| 摘要 |
FLOW SENSOR Abstract A bi-directional flow sensor (10) is adapted for reducing pneumatic noise during 5 pressure sensing with a flow passing through the flow sensor (10). The flow sensor (10) comprises a hollow, tubular member (18) having a throat section (36) disposed between a ventilator end (24) and a patient end (26). A flow restrictor (38) is disposed in the throat section (36) and is adapted to measure differential pressure in the flow. A baffle (56) is mounted at the ventilator end (24) and is adapted to minimize non-axial flow at pressure i0 taps (44a, 44b) located on opposing ends of the flow restrictor (38). The patient end (26) includes a flow obstruction (64) configured to promote uniform velocity across the flow at the pressure taps (44a, 44b) during exhalation flow from the patient end (26) to the ventilator end (24). The flow sensor (10) minimizes pneumatic noise to less than 0.1 LPM to allow accurate patient flow measurement and triggering of inhalation and exhalation is phases at flow rates of 0.2 LPM. Fig. 3 |
