Experimental Testing of Passive Linear TMD for Postural Tremor Attenuation

Research interest to provide a mechanical solution for involuntary tremors is increasing due to the severe side effects caused by the medications used to lessen its symptoms. This paper deals with the design of a cantilever-type tuned mass damper (TMD) used to prove the effectiveness of passive controllers in reducing the involuntary tremor’s vibrational signals transmitted by the muscles to the hand segment. TMD is tested on an experimental arm, reflecting the flexion-extension motion of the wrist, excited by a mechanical shaker with the measured tremor signal of a patient with essential tremor. The designed TMD provides a new operational frequency for each position of the screw fixed to its beam. Modal damping ratios are also calculated using different methods for each position. The effectiveness of the TMD is quantified by measurements using a vibrometer and inertial measurement unit. Three TMDs, representing 15.7% total mass ratio, cause a reduction of 29% for the acceleration, 69% for the velocity, 79% for the displacement, 67% for the angular velocity, and 82% for the angular displacement signals. These encouraging results will allow the improvement of the design of the passive controller in the form of a wearable bracelet suitable for daily life.

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Effectiveness of Location and Number of Multiple Tuned Mass Damper for Seismic Structures

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k2324.049620 ◽

2020 ◽

Vol 9 (6) ◽

pp. 780-783

Keyword(s):

Seismic Response ◽

Software Tool ◽

Tuned Mass Damper ◽

Structure Study ◽

Structural Performance ◽

Mass Ratio ◽

Tuned Mass Dampers ◽

Maximum Reduction ◽

Mass Damper ◽

Earthquake Data

Tuned mass dampers (TMD) are one of the most reliable devices to control the vibration of the structure. The optimum mass ratio required for a single tuned mass damper (STMD) is evaluated corresponding to the fundamental natural frequency of the structure. The effect of STMD and Multiple tuned mass dampers (MTMD) on a G+20 storey structure are studied to demonstrate the damper’s effectiveness in seismic application. The location and number of tuned mass dampers are studied to give best structural performance in maximum reduction of seismic response for El Centro earthquake data. The analysis results from SAP 2000 software tool shows damper weighing 2.5% of the total weight of the structure effectively reduce the response of the structure. Study shows that introduction of 4-MTMD at top storey can effectively reduce the response by 10% more in comparison to single tuned mass damper. The use of MTMD of same mass ratio that of STMD is more effective in seismic response.

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Design and Development of Continuous Passive Motion (CPM) for Fingers and Wrist Grounded-Exoskeleton Rehabilitation System

Applied Sciences ◽

10.3390/app11020815 ◽

2021 ◽

Vol 11 (2) ◽

pp. 815

Author(s):

Husam Almusawi ◽

Géza Husi

Keyword(s):

Experimental Testing ◽

Hand Movement ◽

Evaluation Process ◽

Continuous Passive Motion ◽

Wrist Flexion ◽

Design And Development ◽

Passive Motion ◽

Assistive Robots ◽

Flexion Extension ◽

Design Characteristics

Impairments of fingers, wrist, and hand forearm result in significant hand movement deficiencies and daily task performance. Most of the existing rehabilitation assistive robots mainly focus on either the wrist training or fingers, and they are limiting the natural motion; many mechanical parts associated with the patient’s arms, heavy and expensive. This paper presented the design and development of a new, cost-efficient Finger and wrist rehabilitation mechatronics system (FWRMS) suitable for either hand right or left. The proposed machine aimed to present a solution to guide individuals with severe difficulties in their everyday routines for people suffering from a stroke or other motor diseases by actuating seven joints motions and providing them repeatable Continuous Passive Motion (CPM). FWRMS approach uses a combination of; grounded-exoskeleton structure to provide the desired displacement to the hand’s four fingers flexion/extension (F/E) driven by an indirect feed drive mechanism by adopting a leading screw and nut transmission; and an end-effector structure to provide angular velocity to the wrist flexion/ extension (F/E), wrist radial/ulnar deviation (R/U), and forearm supination/pronation (S/P) driven by a rotational motion mechanism. We employed a single dual-sided actuator to power both mechanisms. Additionally, this article presents the implementation of a portable embedded controller. Moreover, this paper addressed preliminary experimental testing and evaluation process. The conducted test results of the FWRMS robot achieved the required design characteristics and executed the motion needed for the continuous passive motion rehabilitation and provide stable trajectories guidance by following the natural range of motion (ROM) and a functional workspace of the targeted joints comfortably for all trainable movements by FWRMS.

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Analysis study the used of Tuned Mass Damper (TMD) on an existing train bridge due to high speed train with moving mass load approach

MATEC Web of Conferences ◽

10.1051/matecconf/201925805005 ◽

2019 ◽

Vol 258 ◽

pp. 05005 ◽

Cited By ~ 1

Author(s):

Wivia Octarena Nugroho ◽

Dina Rubiana Widarda ◽

Oryza Herdha Dwyana

Keyword(s):

High Speed ◽

Tuned Mass Damper ◽

Dynamic Responses ◽

Mass Ratio ◽

High Speed Train ◽

Maximum Deformation ◽

Mass Load ◽

Mass Damper ◽

Existing Bridges ◽

Comfort Criteria

As the need of the train speed increased, the existing bridges need to be evaluated, especially in dynamic responses, which are deformation and acceleration. In this study, Cisomang Bridge is modeled and analyzed due to the high-speed train SJ X2 in varying speeds, 50 km/h, 100 km/h, 150 km/h, and 200 km/h. The used of tuned mass damper also will be varied on its setting and placing. The tuned mass dampers setting be varied based on the first or second natural frequency and the placing of tuned mass damper be varied based on maximum deformation of the first or second mode. Moreover, the tuned mass damper ratio will be varied 1% and 1.6%. For all speed variations, dynamic responses of structure without TMD still fulfil the Indonesian Government Criterion based on PM 60 - 2012 but do not meet requirement of comfort criteria based on DIN-Fachbericht 101. Furthermore, only for the speed train 50km/h dynamic responses of structure fulfil safety criteria based on Eurocode EN 1990:2002, whereas the other speed variations do not meet that requirement. In the use of TMD 1% mass ratio, the structure fulfils the safety criteria for all speed variations. In the use of TMD 1.6% mass ratio, all the structure fulfils the safety and comfort criteria except 100 km/h speed which only fulfils the safety criteria.

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Inertial mass damper for vibration control of cable with sag

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1177/1461348418814967 ◽

2018 ◽

Vol 39 (3) ◽

pp. 749-760 ◽

Cited By ~ 3

Author(s):

Zhi-Hao Wang ◽

Hui Gao ◽

Bu-qiao Fan ◽

Zheng-Qing Chen

Keyword(s):

Inertial Mass ◽

Damping Coefficient ◽

Stay Cables ◽

Modal Damping ◽

Optimal Damping ◽

Mass Damper ◽

Negative Effect ◽

Supplemental Damping ◽

Antisymmetric Vibrations ◽

General Dynamic

It has been theoretically predicted that superior supplemental damping can be generated for a taut cable with an inertial mass damper. This paper extends previous studies to investigate the effect of the cable sag on the efficiency of an inertial mass damper. The general dynamic characteristics of an inclined sag cable with an inertial mass damper installed close to the cable end are theoretically investigated. The parametric analysis of the inertial mass and the damping coefficient of the inertial mass damper are conducted to evaluate the control performance of the cable with different sags. The results show that the inertial mass damper can alleviate the negative effect induced by the cable sag, and the cable sag can even increase modal damping ratios provided by the inertial mass damper. Sags of stay cables used in actual bridges only affect nearly symmetric vibrations of cables, while having little impact on nearly antisymmetric vibrations. The effect of cable sags will reduce the optimal damping coefficient and inertial mass of the inertial mass damper for the first symmetric mode of the cable.

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Upper limb involuntary tremor reduction using cantilever beam TMDs

Journal of Vibration and Control ◽

10.1177/10775463211051869 ◽

2022 ◽

pp. 107754632110518

Author(s):

Sarah Gebai ◽

Gwendal Cumunel ◽

Mohammad Hammoud ◽

Gilles Foret ◽

Emmanuel Roze ◽

...

Keyword(s):

Stainless Steel ◽

Objective Function ◽

Cantilever Beam ◽

Upper Limb ◽

Wrist Joint ◽

Angular Displacement ◽

Damping Ratio ◽

Vertical Plane ◽

Cross Sectional ◽

Flexion Extension

Tuned mass dampers (TMDs) are proposed as a solution to reduce the involuntary tremor at the upper limb of a patient with postural tremor. The upper limb is modeled as a three-degrees-of-freedom rotating system in the vertical plane, with a flexion-extension motion at the joints. The measured extensor carpi radialis signal of a patient is used to excite the dynamic model. We propose a numerical methodology to optimize the parameters of the TMDs in the frequency domain combined with the response in the time domain. The objective function for the optimization of the dynamic problem is the maximum angular displacement of the wrist joint. The optimal stiffness and damping of the TMDs are obtained by satisfying the minimization of the selected objective function. The considered passive absorber is a cantilever beam–like TMD, whose length, beam cross-sectional diameter, and mass position reflect its stiffness for a chosen additional mass. A parametric study of the TMD is conducted to evaluate the effect of the TMD position along the hand segment, the number of TMDs, and the total mass of TMDs. The sensitivity of the TMD to a decrease of its modal damping ratio is studied to meet the range of stainless steel. TMDs are manufactured using stainless steel beams of the same length (9.1 cm) and cross-sectional diameter (0.79 mm), for which the mass (14.13 g) position is adjusted to match the optimal frequency. Three TMDs holding a mass of 14.13 g each cause 89% reduction in the wrist joint angular displacement.

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Inertial Sensors as a Tool for Diagnosing Discopathy Lumbosacral Pathologic Gait: A Preliminary Research

Diagnostics ◽

10.3390/diagnostics10060342 ◽

2020 ◽

Vol 10 (6) ◽

pp. 342 ◽

Cited By ~ 13

Author(s):

Sebastian Glowinski ◽

Karol Łosiński ◽

Przemysław Kowiański ◽

Monika Waśkow ◽

Aleksandra Bryndal ◽

...

Keyword(s):

Inertial Sensors ◽

Measurement Unit ◽

Disc Disease ◽

Medical Test ◽

Gait Parameters ◽

Acceleration Data ◽

Flexion Extension ◽

Left And Right ◽

Magnetic Resonance Imaging Mri ◽

Normal Health

Background: the goal of the study is to ascertain the influence of discopathy in the lumbosacral (L-S) segment on the gait parameters. The inertial sensors are used to determine the pathologic parameters of gait. Methods: the study involved four patients (44, 46, 42, and 38 years). First, the goal of the survey was to analyze by a noninvasive medical test magnetic resonance imaging (MRI) of each patient. Next, by using inertial sensors, the flexion-extension of joint angles of the left and right knees were calculated. The statistical analysis was performed. The wavelet transform was applied to analyze periodic information in the acceleration data. Results: in the patients with discopathy, the amount of knee flexion attained during stance phase is significantly lower than that of normal (health side), which could indicate poor eccentric control or a pain avoidance mechanism. The biggest differences are observed in the Initial Swing phase. Bending of the lower limb in the knee joint at this stage reaches maximum values during the entire gait cycle. Conclusions: It has been difficult to quantify the knee angle during gait by visual inspection. The inertial measurement unit (IMU) system can be useful in determining the level of spine damage and its degree. In patients in the first stages of the intervertebral disc disease who may undergo conservative treatment, it may also partially delay or completely exclude the decision to perform a complicated imaging examination which is MRI, often showing a false positive result in this phase of the disease.

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Design, Validity, and Reliability of a New Test, Based on an Inertial Measurement Unit System, for Measuring Cervical Posture and Motor Control in Children with Cerebral Palsy

Diagnostics ◽

10.3390/diagnostics10090661 ◽

2020 ◽

Vol 10 (9) ◽

pp. 661

Author(s):

Cristina Carmona-Pérez ◽

Alberto Pérez-Ruiz ◽

Juan L. Garrido-Castro ◽

Francisco Torres Vidal ◽

Sandra Alcaraz-Clariana ◽

...

Keyword(s):

Cerebral Palsy ◽

Motor Control ◽

Inertial Measurement Unit ◽

Measurement Unit ◽

Validity And Reliability ◽

Inertial Measurement ◽

Functional Measures ◽

Flexion Extension ◽

Children With Cerebral Palsy ◽

Cervical Posture

Objective: The aim of this study was to design and propose a new test based on inertial measurement unit (IMU) technology, for measuring cervical posture and motor control in children with cerebral palsy (CP) and to evaluate its validity and reliability. Methods: Twenty-four individuals with CP (4–14 years) and 24 gender- and age-matched controls were evaluated with a new test based on IMU technology to identify and measure any movement in the three spatial planes while the individual is seated watching a two-minute video. An ellipse was obtained encompassing 95% of the flexion/extension and rotation movements in the sagittal and transversal planes. The protocol was repeated on two occasions separated by 3 to 5 days. Construct and concurrent validity were assessed by determining the discriminant capacity of the new test and by identifying associations between functional measures and the new test outcomes. Relative reliability was determined using the intraclass correlation coefficient (ICC) for test–retest data. Absolute reliability was obtained by the standard error of measurement (SEM) and the Minimum Detectable Change at a 90% confidence level (MDC90). Results: The discriminant capacity of the area and both dimensions of the new test was high (Area Under the Curve ≈ 0.8), and consistent multiple regression models were identified to explain functional measures with new test results and sociodemographic data. A consistent trend of ICCs higher than 0.8 was identified for CP individuals. Finally, the SEM can be considered low in both groups, although the high variability among individuals determined some high MDC90 values, mainly in the CP group. Conclusions: The new test, based on IMU data, is valid and reliable for evaluating posture and motor control in children with CP.

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Seismic performances of a structure equipped with a large mass ratio multiple tuned mass damper

The Structural Design of Tall and Special Buildings ◽

10.1002/tal.1803 ◽

2020 ◽

Vol 29 (17) ◽

Author(s):

Ying‐jie Kang ◽

Ling‐yun Peng ◽

Peng Pan ◽

Hai‐shen Wang ◽

Gen‐qi Xiao

Keyword(s):

Large Mass ◽

Tuned Mass Damper ◽

Mass Ratio ◽

Mass Damper ◽

Large Mass Ratio

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Inertial Measurement Unit Based Upper Extremity Motion Characterization for Action Research Arm Test and Activities of Daily Living

Sensors ◽

10.3390/s19081782 ◽

2019 ◽

Vol 19 (8) ◽

pp. 1782 ◽

Cited By ~ 8

Author(s):

Hyung Seok Nam ◽

Woo Hyung Lee ◽

Han Gil Seo ◽

Yoon Jae Kim ◽

Moon Suk Bang ◽

...

Keyword(s):

Action Research ◽

Upper Extremity ◽

Daily Living ◽

Arm Movements ◽

Daily Activities ◽

Measurement Unit ◽

Dominant Hand ◽

Study Results ◽

Flexion Extension ◽

Extremity Motion

In practical rehabilitation robot development, it is imperative to pre-specify the critical workspace to prevent redundant structure. This study aimed to characterize the upper extremity motion during essential activities in daily living. An IMU-based wearable motion capture system was used to access arm movements. Ten healthy subjects performed the Action Research Arm Test (ARAT) and six pre-selected essential daily activities. The Euler angles of the major joints, and acceleration from wrist and hand sensors were acquired and analyzed. The size of the workspace for the ARAT was 0.53 (left-right) × 0.92 (front-back) × 0.89 (up-down) m for the dominant hand. For the daily activities, the workspace size was 0.71 × 0.70 × 0.86 m for the dominant hand, significantly larger than the non-dominant hand (p ≤ 0.011). The average range of motion (RoM) during ARAT was 109.15 ± 18.82° for elbow flexion/extension, 105.23 ± 5.38° for forearm supination/pronation, 91.99 ± 0.98° for shoulder internal/external rotation, and 82.90 ± 22.52° for wrist dorsiflexion/volarflexion, whereas the corresponding range for daily activities were 120.61 ± 23.64°, 128.09 ± 22.04°, 111.56 ± 31.88°, and 113.70 ± 18.26°. The shoulder joint was more abducted and extended during pinching compared to grasping posture (p < 0.001). Reaching from a grasping posture required approximately 70° elbow extension and 36° forearm supination from the initial position. The study results provide an important database for the workspace and RoM for essential arm movements.

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A prosthetic limb managed by sensors-based electronic system: Experimental results on amputees

Bulletin of Electrical Engineering and Informatics ◽

10.11591/eei.v9i2.2101 ◽

2020 ◽

Vol 9 (2) ◽

Author(s):

F. Gaetani ◽

R. De Fazio ◽

G. A. Zappatore ◽

P. Visconti

Keyword(s):

Upper Limb ◽

High Performance ◽

Learning Algorithm ◽

Electronic System ◽

Measurement Unit ◽

Raspberry Pi ◽

Prosthetic Limb ◽

Flexion Extension ◽

Rehabilitation Period ◽

Male Subjects

Taking the advantages offered by smart high-performance electronic devices, transradial prosthesis for upper-limb amputees was developed and tested. It is equipped with sensing devices and actuators allowing hand movements; myoelectric signals are detected by Myo armband with 8 ElectroMyoGraphic (EMG) electrodes, a 9-axis Inertial Measurement Unit (IMU) and Bluetooth Low Energy (BLE) module. All data are received through HM-11 BLE transceiver by Arduino board which processes them and drives actuators. Raspberry Pi board controls a touchscreen display, providing user a feedback related to prosthesis functioning and sends EMG and IMU data, gathered via the armband, to cloud platform thus allowing orthopedic during rehabilitation period, to monitor users’ improvements in real time. A GUI software integrating a machine learning algorithm was implemented for recognizing flexion/extension/rest gestures of user fingers. The algorithm performances were tested on 9 male subjects (8 able-bodied and 1 subject affected by upper-limb amelia), demonstrating high accuracy and fast responses.

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