Apparatus for testing pulmonary functions
First Claim
1. A pulmonary functions testing apparatus comprising in combination:
- a body having a passageway therethrough;
an aspirator orifice entering said passageway through said body;
means to measure the volume of air passing through said passageway, said means being responsive to the negative pressure generated at said aspirator orifice, said means to measure the volume of air passing through said passageway including a reverse acting expansible chamber, which chamber reduces its volume in proportion to the volume of air passing through said passageway; and
indicating means to indicate the volume measured by said measuring means, whereby the volume of gas passing through said passageway can be determined.
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Accused Products
Abstract
An apparatus for testing pulmonary functions uses a hollow tube having a venturi therein and an aspirator orifice in the hollow tube adjacent the venturi. A pressure signal analogous to the flow of air through the hollow tube is generated in the aspirator orifice. Various means are provided to respond to the pressure at the aspirator orifice and a timed cut off of the aspirator orifice is provided for measuring the flow for a predetermined time period, such as one second, thereby indicating the forced expiratory volume for one second (FEV1) without having to blow into expansible chambers, such as bellows or bags to determine the volume of air passing through the tube. The apparatus is adapted to measure the total volume of air passing through the tube, or the total volume during a predetermined time period. Timed cut off of the aspirator orifice is accomplished by both mechanical and electrical means and the measuring of the aspirator orifice pressure is accomplished either with a liquid column or with an enclosed variable volume chamber, having electrical or mechanical indicators to determine the position of the reduced volume in the chamber.
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Citations
50 Claims
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1. A pulmonary functions testing apparatus comprising in combination:
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a body having a passageway therethrough; an aspirator orifice entering said passageway through said body; means to measure the volume of air passing through said passageway, said means being responsive to the negative pressure generated at said aspirator orifice, said means to measure the volume of air passing through said passageway including a reverse acting expansible chamber, which chamber reduces its volume in proportion to the volume of air passing through said passageway; and indicating means to indicate the volume measured by said measuring means, whereby the volume of gas passing through said passageway can be determined. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A pulmonary functions testing apparatus comprising in combination:
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a body having a passageway therethrough and a venturi formed in the passageway thereof; an aspirator orifice opening into said passageway through the wall thereof adjacent said venturi; measuring means to measure the volume of gas passing through said tube responsive to the pressure generated at said aspirator orifice, said means including a reverse acting expansible chamber actuated by negative pressure at said actuator orifice upon a patient breathing through said passageway; and timing means for timing the volume of gas passing through said passageway for a predetermined time period, whereby said measuring means indicates the volume of gas passing through said passageway during said predetermined timed period. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50)
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Specification