Inhalation detector

Details Inhalation detector Inhalation detector

2005-04-12

2005-04-12

Lefkowitz, Edward (Department: 2855)

Measuring and testing

Fluid pressure gauge

Diaphragm

C073S724000, C073S514320

Reexamination Certificate

active

06877382

ABSTRACT:
A detector providing an electrical signal in response to the pressures encountered in sensing breath inhalation in respirators. The detector uses a capacitive pressure sensor formed by a flexible conductive diaphragm separated from fixed electrodes by a layer of dielectric film. Deflection of the diaphragm by pressure introduces a low permittivity space in the sensor resulting in a substantial change in capacitance. The change in capacitance modifies the frequency of an oscillator. A frequency responsive circuit provides balancing electrostatic force feedback voltage to the diaphragm. The force feedback stiffens the diaphragm and maintains it in a high capacitance, high sensitivity state. This feedback reduces sensitivity to changes in the diaphragm mechanical properties. Signal filtering reduces the effects of long term drift and environmental factors.

REFERENCES:
patent: 4366716 (1983-01-01), Yoshida
patent: 5134886 (1992-08-01), Ball
patent: 5531128 (1996-07-01), Ryhanen
patent: 5641911 (1997-06-01), Ryhanen
patent: 6496348 (2002-12-01), McIntosh
patent: 20010047689 (2001-12-01), McIntosh
patent: 20020033048 (2002-03-01), McIntosh et al.

Affiliated with

Also associated with

Rating

Inhalation detector does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Inhalation detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Inhalation detector will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3391267