Measuring flow velocity of swallowed liquid in the human pharynx by tongue pressure sensor and swallowing sound sensor

We measured flow velocity of swallowed liquid passing through pharynx. We put a pressure sensor on a palate to measure tongue pressure when swallowing the liquid. And we put two acoustic sensors on the neck skin in order to measure swallowing sound when liquid passes through the pharynx. From the output of these three sensors, we can know the timing of the liquid passing through each sensor points and can calculate the flow velocity of the swallowed liquid at the pharynx. In this paper, we compare the flow velocity between two swallowing positions, “look forward position” and “look upward position.” As a result, we found that the flow velocity of the “look upward position” was 2.5 times faster than that of “look forward position.”.