Respiratory air flow sensor
First Claim
1. An air flow sensor for measuring respiratory gas flow, said air flow sensor comprising:
- a tubular member, said tubular member having substantially cylindrical walls defining a passage with a first end opening and a second end opening for the flow of air between a patient'"'"'s mouth and a source of air;
a restriction within said passage, said restriction producing a resistance to said air flow, said restriction comprising a plurality of elongated aerodynamically curved surfaces extending from the cylindrical walls of the tubular member partially inwardly into the passage, each aerodynamically curved surface being spaced apart from the other aerodynamically curved surfaces; and
,first and second longitudinally spaced air ports in one of the elongated aerodynamically curved surfaces for measuring a pressure differential of the air flow across said restriction.
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Accused Products
Abstract
The air flow sensor for a respiratory air flow measuring systems includes a tubular member for providing an air passageway for the flow of air between a patient and a ventilator. The passageway includes a fixed orifice-type obstruction comprised of a plurality of aerodynamically curved vanes which produce a pressure drop as the air flows through the passageway. The air flow rate of the patient'"'"'s respirations is calculated by measuring the pressure differential between two longitudinally spaced apart pressure measuring air ports bored within one of the vanes in the air flow sensor. A third air port hole extracts respiratory gas samples for content analysis.
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Citations
27 Claims
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1. An air flow sensor for measuring respiratory gas flow, said air flow sensor comprising:
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a tubular member, said tubular member having substantially cylindrical walls defining a passage with a first end opening and a second end opening for the flow of air between a patient'"'"'s mouth and a source of air; a restriction within said passage, said restriction producing a resistance to said air flow, said restriction comprising a plurality of elongated aerodynamically curved surfaces extending from the cylindrical walls of the tubular member partially inwardly into the passage, each aerodynamically curved surface being spaced apart from the other aerodynamically curved surfaces; and
,first and second longitudinally spaced air ports in one of the elongated aerodynamically curved surfaces for measuring a pressure differential of the air flow across said restriction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A respiratory air flow sensor for measuring inspired and expired respiratory air flow rates, said respiratory air flow sensor comprising:
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a hollow tube structure, said hollow tube structure having substantially cylindrical walls having an internal diameter defining an air passage having a longitudinal axis; a plurality of fixed vanes spaced apart circumferentially around the internal diameter of the tube structure, each vane having an elongated aerodynamically curved surface oriented lengthwise in a direction parallel to said longitudinal axis, and each vane protruding from the cylindrical walls partially inwardly into said air passage so that each vane is radially spaced apart from the other vanes; and
,in one of said vanes, first and second longitudinally spaced apart lumens for measuring the pressure differential of said air flow through said air passage. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. An air flow measuring apparatus comprising:
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an air flow conduit; a first pressure sensing port in said flow conduit; a second pressure sensing port in said flow conduit, said second pressure sensing port being spaced apart from said first pressure sensing port; said first and second pressure sensing ports providing in combination a means for measuring a pressure differential of air flowing between said ports; and an obstruction in said flow conduit for resisting the flow of air therethrough, said obstruction comprising a plurality of fixed arcuate-shaped vanes within said flow conduit, each arcuate-shaped vane extending partially inwardly into the air flow conduit such that each arcuate-shaped vane is circumferentially and radially spaced apart from the other arcuate-shaped vanes in the flow conduit. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification