TidalSense, a respiratory diagnostics startup, has raised £14 million in funding from Cross-Border Impact Ventures, BGF, Airstream Capital and Foresight Group. Based in Cambridge, TidalSense has built N-Tidal Diagnose, a device that detects chronic obstructive pulmonary disease from 75 seconds of normal breathing rather than the forced exhalation required by spirometry.
COPD is the United Kingdom's third biggest cause of death, killing around 30,000 people a year and costing the NHS £1.9 billion annually. An estimated 1.9 million people are living with the condition, diagnosed and undiagnosed combined, and at least 600,000 people in the United Kingdom are currently waiting for a formal COPD diagnosis. Spirometry, the test they are waiting for, requires forceful exhalation and specialist training to administer, and can take the best part of an hour per patient when wait and recovery time are counted. N-Tidal Diagnose instead captures a CO₂ waveform, or capnogram, of the kind traditionally used in critical care, which a set of AI models analyses to detect COPD. Any healthcare professional can be trained to use the device in 10 minutes, with no specialist qualification required, and clinicians can see four to six patients an hour compared with roughly one an hour using traditional spirometry.
The AI diagnostic models behind N-Tidal Diagnose have been trained on more than 2.5 million patient breaths, and the patented technology is the product of more than a decade of R&D led by some of the leading experts in the field. In the first post-market validation of the device, presented at the European Respiratory Society congress in 2025 and conducted on a completely unseen patient cohort, N-Tidal Diagnose achieved above 90% performance across all key metrics of diagnostic accuracy, against the 71% precision of existing spirometry in primary care. In March 2025 the software became the first non-spirometry AI diagnostic device to receive a CE mark under EU MDR (Class IIa) for COPD, and it launched into the NHS in September 2025. Commissioned by Suffolk and North-East Essex Integrated Care Board, use of the device has since expanded into NHS Wales, community lung screening clinics in the South of England, and now Glasgow, with inbound interest arriving from over 60 countries.
The round takes total funding to £30 million, including $11 million of grant funding, and will fund accelerated commercialisation in the United Kingdom, Ireland and Europe, support market entry work in the United States, extend the diagnostic platform to new indications such as asthma, and continue hiring, particularly across a growing commercial and operations team. Ahead of the United States expansion, the senior bench has been deepened with Andrew Wheeler, Director of Market Access and Public Policy, joining from NICE, Eric Mayes as Non-Executive Director, who was founding CEO of Endomagnetics, the UCL spinout acquired by Hologic for $310 million in 2024, and Donna Parr, who joins the board with more than 30 years of tech and health tech investment experience. They join a leadership team including co-founder and Chief Engineering Officer Julian Carter, who has led the technical development of the CE-marked N-Tidal hardware devices since founding.
Respiratory disease has been neglected by governments and health systems for years, often overshadowed by cancer and cardiovascular disease, even though it affects one in five people. That's finally starting to change. The World Health Organization now recognises COPD as a global health priority, and it's about time. Part of the problem has always been how we talk about it: COPD is widely seen as a smoker's disease, but a quarter of cases come from air pollution and the biomass fuel millions still cook with every day. We're still diagnosing in the 21st century with a test invented in the 1800s, and one that needs specialist equipment and training most of the world doesn't have access to. Lower income and minority communities pay the price for that first. That's the gap we want to close at TidalSense, and the NHS is the first place we're doing it.
We look for technology that doesn't just have a compelling story, but a body of clinical evidence behind it. TidalSense has both, with a CEO who has lived the problem she's solving, and a product that's already live within the NHS healthcare environment, saving time for patients who have waited years for an answer. It is also technology that can improve access to appropriate treatment for COPD sufferers on a global basis and especially for women who are often misdiagnosed. This is exactly the kind of impact we want to make with our investments.
GPPC deployed N-Tidal Diagnose last year, and the test has proven to be a simple, effective, and accessible diagnostic tool for patients. Unlike traditional spirometry, N-Tidal Diagnose requires only relaxed, normal breathing rather than forced exhalation, making it suitable for a wider range of patients, including those who may previously have been unable to undertake spirometry due to contraindications or practical challenges. N-Tidal Diagnose has enabled us to offer an alternative diagnostic assessment, supporting earlier and more inclusive access to COPD diagnosis and care. Feedback from patients has been overwhelmingly positive, with many valuing the simplicity of the test and the significantly shorter appointment times compared with traditional spirometry.
