CN121003404A - Slender, steerable device with a defined curvature - Google Patents

Abstract

This application provides an elongated, steerable device for guiding a catheter or endoscope, comprising: an elongated 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 fixed to the distal end of the elongated flexible member; and an actuator configured to activate the at least one shape memory alloy wire from the proximal end of the elongated flexible member, wherein the activatable region of the at least one shape memory alloy wire is configured to present a dormant configuration and an active configuration, the active configuration presenting at least one predetermined curvature, wherein the activatable region of the at least one shape memory alloy wire is configured to, when activated by the actuator, employ the active configuration to guide the distal end of the elongated flexible member to have a predetermined curvature.

Description

Elongated steerable device with defined curvature

Technical Field

The present invention relates to an elongate steering system configured to guide a catheter or endoscope for internal examination of a tubular element having at least one actuatable curvature.

Background

In a wide range of applications, it is desirable to use the device within a tube, catheter or tube, for example to place the distal portion of a flexible tube in a particular location to inspect or carry a drug, or to function in a remote or inaccessible location.

When moving a flexible elongate device in the lumen of a tube, catheter or pipe, it is important that the user be able to carefully and accurately control the movement and placement of such devices. In petroleum engineering or motor engineering, the placement of such equipment within a pipeline is a known technical problem. Placement of devices within a body vessel, such as through the mouth (of a vein, artery, gastrointestinal tract, etc.), is also considered challenging in the medical field.

In the medical field, many cardiovascular diseases leading to death worldwide can be treated using surgical or intravascular techniques. One of the pathologies encountered is myocardial infarction and peripheral vascular disease. The use of catheters and guidewires to reach pathological areas to deliver stents or balloons has been an easy-to-implement solution over the past decades. These intravascular techniques are less invasive than conventional procedures. Their recovery time is shortened and postoperative complications are reduced.

In general, however, the skill and experience of the surgeon is the primary success factor for complex interventions, while recent developments aim to facilitate navigation through complex anatomy as independently as possible of the skill and experience of these surgeons.

Currently, the devices known from the prior art are complex and/or cumbersome and do not provide sufficient bending capability to navigate within the lumen of a tube or duct.

A typical shape memory alloy steering apparatus consists of a shape memory alloy wire crimped at both ends to a structure configured to deflect. For these devices, it is difficult to design to obtain a high deflection angle with a small radius of curvature due to the low shrinkage (less than 8%) of the shape memory alloy wire. Such a large radius of curvature makes the device difficult to use in very tortuous guidance.

Furthermore, due to the considerable radius of curvature, it is difficult to assemble conventional devices, as the wire needs to be held precisely and firmly on the structure to be bent/deflected at each of its ends. It also results in equipment that is quickly worn and cannot operate for long periods of time.

The main object of the present invention is to provide a steerable elongated device which is easy to handle and produce, compact and repeatable and has an angle of curvature of 0 ° to 360 °, preferably 90 ° to 180 °. According to the invention, the resulting steerable device is flexible enough to allow easy navigation within a lumen, tube or duct, and strong enough to drive a catheter or endoscope. The high angle of curvature of the steerable elongate device should be able to access difficult to reach locations in the human anatomy. In this way, the invention makes it possible to avoid the use of the well-known "exchange guide" during the intervention.

Disclosure of Invention

Accordingly, the present invention relates to an elongate steerable device for guiding a catheter or endoscope, comprising:

An elongated 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 being secured to the distal end of the elongate flexible member,

An actuator configured to activate at least one shape memory alloy wire from a proximal end of the elongate flexible member,

Wherein the activatable region of the at least one shape memory alloy wire is configured to assume a dormant configuration and an activated configuration, the activated configuration assuming at least one predetermined curvature,

Wherein the activatable region of the at least one shape memory alloy wire is configured to adopt the activated configuration when activated by the actuator, thereby guiding the distal end of the elongate flexible member to have a predetermined curvature.

Thus, this solution achieves the above object. In particular, it allows to obtain improved performance and ease of manufacture compared to shape memory alloy based steering systems using the contraction of shape memory alloy actuators. The mobility of the steering device of the prior art is necessarily improved, since any bending angle can be reached.

The device according to the invention may comprise one or more of the following features, either independent of each other or in combination with each other:

the actuator comprising heating means associated with 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 activated configuration,

The elongate flexible member comprises a superelastic base,

The elongate flexible member comprises a metal base,

The diameter of the distal end of the elongate flexible member is smaller than the diameter of the proximal end of the elongate flexible member,

The device further comprises a resilient element configured to maintain the at least one shape memory alloy wire in a predetermined resting shape when the at least one shape memory alloy wire is in its resting configuration,

The elastic element is an elastic straightening element configured to hold the at least one shape memory alloy wire in a straight shape when the at least one shape memory alloy is straightened in its resting configuration,

The diameter of the at least one shape memory alloy wire is at least 180 μm,

The diameter of the at least one shape memory alloy wire is at least 200 μm,

At least one shape memory alloy wire exhibiting a variable diameter along a longitudinal axis,

At least one shape memory alloy wire secured to the distal end of the elongate flexible member in a U-shape,

The activatable region of the at least one shape memory alloy wire exhibits at least two predetermined curvatures when in its activated configuration,

The at least one shape memory alloy wire comprises at least two activation regions that are activatable independently of each other, and wherein the actuator is configured to activate each activation region independently of each other,

The retaining sleeve exhibits heat insulating properties.

Drawings

The invention will be better understood and other objects, details, features and advantages of the invention will become more apparent upon reading the following detailed explanatory description of embodiments of the invention, given by way of illustration. For a purely illustrative and non-limiting example, please refer to the accompanying drawings:

figure 1 is a side view of a device according to the invention in a dormant configuration and in an active configuration,

Figure 2 is a partial perspective view of a first embodiment of the device according to the invention in its active configuration,

Figure 3 is a partial perspective view of a second embodiment of the device according to the invention in its active configuration,

Figure 4 is a longitudinal perspective of a second embodiment of the device according to the invention,

Figure 5 is a detailed perspective view of the wire in its resting configuration,

Fig. 6 is a partial perspective view of a third embodiment of the device according to the invention in its activated configuration.

Detailed Description

As shown in FIG. 1, the present invention is directed to an elongate steerable device 10 for guiding a catheter or endoscope within a lumen, such as during a surgical procedure.

The elongate steerable apparatus 10 comprises:

an elongated flexible member 12 extending along a longitudinal axis X, the flexible member 12 having a proximal end 12P and a distal end 12D,

An actuator 14 comprising at least one actuation means 140 controlled by a handle 15, the handle 15 being fixed to the proximal end 12P of the elongate flexible member 12 (see figure 1),

At least one shape memory alloy wire 16 presenting at least one activatable region 17.

At least one shape memory alloy wire 16 at least partially forms the distal end 12D of the flexible member 12 (see fig. 2-6). The distal end 12D of the flexible member 12 also includes an activatable region 17 of the shape memory alloy wire 16.

The elongate flexible member 12 of the apparatus 10 is disposable.

As shown in fig. 3-6, in some embodiments, the shape memory alloy wire 16 generally exhibits a U-shape, the base of which forms the end of the flexible member 12. This U-shape of the shape memory alloy wire 16 enables the strength of the shape memory alloy wire 16 to be enhanced by doubling its width while requiring the same amount of energy to activate its activatable region 17 (see description below).

To ensure its structure and flexibility, the flexible member 12 includes a resilient element 18, the resilient element 18 extending along a longitudinal axis X from its proximal end 12P to its distal end 12D. The resilient element 18 does not necessarily extend as far as the distal end 12D of the flexible member. In some alternative embodiments, the resilient 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 superelastic/superelastic wire or sheet (tab) connected to the shape memory alloy wire 16. In another embodiment, the elastic element 18 may be a superelastic/superelastic conductor surrounding the shape memory alloy wire 16.

In the present invention, the term "super-elastic" refers to a model used to represent the stress-strain behavior of certain specific materials. For many materials, linear elastic models do not accurately describe the observed material behavior. The most common examples of such materials are rubbers, whose stress-strain relationship can be defined as non-linear elastic, isotropic and incompressible. Superelasticity provides a method of modeling the stress-strain behavior of such materials.

The connection 22 of the shape memory alloy wire 16 to the elastic element 18 enables a firm mechanical engagement. Which 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. Such a connection 22 may be achieved by welding or the like. Preferably, the shape memory alloy wire 16 is connected at one end thereof to the resilient element 18 and at the other end is a free end (see fig. 2 and 5).

Preferably, the elastic element 18 presents a variable diameter. The diameter of which 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 resilient element 18 is from 0.7mm at the proximal end 12P of the flexible member 12 to 0.1mm at the distal end 12D of the flexible member 12. The diameter is preferably 0.46mm to 0.15mm. The reduced diameter makes the activation region 17 more easily activated.

For activating the shape memory alloy wire 16 (see the detailed explanation below), the apparatus 10 comprises at least one actuation device 140 as an energy source for the shape memory alloy wire 16.

The distal end 12D of the flexible member 12 further includes at least one actuation device 140. Preferably, the flexible member 12 includes at least two actuation devices 140, and in some embodiments, the flexible member 12 even includes three or more actuation devices (see fig. 3). Each actuation device 140 is preferably connected to a shape memory alloy wire 16. Such connection can be a direct connection 24 or an indirect connection 26 through the elastic element 18. Each actuation device 140 is preferably connected to one end of a shape memory alloy wire 16 (see fig. 2 and 4). In the event that more than two actuators 140 are present, the remaining actuators are connected to the shape memory alloy wire 16 and between the ends of the shape memory alloy wire 16 (see fig. 3). Each actuation means 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 a shape memory alloy wire 16 and a resilient element 18. The connection 26 between the at least one actuating device 140 and the elastic element 18 can be realized by welding. The connection 26 between the at least one actuation means 140 and the elastic element 18 is preferably close to the connection 22 of the shape memory alloy wire 16 with the elastic element 18 or in direct contact with this connection 22 (see fig. 5).

The term "connected" in this embodiment should be understood from a physical perspective and may be interpreted as "fixed".

At least one actuation device 140 extends from the proximal end 12P of the flexible member 12 to the distal end 12D of the flexible member 12. The at least one actuation device 140 may be wound or coiled around the resilient element 18 along the length of the flexible member 12. A more detailed description of the embodiments will be given further below. The function of the activation device will be described in further detail below.

The flexible member 12 of the device 10 may also include a safety shaft 20 configured to surround the flexible member 12. The safety shaft 20 is preferably made of plastic, for example from plasticIs prepared. In some embodiments, as in the embodiment shown in FIG. 1, the safety shaft 20 may exhibit a gradual configuration along the longitudinal axis X, in that on the proximal end 12P of the flexible member 12 it may comprise a single plastic layer, and on the distal end 12D of the flexible member 12 it may comprise a coil or spring 200 and containAnd several plastic layers of Polytetrafluoroethylene (PTFE) that are layered so as to uniformly surround the distal end 12D of the flexible member 12. The spring 200 may also help the distal end 12D resume its resting configuration and ensure a certain straightness and a certain tip stiffness to avoid unnecessary friction along the tubular lumen (which can be more than 1 meter 50 in length). The safety shaft 20 is configured to thermally isolate, for example, the environment in which the elongate steerable device 10 must be introduced.

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

In metallurgy, it is well known that Shape Memory Alloys (SMA) are alloys that are capable of deforming upon cooling ("cold configuration") but recovering their pre-deformed ("memory configuration") shape upon heating. It may also be referred to as a memory metal, memory alloy, smart metal, smart alloy or muscle wire. In the present invention, the shape memory alloy wire 16 is made of such an alloy, for example, nitinol (Nitinol).

In the present invention, each shape memory alloy wire 16 is configured to present:

-a dormant configuration corresponding to the above-mentioned "cold configuration", which dormant configuration assumes a dormant shape, and

An active configuration corresponding to the "memorized configuration" described above, which is a predetermined curved configuration different from the dormant configuration (see fig. 3).

In the present invention, the shape memory alloy wire 16 is capable of exhibiting "single shape memory" or "double shape memory". In the case of "single shape memory," the shape memory alloy wire 16 in its resting shape does not assume a particular shape and remains malleable. In this case, the shape of the sleep configuration is defined by its surroundings. In the case of "dual shape memory," the shape memory alloy wire 16 assumes a memorized predetermined resting shape, such as a straight resting shape.

According to an embodiment, the shape memory alloy wire 16 has a diameter between 50 μm and 300 μm, preferably a diameter of 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, the shape memory alloy wire 16, once activated by the activation device 140, must change its shape, regardless of the resistance of the elongate flexible member 12 and the activation device 140 itself, the elongate flexible member 12 and the activation device 140 being made of a material and thus naturally exerting some reactive force that can prevent the shape memory alloy wire 16 from reaching its full deformation potential. Thus, the larger the shape memory alloy wire 16, the more stable and stronger the activated configuration, thereby enabling better handling 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 resting shape. This results in an increase in the use of energy. As there is more material to deform, the activation energy (preferably heat) provided must be more productive, potentially leading to isolation problems.

The advantage of a straight resting shape is that it provides a convenient way of navigating inside the artery. Any residual curvature, even passive residual curvature, may create friction on the inner wall of the artery, which may limit navigation/guidance performance.

In the present invention, the activatable region 17 of the shape memory alloy wire 16 is defined as an already preformed region and is therefore capable of having a "cold configuration" and a "memory configuration".

Thus, the distal end 12D corresponds to a controllably flexible and shape-changing portion of the elongate flexible member 12. The distal portion 12D of the elongate member 12 has a length of about 10cm to 20cm, preferably 15cm.

As previously described, the 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 elongate flexible member 12.

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, and preferably a plurality of activation devices 140, associated with the shape memory alloy wire 16 and connected to the activatable region 17. The actuator 14 is also connected to an energy source. The actuation 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 activation configuration. The more energy is 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 the energy delivery to the activatable region 17 ceases, the activatable region 17 returns to the dormant configuration. The amount of energy delivered to the actuator 14 is preferably regulated by the handle 15. The handle 15 is designed to fit easily in the hand of an operator. The operator can thus activate the activation device 140 by means of the handle 15 in order to guide the shape memory alloy wire 16 from its resting configuration to its activated configuration. The handle 15 also serves to push the device 10 and steer the device 10 through the interior of the tubular cavity. The handle 15 may be detachably connected to the elongate flexible member 12. The handle 15 may be discarded with the rest of the device 10 or may be reusable.

As shown in the embodiment of fig. 2-6, the elongated steerable device 10 includes a particular activation means 140, which activation means 14 in this embodiment is a heating means 140. These heating means 140 are associated with the activatable region 17 of the shape memory alloy wire 16. The heating device 140 is connected to the handle 15 of the actuator 14 and is capable of heating the activatable region 17 of the shape memory alloy wire 16 in a controlled manner. More specifically, as shown in FIG. 4, these heating devices 140 are first and second copper wires having distal and proximal ends, respectively. The proximal ends of the first and second strands are connected to a 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 by a resilient 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 directed along the elongated flexible member 12 towards the shape memory alloy wire 16 and more specifically towards the activatable region 17 of the shape memory alloy wire 16. To securely connect the shape memory alloy wire 16 with the handle 15 of the actuator 14 by means of copper wire, the copper wire is wrapped around the elongate flexible member 12 between the proximal end 12D and the distal end 12P of the elongate flexible member 12.

In other embodiments, the activation device 140 may be any kind of wire if the activation of the activatable region 17 is based on the joule effect. In another embodiment, the activatable region 17 may be indirectly heated by a chrome aluminum cobalt heat resistant steel (Kanthal) wire. In another embodiment, the activatable region 17 may 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.

Depending on the embodiment and the requirements, the activation region 17 exhibits an angle of curvature of 0 to 360 °, preferably 90 to 180 °, when activated.

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 exhibits the same activated configuration. All shape memory alloy wires are activated by the same driving means 140 and deformed in a synchronized manner. This enables the strength of the distal end 12D of the elongate member 12 to be improved.

In some alternative embodiments, each memory alloy wire presents two different activatable regions 17a, 17b (see fig. 3) regardless of the number of memory alloy wires 16. Each independently 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 independently controlled manner. Each activatable region 17a, 17b can exhibit a different activation configuration.

When the activation device 140 of the actuator 14 is activated (e.g., via the handle 15), 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 the resting configuration (fig. 4 and 5) to the activated configuration (see fig. 1,2, 3 and 6). This configuration change causes a change in shape from a straight (resting) to a curved distal end 12D of the flexible member 12.

As shown in fig. 2, 3 and 6, the shape memory alloy wire 16, when activated, induces at least two predetermined curvatures C ₁、C₂ at the distal end 12D of the elongate flexible member 12. These multiple curvatures C ₁、C₂ enable easier introduction, in particular into twisted and curved pipes.

Thus, the shape memory alloy wire 16, when activated, induces a predetermined curvature C ₁、C₂ at the distal end 12D of the elongate flexible member 12. Preferably, the shape memory alloy wire 16 induces two different curvatures C ₁、C₂ in order to achieve a more accurate steering. The curvature C ₁、C₂ can exhibit the same convexity (fig. 2 and 3) or alternating convexities (fig. 6).

In embodiments including a plurality of activatable regions 17a, 17b, each activatable region 17a, 17b preferably causes a different predetermined curvature C ₁、C₂ (see fig. 3) to the distal end 12D of the elongate flexible member 12 when activated. Or each shape memory alloy wire 16 can induce two different predetermined curvatures C ₁、C₂, of which there is only one activatable region 17 (see fig. 2). These two different predetermined curvatures C ₁、C₂ aim at enabling a specific solution of the predetermined curvature C ₁、C₂ to be formed, enabling a very specific and precise controlled shaping of the distal end 12D of the elongated member 12 of the device 10.

In the present invention, "bending" means bending in a form having curvature. With curvature or curvature to act as a straight back surface. The term "curvature" refers to a non-zero curvature. The curvature can be positive or negative.

In the particular embodiment shown in fig. 1 and 2, the shape memory alloy wire 16 is secured to the distal end 12D of the elongate flexible member 12 in a U-shape, as previously described. 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 elongate flexible member 12 (see fig. 2). This particular form enables, firstly, the heating device 140 and the elastic element 18 to be easily connected to the ends of the shape memory alloy wire 16 by a simple welding process, which does not risk damaging the shape memory alloy wire 16. Secondly, this U-shape can double the diameter of the effective shape memory alloy wire 16, since both branches of the U-shape play the same role in an almost perfect mirror effect (see fig. 3). This results in a stronger and more stable shaping of the distal end 12D of the flexible elongate member 12 without the need to provide and preform a shape memory alloy wire 16 that is very thick and difficult to handle. Third, this U-shaped configuration can reduce the effect of the heating device 20 on the deformation of the shape memory alloy wire 16.

The device 10 of the present invention is very easy to manufacture as it allows for extremely simple assembly as the shape memory alloy wire can be attached/fixed at only one end thereof. It is not necessary to guide along its entire length. There may also be multiple bends in the same shape memory alloy wire 16.

The precision of the device 10 also increases with the prior knowledge of the shape assumed by the activatable region 17, which makes the tool more relevant.

Claims (14)

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), the heating devices (20) being configured to heat the at least one shape memory alloy wire (16) in a controlled manner so as to bring the alloy wire (16) into its activated configuration. 3. The elongated steerable device (10) according to any one of the preceding claims, wherein the elongated flexible member (12) comprises a hyperelastic base (22). 4. The elongated steerable device (10) according to any one of claims 1 to 3, wherein the elongated flexible member (12) comprises 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 comprises an elastic element (24) configured to hold 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 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 retaining sleeve (18) provides thermal insulation.