Thesis Defence: Development and Validation of a Multi-Degree of Freedom Dynamic Platform for Hand Tremor Suppression Device Design

Jintao An, supervised by Dr. Hadi Mohammadi, will defend their thesis titled “Development and Validation of a Multi-Degree of Freedom Dynamic Platform for Hand Tremor Suppression Device Design” in partial fulfillment of the requirements for the degree of Master of Applied Science in Mechanical Engineering.

An abstract for Jintao An’s thesis is included below.

Defences are open to all members of the campus community as well as the general public. Please email hadi.mohammadi@ubc.ca to receive the Zoom link for this defence.

Abstract

Hand tremor is one of the most prevalent motor symptoms associated with Parkinson’s disease and essential tremor, often interfering with activities of daily living and reducing quality of life. Non-invasive mechanical tremor suppression devices have emerged as a promising engineering-based approach for attenuating pathological tremors. However, their development and validation require a repeatable, adjustable, and quantitative testing platform capable of reproducing tremor-like motions under controlled conditions. Existing evaluation methods are often limited by poor repeatability, restricted parameter adjustability, and an inability to assess multi-degree-of-freedom (DOF) responses.

To address these limitations, this thesis presents the development of a three-degree-of-freedom (3-DOF) hand tremor simulation platform. The platform was designed using dynamic hand parameters and tremor characteristics reported in the literature. Rather than replicating the full anatomical and neuromuscular complexity of the human upper limb, the system models hand tremor as a controllable mechanical vibration problem. The simulator reproduces translational motion representative of wrist flexion–extension and rotational motion associated with forearm pronation–supination. Key operating parameters, including excitation frequency, response amplitude, and rotational coupling, can be adjusted to emulate a range of tremor conditions.

A multi-sensor measurement system was implemented to capture both translational and rotational responses. Following calibration, cross-validation between sensors demonstrated greater than 95% agreement, confirming the accuracy and reliability of the measurement framework. To further validate the platform, a previously investigated T-beam vibration absorber was employed as a benchmark tremor suppression device. Across the 4–7 Hz test range, the measured attenuation trends closely matched previously reported theoretical and experimental results, demonstrating the platform’s ability to reproduce expected suppression behaviour.

The results confirm that the developed platform provides a reliable and quantitative environment for evaluating mechanical tremor suppression devices through before-and-after response comparisons. As such, it serves as an effective tool for the design, optimization, and preliminary validation of next-generation non-invasive tremor attenuation technologies.