Continuous monitoring of lung ventilation with electrical impedance tomography

An electrical impedance imaging system has been applied to the non-invasive measurement of lung ventilation. The system uses a simple calibration procedure and by means of a fast reconstrucion algorithm allows real-time monitoring of lung volume at a rate of 8 frames s⁻¹. The performance of the system was assessed on five subjects during exercise on a bicycle ergometer, minute ventilation ranged from 10 to 86 1 min⁻¹. Although there was an underestimation in volume at high levels of ventilation, overall the mean volume error was less than 1% (SO 8.2%) range −17.6% to 20.6%. This is comparable with other non-invasive techniques for monitoring lung ventilation.