US Patent 10316834 Peristaltic pump

A peristaltic pump includes a cam shaft, first and second pinch-valve cams, first and second pinch-valve cam followers, a plunger cam, a plunger-cam follower, a tube receiver, a spring-cam plunger, a position sensor, and a processor. The plunger cam is coupled to the cam shaft. The plunger-cam follower is configured to engage the plunger cam. The spring-biased plunger is coupled to the plunger-cam follower where expansion of the plunger cam along a radial angle intersecting the plunger-cam follower as the cam shaft rotates pushes the plunger cam to disengage the spring-biased plunger from the tube and a spring coupled to the spring-biased plunger biases the spring-biased plunger to apply the crushing force to the tube. The position sensor is operatively coupled to the spring-biased plunger and is configured to determine a position of the spring-biased plunger. The processor estimates fluid flow using the position.