Coordination Versus Pressure in Oesophageal Peristalsis

High Resolution Manometry (HRM) is a new advance in oesophageal measurement that permits the acquisition of pressure data through the entire length of the oesophagus over time via closely spaced sensors that continuously record the motor activity of the oesophagus. This allows not only contractile pressure to be measured, but also the coordination (proximal-distal) of contractions and the development of effective intra-bolus pressure (the force that drives bolus movement). The study hypothesis is that (1) there will be a progressive increase in peristaltic pressure and decrease in velocity as the subjects move from the upright, through the supine to the upside down position and (2) the increase in pressure will be most evident in the mid-oesophagus at the transition zone between the striated and the smooth muscle contractions.