Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Doctor of Philosophy

Program

Biomedical Engineering

Collaborative Specialization

Musculoskeletal Health Research

Supervisor

Trejos, Ana Luisa

2nd Supervisor

Naish, Michael D.

Co-Supervisor

Abstract

Tremor, one of the most disabling symptoms of Parkinson's disease (PD), significantly affects the quality of life of the individuals who suffer from it. These people live with difficulties with fine motor tasks, such as eating and writing, and suffer from social embarrassment. Traditional medicines are often ineffective, and surgery is highly invasive and risky. The emergence of wearable technology facilitates an externally worn mechatronic tremor suppression device as a potential alternative approach for tremor management. However, no device has been developed for the suppression of finger tremor that has been validated on a human.

It has been reported in the literature that tremor can be selectively suppressed by mechanical loading. Therefore, the objectives of this thesis were to develop a wearable tremor suppression device that can suppress tremor at the wrist and the fingers, and to evaluate it on individuals with PD in a pre-clinical trial. To address these objectives, several experiments were performed to quantify hand tremor; an enhanced high-order tremor estimator was developed and evaluated for tremor estimation; and a wearable tremor suppression glove (WTSG) was developed to suppress tremor in the index finger metacarpophalangeal (MCP) joint, the thumb MCP joint, and the wrist.

A total of 18 individuals with PD were recruited for characterizing tremor. The frequencies and magnitudes of the linear acceleration, angular velocity, and angular displacement of tremor in the index finger MCP joint, the thumb MCP joint, and the wrist were quantified. The results showed that parkinsonian tremor consists of multiple harmonics, and that the second and third harmonics cannot be ignored. With the knowledge of the tremor characteristics, an enhanced high-order tremor estimator was developed to acquire better tremor estimation accuracy than its lower-order counterpart.

In addition, the evaluation of the WTSG was conducted on both a physical tremor simulator and on one individual with PD. The results of the simulation study proved the feasibility of using the WTSG to suppress tremor; and the results of the evaluation on a human subject showed that the WTSG can suppress tremor motion while allowing the user to perform voluntary motions. The WTSG developed as a result of this work has demonstrated the feasibility of managing hand tremor with a mechatronic device, and its validation on a human subject has provided useful insights from the user's perspectives,

which facilitate the transition of the WTSG from the lab to the clinic, and eventually to commercial use.

Lastly, an evaluation studying the impact of suppressed tremor on unrestricted joints was conducted on 14 individuals with PD. The results showed a significant increase in tremor magnitude in the unrestricted distal joints when the motions of the proximal joints were restricted. The average increase of the tremor magnitude of the index finger MCP joint, the thumb MCP joint, the wrist and the elbow are 54%, 96%, 124%, and 98% for resting tremor, and 50%, 102%, 49%, and 107% for postural tremor, respectively. Such a result provided additional clinical justification for the significance of the development of a wearable mechatronic device for hand tremor management. Although the focus of this thesis is on hand tremor management, the development and evaluation of a full upper-limb tremor suppression device is required as a future step, in order to advance the use of wearable mechatronic devices as one of the valid tremor treatment approaches.

Summary for Lay Audience

Tremor, one of the most disabling symptoms of Parkinson's disease (PD), significantly reduces the quality of life of the individuals who are living with tremor, creating difficulties for fine motor tasks, such as eating and writing, and causing social embarrassment. Traditional medicines are often ineffective, and surgery is highly invasive and risky. In addition to these two approaches, an externally worn tremor suppression device has become a potential alternative approach for tremor management. However, no device has been developed for the suppression of finger tremor and validated it on humans.

It has been validated in the literature that tremor can be selectively suppressed by applying force. The objectives of this project were to develop a device that can suppress tremor at the wrist and the fingers, and to evaluate it on individuals with PD. To address these objectives, several experiments were performed to quantify the tremor in the hand; a tremor estimation technique was developed and evaluated; and a wearable tremor suppression glove (WTSG) was developed to suppress tremor in the index finger knuckle, the thumb knuckle and the wrist.

A total of 18 patients were recruited in order to characterize tremor. The frequencies and strength of the tremor in the index finger knuckle, the thumb knuckle and the wrist were quantified. With the knowledge of the tremor characteristics, a high-order tremor estimator showed an average of 28.5% increase in tremor estimation accuracy over its lower-order version.

Lastly, the evaluation of the WTSG was conducted on both a physical tremor simulator and on one individual with PD. The results of the simulation study proved the feasibility of using the WTSG to suppress tremor; and the results of the evaluation on a human subject showed that the WTSG can suppress tremor motion while allowing the voluntary motion of the user. Results from the experiment showed an overall suppression of 73.1%, 80.7% and 85.5% in resting tremor, 70.2%, 79.5% and 81% in postural tremor, and 52.6%, 55.5% and 59.8% in kinetic tremor in the index finger MCP joint, the thumb MCP joint and the wrist, respectively.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

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