices 10, 20 or 40 described above, it can be used in different ways during a surgical intervention.

[0040] In the case where the operating room is equipped only with a robotic aiming system, this system has means for registering medical imaging with respect to the coordinates of the robotic arm's reference frame. Typically, the arm is used in cooperative mode to position a mechanical pointer, whose coordinates are constantly known in the robotic arm's reference frame, on at least three characteristic points of the patient's body identified in the medical imaging. Other types of pointers, for example, laser beams located in the geometric reference frame of the robotic arm, can also be used. From the coordinates of these characteristic points in the geometric reference frame of the robotic arm, the geometric transformation is determined that maps the geometric coordinates in the medical imaging to the geometric coordinates in real space. A model of the surgical instrument can then be integrated into medical imaging during the movements of the robotic arm, provided that the position of this surgical instrument is located within the robotic arm's geometric reference frame. Conversely, medical imaging allows for the definition of a no-go zone for the robotic arm, including the surgical instrument, to prevent injury to the patient.

[0041] In the case where the operating room has a navigation system combining a camera and a display screen showing medical imaging.

[0042] To insert the model of the surgical object 22 into this image, the surgical object 22 is calibrated by attaching a first navigation reference 32 to it. During this calibration, the tip of the surgical object 22 is placed in a mechanical reference 31, for example a divot, of a calibration tool 38 with a geometry known to the navigation system. A third navigation reference 33 is attached to this calibration tool at a position known to the navigation system.

[0043] The navigation camera 37 then captures images containing: - the first navigation reference 32 mechanically fixed to the surgical object 22, and - the third navigation reference 33 mechanically fixed to the calibration tool 38, and The third navigation reference 33 allows a computing unit 13 to determine the position, in space, of the mechanical reference where the tip of the surgical object 22 is located. The first navigation reference 32 allows the computing unit 13 to determine the orientation of this tip relative to this first navigation reference 32 and the distance between this tip and this first navigation reference 32. The computing unit 13, which includes the calibration tool 38 and the navigation camera 37, thus performs the calibration of the object 22.

[0044] Two methods can be used to align the medical imaging reference frame with the operating room reference frame. In the first method, which does not involve a robot, the camera uses different positions of a mechanical pointer, to which a navigation reference is attached. These positions correspond to characteristic points on the patient's body identified in the medical imaging. Then, the transformation function from coordinates in real space to coordinates in the medical imaging is determined.

[0045] In the second method implementing a robot, the medical imaging registration means are used with respect to the coordinates of the robotic arm reference frame described above, by following, with the camera, the position of the pointer on which a navigation reference is fixed.

[0046] Next, the geometric model of the surgical object can be inserted into the patient's medical imaging, corresponding to the surgical object's position relative to the patient's body. The movements of this model follow those of the surgical object, via the camera which captures images from the second navigation reference and the coordinate transformation between real space and the space of the medical imaging.

[0047] During a surgical procedure, the surgeon only has to perform the calibration procedure of the instruments, using a calibration tool 38 carried manually (see [Fig.4]) or carried by the aiming robot (see [Fig.5]) or a mechanical reference directly integrated into the end of the aiming robot arm (see [Fig.6]), before starting the navigated surgery.

[0048] In its first embodiment illustrated in [Fig.4], the calibration device 50 comprises the navigation trolley already described opposite [Fig.2] and a computing unit 13, positioned locally or remotely.

[0049] The operator 23 carries the surgical object 22, on which the first navigation reference 32 is fixed in the optical field of the navigation camera 37, resting on a mechanical reference 31, for example a divot, of the calibration tool 38, itself fixed to the third navigation reference 33.

[0050] In its second embodiment illustrated in [Fig.5], the calibration device 60 comprises the navigation trolley already described opposite [Fig.2], the robot 11 described opposite [Fig.1] and the computing unit 13.

[0051] The operator 23 carries the surgical object 22, on which the first navigation reference 32 is fixed in the optical field of the navigation camera 37, in support of a mechanical reference 31, for example a divot, of the calibration tool 38, itself fixed to the third navigation reference 33 and carried by the robotic arm 7.

[0052] In its third embodiment illustrated in [Fig.6], the calibration device 70 comprises the navigation trolley already described opposite [Fig.2], the robot 11 described opposite [Fig.1] and the computing unit 13.

[0053] The operator 23 carries the surgical object 22, on which the first navigation reference 32 is fixed in the optical field of the navigation camera 37, resting on a mechanical reference 71, for example a divot, at the end of the robotic arm 17.

[0054] The computing unit 13 is thus configured, by software, to determine, in a calibration step, the position and orientation of the object 22 resting on the mechanical reference 31 or 71 relative to the navigation camera 37, based on at least one image of a first navigation reference 32 fixed to the object 22 and captured by the navigation camera 37. Then, during the preparation of the surgical operation and / or during the execution of the surgical operation, the computing unit 13: determines, during object movements captured by the navigation camera, the position and orientation of the mechanical reference and then the position and orientation of the object, and positions and orients the geometric model of the object in a virtual space with robotic navigation or targeting software in accordance with this position and orientation of the object.

[0055] Figure 7 illustrates the case where the surgical object 71 does not exhibit rotational symmetry, or even has a concavity 75. In this case, its modeling requires multiple three-dimensional coordinate acquisitions of points on its surface, viewed from different angles. Three successive positions 72, 73, and 74 of the surgical object 71 are shown in Figure 7, with the camera positioned above the object 71. Thus, its entire surface can be covered, and the points on its concave parts are also located in three dimensions to form a point cloud during each acquisition.

[0056] Once the three-dimensional model of the surgical object has been reconstructed on the basis of these point clouds, according to known techniques, this model is transferred into the memory of the navigation system and / or the robotic aiming system.

[0057] Preferably, during the installation of the navigation and / or aiming robotics system within the hospital facility, a three-dimensional model of all the instrument sets and / or implants used by the facility is created. All the data from the three-dimensional models is then transferred to a memory accessible by the navigation and / or aiming robotics system.

[0058] By way of example, the implementation of device 10 follows the following steps of process 80 illustrated in [Fig.8].

[0059] During step 81, the operator turns on the robotic unit.

[0060] During a step 82, the operator turns on the 3D acquisition unit.

[0061] During a distance capture step 83, the operator performs the acquisition 3D modeling of the object is performed using the cooperative mode of the robotic arm or by controlling the movement of the robotic arm, and by memorizing the position in the real space of the acquisition unit during each distance capture. It should be noted that step 83 is performed, possibly in several passes with different viewing angles of the surgical object, preferably rotated between two passes of the acquisition unit. As described opposite [Fig. 2], in some embodiments, during step 83 of distance capture, a second navigation reference 34 is fixed on the acquisition unit 19, the position of the acquisition unit being determined based on images of the second navigation reference fixed on the acquisition unit obtained by the navigation camera 37.

[0062] During a step 84, the three-dimensional geometric model of the object is constructed according to the distances captured, and stored.

[0063] During a step 85, the stored 3D model is transferred to the robotic navigation and / or aiming system.

[0064] During a step 86, the surgical object is equipped with a navigation reference.

[0065] During a step 87, the object is brought into contact with a mechanical reference, by example a divot, of a calibration tool.

[0066] During a step 88, the calibration of the surgical object is carried out within

[0067] the field of vision of the navigation camera.

[0068] Steps 86, 87, and 88 perform the calibration, during which the position and orientation of the object, supported by a mechanical reference, are determined relative to the navigation camera based on at least one image of a first navigation reference fixed to the object and captured by the navigation camera. As described opposite Figures 4 and 5, in some embodiments, during calibration steps 86, 87, and 88, a calibration tool carrying the mechanical reference and a third navigation reference is used. The object carrying the first navigation reference is positioned in contact with the mechanical reference. The positions and orientations of the calibration tool and then of the object are determined based on images of these first and third navigation references obtained by the navigation camera.

[0069] During a step 89, the operator performs a check of the correspondence of positions in real space and in the space of the medical imaging. For example, he positions the part of the tool that was previously positioned on the mechanical reference of the calibration tool on a characteristic point of the patient's body and he verifies that, on the medical imaging, the model of the surgical object is correctly positioned on the representation of this characteristic point.

[0070] If this verification is positive, the surgical object navigation procedure is carried out in step 90. During this step 90, the position and orientation of the mechanical reference, and then the position and orientation of the object, are determined during object movements captured by the navigation camera. During step 90, the geometric model of the object is also positioned and oriented in a virtual space using navigation or robotic aiming software, in accordance with this position and orientation of the object.

[0071] As can be understood from the preceding description, the implementation of the present invention offers numerous advantages: - It allows navigation of all types of instrumentation and / or implants, - It ensures cost savings for the hospital structure, - It allows the surgeon to choose the appropriate instrumentation for the intended procedure. Presentation of the invention

[0072] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0073] To this end, according to a first aspect, the present invention relates to a device for the acquisition and navigation and / or robotic targeting of the geometric shape of an object, which comprises: - an acquisition unit comprising a distance sensor between points on the object and this acquisition unit, - a computer configured to construct a three-dimensional geometric model of the object from the measured distances, - a navigation camera, - a mechanical reference, - a computing unit configured for to determine the position and orientation of the object supported by the mechanical reference relative to a navigation camera, based on at least one image of a first navigation reference fixed to the object and captured by the navigation camera; and determine, during object movements captured by the navigation camera, the position and orientation of the mechanical reference and then the position and orientation of the object, and position and orient the geometric model of the object in a virtual space with robotic navigation or targeting software in accordance with this position and orientation of the object.

[0074] Thus, any surgical instrument or any implant can give rise to a three-dimensional model which is then used by robotic navigation and / or targeting software.

[0075] In embodiments, the device includes a robotic arm to support the acquisition unit during the capture of distances between the points of the object and the acquisition unit.

[0076] The robot can thus be controlled to acquire the three-dimensional model of the surgical object.

[0077] In embodiments, the robotic arm is configured to operate in cooperative mode during the capture of distances between the points of the object and the acquisition unit.

[0078] The robot can thus be used in cooperative mode to acquire the three-dimensional model of the surgical object, under the control of an operator.

[0079] In embodiments, the distance sensor comprises a matrix camera equipped with a lens, the device further comprising a support for the object in the optical field of the camera, this support bearing contrasting optical markers on its surface oriented towards the camera.

[0080] This matrix camera makes it possible to capture all the points on the surface of the surgical object visible to the camera. By successively capturing several images so that the sum of these visible areas covers the entire surface of the surgical object, a three-dimensional modeling software with shape recognition defines the three-dimensional model of the surgical object.

[0081] In embodiments, the device includes a second navigation reference fixed on the acquisition unit, the position of the acquisition unit being determined based on images of the second navigation reference fixed on the acquisition unit obtained by the navigation camera.

[0082] Thanks to the navigation camera and the navigation reference, the position of the acquisition unit can be determined, as well as its movements between two image captures.

[0083] In some embodiments, the calibration means comprises a calibration tool carrying the mechanical reference and a third navigation reference, and the object carrying the first navigation reference is positioned in contact with the mechanical reference. The computing unit is configured to determine the positions and orientations of the calibration tool and then of the object based on images of these first and third navigation references obtained by the navigation camera. In other embodiments, the mechanical reference is carried by a robotic arm, and the calibration of the object is performed based on the position of the mechanical reference carried by the robotic arm, as located by this robotic arm.

[0084] Thanks to each of these arrangements, the respective position of the navigation reference and the surgical object can be determined, which makes it possible to position the three-dimensional model of the surgical object in medical imaging in correspondence with the real position of this object in real space, regardless of the movements of this object.

[0085] According to a second aspect, the present invention relates to a method for acquiring and navigating the geometric shape of an object, which comprises: - a step of capturing distances between points on the object and an acquisition unit, - a step involving the construction of a three-dimensional geometric model of the object based on the measured distances, and - a calibration step, during which the position and orientation of the object, supported by a mechanical reference, are determined relative to a camera navigation based on at least one image of a first navigation reference fixed on the object, captured by the navigation camera, - a determination step, during object movements captured by the navigation camera, of the position and orientation of the mechanical reference and then of the position and orientation of the object and - a positioning and orientation step of the geometric model of the object in a virtual space with navigation or robotic aiming software in accordance with this position and orientation of the object.

[0086] In embodiments, during the distance capture step, a second navigation reference is fixed on the acquisition unit, the position of the acquisition unit being determined based on images of the second navigation reference fixed on the acquisition unit obtained by the navigation camera.

[0087] In embodiments, during the calibration step, a calibration tool carrying the mechanical reference and a third navigation reference is implemented, the object carrying the first navigation reference being positioned in contact with the mechanical reference, the determination of the positions and orientations of the calibration tool and then of the object being carried out according to images of these first and third navigation references obtained by the navigation camera.

[0088] The advantages, purposes and particular characteristics of this process being similar to those of the process which is the subject of the invention, they are not recalled here.

Claims

Demands

1. Device (10, 20, 50, 60, 70) for acquiring and navigating and / or robotically targeting the geometric shape of an object (22), characterized in that it comprises: - an acquisition unit (19) comprising a distance sensor (25) between points of the object and this acquisition unit, - a computer (12) configured to construct a three-dimensional geometric model of the object from the distances captured, - a navigation camera (37), - a mechanical reference (31,71), - a computing unit (13) configured to determine a position and orientation of the object resting on the mechanical reference relative to a navigation camera as a function of at least one image of a first navigation reference (32) fixed on the object captured by the navigation camera;and determine, during object movements captured by the navigation camera, the position and orientation of the mechanical reference and then the position and orientation of the object, and position and orient the geometric model of the object in a virtual space with navigation or robotic aiming software in accordance with this position and orientation of the object.

2. Device (10) according to claim 1, which includes a robotic arm (17) for supporting the acquisition unit (19) during the capture of distances between the points of the object (22) and the acquisition unit.

3. Device (10) according to claim 2, wherein the robotic arm (17) is configured to operate in cooperative mode during the capture of distances between the points of the object (22) and the acquisition unit (19).

4. Device (10, 20) according to any one of claims 1 to 3, wherein the distance sensor (25) comprises a matrix camera (41) equipped with a lens (42), the device further comprising a support (44) for the object (22) in the optical field (43) of the camera, this support having contrasting optical markers (45) on its surface oriented towards the camera.

5. Device (20) according to any one of claims 1 to 4, which includes a second navigation reference (34) fixed on the acquisition unit (19), the position of the acquisition unit being determined as a function of images of the second navigation reference fixed on the acquisition unit obtained by the navigation camera (37).

6. Device (50, 60, 70) according to any one of claims 1 to 5, wherein the calibration means comprises a calibration tool (38) carrying the mechanical reference (31) and a third navigation reference (33) and the object (22) carrying the first navigation reference (32) is positioned in contact with the mechanical reference, the computing unit (13) being configured to determine the positions and orientations of the calibration tool and then of the object as a function of images of these first and third navigation references obtained by the navigation camera (37).

7. Device (60) according to any one of claims 1 to 5, wherein the mechanical reference (31) is carried by a robotic arm (17), the calibration of the object (22) being carried out according to the position of the mechanical reference carried by the robotic arm, located by this robotic arm.

8. A method (80) for acquiring and navigating the geometric shape of an object (22), characterized in that it comprises: - a step (83) of capturing distances between points of the object and an acquisition unit, - a step (84) of constructing a three-dimensional geometric model of the object from the captured distances, and - a calibration step (86, 87, 88), during which the position and orientation of the object, supported by a mechanical reference relative to a navigation camera, are determined as a function of at least one image of a first navigation reference fixed on the object and captured by the navigation camera, - a step (90) of determining, during movements of the object captured by the navigation camera,of the position and orientation of the mechanical reference, then of the position and orientation of the object, and - a step (90) of positioning and orienting the geometric model of the object in a virtual space with robotic navigation or targeting software in accordance with this position and orientation of the object.

9. Method (80) according to claim 8, wherein, during the distance capture step (83), a second navigation reference (34) is fixed on the acquisition unit (19), the position of the acquisition unit being determined as a function of images of the second navigation reference fixed on the acquisition unit obtained by the navigation camera (37).

10. Method (80) according to any one of claims 8 or 9, during the calibration step (86, 87, 88), a calibration tool (38) carrying the mechanical reference (31) and a third navigation reference (33) is implemented, the object (22) carrying the first navigation reference (32) being positioned in contact with the mechanical reference, the determination of the positions and orientations of the calibration tool and then of the object being carried out as a function of images of these first and third navigation references obtained by the navigation camera (37).

Images