Abstract: A breath analyzing and training assembly for detecting CO2 concentration in the breathing gas of a user, includes a selective colorimetric CO2 detector having a detector surface which rapidly and reversibly changes color with CO2 concentration, when exposed thereto, and an adapter including: a docking part for receiving a mobile unit including an image capturing element, a display, and a processing element, the docking part configured to position the image capturing element in a fixed relation to the colorimetric detector, such that the image capturing element captures images of the detector surface; a detector holding part for receiving the colorimetric detector; a conduit for leading breathing gas to and from the user such that part thereof passes the detector surface; wherein the processing element measures CO2 concentration changes in the breathing gas by identifying color changes of images of the detector surface captured by the image capturing element.

Abstract: A breath analyzing and training assembly for detecting CO2 concentration in the breathing gas of a user, includes a selective colorimetric CO2 detector having a detector surface which rapidly and reversibly changes color with CO2 concentration, when exposed thereto, and an adapter including: a docking part for receiving a mobile unit including an image capturing element, a display, and a processing element, the docking part configured to position the image capturing element in a fixed relation to the colorimetric detector, such that the image capturing element captures images of the detector surface; a detector holding part for receiving the colorimetric detector; a conduit for leading breathing gas to and from the user such that part thereof passes the detector surface; wherein the processing element measures CO2 concentration changes in the breathing gas by identifying color changes of images of the detector surface captured by the image capturing element.

Abstract: An optical-fiber cable for the transmission of light has at least one flexible portion and an invariable curved line over at least a section (11A) of its length. The radius of curvature of this section, and the angle it subtends, are such that a predetermined portion of the intensity of an optical signal being transmitted through the cable is lost in the curved section. Preferably, the radius of curvature of this section is smaller than the smallest radius expected in the flexible portion of the cable. The curved section (11A) eliminates the influence of motion in the flexible portion of the cable on the transmitted signal, which are caused by variations in light leakage due to variations in radius in the flexible portion.

Abstract: A method of increasing the shelf life of a reversible calorimetric device for indicating carbon dioxide is disclosed, which method comprises placing said device together with at least one non-toxic pH-lowering gas in a gas-tight wrapping or casing. A package is also disclosed which is prepared by means of said method. The invention also relates to the use of a non-toxic pH-lowering gas for increasing the shelf life of a device of the above mentioned type.