ABSTRACT
Simultaneous videoendoscopy and photodetection has potential for improving the assessment of changes in velopharyngeal (VP) movements and closure over time during speech. The purpose of this project was to examine the linearity of a new system, including a pediatric bronchoscope with an internal instrument channel through which the photodetector fiber was positioned. The results led to the conclusion that the response of the new system was linear. However, further examination indicated that system positioning variables had important effects on the overall level of photodetector light detection. These observations confirm the importance of monitoring and controlling the position of the endoscope-photodetector apparatus in the nasopharynx when using the system to evaluate velopharyngeal movement and closure for speech.