Design and optimization of monitoring and feedback systems in wireless health

The emergence of low cost micro-electronics and wireless systems has enabled the practical application of wearable monitoring systems that promote health and well-being of individuals. This area of research which is in the intersection of medical sciences and engineering is known as Wireless/Mobile Health. It uses the knowledge from medical sciences and employs low-cost micro-electronics and wireless systems along with powerful and sensor-rich handheld devices to enable a new dimension of health care which introduces pervasive monitoring and early diagnosis at low costs. Wireless Health introduces new opportunities to augment functional independence and daily activities of people with physical impairments, serve as monitoring and diagnostic devices and to perform feedback reinforcement. However, wearable medical systems are not yet in widespread use due to a variety of constraints including cost, energy, semantic complexity, required precision levels, reliability and many more. In this dissertation I will discuss challenges associated with design of such systems and develop new methods that can enable widespread use of these systems to address the recently growing demand of accessible health care services. Specifically, I will focus on the most significant challenges which are energy consumption and accuracy vs. cost of these systems. Most wireless health systems are wearable and therefore operate on battery power. On the other hand, in order to enable real-time monitoring round the clock, long life-time is required. In this dissertation I will look at intelligent sampling and data aggregation strategies which are often tied with application level understanding of the semantics of the system in order to minimize energy consumption. In addition, for these systems to be widely exploited in large populations, they need to be designed in-expensively and also sometimes even disposable due to hygiene constraints. But the main limitation is the precision levels required by these systems. I will look into this problem by either taking advantage of sensors already existing on hand-held devices that people carry with the addition of minimal add-ons or by using inexpensive material for system production but taking into account the inaccuracies at different levels of system design. The work in this dissertation can be described in the two categories of: (1) Sensor and algorithm design for medical monitoring systems that ubiquitously collect medical data; and (2) Feedback systems that could enforce awareness, deliver therapies in real-time and increase adherence to rehabilitation and medical instructions with minimal intrusion and cost.