PURPOSE Impacts on hemolysis and backflow using a non-occlusive setting with the Better-Header (BH) roller pump were investigated. METHODS AND RESULTS Pump flow of a non-occlusion setting was measured with a pump speed of 3 L/min and 5 L/min against various after-loads. With the non-occlusive setting (BH-NO350), backflow was less than 10% if the pump pressure head was <300 mmHg. When the outlet line is occluded, 80% of the set flow was shunted through the pressure relief valve and outlet pressure did not develop hazardous overpressure. During surgery with the BH-NO350, flow loss was <5% while the pump pressure was maintained at approximately 200 mmHg. An in vitro hemolysis test was conducted at 5 L/min against 350 mmHg, using the standard occlusion (BH-SO), the non-occlusion (BH-NO350), and the centrifugal pump (CP). The CP demonstrated less hemolysis than the other two groups; the BH-SO and the BH-NO350 had similar hemolytic characteristics. During cardiopulmonary bypass, no significant differences in hemolysis were seen among the BH-SO, the BH-NO350, and the CP. CONCLUSION Possible flow loss of the non-occlusion setting with the BH should be almost negligible in most clinical situations. The BH-NO350 demonstrated hemolytic characteristics similar to those of the BH-SO, but not as good as those of the CP.