Publication

Authors: Ziad A Elhajjaji, Amar S Basu Abstract Orthostatic disorders affect 30% of older adults and increase the risk for falls. The current diagnostic standard, the blood pressure cuff, cannot capture the rapid, multifaceted dynamics of orthostasis physiology, resulting in frequent underdiagnosis. This paper demonstrates multiparameter, real-time measurement of orthostasis using TRACE, an earlobe mounted wearable developed in our group. In prior work, we demonstrated a novel metric called orthostatic hypovolemia (OHV1), the initial loss in cephalic (head) blood volume immediately upon standing. This study significantly advances our prior work by introducing an additional 2 metrics: OHV2, the cephalic blood volume deficit after the body achieves homeostasis after standing; and postural orthostatic tachycardia (POT), the increase in heart rate. The 3 metrics were evaluated in 101 older adults who wore the TRACE device during postural…

Authors: Ziad A. Elhajjaji, Amar S. Basu Abstract Orthostatic hypotension (OH) is a reduction in blood pressure and cerebral blood flow upon standing. Presenting in nearly 30% of older adults, OH is associated with increased fall risk and other co-morbidities. The clinical standard for monitoring OH, a blood pressure (BP) cuff, fails to capture initial orthostatic hypotension (IOH) and rapid hemodynamic changes during orthostasis. In contrast, cerebral blood flow velocity (CBFV) and continuous BP requires costly instrumentation unsuitable for home monitoring. As result OH is often underdiagnosed and poorly managed. This paper proposes a novel method for monitoring OH using TRACE, a wireless earlobe sensor that quantifies orthostatic hypovolemia (OHV), postural orthostatic tachycardia (POT), and motion during a standup test. To our knowledge, OHV is a novel biometric that may be correlated with dizziness upon…