| 摘要 |
<p>An injection device (200) for use in injecting a fluid into a target location comprises a housing (202) defining an inlet (204) for communicating with a source of injection fluid, an outlet (206) for communicating with a target injection location, and a separate reference port (208) for communicating with a reference pressure source. The device (200) also includes first and second valve members (216, 218) mounted within the housing (202), wherein the second valve member (218) defines a flow path (220) therethrough to facilitate fluid communication between the inlet (204) and outlet (206) of the housing (202). A sealing arrangement (222) is provided between the second valve member (218) and the housing (202) and is configured such that fluid pressure at the housing inlet (204) and housing reference port (208) apply a force on the second valve member (218) to cause said second valve member (218) to move relative to the first valve member (216) and vary flow between the inlet and the outlet (204, 206)</p> |
