Quantitative and Portable Instrumentation for the Screening and Assessment of Pharyngeal Dysphagia

Dysphagia, the dysfunction of swallowing, is a common complication of neurological conditions, and presents increased risk of morbidity, mortality, and may critically reduce the subject's quality of life. The early detection of dysphagia is essential to maintaining the subject's health, while accurate diagnosis of the physiological source of dysphagia is essential for successful treatment. 'Silent' dysphagia, where there are no outward symptoms, is a particular concern, as many screening processes rely on patients self-reporting difficulties.

A gap exists in available instrumentation, between simple techniques, which are subjective and require experience to employ, and highly sophisticated instruments, which are invasive to the patient and resource intensive. This thesis addresses this by exploring the possibility of developing instrumentation techniques which present the potential for portable, non-invasive solutions, which are relatively inexpensive and require dramatically less expertise to employ, enabling more effective dysphagia screening procedures to be introduced to clinical practice.

This thesis develops the means for measuring laryngeal motion by the use of a non-invasive throat-mounted sensor in four stages: Firstly, a mathematical and a physical model of the larynx are constructed to develop our understanding of the relationship between laryngeal motion and sensor signals; secondly, swallowing sensor data was captured from 23 healthy participants; thirdly, the data from the participants was analysed to evaluate alternative data processing techniques, and to develop an understanding of practical factors deriving from inter-personal variations in physiology; finally, a prototype instrument was constructed, based on specifications evolved from our analysis.

Initial testing of the prototype instrument has demonstrated the validity of the concepts employed in its design: it is straight-forward to use, compact, portable, non-invasive, and can be used to quantitatively measure laryngeal elevation in a repeatable fashion.