Magnetic exhalation valve with compensation for temperature and patient airway pressure induced changes to the magnetic field
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
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Jun 30, 1998
Grant Date -
N/A
app pub date -
Mar 14, 1997
filing date -
Mar 14, 1997
priority date (Note) -
In Force
status (Latency Note)
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Abstract
The exhalation valve includes a valve housing with a valve seat having an annular shoulder, and a valve poppet having a face with a corresponding annular groove. A soft flexible diaphragm seal disposed between the face of the valve poppet and the valve seat provides a suspended soft seal, ensuring perpendicularity in the valve seal for improved accuracy of valve operation. An annular permanent magnet and an annular magnetic ring are disposed around and spaced apart from a magnetic body to define an air gap in which an electromagnetic coil is disposed. The electromagnetic coil is connected to a control mechanism by a flexible circuit connector that is sufficiently slack that provides minimal force transverse to the longitudinal axis of the valve. An assembly is provided for adjusting uniformity of the air gap and of concentricity of magnetic body and shaft of the poppet, and the control mechanism adjusts the current supplied to the electromagnetic coil, compensating for changes in the magnetic field strength of the valve due to changes in temperature, velocity of the valve poppet, and patient airway pressure. A flexible diaphragm is also connected between the valve poppet and magnetic body to prevent cross-contamination between the exhalation valve and breathing gas.
First Claim
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