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Adaptive Positioning of Probes using Inflective Mechanical Objects - APPRIMO

Project description

The adduction (approach to contact) of biomedical sensors to the human body is an extensive technical problem. All existing solutions don’t solve this task completely. A typical example is the Electroencephalography (EEG). Since 70 years all sensors (electrodes) were positioned and arranged manually during measurement preparation. All efforts of an automatic mechanical approach with technical mechanism (screws, springs, magnets…) failed.

The bionic approach of this project aims at a smart solution. Based on the natural antetype of biologic tentacles (helix pomatia L.) a new general method of positioning biomedical sensors will be investigated. The first concrete aim is to build a demonstration system for automatic adduction of EEG electrodes to the human skin. The necessary compliance for human-machine interaction will be integrated by using medical silicones of different stiffness.

As result of project we expect a new biological inspired basic technology for positioning, holding and manipulating biomedical sensors on the human body. This technology will sustainably influence and improve complexity and patient comfort of biomedical measurments in clinical routine as well as in medical research. Thereby completely new possibilities of sensor applications on the human body will most likely arise. Furthermore new applications in other technological fields, like robotics or gripper techniques, are expected from the investigated mechanism technologies.

Figure 1: 3D FE (finite element) - model of a compliant mechanism for a translational movement of sensitive sensors without (above) and with (below) inner pressure. 

Project status:

During the first project year EEG electrode holders were investigated and developed following the example of nature. A first result is the development of a novel electrode cap. This EEG cap accommodates more than 150 electrodes in an equidistant arrangement. The necessary flexibility at the human-machine-interface is achieved by a distinct compliant design of the overall structure based on different biomedical silicone materials.

This cap was awarded with a gold medal at the international inventors exhibition (iENA) in Nuremburg in November 2009:

Dipl.-Ing. Stefan Griebel, Dipl.-Ing. Sascha Klee, Dipl.-Ing. Patrick Bessler

Figure 2: EEG cap accommodating more than 150 actuators for pressure controlled translational movement

The current project activities aim at the further extension of the previous results by additional mechanisms performing complex movements. At the conference ACTUATOR 2010 a novel compliant actuator with combined translational and rotational movement was presented. This principle enables e.g. optimal perfusion of the hair layer on the head, thus allowing for direct galvanic contact between dry EEG electrodes and the scalp.

Figure 3: Animation of an actuator with combined translational and rotational movement under application of inner pressure.

Project partners

  • Tampere University of Technology, Tampere, Finnland               
  • Politecnico di Milano, Dipartimento di Elettrotecnica, Milano, Italien                         
  • medis. Medizinische Messtechnik GmbH, Ilmenau, Deutschland                         
  • JenaSQUID GmbH & Co. KG, Jena, Deutschland

Publications & patents

Publikationen (Fachzeitschriften):

  • Fiedler, P.; Cunha, L. T.; Pedrosa, P.; Brodkorb, S.; Fonseca, C.; Vaz, F.; Haueisen, J.: Novel TiNx-based biosignal electrodes for electroencephalography; Measurement Science and Technology, Institute of Physics and the Physical Society, United Kingdom, ISSN: 09570233, Status: in print

Publikationen (Konferenzen):

  • Fiedler, P.; Strohmeier, D.; Griebel, S.; Zanow, F.; Haueisen, J.: A Novel, Inexpensive Electrode and Cap System for Dry Multichannel EEG; 45. DGBMT Jahrestagung (BMT 2011), Freiburg, Germany, 2011
  • Griebel, S.; Fiedler, P.; Klee, S.; Bessler, P.; Zentner, L.; Haueisen, J.: Novel concept for an EEG measurement device with dry electrodes; 45. DGBMT Jahrestagung (BMT 2011), Freiburg, Germany, 2011
  • Fiedler, P.; Griebel, S.; Fonseca, C.; Vaz, F.; Zentner, L.; Haueisen, J.: Novel Ti/TiN dry electrodes and Ag/AgCl: A direct comparison in multichannel EEG; European IFMBE MBEC 2011 (EMBEC 2011), Budapest, Hungary, 2011
  • Fiedler, P.; Pedrosa, P.; Griebel, S.; Fonseca, C.; Vaz, F.; Zanow, F.; Haueisen, J.: Novel Flexible Dry PU/TiN-Multipin Electrodes: First Application in EEG Measurements; 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC '11), Boston, USA, 2011
  • Griebel, S.; Linß, S.; Fiedler, P.; Haueisen, J.; Zentner, L.: Classification, design and application of fluid-driven compliant structures for rotary, translatory and screw motion; Second International Symposium on Compliant Mechanisms (CoMe2011), Delft, The Netherlands, 2011
  • Fiedler, P.; Griebel, S.; Fonseca, C.; Vaz, F.; Zanow, F.; Haueisen, J.: Ein integrierter Ansatz neuartiger, trockener Titan-Nitrid-Elektroden für Multikanal-EEG-Anwendungen; 7. Deutsches BioSensor Symposium, Heilbad Heiligenstadt, Germany, 2011
  • Fiedler, P.; Brodkorb, S.; Fonseca, C.; Vaz, F.; Zanow, F.; Haueisen, J.: Novel dry biosignal electrodes based on TiN: Influence of electrode number and arrangement on contact impedance and signal quality in EEG measurements; 55th IWK – Internationales Wissenschaftliches Kolloquium, Ilmenau, Germany, 2010
  • Griebel, S.; Fiedler, P.; Streng, A.; Haueisen, J.; Zentner , L.: Neuartiger nachgiebiger Mechanismus zur Platzierung trockener EEG-Elektroden über eine Schraubenbewegung; Proceedings BMT 2010 / Jahrestagung der DGBMT 2010, Rostock; de Gruyter, Berlin, Germany, 2010
  • Fiedler, P.; Brodkorb, S.; Fonseca, C.; Vaz, F.; Zanow, F.; Haueisen, J.: Novel TiN-based dry EEG electrodes: Influence of electrode shape and number on contact impedance and signal quality; Proceedings of the 12th Mediterranean Conference on Medical and Biological Engineering and Computing - MEDICON 2010; Chalkidiki, Greece, 2010
  • Cunha, L.T.; Fiedler, P.; Pedrosa, P.; Brodkorb, S.; Fonseca, C.; Vaz, F.; Haueisen, J.: Novel biosignal electrodes based on TiNx: First application in EEG measurements; Proceedings of the 4th International Conference on Sensing Technology - ICST 2010; Lecce, Italy, 2010
  • Griebel, S.; Fiedler, P.; Streng, A.; Haueisen, J.; Zentner, L.: Medical sensor placement with a screw motion; Actuator 10 / International Conference on New Actuators, Bremen; WFB Wirtschaftsförderung Bremen, Division Messe Bremen, Bremen, Germany, 2010, S. 1047-1050


  • Griebel, S.; Streng, A.; Zentner, L.: Nachgiebiger Fluidantrieb zur Erzeugung einer komplexen räumlichen Bewegung und dazugehöriges Verfahren. Vom 09.06.2010 unter Aktenzeichen 10 2010 024 056.7
  • Griebel, S., Spillner, R., Bessler, P., Klee, S., Haueisen, J., Zentner, L., Zanow, F.: Vorrichtung und Verfahren zum Positionieren, Halten und Manipulieren von Sensoren auf der Oberfläche eines biologischen Objektes. Vom 01.07.2009 unter Aktenzeichen 10 2009 032 246.9