Body Sensor Networking, Design and Algorithms

3Physical, Physiological, and Biological Measurements

3.1 Introduction

Nowadays, many of the physical, physiological, biological, and behavioural states of the human body can be measured, evaluated, and described by means of wearable sensors. These sensors can monitor the state of the human body for longer than an expert's observation. Often, the fusion of data modalities collected using different sensors is used for diagnostic purposes.

Although the physical state of the human body can be observed in detail using video cameras or in some cases listened to using microphones, such modalities are subject to breach of privacy, costly to deploy, and are less fascinating for automated analysis body movement. Therefore, in this chapter we ignore these two modalities and investigate the cases where humans can wear sensors for a longer time to enable long-term monitoring. Here, the most popular methods for measuring very common human body states are explained and the advanced approaches described. The details as well as experimental considerations are described in later chapters.

3.2 Wearable Technology for Gait Monitoring

As described in Chapter 2, many physical or mental diseases or abnormalities directly or indirectly affect human gait. Stroke, Parkinson's, and leg amputation readily come to mind. Thus, gait analysis can be used to monitor both the cause and the symptoms of a wide range of such abnormalities. The state of gait can be measured using a number of sensing modalities ...