Robots equipped with ultrasound probes for real-time guidance of percutaneous intervention treatments

Abstract

A medical robot (10) comprising a robotic arm (13) equipped with a tool guide (14) for guiding a medical instrument (15) along a trajectory determined from an entry point at the patient's skin and a target point of a lesion to be treated in a target anatomical structure of the patient. The robotic arm is also equipped with an ultrasound probe (40). The medical robot cooperates with a navigation system (30) for determining the position of a robot marker (18) and the position of a patient marker (22). During a preparation phase, the robot is configured to bring the ultrasound probe (40) in contact with the patient (20) and to be placed in a plane containing the lesion and the trajectory to be followed. During a guidance phase, the medical robot is configured to control the robotic arm in real time according to ultrasound images acquired by the ultrasound probe to guide the medical instrument along the trajectory to be followed.

Description

Technical Field

[0001] The methods and apparatus disclosed in this application belong to the field of robotic devices for assisting practitioners during minimally invasive medical interventions, including the insertion of one or more medical devices into a patient's target anatomical structure. Specifically, this application relates to a medical robot configured to track the movement of a target point within a lesion of a patient's target anatomical structure and to adjust the position of the robot's articulated arms in real time to optimally guide the medical device to the target point. Specifically, the movement of the target point may be generated by the patient's breathing or the insertion of the medical device. Background Technology

[0002] In preparation for minimally invasive interventions that use medical devices to reach target anatomical regions within a patient's target anatomical structure, practitioners typically plan the intervention based on preoperative medical images (obtained days or weeks prior to the intervention) or pre-interventional medical images (obtained before the intervention while the patient is on the intervention table). Specifically, minimally invasive medical interventions may aim to perform biopsies or ablation of tumors in organs, vertebroplasty or bone cementation, or even stimulate specific anatomical regions. The target anatomical structure may be, for example, the lung, kidney, liver, brain, tibia, knee, vertebrae, etc. The medical device may be a needle, probe, catheter, etc.

[0003] In this planning step, the practitioner defines a target point within the anatomical region to be treated. The practitioner also defines the entry point for the medical device on the patient's skin. These two points then define the trajectory the medical device must follow to perform the medical intervention. In the specific case of soft organs located in the chest, abdomen, or pelvic regions, respiratory-related movements and / or local organ deformation due to device insertion can cause displacement of the target point during intervention. Preoperative or pre-intervention medical planning images cannot predict this displacement of the target point during intervention. Therefore, the location of the target point (i.e., the location of the region to be treated within the target anatomy) is often different during medical planning image acquisition and during intervention. Consequently, when planning device insertion based on medical planning images, there is a risk that the device may not accurately reach the target point.

[0004] Furthermore, if the planned trajectory that the medical device is to follow is not adjusted accordingly, there is a risk that the medical device may bend during insertion and fail to reach the target point.

[0005] To limit the movement of the target point caused by the patient's breathing, it is conceivable that, upon insertion of the medical device, the patient's breathing is blocked at the respiratory cycle phase corresponding to the acquisition of the medical planning image. If the medical intervention is performed under local anesthesia, the patient may voluntarily block their breathing, or if the medical intervention is performed under general anesthesia (mechanical ventilation interrupted), the practitioner will block breathing in a controlled manner. However, this solution is not always very accurate, as it is difficult to achieve a precise correspondence between the respiratory cycle phase at the time of acquiring the medical planning image and the respiratory cycle phase at the time of respiratory obstruction during the intervention. Furthermore, this solution presupposes relatively rapid insertion of the medical device, as this must be done while the patient's breathing is obstructed.

[0006] It is also conceivable to capture medical planning images during the patient's respiratory cycle and determine the trajectory least affected by deformation and movement of the target anatomy caused by respiration. However, there is still a risk that the medical device may not accurately reach the target point.

[0007] Another approach is to track the location of the target point throughout the intervention by periodically acquiring intra-interventional medical images (images taken when medical devices are inserted into the patient). These medical images are typically obtained via computed tomography (CT), X-ray, or magnetic resonance imaging (MRI). However, in the case of CT or X-ray, this solution has the disadvantage of significant radiation exposure to both the patient and the practitioner during the intervention. In the case of MRI, it is necessary to use specific non-magnetic materials, particularly anesthetic materials, which is especially limiting. This solution also requires the use of bulky imaging equipment throughout the intervention.

[0008] It is also known to use ultrasound imaging to track the location of lesions within target anatomical structures. However, lesions are not always visible on ultrasound images, and existing solutions often lack accuracy.

[0009] Therefore, a solution is still needed, particularly during intervention, to accurately insert the medical device into the target point within the patient's target anatomical structure in the area to be treated when the target point is displaced due to respiratory-related movements and / or local deformation of the target anatomical structure caused by the insertion of the medical device. Summary of the Invention

[0010] The purpose of the methods and apparatus disclosed in this application is to overcome all or some of the shortcomings of the prior art, especially those listed above.

[0011] Therefore, and specifically according to the first aspect, a medical robot is proposed for assisting practitioners in treating lesions in target anatomical structures of patients during medical interventions. The medical robot includes a robotic arm, one end of which is attached to an ultrasound probe and a tool guide for guiding medical instruments. The robot also includes a control unit configured to control the robotic arm. The medical robot is configured to cooperate with a navigation system. The control unit is configured to determine, at any time, the positions of robotic markers intended for positioning on the medical robot and patient markers intended for positioning near target anatomical structures on the patient, based on information transmitted by the navigation system. During the preparation phase, the control unit is configured to:

[0012] -Receives at least one radiopaque element on which a planned image of the lesion and patient markers can be seen.

[0013] - The target point located at the lesion and the entry point located on the patient's skin are determined from the planning image, and the target point and the entry point thus define the trajectory to be followed by the medical device.

[0014] - Control the robotic arm according to the position of the robot marker and the position of the patient marker, so that the ultrasound probe contacts the patient and is placed in a plane containing the lesion and the trajectory to be followed.

[0015] During the guidance phase, the control unit is configured to receive ultrasound images acquired by the ultrasound probe in real time and control the robotic arm in real time based on these ultrasound images to position the tool guide to guide the medical device along the trajectory to be followed.

[0016] In this application, the term "position" must be understood broadly to describe the location and orientation of an object in a three-dimensional reference frame (the term "pose" is sometimes used in English literature). The position of markers (patient markers and robot markers), as well as the position of the target point and the position of the entry point, can be defined in either the robot's reference frame or the navigation system's reference frame. It should be noted that the robot's reference frame can be defined relative to the navigation system's reference frame because the position of the robot markers is known in both the navigation system's and the robot's reference frames (each joint of the robotic arm includes, for example, an encoder, which makes it possible to know the position of the individual articulated elements of the robotic arm in the robot's reference frame, and the control unit has prior knowledge of the position of the robot markers on the robot).

[0017] For example, a planning image is a pre-interventional medical image acquired while the patient is on the intervention table, with the patient marker located near the patient's target anatomical structures. The planning image can also be a pre-operative medical image acquired days or weeks prior to the intervention and registered with the pre-interventional image. The planning image is, for example, a medical image obtained by computed tomography, positron emission tomography, or magnetic resonance imaging. The location of the patient marker in the planning image can be determined using radiopaque markers of the patient markers visible on the planning image.

[0018] The target point and the entry point can be determined on the planning image using a segmentation artificial intelligence algorithm. In another instance, the target point and the entry point can be determined on the planning image by a practitioner.

[0019] Subsequently, during the guidance phase, the target point and the entry point, initially defined by the practitioner on the planning image, can be tracked on the ultrasound images obtained through the ultrasound probe (e.g., via a speckle deformation tracking algorithm). (Speckle represents a set of rapidly fluctuating small spots that appear in the instantaneous texture of the image and give the image a grainy appearance.)

[0020] Therefore, the positions of the target point and the entry point can be tracked in real time based on ultrasound images. The robotic arm can then be moved in real time, continuously positioning itself to guide the medical device along a trajectory defined by the positions of the target point and the entry point. This real-time adjustment of the robotic arm's position allows for compensation for movement of the target point caused by the patient's breathing. This real-time monitoring can be performed, in particular, during the guidance phase of the tool guide, just before the insertion of the medical device.

[0021] This arrangement allows the patient's breathing to be blocked at any point in the respiratory cycle to continue the insertion of medical devices. In fact, regardless of the moment the patient's breathing is blocked, the robotic arm will be correctly positioned to allow the medical device to be inserted along the desired trajectory.

[0022] Furthermore, there is no longer a need to obstruct the patient's airway during the intervention. In fact, the robotic arm moves in real time, allowing its position to be continuously adjusted to guide the medical device along the desired trajectory.

[0023] This application also enables the minimization of lateral recalibration of the trajectory after the insertion of a medical device (which is typically invasive for organs through which the medical device passes).

[0024] Therefore, regardless of the timing of insertion during the respiratory cycle, the medical device can be inserted very precisely into the area to be treated. Insertion of medical devices is typically performed by a practitioner, and the purpose of the medical robot is to guide the practitioner in inserting the device. However, nothing prevents the insertion of medical devices from being automated and controlled through a control unit.

[0025] Furthermore, since the real-time determination of the location of the target point and the entry point during the intervention is performed based on ultrasound images, patients and practitioners are not exposed to ionizing radiation during the intervention.

[0026] Once the medical device is inserted into the patient, the entry point on the patient's skin is fixed and becomes the rotational pivot for the robotic arm's movement. However, the positions of the target point and the entry point can still be tracked in real time based on new ultrasound images acquired during the insertion of the medical device.

[0027] This arrangement allows for consideration of any movement of the target point caused by the insertion of the medical device. In fact, the target point can move along the trajectory it follows during insertion (especially when the target point is a lesion within a soft organ, such as a tumor). Real-time determination of the target point's position using ultrasound imaging allows for real-time updates to the trajectory the medical device must follow and the position of the robotic arm, enabling the device to be guided along that trajectory.

[0028] In specific implementations, this application may further include one or more of the following features, either individually or in combination of all technically possible features.

[0029] In a specific implementation, for each received ultrasound image, during the guidance phase, the control unit is configured to:

[0030] - Generate a fused image obtained from the registration of the ultrasound image and the planned image.

[0031] - Determine the position of the target point and the position of the entry point based on the fused image.

[0032] - Move the robotic arm such that the tool guide is guided along a trajectory defined by the position of the target point and the position of the entry point to the medical device.

[0033] The registration of the ultrasound image with the planning image produces the fused image on which lesions can be seen. The target point and entry point initially determined on the planning image can then also be identified on the fused image.

[0034] In a specific implementation, during the guidance phase, during the insertion of the medical device, and for each new ultrasound image received, the control unit is configured to determine the position of the medical device and adjust real-time control of the robotic arm based on the position of the medical device.

[0035] This arrangement allows the ultrasound probe to remain in contact with the patient's body with sufficient pressure during the patient's respiratory movements.

[0036] In a specific implementation, the ultrasound probe is coupled to a force sensor, which enables the control unit to determine the pressure applied to the patient's body by the ultrasound probe. The control unit is further configured to move the robotic arm such that the ultrasound probe applies a predetermined pressure to the patient's body.

[0037] This arrangement allows for consideration of the risk of the medical device bending during insertion, and corresponding adjustments to the real-time control of the robotic arm (the trajectory the medical device must follow is no longer a straight line between the entry point and the target point).

[0038] In a specific implementation, the planned image is a computed tomography (CT) image, a positron emission tomography (PET) image, or a magnetic resonance imaging (MRI) image.

[0039] In a specific implementation, in order to determine the target point and the entry point based on the planning image, the control unit is configured to use an artificial intelligence algorithm to segment lesions and / or anatomical regions to be avoided on the planning image.

[0040] In a specific implementation, the ultrasound image received from the ultrasound probe is a B-mode ultrasound image.

[0041] In a specific implementation, the control unit is configured to receive and process ultrasound images acquired by the ultrasound probe at a rate of at least 15 images per second.

[0042] This arrangement enables real-time monitoring of the target point's position, and thus real-time adjustment of the robotic arm's position, guiding the medical device along the desired trajectory throughout the intervention process.

[0043] In a specific implementation, the medical robot further includes a user interface, which includes a display screen that allows the practitioner to view the planning image and / or the fused image.

[0044] In a specific implementation, the user interface includes an input device that enables the practitioner to identify target points and / or entry points and / or anatomical areas that the medical device will not cross on the planning image displayed on the screen during the preparation phase.

[0045] In a specific implementation, the user interface includes an augmented reality device for overlaying analytical images and actual images of the patient's body onto the display screen.

[0046] Augmented reality (AR) devices can overlay moving, three-dimensional lesions, along with the progress of medical device insertion, onto a patient's body. These AR devices can be, for example, screens on an intervention table above the patient, or masks, helmets, or AR glasses. This type of display facilitates spatial representation of the patient's target anatomy by practitioners.

[0047] In a specific implementation, the control unit is further configured to compare the ultrasound image with the planned image and determine the direction of moving the ultrasound probe such that the ultrasound image acquired by the ultrasound probe includes the anatomical region where the lesion is located. Attached Figure Description

[0048] This application can be better understood by reading the following description, which is given by way of non-limiting examples and references. Figure 1-6 In progress, including:

[0049] Figure 1 This is a schematic diagram of a medical device including the medical robot and navigation system according to this application.

[0050] Figure 2 This is a schematic diagram of the robotic arm of a medical robot.

[0051] Figure 3 This is a schematic diagram of a "robotic marker" designed to be attached to a medical robot.

[0052] Figure 4 This is a schematic diagram of "patient markers" designed to be located near target anatomical structures on a patient.

[0053] Figure 5 This is a schematic diagram illustrating the steps implemented by the control unit during the preparation and real-time guidance phases of the robotic arm.

[0054] Figure 6 This is a schematic diagram of the planning image (part a), the ultrasound image (part b), and the fused image generated by the registration of the planning image and the ultrasound image (part c).

[0055] In these figures, the same reference numerals from one figure to another denote the same or similar elements. For clarity, unless otherwise stated, the elements represented are not necessarily at the same scale. Detailed Implementation

[0056] Figure 1 A medical robot 10 according to this application is schematically illustrated. The medical robot 10 is used to assist a practitioner during a medical intervention on a target anatomical structure of a patient 20 located on an intervention table 21.

[0057] One example is a minimally invasive or percutaneous medical intervention performed to treat lesions within a patient's target anatomical structure. This type of intervention typically requires the practitioner to insert one or more medical devices (such as needles, probes, catheters, etc.) into the patient at a certain depth to reach the target anatomical region (lesion, such as a tumor) within the target anatomical structure (such as the liver, lungs, kidneys, etc.).

[0058] The medical robot 10 includes a base 11. In the considered example, the base 11 of the medical robot 10 is equipped with movable wheels, which allow the medical robot 10 to move in different directions by translational and / or rotational movements.

[0059] The medical robot 10 also includes an articulated robotic arm 13, one end of which is connected to the base 11. Attached to the other end of the robotic arm 13 are an ultrasound probe 40 and a tool guide 14, which is used to guide medical devices 15, such as needles, probes, catheters, electrodes, etc.

[0060] exist Figure 1 In the example shown, the ultrasound probe 40 is attached to the robotic arm 13 via an additional arm 16. The additional arm 16 is articulated to allow the ultrasound probe 40 to have at least one additional degree of freedom relative to the tool guide 14.

[0061] The medical robot 10 includes a control unit 12 configured to control the movement of the robotic arm 13. In this application, control of the robotic arm 13 is considered to also include control of the auxiliary arm 16. The control unit 12 includes one or more processors 122 and a memory 121 (magnetic hard disk, electronic memory, optical disk, etc.), in which a computer program product is stored as a set of program code instructions to be executed to implement the various steps of the method for positioning the robotic arm 13. The memory 121 may also record images and other information (particularly navigation information) used to implement the method.

[0062] The medical robot 10 can then be used to assist practitioners in positioning, holding, and guiding the medical device 15 during medical interventions. In one variant, the insertion of the medical device 15 can be fully automated and controlled by the control unit 12 of the medical robot 10. Furthermore, the medical robot 10 is used for automatically positioning the ultrasound probe 40.

[0063] The medical robot 10 may also include a user interface 19, which includes a display screen that allows the practitioner to view medical images (e.g., planning images and / or ultrasound images acquired by the ultrasound probe 40 and fused with the planning images). The user interface may also include input devices (keyboard, mouse, touch screen, etc.) that allow the practitioner to identify target points and / or entry points and / or anatomical areas that the medical device 15 will not pass through on the planning images displayed on the screen.

[0064] In a specific implementation, the user interface may include an augmented reality device for overlaying the fused image with an actual image of the patient's body onto the display screen. This device facilitates the spatial representation of the target anatomical structure by the practitioner.

[0065] The medical robot 10 is configured to cooperate with a navigation system 30. The medical robot 10 includes a communication module connected to the control unit 12 for exchanging data with the navigation system 30. The navigation system 30 also includes a communication module for exchanging data with the control unit 12 of the medical robot 10. The communication established between the control unit 12 and the navigation system 30 can be wired or wireless. For simplicity, Figure 1 The communication module is not shown in the image.

[0066] In the considered example, the navigation system 30 is an optical navigation system. The navigation system 30 includes two optical sensors 31, corresponding to the two sensors of a stereo camera operating in the infrared radiation range. In the considered example, the navigation system 30 also includes a camera 32 operating in the visible light range.

[0067] The control unit 12 is configured to determine, at any time, the position of the robot marker 18 to be attached to the medical robot 10 and the position of the patient marker 22 to be positioned near the target anatomical structure on the patient 20, based on information transmitted by the navigation system 30.

[0068] In this application, the term "position" corresponds to the combination of an object's position and orientation in a given reference frame, typically a three-dimensional coordinate system. The term "pose" is used in English literature to describe the combination of an object's position and orientation in space.

[0069] The control unit 12 is configured to receive ultrasound images acquired by the ultrasound probe 40.

[0070] The ultrasound images received from the ultrasound probe 40 and the information received from the navigation system 30 are synchronized in a timely manner by the control unit 12 so that the location of the lesion can be associated with the location of the patient marker 22 at a given time.

[0071] Conventionally, the ultrasound probe 40 includes one or more acoustic wave transmitter-receiver elements (piezoelectric material, capacitive electronic transducer). The ultrasound probe generates ultrasound waves through the indirect piezoelectric effect. Each time a wave encounters an anatomical structure, a portion of the wave returns as an echo via reflection or scattering (“speck”). This echo is converted into an electric current through the direct piezoelectric effect and then reconstructed into an image. The reconstruction of the ultrasound image depends primarily on the number, size, and position of the transmitter-receiver elements of the probe (lateral and longitudinal resolution), the duration of the emitted pulse, and the echo time (axial and / or depth resolution). The energy of the received echo is then encoded into gray levels. The higher the energy, the whiter the corresponding image portion (pixel). This gray-level encoding is called “luminance,” and the associated ultrasound mode is called “B-mode.” The images generated by the ultrasound probe 40 can be two-dimensional or three-dimensional images. Preferably, the ultrasound probe 40 is capable of generating images at a rate of at least 15 images per second.

[0072] When the target anatomical structure is the liver, B-mode is particularly suitable. However, it should be noted that the present invention can also be applied to other ultrasound modalities, such as elastography.

[0073] In the examples considered, such as Figure 2 As shown, the robotic arm 13 includes six rotary joints 131-136 that provide six degrees of freedom, allowing the medical device 15 to be positioned anywhere in three-dimensional space. Advantageously, the joints 131-135 of the robotic arm 13 are misaligned and offset relative to each other, which allows for a wider range of possible configurations for the robotic arm 13. The rotary joints 136 correspond to rotation about an axis parallel to the main axis of the tool guide 14.

[0074] In the considered example, the ultrasound probe 40 is attached to the robotic arm 13 via an additional arm 16 comprising two rotary joints 137 and 138, thereby providing two additional degrees of freedom for the movement of the ultrasound probe 40 relative to the tool guide 14. However, it should be noted that the opposite is also possible: the ultrasound probe 40 can be directly attached to the distal end of the robotic arm 13, and the additional arm can carry the tool guide 14. The tool guide 14 and the additional arm 16 are attached to the end of the robotic arm 13 via a clamp. In the considered example and... Figure 2 In the example shown, the ultrasound probe 40 is also connected to a force sensor 17, enabling the control unit 12 to determine the force exerted on the ultrasound probe 40 by the patient's body 20.

[0075] The additional arm 16 and the tool guide 14 are arranged relative to each other in such a way that the medical device 15 is always in the plane of the ultrasound image acquired by the ultrasound probe 40.

[0076] Each joint 131-138 includes at least one encoder, enabling real-time knowledge of its angular position. The configuration of the robotic arm 13 then corresponds to a set of parameter values ​​(e.g., the rotation angle of each joint) taken by the joints 131-138.

[0077] Figure 3 The robotic marker 18, intended for positioning on the medical robot 10, is schematically illustrated. In the considered example, the robotic marker 10 comprises three optical markers 181, such that the position of the robotic marker 18 can be determined in three spatial dimensions of the reference frame of the navigation system 30. The respective positions of the optical markers 181 of the robotic marker 18 relative to each other are known a priori by the navigation system 30 and / or by the control unit 12. Advantageously, the geometry of each optical marker 181 can also be known a priori. Figure 3 In the example shown, the optical marker 181 is spherical. The spherical shape allows for optimized reflection of optical radiation.

[0078] The use of at least three optical markers 181 allows a plane to be defined, and thus a directly orthogonal three-dimensional reference frame with a z-axis perpendicular to that plane and x and y axes in that plane, such that the reference frame is direct. Therefore, it allows the position and orientation of the reference frame formed by the optical markers 181 to be determined. The three axes x, y, and z allow six degrees of freedom to be defined, namely translation along each x, y, or z axis and rotation about each axis.

[0079] The optical marker 181 can be passive or active. A passive optical marker reflects optical radiation emitted by another element (such as, for example, the navigation system 30). A passive optical marker can correspond to, for example, a reflective sphere detectable by an infrared stereo camera (e.g., one manufactured by Northern Digital Inc.). (used in navigation systems), or corresponding to a black-and-white pattern visible through a stereo camera (e.g., this is ClaroNav). (Used in navigation systems). Active optical markers emit light radiation, such as infrared radiation, which can be detected by navigation system 30.

[0080] However, it should be noted that a single optical marker with a three-dimensional geometric shape can be used in place of a set of spherical optical markers 181.

[0081] Figure 4 Patient markers 22 are schematically shown, designed to be positioned near target anatomical structures on patient 20. The patient markers 22 include at least three optical markers 221 (in... Figure 4 The illustrated example includes four instances, thus allowing the position of the patient marker 22 to be determined in three spatial dimensions of the reference frame of the navigation system 30. The respective positions of the optical markers 221 of the patient marker 22 relative to each other are known a priori by the navigation system 30 and / or by the control unit 12. Advantageously, the geometry of each optical marker 221 can also be known a priori. Figure 4 In the example shown, the optical marker 221 is spherical in shape. The spherical shape allows for optimized reflection of optical radiation. The aforementioned active or passive type optical marker 181 for the tool guide 14 also applies to the optical marker 221 for the patient reference 22. Again, it is conceivable to use a single optical marker with a three-dimensional geometric shape instead of a set of spherical optical markers 221.

[0082] The patient marker 22 also includes radiopaque markers 222 visible on medical images acquired by medical imaging equipment (e.g., by computed tomography, magnetic resonance imaging, ultrasound, CT, positron emission tomography, etc.). The respective positions of the radiopaque markers 222 relative to each other are known a priori by the navigation system 30 and / or by the control unit 12. Advantageously, the geometry of the radiopaque markers 222 may also be known a priori. Preferably, the patient marker 22 comprises at least three radiopaque markers 222 (in the considered example, the patient marker 22 comprises four radiopaque markers). For example, the radiopaque markers 222 may be ceramic beads. It should be noted, however, that a single radiopaque marker having a characteristic three-dimensional geometry may be used instead of a set of spherical radiopaque markers 222.

[0083] In the remainder of this specification, by way of non-limiting example, the optical sensor 31 and various optical markers 181, 221 of the navigation system 30 are designed to operate using infrared optical radiation. It is also assumed that the optical markers 181, 221 are passive markers. The optical sensor 31 is configured to emit infrared radiation. This infrared radiation is reflected by the various optical markers 181, 221 toward the optical sensor 31. The optical sensor 31 is configured to receive this reflected infrared radiation. The navigation system 30 can then determine the distance between the optical markers 181, 221 and the optical sensor 31 by measuring the time taken for the infrared radiation to travel round trip between the optical sensor 31 and the optical markers 181, 221. By knowing the distances between each optical marker 181, 221 and each optical sensor 31, and by knowing a priori the arrangement of optical markers 181 and 221 relative to each other on the robot marker 18 and the patient marker 22, the positions of the robot marker 18 and the patient marker 22 in the reference frame of the navigation system 30 can be determined.

[0084] It should be noted that this application describes an optical navigation system. However, in one variant, nothing prevents the use of an electromagnetic navigation system instead of an optical navigation system. In this case, various "markers" (patient marker 22, robot marker 18) detectable by the navigation system will subsequently correspond to electromagnetic sensors, the positions of which can be determined by the navigation system in the generated electromagnetic field.

[0085] In the considered example, the control unit 12 of the medical robot 10 is configured to receive information from the navigation system 30 regarding the current position of the robot marker 18 in the reference frame of the navigation system 30. The control unit 12 of the medical robot 10 now knows the current position of the robot marker 18 in the reference frame of the medical robot 10 (via the encoders of the joints 131-138). Therefore, the control unit 12 can determine the transformation to be performed to define the position of the reference frame of the medical robot 10 based on its position in the reference frame of the navigation system 30.

[0086] The position of the ultrasonic probe 40 and the position of the tool guide 14 can also be inferred from the position of the robot marker 18 (via the encoder of joints 131-138).

[0087] The control unit 12 is also configured to receive information about the position of the patient marker 22 in the reference frame of the navigation system 30. The control unit 12 can then determine the position of the patient marker 22 in the reference frame of the medical robot 10.

[0088] The positions of the entry point of the medical device 15 on the patient's skin and the target point at the lesion to be treated can be determined relative to the position of the patient marker 22 on a medical planning image, on which the lesion and the radiopaque element 222 of the patient marker 22 are visible. When the position of the patient marker 22 is known in the reference frame of the navigation system or the reference frame of the medical robot 10, the positions of the entry point and the target point within the reference frame of the navigation system or the reference frame of the medical robot 10 can be inferred.

[0089] When the position of the ultrasound probe 40 is known at a given time, the position of a visible element on the ultrasound image acquired by the ultrasound probe 40 at that time can be determined. This visible element may specifically correspond to a target point or an entry point. The target point and the entry point define the trajectory to be followed by the medical device 15. When the positions of the target point and the entry point are known, i.e., when the trajectory to be followed by the medical device 15 is defined, the control unit can automatically move the robotic arm 13 into a configuration that allows the tool guide 14 to guide the medical device 15 along the defined trajectory.

[0090] Motions related to the patient's breathing cause displacement of the target point and entry point in the reference frame of the medical robot 10. Therefore, the trajectory to be followed by the medical device 15 differs at a given moment in the patient's respiratory cycle from one moment to another. Consequently, the positions of the target point and entry point must be monitored in real time to determine the trajectory to be followed by the medical device 15 at any given moment and to adjust the position of the tool guide 14 to guide the medical device 15 according to that trajectory.

[0091] Figure 5 Examples of steps implemented by the control unit 12 to achieve this real-time monitoring are illustrated. Specifically, these steps can be performed before the insertion of the medical device 15. In the first step, the preparation phase mainly involves placing the ultrasound probe 40 in a suitable position to acquire an ultrasound image of the lesion. In the second step, the guidance phase involves controlling the robotic arm 13 based on the ultrasound images acquired by the ultrasound probe 40 to adjust the position of the tool guide 14 in real time, thereby continuously positioning the medical device 15 along the trajectory to be followed.

[0092] The preparation phase includes step 101 of receiving a planning image on which the lesion is visible and at least one radiopaque element 222 of the patient marker 22. For example, the planning image is a medical image acquired before intervention while the patient 20 is on the intervention table, at which point the patient marker 22 is located near the target anatomical structure of the patient 20. The planning image may also be a preoperative medical image acquired days or weeks before intervention and registered with a pre-intervention image. The planning image is, for example, a medical image obtained by computed tomography, positron emission tomography, or magnetic resonance imaging. The location of the patient marker 222 in the planning image can be determined using the radiopaque element 22 of the patient marker 22 that is visible on the planning image.

[0093] The preparation phase then includes step 102 of determining target points and entry points on the planning image. According to a first example, the planning image is displayed on a screen of a user interface 19, which enables the practitioner to identify target points at the area to be treated, and / or entry points on the patient's skin, and / or risk areas to be avoided (e.g., bone or blood vessels), as well as treatment parameters, on the planning image. This step can be facilitated by segmenting certain anatomical regions (target anatomical structures, lesions to be treated, risk areas, etc.) using machine learning algorithms. In another example, target points and entry points can be determined directly on the planning image using artificial intelligence algorithms.

[0094] The preparation phase then includes step 103 of determining the target point location and the entry point location relative to the patient marker 22. In practice, the position of the patient marker 22 can be determined in the planning image using a radiopaque element 222 visible on the planning image. Furthermore, by means of the navigation system 30, the position of the patient marker 22 in the reference frame of the navigation system 30 or the reference frame of the medical robot 10 can be determined at any time. Therefore, the positions of the entry point and the target point in the reference frame of the navigation system or the reference frame of the medical robot 10 can be inferred from this.

[0095] Finally, the preparation phase includes the step of real-time control of the robotic arm 13 to position the ultrasound probe 40 so that it contacts the patient 20 and that the ultrasound image acquired by the ultrasound probe 40 at that position is in a plane containing the lesion and the trajectory to be followed by the medical device 15. As a reminder, the tool guide 14 and the ultrasound probe 40 are arranged relative to each other in such a way that the medical device 15 is always in the plane of the ultrasound image acquired by the ultrasound probe 40. Real-time control of the robotic arm 13 includes control of the additional arm 16 to which the ultrasound probe 40 is attached.

[0096] In the considered example, the force sensor 17 enables the control unit 12 to determine the pressure applied to the patient 20's body by the ultrasound probe 40. The control unit 12 is configured to move the robotic arm 13 such that the ultrasound probe 40 applies a predetermined pressure to the patient 20's body. This arrangement allows the ultrasound probe 40 to remain in contact with the patient 20's body during respiratory movements. When the patient 20's respiratory movements cause excessive pressure on the ultrasound probe 40 (inhalation), the ultrasound probe 40 moves away from the patient 20's body. Conversely, when the patient 20's respiratory movements cause insufficient pressure on the ultrasound probe 40 (exhalation), the ultrasound probe 40 moves towards the patient 20's body.

[0097] The target and entry points, initially defined by practitioners on the planning images, can then be monitored on ultrasound images acquired in real time by an ultrasound probe during the guidance phase.

[0098] Specifically, target point monitoring can be achieved by tracking movement across multiple consecutive images, through speckle deformation analysis, or through artificial intelligence algorithms. When the lesion is not visible on the ultrasound image, tracking the movement of anatomical structures visible on the ultrasound image that are close to the lesion (e.g., blood vessels) may be advantageous to assist in tracking the target point on the fused image. However, the selected anatomical structure must be visible in the plane of the ultrasound image acquired by the ultrasound probe.

[0099] If the lesion is not sufficiently visible on the ultrasound image, the movement of the target point should be tracked on the fused images, with each fused image corresponding to the registration of the ultrasound image and the planned image.

[0100] The guidance phase includes step 201 of receiving ultrasound images acquired by the ultrasound probe 40.

[0101] The guidance phase includes step 202, which involves determining the position of the robotic marker 18 and the position of the patient marker 22 at the instant the ultrasound image is acquired by the ultrasound probe 40.

[0102] The guidance phase then includes step 203 of generating a fused image, which is produced by registering the ultrasound image with the planned image. Therefore, the lesion, target point, and entry point are visible on the obtained fused image.

[0103] Figure 6 The illustration schematically shows the use of ultrasound images for registration. Figure 6 Planning image of part b) Figure 6Part a) to form a fused image resulting from the registration of the planning image and the ultrasound image. Figure 6 (Part c). The lesion 50 to be treated and the target point 51 are visible on the planning image. In the considered example, the reference image is acquired by computed tomography. On the other hand, the lesion 50 to be treated is barely visible on the ultrasound image. The lesion 50 to be treated and the target point 51 become visible on the analysis image generated by the registration of the reference image and the ultrasound image. It should be noted that (although) Figure 6 The radiopaque marker 222 of the patient marker 22 (not shown in the image) is also visible in the planning image and the fused image.

[0104] Registration can be global (registration across the entire target anatomical structure) or local (optimized registration in a specific region of the target anatomical structure). Registration can be rigid (by translation and / or rotation) or non-rigid (by deformation). Specifically, the registration can be based on the identification of specific anatomical structures on the images to be merged using machine learning algorithms. Registration can also be based on the segmentation of radiopaque elements of patient markers on the planning image, followed by registration between a reference frame of the planning image (known by the position of patient marker 22) and a reference frame of the ultrasound image (known by the position of robotic marker 18).

[0105] The guidance phase then includes step 204 of determining the location of the target point and the location of the entry point based on the fused image, the position of the robot marker 18, and the position of the patient marker 22. The location of the target point and the location of the entry point can be defined relative to the position of the patient marker 22 in a reference frame of the fused image. Knowing the position of the patient marker 22 and the position of the robot marker 18 then allows the location of the target point and the location of the entry point to be determined in the reference frame of the navigation system 30 and / or in the reference frame of the medical robot 10.

[0106] However, it should be noted that determining the positions of the robotic marker 18 and the patient marker 22 for each new ultrasound image acquired by the ultrasound probe 40 is not mandatory (meaning step 202 is optional). In fact, since the position of the ultrasound probe 40 is known in the reference frame of the medical robot 10, the reference frame of the fused image can be defined relative to the reference frame of the medical robot 10, and therefore the positions of the target point and the entry point in the reference frame of the medical robot 10 can be determined directly from the fused image.

[0107] The guidance phase then includes step 205 of moving the robotic arm 13 such that the tool guide 14 guides the medical device 15 along a trajectory defined by the position of the target point and the position of the entry point.

[0108] For each new ultrasound image received from the ultrasound probe 40, repeat steps 201-205.

[0109] Therefore, the robotic arm is moved in real time so that it is continuously positioned to guide the medical device 15 along a trajectory defined by the position of the target point and the position of the entry point. This real-time adjustment of the position of the robotic arm 13 allows for compensation for movement of the target point caused by the patient's breathing.

[0110] With this arrangement, the patient's breathing can be blocked at any point in the respiratory cycle in order to continue the insertion of the medical device 15. In fact, at any moment when the patient's breathing is blocked, the robotic arm 13 will be correctly positioned to allow the medical device 15 to be inserted along the desired trajectory.

[0111] Furthermore, there is no longer a need to obstruct the patient's airway during the intervention. In fact, the robotic arm moves in real time, allowing its position to be continuously adjusted to guide the medical device along the desired trajectory.

[0112] Once the medical device 15 is inserted into the patient 20, the position of the entry point on the patient's skin is fixed and becomes the pivot of rotation for the movement of the robotic arm 13. However, the position of the target point and the position of the entry point can still be tracked in real time based on new ultrasound images acquired during the insertion of the medical device 15. Specifically, this allows any movement of the target point caused by the insertion of the medical device 15 to be accounted for. In fact, the target point can move along the trajectory it follows during the insertion of the medical device 15 (especially when the lesion is located in soft tissue). Determining the position of the target point in real time using ultrasound images allows the trajectory to be followed by the medical device 15 and the position of the robotic arm 13 to be updated in real time so as to guide the medical device 15 along that trajectory.

[0113] It should be noted that the position of the ultrasound probe 40 can be adjusted during the guidance phase based on the position of the patient marker 22 and / or based on measurements reported by the force sensor 17, in order to maintain contact with the patient 20 and remain in a plane containing the lesion and the trajectory to be followed by the medical device 15. The additional degrees of freedom provided by the additional arm 16 allow the position of the ultrasound probe 40 to be adjusted without affecting the position of the tool guide 14.

[0114] During the preparation phase, if the lesion is not within the field of view of the ultrasound probe 40, i.e., if the lesion is not visible on the ultrasound image acquired by the ultrasound probe 40 (or from the associated fused image), the ultrasound probe 40 must be moved so that the lesion is within its field of view. For this purpose, the control unit 12 can be configured to compare the ultrasound image with the planned image (on which the lesion is visible) and determine the direction of movement of the ultrasound probe 40 such that the ultrasound image acquired by the ultrasound probe 40 includes the anatomical region where the lesion is located. The control unit 12 can then control the robotic arm 13 to move the ultrasound probe 40 in that direction. Alternatively, the control unit 12 can control the robotic arm 13 to scan with the ultrasound probe 40 until a lesion is detected on the ultrasound image acquired by the ultrasound probe (or from the associated fused image).

Claims

1. A medical robot (10) for assisting a practitioner in treating lesions in a target anatomical structure of a patient during a medical intervention, the medical robot (10) comprising a robotic arm (13) and a control unit (12), one end of the robotic arm being attached to an ultrasound probe (40) and a tool guide (14) for guiding a medical instrument (15), and the control unit being configured to control the robotic arm (13), the medical robot (10) being configured to cooperate with a navigation system (30), the control unit (12) being configured to determine at any time, based on information transmitted by the navigation system (30), the position of a robotic marker (18) intended to be positioned on the medical robot (10) and the position of a patient marker (22) intended to be positioned near a target anatomical structure on the patient, the medical robot (10) being characterized in that: During the preparation phase, the control unit (12) is configured to: At least one radiopaque element (222) receives a planned image of the lesion and patient markers (22) on which the lesion can be seen. The target point located at the lesion and the entry point located on the patient's skin are determined from the planning image, and the target point and the entry point thus define the trajectory to be followed by the medical device (15). The robotic arm (13) is controlled according to the positions of the robot marker (18) and the patient marker (22) to bring the ultrasound probe (40) into contact with the patient and place it in a plane containing the lesion and the trajectory to be followed. During the guidance phase, the control unit (12) is configured to receive ultrasound images acquired by the ultrasound probe (40) in real time and control the robotic arm (13) in real time based on the ultrasound images so as to place the tool guide (14) to guide the medical device (15) along the trajectory to be followed. The control unit (12) is configured to compare the ultrasound image with the planned image and determine the direction of moving the ultrasound probe (40) such that the ultrasound image acquired by the ultrasound probe (40) includes the anatomical region where the lesion is located.

2. The medical robot (10) according to claim 1, wherein during the guidance phase, for each received ultrasound image, the control unit (12) is configured to: Generate a fused image obtained by registering the ultrasound image and the planned image. The location of the target point and the location of the entry point are determined based on the fused image. The robotic arm (13) is moved such that the tool guide (14) guides the medical device (15) along a trajectory defined by the position of the target point and the position of the entry point.

3. The medical robot (10) according to claim 1 or 2, wherein during the guidance phase, during the insertion of the medical device (15), for each new ultrasound image received, the control unit (12) is configured to determine the position of the medical device (15) and adjust the real-time control of the robotic arm (13) based on the position of the medical device (15).

4. The medical robot (10) according to claim 1 or 2, wherein the ultrasound probe (40) is coupled to a force sensor (17), the force sensor enabling the control unit (12) to determine the pressure applied to the patient's body by the ultrasound probe (40), and the control unit (12) is configured to move the robotic arm (13) such that the ultrasound probe (40) applies a predetermined pressure to the patient's body.

5. The medical robot (10) according to claim 1 or 2, wherein the planning image is a computed tomography image, a positron emission tomography image, or a magnetic resonance imaging image.

6. The medical robot (10) according to claim 1 or 2, wherein, in order to determine the target point and the entry point based on the planning image, the control unit is configured to segment lesions and / or anatomical regions to be avoided on the planning image using an artificial intelligence algorithm.

7. The medical robot (10) according to claim 1 or 2, wherein the ultrasound image received from the ultrasound probe (40) is a B-mode ultrasound image.

8. The medical robot (10) according to claim 1 or 2, wherein the control unit (12) is configured to receive and process ultrasound images acquired by the ultrasound probe (40) at a rate of at least 15 images per second.

9. The medical robot (10) of claim 2 further includes a user interface (19) comprising a display screen that enables the practitioner to view the planning image and / or the fused image.

10. The medical robot (10) of claim 9, wherein the user interface (19) includes an input device that enables the practitioner to identify target points and / or entry points and / or anatomical areas that the medical device (15) will not cross on the planning image displayed on the display screen during the preparation phase.

11. The medical robot (10) according to claim 9 or 10, wherein the user interface includes an augmented reality device for overlaying analytical images and actual images of the patient's body onto the display screen.

Images