| 摘要 |
<p>This invention relates to a catheter which is used when inserted into a tubular organ. At least two unidirectional shape memory alloy wires that maintain a length stored in advance at or above a set temperature and can deform freely below the set temperature are disposed near the tip substantially in parallel with the direction of a lengthwise axis, and at those positions where the force generated when at least one of the unidirectional shape memory alloy wire changes to the length stored in advance on heated to or above the set temperature can act as bending force on the other unidirectional shape memory alloy wire having a temperature lower than the set temperature. Therefore, desired bending can be attained in the catheter with a simple structure and operability of the catheter in the tubular organ can be improved. The present invention provides a catheter which is used while being inserted into the tubular organ. It includes at least one flow path extending over the entire length, and at least one bidirectional shape memory alloy wire extending in an axial direction in its tubular wall, or on inner wall or outer wall. When the temperature of the wire is changed, the shape of the tip of the catheter can be changed reversibly. Therefore, the catheter can be bent as desired with a simple structure and operability of the catheter in the tubular organ can be improved.</p> |
