Towards the Development of a Wearable Tremor Suppression Glove

Patients diagnosed with Parkinson’s disease (PD) often associate with tremor. Among other symptoms of PD, tremor is the most aggressive symptom and it is difficult to control with traditional treatments. This thesis presents the assessment of Parkinsonian hand tremor in both the time domain and the frequency domain, the performance of a tremor estimator using different tremor models, and the development of a novel mechatronic transmission system for a wearable tremor suppression device. This transmission system functions as a mechatronic splitter that allows a single power source to support multiple independent applications. Unique features of this transmission system include low power consumption and adjustability in size and weight. Tremor assessment results showed that the hand tremor signal often presents a multi-harmonics pattern. The use of a multi-harmonics tremor model produced a better estimation result than using a monoharmonic tremor model

Rehabilitation Engineering

Population ageing has major consequences and implications in all areas of our daily life as well as other important aspects, such as economic growth, savings, investment and consumption, labour markets, pensions, property and care from one generation to another. Additionally, health and related care, family composition and life-style, housing and migration are also affected. Given the rapid increase in the aging of the population and the further increase that is expected in the coming years, an important problem that has to be faced is the corresponding increase in chronic illness, disabilities, and loss of functional independence endemic to the elderly (WHO 2008). For this reason, novel methods of rehabilitation and care management are urgently needed. This book covers many rehabilitation support systems and robots developed for upper limbs, lower limbs as well as visually impaired condition. Other than upper limbs, the lower limb research works are also discussed like motorized foot rest for electric powered wheelchair and standing assistance device

Magneto-rheological fluid orthosis for suppressing tremor

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user\u27s joints for suppressing tremor. This thesis is based on the concept of smart structures which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable. An MR fluid orthosis satisfies these conditions. This thesis shows the physical properties of MR fluid and the basic concept of a rotational MR fluid damper for suppressing tremor. Specifically, an MR fluid friction damper experimentally provides a damping coefficient capable of suppressing tremor. A simulation confirms that the damping moment of the MR fluid friction damper is sufficient to suppress that of the wrist tremor, with realistic peak to peak torque 0.022 Nm. This allows slower intentional movement to occur with only moderate attenuation. The results of this work show that it is possible to design an MR fluid orthosis that is wearable and capable of suppressing tremors at the wrist. The proportionality of the tremor-reducing torque to electric current allows the potential for both user adjustment as well as automatic feedback control

Management of rapid eye movement sleep behavior disorder in patients with Parkinson's disease

Among all of the devastating effects that Parkinson’s disease (PD) has on an individual, sleep dysfunction is one that can have a profound effect on the entire family of the patient. The most potentially destructive of these sleep syndromes being that of Rapid Eye Movement Sleep Behavior Disorder (RBD). This disorder not only causes sleep impairment to the patient, but can occasionally result in life-threatening injury to the individual or their bed partner. While this condition is manageable with medication, the current treatment of choice is a long-acting benzodiazepine, clonazepam. This drug, while effective in treating RBD, comes with a significant burden of side effects. Patients with neurodegenerative disorders, like PD, are at even higher risk of suffering the negative impacts of this treatment. One potential alternative treatment that has been considered is a supplement of exogenous melatonin, a hormone that plays a role in maintaining one’s circadian rhythm. Several small case studies have shown potential efficacy of this treatment, and with very few side effects. However, this efficacy has not yet been proven by randomized clinical trial. This proposed study will perform a double-blind randomized clinical trial of melatonin vs. placebo in a population of PD patients with RBD. Subjects will be analyzed via polysomnographic sleep study, where symptoms will be scored on the RBD Severity Scale (RBDSS) at baseline and after a treatment intervention. Statistical analysis will then ascertain whether or not a significant symptom reduction is seen following melatonin treatment, compared to a group receiving placebo. If melatonin proves to be efficacious in this patient population, this would give clinicians a new treatment option to consider to effectively manage symptoms of RBD with a much lower risk of potentially harmful side effects. Finding an effective method of managing this condition, the prevalence of which continues to rise worldwide, will have a great impact on improving the safety and quality of life of these patients

Pathological Tremor as a Mechanical System: Modeling and Control of Artificial Muscle-Based Tremor Suppression

Central nervous system disorders produce the undesired, approximately rhythmic movement of body parts known as pathological tremor. This undesired motion inhibits the patient\u27s ability to perform tasks of daily living and participate in society. Typical treatments are medications and deep brain stimulation surgery, both of which include risks, side effects, and varying efficacy. Since the pathophysiology of tremor is not well understood, empirical investigation drives tremor treatment development. This dissertation explores tremor from a mechanical systems perspective to work towards theory-driven treatment design. The primary negative outcome of pathological tremor is the undesired movement of body parts: mechanically suppressing this motion provides effective tremor treatment by restoring limb function. Unlike typical treatments, the mechanisms for mechanical tremor suppression are well understood: applying joint torques that oppose tremor-producing muscular torques will reduce tremor irrespective of central nervous system pathophysiology. However, a tremor suppression system must also consider voluntary movements. For example, mechanically constraining the arm in a rigid cast eliminates tremor motion, but also eliminates the ability to produce voluntary motions. Indeed, passive mechanical systems typically reduce tremor and voluntary motions equally due to the close proximity of their frequency content. Thus, mechanical tremor suppression requires active actuation to reduce tremor with minimal influence on voluntary motion. However, typical engineering actuators are rigid and bulky, preventing clinical implementations. This dissertation explores dielectric elastomers as tremor suppression actuators to improve clinical implementation potential of mechanical tremor suppression. Dielectric elastomers are often called artificial muscles due to their similar mechanical properties as human muscle; these similarities may enable relatively soft, low-profile implementations. The primary drawback of dielectric elastomers is their relatively low actuation levels compared to typical actuators. This research develops a tremor-active approach to dielectric elastomer-based tremor suppression. In a tremor-active approach, the actuators only actuate to oppose tremor, while the human motor system must overcome the passive actuator dynamics. This approach leverages the low mechanical impedance of dielectric elastomers to overcome their low actuation levels. Simulations with recorded tremor datasets demonstrate excellent and robust tremor suppression performance. Benchtop experiments validate the control approach on a scaled system. Since dielectric elastomers are not yet commercially available, this research quantifies the necessary dielectric elastomer parameters to enable clinical implementations and evaluates the potential of manufacturing approaches in the literature to achieve these parameters. Overall, tremor-active control using dielectric elastomers represents a promising alternative to medications and surgery. Such a system may achieve comparable tremor reduction as medications and deep brain stimulation with minimal risks and greater efficacy, but at the cost of increased patient effort to produce voluntary motions. Parallel advances in scaled dielectric elastomer manufacturing processes and high-voltage power electronics will enable consumer implementations. In addition to tremor suppression, this dissertation investigates the mechanisms of central nervous system tremor generation from a control systems perspective. This research investigates a delay-based model for parkinsonian tremor. Besides tremor, Parkinson\u27s disease generally inhibits movement, with typical symptoms including rigidity, bradykinesia, and increased reaction times. This fact raises the question as to how the same disease produces excessive movement (tremor) despite characteristically inhibiting movement. One possible answer is that excessive central nervous system inhibition produces unaccounted feedback delays that cause instability. This dissertation develops an optimal control model of human motor control with an unaccounted delay between the state estimator and controller. This delay represents the increased inhibition projected from the basal ganglia to the thalamus, delaying signals traveling from the cerebellum (estimator) to the primary motor cortex (controller). Model simulations show increased delays decrease tremor frequency and increase tremor amplitude, consistent with the evolution of tremor as the disease progresses. Simulations that incorporate tremor resetting and random variation in control saturation produce simulated tremor with similar characteristics as recorded tremor. Delay-induced tremor explains the effectiveness of deep brain stimulation in both the thalamus and basal ganglia since both regions contribute to the presence of feedback delay. Clinical evaluation of mechanical tremor suppression may provide clinical evidence for delay-induced tremor: unlike state-independent tremor, suppression of delay-induced tremor increases tremor frequency. Altogether, establishing the mechanisms for tremor generation will facilitate pathways towards improved treatments and cure development

Disease modifying therapy for multiple system atrophy – Parkinsonian Type

BACKGROUND: Multiple System Atrophy –Parkinsonian Type (MSA-P) is a rare, rapidly progressive neurodegenerative disease without any current treatment. Recent research has increased the understanding of brain iron accumulation and its association with neurodegenerative synucleinopathies, like MSA-P. Because of this improved understanding of the disease process, there is potential for new therapies that could benefit patients with MSA-P. Unfortunately, many attempts at finding a new and effective treatments for MSA-P have been unsuccessful. Two drugs that have shown potential in neurodegenerative synucleinopathies associated with brain iron accumulation are iron chelators (Deferiprone) and tyrosine kinase inhibitors (Nilotinib.) METHODS: The proposed study is a multicenter, double blind, randomized control study of Nilotinib and Deferiprone for the treatment of MSA-P. There will be two treatment arms; Nilotinib and a placebo group vs. Nilotinib and Deferiprone. There will be a 24 week treatment phase, followed by a 24 week wash-out phase. All patients will have a baseline evaluation including: a full neurological exam with rating scales (UMSARS, UPDRS, SCOPA, and MOCA) to assess motor and non-motor symptoms of MSA-P. Lab and imaging data will include CBC, CMP, serum iron panel, CSF iron panel and brain SWI-MR scans. Neurological exams and rating scales will be assessed every four weeks while imaging and laboratory data will be assessed at baseline (week 0) at the end of the intervention phase (week 24) and at the end of the follow-up phase (week 48). CONCLUSIONS: Deferiprone and Nilotinib when used together will have a synergistic impact on the symptoms of MSA-P and will be more effective when used together versus when they are used individually. SIGNIFICANCE: Patients with MSA-P have shortened life expectancy as well as severely diminished quality of life due to rapidly progressive neurodegeneration. This trial aims to implementing evidence based treatment for MSA-P that could potentially improve life expectancy as well as quality of life in this patient population