periods c and d again during the terminal portion of period c the ab and rc motions tend to be finely paradoxical for example at the time indicated by line 153 the rc volume near a local maximum and the ab volume near a local minimum in contrast at the beginning and throughout period d the ab and rc motions tend to be coincidence for example at the time indicated by line 155 both the ab and rc volume near local maxima fig8 c also illustrates further measures that can be use to quantitatively characterize to above described characteristic of periods of emesis the series of values labeled as vivolrc is the inspiratory rc volume that is the volume difference between beginning and end inspiration these values indicate period c by decreased volumes they indicate period d by increased volumes and they indicate the transition between these periods by a transition between decreased and increased volumes occurring within one to two up to five breaths the series of values trace labeled as vivolab is the similarly defined inspiratory ab volume conversely these values indicate period c by increased volumes they indicate period d by decreased volumes and they indicate the transition between these periods by a transition between increased and decreased volumes occurring within two to three up to six breaths the trace labeled as svivolrc is a running average of the median of vivolrc values over 12 sec window this trace reflects the vivolrc values and is characteristically depressed in period c characteristically elevated in period d and characteristically increasing through the transition between periods c and d by a decrease at a rate reflecting the effects of averaging and taking the median similarly the trace.