US 12,324,570 B2
Apparatus for the detection of carbon dioxide
Jean-Nöel Fehr, Brønshøj (DK); Jean-Christophe Roulet, Brønshøj (DK); Patrizia Weber, Brønshøj (DK); Julien Finci, Brønshøj (DK); and Lukas Scherer, Brønshøj (DK)
Assigned to RADIOMETER BASEL AG, Basel (CH)
Appl. No. 16/954,721
Filed by Radiometer Basel AG, Basel (CH)
PCT Filed Dec. 14, 2018, PCT No. PCT/EP2018/084959
§ 371(c)(1), (2) Date Jun. 17, 2020,
PCT Pub. No. WO2019/121395, PCT Pub. Date Jun. 27, 2019.
Claims priority of application No. PA 2017 00742 (DK), filed on Dec. 22, 2017.
Prior Publication US 2021/0085295 A1, Mar. 25, 2021
Int. Cl. A61B 10/00 (2006.01); A61B 5/00 (2006.01); A61B 5/145 (2006.01); G01N 33/497 (2006.01)
CPC A61B 10/00 (2013.01) [A61B 5/14542 (2013.01); A61B 5/443 (2013.01); G01N 33/497 (2013.01); A61B 2010/0083 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus for detection of carbon dioxide, comprising:
(a) a housing;
(b) a gas measuring chamber;
(c) a radiation source configured to emit radiation;
(d) a first radiation detector;
(e) a second radiation detector; and
(f) a radiation filter;
wherein, the gas measuring chamber, the radiation source, the first radiation detector, the second radiation detector, and the radiation filter are housed within the housing;
wherein, a part of the housing is configured to be placed in contact with a skin area of a patient;
wherein, the part of the housing and the gas measuring chamber are configured such that gases diffusing through the skin area of the patient enter the gas measuring chamber;
wherein, the gas measuring chamber and radiation source are configured such that at least some of radiation emitted by the radiation source enters the gas measuring chamber, and wherein the radiation entering the gas measuring chamber has wavelengths that extend over an absorption band of carbon dioxide and has wavelengths that extend over a region other than the absorption band of carbon dioxide;
wherein, the radiation filter is positioned relative to the gas measuring chamber such that an interaction radiation path is defined between the radiation source through the gas measuring chamber to the radiation filter and wherein the radiation filter acts as a first gaseous seal to the gas measuring chamber;
wherein, the first radiation detector is positioned relative to the radiation filter such that a first detection radiation path is defined that is in addition to the interaction radiation path; and wherein the second radiation detector is positioned relative to the radiation filter such that a second detection radiation path is defined that is in addition to the interaction radiation path;
wherein the radiation filter is configured such that the second detection radiation path comprises radiation transmitted through the radiation filter, and the first detection radiation path comprises radiation reflected from the radiation filter to thereby extend from the radiation filter to the first radiation detector;
wherein the radiation filter is configured such that the radiation in the first detection radiation path has wavelengths that extend over the absorption band of carbon dioxide and with an intensity of radiation that extends over the region other than the absorption band being significantly less than that in the interaction radiation path;
wherein the radiation filter is configured such that the radiation in the second detection radiation path has wavelengths that extend over the region other than the absorption band of carbon dioxide and with an intensity of radiation that extends over the absorption band being significantly less than that in the interaction radiation path; and
wherein signals from the first and second radiation detectors are useable to determine a partial pressure of carbon dioxide in the skin area of the patient.