Reconstruction of MRI images into 3D models: Problems pitfalls and solutions

A peristaltic type pump comprises a reciprocating pumping element which alternately pinches and releases a flexible-walled tube, and, on either side of the pumping element, reciprocating inlet and outlet closure elements respectively. When the pumping element pinches the tube during a pumping stroke the inlet closure element pinches the tube to close it while the outlet closure member releases the tube, and during induction strokes, as the pumping element releases the tube, the inlet closure element is open, while the outlet element is closed. Synchronised operation of the elements is conveniently effected by respective cams.