PRECISION MICROPROCESSOR CONTROLLED GAS MIXER

本项目的目标是建立和评估一个精确的， 微处理器控制的气体混合器。 混合器将以 恒定流量，最多可控制四种组分的浓度 气. 混合器的设计是基于质量流量与 具有固定面积和排放的孔板上的压差 系数 对于每个气体通道（总共四个通道），气体流量为 通过测量经过校准的 孔。 实际流量被反馈到微处理器，并与 操作员输入的所需输出浓度。 更正 通过重新定位步进电机驱动的气流， 控制阀 校正因子存储在微处理器中， 可精确控制各种气体。 第一阶段将解决 设计的可行性和研究应用于各种医疗和 麻醉问题

The objective of this project is to build and evaluate a precision, microprocessor controlled gas mixer. The mixer will provide gas at a constant flowrate with a controlled concentration of up to four component gases. The mixer design is based on the relationship of mass flow to differential pressure across an orifice with fixed area and discharge coefficient. For each gas channel (total of four channels) gas flow is monitored by measuring the differential pressure across a calibrated orifice. The actual flow is fed back to the microprocessor and compared to the desired output concentrations inputed by the operator. Corrections in gas flow are obtained by repositioning the stepper motor driven flow control valve. Correction factors are stored in the microprocessor to allow accurate control of a wide variety of gases. Phase I will address design feasibility and investigate application to various medical and anesthesiological problems.