- TidalSense has secured $19 million to expand N-Tidal Diagnose, a handheld device that can detect chronic obstructive pulmonary disease from normal breathing in less than five minutes. This device offers a modern alternative to spirometry, which dates back to 1846.
- Chief executive Ameera Patel developed the device after waiting a long time for her own asthma diagnosis. With this funding round, total investment reaches $40 million. The money will help TidalSense expand within the NHS, enter the US market, and work on an asthma diagnostic tool.
- More than 600,000 people in the UK are waiting for a formal COPD diagnosis. Over half of NHS regions do not have enough spirometry capacity to meet the need.
The standard test for chronic obstructive pulmonary disease, or COPD, which is the third-leading cause of death worldwide, was created in 1846. The test needs forceful exhalation, takes almost an hour including training and recovery, and must be done by a specialist.
Ameera Patel faced these challenges herself, which inspired her to create a faster option. Now, her startup TidalSense has raised $19 million to bring this solution to more people around the world.
The funding round includes a new investor, Cross-Border Impact Ventures, a North American health tech impact fund, along with returning investors BGF, Airstream Capital, and Foresight Group. This brings TidalSense’s total funding to $40 million, including $11 million in grants from Innovate UK, SBRI, the National Institute for Health and Care Research, and Asthma + Lung UK.
“We’re still diagnosing in the twenty-first 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,” says Patel.
COPD affects an estimated 1.9 million people in the UK, diagnosed and undiagnosed combined, kills around 30,000 people a year, and costs the NHS £1.9 billion annually. More than 600,000 people are currently living undiagnosed, and more than half of NHS regions do not have the spirometry capacity to meet demand. The condition is the second-leading cause of emergency hospital admissions in the UK, and the World Health Organisation has recently designated it a priority among chronic respiratory diseases.
A founder’s struggle with diagnosis led to ten years of innovation
TidalSense, based in Cambridge, UK, is led by Ameera Patel and co-founder Julian Carter, who has managed hardware development from the start. Over the last 10 years, the team created N-Tidal Diagnose, an AI model trained on 2.5 million patient breaths. In March 2025, the device became the first non-spirometry AI diagnostic tool for COPD to receive a CE mark under EU MDR Class IIa, according to the company.
The startup’s device asks patients to breathe normally into a handheld unit for 75 seconds. This captures a CO2 waveform, called a capnogram, using a method from critical care. The AI then checks these waveforms for signs of COPD. Any healthcare worker can learn to use the test in about ten minutes, without needing special qualifications.
In a 2025 post-market study presented at the European Respiratory Society congress, the device showed over 90% accuracy on key diagnostic measures, compared to 71% for spirometry in primary care. This means GP practices can test four to six patients per hour, instead of just one with traditional spirometry.
“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. 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,” Patel adds.
TidalSense works in a diagnostics field where most competitors are in related areas. NuvoAir, based in Stockholm and Boston, has raised about $28 million and focuses on home spirometry and remote monitoring for chronic diseases. PocDoc, another UK startup from Cambridge, offers point-of-care tests for heart health.
TidalSense stands out as the first non-spirometry device with a CE mark specifically for COPD diagnosis, making it more like a spirometer replacement.
The funding round and what’s next
The money will help commercialise the device in the UK, Ireland, and Europe, support entry into the US market, and develop the asthma diagnosis platform. It will also fund hiring for the growing commercial and operations team.
Donna Parr, managing partner at Cross-Border Impact Ventures, who joins TidalSense’s board with the investment, shares, “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.”
TidalSense’s funding round comes as more investors show interest in point-of-care diagnostics, helping companies like Neko Health and Level Zero Health as well. The main challenge is whether busy primary care systems can adopt new devices fast enough to reduce the 600,000-person diagnostic backlog before it grows.
