S. Klages

Closed loop stability analysis of an assistance system for catheterization

Catheterizations are standard procedures of todays vascular treatment for diagnosis and therapy. To improve navigation even into smaller branches a novel device with haptic feedback assisting during catheterization is currently being developed. One aspect of the design is the identification of possible sources for instability, which is focused on in this paper. This requires the analysis and modeling of the interaction between the device, the patient and the medical staff. The resulting open loop response plotted in Bode-diagram demonstrates areas of possible instabilities. As a result design constrains to guarantee stability in any possible situation is derived

Increasing Student Motivation by Linking up Knowledge Transfer with Enjoying Studying

At the Institute of Electromechanical Design at Darmstadt University of Technology a unique course, which is highly motivating for students, is an established part of the studies. In the form of a seminar entitled ‘Practical Engineering Methodology (PEM)’, students learn how to manage a systematic development process, using the established V model. The courses main focus lies in the conception phase, arguably the most demanding one of a development process. This starts with clarifying the tasks and ends with the elaboration and putting into operation of the device. In addition to a theoretical lecture the students work in small groups on a scientific topic. The theoretical learned facts of basic studies can already be applied to sophisticated development topics. A scientific assistant supervises the group. Additionally, soft skills are imparted in the form of mixed teams, oral presentations and elaborations. The PEM seminar results in highly motivated students who are successful at the beginning of their employment.

Piezoelectric Ultrasonic Actuator for a Haptic Display for Catheterisation

During a catheterisation, the surgeons navigation to the coronary vessels is restricted to a two-dimensional X-ray image. The HapCath system presents a haptic feedback to the surgeon to enable a more intuitive navigation similar to a blind mans cane. In this paper the actuation system for the haptic interface is shown. A piezoelectric ultrasonic actuator is used to generate force and torque on the guide wire. The main working principle of the actuator is described. The advantages compared to dynamic actuating systems are described