A THEORETICAL-STUDY OF THE ROBUSTNESS OF THE ISOVOLUME CALIBRATION METHOD FOR A 2-COMPARTMENT MODEL OF BREATHING, BASED ON AN ANALYSIS OF THE CONNECTED CYLINDERS MODEL

The use of the isovolume manoeuvre method as a calibration technique f or respiratory monitoring instrumentation that detects the movement of the ribcage and the abdominal wall is analysed based on a model of tw o connected cylinders whose radii and heights may vary, and evidence i s presented which suggests that this calibration method is robust in m ost circumstances. Some possible functional forms relating the variati ons in cylinder radius and height are examined, and methods for obtain ing calibration constants based on these functional forms, purely from measurements of variations in the cylinder radius, are presented.