Apparatus and methods for magnetically steerable neuro-endovascular intervention

Abstract

Exemplary embodiments of the present disclosure include a magnetically actuated guidewire that represents a major advancement in neurovascular interventions by addressing limitations in current systems. It focuses on timely intervention, accessibility for mechanical thrombectomy MT, procedural precision, cost-efficiency, portability, and seamless integration with existing and future robotic systems. The nitinol-reinforced magnetic head may be integrated at the distal end of the existing neuro guidewires and encased in soft, biocompatible silicone. The magnetically actuated guide wire includes integrated capability to magnetically control the stiffness, in real-time, of the distal end of the guidewire to dynamically adjust between high stability during device delivery and high flexibility while steering. The magnetic head's properties allow for controlled bending of the guidewire with an external magnet, facilitating precise steering at vascular bifurcations. The magnetic localization technology enables accurate tracking without relying solely on X-rays, enhancing control while reducing radiation exposure.

Description

APPARATUS AND METHODS FOR MAGNETICALLY STEERABLE NEURO-ENDOVASCULAR INTERVENTIONREFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the priority benefit of United States provisional application number 63 / 748,642, filed January 23, 2025, the entire contents of which are incorporated herein by reference.BACKGROUND1. Field

[0002] The present disclosure relates generally to the field of medical devices. More particularly, it concerns medical devices used in medical procedures associated with stroke.

[0003] Globally, 8 million individuals suffer from ischemic strokes every year, making it a leading cause of disability and mortality. An ischemic stroke is an acute medical condition that results from a buildup of cholesterol plaque along cerebral arterial walls, leading to the formation of a thrombus (i.e. blood clot) that obstructs critical blood flow to the brain. This deprivation of oxygen rapidly triggers a cascading sequence of damage and inflammation, compromising neuronal function and, if left untreated, leading to permanent neurological deficits or death.

[0004] Stroke is a leading cause of morbidity and mortality worldwide, with large vessel occlusion (LVO) strokes comprising 46% of acute ischemic strokes. Mechanical thrombectomy (MT), the gold standard for treating LVO, restores blood flow by retrieving clots with catheters. The procedure involves manually guiding a guidewire through blood vessels to the target area under fluoroscopic imaging.

[0005] A catheter follows the guidewire and uses suction to remove the clot. While MT is transformative in stroke therapy, timely access remains an issue for many patients, particularly in remote areas. In addition, navigating thin, flexible guidewires through the intricate brain vasculature poses significant challenges. This is due to the limited steerability of current guidewires and the lack of intuitive actuation mechanisms. These challenges highlight the need for robotic systems to expand access to stroke treatment and improve precision during complex neurointerventions. Such systems offer various benefit, forexample, the precision associated with controlled guidewire manipulation reduces risks like vessel injury, improving clot removal. With respect to remote intervention, experienced neurointerventionalists can treat patients remotely, reducing delays, especially in underserved areas during the critical "golden hour."

[0006] For example, with respect to the advantage of scalability and training robotics can be used to address the shortage of skilled professionals and can be used to train new practitioners. For example, with respect to the advantage of lower radiation exposure, by allowing operation at a safe distance from fluoroscopy machines, robotics reduce radiation risks.

[0007] It is desired to design and fabricate a guidewire that enables active steering to the desired location in cerebral vasculature and is compatible with robotic systems. Some embodiments may, for example, include a magnetically steerable guidewire system that utilizes externally applied magnetic torques to precisely guide the wire into position. Accordingly, systems and methods are desired to overcome these and other limitations associated with existing systems and methods.2. Description of Related Art

[0008] The conventional navigation technique relies on manually shaping the distal tip of a guidewire to a predetermined angle before insertion based on approximated trajectories and maneuvers. As the guidewire is within the vasculature, the interventionist then applies torque at the proximal end, with the goal of transmitting the rotational force along the length of the device to control the tip’s orientation and steer into a desired direction. However, as the guidewire advances deeper into the cerebral vasculature, limitations emerge. High friction buildup along the vessel walls, particularly along the pre-shaped distal tip, reduces efficient torque and force transmission, which, in turn, decreases tip steerability. Additionally, the confined space within the narrow, winding pathways of the vasculature limits the amount of torque that can be applied, making precise movements increasingly difficult. These inefficiencies not only increase the risk of procedural failure but may also contribute to vessel perforation or endothelial damage, raising the likelihood of complications.

[0009] Furthermore, as the lack of precision steering prolongs the intervention, the duration of X-ray exposure increases for both the patient and the medical team. The24924-7829-3894, v. 2interventionali sts are particularly susceptible to long-term radiation risks due to the regular use of fluoroscopic guidance in MT procedures. Prolonged exposure has been associated with an elevated risk of radiation-induced skin injuries and malignancies among interventionists over time. Reducing procedural time through improved navigation would not only enhance patient outcomes but also decrease occupational health risks for clinicians.

[0010] In addition, conventional neuro guidewires typically incorporate a fixed soft, low-stiffness design to maximize flexibility and minimize the likelihood of vessel trauma. However, this design trade-off introduces significant challenges when precise control is required, especially at sharp angulations in the cerebral vasculature. Low stiffness limits the effective transmission of force and torque, often leading to buckling and imprecise tip control, which compromises the device's ability to negotiate tortuous pathways. Moreover, this lack of rigidity poses challenges during device delivery. When a larger catheter is advanced over a flexible inner guidewire to deliver therapeutics, such as aspiration, stenting, or coiling, the inner device's inability to provide sufficient structural support can lead to instability (e.g., unintended motions) near the delivery site, resulting in misalignment or partial collapse of the inner lumen. This instability not only hinders the sensitive device delivery process, requiring additional repositioning attempts, but also increases the risk of procedural complications, such as vessel perforation or incomplete recanalization.

[0011] To address these limitations, the development of an advanced delivery system with precision steering capabilities is essential. A system that allows fine control of the guidewire or microcatheter’s tip orientation and stiffness in real-time would streamline procedures by enabling more accurate and efficient navigation through complex vascular pathways. Consequently, this would reduce intervention times, minimize risks associated with vessel trauma, reduce X-ray exposure, and ultimately improve the likelihood of a positive outcome. The integration of active steering systems to navigate the delivery body, therefore, holds the potential to significantly enhance the inherent inefficiencies of conventional MT. In the following chapter, some of the previous attempts to achieve this capability and their resulting limitations are explored.

[0012] With respect to active steering technologies, the development of steering mechanisms for general minimally invasive endovascular interventions has been driven by the need for more precise and time -efficient methods to reach the impeded vessel. Significant34924-7829-3894, v. 2research has been dedicated to the development of actively controlled steering systems that improve maneuverability and enhance procedural outcomes.

[0013] Several engineering approaches have been explored to enable controlled tip articulation, each with its own advantages and challenges. Tendon-driven systems utilize tensioned cables to manipulate the tip’s orientation, providing direct mechanical control of orientation. Shape memory alloys (SMAs) offer a compact alternative by leveraging the thermal activation of certain smart materials to achieve tip control. Magnetic actuation systems have also emerged as a promising solution, utilizing externally applied magnetic fields to achieve contactless steering capabilities. Each of these methods presents unique trade-offs in terms of precision, scale, and clinical feasibility, which are explored in the following sections.

[0014] For example, Tendon-driven steering systems enable guidewire or catheter tip orientation control by manipulating flexible tendons, have previously been explored as a method for enhancing steerability in endovascular interventions. A primary concern is the high friction that develops between the tendons and their surrounding guide channels, particularly in tortuous vascular pathways where frequent directional changes exacerbate resistance. This increased friction not only reduces actuation efficiency but also leads to inconsistent tip responsiveness, making precise navigation more challenging. Furthermore, the inherently bulky structures required to house the tendons and pulleys impose constraints on miniaturization, limiting their applicability to the smaller delivery bodies necessary for accessing distal cerebral vasculature. These challenges make tendon-driven mechanisms less viable for highly intricate anatomy and small-scale passageways typically encountered in neurointerventional procedures.

[0015] With respect to shape memory alloys, another approach that has been explored for steerable delivery bodies involves the use of shape memory alloys, such as nitinol, which leverage the shape memory effect to achieve controlled bending. These systems operate by cyclically heating and cooling the SMA component, causing it to transition between phases, and so creating a load that produces a bending motion at the tip. A primary concern is the requirement for localized heating to induce shape transformation raises significant safety concerns, as temperature fluctuations within the delicate vascular environment could potentially lead to thermal damage or coagulation effects. Additionally, the low machinability of SMAs presents challenges in fabrication, making it difficult to manufacture highly flexible 44924-7829-3894, v. 2yet robust structures with the necessary precision required for neurovascular navigation. Another limitation is the unintuitive operation of SMA-based systems. Due to the inherent time delay associated with thermal activation, real-time control and immediate response to user inputs are difficult to achieve, reducing the system’s overall usability in precision interventions.

[0016] With respect to magnetic actuation systems, magnet-driven steering systems leverage the controlled application of external magnetic fields, generated either using electromagnets or a permanent magnet, to steer a magnetically responsive delivery body tip through the vasculature. By modulating the direction and strength of the external magnetic field, clinicians can achieve smooth, continuous, and real-time tip orientation control, overcoming the limitations of traditional manual torque-based techniques. Additionally, magnetic guidance can be seamlessly integrated with robotic-assisted platforms to further enhance precision guidance capabilities during a procedure. However, challenges remain in extending magnetic navigation to neurovascular interventions.

[0017] With respect to innovations in magnetic steering, given the advantages offered by magnetic actuation systems in steering delivery bodies within the vasculature, both commercial systems and recent research innovations have explored a range of magnetic actuation strategies aimed at enhancing the control, precision, and safety of endovascular navigation.

[0018] With respect to commercial systems, the Stereotaxis Niobe (Stereotaxis, USA) is a commercially available platform designed for robotic magnetic steering of catheters primarily in cardiovascular procedures. It enables active steering by manipulating large external permanent magnets mounted on robotic arms to generate controlled magnetic fields that steer a magnetically responsive catheter tip within the patient’s body. Another example is the CGCl-Maxwell (Magnetecs, USA), which employs an array of external electromagnets to generate dynamically adjustable magnetic fields, enabling actuation of a magnetically responsive distal catheter tip.

[0019] Despite their benefits, such platforms are limited by requiring large magnets that require magnetically shielded operating rooms or large solenoid arrays that generate significant heat to achieve the required force transmission. In addition, these systems occupy a large footprint and require dedicated infrastructure modifications prior to adoption.54924-7829-3894, v. 2Specialized infrastructure not only greatly increases the cost and complexity of deployment but also restricts the system’s accessibility to a limited number of highly equipped medical centers.

[0020] Beyond fabrication complexity, the soft magnetic thread’s continuous, flexible design presents challenges for catheter delivery. Its fixed, relatively low stiffness, while beneficial for minimizing vessel trauma, makes it prone to buckling or uncontrolled small movements, especially near the distal end. This can complicate the smooth advancement of a larger aspiration catheter over the thread, particularly through tortuous cerebral vessels where precise guidance is critical. Furthermore, the soft thread inherently lacks the compatibility to adapt with the tailored mechanical properties found in commercial guidewires, such as optimized stiffness gradients, specialized surface coatings, torque response, and radiopacity, all engineered for specific interventional tasks. This high degree of incompatibility with existing equipment and workflows presents significant challenges for clinical adoption.

[0021] For context, the development of variable stiffness (VS) delivery bodies represents a critical advancement in minimally invasive interventions, where achieving an optimal balance between flexibility and rigidity is essential. VS technologies aim to provide devices that can transition between a compliant state for safe navigation through tortuous pathways and a stiffer state for effective force transmission and device delivery. Two primary approaches have been investigated: jamming-based mechanisms and phase-change materials.

[0022] Jamming technologies leverage the principle of friction between internal elements to modulate stiffness. In these designs, the delivery body is segmented into discrete regions that house internal components such as fibers, granules, or layered structures. When negative pressure is applied, these internal elements are forced closer together, increasing the frictional forces between them. This “jamming” effect transforms the segment from a flexible state into a much stiffer configuration, thereby enhancing the overall rigidity of the delivery body.

[0023] Despite their promise, jamming-based systems face significant challenges in the context of neurovascular interventions. One major limitation is the relatively large diameter of these designs, which typically range from 8 to 24 mm, due to the required internal structures and fiber density. While such dimensions may be acceptable for certain endoscopic or peripheral applications, they are far too large for the intricate and constrained64924-7829-3894, v. 2environment of the neurovascular system. Standard neurovascular guidewires, for example, are often less than 1.5 mm in diameter. The inability to scale down jamming technologies to such small sizes renders them unsuitable for procedures like MT where the necessary delivery bodies are on a significantly smaller scale.

[0024] Phase-change materials offer an alternative mechanism by which stiffness can be actively tuned. These systems employ alloys or polymers that undergo changes in their mechanical properties when exposed to stimulation. Specifically, by raising the temperature beyond a certain transition point for the material, the device can transition from a rigid state to a soft or even liquid state, enabling it to adapt dynamically to the demands of the intervention.

[0025] One of the key advantages of phase-change designs is their suitability for miniaturization. Unlike jamming-based systems, which require bulky internal structures such as air pressure channels or particle-filled chambers, phase-change bodies can be fabricated with elegant architecture. This reduction in size and complexity makes them more compatible with the narrow dimensions required in neurovascular interventions. However, despite this advantage, phase-change systems are not without limitations.

[0026] A primary drawback of phase-change materials is their relatively slow response time. Stiffness transitions in these systems typically occur over a period ranging from around 10 to 100 seconds, which is considerably slower than the rapid (i.e. less than 1 second) transition observed in fiber-jamming approaches. In the delicate environment of cerebral vasculature, this heating process poses potential risks. Excess heat could inadvertently damage surrounding tissues or disrupt the local physiological balance, raising concerns about the safety of the approach in sensitive vascular applications. Therefore, while phase-change materials present a promising route toward creating miniaturized, variablestiffness delivery' bodies, their slower response times and the safety implications associated with thermal activation represent critical challenges.SUMMARY

[0027] Exemplary embodiments of the present disclosure include a magnetically actuated guidewire that represents a major advancement in neurovascular interventions by addressing limitations in current systems, such as limited steerability for complex vascular regions and imprecise motion control, navigability with proximal support, and compatibility 74924-7829-3894, v. 2with cerebral vessels and intracranial catheters. It focuses on timely intervention, accessibility for mechanical thrombectomy (MT), procedural precision, cost-efficiency, portability, and seamless integration with existing and future robotic systems. Unlike alternate solutions which are expensive, bulky, and rely on large magnets or solenoid arrays housed within sizeable external platforms, the magnetically actuated guidewire design eliminates the need for such large-scale hardware, instead of offering a minimal footprint that can be readily integrated into existing medical infrastructure.

[0028] In an illustrative aspect, some embodiments relate to an apparatus comprising: an elongate intraluminal device comprising a proximal end portion and a distal end portion, wherein: the distal end portion comprises: a spring element; and a magnetically -responsive biocompatible material molded around the spring element.

[0029] In some embodiments, the elongate intraluminal device comprises a guidewire, microcatheter, or catheter.

[0030] In some embodiments, elongate intraluminal device comprises a retrofit distal tip assembly coupled via at least one of heat-shrink tubing, an adhesive bond, an over-molded interface, an interference fit, a mechanical collar, a threaded coupling, or a snap-fit coupling.

[0031] In some embodiments, the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion including at least one of a bending stiffness, torsional stiffness, and an axial stiffness in response to a change in a magnetic field intensity at the distal end portion.

[0032] In some embodiments, the apparatus may, for example, be configured such that wherein the magnetically-responsive biocompatible material comprises a biocompatible silicone molded with a neodymium iron boron (NdFeB) powder and optionally further comprises one or more embedded permanent magnets.

[0033] In some embodiments, the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF) contained within a sealed polymeric chamber or lumen of the distal end portion.

[0034] In some embodiments, the magnetically-responsive biocompatible material comprises a polymer embedded with magnetic particles.84924-7829-3894, v. 2

[0035] In some embodiments, the distal end portion comprises a plurality of compartments or sections arranged serially along a longitudinal axis, and wherein each compartment or section comprises a magnetically-responsive biocompatible material.

[0036] In some embodiments, further comprise a controller configured to control movement of the distal end portion.

[0037] In some embodiments, the controller is configured to control an insertion motion, a retraction motion and a twist motion of the guidewire and to position and / or orient the external magnetic source relative to the distal end portion.

[0038] In some embodiments, further comprise an external magnetic source configured to generate the magnetic field at the distal end portion.

[0039] In some embodiments, the magnetically-responsive biocompatible material is configured to be controlled during teleoperation via a remote device.

[0040] In some embodiments, the remote device is configured to control the apparatus via a robotic arm holding an external magnetic source.

[0041] In some embodiments, the distal end portion is configured for handheld control via a permanent magnet or electromagnetic source integrated with an end effector of a passive robotic arm to hold the weight of a magnetic source.

[0042] In some embodiments, the distal end portion is configured for a robot assistive mode, in which a user holds a permanent magnet or electromagnetic source integrated with an end effector of a robotic arm to hold the weight of the magnetic source and assist with the navigation of the magnetically-responsive biocompatible material.

[0043] In some embodiments, the magnetically-responsive biocompatible material comprises a magnetic powder.

[0044] In some embodiments, the elongate intraluminal device is retrofitted without modifying a proximal hub or handle of an existing commercially available guidewire, microcatheter, or catheter.

[0045] In some embodiments wherein the elongate intraluminal device comprises a retrofit distal tip assembly comprising the spring and the magnetically responsive 94924-7829-3894, v. 2biocompatible material molded around the spring element, wherein the retrofit distal assembly is detachable and replaceable.

[0046] In some embodiments, the magnetically-responsive biocompatible material is axially magnetized, radially magnetized, or diametrically magnetized.

[0047] In an illustrative aspect some embodiments, relate to a method of directing a magnetically-responsive guidewire into a lumen, the method comprising: inserting the magnetically-responsive guidewire into the lumen, wherein the magnetically-responsive guidewire comprises: a proximal end and a distal end portion, wherein: the distal end portion comprises a spring element; and the distal end portion comprises a magnetically-responsive biocompatible material molded around the spring element; and exerting a magnetic force on the magnetically-responsive biocompatible material to steer the distal end portion and to vary a stiffness of the distal end portion including at least one of a bending stiffness, torsional stiffness, and an axial stiffness.

[0048] In some embodiments, the lumen is a neurovascular lumen.

[0049] Some embodiments further provide a handheld actuator configured to exert magnetic force on the magnetically-responsive biocompatible material.

[0050] Some embodiments further provide a robotic actuator configured to exert the magnetic force on the magnetically-responsive biocompatible material.

[0051] In an illustrative aspect some embodiments relate to an apparatus comprising: a retrofit distal tip assembly comprising: a spring element; and, a magnetically-responsive biocompatible material molded around the spring element; and, an elongate intraluminal device comprises a proximal end and a distal end, wherein the elongate intraluminal device comprises a guidewire, microcatheter, or catheter; wherein the retrofit distal tip assembly is coupled to the distal end of the elongate intraluminal device.

[0052] In some embodiments, or catheter; the retrofit distal tip assembly is coupled to the distal end of the elongate intraluminal device such that the elongate intraluminal device is retrofitted without modifying a proximal hub or handle of the existing commercially available guidewire, microcatheter, or catheter.104924-7829-3894, v. 2

[0053] In some embodiments, the retrofit distal tip assembly is detachable and replaceable.

[0054] In some embodiments, the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF) contained within a sealed polymeric chamber or lumen of the distal end portion.

[0055] In some embodiments, the magnetically-responsive biocompatible material comprises a polymer embedded with magnetic particles.

[0056] In some embodiments, the distal end portion comprises a plurality of compartments or sections arranged serially along a longitudinal axis, and wherein each compartment or section comprises a magnetically-responsive biocompatible material.

[0057] In some embodiments further comprise a controller configured to control movement of the distal end portion.

[0058] Some embodiments further comprise an external magnetic source configured to generate the magnetic field at the distal end portion.

[0059] In some embodiments, the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF) contained within a sealed polymeric chamber or lumen.

[0060] In some embodiments, the MRF is reinforced by metal or composite fibers.

[0061] In some embodiments, the stiffness of the distal end portion is a bending stiffness.

[0062] In an illustrative aspect, some embodiments relate to a method of manufacturing a magnetically-responsive guidewire, the method comprising: inserting a spring element and a guidewire into a mold; directing a magnetically-responsive material into the mold, wherein the magnetically-responsive material surrounds the spring element and the guidewire; curing the magnetically-responsive material in the mold; and separating the mold from the magnetically-responsive material, the spring element and the guidewire.

[0063] In some embodiments, the method includes directing the magnetically-responsive material into the mold comprises dispensing a silicone material and magnetically- 114924-7829-3894, v. 2responsive particles, wherein the dispensing comprises: (i) dispensing, through a single nozzle, a premixed composition comprising the silicone material and the magnetically-responsive particles, and (ii) dispensing, through a plurality of nozzles, the silicone material and the magnetically-responsive particles as separate streams such that the magnetically-responsive particles are deposited in a predetermined pattern within the silicone material to form one or more sections or compartments of the distal end portion having different compositions and / or different magnetic particle loadings.

[0064] In an illustrative aspect, some embodiments relate to a method of directing a magnetically-responsive guidewire into a lumen, the method comprising: inserting the magnetically-responsive guidewire into the lumen, wherein the magnetically-responsive guidewire comprises: a proximal end and a distal end portion, wherein: the distal end portion comprises a spring element; and the distal end portion comprises a magnetically-responsive biocompatible material molded around the spring element; and exerting a magnetic force on the magnetically-responsive biocompatible material to steer the distal end portion and to vary a stiffness of the distal end portion including at least one of a bending stiffness, torsional stiffness, and an axial stiffness.

[0065] In some embodiments, the apparatus may, for example, be configured such that the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion including at least one of bending stiffness, torsional stiffness, and axial stiffness in response to a change in a magnetic field intensity at the distal end portion.

[0066] In some embodiments, the apparatus may, for example, be configured such that the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF). In some embodiments, the MRF is reinforced by metal or composite fibers.

[0067] In some embodiments, the apparatus may, for example, be configured such that the bending stiffness is increased as the magnetic field intensity at the is increased.

[0068] In some embodiments, the apparatus may, for example, be configured such that the spring element is a coiled metallic spring.

[0069] In some embodiments, the apparatus may, for example, be configured such that the spring element comprises a shape memory alloy.124924-7829-3894, v. 2

[0070] In some embodiments, the apparatus may, for example, be configured such that the spring element is a nitinol spring.

[0071] In some embodiments, the apparatus may, for example, be configured such that the magnetically -responsive biocompatible material comprises a polymer embedded with magnetic particles.

[0072] In some embodiments, the apparatus may, for example, be configured such that the polymer is a biocompatible silicone.

[0073] In some embodiments, the apparatus may, for example, be configured such that the magnetically-responsive biocompatible material comprises a magnetic powder.

[0074] In some embodiments, the apparatus may, for example, be configured such that the magnetically-responsive biocompatible material comprises neodymium iron boron (NdFeB).

[0075] In some embodiments, the magnetically-responsive biocompatible material comprises a biocompatible silicone molded with a neodymium iron boron (NdFeB) powder and optionally further comprises one or more embedded permanent magnets.

[0076] In some embodiments, the distal end portion comprises a plurality of compartments or sections arranged serially along a longitudinal axis, and wherein each compartment or section comprises a magnetically-responsive biocompatible material.

[0077] In some embodiments, the plurality of compartments or sections are selectively controllable by varying at least one of magnetic field intensity, magnetic field orientation, and magnetic field gradient.

[0078] In some embodiments, at least a first compartment or section and a second compartment or section comprise different magnetic particle loadings and / or different magnetization orientations such that the first compartment or section exhibits a first steering response and the second compartment or section exhibits a different steering response under a same applied magnetic field.

[0079] In some embodiments, at least one compartment or section comprises the sealed polymeric chamber or lumen containing the MRF configured to vary bending stiffness,134924-7829-3894, v. 2axial stiffness, and torsional stiffness, and wherein at least one other compartment or section comprises a magnetic-powder elastomer configured to generate steering torque.

[0080] In some embodiments, the apparatus may, for example, further comprise a controller configured to control movement of the distal end portion and / or an external magnetic source configured to generate the magnetic field at the distal end portion.

[0081] In some embodiments, the apparatus may, for example, be configured such that the controller comprises a handheld actuator comprising a magnet.

[0082] In some embodiments, the apparatus may, for example, be configured such that the controller comprises a robotic controller.

[0083] In some embodiments, the apparatus may, for example, be configured such that the controller is configured to control an insertion motion, a retraction motion and a twist motion of the guidewire, and to position and / or orient the external magnetic source relative to the distal end portion.

[0084] In some embodiments, the apparatus may, for example, be configured such that the distal end portion is integrated with an existing guidewire, or an existing catheter or microcatheter.

[0085] In some embodiments, the apparatus may, for example, be configured such that the distal end portion is molded to an existing guidewire or molded to a distal end of an existing catheter or microcatheter.

[0086] In some embodiments, the apparatus may, for example, be configured such that wherein the magnetically-responsive biocompatible material is axially magnetized, and / or radially magnetized and / or diametrically magnetized.

[0087] In some embodiments, the apparatus may, for example, be configured such that the apparatus is configured for tele operation control via a remote device.

[0088] In some embodiments, the apparatus may, for example, be configured such that the remote device comprises a haptic device or a spatial mouse.

[0089] In some embodiments, the apparatus may, for example, be configured such that the external magnetic source comprises a permanent magnet to control orientation and 144924-7829-3894, v. 2steering of the distal end portion, and to modulate the magnetic field intensity to adjust bending stiffness and / or axial stiffness.

[0090] In some embodiments, the apparatus may, for example, be configured such that the external magnetic source comprises an electromagnetic source to control orientation and steering of the distal end portion, and to modulate magnetic field intensity to adjust bending stiffness, axial stiffness, and torsional stiffness.

[0091] In some embodiments, the apparatus may, for example, be configured such that the remote device is configured to control the apparatus via an insertion mechanism configured to control an insertion motion, a retraction motion and a twist motion of the guidewire.

[0092] In some embodiments, the apparatus may, for example, be configured such that apparatus is configured for handheld control via a permanent magnet or electromagnetic source integrated with an end effector of a passive robotic arm to hold the weight of a magnetic source.

[0093] In some embodiments, the apparatus may, for example, be configured such that the passive robotic arm is a component of a humanoid robot that is configured for remote operation.

[0094] In some embodiments, the apparatus may, for example, be configured such that the handheld control comprises a magnetic glove to give steering cues through vibrations to a user for steering of the magnetically-responsive biocompatible material or uses visual feedback to control the steering of the apparatus.

[0095] In some embodiments, the apparatus may, for example, be configured such that insertion of the guidewire is controlled through a button integrated at the end effector of the passive robotic arm or in the magnetic glove through an insertion mechanism.

[0096] In some embodiments, the apparatus may, for example, be configured such that wherein the apparatus is configured for a robot assistive mode, in which a user holds a permanent magnet or electromagnetic source integrated with an end effector of a robotic arm to hold the weight of the magnetic source and assist with the navigation of the magnetically-responsive biocompatible material.154924-7829-3894, v. 2

[0097] In some embodiments, the apparatus may, for example, be configured such that the apparatus is configured to be controlled by a user who holds the end effector and gives steering commands and wherein the robot corrects the steering motion using computer algorithms.

[0098] In some embodiments, the apparatus may, for example, be configured such that insertion of the guide wire is controlled through a button integrated at the end effector of the robotic arm.

[0099] In some embodiments, the apparatus may, for example, be configured such that the apparatus is configured such that insertion and steering of the guidewire is performed autonomously using preplanned algorithms.

[0100] In an illustrative aspect, embodiments include a method of manufacturing a magnetically-responsive guidewire, the method comprising: inserting a spring element and a guidewire into a mold; directing a magnetically-responsive material into the mold, wherein the magnetically-responsive material surrounds the spring element and the guidewire; curing the magnetically-responsive material in the mold; and separating the mold from the magnetically-responsive material, the spring element and the guidewire.

[0101] In some embodiments, the method may, for example, be configured such that the magnetically-responsive material comprises a magnetorheological fluid.

[0102] In some embodiments, the method may, for example, be configured such that: the magnetically-responsive guidewire comprises a proximal end and a distal end; the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion of the magnetically-responsive guidewire in response to a change in a magnetic field intensity at the distal end portion.

[0103] In some embodiments, the method may, for example, be configured such that the stiffness of the distal end portion is a bending stiffness, and / or torsional stiffness, and / or axial stiffness.

[0104] In some embodiments, the method may, for example, be configured such that bending stiffness and / or torsional stiffness, and / or axial stiffness is increased, wherein the164924-7829-3894, v. 2bending stiffness is increased as the magnetic field intensity at the distal end portion of the magnetically -responsive guidewire is increased.

[0105] In some embodiments, the method may, for example, be configured such that the magnetically-responsive material comprises a polymer mixed with magnetically-responsive particles.

[0106] In some embodiments, the method may, for example, be configured such that the polymer is a silicone material.

[0107] In some embodiments, the method may, for example, be configured such that the magnetically-responsive particles comprise permanent magnets. The method may, for example, be configured such that the magnetically-responsive particles comprise magnetic powder and permanent magnets. The method may, for example, be configured such that the magnetically-responsive particles comprise a magnetic powder. The method may, for example, be configured such that the magnetic powder is a powder comprising five -micron neodymium iron boron NdFeB particles. The method may, for example, be configured such that the magnetically-responsive particles and the polymer are mixed at a 1:1 mass ratio. The method may, for example, be configured such that the magnetically-responsive particles and the polymer are mixed at a 2:1 mass ratio. The method may, for example, be configured such that the magnetically-responsive particles and the polymer are mixed at a 3:1 mass ratio. The method may, for example, be configured such that the magnetically-responsive particles and the polymer are mixed at a 4: 1 mass ratio. The method may, for example, be configured such that the magnetically-responsive particles and the polymer are mixed at a 5: 1 mass ratio.

[0108] In some embodiments, the method may, for example, be configured such that separating the mold from the magnetically-responsive material, the spring element and the guidewire comprises dissolving the mold. The method may, for example, be configured such that separating the mold from the magnetically-responsive material, the spring element and the guidewire comprises separating a first portion of the mold from a second portion of the mold and removing the magnetically-responsive material, the spring element and the guidewire from the mold.

[0109] In some embodiments, the method may, for example, be configured such that the spring element is a coiled metallic spring. The method may, for example, be configured174924-7829-3894, v. 2such that the spring element comprises a shape memory alloy. The method may, for example, be configured such that the spring element is a nitinol spring.

[0110] In some embodiments, the method may, for example, be configured such that the lumen is an industrial conduit.

[0111] In some embodiments, the method may, for example, be configured such that a handheld actuator exerts the magnetic force on the magnetically-responsive biocompatible material. The method may, for example, be configured such that a robotic actuator exerts the magnetic force on the magnetically-responsive biocompatible material. The method may, for example, be configured such that the robotic actuator is controlled via a glove worn by a user; and the glove provides vibratory and / or tactile feedback to the user to help with the intuitive steering.

[0112] In some embodiments, the method may, for example, be configured such that the magnetically-responsive material comprises a polymer mixed with a magnetically-responsive particles. The method may, for example, be configured such that the magnetically-responsive particles are a magnetic powder.

[0113] In some embodiments, the apparatus may, for example, be configured such that the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF) that may be reinforced by metal or composite fibers. The apparatus may, for example, be configured such that the stiffness of the distal end portion is a bending stiffness.

[0114] In some embodiments, the apparatus may, for example, be configured such that bending stiffness is increased as the magnetic field intensity at the distal end portion of the guidewire is increased.

[0115] In some embodiments, torsional stiffness is increased as the magnetic field intensity at the distal end portion of the guidewire is increased. In some embodiments, the axial stiffness is increased as the magnetic field intensity at the distal end portion of the guidewire is increased.

[0116] A specific embodiment includes a magnetized soft silicone head, molded around an inner nitinol micro spring, is attached to the distal end of a commercial guidewire to enable steering through external magnetic torques, such as with a permanent magnet184924-7829-3894, v. 2mounted to a handheld or robotic arm. A robotic insertion and retraction mechanism controls the translational and twist degrees of freedom through a remote joystick controller.

[0117] Important features of exemplary embodiments include full range steering control of the magnetic guidewire head by applying external magnetic torque with a permanent magnet, as well as navigability with non-traumatic design of the wire tip (usable for cerebral vasculature), small diameter making it compatible to use with intracranial catheters, and stiff proximal wire support for optimal pushability, resulting in all-in-one robotic delivery system for stroke treatment

[0118] In addition, precision control at complex vascular bifurcations to efficiently access difficult-to-reach site of obstruction is provided. Exemplary embodiments also include robotic insertion, retraction, and twist of guidewire without need of manual pushing, pulling, or rotation.

[0119] Such features allow for enhanced steerability to perform more complex minimally invasive procedures, a compact footprint without large hardware actuation platforms, and enable quick, efficient minimally invasive surgical treatment methods.

[0120] Exemplary embodiments of the present disclosure include a guidewire that enables active steering to the desired location in cerebral vasculature and is compatible with robotic systems. Exemplary embodiments of the present disclosure also include a magnetically steerable guidewire system that utilizes externally applied magnetic torques to precisely guide the wire into position.

[0121] Mechanical thrombectomy is increasingly used to treat ischemic strokes, which account for 87% of the 800,000 annual stroke cases in the U.S. Cardiovascular diseases, the leading cause of death in the country, also drive demand. The U.S. thrombectomy device market is expected to grow at a 6.7% CAGR, bolstered by advancements in clinical outcomes and a growing preference for minimally invasive procedures. Globally, the mechanical thrombectomy devices market was valued at $1.46 billion in 2023 and is projected to reach $2.1 billion by 2028, growing at a 7.4% CAGR. Key drivers include the aging population, rising stroke cases, and technological innovations like stent retrievers and aspiration devices. The proposed guidewire system aligns well with these trends, offering a promising solution in a rapidly expanding market.194924-7829-3894, v. 2

[0122] In the following, the term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically.

[0123] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and / or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.”

[0124] The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way but may also be configured in ways that are not listed.

[0125] As used herein, the terms “cut” (and related terms such as “cutting”, etc.) and “break the mechanical integrity” (and related phrases such as “breaking the mechanical integrity”) are used to refer to a process of breaking the molecular bonds in tissue.

[0126] As used herein, the term “light source” is understood to include any source of electromagnetic radiation, including for example, a laser. It is also understood that a “first light source” and a “second light source” may originate from a single laser. For example, a laser configured for operating under a first set of parameters (e.g. wavelength, amplitude, continuous wave or continuous pulse mode) may be considered a “first light source”, while the same laser configured for operating under a second set of parameters may be considered a “second light source.”204924-7829-3894, v. 2

[0127] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.

[0128] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.BRIEF DESCRIPTION OF DRAWINGS

[0129] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure. The invention may be better understood by reference to one of these drawings in combination with the detailed description of specific embodiments presented herein.

[0130] FIG. 1 shows a magnetically steerable guidewire concept illustration for mechanical thrombectomy (MT).

[0131] FIG. 2 shows an overview of operation approach of the magnetic guidewire.

[0132] FIG. 3 shows a fabrication process of magnetic guidewire.

[0133] FIG. 4 shows a CAD model of a) prototype handheld actuation magnet mount and b) robotic mechanism for guidewire insertion, retraction, and twist motion control.

[0134] FIG. 5 shows results in manual actuation of fabricated guidewire using an external magnet.

[0135] FIG. 6 shows a conceptual illustration of a neuroendovascular intervention with a clinician remotely controlling the robotic manipulator and insertion system to steer the magnetic head according to an exemplary embodiment of the present disclosure.214924-7829-3894, v. 2

[0136] FIG. 7 shows a conceptual illustration of a robot-assisted neuroendovascular intervention with a surgeon manually positioning the steering magnet to manipulate the magnetic head according to an exemplary embodiment of the present disclosure.

[0137] FIG. 8 shows a zoomed in illustration of the surgical site depicting the robotic arm positioning the steering magnet to manipulate the magnetic head orientation according to an exemplary embodiment of the present disclosure.

[0138] FIG. 9 shows a robot-mounted permanent magnet steering the delivery body by controlling the orientation of the magnetic head as it is advanced using the insertion system according to an exemplary embodiment of the present disclosure.

[0139] FIG. 10 depicts an exemplary setup and environment configuration for experimental validation of the magnetic delivery system.

[0140] FIG. 11 depicts soft, realistic vasculature phantom with live fluid flow and simulation of human respiration used for the experimental validation of the magnetic delivery system.

[0141] FIG. 12 depicts X-ray imaging snapshots of magnetically navigating a guidewire through vascular bifurcations to reach the target cerebral blood vessel.DETAILED DESCRIPTION

[0142] Exemplary embodiments of the present disclosure include a magnetically actuated guidewire that represents a major advancement in neurovascular interventions by addressing limitations in current systems. The magnetically actuated guidewire focuses on timely intervention, accessibility for MT, procedural precision, cost-efficiency, portability, and seamless integration with existing and future robotic systems. One exemplary key innovation is the nitinol-reinforced magnetic head, that can be integrated at the distal end of the existing neuro guidewires and encased in soft, biocompatible silicone. The magnetic head’s properties allow for controlled bending with an external magnet, facilitating precise steering at vascular bifurcations.

[0143] The magnetic localization technology enables accurate tracking without relying solely on X-rays, enhancing control while reducing radiation exposure. This guidewire’s fabrication process is cost effective and scalable. Unlike bulkier, expensive224924-7829-3894, v. 2systems like the Stereotaxis Niobe or CGCI-Maxwell, which require extensive infrastructure, the magnetically actuated guidewire’s design is compact and portable. The single external magnet for steering eliminates the need for large equipment, making it adaptable to existing clinical setups.

[0144] Exemplary embodiments of the present disclosure balances cost, accessibility, and steering precision, addressing disadvantages of alternative systems. Removing the need for large, costly equipment reduces financial burdens, especially in resource-limited areas where remote intervention is vital. This approach can be scaled with minimal capital costs and is compatible with standard commercial guidewires. The enhanced steering precision due to the proposed robotic system’s guidewire improves access to complex vascular regions, making catheterization faster and less challenging than manual methods. This system’s versatility advantageously may, for example, have application in any catheterization procedure requiring advanced steering, making it valuable across a range of minimally invasive interventions.

[0145] Exemplary embodiments of the present disclosure include a magnetically actuated guidewire system including a robotic actuation system for insertion and twist of the catheter to be controlled by a clinician, and a nitinol-reinforced magnetic guidewire that can readily be integrated with the distal end of the existing commercialized catheter.

[0146] In particular, the guidewire design incorporates biocompatible silicone embedded with ferromagnetic powder molded around a nitinol micro-spring, offering a balance between flexibility and stiffness. This reduces buckling and minimizes friction with arterial walls. The ferromagnetic particles inside the silicone increase steerability while maintaining a compact wire diameter of 1 -2 mm. The fabrication process of guidewire may, for example, be manufactured with 3D-printed molds to shape the magnetic head.

[0147] The guidewire's magnetic properties may, for example, be integrated with a developed magnetic sensing solution, enabling tip localization without relying solely on fluoroscopy, thereby reducing X-ray exposure. The guidewire is externally controlled using a single NdFeB permanent magnet mounted on a handheld or robotic arm, while a stepper motor controls insertion and retraction.

[0148] This system provides a compact approach for navigating complex vasculature, especially in neurointervention, and is designed for seamless integration with a robotic 234924-7829-3894, v. 2insertion and twist mechanism that can be controlled using a game controller enabling remote and in person treatment and diagnosis for clinicians. As opposed to existing commercialized robotic systems, exemplary embodiments of the present disclosure are smaller in size, portable, and more affordable while providing a comparable precision that can be integrated into existing medical infrastructure and is applicable to a broader range of minimally invasive procedures.I. Definitions

[0149] Active Steering: The ability to dynamically control the orientation and movement of a body in real-time during navigation.

[0150] Catheter: A flexible, tubular medical device used for navigating through blood vessels for diagnostic or therapeutic purposes.

[0151] Delivery Body: The core device, typically a guidewire or microcatheter, that is inserted into the vasculature to deliver therapeutic devices or enable clot retrieval.

[0152] Endothelial Damage: Injury to the thin layer of endothelial cells lining the interior surface of blood vessels. Result of excessive maneuvers, rigid device tips, or high friction.

[0153] Endovascular Interventions: Minimally invasive procedures performed inside blood vessels using catheters and guidewires.

[0154] Guidewire: A highly thin, flexible wire used to navigate blood vessels and guide catheters or other devices during minimally invasive procedures.

[0155] Ischemic Stroke: A type of stroke caused by a blood clot blocking blood flow to the brain, leading to severe tissue damage and requiring immediate medical intervention.

[0156] Magnetorheological Fluid (MRF): A suspension of ferromagnetic particles in a carrier fluid that stiffens when exposed to a magnetic field.

[0157] Magnetic Actuation: The process of using magnetic fields to manipulate or steer devices containing magnetic materials, allowing for contactless control.244924-7829-3894, v. 2

[0158] Magnetic Head: A biocompatible silicone tip embedded with magnetic particles and micro-magnets, designed for atraumatic navigation and precise magnetic steering.

[0159] Mechanical Thrombectomy (MT): A minimally invasive procedure that removes a blood clot from a blocked brain artery to restore blood flow during an ischemic stroke.

[0160] Microcatheter: A small-diameter catheter designed for navigating the cerebral vasculature in neurointerventional procedures.

[0161] NdFeB Magnet: Rare-earth neodymium-iron-boron permanent magnet known for strong magnetic strength. Used in powdered, micro-magnet, and macro disc forms in this system. A higher grade NdFeB implies higher magnetic strength.

[0162] Neuro-Endovascular Intervention: Minimally invasive procedure targeting the blood vessels of the brain to treat conditions like ischemic stroke.

[0163] Nitinol: A nickel-titanium alloy with shape memory and superelasticity, used as micro-springs in this work for reinforcement and flexibility of the magnetic head.

[0164] Recanalization: The process of removing the obstructions in a blood vessel and restoring normal blood flow.

[0165] Remanence: The level of residual magnetization that remains in a magnetic material after an external magnetic field is removed. High remanence is desirable to maintain strong magnetic responsiveness.

[0166] Steering (External) Magnet: A mobile magnet mounted on a robotic arm, generating the magnetic field used for orienting the magnetic head and controlling the variable stiffness.

[0167] Thrombus: An obstruction that forms within a blood vessel and impedes blood flow. Also known as a blood clot.

[0168] Variable Stiffness (VS): The ability of a device to dynamically adjust its rigidity, balancing flexibility for navigation and stiffness for support and device delivery.254924-7829-3894, v. 2

[0169] Vessel Perforation: Accidental puncture of the blood vessel wall, a serious risk mitigated by using atraumatic and flexible device designs.

[0170] As used herein, “essentially free,” in terms of a specified component, is used herein to mean that none of the specified component has been purposefully formulated into a composition and / or is present only as a contaminant or in trace amounts. The total amount of the specified component resulting from any unintended contamination of a composition is therefore well below 0.05%, preferably below 0.01%. Most preferred is a composition in which no amount of the specified component can be detected with standard analytical methods.

[0171] As used herein the specification, “a” or “an” may mean one or more. As used herein in the claim(s), when used in conjunction with the word “comprising,” the words “a” or “an” may mean one or more than one.

[0172] The use of the term “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.” As used herein “another” may mean at least a second or more.

[0173] Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the inherent variation in the method being employed to determine the value, the variation that exists among the study subjects, or a value that is within 10% of a stated value.II. Examples

[0174] The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, considering the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.264924-7829-3894, v. 2

[0175] Referring initially to FIG. 1 a schematic view of a magnetically steerable guidewire concept illustration 100 for mechanical thrombectomy (MT) is shown. Concept illustration 100 includes a magnet 105. Magnet 105 may, for example, include a NdFeB N42 magnet. Magnet 105 may, for example, be dimensioned as a 4” x 2” magnet. Illustration 100 includes a guidewire 110. Guidewire 110 may, for example, include a commercial guidewire. Guide wire 110 includes a magnetic tip 115. Magnetic tip may, for example, be affixed to guidewire 110. Magnetic tip 115 may, for example, be manufactured with a NdFeB magnetized silicone material 120. Guidewire 110 may, for example, be controlled by magnet 105 in connection with magnetic tip 115 to navigate a cerebral artery 120. Cerebral artery 120 has a blood clot 125 that blocks the artery. Blood clot 125 was formed from cholesterol plaque build-up 130.

[0176] For context, over 80% of ischemic strokes are caused by the blockage of a primary cerebral artery (FIG. 1), categorized as a medium vessel occlusion (MeVO) or a large vessel occlusion (LVO). LVOs, which involve major brain arteries like the internal carotid, middle cerebral, or basilar arteries, are especially severe due to their impact on regions responsible for important sensory, motor, and cognitive functions. MeVOs, though affecting smaller blood vessels, are increasingly recognized as a major contributor to poststroke disability and, due to the smaller scale and the inherent geometry of the cerebral vasculature, are more challenging to access during surgical intervention.

[0177] Time is a critical factor in stroke treatment. Following the onset of an occlusion, an estimated four million neurons perish each minute, causing irreversible damage to brain tissue and increasing the likelihood of long-term impairment for the patient. This highlights the importance of early intervention within the so-called "golden hour," the crucial 60-minute window during which successful treatment can significantly improve outcomes. Rapid recanalization of the affected vessel(s) and restoration of blood flow has been shown to significantly reduce morbidity and mortality rates, but existing procedures suffer from limitations that impact efficient intervention.

[0178] An overview 200 of operation approach of a magnetic guidewire according to one embodiment of the present disclosure is shown in FIG. 2. Overview 200 includes a magnetized silicone 205. The magnetized silicone may, for example, be manufactured via 3D printing. The magnetized silicone may, for example, include a 3D printed ABS mold. The mold may, for example, be reinforced with a nitinol spring core. Magnetized silicone 205274924-7829-3894, v. 2may be cured onto a guide wire, and the ABS printed mold may, for example, be dissolved in a dissolution process onto to form a magnetic guidewire 210 including a magnetized silicone head 215 and a guide wire 220. Magnetized silicone head 215 may, for example, have an outer diameter of 1.8 mm. Guidewire 220 may, for example, have an outer diameter of 0.9 mm.

[0179] Guide wire 220 may, for example, be steered in a control process 225 using the affixed magnetic silicone head 215. Control process 220 includes steering with an axially magnetized disc 230. The axially magnetized disc may, for example, include a 4" x 2” axially NdFeB disc.

[0180] By leveraging this magnetically tunable stiffness, the system enables targeted control of flexibility and rigidity during critical phases of navigation and device deployment. For instance, when steering through torturous neurovascular angulations or complex bifurcations, the selectively increase the stiffness of the VS segment. This localized stiffening focuses the steering torque at just the distal end of the system (i.e. the tip of the magnetic head), improving directional precision and minimizing undesired bending along the length of the guidewire. Once the desired branch is successfully accessed, the magnetic field can be reduced, softening the MRF-filled segment to minimize friction and facilitate smooth advancement through the entered vessel.

[0181] For context, the current gold standard interventional procedure for treating ischemic strokes is mechanical thrombectomy (MT). MT involves a neurointerventionalist deploying an extremely thin (i.e., typically less than 1 mm in diameter) and flexible delivery body, such as a guidewire or microcatheter, from the patient’s femoral or radial artery and manually advancing it through the intricate vascular network to reach the site of obstruction in the brain. Navigation is performed under real-time fluoroscopic imaging, requiring the interventionist to carefully manipulate the distal end of the delivery body while minimizing trauma to the vessel walls using X-ray visuals. Once the occlusion is reached, a larger catheter is deployed over the delivery body to perfoim aspiration to suction out the clot, thereby restoring blood flow to the afflicted region.

[0182] Despite the general effectiveness of MT in recanalizing blocked vessels, the absence of an active steering system presents a major challenge in such a time-sensitive procedure. Interventionalists often struggle to maneuver the delivery body through the highly284924-7829-3894, v. 2complex and tortuous cerebrovascular network, as shown in FIG. 1. This difficulty is particularly pronounced when accessing distal branches of the brain’s vasculature, such as the M3 and M4 segments of the middle cerebral artery (MCA) or the anterior and posterior cerebral artery branches, where vessel geometry is especially torturous, and navigation is constrained by sharp angulations and complex bifurcations. These barriers significantly increase procedural time in a situation where time is critical to the outcome.

[0183] For example, a fiber-reinforced MRF-filled silicone tube attached to a commercial guidewire would change its stiffness in the presence of no magnetic field compared to a magnetic field.

[0184] Moreover, during the exchange or deployment of a larger catheter over the inner delivery body (e.g. the guidewire as presented in FIG. 2), the system can once again be stiffened to provide enhanced structural support. This added rigidity mitigates the risk of buckling, kinking, or misalignment, which are common challenges when navigating large-bore devices through tortuous anatomy.

[0185] Overall, the integration of the MRF-filled segment offers advantages. For example, magnetized guide wire 210 improves navigation efficiency, enabling the system to reach the clot more quickly and safely. For example, magnetized guide wire 210 provides adaptive support during clot retrieval, ensuring stable deployment of the aspiration catheter. This magnetically controlled VS capability represents a significant advancement over conventional fixed-stiffness delivery bodies, offering superior adaptability for complex neurovascular interventions encountered in MT.

[0186] As depicted in FIG. 2, a compact 101 mm x 51 mm N40-grade NdFeB axial magnetic disc (Applied Magnets, USA) provides the actuation and stiffness controlling external magnetic field. The magnet is securely mounted to the end-effector of a medical robotic arm. By adjusting the position and orientation of the robot’s end-effector, contactless manipulation of the magnetic head’s orientation can be achieved in real-time, and, due to the motion precision of the robot and the magnetic responsiveness of the magnetic head, the system is capable of sub-millimeter motion precision.

[0187] A simplified form of the interaction between the steering magnet and magnetic head can be modeled as a beam of diameter d and length L undergoing bending due to the294924-7829-3894, v. 2applied torque of magnetic field B at angle 0 relative to the axial magnetization profile M of the magnetic head,

[0188] where 3 denotes the deflection of the magnetic head and G is the shear modulus of the material composition for the magnetic head. Equation (1) serves as the foundation to relate the material and geometric properties of the magnetic head to the achieved 3 resulting from the applied B.

[0189] The behavior of the magnetic field that the head is subject to can be modeled as a dipole field that is characterized by a non-linear spatial dependence with the distance r between the surface of the external magnet along its central axis and the magnetic head, written as

[0190] where R and Bre denote the radius and remanence of the external magnet, respectively. Equations (1) and (2) reveal how changes in r and 0 (i.e., the position and orientation of the external magnet) influence the steering outcome for the magnetic head at the current bifurcation or angulation.

[0191] Due to the integrated design of the magnetic head and VS segment, the same magnet controls the rigidity of the distal end. As the magnet approaches the magnetic head to manipulate its orientation for steering purposes, it simultaneously constrains the motion of the VS segment by increasing stiffness. In turn, the steering manipulation is concentrated on the magnetic head while the remaining length of the delivery body is held fixed, therefore maximizing the magnetic responsiveness at the distal end. Once the desired branch or angulation is achieved, the external magnet is retracted, which softens the VS segment, therefore returning it to its flexible state for advancement into the chosen vessel. During the deployment of final device delivery catheter, the external magnet is held fixed at the closest point possible over the VS segment, thereby maintaining high stiffness to efficiently navigate the catheter to the target site and perform the necessary aspiration or deliver other therapeutics.304924-7829-3894, v. 2

[0192] Referring now to FIG. 3, a one exemplary embodiment of a fabrication process 300 of a magnetic guidewire according to the present disclosure is shown. In step (A) of FIG. 3, five-micron NdFeB powder 310 is mixed with Smooth-On Dragon-Skin 20 silicone in a 2:1 mass ratio, then in step (B) the magnetic silicone 305 is obtained in a syringe and in step (C) of FIG. 3 is injected into a 3D printed ABS mold 315 of the magnetic head. In FIG. 3 step (D) the nitinol spring 325 is inserted, and commercial guidewire 320 is attached via silicone curing. In step (E) of FIG. 3 the silicone is axially magnetized during curing using two N52 NdFeB magnetic discs 330. Upon curing, in step (F) of FIG. 3, the ABS mold is dissolved in an acetone bath 335 in step (G) of FIG. 3 to acquire the magnetic guidewire. In step (G), a magnetic head 340 is formed.

[0193] For context concerning the design and fabrication of the magnetic delivery system, given the shortcomings of existing solutions and the discussed strengths of magnetic actuation relative to other methods, there is a clear need for a magnetic steering system that not only enables precision control capable of complex neurovascular procedures but also integrates seamlessly with the existing medical workflows and equipment. Such a system would harness the inherent advantages of commercial guidewires and catheters that clinicians are well-experienced with and concurrently address conventional procedural challenges by adding active, real-time precision steering and stiffness control to efficiently arrive at the target vessel and complete the procedure. The desired outcome is an affordable and adaptable steering solution to better complete time-critical interventions.

[0194] For example, in a magnetic delivery system with real-time dynamic stiffness is presented. The proposed system may in some embodiments be adapted to conventional applications.

[0195] For example, the system features a soft, biocompatible silicone magnetic head designed as the primary interface for magnetic actuation. A detailed schematic of the manufacturing and assembly process is shown in FIG. 3. The magnetic head is fabricated from a composite mixture consisting of silicone elastomer (Dragon Skin 20, Smooth-On, USA) combined with N52-grade neodymium-iron-boron (NdFeB) 5-micron particle size magnetic powder (MQFP-B+, Neo Magnequench, Singapore) at a 1:2 mass ratio. To reduce the viscosity of the mixture and facilitate smooth injection into a mold, a silicone thinner (DOWSIL OS-10, Dow, USA) is added at 10% of the base silicone mass. The composite314924-7829-3894, v. 2mixture is thoroughly degassed in a vacuum chamber (762 mm Hg) for five minutes to eliminate trapped air bubbles.

[0196] The degassed mixture is injected into a rapid-prototyped cylindrical mold with a rounded tip (25 mm height x 1 mm diameter) designed in SolidWorks (Dassault Systemes, France) and fabricated with acrylonitrile butadiene styrene (ABS). A closed-pitch nitinol micro-spring (Kellogg’s Research Labs, USA) is placed and aligned centrally along the mold cavity prior to injection. This internal reinforcement provides axial support to the magnetic head, effectively mitigating buckling during vascular insertion while minimizing motion due to frictional contact with arterial walls. Notably, the micro-spring preserves the high flexibility necessary for precise magnetic navigation through complex anatomical pathways.

[0197] Following injection and reinforcement placement, the assembly undergoes axial magnetization. This is achieved by positioning two N52-grade NdFeB 25.4 mm diameter x 6.35 mm thickness disc magnets (5862K253, McMaster-Carr, USA) at the base and lid of the mold, oriented to produce a magnetic field counteracting gravitational force. The applied field induces a uniform axial magnetization profile within the magnetic head, aligning the distal tip as the North pole and the proximal end as the South pole. This configuration enables controlled manipulation of the device’s orientation using a single external magnet.

[0198] The silicone composite is cured inside the mold for eight hours to ensure complete crosslinking. After curing, the magnetization discs are removed, and the entire mold is immersed in a sealed acetone bath for six hours. Acetone acts as an effective solvent for ABS due to its polarity and ability to disrupt intermolecular forces within the polymer matrix. The solvent molecules penetrate the ABS structure, causing it to swell, soften, and eventually dissolve into a viscous solution. This dissolution process enables the safe extraction of the cured magnetic silicone head, yielding a final structure with a diameter of 1 mm, which is a scale suitable for accessing most cerebral vessel pathways.

[0199] For example, concerning the embedded micro-magnet chain, a key innovation of the proposed system is the integration of a micro-permanent magnet array embedded within the distal end of the magnetized soft silicone head. This array, composed of a 5-mm tall chain of 0.3 mm diameter NdFeB magnets (CYL0003-50, SuperMagnetMan, USA), is precisely positioned along the central axis of the ABS mold prior to the placement of the324924-7829-3894, v. 2reinforcing nitinol micro-spring (Fig. 3, step d). Concentrating these micro-magnets at the distal tip of the magnetic head enhances the magnetic responsiveness of the system, enabling a more focused and efficient steering effect when subjected to external magnetic fields because this allows for localized torque generation at the tip, which is essential for navigating tortuous vascular pathways.

[0200] In contrast, most existing magnetically actuated catheters or guidewire systems rely exclusively on rigid permanent magnets or fine magnetic powder to achieve steerability. While the rigid permanent magnets provide strong magnetic forces, their larger size and hardness introduce significant risks, including vessel trauma or perforation, especially within delicate vascular structures. Alternatively, systems that solely use embedded fine magnetic powder, such as the 5-micron NdFeB particles used in the magnetic silicone head, offer flexibility and a soft exterior but suffer from reduced magnetic steering performance due to the decreased magnetic force associated with the smaller particle size and distributed magnetic domains.

[0201] The proposed design balances these trade-offs by embedding the micromagnet chain within an atraumatic polymer matrix. This configuration improves the magnetic strength available for manipulation of orientation while maintaining the high flexibility and the soft, compliant attribute of the magnetic head’s outer surface. By localizing the strong, rigid magnetic components internally, the proposed design minimizes the risk of endothelial damage and vessel wall irritation during intervention.

[0202] For example, concerning magnetically controlled variable stiffness segments, the system incorporates a hollow segment filled with magnetorheological fluid (MRF) as a dynamic interface between the soft silicone head and the commercial delivery body. MRFs are suspensions of micron-sized ferromagnetic particles dispersed uniformly in a carrier liquid such as silicone oil. In the absence of a magnetic field, the MRF behaves like a conventional viscous fluid, allowing the silicone tube to remain highly flexible and compliant for easy navigation through tortuous vascular pathways. This alignment substantially increases the fluid's apparent viscosity and yield stress, effectively transforming the MRF from a free-flowing liquid into a semi-solid state. This phase change is both rapid and reversible, allowing for real-time modulation of the stiffness of the MRF-filled segment with precise control over the applied magnetic field.334924-7829-3894, v. 2

[0203] Specifically, the hollow segment filled with magnetorheological fluid (MRF) as a dynamic interface between the soft silicone head and the commercial delivery body is advantageous as if benefits from the rapid response offered by pressure-jamming methods. The miniature scale of phase-change methods is advantageous. The mechanical structure with no moving, frictional interfaces is advantageous. The rigidity control without the use of heating coils within delicate vasculature is advantageous.

[0204] In the presented system, an industrial-grade MRF (AMT-DAMPRO+, ARUS MR TECH, India) is injected into a 0.5 mm ID x 1 mm OD soft silicone tube with a length of 25 mm. The base stiffness of this assembly is increased by internally reinforcing the tube with 30-micron 304 stainless steels fibers. The tube’s ends are sealed, and the resulting VS segment is attached to the proximal end of the magnetic head depicted in FIG. 3 using a medical-grade heat-shrink tubing for a quick and robust connection interface. Similarly, this assembly can then be attached to the distal end of an existing commercial delivery body using the same connection interface (FIG. 3, step G).

[0205] When exposed to an external magnetic field, the suspended particles rapidly align along the magnetic flux lines, forming chain-like structures within the fluid. The exemplary fabrication process of the guidewire shown in this embodiment is cost-effective yet innovative, using 3D-printed molds to shape the magnetic head. Upon silicone curing, the ABS mold is dissolved in an acetone bath to obtain the magnetic guidewire. This molding process enables the fabrication of highly intricate feature sizes.

[0206] Additionally, the guidewire’s magnetic properties allow integration with the inventors’ previously developed magnetic sensing solution, enabling tip localization without relying solely on fluoroscopy, thereby reducing X-ray exposure for surgeons and patients.

[0207] Referring now to FIG. 4, a CAD model of (a) prototype handheld actuation magnet mount and (b) robotic mechanism for guidewire insertion, retraction, and twist motion control is shown. The guidewire is externally controlled using a single NdFeB permanent magnet mounted on a handheld 405 or robotic arm, while a stepper motor controls 410 insertion and retraction. This system provides a compact approach for navigating complex vasculature, especially in neuro-intervention, and is designed for seamless integration with a robotic insertion and twist mechanism 415 that can be controlled using a Xbox game controller enabling remote and in person treatment and diagnosis for clinicians.344924-7829-3894, v. 2

[0208] Referring now to FIG. 5 results in manual actuation of fabricated guidewire with a magnetic head using an external magnet are shown. As opposed to existing commercialized robotic systems, exemplary embodiments of the present disclosure are smaller in size, portable, readily integrated into existing neuroendovascular catheters and systems, and more affordable while providing a comparable precision that can be integrated into existing medical infrastructure and is applicable to a broader range of minimally invasive procedures.

[0209] In addition, the magnetically steerable guidewire presents unique advantages to address the aforementioned problems. For example, in the context of steerability and navigability, a significant advantage of this device is that it enables full range control of the guidewire tip orientation, non-traumatic design of the wire tip (usable for cerebral vasculature), small diameter making it compatible to use with intracranial catheters, and stiff proximal wire support enhancing maneuverability for surgical procedures within complex vasculature. For example, in the context of accessibility: the system advantageously enhances accessibility to vascular sites within human bodies that are usually difficult to reach using conventional catheterization procedures due to intricate bifurcations. For example, in the context of compactness, this system offers a compact and portable solution with a minimal hardware footprint to be readily integrated within existing infrastructure. For example, in the context of cost, this system may, for example, be produced at scale with minimal capital costs and is compatible with a wide range of existing commercial guidewires

[0210] In addition to the discussed medical applications, a scaled-up version of this system can be used in industrial applications such as inspection of oil and gas pipes or conduits to find / repair internal damage and blockages.

[0211] FIGS. 6-8 depict a zoomed in illustration of the surgical site 600 depicting a robotic arm 605 positioning a steering magnet 610 to manipulate the magnetic head orientation according to an exemplary embodiment of the present disclosure. Robotic arm may, for example, be configured such that the passive robotic arm is a component of a humanoid robot that is configured for remote operation.

[0212] In some embodiments, the passive robotic arm can be controlled by a humanoid robot configured for remote operation, or the magnetic source directly is grasped and controlled by a humanoid robot remotely or autonomously.354924-7829-3894, v. 2

[0213] The robot-mounted external magnet orients the magnetic head and increasing the stiffness of the VS segment while an insertion mechanism 620 is used to advance a guidewire forward. An X-ray 615 is communicatively coupled to a clinical interface 625. A surgeon 630 (e.g., an interventionalist) uses the clinical interface 625 while performing the surgery. With respect to the evaluation results, the guidewire may, for example, be inserted through the femoral artery and carefully navigated up through the vasculature toward the cerebral arteries using the automated insertion system 620 by surgeon 630. Surgeon 630 actively maneuvered the robotic end-effector, under the fluoroscopic feedback, to control the orientation of the magnetic head in real-time. This precise control may, for example, be important critical when navigating torturous anatomical regions, such as areas with sharp angulations, narrowing vessel pathways, or challenging vascular bifurcations, where conventional guidewire manipulation (e.g., rotating the distal end to steer) often struggles.

[0214] In the context of automated insertion and twist mechanism, the system offers an integrated control approach of both magnetic steering and automated mechanical insertion. Unlike some prior systems that rely exclusively on magnetic actuation, where an external magnetic field comprising extremely large permanent magnets or electromagnet housing controls the full range of motion for the delivery body, the proposed approach enables independent and simultaneous control of three critical degrees of freedom: insertion, axial rotation (twist), and magnetic steering. This comprehensive control allows the operator to finely adjust the distal end’s orientation at every stage of the intervention and concurrendy advance it or retract it from the current position as required. In addition, this gready reduces the footprint of the actuating system by decreasing the magnetic strength required relative to similar technologies.

[0021] FIG. 9 shows a robot-mounted permanent magnet steering a delivery body 910 by controlling the orientation of the magnetic head 905 as it is advanced using the insertion system according to an exemplary embodiment of the present disclosure. Insertion mechanism 620 comprises two daisy-chained servo motors (DYNAMIXEL XC330, ROBOTIS, South Korea), with one controlling a high-friction rubber-coated shaft. The rubber layer compresses delivery body 910 against a linear bearing-drive assembly consisting of an array of 2-mm stainless steel ball bearings that enable smooth motion of the delivery body. Driving this shaft controls the insertion and retraction, with the direction dependent on the shaft’s direction of rotation. The second motor controls a lead screw that can be locked with a pin (for twist control) or unlocked (without twist control) to the rubber-coated shaft such that rotating the lead screw slides the rubber-coated shaft along the axis of the motor’s 364924-7829-3894, v. 2rotation. The sliding motion of the shaft translates to a rotary motion of the delivery body, therefore enabling twist motion at the distal end. Both motors are controlled via an XBOX joystick controller that allows for intuitive motion control.

[0216] FIG. 10 depicts an exemplary setup and environment configuration 1000 for experimental validation of the magnetic delivery system. For real-time imaging feedback, X-ray 615 may, for example, include a C-arm X-ray fluoroscopy system (OEC One CFD, GE Healthcare, USA) positioned over the workspace. The C-arm provided continuous high-resolution imaging, allowing the interventionist to visualize the progression through a vascular phantom 1005 and decide the necessary navigation maneuvers to reach a chosen target vessel along each vascular bifurcation and angulation. This fluoroscopy feedback allowed for assessing the responsiveness of the magnetic steering and performing the necessary steering maneuvers.

[0217] The magnetic head-equipped guidewire (Amplatz Super Stiff, Boston Scientific, USA) was deployed using the automated insertion and twist mechanism operated through a joystick interface.

[0218] Upon arriving at a complex vascular section, the interventionist used the system’s magnetic steering capability to achieve the optimal orientation of the guidewire tip. By adjusting the external magnetic field, the interventionist could finely tune the direction of the magnetic head, aligning it with the desired vessel trajectory. Once properly oriented, forward advancement of the guidewire was once again performed using the joystick controller. This enabled smooth and controlled motion through the vessel lumen until the next tortuous segment was encountered. This iterative process of orienting and advancing enabled efficient progression through the cerebral vasculature.

[0219] In parallel with the steering and stiffness control magnet, the incorporation of the insertion and twist mechanism enables a highly compact footprint for the full actuation module. Therefore, the system is highly adaptable with existing interventional suites for seamless point-of-care usage.

[0220] With respect to experimental validation, the magnetic delivery system has been validated with a series of case-study experiments conducted in a realistic vasculature model with a practicing neurointerventionalist operating the system for a set of tasks. In the374924-7829-3894, v. 2following sections of this chapter, the experimental configuration of these tests and the results of the robot-assisted magnetic navigation are presented.

[0221] FIG. 11 illustrates the experimental setup designed to evaluate the magnetic delivery system. FIG. 12 presents a series of X-ray snapshots illustrating the navigation technique at vascular bifurcations, where the magnetic head was steered with precision into the chosen vessels at branches using the robotic system to reach the target distal cerebral vessel.

[0222] The magnetic actuation was provided by a high-strength external magnet (Applied Magnets, USA), which was securely mounted to the end-effector of a KUKA LBR Med 7-degree-of-freedom robotic arm (KUKA, Germany). The robotic arm was operated in admittance mode, allowing compliant interaction and real-time adjustment of the magnet’s position and orientation based on user input. This setup enabled precise modulation of the magnetic field acting on the magnetized soft silicone head attached to the guidewire. The experiments were performed in a soft, anatomically realistic neurovascular phantom (United Biologies, USA) that simulates the geometry of human blood vessels (FIG. 12). The phantom incorporates live fluid flow to simulate blood circulation and respiratory-induced motion to replicate physiological vessel movement during breathing. This setup provided a dynamic and challenging environment, closely mirroring the conditions encountered in real world endovascular interventions.

[0223] For real-time imaging feedback, a C-arm X-ray fluoroscopy system (OEC One CFD, GE Healthcare, USA) was positioned over the workspace. The C-arm provided continuous high-resolution imaging, allowing the interventionist to visualize the progression through a vascular phantom and decide the necessary navigation maneuvers to reach a chosen target vessel along each vascular bifurcation and angulation. This fluoroscopy feedback allowed for assessing the responsiveness of the magnetic steering and performing the necessary steering maneuvers.

[0224] The magnetic head-equipped guidewire (Amplatz Super Stiff, Boston Scientific, USA) was deployed using the automated insertion and twist mechanism operated through a joystick interface.

[0225] With respect to the evaluation results, the guidewire was inserted through the femoral artery and carefully navigated up through the vasculature toward the cerebral arteries 384924-7829-3894, v. 2using the automated insertion system. Thet interventionist actively maneuvered the robotic end-effector, under the fluoroscopic feedback, to control the orientation of the magnetic head in real-time. This precise control was particularly critical when navigating torturous anatomical regions, such as areas with sharp angulations, narrowing vessel pathways, or challenging vascular bifurcations, where conventional guidewire manipulation (e.g., rotating the distal end to steer) often struggles.

[0226] Upon arriving at a complex vascular section, the interventionist used the system’s magnetic steering capability to achieve the optimal orientation of the guidewire tip. By adjusting the external magnetic field, the interventionist could finely tune the direction of the magnetic head, aligning it with the desired vessel trajectory. Once properly oriented, forward advancement of the guidewire was once again performed using the joystick controller. This enabled smooth and controlled motion through the vessel lumen until the next tortuous segment was encountered. This iterative process of orienting and advancing enabled efficient progression through the cerebral vasculature.

[0227] Notably, this method eliminated the need for traditional pre-shaping of the distal guidewire tip based on pre-procedural planning or anticipated anatomical challenges. The procedure was completed without any device exchanges or excessive manipulation at vascular bifurcations, which are common in interventions following the conventional methods. Instead, the integrated magnetic steering system enabled direct, efficient navigation through the tortuous cerebral vasculature to the target vessel. Upon reaching the desired location, the magnetic head provided stable positioning as a reperfusion catheter (RED 62, Penumbra, USA) was advanced over the guidewire, securing access for subsequent therapeutic intervention, such as thrombus aspiration and vessel recanalization in the context of MT.

[0228] Furthermore, the system served as an assistive precision tool for the interventionist to enhance procedural efficiency with minimal workflow disruption. In a clinical scenario, this would contribute towards better patient outcomes and lower cumulative X-ray exposure for both the patient and clinical staff, which is a critical factor when prolonged procedures, and therefore extended radiation exposure, are common in the conventional approach. Of note, the magnetic steering component was utilized only, when necessary, such as in situations where manual guidance would involve a device exchange or multiple repositioning attempts to enter a specific vessel. Therefore, it is evident that the 394924-7829-3894, v. 2presented approach is readily adoptable to existing interventional workflows while concurrently addressing the conventional limitations.

[0229] In some aspects, the present disclosure provides the apparatus and methods described below:1. An apparatus comprising:a guidewire comprising a proximal end and a distal end portion, wherein:the distal end portion comprises a spring element; andthe distal end portion comprises a magnetically-responsive biocompatible material molded around the spring element.2. The apparatus of embodiment 1, wherein the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion of the guidewire in response to a change in a magnetic field intensity at the distal end portion of the guidewire.3 The apparatus of embodiment 2, wherein the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF).4. The apparatus of embodiment 2 or 3, wherein the stiffness of the distal end portion is a bending stiffness.5. The apparatus of embodiment 4, wherein the bending stiffness is increased as the magnetic field intensity at the distal end portion of the guidewire is increased.6. The apparatus of any one of embodiments 1-5, wherein the spring element is a coiled metallic spring.7. The apparatus of any one of embodiments 1-5 wherein the spring element comprises a shape memory alloy.8. The apparatus of any one of embodiments 1-6 wherein the spring element is a nitinol spring.9. The apparatus of any one of embodiments 1-7 wherein the magnetically-responsive biocompatible material comprises a polymer embedded with magnetic particles. 10. The apparatus of embodiment 9 wherein the polymer is a biocompatible silicone.404924-7829-3894, v. 211. The apparatus of any one of embodiments 1-10 wherein the magnetically-responsive biocompatible material comprises a magnetic powder.12. The apparatus of any one of embodiments 1-11 wherein the magnetically-responsive biocompatible material comprises neodymium iron boron (NdFeB).13. The apparatus of any one of embodiments 1-11 wherein the magnetically-responsive biocompatible material comprises a biocompatible silicone molded with a neodymium iron boron (NdFeB) powder.14. The apparatus of any one of embodiments 1-13 further comprising a controller configured to control movement of the distal end portion of the guidewire.15. The apparatus of embodiment 14 wherein the controller comprises a handheld actuator comprising a magnet.16. The apparatus of embodiment 14 wherein the controller comprises a robotic controller.17. The apparatus of any one of embodiments 13-16 wherein the controller is configured to control an insertion motion, a retraction motion and a twist motion of the guidewire.18. The apparatus of any one of embodiments 1-17 wherein the distal end portion is integrated with an existing guidewire.19. The apparatus of any one of embodiments 1-17 wherein the distal end portion is molded to an existing guidewire20. The apparatus of any one of embodiments 1-19 wherein the magnetically-responsive biocompatible material is axially magnetized.21. The apparatus of any one of embodiments 1-19 wherein the apparatus is configured for tele operation control via a remote device.22. The apparatus of embodiment 21 wherein the remote device comprises a haptic device or a spatial mouse.23. The apparatus of embodiment 21 or embodiment 22 wherein the remote device is configured to control the apparatus via a robotic arm holding an external magnetic source.414924-7829-3894, v 224. The apparatus of embodiment 23 wherein the external magnetic source comprises a permanent magnet to control orientation and steering of the distal end portion.25. The apparatus of embodiment 23 wherein the external magnetic source comprises an electromagnetic source to control orientation and steering of the distal end portion. 26. The apparatus of embodiment 21 or embodiment 22 wherein the remote device is configured to control the apparatus via an insertion mechanism configured to control an insertion motion, a retraction motion and a twist motion of the guidewire.27. The apparatus of any one of embodiments 1-19 wherein the apparatus is configured for handheld control via a permanent magnet or electromagnetic source integrated with an end effector of a passive robotic arm to hold the weight of a magnetic source.28 The apparatus of embodiment 27 wherein the passive robotic arm is a component of a humanoid robot that is configured for remote operation.29. The apparatus of embodiment 27 wherein the handheld control comprises a magnetic glove to give steering cues through vibrations to a user for steering of the magnetically-responsive biocompatible material or uses visual feedback to control the steering of the apparatus.30. The apparatus of embodiment 29 wherein insertion of the guidewire is controlled through a button integrated at the end effector of the passive robotic arm or in the magnetic glove through an insertion mechanism.31. The apparatus of any one of embodiments 1-19 wherein the apparatus is configured for a robot assistive mode, in which a user holds a permanent magnet or electromagnetic source integrated with an end effector of a robotic arm to hold the weight of the magnetic source and assist with the navigation of the magnetically- responsive biocompatible material.32. The apparatus of embodiment 31 wherein the apparatus is configured to be controlled by a user who holds the end effector and gives steering commands and wherein the robot corrects the steering motion using computer algorithms.33. The apparatus of embodiment 31 or embodiment 32 wherein insertion of the guide wire is controlled through a button integrated at the end effector of the robotic arm.424924-7829-3894, v 234. The apparatus of any one of embodiments 1-19 wherein the apparatus is configured such that insertion and steering of the guidewire is performed autonomously using preplanned algorithms.35. A method of manufacturing a magnetically-responsive guidewire, the method comprising:inserting a spring element and a guidewire into a mold;directing a magnetically-responsive material into the mold, wherein the magnetically- responsive material surrounds the spring element and the guidewire; curing the magnetically-responsive material in the mold; andseparating the mold from the magnetically-responsive material, the spring element and the guidewire.36. The method of embodiment 35 wherein the magnetically-responsive material comprises a magnetorheological fluid.37. The method of embodiment 36 wherein:the magnetically-responsive guidewire comprises a proximal end and a distal end; the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion of the magnetically-responsive guidewire in response to a change in a magnetic field intensity at the distal end portion of the guidewire.38. The method of embodiment 37 wherein the stiffness of the distal end portion is a bending stiffness.39. The method of embodiment 38 wherein the bending stiffness is increased in as wherein the bending stiffness is increased as the magnetic field intensity at the distal end portion of the magnetically-responsive guidewire is increased.40. The method of any one of embodiments 35-39 wherein the magnetically-responsive material comprises a polymer mixed with magnetically-responsive particles.41. The method of any one of embodiments 35-40 wherein the polymer is a silicone material.434924-7829-3894, v 242. The method of embodiment 41 or embodiment 42 wherein the magnetically- responsive particles comprises permanent magnets.43. The method of any one of embodiments 41 - 43 wherein the magnetically -responsive particles comprises magnetic powder and permanent magnets.45. The method of embodiment 41 or embodiment 42 wherein the magnetically - responsive particles comprises a magnetic powder.46. The method of embodiment 45 wherein the magnetic powder is a powder comprising five micron neodymium iron boron NdFeB particles.47. The method of any one of embodiments 41-46 wherein the magnetically-responsive particles and the polymer are mixed at a 1 : 1 mass ratio.48. The method of any one of embodiments 41-46 wherein the magnetically-responsive particles and the polymer are mixed at a 2:1 mass ratio.49. The method of any one of embodiments 41-46 wherein the magnetically-responsive particles and the polymer are mixed at a 3 : 1 mass ratio.50. The method of any one of embodiments 41-46 wherein the magnetically-responsive particles and the polymer are mixed at a 4:1 mass ratio.51. The method of any one of embodiments 41-46 wherein the magnetically-responsive particles and the polymer are mixed at a 4:1 mass ratio.52. The method of any one of embodiments 40-51 wherein separating the mold from the magnetically-responsive material, the spring element and the guidewire comprises dissolving the mold.53. The method of any one of embodiments 40-51 wherein separating the mold from the magnetically-responsive material, the spring element and the guidewire comprises separating a first portion of the mold from a second portion of the mold and removing the magnetically-responsive material, the spring element and the guidewire from the mold.54. The method of any one of embodiments 40-53 wherein the spring element is a coiled metallic spring.55. The method of any one of embodiments 40-54 wherein the spring element comprises a shape memory alloy.444924-7829-3894, v 256. The method of any one of embodiments 40-55 wherein the spring element is a nitinol spring.57. A method of directing a magnetically-responsive guidewire into a lumen, the method comprising:inserting the magnetically-responsive guidewire into the lumen, wherein the magnetically-responsive guidewire comprises:a proximal end and a distal end portion, wherein:the distal end portion comprises a spring element; andthe distal end portion comprises a magnetically-responsive biocompatible material molded around the spring element: andexerting a magnetic force on the magnetically-responsive biocompatible material. 58. The method of embodiment 57 wherein the lumen is a neurovascular lumen.59. The method of embodiment 57 wherein the lumen is an industrial conduit.60. The method of any one of embodiments 57-59 wherein a handheld actuator exerts the magnetic force on the magnetically-responsive biocompatible material.61. The method of any one of embodiments 57-59 wherein a robotic actuator exerts the magnetic force on the magnetically-responsive biocompatible material.62. The method of embodiment 61 wherein:the robotic actuator is controlled via a glove worn by a user; andthe glove provides vibratory and / or tactile feedback to the user to help with the intuitive steering.63. The method of any one of embodiments 57-63 wherein the spring element is a coiled metallic spring.64. The method of any one of embodiments 57-63 wherein the spring element comprises a shape memory alloy.65. The method of any one of embodiments 57-64 wherein the spring element is a nitinol spring.66. The method of any one of embodiments 57-65 wherein the magnetically-responsive material comprises a polymer mixed with a magnetically-responsive particles.454924-7829-3894, v 267. The method of embodiment 66 wherein the polymer is a silicone material.68. The method of embodiment 66 or embodiment 67 wherein the magnetically- responsive particles are a magnetic powder.69. The method of embodiment 68 wherein the magnetic powder is a powder comprising five micron neodymium iron boron NdFeB particles.70. An apparatus comprising:a guidewire comprising a proximal end and a distal end portion, wherein:the distal end portion comprises a magnetically-responsive biocompatible material andthe magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion of the guidewire in response to a change in a magnetic field intensity at the distal end portion of the guidewire.71. The apparatus of embodiment 70 wherein the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF).72. The apparatus of embodiment 70 or embodiment 71 wherein the stiffness of the distal end portion is a bending stiffness.73. The apparatus of embodiment 72 wherein the bending stiffness is increased as the magnetic field intensity at the distal end portion of the guidewire is increased.* * *

[0230] All of the methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. 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Claims

1. WHAT IS CLAIMED IS:

1. An apparatus comprising:an elongate intraluminal device comprising a proximal end portion and a distal end portion, wherein:the distal end portion comprises:a spring element; anda magnetically-responsive biocompatible material molded around the spring element.

2. The apparatus of claim 1, wherein the elongate intraluminal device comprises a guidewire, a microcatheter, or a catheter.

3. The apparatus of claim 1, wherein elongate intraluminal device comprises a retrofit distal tip assembly coupled via at least one of heat-shrink tubing, an adhesive bond, an over-molded interface, an interference fit, a mechanical collar, a threaded coupling, or a snap-fit coupling.

4. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material is configured to vary a stiffness of the distal end portion including at least one of a bending stiffness, torsional stiffness, and an axial stiffness in response to a change in a magnetic field intensity at the distal end portion.

5. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material comprises a biocompatible silicone molded with a neodymium iron boron (NdFeB) powder and optionally further comprises one or more embedded permanent magnets.

6. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material comprises a magnetorheological fluid (MRF) contained within a sealed polymeric chamber or lumen of the distal end portion.

7. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material comprises a polymer embedded with magnetic particles.554924-7829-3894, v 28. The apparatus of claim 1, wherein the distal end portion comprises a plurality of compartments or sections arranged serially along a longitudinal axis, and wherein each compartment or section comprises a magnetically-responsive biocompatible material.

9. The apparatus of claim 8, wherein the plurality of compartments or sections are selectively controllable by varying at least one of magnetic field intensity, magnetic field orientation, and magnetic field gradient.

10. The apparatus of claim 9, further comprising a controller configured to control movement of the distal end portion.

11. The apparatus of claim 10, wherein the controller is configured to control an insertion motion, a retraction motion and a twist motion of the guidewire and to position and / or orient the external magnetic source relative to the distal end portion.

12. The apparatus of claim 1, further comprising an external magnetic source configured to generate the magnetic field at the distal end portion.

13. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material is configured to be controlled during teleoperation via a remote device.

14. The apparatus of claim 1, further comprising a humanoid robot comprising a passive robotic arm that is configured for remote operation.

15. The apparatus of claim 1, wherein the distal end portion is configured for handheld control via a permanent magnet or electromagnetic source integrated with an end effector of a passive robotic arm to hold the weight of a magnetic source.

16. The apparatus of claim 1, wherein the distal end portion is configured for a robot assistive mode, in which a user holds a permanent magnet or electromagnetic source integrated with an end effector of a robotic arm to hold the weight of the magnetic source and assist with the navigation of the magnetically-responsive biocompatible material.

17. The apparatus of claim 1, wherein the magnetically-responsive biocompatible material comprises a magnetic powder.564924-7829-3894, v 218. The apparatus of claim 1, wherein the elongate intraluminal device is retrofitted without modifying a proximal hub or handle of an existing commercially available guidewire, microcatheter, or catheter.

19. The apparatus of claim 1, wherein the elongate intraluminal device comprises a retrofit distal tip assembly comprising the spring and the magnetically responsive biocompatible material molded around the spring element, wherein the retrofit distal assembly is detachable and replaceable.

20. The apparatus of claim 1, wherein the magnetically -responsive biocompatible material is axially magnetized, radially magnetized, or diametrically magnetized.

21. A method of directing a magnetically -responsive guidewire into a lumen, the method comprising:inserting the magnetically-responsive guidewire into the lumen, wherein the magnetically-responsive guidewire comprises:a proximal end and a distal end portion, wherein:the distal end portion comprises a spring element; andthe distal end portion comprises a magnetically-responsive biocompatible material molded around the spring element; andexerting a magnetic force on the magnetically-responsive biocompatible material to steer the distal end portion and to vary a stiffness of the distal end portion including at least one of a bending stiffness, torsional stiffness, and an axial stiffness.

22. The method of claim 21, wherein the lumen is a neurovascular lumen.

23. The method of claim 21, further providing a handheld actuator configured to exert magnetic force on the magnetically-responsive biocompatible material.

24. The method of claim 21, further providing a robotic actuator configured to exert the magnetic force on the magnetically-responsive biocompatible material.

25. A method of manufacturing a magnetically-responsive guidewire, the method comprising:inserting a spring element and a guidewire into a mold;574924-7829-3894, v 2directing a magnetically-responsive material into the mold, wherein the magnetically- responsive material surrounds the spring element and the guidewire; curing the magnetically-responsive material in the mold; andseparating the mold from the magnetically-responsive material, the spring element and the guidewire.584924-7829-3894, v 2

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