Apparatus and method for the autotransfusion of blood

An autotransfusion system to remove particulate refuse and clean blood cells for return to a patient which comprises:

• means for salvaging a blood mixture from a patient;
• a filter assembly in fluid communication with said salvaging means, said filter assembly having a first membrane and defining a first filtration zone, having a second membrane and defining a second filtration zone, where said first and second membranes are selected to allow the forced infiltration of fluids in the blood mixture, under pressure into a discharge chamber, while passing the red blood cells within the filtration zones;
• means for injecting after said first filtration zone a pressurized flow of a washing solution into said red blood cells which defines a washing zone;
• means for pressurizing the filtration zones of said filter assembly wherein at least a portion of the fluids in the blood are forced through said membranes;
• a partition which partially bounds and separates said filtration zones and sequentially channels the flow of filtered blood through the first filtration zone, the washing zone, and the second filtration zone,
• means in fluid communication with filtration zones for removing the filtrate from said filter assembly;
• and
• means in fluids communication with the second filtration zone for returning clean red blood cells to the patient.

A filter assembly, comprising:

• a first plate which includes:
• an inlet port for receiving blood;
• a first membrane adjacent said inlet port, said membrane selected to allow the infiltration of refuse and prevent the infiltration of cells as the filtered blood flows across said first membrane;
• and
• a first discharge chamber adjacent said first membrane for receiving the filtrate;
• a second plate attached on the perimeter to said first plate to create an interior space which includes:
• an outlet port for the removal of the filtered and washed cells;
• a second membrane selected to allow the infiltration of washing solution and, residual blood fluids and prevent the infiltration of cells flowing across said second membrane;
• a second discharge chamber adjacent said second membrane for receiving the filtrate;
• a partition dividing said interior space between said plates creating a first filtration zone and a second filtration zone and a washing zone intermediate the filtration zones proximate the edge of said partition;
• and
• an injection manifold about the perimeter of said plates external said membranes which receives pressurized washing solution for injection into a washing zone for filtered cells, said manifold having a plurality of injection ports to provide fluid communication between said injection manifold and washing zone for receiving washing solution.

An apparatus for autotransfusion from a surgical patient, comprising:

• means for continuously receiving a mixture of blood cells, liquid, and particulate refuse from a patient;
• a filtration unit capable of removing at least a portion of the liquid from the mixture comprising:
• (i) a disc-shaped body having a saucer shaped top and bottom, an inlet port in said bottom and an outlet port in said top, an annular cavity in said bottom and top, each covered by a membrane and defining a first and second filtration zone, respectively, to receive filtrate passing through said membranes and an injection port for washing solution located on said body after the first filtration zone;
• and
• (ii) a rotatable disc interposed within said disc-shaped body separating the first and second filtration zones;
• and
• (iii) means for removing the concentrated red blood cells through the outlet port from said filtration unit for return to the patient.