| 摘要 |
<p>An anaesthetic vaporiser comprises an inlet for a carrier gas, an outlet for carrier gas and anaesthetic agent, and a pump for delivering a quantity of an anaesthetic agent into a stream of carrier gas, the pump comprising (a) a chamber having an inlet port (37), a reservoir port (32) and an outlet port (41); (b) a valve member (31) which can be moved between a first position in which anaesthetic agent can flow through the chamber between the inlet port and the reservoir port, and a second position in which the agent can flow through the chamber between the reservoir port and the outlet port; (c) a reservoir (38) connected to the reservoir port in which the agent can be retained prior to delivery, the reservoir being defined by an expandable body (33); and (d) a drive unit (34, 35, 36) by which the reservoir body can be expanded or contracted, to receive or to expel the agent respectively.</p> |
