Mechanism for control pulsatile fluid flow

Claim 1

In an organ perfusion apparatus for passing fluid in a conduit through an organ in a container including pump means for providing a pulsatile pressure to cause flow of fluid in said conduit, in which said pump means comprises a cylinder containing an elastic tube positioned axially therein, means for sealing the interior of said tube from the exterior thereof to define a sealed flow path for fluid to be pumped, and inlet and outlet means to allow said fluid to pass through the tube, said inlet and outlet means each containing a one-way valve to prevent backflow of fluid, said cylinder defining an entrance port to receive fluid within the cylinder and outside said tube from first oscillatory pressure providing means, to actuate said pulsatile pressure providing means by repeatedly collapsing said tube and permitting it to expand again by application of oscillatory pressure, in which a portion of said conduit defines an atrium space of enlarged transverse dimension, said atrium space being located directly upstream of and extending to said inlet means of the pump means, in which said atrium space is surrounded by a second sealed sleeve to define a second pressurizable space about said portion of conduit, and in which said second sleeve has second means for pressurizing said second space with oscillatory pressure which is out of phase from the oscillatory pressure provided by said first oscillatory pressure providing means, so that when the elastic tube of the pump means is in its filling phase, the portion of conduit defining said atrium space is in its collapsing phase to provide pressurized fluid to said inlet means, for greater pumping efficiency.