Wanted: the right knack

As an inter-university course between the Universities of Stuttgart and Tübingen, the Medical Engineering degree trains experts with a broad knowledge base, who can even find room for improvement in such commonplace components as the rotary knob.

We turn knobs when we switch on the oven or select the desired washing machine program. In many cars too, the Satnav, radio and other functions are operated by rotary controls, whereby we are not usually conscious of how these rotary controls provide us with information. But, what if we start to lose our tactile sensitivity, i.e., sense of touch, in old age? Are there rotary controls available whose function can be modified in an age-appropriate manner?Peter Schmid of the Technical Design Research and Teaching Department at the University of Stuttgart's Institute of Engineering Design and Industrial Design (IKTD) is conducting research into these questions. For his doctoral studies, the young researcher is looking into so-called haptic man-machine interfaces in a study funded by the German Research Foundation (DFG). What sounds quite complicated are actually simple, manually operated elements such as rotary knobs, slide controls and switches, which the industrial sector could design more precisely and better cater to the needs of older users in future.

“We're interested in age-appropriate product development”, says Peter Schmid. The research is focused on the question of how a rotary knob would have to be changed to ensure that it also provides older people with the desired information, whereby there are more design options for such knobs as first meets the eye. On the one hand, developers could change the angle of rotation, i.e., the path of travel between one resting point and the next. On the other hand, the force required to overcome the resting point can also be adapted. These parameters are perceived solely through the sense of touch. To refine the information transmitted passively via the knob even further, various angles of rotation and torque values can be combined.

“We want to equip the rotary knob with information, so that people can, for example, feel a menu change in the car” Schmid explains. And, it is not just about convenience: people who become distracted by an unclearly coded knob when driving could put themselves and others at risk. Clearly coded knobs in the home could, for example, help visually impaired users to operate their appliances correctly. For this reason, Schmid has used test subjects aged between 21 and 82 for his test series. Having first tested the fine motor skills of his test subjects, he then asked them to select pre-specified values on a rotary knob on the central console of a driving simulator. Among other things, Schmid measured the extent to which these tasks distracted the test subjects from their primary task of driving.“We found significant discrepancies between younger and older test subjects in terms of the time taken to select the right setting and to complete the task, the ability to stay in lane and our accuracy assessment”, the researcher explains. From this data, we were able to design a rotary knob configuration, which functions best across all generations. The knob turns through 30 degrees between the individual points of rest, whereby it takes 0.09 Nm of force to move it on from any given rest point.

“This is not just about research; we also have a specific application in mind”, Professor Thomas Maier, Head of the Technical Design Research and Teaching Department at the KTD, emphasizes. The objective of the project, which ended in September 2018, was to produce a set of design guidelines for age-appropriate man-machine interfaces to enable companies to cater better to the needs of older users during product development. “In our opinion”, says Maier, “touch screens are not always the optimum solution in every situation. The degree of distraction during driving is significant because users first have to look to see where to place their fingers on the control panel”. Schmidt agrees: “Older people are glad that rotary knobs still exist and that their sense of touch becomes an additional support for them when their sense of sight starts to deteriorate”. Nevertheless – or precisely because of this – the researchers at the IKTD are hoping to get approval for a follow-up project in the course of which they want to explore design concepts for a tactile touch screen. This, according to Maier, could transmit minute impulses to the finger thereby practically producing a tangible scale.

It may be surprising that this research, which is aimed at such a wide range of practical applications, has its origins in the Medical Engineering degree. But, as Professor Maier points out: “It does involve medical engineering simply by dint of the fact that we are taking sensory and motoric impairments in consideration”. Whist one usually associates medical engineering with developments for the treatment of medical disorders or for rehabilitation purposes, he continues, the rotary knob development “intervenes even before severe handicaps arise”. Not only identifying these wide ranging approaches and potentials for medical engineering, but also to realize them in practically-oriented research is, in Maier's view, one of the major strengths of the still new Medical Engineering degree program.

The Bachelor in Medical Engineering course was first offered in 2010. “It was created based on the idea of setting up an inter-university degree course in collaboration with the University of Tübingen”, says Thomas Maier, one of the course founders. The ultimate idea was to combine the University of Tübingen's medical know-how with the University of Stuttgart's technical expertise. Right from the start, the project was met with a lot of enthusiasm: “In 2010, we had 100 places available, but received 456 applications”, says Maier. There are up to 700 applications per year.

“Medical engineering degree programs are not a rarity in Germany”, Maier admits, but points out that: “The fact that two such prestigious universities are collaborating so closely, remains unique to this day”. The students are matriculated at both universities and commute between the lecture venues. The Masters in Medical Engineering degree program Photo: Stock / Tobias Langner was launched with 36 students in 2013. Over 50 per cent of today's 300 students are women. Two professorships for optical design and medical device construction have also been established since then. And, not to be forgotten: the demand for course graduates has been considerable right from the start. “Most of them go into industry, where there is a huge demand for our graduates”, says Professor Maier. In the past, he continues, medical engineering companies were often forced out of necessity to employ mechanical engineers, and to provide them with further medical training, or else trained medical professionals who were retrained as design engineers. The Medical Engineering degree program, he goes on to say, produces experts with a broad set of skills and knowhow. Peter Schmid was among the first intake into the Medical Engineering degree. “I was motivated by the desire to help people and, at the same time, I’m a bit of a technology geek”, the doctoral student explains, and goes on to say that this field offers many challenges even beyond traditional medical devices for hospitals and clinics.

Jens Eber

How can senior citizens stay mobile even when faced with health challenges and still reliably call for help in an emergency? These are the questions that interest the recently founded company AGEIng (ageing), which was established by engineers Benedikt Janny and Matti Schwalk both former academic staff at the Technical Design Research and Teaching Department at the IKTD. They have developed a so-called wearable device, a hightech’ product in the form of a chain or bracelet, which is easy to operate and ensures personal safety using a mix of mobile communications and GPS technology. By contrast with many smart and emergency call watches, AGE-ing’s emergency call system depends on functionality that is as reduced and clear as possible without putting the wearer at risk of stigmatization due to its design. The interesting thing about it is that potential users were integrated into the development process right from the start. “We concentrated on user-centric technology design and organized a test subject pool during our doctoral studies”, Benedikt Janny explains. Some 65 senior citizens are involved inthe design process, trying out prototypes and providing valuable feedback. Additional test subjects are always welcome, says Schwalk. The start-up is also working on other projects in collaboration with this pool of test subjects, such as the optimization of technology to meet the needs of older users, for example the electrification of walker frames. AGE-Ing is the first spin-off from the IKTD. The company was launched in early 2018 with startup capital from a research scholarship. Professors Thomas Maier and Hansgeorg Binz of the University of Stuttgart serve as mentors. The two entrepreneurs see the interdisciplinary Medical Engineering degree program as a major advantage. According to Janny, the former course manager: “The connection between man and technology as well as biological, medical and technical principles is a great field to work in, and students graduate with a broad basis of expertise in preparation for it”. In addition, say Schwalk and Janny, given the breadth of the subject, it takes personal commitment on the part of the students to acquire more detailed expertise.