Class: BE-310
Group: T6
Members: Richard Kiok, Jinwah Lau, Pear Musikabhumma, Jim Oh, Mark Phong
Date: May 4, 1998
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Abstract:
The accuracy comparison of cardiac output measurements between the thermodilution and the dye dilution method with application to atherosclerosis was evaluated in an in vitro model. For cardiac output determination of thermodilution, a Swan-Ganz Catheter with a thermistor was used. Evans Blue dye and Milton Roy Spectronic 20D spectrophotometer were used for dye dilution. Chilled dye was used as an injectate, which allowed its use for both thermodilution and dye dilution simultaneously. LabVIEW recorded the changes in temperature and concentration. Actual flow rates were obtained by collecting the flow and timing it with a stopwatch at the output. Flow rates ranged from 0.89 ml/s to 1.442 ml/s. Totals of 7 sets of 7 measurements at known flow rates were made. At high flow rate (1.314 to 1.442 ml/s), accuracy of 26.04 % error for thermodilution and 94.59 % error for dye dilution were achieved. For medium flow rates (1.270 to 1.412 ml/s) accuracy of 26.89% error for thermodilution and 94.64% error for dye dilution. For slow flow rate (0.89 to 1.270ml/s), 117.91% error and 89.59 % error respectively. In addition, two different data analysis were used and compared for thermodilution. Triangular area and the logarithmic area were calculated as areas under the temperature vs. time curve. Overall, the experiments were reproducible. Thermodilution was found to be more accurate over fast and medium flow rates, but dye dilution showed the most accurate results for slow flow rate.