AIRO Study - Measuring Airway Resistance and Oxygenation during an Exercise Challenge

Exercise Challenge with Neck Pulse Sensor and At-Home Spirometer All participants undergo the same protocol (single-cohort design) WHY: Test non-invasive devices for detecting exercise-induced changes in venous oxygen saturation (SvO2) and airway function, including exercise-induced bronchoconstriction (EIB). MATERIALS: • Custom-developed reflectance pulse oximetry sensor with red and infrared LEDs, photodetectors, and integrated temperature protection (potential at-home sensor). This sensor measured venous oxygen saturation (SvO2) from the jugular veins and arterial oxygen saturation (SaO2) from the carotid artery, rather than just SaO2 like current existing sensors. • Custom-developed at home spirometer for lung function testing (potential at-home sensor) • EasyOne spirometer for reference • COSMED Quark Metabolic Cart • Cycle ergometer (stationary bike) • Face mask to connect to cart • Medical-grade adhesive (Tegaderm) for sensor placement • Commercial finger pulse oximeter for SaO2 reference PROCEDURES: • Participant demographics and baseline measurements recorded (age, sex, height, weight, skin type, predicted max heart rate) • Neck sensor applied using neck ultrasound for guiding placement over the jugular veins with the sensor held in place with medical grade adhesive (Tegaderm) before recording initiated • Baseline spirometry measured using at-home developed device and EasyOne spirometer (~1 minute each test) • Participant cycles on ergometer for 8 minutes: • First 2–4 minutes: ramp up to 80–90% predicted maximum heart rate • Remaining time: maintain target workload until 8 minutes completed • Post-exercise spirometry measurements at 5, 10, 15, and 30 minutes using both at-home developed device and EasyOne spirometer • Neck sensor is removed and cleaned along with facemask according to protocol WHO PROVIDED: Research staff will perform the testing and monitor sensor performance. Staff have GCP certificates and are trained in using the metabolic cart and sensors HOW: • Single, face-to-face supervised session • Individual use • Testing will be completed within an hour period • Neck sensor will be on and recording for the entire test • Spirometry measurements will be recorded before exercise and 5, 10, 15 and 30 minutes post exercise • Metabolic cart will collect data during the 8-minute exercise challenge LOCATION: Sports Lab, University of Canterbury, Christchurch, New Zealand TAILORING: • Sensor placement adjusted for neck anatomy using an ultrasound for optimal placement • Ergometer settings adjusted for participant height and leg length • Mask fitted to participant face for minimal leakage (XS, S, M, L and XL mask available) NUMBER AND DURATION OF SENSOR ASSESSMENTS: • Single visit per participant, ~1 hour in total • Neck sensor records continuously during the exercise and recovery period (~30–40 minutes of active monitoring) Spirometer measurements take ~1 minute each test ADHERENCE MONITORING STRATEGIES: • Research staff check sensor positioning and signal quality before, during, and after exercise • Metabolic cart will be calibrated before every patient • Any sensor issues or signal loss documented • Spirometer testing will be repeated if unsatisfactory