Detection of ventilatory threshold by an automatic parabolic model

This work aims at presenting a method for automatic detection of the ventilatory threshold by modeling ventilatory equivalent of oxygen by a parabolic function. Thirty healthy male subjects were submitted to a single maximal oxygen uptake test, being monitored the ventilatory gas exchange signals. Ventilatory threshold by visual inspection, automatic v-slope and parabolic function methods was compared. The automatic methods showed no significant differences with visual inspection, but the parabolic technique presented higher consistence than v-slope. Since the parabolic method have low computation cost and is a simple method, it can be recommended as an alternative choice to v-slope method.