Hemolysis test of disposable type vibrating flow pump.

Abstract

The vibrating flow pump (VFP) can generate high frequency oscillated blood flow. Because of the high frequency driving with short stroke volume, the pump system can be small. The disposable type VFP (D-VFP) was developed for use for extracorporeal circulation. The electromagnetic actuator was detached from the vibrating tube, which was newly designed to be a disposable tube with a jellyfish valve. Hemolysis tests of the D-VFP, VFP, centrifugal pump, and roller pump were performed in a mock circulation study using goat blood. Plasma free hemoglobin was measured every 15 min under the same conditions. The plasma free hemoglobin of the D-VFP was 16 mg/dl although that of the VFP was 160 mg/dl at 30 min. The plasma free hemoglobin of the centrifugal pump and roller pump at 30 min were 3 mg/dl and 9 mg/dl, respectively. The hemolysis performance of the D-VFP may be studied further as a result of this study. Two important factors affecting hemolysis development may be the materials of which the vibrating tube is made and heat transmission from the actuator. The D-VFP has a smooth acrylic surface for blood contact compared with the metal surface of old type VFP. The electromagnetic actuator of the VFP surrounded the vibrating tube, so heat from the actuator could be easily transmitted to the blood. Because the D-VFP has a disposable vibrating tube that is detached from the actuator, heat is not readily transmitted to the blood. A mock circulation study of heat transmission was performed using the D-VFP and VFP. Results of the heat transmission study showed that the fluid temperature of the D-VFP was not increased and stayed at room temperature although that of the VFP increased approximately 1 degree C above room temperature. The D-VFP may be a good style for the development of the VFP for use for extracorporeal circulation.