A smartphone oximeter with a fingertip probe for use during exercise training: usability, validity and reliability in individuals with chronic lung disease and healthy controls

• Published in: Physiotherapy Vol. 105; no. 3; pp. 297 - 306
• Main Authors: Chan, C., Inskip, J.A., Kirkham, A.R., Ansermino, J.M., Dumont, G., Li, L.C., Ho, K., Novak Lauscher, H., Ryerson, C.J., Hoens, A.M., Chen, T., Garde, A., Road, J.D., Camp, P.G.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2019
• Subjects: Adult; Aged; Case-Control Studies; Chronic obstructive pulmonary disease; Exercise; Female; Fingers - blood supply; Heart Rate; Humans; Lung Diseases - physiopathology; Male; Middle Aged; Mobile Applications; Oximetry - instrumentation; Oxygen - blood; Oxygen saturation; Pulmonary rehabilitation; Reproducibility of Results; Smartphone; Telemedicine; Telerehabilitation; Usability; Chronic obstructive pulmonary disease; Telerehabilitation; Pulmonary rehabilitation; Usability; Oxygen saturation
• ISSN: 0031-9406; 1873-1465
• DOI: 10.1016/j.physio.2018.07.015

Telehealth is a strategy to expand the reach of pulmonary rehabilitation (PR). Smartphones can monitor and transmit oxygen saturation (SpO2) and heart rate (HR) data to ensure patient safety during home-based or other exercise. The purpose of this study was to evaluate the usability, validity and reliability of a Kenek O2 pulse oximeter and custom prototype smartphone application (smartphone oximeter) during rest and exercise in healthy participants and those with chronic lung disease.
Fifteen individuals with chronic lung disease and 15 healthy controls were recruited. SpO2 and HR were evaluated at rest and during cycling and walking. SpO2 was valid if the mean bias was within +±2%, the level of agreement (LoA) was within ±4%; HR was valid if the mean bias was within ±5 beats per min (bpm), LoA was within ±10bpm. Usability was assessed with a questionnaire and direct observation.
The smartphone oximeter was deemed easy to use. At rest, SpO2 measures were valid in both groups (bias <2%, lower bound LoA −2 to 3%). During exercise, SpO2 measurement did not meet validity and reliability thresholds in the patients with chronic lung disease, but was accurate for the healthy controls. HR recording during exercise or rest was not valid (LoA>10bpm) in either group.
The smartphone oximeter did not record HR or SpO2 accurately in patients with chronic lung disease during exercise, although SpO2 was valid at rest. During exercise, patients with chronic lung disease should pause to ensure greatest accuracy of SpO2 and HR measurement.