A medical device for collecting objects from a body lumen comprises a catheter, a basket having a closed first end and an open second end, and an actuator connected to the closed first end of the basket, the catheter and basket moveable relative to one another between a first configuration and a second configuration to draw objects from a body lumen into the basket. In the first configuration the closed first end of the basket is inside the catheter and the open second end is everted over at least a part of the closed first end. The apparatus may be actuated to pull the closed first end of the basket further into the catheter and invert the second end of the basket, the second end scraping the sides of the lumen as it inverts, surrounding an object in the lumen, and drawing the object into the basket.
