In 2012, German health insurance companies paid out almost seven billion euros for medical equipment. A significant proportion of that money went into orthopedic devices. To ensure products listed in medical catalogs provide tangible benefit, manufacturers have to provide evidence that they are safe and effective. The Steinbeis Transfer Center for Biomechanics, Training and Sports Technology (BTS) conducted a study to examine the properties of three different foot and lower thigh support solutions for treating patients following Achilles tendon injuries and operations.
To stabilize the feet of patients with Achilles tendon problems, there are industrially manufactured tall boots with specially incorporated removable and adjustable reinforcement parts to support the heel. I n the front section there is a strong but pliable tongue. Sometimes plaster casts or removable plaster replacement devices are used. For ligament and tendon injuries without injuries to bones, treatment is increasingly offered to provide extra functional stability. This is to prevent the negative consequences of complete immobilization (such as muscular dystrophy).
As part of a study conducted by the Steinbeis transfer center, healthy volunteers were invited to a biomechanical test lab and asked to wear a variety of medical devices and walk with them on a treadmill for 15 minutes. Mechanical stability was measured directly on the lower leg while walking. Muscle activity was also measured by placing an electromyography device on the skin and with each step taken, the distribution of pressure was measured under the shoe. Miniature acceleration sensors were also used to measure oscillations at the Achilles tendon. It was discovered that the stabilization effect of all three devices was similar but while walking there were differences in muscle stimulation during the upright leg phase. By conducting complex biomechanical evaluations, it may be possible to gain new insights into the functional properties of orthopedic medical devices.
To exhibit local construction projects and show decision-makers and people from the community what something will look like, 3D models are often used. In the past, these models had to be designed by hand and pieced together from small parts. Thanks to lightning-fast developments in 3D printing technology, the traditional separation between models in digital and physical formats has now been eroded. Modern 3D printers can automatically produce cheap 3D models as required based on digital designs. Experts at the Steinbeis Transfer Center for Technology Consultancy at the HFT Stuttgart are currently carrying out experiments with 3D printing processes and testing different techniques.
The center has already been using 3D printers on architecture projects since 2010 in order to produce physical models based on digital 3D models. The starting point of the process is a digital 3D model of the building in a format called CityGML. After quality checks are carried out, the model is converted into a format that can be processed by a 3D printer, which produces the model layer by layer. To do this, a 3D printer called ZPrinter 450 is used. The printer can produce detailed 3D models in color by using a roll to add thin layers of powder only about 0.1mm thick. A liquid bonding agent is then added, carefully retracing the model outline so that each powder layer hardens into place where the model needs to be. This is repeated layer by layer until the entire printed model is ready. The vertical height of the model is dictated by the dimensions of the 3D printer. If larger models are needed, models have to be divided into sections and each piece can then be connected after printing. Examples of the Steinbeis experts’ work include a model of the convention center on the island of Lindau. 3D printers offer a number of interesting possibilities, especially in combination with photogrammetric datagathering techniques. There are already Web-based services that can be used to reconstruct printable 3D models from photos. It is thus possible for private individuals to quickly create and print 3D models.
Prof. Dr. Volker Coors, Prof. Dr. Peter Breuer
Steinbeis Transfer Center Technical Consulting at HFT Stuttgart (Stuttgart)
Volker.Coors@hft-stuttgart.de, Peter.Breuer@stw.de | www.steinbeis.de/su/35