Other

Kawasumi Laboratories. Inc.

Agency of Industrial Science and Technology

Ikeuchi, Takeshi

Iwata, Hiroo

Mori, Kouji

Mitsudou, Kazuaki

Hiroaki Nomiyama

Hiroo Iwata

Masatoshi Watanabe

Kazuaki Mitsudou

Kouji Mori

Yoshiharu Yoshikawa

Masuhiro Kogoma

Sachiko Okazaki

Michio Abe

Kazunori Murakami

Makoto Kodama

Ken Ikeuchi

Takeshi Ikeuchi

Tohru Maruyama

Shuzou Yamashita

A stent having a generally tubular body formed of ring units formed of a plurality of cells each and expandable in the radial direction, wherein each ring unit is constituted of cells connected to one another above and below, arranged to surround the center line of the stent, the ring units are arranged in the axial direction of the stent, and are connected with connector portions, each connector portion is formed of curved portions each having an arch and a generally linear portion continued thereto, 3 to 8 cells are arranged in the axial direction per 10 mm of the length of the stent, and the ratio of the length of the cell in the axial direction and the length of the connector portion is determined such that on the basis that when the length of the cell is 100, that of the connector portionto, thereby securing flexibility and radial sustaining force.

Stent

A stent () formed into a generally or substantially tubular body and expandable radially outward from inside of the tubular body, wherein cells () are connected vertically and so arranged as to surround the central axis (C) of the stent () and thereby to form annular units (), the annular units () are extended along the axis of the stent (), adjacent annular units () are connected at least at one portion by a connecting part (), each of the cells () has at least one bent portion, and the angle of the bent portion after expansion of the tubular body until the diameter becomes 2.5 mm is larger than 30&#xb0;. The stent ensures a high flexibility and radial support force, enhances the blood vessel expandability, and suppresses the foreshortening phenomenon and the flare phenomenon.

A plastic tube extruded from an extruder is conveyed through a plasma treatment apparatus. The plasma treatment apparatus is equipped with a tubular electrode body having a high-voltage side electrode and a grounded-side electrode disposed on a tubular insulator and a high frequency electric power source connected to the electrodes. When the plastic tube is conveyed through the electrode body with one end of the tube open to the atmosphere, a mixture of a glow discharge-stabilizing gas and a treating gas is fed into the other end of the tube and an alternating-current high-voltage is applied to generate a plasma region at a pressure near to atmospheric pressure in which the tube is treated with a glow discharge plasma. This method allows an interior and/or exterior surface of a plastic tube designed to convey a medical fluid to be continuously treated by a glow discharge plasma at atmospheric pressure to form an anti-thrombotic and blood-compatible film on the surface treated. The resulting surface-treated medical material can be produced at a comparatively low cost and maintains its original bulk material properties.

Method for producing medical materials

Growing community of inventors

Oita, Japan

Hiroaki Nomiyama