Abstract:
This paper aims to establish a block-structured model to predict oxygen uptake in humans during
moderate treadmill exercises. To model the steady state relationship between oxygen uptake (oxygen
consumption) and walking speed, six healthy male subjects walked on a motor driven treadmill with
constant speed from 2 to 7 kilometer/hour. The averaged oxygen uptake at steady state (V O2) was
measured by a mixing chamber based gas analysis and ventilation measurement system (AEI Moxus
Metabolic Cart). Based on these reliable date, a nonlinear steady state relationship was successfully
established using Support Vector Regression methods. In order to capture the dynamics of oxygen
uptake, the treadmill velocity was modulated using a Pseudo Random Binary Signal (PRBS) input.
Breath by breath analysis of all subjects was performed. An ARX model was developed to accurately
reproduce the measured oxygen uptake dynamics within the aerobic range. Finally, a Hammerstein
model was developed, which may be useful for implementing a control system for the regulation of
oxygen uptake during treadmill exercises.
