Design for life

It is a scene familiar from hundreds of episodes of ER and Casualty. The patient stops breathing; the doctors need to force air into his lungs. Somebody calls for an intubation and one of the stressed medics grabs a piece of equipment, puts it into the patient’s mouth, jiggles it around, yells ‘I’m in!’ and shoves a plastic tube down the throat.

Intubation, while not as common as television shows would have us think, is a routine procedure in all accident and emergency departments. However, some of the routines are more difficult than others and the result can be serious.

The device that allows doctor to see down the patient’s throat, called a laryngoscope, uses a spade-shaped metal blade to push the tongue aside and open up the larynx; the doctor can then guide the breathing tube down into the windpipe.

But the standard laryngoscope was designed in the 1940s and has not changed much since; it can be cumbersome and is sometimes difficult to insert. In those cases — two to 10 per cent — the doctor may need to use force to get the blade in, which can damage the tissues of the mouth, tongue or throat, and frequently breaks patients’ teeth. Even when the instrument is in place, the doctor is trying to look ‘around a corner’ down the curved windpipe, so inserting a breathing tube is not straightforward. While the doctor is trying to get the tube in, the patient is not breathing and the longer it takes, the less oxygen is getting to the brain, leading to the possibilities of brain damage and death.

The need for a better model was one brief given to the Royal Society of Arts’ industrial design students in 1999 and it immediately interested Matt McGrath, then in his final year at Northumbria University.

The instrument he designed, since perfected as the McGrath Model 5 video laryngoscope, went on sale in the US last year and quickly captured 40 per cent of the video laryngoscope market.

The McGrath laryngoscope is a self-contained device incorporating a small video camera aligned with the blade and a video display screen mounted on the handle. Even the battery is contained within the device, making it the first completely portable, single-piece video laryngoscope. Other video laryngoscopes typically have separate viewscreens, meaning they are more difficult to use in emergencies,especially by paramedics.

The camera on the updated model is positioned so that it gives doctors a clearer view into the windpipe and allows them to use less force when inserting both blade and breathing tube.

In a trial at Edinburgh University it achieved a ‘grade 1’ view in 94 per cent of 150 patients, compared with 70 per cent for conventional laryngoscopes.

This makes intubation quicker and less stressful both for doctor and patient. ‘Even though difficult intubations are only a fraction of all procedures, once doctors use the video device they tend to use it for all intubations, because it’s just so much more pleasant to use,’ said McGrath.

After the competition, McGrath found there was considerable interest in the instrument.

A grant from the Audi Design Foundationallowed him to build some prototypes, while another from the Prince’s Youth Business Trust helped him establish a company, Aircraft Medical, in 2001. The Wellcome Trust then stepped in with a translation award, which helped him to design further prototypes before launching the Model 5 (despite the name, the first commercially available version) in 2006.

Designing the device was a considerable challenge, said McGrath. ‘It wasn’t based on anything that was readily available. For example, it needed a lot of miniaturisation, because the size of the camera and the screen that I needed wasn’t available off the shelf. It contains 150 separate parts, a quarter of which are moving. Of those, I think about two-thirds had to be custom-designed and manufactured,’ he said.

Other design features include a blade whose length can be adjusted. ‘It’s more curved than the blade on a standard laryngoscope, because with the camera, that gives the operator an even clearer view,’ explained McGrath.

Also, the blade section is a disposable, single-use unit that is guaranteed to be sterile. Standard laryngoscopes can harbour bacteria and lead to infections. Its sterility and compact size allows a paramedic to carry it in his or her pocket without risk of cross-contamination.

Somewhat surprisingly, McGrath had no medical training or experience before taking on the project. But this was not a disadvantage, he said. ‘It meant that I didn’t have any preconceived ideas about what the laryngoscope would look like or how it would be used; I could come at the design with a completely clean slate, which I found a distinct advantage.

‘We consulted with dozens of medics, and around 1,500 end-users, to arrive at the final design.’

Still only 30, McGrath now employs 17 people at Aircraft Medical, and has secured orders for the laryngoscope from the US, Italy and Canada, which he believes could generate some £30m. ‘The export market is huge, and that’s where we’re seeing most of our sales,’ he said. ‘It’s proving especially popular in the US.’

It has also brought him recognition: in 2001, regional development company Scottish Enterprise named him John Logie Baird Young Innovator of the Year, while last year, the Institute of Contemporary Scotland named him Young Scot of the Year.

This has proved a double-edged sword recently, as a US manufacturer of video laryngoscopes, Verathon, has filed a suit claiming that Aircraft Medical infringed its European patent for its GlideScope design and is claiming the company has cost it £37m in lost sales.

McGrath has responded combatively, counter-suing and demanding that Verathon’s patent is revoked. The US Patent Office has already ruled that Verathon’s US patent made invalid claims.