Respiratory sound analysis as a diagnosis tool for breathing disorders

This paper provides an overview of respiratory sound analysis (RSA) and its functionality as a diagnostic tool for breathing disorders. A number of respiratory conditions and the techniques used to diagnose them, including sleep apnoea, lung sound analysis (LSA), wheeze detection and phase estimation are discussed. The technologies used, from multi-channel bespoke recording systems to using a smart phone application are explained. A new study that focusses on developing a non-invasive tool for the detection and characterisation of inducible laryngeal obstruction (ILO) is presented. ILO is a debilitating condition, caused by malfunctioning structures of the upper airway, commonly triggered by exertion, leaving children feeling out of breath and unable to exercise normally. In rare cases it can lead to critical laryngeal obstruction and admission to intensive care for endotracheal intubation. The current definitive method of diagnosis is by inserting a camera through the nose while the person is exercising. This approach is invasive, uncomfortable (in particular for young children) subjective and relies on the consultant's expertise. There are only a handful of consultants with the appropriate level of expertise in the UK to diagnose this condition.