In order to record intracranial pressure continuously, we have recently developed a microminiature pressure transducer using semiconductor strain gauges. The pressure cell has a small disk-shaped structure, and it can be directly inserted into the intracranial cavity through a small burr hole. Previous investigations of the semiconductor strain gauge have dealt almost exclusively with the field...

This paper presents a high sensitive micro-sensor designed for pressure measurements in a wide range around atmospheric pressure, for application in aerodynamics. The sensor is a temperature-resistance transducer operating with the Pirani effect, which states that below a certain pressure limit, the thermal conductivity of a gas is pressure-dependent. The sensor presents a wide measurement rang...

Eustachian tube function is important in pressure regulation of the middle ear. The efficacy or magnitude of pressure equilibration by tube openings should be determined by the gradient between middle ear and ambient pressure, but in theory also the duration of the tube opening may play a role. This study employed direct measurements of middle ear pressure in patients, who after parotidectomy h...

This paper presents an ultra low-power and low-voltage pulse-width modulation based ratiometric capacitive sensor interface. The interface was designed and fabricated in a standard 90 nm CMOS 1P9M technology. The measurements show an effective resolution of 10 bits using 0.5 V of supply voltage. The active occupied area is only 0.0045 mm2 and the Figure of Merit (FOM), which takes into account ...

Sir,—The study by Shah, Swai and Latto (1986) comparing the venous pressures measured from the proximal external jugular vein and from a central vein was interesting. The authors found a mean difference in pressure of 3 mm Hg from the two sites which was not influenced by alterations in the head position or the side of jugular venous catheterization. Whether the reference zero is the right atri...