Medical retrieval device

摘要

A medical retrieval basket used for entrapping and extracting objects such as urinary and biliary calculi from the body comprising a handle assembly, a flexible shaft, and a basket. The basket comprises a plurality of outwardly disposed shape memory wires and is bulbous in shape at its distal end. Located at the intersection point of the wires at the distal end of the basket is a hub that restricts the degree of relative movement between the wires. This hub also serves to increase contact points with the object to be retrieved and to stabilize the orientation of the basket wires. The substantially tipless configuration of the distal end of the basket permits the basket to retrieve objects from difficult to reach locations and reduces tissue trauma caused by the basket tip. The basket wires have varying cross sectional shapes and sizes in different sections of the basket to optimize the performance to the needs of each section within the basket. The flexible shaft contains a drive wire that exhibits different flexibilities within the same strand of material by varied cross sectional shapes or diameters. This permits the distal section of the shaft to be more flexible, which reduces the possibility of the device shaft limiting the deflection of a flexible endoscope.

主权项

1. A medical retrieval device for use in a medical procedure for extraction of a stone, the device comprising:
a sheath having a proximal end, a distal end, and a lumen defined therebetween; a basket formed of a plurality of wires, the basket including:
a closed configuration wherein the basket is retracted within the lumen of the sheath;an open configuration wherein the basket is extended from the lumen of the sheath so as to define an entrapment space therein for entrapping a stone, the open configuration having a proximal portion proximate the sheath and a distal portion having a substantially tipless configuration; andat least two of the wires each having a plurality of cross sectional shapes, one of the cross sectional shapes being generally uniform along a first longitudinal portion of the wire and another of the cross sectional shares being generally uniform along a second longitudinal portion of the wire, and each of the cross sectional shapes having a different corresponding thickness, the thickness being a cross sectional dimension of the wire along a line defined perpendicular to the wire and coplanar with a longitudinal axis of the basket; and a drive wire which is configured to be movable within the lumen of the sheath, the drive wire connected to the basket at the distal portion such that the drive wire is able to push the basket out of the lumen of the sheath into the open configuration or pull the basket into the lumen of the sheath into the closed configuration.