Patent Description:
The use of intravascular implants, such as stents, stent grafts, flow-diverters, aneurysm occlusive devices, vena cava filters, etc., has become an effective method for treating many types of vascular disease. In general, a suitable intravascular implantable device is inserted into the vascular system of the patient and navigated through the vasculature to a targeted implantation site using a delivery system.

Minimally invasive delivery systems include catheters, push or delivery wires, and the like, are percutaneously introduced into the patient's vasculature over a guidewire. Commonly used vascular application to access a target site in a patient involves inserting a guidewire through an incision in the femoral artery near the groin, and advancing the guidewire until it reaches the target site. Then, a catheter is advanced over the guidewire until an open distal end of the catheter is disposed at the target site. Simultaneously or after placement of the distal end of the catheter at the target site, an intravascular implant is advanced through the catheter via a push or delivery wire.

In certain applications, such as neurovascular, the guidewires, pushwires, and delivery wires are required to navigate tortuous and intricate vasculature, including travel within relatively fragile blood vessels in the brain, and are often required to change direction and to even double back on themselves. Thus, these wires (i.e., guidewires, pushwires, and delivery wires) should have suitable flexibility, kink resistance, pushability and torqueability to successfully navigate the vasculatures, such as cerebral and peripheral vasculature. Suitable flexibility and kink resistance of these wires allow them to navigate through a relatively tight bend without breaking or permanently deforming. Further, the forces applied at the proximal end of these wires should be transferred to the distal ends for suitable pushability (axial rigidity) and torqueability (rotation). Achieving a balance between these features is highly desirable. For example, the guidewires, push and/or delivery wires may comprise variable stiffness sections (e.g., varying ratio of material, including selective reinforcement, such as braids, coils, or the like) suitable to provide sufficient flexibility, kink resistance, pushability, and torqueability to allow navigation through vasculature.

Further, in certain applications, it may be desirable for the distal end of guidewires, pushwires, and/or delivery wires to be configured to deflect or bend during navigation through blood vessels, and/or when near a target site in the vasculature, which allows them to access the target site. Some guidewires, pushwires, and/or delivery wires have a pre-bent distal end to reach particular tight bends in the vasculature. However, these pre-bent wires may end up inadvertently colliding into, catching and/or scraping the inner wall of the vessel, especially in a tortuous and intricate vascular system, and at bifurcated vessels walls, aneurysms, and other anatomical features, during navigation and advancement of the wires. Such navigational difficulties may undesirably increase the time needed for performing a medical procedure, and may further increase the risk of trauma or damage to the blood vessels.

<CIT> describes a maneuverable distal apparatus including a temperature-activated memory element moving in a first direction to assume a predetermined shape when heated to a predetermined temperature and control means for selectively heating the memory element so that the memory element is moved in the first direction. A spring is provided for yieldably urging the memory element in a second direction away from the first direction upon cooling of the memory element to a temperature less than the predetermined temperature so that the memory element is moved to assume a shape other than the predetermined shape.

<CIT> describes a steerable surgical device including a flexible joint positioned between first and second tubular elements, with multiple shape memory alloy wire elements extending across or through the joint being circumferentially spaced relative to one another and independently actuatable to effectuate pivotal movement between the first and second tubular elements to provide enhanced maneuverability relative to single degree of freedom steerable devices.

<CIT> describes a medical guide wire or the like that is comprised in part or entirely of one or more heat activated memory alloys alone or in conjunction with one or more non-heat activated memory materials. The tip or any portion of a guide wire comprised of memory alloy or components thereof can be aimed, deflected or steered on command by applying heat to the alloy.

<CIT> describes an actuating medical device and methods for making and using the same. The actuating medical device may include a proximal shaft portion having a distal end region, an actuating shaft portion attached to the distal end region, one or more actuating members coupled to or otherwise disposed adjacent the actuating shaft portion, and a distal shaft portion attached to the actuating shaft portion. The actuating shaft portion may include a shape memory material and may be adapted to shift between a first configuration and a second configuration. Using the actuating medical device may include positioning the actuating medical device in a blood vessel and shifting the actuating shaft portion between the first and second configurations.

The invention is based on the task of providing an improved medical device of the type described above. The task is solved by a device according to claim <NUM>. Advantageous embodiments are indicated in the dependent claims.

The invention is defined by a medical device according to claim <NUM>.

According to an example that may, if applicable, provide details to further specify embodiments claimed or described in this application a medical device includes: an elongated member having a proximal end, a distal end, and a body extending between the proximal end and the distal end; wherein at least a first portion of the elongated member comprises a first segment made from a shape-memory material, and a second segment made from a non-shape-memory material, the first portion being a distal portion of the elongated member; wherein the first segment and the second segment of the distal portion of the elongated member are secured to each other along their respective longitudinal sides; and wherein the first segment is configured to undergo length change to cause the distal portion of the elongated member to bend.

Optionally, the first segment is configured to change length in response to a temperature that is above a body temperature.

Optionally, the temperature is at least ten degrees Fahrenheit (<NUM>,<NUM>) above the body temperature.

Optionally, the medical device further includes an energy source coupled to the elongated member, wherein the energy source is configured to deliver a current to the elongated member to increase a temperature of the distal portion of the elongated member.

Optionally, the medical device further includes a user interface configured to allow a user to adjust the current from the energy source to affect a corresponding change in a curvature of a bending of the distal portion of the elongated member.

Optionally, the shape-memory material of the first segment comprises shape-memory Nitinol.

Optionally, the non-shape-memory material of the second segment comprises non-shape-memory Nitinol.

Optionally, the elongated member comprises a second portion proximal to the distal portion.

Optionally, the second portion and the distal portion of the elongated member are made from different materials.

Optionally, the second portion comprises stainless steel, and the distal portion comprises Nitinol.

Optionally, the second portion of the elongated member comprises non-shape-memory Nitinol, and the first segment of the distal portion of the elongated member comprises shape-memory Nitinol.

Optionally, the medical device further includes a coil coupled to the elongated member.

Optionally, the medical device further includes a jacket or a slotted tube disposed around at least the distal portion of the elongated member.

Optionally, the medical device further includes a marker coupled to the distal portion of the elongated member.

A medical device includes: an elongated member having a proximal end, a distal end, and a body extending between the proximal end and the distal end; wherein at least a first portion of the elongated member comprises a first segment and a second segment, the first portion being a distal portion of the elongated member; wherein the first segment and the second segment of the distal portion of the elongated member are secured to each other along their respective longitudinal sides; and wherein the first segment is configured to undergo length change in response to a temperature that is above a body temperature, and wherein the second segment is configured to undergo zero length change or less length change compared to the first segment in response to the temperature.

Optionally, the first segment is configured to undergo the length change to cause the distal portion of the elongated member to bend.

Optionally, the first segment comprises a shape-memory material, and the second segment comprises a non-shape-memory material.

Optionally, the shape-memory material of the first segment comprises shape-memory Nitinol, and wherein the non-shape-memory material of the second segment comprises non-shape-memory Nitinol.

Other and further aspects and features will be evident from reading the following detailed description.

The drawings illustrate the design and utility of embodiments, in which similar elements are referred to by common reference numerals. These drawings are not necessarily drawn to scale. In order to better appreciate how the above-recited and other advantages and objects are obtained, a more particular description of the embodiments will be rendered, which are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments and are not therefore to be considered limiting in the scope of the claims.

The figures are not necessarily drawn to scale, and elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be understood that the figures are only intended to facilitate the description of the embodiments, and are not intended as an exhaustive description of the claimed inventions, or as a limitation on the scope thereof, which is defined only by the appended claims.

In addition, the respective illustrated embodiments need not have all of the depicted features. Also, an aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

<FIG> illustrate a method of accessing a bifurcated vasculature <NUM> using a guidewire <NUM> having a distal end <NUM>. A distal segment (including the distal end <NUM>) of the guidewire <NUM> is composed of a single material (e.g., Nitinol) with shape-memory properties, which can be thermally or electrically activated. The bifurcated vasculature <NUM> includes a main blood vessel <NUM>, a first blood vessel branch <NUM>, a second blood vessel branch <NUM>, and a bifurcated angle <NUM> between the first branch <NUM> and the second <NUM> branch. The guidewire <NUM> is advanced through the main blood vessel <NUM> and maneuvered to access a target site within the first blood vessel branch <NUM>. The guidewire <NUM> advances along a path of least resistance by sliding through the main blood vessel <NUM>, favoring access to the second blood vessel branch <NUM> (<FIG>). While corrective action may be taken by the attending physician to maneuver the guidewire <NUM> into the desired first blood vessel branch <NUM>, in some cases, the distal end <NUM> of the guidewire <NUM> may still catch and bump against the bifurcated angle <NUM> (<FIG>). This is because single material guidewire may suffer from poor shape-retention when its distal segment is deflected, due to the extreme ductility of Nitinol when operating below its active temperature (e.g., Austenite finish temperature). The bumping against the bifurcated angle <NUM> by the distal end <NUM> of the guidewire <NUM> can damage the blood vessel, particularly, a relatively fragile neurovascular vessel. This may also increase the time of the medical procedure when several attempts to maneuver the guidewire <NUM> towards the desired first blood vessel branch <NUM> are unsuccessful.

In some cases, a guidewire may have a pre-bent distal segment to assist navigation through certain blood vessels. However, such guidewire may unintentionally cause trauma to the blood vessel. By way of further illustration, <FIG> illustrate a method of accessing the bifurcated vasculature <NUM>, which involves use of a guidewire <NUM> having a pre-bent distal segment <NUM>. When the guidewire <NUM> is navigated towards the desired first blood vessel branch <NUM>, the guidewire <NUM> may favor access to the unintended second blood vessel branch <NUM> due to the geometry of the bifurcated vasculature <NUM>. As a result, the pre-bent distal segment <NUM> of the guidewire <NUM> may catch and cause trauma to the inner walls <NUM> of the blood vessel <NUM> (<FIG>), and/or may catch and cause trauma to the bifurcated angle <NUM> (<FIG>). As shown in <FIG>, after the pre-bent distal segment <NUM> abuts against the bifurcated angle <NUM>, further attempts to advance the distal segment <NUM> distally may deflect the distal segment <NUM> towards the proximal end, and may further increase the risk of trauma to the blood vessel.

<FIG> illustrates an implant delivery system <NUM> in accordance with some embodiments. The implant delivery system <NUM> comprises an elongated sheath <NUM>, an elongated tubular member <NUM> slidably disposed in the elongated sheath <NUM>, and a guidewire (or wire) <NUM> slidably disposed in the elongate sheath <NUM>. In some embodiments, the guidewire <NUM> is configured to access a blood vessel in a patient. In other embodiments, the guidewire <NUM> may be configured to deliver an implant (not shown). In such cases, the guidewire <NUM> may function as a delivery wire or a pushwire.

The elongated member <NUM> has a tubular configuration, and may, e.g., take the form of a sheath, catheter, micro-catheter or the like. The elongated member <NUM> has a proximal end <NUM>, a distal end <NUM>, and a lumen <NUM> extending through the elongated member <NUM> between the proximal end <NUM> and the distal end <NUM>. The proximal end <NUM> of the elongated member <NUM> remains outside of the patient and accessible to the operator when the implant delivery system <NUM> is in use, while the distal end <NUM> of the elongated member <NUM> is sized and dimensioned to reach remote locations of a vasculature. The elongated member <NUM> is advanced over a guidewire <NUM> (an example of which will be described with reference to <FIG>) until the distal end <NUM> of the elongated member <NUM> is disposed at a target site. Simultaneously or after placement of the distal end <NUM> of the elongated member <NUM> at the target site, an intravascular implant may be advanced through the elongated member <NUM> via the guidewire <NUM>.

As shown in <FIG>, the implant delivery system <NUM> also includes a handle <NUM> coupled to the proximal end of the guidewire <NUM> (<FIG>). The handle <NUM> of the implant delivery system <NUM> includes a user interface <NUM> configured for allowing a user (e.g., physician, technician or the like) to control a bending of the guidewire <NUM>. The user interface <NUM> is illustrated as being implemented at the handle <NUM>, but in other embodiments, the user interface <NUM> may be implemented as another device that is separate from the handle <NUM>. For example, in other embodiments, the user interface <NUM> may be a computer or any electronic device (e.g., cell phone, tablet, etc.) that is capable of generating electrical signals and/or radiofrequency signals. The user interface <NUM> may include an electrical controller, power supply or the like, configured to deliver current to the components of the implant delivery system <NUM> (e.g., to the guidewire <NUM>). In some embodiments, the user interface <NUM> may include one or more controls, which may be one or more physical button(s), knob(s), switch(es), etc. In other embodiments, the one or more controls may be a touch screen with graphical elements configured to allow the user to selectively activate the guidewire <NUM> for bending the guidewire <NUM>.

In some embodiments, the handle <NUM> may also be optionally coupled to the proximal end <NUM> of the elongated member <NUM>, and/or to a proximal end <NUM> of the elongated sheath <NUM>. In such cases, the user interface <NUM> may also allow a user to control a bending of the elongated member <NUM>, and/or the elongated sheath <NUM>. The elongated member <NUM> and/or the elongated sheath <NUM> may include actuation elements (e.g., steering wires), which are actuatable in response to tension forces provided by the user interface <NUM>, to thereby bend the elongated member <NUM> and/or elongated sheath <NUM>. The user interface <NUM> may include one or more controls for allowing the user to apply tension to the steering wires. In some embodiments, the one or more controls may be one or more physical button(s), knob(s), switch(es), etc. In other embodiments, the one or more controls may be a touch screen with graphical elements configured to allow the user to activate the actuating element(s) of the elongated member <NUM> and/or elongated sheath <NUM>.

In other embodiments, the elongated member <NUM> and/or the elongated sheath <NUM> may not include any steering wires. In such cases, the bending of the elongated member <NUM> and/or the elongated sheath <NUM> may be controlled by the guidewire <NUM>.

In further embodiments, the delivery system <NUM> may not include the sheath <NUM> and/or the elongated member <NUM>.

Furthermore, in other embodiments, the system <NUM> may not be an implant delivery system. Instead, the system <NUM> may be other types of medical devices, or components of other types of medical devices. For example, the system <NUM> with the guidewire <NUM> may be a part of a drug delivery system, a biopsy system, a treatment system that includes an energy source, etc..

<FIG> illustrate the guidewire <NUM> in accordance with some embodiments. As shown in the figures, the guidewire <NUM> includes a proximal end <NUM>, a distal end <NUM>, and a body <NUM> extending between the proximal end <NUM> and the distal end <NUM>. The guidewire <NUM> also includes a distal portion <NUM> having the distal end <NUM>. The guidewire <NUM> has a linear configuration that is relatively straight (compared to a bent configuration) at room and/or body temperature, yet flexible to bend when subjected to external forces. The guidewire <NUM> further includes variable stiffness sections from higher stiffness at a proximal portion, while gradually reducing stiffness along the body <NUM>, to a lower stiffness along the distal portion <NUM>. Such configuration provides sufficient flexibility, kink resistance, pushability, and torqueability for the guidewire <NUM> for navigation through vasculature. Alternatively, the variable stiffness sections of the guidewire <NUM> may be distinct instead of gradual. For example a first portion of the guidewire <NUM> that is closer to the proximal end <NUM> than to the distal end <NUM> may have a first stiffness, a second portion of the guidewire <NUM> that is distal to the second portion may have a second stiffness, and a third portion of the guidewire <NUM> that is distal to the second portion may have a third stiffness. The third portion may be the distal portion <NUM>. The first stiffness may be higher than the second stiffness, and the second stiffness may be higher than the first stiffness.

It should be noted that the term "body temperature", as used in this specification, may refer to a range of temperatures, such as a temperature range of <NUM>° to <NUM>° Fahrenheit (<NUM> to <NUM>,<NUM>), or more preferably a temperature range of <NUM>° to <NUM>° Fahrenheit (<NUM> to <NUM>), or more preferably a temperature range of <NUM>° to <NUM>° Fahrenheit (<NUM> to <NUM>). Also, as used in this specification, the term "room temperature" may refer to any temperature that is different from the body temperature. For example, room temperature may be any temperature that is lower than body temperature. In some embodiments, the room temperature may be any temperature that is at least <NUM>° Fahrenheit (<NUM>,<NUM>) below the body temperature, or that is at least <NUM>° Fahrenheit (<NUM>) below the body temperature.

As shown in <FIG>, the distal portion <NUM> of the guidewire <NUM> comprises a first segment <NUM> and a second segment <NUM>, wherein the first segment <NUM> is coupled to the second segment <NUM>. The distal portion <NUM> of the guidewire <NUM> may optionally also include a radio-opaque marker <NUM>. The first segment <NUM> of the distal portion <NUM> of the guidewire <NUM> is configured to change to a more curvilinear configuration from its relatively straight configuration in response to temperature change(s), while the second segment <NUM> is independent of temperature changes. When the first segment <NUM> changes its shape from its relatively straight configuration in response to temperature change(s), the first segment <NUM> displaces or moves the second segment <NUM> along with it, so that the distal end <NUM> of the distal portion <NUM> of the guidewire <NUM> deflects, as represented by the broken lines in <FIG>, which will be described in further details below. In the illustrated embodiments, the first segment <NUM> is configured to contract in response to temperature change(s). In such cases, a contraction of the first segment <NUM> will cause the distal portion <NUM> of the guidewire <NUM> to bend in a direction that is towards the side of the first segment <NUM>. In accordance with the invention, the first segment <NUM> is configured to extend or elongate in response to temperature change(s). In such cases, an extension of the first segment <NUM> will cause the distal portion <NUM> of the guidewire <NUM> to bend in a direction that is towards the side of the second segment <NUM>.

In some embodiments, the first segment <NUM> of the distal portion <NUM> of the guidewire <NUM> is composed of shape-memory Nitinol, and the second segment <NUM> of the distal portion <NUM> of the guidewire <NUM> is composed non-shape-memory Nitinol. In other embodiments, the first segment <NUM> may be made from other shape-memory materials, such as shape-memory metal, shape-memory alloy, etc. Also, in other embodiments, the second segment <NUM> may be made from other non-shape-memory materials, such as non-shape-memory metal, non-shape memory alloy, etc. In accordance with the invention, the first segment <NUM> and second segment <NUM> of the distal portion <NUM> are fixedly attached (e.g., laminated) at one or more points along a longitudinal axis of the guidewire <NUM> by suitable techniques, such as solder, adhesive, laser spot welds, or their like.

In some embodiments, the first segment <NUM> of the distal portion <NUM> is configured to be thermo-electrically actuated to deflect the distal portion <NUM> of the guidewire <NUM>. In the illustrate embodiments, the first segment <NUM> has been thermo-mechanically processed so that it will shorten (e.g., contracts) when heated above an activation temperature. The second segment <NUM> does not include a shape memory behavior, and thus, when the distal portion <NUM> of the guidewire <NUM> is heated above the activation temperature, the first segment <NUM> shortens while the second segment <NUM> retains its length. The shortening of the first segment <NUM> relative to the second segment <NUM> will cause the distal portion <NUM> of the guidewire <NUM> to bend. The shortening/contraction of the first segment <NUM> creates a deflection of the distal portion <NUM> of the guidewire <NUM>, as represented by the broken lines in <FIG>.

In some embodiments, the activation temperature may be an Austenite finish temperature (AF). The term Austenite finish temperature ("Af"), as used in this specification, is the temperature at which martensite to austenite transformation is completed on heating of a material, such as metal alloy (e.g., Nitinol). When the material is fully martensite and is subjected to heating, austenite starts to form at the austenite start temperature (As), and finishes at the austenite finish temperature (Af).

In some embodiments, heating the distal portion <NUM> of the guidewire <NUM> can be affected by running current through the guidewire <NUM> via the user interface <NUM> at handle <NUM> (<FIG>). The resistivity of the material forming the distal portion <NUM> creates heating which can be controlled with electrical power modulation in the user interface <NUM>. In some embodiments, the Af temperature of the first segment <NUM> can be selected to be slightly above body temperature so that the actuation of the distal portion <NUM> of the guidewire <NUM> does not require heating above a safe limit for blood contact. In such cases, the distal portion <NUM> of the guidewire <NUM> will not deflect during storage or advancing of the guidewire until a current is applied to the guidewire <NUM> and the Af temperature of the first segment <NUM> is reached to be slightly raised above body temperature.

It should be noted that having the first segment <NUM> and second segment <NUM> of the distal portion <NUM> coupled in a laminated configuration allows the distal portion <NUM> of the guidewire <NUM> to achieve larger deflections with a substantially short first segment <NUM>. The amount of deflection of the distal portion <NUM> of the guidewire <NUM> is governed by the differential properties of the first segment <NUM> and second segment <NUM>, and/or an amount of current being delivered to the distal portion <NUM> of the guidewire <NUM>. In some embodiments, the non-shape-memory second segment <NUM> may have mechanical properties independently tuned and/or selected to also provide shapeability and functionality of the distal portion <NUM> of the guidewire <NUM>.

In some embodiments, the first segment <NUM> of the distal portion <NUM> of the guidewire <NUM> may have a length that is anywhere between <NUM> to <NUM>, or that is anywhere between <NUM> to <NUM>, or that is anywhere between <NUM> to <NUM>,<NUM> (e.g., approximately, the full length the guidewire). The second segment <NUM> may be shorter than the first segment <NUM>, the same length as the first segment <NUM>, or longer than the first segment <NUM>.

The deflection of the distal portion <NUM> of the guidewire <NUM> is produced due to the magnitude of differences between the coefficient of thermal actuation of the first segment <NUM> and the non-thermal actuation of the second segment <NUM>. In some embodiments, the thermal/electrical actuation of the distal portion <NUM> of the guidewire <NUM> creates a four percent or greater (≥ <NUM>%) shorten/contraction or length change differential over a relatively small change in temperature range (e.g., <NUM>° Fahrenheit (<NUM>) or higher, <NUM>° Fahrenheit (<NUM>) or higher, <NUM>° Fahrenheit (<NUM>) or higher, etc.), such that large distal portion <NUM> deflection may be achieved with small temperature changes. In some cases, the tightest achievable radius of curvature for the distal portion <NUM> of the guidewire <NUM> is in the range of <NUM>" (e.g. <NUM>" +/- <NUM>") (<NUM> +/- <NUM>). In other cases, the radius of curvature for the distal portion <NUM> of the guidewire <NUM> may be higher, such as <NUM>", <NUM>", <NUM>", <NUM>", etc., +/- <NUM>") (<NUM>, <NUM>, <NUM>, <NUM>, etc,, +/- <NUM>).

In some embodiments, the deflection angle of the distal portion <NUM> of the guidewire <NUM> may be controlled by thermal/current modulation applied to the guidewire <NUM>. The current may be applied using a monopolar technique, where the current passes from the guidewire <NUM>, through the patient's tissue to a return pad to complete the electric current circuit, or using a bipolar technique, where the current return path is along the guidewire <NUM> back to the electrical controller at the user interface <NUM>. Also, in some embodiments, the curvature of the bending of the distal portion <NUM> may be selectively adjusted using the control at the handle <NUM>. The control may be manipulated to change an amount of current applied to the distal portion <NUM> of the guidewire <NUM>. In one mode of operation, the amount of current may be increased to increase a curvature of the bending at the distal portion <NUM> of the guidewire <NUM>. In another mode of operation, the amount of current may be decreased in decrease a curvature of the bending at the distal portion <NUM> of the guidewire <NUM>.

Furthermore, in some embodiments, annealing parameters may be tuned to achieve a desired level of elasticity and shapeability in the material (e.g., Nitinol) forming the distal portion <NUM> of the guidewire <NUM>. In some embodiments, the second segment <NUM> of the distal portion <NUM> of the guidewire <NUM> may be heat treated to a semi or partially annealed condition, such that the second segment <NUM> may be shapeable and could retain a standard-like shapeable tip guidewire, yet the distal portion <NUM> of the guidewire <NUM> still includes the thermo-electrically actuated first segment <NUM> to actively deflect the distal portion <NUM> when needed. In such cases, active deflection (e.g., applying current or heat to the guidewire <NUM>) may not be required for one usage of the guidewire <NUM>, but the active deflection may be used when navigating the guidewire <NUM> through more challenging and tortuous vasculature in another usage.

<FIG> illustrate a method, not forming part of the present invention, of accessing a bifurcated vasculature <NUM> using the guidewire <NUM>. The bifurcated vasculature <NUM> includes a main blood vessel <NUM>, a first blood vessel branch <NUM>, a second blood vessel branch <NUM>, and a bifurcated angle <NUM> between the first <NUM> and second <NUM> branches. The guidewire <NUM> having the distal portion <NUM> is advanced through the main blood vessel <NUM> and maneuvered to access a target site within the first blood vessel branch <NUM>.

As the guidewire <NUM> is being advanced inside the patient, the user interface <NUM> may be operated by the user to actuate the guidewire <NUM> to bend in a desired manner. With the assistance of known imaging technologies and the marker <NUM> disposed at the distal end <NUM> of the guidewire <NUM>, the user can determine the location of the distal portion <NUM> of the guidewire <NUM> within the main blood vessel <NUM> (<FIG>). If the user determines that bending of the distal portion <NUM> is desired, the user may operate the user interface <NUM> to apply heat or current to the distal portion <NUM> of the guidewire <NUM> to thermally or electrically actuate the first segment <NUM> composed of shape-memory material, such that the distal portion <NUM> of the guidewire <NUM> deflects towards the desired first blood vessel branch <NUM> (<FIG>). The distal portion <NUM> of the guidewire <NUM> may then be advanced distally into the first blood vessel branch <NUM>. To achieve this deflection for distal portion <NUM> of the guidewire <NUM>, the angle of distal portion <NUM> relative to the longitudinal axis of elongate body of the guidewire <NUM>, as illustrated by angle " Φ", can range from about five degrees to about <NUM> degrees, or more.

As illustrated above, the bending of the distal portion <NUM> allows the distal end <NUM> of the guidewire <NUM> to be steered through different curvatures along a passage way (e.g., blood vessel) inside the patient. In some embodiments, the guidewire body <NUM> may be rotated about its longitudinal axis to allow the bending to occur at different bending planes. Also, in some embodiments, a degree (e.g., curvature, angle, etc.) of bending of the guidewire <NUM> may be adjusted by varying a magnitude of the heat or current provided by the user interface <NUM>.

After the distal end <NUM> of the guidewire <NUM> has been desirably positioned inside the patient, the elongated member <NUM> and/or sheath <NUM> of <FIG> may then be advanced over the guidewire <NUM>, and may be utilized in a medical procedure to diagnose and/or treat the patient. For example, the elongated member <NUM> and/or the sheath <NUM> may be used to deliver a substance (e.g., drug, medicine, contrast, saline, etc.), deploy a device (e.g., implant, tissue dissector, imaging scope, treatment energy source, etc.), or perform other functions in different embodiments.

It should be noted that the guidewire <NUM> is not limited to the examples of <FIG>, and that the guidewire <NUM> may have other configurations in other embodiments. In other embodiments, the guidewire <NUM> may include more than two distal segments that are coupled to form the distal portion <NUM> of the guidewire <NUM>. For example, in other embodiments, the distal portion <NUM> may have three distal segments that are stacked and coupled together to form the distal portion <NUM> of the guidewire <NUM>. In other embodiments, the guidewire <NUM> may include other components along a longitudinal axis of the guidewire <NUM>, such as an outer jacket, sleeve, reinforcement segments, coils, radiopaque coatings, markers, or the like.

In accordance with the invention, instead of being a guidewire, the wire <NUM> may be a pushwire, or a delivery wire.

In some embodiments, the wire <NUM> may have a stiffer proximal portion compared to the distal portion <NUM>. The stiffer proximal portion may be at least <NUM>%, at least <NUM>%, at least <NUM>%, or at least <NUM>%, of an entire length of the wire <NUM>. Also, in some embodiments, the wire <NUM> may have a proximal portion that is proximal to the distal portion <NUM>, wherein the proximal portion may be made from stainless steel, Nitinol, Cobalt-Chromium alloy (e.g., MP35N alloy), other alloys, or combination thereof.

In other embodiments, the wire <NUM> may be formed of stainless steel (or other rigid alloy) along a proximal portion, and having nitinol at the distal portion <NUM>.

In other embodiments, the wire <NUM> may include a hybrid core. For example, a portion of the body <NUM> that is proximal to the distal portion <NUM> may be made from Nitinol and another material (e.g., stainless steel) to provide a stiffer proximal portion for the wire <NUM>.

In further embodiments, the wire <NUM> may have a Nitinol segment that extends the full length of the wire <NUM>. In such cases, one or more portions of the Nitinol core may be heat treated to provide shape-memory characteristics, as similarly described herein.

In further embodiments, the wire <NUM> may function as a core wire or backbone for a variety of elongated medical devices, such as complex guidewires, sheath, catheters, or the like. The compact size of the wire <NUM> allows incorporation of it as a core wire into sheath, catheters or their like without impacting other performance characteristics (torque transmission, stiffness, tip shapeability, etc.).

<FIG> illustrate different examples of medical devices that incorporate the wire <NUM> described herein. The wire <NUM> in <FIG> include a reduced diameter (i.e., taper) from the proximal end (not shown) and/or the body <NUM> towards the distal end <NUM> of the wire <NUM>. The tapering of the wire <NUM> may be a constant reduction of diameter of the wire <NUM> along a longitudinal axis <NUM> (as shown in <FIG>), or may have distinct transitions between tapered sections (as shown in <FIG>), or a combination thereof.

As shown in <FIG>, the medical device <NUM> includes the wire <NUM> and an outer jacket <NUM> disposed around at least a portion of the distal portion <NUM> of the wire <NUM>. The outer jacket <NUM> may be any tubular member, and may be made from any suitable materials, such as metal, polymer, etc. In some embodiments, the outer jacket <NUM> may be made from nitinol. As better appreciated in detailed <FIG>, the outer jacket <NUM> includes a plurality of slots and/or openings to increase flexibility. By way of nonlimiting examples, the outer jacket <NUM> may be implemented using slotted hypotube, coiled sleeve, tungsten-loaded polymer sleeve, or a combination thereof. The medical device <NUM> may further include a coil <NUM> disposed around the distal portion <NUM> of the wire <NUM> and concentrically disposed between the distal portion <NUM> of the wire <NUM> and the outer jacket <NUM>. The coil <NUM> may be made of radiopaque material and/or platinum tungsten. The medical device <NUM> further includes a blunt atraumatic tip <NUM> coupled to the distal portion <NUM> of the wire <NUM>.

<FIG> illustrates another medical device <NUM> having the wire <NUM> and an outer jacket <NUM> concentrically disposed around at least the distal portion <NUM> of the wire <NUM>. The outer jacket <NUM> is composed of suitable polymeric material. In other embodiments, the outer jacket <NUM> may be made from other materials. The medical device <NUM> further includes a blunt atraumatic tip <NUM> coupled to the distal portion <NUM> of the wire <NUM>.

<FIG> illustrates another medical device <NUM> having the wire <NUM> and a coil <NUM> concentrically disposed around at least the distal portion <NUM> of the wire <NUM>. As shown in the figure, a proximal end <NUM> of the coil <NUM> is secured to the body <NUM> of the wire <NUM>, while the distal end <NUM> of the coil <NUM> is secured to the distal portion <NUM> of the wire <NUM>. The securing may be accomplished using an adhesive, welding, mechanical connector, fusion, etc. The medical device <NUM> further includes a blunt atraumatic tip <NUM> coupled to the distal portion <NUM> of the wire <NUM>.

Claim 1:
A medical device (<NUM>), comprising:
an elongated member (<NUM>) having a proximal end (<NUM>), a distal end (<NUM>), and a body (<NUM>) extending between the proximal end (<NUM>) and the distal end (<NUM>);
wherein at least a first portion of the elongated member (<NUM>) comprises a first segment (<NUM>) made from a shape-memory material, and a second segment (<NUM>) made from a non-shape-memory material, the first portion being a distal portion (<NUM>) of the elongated member; and
wherein the first segment (<NUM>) is configured to undergo length change to cause the distal portion of the elongated member (<NUM>) to bend in response to an application of heat or current;
wherein the elongated member (<NUM>) is a guidewire, a pushwire, a delivery wire, or a wire of the medical device;
characterized in that:
the first segment (<NUM>) and the second segment (<NUM>) of the distal portion (<NUM>) of the elongated member (<NUM>) are fixedly attached to each other at one or more points along a longitudinal axis of the elongated member (<NUM>) via an adhesive, solder, or weld along their respective longitudinal sides to form a laminated configuration.