| 摘要 |
An apparatus conserves oxygen delivered from a supply (28) to a patient through a cannula (44) by providing oxygen delivery selectively in accordance with the physiological requirements and current breathing pattern of the patient. Oxygen flow is set at a prescribed flow rate from the supply by a regulator (30). An oxygen conserving unit (38) includes a controller (64) that operates responsive to timed relationships among pressure signals determined by a fuzzy logic program to deliver oxygen to the patient by opening a valve (72) when a sensed pressure in the patient's nasal passage reaches a threshold level and when the controller determines that the reaching of the threshold is indicative of an inhalation cycle. The controller is further operative to adjust the time period that oxygen is delivered to the patient in accordance with a programmed relation to meet the dynamically changing needs of the patient. The apparatus further includes features which provide fast response, conservation of the energy from a battery power source (86) and both visual and audio indicators (54, 56) to provide indications of alert and alarm conditions. The apparatus further provides control by the user through a single manually actuated switch (52), and mechanical interconnection with the switch and valve to assure continuous flow when the switch is set to a continuous flow setting. |
