Highly accurate breath test system
First Claim
1. A system for testing the air present in the breath of a person, said system comprising:
- a sensor unit comprising;
a chamber having an inlet disposed at one end of said chamber and an outlet disposed at the opposite end of said chamber;
a fan disposed in said inlet for selectively flowing air from a breath of a person through said inlet and into said chamber, wherein said fan is configured to (i) permit air to flow through said inlet when said fan is rotating, and (ii) substantially prevent air from flowing through said inlet when said fan is not rotating;
a one-way valve disposed in said outlet for (i) permitting air to exit said chamber through said outlet and (ii) preventing air from entering said chamber through said outlet;
a first sensor element configured to detect the presence and/or concentration of a volatile substance present in said chamber and to generate a signal corresponding to the presence and/or concentration of said volatile substance; and
a second sensor element configured to detect the presence of a tracer gas in the air in said chamber;
wherein said sensor unit is configured to stop rotation of said fan upon detection of said tracer gas in said chamber by said second sensor element so as to substantially prevent air from flowing through said inlet; and
an analyzer configured to determine the concentration of said volatile substance in the breath of the person, the determination being based on said signal from said first sensor element corresponding to the volatile substance concentration.
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Accused Products
Abstract
The invention relates to a system for breath test of a person. It includes a sensor unit configured to sense the presence/concentration of a volatile substance, e.g. alcohol, present in air flowing through a predefined inlet area and generating a signal corresponding to the concentration of said substance. An analyzer determines the concentration of said substance in the breath of said person. It comprises means for the temporary interruption of said air flow at a point in time coinciding with the detection of a breath. It also relates to a method comprising interrupting the flow through said predefined area for a predetermined period of time, and detecting the concentration of said substance during said interruption.
114 Citations
13 Claims
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1. A system for testing the air present in the breath of a person, said system comprising:
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a sensor unit comprising; a chamber having an inlet disposed at one end of said chamber and an outlet disposed at the opposite end of said chamber; a fan disposed in said inlet for selectively flowing air from a breath of a person through said inlet and into said chamber, wherein said fan is configured to (i) permit air to flow through said inlet when said fan is rotating, and (ii) substantially prevent air from flowing through said inlet when said fan is not rotating; a one-way valve disposed in said outlet for (i) permitting air to exit said chamber through said outlet and (ii) preventing air from entering said chamber through said outlet; a first sensor element configured to detect the presence and/or concentration of a volatile substance present in said chamber and to generate a signal corresponding to the presence and/or concentration of said volatile substance; and a second sensor element configured to detect the presence of a tracer gas in the air in said chamber; wherein said sensor unit is configured to stop rotation of said fan upon detection of said tracer gas in said chamber by said second sensor element so as to substantially prevent air from flowing through said inlet; and an analyzer configured to determine the concentration of said volatile substance in the breath of the person, the determination being based on said signal from said first sensor element corresponding to the volatile substance concentration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. The method of performing a breath test of a person, comprising the steps of:
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providing a system for testing the air present in the breath of a person, said system comprising; a sensor unit comprising; a chamber having an inlet disposed at one end of said chamber and an outlet disposed at the opposite end of said chamber; a fan disposed in said inlet for selectively flowing air from a breath of a person through said inlet and into said chamber, wherein said fan is configured to (i) permit air to flow through said inlet when said fan is rotating, and (ii) substantially prevent air from flowing through said inlet when said fan is not rotating; a one-way valve disposed in said outlet for (i) permitting air to exit said chamber through said outlet and (ii) preventing air from entering said chamber through said outlet; a first sensor element configured to detect the presence and/or concentration of a volatile substance present in said chamber and to generate a signal corresponding to the presence and/or concentration of said volatile substance; and a second sensor element configured to detect the presence of a tracer gas in the air in said chamber; wherein said sensor unit is configured to stop rotation of said fan upon detection of said tracer gas in said chamber by said second sensor element so as to substantially prevent air from flowing through said inlet; and an analyzer configured to determine the concentration of said volatile substance in the breath of the person, the determination being based on said signal from said first sensor element corresponding to the volatile substance concentration; detecting the presence of said tracer gas in said chamber using said second sensor element; interrupting the flow of air into said chamber by stopping rotation of said fan; detecting the presence and/or concentration of said volatile substance present in said chamber using said first sensor element; generating a signal corresponding to the concentration of said volatile substance; determining the concentration of said volatile substance in the breath of said person using said analyzer, wherein said determination is based on said signal corresponding to the concentration of said volatile substance in said chamber.
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Specification