Japan Science and Technology Agency

Tokin Corporation

Terumo Kabushiki Kaisha

Tohoku University

Nec Tokin Corporation

Other

Japan Stent Technology Co., Ltd.

Clino Corporation

Tohoku Metal Industries

Piolax Medical Devices, Inc.

Japan Medical Device Technology Co., Ltd.

Kyoei Denko Co., Ltd.

Tokin Corporation and Tomy, Inc.

Kiyoshi Yamauchi

Yuji Sutou

Kiyohito Ishida

Ryosuke Kainuma

Toshihiro Omori

Shuzou Yamashita

Kouji Mori

Hiraku Murayama

Takahiro Kugo

Yuuki Tanaka

Michihide Ozawa

Takamitsu Takagi

Ryouichi Souba

Akihiko Umeno

Naoharu Yamamoto

Toshiyuki Takagi

Hiroyuki Yoshida

Hideo Takaara

Hiroshi Ishikawa

Shoichi Sato

Toshio Honma

Minoru Nishida

Atsushi Kita

Tadashi Seto

Shinyou Tanaka

Yasuo Miyano

Minoru Matsumoto

Junji Tani

Akira Ogawa

Katsuhiko Komatsu

Kazutaka Kamikihara

A highly elastic stent is made of an alloy that exhibits superelasticity at body temperature. At least a part of the highly elastic stent has such a property that load increases with displacement without exhibiting a distinct yield on a load-displacement curve obtained by a compression test and a bending test.

Highly elastic stent and production method for highly elastic stent

A Ti&#x2014;Ni&#x2014;Nb alloy device is provided which is a shape memory device excellent in response characteristics. The Ti&#x2014;Ni&#x2014;Nb alloy device is made of a Ti&#x2014;Ni&#x2014;Nb alloy which finishes transformation at a temperature lower than 10&#xb0; C. after start of reverse transformation.

Ti-Ni-Nb alloy device

A method of manufacturing a tubular structure is implemented by housing a tubular base, which has a side circumference surface formed in a bellows-like shape, in a polishing container, causing magnetic particles to flow along a circumferential direction of the tubular base due to action of magnetic poles, and supplying abrasive particles to the polishing container so that the abrasive particles flow along an axial direction of the tubular base, thereby polishing a surface of the tubular base. The method includes: a first polishing step of polishing an exposed surface of the tubular base by causing the magnetic particles and the abrasive particles to flow while an inner surface of the tubular base remains covered; and a second polishing step of polishing an exposed surface of the tubular base by causing the magnetic particles and the abrasive particles to flow while an outer surface of the tubular base remains covered.

Method of manufacturing tubular structure, and stent

To provide a stent which holds various performances such as deliverability, prevention of restenosis, flexible shape conformability, and so on and is therefore adaptable not only to a bile duct but also to a blood vessel system such as a tortuous coronary artery substantially without causing restenosis. A stent with an autonomic function is made of a Ti&#x2014;Ni based shape memory alloy and has a maximum expanding force at a center portion in its lengthwise direction.

Stent with autonomic function

A guide wire includes a distal core member made of a ferrous alloy which has shape memory properties and superelasticity. The ferrous alloy preferably includes substantially two phases, and has a difference of 100&#xb0; C. or less between an Af point and an Ms point in a thermal hysteresis of martensitic transformation and reverse transformation. The guide wire may include a proximal core member made of an iron-containing alloy and having a higher modulus of elasticity than the distal core member. The two core members may be joined together by welding to form a core of the guide wire.

Guide wire and stent

A Co-based alloy being useful as a spiral spring, common spring, wire, cable guide, steel belt, build-up material, guide wire, stent, catheter, etc. There is provided a Co-based alloy having a composition of Co&#x2014;Al binary system containing 3-13% Al loaded with at least one workability enhancing element selected from among 001 to 50% Ni, 0.01 to 40% Fe and 0.01 to 30% Mn and having a lamellar structure wherein f.c.c. structure &#x3b1;-phase and &#x3b2;(B2)-phase are repeated in layers. The lamellar structure is so regulated that the occupancy ratio of the whole structure is 30 vol. % or above and the layer spacing is 100 &#x3bc;m or less. The Co-based alloy may contain at least one optional component selected from among Ga, Cr, V, Ti, Mo, Nb, Zr, W, Ta, Hf, Si, Rh, Pd, Ir, Pt, Au, B, C and P may be added in a total amount of 0.01 to 60%.

High-strength co-based alloy with enhanced workability and process for producing the same

An elastic metal strip aligning a longitudinal direction with a rolling direction of a cold-rolled plate is collected and processed to a shape including a correction plate with the longitudinal direction of the elastic metal as a width direction of a nail and a plurality of tongue strips protruded from the edge of the correction plate near the nail tip. Each tongue strip is folded and bent to form a hooked claw with a double structure of a folding part and a bending part. A nail tip of a deformed nail is inserted between the hooked claw and the correction plate to apply a restoring force of elasticity in the correction plate to the deformed nail as correction ability for deformed nails. A wrought wire rod can be used instead of a cold-rolled plate and a Cu&#x2014;Al&#x2014;Mn type shape-memory alloy may further be used as a raw material.

Corrective device for deformed nails

A Co-based alloy having a fundamental composition of Co&#x2014;Al system containing 3-15% Al and having lamellar structure wherein f.c.c. structure &#x3b1;-phase and &#x3b2;(B2)-phase are superimposed on each other in layers, and the Co-based alloy is modified so as to have a porous surface layer region effective for chemical retaining capability, sustained release, biocompatibility, etc. through selective removal of either the &#x3b1;-phase or the &#x3b2;-phase from the surface layer. As a third component, at least one member selected from among Ni, Fe, Mn, Ga, Cr, V, Ti, Mo, Nb, Zr, W, Ta, Hf, Si, Rh, Pd, Ir, Pt, Au, B, C and P may be contained in a total amount of 0.001 to 60%.

Functional member from co-based alloy and process for producing the same

A balloon expandable superelastic stent is made of a Ti&#x2014;Ni&#x2014;Nb (the content of Nb being at least 3 at %) shape memory alloy. A shape recovery temperature of the stent is lower than a living body temperature in an unloaded state after shape memory treatment. The shape recovery temperature exceeds the living body temperature after the stent is mounted to a catheter and released from the catheter in a living body.

Balloon expandable superelastic stent

In an NiMnGa alloy represented by the chemical formula of Ni Mn Ga, a composition ratio parameter X (mol) is selected within a range of 0.10&lE;X&lE;0.30. With this composition, the finish point of the reverse transformation of the martensitic transformation can be selected to a desired temperature within the range between &minus;20&deg; C. and 50&deg; C., while the Curie point is also selected to a desired temperature within the range between 60&deg; C. and 85&deg; C. The alloy has the shape memory effect by the martensitic transformation and the reverse transformation. Furthermore, the alloy is induced with the reverse transformation by application of an external magnetic field at the martensite phase to exhibit the shape recovery.

NiMnGa alloy with a controlled finish point of the reverse transformation and shape memory effect

A foot correction method comprises the steps of raising a plantar arch (15) and applying a pressure on either side of a foot (13) to thereby maintain a configuration of a longitudinal arch and a transversal arch of the foot (13) so as to prevent and correct a spraying phenomenon of the foot (13). A splint (11, 23) for practicing the method comprises shape memory alloy wires preferably in the form of either woven fabric, such as a mesh (17), or a nonwoven fabric plate. The shape memory alloy wires preferably consists of a Ti-Ni series alloy exhibiting superelasticity at a normal or used temperature.

Method of correction of the foot, splint for use in practicing the

A vascular dilatation instrument 1 includes an outer tube 2, an inner tube 5 extending through the outer tube 2, and an inflatable member 3 having one end attached to the inner tube 5 and another end attached to the outer tube 2. The outer tube 2 includes a superelastic or pseudoelastic metal tube 2b and a synthetic resin tube 2a covering the metal tube, the metal tube 2b having a distal zone provided with a slit or perforations 2e so that the distal zone is more flexible and deformable than the remainder of the metal tube. Also provided is a catheter 100 comprising a main body section which includes a superelastic metal tube 101 and a synthetic resin layer 104 covering the metal tube, the metal tube 101 having a distal zone provided with a slit or perforations 106 so that the distal zone is more flexible and deformable than the remainder of the metal tube.

Vascular dilatation instrument and catheter

An orthodontic teeth alignment correction wire element made of an alloy represented by the chemical formula of Ti.sub.a Ni.sub.b-c C.sub.c, wherein a+b=100, b=50-52, c=0.25-5.0, or an alloy represented by the chemical formula of Ti.sub.a Ni.sub.b-c-d C.sub.c X.sub.d, wherein X is at least one element selected from V, Cr, Fe, Nb, Ta, W, and Al, wherein a+b=100, b=50-52, c=0.25-5.0, d=0.25-2.0, and exhibits pseudoelasticity at the natural human body temperature. The wire has different recovery forces at different sections therealong by heat treating those sections at controlled temperatures of 400.degree.-600.degree. C. and for controlled time periods of 10-150 minutes and thereafter reheat treating them. An orthodontic coil is made of each of the above-described alloy wires for correction of mismatch of the upper and the lower jaws.

Orthodontic implement controllable of correction force

A catheter guide wire is for use in guiding of a catheter to a destination position in vessels in body and comprises a solid core wire of a Ti-Ni shape memory alloy and an outer jacket covering the core wire. In order to provide a plasticity to one end portion of the core wire, at least one end portion is made of a 45.0-51.0 at % Ni-0.5-5.0 at % Fe-Ti shape memory alloy and is heat treated at 400.degree.-500.degree. C. The end portion is provided with a pseudo elasticity at a temperature about 37.degree. and a plasticity at a temperature below 80.degree. C. Alternatively, the end portion may be made of a 50.3-52.0 at % Ni-Ti alloy and is heat treated at a temperature of 700.degree. C. In order to improve operability of the catheter guide wire, the remaining portion other than the end portion is made of provided with a comparatively high rigidity by a usual Ti-Ni shape memory alloy which is not heat treated. Alternatively, the remaining portion is covered with an inorganic layer. The inorganic layer is a coating and alternatively is a cladding. The solid core wire is covered with a synthetic resin layer to form the catheter guide wire.

Catheter guidewire with pseudo elastic shape memory alloy

Growing community of inventors

Sendai, Japan

Kiyoshi Yamauchi