Related Experiment Video
Updated: Feb 6, 2026

Hemi-laryngeal Setup for Studying Vocal Fold Vibration in Three Dimensions
Published on: November 25, 2017
Can Ultrasound Identify Paradoxical Vocal Fold Movement? A Pilot Study
Jonathan T Finnoff1, Diana M Orbelo2, Dale C Ekbom3
1Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine and Science, Rochester, Minnesota.
Objective:
Vocal cord dysfunction (VCD) is characterized by paradoxical vocal fold movement (PVFM) during inspiration. The aim of this study was to determine whether ultrasound could accurately differentiate between normal and PVFM during respirations in a resting state.
Design:
Prospective, single-subject design.
Setting:
Academic medical center.
Patients:
A speech-language pathologist who was able to volitionally alternate between normal and PVFM when breathing at rest was recruited to participate in the study.
Interventions:
The subject was instructed to randomly alternate between normal and PVFM 20 times (10 times each). A single investigator imaged the vocal folds using ultrasound and reported when the subject alternated between the 2 respiratory states.
Main Outcome Measures:
The subject recorded when they changed between the 2 respiratory states, whether the investigator identified with the change occurred, and if the correct respiratory state was identified.
Results:
The investigator recognized when the subject changed respiratory states and correctly identified the new respiratory state 100% of the time.
Conclusions:
The findings of the current study were promising and suggest that ultrasound may have utility in the diagnosis of VCD. However, because of the preliminary nature of these results, further research is required before recommending its clinical implementation.
Related Concept Videos
Protein Folding
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Pilot and Numeric Relaying
Molecular Chaperones and Protein Folding
The...
Molecular Chaperones and Protein Folding
Anatomical Movements
Here are some common anatomical movements:
Flexion and extension motions are in the sagittal (anterior–posterior) plane of motion. These movements take place at the shoulder, hip, elbow, knee, wrist,...

