Until recently, assessing and quantification of gait function outside of the constraints and subsequent methodological issues of the gait lab have been elusive. Traditionally, gait is assessed using laboratory-based instruments such as optical motion measurement systems and force platform in a gait laboratory. Although these systems are clinically accepted as ‘the gold standard’, there have been several drawbacks. Firstly, the number of consecutive strides that can be measured is limited. This means that inter-cycle variability of gait, involved in balancing the body and walking during varying circumstances, cannot be investigated using the existing systems as it requires a larger number of consecutive strides to be measured. Instrumented treadmills can address this limitation; however, uncertainty remains regarding the extent to which treadmill walking can be used to mimic overground walking. In addition, the narrow path offered by the treadmill as well as small freedom for inter-cycle speed variability may hinder freedom in selection of gait trajectory or speed. Therefore, it may not replicate natural gait behavior of subject during everyday life. Finally, our recent study published at the Gait&Posture 2009 revealed that subjects may modify their gait pattern when walking outside of a gait laboratory environment. These results may indicate that gait parameters assessed inside of a gait laboratory environment may not replicate subject’s gait outdoors in which subjects may walk a longer walking distances on different walking surfaces and irregular pathways.
Advances in the technology of body-worn sensors during the last decade have allowed investigators to use this technology for measuring various aspects of human motor performance. These studies are based on the use of miniaturized and integrated sensors in combination with lightweight, small measuring devices that can be carried without interfering with normal activity. One of the main advantages of body-worn sensors compared to laboratory-based measuring systems is that they are ambulatory and can be used in free conditions continuously over long periods of time. Dr Najafi, Scholl Assoc of Applied Biomechanics, one of our team members will present various advantages of body worn sensors for gait analysis in the invited session at the 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMEC’11, Boston) on September.
The application of body worn sensor technology is quickly opening its way for many other medical applications. Recently an international working group named ‘Wearable Sensors in Health Care: http://www.wearable-sensors.org has been established to promote medical informatics research in the area of wearable sensor technology in healthcare by providing a joint comprehensive platform for information exchange and scientific collaboration. The group aims to attract experts from different areas of expertise, such as medical informatics, biomedical engineering, nursing and medicine.
Body worn sensors also opened its way for various commercialized products in health care. For example, recently Intel and GE General Electric Co., have joined forces to team up on a 50-50 joint venture that will develop technologies that would cater to healthy, independent living at home and in senior housing communities, as well as for the growing telehealth market. Based on their estimation the telehealth and remote patient monitoring business will balloon from $3 billion in 2009 to $7.7 billion in 2012. That means there is plenty of room for innovation and certainly body worn sensor technology is part of it.