Abstract: A respiration monitor for use in an apnea monitor is disclosed in which a threshold value signal is automatically generated proportional to the average value of the monitored impedance of the subject during a base period selected by the operator. A comparator circuit operates to indicate respiration when the ratio between the threshold value signal and the impedance signal reaches a predetermined proportionality factor.

Abstract: A sensor for transcutaneous measurement of physiological phenomena of living tissues is provided with a thermostatically-controlled electric heater. The purpose of the heater is to induce local hyperemia to enable operation of the sensor. The heater is thermostatically controlled. An independent temperature sensor is provided to disable the heater in the event of catastrophic failure of the thermostat circuit.

Abstract: Disclosed herein is an arrangement for counteracting mass unbalance in a rotatable assembly, such as the rotor assembly of a gyroscope. The invention proposes the use of two coaxially and mutually independently rotatably displaceable, mass eccentricity-producing balance weights, of which each can be assembled with a support element forming part of the rotatable assembly in any one of a great number of angular orientations.

Abstract: Disclosed herein is a fastening element which is susceptible of forming a fastener assembly by engagement with a self-tapping screw. An oblique rib is formed within a bore within a blank, or other structural element, close to the end of the bore. The rib is thus oriented at an angle with respect to the axis of the bore. The result is a rib of substantially eliptical configuration protruding radially inwardly into the bore exclusively from locations along a substantially elliptical closed-loop line upon the cyindrical surface of the bore, the closed-loop line having two turning points of reversal in axial direction component by virtue of the closed-loop line returning into itself. Also disclosed is a void in the rib, and dimensions of the fastener relative to standard externally threaded fasteners which are preferred for high strength and easy driving.