A sensor for measuring the deflection of a thorax of an anthropomorphic dummy includes a base for mounting on a thoracic spine assembly, a tape drum rotatably mounted on the base, at least a pair of spring tapes each having one end connected to the base and an opposite end attached to the tape drum,...http://www.google.com/patents/US5317931?utm_source=gb-gplus-sharePatent US5317931 - Apparatus for sensing deflection in a crash test dummy thorax
