Abstract: A humidifier system including a humidifier chamber and heater assembly, microprocessor based control circuitry, and a housing for the control circuitry. The humidifier system is adapted to provide air at nearly 100 percent relative humidity and at a predetermined temperature (e.g. 35.degree. C.) to a medical (e.g. critical care) patient. The humidifier chamber includes a continuous spiral heat exchange path which extends between a vapor storage chamber and an outlet of the humidifier chamber at which an air heating tube is connected, so that outgoing air can be delivered to the patient. The vapor storage chamber is interfaced with a ventilator source of incoming air and a relatively small reservoir in which a supply of water is boiled by the heater assembly for providing vapor saturated air from the vapor storage chamber to the heat exchange path.

Abstract: A system for sequentially providing a volume of gas containing a high frequency oscillation to a proximal airway. In a preferred embodiment a control means periodically drives in synchronism both inhalation and exhalation means into an inspiratory phase of an oscillatory cycle and then into an expiratory phase of the oscillatory cycle. The inhalation means during the inspiratory phase delivers a volume of fresh gas to the proximal airway of a patient, and during the expiratory phase refills itself from a source of low pressure gas while simultaneously blocking therefrom expired gas from the proximal airway. The exhalation means during the inspiratory phase vents to atmosphere expired gas withdrawn from the proximal airway during the previous expiratory phase and simultaneously blocks therefrom fresh gas from said inhalation means and during the expiratory phase extracts the expired volume of gas from the proximal airway.

Abstract: An annular ring having a sealing lip and having two or more annular beads, is installed in a groove. Interacting dimensions of ring and groove are such that the height of one bead added to the thickness of the ring is less than the width of the groove while the height of two opposed beads together plus the thickness of the ring is greater than the width of the groove. The annular beads are formed on the ring such that the ring must deform in order to fit into the groove. Deformation of the ring is accompanied by an angular displacement of the sealing lip so as to form a positive seal.

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 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.