Abstract: Embodiments of the invention relate to a mask assembly for use in treatment systems for treating obstructive sleep apnea using continuous positive air pressure (CPAP). The mask assembly comprises a mask or nasal interface for supplying gas to the nose of a wearer of the mask assembly. The mask assembly also comprises a strap or harness attached to the mask for securing the mask assembly to the wearer and sensors located on the mask assembly for measuring physiological signals of the wearer. These physiological signals are communicated to a monitoring unit which, in association with a CPAP device, serves to determine the efficacy of the CPAP treatment and to vary operational parameters of the treatment.

Abstract: Embodiments of the invention generally relate to needles having more than one electrode and which are particularly suited for use in electromyography. One embodiment relates to a tripolar needle having three concentric electrodes. The tripolar needle is formed by providing a needle blank having first and second concentric electrodes and forming a third concentric electrode around the needle blank. The tripolar needle has an outer diameter which is substantially constant along the shaft of the needle, except at the tip, where the needle is sharpened.

Abstract: An electronic light pen used in conjunction with a video display permits the position of the light pen to be determined with respect to the video display by the particular color or grey scale value of light emitted by the video display and received by the electronic light pen. The light from the video display is separated into three primary colors for a color display, namely red, blue, and green, and separated into grey scale shades for a monochrome display. Positional information of the light pen is calculated based on the relation of the color measured to the color previously programmed and presently displayed on that area of the screen, at any instant in time. The light pen has a focusing system that focuses light from the display to its optical detectors. The optical detectors have red, green, and blue filters to determine the brightness of each color. A grey scale value may be determined if the display is monochrome.

Abstract: A therapeutic ultrasound generator controlling an ultrasonic transducer based on actually sensing the amount of power radiated by the transducer to the patient. A controllable ultrasound generator, supplies a controllable amount of electric power to a transducer. A sensing circuit, coupled to the transducer, senses an amount of power radiated by the transducer. A control loop, which is responsive to the amount of power radiated, and a preset radiation power, controls the controllable amount of electric power delivered to the transducer. The radiation power is sensed by detecting an instantaneous current through the transducer, and an instantaneous voltage across the transducer. The instantaneous current and voltage are then used to compute an impedance. The computed impedance, and known characteristics of the transducer, are used to determine the actual amount of power radiated by the transducer to the patient.