BREATH ANALYZER

• US 20170227455A1
• Filed: 09/24/2015
• Published: 08/10/2017
• Est. Priority Date: 03/18/2015
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: KAKUNO, Tsutomu, TAKAGI, Shigeyuki, SHIOMI, Yasutomo, MAEKAWA, Akira, KUSABA, Miyuki, MURAOKA, Isao, HASEGAWA, Hiroshi, MAGARA, Takashi
• Granted Patent: US 9,835,550 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: A61B 5/0833 Measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: G01N 2033/4975 other than oxygen, carbon dioxide or alcohol, e.g. organic vapours
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/0612 Laser diodes
• CPC Class Codes: G01N 2201/12 Circuits of general importance; Signal processing
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/3402 intersubband lasers, e.g. transitions within the conduction or valence bands

Abstract

A breath analyzer includes a light source, a gas cell, a detection unit and a data processing unit. The light source emits infrared light of a wavelength band including an absorption line for acetone. A breath containing sample gas is introduced to the gas cell. The infrared light is incident on the gas cell. The detection unit receives transmitted light emerging from the gas cell, and outputs a sample signal value corresponding to an acetone discharge amount. The data processing unit determines an approximation formula of dependence of fat oxidation rate on acetone discharge amount in advance, and calculates a fat oxidation rate for individual sample signal values using the approximation formula. When the acetone discharge amount (microliter/min) is x, the fat oxidation rate (milligram/min) y is approximated by a following formula: y=Ax+B (where A and B are constants).

Claims

1. A breath analyzer comprising:

a light source that emits infrared light of a wavelength band including an absorption line for acetone;

a gas cell to which a breath-containing sample gas is introduced, and on which the infrared light is incident;

a detection unit that receives transmitted light emerging from the gas cell, and outputs a sample signal value corresponding to an acetone discharge amount; and

a data processing unit that, on the basis of the sample signal value, determines an approximation formula of dependence of fat oxidation rate on acetone discharge amount in advance, and calculates a fat oxidation rate for individual sample signal values using the approximation formula,

the fat oxidation rate (milligram/min) y being approximated by a following formula;

y=Ax+B,

where x is the acetone discharge amount (microliter/min), A is 6 or more and 7 or less, and B is 0 or more and 50 or less.

3. The analyzer according to claim 1, wherein A is 6.52, and B is 33.3.

4. The analyzer according to claim 1, wherein the acetone discharge amount is the product of a breath discharge amount and an acetone concentration.

5. The analyzer according to claim 4, further comprising a flowmeter for measuring the breath discharge amount.

7. The analyzer according to claim 4, wherein A is 6.52, and B is 33.3.

8. The analyzer according to claim 1, wherein the light source includes a quantum cascade laser.

9. The analyzer according to claim 8, wherein the quantum cascade laser has an InP substrate, and an active layer provided on the InP substrate, and including a quantum well layer containing InGaAs, and a barrier layer containing AlInAs.

10. The analyzer according to claim 9, wherein the quantum well layer and the barrier layer are strain compensated.

11. The analyzer according to claim 8, wherein the quantum cascade laser has a GaAs substrate, and an active layer provided on the GaAs substrate, and including a quantum well layer containing GaAs, and a barrier layer containing InGaAs.

2. (canceled)

6. (canceled)

12. A breath analyzer comprising:

a light source that emits infrared light of a wavelength band including an absorption line for acetone;

a gas cell to which a breath-containing sample gas is introduced, and on which the infrared light is incident;

a detection unit that receives transmitted light emerging from the gas cell, and outputs a sample signal value corresponding to an acetone concentration; and

a data processing unit that, on the basis of the sample signal value, determines an approximation formula of dependence of fat oxidation rate on acetone concentration in advance, and calculates an acetone concentration for individual sample signal values using the approximation formula,

the fat oxidation rate (milligram/min) y being approximated by a following formula;

y=Cx+D,

where x is the acetone concentration (ppm), C is 40 or more and 60 or less, and D is 0 or more and 50 or less.

14. The analyzer according to claim 12, wherein C is 51, and D is 32.3.

15. The analyzer according to claim 12, wherein the light source includes a quantum cascade laser.

16. The analyzer according to claim 15, wherein the quantum cascade laser has an InP substrate, and an active layer provided on the InP substrate, and including a quantum well layer containing InGaAs, and a barrier layer containing AlInAs.

17. The analyzer according to claim 16, wherein the quantum well layer and the barrier layer are strain compensated.

18. The analyzer according to claim 15, wherein the quantum cascade laser has a GaAs substrate, and an active layer provided on the GaAs substrate, and including a quantum well layer containing GaAs, and a barrier layer containing InGaAs.

13. (canceled)