Technological innovations have lead to the development of Wearable Physiological Monitoring devices, that have enabled researchers and clinicians in real-time monitoring of physiologic function within a field setting. However, it is important to establish the psychometric properties of a device prior to its utilization. A systematic review was conducted to provide a summary and appraise the quality of the literature on psychometric parameters of Zephyr Bioharness and Fitbit devices. Based on this review, we addressed the current gaps in the literature regarding the reliability parameters of Zephyr Bioharness and Fitbit Charge devices, and established the validity and agreement properties of Fitbit Charge device. For our systematic review, we searched the Google Scholar and PubMed databases to identify articles. To establish the reliability, validity and agreement parameters of Zephyr Bioharness and Fitbit Charge devices, a convenience and snowball sampling approaches were used to recruit sixty participants (30 females) from university student, staff, faculty population, and MacSeniors Community Program at McMaster University. The performance of Zephyr and Fitbit devices were assessed throughout three phases; rest, Modified Canadian Aerobic Fitness Test and recovery. In our study, at rest, inter-session average heart rate (beats/min.) ICCs (SEM) for Zephyr and Fitbit ranged from 0.90 – 0.94 (1.73 – 2.37) and 0.88 – 0.94 (1.83 – 2.67) respectively. At mCAFT, the Zephyr ICCs (SEM) ranged from 0.91 – 0.97 (3.12 – 4.64) and 0.85 – 0.98 (3.28 – 4.88) for the Fitbit. Throughout the recovery, the ICCs (SEM) ranged from 0.93 – 0.97 (2.65 – 4.66) and 0.76 – 0.91 (3.17 – 4.67) for Zephyr and Fitbit devices respectively. Pearson’s correlation coefficients and (Mean differences) for heart rate variable were 0.97 – 0.99 (-0.60 – 0.02) at Rest, 0.89 – 0.99 (13.51 – 0.62) at submaximal testing and 0.70 – 0.84 (-0.54 – 2.52) throughout recovery. The average agreement bias of heart rate in pair-wise device comparison indicated mean differences of -0.20, 4.00 and 1.00 at rest, sub-maximal testing and recovery respectively. We identified fair to very good quality evidence from 14 studies. The Zephyr Bioharness and Fitbit Charge devices demonstrated excellent reliability measures, and the Fitbit Charge device heart rate variable demonstrated strong to very strong correlations when concurrently compared with Zephyr, and provided valuable information regarding its interchangeable use in a sample of sixty healthy male and female participants of various age groups during a resting, standardized submaximal fitness and recovery phases. / Thesis / Master of Science (MSc)

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Obstructive sleep apnea (OSA) is a condition characterized by upper airway obstruction during sleep causing intermittent hypoxia and nighttime awakening. It is a common condition in the United States that is often undiagnosed. It is a significant risk factor for decreased daytime productivity, quality of life, cardiovascular disease, and death. The current gold standard for diagnosis of OSA is laboratory‐based polysomnography (PSG). While PSG is necessary for the diagnosis and monitoring of OSA, many patients have limited access to PSG due to wait times at PSG laboratories or economic or geographic limitations. Portable sleep monitoring has been studied as a possible solution for patients who do not have access to timely PSG. This study aimed to use the Zephyr BioHarness 3, a chest‐worn physical activity monitor that records movement and physiologic data in real‐time, to detect apnea events in patients with suspected OSA undergoing single‐night laboratory PSG. Twenty patients underwent single‐night laboratory‐based PSG while simultaneously wearing the Zephyr BioHarness 3. The Zephyr BioHarness 3 data was analyzed using three methods. First, apnea events were identified in 10‐second windows of Zephyr data via support vector machine, logistic regression, and neural network (sensitivity = 76.0 ± 0.3%, specificity = 62.7 ± 0.2%, accuracy = 63.7 ± 0.1%). Second, apnea events were identified using the mean, median, and variance of the 10‐second windows (sensitivity = 72.3 ± 0.3%, specificity = 69.4 ± 0.1%), accuracy 69.6 ± 0.1%). Third, apnea events were identified using phase‐space transformation of the Zephyr BioHarness 3 data (sensitivity = 76.9 ± 0.3%, specificity = 77.9 ± 0.1 %, accuracy = 77.9 ± 0.1%). The Zephyr BioHarness shows initial promise as a possible OSA screening tool for patients suspected of OSA but who lack access to timely laboratory‐based PSG.