The colorimetric method for detecting CO2 in a durable way was originally conceived for visual indication of the presence of the gas to verify proper tracheal intubation. In the first publication describing this durable technology it is compared to the water vapor sensitive Fenem-technology.
A new colorimetric breath indicator (Colibri). A comparison of the performance of two carbon dioxide indicators. (A. Gedeon, P. Krill and C. Mebius: Anaesthesia 1994;49,798)
This technology has been developed further and used in the products described below as Capnoedge and 2CC sticker
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The colorimetric CO2 indicator can also be used with good results for quatitative CO2 concentration measurements as demonstrated at the ASA meeting in New Orleans in 2014 with the poster shown below.
Mincor AB has further developed this technology for measuring the concentration of CO2 in expired gas using an optical readout and software for quantitative color determination. It is simple, inexpensive and can accurately measure the end expiratory CO2 level and the respiratory rate. It is used in the ELFA device. (see prototype devices)
