초록 ▼

A method and apparatus for selectively engaging and disengaging an anchor to fix a medical device at a selected site within a patient's body. A shape memory alloy (SMA) such as Nitinol is used to fabricate one or more anchors for the medical device. The shape memory effect exhibited by the SMA is th

A method and apparatus for selectively engaging and disengaging an anchor to fix a medical device at a selected site within a patient's body. A shape memory alloy (SMA) such as Nitinol is used to fabricate one or more anchors for the medical device. The shape memory effect exhibited by the SMA is thermally activated. One embodiment of the anchor has a substantially circular shape when at its martensite temperature and reverts to an elliptical shape at its austenite temperature. Another embodiment is a substantially straight strip at its martensite temperature and has an end that curls to engage tissue when at its austenite temperature. Still another embodiment includes a pair of anchors that extend outwardly from each side of an elongate probe at their austenite temperature and retract inwardly against the sides of the probe at their martensite temperature. The change in the shape of the SMA elements tends to anchor the medical device or probe at the treatment site. To change the temperature of the SMA elements, an electrical current is selectively energized to provide heat, or thermal conduction between the SMA and a heat source or a heat sink is employed.

대표청구항 ▼

[ The invention in which an exclusive right is claimed is defined by the following:] [1.] A method for fixing a medical device at a site within a patient's body, comprising the steps of:(a) providing an anchor for the medical device, comprising a shape memory metal, said shape memory metal having a

[ The invention in which an exclusive right is claimed is defined by the following:] [1.] A method for fixing a medical device at a site within a patient's body, comprising the steps of:(a) providing an anchor for the medical device, comprising a shape memory metal, said shape memory metal having a first shape associated with a first state and a second shape associated with a second state, and changing from said first state to said second state as a function of temperature;(b) inserting the medical device into the patient's body so that it is disposed at the site, said shape memory metal being in said first state while the medical device is positioned at the site; and(c) changing the temperature of the shape memory metal so that it transitions from said first state to said second state and thus changes from said first shape to said second shape, said second shape causing engagement of tissue within the patient's body so as to resist movement of the medical device relative to the site in at least one direction, and thus tending to fix the medical device at the site.