Skip to content
iLab: From Brain to Machine and Back

iLab: From Brain to Machine and Back

iossifidis Lab

  • Home
  • Research Projects
  • Publications
  • Software
  • Press and Media
  • Student’s Zone — Teaching
    • Thesis topics
    • Student Projects
    • Journal Club & Progress Club
    • Lab Course
    • Lectures – Vorlesungen
  • About us
    • The Team
    • Contact
    • Impressum
  • Home
  • 2017
  • September
  • 21
  • SfN 2017: Low dimensional representation of human arm movement for efficient neuroprosthetic control by individuals with tetraplegia

SfN 2017: Low dimensional representation of human arm movement for efficient neuroprosthetic control by individuals with tetraplegia

Posted on September 21, 2017October 9, 2020 By jannis No Comments on SfN 2017: Low dimensional representation of human arm movement for efficient neuroprosthetic control by individuals with tetraplegia
Conference participation, scientific publication

KUKAMenschCropOver the last decades the generation mechanism and the representation of goal- directed movements has been a topic of intensive neurophysiological research. The investigation in the motor, premotor, and parietal areas led to the discovery that the direction of hand’s movement in space was encoded by populations of neurons in these areas together with many other movement parameters. These distributions of population activation reflect how movements are prepared ahead of movement initiation, as revealed by activity induced by cues that precede the imperative signal (Georgopoulos, 1991).

Inspired by those findings a model based on dynamical systems was proposed both, to model goal directed trajectories in humans and to generate trajectories for redundant anthropomorphic robotic arms. The analysis of the attractor dynamics based on the qualitative comparison with measurements of resulting trajectories taken from arm movement experiments with humans (Grimme u. a., 2012) created a framework able to reproduce and to generate naturalistic human like arm trajectories (Iossifidis und Rano, 2013; Iossifidis, Schöner u. a., 2006).

The main idea of the methodology is to choose low-dimensional, behavioral va- riables of the goal task can be represented as attractor states of those variables. The movement is generated through a dynamical system with attractors and repellers on the behavioral space, at the goal and constraint positions respectively. When the motion of the robot evolves according to the dynamics of these systems, the behavioral variables will be stabilized at their attractors.

Movement is represented by the polar coordinates φ,θ of the movement direction (heading direction) and the angular frequency ω of a hopf oscillator, generating the velocity profile of the arm movement. Therefore, the system dynamics will be expressed in terms of these variables. The target and each obstacle induce vector fields over these variables in a way that states where the hand is moving closer to the target are attractive, while states where it is moving towards an obstacle are repellant. Contributions from different sources are weighted by different factors, e.g. in the vicinity of an obstacle, the contribution from that obstacle must dominate the behavior to guarantee constraint satisfaction (collision prevention).

Based on three parameters the presented framework is able to generate temporal stabilized (timed) discrete movements, dealing with disturbances and maintaining an approximately constant movement time.

In the current study we will implant two 96-channel intracortical microelectrode arrays in the primary motor and the posterior parietal cortex (PPC) of an individual with tetraplegia.

In the training phase the parameters of the dynamical systems will be tuned and optimized by machine learning algorithms. Rather controlling directly the arm movement and adjusting continuously parameters, the patient adjust by his or hers thoughts the three parameters of the dynamics, which remain almost constant during the movement. Only when the motion plan is changing the parameters have to be readjusted. The target directed trajectory evolves from the attractor solution of the dynamical systems equations, which means that the trajectory is generated while the system is in a stable stationary state, a fixed-point attractor.

The increase of the degree of assistance lowers the cognitive load of the patient and enables the acknowledgement of the desired task without frustration. In addition we aim to replace the robotic manipulator by an exoskeleton for the upper body which will enable the patients to move his or hers own limbs, which would complete the development of a real neuroprosthetic device for every day use.

Literatur

Iossifidis, Ioannis und Ianki Rano (2013). „Modeling Human Arm Motion by Means of Attractor Dynamics Approach“. In: Proc. IEEE/RSJ International Conference on Robotics and Biomimetics (RoBio2013).

Grimme, Britta u.a. (2012). „Naturalistic Arm Movements during Obstacle Avoi- dance in 3D and the Identification of Movement Primitives“. In: Experimental brain research 222.3, S. 185–200.

Iossifidis, Ioannis, Gregor Schöner u.a. (2006). „Dynamical Systems Approach for the Autonomous Avoidance of Obstacles and Joint-limits for an Redundant Ro- bot Arm“. In: 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE, S. 580–585. isbn: 1-4244-0258-1.

Georgopoulos, AP (1991). „Higher order motor control“. In: Annual review of neu- roscience 14, S. 361–377.

Post navigation

❮ Previous Post: MINT TAG 2015: From Brain To Machine and Back
Next Post: Low dimensional representation of human arm movement for efficient neuroprosthetic control by individuals with tetraplegia ❯

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Recent Posts

  • (no title) June 18, 2026
  • New journal article: Predicting Muscle Activity from Upper Limb Kinematics with LSTM Networks June 7, 2026
  • New preprint: The Spatial and Temporal Resolution of Motor Intention in Multi-Target Prediction June 7, 2026
  • New paper: Performance Boundaries for BCIs Using Error-Related Potentials and Reinforcement Learning June 7, 2026
  • New paper: Distributional Properties of ReLU-Activations in Neural Networks That Learn by Memorization June 7, 2026

Recent Comments

    Archives

    • June 2026
    • May 2026
    • October 2025
    • January 2025
    • October 2024
    • September 2024
    • September 2023
    • June 2023
    • December 2022
    • October 2022
    • September 2022
    • May 2022
    • February 2022
    • January 2022
    • November 2021
    • August 2021
    • June 2021
    • April 2021
    • March 2021
    • February 2021
    • December 2020
    • November 2020
    • October 2020
    • September 2020
    • September 2019
    • October 2018
    • December 2017
    • September 2017
    • July 2016
    • December 2015
    • November 2013
    • October 2013
    • August 2013
    • May 2013
    • July 2012
    • March 2012
    • February 2012
    • January 2012
    • December 2011
    • September 2011
    • March 2011
    • June 2010
    • May 2010
    • April 2010
    • March 2010
    • September 2009
    • July 2009
    • May 2009
    • April 2009
    • March 2009
    • February 2009

    Categories

    • Conference participation
    • Grant
    • invited talk
    • journal club
    • press release
    • progress club
    • publication
    • research grand
    • scientific publication
    • software released
    • teaching
    • workshop

    Meta

    • Log in
    • Entries feed
    • Comments feed
    • WordPress.org

    Copyright © Ioannis Iossifidis 2020 iLab: From Brain to Machine and Back.

    Theme: Oceanly by ScriptsTown

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
    CookieDurationDescription
    cookielawinfo-checkbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
    cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
    cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
    cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
    cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
    cookielawinfo-checkbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
    cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
    cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
    viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
    viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
    Functional
    Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
    Performance
    Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.
    Analytics
    Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
    Advertisement
    Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.
    Others
    Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.
    SAVE & ACCEPT