Extending Human Lung Monitoring by Laser Spectroscopy From Infants Toward Adults: Initial Proof of Concept in a Porcine Lung Model

ABSTRACT Lung function monitoring and prompt diagnosis of lung impairment are essential for optimal patient care. During surgery, anesthesia and ventilator assistance are standard, and mechanical ventilation is often required in severe cases, as highlighted during the recent COVID‐19 pandemic. There is a clear need for powerful, real‐time lung surveillance techniques that can provide feedback to ventilator settings. Gas in Scattering Media Absorption Spectroscopy (GASMAS) measures oxygen and water vapor in the gas‐filled cavities of the lungs, enabling assessment of lung aeration and oxygen concentration. Proof‐of‐concept studies in neonates have demonstrated the potential of GASMAS for continuous lung monitoring. This paper presents progress toward extending the method to older children and adults. By employing a semiconductor tapered amplifier, the diode‐laser output at the oxygen absorption wavelength (764 nm) was increased from ~30 mW to 900 mW. This enhanced power enabled model experiments on a polystyrene phantom and on ventilated porcine lungs, with added pork slabs simulating up to 9 cm total tissue thickness. Strong oxygen absorption signals were detected with both external illumination and internal delivery via the tracheal tube, demonstrating the potential of GASMAS for non‐invasive lung monitoring in large tissue phantoms simulating larger patient populations.