An automatic syringe for coronary occlusion in long-term collateralization studies.

A portable apparatus for performing repeated, brief coronary artery occlusions automatically in long-term chronic studies involving dogs and larger animals is described. The battery-operated, back-pack-carried device uses a motorized syringe driven by a digital-programmable timing circuit to inflate a coronary artery occluder for durations of 10 s to 3 min at intervals from 14 s to 16 h. A single battery charge produces 450 occlusions. The generated pressure is adjustable to 1,000 mmHg maximum. A separate fail-safe circuit monitors system operation to open a pressure-relief valve if occlusions exceed a preset duration.