VENTILATOR SYSTEM

摘要

A portable mechanical ventilator (10) uses a constant-speed compressor (20) and a recirculating bypass circuit. Bypass flow is governed by a spring-biased bypass valve (26) so connected to both the inlet and the outlet of the main flow control valve (12) as to maintain a differential pressure across the flow valve (12) sufficient to operate the ventilator (10) with minimal energy consumption. The flow valve (12) is operated by a microprocessor (82) in accordance with empirically derived lookup tables to both produce the desired air flow and provide a measure of that air flow.