Abstract: A catheter tip pressure transducer is employed for purposes of measuring fluid pressure within a living body. This includes a tubular housing having a pressure inlet aperture therein. A semiconductor block is carried within the housing and has first and second oppositely facing surfaces, one of which faces the inlet aperture and the other faces in the opposite direction. One of the surfaces has a recess formed therein of such a depth to define an elongated rectangular shaped membrane. A pair of elongated grooves are formed in the nonrecessed surface of the semiconductor block. These grooves are in registry with and straddle the longitudinal side edges of the membrane and define therebetween a raised longitudinally extending central portion in the form of a membrane beam which acts as a free beam supported at its opposite ends by the semiconductor block.

Abstract: The measuring device (10) comprises an ISFET (12) used as a chemically selective ion sensor, a reference electrode (20) positioned adjacent the ISFET (12), an amplifier (22) coupled to the ISFET and control/correction circuitry (30) coupled to the ISFET (12), to the reference electrode (20) and to the amplifier (22). The control/correction circuitry (30) is operable to maintain the drain-source current I.sub.DS of the ISFET (12) at a constant value and to correct drift effects of the ISFET (12) on the basis of the logarithmic equation:.DELTA.V.sub.p =A 1n(t/t.sub.o +1 )where:.DELTA.V.sub.p =potential driftA=scale factor for drift and amplitudet.sub.o =time constant defining the dependence on timet=time during which the sensor is operative in the event of continuous operation.

Abstract: YA hand-operable dispenser for fluid medicaments is provided in a form which is suitable for implanting same within a human body which permits controlled and convenient dispensing of fluid medicament to a desired somewhat remote location within the body. Propelling assemblies and blocking assemblies are provided and positioned so that they cooperate with each other along a medicament flow channel within the device in order to provide a controlled dispensing of a unit dose of medicament to the desired remote location. The medicament flow channel includes a blocking assembly at its downstream end.