Biopsy needle

A biopsy needle for collecting a tissue specimen comprising:

• a handle housing;
• an outer cannula that is at least partially received within the handle housing;
• an inner tube received within the outer cannula and configured to receive a stylet,
• wherein the outer cannula and inner tube extend distally beyond a distal end of the handle housing;
• a snare coil attached between the inner tube and the outer cannula;
• a movable sled disposed within the handle housing, wherein the outer cannula is fixedly coupled to the movable sled, the movable sled being axially movable within the handle housing along one or more guides;
• an inner driven structure that is coupled to the inner tube and is configured to travel axially a defined distance within a track formed in the movable sled while at the same being prevented from rotating during axial travel, wherein one of the inner tube and the inner driven structure includes a pin and the other of the inner tube and the inner driven structure includes a groove that receives the pin such that the axial driving of the inner driven structure imparts rotation to the inner tube relative to the outer cannula;
• a first biasing mechanism coupled to the movable sled for driving the movable sled in a distal axial direction when the first biasing mechanism releases its stored energy;
• a second biasing mechanism coupled to the inner driven structure for driving the inner driven structure in the distal axial direction along the movable sled when the second biasing mechanism releases its stored energy;
• wherein the first biasing mechanism defines a first stage of operation and the second biasing mechanism defines a second stage of operation, wherein in the first stage, the release of the stored energy of the first biasing mechanism causes the movable sled and the inner tube and the outer cannula to travel axially in the distal direction for a defined distance and the second biasing mechanism is configured such that after the movable sled travels a prescribed distance, the second biasing mechanism is automatically tripped and releases its stored energy to cause the axial driving of the inner driven structure resulting in rotation of the inner tube relative to the outer cannula, thereby causing activation of the snare coil.