Videofluoroscopic Swallowing Study (VFSS)

DDS signals and VFSS will be recorded simultaneously (for the same bolus) using barium contrast agent stimuli prepared in three consistencies: thin, mildly-thick and moderately-thick. Subjects will undergo VFSS with simultaneous DDS using up to 5 boluses of thin barium stimulus ("THIN-Ba"), and up to 4 boluses of barium thickened to mildly ("MILD-Ba") thick and up to 4 boluses of moderately ("MODERATE-Ba") thick barium consistencies using Resource Thicken Up Clear Nestlé Health Science (TUC). 4, 3 and 3 boluses for THIN-Ba, MILD-Ba and MOD-Ba will be analyzed using the classifier algorithms for sensitivity/specificity results. According to the exploratory trial, VFSS data for safety or efficiency can be missing for up to 14% boluses due to quality of VFSS recording. To compensate for potential losses of boluses due to missing gold standard (VFSS) data, 5, 4 and 4 boluses will be collected for the three consistencies respectively . The DDS signals will be sent to a dedicated application software installed at the CRO, which interprets the acceleration data and displays the examination result. The VFSS recording will be sent to CRO and provided for blinded assessment by the independent central VFSS laboratory.The study procedure of simultaneous VFSS and DDS measurement will be completed in one day and the subject will be followed within 2 business days after the study procedure to monitor for adverse events.