Abstract: Intravascular catheters having a curved portion subjected to heat at or above the melt temperature thereof to reduce residual stress and eliminate heat history.

Abstract: The apparatus includes a flexible, elongated tubular member and is comprised of a tube of superlastic metal which in response to changing temperatures resists to a greater or less degree the bending moment imposed by a biasing element, thereby altering the shape of the tubular member as a function of temperature and producing a broad range of shapes.

Abstract: An insertion instrument body includes a longitudinal metallic core portion, a distending portion and a power supply means. The metallic core portion is inserted into a lumen such as a blood vessel. The distending portion is fixed to an outer face of the metallic core portion. The power supply means heats the distending portion above a transforming temperature. The distending portion includes a cylindrical portion which is mountable on the metallic core portion; and a plurality of rod-shaped portions which are integrally formed in the cylindrical portion and which are made of a shape-memory material. The rod-shaped portion returns to an original shape by displacing in an intersecting direction with respect to a longitudinal direction of the metallic core portion. An electrical insulating layer is formed on an outer surface of the metallic core portion, and the electrical insulating layer is covered with a flexible sleeve.

Abstract: A shape memory alloy actuator array comprising a plurality of individually trained shape memory alloy actuators to provide relative movement of different actuator array portions and a thin-film heating element positioned adjacent at least one shape memory alloy actuator to thermally activate the actuator for movement away from its initial shape. A shape memory alloy medical device such as a catheter or a conduit is further provided comprising a lattice network or scaffolding of individually activated and oppositely trained shape memory alloy actuators set with a predetermined shape to provide a full range of directional movement within a body, and a network of thin-film heating elements to selectively activate a combination of actuators for movement or variable stiffness.

Abstract: An apparatus having a steerable distal end portion for insertion in a body lumen comprises a superlastic shape memory member which adopts a memorized shape in an unloaded austenitic state, and stationary heating means for heating at least a portion of the superlastic shape memory member to a temperature above the temperature inside the body lumen. Heating the superlastic shape memory member inside the body lumen causes it to increase in stiffness and tend toward the memorized shape, and subsequent discontinuation of heating causes the superlastic shape memory member to decrease in stiffness, allowing the distal end portion to be deformed from the memorized shape, thereby resulting in movement of the distal end portion which assists in steering it through the body lumen. Preferably, the elongate shape memory member is tubular, having a lumen extending therethrough, and the heating means comprises electrical heating means.

Abstract: A guidewire having a core section formed of a NiTi alloy which is in an austenite phase when being manufactured but which is converted to the martensite phase at operating (body) temperature (37° C.) and can be transformed to an austenite phase by heating to a temperature above body temperature but below 50° C. When in the austenite phase, the core section is at a high strength level which ensures the tracking of a catheter over the guidewire within a patient's body lumen.

Abstract: A guidewire having a core section formed of a NiTi alloy which is in an austenite phase when being manufactured but which is converted to the martensite phase at operating (body) temperature (37° C.) and can be transformed to an austenite phase by heating to a temperature above body temperature but below 50° C. When in the austenite phase, the core section is at a high strength level which ensures the tracking of a catheter over the guidewire within a patient's body lumen. In one preferred embodiment the core section is heated by electrical resistance or inductance.

Abstract: An improved guiding member for use within a body lumen having a unique combination of superelastic characteristics. The superelastic alloy material has a composition consisting of about 30% to about 52% (atomic) titanium, and about 38% to 52% nickel and may have one or more elements selected from the group consisting of iron, cobalt, platinum, palladium, vanadium, copper, zirconium, hafnium and niobium. The alloy material is subjected to thermomechanical processing which includes a final cold working of about 10 to about 75% and then a heat treatment at a temperature between about 450° and about 600° C. and preferably about 475° to about 550° C. Before the heat treatment the cold worked alloy material is preferably subjected to mechanical straightening. The alloy material is preferably subjected to stresses equal to about 5 to about 50% of the room temperature ultimate yield stress of the material during the thermal treatment.

Abstract: A drive mechanism for a medication delivery device includes a force receiving member, a force applying member and a shape memory alloy (SMA) actuator. The force applying member is operatively coupled to the force receiving member to move the force receiving member to a different position relative to the force applying member. The shape memory alloy actuator is formed from a shape memory alloy material and is operatively coupled to the force applying member. The shape memory alloy actuator is heat activated to distort the shape memory actuator from a first shape to a second shape to activate the force applying member to act upon the force receiving member to move the force receiving member to a different position relative to the force applying member. Also, the shape memory alloy actuator is returned to the first shape from the second shape after the force receiving member is moved to a different position relative to the force applying member.

Abstract: A catheter for delivering energy to a surgical site is disclosed. The catheter includes at a proximal end a handle and at a distal end a probe. The catheter includes at least one energy delivery device and an activation element. The at least one energy delivery device is located at the distal end of the catheter to deliver energy to portions of the surgical site. The activation element is located at the distal end of the catheter, to transition the probe from a linear to a multi-dimensional shape, within the surgical site. Methods for deploying the probe from the linear to multi-dimensional shape are disclosed.

Abstract: The present invention relates to medical vascular catheters adapted to be inserted into a blood vessel from an incision through the skin of a patient for introducing ther devices or fluids for diagnostic or therapeutic purposes, and particularly to an improved distal soft tip or segment attachment with a relatively stiff proximal catheter shaft. A tubular sleeve is bonded through the application of pressure and heat to a distal portion of the catheter shaft and a proximal portion of the distal segment of soft distal tip bridging the attachment junction. In the preferred method, the catheter shaft distal end is aligned with the distal segment or soft tip proximal end and the sleeve is fitted over the attachment junction. A heat shrink tube is fitted over the sleeve and adjoining portions of the catheter shaft and the distal segment or distal soft tip and heat is applied.

Abstract: This is a section of a catheter which self-forms a selected shape upon application of a modest amount of heat and retains that shape upon cooling and, indeed, upon any reheating. The catheter section includes in its wall a forming member which typically comprises a super-elastic alloy oven braid or at least one coil. The forming member may include other materials and components in addition to the super-elastic element of the forming member. The forming member is typically covered by at least an outer polymeric covering which holds the forming member in a first shape prior to the heating step. Upon softening of the outer layer during that heating step, the forming member self-forms into the desired second shape. The catheter section may be used either in its first shape or its second shape or in any transitional shape between the two. Often the inner lumen of the forming member may contain a second polymeric tubing member. The inner polymeric tubing member is often lubricious.

Abstract: A stent system and method for use in the prostate gland. The stent is made of a shape memory alloy such as nitinol, and has a low temperature martensite state, with a martensite transition temperature below body temperature, and a high temperature austenite state, with an austenite transition temperature at or above body temperature, and a memorized shape in the high temperature austenite state which is a helical coil of diameter large enough to hold the prostatic urethra open. The stent is used to heat the prostate and is left in the prostatic urethra while the prostate heals. After the prostate is substantially healed, the stent is cooled to its martensite state and is easily removed from the urethra.

Abstract: A spiral balloon perfusion catheter assembly having a retaining wire and method of making the balloon. Also, a retaining wire for such a catheter and method of forming the retaining wire. A typical spiral catheter balloon has a spiral configuration of lobes and channels mounted on a catheter extending beyond the balloon ends. A retaining wire formed from a shape memory alloy is configured to have a central region having a spaced spiral configuration conforming to the spiral balloon channel and end regions configured to have a contiguous spiral configuration conforming to the catheter diameter. When placed over a spiral balloon, the central spiral region prevents expansion of the channel when the balloon is inflated, while the end regions secure the retaining wire to the catheter. Preferred shape memory alloys comprise nickel and titanium.

Abstract: A conformable catheter comprising a catheter handle, an elongated catheter tube, and a distal tip portion of the catheter tube, capable of assuming a desired pre-programmed shape. A wire member is disposed within the core of the catheter's tip portion and is formed of a material, such as, for example, a shape-memory binary nickel-titanium alloy, that will assume a pre-programmed shape after pre-shaping, heat treatment, cooling and subsequent heating. To pre-program the shape of the wire member, prior to assembly of the catheter, the wire member is wound around a shaped, heat resistant fixture, heated until the temperature of the wire member exceeds the temperature at which the shape of the wire member on the fixture becomes programmed into the wire member, and cooled.

Abstract: An indwelling catheter is made of a polyurethane resin having a Shore hardness of 60D or more. The soft segment of the polyurethane resin is constituted by polycaprolactone. The indwelling catheter has a kinking resistance of 10 mm or more when measured at 37.degree. C. in wet state. The Young's modulus is at first 20 kgf/mm.sup.2 or more when measure at 25.degree. C. in dry state, and reduces to 15 kgf/mm.sup.2 or less by soaking it in water of 37.degree. C. for 5 minutes or less.

Abstract: A stent system and method for use in the prostate gland. The stent is made of a shape memory alloy such as nitinol, and has a low temperature martensite state, with a martensite transition temperature below body temperature, and a high temperature austenite state, with an austenite transition temperature at or above body temperature, and a memorized shape in the high temperature austenite state which is a helical coil of diameter large enough to hold the prostatic urethra open. The stent is used to heat the prostate and is left in the prostatic urethra while the prostate heals. After the prostate is substantially healed, the stent is cooled to its martensite state and is easily removed from the urethra.