| Project/Area Number |
06557086
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Urology
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
ORIKASA Seiichi Professor School of Medicine, Tohoku University, 医学部, 教授 (60001004)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMOTO Minoru Lecturer Institute for Advanced Materials Processing, Tohoku University, 素材工学研究所, 講師 (30006043)
FURUYA Yasubumi Research Associate School of Engineering, Tohoku University, 工学部, 助手 (20133051)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥19,300,000 (Direct Cost: ¥19,300,000)
Fiscal Year 1995: ¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1994: ¥13,900,000 (Direct Cost: ¥13,900,000)
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| Keywords | Artificial urethral valve / Shape memory alloy (Nitinol) / Urinary incontinence / Artificial urethral sphincter |
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| Research Abstract |
Although Urinary incontinence decreases markedly the quality of life, the condition cannot be treated simply by drugs or surgery. An artificial sphincter made of silicone is under clinical use that consists of a drive balloon for closing and opening the urethra. However, the liquid drive mechanism and structure of the device are very complicated, so damage due to long use or inflammation and infiltration into the urethra are possible. For these reasons we developedartificial urethral valve. This prototype valve uses four thin shape memory alloy (Nitinol, nickel-titanium alloy) plates 0.2mm thick with a shape memory effect in two directions. The characteristic of the alloy at normal temperature is to assume the shape of a circular arc, but at a higher temperature a flat shape. The alloy working temperature can be set by optimizing the valve composition, so the opening and closing can be controlled freely by local heating. Experiments were conducted using the urethral model of silicone tube with an inside diameter of 6mm. This tube is fitted with artificial valve wound with an electrothermal wire, and heated with DC 4.5 V.while passing water at 70-100cm H_2O.The valve prevented flow at room temperature, but the valve started to open at 46ﾟC in 30 seconds after heating.
Next, canine urethra was fitted with valve and valve functioned well inside body. For use inside the human body, the valve would be coated with silicone rubber, and a high-frequency induction heating technique that enable non-contact heating from outside the body is under study.
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