Catch your breath: a device that spots critical Covid-19 cases

Amid the Covid-19 crisis, Cambridge Respiratory Innovations has been working to scale up production of its flagship capnometer. Natalie Healey speaks to CEO James Whitticase to find out more about the tech, and the challenges for a small company looking to make a dent in a global challenge.


ames Whitticase certainly didn’t have a pandemic in mind when he took over the reins of start-up Cambridge Respiratory Innovations last September. But, while many people brushed off reports of a deadly pneumonia of unknown cause in Wuhan, China at the start of the year, he grew anxious. He had a feeling the then-mysterious infection wasn’t going to be contained. He then started to wonder if his company might be able to help should his worst fears be realised.

“I think a lot of doctors looking at China knew Covid-19 was coming over,” says health tech CEO and former NHS clinician Whitticase. “We knew it was different from SARS and bird flu. The general impression was this is more contagious, it's spreading easier and it's more vicious when it gets hold of you.”

Whitticase was right to trust his instincts, because spread it did. The World Health Organization declared the coronavirus SARS-CoV-2 a pandemic on 11 March. It soon became clear that in many countries there would be too few ventilators for the number of patients succumbing to the infection. Doctors would likely have to make tough decisions about who they should prioritise for this treatment. But it can be hard to quickly work out which Covid-19 patients need ventilating and who can safely remain on the wards.

“All patients are presenting with symptoms but they're also all sitting there happily on their mobile phones with oxygen masks on,” Whitticase points out. “The clinical teams are thinking ‘everybody's looking comfortable, but they're all pretty critical, how do we spot who we should be ventilating?’.”

He hopes the company’s flagship product, N-Tidal, an ultrasensitive handheld capnometer which monitors patients’ breathing could soon flag to NHS clinical teams which patients are deteriorating and need urgent treatment, and potentially save lives.

N-Tidal has an unlikely origin story. It’s the brainchild of two founding directors, engineer Julian Carter and physician John Altrip, who stumbled upon a commercial air conditioning unit with impressive sensitivity. They wondered if they could make a similarly sensitive device to monitor carbon dioxide at a patient’s mouth. Collecting this data from normal breathing could provide new insights into an individual’s lung function, they reasoned.

In the breath

The purpose of the lungs is to supply blood with oxygen and remove carbon dioxide from it. Therefore, measuring carbon dioxide levels in the breath is an indicator of how well these organs are working. Traditionally, measuring the gas breathed out is achieved via a diverted breath sample.

“You breathe into a face mask, it takes your breath down the tube, and then you have a little sensor somewhere down that tube that measures carbon dioxide,” Whitticase says. “But it does it really crudely. By doing it straight from the mouth, it's very accurate, very sensitive and collects a huge amount of data.”

By measuring patients’ normal breathing at rest, the handheld N-Tidal device transmits respiratory data in real-time via 3G mobile phone networks to a cloud-based software platform. Originally developed for conditions such as chronic obstructive pulmonary disease and asthma, the same principles can apply to Covid-19. It can tell doctors how badly the disease is impacting the lungs.

“Importantly for a highly contagious virus, the data captured from N-Tidal is a non-aerosol-generating process.”

Used on coronavirus wards, respiratory readings could be produced without doctors needing to supervise the data capture. And the information may provide intensive care units with a picture of a patient’s evolving clinical condition, helping doctors to identify patients who are deteriorating by picking up on subtle clues in their breathing that might otherwise be missed.

“We should help the team identify who to step up into an intensive care environment, who to keep on the general ward, and potentially who we could send home with a device so the team could still watch them,” says Whitticase.

Importantly for a highly contagious virus, the data captured from N-Tidal is a non-aerosol-generating process. Plus, the design incorporates two replaceable parts which form a single user, disposable breath pathway. These are separate from the rest of the device and can be easily replaced between users.

Whitticase had not foreseen the device being used by NHS trusts though. Before Covid-19 hit, the route to market for N-tidal was likely to be pharmaceutical companies, so research teams could use the device to assess the efficacy of COPD drugs in development. That all changed when it became clear the novel coronavirus was going to be a major crisis.

Knowing when to jump

But making such a major business pivot isn’t easy. Although N-Tidal had been manufactured and was ready to be shipped, the accompanying software wasn’t suitable for hospitals. It had been built for pharmaceutical companies and clinical trials, rather than doctors. Luckily, a prototype clinical monitoring system was already in development. Cambridge Respiratory Innovations originally had a launch date in mind for it of late 2021.

“As soon as Covid hit China, we started working on it and by the time it got into Europe, we repurposed the whole company's focus on clinical dashboards to support doctors with the Covid challenge,” reveals Whitticase.

“By the time [Covid-19] got into Europe, we repurposed the whole company's focus.”

Finances were another hurdle. The company was just embarking on a seed funding round, but the money wasn’t there at the start of the year. Quick cash was needed to ramp up supply for the increased demand of the devices. Luckily, commercial partners WideBlue and Gas Sensing Solutions who manufacture the tech inside the N-tidal product stepped in, allowing materials to be pre-ordered without Cambridge Respiratory Innovations having to make a down payment.

The company’s focus will remain firmly on the coronavirus challenge for the next few months. But there’s also been interest from the primary care sector. As well as aiding critical care decisions, N-Tidal could help GPs decide who to admit to the hospital and who to watch at home remotely. Beyond the pandemic, the device could also mean greater convenience for asthma patients – allowing them to send respiratory data to doctors from their own homes, meaning fewer hospital appointments.

Ultimately, Whitticase believes a greater focus on digital diagnostic technology in respiratory medicine will ensure people with lung conditions are better supported in future. “We're incredibly proud as a team to be involved in it and I think it's going to do some amazing good for patients around the world.”