Theoretical Development and Experimental Validation of an Adaptive Controller for Tremor Suppression at Musculoskeletal Level

2013 ◽  
Author(s):  
Behzad Taheri ◽  
David Case ◽  
Edmond Richer
Keyword(s):  
Body Part ◽  
Adaptive Controller ◽  
Theoretical Development ◽  
Pneumatic Cylinder ◽  
Medical Treatments ◽  
Non Invasive ◽  
Oscillatory Movement ◽  
Tremor Suppression ◽  
Tremor Frequency ◽  
Intentional Motion

Tremor is a rhythmical and involuntary oscillatory movement of a body part. Mechanical loading via wearable exoskeletons is a non-invasive tremor suppression alternative to medical treatments. In this approach, the challenge is attenuating the tremor without affecting the patient’s intentional motion. An adaptive tremor suppression algorithm was designed to estimate and restrict motion within the tremor frequency band. An experimental setup was designed and developed to simulate the dynamics of a human arm joint with intentional and tremorous motion. The required orthotic suppressive force was applied via a pneumatic cylinder. The algorithm was implemented with a real-time controller and experimental results show tracking of the tremor frequency and a 97% reduction of tremor amplitude at the fundamental frequency.

scholarly journals A Review on Wearable Technologies for Tremor Suppression

2021 ◽  
Vol 12 ◽  
Author(s):  
Julio S. Lora-Millan ◽  
Gabriel Delgado-Oleas ◽  
Julián Benito-León ◽  
Eduardo Rocon
Keyword(s):  
Side Effects ◽  
Upper Limb ◽  
Daily Living ◽  
Body Part ◽  
Wearable Technologies ◽  
Oscillatory Movement ◽  
Tremor Suppression ◽  
Management Paradigms ◽  
Validation Procedure ◽  
Hazardous Procedure

Tremor is defined as a rhythmic, involuntary oscillatory movement of a body part. Although everyone exhibits a certain degree of tremor, some pathologies lead to very disabling tremors. These pathological tremors constitute the most prevalent movement disorder, and they imply severe difficulties in performing activities of daily living. Although tremors are currently managed through pharmacotherapy or surgery, these treatments present significant associated drawbacks: drugs often induce side effects and show decreased effectiveness over years of use, while surgery is a hazardous procedure for a very low percentage of eligible patients. In this context, recent research demonstrated the feasibility of managing upper limb tremors through wearable technologies that suppress tremors by modifying limb biomechanics or applying counteracting forces. Furthermore, recent experiments with transcutaneous afferent stimulation showed significant tremor attenuation. In this regard, this article reviews the devices developed following these tremor management paradigms, such as robotic exoskeletons, soft robotic exoskeletons, and transcutaneous neurostimulators. These works are presented, and their effectiveness is discussed. The article also evaluates the different metrics used for the validation of these devices and the lack of a standard validation procedure that allows the comparison among them.

scholarly journals Natural Sensations Evoked in Distal Extremities Using Surface Electrical Stimulation

2018 ◽  
Vol 12 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Julia P. Slopsema ◽  
John M. Boss ◽  
Lane A. Heyboer ◽  
Carson M. Tobias ◽  
Brooke P. Draggoo ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Low Frequency ◽  
Pulse Amplitude ◽  
Neural Stimulation ◽  
Phantom Limb ◽  
Neural Function ◽  
Medical Treatments ◽  
Non Invasive ◽  
Knee Strength ◽  
Better Than

Background: Electrical stimulation is increasingly relevant in a variety of medical treatments. In this study, surface electrical stimulation was evaluated as a method to non-invasively target a neural function, specifically natural sensation in the distal limbs. Method: Electrodes were placed over the median and ulnar nerves at the elbow and the common peroneal and lateral sural cutaneous nerves at the knee. Strength-duration curves for sensation were compared between nerves. The location, modality, and intensity of each sensation were also analyzed. In an effort to evoke natural sensations, several patterned waveforms were evaluated. Results: Distal sensation was obtained in all but one of the 48 nerves tested in able-bodied subjects and in the two nerves from subjects with an amputation. Increasing the pulse amplitude of the stimulus caused an increase in the area and magnitude of the sensation in a majority of subjects. A low frequency waveform evoked a tapping or tapping-like sensation in 29 out of the 31 able-bodied subjects and a sensation that could be considered natural in two subjects with an amputation. This waveform performed better than other patterned waveforms that had proven effective during implanted extra-neural stimulation. Conclusion: Surface electrical stimulation has the potential to be a powerful, non-invasive tool for activation of the nervous system. These results suggest that a tapping sensation in the distal extremity can be evoked in most able-bodied individuals and that targeting the nerve trunk from the surface is a valid method to evoke sensation in the phantom limb of individuals with an amputation for short term applications.

scholarly journals Multi-Pig Part Detection and Association with a Fully-Convolutional Network

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 852 ◽  
Author(s):  
Eric Psota ◽  
Mateusz Mittek ◽  
Lance Pérez ◽  
Ty Schmidt ◽  
Benny Mote
Keyword(s):  
Body Part ◽  
Training Set ◽  
Convolutional Network ◽  
Fully Convolutional Network ◽  
Non Invasive ◽  
Significant Challenge ◽  
Lighting Conditions ◽  
Computer Vision Systems ◽  
Public Datasets ◽  
Private Datasets

Computer vision systems have the potential to provide automated, non-invasive monitoring of livestock animals, however, the lack of public datasets with well-defined targets and evaluation metrics presents a significant challenge for researchers. Consequently, existing solutions often focus on achieving task-specific objectives using relatively small, private datasets. This work introduces a new dataset and method for instance-level detection of multiple pigs in group-housed environments. The method uses a single fully-convolutional neural network to detect the location and orientation of each animal, where both body part locations and pairwise associations are represented in the image space. Accompanying this method is a new dataset containing 2000 annotated images with 24,842 individually annotated pigs from 17 different locations. The proposed method achieves over 99% precision and over 96% recall when detecting pigs in environments previously seen by the network during training. To evaluate the robustness of the trained network, it is also tested on environments and lighting conditions unseen in the training set, where it achieves 91% precision and 67% recall. The dataset is publicly available for download.

Tremor and other abnormal movements

2018 ◽  
Author(s):  
Susanne Schneider ◽  
Alexander Schmidt ◽  
Kailash P. Bhatia ◽  
Peter G. Bain
Keyword(s):  
Differential Diagnosis ◽  
Diagnostic Tests ◽  
Body Part ◽  
Body Parts ◽  
Abnormal Movements ◽  
Oscillatory Movement

Tremor is a rhythmic involuntary oscillatory movement of a body part, most commonly affecting the hands and arms but other body parts can also be affected including the legs, head, jaw, chin, palate, voice, and trunk. This chapter covers the differential diagnosis of tremor, the approach to diagnosis (including key diagnostic tests), therapies, and prognosis.

Hyperkinetic Movement Disorders: Tremor and Myoclonus

2021 ◽  
pp. 593-601
Author(s):  
Farwa Ali ◽  
Jeremy K. Cutsforth-Gregory
Keyword(s):  
Movement Disorders ◽  
Signs And Symptoms ◽  
Body Part ◽  
Underlying Disease ◽  
Metabolic State ◽  
Oscillatory Movement ◽  
Underlying Causes

Hyperkinetic movement disorders are characterized by excess movement. Tremor and myoclonus are the most common hyperkinetic movement disorders and signify various possible underlying causes or diagnoses. Tremor is an involuntary, rhythmic, oscillatory movement of a body part. It can be distinguished from myoclonus by its regular frequency and from chorea by its stereotyped nature. The subtypes of tremor vary in frequency, conditions of activation and relief, and associated signs and symptoms. Tremor can be primary, being the only manifestation of a condition, or secondary, being symptomatic of a metabolic state or other underlying disease.

Active Control of MR Wearable Robotic Orthosis for Pathological Tremor Suppression

2015 ◽  
Author(s):  
David Case ◽  
Behzad Taheri ◽  
Edmond Richer
Keyword(s):  
Real Time ◽  
Active Control ◽  
Control Strategy ◽  
Weight Ratio ◽  
High Strength ◽  
Current Approach ◽  
Theoretical Development ◽  
Constant Current ◽  
Tremor Suppression ◽  
Pathological Tremor

Given the side effects and possible complications of current clinical treatments for severe pathological tremor, many researchers pursue the less invasive alternative of suppression at the musculo-skeletal level. In wearable robotics applications, the high strength-to-weight ratio, the low power consumption, and their adaptability allow magnetorheological (MR) fluid dampers and actuators to be personalized to the individual needs of a patient. Moreover, their rapid dynamic response makes them suitable for use in real time active devices. This paper presents the theoretical development and experimental validation of a tremor suppression control algorithm based on a dynamic lump parameter model of the MR damper and a real time adaptive tremor frequency estimator. The control strategy was experimentally evaluated using a one-DOF joint simulator. Experiments with ten datasets from patients with severe Parkinsonian and Essential Tremor show suppressions for the first and second harmonics of 28.7±2.2 dB and 11.8±4.8 dB, respectively. These results compare favorably with the suppression levels obtained by other researchers using constant current approach. In addition, the resistance that the orthotic device imposes to the voluntary motion was reduced by 33% under the active control strategy, while the power usage was dramatically reduced by nearly an order of magnitude.

Adaptive Disturbance Rejection Controller for Pathological Tremor Suppression With Permanent Magnet Linear Motor

2017 ◽  
Author(s):  
Amir Hosein Zamanian ◽  
Edmond Richer
Keyword(s):  
Permanent Magnet ◽  
Disturbance Rejection ◽  
Linear Motor ◽  
Resistance Force ◽  
Pneumatic Actuators ◽  
Tremor Suppression ◽  
Tremor Frequency ◽  
Permanent Magnet Linear Motor ◽  
Magneto Rheological ◽  
Pathological Tremor

This paper presents an adaptive disturbance rejection (ADR) controller developed for the suppression of the pathological tremor in the humans’ wrist. An experimental setup, based on a slotted permanent magnet linear motor (PMLM), was developed to evaluate the ADR’s performance in real-time suppression of the tremor signal recorded from Parkinson’s disease patients. A model-base compensator was utilized to minimize the resistive and cogging forces exhibited by the PMLM. Experimental results showed an average tremor amplitude suppression of 32.61 dB (97.6%) in the first, and 15.23 dB (82.7%) in the second tremor frequency respectively. The average magnitude of the resistance force induced by the system against voluntary motion was 0.36 N. Furthermore, to evaluate the tremor suppression performance of the presented technique the results were compared with two other studies that used pneumatic actuators and magneto-rheological dampers (MRD). The performance of the PMLM was analogous to actively controlled pneumatic actuators and was significantly better than the semi-active controller with MRD.

scholarly journals Non-invasive Amelioration of Essential Tremor via Phase-Locked Disruption of its Temporal Coherence

2020 ◽  
Author(s):  
Sebastian R. Schreglmann ◽  
David Wang ◽  
Robert Peach ◽  
Junheng Li ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Statistical Learning ◽  
Temporal Coherence ◽  
Neural Oscillations ◽  
Brain Disorders ◽  
Neural Oscillation ◽  
Non Invasive ◽  
Tremor Suppression ◽  
Feature Based ◽  
Stimulation Of

AbstractAberrant neural oscillations hallmark numerous brain disorders. Here, we first report a method to track the phase of neural oscillations in real-time via endpoint-corrected Hilbert transform (ecHT) that mitigates the characteristic Gibbs distortion. We then used ecHT to show that the aberrant neural oscillation that hallmarks essential tremor (ET) syndrome, the most common adult movement disorder, can be noninvasively suppressed via electrical stimulation of the cerebellum phase-locked to the tremor. The tremor suppression is sustained after the end of the stimulation and can be phenomenologically predicted. Finally, using feature-based statistical-learning and neurophysiological-modelling we show that the suppression of ET is mechanistically attributed to a disruption of the temporal coherence of the oscillation via perturbation of the tremor generating a cascade of synchronous activity in the olivocerebellar loop. The suppression of aberrant neural oscillation via phase-locked driven disruption of temporal coherence may represent a powerful neuromodulatory strategy to treat brain disorders.

scholarly journals Inter- and intra-patient circadian variabilities in eight urinary modified nucleosides excretion in patients with metastatic colorectal cancer

2019 ◽  
Author(s):  
Sandrine Dulong ◽  
Huang Qi ◽  
Innominato Pasquale Fabio ◽  
Karaboue Abdoulaye ◽  
Bouchahda Mohamed ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Urinary Excretion ◽  
Cellular Proliferation ◽  
Modified Nucleosides ◽  
Activity Data ◽  
Medical Treatments ◽  
Non Invasive ◽  
R1 Resection ◽  
Circadian Timing System ◽  
Colorectal Cancer Patients

Abstract Background : Modified nucleosides reflect nucleic acids turnover, and are eliminated into the urine. They can serve as non-invasive biomarkers for monitoring tumour dynamics, and treatment responses. Methods : 8 modified nucleosides were determined by LC-HRMS in urine voids collected in three linical trials recorded on NCT01693848, NCT01693861 and NCT01693835 by a total of 39 patients. The patients’ circadian timing system was studied by wrist actimetry. Rhythms parameters were estimated using Hidden Markov model (HMM) for telemetric activity data and cosinor analysis for urinary nucleosides excretion. Results : Pseudouridine, was ~ 10-fold larger than those of 1-methylguanosine, 1-methyladenosine, or 4-acetylcytidine, and ~100 fold larger than those of adenosine and cytidine. In St 1, a significant increase in the overnight urinary excretion of 1-methylguanosine was associated with prolonged 4-year survival in patients with R1 resection for liver metastases. In St 2, a significant increase in one nucleoside excretion after chemotherapy was associated with that in plasma carcinoembryonic antigen 1-2 months later, and poor survival. In St3, ten fractionated urines were collected over 2-days. Circadian and/or 12-h rhythms were found in up to 48.3% of the patients for pseudouridine. Rhythm amplitudes were significantly associated with rest-activity circadian parameters. Conclusion : Urinary excretion dynamics of modified nucleosides appeared useful for tracking early responses to surgical or medical treatments, and for characterizing circadian control of cellular proliferation in colorectal cancer patients.

scholarly journals Microarray analysis of ductal carcinoma in situ samples obtained by puncture from surgical resection specimens

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tomoo Jikuzono ◽  
Eriko Manabe ◽  
Shoko Kure ◽  
Haruki Akasu ◽  
Tomoko Ishikawa ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Mammographic Screening ◽  
Medical Treatments ◽  
Non Invasive ◽  
Genome Wide ◽  
Invasive Property

Abstract Objective The incidence of ductal carcinoma in situ (DCIS) is increasing due to more widespread mammographic screening. DCIS, the earliest form of breast cancer, is non-invasive at the time of detection. If DCIS tissues are left undetected or untreated, it can spread to the surrounding breast tissue. Thus, surgical resection is the standard treatment. Understanding the mechanism underlying the non-invasive property of DCIS could lead to more appropriate medical treatments, including nonsurgical options. Data description We conducted a microarray-based genome-wide transcriptome analysis using DCIS specimens obtained by puncture from surgical specimens immediately after surgery.

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