Date: November 15, 2013, No. 90

From mechanical engineering to the middle ear

University of Stuttgart opens Centre of Excellence for Laser-Doppler vibrometry in biomechanics

A new centre of excellence for Laser-Doppler vibrometry is opening today at the University of Stuttgart, the aim of which is to make measurement techniques from mechanical engineering beneficial for biomechanics. The cooperation is supported by the Institute for Technical and Numeric Mechanics (ITM) at the University of der Stuttgart as well as Polytec from Waldbronn, the world market leader in the field of non-contact vibration measurement technology. Those with hearing impairments in particular will benefit from the research. “Thanks to our equipment in laser measurement technology, we are creating conditions for excellent research and a sound training”, according to the Head of ITM, Prof. Peter Eberhard. Dr. Stefan König, responsible for sales in South Germany at Polytec: “Laser-Doppler vibrometry at ITM enables us to make interesting applications and profound analyses .“

Laser-Doppler vibrometry is a measurement technique that records even the smallest of movements in the nanometre range, and through this makes highly dynamic processes in particular accessible without influencing the measurement object. They are traditionally used in technical systems like machines, robots or vehicles. “Laser vibrometry is a basic methodological approach to record and to understand vibrations. It can therefore also be used with biomechanical processes, such as sound transmission through the middle ear to the inner ear“, explained Dr. Albrecht Eiber. The deputy head of ITM has already been researching for several years with processes, such as computer simulation on implants that enables hearing damaged through age, illness or an accident to be reconstructed. Along with passive prostheses with the function of “spare parts”, active prostheses are also thereby developed that strengthen the incoming acoustic signal within the ear.

How the prostheses actually behave in the case of different tones and how well the patient hears again after an operation was, however, hard to determine for a long time due to the tight conditions in the middle or inner ear and the patient’s exposure to pain. These types of measures are possible with the help of the contact-free Laser-Doppler vibrometry. It therefore makes a valuable contribution to the development of passive implants and active hearing aids that are effective and favourably priced, can be used in a minimally invasive way and offer the patient the maximum degree of comfort and security.

On the way there ITM has been cooeprating with the university clinics of Zurich, Cologne and Hanover as well as with several business partners. For several years the institute has been working with varoius types of Laser-Doppler vibrometres from Polytec, so that considerable joint competences have been able to be established. The idea is to exchange experiences and know-how in the framework of the centre of excellence and to show future application possibilities for Laser-Doppler vibrometry in biomechanics, medicine and mechanical engineering. In addition, linking measurement and simulations plays an important role. A diverse range of questions for project, degree and doctoral work arise for the students regarding everything to do with the topic of vibration measurement technology and Laser-Doppler vibrometry.

Further information:
Prof. Peter Eberhard, Dr. Albrecht Eiber, University of Stuttgart, Institute for Technical and Numeric Mechanics, Tel. 0711/685- 66389, -66393,
Email: peter.eberhard (at), albrecht.eiber (at)

Andrea Mayer-Grenu, University of Stuttgart, Department of University Communication, Tel. 0711/685-82176,
Email: andrea.mayer-grenu (at)

3D – vibration measurement on an experimental model.