Feature: Intelligent design - the engineering approach to healthcare
7 October 2009. By Mun-Keat Looi
In a nutshell
- Medical engineering is the fastest growing area of engineering.
- Medical engineers are developing bioengineered implants, diagnostic technologies and treatments to provide more personal and more durable solutions to health problems, particularly as people continue to live longer.
- New technologies could complement, and in some ways replace, our reliance on drugs.
- The field brings together expertise from multiple areas of science and engineering.
Replacement joints that exactly fit your body's needs and monitoring tools that tell you which type of medicine will best cure your illness may sound far-fetched, but these are precisely what the field of medical engineering is all about: the systematic approach of engineering - designing a solution appropriate to a problem - applied to medicine.
"Medical Engineering is the fastest growing area of engineering," says Professor Ross Ethier from Imperial College London. "The synergy of medicine and engineering is a powerful combination that both medics and engineers can benefit from."
The field has received a further boost from the launch of four Centres of Excellence funded by a Medical Engineering initiative from the Wellcome Trust and the Engineering and Physical Sciences Research Council (EPSRC). Projects range from improved diagnostic technologies to better knee or hip implants (see box below).
50 more years after 50
With an ageing population and the rising cost of drug-based treatments, the focus is on developing treatments to ensure that we can enjoy the added years that better medicine is bringing us, says Professor John Fisher, Director of the Institute of Medical and Biological Engineering at the University of Leeds.
"As we live longer, and as our musculoskeletal and cardiovascular systems degenerate, we need a greater level of intervention for tissue repair, replacement," he says.
Researchers at Imperial and Leeds are using sophisticated diagnostic tools to take accurate measurements of a patient's knee and hips, and using these to produce implants sculpted exactly to their needs. Professor Ethier's group at Imperial are also tracking how a person moves through wireless sensing - a method that is also fast, cheap and easy to scale up.
"If you have a predisposition toward a disease like osteoarthritis you may have gait abnormalities - walking in a way that is bad for your knees," says Professor Ethier.
"Traditionally, the way to treat that is to put an insert into your shoe, but the thickness can only be estimated - wouldn't it be better to measure that exactly and sculpt it for the person to create a better correction of the person's gait?"
Such tailored interventions rely on improved diagnostic technologies. "One of biggest barriers to implementing new technology and new interventions is the need to select the right type of intervention at the right time for the right patient," says Professor Fisher.
"Some of the tools that are being developed by medical engineers today include advanced biosensors, next-generation magnetic resonance imaging (MRI) for the musculoskeletal system (particularly for the soft tissues) and 3D virtual pathology where we can reconstruct diseased tissue in virtual systems that allow us to analyse disease progression at a cellular level."
Drug culture
Such interventions could reduce problems such as chronic pain, and consequently our society's reliance on drugs.
"COX2 inhibitors were widely taken for pain control in osteoarthritis. But if you have a better knee implant, say, and restore body function in a pain-free way you don't need the drugs," says Professor Ethier. "What we're doing isn't going to replace drugs but it will reduce the need."
"Better diagnostic technologies can help us make more efficient use of drugs and occasionally develop therapies that don't involve drugs at all," agrees Professor Lionel Tarassenko, Director of the Institute of Biomedical Engineering at the University of Oxford.
"Diabetes, for example, if diagnosed early enough, can be managed with diet and exercise rather than medication. The earlier you can detect the problem the more likely you can have a therapy that may not be drug-dependent."
"Lots of people take drugs that don't benefit them," says Professor Reza Razavi, Professor of Paediatric Cardiovascular Science at King's College London.
"Heart disease patients have to take many drugs, which can be a burden, may have side-effects and are expensive for the NHS. Technology may help you get away from that and go back to being a normal person. New treatments that are better and more accurate could mean a patient can stop their medicines. And better technologies can help us focus the medicines on those who will really benefit."
This could be of particular benefit for treating mental disorders.
"If you look at the treatments that we give for conditions like depression, half the time they don't work," says Professor Razavi. "But we don't realise this until eight to ten weeks, maybe two to three months later."
"Improved medical imaging can tell us, first, if the patient actually has depression - is there something physically different in the brain? But it can also tell us if a treatment is working - if it is having a physiological effect - soon after the patient starts it. By using computers to analyse lots of different images we can see if the patients are responsive."
Technology has other, commercial, advantages over pharmaceuticals. The regulatory 'red tape' around medical devices is much less than for drugs and the time it takes to get them to market tends to be shorter.
As Professor Ethier points out, "There's an opportunity now to bring in more technological solutions to the pipeline and get products to market without the development and overhead costs of drug development."
"Drug development is getting more expensive, and the cost of delivering some drugs is prohibitory - particularly in the developing world," says Professor Fisher. "Medical engineered technologies have the potential to deliver treatments at a cost level that patients, communities and developing countries can afford."
For example, one of Professor Fisher's projects is a bioscaffold to repair cartilage and bone damage, which regenerates using a patient's own stem cells.
"The economics of delivering that to a patient are tenfold less than trying to produce artificial scaffolds that require very complex manufacturing processes outside the body before they are implanted. The cost and regulatory burden for the latter is substantial and a real barrier to getting effective treatments to clinical trials," says Professor Fisher.
"There's a role for engineers to develop and use technologies in innovative ways that deal with these regulatory issues and get around the economic barriers that prevent patients from benefitting from these developments in bioscience."
Teamwork
What ultimately drives medical engineering is its multidisciplinary nature. By definition, the field is a collaboration between different areas of science and engineering: clinicians, engineers, chemists, physicists and economists.
At Leeds, there are 200 doctoral researchers working on a variety of areas, from the bench to the bedside, taking information from clinical studies and feeding those back into basic research and technology development at an early stage.
"You need all types of people in your team: stem cell scientists who want to do the basic science, surgeons who know the practical difficulties but who can also can be important in defining the clinical need at the outset," says Professor Fisher.
"My definition of engineering is the application of science in the broadest sense: maths, biological science, economic and social science. All of these are just as important in engineering as physics."
Medical Engineering Centres of Excellence funded by the Wellcome Trust-EPSRC funding scheme
Osteoarthritis
Imperial College London Department of Bioengineering
Osteoarthritis is the most common cause of chronic pain in the UK. The work of Professor Ross Ethier and colleagues includes developing small, tailored artificial knee implants that replace only the damaged part rather than the whole joint. They also work on tissue-engineered implants: by preconditioning these implants in the lab, they hope to make them strong enough to withstand the wear and strain of the individual patient's daily life before they are implanted.
Meanwhile, improved robotic technologies based on minimally invasive keyhole surgery are being developed to place implants or scaffolds exactly where needed in the body and bond them to the surrounding tissue. They are also using the body's own stem cells to repair damaged joints.
Other projects include wireless sensing technology to help guide rehabilitation exercises at home, providing feedback to patients and data to physiotherapists on whether rehabilitation exercises are being done properly.
Personalised healthcare
Institute of Biomedical Engineering, University of Oxford
At Oxford, researchers led by Professor Lionel Tarassenko are focusing on 'personalised healthcare' that targets the individual patient's needs at different stages of their life. For example, they are developing mobile phone software to teach patients how to manage conditions such as diabetes and asthma early on.
They are also developing liver cancer treatments that are encapsulated in nanoparticles and using ultrasound to both monitor and release them at the right place and time. And they are fashioning made-to-measure stents (supports placed inside a blood vessel) to treat aneurysms, based on accurate images of the patient's own blood vessels.
'50 more years after 50'
Institute of Medical and Biological Engineering, University of Leeds
The Leeds group's motto is '50 more years after 50', with a broad variety of projects to make the last 50 years of (our increasingly longer) lives as comfortable as the first 50.
As well as developing low-wearing, durable hip and knee joint replacements, Professor John Fisher and colleagues are looking at new implants to replace discs in the lower back and the cervical spine, and bioregenerative scaffolds to repair damage to the meniscus (the sliding bit of cartilage in the knee) and bone. Improved dental technologies are also on their agenda, as well as regenerative biological scaffolds to repair heart valves and blood vessels.
Imaging the body
Division of Imaging Sciences, King's College London
Professor Reza Razavi and colleagues are concentrating on new imaging technologies to help diagnosis and treatment. For heart disease, they are working on improved imaging tools for detecting arrhythmia and robotic guides to aid keyhole surgery procedures. They are also developing computer models and combining PET and MRI scanners to simulate how the heart works and look at cardiovascular disease at the cellular level.
And in the field of neurological psychiatric diseases, such as depression, they are developing neuroimaging techniques that could help improve the initial diagnosis of the condition and monitor whether drug treatments are having any effect.
Top image: Testing sensory chips at the University of Leeds. Credit: Wellcome Library, London