The above plot was generated by monitoring the resistivity changes in a region of interest representing the stomach. To define this region of interest the stomach image with the maximum change in resistivity was used. The region of interest was then used to monitor the overall change in resistivity within, referred to as the integral value. The variation of this integral value with time is plotted above.
From the above plot four main sections can be identified. Initially the plot is approximately flat as the subject's stomach is empty after fasting. A clear decrease in resistivity then occurs as the subject ingests a conductive meal. After the food enters the stomach the integral remains fairly constant during the lag phase, before finally gastric emptying starts and the food starts to leave the stomach. From these sort of plots it is therefore possible to measure the half time for emptying of the stomach.
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