Spectroscopic Breath Analysis

The Laser Gas Analyser (LGA) has been developed within the Ritchie Group, and provides highly precise measurements of inhaled and exhaled breath profiles. Spectroscopic systems are embedded within a precision flow sensor, allowing breath-to-breath oxygen consumption and carbon dioxide production to be measured. Recent developments to the LGA have even allowed cardiac function to be assessed in a safe non-invasive way.

Data from the LGA is used in conjunction with a computational model of the lung to provide novel indices of lung inhomogeneity. The level of inhomogeneity in the lung increases with respiratory disease. Our indices of inhomogenity have shown clinical potential in the early-stage diagnosis of COPD, as measures of disease control within asthma, and mostly recently as an assessment of the effect of Covid-19.

The Nitric Oxide (NO) project uses mid-infrared laser radiation produced by a quantum cascade laser combined with cavity enhanced absorption spectroscopy in order to measure the fraction of exhaled NO in breath. Elevated levels of NO indicate the presence of inflamation in the airway and can therefore be used to monitor respiratory disease, most commonly asthma.