Abstract: An apparatus is disclosed for abrading contaminants from the surface of a workpiece using plasma glow discharge. The workpieces are positioned in a low pressure chamber with an ionizable gas. A pair of spaced, conductive, interfacing panels form electrodes mounted within the chamber and defining a three-dimensional cleaning space between the electrodes. The electrodes are energized by a power supply, providing an alternative voltage at an ultrasonic frequency and the pressure is maintained to allow only abnormal glow discharge. After initiation of the abnormal glow discharge the electrode current is sensed to detect when to inject additional ionizable gas into the low pressure chamber.

Abstract: A method for testing the visual system to detect the presence of disease, and to distinguish disease which has degraded the linear visual pathway from disease degrading the nonlinear visual pathway in a manner which is substantially independent of the stimulus applied to the eye and the connection of the instrumentation to the patient being tested. Three light sources having their amplitude varied at different frequencies stimulate the eye. The response evoked in the brain is detected and Fourier analyzed. The amplitude of selected Fourier components are detected and used to compute a ratio which removes the dependence upon the factors stated above. The Fourier component amplitude factors are selected so that the number of factors in the numerator of the ratio is equal to the number in the denominator and the sum of the orders of the factors in the numerator are equal to the sum of the orders in the denominator.

Abstract: A dental implant having a root member formed with a narrowed shoulder at its top around which bone growth stimulating material is packed. The head member has an upstanding taper for receipt of a crown, a frusto-spherical basal portion extending down from the upstanding taper and a tapered rod or socket for connection to the root. The upstanding taper and the root connector rod or socket are aligned along radii of the sphere which defines the spherical surface of the basal portion.

Abstract: A sonic transducer, having a drive electromechanical transducing element and a pickup electromechanical transducing element or a single transducing element electronically operating as both, is excited through suitable power amplifiers by a voltage controlled oscillator. A phase comparator connected to these transducing elements detects the phase difference between stress and strain in the transducer. Its output is connected to an integrator circuit means which integrates the phase difference signal and applies the integrated signal to control the voltage controlled oscillator. The maximum and minimum values of the voltage which is applied to control the oscillator are independently limited by a pair of diodes connected to sources of two different voltages. An adjustably fixable phase shift circuit is interposed between the pickup transducing element and the phase comparator to permit calibration of the system for optimal operation.