Peristaltic liquid pump for medical use - has recess in hose to provide minimum free area(BE070177)

摘要

The pump has a flexible hose (1) which is periodically compressed between rollers and released to vary the internal volume and thus propel liquid through it. A semi-circular recess (3) is cut longitudinally on the inside of the hose at one part of the cross section. Because of this at least the cross section of the recess is left open even when the rollers fully compress the hose. There is thus a minimum free area left through which air entrained in the liquid is free to flow back to an air vent and this area is maintained at all rates of pumping and delivery pressures. This provides the safety required of blood pumps used during certain surgical operations.