Magnetically steerable device for interior of mammalian body

Abstract

A steerable device for use in the body of a mammal, comprising a flexible elongate element (1) and a magnetic element (4) located at a distal end portion of the elongate element (1), steerable by an external magnetic field. The steerable device includes a structural section proximate the magnetic element, the structural section having a plurality of elongated protrusions formed on an outer surface of the elongated element. Each elongated projection has a projection longitudinal axis, each projection longitudinal axis forming an angle with the device longitudinal axis, where each angle is less than 90 DEG such that when the elongated element (1) is rotated in a clockwise direction about the device longitudinal axis (12), the elongated element (1) is moved forward relative to the soft tissue. In another aspect, the structural section is in the form of an external thread structure (2).

Description

Technical Field

[0001] The present invention relates to a manipulable device for use in a mammal. The device may be a needle, a guide wire, a catheter, an endoscope or any other flexible device designed to be inserted into a mammal for diagnostic or interventional purposes. Background Art

[0002] Many medical procedures require guiding medical devices to specific locations in the body. Examples include deep brain stimulation, organ biopsy, targeted drug delivery, tumor resection, etc. The methods for inserting and guiding such devices vary, depending on the application.

[0003] When performing surgery inside an organ such as the brain or liver, a semi-rigid needle or guidewire is passed from an incision through the soft tissue of the organ to the target site. The needle is usually rarely or not steered or guided, so the path from the incision to the target site is essentially a straight line. The number of target points that can be reached is very limited (for example, it is difficult to reach a target site that is at a large angle to the insertion site). Because these devices are relatively rigid, they need to be guided to different target sites within the organ using a dedicated path from the incision to the target site. This can cause great damage to the tissue between the insertion site and the target site. Friction between the soft tissue and the outer surface of the device can also cause problems, and if the needle or guidewire is flexible enough, it will often bend, further damaging the tissue and limiting the effectiveness of the surgery.

[0004] When performing surgery in a body cavity such as the abdomen or bladder, a flexible device is typically manipulated by pulling on a wire or rotating the pre-bent distal end while pushing on its proximal end. There is a trade-off between the device's ability to reach the target site and its ability to advance without bending - if the device is flexible enough to allow for wide angles of manipulation from the insertion site, it is also more likely to bend or form loops when advanced.

[0005] When performing a procedure in a blood vessel, the proximal end of the catheter or guidewire is pushed into the vessel and guided to the target site, again by a pull-wire or pre-bent tip. Again, there is a trade-off between rigidity (so that it does not bend when pushed) and the flexibility required to reach the target site. Since the device is advanced by pushing on its proximal end, prolapse of the device often limits its ability to reach the target site deep in the vessel and may cause damage to the vessel wall.

[0006] Some proposed devices use magnetic device tips, which can make the device more flexible and its trajectory more precisely controlled, but these devices still rely on propulsion to move forward, which has all the above difficulties. In addition, the rigidity required to propel the device also greatly limits its ability to be manipulated by magnetic forces.

[0007] US7,815,580B2 discloses a magnetic navigation guidewire, which is designed to pass through an occluded blood vessel. The guidewire consists of an elongated guidewire with a distal tip. A magnetic response element is arranged at the proximal end of the tip, which can respond to an external magnetic field to guide the distal end of the guidewire. A spiral thread is formed on the surface outside of the distal tip for screwing into the blockage in the occluded blood vessel. The guidewire is normally pushed through the blood vessel until it encounters an embolism. The guidewire is then rotated so that the spiral thread of the distal tip penetrates the embolism. When the guidewire is pulled out of the blood vessel, the embolism can be removed together with the guide wire, or a stent can be placed at the embolism. The spiral thread only extends a short length at the distal tip and is specifically used to drill the tip into the blood vessel blockage. The function of the guidewire is to install a stent and relieve the embolism caused by blood vessel blockage. Therefore, the tip of the guidewire only needs to reach the blockage and pass through the blockage with the help of the spiral thread. The guidewire still relies on a pushing device to move its tip through the blood vessel until the embolism, and retracting the guidewire requires pulling the proximal end of the guidewire. The helical threads do not extend beyond the outer surface of the main guide wire body, so they do not scratch or otherwise damage the vessel wall tissue. In addition, the helical threads are solid and can be screwed into the obstruction, rather than the flexible threads of the present invention.

[0008] US20100069718A1 discloses a different catheter for insertion into a body cavity of a human body. The distal end portion of the catheter is covered by a spiral thread structure, and the catheter can be advanced by rotation through a so-called rotary advancement device.

[0009] US2005272976A1 discloses an endoscope insertion aid, which has a flexible tube and a distal component, the outer diameter of the distal component is equal to or greater than the outer diameter of the tube. The outer circumferential surface of the tube has a spiral structure.

[0010] WO2021126905A1 and EP3643353A1 disclose a microdevice that can be moved in a patient's body under the manipulation of an external magnetic field and selectively perform a predetermined function. The microdevice includes a shell having an inner cavity and a magnetic device in the inner cavity. However, these devices do not form an elongated element having a proximal portion of the manipulable device, which is opposite to a distal portion that remains outside the mammal for external operation.

[0011] US2019060608A1 discloses a catheter, comprising an elongated shaft and a tip component disposed at the distal end of the shaft. The shaft may include a liner, a braided component surrounding the liner, a multilayer coil surrounding the braided component, and a polymer covering surrounding the multilayer coil. The outer surface portion of the polymer covering may include one or more spiral threads, and the spiral threads may be wrapped in an outer layer.

[0012] EP3854328A1 discloses a dilator that can be advanced and / or retracted by rotating a hollow shaft, and can also smoothly perform movement when linearly pushed in and / or pulled out. The dilator includes a hollow shaft, the hollow shaft includes a tapered portion whose diameter gradually increases from the distal end to the proximal end, and a helically arranged protruding portion, the protruding portion is provided on the outer peripheral surface of the hollow shaft, and includes a gap between adjacent portions along the axial direction of the hollow shaft.

[0013] EP3772317A1 relates to an endoscope for inspecting the gastrointestinal tract of a mammal (particularly the small intestine of a human), the endoscope comprising an elongated flexible tubular structure and a flexible elongated element disposed in the tubular structure, so that the distal end portion of the elongated element extends from the distal end of the tubular structure and is connected to the endoscope tip. The elongated element is engaged with the tubular structure in such a manner that when the tubular structure rotates around the elongated element in a first rotation direction, the gap between the endoscope tip and the distal end of the tubular structure increases, i.e., the endoscope becomes longer, and when the tubular structure rotates around the elongated element in a second rotation direction (opposite to the first rotation direction), the gap between the endoscope tip and the distal end of the tubular structure decreases, i.e., the endoscope becomes shorter.

[0014] In one embodiment disclosed in EP3772317A1, the tubular structure includes an outer helical surface structure, i.e., a groove that spirally rises along the length of the tubular structure, and the outer helical surface structure forms a continuous structure. During the operation of the endoscope, the doctor rotates the tubular structure, thereby rotating the elongated element to move the endoscope tip forward. The movement of the endoscope is the result of continuous elongation and contraction of the endoscope, and the length of the endoscope is variable. The movement of the endoscope tip is only indirectly related to the rotation applied by the doctor to the tubular structure. In fact, the movement of the tubular structure can correspond to the endoscope tip moving outward relative to the tubular structure that remains stationary, or the tubular structure moving toward the endoscope tip that remains stationary. When the device needs to be miniaturized, the structure of the endoscope itself will limit the possibility of miniaturization of the device, especially for the slender tubular structure required for transmission movement, the diameter of the endoscope is more difficult to reduce. Therefore, this concept is not suitable for intervention in the vascular system, which is usually less than 4 mm in diameter, not to mention the need for catheters with a diameter of even less than 2 mm in the human brain. Summary of the invention

[0015] The object of the present invention is to provide a device for use in mammals, which can be widely used for inspection and / or manipulation, diagnosis and / or intervention purposes in a reliable and reproducible manner in mammals, and does not have the disadvantages of the above-mentioned devices, in particular, there is no need to make a trade-off between flexibility and pushability.

[0016] This object is achieved by the invention by providing a device having the features of claim 1 or 10. Further advantageous embodiments of the invention are subject matter of the dependent claims.

[0017] The manipulable device can be a needle, a wire, a catheter, an endoscope, etc., used in a mammal, especially in a human body, for example, to perform inspection and / or operation. The manipulable device can be used to inspect and / or operate inside an organ (such as the liver, lung, kidney, brain, etc.), inside a body cavity (such as the abdomen, spinal cord, sinuses, etc.), or a blood vessel.

[0018] The device comprises an elongated element extending along a longitudinal axis of the device and configured to enter soft tissue of a mammalian body through an incision or other suitable means. A device tip may be placed at the distal end of the elongated element. In particular, the elongated element ends at the distal end with a device tip. The device tip may contain or carry a measuring and / or actuating device, such as a camera, a sensor, an ablation tip, a needle, an electrode, etc. The device may comprise an inner cavity, which may deliver a liquid, a needle, a biopsy tool, etc. to a target site. The end opposite to the device tip, i.e., the proximal end of the device, is designed to remain outside the mammalian body for external manipulation by a doctor or a robot, etc.

[0019] Furthermore, the length of the steerable device is fixed, that is, according to the invention, the length of a given steerable device remains constant during the intervention, unlike the device disclosed in EP 3 772 317 A1, whose length varies continuously so that it is constantly advanced.

[0020] The manipulable device also includes a magnetic element, which is located at the distal portion of the slender element and is configured to manipulate the slender element through an external magnetic field. The proximal portion of the manipulable device opposite to the distal portion remains outside the mammal's body so that the manipulable device can be manipulated from the outside. In a preferred embodiment, the magnetic element constitutes the front end of the manipulable device, so that the manipulable device can achieve the best manipulation effect. The magnetic element is preferably a permanent magnetic element. In a preferred embodiment, the magnetic element is arranged at the tip of the device, which contains or consists of at least one magnetic response element, so that the external magnetic field can control the direction of the tip of the device. In a preferred embodiment, the magnetic element includes a plurality of magnetic components, which are distributed along the distal portion of the slender element to form a magnetic element, and there are bending points between the magnetic elements, so that it is flexible.

[0021] An important limiting factor that hinders the advancement of traditional flexible medical devices in the soft tissues of mammals is friction: after a certain distance, the friction between the slender element and the soft tissue becomes too large to continue to effectively advance the device. In this case, the slender element either cannot be pushed forward or bends, both of which hinder further advancement of the distal end. All flexible medical devices that rely on traditional manipulation and propulsion have to make a trade-off between flexibility and propulsability.

[0022] According to one aspect of the invention, the manipulable device includes a structural section arranged near the magnetic element, the structural section including a plurality of elongated protrusions, the elongated protrusions formed on the outer surface of the elongated element, each protrusion having a protrusion longitudinal axis, the protrusion longitudinal axis forming an angle with the device longitudinal axis of the elongated element. The plurality of elongated protrusions form a plurality of angles with the device longitudinal axis, wherein the plurality of angles are all less than 90°. The angle is measured in a clockwise direction from the direction of the device longitudinal axis pointing from the proximal end to the distal end. This arrangement allows the elongated element to move forward along the device longitudinal axis relative to the soft tissue when the elongated element rotates in a clockwise direction around the device longitudinal axis.

[0023] The surface roughness of the structured section is greater than the surface roughness of the remaining non-structured section of the elongated element.

[0024] The basic principle of the present invention is to combine a structural segment with a magnetic element in a steerable device. The rotation of the structural segment disclosed above can push the elongated element forward in the soft tissue, while the magnetic element arranged at the distal end of the structural segment allows precise steering of the steerable device.

[0025] The flexibility of the magnetic element is usually lower than the flexibility of the elongated element. In addition, the flexibility of the elongated element with the structural section is also lower than the flexibility of the elongated element without the structural section. Therefore, it is preferred to arrange the structural section near the magnetic element to avoid overlapping of the structural section and the magnetic element. Therefore, the flexibility of the manipulable device is not excessively weakened, for example, it can still be accurately advanced in a blood vessel or at a branch vessel. More preferably, the magnetic element is arranged in a non-structural section. Therefore, the distal part can be manipulated by the magnetic field, and the friction of the device is limited.

[0026] In embodiments where the structural section is arranged close to the magnetic element, the distal portion of the structural section may at least partially overlap the magnetic element. Thus, the distal portion may be slightly reinforced by the elongated protrusion and the magnetic element, thereby reducing bending.

[0027] When the elongated element is rotated in the clockwise direction, the structural section is configured to advance the elongated element by rotating a plurality of the elongated elements. This simultaneously enables the structural section to remain flexible, especially more flexible than a portion of the same length with a continuous thread, and is simple in design and easy to manufacture.

[0028] The rotational movement generates a propulsion force over the entire length of the elongated element where the structural segments engage the surrounding soft tissue via the outer surface of the elongated element. The device is therefore flexible and does not present the above-mentioned problems typically associated with flexible medical devices. The magnetic steering device can even control it while rotating, which is not possible with conventional devices based on steering with pull wires or pre-bent distal portions.

[0029] Advantageously, when manufacturing a structural section comprising a plurality of elongated protrusions, a greater tolerance in the orientation of the elongated protrusions can be tolerated, as long as the angle formed with the longitudinal axis of the device is less than 90°. Thus, the structural section can be manufactured easily and at low cost.

[0030] The plurality of angles are measured in a clockwise direction relative to a longitudinal axis of the device oriented from the proximal end to the distal end. In other words, when the elongated member is oriented from the proximal end to the distal end, the longitudinal axis of the device is oriented from the 6 o'clock direction (corresponding to the proximal end) to the 12 o'clock direction (corresponding to the distal end), and the angle between the longitudinal axis of the device and the longitudinal axis of the projection is measured clockwise from the 12 o'clock direction as seen on a clock.

[0031] In a preferred embodiment, the plurality of angles have a single angle value between 5° and 80°, i.e., the angle value of all the angles in the plurality of angles is the same. The advantage of a single angle value is that the thrust along the longitudinal axis of the device is increased, and the disclosed range allows the maneuverable device to be propelled from the proximal end to the distal end when rotated in a clockwise direction. In a more preferred embodiment, the single angle value is between 10° and 60°, thereby optimizing the thrust along the longitudinal axis of the device. In a more preferred embodiment, the single angle value is preferably between 20° and 30°. Experiments have shown that within the above range, the maneuverable device has achieved excellent progress. It should be noted that the term "single angle value" must be understood as a single angle value within the manufacturing tolerance range. Therefore, a "single angle value" can include more than one value, and within the manufacturing tolerance range, these values ​​are distributed around the center value (i.e., the single angle value).

[0032] The elongated protrusion may have an elliptical shape, the major axis of which defines the longitudinal axis of the protrusion. Other elongated shapes are also possible, such as a rectangle with the long side defining the longitudinal axis of the protrusion.

[0033] The plurality of elongated protrusions are separated from each other, that is, no common contact area exists between two elongated protrusions.

[0034] Furthermore, the circumference of each of the plurality of elongated protrusions is shorter than the circumference of the elongated element in the region of the structure in which the elongated protrusion is located. In other words, the elongated protrusions extend less than one turn around the elongated element as viewed in the longitudinal direction. The elongated protrusions extend only over a portion of the circumference of the elongated element and are separated from one another. This is in stark contrast to a helical structure, which extends continuously in the longitudinal direction for more than one turn.

[0035] The circumferential extension of each elongated protrusion can be characterized by a circular sector measured on a plane perpendicular to the longitudinal axis of the device, the angle of which corresponds to the angle of the projection of the radius passing through the proximal and distal ends of the elongated protrusion on the above plane. Since the longitudinal length of the plurality of elongated protrusions is shorter than the circumference of the elongated element, the angle of the circular sector is less than 360°.

[0036] In a preferred embodiment, the circular sectors of the plurality of elongated protrusions range from 30° to 150°. The angle of the circular sectors is preferably between 60° and 120°. On the one hand, the extension of the elongated protrusions is sufficient to engage with the surrounding soft tissue, and on the other hand, the extension of the elongated protrusions is not sufficient to significantly reduce the flexibility of the steerable device in the structural section. More preferably, the angle of the circular sectors is 100°. This configuration can optimize the two aspects described above.

[0037] In a preferred embodiment, two continuous elongated protrusions among a plurality of elongated protrusions overlap at least partially on the circumference. In other words, the circular sector angles corresponding to the two continuous grooves overlap. The circular sector angles preferably overlap by 10% to 30% at each location. More preferably, the circular sector angles overlap by 20% at each location. The two continuous elongated protrusions overlap to form a continuous area that engages with the surrounding soft tissue. As a result, continuous engagement with the surrounding soft tissue is formed, which promotes the advancement of the manipulable device. It must be noted that the overlap of the circular sector angles occupied by two continuous elongated protrusions does not mean that the elongated protrusions intersect. In fact, whether there is an intersection also depends on the axial extension of the elongated protrusions.

[0038] In a preferred embodiment, a plurality of elongated protrusions are arranged along a thread path, and the thread path angle is equal to a single angle value. The thread path angle is defined as the angle of the thread path relative to the longitudinal axis of the device when viewed from the side. In this embodiment, the thread path forms a discontinuous thread spiral. The arrangement of the elongated protrusions along the thread path, in particular along the helical path, further improves the propulsion capability of the steerable device when it is rotated. This ensures that the force distribution is uniform across the entire structural section, thereby improving the control of the propulsion.

[0039] The thread path preferably extends at least one turn from the proximal end to the distal end of the structural region. This embodiment ensures the stability of the structural region in length. More preferably, the spiral path extends multiple turns from the proximal end to the distal end. Experimental results show that in this case, the stability of the structural region in length is optimized.

[0040] In another preferred embodiment, a plurality of elongated protrusions may overlap end to end and form a continuous thread on the outer surface of the elongated element. The continuous thread formed by the elongated protrusions ensures uniform force distribution around the structural segment, thereby improving control of propulsion.

[0041] In a preferred embodiment, the plurality of angles have at least two angle values, the angle values ​​being selected between 5° and 80°. In another preferred embodiment, the at least two angle values ​​are selected between 20° and 60°. More preferably, the at least two angle values ​​are between 20° and 30°. The advantage of having at least two angle values ​​is that the thrust along the longitudinal axis of the device can be optimized according to the angle at which the manipulable device contacts the soft tissue. If the elongated element having one of the at least two angle values ​​cannot support the advancement of the manipulable device because the contact with the soft tissue at this angle value is not suitable, then the elongated element having another angle value in the at least two angle values ​​can support the advancement of the manipulable device. In a more preferred embodiment, the plurality of angles have two angle values, the two angle values ​​being selected between 20° and 60°, i.e., all the angles in the plurality of angles are selected in the set of two angle values. More preferably, the two angle values ​​are selected between 20° and 30°. The embodiment with only two angle values ​​is a good compromise between improved propulsion capability and manufacturing complexity. In a more preferred embodiment, the two angle values ​​are 30° to 60° apart. The two angle values ​​are separated from each other to optimize the possibility of contact with soft tissue.

[0042] In a preferred embodiment, the plurality of angles have at least two angle values, the plurality of elongated protrusions are arranged along at least two thread paths, and the thread path angle of each thread path is equal to one of the at least two angle values. Preferably, the at least two thread paths extend at least one turn from the proximal end to the distal end of the structural region. The features related to the elongated protrusions discussed in the above embodiment with one thread path are also applicable to the embodiment with at least two thread paths.

[0043] In a preferred embodiment, the outer tubular structure surrounds a portion of the elongated element, and the tubular structure includes an engagement element configured to engage with a plurality of elongated protrusions so that when the elongated element rotates about its device longitudinal axis, the elongated element moves relative to the tubular structure along the device longitudinal axis. The tubular structure will be described in detail in another embodiment below. The effects and advantages associated with the tubular structure are also applicable to this embodiment.

[0044] In a preferred embodiment, the plurality of elongated protrusions have a triangular cross section for better contact with soft tissue. In a preferred embodiment, the plurality of elongated protrusions have a circular cross section for forming a smooth contact surface with the soft tissue. In a preferred embodiment, the plurality of elongated protrusions have a hump-shaped cross section, preferably a cross section approximating a sine curve form, for forming a smoother contact surface with the soft tissue.

[0045] In a preferred embodiment, the structural section is interrupted by a plurality of non-structural sections without elongated protrusions. The non-structural sections have a higher flexibility, while the flexibility of the elongated elements in the structural sections is reduced. In this way, the steerable device can be configured with a portion having a higher flexibility (i.e., the non-structural section), thereby reducing the reduction in flexibility of the structural section, thereby optimizing the propulsion capability of the steerable device.

[0046] In a more preferred embodiment, the non-structural sections of the plurality of non-structural sections have the same length and are separated from each other by a constant spacing. This simple design also provides a uniform flexibility profile along the longitudinal axis of the device, making the steerable device easy to control.

[0047] The elongated protrusion may be made of a material suitable for biomedical applications. In particular, it may be a magnetically non-responsive material, such as a non-ferromagnetic material, to avoid interaction with the magnetic field used to guide the elongated element. For example, suitable materials may be nylon, polyurethane, polyethylene, polyether block amide (e.g. trade name ) or polymer materials such as silicone.

[0048] Additionally, an embodiment of a steerable device is disclosed wherein a flexible elongated member extends along a longitudinal axis of the device and is configured to access soft tissue of a mammalian body.

[0049] In addition, the magnetic element is located at the distal portion of the elongated element and is configured to manipulate the elongated element by an external magnetic field. The proximal portion of the manipulable device opposite the distal portion remains outside the mammal so that the manipulable device can be manipulated from the outside. Since the magnetic element is not as flexible as the elongated element, it is more advantageous to arrange it at the distal portion, so that when manipulating the manipulable device, for example, in a blood vessel or at a branch vessel, it is easier to advance and more accurately position the magnetic element. The magnetic element includes or consists of at least one magnetically responsive element, so that the external magnetic field can control the direction of the device tip. The magnetic element is preferably a permanent magnetic element.

[0050] The magnetic element is responsive to an external magnetic field so that manipulation of the elongate element can be controlled.The magnetic field may be generated by a device placed outside the mammal's body or by any other suitable means.

[0051] In another aspect of the invention, the manipulable device comprises a structural section in the form of an external thread structure formed on the outer surface of the elongated element and having a radial extension beyond the outer surface of the elongated element. In a preferred embodiment, the thread structure is a helical thread structure. The thread structure may take the form of an auger.

[0052] Furthermore, the length of the steerable device is fixed, that is, according to the invention, the length of a given steerable device remains constant during the intervention, unlike the device disclosed in EP 3 772 317 A1, whose length varies continuously so that it is continuously advanced. The diameter of the elongated element is substantially the same, preferably the same over the entire length of the steerable device.

[0053] According to the present invention, the thread structure is made of a magnetically non-responsive material and is configured to engage with soft tissue surrounding the elongated element in a mammal so that when the elongated element is rotated about its device longitudinal axis, the elongated element moves relative to the soft tissue along the device longitudinal axis.

[0054] The rotation of the threaded structure allows the elongated element within the soft tissue to be pushed forward, while the magnetic element allows the device to be steered. When the elongated element is rotated in a clockwise direction, the configuration of the structural segments, i.e. the threaded structure, supports the advancement of the elongated element. The rotational movement generates a thrust over the entire length of the elongated element, wherein the threaded structure contacts the surrounding soft tissue through the outer surface of the elongated element. As a result, the device can be extremely flexible without the above-mentioned problems usually associated with flexible medical devices. The magnetic steering device can even control it during rotation, which is not possible with traditional devices based on the steering of a pull wire or a pre-bent distal portion.

[0055] The thread structure may be formed by a wire which is wound around the elongated element along its length. Alternatively, the thread structure may be formed by extrusion molding on the outer wall of the elongated element.

[0056] The threaded structure is made of a magnetically non-responsive material to avoid interaction between the threaded structure and the magnetic field used to manipulate the magnetic element, thereby avoiding deviations in the path of the manipulable device. This embodiment can optimize manipulation. For example, the magnetically non-responsive material can be a non-ferromagnetic material. However, the magnetically non-responsive material can also be a material with diamagnetic or paramagnetic properties, and its magnetic contribution is negligible compared to the magnetic contribution of the magnetic element used to manipulate the device. These properties make the interaction between the external threaded device structure and the magnetic field several orders of magnitude smaller than the interaction between the magnetic element and the magnetic field, so the interaction between the external threaded structure and the magnetic field does not need to be considered when manipulating the manipulable device in a mammal.

[0057] In a preferred embodiment, the thread structure has a triangular cross section to better contact the soft tissue. In a preferred embodiment, the thread structure has a circular cross section to form a smooth contact surface with the soft tissue. In a further preferred embodiment, the thread structure has a hump-shaped cross section, preferably a cross section similar to a sine curve, to form a smoother contact surface with the soft tissue. Another advantage of the hump-shaped cross section is that it can avoid the formation of cavities between the thread structure and the outer surface of the elongated element.

[0058] In a preferred embodiment, the thread structure is interrupted by a plurality of non-structured sections without thread structure. The flexibility of the non-structured sections is relatively high, while the flexibility of the thread structure is relatively low. In this way, the steerable device can be configured with sections having relatively high flexibility, i.e., non-structured sections, thereby mitigating the reduction in the flexibility of the thread structure and thus optimizing the propulsion of the steerable device.

[0059] Furthermore, according to the invention, the threaded structure is arranged near the magnetic element. The flexibility of the magnetic element is usually lower than the flexibility of the elongated element. Furthermore, the flexibility of the elongated element with the threaded structure is also poorer than the flexibility of the elongated element without the threaded structure. Therefore, it is advantageous to avoid overlapping of the threaded structure and the magnetic element, so that the flexibility of the manipulable device is not excessively reduced and accurate advancement can be achieved, for example, in a blood vessel or at a branch vessel. More preferably, the magnetic element is arranged in a non-structured section. Therefore, the distal part can be manipulated by the magnetic field and the friction of the device is limited.

[0060] In a preferred embodiment, the radial extension of the thread structure measured from the outer surface of the elongated element has a first value in a first part of the structure portion and a second value different from the first value in a second part of the structure portion (arranged proximal to the first part), so that the first part has a different flexibility than the second part. In this way, the thread structure itself can be configured to be flexible. In another preferred embodiment, the second value is greater than the first value, and the radial extension gradually decreases from the second value to the first value towards the distal end of the device tip.

[0061] The thread structure extends radially beyond the outer surface of the elongated element. An advantage of this configuration is that the thread structure can be embedded in the soft tissue surrounding the elongated element and generate a thrust along the longitudinal axis of the device when the elongated element is rotated around or about the longitudinal axis of the device.

[0062] Since the force that propels the elongated element forward is generated by its rotational engagement with the soft tissue, thrust is generated at all locations on the elongated element where the threaded structure engages the soft tissue. As a result, the elongated element can be designed to be more flexible and / or resilient than a device that relies solely on proximal thrust for movement, without the risk of bending the elongated element. Furthermore, since the angle of rotation can very reliably determine the amount of linear movement, the advancement movement of the manipulator in the distal direction and the retreat or retraction movement in the proximal direction can be controlled more accurately.

[0063] Therefore, the longitudinal axis or centerline of the device must be understood as a line passing through the center of the slender element, or in other words, a line connecting the centers of all cross-sectional circles obtained when observing each cross-section of the slender element along its length.

[0064] When the elongated element is moved within soft tissue (such as the brain or liver), the elongated element may be guided or moved along a curved path. In a preferred embodiment, the magnetic element is mounted at the tip of the device. Compared to traditional pull-wire-based manipulation, magnetic manipulation makes the device more flexible and can turn during rotation, which cannot be done by a pull-wire. In a preferred embodiment, the tip of the device constitutes the front end of the manipulable device, allowing the manipulable device to achieve optimal manipulation. In particular, the tip of the device itself can be magnetic and used as the magnetic element described herein.

[0065] Because the device uses rotational motion to generate forward and backward movement, it is more flexible than traditional devices that rely on proximal push / pull forces for movement. This flexibility is critical to being able to effectively pass magnetic manipulation devices, as the forces generated by magnetic manipulation are far less than those generated by traditional manipulation methods such as pull wires. In addition, when manipulating the device along a tortuous path, the nature of the rotational motion mechanism allows the device to continue to advance or retreat without the risk of bending or cutting tissue. The rotational motion mechanism and remote magnetic manipulation device work together to enable the device to move along complex and tortuous paths that traditional devices cannot do.

[0066] According to an advantageous embodiment, the thread structure is formed along at least 10%, 50% or 80% of the length of the elongated element.The longer the thread structure, the more the force pushing the elongated element is distributed over the length of the elongated element.

[0067] The engagement of the threaded structure with the soft tissue will stabilize the device and prevent it from being pushed back when the tool is inserted through the device into the target site (such as an injection); it will also allow the tool to pass through the device to apply greater tension to the tissue at the target site than can be achieved using such a flexible device (such as a biopsy). In some embodiments, the slender element may include two or more threaded structures spaced apart along the length of the slender element.

[0068] The thread path angle of the thread structure is preferably between 5° and 60°. In particular, the thread path angle of the thread structure should be such that the intermediate gap between the threads is sufficient to engage with soft tissue.

[0069] For body cavities, the overall diameter of the device is preferably no more than 15 mm; for organs, the overall diameter of the device is preferably no more than 6 mm; for blood vessels, the overall diameter of the device is preferably no more than 3 mm.

[0070] Advantageously, the thread structure has a thickness measured radially from the outer surface of the elongated element of 5% to 15% of the diameter of the elongated element, in particular 5% to 15% of the outer diameter of the elongated element.

[0071] In a preferred embodiment, the magnetic element comprises a plurality of magnetic components which are distributed along the distal portion of the elongated element to form a magnetic element having bending points and thus being flexible.

[0072] In a preferred embodiment, a section of the elongated element is surrounded by an outer tubular structure, such as a sheath. The tubular structure may be flexible. The elongated element and the tubular structure may in particular be arranged coaxially or substantially coaxially.

[0073] Advantageously, the tubular structure comprises an engagement element configured to engage with the threaded structure so that the elongated element moves relative to the tubular structure along the longitudinal axis of the device when the elongated element rotates about its longitudinal axis of the device. In particular, the engagement element, such as a protruding element such as a pin, a nail or a bearing ball, can extend into the thread of the threaded structure, or, where applicable, into a plurality of elongated protrusions, converting the rotation of the elongated element relative to the engagement element into a translational movement of the elongated element relative to the engagement element. In particular, the engagement element can be an internal thread, with only a few turns of winding, complementary to the threaded structure, and arranged on the inner wall of the tubular structure. This feature facilitates the advancement of the manipulable device, as the tubular structure can act as a temporary anchor, allowing the elongated element to be pushed forward or backward. The tubular structure helps to increase the rigidity of the device and / or reduce the number of threads in contact with soft tissue, or (if applicable) reduce the number of multiple elongated protrusions in contact with soft tissue.

[0074] In a preferred embodiment, the engaging element can be designed to seal with the threaded structure to prevent the backflow of body fluids, or it can be designed to allow the body fluids pumped into the tubular structure to freely enter the body.

[0075] Advantageously, the elongated element can freely pass through the lumen of the tubular structure and is connected to the tubular structure only by such a rotational engagement mechanism. In particular, the linear range of motion of the elongated element is not limited by its connection to the tubular structure. Preferably, a portion of the elongated element extending out of the tubular structure, between the tip of the device and the distal end of the tubular structure, is exposed to the outside, in particular to the environment of the surrounding soft tissue, i.e. not protected by other parts of the steerable device.

[0076] In a preferred embodiment, the thread structure is freely wound around the elongated element, wherein the distal end of the thread structure is fixed to the elongated element, and the proximal end of the thread structure is detachably fixed to the elongated element so as to provide different thread pitches by longitudinal displacement of the proximal or distal end, i.e., by extending or compressing the thread structure. An advantage of this embodiment is that when contact with soft tissue is not suitable for supporting advancement at a given thread pitch, the thread pitch can be modified, i.e., compressed or extended or both (e.g., alternately), to better support the advancement of the steerable device.

[0077] In a preferred embodiment, the threaded structure is freely wound around the elongated element and is fixed to the elongated element by a locking device, which engages with the threaded structure in a first rotational direction of the elongated element to transmit the rotational movement of the elongated element to the threaded structure and disengages from the threaded structure in a second rotational direction opposite to the first rotational direction to allow the threaded structure to rotate freely. More advantageously, such an embodiment can control friction with surrounding soft tissue, which is not conducive to safe advancement of the manipulator.

[0078] In another preferred embodiment, the locking device is retractable, allowing the threaded structure to rotate freely in the first rotational direction and the second rotational direction. More advantageously, if the external thread is blocked or the friction with the surrounding soft tissue is too large, which is not conducive to the safe advancement of the manipulable device, this embodiment can release the external thread engaged with the surrounding soft tissue.

[0079] The elongated element should be flexible enough to move along the curved paths of human soft tissue. On the other hand, the elongated element should be rotationally rigid enough to allow torque applied to the proximal portion of the elongated element to be directly transmitted along the length of the elongated element to the more distal section where the threaded structure is located. This direct torque transmission is particularly important for the above-mentioned rotational motion mechanism. Longitudinal flexibility and torsional rigidity of the elongated element can be achieved through a combination of material and design features, such as the use of multiple layers of tubular materials and hollow stranded wire coils, as described below.

[0080] Advantageously, the elongated element comprises a plurality of coaxially arranged tubular layers. Preferably, at least 2 or 3 coaxially arranged tubular layers are stacked radially, ie along the thickness of the elongated element.

[0081] In a preferred embodiment, the elongated element comprises at least one tubular layer, which is made of a plurality of wires, in particular metal wires (e.g., metal wires made of a stainless steel alloy), which are wound in a spiral manner on a tubular surface along the longitudinal axis of the device, so that the plurality of wires are closely arranged together. In other words, in a cross-sectional view of the tubular layer, the cross section is perpendicular to the longitudinal axis of the device of the elongated element, and each wire has a wire cross section on the circumference of the tubular layer. The tubular layer is preferably composed of at least 7, 9 or 11 wires. Such a tubular layer can be referred to as a wire stranded hollow coil body as described in EP1428547A2, or a hollow wire stranded coil as described in EP2263736A1.

[0082] In an advantageous embodiment, the wire winding direction of one tubular layer is opposite to the wire winding direction of another tubular layer. This means that when looking at a cross section of the elongated element and looking along the length of the elongated element, the wire wound in one tubular layer will rotate in one direction, while the wire wound in the other tubular layer will rotate in the opposite direction. Preferably, the tubular layers with opposite winding directions are closely adjacent in the elongated element. It is further preferred that the winding direction of successive tubular layers alternates from one tubular layer to an adjacent tubular layer, across three or more tubular layers.

[0083] According to another embodiment, the elongated element comprises a tubular layer having perforations along its length and circumference. The size and distribution of the perforations in the tubular layer may determine the flexibility of the elongated element. Alternatively, the tubular layer may comprise indentations distributed along the length and circumference of the tubular layer in addition to the perforations. In particular, the distribution of the perforations or indentations along the length of the tubular layer may be periodic.

[0084] Advantageously, the tubular layer comprises slits extending in a circular or helical direction along its surface.Each slit may extend over the entire circumference of the tubular layer, interrupted at two or more points by a bridging structure.

[0085] The elongated element may be composed of multiple parts with different flexibility along its length. For example, the distal section toward the tip of the device may have greater flexibility than other parts of the elongated element to achieve more effective magnetic manipulation in narrow spaces.

[0086] The elongated element may include an inner cavity through which medical devices (such as needles, biopsy tools, etc.) and liquids (such as drugs, contrast agents, coagulants, solutions, etc.) can be passed, especially through the inner cavity where the inner cavity terminates at the distal end of the device tip, so that the liquid can be delivered to the desired location in the mammal body.

[0087] In addition, the use of a manipulable device and a medical system according to any of the above embodiments is also disclosed, the medical system comprising a magnetic field generator, which is designed to generate a force magnetic field with a predetermined direction, amplitude and spatial variation for application to the manipulable device, and a unit for applying a rotational motion to the manipulable device. The medical system can be widely used for inspection and / or operation, diagnosis and / or intervention in mammals. The magnetic field force generator is preferably in the form of a magnetic navigation system with a plurality of electromagnets or permanent magnets, which are located around the patient and can move, and provide an inhomogeneous magnetic field at a predetermined position in space, in which the manipulable device moves.

[0088] As used herein, "proximal" and "distal" are relative to the position at which a medical professional uses a manipulable device. Thus, the term "distal" describes a part, portion or direction that is directed toward or placed inside a patient's body and that cannot be directly manipulated by the medical professional's hands. Similarly, "proximal" refers to a part, portion or direction that is located at or toward the position of the medical professional. In particular, the proximal end refers to the end of an elongated element that will extend out of an incision during use, i.e., the proximal end of the elongated element extends outside the mammalian body during use, while the distal end of the elongated element refers to the end of the elongated element that is inside the patient's body during surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Some embodiments of the present invention will be described in detail in the following description with reference to the accompanying drawings, in which:

[0090] Figure 1 shows a cross-sectional view of a steerable device according to a first embodiment;

[0091] Figure 2 shows a cross-sectional view of a steerable device according to a second embodiment;

[0092] Figure 3 shows a cross-sectional view of a steerable device according to a third embodiment;

[0093] Figure 4 shows a cross-sectional view of a steerable device according to a fourth embodiment;

[0094] Figure 5 shows a cross-sectional view of an elongated element covered by a thread structure according to a fifth embodiment;

[0095] Figure 6 shows a tubular layer of an elongated element according to a sixth embodiment;

[0096] Figure 7 shows a perspective view of a maneuverable device with structural segments according to a seventh embodiment;

[0097] Figure 8 shows a detailed side view of a structural section according to a preferred embodiment;

[0098] Fig. 9 shows a detailed side view of a structure section according to a further preferred embodiment;

[0099] Fig.10 shows a detailed side view of a structure section according to a further preferred embodiment;

[0100] Fig.11 A side view showing the thread structure of the steerable device according to the preferred embodiment;

[0101] Fig.12 A side view showing the thread structure of a manipulable device according to a further preferred embodiment;

[0102] Fig.13 A side view showing the thread structure of a manipulable device according to a further preferred embodiment;

[0103] Fig.14 A cross-sectional view showing the thread structure of a manipulable device according to a preferred embodiment;

[0104] Fig.15 a cross-sectional view showing the thread structure of a steerable device according to a further preferred embodiment; and

[0105] Fig.16 A cross-sectional view of a thread structure of a steerable device according to a further preferred embodiment is shown. DETAILED DESCRIPTION

[0106] Figure 1 A cross-sectional view of a manipulable device according to one possible embodiment is shown. In this embodiment, the device comprises an elongated element 1 having a device tip 3 at its distal end. The elongated element 1 has a wall 11 enclosing an inner cavity 10 extending along the longitudinal axis of the device. Various medical devices and / or substances can enter through the inner cavity 10 of the elongated element 1 and flow out of the device tip 3 to a desired internal body site.

[0107] The outer surface of the elongated element 1 has a structural area in the form of a thread structure 2. The thread structure 2 is formed as a spiral drill, and the thread structure 2 is spirally wound around the outer surface of the elongated element 1 and extends to the device tip 3. When the device is inserted into the soft tissue of the mammal's body (such as an organ, body cavity, blood vessel or other soft tissue) through an incision, the thread structure 2 engages with the tissue around the elongated element 1, so that the rotation of the elongated element 1 will cause the elongated element to advance or retreat along its longitudinal axis of the device. Depending on the direction of rotation of the elongated element 1, the device can be advanced or backward.

[0108] The device tip 3 is magnetic, ie, partially or completely made of magnetically responsive material. This is a possible implementation method of placing a magnetic element 4 at the device tip 3 or in the vicinity thereof.

[0109] Figure 2 A slightly different embodiment of the steerable device is shown. In this embodiment, the threaded structure 2 does not extend all the way to the device tip 3. Instead, the magnetic element 4 is designed as a magnetic assembly in the form of a plurality of magnetic rings, which are placed equidistantly in the gap between the device tip 3 and the distal end of the threaded structure 2. The magnetic rings will increase the effect of the magnetic field on the device steering, while maintaining the flexibility of the elongated element between the magnetic rings.

[0110] Fig.11 Another embodiment of a manipulable device is shown, which has a structure similar to Figure 1 The embodiment of is similar, in which the thread structure 2 is interrupted by a plurality of non-structural sections 106, which have no thread structure and thus have a higher flexibility.

[0111] exist Fig.12 One of the public Figure 1 In an embodiment of a manipulable device having a similar structure, the radial extension of the thread structure 2 (measured from the outer surface of the elongated element 1) has a first value at the distal end 108 of the structure segment and a second value greater than the first value at the proximal end 110 of the structure segment, the radial extension gradually decreasing from the second value to the first value at the distal end towards the tip of the manipulable device. In an embodiment in which the cross section of the thread structure 2 is circular, the radial extension corresponds to the diameter of the thread structure 2, the radial extension having a greater value at the distal portion 108 than at the proximal portion 110.

[0112] exist Fig.13 One of the Figure 1 In an embodiment of a manipulable device having a similar structure, the thread structure 2 has a thread pitch 112, and the thread pitch 112 gradually increases from the distal end to the proximal end, so that the flexibility gradually increases from the distal end to the proximal end.

[0113] Figure 3 Another embodiment of a manipulable device is shown. Figure 1 The illustrated embodiment differs in that a portion of the elongated element 1 is surrounded by an outer tubular structure 5. The tubular structure 5 includes an engagement element 6 that engages a portion of the threaded structure 2 such that relative rotation between the elongated element 1 and the tubular structure 5 results in translational movement of the elongated element 1 relative to the tubular structure 5. This feature can help secure the device, improve the ability to advance and / or retract the elongated element, and provide another lumen for pumping fluid.

[0114] Figure 4 Displays manipulable devices (such as Figure 1 1 . It can be seen here that if the elongated element 1 is not in a straightened state, the device longitudinal axis 12 of the elongated element 1 can be a curved line.

[0115] Fig.14 , Fig.15 and Fig.16 A cross-sectional view of a possible but non-limiting embodiment of a thread structure is disclosed, and shows Fig.11 An enlarged area A of an exemplary embodiment of a manipulable device is shown. It is noteworthy that the disclosed cross-section is also similar to Figure 8 , Fig. 9and Fig.10 Possible cross-sections of the disclosed elongated protrusions. Fig.14 In the embodiment, the thread structure 2 has a triangular cross section so as to better contact with the soft tissue. Fig.16 In the embodiment, the thread structure 2 has a circular cross section so as to form a smooth contact surface with the soft tissue. Fig.15 In the embodiment, the thread structure 2 has a hump-shaped cross section and is a sinusoidal curve shape so as to form a smoother contact surface with the soft tissue and avoid the formation of a cavity between the thread structure 2 and the outer surface of the elongated element.

[0116] Figure 5 Details of the structure of an elongated element 1 designed according to a preferred embodiment are shown. The elongated element consists of a first tubular layer 7 and a second tubular layer 8 which is smaller in diameter and is mounted inside the first tubular layer 7. Figure 5 A cross-sectional view is shown with the left portion of the first tubular layer 7 removed, thereby revealing the second tubular layer 8 hidden underneath.

[0117] Each tubular layer 7, 8 is composed of a plurality of wires. For example, the first tubular layer 7 is composed of 12 individual wires 71, 72, 73, each of which is spirally wound to form the surface of the tubular layer 7. The wires 71, 72 and 73 together constitute the first tubular layer 7. The second tubular layer 8 is formed in a similar manner, but with a smaller overall diameter. In addition, the winding direction of the wires of the first tubular layer 7 is opposite to the winding direction of the wires of the second tubular layer 8. The spiral structure 2 is formed on the outer surface of the first tubular layer 7. The spiral structure 2 is composed of a single wire, which is wound in a manner similar to any of the wires 71, 72, 73 of the first tubular layer 7.

[0118] exist Figure 6 , a tubular layer 9 for an elongated element 1 according to various embodiments is shown. The tubular layer 7 is made of a solid tube with perforations to control the bending stiffness of the tubular layer. The perforations 91 form an annular gap along the length of the tubular layer 9. A plurality of such coaxially arranged tubular layers can be combined to form an elongated element 1. In addition, such a tubular layer can also be combined with Figure 5 One or more tubular layers 7, 8 are shown used in combination.

[0119] Figure 7 The steerable device shown comprises an elongate element 1 extending along a device longitudinal axis 12 and a device tip 3 at the distal end of the elongate element 1. The device tip 3 is magnetic, ie made partially or entirely of a magnetically responsive material, to steer the steerable device in a magnetic field.

[0120] Furthermore, the steerable device comprises a structural section 100 comprising a plurality of elongated protrusions 102. In this embodiment, the structural section 100 is interrupted by a plurality of non-structural sections 106 (here two non-structural sections) which are devoid of elongated protrusions.

[0121] from Figure 8 , Fig. 9 and Fig.10 You can see in more detail, Figure 8 , Fig. 9 and Fig.10 1 and 10. Each of the plurality of elongated protrusions 102 defines a protrusion longitudinal axis 104. The portion has a proximal end 110 and a distal end 108. Each protrusion longitudinal axis 104 defines an angle α1 (alpha1), α2 (alpha2) with the device longitudinal axis 12, and the plurality of elongated protrusions 102 form a plurality of angles, wherein the plurality of angles are measured in a clockwise direction relative to the longitudinal axis 12 oriented from the proximal end to the distal end, and the plurality of angles are less than 90°. In other words, in Figure 8 , Fig. 9 and Fig.10 In the figure, the direction from the proximal end to the distal end is the direction from the bottom to the top in the figure. Due to the arrangement of the elongated protrusions, the rotation of the elongated element 1 about the longitudinal axis 12 of the device causes the elongated element to move along the longitudinal axis of the device relative to the soft tissue. For the sake of clarity, only a limited number of the longitudinal axes 104 of the protrusions and the angles α1, α2 are shown.

[0122] exist Figure 8 and Fig. 9 In the embodiment of the present invention, the elongated protrusion is substantially elliptical, wherein the major axis of the ellipse defines the protrusion longitudinal axis 104. Figure 8 In the embodiment, the plurality of angles have two angle values ​​α1 and α2, wherein α1 is about 60° and α2 is about 30°. In this embodiment, the angle α1 and the angle α2 differ by about 30°. Fig. 9 In the embodiment of the present invention, the plurality of included angles have a single included angle value α1. In addition, the plurality of elongated protrusions 102 are arranged along a thread path having a thread path angle equal to the included angle value α1 and having a thread pitch 112. In this embodiment, the thread path forms a discontinuous thread spiral, of which only one visible side is shown.

[0123] exist Fig.10 In the embodiment of the present invention, the elongated protrusion is substantially rectangular, wherein the length of the rectangle defines the protrusion longitudinal axis 104, and the protrusion longitudinal axis 104 forms an angle α1 with the device longitudinal axis 12. It should be noted that a single angle value of the plurality of angles is α1.

[0124] Reference numerals:

[0125] 1 Slender elements

[0126] 10 Lumen of elongated element

[0127] 11 Walls of slender elements

[0128] 12 Longitudinal axis of the device

[0129] 2 External thread structure

[0130] 3 Device Tip

[0131] 4 Magnetic rings

[0132] 5 Tubular structure

[0133] 6 Engaging elements

[0134] 7 (First) Tubular Layer

[0135] Lines 71, 72, 73

[0136] 8 Second tubular layer

[0137] 9 Tubular Layer, Further Embodiments

[0138] 91 Annular cracks, perforations

[0139] 100 Structure segments

[0140] 102 Slender protrusions

[0141] 104 protrusion longitudinal axis

[0142] 106 Unstructured sections

[0143] 110 Proximal end of structural segment

[0144] 108 The distal end of the structural segment

[0145] 112 thread pitch

Claims

1. A manipulable device for use inside a mammal's body, comprising: a flexible, elongated member (1) extending along a device longitudinal axis (12) and configured for accessing soft tissue of a mammalian body; A magnetic element (4) disposed at the distal end of an elongated element (1) and configured to manipulate the elongated element (1) by means of an external magnetic field, wherein the proximal end of the elongated element extends outside the body of a mammal when in use, characterized in that a structural section (100) is disposed near the magnetic element (4) and the structural section (100) comprises a plurality of elongated protrusions (102), the elongated protrusions (102) being formed on the outer surface of the elongated element and each of the elongated protrusions (102) having a protrusion longitudinal axis (104), each protrusion longitudinal axis forms an angle (α1, α2) with the axial axis of the device, and multiple slender protrusions (102) form multiple angles (α1, α2) with the longitudinal axis of the device, wherein each of the multiple angles is less than 90°, and the angle is measured clockwise from the longitudinal axis of the device from the proximal end to the distal end, so that when the slender element (1) rotates clockwise around the longitudinal axis (12) of the device, the slender element (1) moves relative to the soft tissue along the longitudinal axis (12) of the device.

2. The device according to claim 1, characterized in that When viewed longitudinally, the plurality of elongated protrusions (102) each extend less than one turn around the elongated element (1).

3. The device according to claim 1 or 2, characterized in that: The multiple angles (α1, α2) each have the same single angle value, and the angle value is between 5° and 80°, preferably between 10° and 60°, and more preferably between 20° and 30°.

4. The device according to claim 3, characterized in that A plurality of elongated protrusions (102) are arranged along a thread extending along the elongated element (1), wherein a thread path angle of the thread is equal to the single included angle value.

5. The device according to claim 1 or 2, characterized in that: The plurality of angles (α1, α2) are distributed according to at least two angle values, and the at least two angle values ​​are between 5° and 80°, preferably between 10° and 60°, and more preferably between 20° and 30°.

6. The device according to claim 5, characterized in that A plurality of elongated protrusions (102) are arranged along at least two threads, and the thread path angle of each thread is equal to one of at least two included angle values ​​(α1, α2).

7. The device according to any one of claims 3 to 6, characterized in that An outer tubular structure (5) surrounds a portion of the elongated element (1), the tubular structure (5) comprising an engagement element (6) configured to engage with a plurality of elongated protrusions (102) so that when the elongated element (1) rotates about its device longitudinal axis (12), the elongated element (1) moves relative to the tubular structure (5) along the device longitudinal axis (12).

8. The device according to any one of claims 1 to 7, characterized in that The plurality of elongated protrusions (102) have a triangular cross section, a circular cross section or a hump-shaped cross section, preferably a cross section approximating a sinusoidal form.

9. The device according to any one of claims 1 to 8, characterized in that The structural section (100) is interrupted by a plurality of non-structural sections (106) that do not have the elongated protrusions (102).

10. A manipulable device for use inside a mammal's body, comprising: a flexible, elongated member (1) extending along a device longitudinal axis (12) and configured for accessing soft tissue of a mammalian body; A magnetic element (4) is located at the distal end of the slender element (1) and is configured to manipulate the slender element (1) through an external magnetic field, wherein the proximal end of the slender element extends outside the mammalian body when in use, and a structural section (100) is in the form of an external threaded structure (2) formed on the outer surface of the slender element (1) and has a radial extension beyond the outer surface of the slender element (1), characterized in that the threaded structure (2) is arranged near the magnetic element (4) and is made of a non-magnetic responsive material, wherein the threaded structure (2) is configured to engage with soft tissue surrounding the slender element (1) in the mammalian body, so that when the slender element (1) rotates around its device longitudinal axis (12), the slender element (1) moves relative to the soft tissue along the device longitudinal axis (12).

11. The device according to claim 10, characterized in that The thread structure (2) has a triangular cross section, a circular cross section or a hump-shaped cross section, preferably a cross section approximately in the form of a sine curve.

12. The device according to any one of claims 10 to 11, characterized in that The structural section (100) is interrupted by a plurality of non-structural sections (106) which do not have a thread structure (2).

13. The device according to any one of claims 10 to 12, characterized in that The radial extension of the thread structure (2) measured from the outer surface of the elongated element (1) has a first value in a first part of the structure segment and a second value different from the first value in a second part of the structure segment, so that the first part has a different flexibility than the second part.

14. The device according to any one of claims 10 to 13, characterized in that The thread structure (2) is freely wound around the elongated element (1), wherein the distal end of the thread structure (2) is fixed to the elongated element (1), and the proximal end of the thread structure (2) is detachably fixed to the elongated element (1) so as to provide different thread pitches (112) by moving the proximal end or the distal end in the longitudinal direction.

15. The device according to any one of claims 10 to 13, characterized in that The threaded structure (2) is freely wound around the slender element (1), wherein the slender element (1) includes a locking device, which engages with the threaded structure (2) in a first rotational direction of the slender element (1) to transmit the rotational movement of the slender element (1) to the threaded structure (2), and disengages from the threaded structure (2) in a second rotational direction opposite to the first rotational direction to allow the threaded structure (2) to rotate freely.

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