Sharon Ann Holgate
April 18 2016 online, and in the May 2016 print edition
New technologies in medicine
Sharon Ann Holgate
November 8 2010 online, and in the Nov 2010 print edition
As the NHS faces a funding gap of £6 bn a year by 2015, E&T looks at the new technologies for better and less costly medical treatment of the UK's increasingly infirm and ageing population.
One evolving area is software that can carry out online patient interviewing prior to a visit to the GP. 'Computer-patient interviewing will develop over the next few years, and should make consultations more efficient,' says Ray Jones, Professor of Health Informatics at Plymouth University. 'If the interview makes it clear what is needed, the GP might not need to see the patient at all, or might be able to carry out the consultation via telephone or Skype. Also a lot of research shows patients are happier revealing embarrassing things to a computer than to their GP.'
Jones also sees the Internet being used more for both self-care (see 'DIY Healthcare' boxout, p25) and for remote group consultations, as in current US projects where clinicians run websites for groups of diabetics. 'Where you get clinicians involved, you could probably see a reduction in the number of face-to-face consultations, which in remote areas would have major implications for global warming by saving a lot of travel,' he says.
The program is based on Cognitive Behavioural Therapy (CBT), a proven method of helping people stop underestimating their strengths and overestimating threats. Unlike the previous generation of software used to deliver CBT, Blues Begone - which has been adopted by some UK local area health authorities - assesses the user via a questionnaire, then tailors the self-help exercises to fit by drawing on a database of 306 different program elements. A talking computer animation of Purves helps guide the user through the tasks selected by the program, while further animated characters describe their problems in case studies. Throughout the treatment, telephone contact by mental health workers helps keep people engaged with the program, which constantly monitors progress via built-in evaluation tests.
'In truth, all psychological treatment is self-help. So you have to empower the client to get the best outcome, and we need electronic systems that people can access and so help themselves,' says Purves, adding that in a recent study Blues Begone cured 60 per cent of patients with depression, and 50 per cent of anxiety patients. 'The World Health Organisation say that by 2020 depression will be the second largest burden of disease in the world. This [sort of technology] is something you can just scale up and deliver when people want it.'
Falls have a tremendous impact on the UK healthcare system, as 30 per cent of the over-65s have a fall each year, costing the NHS over £1bn - and, more importantly, lives.
'Half a million elderly are at risk of falling, and the majority of falls are due to an abnormal gait,' says Dr Diana Hodgins from European Technology for Business Ltd, designer of the Pegasus gait analysis device featured in 'A Question of Balance' (E&T Issue 17, 2009).
This small, strap-on device sends data from inertial measuring units to an ordinary PC or laptop and enables a gait analysis to be performed in under 10 minutes at a GP's surgery. 'Our goal is to quantify their gait (by measuring joint angle, stride duration and variability and phasing between the limbs) so they can be given an exercise regime to take them off the 'at risk' register. Everybody has got to look more at how to save money in the NHS, and the best way is early and correct diagnosis,' continues Hodgins.
Monitoring technologies can also help with rehabilitation. The main aims of Activ4Life's Pro V3.8 orthopaedic activity monitoring system, for example, are quicker hospital discharges, fewer post-operative visits to clinicians and an early detection of complications following hip and knee replacements.
The system consists of a wristwatch-sized monitor, attached with double-sided medical sticky tabs to the users' waist, and a docking station that receives encrypted data from the monitor's 2D accelerometers. Each night, the monitor is recharged in the dock, while the encrypted acceleration patterns that reveal if a user has been running, walking, shuffling or taking the stairs are sent to a secure server via the mobile phone network, along with the patient's report on how much pain they have been in.
By comparing the new data with a profile in the database (built up from results of ongoing trials) that matches the age, gender, BMI and post-operative state of the patient, a prediction is made of either degeneration of their condition or improvement. Exercise regimes are then suggested to optimise recovery, and try to stop people doing too much too soon and undoing their operation, or worse still not moving at all.
'The device shows patients what their daily activity has been and tells them what their clinician has indicated they should do,' says Dr Ian Revie who designed the system. 'Self-management encourages the patient to be less poorly, and we've shown in our trials that the clinical outcome for patients is 10-12 per cent better, if they are monitored.' In addition, Revie's estimates suggest standard use of the monitor would save at least 20 per cent of the current cost of treating each patient. 'The more treatments can be done in a remote fashion that we don't really need to see a doctor for, the more clinicians can focus on complex diseases,' says Revie.
Vital signs, such as blood pressure and pulse, can also be remotely monitored, and could play a role in managing patients with long-term disease.
The Mayo Clinic in the US (in collaboration with GE Healthcare and Intel) is half way through a year-long study to evaluate the effectiveness of in-home monitoring technology - which includes videoconferencing capability - in reducing hospital visits for patients with chronic health conditions. The hope is that detecting deterioration in a patients' condition at an early stage will enable prompt treatment that reduces the need for hospitalisation. An existing teleheaith service in the USA has alreday reduced hospital admissions by 20 per cent.
In pathology, not only is technology enabling access to specialists, it is also helping address a deficit of qualified staff. 'There is a severe shortage of pathologists in most parts of the world, including Japan, Canada, Australia, New Zealand and the UK,' explains Dr Jared N. Schwartz MD, former president of the College of American Pathologists and chief medical officer of digital pathology systems suppliers Aperio Technologies. 'So these countries are increasingly adopting a new technology, called 'whole slide scanning' where you scan the tissue sample on a slide and end up with an identical digital microscopic image of what you would have seen, had you been looking through the microscope.'
This scan does not suffer distortion during transmission, so can be sent to another location either via a secured network or over the Internet as long as patient identity is protected. This not only helps hospitals with no pathology staff on site, but provides access to pathologists specialising in particular areas, such as neuro-pathology when a second opinion is required, without lengthy delays and potential risk of loss or damage when mailing samples. In the future, digitising slides could reduce the need for storing the original samples for years, which Schwartz says 'would save significant space and money'.
Digitising the slides also enables computer-assisted diagnostic tools to be used. In general, pathologists are looking for a particular pattern or cell type within a tissue sample. Finding these specific cells involves looking through a microscope at hundreds of them, and the results are bound to be subjective. 'Five pathologists might give three different opinions, but a computer-assisted algorithm that counts thousands of cells may give the pathologist a statistically more standardised result,' says Schwartz. 'One of the hopes is that by using computer software that will improve over time, there will be increased standardisation of diagnoses, and we can be confident that our interpretation is more accurate.'
Despite predicting a range of new computer applications to help pathologists diagnose and forecast the progress of diseases, human analysis will not be eliminated in the foreseeable future, says Schwartz. 'I am optimistic that we will continue to have extraordinarily well-trained physicians to make sure the technology makes sense. No technology is foolproof, and when you're talking about people's health and lives, you are still going to have to have somebody to make sure all the results fit into what you're seeing from the patient.'
'When you're looking at what technology we should be encouraging, you're saying: what do the majority of patients want that can enhance what we know and delivers the best quality of healthcare for the best cost?' says general practitioner Grant Ingrams, chair of the British Medical Association's GP IT committee. This doesn't have to be high tech. 'I think telephone consultations and email will become more common, but in addition to normal consultations - which have gone up by a third over the last 10 years and continue to rise. So we've got to look at how to be more efficient, and these things might help,' explains Ingrams.
He finds email particularly useful, if he needs patients to record regular measurements of things, like blood sugar levels, then send them to him for review. 'It's a fantastic way of doing it because it means they haven't got to wait for me to have an appointment free to talk to them,' says Ingrams.
One feature of all these advances is the human intervention required, so the idea of being cured by a 'virtual doctor' is likely to remain science-fiction for some time. 'I still need to read and interpret any information, and the majority of patients prefer to see a doctor above any other type of service,' concludes Ingrams.
© IET. Reproduced with permission.
Sharon Ann Holgate
5 October 2009 online and in the vol 4 issue 17 print edition
Technologists have come up with a kitchen that keeps an eye on Alzheimer’s sufferers, and bracelets that monitor blood pressure. But will people wear them or reject them? E &T asks the question.
“It’s not that it would be nice or interesting research-wise to use technology to help support people; we are going to have to, because there just won’t be enough younger people around to care for the elderly,” she says.
An electronic blood pressure monitor that transmits readings wirelessly is just one example of a new technology that could be seen as quite invasive. But Brooker thinks the accurate picture of symptoms they give is useful. “Typically if you interview a person with dementia about their health they will say they are absolutely fine, although they may be having quite big problems. They’re just not remembering that they have,” she explains.
Electronic tagging for dementia
Fear of technology
However it is equally important for things to look familiar. This was one of the main aims of a University of Newcastle project to design an ‘Ambient Kitchen’ for people with dementia.
Newcastle is one of three research hubs announced in April this year – the others being based at Aberdeen and Nottingham universities – to develop digital technologies to transform the lives of the elderly, disabled and isolated.
Towards a less claustrophobic scanning
Sharon Ann Holgate
5 October 2009 online, and in the vol 4 issue 17 print edition
E&T investigates some of the latest 'open' MRI scanners and finds out what benefits patients and doctors can expect.
It is unlikely anyone undergoing a magnetic resonance imaging (MRI) scan would describe the experience as pleasant. Having to lie very still in a narrow tube for anything up to an hour, while the machine loudly bangs its way through the scanning procedure, is hardly fun. In fact, some patients find it so traumatic they have to be sedated - at times, put under general anaesthetic - before being scanned. That is if they can fit inside it at all.
However, claustrophobia and a tight squeeze could soon become problems of the past as more of the latest generation of 'open' scanners, with very wide bores or completely open gaps for the patient, appear in clinics around the world. These systems also offer the potential for MRI-guided surgery.
Wider bore systems
According to the World Health Organization, there are at least 300 million clinically obese adults worldwide, so not surprisingly this has been a driving factor for developments in scanner technology. Siemens, for instance, have been producing scanners with wide bores - 70cm as opposed to the standard 60cm - since 2004.
"We see a trend towards more patient comfort. Growing obesity will push this trend, and patients are better informed than they used to be - they look on the Internet and pick an institution. So with an ever higher density of MR systems in the world, our customers are in a competitive situation," says Mathias Blasche, principal key expert in the MR Business Unit of Siemens Healthcare. Children, intensive care patients, or anyone dependent on medical equipment can also benefit from wider bores, explains Blasche. "We see better image quality with anxious patients who are prone to move during the scan if they do not feel comfortable," he adds.
All patients can gain from these developments. Siemens's new wide-bore Magnetom Espree-Pink breast scanner, for example, allows spectroscopy and biopsies to be carried out in situ, aided by dedicated software and a specially designed coil (see 'How MRI works' p22) that can be adjusted to optimise scanning of any breast size.
Don't take it lying down
Some conditions, like certain back injuries, can actually be made worse by patients lying flat on their backs in a conventional scanner. In open scanners they don't have to.
At the Nuffield Orthopaedic Centre (NOC) in Oxford, where they installed a FONAR 360° open scanner in a purpose-built building in 2006, they can now scan patients lying on their sides. Their scanner also accommodates larger patients and has seen the number of people requiring pre-scan sedation fall from roughly one a week (when using a conventional scanner) to one every two months, says Ruth McDonnell, MRI lead radiographer at the NOC.
"Patients are often relieved to find the scanner is not a tube like they've seen on TV. Being able to see out of the scanner throughout the examination makes them feel much less enclosed," explains McDonnell. Philips's patient studies echo this experience: their Panorama HFO open scanner reduced the rejection rate by claustrophobic patients by a half.
Systems like the FONAR UPRIGHT multi-position scanner take the idea a stage further. "It can scan patients upright in weight-bearing positions, in positions of pain, and in positions of flexion, extension, lateral bending and rotation," says a spokesperson for US-based FONAR. Patients can also be scanned sitting upright or lying horizontally. This provides a new route to diagnoses for doctors and physiotherapists, and is particularly valuable for spinal problems that can look significantly different when lying down.
Italian manufacturers Esaote, who produce dedicated musculoskeletal scanners, allow study of joints and the spine in weight-bearing positions via their G-scan. As the whole unit can be rotated from horizontal to vertical, the scan can be performed at any angle. In their most open system, the C-scan, the patient inserts the joint to be studied while the rest of their body is outside the machine.
The technical challenge
Open and wider-bore MRI machines may seem like an obvious step that should have been taken years ago. However, the technical challenges involved in obtaining a high-resolution image from these systems has been considerable. For a start, in order to get a clear MR image the magnetic field provided by the scanner magnet needs to be uniform - and the shorter the magnet, the more difficult this is to achieve.
"We addressed this by developing a [superconducting] magnet with seven field-generating coils instead of six," says Blasche from Siemens, who specialise in wide bore scanners. This gave a field uniform enough to image any organ in a single step, despite a short 125cm system length. Siemens also worked on improving the perfor-mance of the radio-frequency (RF) system and RF coils that create the pulse required to obtain an MRI signal, as the more RF channels available, the higher the signal-to-noise ratio and the faster the imaging.
Meanwhile, new types of receiver coil have had to be developed for completely open systems to obtain good image quality. "The rule in MRI is that the axis of symmetry of the receiver coil needs to be perpendicular to the orientation of the main magnetic field. Conventional high-field superconducting MRI systems have a horizontal magnetic field that is parallel to the long axis of the body, so they can use planar (flat) coils to image the spine. The open MRIs operate with a vertical magnetic field and use solenoidal ('wrap-around') receiver coils," explain FONAR.
As truly open scanners have a gap between two magnet pole-pieces, a new 'iron-frame' technology was also needed to provide a suitable magnetic field. This forms the basis for all open MRI scanners. Iron-frame technology uses iron to provide a conduit for the magnetic flux to complete its circuit from the north pole of the magnet to the south pole. In the FONAR 360° scanner, it is partly built into the scanner room walls.
The surgery of the future?
Open scanners lend themselves to MRI-guided surgical procedures, known as 'interventional MRI' - something currently in its infancy. The hope is that complex surgery, including the removal of cancerous tumours, could be performed under MR guidance making it more accurate. But there is a catch.
Many metals are strongly attracted by the large magnetic field generated by MRI scanners, so surgeons cannot use conventional surgical instruments. "A scalpel must be sharp, but if it cannot be made from a ferromagnetic or conductive material, what material do you use? Interventional MRI is not just an engineering challenge, but a challenge for materials scientists too," explains Steve Keevil, senior lecturer in Imaging Sciences at St Thomas' Hospital in London.
Guy's and St Thomas' Hospital has carried out MRI guiding of cardiac catheters since 2001 using a conventional scanner. "We have been restricted to using devices that are MR safe by chance," says Keevil. Meanwhile, the NOC have conducted preliminary research into interventional procedures using their open scanner. "However, there have been limitations including the supply of MR-safe needles suitable for interventional musculoskeletal work," says McDonnell.
While some specialist devices, such as biopsy kits and needles produced by DAUM, do exist there are few general instruments available. Significant investment will be required to develop new products and get them through all the regulatory tests, then, once approved, the market for them will be very small. "Interventional MR has not grown a lot within the last ten years and, given the practical problems, you do wonder whether it is ever really going to take off," Keevil warns.
Spanner in the works
Even if interventional MRI never reaches its true potential, open systems still greatly improve the patient experience and offer examinations impossible by any other means. Not surprisingly then, the number of open systems in clinical use is steadily increasing. But what can we expect in the future?
Developments in the MRI field are driven both by the needs of the end-users and by advances in science and materials, says Blasche from Siemens. "We take care to understand the needs of our customers in different institutions, different countries, and with different healthcare systems," he says. "At the same time, we closely watch new developments and learn from experience. The best solutions are created when all these factors match perfectly."
"We see a trend towards higher magnetic field strength," continues Blasche. "Twenty years ago, most routine scanners were sold at 1 tesla (T). Ten years ago, 1.5T became the clinical standard and is still approximately two-thirds of the world market, but the share of 3T systems has increased to approximately 20 per cent over the last few years."
High magnetic field strengths are generally desirable in MRI because the higher the field, the higher the image resolution. Superconducting magnets produce the highest fields, yet lower cost electromagnets (as used by FONAR) and permanent magnets (the base of Esaote's scanners) can produce enough resolution for many studies. According to Esaote's Strategic Marketing Department, optimising all their scanners' components allows good image quality for bone, muscles and tendons in joints at the relatively low fields they use (0.25T for their G-scan for example). They see musculoskeletal scans being increasingly performed in dedicated systems.
"We believe it is a waste of healthcare resources to use a 3T system for a routine knee examination," they say. FONAR also cite cost-effectiveness, along with high performance and a desire to "provide a set of unique imaging applications" as main R&D drivers.
The future development - and use - of MRI scanners could, however, be thrown into jeopardy by the 2004 European Commission (EC) directive restricting occupational exposure to electromagnetic fields (Directive 2004/40/EC). This was due to come into effect in April 2008 and would, in its present form, limit the use of all MRI systems, including the open scanners. But as a result of further investigations showing workers routinely exceed the recommended limits for exposure with no evidence of side-effects and lobbying - in part by the UK's Institute of Physics - the implementation has been stalled until April 2012.
Keevil, who was part of the lobbying process, says a working party is currently trying to re-word the directive in such a way that MRI will not be affected. If they don't succeed, we could be forced back to poorer quality imaging of soft tissues using harmful ionising radiation, which surely cannot be in anyone's interest.
How MRI works
MRI scanners contain either permanent magnets or electromagnets (some of which are superconducting) typically able to produce a magnetic field of 1.5 tesla, which is 30,000 times greater than the Earth's magnetic field. The human body is almost 65 per cent water, and MRI images are obtained from the proton within each hydrogen atom in this water.
Each of these protons spins about an imaginary axis like a spinning top, which makes the proton magnetic. The proton spins points in random directions until a body is placed in a scanner. Under the influence of the high magnetic field created by the scanner magnet, the proton spins align either parallel or anti-parallel to the field. Slightly more protons position themselves parallel to the field, creating a net magnetisation.
A radio frequency pulse (a time-varying magnetic field) is directed at the area of the body that is to be studied. This changes the magnetisation of the protons in that region. Once this pulse is switched off, the protons relax into the state they were in before it was turned on.
A conducting coil works as an antenna and detects - via electromagnetic induction - the small changes in magnetic field that the relaxation produces. As the type of tissue surrounding a proton influences its behaviour after the radio frequency pulse, computer software can analyse the detected signals and build up a detailed image of the body that shows different types of tissue. Graphical processors, originally developed by the computer gaming industry, are now used by some MRI systems to reconstruct and display images quickly.
© IET. Reproduced with permission.