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hi tech Bern University of Applied Sciences Engineering and Information Technology

2/2013 Magazine

Research that benefits people Diagnosis Therapy Rehabilitation Sport

Focus

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EDITORIAL

BUAS-EIT – bringing high-technology disciplines together under one roof

Research that benefits people

BUAS-EIT – bringing high-technology disciplines together under one roof

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Institute for Human Centered Engineering (HuCE)

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Activity recognition and tracking in sport and healthcare

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Towards more reliable glaucoma diagnosis

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Innovative oesophageal long-term ECG

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VoiSee – modern electronics help those with severe visual impairment

12 New vaginal sensors for stress urinary incontinence diagnosis 13 How to make artificial respiration a safer process 14 MSc in Biomedical Engineering: An open door into science, research,

development, and other interesting positions 17 Automatic segmentation of aortic dissections 18 Helping physician and patient see clearly 19 Virtual reality training in hand surgery

Prof. Dr. med. et phil. nat. Rolf Vogel Head of Cardiology at the Solothurn Bürgerspital Hospital and the Cantonal Hospital in Olten Photo: Sahli

20 OCT enables the use of femtosecond lasers for cataract surgeries 21 Helping to reduce myopia in childhood 23 Treatment for osteoarthritis in ankles 24 Vaporising medicinal plants at the correct temperature 25 Recovering normal balance with Balance FreedomTM 27 The Institute for Rehabilitation and Performance Technology 28 Technology meets rehabilitation

Events

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Graduation ceremony

31 News

I m pressu m Editors Patrick Studer, Diego Jannuzzo Translations Nicholas MacCabe Adress BUAS-EIT, hitech-Redaktion, P.O. Box, CH-2501 Biel, Switzerland Editors’ e-mail hitech@bfh.ch Homepage hitech.bfh.ch Website hitech.bfh.ch Print run 1000 copies Graphic design, layout Ingrid Zengaffinen Printed by Stämpfli Publikationen AG, Wölflistrasse 1, P.O. Box CH-3001 Bern, Switzerland – hitech 2/2013: June 2013

Title page: C. Tschopp wearing a PARTwear sensor during volleyball training. PARTwear makes it possible to analyse training sessions in detail as an aid to enhanced performance.

Photo: Ulrich Känzig (BASPO) Graph: Jonas Hubacher

There has been a paradigm shift in cardiovascular medicine. Therapy no longer depends solely on new drugs, but mostly on devices such pace-makers, defibrillators, stents and artifical heart valves.

While we medical practitioners certainly think about ideas and potential concepts for medical and therapeutical devices as part of our day-to-day work, it is often difficult to work with industry to put them into effect. Intellectualproperty issues arise and companies hesitate to invest into high-risk development.

Moreover, their primary focus is on generating profits from marketable products. The BUAS-EIT is not commercially oriented. Its engineers have ready access to the latest technologies and are familiar with their use. Everything they need is usually available under one roof and, should that not be the case, they have networks at their disposal from which to source their requirements.

A particular benefit of the BUAS-EIT to us doctors is the practical, problem-solving approach that its engineers take to their work. They understand that people do not behave like machines and that, in taking care of them, we always need to be ready for the unexpected and able to react to it appropriately. Having worked with each other for many years, physicians and engineers now share a common language. We physicians know how to define our requirements precisely and the BUAS research staff know how to translate the ideas into practice in a manner appropriate to patients’ needs.

It is important that people be freed up to work on projects for long periods of time. Today, we at the University of Bern and our colleagues at the BUAS-EIT share doctoral students. Formally, these students work at the University, where I supervise their dissertations, but they are also actively involved in projects at the BUAS-EIT. Candidates who have completed their master’s degree may apply for their doctorate at the University. Specialists with that degree of interdisciplinary training are very much in demand in today’s medical technology industry; they are at the creative heart of the medical-technology innovations for which Switzerland has earned international recognition.

Prof. Dr. med. et phil. nat. Rolf Vogel Head of Cardiology, Solothurn Hospitals

German, French and English editions of this magazine are available on: www.hitech.bfh.ch

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F O C U S | I nstitute for H uman centered E ngineering ( H u C E )

Institute for Human Centered Engineering (HuCE) Technology serving human beings. Making that vision reality is one of the major challenges facing the Institute for Human Centered Engineering. After all, the greatest possible reward for a young engineer is to see his or her ideas and creative inspiration result in a product that is both useful and commercially successful.

Interdisciplinarity – the key for innovative development Innovation takes place in people’s heads. Having an interdisciplinary team working on a project often provides a basis for ideas and solutions that are both unconventional and creative. The wide range of subjects taught at the HuCE institute with its six research laboratories (see box), three B.Sc. and two M.Sc. degree programs, enables the Institute to foster plenty of active interdisciplinary collaboration between the individual curriculums it offers – its B.Sc. in Electrical and Communications Engineering, B.Sc. in Micro- and Medical Technology and B.Sc. in Information Technology, as well as its M.Sc. in Engineering and M.Sc. in Biomedicine.

Prof. Dr. Marcel Jacomet HuCE Institute Director, BUAS-EIT (Bern University of Applied Sciences, Engineering and Information Technology) Photo: arteplus.ch

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Core skill – the key to applied research While interdisciplinarity between its complementary key technologies is critical to innovation at HuCE, in-depth knowledge and sound core skills in each of them are equally decisive. All its six laboratories are engaged in applied research and development. By presenting more than a dozen publications at international conferences and in research journals each year, HuCE researchers are able to share their latest results with colleagues worldwide.

Even more important, these activities also provide the Institute’s teaching faculty and young engineers with the opportunity for face-to-face exchanges with their peers on new ideas and problem-solving approaches.

The HuCE laboratories’ core areas of expertise are: – Complex signal and image processing and control.

– High-speed hardware algorithms in FPGAs or ASICs, low- power chip design technologies.

– In-house development of miniaturised, mechanic and electronic systems from prototype to production (3D print ing, PCB assembly, ASIC bonding).

– High-resolution optical measurement for surfaces and 3D images.

– Optics and Optical Coherence Tomography (OCT).

– Computer-based perception and virtual reality.

– Sensor systems, RFID, biometrics, haptic perception.

– Robotics and automated manufacturing technology.

– Numerical analysis, statistics, data mining.

– Medical-technology applications in biomechanics, intel ligent medical instruments, electronic implants, imaging in medical technology.

Close contacts with Industry – the key to successful products The industrial surrounding and the numerous ongoing industrial projects have played a key role in determining the technologies on which the Institute is focusing. The core skills in which the individual research groups have chosen to specialise reflect the requirements of the Institute’s industrial partners, which is why further focus on the core skill has been made in recent years. HuCE has also placed a clear strategic emphasis on the following three growing areas of interdisciplinary applications.

– OCT, from optics via signal processing and hardware algorithms to image processing, with denoising and im age segmentation for medical applications.

– Sensors in industrial applications and sensor networks for sports and rehabilitation.

– In addition to the BME Lab, all HuCE research groups are active in interdisciplinary medical technology appli cations.

The Institute’s first spin-off companies demonstrate that HuCE engineers are in touch with the needs of industry and are able to develop successful products.

Highly motivated research scientists – the key to efficient project execution The Institute’s 60 highly motivated scientific and teaching staff are its most precious resource. Shortly after completing their bachelor or master’s degrees, the HuCE’s young engineers often work with faculty members on industrial, CTI and SNSF projects. While the problems these projects address are rarely spectacular, they are invariably absorbing. An increasingly important contribution is also being made by those B.Sc. graduates enrolled in the Institute’s two specialised M.Sc. programs. Part-time employment at the institute alongside their master studies gives students the possibility to both specialise and to satisfy their urge to become involved in industrial and research work as soon as possible.

Collaboration with SMEs – the key to a modern engineering curriculum Practical problems from industry are the most interesting and challenging assignements for engineers. Besides the insights they offer into real-life product-development problems in various industrial sectors, these industrial projects frequently affect HuCE in ways which go beyond the projects themselves. Solutions developed for one project often influences approaches in related R&D projects.

Feedback from these industrial projects is very valuable and is a condition to provide a highly practical orientation in the engineering curriculum.

Flexible collaboration models – the key to tailormade SME projects The HuCE’s objectives are different from those of engineering consultant companies, which is reflected in its approach to handling industry and research mandates. At the beginning of an R&D project, technical specifications can often still be somewhat vague and the approach required to implement them may seem unclear. The Institute’s flexible collaboration models are especially useful in such situations.

The «flex model», for example, is based on a time and not on cost estimation, while the «open model» can guarantee the availability of engineers’ time based solely on an initial estimation of the required resources. In addition, it offers clients the option of doubling the engineering resources devoted to a project without prior reservation if needed. With either model, it is usually possible to get an industrial project up and running within a week. The HuCE is able to offer this degree of flexibility thanks to the mix of industrial and internal projects on which it is engaged and its willingness to accord higher priority to its industrial over its internal research projects.

The majority of HuCE Institute team relaxing after a demanding conference in Zermatt in 2011.

Photo: BUAS-EIT

Contact: > marcel.jacomet@bfh.ch > Info: huce.ti.bfh.ch

Institute for Human Centered Engineering (HuCE) The six research groups: HuCE - BME Lab: Biomedical engineering HuCE - cpvrLab: Computer perception and virtual reality HuCE - microLab: Hardware algorithms in micro-electronics,

signal processing and control HuCE - roboticsLab: Micro-mechanical and mobile robot systems HuCE - optoLab: Optics; optical coherence tomography (OCT) HuCE - scienceLab: Services, sensory perception, measurement

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FOCUS | HUCE - MICROLAB

Activity recognition and tracking in sport and healthcare

Towards more reliable glaucoma diagnosis

Advances in sensor-building technology and in the way low-power micro-computers are manu-

Glaucoma is one of the most common diseases which can result in blindness. Worldwide,

factured and programmed have made it possible to develop new approaches to real-time

it is estimated that the condition afflicts some 70 million people, half of whom are unaware

monitoring and the way activity is recorded and evaluated in championship sports, mass sports

that they are affected.

and healthcare. Extendible networks of body sensors, coupled with flexible software to interpret the data they generate, can now produce a multi-dimensional range of variables which can be ment methodology, this device can obtain very precise IOP measurements, undistorted by the properties of the patient’s cornea. The PASCAL system is acknowledged as the most exact and precise tonometer available in today’s market. Numerous studies confirm the accuracy of its measurements and SMT has patented its DCT technology.

used to observe movement objectively and describe it with great accuracy. These descriptions can be used to provide feedback during training sessions, both in sports and rehabilitation.

From left: Michael Gasser (microLab), Martin Rumo (BASPO), Benjamin Habegger (microLab) and Damian Weber (microLab); absent: Dr. Josef Götte Photo: BUAS-EIT

The PARTwear project, which is being carried out jointly by the Swiss Federal Institute of Sports Magglingen (SFISM) and HuCE’s microLab, is taking the work of an earlier body-sensor-network project a stage further. The research group is engaged in developing the basic concept and building the initial autonomous low-power nodes which will be used in a modular, extendible network of sensors. The objective is to record data from sensors placed on the body which are as «invisible» as possible.

To qualify as «invisible» in this context, a sensor – and, later on, an entire network of sensors – needs to be something an athlete (or a patient) can wear without it impeding his or her actions in any way. The concept for the system must be designed so that – with minimal support from engineers – sports scientists and rehabilitation specialists can use it for new monitoring tasks, producing the requisite hardware and software components themselves and ultimately validating the new measurement methods for which they are deployed1.

Currently, the project has developed a network of sensors which can measure the body’s acceleration and heart rate. The requisite data can either be stored locally, or, in the case of the SFISM, transmitted to a Local Positioning Measurement System (LPM2). We have also used these networks on two inert objects, a racing bicycle and a BMX bike, where we have measured acceleration using sensors at the joints in the frame and fork as well as force, frequency and power using additional sensors mounted on the pedals.

Further research is being conducted into the use of sensors in new applications. One such project is delivering encouraging results measuring sprinters’ ground-contact duration, horizontal force and step rates (see picture). We have also managed to measure BMX riders’ cadence during acceleration phases and the time they spend in the air.

In tennis we are trying to measure ball speed during serves and count the number of forehand and backhand strokes. In rowing, we intend to monitor rowing techniques and the synchronicity between individual rowers in a team.

Text: Dr. Josef Götte, Professor for Signal Processing and Control Technology Contact: > josef.goette@bfh.ch > Info: huce.ti.bfh.ch/microlab

A professional sprinter wearing body sensors.

Real-time data is displayed on the tablet.

Photo: BUAS-EIT

The network concept not only enables the developers to link up the new hardware they design, but also supports links to commercial third-party products.

2 In 2011 the SFISM acquired a commercial LPM system from Abatec Austria for research and service purposes. It can be used for tactical analysis in team sports, physiological load analysis, activity recognition, the visualisation of measurement results and the like. The FSISM’s indoor and outdoor sports facilities are both equipped with this LPM system.

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Dr. sc. ETH Sonja Spichtig Ziemer Ophthalmic Systems AG project manager Photo: arteplus.ch

At present, increased levels of intraocular pressure (IOP) are the only risk factor associated with glaucoma which can be treated medically. While IOP can fluctuate substantially during a single day, the systems currently available can measure it only sporadically and for a few seconds.

The IOP measurements now being used to diagnose and manage glaucoma are thus mere snapshots of a continuous and variable process.

Experts believe that IOP fluctuations, particularly those resulting in short periods of peak pressure during the night, contain significant indicators which would support more reliable glaucoma diagnosis. Early diagnosis is critical, because any nerve damage which has already occurred is irreversible. Moreover, continuous day-long time series data would provide insights into the physiological factors affecting glaucoma and make it possible to prescribe medication appropriate to individual patients. Physicians therefore require new systems which would make it possible to measure IOP continuously, as is done with blood pressure.

Swiss MicroTechnology AG (SMT, a subsidiary of the Ziemer Group) began selling its PASCAL tonometer in 2004.

Thanks to its dynamic contour tonometry (DCT) measure-

Innovative DCT contact lenses In order to measure IOP continuously over a 24-hour period, the DCT technology is being integrated into a contact lens. The Bern University of Applied Sciences (BUAS) and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) are working together on a Swiss Federal Commission for Technology and Innovation (CTI) project to develop the new DCT contact lenses. The BUAS’s HuCE - microLab is developing a miniaturised data logging device which can be worn on the body, as well as additional sensors and software to evaluate the data they generate. The FHNW’s Institute of Optometry is designing special lenses which can house the DCT device which will make the requisite measurements and which can be worn comfortably by a large proportion of the population.

The project has already made its first IOP measurements using wired DCT contact lenses. That is a world first by the project team – the first-ever direct IOP measurement of several hours’ duration. This is the longest period over which IOP has so far been measured independently of the attributes of the patient’s cornea.

The objective of the next stage of development is to replace the wired DCT contact lenses with telemetric DCT contact lenses which will be powered by, and transmit data to, the HuCE - mibrolab’s RFID data logger. This will enable measurements to be made for longer periods of time, as well as making the lenses more comfortable to wear and moving the project a decisive step closer to its ultimate prototype.

Contact: > sonja.spichtig@ziemergroup.com > Info: www.ziemergroup.com huce.ti.bfh.ch/microlab

The CTI project team from left to right: Roland E. Joos (FHNW), Marcel Jacomet (BUAS), Damian Weber (BUAS), Hartmut Kanngiesser (Ziemer Ophthalmic Systems AG), Josef Götte (BUAS), Daniela Nosch (FHNW), Sonja Spichtig (Ziemer Ophthalmic Systems AG). Absent: Helga Seiler (FHNW), Markus Dachs (Ziemer Ophthalmic Systems AG).

Photo: Chris Eckert

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F O C U S | H U C E - microlab

Innovative oesophageal long-term ECG Long-term ECG recorders: Conventional ECG recorder which records signals from electrodes on the skin (above).

Oesophageal long-term ECG recorder (below).

Note that the two pictures are not to the same scale, as the 1 euro coin in each photograph indicates Photo: Adrian Zurbuchen (ARTORG)

Electrocardiograms (ECGs) are used to diagnose heart rhythm disorders. This often requires ECG measurements to be carried out over many days. The quality of the recorded data is often poor and patients are impaired by these investigations. That is why engineers and physicians are working together to develop a better ECG diagnostic technology, oesophageal long-term ECG.

Dr. med. Andreas Häberlin Assistant Physician, Cardiology/Electrophysiology, Inselspital Hospital, Bern & ARTORG Cardiovascular Engineering, University of Bern Photo: Adrian Zurbuchen (ARTORG)

Several thousand people in Switzerland suffer from heart rhythm disorders, or arrhythmias. Those affected often do not notice these disorders, particularly as they frequently occur only briefly and then disappear. Nevertheless, arrhythmias can lead to severe complications, such as strokes, more or less unexpectedly. It is for this reason that timely and correct diagnosis of heart rhythm disorders is very important.

The conventional method of identifying and dianosing arrhythmias is to register a so-called long-term ECG. This involves placing electrodes on the patient’s skin. These electrodes are connected to an ECG recorder (see long-term ECG recorder illustration above), which records the electrical signals from the heart for several days. The recorded ECG data are then examined for any relevant arrhythmia.

That, at least, is the theory. In practice, the ECG signals (particularly those from the atria) are often of poor quality and the ECG electrodes cause skin irritations which patients find bothersome.

One-of-a-kind interdisciplinary collaboration In an effort to avoid the disadvantages of conventional ECG recordings mentioned above, physicians at the Cardiology Department of the Inselspital Hospital in Bern set out to find an alternative. Working in close collaboration with the HuCE Institute and the University of Bern’s ARTORG Center for Cardiovascular Engineering, they specified the requirements which an oesophageal long-term ECG should meet.

This technology involves recording the heart’s electrical activity by means of a thin catheter inserted in the oesophagus. The oesophagus is located behind the left atrium, a point which is of particular significance for arrhythmia diagnosis. The proximity between the heart and the electrodes makes it possible to record signals of excellent quality (see ECG signals illustration above). After a short familiarisation period, patients do not find the oesophageal ECG recording process bothersome or unpleasant.

Innovative technological approach The medical requirements placed on a long-term oesophageal ECG recording system are very demanding. While the patient’s comfort is a key consideration, it is also important that the recordings are of a very high quality. That is why the physicians and engineers working on this project are aiming to miniaturise the entire recorder to the greatest possible degree. Given that objective, it is important to ensure, for example, that the quantity of data stored and the energy used by the device are kept to a minimum. In order to achieve this, innovative solutions such as sub-Nyquist sampling and

The project team: Marcel Jacomet, Josef Götte, Andreas Häberlin, Lukas Bösch, Thomas Niederhauser, Sandro Burn, Thanks Marisa, Andreas Habegger, Michael Nydegger absent: Rolf Vogel Photo: BUAS-EIT

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ultra-low power chip technology, as used in the watch industry, are being deployed. A powerful PC is required to process the recorded ECG signals digitally. This involves filtering and pre-classifying the data. The processed ECG data are then presented to the physician in a clear format, which can be interpreted rapidly. The prototype recorder developed for the first clinical trials (see picture of long-term ECG recorders below) already meets many of the requirements specified.

The recorder, which is worn behind the ear, is however still relatively large and it can record data only for a few days.

Outlook The close collaboration between physicians and engineers has made it possible to analyse key aspects of oesophageal long-term electrocardiography. Oesophageal long-term ECG devices have already been used to diagnose relevant heart rhythm disorders in several cases where conventional ECG recordings were not diagnostic. The work jointly carried out by the HuCE micro-lab and ARTORG means that physicians at the Inselspital Hospital have been able to accumulate experience with this new technology and deploy it for diagnostic purposes in ways which are unparalleled anywhere else in the world. Based on the encouraging clinical results achieved to date and the high levels of patient acceptance this method enjoys, the project partners have decided to continue developing this innovative approach. The device will soon be miniaturised further and subjected to a new clinical evaluation.

The objective is to integrate the entire power source and all the electronic components inside the thin oesophageal catheter. This should ensure that the catheter is not visible externally and that patients are able to wear it for several weeks. This would make it possible to record high-quality

long-term ECG using a method which is well tolerated by patients, thus helping to prevent the potentially severe consequences which arrhythmias can have. A definite plus for

the patient.

Contact: > Andreas.haeberlin@insel.ch > Info: huce.ti.bfh.ch/microlab

ECG signals: Simultaneous recordings – from an oesophageal ECG device (above) and a conventional long-term ECG device (below).

The signal from the atrium has a much greater amplitude on the oesophageal ECG recording, making it much easier to identify.

Source: Cardiology Clinic, Inselspital Hospital

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FOCUS | HUCE - BME LAB

VoiSee – modern electronics help those with severe visual impairment Age-related macular degeneration (AMD) is an insidious ocular disease. It affects the very area of the retina where vision is at its sharpest and clearest and on which the eye’s lens automatically focuses. Those affected thus have their vision restricted to the periphery of the eye, severely impairing the precision and focus of what they see. Because no cure has yet been discovered, enlarging visual aids are the only effective way of addressing the condition.

Prof. Dr. Jörn Justiz Co-Head, HuCE - BME Lab Photo: arteplus.ch

David Aymeric Niederhauser MSc in Biomedical Engineering Photo: arteplus.ch

André Reber is an electrical engineer with his own small independent practice. When his otherwise hale and hearty mother was diagnosed with AMD, he set out to find a technical solution which would allow her to remain mobile despite her visual disability. He was confident of finding something suitable, as this is a widespread condition. In industrialised countries like Switzerland, three in ten people aged over 75 are affected, as are 50% of those aged 85 and over. However, he soon realised that, while there are very good stationary devices available for home use which enable the visually impaired to read books and newspapers, for example, the portable devices available either had too restricted an enlargement focus, too small a screen or were too heavy and bulky. An ideal portable device, it seemed, was faced with the task of squaring the circle. On the one hand, texts have to be enlarged substantially for AMD patients to read them, while, on the other hand, the enlarged picture should ideally display as many sequential words as possible, rather than merely a few individual letters. That requires a large screen.

How, then, could the whole thing be kept light and small enough for Mrs. Reber to use it at the shops to read labels or at the station to ready the departure board?

André Reber’s solution was based on the use of special displays with modified optical characteristics generating a very large picture in a virtual format.

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He recognised that a device of this kind had significant potential, both as a means of improving the quality of life enjoyed by AMD patients and as a commercially viable product. However, since he lacked the resources to develop the idea on his own, he turned to the Biomedical Engineering Lab (BME Lab) at the BUAS’s HuCE Institute.

The VoiSee principle A CTI project was set up, supervised by biomedical engineers Prof. Dr. Jörn Justiz and Prof. Dr. Volker Koch, with the objective of putting these ideas and concepts into practice. At first, this proved harder than originally expected. It emerged that while the proposed solution would produce a device which was highly portable, the optical technology it required was extremely intricate, thus making it quite large and, above all, expensive.

The BUAS researchers experimented with a number of new concepts until they eventually had an inspiration which provided a breakthrough. By skilfully modifying existing display systems, they were able to develop an approach which made the new device simpler and cheaper, while at the same time delivering a huge virtual screen. The design principles are currently being patented and are thus still confidential at this stage.

«The perceived size of our display is comparable to that of a 53'' (=53 inches) television viewed from a distance of 1 metre», explains Jörn Justiz. With that amount of space, it is possible to enlarge an image enormously and still display a large quantity of text. The device has an inbuilt image sensor which AMD patients can use to select the area they want to view and then enlarge it.

The VoiSee principle in action – a very large, virtual-format image which supports substantial enlargement despite the handy dimensions of the device itself.

Diagram: HuCE - BME Lab

Individual configuration Besides having to cope with unfocused vision, AMD patients also find that there is less contrast in the things they look at and that they react unfavourably to bright ambient light. The contrast and ambient brightness of VoiSee images can be configured to suit individual patients, and initial tests have shown that this in fact reduces the need for image enlargement. This means that VoiSee actually enables patients to see things more clearly, as well as larger.

High acceptance levels In his master’s degree thesis, Aymeric Niederhauser evaluated how well patients accepted the first VoiSee prototype and what they thought of its performance. His conclusions are unmistakably positive. «VoiSee enjoyed excellent levels

of acceptance and most of those suffering from AMD said they would immediately make a device like this part of their everyday lives.» Another very encouraging sign was that nearly all those interviewed said they would like to take part in further trials, which may partly be explained by their desire to be able to benefit from this system as soon as possible.

The HuCE - BME Lab is currently developing a prototype which already incorporates all the key functions of the design and is intended as a template for an initial low-volume production run. The plan is to bring VoiSee to market by the end of this year.

Contact: > joern.justiz@bfh.ch > Info: huce.ti.bfh.ch/bmelab

Impression of what a person suffering from age-related macular degeneration (AMD) actually sees. The red cross in the centre shows what the person is trying to focus on.

Diagram: HuCE - BME Lab

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F O C U S | huce - bme lab

New vaginal sensors for stress urinary incontinence diagnosis

How to make artificial respiration a safer process

Many women suffer from stress urinary incontinence. This involves involuntary loss of urine

Artificial respiration can result in serious, potentially fatal complications. Electrical

due to coughing or sporting activities, for example. The condition is usually caused by an

impedance tomography (EIT) is one possible way of improving this situation.

insufficiently rapid muscular reaction in the pelvic floor. Treatment is always preceded by a thorough pelvic-floor examination. While vaginal sensors are available commercially, they do not accurately measure reflex contractions, because they cannot simultaneously record fast-changing muscular signals and changes in force intensity and force direction.

electrodes and force sensors. These force sensors are based on thin-film strain gage technology. Using an electromagnetic tracking system, it is also possible to determine the orientation and position of the sensor within the vagina. The sensors can thus be used to provide significant new data on the reaction processes of the pelvicfloor muscles. These data have enabled functional patterns to be identified which are useful in helping determine treatment suitable for patients. The team is currently awaiting approval from the Ethics Commission and Swissmedic. Once this has been obtained, they will soon be able to start clinical trials with the devices, the only ones of their kind worldwide. The team plans to publish its results in renowned scientific journals.

Prof. Dr. Volker M. Koch Co-Head, HuCE - BME Lab Photo: arteplus.ch

Damien Maurer M.Sc. in Biomedical Engineering B.Sc. in Microtechnology, research scientist HuCE - BME Lab Photo: arteplus.ch

Under the supervision of Prof. Dr. Volker M. Koch at the HuCE - BME Lab in Biel – initially in the context of an internal BUAS project and then as part of his M.Sc. in Biomedical Engineering studies – research scientist Damien Maurer has developed a number of chemically disinfectable intravaginal sensors, each of which is equipped with

Success based on interdisciplinary collaboration Development of these sensors would not have been possible without the best possible collaboration between the disciplines involved. In addition to its principal research partner, Prof. Dr. Lorenz Radlinger (sports trainer and sports scientist at the BUAS’s Department of Health), this project has also benefited from the contributions made by lecturer (Privatdozent) Dr. Annette Kuhn (medical doctor, University Gynaecological Clinic, Inselspital Hospital), Helena Luginbuehl (PT, MME, PhD cand.), Corinne Lehmann (physiotherapist, Institute of Physiotherapy, Inselspital Hospital) and Dr. Peter A. Neukomm (engineer, BUAS-EIT).

By overcoming the initial challenges it faced, the team has made a major step forward, increasing its knowledge and expertise applicable to related issues. This project is not only proving enriching for research, but for teaching as well, which is also benefiting from the insights gained.

Contact: > volker.koch@bfh.ch > Info: huce.ti.bfh.ch/bmelab

Prototype of an intravaginal sensor Photo: arteplus.ch

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Prof. Dr. Volker M. Koch Co-Head, HuCE - BME Lab Photo: arteplus.ch

Dr. Pascal O. Gaggero Research scientist HuCE - BME Lab Photo: arteplus.ch

EIT is a safe, low-cost process enabling medical staff to determine the electrical conductivity of specific areas of a patient’s body. It supports remote monitoring of pulmonary functions during artificial respiration (AR). While the technology is not new, hospitals rarely use it at present mainly because of the effort required to place multiple electrodes on a patient’s body and the poor quality of the signals they produce.

and thus avoiding the risk of complications such as collapse or overextension of the lungs. AR devices with integrated EIT measurement technology are setting new standards worldwide.

The HuCE - BME Lab at the BUAS-EIT in Biel is working with Swisstom AG on a CTI project which is being supervised by Prof. Dr. Volker M. Koch and Prof. Dr. Jörn Justiz and in which Dr. Gaggero is actively involved. Scientists at Carleton University in Ottawa, Canada and at the HSR in Rapperswil are also taking part. Working with BME M.Sc. student Andreas Waldmann, the BUAS researchers have developed an automated measurement methodology which quantifies the functional performance of EIT devices. They are using a cylinder filled with saltwater as an idealised model of the human thorax. Using an industrial-robot arm, they can place objects such as plastic ball bearings inside the cylinder. They have now created a test environment, unparalleled elsewhere in the world, in which very precise, and reproducible, EIT measurements can be made. This is enabling the BUAS to establish an EIT competence centre which will act as an independent laboratory using standardised tests on the images generated by various types of EIT device to assess their quality and suitability for clinical use. It will be first of its kind in the world.

Contact: > volker.koch@bfh.ch > Info: huce.ti.bfh.ch/bmelab

Towards routine use in patient care As part of his dissertation at the CSEM, Dr. Pascal Gaggero developed a belt-based EIT system with active electrodes. The belt is easy to put on and has amplifiers close to the electrodes which produce high-quality signals. This work earned Dr. Gaggero the Electrosuisse ITG innovation prize in November 2012.

A start-up company, Swisstom AG (www.swisstom.ch), will now bring the invention to market. The idea is to integrate EIT components into existing AR systems. The system uses simple pictograms to display key respiration data. These provide physicians with important lung-function data, enabling them to carry out AR more effectively

EIT-generated cross sectional images of the lungs after exhalation (left) and after inhalation (right) Source: HuCE - BME Lab

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F O C U S | huce - bme lab

MSc in Biomedical Engineering: An open door into science, research, development, and other interesting positions The study program Master of Science in Biomedical Engineering, offered by the University of Bern in close cooperation with the BUAS-EIT, is a state-of-the-art university-level interdisciplinary master's program in engineering and the life sciences. It promotes scientific discovery and development of novel technologies.

Graduates have above-average career prospects in industry and research institutions and can even enter doctoral programs.

Course structure Diagram: BUAS-EIT Prof. Dr. Volker M. Koch Program Director at BUAS-EIT, MSc in Biomedical Engineering Photo: arteplus.ch

For the first time in Switzerland, graduates of universities of applied sciences who have studied relevant disciplines (e.g., electrical engineering, microtechnology, mechanical engineering, physics, and computer science) are qualified to commence a university-level master's program without any preconditions. They can thus enter the world of science and basic research as well as interesting positions in industry.

The program offers a broad spectrum covering engineering, medicine, innovation management, regulatory affairs and many other subjects. This gives students a strong background that allows them to work both in development projects in medical technology companies as well as in basic research.

Almost all courses are held in English, which ensures an international environment where one can learn the relevant English vocabulary for business purposes. Today, this is not only important for an international career but for all qualified positions. In this program, students from the vicinity of Bern get this additional benefit for free while being able to stay in Switzerland with their friends and family.

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Duration of Studies and Part-Time Professional Occupation The full-time study program takes 4 semesters, which corresponds to 120 ECTS points. It can be extended to a maximum of 6 semesters. When a student decides to complete the studies in parallel to a part-time professional occupation, further extension is possible on request. To support regular part-time work, mandatory courses take place (with rare exceptions) on only 3 days per week.

Basic Modules The basic modules provide the students with the necessary background to be able to fully understand the highly complex subject matter in the specialized courses. All students with an engineering background have to complete all courses in the Basic Modules Human Medicine, Applied Mathematics, Biomedical Engineering, and Engineering Mechanics.

Major Modules The choice of one of three major modules Musculoskeletal System, Electronic Implants, or Image-Guided Therapy after the first semester constitutes the first opportunity for specialization. Approximately one third of the major modules consist of mandatory courses. In the elective part of the major module, the student is allowed to select any course from the list of courses in the master’s program, giving rise to a high degree of diversity and flexibility and allowing for numerous course combinations.

Module «Unrestricted Electives» Unrestricted electives can be freely chosen by the student from the entire curriculum of the University of Bern and the BUAS-EIT. It is advisable to select courses which fit into the context of the student’s study plan, either to make up for missing knowledge or to add new and interesting aspects to the individual study program.

Master’s Thesis The last semester is dedicated to a master’s thesis project on an individually suited topic in an academic research group or, for particular cases, in an industrial research and development environment.

Contact: > volker.koch@bfh.ch > Info: www.ti.bfh.ch/bme-master www.bioeng.master.unibe.ch

Major Modules Electronic Implants Electronic implants are devices like cardiac pacemakers and cochlear implants. Due to miniaturization and other developments, many new applications become feasible and this exciting area is growing rapidly. In this module, students will learn about the basics of electronic implants. This includes, e.g., electronics, sensor and measurement technology, biomedical signal processing and analysis, microcontroller programming, actuator technology, and miniaturization of micro-electro-mechanical systems. Application-oriented topics are also taught, e.g., cardiovascular technology and biomedical acoustics.

Image-Guided Therapy Originally, medical imaging was only applied during diagnosis. Later, X-ray systems were introduced in operating rooms.

Recently, fluoroscopes and non-ionizing ultrasound devices became the predominant imaging modalities used in Image-Guided Therapy. Today's developments furthermore try to integrate computed tomography and magnetic resonance imaging systems in the operating room to support intra-operative navigation. In this major module, students will gain a comprehensive understanding of all technical fundamentals required to understand, improve and develop Image-Guided Therapy systems.

Musculoskeletal System The musculoskeletal system is the structural basis for our physical activities and its health has a profound influence on our quality of life. Musculoskeletal injuries and pathologies are the most costly ailments facing our health care systems. In this module, students will gain a comprehensive understanding of the multi-scale organization of the musculoskeletal system, combining knowledge from the cell, tissue, organ to the body level. They will learn how to apply engineering, biological and medical theory and methods to resolve complex problems in biomechanics and mechanobiology.

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FOCUS | HUCE - CPVRLAB

Automatic segmentation of aortic dissections Until fairly recently diagnosis of conditions affecting the aorta was carried out entirely by hand – a very demanding and long-drawn-out process. Thanks to a new process developed at the HuCE - cpvrLab, MRI data of an aortic dissection can now be rapidly and automatically segmented

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Aortic dissection is the result of a tear in the inner wall of the aorta (the body’s principal artery). This causes the blood to separate (or dissect) the internal and external layers of the aorta, thus creating a «false» channel filled with blood. The organs of the body – initially the heart or the brain – are thus no longer sufficiently irrigated. The extreme pressure caused by dissection can even burst the external wall of the aorta, a medical emergency which can soon prove fatal if left untreated. Magnetic resonance imaging (MRI) is currently the standard method used to identify and evaluate aortic dissections. Besides identifying the condition, MRI can also be used to make valuable calculations of the blood flow rate, i.e. the speed at which it is circulating. These data can be used in clinical analysis, enabling medical staff to determine the precise nature of a dissection and the treatment it requires. In order to determine the flow rates at the tear points, it is necessary to pinpoint the precise location of the entry points. Automatic segmentation of 3-dimensional tomography data is one way of doing this.

Contact : > marcus.hudritsch@bfh.ch > Info: huce.ti.bfh.ch/cpvrlab

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Stephan Raible MSc in Engineering Computer vision engineer at the Inselspital Hospital in Bern Photo: S. Raible

Applying the principle in practice In addition to the course of a dissection, the images also provide much information on the surrounding tissue. However, for automatic evaluation of the relevant data, it is essential to perform a full segmentation of the ascending and descending aorta and the aortic arch in a first step. The approximate position of the aorta within the images is initially estimated for segmentation. Based on this information and the geometric properties of an aorta, the descriptive parameters can be derived to create a virtual image of the aorta (figure 1). This representation can then be used to highlight – or to mask – the relevant zones of the aorta in both 2-d cross-sectional images (figure 2) and 3-d visualisations (figure 3). Since the membrane has on the individual cross sections a tube-like shape, it can be detected with the aid of a suitable filter for the detection of vessels and, as the ultimate objective of the exercise, examine the

entry points.

1 3D model of the aorta, 2 2D cross-section of the aorta, 3 3D image of the segmentation Figures: HuCE - cpvrLab

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FOCUS | HUCE - CPVRLAB

Helping physician and patient see clearly

Virtual reality training in hand surgery

Speckle interference is one of the major challenges facing optical coherence tomography

Today’s hand-surgery training uses traditional teaching methods, such as anatomical atlases,

(OCT) today. The phenomenon causes image noise and information distortion in OCT

medical text books, X-ray images, artificial bone models, cadaver disection and training

images, thus not only making it difficult for opthalmologists to interpret them but also

with live patients. As part of a BUAS-EIT research project, the HuCE - cpvrLab has

constraining their use for further software-based processing in applications such as image

developed a virtual reality simulator which can be used to train students to carry out hand

segmentation. The HuCE - cpvrLab has developed an algorithm which successfully coun-

surgery and to evaluate their work.

teracts this phenomenon, thus opening up entirely new diagnostic possibilities.

Cyrill Gyger MSc in Engineering / BSc in Computer Science, research scientist HuCE - cpvrLab Photo: C. Gyger

Adrian Pauli MSc in Engineering / BSc in Computer Science, research scientist HuCE - cpvrLab Photo: A. Pauli

Spoilsport speckles Image layering allows modern OCT scanners to generate large volumes of image data for individual areas of tissue.

This makes it possible, for example, to produce high-resolution 3D images of the human retina, which can then be used in medical diagnosis. Unfortunately, the physical processes used to record the images cause these OCT pictures to be blighted by characteristic speckles, thus making it substantially harder to evaluate them or to subject them to further computer-assisted processes.

Speckle reduction and image segementation in 3D OCT Ironically, it is precisely these computer-assisted processes which have the potential to deliver enormous benefits.

Identification and reconstruction of the blood vessels in the choroid of the eye, for example, would provide an unprecedented wealth of information for evaluating and analysing a large number of eye diseases. Scientists surmise that pathological changes in these blood vessels are linked to both macular degeneration and glaucoma.

The HuCE - cpvrLab is actively engaged in research on the image-processing aspects of OCT and has developed an innovative process for reducing image interference which has rapidly delivered results of convincing quality. The algorithm has recently also been adapted for use in a massively parallel hardware architecture, cutting processing times from over an hour to only a few seconds.

Speckle reduction will also help the subsequent segmentation of the images – or indeed make it possible in the first place. Based on the speckle-reduction filter it has developed, the HuCE - cpvrLab has gone on to create a process sequence which can isolate the blood vessels of the retina from volume images generated by commercial OCT devices. By using these images to construct a 3D picture, it is then possible to measure and visually represent the network of blood vessels in isolation. Building on the potential of these applications, the HuCE - cpvrLab has now initiated a number of follow-up studies with external partners, ensuring the continuing importance of image-processing and OCT in the HuCE - cpvrLab’s work

Robert Hauck MSc in Computer Science from the University of Bern, research scientist HuCE - cpvrLab Photo: arteplus.ch

Currently, computer-assisted training in hand surgery is limited to e-learning modules. For hand-surgery operations, there are as yet no virtual reality simulators (using a computer-generated, interactive virtual environment) of the type used in pilot training. Such applications are however already in use in other areas of medicine, such as endoscopy or laparoscopy.

Training students by working with live patients has several disadvantages. First, the number of suitable patients in hospitals is limited. Second, there are ethical issues regarding patient safety when students are trained by working directly with them. Cadaver specimens and artificial bones can be used instead, but both are relatively expensive. That is why using a simulator to provide students with virtual training in surgical techniques helps them to learn more effectively and to keep patients safe.

Virtual training scenario The virtual training scenario is inspired by Müller’s AO classification of bone fractures. A simulator is being developed based on the four steps in fracture therapy – indication, access, repositioning and setting.

The simulator enables to carry out, and then evaluate, interventions in accordance with a clearly structured scenario.

The simulator is equipped with haptic input devices which use force feedback to simulate the use of medical instruments. These enable the surgeions to feel the forces which arise when they use a surgical drill to put an implant in place and then screw it into position.

Contact: > robert.hauck@bfh.ch > Info: huce.ti.bfh.ch/cpvrlab

Contact: > cyrill.gyger@bfh.ch > Info: huce.ti.bfh.ch/cpvrlab

OCT scan of a retina, before and after filtering Image: HuCE - cpvrLab

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Test environment used for interviews with hand surgeons in Switzerland and England in order to define the functional specifications a virtual reality simulator has to meet.

Photo: HuCE - cpvrLab

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F O C U S | huce - optolab

OCT enables the use of femtosecond lasers for cataract surgeries

Helping to reduce myopia in childhood

New technologies such as high-resolution optical coherence tomography (OCT) and femtosec-

The BUAS-EIT’s HuCE - optoLab is engaged in an international dual research project with

ond laser surgery are already well established in the field of ophthalmology. The HuCE - opto-

partners in Hong Kong and Guangzhou in China. The University of Bern’s ARTORG Center

Lab and Ziemer Ophthalmology are now working together on a project to combine this highly

- Ophthalmic Technology Group is also taking part. The project is being funded by the

accurate measurement method with the micrometer-scale optical knife to make cataract

Swiss National Science Foundation and the National Natural Science Foundation of China.

operations safer and more exact.

The project aims to gain a better understanding of the axial development of the eyeball, to monitor it in a non-invasive fashion and ultimately to control it.

Christoph Meier Professor of Optical Science, Director HuCE - optoLab Photo: arteplus.ch

Michael Peyer BSc in Microtechnology, MSc student, research scientist, HuCE - cpvrLab Photo: arteplus.ch

Patients afflicted with a cataract suffer from impaired vision whose extent can reach complete blindness. Some 50% of today’s worldwide population of blind people lost their sight due to age-related cataracts. This lens opacity is surgically treatable. The procedure usually involves using ultrasound to liquefy and remove the natural lens of the eye and replacing it with an artificial intraocular lens (IOL) placed inside the capsular bag of the eye.

Application of femtosecond lasers Nowadays, the eye lens can also be emulsified using micrometer- scale femtosecond lasers – laser devices with a high pulse frequency, an ultra-short pulse duration and low pulse energy. Therefore the surgeon has to know the exact depth of operation, in order to avoid damaging the capsular bag. However, since eye geometry varies substantially from one patient to another, the required depth needs to be assessed for each patient individually. This is where OCT technology makes it possible to carry out rapid, non-invasive layer-imaging of the eye. The «Seeing Surgical Laser» CTI project is now working on developing a spectrometer-based OCT system (SD OCT) which will be incorporated into the Ziemer FEMTO laser system.

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The challenges of OCT integration For the project to be implemented successfully, demanding objectives have to be met in the areas of designing and implementing the spectrometer, scanner optics and signal processing.

In order to generate an image of the whole anterior segment of the eye, including its lens, an SD OCT system with a large measurement range and limited loss in signal quality at the extremity of the measurement area is required.

The system also needs to be incorporated into a mobile FEMTO laser base station, an undertaking which requires both a very precise mechanical fit and limited exposure to shocks and sources of heat. The scanner presents further challenges, because the highly complex objective of the femtosecond laser is also used for the OCT laser. The scanner itself will also house moving parts and a mirrorarticulated arm. Finally, in order to generate reproducible high-quality images with substantial measurement depth, additional special algorithms have to be used alongside the usual signal-processing routines in the SD OCT system.

These algorîthms support a measuring range double that of a conventional OCT system. The additional OCT makes it possible to use the same device to measure the eye immediately before and after the operation, thus significantly enhancing the safety and reliability of the system.

Contact: > michael.peyer@bfh.ch christoph.meier@bfh.ch > Info: huce.ti.bfh.ch/optolab

Ziemer Femtolaser LDV Z6: mobile base station.

Photo: Ziemer Ophthalmic Systems AG

Dr. Boris Považay SNSF research-project leader Photo: Lisa Kinz

Myopia – an overlooked epidemic?

Short-sightedness (myopia) is a pathological eye condition occurring worldwide which permanently impinges on the quality of life. In addition to mild forms of distorted axial length development of the eye, the condition also manifests itself in more severe forms, leading to blindness in some cases. Spectacles, contact lenses and, more recently, even laser treatment have been used to correct this ever-more-frequent condition. In countries characterised by pronounced genetic sensitivity and increasing eye strain during childhood – in industrialised societies, in other words – intense and long hours of nearwork tends to disturb the balance between the optical power of the eyeball and its length. In the age of the smartphone this condition is also affecting increasing numbers of children and adolescents.

Analysis carried out at the right stage of growth While a person is growing, biological mechanisms monitor the shape of the eye and actively align it with the images they are seeing. In order to obtain a precise picture of these changes, a team of highly motivated HuCE - optoLab staff is working on developing hardware and software for an OCT system. Unlike conventional devices, this will not only enable them to see into the highly sensitive human retina, which is only a few tenths of millimetre in thickness, but also into the dynamically changing choroid layer and even into the sclera, the ridgid white shell which gives the eyball its shape.

Through this initiative, the BUAS scientists support their Chinese colleagues in large cities like Hong Kong, where more than 90% of schoolchildren and students now suffer from myopia. The new device they are developing will provide a controlled means of using a new and highly promising type of contact lens.

The lens, which has been developed at the Hong Kong Polytechnic University, modifies the image that the young eye sees in such a way that it reconfigures its rates of axial and volume growth. This in-depth monitoring of the treatment aims to ensure that the different individual reactions to the treatment yield the desired results in each case – that is, improved visual perception lasting into old age, but without the need for further continuous wear of lenses and spectacles, or surgical intervention.

A system for clinical use In order to prevent the recorded images (comprising more than 140 million individual points per second) being blurred by eye movement, the team working under Prof. Dr. Jens Kowal at the University of Bern’s ARTORG Center will provide the expertise required to reconstruct the images appropriately. They are working with the HuCE - optoLab to develop software which minimises the blurring effects caused by eye movement. The tool will subsequently be used in clinical tests to help ophthalmologists reduce the number of patients they will that need lifelong treatment and sustainably improve their quality of life.

Contact: > boris.povazay@bfh.ch > Info: huce.ti.bfh.ch/optolab

Research scientists Michael Peyer and Markus Stoller at work on the spectrometer, optimising its transmission functions for a better image of the retina.

Photo: Boris Považay

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FOCUS | HUCE - SCIENCELAB

Treatment for osteoarthritis in ankles In some cases, ankle arthritis might be cured by making a horizontal cut through the heel bone and moving the lower part sideways. Is this always a good idea? A master student, in collaboration with BUAS-EIT, is trying to find answers.

Experimenting with lower legs The lower legs were placed in a loading apparatus. A thin layer of pressure sensors was placed in the ankle joint. The deformities were created by means of an aluminum wedge on the lower part of the tibia (the bone section above the ankle). The lower bone was cut obliquely and different displacements sideways (surgical distal realignments) were performed. A force replicating a single-leg stand was applied and the static pressure distribution was recorded.

Prof. Dr. Andreas Stahel Head HuCE - scienceLab Photo: BUAS-EIT

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Rosablanca Ramirez MSc in Biomedical Engineering Photo: R. Ramirez

Misalignment of the hindfoot is one of the main risk factors for osteoarthritis of the ankle joint. It has been suggested that asymmetric osteoarthritis can be addressed with a realignment surgery, as an alternative to total ankle replacement. Only very recently PD Dr. med. Markus Knupp (Kantonsspital Liestal) examined the problem carefully. He used fourteen cadaveric lower legs and loaded them with forces of 700 N (i.e. the full weight of a person) to measure the force densities within the ankle joint.

In the framework of her Master’s thesis in Biomedical Engineering at University of Bern, Rosablanca Paez Ramirez analyzed the data gathered by the work of Markus Knupp. The main goal was to examine the influence of the realignment surgeries on the force distribution within the ankle joint.

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A new statistical approach Parameters, such as position of centroid of force, maximal pressure or the size of severely loaded areas were then analyzed statistically. The analysis showed that deformities affect the ankle joint load distribution differently.

Although the overall alignment of the lower extremity is the same, the changes in the ankle joint are different in supramalleolar and inframalleolar deformities.

We found that non-anatomical alignment correction of the hindfoot does not restore the ankle mechanics. Therefore, cutting the heel bone and shifting it sideways may not be appropriate for the treatment of ankle arthritis. These findings underline that the ankle joint is part of a kinematic chain involving the lower leg, the hind-, mid- and the forefoot.

Towards a tool for planning surgeries A Finite Element Method (FEM) model was used as a first step towards prediction of the load distribution. The purpose of the simulation was to assess whether static pressure distribution of the neutral position, as measured experimentally, could be reproduced using FEM results based on a generic ankle model. Through comparison of the FEM model with experimental data we verified that a good FEM model could provide an ideal vehicle for the study of joint contact stresses on a patient-specific basis.

It could become a helpful tool for planning surgeries.

Contact: > andreas.stahel@bfh.ch > Info: huce.ti.bfh.ch/sciencelab

Experimental setup, lower leg seen from behind Photo: Dr. Markus Knupp

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F O C U S | huce - sciencelab

Vaporising medicinal plants at the correct temperature

Recovering normal balance with Balance FreedomTM

During phyto-inhalation, the active ingredients in a medicinal plant are inhaled by means of a vaporiser.

Balance is critical to humans’ ability to walk upright. Certain diseases (such as MS) and old age

Thanks to a new heating device developed at the HuCE - scienceLab, it is now possible to heat a

can severely impinge on our sense of balance. Building a device which diagnoses and treats

vaporiser manufactured by Element Medical SA precisely, rapidly and efficiently.

balance impairment, thus helping to reduce the risk of falling, was the obvious response.

The heating station The objective is to bring the vaporiser to the correct temperature in less than 10 seconds. To achieve that, the station’s heating element needs to be raised to a much higher temperature, about 100°C higher than the target temperature for the vaporiser. The heating station is therefore equipped with a powerful cartridge heater capable of reaching temperatures of up to 330°C. In order to ensure that all their active ingredients are released, the plants in the vaporiser need to be heated several times. This means that the heating station may still be very hot when the vaporiser is placed on it. It is therefore important that the heating station be able to measure and control the temperature of the vaporiser so as to prevent the plants in it being overheated.

Bertrand Dutoit Professor of Sensor Technology HuCE - scienceLab Photo: arteplus.ch

Micha Kernen HuCE - scienceLab research scientist Photo: arteplus.ch

During phyto-inhalation, a vaporiser is used to heat medicinal plants (phyto). The plants’ active ingredients are vaporised and then inhaled (inhalation). Phyto-inhalation may be used either therapeutically or as a means of enjoying the benefits of certain herbs and essences.

The vaporiser Vapman is a pocket-sized vaporiser manufactured by Element medical SA. It enables the active ingredients in a plant to be inhaled by heating it beyond its boiling point. For the active ingredients in commonly used plants, the required temperature is generally between 110°C and 230°C. Until now, a special lighter had always been used to heat the Vapman. The drawback of this approach was that it did not allow the plants to be heated to a precise temperature. To address this, the HuCE - scienceLab have developed an electronically controlled heating station as an accessory to the Vapman.

Temperature measurement is tricky Measuring the temperature of the vaporiser when it is placed on the heating station proved difficult. As professor Bertrand Dutoit explains, “The vaporiser itself is too small for its temperature to be measured directly, so we circumvented that problem by measuring the cooling of the cartridge heater in the heating station.”

A photo-electric cell detects when the vaporiser is inserted on the heating station. Once the light threshold has been crossed, the cartridge heater is activated. The station is then able to determine the temperature of the vaporiser by reference to the cooling curve of the cartridge heater.

Three LED’s placed on the front panel of the heating station indicate to the user when the plants have reached the required temperature. Because the temperature at which different medicinal plants release their active ingredients varies, the heating station has an incremental potentiometer for regulating the target temperature.

Several prototypes of this heating station are currently being tested. The finished product will soon be commercially available.

Daniel Debrunner Professor of Mechanical Engineering at the HuCE - scienceLab Photo: arteplus.ch

Lorenz Baer BSc in Microtechnology, research scientist HuCE - scienceLab Photo: L. Baer

Prof. Dr. J. Allum has been engaged in experimental research on human balance at the Basel University Hospital for many years. He has developed a specialised device, SwayStarTM, with a wide range of applications for measuring and evaluating a person’s balance when standing or walking. The device has been successfully deployed in many clinics for monitoring and therapeutic purposes.

The SwayStarTM system has a measurement unit attached to the lower part of the wearer’s back by a belt. Two highprecision gyroscopes measure the angular deviation and angular velocity of the wearer’s upper body. A Bluetooth® wireless transmitter sends data to a PC, which records the wearer’s movements. SwayStarTM’s software then records and evaluates a number of variables specific to the wearer’s movements.

Feedback via a headband The Balance FreedomTM rehabilitation system was developed to complement the measurement unit. Should there be indications of imminent loss of balance, the system alerts the patient by means of a perceptible signal sent to a headband. This biofeedback helps the patient to learn to avoid a fall. The BUAS-EIT participated in the development of this system as part of a CTI project.

In a further development project, the HuCE - scienceLab was tasked with replacing the original measurement unit with a low-cost, low-energy, miniature wireless version replicating the functionality of the larger device. The solution they developed uses a conventional commercial multi-media remote control unit and micro-controller system with an infra-red-signal interface which executes a range of predetermined commands. This hardware is now housed in a single small box attached to the headband. The device can generate a range of vibro-tactile feedback signals in eight different directions, acoustic feedback via bone conduction in four directions and an optical warning signal visible to the patient. The system can also be used in sports – particularly in training figure skaters and ice-hockey players. The devices are now being manufactured in low-volume production runs by Damedics GmbH, an engineering firm based in the Biel region.

Contact: > daniel.debrunner@bfh.ch > J. Allum, Balance International Innovations GmbH: jallum@b2i.info > Info: www.b2i.info

Contact: > bertrand.dutoit@bfh.ch micha.kernen@bfh.ch > Info: www.vapman.ch

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hitech 2/ 2013

Photo showing the new heating station (left) and the current vaporiser (centre ) Photo: Micha Kernen

Balance FreedomTM: headband with feedback mechanism and infra-red remote control Photo: Lorenz Baer

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F O C U S | I nstitute for R ehabilitation and P erformance T echnolog y

The Institute for Rehabilitation and Performance Technology By harnessing advanced technologies and combining these with methods from high-performance sports, the IRPT is helping people living with disability to realise their full potential.

Prof. Dr. Kenneth J. Hunt Head, Institute for Rehabilitation and Performance Technology Division of Mechanical Engineering BUAS-EIT Photo: BUAS-EIT

The Institute for Rehabilitation and Performance Technology (IRPT) was established in Burgdorf in 2011. Our research programme is shaped by the idea of taking methods which have been developed in the field of highperformance sports and adapting these for the optimal rehabilitation of patients with neurological impairments; we are focused on the development and clinical assessment of novel rehabilitation-engineering systems that can be used for fitness training and assessment, even in patients who have become severely disabled through injury or disease. We term this approach cardiopulmonary rehabilitation.

Close collaboration with rehabilitation centres The IRPT works closely with leading rehabilitation centres in Switzerland. Our principal medical collaborator is the neuro-rehabilitation clinic Reha Rheinfelden. As described on pages 28-29 of this issue, our research in Rheinfelden

is applying advanced locomotion-robotics systems to the cardiopulmonary rehabilitation of patients who have suffered a stroke. We have carried out similar work at the Swiss Paraplegic Centre in Nottwil: that research involved people with a spinal cord injury.

Advancing innovation in rehabilitation robotics The technology of rehabilitation robotics lies at the heart of the IRPT’s endeavours and for this reason we have established joint product development projects with major players in the medical technology industry. A key IRPT partner is the company Hocoma AG, a global leader in robotic rehabilitation systems based near Zürich. One exemplary research project involves Hocoma’s Lokomat gait rehabilitation robot which we have adapted for cardiopulmonary rehabilitation and are presently assessing at our research facility in Reha Rheinfelden (see pp. 28-29).

IRPT – a multidisciplinary team effort To meet the complex challenges posed by research in the field of medical technology and rehabilitation, a highlyqualified multidisciplinary team has been established in the IRPT. The team currently comprises a medical doctor with specialisation in rehabilitation, two physiotherapists, a human movement scientist, together with specialists from the various engineering disciplines. It is only through close teamwork involving engineers and clinicians that real progress can be made. We hope that this brief overview and the applications article on pages 28-29 will arouse your interest and give you some insight into this fascinating and rewarding field of research.

Contact: > kenneth.hunt@bfh.ch > Info: huce.ti.bfh.ch/irpt

The IRPT’s research Lokomat at Reha Rheinfelden.

Photo: IRPT

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F O C U S | I nstitute for R ehabilitation and P erformance T echnolog y

Technology meets rehabilitation The World Health Organisation states that «every six seconds, someone’s quality of life will forever be changed – they will permanently be physically disabled due to stroke.» In Switzerland, every year more than 16 000 people experience a stroke.

Innovative rehabilitation methods are sought which facilitate recovery.

Oliver Stoller PhD candidate and Research Assistant, Institute for Rehabilitation and Performance Technology, BUAS-EIT Photo: BUAS-EIT

Dr. Corina Schuster Head of Research Department Reha Rheinfelden, and Research Assistant, Institute for Rehabilitation and Performance Technology, BUAS-EIT Photo: BUAS-EIT

Research collaboration Technology meets rehabilitation – that is the fundamental idea of the joint cooperation between the Institute for Rehabilitation and Performance Technology (IRPT) and the Reha Rheinfelden. Engineers and health professionals are working together to develop, evaluate, and improve promising rehabilitation technologies for clinical practice. Here we describe research directions within this collaborative programme.

CardioRobot: A cooperative research project Human endurance beats that of nearly all species on the planet – this means that we are optimally designed to perform extended aerobic exercise (e.g. running, walking). Unsurprisingly, regular aerobic exercise training has positive effects on several healthcare related aspects such as cardiovascular fitness, stress reduction, body fat oxidation, and it might be responsible for various health-conserving mechanisms during our lifetime.

As a consequence of constrained immobilisation, the majority of patients suffering from serious disease such as neurological or cardiac pathologies have low endurance for exercise. Thus the early and continuous promotion of physical activity (e.g. cardiovascular exercise) is highly important for maintenance and improvement of aerobic capacity in these deconditioned individuals. The aim of the CardioRobot project is to explore early cardiovascular exercise strategies for patients suffering from severe neurological diseases such as stroke.

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We developed appropriate concepts to optimally facilitate cardiovascular exercise in this population by refining existing robotics-assisted training devices; we implemented a human-in-the-loop feedback-control structure to guide patients during robotics-assisted treadmill exercise by defining specific target work rate profiles. Graded stress tests and prolonged exercise have demonstrated effectiveness and feasibility in the early stages after stroke. Patients had to perform extensive workouts to reach their maximal aerobic capacity; cardiovascular performance parameters (e.g. oxygen uptake, respiratory volume and heart rate) were recorded continuously.

Currently, we are conducting a clinical intervention study at the Reha Rheinfelden. Patients after stroke will randomly be allocated to a cardiovascular intervention programme or to conventional care only. We are interested in the feasibility and efficacy of additional cardiovascular exercise in severely impaired stroke patients using feedback-controlled roboticsassisted treadmill exercise during the early rehabilitation phase. We expect that this concept might have the potential to improve aerobic capacity in non-ambulatory patients, and could be prospectively used to explore the effects of early cardiovascular exercise on several important health aspects such as neural plasticity, motor recovery, and quality of life.

Innovative clinical rehabilitation methods: therapy robots, virtual reality, and motor imagery Over the last decade several innovative rehabilitation methods have been developed. One of them is therapy with robotic devices that can be used to improve locomotion or cardiovascular fitness as mentioned before. The family of therapy robots also includes devices to practice upper limb functions. Recently, the ARMin III robot was evaluated for its effectiveness in a multi-centre study. Patients after stroke were recruited to receive conventional therapy or robot therapy over an eight week period. The results have not been fully analysed yet, but it is expected that they will support trends from the literature indicating that electromechanical or robotics-assisted training can add beneficial effects during the upper limb recovery process in patients after stroke.

Going one step further, the Reha Rheinfelden initiated a project to introduce the ARMin III for a wider spectrum of patients with other diseases of the brain or after an injury, e.g.

Parkinson’s, Multiple Sclerosis, and Spinal Cord Injury. It is highly important to gain more knowledge on the clinical applicability and to develop treatment guidelines for these new therapy methods.

Virtual reality has been widely used in the gaming industry for decades and has now found its way into neurorehabilitation. In cooperation with the University of Zürich, ETH Zürich, and YouRehab Inc. a multi-centre study (Bürgerspital Solothurn, Inselspital Bern, and Reha Rheinfelden) was initiated to evaluate the benefits of upper limb training comparing vir-

tual reality and conventional physiotherapy in patients after stroke. With the help of movement sensors that are attached to gloves, patients’ finger and arm movements can be displayed in real time on a computer screen. In this way, the displayed fingers and arms can be directed to move and manipulate objects in various virtual environments.

Can you imagine moving your arm to touch your head or nose? The imagination of movements is called motor imagery. It is an easy-to-learn-and-use treatment technique with its origin in sport psychology. If motor imagery is combined with the physical performance of the imagined movement it can help in re-learning of movements after stroke or surgery. The technique is being investigated in several patient studies at the Reha Rheinfelden to develop successful treatment strategies.

Outlook The collaborative programme opens a variety of possibilities to implement technology into clinical rehabilitation. Together, patients’ needs and technological challenges can be met.

Contact: > oliver.stoller@bfh.ch c.schuster@reha-rhf.ch > Info: http://clinicaltrials.gov/show/NCT01679600 www.reha-rheinfelden.ch

CardioRobot: The experimental setup of a graded stress test using feedback-controlled robotics-assisted treadmill exercise early after stroke Photo: IRPT

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events

events

News

Graduation ceremony The spring graduates from the BSc programmes in Automotive Technology, Electrical and Communication Technology, Information Technology, Mechanical Engineering and Microtechnology and Medical Technology received

their diplomas on March 8, 2013, as did 16 graduates from the MSc in Engineering programme.

The diplomas were awarded at a festive graduation ceremony held at the Stade de Suisse in Bern.

Many thanks to our sponsors: Main sponsor: Noser Engineering

Co-sponsors: Puzzle ITC / Ziemer Ophthalmology The Bigballs Photo: BUAS-EIT

Energie. erzeuge

Ich

Von Windpark bis Fitnesscenter: Als Mitarbeitende/r der BKW-Gruppe fliesst Ihre Energie an vielen Orten. Und mit klimafreundlichem Strom aus Wasser, Wind, Sonne und Kernkraft lassen Sie täglich mehr als eine Million Menschen daran teilhaben – unterstützt von 3’000 kompetenten Kolleginnen und Kollegen.

Wir entwickeln und realisieren die Energieinfrastruktur von heute und morgen. Bei Ihrem Berufseinstieg in der BKW entdecken Sie Ihr eigenes Energiepotenzial und werden zum Fachspezialisten und Projektprofi, zum Beispiel als Teil unseres Engagements in der Windkraft. Für junge Ingenieurinnen und Ingenieure gibt es bei uns viel zu tun! Bewerben Sie sich jetzt – Informationen und Einstiegsmöglichkeiten finden Sie auf der zentralen Stellenbörse unserer Webseite:

www.bkw-fmb.ch/karriere

International exchange With effect from March 1, Alexander Leu has taken over the International Exchanges mandate from David-Olivier Jaquet-Chiffelle and Max Felser. He is responsible for matters relating to the international mobility of students (under the ERASMUS and IAESTE programmes) and of teaching faculty.

Contact: international.ti@bfh.ch

La famille canard To mark its 25th anniversary, «Sensors.ch» has awarded a grant of CHF 5,000 to the «La famille canard» (in English, «the duck family») project.

Xavier Mauron is currently working on his bachelor thesis in Microtechnology on this subject, under the supervision of Prof. Bertrand Dutoit.

Contact: bertrand.dutoit@bfh.ch

Institute of Mechanical Engineering Systems Since April 1, 2013, the IFMS team has a new director, Norman Urs Baier, who is also responsible for the Department of Electrical and Communication Technology.

Contact: norman.baier@bfh.ch

Prize for innovative energy systems Integrated Power Solutions AG (IPS AG), a Bern University of Applied Sciences spin-off, presented a new lithium-ion energy system at the Stuttgart Logimat Industrial Fair, for which it was awarded first prize in the «Beschaffen, Fördern, Lagern» (in English, «Sourcing, shipping, storing») category.

Contact: andrea.vezzini@bfh.ch

Bachelor Plus For many years, the Bern University of Applied Sciences has supported bilingualism. At the beginning of the coming academic year next September, its existing range of bilingual programmes at the BUAS-EIT will be extended to include a new «Bachelor Bilingue» programme. Thanks to this new curriculum, the BUAS-EIT is able to provide its students with an additional opportunity to make the most of their studies by improving their language skills while studying for their BSc degree.

Info: ti.bfh.ch/bachelorplus

The search for the optimum The German specialist magazine «Mikroproduktion» published an article on the bachelor thesis written by a BUAS Mechanical Engineering student in the micro assembly section of its February 2013 edition. Beat Zulauf wrote his thesis, entitled «Computergestütztes Ausrichten optischer Fasern» (in English, «Computer-assisted optical-fibre configuration»), at the ALPS Institute’s Applied Fibre Technology group.

Contact: valerio.romano@bfh.ch

BUAS-EIT Information Days 13.06.2013 14 06.2013 (Information Technology and Medical IT in Biel) Info and registration: ti.bfh.ch/infotage IT diploma theses exhibition 14.06.2013, in Biel (Höheweg 80).

Techdays 20.–21.09.2013 in Biel, Vauffelin and Burgdorf ti.bfh.ch/techdays Graduation ceremony 21.09.2013 Bern Kursaal Arena

IIHS small overlap crash test DTC Dynamic Test Center AG used a Renault Scénic II to carry out four crash tests to determine how precisely a head-on collision between two cars could be reproduced using the static IIHS barrier and what improvements to vehicle construction could be used to improve passenger protection in the IIHS small overlap crash test. Info: dtc-ag.ch Contact: bernhard.gerster@bfh.ch

Prof. Dr. V.Koch receives award Prof. Dr. Volker M. Koch, the BUAS’s MSc in Biomedical Engineering programme director, became a Senior Member of the IEEE. Prof. Koch is currently Vice-Chairman of IEEE Switzerland and head of the Swiss IEEE chapter on Engineering in Medicine and Biology. The IEEE is the world’s largest professional association for the advancement of technology.

Info: www.ieee.org

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Best choice.

A career with Bystronic.

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