Patent Description:
Interventional radiology (IR) is a sub-speciality of radiology using minimally invasive image-guided procedures to diagnose and treat nearly all organs of the human body. The medical procedure mainly relies on both catheters allowing access through the vascular system (also includes the biliary tract, the gastrointestinal tract, etc.) and imaging methods (fluoroscopy, ultrasound, computed tomography) which allows precise navigation. IR is largely minimally invasive, as it takes advantage of the naturally present blood distribution system; for instance, vascular access is often provided through a single femoral artery/vein entry point, thus minimizing the risk to the patients and improving health outcomes. These procedures are most often less risky, produce less pain and decrease the recovery time in comparison to open surgeries.

Medical devices in IR are mainly composed of guidewires and catheters. At least the tip of these elements is radiopaque to enable image-guided navigation. The guidewires are introduced first in the vascular system and advanced in the blood vessels until reaching the targeted location. Catheters, which comprise a lumen, are advanced over guidewires which serve as a guiding element to reach the targeted location as well. Once the catheter is in place, it is used as a support channel for the introduction of other specific catheter devices aiming, for instance, at revascularization or embolization.

Guidewires have therefore the critical role of providing the initial access in order to reach a targeted region. Current guidewires can be either translated and/or rotated during this operation. They most often comprise a bent-shaped tip by which, through the external rotation and translation of the guidewire, the surgeon can select vascular intersections. Combined with imaging methods, this allows the surgeon to navigate the guidewire to the intended region.

The shape of the guidewire distal tip therefore largely impacts the navigation success of the device through the vascular system. Currently, guidewires are proposed with different pre-bended shapes, the surgeon selecting the best suited option according to the vessels geometry and the region he wants to reach. During the procedure, (s)he commonly needs to replace the guidewire by another, more appropriate one. Similarly, the guidewire is often extracted from the patient, bended by hand by the surgeon (some guidewires propose this feature), before being reintroduced in the patient. This results in increased surgery time and procedure-related risks such as infections.

Guidewires replacement and distal tip repeated bending (by hand) is particularly frequent when the surgeon is confronted to tortuous blood vessels. This includes (and is not limited to) the neurovascular system, the cardiovascular system and the peripheral vascular system. In general, the blood vessels are more prone to present irregular, tortuous shapes at the distal portions of the vascular system (e.g. second and third level of the brain arteries).

Several solutions have been proposed in the past for solving the above shortcomings, in particular by providing steerable surgical tools to facilitate the surgeons' operation. For instance, <CIT> describes a neuro-surgery assembly including a neuro-catheter slidably received over a wire guide. The wire guide includes an inner tube positioned within an elongated hollow tube that includes a pattern of openings at its distal segment to provide an atraumatic tip for reaching sensitive locations in the brain. The wire guide is changeable between a stiff condition in which the inner tube is pressurized and a soft condition in which the inner tube is depressurized. The user may switch between the stiff and soft conditions to negotiate the tortuous pathway to a brain treatment site without a need to swap out to a different wire guide to support advancement of the neuro-catheter.

<CIT> discloses an elongate, steerable apparatus such as a guidewire including an elongated body having at least one inner lumen, one, or more preferably multiple, tendons coupled to a distal bending region (e.g., the distal tip region) at a distal end and coupled to a proximal axial translation region at a proximal end. The proximal end may be configured to have multiple, in-line axial translation regions that each couple to a pull-wire or tendon so that axially moving the axial translation region relative to other regions of the device (e.g., pushing or pulling it longitudinally in the direction that the apparatus extends) may result in moving the pull-wire or tendon and bending the bendable distal region. The in-line axial translation regions may be connected to each other, e.g., elastically connected to each other via a spring or stretchable/compressible material.

In <CIT> it is described a steerable catheter probe having a body portion adapted for being connected to a proximal hub and a distal end portion connected to the body portion, wherein the catheter body defines a lumen; the distal end portion having a compressible segment and a non-compressible segment, the compressible segment having a longitudinal centerline; and a pull member attached to the distal end portion and adapted for applying a proximally directed force to the distal end portion whereby at least a portion of said compressible segment is compressed. Steering is provided by the positioning of the pull member and the design of the compressible segment: this comprises several compression coils, and at least one of its members of smaller diameter than the other larger and equal diameter coils. Pull wire is attached at fixation point to one of the large diameter coils distal to the small diameter coil, and within the lumen of large diameter coils but outside the lumen of any smaller diameter coils. Further examples of prior art steerable devices/guidewires are described for instance in <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

<CIT> relates to a steerable laser probe which comprises a handle, an actuation structure, an optic fiber, and a housing tube. The document further discloses that a compression of the actuation structure may be configured to extend the housing tube relative to a handle proximal. An extension of the housing tube relative to the handle proximal end may be configured to gradually compress the first housing tube portion causing the housing tube to gradually curve.

<CIT> discloses an actuation part of an instrument for endoscopic applications with a handling end portion, a flexible portion, and actuating means located on the other end portion. The actuating means comprise a cylindrical part which is connected to the handling end portion, the actuating means, and a longitudinal element for transferring movement to the handling end portion.

<CIT> relates to an improved deflectable guiding apparatus which employs tube axially spaced apart radial slits. The slits extend partially through a circumference of the tube, such that when a compressive force is applied to the slits, the distal portion of the tube bends towards the side of the slits.

All the above-cited prior art solutions present several shortcomings. For instance, many of the known steerable guidewires/catheters are bulky, with a complicated actuation system and resulting in complex manufacturing, which raises production costs and limit the miniaturization of the final product, that in some instances is critical for e.g. navigating in tortuous, tiny blood vessels as found in the brain vascular network. Additionally, many of the known devices can deflect in several directions, a feature that enhance even more the fabrication complexity and the operation of the device itself, mainly due to sophisticated actuation means. In this context, it should be mentioned that medical practitioners intended to use guidewires or catheters are generally quite reticent to drift from common clinical practice; the use of such complex tools would require a certain training for mastering their use, and this could hinder or at least limit the adoption of the technology. Furthermore, actuators are always located at the very proximal end of the guidewire; up to the inventors' knowledge, no existing systems provide a clutchable manipulator which can be fixed by the surgeon at any desired portion of a guidewire's body while still providing actuation means to the deflectable tip.

A further, non-negligible drawback of the solutions known in the art relates to the functional combination of the steering functionality in a guidewire with a sufficient pushability and torqueability (transmission of a torque or rotational stiffness) upon operation of the guidewire. Typically, some designs have been proposed in the past for guidewires to enhance the transmission of the torque and the capability to push a guidewire along blood vessels, such as for instance in the <CIT> and <CIT>, without however implementing any solutions to actively steer a guidewire to choose a path within a body cavity.

There is therefore still need for simple and user-friendly steerable guidewires which can be reliably miniaturized to commonly used dimension in IR while providing enhanced control, pushability and torque transmission for navigating in tortuous blood vessel networks.

In view of what previously discussed, the present inventors developed a device, system that address and overcome the drawbacks of the prior art solutions as summarized above. Methods for using the above-mentioned device and system are also described but do not form part of the invention (not claimed).

In particular, the invention relates to a steerable guidewire for surgical procedures and an associated system further comprising an actuator with advanced features to allow a user to control the insertion and guiding of the device.

A first aim of the invention was to manufacture a steerable guidewire through a simple, reliable and cheap manufacturing process.

A second aim of the invention was to create a guidewire having steering properties which is easy to operate and manipulate so to access complex and tortuous vascular networks.

A further aim of the invention was to create a system comprising a steerable guidewire which can be used by an operator (such as a surgeon) by minimally drifting from the common clinical practice.

Still a further purpose of the invention was to develop a steerable guidewire having optimized performances in terms of pushability and torque transmission without compromising the steering performances.

All these aims have been accomplished by the present invention as defined hereinafter and in the appended claims.

The invention relates to a guidewire comprising a tubular structure and a core wire fixed both at the proximal and the distal end of the tubular structure. The tubular structure is designed to transmit torque from its proximal end to its distal end with high fidelity. The tubular structure, when combined with the core wire (fixed at both ends), forms a device designed to actively change the distal tip shape in a controlled manner, while imparting a mechanical constraint to another part of said device. Typically, the system can change the profile of its distal end (bend, helix, hook, etc.) when the proximal region is elongated.

This was made possible by a careful study of the local mechanical properties of the tubular element. In particular, it is herein disclosed a way to drastically and elastically extend a tube without reaching permanent deformation. At the same time, the device herein disclosed presents different tubular designs which, when subjected to mechanical compression, spatially reconfigure from a straight "parent" shape at rest to various shapes.

Accordingly, in one aspect the invention relates to a steerable guidewire for insertion into a body cavity, said guidewire comprising:.

Another aspect of the invention relates to a system comprising the steerable guidewire as described herein and an actuator adapted to impart a tension force on the pull wire resulting in a distally-directed compression force to the spatially reconfigurable region.

Further embodiments of the present invention are defined by the appended claims.

The above and other objects, features and advantages of the herein presented subject-matter will become more apparent from a study of the following description with reference to the attached figures showing some preferred aspects of said subject-matter. However, the present invention is not limited to the embodiments as described in the following and/or depicted in the drawings; to the contrary, the scope of the present invention is defined by the appended claims.

The subject-matter herein described will be clarified in the following by means of the following description of those aspects which are depicted in the drawings. It is however to be understood that the subject matter described in this specification is not limited to the aspects described in the following and depicted in the drawings; to the contrary, the scope of the subject-matter herein described is defined by the claims. Moreover, it is to be understood that the specific conditions or parameters described and/or shown in the following are not limiting of the subject-matter herein described, and that the terminology used herein is for the purpose of describing particular aspects by way of example only and is not intended to be limiting.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, unless otherwise required by the context, singular terms shall include pluralities and plural terms shall include the singular. The methods and techniques of the present disclosure are generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification unless otherwise indicated. Further, for the sake of clarity, the use of the term "about" is herein intended to encompass a variation of +/-<NUM>% of a given value.

The following description will be better understood by means of the following definitions.

As used in the following and in the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Also, the use of "or" means "and/or" unless stated otherwise. Similarly, "comprise", "comprises", "comprising", "include", "includes" and "including" are interchangeable and not intended to be limiting. It is to be further understood that where for the description of various embodiments use is made of the term "comprising", those skilled in the art will understand that in some specific instances, an embodiment can be alternatively described using language "consisting essentially of" or "consisting of.

In the frame of the present disclosure, the expression "operatively connected" and similar reflects a functional relationship between the several components of a device or a system among them, that is, the term means that the components are correlated in a way to perform a designated function. The "designated function" can change depending on the different components involved in the connection; for instance, the designated function of an actuator operatively connected with an actuation region on the guidewire is that of operating the actuation region in such a way that a deflection is obtained at the distal end of the guidewire. A person skilled in the art would easily understand and figure out what are the designated functions of each and every component of the device or the system of the invention, as well as their correlations, on the basis of the present disclosure.

As used herein, the terms "torque" is a twisting, tangent or turning force that tends to cause rotation around an axis, and particularly the longitudinal axis of the guidewire. Further, the term "torqueability" is used herein to mean the ability of a guidewire that is rotating to overcome turning or torque resistance. It is generally measured in pounds per foot or newtons per meter.

The term "steerability" generally refers to the ability to controllably direct the distal tip of a guidewire to point its tip in the desired direction during an advancement procedure. Steerability is an important performance characteristic for a steerable guidewire; the ability to controllably orient the tip allows the guidewire to be navigated into e.g. different branches of vessels and/or across a stenosis. However, in the frame of the present disclosure, "steerability" refers to the capability to actively control the tip of the guidewire of the invention by acting on an actuation portion thereof to reconfigure a spatially reconfigurable portion. Accordingly, the term "steerable" when referred to the guidewire of the invention is to be intended as "actively steerable" or "dynamically steerable", i.e. the guidewire of the invention can be actively deflected by a user operating it by mechanically acting on an actuation portion depending on the needs and circumstances.

The expression "<NUM>:<NUM> torque response" is used herein to refer to the ability of the distal tip to rotate exactly in step with rotation of the proximal end of a guidewire. For example, if the proximal end of the guidewire is rotated through <NUM> degrees, the tip will ideally rotate through <NUM> degrees - hence a <NUM>:<NUM> response - in a very short period of time (less than <NUM>). It shall be noted that a torque, and therefore a torque response, of the guidewire of the invention is not linked to the steerability of the same, the former being the ability of the guidewire to rotate about its longitudinal axis, whereas the latter is the ability of the guidewire to deflect its tip off axis and reconfigure the distal end.

The present invention stems for a previous work described in the patent application <CIT> owned by the present Applicant. The invention is directed to a steerable guidewire capable of being actively/dynamically bent, deflected or otherwise controlled off-axis in order to move towards a certain target location along a path within a vessel, body cavity or hollow organ(s).

With reference to <FIG>, depicting a schematic sketch of one embodiment of the invention, a steerable guidewire for insertion into a body cavity is shown, said guidewire comprising:.

The steerable guidewire of the invention comprises a proximal end <NUM>, an elongated body <NUM> and a distal end portion <NUM>. A lumen <NUM> spans from the distal end <NUM> up to the proximal end <NUM> and along the entire body <NUM>, said lumen <NUM> being coaxially arranged compared to the longitudinal axis of the device. The distal end portion <NUM> comprises a bendable portion <NUM> and a tip <NUM> at its very end. Tip <NUM> is generally an atraumatic and non-sharp tip, with a rounded, oval, or similar appearance. Materials opaque to X-rays, such as platinum, gold, tungsten, tantalum or the like, may be advantageously incorporated therein, to act as a fluoroscopic marker to aid in visualization. The spatially reconfigurable portion <NUM> is a region at the distal end <NUM> of the device that is significantly more flexible and susceptible to deflection than the remaining body <NUM> and/or proximal region <NUM>.

A pull wire <NUM> is affixed on at least two anchor points along the device, a first anchor point being close or on the distal end of the bendable portion <NUM> and a second anchor point being close or on the proximal end <NUM>. The pull wire <NUM> can include any suitable structure for use as a core wire, as will be understood by those of skill in the art. It can have a solid cross section, but in some embodiments, can have a hollow cross-section. In yet other embodiments, the pull wire <NUM> can include a combination of areas having solid cross-sections and hollow cross sections.

The pull wire <NUM> extends from said first, distal anchor point up to said second, proximal anchor point along said lumen <NUM>. In one embodiment, for instance, said pull wire <NUM> is affixed on the distal end of the bendable portion <NUM>, which might be on the tip <NUM> of the guidewire, and on the terminal portion of said proximal end <NUM>. In the depicted embodiment, the spatially reconfigurable portion <NUM> is located at the very distal end of the device, and the pull wire <NUM> is connected to the tip <NUM>; alternative embodiments are shown on <FIG> and <FIG>. The guidewire comprises, in the spatially reconfigurable portion <NUM>, a reinforcement structure <NUM> advantageously located on one lateral side and a flexible, stress relief portion <NUM>, located on the opposed lateral side.

The active steerability, deflection or spatial reshape of a distal region <NUM> of the guidewire device, in particular of the spatially reconfigurable portion <NUM> thereof, is obtained by imparting an indirect, longitudinal tension force on the pull wire <NUM>. Particularly, this is accomplished by operating an actuation region <NUM> located on the proximal end portion <NUM>, the pull wire <NUM> being further affixed to said proximal end portion <NUM>, said actuation region <NUM> being adapted to impart a tension force on the pull wire <NUM> resulting in a distally-directed compression force to the spatially reconfigurable region <NUM>, as will be detailed later on. The inner pull wire <NUM>, which is longitudinally arranged with respect to the device's body inside the lumen <NUM> thereof, is not compressible nor extensible longitudinally, while being flexible.

The steerable device is fabricated so that it is substantially straight from its proximal end <NUM> to its distal end <NUM>. As will be explained later on in more details, the manipulation of a control mechanism <NUM> at the proximal end <NUM> causes the distal, spatially reconfigurable region <NUM> of the steerable device to be actively bent or curved away from its longitudinal axis. However, in some embodiments a pre-bending of the distal end <NUM> might be present.

In terms of materials, one or more of the portions composing the guidewire of the invention (the entire body <NUM> or at least one of the distal end <NUM>, the intermediate tubular member <NUM> and the proximal end <NUM>, as well as any combinations thereof) can be substantially made of elastic and/or super-elastic polymers, super-elastic metals or various metals/alloys/oxides
such as for instance various elastomers, silicon polymeric materials like Polydimethylsiloxane (PDMS), silicon adhesives, silicone rubbers, natural rubbers, thermoplastic elastomers, polyamide, polyimide, poly ethylene (PE), poly propylene (PP), polyether etherketone (PEEK), Acrylonitrile butadiene styrene (ABS), epoxys, polytetrafluoroethylene (PTFE), polyurethane, thermoplastic polyurethanes (TPU), Nylon, Polyether block amide (PeBax), Kevlar, stainless titanium, steel or stainless steel, nickel titanium alloy (Nitinol), nickel-chromium alloy, nickel-chromium-iron alloy, cobalt alloy, tungsten, cobalt, chrome, nickel, aluminum, copper, molybdenum or any combination thereof.

The spatially reconfigurable region <NUM> is characterized by the presence of two distinct portions, each positioned on one side of said region <NUM>, and one opposed to the other, that are named herein for the sake of clarity and simplicity stress relief portion <NUM> and constrained portion <NUM> (<FIG>). Those two portions are designed to induce an asymmetric resistance to compression in the spatially reconfigurable region <NUM> that guides the direction of bending when a longitudinal compression force (stress) is indirectly applied thereon by the pull wire <NUM>. To do so, the stress relief portion <NUM> comprises a series of stress relief elements <NUM> separated by hollow spaces <NUM>' that allows for the compressibility of the spatially reconfigurable region <NUM>; to the contrary, the constrained portion <NUM> is characterized by the presence of a so-called reinforcement structure <NUM> that limits the compressibility of one side of said region <NUM> so that the generation of a compression stress will induce a deflection which is opposed to the side of the reinforcement structure <NUM>, as schematically depicted in <FIG>.

In the most preferred set of embodiments, the device is composed, at least at its distal end <NUM> and particularly at the spatially reconfigurable region <NUM>, of a tubular solid body, containing a longitudinally-arranged thru hole defining the lumen <NUM> into which a pull wire <NUM> is located. The pull wire <NUM> is attached by any suitable attachment techniques such as for instance welding, soldering, brazing, adhesive and the like on e.g. the distal end tip <NUM> of the solid body. The spatially reconfigurable region <NUM> of the solid tubular body, which can have any lateral cross-section (perpendicular to the longitudinal axis) such as round, elliptic, square, rectangular and the like, comprises a plurality of stress relief elements <NUM> in its stress relief portion <NUM> embodied as cutouts (<FIG>). In embodiments where the elongated body <NUM> of the device is also made of the same material of said solid body, such as a polymeric material or a metal as previously listed, the reinforcement structure <NUM> constitutes an integral part of said body <NUM>. Briefly, a tubular element can be shaped to include a plurality of cutouts on one side of one of its extremities while leaving the other side unaltered, so to define a built-in blocked lateral side <NUM> and a lateral bendable side <NUM>. Accordingly, in one embodiment the steerable guidewire of the invention is characterized by having said elongated body <NUM> configured as a monolithic, or single part, element. This configuration is advantageous for what concerns the possibility of rationally engineering the flexibility of the guidewire through manufacturing method(s) adapted to be applied on a single tubular element, which in turn might facilitate the rational enhancement of the pushability and torque transmission thereof.

With regards to the manufacturing methods, for instance, non-conventional ones are typically used for the device of the invention, due to the particularly small dimensions, materials (metals, polymers) and thicknesses presented. The raw material forming the tubular structure to be machined is formed of material directly extruded to the right dimensions (outer, inner diameters and length). Another method is adapting the outer diameter of the tubing by precision machining methods such as EDM (Electro Discharge Machining), mechanical abrasion or laser light abrasion. Another method of forming the raw tubular structure is rolling about <NUM>° a polymer or metal thin film/sheet and bring the two edges together by laser welding said edges. The machining of complex structures are obtainable by the use of high precision methods such as laser light with pulsing frequencies of milli-, nano-, pico- or femtoseconds. The laser heads are typically mounted on a X-Y-Z axis and the tubing is fed through a rotary and linear feeding mechanism. Additionally or alternatively, methods such as mechanical abrasion using radial abrasive blades, Computer Numerical Control (CNC) mechanical machining and/or electro-chemical / chemical etching can be employed.

In one embodiment as exemplarily represented in <FIG>, the distal end <NUM> of a tubular element is rendered single-sided deflectable by cutting slots or gaps <NUM>', hereinafter also called "motifs", passing completely through the entire thickness of the tubular element so that a sort of spine with ribs is formed. The distal end <NUM> of the device of the invention fulfills the following requirements: imitates the most common guidewire tip configurations as typically used as of today in interventional radiology surgeries; maintain an optimal torqueability despite its floppy nature; and is sufficiently flexible and atraumatic to avoid artery puncture during navigation.

In a set of embodiments, the reinforcement structure <NUM> can have various different shapes, and even more than one reinforcement structures <NUM> can be present along the spatially reconfigurable portion <NUM>. Moreover, in some embodiments the reinforcement structure <NUM> can span from the distal tip <NUM> all along the spatially reconfigurable portion <NUM>, so that a constrained portion <NUM> would cover one entire side thereof, or the reinforcement structure <NUM> can define a more limited portion of spatially reconfigurable region <NUM> as a constrained portion <NUM>. Put it differently, one single spatially reconfigurable region <NUM> might be present on the distal end <NUM> of the device when a single reinforcement structure <NUM> is present, or a plurality of spatially reconfigurable regions <NUM> might be present when more than one reinforcement structure <NUM> is present, as depicted for instance in <FIG>. When the device is embodied as a monolithic element, or at least its distal end, the reinforcement structure(s) <NUM> result(s) from the cut-outs defined within the spatially reconfigurable portion <NUM>, and referring to a plurality of spatially reconfigurable regions <NUM> might be more sensitive for the sake of clarity.

For instance, more than one reinforcement structure <NUM>, or a sectioned one, can be implemented on the spatially reconfigurable region <NUM> in order to set a plurality of constrained portions <NUM>. This embodiment is particularly useful for obtaining "elbow" deflections of the spatially reconfigurable region <NUM>, wherein by "elbow" deflection it is meant that the deflection in the reconfigurable region <NUM> does not occur in a uniform way along the said region <NUM> but at a relatively discrete position(s) displaced proximally from the tip <NUM> of the guidewire (<FIG>). This arrangement could enable or facilitate negotiation of the artery with e.g. minimal trauma to the vascular intima.

Each spatially reconfigurable region <NUM> comprises a plurality of stress relief elements <NUM> separated by slots or gaps <NUM>', so to form a stress relief portion <NUM> configured as sets of "ribs". In preferred aspects, each portion <NUM> is embodied as a solid tubular member comprising radially aligned slots <NUM>' separated by ribs <NUM>. Particularly, the spacing and disposition of the slots <NUM>' offer the possibility to establish a plurality of designs, and therefore of functions in terms of steerability. In some embodiments, slots <NUM>' may be substantially equally spaced along a spatially reconfigurable region <NUM>. However, in some embodiments, slots <NUM>' may be spaced unequally along a spatially reconfigurable region <NUM>, may be of unequal sizes, or both.

The reinforcement structure <NUM> may have e.g. a rectangular, triangular, rhomboidal or any other suitable contour appearance depending on the needs and circumstances; the contour shape would define the resistance to the bending of the constrained portion <NUM> upon application of a tensile stress, which will be higher in those portions of the constrained region <NUM> having larger width of the reinforcement structure <NUM> and vice versa, assuming an homogeneous thickness of the reinforcement structure.

In view of the above, it will be apparent that the distal end <NUM> can present different tubular designs which, when subjected to mechanical compression, spatially reconfigure from a straight parent shape to various shapes. These different shapes allow the guidewire to help a surgeon access complex anatomic configurations that would normally be close to impossible to access with a classical, non-actively steerable guidewire. Other configurations result in new, unexplored functions to the guidewire, such as, for example, gently anchoring the guidewire into a specific location in a small artery. For instance, as exemplarily shown in <FIG>, the guidewire of the invention allows, based on the rational design of its distal end <NUM> (which will be detailed later on), to obtain some of the most common tip configurations used in interventional neuroradiology, such as for instance so called an angled shape, J-shape, Simon shape or Cobra shape (<FIG>, respectively).

Commercially available devices are delivered out of the package with their tips pre-shaped with these common configurations, as they help the surgeons navigate specific difficult cases. Alternatively, the devices are delivered straight and allow a tip shape remodeling performed by hand by the surgeon. Advantageously, the steerable guidewire of the invention can actively and on-demand change its geometrical configuration when subjected to an actuation.

In one embodiment, the guidewire can have its distal end <NUM>, and particularly its bending portion <NUM>, designed to obtain an "anchor shape" (<FIG>) upon actuation. The anchor shape allows the flexible distal end <NUM> of the guidewire to be curled-up in a helicoidal shape against the inner wall of an artery. To do so, an elongated reinforcement structure <NUM> is located in a helicoidal fashion on the distal end <NUM> to define a constrained region <NUM>, and therefore a stress relief region <NUM>, winding about the spatially reconfigurable region <NUM> (and defining it). The flexibility of the tip region allows the curled shape to accommodate nearly any artery tortuosity and curve. The main application of this "anchor" is to give the ability to the surgeon to fix the guidewire's tip at a specific location and create a so-called "fixed point" which will facilitate the insertion of catheter devices on top of the established guiding wire and avoid unwanted movement (slipping) of the guidewire.

The high versatility of the inventive concept proposed by the present invention permits to envisage various configurations, as already outlined above, but also diverse, unprecedented applications for a guidewire. In particular, the spatially reconfigurable region <NUM> can be configured and adapted to further create, in addition to the above-described two-dimensional configurations, three-dimensional shapes in a very easy and intuitive way. As depicted for instance in <FIG>, and as a way of non-limiting example, a helicoid shape can have a varying projected diameter, therefore becoming, on at least a portion thereof, a conical helix or spiral, or can have a fixed projected diameter that gives rise to a cylindrical helix. Shapes like conical or cylindrical spirals, positioned at the distal portion of the device, can be exploited for new applications going beyond the typical guiding functioning of guidewires: in fact, 3D arranged tips may be advantageously used for anchoring to, and/or removing, blood or other aggregates that may be formed e.g. in the vasculature, including blood clots or foreign body impairing blood circulation. Additionally or alternatively, a so-configured guidewire according to the invention may theoretically be used for removing other bodies located into tubular bodily structures, such as kidney stones.

Concerning the spatially reconfigurable region <NUM>, this is typically smaller or equal in length than the reinforcement structure <NUM> length, such as about from <NUM>% to <NUM>% of reinforcement structure <NUM> length. A typical range for the width of reinforcement structure w is <NUM>% to <NUM>% of the portion <NUM> diameter, D.

The proximal region <NUM> of the guidewire is designed and intended to enable the handling of the device by the surgeon's hands. Because of these requirements, the proximal end <NUM> is configured and optimized so to represent a tool for the surgeon to be able to navigate the device towards a target spot into a body cavity during a surgery (push-pull, rotation). Particularly, the design and the materials of the proximal end <NUM> are tailored in order to provide a <NUM>:<NUM> torque response and excellent pushability; at the same time, the proximal end <NUM> comprises an actuation region <NUM> where a manipulator/actuator can be clutched or otherwise connected and used in order to allow the surgeon to induce the deflection at the distal end <NUM>, which is one of the key features of the device of the invention. Additionally, the proximal end <NUM> may comprise an end portion adapted for connecting to a longitudinal guidewire extension.

As anticipated, the steerable guidewire comprises an actuation region <NUM> at its proximal end <NUM> which is adapted to impart an indirect tension force on the pull wire <NUM> bringing to a compression force on the spatially reconfigurable region <NUM> resulting in a reshape thereof, in order to control the articulation at the distal end <NUM>, particularly at the region <NUM>. The actuation region <NUM> is designed to permit a functional access to the pull wire <NUM> and manipulation thereof; for instance, the actuation region <NUM> can be placed at the very proximal end extremity of the device where it can be directly clamped, grasped or otherwise manipulated to impart distal longitudinal forces.

The steering mechanism of action consists of a collapse of the bendable region <NUM> by means of longitudinal stress forces applied on the actuation region <NUM>. In particular, upon operation, the actuation region <NUM> may be maintained e.g. by clamping, on two opposed, longitudinally-placed anchor points <NUM> and <NUM> (see <FIG>). The relative displacement of the blocking point <NUM> and <NUM> imparts an axially, longitudinally directed force on the entire body <NUM> up to the distal end <NUM>, which tends to collapse the hollow spaces <NUM>' in the stress relief portion <NUM> of the spatially reconfigurable region <NUM>, finally bringing the stress relief elements <NUM> closer together.

The actuation region <NUM>, because of its inherent function, is elastic in nature; in particular, the actuation region <NUM> is conceived to be elongated (deformed axially) without irreversibly deform, so to be actuated several times depending on the needs and circumstances without lost in performance. At the same time, the actuation region <NUM> is also designed in such a way as to reduce as much as possible its compression factor, i.e. when the axially deformable region is compressed a minimum relative displacement is induced. This is particularly important during push-pull procedures in surgeries not to impact the pushability of the entire device, as well as to maintain the torque transmission. To maintain a high torqueability and pushability, the steerable guidewire of the invention is devoid of any coiled member along the entire body <NUM>, in that the actuation region <NUM> is devoid of any coiled member. To the contrary, a tubular element is preferred in this context.

In some embodiments, and within the scope of the invention, the actuation region <NUM> is configured as to comprise at least one of an assembly of discrete members or segments and a single-body elastic structure, as exemplarily shown in Figures 5A to 5E. In embodiments of the invention, an assembly of discrete members or segments (DMs) includes without limitations a plurality of interlocking members or segments, a plurality of conical or tapered members or segments, a plurality of magnetic members or segments and any combinations of the foregoing (Figures 5A to 5C). In at least some embodiments, each of the segments DM is typically a separate and discrete structure, structurally independent from any adjacent segment or segments DM. Each of the plurality of interlocking segments are adapted and configured to interlock or otherwise connect with those segments that are adjacent thereto in a way as to inhibit rotation of adjacent segments relative to one another, while still allowing the elongation of an actuation region <NUM> through the disconnections of any segments or members along the longitudinal axis of the guidewire creating disconnecting gaps DG. The inhibition of rotation of adjacent segments relative to one another favors an optimal transmission of torque along the elongated tubular assembly in both rotational directions.

Similarly, an assembly of conical segments or otherwise tapered members act to advantageously connected the one with the others without limiting pushability and torqueability of the device.

Each of the segments DM can include interlocking means, for example crenations, teeth, serrations, bends, grooves, protrusions, notches, tongue and groove arrangements and the like, that are adapted and configured to mate with each other adjacent segments interlock in a mechanical or frictional manner to inhibit rotation of adjacent segments in relation to one another.

Any assembly can include from about ten to about five thousands of individual members. Generally, all of the segments within an assembly can be of uniform length, and the total length of the assembly can be in the range of about <NUM> microns to about <NUM> centimeters.

In embodiments of the invention, an actuation region <NUM> having a single-body elastic structure includes without limitations an accordion-like structure, a ribbon structure or combinations thereof (Figures 5D and 5E). Those structures are characterized by an unidirectional elastic behavior and an excellent torque transmission deriving from their intrinsic nature, particularly their structure, and are therefore highly adapted to be included into actuation regions according to the invention. With regards to a ribbon structure, this preferably includes protrusions IP along its length, or "fingers", interlocking with a matching notch MN on an opposed side of the ribbon. Such a configuration allows at the same time an optimal stretchability upon actuation as well as an excellent, lossless bi-directional torque transmission.

In one particular embodiment, the steerable guidewire of the invention comprises an actuation region <NUM> having throughout cuts or motifs <NUM> configured to both allow the longitudinal elongation and hinder the longitudinal compression of said actuation region <NUM> in an optimized fashion. According to this configuration, the proximal end <NUM> is embodied as a tubular member patterned with said plurality of throughout cuts or motifs <NUM> spanning through the thickness of the tubular member. The cut-out shapes <NUM> are rationally designed to be as much as possible extensible and non-compressible at the same time, in such a way to allow a relative extension of the proximal end <NUM> in a designated region (actuation region <NUM>) while restricting compression thereof. Because of this configuration and of the presence of a solid-bodied, tubular-membered proximal end <NUM>, torque transmission is optimized as well. Preferably, said throughout cuts or motifs <NUM> comprise a portion substantially perpendicular to the longitudinal axis of said guidewire (with regards to the external wall of the proximal end <NUM>). Still more preferably, said throughout cuts or motifs <NUM> further comprise a portion substantially parallel to the longitudinal axis of said guidewire (with regards to the external wall of the proximal end <NUM>). This embodiment is exemplarily depicted in <FIG>, in which a so-called "mustache" motif <NUM> is depicted in an isometric view of a portion of the actuation region <NUM>, representing the extreme design optimization for said region of the guidewire concerning the concomitant combination of elastic extension, torqueability and stiffness.

In a particular embodiment, when an actuation region <NUM> comprises a plurality of mustache motifs <NUM>, the pull wire <NUM> can be a multi-filament wire designed to transmit in turn a compression and an extension force on the spatially reconfigurable region <NUM>, thus allowing a two-direction, in plane tip deflection. This is possible thanks to a light compression of the actuation region <NUM>, which is possible thanks to the specific design of the mustache motifs.

As shown in <FIG>, two adjacent cut-outs <NUM> and <NUM>' form a beam <NUM> that can bend and therefore procure a longitudinal displacement; accordingly, the cut-out shapes perfect the distribution of the stress throughout the proximal end <NUM> structure to avoid stress points that could lead to mechanical failure. The cut-out <NUM> defines a compression stop <NUM> that is characterized by the parameters w, h and R, as depicted in <FIG>, with w smaller to a certain extend than h and R and providing for a limited longitudinal displacement that is limited to the value of its size. In order to reach optimal performances, the relationships listed in following Table <NUM> have to be preferably maintained:.

The guidewire of the invention further comprises an intermediate region tubular element <NUM> on said body <NUM> located between said spatially reconfigurable region <NUM> and said proximal end <NUM> (<FIG>). The intermediate region <NUM> of the guidewire connects the proximal region <NUM> and the distal end <NUM>, providing a link between the actuation region <NUM> (proximal) and the deflectable region <NUM> (distal tip) while imparting to the entire device specific functions and performance.

The intermediate region is designed and conceived to fulfill the following characteristics: <NUM>) providing support to guide a catheter device efficiently up to a targeted area; and <NUM>) offering optimum torque transmission and tailored pushability/flexibility from an actuation region to the distal tip of the device. In one embodiment, in order to achieve the above results, the distal end portion <NUM> and said tubular element <NUM> form together a monolithic element, particularly in those cases where the entire body <NUM> does not form a monolithic, tubular element.

In some embodiments, region <NUM> can be a tube, a slotted tube or preferably a combination thereof. A combination of these sub regions is schematically presented for instance in <FIG>. Accordingly, in embodiments of the invention, the intermediate region <NUM> comprises a plurality of throughout cuts or motifs <NUM> extending through the thickness of said tubular element <NUM>, said motifs <NUM> being configured to create one or more patterns locally changing the stiffness of said element <NUM>. Such a configuration may contribute to locally changing the stiffness of the guidewire, and of the intermediate region <NUM> in particular, in a controlled manner. In particular, a rigid sub-region providing high support is often desired on a proximal side of the region <NUM> (sub-region <NUM>), while (a) more flexible region(s) is (are) preferred distally for improving navigability when used in endovascular applications (sub-regions <NUM> and <NUM>).

A particular embodiment is depicted in <FIG>, wherein the intermediate region <NUM> is embodied as a solid tubular member comprising radially aligned strait slits <NUM> separated by rings <NUM>. Particularly, the spacing and disposition of the cut outs <NUM> offer the possibility to establish a gradient of stiffness and a flexibility transition in order to reduce the concentration of a high stress in the material that would lean towards a mechanical failure. Typically, slits <NUM> are formed part way through tubular member <NUM>, leaving axial beams or segments <NUM> joining rings <NUM>.

Slits <NUM> may be formed in groups of two, three, or more slits <NUM>, which may be located at substantially the same location along the axis of intermediate region <NUM>, and may be substantially perpendicular to the axis. <FIG> illustrates an exemplary embodiment having groups <NUM> of two slits <NUM> and <NUM>' each. A ring <NUM> is formed between any two adjacent groups of slits <NUM> and <NUM>', and adjacent rings <NUM> are attached by a number of segments <NUM> equal to the number of slits in a group. With groups of two slits <NUM> and <NUM>', bending of tubular member <NUM> may result from distortion of segments <NUM>, rings <NUM>, or both, thus reducing fatigue on the entire structure.

Adjacent slits <NUM> may be patterned so that axial beams or segments <NUM> are rotated by an angle relative to each other about the axis of tubular member <NUM>. The angle of rotation can change along the length of the member <NUM> at any given position, and can be set to create patterns such as helical patterns to specifically tailor the stiffness of the intermediate region <NUM>. Additionally, helical patterns represent a mean to optimize manufacturing process and related costs.

In general, in embodiments having groups of two slits, the angle of rotation may be <NUM> degrees plus or minus no more than <NUM> degrees, that quantity divided by two (the number of slits in the group). In other words, the angle of rotation may be within the range of <NUM> to <NUM> degrees divided by two. In other embodiments, the angle of rotation may be <NUM> degrees plus or minus an angle between <NUM> and <NUM> degrees, that quantity divided by two. In other embodiments, the angle of rotation may be <NUM> degrees plus or minus no more than <NUM> degrees, that quantity divided by two. In some embodiments, the angle of rotation may be slightly more or slightly less than the angle values given above. Thus, segments <NUM> may be a slight angle from lining up with the midpoint of slits <NUM> in adjacent groups. This slight angle may be, for example, <NUM> to <NUM> degrees for groups <NUM> of two slits <NUM> and <NUM>' each. The same calculations are applicable, mutatis mutandis, to groups of slits of three or more. In some embodiments, slits <NUM> may be substantially equally spaced around the axis. However, in some embodiments, slits <NUM> may be spaced unequally around the axis, may be of unequal sizes, or both.

Slits <NUM> may be formed by cutting or grinding, for example, with a semiconductor dicing blade or lasers. For instance, each slit <NUM> in a group may be cut in turn by rotating tubular member <NUM>. Then tubular member <NUM> may be advanced axially, rotated the desired amount, and the axially adjacent group of slits <NUM> may be cut. In some embodiments, slits <NUM> are cut out with an angle α relative to the longitudinal axis of the region <NUM>, following an imaginary spiral path wrapped around the perimeter of the region <NUM>. The angle α can be comprised between typically <NUM> and <NUM> degrees, such as between <NUM> and <NUM> degrees, or between <NUM> and <NUM> degrees. This embodiment is particularly advantageous for what concerns automated manufacturing, drastically reducing the production time.

In order to reach optimal performances, the relationships listed in following Table <NUM> have to be preferably maintained:.

A steerable guidewire according to the invention can be fabricated to have diameters ranging from about <NUM> inches to about <NUM> inches. The external diameter of the guidewires will of course be a function of the intended application. For instance, a steerable guidewire according to the invention intended for coronary angioplasty has preferably an external diameter in the range of from about <NUM>" to about <NUM>".

The guidewire of the invention can come in various stiffnesses, and its length can range from about <NUM>-cm to about <NUM>-cm or longer. Typical guidewire for cardiovascular use have diameters in the range of <NUM>" to <NUM>" to <NUM>", a length in the range of <NUM> to <NUM>, and a tip stiffness of <NUM> to <NUM> grams for access to unoccluded vessels, and <NUM> to <NUM> grams for crossing occluded or stenosed vessels. Tip stiffness is measured by the amount of force/weight needed to deflect the tip by <NUM>%. Peripheral and neurovascular guidewires are in the range of about <NUM>" to <NUM>" and less often <NUM>" to <NUM>" while having various tip stiffness depending on their function. A key advantage of the inventive concept behind the invention relies in the presence of a reinforcement structure <NUM> that minimally alter the entire structure of a guidewire, rendering even very thin wires adapted to deflect without the need of bulky apparatuses or actuation mechanisms.

For some applications, such as coronary access, the distal end <NUM> will be floppier (have a lower stiffness) than the body <NUM> of the guidewire, while in other applications, such as aortic access or CTO (Chronic Total Occlusion) crossing, the distal end <NUM> elongated body <NUM> may have substantially similar stiffness, without impairing its ability to actively deflect. The distal end <NUM> may extend <NUM> to <NUM> from the distal tip, and is typically in the range of <NUM> to <NUM> centimeters.

In some embodiments, the exterior surface of the device is entirely or partially equipped with an elastic or otherwise compliant, biocompatible coating or sheath to provide a smooth outer surface hydrophobic or hydrophilic, depending on the needs and circumstances. Suitable coatings can be formed by dipping, spraying or wrapping and heat curing operations and any other operation known in the art. A coating material is selected to minimize sliding friction of the device during insertion and removal into a subject's body, and is substantially chemically inert in the in vivo vascular environment. A variety of suitable materials are known, including, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene (TFE), urethane, polyurethane, thermoplastic polyurethanes (TPU), silicone Polyether block amide (PeBax), Nylon or polyethylene (PE). Similarly, the coating material may be selected for its hydrophilic properties thus improving gliding in blood and navigability. Typically, this kind of coating are applied at the guidewires distal tip and extends up to <NUM> from the tip.

The actuation mechanism of the actively steerable guidewire of the invention can be favored by the use of an actuator adapted to impart a distally-directed compression force on the spatially reconfigurable portion <NUM>. This is mainly due to the physical and mechanical nature (e.g. a smooth surface), as well as the size (e.g. small diameter), of guidewires conventionally used in clinical practice, which renders their manipulation hard to be performed by hands. In this contexts, medical practitioners are used to operate guidewires with the help of small devices adapted to favour the grip and the torque of said wires, thus facilitating manoeuvrability thereof. A so-called torque device is used to provide a "handle" whereby the surgeon can have maximum control over the positioning and orientation of the guidewire.

Accordingly, a further object of the present invention relates to a system comprising the device <NUM> of the invention and an actuator <NUM> adapted to impart a compression force on the spatially reconfigurable portion <NUM> (<FIG>). The actuator, also referred to herein as "torque device", "torque actuator" or "torquer", features a controlling mechanism for permitting the articulation at the distal end <NUM> of the device of the invention, and can advantageously be releasably affixed to the proximal end <NUM> to follow the advancement of the device along a path, such as the endoluminal space of a blood vessel, and allowing negotiation, pushing/pulling and steering operations.

In the implementation of the invention, a plurality of non-limiting embodiments of said actuator <NUM> have been developed, depicted mainly in <FIG>. Generally speaking, the developed torque actuator <NUM> comprises:.

A torquer <NUM> according to the invention securely holds and controls a guidewire with one hand and with smooth operation. The actuator is simple in its construction, fast to load and adjust, easily gripped and ungripped and free of jerking wire movements during operating procedures.

The torquer <NUM> is composed of two handles <NUM> and <NUM> connected or connectable between them through a variety of solutions; as a way of example, said handles <NUM> and <NUM> can be coupled and/or fixed one with respect to the other by means of an accordion-like, corrugated element <NUM> (<FIG>), via a spring clip <NUM> (<FIG>), or thanks to a male-female arrangement, permitting to insert e.g. handle <NUM> into handle <NUM> (<FIG> and B; <FIG>). Notwithstanding the connection setup, handles <NUM> and <NUM> are substantially coaxially arranged one with respect to the other along their longitudinal axes.

As exemplary depicted in <FIG>and <FIG>, an interior long axial channel or lumen (<NUM>, <NUM>) extends between the proximal end (<NUM>, <NUM>) and the distal end (<NUM>, <NUM>) through the elongated body (<NUM>, <NUM>) of each of the first and second handles <NUM> and <NUM>. An aperture formed at the proximal end (<NUM>, <NUM>) and an aperture formed in the distal end (<NUM>, <NUM>) provide access to the passage, and facilitate advancement, of a guidewire <NUM> through body. Channels or lumens <NUM> and <NUM> are substantially coaxially arranged one with respect to the other along their longitudinal axes so to create, upon connection of handles <NUM> and <NUM>, a unitary passage or channel.

In preferred embodiments, gripping and ungripping means <NUM> and/or <NUM> comprise a spring collet clamp. A collet locking system comprises a chuck that forms a collar around an object to be held (in the present case, guidewire device <NUM>) and exerts a strong clamping force on said object when it is tightened. The collet is a sleeve with an inner surface normally matching that of a guidewire and a conical outer surface. The collet can be squeezed against a matching taper such that its inner surface contracts to a slightly smaller diameter, squeezing the guidewire to hold it securely. This is achieved with a spring collet, made of e.g. spring steel, with one or more kerf cuts along its length defining at least two flanges that allow the spring collet to expand and contract. With enough compression, the collet locking mechanisms <NUM> and <NUM> exert sufficient frictional force upon the guidewire <NUM> such that this is "locked" relative to torque device <NUM>, preventing the guidewire from sliding freely within the hollow inner bores <NUM> and <NUM> of torque device <NUM>.

To perform said compression, in one embodiment the system further comprises a first and second tapered fasteners <NUM> and <NUM> adapted to releasably engage and tighten said gripping and ungripping means <NUM> and/or <NUM>, such as a spring collect clamp, of said first and second handles <NUM> and <NUM>, respectively. As shown for instance in <FIG> and <FIG>, fasteners <NUM> and <NUM> are caps including a first end (<NUM>, <NUM>) and a second end (<NUM>, <NUM>), with a hollow passage extending therebetween (<NUM>, <NUM>). An aperture formed in the first end (<NUM>, <NUM>) and an aperture formed in the second end (<NUM>, <NUM>) provide access to the passage and facilitate advancement of a guidewire <NUM> through the cap (<NUM>, <NUM>). Hollow passages <NUM> and <NUM> are substantially coaxially arranged with respect to channels or lumens <NUM> and <NUM> along their longitudinal axes so to create, upon connection with handles <NUM> and <NUM>, a unitary passage or channel. The first end (<NUM>, <NUM>) is tapered so that, upon connection with distal end (<NUM>, <NUM>) of a handle (<NUM>, <NUM>), the spring collect clamp (<NUM>, <NUM>) is locked against a wire inserted therein. Threads formed adjacent the second end (<NUM>, <NUM>) on an interior of the fastener (<NUM>, <NUM>) can cooperate with threads at the distal end (<NUM>, <NUM>) of a handle (<NUM>, <NUM>).

In one additional or alternative embodiment, said distal ends <NUM> and <NUM> of said first and second handles <NUM> and <NUM> each comprise a tapered tip adapted to engage said gripping and ungripping means <NUM> and/or <NUM> such as a spring collect clamp and tighten them upon a longitudinal relative displacement of said first and second handles <NUM> and <NUM>. In this embodiment, a collet clamp <NUM> or <NUM> is designed as a tubular element coaxially arranged along its longitudinal axis within the hollow elongated body of the handle (<NUM> or <NUM>). The diameter of the collet (<NUM>, <NUM>) matches the bore (<NUM>, <NUM>) of the handle (<NUM>, <NUM>), having the larger, distal tapered end slightly greater than the bore while the smaller, proximal diameter is slightly less than the bore. A longitudinal relative displacement of the first and second handles <NUM> and <NUM> pushes the distal ends <NUM> and <NUM> thereof against the distal, larger end of the collet <NUM> and <NUM>, forcing the tapered distal end of the collet clamp (<NUM>, <NUM>) to slide within the hollow elongated body of the handle (<NUM> or <NUM>), thus locking the two elements together. Upon release of the force necessary to perform the relative displacement of handles <NUM> and <NUM>, the elastic spring nature of the collet (<NUM>, <NUM>) allows this latter to be pushed outside the body (<NUM>,<NUM>), thus consequently releasing the clamping force. As it will be evident to a person skilled in the art, combinations of the above-described embodiments are also envisageable; for instance, in operation, the first handle <NUM> is proximally arranged compared to the operator, while the second handle <NUM> is distally located. The operator can fix a proximally-located anchorage point <NUM> by screwing the fastener <NUM> about the threaded distal end <NUM> of handle <NUM>, so to tight the collet <NUM> and apply a clamping force on the device <NUM>. In this way, the actuator <NUM> can be operated as a torquer conventionally used in clinical practice; however, the distal end <NUM> of distally-located handle <NUM> can be tapered as to engage the collet <NUM> and automatically clamp and tighten it on an anchorage point <NUM> upon a longitudinal relative displacement of said first and second handles <NUM> and <NUM>.

Moreover, in a further embodiment according to the invention, each of said first and second handles <NUM> and <NUM> can comprise a plurality of corrugations <NUM> on their inner lumen adapted to work as snaps. In this way, handles <NUM> and <NUM> can be fixed one relative to the other in defined positions depending on the needs (<FIG>). This feature is particularly advantageous for providing a tactile feedback to the operator, for maintaining a given tip deflection during guidewire operation, and to facilitate the incremental actuation of the handles' displacement -acting in turn on the incremental deflection of the device's distal end- especially with actuators as those depicted in <FIG>.

Preferably, handles <NUM> and <NUM> are designed to impede or at least limiting as much as possible their relative rotation. Advantageously, handles <NUM> and <NUM> are longitudinally constrained by e.g. a guiding mechanism having grooves and guided pins, or via matching slots designed on the inner surface of their lumens.

In still another embodiment, one of the first or second handle <NUM> or <NUM> comprises a longitudinal slot <NUM> along its body, and the other of the first or second handle <NUM> or <NUM> comprises a protrusion <NUM> adapted to fit and slide along said longitudinal slot <NUM>. In this context, the system further comprises a gear rotational actuator <NUM> adapted to engage said protrusion <NUM> and operate, upon rotation, a longitudinal relative displacement of said first and second handles <NUM> and <NUM> (<FIG> and <FIG>).

As a way of example not forming part of the invention, one method of use involves performing a percutaneous or cutdown procedure to gain access to structures such as, but not limited to, the vasculature, either a vein, an artery, a body lumen or duct, a hollow organ, musculature, fascia, cutaneous tissue, the abdominal cavity, the thoracic cavity, and the like. An introducer, which is usually a hollow, large diameter, hypodermic needle, and the steerable guidewire are placed within the vasculature and the steerable guidewire is advanced through the central lumen of said introducer to be routed proximate to the target treatment site. The introducer can be removed at this time or substantially at the time the guidewire is introduced into the body lumen.

The torque device <NUM> is assembled or otherwise arranged so that the steerable guidewire <NUM> is fed within the unitary channel formed by channels <NUM> and <NUM>, collet clamps' bores <NUM> and <NUM> and, whenever present, hollow passages <NUM> and <NUM> of the fasteners <NUM> and <NUM>, as well as through the apertures of the foregoing. Deflection of the distal end <NUM> to varying degrees of curvature, under control from the proximal end <NUM> or body <NUM> of the guidewire can be performed. The curve can be oriented along the direction of a branching vessel or vessel curve so that the steerable guidewire can then be advanced into the vessel by way of its high column strength and torqueability (<FIG>).

For instance, when a branch or bend in the body vessel is reached, the first and second handles <NUM> and <NUM> are rotated and threaded into the second ends <NUM> and <NUM> on an interior of the fasteners <NUM> and <NUM> (or vice versa), so that the handles' distal ends <NUM> and <NUM> are advanced into the narrowing passage of the fasteners <NUM> and <NUM> towards the tapered portions thereof <NUM>, <NUM>. As distal ends <NUM>, <NUM> and first ends <NUM>, <NUM>, respectively, converge, the flanges of spring collet clamps <NUM> and <NUM> are compressed around the guidewire to produce sufficient frictional force to grasp the guidewire, thereby locking it relative to the torque device <NUM>. In this configuration, the torque device <NUM> is therefore in a closed position and advancement of the guidewire through it is impeded. The user can exploit the torque device <NUM> as a handle to easily manipulate the guidewire (e.g. twisting and/or laterally move it).

At this point, a relative displacement between first and second handles <NUM> and <NUM> can be performed by the user (<FIG>). A connection element between said first and second handles <NUM> and <NUM>, such as an accordion-like, corrugated element <NUM> (<FIG>), a spring clip <NUM> (<FIG>) or longitudinal slot <NUM>/protrusion <NUM> coupled by a gear rotational actuator <NUM> (<FIG> and <FIG>), is operated by the user to move away first and second handles <NUM> and <NUM> along their common longitudinal axis. Being the torque device <NUM> anchored on the proximal end <NUM> or the body <NUM> of the guidewire on two anchor points <NUM> and <NUM> via its first ends <NUM> and <NUM>, the displacement of the handles on the designated actuation region <NUM> imparts a compression force on the spatially reshapeable portion <NUM>, that in turn collapses the hollow spaces <NUM>' in the stress relief portion <NUM> of the guidewire's region <NUM>, bringing the stress relief elements <NUM> closer together and permitting the device's bending towards the target vessel or capillary. The surgeon can also release the stress tension when convenient. To do so, the first and second handles <NUM> and <NUM> are moved back in the initial position by acting on the connection element (e.g., spring clip <NUM> or gear rotational actuator <NUM>). The fasteners <NUM> and <NUM> can be, at this point, unscrewed from distal ends <NUM> and <NUM> to allow the guidewire to be fed through the torquer <NUM>. Once the guidewire is in the desired location and advancement through the body vessel is complete, the torque device <NUM> may be opened and slidably removed from the guidewire by its proximal end. Once the guidewire is in place, the surgeon can further proceed with the endovascular procedure.

Claim 1:
A steerable guidewire for insertion into a body cavity, characterized in that is comprises:
a) an elongated body (<NUM>) defining a longitudinally-arranged lumen (<NUM>) comprising
i) a proximal end portion (<NUM>) and
ii) a distal end portion (<NUM>) comprising a spatially reconfigurable portion (<NUM>) and a tip (<NUM>);
b) exactly one pull wire (<NUM>) located along said lumen (<NUM>) and affixed to said distal end portion (<NUM>) and to said proximal end (<NUM>);
c) said proximal end portion (<NUM>) comprises an elastic actuation region (<NUM>) adapted to impart an indirect tension force on the one pull wire (<NUM>) resulting in a compression force to the spatially reconfigurable region (<NUM>), wherein said elastic actuation region (<NUM>) is devoid of any coiled member; and
d) an intermediate region tubular element (<NUM>) on said body (<NUM>) located between said spatially reconfigurable portion (<NUM>) and said proximal end (<NUM>).