摘要:
A stent and method for manufacturing a stent that achieves both strength as well as ductility. In the manufacturing process, the material used to form the stent is only partially annealed to lower the grain size across the thickness of the stent. The material is partially annealed either prior to or after the cutting a stent pattern into a tube.
摘要:
The present disclosure is directed to a drug-eluting implantable medical devices that includes a tantalum-alloy body having a drug-eluting coating thereon for delivering a drug to treat, for example, restenosis. In an embodiment, an implantable medical device includes a body sized and configured to be implanted in a living subject. At least a portion of the body may comprise a tantalum alloy. The tantalum alloy includes a tantalum content of about 77 weight % (“wt %”) to about 92 wt %, a niobium content of about 7 wt % to about 13 wt %, and a tungsten content of about 1 wt % to about 10 wt %. The tantalum alloy exhibits at least one mechanical property modified by heat treatment thereof. The body has a drug-eluting coating thereon.
摘要:
Embodiments are directed to radiopaque implantable structures (e.g., stents) formed of cobalt-based alloys that comprise cobalt, chromium and one or more platinum group metals, refractory metals, or combinations thereof. Platinum group metals include platinum, palladium, ruthenium, rhodium, osmium, and iridium. Here, the term “refractory metals” include zirconium, niobium, rhodium, molybdenum, hafnium, tantalum, tungsten, rhenium, as well as the precious metals silver and gold. In one embodiment, the one or more included platinum group or refractory metals substitute for nickel, such that the alloy is substantially nickel free. The stents exhibit improved radiopacity as compared to similar alloys including greater amounts of nickel.
摘要:
Methods for making devices include providing a tubular member to be formed into a device, placing a removable sacrificial block material in the lumen of the tubular member and laser cutting the tubular member. A doping material can be added to the melted portion of the tubular member to promote the formation of brittle slag. A fixture can be used to hold a cut workpiece in order to ream sacrificial material from the surface of the workpiece. Pressurized gas can be supplied to the inner lumen of the tubular member to cause slag to form on the outside surface, rather than the inner surface, of the tubular member. A tubular member made from nickel-titanium alloy can be tightly adhered to a sacrificial sleeve utilizing the phase changes associated with nickel-titanium. A rotating mandrel can be placed within the lumen of the tubular member during laser cutting. A mandrel which includes an enlarged diameter section causes the workpiece to expand slightly within its elastic deformation range to dislodge islands from the workpiece. Such a mandrel could be formed from a tubular member which has a central lumen that can be used to deliver a pressurized medium to “blast” islands from the workpiece.
摘要:
Embodiments of methods for vacuum heat treating refractory metal articles (e.g., implantable medical devices), and heat treating apparatuses for use in such methods are disclosed. Heat treating refractory metal articles under high vacuum (e.g., 10−6 Torr) may improve strength and ductility and remove material contaminants (e.g., oxygen or hydrogen) that may be absorbed during manufacturing processes. Heat treating methods include disposing a refractory metal article in a heat treating apparatus, drawing a vacuum therein, and moving the article to a heated zone in the furnace using a drive system that permits movement of the article while the vacuum is maintained in the apparatus. A heat treating apparatus may include an elongate furnace tube that may be sealed and placed under vacuum, a heating element disposed around at least a portion of the tube, and a drive system configured for moving articles disposed inside the furnace tube while under vacuum.
摘要:
The invention relates to a method and apparatus of reducing stress during stent manufacture. Particularly, the invention is directed to a method and apparatus for expanding a stent using primarily radial loads thereby reducing the stresses that are generated due to the axial loads applied during loading of the stent onto a mandrel or other expansion device. The method of the invention provides for the stepwise expansion of shape memory stents, while reducing the overall stresses that the stent encounters, and thereby improving manufacturing yields due to fractured struts during expansion.
摘要:
Expandable biodegradable devices formed of bistable and multistable unit cells for use in devices, such as stents and graft systems, are provided, in which the device has two or more stable configurations, including a contracted configuration and an expanded configuration, the contracted stable configuration having a smaller diameter than the expanded configuration.
摘要:
A laser cutting system including a chamber configured to provide a controlled environment while the laser is being used to cut a pattern into a material to reduce or eliminate heat and oxygen related changes to the mechanical characteristics of the material. A system for providing a gas to the controlled environment within the chamber, as well as a means for exhausting gas and cutting debris from the chamber is also described. A cutting mandrel that provides for flow of a shielding gas and also provides a means for dispersing a laser beam before it can produce unwanted damage to a section of tubing is also described.
摘要:
Implants and methods of making same are provided for treatment or prophylaxis of coronary or peripheral vascular constrictions or vascular occlusions, and particularly, stenoses or restenoses, that comprise FK506 in chemically covalently bound, non-covalently bound or physically immobilized form.
摘要:
A power driven vessel closure device is configured for closing a hole in a wall of a body lumen. The vessel closure device can include a power operated drive system and a closure element delivery system. The closure element delivery system can be removably, operably, couplable with the power operated drive system. That is, the closure element system can be directly or indirectly attached to and removed from the power operated drive system, or components thereof. The operation of the power operated drive system can operate the closure element delivery system so as to move the closure element within the vessel closure device and deploy the closure element to close the hole.