Design of an Optical Fibre Carbon Dioxide Sensor for Identifying Oesophageal Intubation

This paper presents a Polydimethylsiloxane (PDMS) coated optical fibre carbon dioxide (CO2) sensor to enable correct tube placement during tracheal intubation. Tube placement remains an important focus as unrecognised oesophageal intubation can lead to severe health complications. The tip of the optical fibre carbon dioxide sensor was functionalised using the Sol-Gel chemical deposition method and attached to the lumen of the tracheal tube, with the tip placed below the Murphy eye. Tracheal and oesophageal intubation has been conducted on 12 sheep using our CO2 monitoring tracheal tube. Results demonstrated that the sensor was able to distinguish between the trachea and oesophagus in 11 out of the 12 subjects, with the sensor on the final sheep being damaged, preventing accurate identification. The sensor also successfully detected breath-to-breath variation of humidity and CO2 in the trachea.Clinical Relevance- Verifying correct tracheal tube placement during intubation is crucial for patient safety, as it reduces the risk of oesophageal intubation. If unrecognised, oesophageal intubation can lead to hypoxia, aspiration, brain injury, and death if not promptly identified and corrected.