Seeking inspiration: Development and evaluation of a new mHealth app for respiratory therapy using built-in smartphone sensors

Incentive spirometry (ISy) is a longstanding respiratory therapy technique for clearing mucus from the airways to prevent respiratory complications such as chest infections or pneumonia. Slow gradual maximal inspirations are encouraged by levitation of spheres or a piston encased in a clear plastic ISy device as an ‘incentive’ to persist with repeated inhalations using an attached tube; such therapies are termed therapeutic exergames. The intent of ISy therapy is dislodgement of mucus from the airways and expulsion by coughing. Settings where ISy therapy is practiced include post-operative convalescence in hospital environments and in the management of chronic conditions such as chronic obstructive pulmonary disease (COPD) in home and nursing home settings. ISy devices cost between AUD $20 and $50. At rest, normal breaths are almost silent. If one’s lips are pursed in preparation to whistle, vigorous inhalation produces an audible sound resulting from turbulence as air flows into the mouth. Smartphone mHealth apps have been developed to detect breath sounds in contexts such as respiratory function testing, cough analysis and coaching correct medication inhaler techniques for asthma and COPD sufferers. These apps often employ complex sound frequency analysis and may use spacer devices or calibrated whistles to optimise sound detection by smartphone microphones. The results of a recently conducted survey will be presented, regarding available mHealth apps using built-in sensors in curated international mHealth app libraries including the NHS App Library, AppScript and MyHealthApps, finding only 18 out of 1200 available apps used built-in smartphone sensors for diagnosis or therapy, with a paucity of respiratory therapy mHealth apps using phone sensors offered for health improvement. The World Health Organisation identify the need for more rigorous mHealth evaluation and the Royal Australian College of General Practitioners cite a lack of evidence regardin