Medicine has always been a fruitful area for inventors and innovators, as well as a business battleground. And while recent decades have seen much of that action concentrated on the areas of drug discovery and pharmaceuticals, it’s increasingly becoming a fruitful area for engineering. Latest figures from the European Patent Office (EPO) show medical devices as the fastest-growing sector for patent applications, while pharmaceutical applications have declined at roughly the same rate.
Jeremy Philpott, who leads the innovation unit at the EPO’s Munich office, thinks the matching rates of growth and decline in these sectors is a coincidence. But the trend is clear, he says, and may be linked to the costs associated with the different kinds of research. ‘It’s phenomenally expensive to take a drug to the market,’ he told The Engineer at the EPO’s recent European Inventor Award event in Berlin. ‘For every compound that makes it to clinical trial, there are many that fall by the wayside and, of course, it costs to develop those as well. And the cost of complying with international regulations around the world is enormous.’
Medical devices also have to pass through regulatory approval, but the procedures are different from those for drugs and, Philpott argued, somewhat cheaper. ‘So it might be the case that medical devices allow inventors, and the companies they work for, faster and cheaper access to that lucrative market.’ This is even the case for devices such as diagnostics, which incorporate chemistry that is in many cases quite similar to that found in pharmaceuticals. ‘We’re increasingly finding that the biotechnology companies we deal with have dedicated medical device departments,’ Philpott said. ‘And when we talk about medical devices we’re also talking about the increasingly automated and robotic equipment that pharmaceutical companies use to synthesise and test libraries of compounds for drug discovery.’
Engineers working in the medical field report a variety of experiences. Swiss electrical engineer Erwin Hochmair — who with his wife Ingeborg invented multi-channel cochlear implants that have restored hearing to more than 300,000 people since their introduction in 1986 — said that although when he started working on the technology in the 1970s it was already established that electrical engineering could help with hearing replacement, he faced scepticism from physiologists. The implant works by stimulating the nerves in the cochlea at several points. ‘The physiologists said that there are 20,000 nerve fibres and you have eight contacts; it’ll never work and you should give up,’ he said.
But with support from the leader of the Ear, Nose and Throat Clinic that was sponsoring their work, the Hochmairs did not give up. Using information about how the cochlea processes the pitch of sound signals (with nerve excitation at different points, and with different periodicity) they produced a device that could be connected to a signal processor that worked at low voltage and could be completely implanted, to produce a device that could allow people suffering from severe hearing loss to understand speech.
‘The first patient received her implant in March 1980,’ recalls Ingeborg Hochmair, who, unlike her husband, has some medical training along with her qualifications in electrical engineering. ‘And she could straight away understand speech without lipreading.’ That first implant gave more than 50 per cent understanding of monosyllabic words; sufficient to understand a telephone conversation about a subject that the listener previously had no knowledge of, with a person whose voice they did not know. Subsequent improvements have allowed conversation in second languages in noisy spaces and the Hochmairs’ implant remains the only technology to have successfully replaced a lost sense.
When I started at Imperial I was in awe of the medical community; I felt there was a culture and mindset [that] they were the prima donnas and we [the engineers] were technicians who provided them with instruments they needed
Prof Christofer Toumazou
The low-power processor so important to the Hochmairs’ work was developed by another electrical engineer, Christofer Toumazou. It was his first foray into biomedical engineering; an auspicious beginning, as he now holds the Regius Professorship in that subject at Imperial College, as regular readers of The Engineer may remember. Toumazou credits the policy of former rector of Imperial, Sir Richard Sykes, for his relatively easy transition from consumer electronics to biomedical engineering.
Toumazou’s early work focused on using low-power electronics to process analogue signals. ‘It was more creative than crushing it into digital technology; I felt analogue offered different and often better options than the Boolean algebra of ones and zeroes,’ he explained; but the sideways turn into medicine wasn’t obvious. ‘When I started at Imperial I was in awe of the medical community; I felt there was a culture and mindset [that] they were the prima donnas and we [the engineers] were technicians who provided them with instruments they needed. When Richard Sykes came in, he pushed the ideas of personalised healthcare; companion diagnostics and that as people were all different, healthcare was something that could be tailored.’
Sykes broke down the ‘silos’ between faculties at Imperial, insisting that it was not relevant which department had brought in research grant funding, but that it should be shared between the departments involved in a project. Toumazou found himself supervising a PhD in clinical medicine. ‘And that’s when I felt that if you just applied a fraction of consumer electronics technology to healthcare you could make a major innovation. I had experiences with Magdi Yacoub and other heart surgeons and oncologists that were really around the ability to not replace the clinician — which has always been a concern medics have had around medical devices — but to use them as an assistant to the clinician.’
Regulation is still a stumbling block for getting technologies approved for human use, but Serge Cosnier and Philippe Cinquin of the Joseph Fourier University in Grenoble have found a novel way to handle the process. Cosnier and Cinquin have developed implantable bio-fuel cells that generate electricity from glucose in the bloodstream, providing sufficient power to operate devices such as pacemakers without any need for additional batteries that need to be replaced, incurring more surgery, when they run out.
The current we can generate can power processors for implantable diagnostics, devices such as pacemakers, or even small robotic devices that can replace the function of damaged muscles, such as the sphincter muscle in men who have undergone prostate surgery.
Serge Cosnier - Joseph Fourier University
The Grenoble team is currently working its way through animal trials. ‘We started with rat and we’re working up through higher animals; next will be rabbits, which are more difficult because they are more prone to infection than rats, as you can imagine from the conditions rats live in,’ said Cinquin. ‘And this is made more difficult because for these trials on small animals, we have to test the current outside the body, so we have wires coming through the skin; that wouldn’t be the case in humans.’
But the team has now formed an alliance with a French company that produces chips that monitor the blood chemistry of cows, to help maximise milk yields and meat quality. Cosnier and Cinquin’s cells will provide the power for these chips, which, when approved for use by veterinary authorities, will be a commercial product. The data they can gather from this bovine usage will help them in their further application to extend into human clinical trials, while at the same time providing an income stream.
‘The current we can generate is small but still very useful,’ said Cosnier. ‘It can power processors for implantable diagnostics, devices such as pacemakers, or even small robotic devices that can replace the function of damaged muscles, such as the sphincter muscle in men who have undergone prostate surgery.’
Even engineers with little connection to medicine have found their work being used in this sector. Charles Hull, one of the inventors of 3D printing, said that the most surprising use of his innovation is to make models for surgeons to practice complex procedures on. ‘Particularly for things such as separation of conjoined twins, which can take upwards of 20 hours of intense work, they make models of the structures they will encounter during the surgery so they are prepared,’ he said. ‘I invented stereolithography to speed up prototyping of plastic components; I never expected it to be used there.’