| 摘要 |
A medical dosing device/method for providing small discrete volumes of gas, for example sulfur hexa fluoride or nitric oxide, to the breathing gases of a patient. The device includes a charging valve interposed between a gas supply and a dosing chamber. A discharge valve is connected between the dosing chamber and an outlet of the device. The dosing chamber has a pressure sensor connected to a control means for the valves. In operation, the control means closes the discharge valve and opens the charging valve until a predetermined pressure is sensed in the dosing chamber. The charging valve is closed and thereafter the discharge valve is opened to supply gas from the dosing chamber until the pressure sensed by the pressure sensor falls to a second, lower level. The discharge valve is then closed. The gas so discharged forms the volume of gas.
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