摘要:
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.degree. and about 600.degree. C. and preferably about 475.degree. to about 550.degree. 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. The guiding member using such improved material exhibits a stress-induced austenite-to-martensite phase transformation at an exceptionally high constant yield strength of over 90 ksi for solid members and over 70 ksi for tubular members with a broad recoverable strain of at least about 4% during the phase transformation. An essentially whip free product is obtained.
摘要:
An elongated flexible housing for an atherectomy or other intracorporeal catheter which is formed of a shape memory alloy such as an alloy formed predominantly of NiTi intermetallic compound. The housing preferably has an inner chamber with a tissue cutter or other diagnostic or therapeutic system provided within the chamber to sever stenotic material which is urged into the chamber through a opening or window in the housing. In one embodiment the housing has at least one section which is relatively flexible with adjacent sections which are relatively stiff to provide an increase in the overall flexibility of the housing.
摘要:
A radially expandable, endovascular stent designed for placement at a site of vascular injury, for inhibiting restenosis at the site, a method of using, and a method of making the stent. The stent includes a radially expandable body formed of one or more metallic filaments where at least one surface of the filaments has a roughened or abraded surface. The stent may include a therapeutic agent on the abraded surface.
摘要:
This invention is directed to an intracorporeal device formed of a high strength Co—Ni—Cr alloy and is particularly suitable for forming a composite product with a pseudoelastic member formed of NiTi alloy. Suitable intracorporeal products include guidewires and stents. The high strength alloy consists essentially of about 28 to about 65% cobalt, about 2 to about 40% nickel, about 5 to about 35% chromium, up to about 12% molybdenum, up to about 20% tungsten, up to about 20% iron and the balance inconsequential amounts of impurities and other alloying constituents, with a preferred alloy composition including about 30 to about 45% cobalt, about 25 to about 37% nickel, about 15 to about 25% chromium and about 5 to about 15% molybdenum. Intravascular devices such as guidewires, stents and the like can be formed of this high strength Co—Ni—Cr alloy.
摘要:
The methods disclosed herein are directed to altering gaseous flow within a lung to improve the expiration cycle of, for instance, an individual having Chronic Obstructive Pulmonary Disease. More particularly, these methods produce and maintain collateral openings or channels through the airway wall so that expired air is able to pass directly out of the lung tissue to facilitate both the exchange of oxygen ultimately into the blood and/or to decompress hyper-inflated lungs. Devices and methods apply cryo-energy to maintain the patency of the surgically created openings.
摘要:
A stent delivery catheter comprises a catheter body having a proximal end, a distal end, and a guidewire lumen extending from the distal end to at least part way between the proximal end and the distal end. A balloon is disposed over the catheter body near the distal end, and a stent is positioned over the balloon. The stent has a proximal end, a distal end, and a side opening between the proximal end and the distal end. A side sheath is coupled to the catheter body and has a proximal end, a distal end, and a guidewire lumen extending between the proximal end and the distal end. The proximal end of the side sheath is located between the proximal end of the catheter body and the balloon, and the side sheath exits out of the side opening of the stent.
摘要:
A radially expandable, endovascular stent designed for placement at a site of vascular injury, for inhibiting restenosis at the site, a method of using, and a method of making the stent. The stent includes a radially expandable body formed of one or more metallic filaments where at least one surface of the filaments has a roughened or abraded surface. The stent may include a therapeutic agent on the abraded surface.
摘要:
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. The guiding member using such improved material exhibits a stress-induced austenite-to-martensite phase transformation at an exceptionally high constant yield strength of over 90 ksi for solid members and over 70 ksi for tubular members with a broad recoverable strain of at least about 4% during the phase transformation. An essentially whip free product is obtained.
摘要:
An elongated flexible housing for an atherectomy or other intracorporeal catheter which is formed of a shape memory alloy such ass an alloy formed predominantly of NiTi intermetallic compound. The housing preferably has an inner chamber with a tissue cutter or other diagnostic or therapeutic system provided within the chamber to sever stenotic material which is urged into the chamber through a opening or window in the housing. In one embodiment the housing has at least one section which is relatively flexible with adjacent sections which are relatively stiff to provide an increase in the overall flexibility of the housing.
摘要:
A process for adjusting the physical and mechanical properties of a shape memory alloy member of a known chemical composition comprising the steps of increasing the internal stress level and forming said member to a desired configuration and heat treating said member at a selected memory imparting temperature.