The angle between a small radio frequency coil and a spatially uniform magnetic field is measured and a signal commensurate with the measured angle is employed in a computation of angular position. The apparatus employed in the angle measurement is characterized by a DC frequency response whereby an output signal is produced in the absence of motion between the coil and field.
A self contained sensor apparatus generates a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame. A sensor generates first sensor signals that correspond to rotational accelerations or rates of the body about certain body axes. The sensor may be mounted to the body. Coupled to the sensor is a signal processor for generating orientation signals relative to the external reference frame that correspond to the angular rate or acceleration signals. The first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources. The sensors may be rate sensors. An integrator may integrate the rate signal over time. A drift compensator is coupled to the rate sensors and the integrator. The drift compensator may include a gravitational tilt sensor or a magnetic field sensor or both. A verifier periodically measures the orientation of the body by a means different from the drift sensitive rate sensors. The verifier may take into account characteristic features of human motion, such as stillness periods. The drift compensator may be, in part, a Kalman filter, which may utilize statistical data about human head motion.
A perceptual motor training device uses a non-tactile method of training a patient who has suffered some interruption of his neurological functions to recognize the spatial position and orientation of his body and/or the parts thereof. The device includes an alarm that is activated when a portion of the patient's body moves out of a predetermined test area. The alarm alerts the patient without touching the patient so the patient is forced to use his own internal systems to determine the location and orientation of his body and the parts thereof. The test area is defined by beams and/or fields and can include test areas within the overall test area. The device can also be used in conjunction with the training of gross motor developmental sequences as well.
A self contained sensor apparatus generates a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame. A sensor generates first sensor signals that correspond to rotational accelerations or rates of the body about certain body axes. The sensor may be mounted to the body. Coupled to the sensor is a signal processor for generating orientation signals relative to the external reference frame that correspond to the angular rate or acceleration signals. The first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources. The sensors may be rate sensors. An integrator may integrate the rate signal over time. A drift compensator is coupled to the rate sensors and the integrator. The drift compensator may include a gravitational tilt sensor or a magnetic field sensor or both. A verifier periodically measures the orientation of the body by a means different from the drift sensitive rate sensors. The verifier may take into account characteristic features of human motion, such as stillness periods. The drift compensator may be, in part, a Kalman filter, which may utilize statistical data about human head motion.
A system is described for sensing the relative angular orientation of two relatively movable joint segments of a living body joined together at a joint. The system comprises at least two links coupled together about a pivot axis so that the links are pivotable relative to one another about the axis so as to define a variable mechanical angle between the links about the axis. The two links are secured respectively to the joint segments so that the links pivot about the pivot axis when the joint segments pivot about said joint. A Hall effect sensor is used to accurate sense the mechanical angle. The mechanical angle sensed by the sensor is then correlated with the actual angle made by the joint segments. The arrangement is used with each finger and thumb joint of the hand to provide data representative of finger and thumb orientations of a hand.
A self contained sensor apparatus generates a signal that corresponds to at least two of the three orientational aspects of yaw, pitch and roll of a human-scale body, relative to an external reference frame. A sensor generates first sensor signals that correspond to rotational accelerations or rates of the body about certain body axes. The sensor may be mounted to the body. Coupled to the sensor is a signal processor for generating orientation signals relative to the external reference frame that correspond to the angular rate or acceleration signals. The first sensor signals are impervious to interference from electromagnetic, acoustic, optical and mechanical sources. The sensors may be rate sensors. An integrator may integrate the rate signal over time. A drift compensator is coupled to the rate sensors and the integrator. The drift compensator may include a gravitational tilt sensor or a magnetic field sensor or both. A verifier periodically measures the orientation of the body by a means different from the drift sensitive rate sensors. The verifier may take into account characteristic features of human motion, such as stillness periods. The drift compensator may be, in part, a Kalman filter, which may utilize statistical data about human head motion.
