Measurement of ejection fraction with standard thermodilution catheters.
Right ventricle ejection fraction (RVEF) is clinically used to evaluate right ventricular function. The thermodilution method can be modified to estimate the RVEF. However, this method requires a thermistor with a fast time response in order to yield correct estimates. Digital signal processing techniques that were developed in previous works, allow the use of industry-standard slow time response thermistors for the measurement EF. However, these algorithms were not automated, and the works did not present a complete evaluation of the method's performance. This article presents a modified automated version of these algorithms, and uses numerical and in vitro simulations to test their performance. In the simulations, the measured ejection fraction was compared to the true ejection fraction. RVEFs ranging from 0.20 to 0.80 were tested for heart rates ranging from 30 to 120 heart beats per min. Statistical analysis of data showed that the new method presents an improved performance.
dos Santos
Icaro
I
University of Texas at Austin, Biomedical Engineering Program, ENS 610, Austin, TX 78712, USA.
Ferreira da Rocha
Adson
A
Assis de O Nascimento
Francisco
F
Souza Neto
Joao
J
Valvano
Jonathan W
JW
D000465:Algorithms; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods; D003198:Computer Simulation; D004867:Equipment Design; D006801:Humans; D008955:Models, Cardiovascular; D016571:Neural Networks, Computer; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D013696:Temperature; D013815:Thermodilution / Q000295:instrumentation / Q000379:methods*; D014159:Transducers