Device for dilating vascular tissue - comprises helical spring element which is expanded by relatively rotating ends using external knobs

摘要

The implanted device comprises a helical spring (36) which can be expanded radially by rotating the ends (38,39) relative to one another. One end (38) of the spring is attached to a shaft (42a) mounted axially within the spring. The other end is attached to a sleeve (42b) which covers the spring and the shaft. The proximal end of the shaft carries a rotatable knob (44) and a second knob (43), spaced from it, is carried by the proximal end of the flexible sleeve. By rotating the knobs the number of spring turns and the pitch of the turns can be altered.