Abstract: A method and apparatus detect occlusion in a tube to a passage into a body cavity. An argon gas supply output received by plural selectable flow orifices so one or more of the orifices delivers predetermined metered gas. A duct with a volume of gas selectively provides metered gas to the passage. The tube connects the passage and the duct periodically so a duct pressure transducer can signal. A circuit tests signals of tube equalization with a back pressure. A three way valve controlled by the circuit connects the duct transducer to gas metered to the cavity. The valve alternatively connects the duct transducer to the tube to equalize the tube with metered gas to the back pressure. A monitor of the signals determines the rate of pressure change after the valve connection. The monitor indicates pressure equalization after a timed interval with a timer to establish intervals for checking back pressure.

Abstract: A medical insufflator has a flexible tube having a downstream end provided with a needle and an upstream end, the tube and needle forming an insufflation flow path for a neutral gas into a surgical cavity into which the needle is inserted, a supply of the neutral gas under pressure connected to the upstream end, and a flow-control valve along the flow path at the upstream end.