UC Berkeley

Pervasive health monitoring is the application of non-invasive ambulatory monitoring technologies towards continuous physiologic monitoring. These technologies can be used for the detection of sudden, acute, health problems and the management of chronic disease. For people at risk for specific incidents, such as a heart attack in an individual with heart disease or a fall from an elderly individual, being able to detect a potentially life threatening incident and alerting a care provider can mean the difference between life and death. Likewise, individuals who have chronic health conditions, such as congestive heart failure, can benefit from tracking the progress of their disease. Feedback provided from an ambulatory monitor can be used to help manage the treatment of the disease with the goal of keeping the individual out of the hospital. Currently, people wait until a health problem manifests itself in a way which necessitates a visit to a doctor or a hospital. This type of management is the antithesis of early detection. Often, many conditions have simpler, more effective, and less costly treatments if detected and diagnosed at an early stage. Not only does this result in a better quality of life, but can help to by reducing the costs to the healthcare system. In 2010, U.S. healthcare costs were $2.6 trillion, and it is expected to grow to an incredible $4.6 trillion by 2020.

In order to enable a wide range of pervasive monitoring applications, a highly integrated ambulatory physiologic monitor was developed and used in a number of studies. The hardware platform is called The Berkeley Tricorder, and is capable of acquiring a high resolution data from a number of physiologic sensors including an electrocardiograph, an electromyography, a photoplethysmograph, a bioimpedance spectrometer, and an accelerometer. In addition, The Berkeley Tricorder is capable of storing data on an SD memory card, or transmitting it wirelessly over Bluetooth to a local target, or to a remote target using the dial-up-networking Bluetooth profile and a mobile phone. The latest version of the hardware measures 1.4"x1.85".

The first chapter explores a number of acute and chronic health conditions to better understand which physiologic monitors are of the most value in an ambulatory system. Next, the physiologic basis of the biosignals are examined, along with the technology which enables their measurement. Based on the methodology used to measure the biosignals, a detailed set of requirements for the implementation of the ambulatory monitor is derived. The requirements are then translated into a physical implementation along with a set of lessons learned along the way. The hardware is then examined to see how it compares to the original design and to quantify its signal quality. Finally, a study used to explore the physiology of stress is using the ambulatory monitor is discussed.