Abstract: An active and continuous passive motion (CPM) devices for exercising and/or providing therapy to the upper and lower extremities comprising a frame, a disc pivotally mounted to the frame and hand or feet support members attached to the disc. A motor is provided and is coupled to the disc for rotating the disc in the active mode. A control circuit is provided for adjusting the speed of the disc in the passive mode and for adjusting the resistance to movement of the disc in the active mode.

Abstract: The present invention provides a method and apparatus for nondestructive, in situ measuring thicknesses of layers on substrates. The method and device uses a probe including a radioactive source in a source holder and a photodetector mounted behind the source for detection of backscattered photons. In one aspect the method is used to measure the thickness of paint deposited onto metal substrates. The source holder and photodetector array forms a cylindrically symmetric probe for producing an axially symmetric beam of primary photons. A source containing radioactive .sup.109 Cd producing high energy photons of energy 22 and 25 keV is spaced from the painted surface so the photons impinge on the painted substrate. The intensity of photons backscattered by Compton scattering in the paint layer is proportional to the mass density of the paint to give a direct measurement of the paint thickness. The photons penetrating through to the substrate are absorbed within the substrate.

Abstract: An electronic inductive switching power amplifier designed for but not limited to amplification of electrical audio signals consists of a power conversion system, a signal control system together with a direct current power source wherein the power conversion system comprising of a pulse width modulator circuit, primary semiconductor switches and a high frequency switching transformer wherein the direct current power source is pulse width modulated through primary winding on the switching transformer by the primary semiconductor switches being controlled by the pulse width modulator. The switching transformer further comprises of a secondary winding wherein the primary to secondary winding ratio effects the required power conversion and amplification.