Sidebar Menu

 

M. Sc. Johannes Hoffmann

Room D-017
Kaiserstraße 2, 24143 Kiel, Germany
Phone: +49 431 880-6130
Telefax: +49 431 880-6128
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Research: Real-time Movement Analysis

Parkinson's disease (PD) is a neurodegenerative disease related to various movement disorders including tremor. Patients often experience a reduced quality of life due to degradation of motoric abilities like speech and gait. While the symptoms can be relieved by dopamine medication, PD itself is an incurable disease. Improvements in treatment are of vital interest in our increasingly aging society. This includes the assessment of motoric markers for an earlier and more specific diagnosis as well as regular monitorings to ensure appropriate medication in therapy. The medical examination is usually done in a clinical motor lab using stationary and highly accurate sensor systems.

Symptoms vary in severity over time, which drives the motivation for daily life measurements using body worn sensor technology. These techniques offer the potential for a more quantitative and reliable approach in comparison to self-assessment using questionnaires. The "DSS Movement Jacket" is designed as a wearable sensor system combining different sensor types to achieve highly accurate, non-stationary analyses of various movements including arm swing as an early marker for PD. The setup includes medical grade Inertial Measurement Units (IMUs) comprised of accelerometers (gravity, motion), gyroscopes (rotation) and magnetometers (geomagnetic reference). Some drawbacks are limitations for magneting sensing in distorted areas (buildings) and deviations through numeric integration (drift). Motion capturing using these sensors requires sophisticated digital signal processing approaches like Extended Kalman Filters (EKF). This includes a priori knowledge comprised in a state space representation of the human body.

Novel magnetoelectric (ME) sensors from the Collaborative Research Center CRC 1261 in combination with excitation coils are suitable for the indirect measurement of non-magnetic quantities such as movements. These sensor-coil-systems are highly sensitive and therefore low power (< 200 mW) as well as robust regarding magnetic distortions (AC field). It was recently shown that movement parameters like frequency and distance can be extracted from the measured signals. These reference data points can potentially be included into the EKF to improve the overall performance. Multiple sensor-coil-systems with optimized access schemes like Code Division Multiple Access (CDMA) are interoperable. This promises a quadratic relation between systems and data points and hence further accuracy improvements.

Related topics:

  • IMU sensors
  • Magnetoelectic sensors
  • Sensor fusion
  • Pattern recognition

 

Further interests:

  • Real-time digital signal processing
  • Wearable sensors
  • Hardware development

 

Short CV

 
 
Time span   Details  
  2020 - current   Research assistant at the Christian-Albrechts-Universität zu Kiel, Kiel, Germany  
  2018 - 2020   M.Sc. in Electrical Engineering and Business Administration
Christian-Albrechts-Universität zu Kiel, Kiel, Germany
 
  2017 - 2018   Internship at Dräger Safety, Lübeck, Germany  
  2014 - 2018   B.Sc. in Electrical Engineering and Business Administration
Christian-Albrechts-Universität zu Kiel, Kiel, Germany
 

 

Publications

  1.    

    J. Hoffmann, E. Elzenheimer, C. Bald, C. Hansen, W. Maetzler, G. Schmidt: Magnetoelektrische Sensoren zur Bewegungsdetektion und -analyse, Biosignale Workshop, 2020, Kiel, Germany