Abstract: A flow head for ventilators includes a tubular open-ended breath transmission passage, and a tubular open-ended inside tube mounted axially inside the breath transmission passage. The inside tube is mounted in the passage by a fixed annular partition, and the ends of the inside tube extend slightly beyond a pair of perpendicular outlet ports on opposite sides of the partition. The inside tube produces a constriction to bi-directional gas flow in the passage which produces a pressure drop across the outlet ports. A pressure sensor connected across the outlet ports measures the pressure drop and therefore produces a measurement of gas flow in the passage. Various sizes of patient gas delivery tubes, endotracheal tubes for ventilator therapy, or tubes for spirometry or anesthesia can be connected to the upstream end of the flow head for producing accurate measurements of gas flow.

Abstract: A flip-type display sign having a plurality of parallel louvers mounted in a frame utilizes flexible fabric louver covers to define the faces of the louvers, with the louver covers being supported on a plurality of cables, extending between a pair of end caps held in spaced relation by a lightweight tubular frame. The fabric covers may be independently removed or replaced or may be internally illuminated.