COLUMNAR FLOW GAS SAMPLING AND MEASUREMENT SYSTEM
A breath analysis device is described which minimizes mixing of gases between one section of a breath and another section of breath. In particular for example, when sampling and analyzing the end-tidal section of exhaled gas, the system may avoid mixing that can occur inside the device, between the end-tidal sample and the gases before and after the end-tidal sample. The system accomplishes this with an ultra-low uniform cross section fluid pathway, which includes componentry with ultra-low dead space.
1 . An apparatus for measuring a breath analyte comprising:
a nasal prong;
a nosepiece comprising an inlet and an outlet;
a first flow channel extending from the nasal prong to the nosepiece inlet;
a second flow channel within the nosepiece and extending from the nosepiece inlet to the nosepiece outlet, wherein the cross-section of the second flow channel is substantially constant between the nosepiece inlet and nosepiece outlet; and
a third flow channel extending from the nosepiece outlet to a breath measurement system.
2 . The apparatus of claim 1 , wherein all three flow channels form part of a continuous tube.
3 . The apparatus of claim 2 , wherein the continuous tube comprises a cross-sectional diameter between 0.01″ and 0.06″.
4 . The apparatus of claim 3 , wherein the cross-sectional diameter is between 0.02″ and 0.04″.
5 . The apparatus of claim 1 , further comprising a support connected to the nosepiece on an opposite side of the nosepiece outlet, wherein the support is not fluidly connected to the second flow channel.
6 . The apparatus of claim 5 , wherein the support and the third channel are connected, and wherein the support, the third channel, and the nosepiece comprise a loop.
7 . The apparatus of claim 6 , further comprising a connection to couple the support and the third channel, and wherein the loop comprises the connection.
8 . The apparatus of claim 1 , wherein the first, second, and third flow channels are configured for a liner gas flow profile there through.
9 . The apparatus of claim 8 , wherein the flow channels' cross-section diameters are between 0.01″ and 0.06″.
10 . The apparatus of claim 9 , wherein the flow channels' cross-section diameters are between 0.02″ and 0.04″.
11 . A method for measuring a breath analyte comprising:
inserting a nasal prong into a patient, wherein
a first flow channel extends from the nasal prong to the nosepiece inlet, wherein
a second flow channel extends from the nosepiece inlet to a nosepiece outlet, wherein the cross-section of the second flow channel is substantially constant between the nosepiece inlet and nosepiece outlet, and wherein
a third flow channel extends from the nosepiece outlet to a breath measurement system.
12 . The method of claim 11 , wherein all three flow channels form part of a continuous tube.
13 . The method of claim 12 , wherein the continuous tube comprises a cross-sectional diameter between 0.01″ and 0.06″.
14 . The method of claim 13 , wherein the cross-sectional diameter is between 0.02″ and 0.04″.
15 . The method of claim 11 , further comprising a support connected to the nosepiece on an opposite side of the nosepiece outlet, wherein the support is not fluidly connected to the second flow channel.
16 . The method of claim 15 , wherein the support and the third channel are connected, and wherein the support, the third channel, and the nosepiece comprise a loop.
17 . The method of claim 16 , further comprising a connection to couple the support and the third channel, and wherein the loop comprises the connection.
18 . The method of claim 11 , wherein the first, second, and third flow channels are configured for a liner gas flow profile there through.
19 . The method of claim 18 , wherein the flow channels' cross-section diameters are between 0.01″ and 0.06″.
20 . The method of claim 19 , wherein the flow channels' cross-section diameters are between 0.02″ and 0.04″.