Elongated steerable device with determined curvature

Abstract

An elongate steerable device for guiding a catheter or endoscope includes an elongate flexible member extending along a longitudinal axis, the flexible member having a proximal end and a distal end, at least one shape memory alloy wire presenting at least one activatable region and secured to the distal end of the elongate flexible member, an actuator configured to actuate the at least one shape memory alloy wire, and an actuator configured to actuate the at least one shape memory alloy wire. And at least one shape memory alloy wire configured to activate the at least one shape memory alloy wire from a proximal end of the elongate flexible member, where an activatable region of the at least one shape memory alloy wire is configured to assume a dormant configuration and an activated configuration, where the activated configuration assumes at least one predetermined curvature, where the at least one shape memory alloy wire is configured to assume a dormant configuration. The activatable region of the at least one shape memory alloy wire is configured to assume the activated configuration when activated by the actuator to direct the distal end of the elongate flexible member to have a predetermined curvature.

Description

TECHNICAL FIELD

[0001] The present invention relates to an elongated steering system configured to guide a catheter or an endoscope to internally inspect a tubular element, having at least one actuatable curvature. BACKGROUND

[0002] In a wide range of applications, there is a need to use a device within a pipe, a conduit or a tube, for example to place a distal portion of a flexible tube in a specific location to inspect or carry a drug, or to act in a remote or difficult to access location.

[0003] When moving a flexible elongated device in the lumen of a pipe, a conduit or a tube, it is important that the user is able to carefully and precisely control the movement and placement of such a device. Placing such a device within a pipe is a known technical problem in the field of petroleum engineering or electrical engineering. It is also considered challenging in the field of medicine, for example by placing a device in a body tube through an orifice (vein, artery, gastrointestinal tract, etc.).

[0004] In the field of medicine, many cardiovascular diseases that cause death worldwide can be treated using surgical or endovascular techniques. One of the pathologies encountered is myocardial infarction and peripheral vascular disease. Over the past few decades, the use of catheters and guide wires to reach the pathological area to deliver a stent or a balloon has become an easy-to-implement solution. These endovascular techniques are less invasive than conventional surgery. Their recovery time is shortened, and postoperative complications are reduced.

[0005] However, in general, the skill and experience of the surgeon are the main success factors for complex interventions, and recent developments aim to facilitate navigation through complex anatomy as independently as possible from these surgeons' skills and experience.

[0006] Currently, the devices known from the prior art are complex and / or bulky and do not provide sufficient bending capabilities to navigate within the lumen of a tube or a pipe.

[0007] A typical shape memory alloy steering device consists of a shape memory alloy wire crimped at its two extremities onto a structure configured to be deflected. With these devices, it is difficult to design a high deflection angle with a small radius of curvature due to the low shrinkage rate of the shape memory alloy wire (lower than 8%). Such a large radius of curvature makes it difficult to use the device in very tortuous guides.

[0008] In addition, due to the rather large radius of curvature, it is difficult to assemble the conventional device as the wire needs to be held precisely and firmly at each of its extremities on the structure to be bent / deflected. It also leads to a device that will quickly be worn out and cannot work for a long time.

[0009] The main aim of the present invention is to provide a steerable elongated device which is easy to handle and produce, compact and repeatable, and which has a curvature angle comprised between 0° and 360°, preferably between 90° and 180°. According to the present invention, the obtained steerable device is flexible enough to allow easy navigation inside a lumen, a tube or a duct, and strong enough to drive a catheter or an endoscope. The high curvature angle of the steerable elongated device should enable to access difficult to reach locations in the human anatomy. In this way, the present invention enables to avoid the use of the well-known "exchange guide" during the intervention. SUMMARY

[0010] The present invention therefore relates to an elongated steerable device for guiding a catheter or an endoscope, comprising:

[0011] - an elongated flexible member extending along a longitudinal axis, the flexible member having a proximal end and a distal end,

[0012] - at least one shape memory alloy wire exhibiting at least one activable region and being fixed to the distal end of the elongated flexible member,

[0013] - an actuator configured to activate the at least one shape memory alloy wire from the proximal end of the elongated flexible member,

[0014] wherein said activable region of said at least one shape memory alloy wire is configured to exhibit a dormant configuration and an active configuration, said active configuration exhibiting at least one predetermined curvature,

[0015] wherein said activable region of said at least one shape memory alloy wire is configured to adopt said active configuration when activated by said actuator, thereby guiding the distal end of the elongated flexible member to have a predetermined curvature.

[0016] This solution therefore achieves the above mentioned aims. In particular, it allows to obtain improved performances and is easy to manufacture compared to shape memory alloy based steering systems using the contraction of shape memory alloy actuators. The manoeuvrability of the steering devices of the prior art is necessarily improved since any bending angle can be reached.

[0017] The device according to the present invention can comprise one or more of the following features, independently from each other or in combination with each other:

[0018] - the actuator comprises heating means associated with the at least one shape memory alloy wire, the heating means being configured to heat the at least one shape memory alloy wire in a controlled manner so as to bring the alloy wire in its active configuration,

[0019] - the elongated flexible member comprises a super-elastic base,

[0020] - Slender, flexible components include a metal base.

[0021] - The diameter of the distal end of the slender flexible member is smaller than the diameter of the proximal end of the slender flexible member.

[0022] The device also includes a resilient element configured to maintain at least one shape memory alloy wire in a predetermined dormant shape when the at least one shape memory alloy wire is in its dormant configuration.

[0023] - The elastic element is an elastic straightening element configured to maintain at least one shape memory alloy wire in a straight shape when at least one shape memory alloy wire is in its dormant configuration.

[0024] - At least one shape memory alloy wire has a diameter of at least 180 μm.

[0025] - At least one shape memory alloy wire has a diameter of at least 200 μm.

[0026] -At least one shape memory alloy wire exhibits a variable diameter along its longitudinal axis.

[0027] - At least one shape memory alloy wire is fixed in a U-shape to the distal end of a slender, flexible component.

[0028] - The activatable region of at least one shape memory alloy wire exhibits at least two predetermined curvatures when in its activated configuration.

[0029] - At least one shape memory alloy wire includes at least two activation regions that can be activated independently of each other, and wherein an actuator is configured to activate each activation region independently of each other.

[0030] - The retaining sleeve provides thermal insulation. Attached Figure Description

[0031] A better understanding of the invention will be achieved by reading the following detailed explanatory description of embodiments of the invention given with reference to the illustrations, and other objects, details, features, and advantages of the invention will become clearer. For purely illustrative and non-limiting examples, please refer to the accompanying drawings:

[0032] - Figure 1 This is a side view of the device according to the invention in both sleep and active configurations.

[0033] - Figure 2 This is a partial perspective view of a first embodiment of the device according to the invention in its active configuration.

[0034] - Figure 3 This is a partial perspective view of a second embodiment of the device according to the invention in its active configuration.

[0035] - Figure 4 This is a longitudinal perspective view of a second embodiment of the device according to the present invention.

[0036] - Figure 5 This is a detailed perspective view of the line in its hibernation configuration.

[0037] - Figure 6 This is a partial perspective view of a third embodiment of the device according to the invention in its active configuration. Detailed Implementation

[0038] like Figure 1 As shown, the present invention relates to an elongated, steerable device 10 for guiding a catheter or endoscope within a lumen, for example, during surgical procedures.

[0039] The slender, steerable device 10 includes:

[0040] - An elongated flexible member 12 extending along the longitudinal axis X, the flexible member 12 having a proximal end 12P and a distal end 12D.

[0041] - Actuator 14, which includes at least one actuation device 140 controlled by a handle 15, the handle 15 being fixed to the proximal end 12P of an elongated flexible member 12 (see...). Figure 1 ),

[0042] - At least one shape memory alloy wire 16, which presents at least one activatable region 17.

[0043] At least one shape memory alloy wire 16 at least partially forms the distal end 12D of the flexible member 12 (see Figures 2 to 6 The distal end 12D of the flexible component 12 also includes an activatable region 17 of the shape memory alloy wire 16.

[0044] The slender, flexible component 12 of device 10 is disposable.

[0045] like Figures 3 to 6 As shown, in some embodiments, the shape memory alloy wire 16 is generally U-shaped, with the bottom of the U-shape forming the end of the flexible member 12. This U-shaped shape of the shape memory alloy wire 16 allows the strength of the shape memory alloy wire 16 to be increased by doubling its width, while requiring the same amount of energy to activate its activatable region 17 (see description below).

[0046] To ensure its structural integrity and flexibility, the flexible member 12 includes an elastic element 18 extending along the longitudinal axis X from its proximal end 12P to its distal end 12D. The elastic element 18 does not necessarily extend to the distal end 12D of the flexible member. In some alternative embodiments, the elastic element 18 extends along the longitudinal axis X throughout the flexible member 12 from its proximal end 12P to its distal end 12D. For example, the elastic element 18 may be a hyperelastic / superelastic wire or tab connected to the shape memory alloy wire 16. In another embodiment, the elastic element 18 may be a hyperelastic / superelastic conductor surrounding the shape memory alloy wire 16.

[0047] In this invention, the term "hyper-elastic" refers to a model used to represent the stress-strain behavior of certain materials. For many materials, linear elastic models cannot accurately describe the observed material behavior. The most common example of such materials is rubber, whose stress-strain relationship can be defined as nonlinear elastic, isotropic, and incompressible. Hyperelasticity provides a method for modeling the stress-strain behavior of such materials.

[0048] The connection 22 between the shape memory alloy wire 16 and the elastic element 18 enables a robust mechanical engagement. This allows torque to be transferred from the proximal end 12P to the activatable region 17 within the distal end 12D of the flexible member 12. This connection 22 can be achieved by welding or the like. Preferably, the shape memory alloy wire 16 is connected to the elastic element 18 at one end, with the other end being a free end (see...). Figure 2 and Figure 5 ).

[0049] Preferably, the elastic element 18 has a variable diameter. Its diameter is larger at the proximal end 12P of the flexible member 12 and smaller at the distal end 12D of the flexible member 12. The diameter of the elastic element 18 ranges from 0.7 mm at the proximal end 12P of the flexible member 12 to 0.1 mm at the distal end 12D of the flexible member 12. This diameter is preferably between 0.46 mm and 0.15 mm. The reduction in diameter makes the activation region 17 easier to activate.

[0050] In order to activate the shape memory alloy wire 16 (see detailed explanation below), the device 10 includes at least one actuation device 140 as an energy source for the shape memory alloy wire 16.

[0051] The distal end 12D of the flexible member 12 also includes at least one actuating device 140. Preferably, the flexible member 12 includes at least two actuating devices 140, and in some embodiments, the flexible member 12 even includes three or more actuating devices (see...). Figure 3Each actuation device 140 is preferably connected to the shape memory alloy wire 16. This connection can be a direct connection 24 or an indirect connection 26 via the elastic element 18. Each actuation device 140 is preferably connected to one end of the shape memory alloy wire 16 (see...). Figure 2 and Figure 4 In the presence of more than two actuators 140, the remaining actuators are connected to the shape memory alloy wire 16 and connected between the ends of the shape memory alloy wire 16 (see...). Figure 3 Each actuating device 140 can also be connected to the elastic element 18 so as to be supported and held in place even when the activatable region 17 is activated. It is preferably connected to the shape memory alloy wire 16 and the elastic element 18. The connection 26 between at least one actuating device 140 and the elastic element 18 can be achieved by soldering. The connection 26 between at least one actuating device 140 and the elastic element 18 is preferably close to or in direct contact with the connection 22 between the shape memory alloy wire 16 and the elastic element 18 (see...). Figure 5 ).

[0052] The term "connection" in this embodiment should be understood from a physical perspective and can be interpreted as "fixed".

[0053] At least one actuating device 140 extends from the proximal end 12P of the flexible member 12 to the distal end 12D of the flexible member 12. At least one actuating device 140 may be wound or coiled around the elastic element 18 along the length of the flexible member 12. A more detailed description of the embodiments will be given below. The function of the activating device will be further detailed below.

[0054] The flexible member 12 of the device 10 may further include a safety shaft 20 configured to surround the flexible member 12. The safety shaft 20 is preferably made of plastic, for example, of... Made. In some embodiments, such as in Figure 1 In the illustrated embodiment, the safety shaft 20 may present a progressive structure along the longitudinal axis X: at the proximal end 12P of the flexible member 12, it may include a single plastic layer, while at the distal end 12D of the flexible member 12, it may include a coil or spring 200 and contain... Several layers of polytetrafluoroethylene (PTFE) plastic are layered to uniformly surround the distal end 12D of the flexible member 12. The spring 200 also helps the distal end 12D return to its dormant configuration and ensures a certain degree of straightness and end rigidity to avoid unwanted friction along the tubular cavity (which can exceed 1.5 meters in length). The safety shaft 20 is configured to isolate, for example, the environment in which the slender, steerable device 10 must be introduced from thermal insulation.

[0055] The slender flexible member 12 can be from 0.5m to 4m. The diameter of the slender flexible member 12 can vary from 0.35mm at its distal end 12D to 2mm at its proximal end.

[0056] In metallurgy, shape memory alloys (SMAs) are well known to be alloys that can deform upon cooling (“cold configuration”) but recover their original shape upon heating (“memory configuration”). They can also be referred to as memory metals, shape memory alloys, smart metals, smart alloys, or muscle wires. In this invention, the shape memory alloy wire 16 is made of such an alloy, for example, of nitinol.

[0057] In this invention, each shape memory alloy wire 16 is configured to present:

[0058] - Corresponding to the above "cold configuration" hibernation configuration, this hibernation configuration presents a hibernation shape, and

[0059] - The activation configuration corresponding to the "memory configuration" above is a predetermined curved configuration that differs from the dormant configuration (see [link]). Figure 3 ).

[0060] In this invention, the shape memory alloy wire 16 can exhibit either "single shape memory" or "dual shape memory". In the case of "single shape memory", the shape memory alloy wire 16 in its dormant shape does not exhibit a specific shape and retains its ductility. In this case, the shape of the dormant configuration is defined by its surrounding environment. In the case of "dual shape memory", the shape memory alloy wire 16 exhibits a predetermined dormant shape, such as a straight dormant shape.

[0061] According to embodiments, the shape memory alloy wire 16 has a diameter between 50 μm and 300 μm, preferably at least 180 μm. In some alternative embodiments, the shape memory alloy wire has a diameter of at least 200 μm. The diameter of the shape memory alloy wire 16 is important for two main reasons. First, once the shape memory alloy wire 16 is activated by the activation device 140, it must change its shape, regardless of the resistance of the elongated flexible member 12 and the activation device 140 themselves, which are made of material and therefore naturally exert some reaction force that prevents the shape memory alloy wire 16 from reaching its full deformation potential. Therefore, the larger the shape memory alloy wire 16, the more stable and stronger the activation configuration, thus enabling better manipulation of the device 10. On the other hand, the larger the shape memory alloy wire 16, the more difficult it is to restore it to its dormant shape. This leads to increased energy usage. Since more material needs to be deformed, the activation energy (preferably heat) provided must be more effective, which may lead to isolation problems.

[0062] The advantage of a straight dormant shape is that it provides convenient navigation within the artery. Any remaining residual curvature, even passive residual curvature, can create friction on the inner wall of the artery, which may limit navigation / guidance performance.

[0063] In this invention, the activatable region 17 of the shape memory alloy wire 16 is defined as a pre-formed region and is therefore capable of having a "cold configuration" and a "memory configuration".

[0064] Therefore, the distal end 12D corresponds to the controllable flexibility and shape-changing portion of the elongated flexible member 12. This distal portion 12D of the elongated member 12 has a length of about 10 cm to 20 cm, preferably 15 cm.

[0065] As previously described, actuator 14 is configured to activate the activatable region 17 of the at least one shape memory alloy wire 16 from the proximal end 12P of the elongated flexible member 12.

[0066] To activate the at least one activatable region 17 of the shape memory alloy wire 16, as previously described, the actuator 14 includes at least one activation device 140, preferably multiple activation devices 140, associated with and connected to the activatable region 17. The actuator 14 is also connected to an energy source. The activation device 140 is configured to deliver energy from the energy source to the activatable region 17. The delivered energy causes the activatable region 17 to be activated and deformed according to its activated configuration. The more energy delivered to the activatable region 17, the closer the activatable region 17 is to its activated configuration, and the longer the activatable region 17 remains in the activated configuration. Once energy delivery to the activatable region 17 stops, the activatable region 17 returns to the dormant configuration. The amount of energy delivered to the actuator 14 is preferably adjusted by a handle 15. The handle 15 is designed to be easily fitted into the hand of the operator. The operator can thus activate the activation device 140 by means of the handle 15 to guide the shape memory alloy wire 16 from its dormant configuration to its activated configuration. The handle 15 is also used to push the device 10 and turn it to pass through the interior of the tubular cavity. The handle 15 may be detachably attached to the elongated flexible member 12. The handle 15 may be discarded along with the rest of the device 10, or it may be reusable.

[0067] like Figures 2 to 6 As shown in the embodiment, the elongated, steerable device 10 includes specific activation devices 140, which in this embodiment are heating devices 140. These heating devices 140 are associated with the activatable region 17 of the shape memory alloy wire 16. The heating devices 140 are connected to the handle 15 of the actuator 14 and are capable of heating the activatable region 17 of the shape memory alloy wire 16 in a controlled manner. More specifically, asFigure 4 As shown, these heating devices 140 are a first copper wire and a second copper wire, each having a distal end and a proximal end. The proximal ends of the first and second copper wires are connected to the handle 15 of the actuator 14. The distal end of the first copper wire is directly connected to the free end of the shape memory alloy wire 16. The distal end of the second copper wire is indirectly connected to the other end of the shape memory alloy wire 16 via an elastic element 18. By activating the activation device 140 of the actuator 14 by means of the handle 15, an electric current (and thus heat) is generated and guided along the elongated flexible member 12 toward the shape memory alloy wire 16, and more specifically toward the activatable region 17 of the shape memory alloy wire 16. To securely connect the shape memory alloy wire 16 to the handle 15 of the actuator 14 by means of the copper wire, the copper wire is wound around the elongated flexible member 12 between the proximal end 12D and the distal end 12P.

[0068] In other embodiments, if the activation of the activatable region 17 is based on the Joule effect, the activation device 140 can be any type of wire. In another embodiment, the activatable region 17 can be indirectly heated using Kanthal wire. In yet another embodiment, the activatable region 17 can be activated by bringing a laser to the distal end of the flexible member 12 via an optical fiber. In this last example, at least one activation device 140 is individually connected to the elastic element 18.

[0069] According to the embodiments and needs, the activation region 17 presents a curvature angle of 0 to 360° when activated, preferably a curvature angle of 90 to 180°.

[0070] In some embodiments, the device 10 includes a plurality of shape memory alloy wires 16, and each shape memory alloy wire 16 presents at least one activatable region 17 (not shown). Each shape memory alloy wire 16 presents the same activation configuration. All shape memory alloy wires are activated by the same drive device 140 and deform synchronously. This makes it possible to increase the strength of the distal end 12D of the elongated member 12.

[0071] In some alternative embodiments, regardless of the number of shape memory alloy wires 16, each shape memory alloy wire presents two distinct activatable regions 17a, 17b (see... Figure 3 Each individual activatable region 17a, 17b is associated with an independent activation device 140 (e.g., a heating device) for activating (e.g., heating) each activatable region 17a, 17b in an independent controlled manner. Each activatable region 17a, 17b can present a different activation configuration.

[0072] When the activation device 140 of the actuator 14 is activated (e.g., via the handle 15), the energy (more specifically, heat) provided by the activation device 140 reaches the shape memory alloy wire 16, which changes the shape of the shape memory alloy wire: from a dormant configuration ( Figure 4 and 5 ) becomes the active configuration (see Figure 1 , 2 (3 and 6). This configuration change causes a shape change from straight (dormant) to curved at the distal end 12D of the flexible member 12.

[0073] like Figure 2 , 3 As shown in Figure 6, when the shape memory alloy wire 16 is activated, it induces at least two predetermined curvatures C1, C2 at the distal end 12D of the elongated flexible member 12. These multiple curvatures C1, C2 make it easier to introduce into conduits, especially tortuous and bent ones.

[0074] Thus, when the shape memory alloy wire 16 is activated, it induces predetermined curvatures C1 and C2 at the distal end 12D of the elongated flexible member 12. Preferably, the shape memory alloy wire 16 induces two different curvatures C1 and C2 to achieve more precise steering. The curvatures C1 and C2 can exhibit the same convexity (…). Figure 2 and Figure 3 ) or alternating convexity ( Figure 6 ).

[0075] In embodiments including multiple activatable regions 17a, 17b, each activatable region 17a, 17b preferably induces different predetermined curvatures C1, C2 towards the distal end 12D of the elongated flexible member 12 when activated (see...). Figure 3 Alternatively, each shape memory alloy wire 16 can induce two different predetermined curvatures C1, C2, of which only one region 17 is activatable (see...). Figure 2 The purpose of these two different predetermined curvatures C1 and C2 is to enable the formation of specific schemes of predetermined curvatures C1 and C2, thereby enabling very specific and precise controlled shaping of the distal end 12D of the elongated member 12 of the device 10.

[0076] In this invention, "bending" refers to bending in a curvature. Curvature or bending is used as the opposite of straightness. The term "curvature" refers to non-zero curvature. Curvature can be positive or negative.

[0077] exist Figure 1 and Figure 2In the specific embodiment shown, as previously described, the shape memory alloy wire 16 is fixed in a U-shape to the distal end 12D of the elongated flexible member 12. When formed into a U-shape, the shape memory alloy wire 16 has two free ends. Each free end of the U-shape faces the proximal end 12P of the elongated flexible member 12 (see...). Figure 2 This particular form allows for easy connection of the heating element 140 and the elastic element 18 to the end of the shape memory alloy wire 16 via a simple welding process without the risk of damaging the shape memory alloy wire 16. Secondly, this U-shape allows for doubling the effective diameter of the shape memory alloy wire 16 because the two branches of the U-shape function identically in a near-perfect mirror effect (see...). Figure 3 This results in stronger and more stable shaping of the distal end 12D of the flexible elongated member 12 without the need to provide and pre-shape very thick and difficult-to-handle shape memory alloy wire 16. Third, this U-shaped configuration can reduce the effect of the heating device 20 on the deformation of the shape memory alloy wire 16.

[0078] The device 10 of this invention is very easy to manufacture because it allows for extremely simple assembly, as the shape memory alloy wire can be connected / secured at only one end. Guiding along its entire length is not required. Multiple bends may also be possible on the same shape memory alloy wire 16.

[0079] The accuracy of device 10 also increases with the prior knowledge of the shape taken by the activatable region 17, making the tool more relevant.

Claims

1. An elongated, steerable device (10) for guiding a catheter or endoscope, comprising: An elongated flexible member (12) extending along a longitudinal axis (X) has a proximal end (12P) and a distal end (12D). At least one shape memory alloy wire (16) having at least one activatable region (17) and fixed to the distal end (12D) of the elongated flexible member (12), An actuator (14) configured to activate the at least one shape memory alloy wire (16) from the proximal end (12P) of the elongated flexible member (12), The activatable region (17) of the at least one shape memory alloy wire (16) is configured to present a dormant configuration and an active configuration, wherein the active configuration presents at least one predetermined curvature (C1, C2). The activatable region (17) of the at least one shape memory alloy wire (16) is configured to, when activated by the actuator (14), employ the activation configuration to guide the distal end (12D) of the elongated flexible member (12) to have a predetermined curvature (C1, C2).

2. The elongated steerable device (10) according to the preceding claim, wherein, The actuator (14) includes heating devices (20) associated with the at least one shape memory alloy wire (16), which are configured to heat the at least one shape memory alloy wire (16) in a controlled manner so as to put the alloy wire (16) in its activated configuration.

3. The elongated steerable device (10) according to any one of the preceding claims, wherein, The slender flexible component (12) includes a hyperelastic base (22).

4. The elongated steerable device (10) according to any one of claims 1 to 3, wherein, The slender flexible component (12) includes a metal base (22).

5. The elongated steerable device (10) according to any one of the preceding claims, wherein, The diameter of the distal end (12D) of the elongated flexible member (22) is smaller than the diameter of the proximal end (12P) of the elongated flexible member (22).

6. The elongated steerable device (10) according to any one of the preceding claims, wherein, The device (10) further includes an elastic element (24) configured to maintain the at least one shape memory alloy wire (16) in a predetermined dormant shape when the at least one shape memory alloy wire (16) is in its dormant configuration.

7. The elongated steerable device (10) according to the preceding claim, wherein, The elastic element (24) is an elastic straightening element configured to maintain the at least one shape memory alloy wire (16) in a straight shape when the at least one shape memory alloy wire (16) is in its dormant configuration.

8. The elongated steerable device (10) according to any one of the preceding claims, wherein, The diameter of the at least one shape memory alloy wire (16) is at least 180 μm.

9. The elongated steerable device (10) according to the preceding claim, wherein, The diameter of the at least one shape memory alloy wire (16) is at least 200 μm.

10. The elongated steerable device (10) according to any one of the preceding claims, wherein, The at least one shape memory alloy wire (16) has a variable diameter along the longitudinal axis (X).

11. The elongated steerable device (10) according to any one of the preceding claims, wherein, The at least one shape memory alloy wire (16) is fixed in a U-shape to the distal end (12D) of the elongated flexible member (12).

12. The elongated steerable device (10) according to any one of the preceding claims, wherein, The activatable region (17) of the at least one shape memory alloy wire (16) exhibits at least two predetermined curvatures (C1, C2) in its activated configuration.

13. The elongated steerable device (10) according to any one of the preceding claims, wherein, The at least one shape memory alloy wire (16) includes at least two activation regions (17) that can be activated independently of each other, and wherein the actuator (14) is configured to activate each activation region (17) independently of each other.

14. The elongated steerable device (10) according to any one of the preceding claims, wherein, The fixing sleeve (18) has thermal insulation properties.

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