Preliminary in vitro hemolysis evaluation of MR-conditional blood pumps

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Medical Imaging

Background:

• Conventional heart-lung machines are incompatible with Magnetic Resonance Imaging (MRI) due to metallic components.
• This incompatibility limits the use of MRI during cardiopulmonary bypass procedures, particularly in neonatal surgery.
• Developing MR-conditional blood pumps is crucial for enabling advanced imaging during critical cardiac interventions.

Purpose of the Study:

• To evaluate the hemolytic performance of three MR-conditional blood pump prototypes: roller, non-occlusive roller, and centrifugal.
• To assess the suitability of these pumps for use during neonatal surgery requiring cardiopulmonary bypass.
• To identify the pump with the most favorable hemolysis profile for MRI-guided procedures.

Main Methods:

• Three MR-conditional blood pump prototypes (roller, non-occlusive roller, centrifugal) were tested.
• Experiments used bovine blood stabilized with acid-citrate dextrose at a neonatal-relevant flow rate of 1 L/min.
• Hemolysis was quantified using the normalized index of hemolysis, with analysis accounting for experimental variability via a linear mixed-effects model.

Main Results:

• The roller pump exhibited the lowest hemolysis (1.84 ± 1.90 mg/100 L).
• The centrifugal pump demonstrated the highest hemolysis (8.43 ± 1.63 mg/100 L) and experienced mechanical leakage.
• Inter-experimental variability was moderate, with a standard deviation of 2.07.

Conclusions:

• All tested prototypes showed comparable performance to standard references under controlled, low-pressure conditions.
• Further validation is required at physiological pressure levels to fully assess pump performance.
• Adherence to ASTM F1841 standards is necessary for broader clinical applicability of these MR-conditional blood pumps.