Portable, open-source solutions for estimating wrist position during reaching in people with stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Traditional optical tracking systems for measuring arm movement kinematics in stroke survivors are often impractical due to environmental limitations, cost, and calibration difficulties.
• Arm movement kinematics offer a potentially more sensitive metric for assessing neurorehabilitation outcomes compared to existing methods.

Purpose of the Study:

• To present and validate two open-source methods using inertial measurement units (IMUs) and virtual reality (Vive) sensors for accurate arm movement kinematic measurements in individuals with stroke.
• To assess the ability of these methods to track key kinematic metrics like sweep area and smoothness.

Main Methods:

• Developed and implemented two open-source systems: one utilizing IMUs and another using Vive sensors.
• Assessed the accuracy of wrist position tracking relative to the shoulder during 3D reaching movements in stroke patients.
• Evaluated the tracking of sweep area and smoothness metrics in individuals with chronic stroke.

Main Results:

• Both IMU and Vive sensor methods demonstrated high accuracy in tracking wrist position during reaching movements, with low mean signed errors compared to optical tracking.
• Kinematic data estimated by both IMU and Vive methods showed high correlation (p < 0.01).
• The methods successfully tracked kinematic metrics such as sweep area and smoothness.

Conclusions:

• Open-source methods using inexpensive wearable sensors (IMUs and Vive) provide accurate and reliable measurements of arm kinematics in stroke survivors.
• These sensor-based approaches are suitable for both laboratory and clinical environments, facilitating the development of sensitive kinematic metrics for evaluating stroke rehabilitation.
• The proposed methods enhance the feasibility of using kinematic analysis for objective assessment of neurorehabilitation progress.