Smart phone-based peak expiratory flow meter

• Published in: Electronics letters Vol. 52; no. 11; pp. 904 - 905
• Main Authors: Natarajan, S, Castner, J, Titus, A.H
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 26.05.2016
• Subjects: Asthma; asthma condition monitoring; asthma sufferers; AudioFlow; Biomedical technology; Devices; diseases; Electronics; flow measurement; Flow rate; Flowmeters; headphone jack; Meters; Monitors; patient monitoring; PEF; pneumodynamics; pressure‐dependent frequency signal; smart phones; smart phone‐based peak expiratory flow meter; Smartphones; PEF; flow measurement; AudioFlow; diseases; smart phones; pressure-dependent frequency signal; smart phone-based peak expiratory flow meter; pneumodynamics; headphone jack; patient monitoring; asthma sufferers; asthma condition monitoring
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2016.0734

The design and performance of a smart-phone-based device, called AudioFlow, that measures and records peak expiratory flow (PEF) is presented. PEF is a measure used by asthma sufferers to monitor their asthma conditions. The device is comprised of a custom 3D printed airtube and a minimal number of electronic components that communicate with a smartphone via a custom app. A pressure-dependent frequency signal generated when the user blows into the tube is sent to a smartphone app via the headphone jack. The custom designed app reads the signal and converts the frequency to a flow rate, which is displayed for the user to see and logged for condition tracking. The device has been validated with a commercial gas flow meter and is ready for human subject testing.