Abstract:
A mathematical model, based on our previous
pulsatile nonlinear multi-element cardiovascular model, was
tested and improved to study cardiovascular response under
graded exercise levels. Ten healthy subjects were studied
using cycle-ergometry exercise test with constant workloads
ranging from 25 Watt to 125 Watt. Breath by breath gas
exchange, heart rate, cardiac output, stroke volume and
blood pressure were measured at each stage. Based on the
experimental data, firstly we proved that our previous model
is capable to regenerate the cardiovascular variables
observed in the subjects under different exercise levels.
Secondly, we improved the model by incorporating a robust
and efficient function to estimate metabolic demand. Then
the new model can estimate both cardiovascular variables
and metabolic demand with its simulation results within the
range of SD (Standard Deviation, N=10) of the experimental
data.
