The invention relates to evaluation of maturity of arteriovenous (AV) fistula using guidewires that measure intravascular blood flow and/or pressure. The invention provides methods of evaluating AV fistula maturation using an instrumented guidewire to measure intravascular flow and/or pressure. By using a small diameter guidewire that does not interfere substantially with the flow, an accurate measurement can be made that is useful for identifying when a fistula is mature and therefore ready to be used for hemodialysis. The flow of blood through the fistula is measured using the guidewire and the measured flow and/or pressure of blood is used to determine if the fistula is mature.

A guide wire which is flexible in a distal portion and which can prevent occurrence of damage such as breakage and separation of a coil in the distal portion has an elongated core member and a tubular body located so as to cover a periphery of a distal portion of the core member. The tubular body is formed using a belt-shaped member wound in a spiral shape, and has an engagement portion which causes side portions adjacent in a longitudinal axis direction of the core member to engage with each other in the belt-shaped member.

The disclosure generally relates to a guidewire with controllable stiffness and to a method of use thereof. A distal section of the guidewire includes a core wire, a shape memory coil, and a distal element electrically connecting the core wire to the shape memory coil. The shape memory coil has an expanded configuration with smaller stiffness and a compressed configuration having larger stiffness. Upon passage of an electric current through the shape memory coil, the shape memory coil may switch between the expanded and compressed configurations, thus changing the stiffness of the distal section of the guidewire.

The invention relates to a wire device (100), in particular a wire device for insertion in a body lumen, comprising a stiffening portion with a pressure tube (2), a stiffening layer (3) and an outer tube (4). The stiffening layer is arranged concentrically about the pressure tube, and the outer tube is arranged concentrically outside of the stiffening layer. The outer tube is radially stiff and the stiffening layer is radially movable. Pressure can be built up inside the pressure tube such that the stiffening layer can be forced against the outer tube from the inside and the stiffening portion can be reversibly stiffened under pressure. The pressure in the pressure tube can in particular be reduced so that the stiffening portion becomes flexible again.

The disclosure provides a system and method for a programmable medical wire that can be preprogrammed, and controlled and reshaped upon command. The system can include a power supply, a controller, and a multilayered wire assembly. The wire assembly includes a core conductor, actuator conductors coupled to the core conductor, selective conductors formed adjacent the core conductor and the actuator conductors, and a protective biocompatible shield around the layers. The selective conductors can be energized to activate the actuator conductors and cause the actuator conductors to bend or twist in a preprogrammed manner. By selectively controlling the direction of movement of the actuator conductors, the wire assembly can be remotely guided through body passageways to the target. Auxiliary equipment such as sensors, micro cameras, detectors, cutters, and other equipment can also be coupled to the wire assembly, and controlled and communicated with through one or more of the selective conductors.

A medical guidewire system including an inner member having an outer diameter and an outer member having an inner diameter, the inner diameter being larger than the outer diameter. The inner and outer members are relatively slidable to adjust a stiffness of the guidewire system. The lumen of the outer member forms a gap for fluid flow therethrough. A connector to the inner member and a fluid infusion channel communicating with the gap for injection of fluid through the gap to exit a distal portion of the outer member.

Disclosed herein is a guidewire configured for placement of large bore catheters and cannulae inside of a patient's blood vessels without fluoroscopic guidance. The guidewire, in accordance with certain aspects of an embodiment of the invention, comprises sections of varying stiffness throughout optimally fixed length portions of the guidewire that particularly ease placement of such large bore catheters and cannulae in ECMO applications.

A device including a catheter (14) and a medical instrument (12). The catheter includes an inner portion (16) and one or more unlocking features (18). The medical instrument includes one or more locking features (24). When the medical instrument is in the inner portion of the catheter, the one or more unlocking features engage the one or more locking features so that the medical instrument can bend in the catheter. When the medical instrument is outside the catheter, the one or more unlocking features disengage from the one or more locking features so that the medical instrument is restricted from bending.

Medical devices and methods for making and using a medical device are disclosed. An example medical device may include a guidewire for accessing and treating a region of the neural vasculature. The guidewire may include an elongate shaft having a distal end region. The elongate shaft may include an inner tubular member and an outer tubular member. The inner tubular member may have a plurality of openings formed therein. The outer tubular member may have a plurality of slots formed therein. An occlusive balloon may be coupled to the distal end region of the elongate shaft and disposed about at least some of the plurality of openings. The inner tubular member may define a lumen in fluid communication with the occlusive balloon through the plurality of openings. The tip member may be coupled to the distal end region of the elongate shaft.

An apparatus and method of manufacture includes a helical wire coil body having a proximal body end portion and a distal body end portion that extend along a longitudinal coil axis. The apparatus also includes a non-extensible, core wire assembly configured to inhibit longitudinal elongation of the helical wire coil body along the longitudinal coil axis. The core wire assembly has a first core wire and a second core wire respectively extending from the proximal body end portion toward the distal body end portion. The second core wire proximally terminates relative to the first core wire such that the distal body end portion is more flexible than the proximal body end portion. The first and second core wires transversely overlap to provide a collective column strength to the helical wire coil body along the longitudinal coil axis.