Instrumentation for bedside analysis of swallowing disorders

Disordered swallowing, or dysphagia, is a common problem seen in patients undergoing treatment for cancer, stroke and neurodegenerative illnesses. This disease is associated with aspiration-induced chest infections. The methods currently used for diagnosis, however, are qualitative or based on expensive equipment. Swallowing accelerometry is a promising low-cost, quantitative and noninvasive tool for the evaluation of swallowing. This work describes the design and application of a bedside instrument able to evaluate swallowing mechanisms and to identify patients at risk of aspiration. Three-axis swallowing accelerometry was used to measure the neck vibrations associated with deglutition, providing analog signals to a virtual instrument developed in LabVIEW environment. In vivo tests in normal subjects as well as tests with disphagic patients showed that the system was able to easily and non-invasively detect changes in the swallowing acceleration pattern associated with increasing values of water volume (p < 0.02) and disphagia. We concluded that the developed system could be a useful tool for the objective bedside evaluation of patients at risk of aspiration.