DETECTING OCCLUSION OF PROXIMAL OR DISTAL LINES OF AN IV PUMP

摘要

2113474 9304284 PCTABS00020 A volumetric pump (30) includes a motor (146) that rotatably drives a cam assembly (142), which actuates a plunger (48), causing it to compress a pumping portion (34b) of a flexible tubing (34). Compression of the tubing displaces fluid trapped within the pumping portion, causing it to flow past an outlet cracking valve (52). A proximal pressure sensor (44) and a distal pressure sensor (56) each produce signals indicative of the pressure within the proximal portion and distal portion of the flexible tubing, which are used to determine whether a proximal or distal occlusion of the flexible tubing has occurred. Both pressure sensors comprise strain gauges connected to flexures that apply a spring-biased force against the proximal and distal portions of the flexible tubing. These sensors thereby respond to the cross-sectional size (diameter) of the tubing, as affected by fluid pressure therein. Proximal and distal pressures are thus monitored without violating the integrity of the flexible tubing.