Device comprising a micro robot, system comprising such device and method for controlling such device

Abstract

The invention relates to a device arranged to be inserted into a human or animal body, for example in a vessel thereof, and to move through said human or animal body, said device comprising a micro robot comprising at least one magnet or magnetizable element for cooperating with an externally applied magnetic field so as to control the movement of said device in the human or animal body by a magnetic field, said device further comprising a gripper for gripping a material part, such as a blood clot or any other occlusion.

Description

[0001] DEVICE COMPRISING A MICRO ROBOT, SYSTEM COMPRISING SUCH DEVICE AND METHOD

[0002] FOR CONTROLLING SUCH DEVICE

[0003] The invention relates to a device arranged to be inserted into a human or animal body, for example in a vessel thereof, and to move through said human or animal body, said device comprising a micro robot comprising at least one magnet or magnetizable element for cooperating with an externally applied magnetic field so as to control the movement of said device in the human or animal body by a magnetic field said device further comprising a gripper for gripping a material part, such as a blood clot or any other occlusion.

[0004] The micro robot is in particular an untethered robotic device, more in particular an untethered micro-robotic device.

[0005] The size of the micro robot is chosen such that it can be inserted into the human or animal body, in particular in vessels thereof. The size may for example be in the range of some millimetres, for example 1 - 10 mm.

[0006] Examples of vessels include blood vessels such as veins or arteries, lymphatic vessels, urinary system vessels such as the urethra or ureters, seminal vessels, saliva ducts, bile ducts and more.

[0007] The device may for example be used to remove or dissolve a material part, such as a blood clot or any other occlusion, from a human or animal body.

[0008] For example, the device can be used to be inserted into the human or animal body, for example into a vessel thereof, and can be controlled to move towards the material part and to enter the material part by means of the gripper, which is optionally provided with a tapered tip. Next, the device is controlled to move in an opposite direction.

[0009] In an embodiment, the gripper comprises a longitudinal body with a plurality of barbs distributed along the length and / or the circumference of the longitudinal body. Alternatively, the plurality of barbs may be arranged around a distal portion of the longitudinal body.

[0010] In an embodiment, the barbs are flexible with respect to the longitudinal element, such that the barbs can adopt a first state in which the barbs extend close and / or substantially parallel to the longitudinal element and a second state in which the barbs extend outwardly with respect to the longitudinal element for gripping the material part.

[0011] In particular, the barbs adopt the first state when pushed into the material part and the second state when pulled in a backward direction, for gripping or scooping the material part.

[0012] An advantage is that in such embodiment the barbs extend close to the longitudinal body during penetrating the blood clot, such that the gripper may easily penetrate the blood clot, and that the barbs extend outwardly, in other words are open, when the gripper retrieves the blood clot, such that the barbs may strongly grip the blood clot.

[0013] The barbs may move between the first state and second state in a passive manner.

[0014] Alternatively, the barbs may be actuated to move between the first state and second state. In such an embodiment the device comprises actuating means for actuating the barbs between the first state and the second state, for example wherein said actuating means are controllable by the externally applied magnetic field. If for example the barbs comprise a magnet or magnetisable element, the barbs may be moved by applying the magnetic field.

[0015] The barbs may be leaf-like elements, made of polymers or other material.

[0016] The barbs may be distributed in a helical manner with respect to the longitudinal body.

[0017] In an embodiment, the barbs may comprise a plurality of micro-surface-mounted projections. Such a plurality of micro sized surface-mounted projections may be arranged on the inner surface of each extension that mechanically can interact with the microstructure of the thrombus material, engage with it and remove the material out of the human or animal body.

[0018] In other words, the device is provided with a gripper having an elongated body with barbs, which can hook the blood clot and literally pull it back, allowing to remove the obstruction. Preferably, the barbs are configured such that the penetration force required to enter the material obstruction is substantially smaller than the retrieval force generated when the barbs secure and extract the obstruction, thereby enabling effective clot removal from a vessel using the device.

[0019] In an embodiment, the gripper comprises a sharp or tapered tip. Such a tapered tip facilitates the penetration of gripper into a blood clot or thrombus.

[0020] In an embodiment, the micro robot comprises a hollow body, in particular a cylindrical hollow body, and wherein said device further comprises a pin-shaped element, said pin-shaped element extending through the hollow body.

[0021] In an embodiment, the longitudinal body of the gripper is hollow, said pin-shaped element extending through the longitudinal body.

[0022] Both the gripper and the micro robot may be coupled to the pin-shaped element, such that the pin-shaped element functions as a coupling element for couplingthe gripper and robot.

[0023] For example, the longitudinal body and the hollow body may be aligned along a common longitudinal axis, wherein the pin-shaped element first extends though the hollow body and then through the longitudinal body as seen alongthe longitudinal axis. In such an arrangement the pin-shaped element is coupled to both the gripper and the micro robot, thereby coupling the gripper and micro robot with respect to each other. In an embodiment, the pin-shaped element comprises a tapered tip, wherein the pinshaped element extends out the longitudinal end of the gripper such that the tapered tip defines a first end of the device. In this way the pin shaped elements helps penetration of the gripper into the blood clot.

[0024] In an embodiment, the pin-shaped element is in a frictional rotational engagement with the hollow body via a frictional interface having a friction threshold, said frictional interface allowing relative rotational movement between the hollow body and pin-shaped element if the rotational force exceeds the friction threshold and preventing relative rotational movement between the hollow body and pin-shaped element if the rotational force is below the friction threshold.

[0025] As described above, the pin-shaped element may be arranged to couple the gripper and micro robot. As long as the device has not yet gripped a blood clot or other occlusion, it is advantageous if the gripper and micro robot are in a rotational fixed relationship, such that the gripper and robot both rotate during their movement through the vessel. However, as soon as the gripper grips a blood clot or other occlusion and is retrieved from the vessel to remove the blood clot or other occlusion, it is advantageous if the gripper is no longer rotating, because such rotation would cause rotation of the blood clot or other occlusion, and such rotation of the blood clot may impede the retrieval of the device. Therefore, it is advantageous to provide said frictional interface that prevents relative rotational movement between the hollow body and pinshaped element if the rotational force therebetween is below the friction threshold, which rotational force is low as long as the gripper has not yet gripped a blood clot because in that case both the robot (hollow body) and the gripper (attached to pin-like element) can freely rotate and thus there is no or limited rotational force therebetween. As soon as the gripper grips a blood clot or other occlusion, the gripper experiences resistance when rotating, because the blood clot has to rotate therewith and that causes rotational resistance. As a result thereof, the rotational force between the gripper and thus the pin-shaped element that is attached to the gripper on the one hand, and the hollow body of the robot on the other hand, is increased, in particular to above the frictional threshold, thereby allowing the robot to continue rotating under the influence of the magnetic field and the gripper to stop rotating, such that the blood clot is not rotated after and optionally during being gripped.

[0026] The rotational force is thus defined here as the rotational force between the hollow body, i.e. robot, and pin-shaped element, i.e. gripper.

[0027] The friction threshold is thus chosen in accordance with the above requirements and in particular in accordance with the rotational friction caused by the blood clot or other occlusion when gripped. In an embodiment, the frictional interface comprises a hollow, cylindrical bearing that is positioned between the hollow body and the pin-shaped element, said bearing having a fixed rotational relationship with the hollow body, such that rotational movement between the bearing and the hollow body is prevented, and said bearing providing said frictional rotational engagement with the pin-shaped element.

[0028] The frictional interface may comprise said at least one magnet or magnetizable element.

[0029] In an embodiment, a coating is provided that determines said friction threshold.

[0030] Said coating may provide said rotational friction to said frictional interface between the hollow body and pin-shaped element, and by selecting a suitable coating having a suitable friction or resistance value, said friction threshold may be selected.

[0031] For example said coating may be applied to said bearing, in particular to a surface thereof that extends between the pin-shaped element and the bearing.

[0032] Said pin-shaped element may have a fixed rotational relationship with the gripper.

[0033] In an embodiment, the at least one magnet or magnetizable element substantially has the shape of a hollow cylinder, and wherein the at least one magnet or magnetizable element is positioned between the pin-shaped element and the hollow body.

[0034] In an embodiment, the micro robot, for example the hollow body thereof, comprises a helical vane. Such a vane helps to create thrust when the micro robot is rotating.

[0035] In an embodiment, the helical vane has a pitch that is determined in accordance with a desired movement of the device through the body.

[0036] In an embodiment, the pitch of the helical distribution of the barbs is different from the pitch of the helical vane, wherein the pitch of the helical distribution of the barbs is in particular larger than the pitch of the helical vane.

[0037] In an embodiment, the pitch of the helical distribution of the barbs and / orthe pitch of the helical vane is chosen in accordance with the diameter of the longitudinal body and / orthe device, for example of the hollow body thereof, respectively.

[0038] In an embodiment, the at least one magnet is a permanent magnet. A permanent magnet can be relatively small so as to be arranged in a micro robotic device.

[0039] In an embodiment, the micro robot comprises a composite biocompatible resin with embedded magnetic nanoparticles. These nanoparticles may be chosen to (i) optimize buoyancy in blood, (ii) maximize X-ray or ultrasound visibility, and / or (iii) generate torque under rotating magnetic fields.

[0040] The device may be moved in the human or animal body by applying said external magnetic field. The term ’external’ means external to the human or animal body. By applying the magnetic field the device can be controlled to move forward, in particular by rotating the micro robot along its longitudinal axis in a first direction, for example clockwise, or backward, in particular by rotating the device along its longitudinal axis in a second, opposite direction, for example anti-clockwise, and / or to make a turn. The speed of the micro robot may also be controlled. Because the micro robot is externally controlled, the total device may be relatively small for insertion into the body.

[0041] In a preferred embodiment, the gripper is rotatably coupled to the micro robot. In this way, the micro robot can rotate while the gripper can stay still without any rotation during the engagement and retrieval of the occlusion material.

[0042] The invention also relates to a collector device configured to radially centralize and extract a clot transported by a device as described above, thereby preventing loss or fragmentation of the clot.

[0043] The invention further relates to a system, comprising a device as described above and a source for creating a magnetic field, said source being controllable for controlling a direction and / or magnitude of the magnetic field.

[0044] In an embodiment, the system comprises a robotic manipulator comprising an endeffector, wherein the source for creating the magnetic field comprises one or more rotating magnets, rotatably arranged at the end-effector, wherein the robotic manipulator comprises a controlling system for controlling rotation, position and orientation of the rotating magnets. The rotating magnets may comprise at least one permanent magnet. Such a permanent magnet provides a stable magnetic field without requiring power or cooling for field generation, thereby enabling safe and continuous actuation of the device within the vessel.

[0045] In an embodiment, the controlling system is arranged to drive the device when being in a bodily fluid or tissue, by way of suitably manoeuvring the rotating magnet in the vicinity of the device.

[0046] In an embodiment, the robotic manipulator is a 6-degrees-of-freedom (DOF) manipulator. Such a robotic manipulator enables flexibility in steering the device byway of controlling the location and orientation of the rotatable magnet.

[0047] In an embodiment, the system comprises detecting means for detecting the device in the bodily fluid or tissue. The detecting means may comprise an imaging system, such as fluoroscopy, computed tomography system, magnetic resonance imaging system, ultrasound system.

[0048] In an embodiment the controlling system is arranged to receive information from the detecting means and to control the device using the received information.

[0049] By integrating real-time imaging techniques into the system, real-time visualization of the device's position and the surrounding vascular environment is possible. Also, computational modelling may be used to simulate various vascular conditions, optimizing the design and functionality of the device for different clinical scenarios.

[0050] In an embodiment, the controlling system is arranged to receive a backward instruction, and drive the device in a backward direction by reversing the rotation direction of the rotating magnet.

[0051] The invention further relates to a method for controlling the movement of a device as described above in a human or animal body by a controlling a magnetic field, in particular a direction and / or magnitude of the magnetic field.

[0052] In an embodiment the direction of the magnetic field causes the device to rotate along its longitudinal axis either in a first direction or in a second, opposite direction, and wherein the rotation of the device in the first direction causes the device to move in a first, substantially longitudinal direction and the rotation of the device in the second direction causes the device to move in a second, opposite direction.

[0053] Finally, the invention also relates to a method for removing a material part, for example a blood clot or any other occlusion, from a human or animal body, said method comprising the use of the device as described above.

[0054] Embodiments of the device, system and method that are used for removing clots or other occlusions, are described below in more detail. The device, system and method may have any one or more of the below described features, alone or in any suitable combination. None of the described features is essential.

[0055] Problem Statement: Current methods for clot (refers to blood clots and other occluding materials) retrieval in vessels interventions, such as catheter-based techniques, face significant limitations in terms of penetration into occlusive material, manoeuvrability, and dependency on tethered systems. These limitations often result in incomplete clot removal, prolonged procedure times, and increased risk of complications. Effective and efficient treatment of vascular occlusions, which can lead to critical conditions like strokes, and heart attacks and limbs amputations, remains a major medical challenge.

[0056] Examples of vessels include blood vessels such as veins or arteries, lymphatic vessels, urinary system vessels such as the urethra or ureters, seminal vessels, saliva ducts, bile ducts and more.

[0057] Occlusions are any flow limiting blockages in the vessel which are caused by local buildup of atherosclerotic material, atherosclerotic emboli, migrating blood clots, biological stones or the like. Invention Overview: The Wireless Clot Retrieval (WCR) device comprises an untethered robotic device designed to revolutionize the approach to clot retrieval in vascular interventions and occlusions in any other vessels. By using advanced magnetic actuation technology, this invention addresses the key limitations of traditional catheter-based methods, providing a wireless, highly manoeuvrable solution that enhances procedural efficiency and patient safety.

[0058] The WCR operates by using external magnetic fields to induce controlled motion and rotation in the robotic device. External is with reference to the human or animal body. The micro robotic device may be composed of a flexible, biocompatible material embedded with magnetic nanoparticles and ferromagnetic cores. The device may be coated with LipoCoat 4AC to prevent any coagulation during the locomotion in the bloodstream. When subjected to an external magnetic field, the magnetic material generate torque, causing the micro robotic device to rotate and propel through the bloodstream. The rotational motion is precisely controlled by adjusting the magnetic field's strength and orientation, allowing the WCR to navigate through intricate vascular structures and reach the site of the clot. Once the WCR reaches the clot, it deploys a micro-scale retrieval mechanism, which can engage and securely capture the clot. The captured clot is then safely transported through the vascular system to a retrieval site, where it can be removed from the body.

[0059] Comparison to Other Inventions:

[0060] The WCR stands out from other clot retrieval methods due to its wireless, magnetic actuation system. Traditional catheter-based systems rely on manual navigation, which can be limited by the operator's skill and the vascular anatomy's complexity. These systems often struggle with reaching clots in tortuous, and or distal and / or narrow vessels, posing a risk of vessel damage.

[0061] The WCR is the first device capable of swimming untethered toward a blood clot, gripping its fibrin network, and then reversing direction for retrieval (see Fig. 2). This capability is enabled by a unique design featuring a hollow screw-shaped magnetic body housing at its distal side a retrieval device including but not limited to a distal elongated body with plurality of leaflike projections arranged around it for delivering the body into the clot and engage with it. These leaf-like projections provide additional propulsive thrust during targeting and grip the fibrin network during retrieval to pull the clot from the blood vessel. Each of the plurality of leaf-like projections in its inner side, may including an array of micro-surface-mounted projections. The helical body and the elongated body with the plurality of projections have an optimal helical pitch based on their diameter, ensuring optimal swimming speed when deployed within a confined space. The hollow screw-shaped micro robot can also house at its distal side other retrieval devices that will be adapted to this purpose, such as Stent retrievers, Aspiration catheters and a like.

[0062] Components and Functionality:

[0063] Untethered Micro-Robotic Device: The WCR system comprises a compact, untethered robotic device capable of navigating through the intricate vascular pathways. Its small size and wireless nature allow it to reach locations that are difficult or impossible for traditional catheters.

[0064] Scalability: The optimal combination of helical pitch relative to the diameter of the elongated body with the plurality of leaf-like projections and screw enables the WCR to be scaled according to the vessel diameter between the point of deployment and the location of the blood clot.

[0065] Magnetic Actuation Mechanism: The micro-robotic device is equipped with magnetic elements that enable precise control and manoeuvrability via an external magnetic field. This allows the WCR to be steered accurately through the bloodstream, avoiding obstacles and reaching the site of the clot with minimal disruption to the surrounding tissues.

[0066] The magnetic actuation works in sync with the unique body design, enabling propulsive thrust to be generated by the screw-shaped body and the elongated body with the plurality of leaf-like projections or any other retrieval devices (“Gripper””).

[0067] The specific relationship between the diameters of the screw and Gripper and the helical pitch of both is advantageous. This unique configuration provides optimal thrust for a given vessel diameter, a feature that distinguishes this invention and ensures its superior performance in navigating vascular pathways and retrieving blood clots and other occluding materials.

[0068] Capture and Retrieval Mechanism: The WCR system includes a specialized mechanism designed to engage and securely capture blood clots. Once the clot is captured, the device can be guided out of the vascular system, via a collector (funnel) which is designed to contact the vessel walls at its distal opening such that the leaf-like projections and clot are centralized and collected into the funnel without clot fragmentation or loss, thus, effectively removing the obstruction.

[0069] Real-Time Imaging and Computational Modelling: Advanced imaging techniques are integrated into the system to provide real-time visualization of the device's position and the surrounding vascular environment. Computational modelling is used to simulate various vascular conditions, optimizing the design and functionality of the WCR for different clinical scenarios. The WCR may be fabricated using a composite material of resin and magnetic nanoparticles, offering a unique dual functionality. The magnetic nanoparticles not only enhance the magnetic moment during wireless magnetic actuation, providing superior control and manoeuvrability, but also significantly increase radiation absorption and reflection. This dual enhancement ensures exceptional visibility and accuracy during X-ray-guided or ultrasound-guided imaging, making the WCR distinctly more effective for precise navigation and clot retrieval.

[0070] The specific ratio of resin to nanoparticles in the WCR can be optimized to ensure optimal buoyancy in blood. A precise balance is beneficial for maintaining effective propulsion and stability within the vascular environment.

[0071] Novelty and Advantages

[0072] Minimally Invasive: Unlike traditional catheter-based systems, the WCR is untethered, significantly reducing the invasiveness of the procedure. This leads to shorter recovery times and lower risk of complications for patients.

[0073] Enhanced Manoeuvrability: The wireless and magnetically actuated nature of the WCR allows for superior manoeuvrability, enabling the device to navigate complex and narrow vascular pathways that are challenging for conventional methods.

[0074] Improved Efficiency and Efficacy: The precise control afforded by the magnetic actuation mechanism ensures efficient and accurate clot retrieval, potentially reducing procedure times and improving overall outcomes.

[0075] Interdisciplinary Innovation: The WCR system represents a convergence of robotics, micro robotics, magnetic actuation, and advanced imaging techniques. This interdisciplinary approach brings together expertise from various fields, resulting in a highly innovative and effective solution for vascular interventions.

[0076] The invention will be described with respect to the following figures:

[0077] Fig. 1 shows a schematic view of the device according to an embodiment of the invention, as it is moved through a human or animal vessel;

[0078] Fig. 2 shows three pictures of the vessel branch to explain the removal of the blood clot;

[0079] Fig. 3 shows the device of Figure 1 in more detail;

[0080] Fig. 4A schematically shows the device according to a second embodiment of the invention in more detail in a side view, a perspective, exploded view, a perspective, exploded transparent view, and a perspective view;

[0081] Fig. 4B shows a perspective view of part of a barb comprising a plurality of projections, and

[0082] Fig. 5 schematically shows a system according to an embodiment of the invention. Fig. 1 shows a schematic view of the device 10 according to an embodiment of the invention, as it is moved through a human or animal vessel 11 . An arrow 12 indicates a direction of the blood flowthrough the vessel 11 . As can be seen from the figure, the device 10 is driven upstream towards a branch 13 of the vessel 11. In this branch 13 a blood clot 14 is present. Through suitably manipulating the external magnetic field, the device 10 in driven into the vessel branch 13.

[0083] Figure 2 shows three pictures of the vessel branch 13 to explain the removal of the blood clot 14. In the upper picture, the device 10 penetrates a longitudinal body 3, acting as the gripper, into the blood clot 14. In the following picture, the device 10 is operated to drive in a reverse direction so as to retract the elongated body 3. The elongated body 3 comprises specific leaf-like elements which, in a retracting state extend outwardly with respect to the longitudinal body for gripping the material part (i.e. the blood clot). In the bottom picture of Figure 2, shows that the device 10 is pulling the blood clot 14 out of its position. The blood clot 14 can now be transported out of the vessel branch, through the vessel 11 , and even further to a location where the blood clot can be removed from the body.

[0084] Fig. 3 shows the device 10 in more detail. The device 10, also referred to as the Wireless Clot Retriever (WCR) features a screw-shaped untethered micro robot (UMR) 31 with a diameterdependent helical pitch, ensuring optimal propulsive thrust within blood vessels. The UMR 31 is rotatably coupled to a longitudinal body 3 to engage with the blood clots. In this embodiment, the longitudinal body 3 comprises a number of claws or leaf-like elements 32 which function as barbs. The longitudinal body 3 may further comprises radio-opaque markers 33 which can be detected using external detection means for localizing the longitudinal body 3.

[0085] Fig. 4 schematically shows the device 10 according to a second embodiment of the invention in more detail in a side view, a perspective, exploded view, a perspective, exploded transparent view, and a perspective view. The device 10 comprises in this exemplary embodiment a pin-shaped element or needle 1 , two magnets 4, 5, a hollow, cylindrical body with helical vane 2. It is noted that the hollow cylindrical body 2 together with the two magnets 4, 5 embody the micro robot. Figure 4A further shows a gripper 3 comprising a longitudinal body with a plurality of barbs that are distributed along the length and / or the circumference of the longitudinal body. Preferably the barbs are distributed in a helical pattern around the longitudinal element. Such a helical arrangement increases contact surface and gripping efficiency within the obstruction during retrieval.

[0086] The longitudinal body is in this embodiment a hollow, cylindrical element. The needle 1 can be inserted into both the hollow body 2 of the micro robot and into longitudinal body of the gripper 3, wherein the hollow body 2 and longitudinal body are aligned along the longitudinal axes thereof and in particular located next to each other in the longitudinal direction in an assembled condition. In this embodiment the magnets 4,5 are in a fixed rotation relationship with the hollow body 2. This way the movement of the hollow body 2 can be controlled, because it rotates and moves together with the magnets 4, 5. The needle 1 is in a fixed rotation relationship with the magnets 4,5 when the device 10 is inserted into the human or animal body and moves in a first direction. When the device 10 grips the blood clot or other material part and the barbs hook into the blood clot, the micro robot of the device 10 is controlled to move in an opposite direction. The friction on the gripper 3 and thereby needle 1 is in that case increased, such that the friction overcomes the fixed rotational relationship between the magnets 4, 5 and needle 1 , such that the magnets 4, 5 and thereby the hollow body with vane 2 is able to rotate with respect to the gripper 3. This way, the gripper 3 and thereby the blood clot does not rotate when the device is moved in the opposite direction. As can be seen in Figure 4A in the assembled picture, the tip of the needle extends through the longitudinal body 3. In this way, the tip of the needle is configured to initiate penetration into the material obstruction and guide the into the obstruction with reduced insertion force.

[0087] The pin-shaped element (e.g. the needle 1 ) may be in a frictional rotational engagement with the hollow body 2 via a frictional interface having a friction threshold, said frictional interface allowing relative rotational movement between the hollow body and pin-shaped element if the rotational force exceeds the friction threshold and preventing relative rotational movement between the hollow body and pin-shaped element if the rotational force is below the friction threshold. The frictional interface may comprise a hollow, cylindrical bearing that is positioned between the hollow body and the pin-shaped element, said bearing having a fixed rotational relationship with the hollow body, such that rotational movement between the bearing and the hollow body is prevented, and said bearing providing said frictional rotational engagement with the pin-shaped element. In an embodiment, a coating is provided that determines said friction threshold. The coating may be applied to a surface of the frictional interface to define or adjust the friction threshold, the coating thereby controlling the rotational decoupling between the hollow body and the pin-shaped element during propulsion and retrieval.

[0088] Figure 4B shows a perspective view of part of a barb 32 comprising a plurality of projections 44. In this example, the barb is a leaf-like element. The inner surface of each leaf-like element may be manufactured with projections 44 which, in this example, are conical in shape and are randomly yet homogenously distributed on the surface. These projections may be 3D printed (along with the extension and carrier tube), so that an exact structure and dimensions can be achieved. The diameter of the projections 44 may be around 100 microns and the height may be around 200 microns.

[0089] Figure 5 schematically shows a system 500 according to an embodiment of the invention. The system 500 comprises a robotic manipulator 501 comprising an end-effector 502. A rotating magnet 503 is rotatably arranged at the end-effector 502. The rotating magnet 503 creates a rotating magnetic field. The system further comprises a controlling system 504 for controlling rotation, position and orientation of the rotating magnet 503. Preferably, the rotating magnet is a rotating permanent magnet. In this embodiment, the system also comprises detecting means 505. A human body 506 is lying on a table in the vicinity of the rotating magnet 503. A device 510 as described above has been inserted into the human body 506, for example into the vessels. The controlling system 501 is arranged to drive the device 510 when being in a bodily fluid or tissue, by way of suitably manoeuvring the rotating magnet 503 in the vicinity of the device 510.

[0090] The robotic manipulator 501 may be a 6-degrees-of-freedom (DOF) manipulator. Such a manipulator is preferred so as to be able to manoeuvre the magnet 503 over the body 506 in any possible way.

[0091] The detecting means 505 are arranged for detecting the device 510 in the bodily fluid or tissue of the body 506. Examples of such detecting means are optical detection means using reflection or fluorescence, ultra-sound detection means, radiation detection means, such as X- ray or CT, and magnetic detection means using MRI, MPI or other magnetic techniques.

[0092] The controlling system 504 may be arranged to receive information from the detecting means 505 and to control the device 510 using the received information. This enables real time control of the device 510, and even automatic control of the device 510.

[0093] Although the invention is elucidated above on the basis of a number of specific examples and embodiments, the invention is not limited thereto. Consequently, the scope of the invention is defined by the following claims.

Claims

Claims1. Device (10) arranged to be inserted into a human or animal body, for example in a vessel thereof, and to move through said human or animal body, said device (10) comprising a micro robot (31) comprising at least one magnet or magnetizable element for cooperating with an externally applied magnetic field so as to control the movement of said device in the human or animal body by a magnetic field, said device further comprising a gripper (3) for gripping a material part, such as a blood clot or any other occlusion.

2. Device according to claim 1 , wherein the gripper comprises a longitudinal body with a plurality of barbs distributed along the length and / or the circumference of the longitudinal body.

3. Device according to claim 2, wherein the barbs are flexible with respect to the longitudinal body, such that the barbs can adopt a first state, for example when pushed into the material part, in which the barbs extend close and / or substantially parallel to the longitudinal body and a second state in which the barbs extend outwardly with respect to the longitudinal body, for example when pulled in a backward direction, for gripping the material part.

4. Device according to any of the claims 3, wherein the device comprises actuating means for actuating the barbs between the first state and the second state, for example wherein said actuating means are controllable by the externally applied magnetic field.

5. Device according to any of claims 2 - 4, wherein the barbs are leaf-like elements and / or wherein the barbs are distributed in a helical manner with respect to the longitudinal body.

6. Device according to any of the claims 2 - 5, wherein the barbs comprise a plurality of micro- surface-mounted projections (44).

7. Device according to any of the preceding claims, wherein the gripper comprises a tapered tip.

8. Device according to any of the preceding claims, wherein the micro robot comprises a hollow body, in particular a cylindrical hollow body, and wherein said device further comprises a pinshaped element, said pin-shaped element extending through the hollow body.

9. Device according to claim 8 and at least claim 2, wherein the longitudinal body of the gripper is hollow, said pin-shaped element extending through the longitudinal body.

10. Device according to any one of claims 8 and 9, wherein the longitudinal body and the hollow body are aligned along a common longitudinal axis, and wherein the pin-shaped element first extends though the hollow body and then through the longitudinal body as seen along the longitudinal axis.11 . Device according to claim 9 or 10, wherein the pin-shaped element comprises a tapered tip, wherein the pin-shaped element extends out the longitudinal end of the gripper such that the tapered tip defines a first end of the device.

12. Device according to any of the preceding claims and at least claim 8, wherein the pinshaped element is in a frictional rotational engagement with the hollow body via a frictional interface having a friction threshold, said frictional interface allowing relative rotational movement between the hollow body and pin-shaped element if the rotational force exceeds the friction threshold and preventing relative rotational movement between the hollow body and pinshaped element if the rotational force is below the friction threshold.

13. Device according to claim 11 , wherein the frictional interface comprises a hollow, cylindrical bearing that is positioned between the hollow body and the pin-shaped element, said bearing having a fixed rotational relationship with the hollow body, such that rotational movement between the bearing and the hollow body is prevented, and said bearing providing said frictional rotational engagement with the pin-shaped element.

14. Device according to claim 12 or 13, wherein the frictional interface comprises said at least one magnet or magnetizable element.

15. Device according to any of claims 12 - 14, wherein a coating is provided that determines said friction threshold.

16. Device according to any of the preceding claims and at least claim 8, wherein the at least one magnet or magnetizable element substantially has the shape of a hollow cylinder, and wherein the at least one magnet or magnetizable element is positioned between the pin-shaped element and the hollow body.1517. Device according to any of the preceding claims, wherein the micro robot, for example the hollow body thereof, comprises a helical vane.

18. Device according to claim 17, wherein the helical vane has a pitch that is determined in accordance with a desired movement of the device through the body.

19. Device according to at least claims 5 and 17, wherein the pitch of the helical distribution of the barbs is different from the pitch of the helical vane, wherein the pitch of the helical distribution of the barbs is in particular larger than the pitch of the helical vane.

20. Device according to at least claim 5 and / or 17, wherein the pitch of the helical distribution of the barbs and / or the pitch of the helical vane is chosen in accordance with the diameter of the longitudinal body and / or the device, for example of the hollow body thereof, respectively.21 . Device according to any of the preceding claims, wherein the at least one magnet is a permanent magnet.

22. Device according to any of the preceding claims, wherein the micro robot (31 ) comprises a composite biocompatible resin with embedded magnetic nanoparticles.

23. A collector device configured to radially centralize and extract a clot transported by a device according to any of the preceding claims, thereby preventing loss or fragmentation of the clot.

24. System, comprising a device according to any of claims 1 - 22 and a source for creating a magnetic field, said source being controllable for controlling a direction and / or magnitude of the magnetic field.

25. System according to claim 24, comprising a robotic manipulator (501 ) comprising an endeffector (502), wherein the source for creating the magnetic field comprises one or more rotating magnets, rotatably arranged at the end-effector, wherein the robotic manipulator comprises a controlling system (504) for controlling rotation, position and orientation of the one or more rotating magnets.1626. System according to claim 25, wherein the rotating magnets comprise at least one permanent magnet.

27. System according to any one of claims 24 - 26, wherein the controlling system is arranged to drive the device when being in a bodily fluid or tissue, byway of suitably manoeuvring the rotating magnet in the vicinity of the device.

28. System according to any one of claim 25-27, wherein the robotic manipulator is a 6-degrees- of-freedom (DOF) manipulator.

29. System according to any one of claim 25-28, wherein the system comprises detecting means for detecting the device in the bodily fluid or tissue.

30. System according to any one of claim 25-29, wherein the controlling system is arranged to receive information from the detecting means and to control the device using the received information.31 . System according to any one of claims 25 - 30, wherein controlling system is arranged to:- receive a backward instruction, and- drive the device in a backward direction by reversing the rotation direction of the rotating magnet.

32. Method for controlling the movement of a device according to any of claims 1 - 22 in a human or animal body by a controlling the magnetic field, in particular a direction and / or magnitude of the magnetic field.

33. Method according to claim 32, wherein the direction of the magnetic field causes the device to rotate along its longitudinal axis either in a first direction or in a second, opposite direction, and wherein the rotation of the device in the first direction causes the device to move in a first, substantially longitudinal direction and the rotation of the device in the second direction causes the device to move in a second, opposite direction.

34. Method for removing a material part, for example a blood clot or any other occlusion, from a human or animal body, said method comprising the use of the device as claimed in any of claims 1 - 22.

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