Method and apparatus for detecting the type of anesthetic gas

• US 7,582,873 B2
• Filed: 12/30/2005
• Issued: 09/01/2009
• Est. Priority Date: 06/10/2005
• Status: Active Grant

• Current Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Original Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Inventors: Zhang, Wei, Li, Xinsheng, Zhou, Huiling, Ye, Jilun
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Baker; David S
• Application Number:
  US11/323,703
• Publication Number:
  US 20060278829A1
• Time in Patent Office: 1,341 Days
• Field of Search: 250/339.13, 250/339.01, 250/339.06, 250/339.12, 250/341.1, 250/343
• US Class Current: 250/339.13
• CPC Class Codes: G01N 2021/3133 with selection of wavelengths before the sample
• CPC Class Codes: G01N 2021/3174 Filter wheel
• CPC Class Codes: G01N 2021/3188 band-limited
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

Disclosed is a method and apparatus for detecting the type of anesthetic gas. The method comprises the steps of: generating a light with a plurality of wavelengths, the light being able to be separated to a plurality of light beams whose central frequencies correspond to the plurality of wavelengths; passing said light through a gas chamber, wherein, the gas chamber being filled with said anesthetic gas, said anesthetic gas having absorption characteristic with respect to said plurality of light beams; detecting the light intensity of the attenuated light beams transmitted from the gas chamber respectively, to obtain the relative absorption characteristic of said attenuated light beams, which attenuated light beams having been absorbed by said anesthetic gas; and determining the type of said anesthetic gas based on the relative absorption characteristic between said attenuated light beams.

Claims

1. A method for detecting a type of anesthetic gas, comprising:

generating a light with a plurality of wavelengths, the light comprising a plurality of light beams with central frequencies corresponding to the plurality of wavelengths;

passing said light through a gas chamber, wherein the gas chamber is filled with said type of anesthetic gas, and said type of anesthetic gas has an absorption characteristic with respect to said plurality of light beams;

detecting a light intensity of each of the plurality of light beams transmitted through the gas chamber to obtain a relative absorption coefficient between selected two of said plurality of light beams attenuated, wherein the plurality of light beams are absorbed by said type of anesthetic gas and are attenuated; and

determining the type of anesthetic gas based on the relative absorption coefficient between the selected two of said plurality of attenuated light beams without determining or identifying a concentration of the anesthetic gas.

2. A method according to claim 1, wherein the act of determining the type of anesthetic gas comprises:

calculating the relative absorption coefficient based on the relative absorption characteristic;

identifying the type of said anesthetic gas based at least in part upon said relative absorption coefficient.

3. A method according to claim 2, wherein, said light is infrared light.

4. A method according to claim 3, wherein, said wavelengths comprise:

8.37 μ

m, 8.55 μ

m, 8.75 μ

m, 9.62 μ

m, and 12.3 μ

m.

5. A method according to claim 4, wherein, said relative absorption coefficient relative to wavelength of 8.55 μ

m are calculated respectively.

6. A method according to claim 2, further comprising:

encoding said relative absorption coefficient; and

sending an encoded information concerning the type of said anesthetic gas.

7. A method according to claim 6, wherein the act of encoding said relative absorption coefficient comprises:

setting a threshold value for the relative absorption coefficient and a determination criteria, wherein if the relative absorption coefficient is larger than the threshold value, setting a corresponding bit in a coding byte as 1, otherwise, as 0.

8. A method according to claim 6, wherein the act of encoding said relative absorption coefficient comprises:

comparing a magnitude of the relative absorption coefficient with a first magnitude of another one or more relative absorption coefficients, wherein if a certain relative absorption coefficient is maximum, setting the corresponding bit in a coding byte as 1, otherwise, as 0.

9. A method according to claim 6 wherein the act of encoding said relative absorption coefficient comprises:

where the relative absorption coefficient is maximum and another particular relative absorption coefficient is minimum, setting the corresponding bit in a coding byte as 1, otherwise, as 0.

10. The method according to claim 1, wherein the act of generating a light comprises:

filtering said light by utilizing a plurality of light filters corresponding to said central frequencies in order to sequentially pass the plurality of light beams each of which corresponds to one of said respective light filters through said gas chamber.

11. The method according to claim 1, wherein the act of detecting one or more light intensities comprises:

filtering said light utilizing a plurality of light filters corresponding to said central frequencies respectively in order to separately detect the each of the plurality of light beams that corresponds to a respective light filter of the plurality of light filters.

12. A method according to claim 1, further comprising:

generating a reference light beam;

passing the reference light beam through said gas chamber filled with said anesthetic gas, wherein said anesthetic gas exhibits substantially no absorption characteristic with respect to said reference light wave; and

calibrating said light intensity of said each of the plurality of light beams which are attenuated after being transmitted through said gas chamber by utilizing said reference light beam as a reference.

13. An apparatus for detecting a type of anesthetic gas, comprising:

at least one light source configured for generating a light with a plurality of wavelengths, the light being separated to a plurality of light beams whose central frequencies correspond to the plurality of wavelengths;

a gas chamber, to which said anesthetic gas is injected, wherein said type of anesthetic gas has an absorption characteristic with respect to one of said plurality of light beams having passed through said gas chamber;

a detecting unit configured for detecting light intensity of the one of the plurality of light beams transmitted through the gas chamber to obtain a relative absorption coefficient between the one of the plurality of light beams and another light beam of the plurality of light beams, wherein the light beams are absorbed by said anesthetic gas after being injected into the gas chamber; and

a determining unit configured for determining the type of said anesthetic gas based at least in part on the relative absorption coefficient without determining or identifying a concentration of the anesthetic gas.

14. An apparatus according to claim 13, wherein said determining unit further comprises:

a calculating unit configured for calculating the relative absorption coefficient based on the relative absorption characteristic;

an identifying unit configured for identifying the type of said anesthetic gas based at least upon said relative absorption coefficient.

15. An apparatus according to claim 14, wherein, said light source is operative to generate infrared lights and said wavelengths comprise:

8.37 μ

m, 8.55 μ

m, 8.75 μ

m, 9.62 μ

m and 12.3 μ

m.

16. An apparatus according to claim 15, wherein, said relative absorption coefficient relative to the wavelength of 8.55 μ

m are calculated respectively.

17. An apparatus according to claim 14, further comprising:

an encoding unit configured for coding said relative absorption coefficient so as to send an information about the type of said anesthetic gas.

18. An apparatus according to claim 13 further comprises:

a plurality of light filters corresponding to said central frequencies being configured to filter said light to pass one of the plurality of light beams which corresponds respectively to one of said light filters through said gas chamber sequentially.

19. An apparatus according to claim 13, further comprises:

a plurality of light filters corresponding to said central frequencies to respectively filter said light having passed through said gas chamber in order to separately detect a respective attenuated light beam which corresponds to one of the plurality of light filters.

20. An apparatus according to claim 13, further comprises:

an unit configured for generating a reference light beam to calibrate the light intensity of said one of the plurality of light beams transmitted through said gas chamber by utilizing a reference light beam as a reference, wherein said anesthetic gas substantially exhibiting no absorption characteristic with respect to said reference light beam.