Auxiliary device for calibration of roller pumps: development and experimental results.
BACKGROUND
Roller pumps are commonly used in surgeries involving extracorporeal circulation and its regulation may influence the hemolysis rate.


OBJECTIVE
To describe an auxiliary device for adjusting roller pumps using the dynamic calibration method and show preliminary results of its application in surgical procedures.


METHODS
The device was tested in the laboratory environment with three disposable pressure transducers normally used in surgeries. In the operation room, tests were carried out with two groups of patients. Free hemoglobin plasma rates were measured, 5 minutes after perfusion started and immediately before the passage of the residual volume of the pump. For Group 1 (n = 22), occlusion measurements were carried out using the drop rate method and for Group 2 (n = 18), measurements were carried out using the auxiliary device and 300 mmHg calibration (mean pressure for the dynamic calibration method).


RESULTS
The auxiliary calibration device has shown calibration results statistically equal to those obtained with a reference device in the laboratory environment. We have found less variability of hemolysis rates in the operating room, using the auxiliary device and we did not observe any influence of unbalanced rollers in the hemolysis rates.
Center for Biomedical Engineering, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil. ubaldo@ceb.unicamp.br
F U
FU
Vieira
J
J
Dantas de Medeiros
N
N
Antunes
R W
RW
Vieira
E T
ET
Costa
D002138:Calibration; D002315:Cardiopulmonary Bypass / Q000295:instrumentation*; D004867:Equipment Design; D005112:Extracorporeal Circulation / Q000295:instrumentation*; D005260:Female; D006461:Hemolysis; D006801:Humans; D008297:Male; D008875:Middle Aged