Abstract: The present invention relates to a system for use in rehabilitation and/or physical therapy for the treatment of injury or disease. The system can overcome gravity-induced dysfunction in extremity paresis following stroke or other neurological disorders.

Abstract: A flight simulating system is provided with a manually operated control member connected to a servomechanism which responds to manual input by the control member and reacts to provide realistic feedback to the control member in accord with simulated flight conditions. For this purpose, a combining circuit, a dividing circuit and two integrator circuits are provided in series. The combining circuit has an input which represents manual input force to the control member and another input from the flight-simulating computer which represents simulated internal forces acting on the controlled member and the dividing circuit divides the output of the combining circuit by a value representing the mass of the control member to produce a control member acceleration-related signal. This acceleration-related signal is integrated twice to produce, respectively, a control member velocity-related signal and a control member position-related signal.

Abstract: A method of measuring the rigidity, the damping coefficient and the inertia of a system consisting of a damped, spring-supported mass, particularly, the manually operable member of the control-system of an aircraft or a flight simulator, in which method the measurement of the rigidity takes place by determining the relationship between the force exerted on the mass and the deviation of the mass from the state of equilibrium at a speed and an acceleration of substantially zero value and storing the relationship. The method is characterized by the initial step of forming three electric signals--namely, a force signal having a value directly proportional to the force exerted on the mass, an acceleration signal having a value directly proportional to the acceleration of the mass, and a velocity signal having a value directly proportional to the speed of the mass.