The videofluoroscopic swallowing study has been considered a gold standard assessment tool for oral-pharyngeal dysphagia for decades. However, swallowing biomechanics are complex, and the absence of sophisticated image processing tools has made it difficult to quantitatively analyze fluoroscopic studies.

As a result, the full potential of VFS Studies has generally not been realized. The primary means of interpretation has been through subjective impressions. Though invaluable for some purposes, such as documenting aspiration or penetration, subjective determination of mechanical events is problematic, and can lead to poor reliability across raters.


Swallowtail is a state-of-the-art software application with a number of integrated tools designed to allow sophisticated and powerful quantitative analysis of VFS Studies.

The Swallowtail measurement methodology is easy to learn, easy to perform, fast and yields reproducible results.

Swallowtail is based on the quantitative measurement methodology developed by Dr. Rebecca Leonard and Dr. Katherine Kendall at the University of California, Davis. However, the program is not limited to their methods. Swallowtail tools can be used to make a wide variety of linear, area and temporal measures that may be of interest to, or developed by, clinicians and researchers.

With the inclusion of quantitative assessment to their fluoroscopic analyses, Leonard and Kendall hoped to reduce their dependence on subjective impressions, which often failed to achieve agreement among members of their Dysphagia Team. In addition, they felt it would force them to focus on the specific gestures responsible for bolus movement, as well as on bolus movement itself, which is more easily visualized due to contrast-enhancement. Finally, they felt obligated to maximize the potential of the fluoroscopic study, which exposes patients to ionizing radiation. Over time, this approach has proved to be extremely valuable for both clinical and research purposes. A particular goal for Swallowtail has been to retain clinician/investigator judgment in determining critical locations of significant swallowing events, while making the actual measurement of these events as facile, and automatic, as possible.

The straightforward user interface enables the practitioner to take and store the multitude of measurements described above.  On-screen controls allow adjustments to video brightness and contrast, as well as playback features like roll forward, reverse and stop action.  These and other convenient features give Swallowtail a dramatic edge over manual objective measurement methods and make detailed, accurate analysis a reality.

Swallowtail Academic - Student Version

Swallowtail Student - is a fully featured version of Swallowtail, for the cost of a textbook. It can also be upgraded annually for a small fee. As Swallowtail increases in capabilities and sophistication, the dysphagia specialists who keep their versions up to date can have a 

state-of-the-art lifelong learning tool.

Ease of Learning - Swallowtail can make it significantly easier to learn swallowing biomechanics.

Learn by Measuring - Analyzing and measuring mechanical events that occur during swallowing can help students understand both normal and impaired swallowing biomechanics.

Confidence - Learning to use Swallowtail will help students develop confidence in their ability to approach dysphagia assessment in an objective, systematic and reproducible manner. They will also learn that Swallowtail can help them perform a sophisticated quantitative analysis 

that is a powerful complement to important subjective impressions.

Swallowtail Academic - Professor Version

Swallowtail Professor - For the first time, Swallowtail provides dysphagia educators with an easy-to-use tool for teaching swallowing biomechanics and biokinetics. Swallowtail demonstrates the value of systematic, quantitative analysis in dysphagia assessment.

Elucidate - Swallowtail can allow you to quickly elucidate for students differences between normal and impaired swallowing mechanics.

Objective Evaluation - Since Swallowtail provides an objective method for analyzing swallowing biomechanics, it offers an objective method to evaluate students’ knowledge of swallowing.

Multiple Levels - Swallowtail can easily be adapted to multiple educational and experience levels, from beginning master’s students just introduced to normative swallowing biomechanics, to advanced doctoral candidates who can use Swallowtail to explore disease specific manifestations of dysphagia, compare patient populations within or across different dysphagia etiologies, or elaborate normal swallow mechanics and characteristics.

Thesis or Dissertation Tool - Swallowtail can provide your graduate students with a powerful and elegant (primary or supplemental) research tool useful at any educational level.

Swallowtail - Research Version

Quantitative Analysis - Swallowtail is the first product in the world to make quantitative analysis of VFS Studies easy, fast, reproducible and affordable.

Scientific Data - Swallowtail can provide the scientific data for evidence-based medicine, output in either tabular or graphic format.

Larger Study “n’s” - Because of Swallowtail’s ease of use and speed of analysis, researchers can include larger numbers of investigated subjects, thus improving the statistical power of their research.

Baseline Physiology - Swallowtail can be used to establish a baseline of swallowing physiology, for individuals and groups, to which subsequent changes can be compared.

Large Normative Database - Swallowtail includes normative measurement data derived from VFSS tests of healthy individuals grouped by age and sex.

Multi-Center Research - Because Swallowtail has been designed to make quantitative analysis reproducible, multi- center studies can be conducted with the knowledge that cross-institutional measures can be reliably obtained.

Automated Measures - For specific measurements that are time-consuming to reproduce by hand, sophisticated mathematical algorithms are being developed that will make reproducibility fast and accurate.

Standardization - Swallowtail allows VFS Study protocols and measurements to be standardized, in a specific research lab, or in multiple labs.

Customization - Swallowtail allows you to customize your protocols and measurement methodologies to suit specific research requirements and projects.

Improve the Quality of Research - By enabling quantitative, reproducible analyses, Swallowtail has the potential to significantly improve the quality of dysphagia research involving fluoroscopy.

Grant Funding - The inclusion of quantitative analysis tools in oral-pharyngeal dysphagia research involving fluoroscopy is likely to appeal to grant application reviewers, possibly increasing the likelihood of funded research proposals.