Gas identification system and volumetrically correct gas delivery system
View Patent ↗A gas delivery system, having a gas identification, by which a gas supplied to the gas delivery system is identified, a blender, blending oxygen and the gas to provide a gas mixture with an oxygen flow rate set up by an operator, and at least one flow sensor, to measure a flow rate of the gas mixture. The blender is driven by an actuator motor to various blender positions with the blender positions being calibrated based on the specific heat ratio and the gas constant of the gas. The flow sensor can be installed at the inspiratory circuit, the proximal circuit and the expiratory circuit of the gas delivery system. The flow sensor output is corrected based on the actual conditions, including the temperature, pressure and humidity, and characteristics of the gas mixture.
1. A gas delivery system, comprising:
a gas identifier, by which a gas supplied to the gas delivery system is automatically identified;
a blender, blending oxygen and the gas to provide a gas mixture with a preselected oxygen flow rate;
an actuator, driving the blender into various blending positions according to the oxygen flow rate of the gas mixture, wherein the blending positions of the blender are corrected based on characteristics of the gas mixture; and
at least one flow sensor, to measure a flow rate of the gas mixture, wherein the flow sensor is corrected based on the characteristics of the gas mixture.
2. A ventilating system, comprising:
at least two gas inlets, with one inlet connected to an oxygen source and the other one connected to a gas source;
a gas identifier, attached to the gas inlet connected to the gas source to identify a gas supplied therefrom;
a blender, blending the oxygen and the gas into a mixture, wherein the blender is driven by an actuator into various positions according to a selected oxygen flow rate of the mixture, and the blender positions are calibrated based on the specific heat ratio and gas constant of the gas;
an inspiratory circuit, on which an inspiratory flow sensor is installed, wherein the inspiratory flow sensor is calibrated according to temperature, pressure and humidity in the inspiratory circuit, and a gas constant of the gas;
a proximal circuit, through which a patient inhales and exhales, on which a proximal flow sensor is installed, wherein the proximal flow sensor is calibrated according to temperature, pressure, and humidity in the proximal circuit, and a gas constant of the gas; and
an expiratory circuit, on which an expiratory flow sensor is installed, wherein the expiratory flow sensor is calibrated according to temperature, pressure and humidity in the expiratory circuit, and a gas constant of the gas.
3. The ventilating system according to claim 2 , wherein a flow control valve is installed at the inspiratory circuit to adjust the flow rate according to reading of the inspiratory flow sensor.
4. The ventilating system according to claim 2 , wherein the inspiratory flow sensor, the proximal flow sensor and the expiratory flow sensor are calibrated further according to viscosity when the flow rate drops under a certain magnitude.
5. The ventilating system according to claim 2 , wherein inspiratory flow sensor, the proximal flow sensor and the expiratory flow sensor are calibrated based on a reference volumetric flow calculated at a body temperature, a gas constant of air, and a barometric pressure.
6. The ventilating system according to claim 5 , wherein the reference volumetric flow is pre-stored in a calibration table.
7. The ventilating system according to claim 6 , wherein the reference volumetric flow is converted from a volumetric flow calculated at 21% of oxygen, ambient pressure and temperature.