Cou1

{"type":"CredibilityFactor","factorType":"Software quality assurance","requiredLevel":1,"achievedLevel":1,"factorStatus":"assessed","acceptanceCriteria":"Goal (a): commercial CFD solver commonly used by industry and academia for blood pump evaluation. No major SQA issues previously reported. User may reference SQA documentation provided by code developer. [Morrison Table 3, COU1]","rationale":"ANSYS CFX v15.0 is widely used for centrifugal blood pump CFD. SQA documentation available from vendor. Low model influence for COU1 justifies minimal SQA rigor.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Numerical code verification","requiredLevel":3,"achievedLevel":3,"factorStatus":"assessed","acceptanceCriteria":"Goal (c): numerical solution compared to an accurate benchmark analytical solution. Comparison against Hariharan et al. verification benchmarks for the Eulerian power-law hemolysis model is mandatory due to previously reported user implementation errors. [Morrison Table 3, COU1]","rationale":"Eulerian HI model benchmarked against analytical solutions from Hariharan et al. (2015). Previous literature reported user error in implementing Eulerian hemolysis models, making benchmark comparison necessary.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Discretization error","requiredLevel":3,"achievedLevel":3,"factorStatus":"assessed","acceptanceCriteria":"Goal (c): grid convergence performed, conservation equation balances checked, no estimation of discretization error required. Grid convergence essential because hemolysis occurs in high shear regions and shear stress estimations are grid-sensitive. [Morrison Table 3, COU1]","rationale":"Three mesh densities evaluated. Velocity and hemolysis index predictions changed by less than 1% with mesh refinement. Conservation equation balances verified.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Test conditions","requiredLevel":2,"achievedLevel":2,"factorStatus":"assessed","acceptanceCriteria":"Goal (b): key characteristics of test conditions measured — flow rate, impeller rotational speed, viscosity and density of blood or blood-analog fluid. Experiments repeated five times per operating condition to quantify uncertainties. [Morrison Table 4, COU1]","rationale":"Flow rate measured via calibrated ultrasound flow meter. Impeller speed measured via tachometer. Fluid viscosity and density measured before every experiment via rheometer and densitometer. Five repeats per condition.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Output comparison","requiredLevel":2,"achievedLevel":2,"factorStatus":"assessed","acceptanceCriteria":"Quantity goal (b): two outputs compared — velocity and relative hemolysis (RH). Rigor goal (c): experimental uncertainty quantified and used in comparison; CFD uncertainty quantification not required for COU1 (model influence Low). Agreement goal (b): difference between CFD and experimental RH small relative to safety threshold (RH < 1). [Morrison Table 4, COU1]","rationale":"Velocity comparison: CFD peak velocity matched PIV data within ~15%. Hemolysis comparison: CFD predicted RH fivefold lower than safety threshold at validation point, so ~40% model error still acceptable.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Relevance of the quantities of interest","requiredLevel":2,"achievedLevel":2,"factorStatus":"assessed","acceptanceCriteria":"Hemolysis is directly applicable to the question of interest. Relative hemolysis (RH) is an acceptable validation metric — measures hemolysis relative to a predicate device threshold. [Morrison Results, COU1 Applicability]","rationale":"RH compares subject device hemolysis to commercially available predicate device. RH < 1 means subject device causes less hemolysis than predicate. Directly addresses the question of interest.","factorStandard":"ASME-VV40-2018"}

{"type":"CredibilityFactor","factorType":"Relevance of the validation activities to the COU","requiredLevel":2,"achievedLevel":2,"factorStatus":"assessed","acceptanceCriteria":"Goal (b): partial overlap between validation points and COU conditions. Since model influence is Low (COU1), partial overlap is acceptable — validation point (condition 1) lies within the COU operating range. [Morrison Table 4, COU1]","rationale":"Validation at condition 1 (2.5 lpm, 2500 rpm) lies within the COU operating range. Model used to identify worst-case conditions, which are then confirmed by in vitro testing. Partial overlap sufficient because model influence is Low.","factorStandard":"ASME-VV40-2018"}

{"@value":"1.00","@type":"xsd:decimal"}

{"@value":"0.71","@type":"xsd:decimal"}

{"@value":"0.60","@type":"xsd:decimal"}

{"@value":"0.50","@type":"xsd:decimal"}

{"@value":"0.0","@type":"xsd:decimal"}