14781-koppen

184 Chapter 8 have met the definition for HAPCs if we had measured a longer segment of the colon. In one child with this type of propagating contraction, no HAPCs were observed according to our preset definition of HAPCs. Solid state catheter Water perfused catheter Transverse Colon Transverse Colon Descending Colon Descending Colon Sigmoid Colon Sigmoid Colon Pre-meal Post-meal minutes/cycle cycles/minute minutes/cycle cycles/minute FIGURE 1. The left and center images display dominant frequencies of contractile activity recorded prior to and after a meal in the proximal colon (ascending and transverse colon), the descending colon and the sigmoid colon. X-axis: the frequency of pressure waves in each region from 1 every 16 min to 16 per min. Y-axis: the amplitudes from the global wavelet spectrum. The shaded regions (magenta = water perfused; grey = solid state) represent the bootstrap 95% confidence intervals for the mean. The width of the shaded regions overlap indicating there is no difference between the two groups.