Pressure distribution sensors have been widely used for the
evaluation of weight supporting surfaces in shoes, chairs, and
beds. Examples of shoe studies include the assessment of seven
types of shoes with regard to their ability to reduce peak pressure
during walking for leprosy patients [2], the evaluation of
the generalizability of in-shoe peak pressure measures with data
collected from numerous subjects over a period of time using
two calibration schemes [16], and the validation of the use of
total contact casts for healing plantar neuropathic ulcerations
through reduction of pressure over the ulcer [6]. Studies of seats
include the development of a measurement protocol and analysis
technique for assessing pressure distribution in office chairs
[23], the use of body pressure distribution measures as part of
a series of tests for assessing comfort associated with five automobile
seats [12], and an interesting review of how objective
pressure measures can lead to improved aircrew seating with
more evenly distributed pressure patterns, thereby potentially
improving a pilot’s task performance by reducing or eliminating
pain endured during high-acceleration maneuvers of the aircraft
[5]. Examples of bed studies include an investigation of support
surface pressure and reactive hyperemia (the physiological response
to pressure) in older population [1], and a recent development
of body posture estimation system for sleepers based on
pressure distribution measures and a human skeletal model [11].
Our sensing chair project is similar to the last study cited [11] in
that we focus on the automatic processing and interpretation of
contact sensor information, whereas the other studies reply on
expert analysis of pressure distribution measures. Of particular
importance is the development of real-time systems that can be
used to drive other processes such as the automatic control of
airbag deployment force based on the size, weight, and sitting
posture of a driver or passenger