A method of controlling a fluid level in an arterial drip chamber (123) and/or venous drip chamber (125), comprising: selectively activating or deactivating one or more valves in a pneumatic manifold (101), while a blood pump (127) is operating said pneumatic manifold (101), comprising: an internal conduit (102)； a first fluid line (121) fluidly connected to the internal conduit (102)； the first fluid line (121) fluidly connectable to a venous drip chamber (125) in an extracorporeal circuit of a dialysis system； a second fluid line (120) fluidly connected to the internal conduit (102)； the second fluid line (120) fluidly connectable to an arterial drip chamber (123) in the extracorporeal circuit of the dialysis system； a venous valve (104) fluidly connecting the first fluid line (121) to the internal conduit (102)； an arterial valve (103) fluidly connecting the second fluid line (120) to the internal conduit (102)； a negative valve (106) fluidly connecting the internal conduit (102) to an outlet (109)； a positive valve (105) fluidly connecting the internal conduit (102) to an inlet (110)； the inlet (110) and outlet (109) fluidly connectable by a third fluid line containing a pump (108)； and a controller selectively activating or deactivating the venous valve (104), arterial valve (103), positive valve (105), and negative valve (106)； the controller controlling a fluid level in the venous drip chamber (125) and arterial drip chamber (123) by activating or deactivating the valves, wherein said blood pump (127) is a pulsatile pump configured to move blood through the extracorporeal circuit.
