Inversible tubular member and a gripping device including such a member

摘要

This invention relates to a gripping device (10), e.g. a surgical retrieval device. The device includes an inversible tubular member (28), which is composed of interengaged stitches of resiliently flexible filamentary material and which is progressively transformable between an everted condition and an inverted condition. The device includes also actuation means (12,20) carrying the inversible tubular member and operable for effecting progressive inversion and eversion of the inversible tubular member. Through progressive inversion of the inversible tubular member, an object can be gripped thereby.

主权项

1. An inversible tubular member, the inversible tubular member being substantially round in cross-section and progressively transformable between an everted condition and an inverted condition, with a transformation end being defined intermediate an everted length and an inverted length of the inversible tubular member during such transformation and with the inverted length and the everted length defining opposite to the transformation end respectively an inverted end and an everted end of the inversible tubular member,
wherein the inversible tubular member is composed of interengaged knitted stitches of resiliently flexible filamentary material; wherein, with the inversible tubular member at least partially inverted, the inverted length has sufficient stiffness to cause eversion of the inversible tubular member at the transformation end upon axial displacement of the inverted end towards the transformation end, for a length of the inverted length up to X times an average relaxed outer diameter of the inverted length; wherein X>=2.0; wherein, with the inversible tubular member at least partially everted, the everted length has sufficient stiffness to cause inversion of the inversible tubular member at the transformation end upon axial displacement of the everted end towards the transformation end, for a length of the everted length up to Y times an average relaxed outer diameter of the inverted length; wherein Y>=2.0; wherein an outer diameter in the everted condition is larger than an outer diameter in the inverted condition, and an inner diameter in the everted condition is larger than an outer diameter in the inverted condition; wherein the stitches are of at least one length of the filamentary material, the stitches are plaited stitches, and the stitches each define a loop and are knitted to form circumferential rows arranged in a helix pattern; wherein each stitch includes a loop, the loops of the inverted length being on the inside of the inversible tubular member and the loops of the everted length being on the outside of the inversible tubular member; and wherein each loop is connected to the loop of an adjacent stitch by a root, the roots of the stitches of the everted length being positioned on the outside of the loops of the stitches of an adjacent row of stitches and the roots of the stitches of the inverted length being positioned on the inside of the loops of the stitches of an adjacent row of stitches.