A ventilator gas ratio control method and device

Abstract

A method and a device for controlling the gas ratio of a breathing machine. The method comprises: a: acquiring an opening-flow rate relationship of an air ratio valve and an oxygen ratio valve of the breathing machine; b: controlling the air ratio valve and the oxygen ratio valve according to the opening-flow rate relationships and a preset oxygen concentration value; and c: fine-tuning the air ratio valve and the oxygen ratio valve according to a current oxygen concentration value and the preset oxygen concentration value. The control device comprises: an acquisition module (401), configured to acquire the opening-flow rate relationship of an air ratio valve and an oxygen ratio valve of the breathing machine; a control module (403), configured to control the air ratio valve and the oxygen ratio valve; and a fine-tuning module (405), configured to fine-tune the air ratio valve and the oxygen ratio valve. Through the method and the device, the oxygen concentration of the gas can be monitored in real time, so as to perform double loop control on the oxygen concentration, so that the oxygen concentration of the provided gas is the same as the set oxygen concentration, thereby improving the accuracy of oxygen mixture control.

Description

technical field [0001] The invention belongs to the field of medical equipment, and relates to a method and a device for controlling the gas ratio of a ventilator. Background technique [0002] The ventilator needs to provide air with adjustable oxygen concentration according to the needs of users. For the pneumatic and electronically controlled ventilator realized by double proportional valves, if oxygen mixing is required, two proportional valves need to be opened at the same time, and the opening of the two proportional valves The temperature and opening time directly affect the oxygen concentration of the output gas. Since the opening degree and flow rate curve of the proportional valve are changed by the pressure of the gas source, the gas oxygen concentration control given by the double proportional valve ventilation will deviate. In addition, the minimum flow rate that the proportional valve can give is determined by the proportional valve itself. Due to the characte...

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Problems solved by technology

Since the opening degree and flow rate curve of the proportional valve are changed by the pressure of the gas source, the gas oxygen concentration control given by the double proportional valve ventilation will deviate. In addition, the minimum flow rate that the proportional valve can give is determined by the proportional valve itself. Determined by the characteristics, when the proportional valve cannot give the required flow rate, the oxygen concentration control of the gas given by the double proportional valve ventilation will deviate

In the prior art, the oxygen concentration sensor is generally used for monitoring the oxygen concentration sensor, and the oxygen concentration sensor will drift, and the sensor needs to be calibrated frequently, otherwise, the monitoring will be deviated, affecting the clinical use effect, and even misleading the operator

[0003] In the prior art, no effective solution has been given for the above-mentioned problem of oxygen concentration offset

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