Fluid pressure actuated blood pumping systems and methods with continuous inflow and pulsatile outflow conditions

Abstract

Blood processing systems and related methods place first and second fluid pressure actuated pump stations in in-line communication between a source and a destination. The systems and methods apply fluid pressure pump strokes to the first and second pump stations to convey fluid from the source to the destination. The systems and methods switch between a first flow mode and a second flow mode. In the first flow mode, the pump strokes draw a fluid volume into the first pump station from the source and expel a fluid volume from the second pump station to the destination. In the second flow mode, the pump strokes draw a fluid volume into the second pump station from the source and expel a fluid volume from the first pump station to the destination. The systems and methods synchronize the pump strokes so that fluid flow from the source is essentially continuous while fluid flow to the destination is pulsatile.

1 . A blood processing system comprising 
 a filter for removing leukocytes from blood,    first and second fluid pressure actuated pump stations, and    a fluid pressure actuator operating to selectively apply fluid pressure pump strokes in tandem to the first and second pump stations to convey fluid from a source to the filter, the fluid pressure actuator including a control function to switch between a first flow mode, in which the pump strokes draw a fluid volume into the first pump station from the source and expel a fluid volume from the second pump station to the filter, and a second flow mode, in which the pump strokes draw a fluid volume into the second pump station from the source and expel a fluid volume from the first pump station to the filter, the control function operating to synchronize the pump strokes so that fluid flow from the source is essentially continuous while fluid flow to the filter is pulsatile.    
   
   
       2 . A system according to  claim 1   wherein the source comprises a blood collection container.    
   
   
       3 . A system according to  claim 2   wherein the blood collection container receives blood from a blood separation device.    
   
   
       4 . A system according to  claim 1   wherein the first and second fluid pressure actuated pump stations apply positive and negative fluid pressure.    
   
   
       5 . A system according to  claim 1   wherein the first and second fluid pressure actuated pump stations apply positive and negative pneumatic pressure.    
   
   
       6 . A system according to  claim 1   wherein the filter communicates with a blood collection container located in a downstream flow direction to receive blood after passage through the filter.