Diagnosing chronic lung disease still depends heavily on a test that many patients find difficult to complete.
Spirometry requires forceful exhalation, specialist training and equipment that is not consistently available in community care. In the UK alone, at least 600,000 people are waiting for a formal COPD diagnosis, according to figures cited by TidalSense.
Cambridge-based TidalSense has raised $19 million to expand an alternative built around something considerably simpler: asking the patient to breathe normally.
The financing includes new investor Cross-Border Impact Ventures, alongside returning backers BGF, Airstream Capital and Foresight Group. It takes TidalSense’s total funding to $40 million, including $11 million secured through grant programs.
Led by CEO Dr. Ameera Patel, whose own prolonged search for an asthma diagnosis helped shape the company’s mission, TidalSense will use the capital to accelerate commercialization and prepare for US market entry.
The diagnostic information hidden inside an ordinary breath
TidalSense’s N-Tidal Diagnose device asks patients to breathe normally into a handheld instrument for 75 seconds.
The device captures a carbon-dioxide waveform known as a capnogram. AI models then analyze the shape and behavior of that waveform to identify patterns associated with COPD. The company says the full diagnostic process can be completed in under five minutes.
That changes more than the patient experience.
TidalSense says healthcare workers can be trained to operate the device in approximately 10 minutes, without requiring specialist qualifications. A clinic can potentially assess four to six patients an hour, compared with roughly one patient an hour when conventional spirometry appointment and recovery time are included.
Clinical credibility now has to become operational scale
N-Tidal Diagnose became the first non-spirometry AI diagnostic device to receive a Class IIa CE mark under the EU Medical Device Regulation for COPD in March 2025. It entered the NHS later that year and has since been used across healthcare settings in England, Scotland and Wales.
The company reports that its diagnostic models were trained on more than 2.5 million patient breaths. In post-market validation presented at the 2025 European Respiratory Society congress, the system achieved above 90% across major diagnostic-accuracy measures on an unseen patient cohort. These findings are company-reported clinical results and should not be interpreted as universal performance across every population or care setting.
The next challenge is therefore less about proving that the device can recognize respiratory patterns and more about fitting it into everyday healthcare.
Primary-care teams will assess training requirements, referral pathways and whether faster testing translates into earlier treatment. Health systems will examine cost, throughput and performance across more diverse patient populations.
Expansion begins with COPD but does not end there
The funding will support commercialization across the UK, Ireland and Europe, development work for a US launch and further hiring across commercial and operational teams. TidalSense is also extending its diagnostic platform toward additional respiratory conditions, including asthma.
The company says it has received interest from more than 60 countries, reflecting a problem that is not unique to the NHS. Traditional lung-function testing remains difficult to access in many communities, particularly where specialist equipment and trained staff are limited.
TidalSense is not trying to make patients perform spirometry more efficiently. It is asking whether the forced breathing test needs to remain the default at all.
The answer will depend on whether a short, natural breath can produce evidence that clinicians trust across different healthcare systems—not only in controlled validation, but in the crowded reality of frontline care.
Source : Official Announcement