Noninvasive monitoring of transient cardiac changes with impedance cardiography

Cardiac impedance change is important in the noninvasive evaluation of stroke volume. Its transient change during postural motion has not been extensively explored. We designed an impedance cardiography device to monitor the continuous change of the cardiac impedance during motion of the upper body. The results showed a significant increase in relative impedance levels from supine to transient state and then decreased during the upright position. Additionally, the supine position had a higher (dZ/dt)_max than sitting, resulting in a reduction in stroke volume