Dual pump arthroscopic irrigation/aspiration system with outflow control

A fluid pump system, comprising:

• a first fluid pump for pumping fluid from a source to a surgical site;
• a second fluid pump for removing fluid from the surgical site at a first predetermined rate, wherein said fluid pump system intermittently operates in conjunction with a surgical tool which, when operational, removes fluid from the surgical site at a second predetermined rate greater than said first predetermined rate;
• a first fluid input tube joining the surgical site to the second pump and a second fluid input tube joining the surgical tool to the second pump;
• a shuttle valve for alternatively pinching one or the other of said first and second fluid input tubes, or neither tube, said shuttle valve including a pinching member that has a linear slot and is positioned in a track for movement between a first position in which neither of said first or second fluid input tubes is closed, a second position in which only said first fluid input tube is closed, and a third position in which only said second fluid input tube is closed;
• a motor having a rotatably reciprocating output drive shaft;
• a first cam member fixedly attached to said output drive shaft and supporting a drive pin that is received in the linear slot of the pinching member to reciprocate between two arcuately spaced positions when said drive shaft rotatably reciprocates;
• a sensor positioned to sense the position of said arcuate cam and for producing signals alternatingly representing said first, second and third positions.