Special Sensors for Special Applications

Sensors are the interface between the real world and technology. Only what can be measured can be analysed, controlled or evaluated. At IMT, we deal with numerous, sometimes very specific, measurement tasks in the field of medical technology.

In physiotherapy, patients are expected to regularly repeat exercises learned in the practice at home. The success of the therapy depends largely on the quality of the exercises. This could be supported by a mat that measures the forces during the exercises in a location-specific manner. At IMT, we have developed a demonstrator that can measure forces under the feet, hands, knees, etc. It is rollable, robust, accurate and, above all, inexpensive.

• Straub LF, Pott PP, Novel low-cost approach to build large-scale flexible sensors for spatially distributed ground reaction force measurements, Zeitschrift für Biomedizinische Technik, 2025, doi 10.1515/bmt-2024-0453

For the use of medical robots in hollow organs, it is important to avoid collisions with the organ surface. At IMT, we are researching systems that can move flexibly and autonomously in the large intestine. To this end, we are developing sensors that can measure the distance to the intestinal wall in three dimensions and at high resolution. We are investigating camera-based methods, capacitive measurements and optical approaches as measurement modalities.

• Giacoppo GA, Mayer J, Hartmann J, Bachmann AL, Pott PP, Actively shielded capacitive proximity sensor for endoscopy, Current Directions in Biomedical Engineering, vol. 9, pp. 93–96. doi: doi:10.1515/cdbme-2023-1024
• Giacoppo G, Tzellou A, Kim J, Kim H, Kwon D-S, Stewart KW, Pott PP, An optical colon contour tracking system for robot-aided colonoscopy Localization of a balloon in an image using Hough-Transformation, Workshop Bildverarbeitung für die Medizin, 7.-9.3.2021 OTH Regensburg

Particularly in delicate procedures, e.g. in the eye, it is important for the development of new forms of robotic therapy to measure the actual forces at the site but also at the trocar. For this purpose, at IMT we have developed a powerful, lightweight and high-resolution system that is hand-held and can measure forces and moments in all spatial calculations.

To validate such sensors, we build test benches, develop statistically valid measurement protocols and program automated measurement sequences.

• Mayer J, Schäfer MB, Liu J, Giacoppo GA, Markert T, Matich S, Pott PP, Hand-held Device for Force Estimation during Tool Tissue Interaction, ACTUATOR22, Mannheim, 28.-30.06.2022

Bruxism (teeth grinding) is a much-discussed topic in dentistry due to its diverse effects on the human body. It can damage the tooth structure or cause pain through muscle tension. At IMT, we have developed a small, portable, app-controlled sensor unit that allows patients to monitor their teeth grinding in everyday life. Thanks to an integrated biofeedback option through vibration, it also offers a treatment opportunity. In order to make the device as affordable as possible, only commercially available electronic components and no proprietary software were used. In initial tests, the measuring device showed high measurement accuracy in measurements without feedback at rest.

• Eisenhardt LE, Mayer J, Pott PP, Development of an app-controlled simple, wearable teeth grinding sensing device, Current Directions in Biomedical Engineering, vol. 7, no. 2, 2021, pp. 331-334. https://doi.org/10.1515/cdbme-2021-2084

Intravenous needle insertion is usually performed manually, with the needles being inserted into the vessels by touch, while a short red ‘flash’ is looked for in a corresponding window on the needle. This process is inaccurate and leads to incorrectly positioned needles, multiple insertion attempts, longer treatment times and higher costs for the hospital. At IMT, we have developed a method that indicates when the needle has reached the vein by measuring the change in the mechanical impedance of the needle as it passes through different tissue layers. Tests on a phantom have shown that this method can be used to detect tissue boundaries.

The work was carried out in collaboration with Alex Slocum and Nevan Hanumara from MIT in Boston, funded by the MITSI Program (grant to Kent Stewart).

• Grown-Haeberli S, Montague-Alamin H, Slocum A, Hanumara N, Ramirez A, Connor J, Hom G, Pott PP, Stewart KW, Design and Applicability of a Mechanical Impedance Sensor for Vein Penetration Detection, 42nd Annual International Conferences of the IEEE Engineering in Medicine and Biology Society, 20.-24.07.2020, Québec, Canada
• Rehling D, Liu J, Stewart KW, Pott PP, Investigation of different vibration parameters and their influences on needle insertion forces, DGBMT Jahrestagung, 29.09.-01.10.2020, Leipzig

• Straub LF, Pott PP, Novel low-cost approach to build large-scale flexible sensors for spatially distributed ground reaction force measurements, Zeitschrift für Biomedizinische Technik, 2025, doi 10.1515/bmt-2024-0453
• Giacoppo GA, Mayer J, Hartmann J, Bachmann AL, Pott PP, Actively shielded capacitive proximity sensor for endoscopy, Current Directions in Biomedical Engineering, vol. 9, pp. 93–96. doi: doi:10.1515/cdbme-2023-1024
• Mayer J, Schäfer MB, Liu J, Giacoppo GA, Markert T, Matich S, Pott PP, Hand-held Device for Force Estimation during Tool Tissue Interaction, ACTUATOR22, Mannheim, 28.-30.06.2022
• Giacoppo G, Tzellou A, Kim J, Kim H, Kwon D-S, Stewart KW, Pott PP, An optical colon contour tracking system for robot-aided colonoscopy Localization of a balloon in an image using Hough-Transformation, Workshop Bildverarbeitung für die Medizin, 7.-9.3.2021 OTH Regensburg
• Eisenhardt LE, Mayer J, Pott PP, Development of an app-controlled simple, wearable teeth grinding sensing device, Current Directions in Biomedical Engineering, vol. 7, no. 2, 2021, pp. 331-334. https://doi.org/10.1515/cdbme-2021-2084
• Grown-Haeberli S, Montague-Alamin H, Slocum A, Hanumara N, Ramirez A, Connor J, Hom G, Pott PP, Stewart KW, Design and Applicability of a Mechanical Impedance Sensor for Vein Penetration Detection, 42nd Annual International Conferences of the IEEE Engineering in Medicine and Biology Society, 20.-24.07.2020, Québec, Canada
• Rehling D, Liu J, Stewart KW, Pott PP, Investigation of different vibration parameters and their influences on needle insertion forces, DGBMT Jahrestagung, 29.09.-01.10.2020, Leipzig