Abstract: Apparatus and methods provide a physiological status sensing device (40) for sensing a physiological status of a patient (4) and minimizing an amount of interference (78) generated during a resonance (MR) scan by a magnetic resonance (MR) system (8). The device (40) includes a first, active sensor (64) located to sense the physiological status and experience MR scan related interference and to generate a first signal (80) having a physiological status component (76) and an interference component (78). A second non-active sensor (70) is located closely adjacent to the first sensor (64) to experience substantially the same MR scan related interference (78) as the first sensor (64) and generate a second signal (82) having only the interference component (78). A circuit or processor (56, 84, 110, 116) subtractively combines the first (80) and second signals (82) to cancel the interference component (78).

Abstract: For automatically predicting machine failure a transducer sensor, such as piezoelectric crystal, is applied to a machine for sensing machine motion and structure-borne sound, including vibration friction, and shock waves. The structure-borne sound and motion sensed is converted to electrical signals which are filtered to leave only the friction and shock waves, which waves are processed, as by detecting the envelope and integrating beneath the envelope, resulting in a measure of friction and shock wave energy, i.e., stress wave energy. This measure is computed and processed for producing fault progression displays for periodic and aperiodic damage. This is accomplished in a personal computer, menu-driven environment.