Exhalon: blowing to diagnose
Exhalon is a start-up that has developed a technology combining high-resolution mass spectrometry and artificial intelligence to provide ultra-fast, non-invasive diagnosis of respiratory diseases based on exhaled air. Driven by the COVID-19 pandemic, it promises to detect numerous diseases of the lungs and other organs in a range of therapeutic areas.
In 2017, Stanislas Grassin-Delyle, a researcher at the Infection and Inflammation Laboratory (2I - Univ. Paris-Saclay/UVSQ/Inserm) and professor of medicine at UVSQ and Foch Hospital, began working with his team on the analysis of exhaled air. In 2020, boosted by the boom in research into respiratory diseases linked to the COVID-19 pandemic, they developed an initial proof of concept with a patent for the diagnosis of COVID-19. "During the pandemic, we demonstrated in three clinical studies that we could detect the disease in exhaled air with very high sensitivity. Our method allows screening to be carried out in less than a minute, without reagents, using only the patient's breath. Our project is also part of a programme on sepsis (the RHU RECORDS university hospital health research project) at the Prometheus University Hospital Institute (IHU) dedicated to sepsis," explains Stanislas Grassin Delyle. His research is also supported by the Saint-Quentin-en-Yvelines urban community, the Île-de-France region and the French National Research Agency (ANR).
Exhalon was founded in late July 2025 based on these research findings. “Exhalon represents an opportunity to transform innovative technology into a product and to enable the practical application of this research, while meeting market needs,” explains Cécile Chevalier, CEO of Exhalon. The company is made up of a multidisciplinary team of co-founders and is headquartered in Montigny-le-Bretonneux (Yvelines). It is currently incubated at IncubAlliance Paris-Saclay, the public research incubator of the Paris-Saclay cluster. The start-up has been awarded a grant by CARB-X and has received $1 million in funding to support the development of its platform for diagnosing respiratory infections from exhaled air. CARB-X is an international non-profit organisation that promotes the deployment of new solutions to fight antibiotic-resistant bacterial infections.
Detecting molecular signatures
The technology developed by Exhalon analyses the compounds present in exhaled air. "It is based on a completely non-invasive approach: a simple exhalation allows the detection and examination of a large number of molecules that reflect certain physiological processes in the body. The results are obtained quickly, within a few minutes," explains Cécile Chevalier. "It is therefore particularly suitable for sensitive populations, such as children, and specific clinical contexts, for example continuous monitoring in intensive care, where the device is connected directly to the ventilator," adds Stanislas Grassin Delyle.
Using proton transfer mass spectrometry combined with artificial intelligence models, Exhalon is able to detect volatile organic compounds (VOCs) produced by all organs, released into the bloodstream and then eliminated by the lungs in exhaled air. This method could help diagnose various diseases or assess response to drugs in a wide range of therapeutic areas.
More specifically, the patient breathes directly into the mass spectrometer, which then measures the mass of each of the molecules present. The different compounds are quantified by software tools developed with AI. These tools then determine the characteristic signatures of the pathologies of interest. "Thanks to our technology, we have established the signature of the molecules associated with COVID-19. With our data processing algorithm, we can be 98% sure that someone does not have COVID. Positive patients can then take a confirmatory test, but this method reliably identifies negative individuals at a high throughput," explains Stanislas Grassin-Delyle.
Exhalon is focusing initially on detecting respiratory infections, as part of the funding received from CARB-X. The aim is to identify viral and bacterial infections in order to address the challenges posed by antibiotic resistance. Without rapid diagnosis, it remains difficult to provide appropriate treatment for patients. To achieve this, the start-up will conduct a multicentre clinical study analysing the exhaled air of patients of all ages, including those who are intubated, in order to identify molecular signatures associated with respiratory infections.
Launch on the market in 2030
For the time being, the technology developed by Exhalon is only used for medical research, with applications in diagnosis or predicting response to drugs. "We want to transform this technology into a medical device that can be used at the patient's bedside and enable a medical diagnosis to be made with a single breath," explains Cécile Chevalier. It will take between five and seven years before it is available on the healthcare market, as this is how long it takes to obtain CE marking for medical devices.
Once the technology has been validated, the integrated software will be regularly updated to enrich the detectable signatures and expand the range of diagnoses. "This is a project that could bring about a real transformation in patient care. Performing high-throughput diagnostics in a non-invasive manner will help to better monitor patients while improving their comfort and quality of life. Before COVID-19, this was a fledgling discipline and few technologies had been developed. Today, it is a very dynamic field of research. But there is still a lot of knowledge to be gained from a fundamental point of view," concludes Stanislas Grassin Delyle.