SenseIR: Keeping cardiovascular disease in check
Aurore Vicet, a lecturer at the University of Montpellier and researcher in the Nanomir team at the Institute of Electronics and Systems (IES), is behind the SenseIR project. This technology uses infrared lasers to detect cardiovascular diseases in exhaled air. The clinical study has just begun.
A rapid, non-invasive diagnosis that can be carried out on the move, at the patient's bedside... This is the ambition of the SenseIR project. The fruit of collaboration between the IES, the CHU, the Physiology and Experimental Medicine of the Heart and Muscles laboratory(PhyMedExp), and the Desbrest Institute of Epidemiology and Public Health(Idesp), this promising tool could soon enable the medical world to diagnose cardiovascular diseases thanks to a device capable of detecting certain biomarkers in the air exhaled by patients.
The idea germinated in 2020 on a corner of a table at CHU, when Aurore Vicet, a researcher on the NanoMir team, met CHU physiologist and pulmonologist Fares Gouzi. Until now, NanoMir had only been working on sensors for environmental pollutants, but after a few informal tests on the detection of carbon monoxide levels in breath, the duo got excited. "We knew infrared had great potential. We thought we had to work together. During containment, we responded to a call for projects from Musecall for projects, and we started in October 2020 with Diba Ayache's thesis, followed by Tarek Seoudi's post-doc", recalls Aurore Vicet.
Focusing
In the first few months, the small team set about identifying molecules symptomatic of certain cardiovascular diseases, such as heart failure, and certain respiratory pathologies. In these cases, patients' breath can be overloaded with acetone and carbon monoxide. A total of four gases were selected by Aurore Vicet and Fares Gouzi, who then worked on the different lasers capable of analyzing each of the molecules to get the finest possible reading of the levels present.
A complex and necessary stage. "There were a lot of optical adjustments and instrumentation. We had to set up data acquisition programs and simulations... For some molecules, the fine-tuning was difficult. It requires a high degree of precision", explains Aurore Vicet, who uses the photoacoustic spectroscopy technique here. In short, the idea is to excite the molecules of interest by modulating the infrared rays that each of them is capable of absorbing. This produces a sound that is imperceptible to the ear, but which the researchers are able to relay using a mini quartz tuning fork, like those used in watchmaking.
Clinical study
At the same time, it was necessary to recreate the fictitious conditions of air exhalation for the first tests. "Our breath is hot, full of water and CO2, with great variability between individuals. All these parameters bring additional experimental difficulties. In vivo measurements are always more complicated than basic calibration curves on gas cylinders in a lab", stresses the researcher.
Since the beginning of May, the team has been conducting a clinical study, sponsored by Montpellier University Hospital. In total, it will analyze data collected from 55 heart failure patients and around 20 healthy volunteers. "The study is progressing step by step, regularly including new patients. The idea is to validate the protocol and establish the link between cardiovascular pathologies and gas concentrations at time t", continues Aurore Vicet, who hopes to finish by next autumn, before handing over to Nicolas Molinari, from Idesp, for mathematical modelling which would then enable a "signature" to be defined in heart failure patients.
Patent in the making
Following on from the clinical study, the SenseIR technology could be patented and entrusted to a biomedical company capable of distributing the device. For the time being, however, Aurore Vicet prefers to stick to her core business: research. With Fares Gouzi and an enlarged consortium, she will be launching a new project in the coming months, this time on the influence of environmental pollution on human beings. An opportunity to perpetuate a "very fertile" encounter . It's a wonderful collaboration between medicine and the science of lasers and electronic sensors," enthuses Aurore Vicet. And it's rare enough to be highlighted".