Abstract: A respiratory test apparatus for lung function comprises a chamber into which air can be blown by a subject to displace a piston. The chamber communicates with a space shielded from the incoming air flow to provide a measure of the static air pressure in the chamber, a pressure transducer providing an input of that pressure value a data processor. The data processor is arranged to provide outputs indicative of such functions as a subject's peak respiratory flow rate and the volume of air exhaled.

Abstract: An apparatus for detecting and measuring changes in the shape of a wall of a body includes a detector capsule adapted for attachment to the wall and pneumatically connected to a volume transducer responsive to changes in the internal volume of the apparatus produced by changes in the shape of the wall. The internal volume of the capsule is partially defined by a flexible diaphragm for engagement and complementary movement with the wall. The capsule contains a resiliently deformable material which presses the diaphragm into contact with the wall regardless of the convex or concave shape of the wall.

Abstract: It is proposed that respiration in neonates, and respiration and contractions in woman in advanced pregnancy and labour, be detected and measured by direct reference to change of curvature of the abdominal wall during expansion and contraction thereof. An apparatus for this purpose, an abdominal spherometer, comprises a detector capsule having one wall defined by a resilient diaphragm for engagement with the abdominal wall, the capsule being pneumatically connected to a variable volume compartment operably connected, in turn, to a volume-responsive transducer. The compartment is suitably of similar form to the capsule with the transducer being a capacitor having electrodes respectively located as or on the compartment diaphragm and opposite thereto.

Abstract: A breath sampling device in which a main flow tube through which a subject blows is provided with a venturi restriction. The main flow tube communicates through a passage at the restriction to pressure sensing, constituent sensing, and expansible sample collecting chamber. A control responsive to pressure change delays the operation of the sampler and sensor until breath flow rate diminishes, thus insuring that sampling and sensing occur near the end of expiration.

Abstract: Apparatus for driving a medical syringe plunger into its barrel at a variable controlled rate comprises an elongate support along which the syringe is secured, an electric motor, a transmission assembly drivably coupled with the motor to close the plunger into the barrel, a drive control for pulsing the motor to effect repeated constant incremental movements of the plunger through the transmission assembly, and a safety control operable to inhibit the drive control in response to continuous energization of the motor beyond a predetermined period. The safety control conveniently involves a capacitor charged by the motor pulses, and a latch activated by an "excess" charge on the capacitor relative to a normal situation.