Abstract: This invention relates to a surgical cannula that has a simple ball valve assembly comprising a ball, rotatably mounted on an axle extending between opposing legs of a pivotable yoke, which engages a seat to seal the instrument inlet to the cannula passageway when a trocar instrument is removed and moves out of the path of the instrument during insertion thus avoiding wear and strain on the valve and the instrumentation.

Abstract: A trocar has an elongated body with a frustro-conical end which terminates in a blunt tip. A plurality of blades are radially attached to a blade housing connected to the trocar body. In one embodiment the blade housing moves toward the trocar body in response to a force causing the blades to extend to a cutting position. When the force is removed the blades return to a retracted position.

Abstract: An improved cannula for providing access to a body passage for inserting instruments. The cannula of the present invention includes an improvement in the form of a biased ball valve for sealing the inlet of a housing attached to the proximal end of the cannula. The ball valve includes a seal member with an upwardly curved portion that is biased towards a second seal portion at a second end of the housing whereby the ball seats and seals the inlet to the housing cavity.