Abstract: Method, device and system for measuring a degree of torsion or bending of a joint. The method comprises the steps of attaching a sensor (56) to the limbs that are joined by the joint, measuring an output signal of the sensor during torsion or bending at the joint, and a final step of relating said output signal of the sensor to a degree of torsion or bending. The sensor comprises an electrically conductive loop (51), with loop parts that run from one limb to other and back in the loop, the area of said loop at least partially covering both limbs from one limb to the other. The limbs may be limbs of the human or animal body, for instance limbs at a knee. The sensor further comprises an output unit (57) for providing an output signal that is a measure for the inductance of the loop. Calibration data for the sensor may be determined by detecting the output signal of the sensor for a well defined degree of torsion or bending at said joint under static conditions and storing the calibration data.

Abstract: The invention relates to a motion determination apparatus for determining motion of a moving object, wherein the motion determination apparatus (1) comprises a multi-axial accelerometer (2) for being positioned at the moving object (4), wherein the multi-axial accelerometer (2) is adapted to generate accelerometer signals indicative of the acceleration along different spatial axes. The motion determination apparatus further comprises a motion signal generation unit (3) for generating a motion signal indicative of the motion of the object (4) by combining the accelerometer signals of different spatial axes. The combination of the accelerometer signals of different spatial axes yields a motion signal having a large signal-to-noise ratio, even if an axis is located close to a rotational axis of the movement.

Abstract: Method, device and system for measuring a degree of torsion or bending of a joint. The method comprises the steps of attaching a sensor (56) to the limbs that are joined by the joint, measuring an output signal of the sensor during torsion or bending at the joint, and a final step of relating said output signal of the sensor to a degree of torsion or bending. The sensor comprises an electrically conductive loop (51), with loop parts that run from one limb to other and back in the loop, the area of said loop at least partially covering both limbs from one limb to the other. The limbs may be limbs of the human or animal body, for instance limbs at a knee. The sensor further comprises an output unit (57) for providing an output signal that is a measure for the inductance of the loop. Calibration data for the sensor may be determined by detecting the output signal of the sensor for a well defined degree of torsion or bending at said joint under static conditions and storing the calibration data.

Abstract: The invention relates to a motion determination apparatus for determining motion of a moving object, wherein the motion determination apparatus (1) comprises a multi-axial accelerometer (2) for being positioned at the moving object (4), wherein the multi-axial accelerometer (2) is adapted to generate accelerometer signals indicative of the acceleration along different spatial axes. The motion determination apparatus further comprises a motion signal generation unit (3) for generating a motion signal indicative of the motion of the object (4) by combining the accelerometer signals of different spatial axes. The combination of the accelerometer signals of different spatial axes yields a motion signal having a large signal-to-noise ratio, even if an axis is located close to a rotational axis of the movement.