Abstract
Aspiration pneumonia is a respiratory infection that can occur after the inhalation of foreign material or oropharyngeal or gastric contents. It is common among elderly patient populations and in patients with neurological disorders such as stroke. Timely prediction of the disease in at-risk patients is important to reduce its incidence. Speech—language therapists evaluate swallowing function and the efficacy of the cough reflex to assess patients' risk of developing aspiration pneumonia; however, many existing methods of swallowing and coughing assessment are costly, invasive, impractical for highly-impaired patients, or lack accuracy. In this study we present a novel portable medical device intended for the bedside measurement of physiological risk factors for aspiration pneumonia. The developed device comprises an air flow meter and microphones to measure (1) respiratory flow rate surrounding swallowing to characterize swallowing—respiratory coordination; (2) acoustics from the external auditory meatus to detect occurrence of swallowing; and (3) cough audio and air flow rate. The device connects to a computer application via USB for real-time data acquisition and display. Airflow and acoustic measurement systems were compared against commercial flow and sound meters under controlled conditions. A preliminary study was performed with 22 healthy adult volunteers to measure respiratory air flow during volitional and cued swallows as well as air flow and audio during volitional coughs. These tests show that the proposed device is likely capable of appropriately measuring the targeted physiological signals, which provides a solid foundation for future aspiration pneumonia risk estimation development.
