Patent ID: 7661294

Claim:
An integrated multi-function sensor system comprising: a head having a slot to accept a tube of a deformable material; a plurality of sensor elements mounted in said head to confront a tube in said slot, each said sensor element for affecting sensing of a condition relating to a liquid in the tube; wherein said plurality of sensor elements comprise: a pair of piezoelectric elements mounted opposing each other on the side walls of said slot, one of said piezoelectric elements of said pair to transmit ultrasonic energy through the outer wall of a tube in the slot to be received by the other of said piezoelectric elements of said pair; and a force sensor mounted on one wall of said slot to contact the outer wall of a tube in said slot; wherein each of said plurality of sensor elements performs its respective sensing function while being located outside of the wall of a tube in said slot; and an electronic circuit to which said plurality of sensor elements are connected to provide a measurement of the condition sensed by each of said plurality of sensor elements, wherein said electronic circuit comprises: a microprocessor; an air bubble and particle detection circuit controlled by said microprocessor to cause ultrasonic energy to be transmitted by said one piezoelectric element though the tube to be received by said other piezoelectric element, and to determine from the received energy the presence of air bubbles and/or particles in liquid flowing in a tube in the slot; and a force detection circuit controlled by said microprocessor to determine from a change in deformation of a tube in said slot a change in pressure of a liquid flowing in the tube which indicates an occlusion of the liquid flow.