Abstract: A flow detector including an orifice for forming a vena contracta to activate a connected pressure detector so as to trigger an alarm mechanism upon the occurrence of disconnect of the patient exhalation valve in a mechanical ventilator system. A configuration of the flow detector makes erroneous hookup of the ventilator and pressure detector hoses all but impossible.

Abstract: Fluid level detection means utilizing a thermally conductive element in the general shape of a cone, in one embodiment, in direct contact with fluid whose level is to be detected. A portion of the element, excluding the apex, is directly heated. A thermal sensor is bonded to the apex. When the fluid depletes such that the apex is exposed to air, the temperature in the immediate vicinity of the apex rises to a new point of equilibrium. The sensor converts this elevated temperature into a signal recognized by electronic circuitry as a flow fluid level. This signal may subsequently be used to provide visual or audible alarm.

Abstract: A refilling device incorporated into mechanical ventilator machines as used in medical systems wherein a funnel is incorporated into the molded cover of a humidifier chamber. A lower portion of the incorporated funnel when attached to the humidifier chamber, defines a high fluid level at its narrow cylindrical dimension while the upper, wide cone-like dimension is covered by being fitted with sealing filler cap.

Abstract: A sensor for the detection of a very feeble effort to breathe on the part of a patient whose breathing needs are under the influence and control of a mechanical ventilator. A self-heated thermistor is mounted in a small diameter sensor tube. A diaphragm and chamber arrangement limits the volume of air that flows in the sensor tube past the self-heated thermistor. The self-heated thermistor is mounted in the center of the small diameter sensor tube so that a low volume flow rate of fluid will cause a relatively large amount of cooling. Thus a very small effort to breathe will draw a limited volume of fluid past the thermistor at a high velocity, causing rapid cooling. A voltage change resulting across the thermistor is utilized to signal a patient effort to breathe and to command the ventilator to furnish an assisted breath where appropriate.

Abstract: A one-piece, integrally molded diaphragm for use in exhalation valves of respiratory apparatus to prevent the propagation of harmonic acoustic vibrations. High frequency oscillations are prevented from propagating by means of mechanical damping. The damper takes the form of a thin circular flutter sheet molded onto the face of the diaphragm and extending past the sealing area of a valve seat.