scholarly journals Geometric Design and Prototyping of a (2-RRU)-URR Parallel Mechanism for Thumb Rehabilitation Therapy

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 50
Author(s):  
Woo-hyeok Choi ◽  
Yukio Takeda
Keyword(s):  
Parallel Mechanism ◽  
Measurement Data ◽  
Design Procedure ◽  
Careful Consideration ◽  
Rehabilitation Therapy ◽  
Flexion Extension ◽  
3D Printed ◽  
Practical Performance ◽  
Trajectory Measurement ◽  
User Experiment

In this paper, the geometrical design of a (2-RRU)-URR (where R and U stand for the revolute and universal joints, respectively) parallel mechanism was demonstrated for thumb rehabilitation therapy. This paper consists of two parts: the design procedure for the development of a thumb rehabilitation device and the user experiment with the prototype. Because the hand generally has a limited working area, the design of the hand attachment parts and the placement of the actuators requires careful consideration of the various factors. Along with the kinematic requirements of the device, the interaction between the mechanism and the fingers must be considered. The proposed mechanism has three actuators placed in the hand attachment. When the mechanism is attached to the hand, there is the possibility of collisions between the fingers of the user and the mechanism. Two design candidates were devised while considering the limited working area of the hand and the need to avoid collisions. Due to the dependency of the workspace on the placement of the actuators, a comparison of the workspace of the two candidate designs and the target workspace was carried out. The target workspace was determined through the use of thumb trajectory measurement data. A prototype was manufactured using 3D printed plastic and aluminum materials. To confirm the practical performance of the prototype, user experiments were conducted in which a comparison between the thumb measurement data and the controlled trajectory of each person was done. Motion in two directions, specifically, adduction–abduction and flexion–extension were performed. The results showed that the controlled trajectory of flexion–extension were closely matched to the thumb measurement trajectory. Finally, the experimental results are discussed.

Research Methods in Clinical Psychology

2010 ◽  
pp. 51-76 ◽  
Author(s):  
Philip C. Kendall ◽  
Jonathan S. Comer
Keyword(s):  
Scientific Community ◽  
Measurement Data ◽  
Design Procedure ◽  
Mechanisms Of Change ◽  
Random Assignment ◽  
Scientific Evaluation ◽  
Scientific Rigor ◽  
Design Considerations ◽  
Key Concepts ◽  
Treatment Manuals

This chapter describes methodological and design considerations central to the scientific evaluation of treatment efficacy and effectiveness. Matters of design, procedure, measurement, data analysis, and reporting are examined and discussed. The authors consider key concepts of controlled comparisons, random assignment, the use of treatment manuals, integrity and adherence checks, sample and setting selection, treatment transportability, handling missing data, assessing clinical significance, identifying mechanisms of change, and consolidated standards for communicating study findings to the scientific community. Examples from the treatment outcome literature are offered, and guidelines are suggested for conducting treatment evaluations that maximize both scientific rigor and clinical relevance.

scholarly journals Calibration Method for a Parallel Mechanism Type Machine Tool by Response Surface Methodology –Consideration via Simulation on a Stewart Platform Mechanism–

2010 ◽  
Vol 4 (4) ◽  
pp. 355-363 ◽  
Author(s):  
Hiroshi Yachi ◽  
◽  
Hiroshi Tachiya
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Parallel Mechanism ◽  
Measurement Data ◽  
Calibration Method ◽  
Stewart Platform ◽  
Parallel Mechanisms ◽  
Data Set ◽  
Efficient Data ◽  
Efficient Measurement

This paper proposes a calibration method for parallel mechanisms usingResponse Surface Methodology. This method is a statistical approach to estimating an unknown input-output relationship using a small set of efficient data collected on an intended system. Although identifying locations causing positional errors in a parallel mechanism and precisely measuring the position and posture of the output point are difficult, the proposed calibration method based onResponse Surface Methodologyaims to compensate for positional and postural errors, without indentifying the locations causing these errors, by using a small yet efficient measurement data set. This study analyzes the effectiveness of the method we propose by applying it to a Stewart platform, which is a typical spatial 6-DOF parallel mechanism.

scholarly journals Displacement Analysis and Design of a (2–RRU)–URR Parallel Mechanism Performing 2R1T Output Motion for Thumb Rehabilitation

Robotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Woo-hyeok Choi ◽  
Yukio Takeda
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Human Hand ◽  
Displacement Analysis ◽  
Analysis And Design ◽  
Reachable Workspace ◽  
Flexion Extension ◽  
Basic Characteristics ◽  
Narrow Space ◽  
Input Torque

The thumb assists other fingers, and any damage in its functionality prevents the human hand from performing dexterous functions. In this paper, the kinematic design of the (2–RRU)–URR parallel mechanism as the application of the thumb rehabilitation device is proposed. This mechanism is an over-constrained mechanism capable of achieving the required mobility with fewer joints. Three degrees of freedom exist—two rotational and one translational mobility—that are related to each thumb movement: adduction–abduction and flexion–extension. Considering the narrow space of the hand, actuators are designed to divide its placement into the surface of the palm. To avoid the collisions between the device and the hand, an offset was adopted. The displacement analysis problem is solved by dividing it into two parts: the planar motion generator (PMG) and orientation generator (OG), according to each functional motion, and the corresponding equations and procedures are presented. To clarify the basic characteristics of this mechanism, the reachable workspace of the PMG and rotational ability and sensitivity of the OG is demonstrated numerically. Because a large input torque difference is dangerous in the rehabilitation mechanism, the effective workspace is determined according to the magnitude of the input torque differences and compared with the measured thumb movements.

Design of a Deformable Smart Tire Using Soft Actuator

2019 ◽  
Author(s):  
Vidya K. Nandikolla ◽  
Michael Costa ◽  
Nathan Boyd ◽  
Gilberto Rosales
Keyword(s):  
Force Feedback ◽  
Design Procedure ◽  
Nickel Titanium ◽  
Operating Conditions ◽  
Mechanical Modeling ◽  
Soft Actuator ◽  
Voltage Signal ◽  
3D Printed ◽  
Primary Focus ◽  
Soft Actuators

Abstract The unique functional properties of nickel-titanium Shape Memory Alloys (SMA) enable them to be used as actuators. This research paper demonstrates theoretically and experimentally the feasibility of using SMA in smart tires for a mobile robot. The design procedure for SMA as a coil spring actuator for a soft deformable wheel is described. The primary focus is the mechanical modeling, manufacturing, and system dynamics of a soft deformable wheel. The 3D printed soft tire exploits the capabilities of the SMA actuation using a voltage signal. The printed components are activated and integrated with electromechanical circuit for wireless communication system. The performance of the force feedback control system is evaluated at different operating conditions to demonstrate the shape-changing characteristic of the smart tire. The developed prototype is designed to propel forward and backward on flat and uneven surface. The experimental results obtained demonstrate the potential of SMA as soft actuators, its benefits and limitations as flexible systems.

scholarly journals Fresh and Hardened Properties of Extrusion-Based 3D-Printed Cementitious Materials: A Review

2020 ◽  
Vol 12 (14) ◽  
pp. 5628
Author(s):  
Zhanzhao Li ◽  
Maryam Hojati ◽  
Zhengyu Wu ◽  
Jonathon Piasente ◽  
Negar Ashrafi ◽  
...  
Keyword(s):  
3D Printing ◽  
Experimental Testing ◽  
Design Procedure ◽  
Cementitious Materials ◽  
Material Point ◽  
Point Of View ◽  
Open Time ◽  
Potential Benefits ◽  
3D Printed ◽  
Hardened Properties

3D-printing of cementitious materials is an innovative construction approach with which building elements can be constructed without the use of formwork. Despite potential benefits in the construction industry, it introduces various engineering challenges from the material point of view. This paper reviews the properties of extrusion-based 3D-printed cementitious materials in both fresh and hardened states. Four main properties of fresh-state printing materials are addressed: flowability, extrudability, buildability, and open time, along with hardened properties, including density, compressive strength, flexural strength, tensile bond strength, shrinkage, and cracking. Experimental testing and effective factors of each property are covered, and a mix design procedure is proposed. The main objective of this paper is to provide an overview of the recent development in 3D-printing of cementitious materials and to identify the research gaps that need further investigation.

Development of a whole arm wearable robotic exoskeleton for rehabilitation and to assist upper limb movements

Robotica ◽  
2014 ◽  
Vol 33 (1) ◽  
pp. 19-39 ◽  
Author(s):  
M. H. Rahman ◽  
M. J. Rahman ◽  
O. L. Cristobal ◽  
M. Saad ◽  
J. P. Kenné ◽  
...  
Keyword(s):  
Upper Limb ◽  
Wrist Joint ◽  
External Rotation ◽  
Lateral Side ◽  
Limb Movements ◽  
Rehabilitation Therapy ◽  
Robotic Exoskeleton ◽  
Flexion Extension ◽  
Upper Limb Movements ◽  
Physically Disabled People

SUMMARYTo assist physically disabled people with impaired upper limb function, we have developed a new 7-DOF exoskeleton-type robot named Motion Assistive Robotic-Exoskeleton for Superior Extremity (ETS-MARSE) to ease daily upper limb movements and to provide effective rehabilitation therapy to the superior extremity. The ETS-MARSE comprises a shoulder motion support part, an elbow and forearm motion support part, and a wrist motion support part. It is designed to be worn on the lateral side of the upper limb in order to provide naturalistic movements of the shoulder (vertical and horizontal flexion/extension and internal/external rotation), elbow (flexion/extension), forearm (pronation/supination), and wrist joint (radial/ulnar deviation and flexion/extension). This paper focuses on the modeling, design, development, and control of the ETS-MARSE. Experiments were carried out with healthy male human subjects in whom trajectory tracking in the form of passive rehabilitation exercises (i.e., pre-programmed trajectories recommended by a therapist/clinician) were carried out. Experimental results show that the ETS-MARSE can efficiently perform passive rehabilitation therapy.

Validation of a Novel 3D-Printed Instrumented Spatial Linkage That Measures Changes in the Rotational Axes of the Tibiofemoral Joint

2013 ◽  
Author(s):  
Daniel P. Bonny ◽  
S. M. Howell ◽  
M. L. Hull
Keyword(s):  
Degrees Of Freedom ◽  
Rigid Bodies ◽  
Anatomic Landmarks ◽  
Tibiofemoral Joint ◽  
Six Degrees Of Freedom ◽  
Revolute Joints ◽  
Flexion Extension ◽  
3D Printed ◽  
Total Knee ◽  
Position And Orientation

The two kinematic axes of the tibiofemoral joint, the flexion-extension (F-E) and longitudinal rotation (LR) axes [1], are unrelated to the anatomic landmarks often used to align prostheses during total knee arthroplasty (TKA) [1, 2]. As a result, conventional TKA changes the position and orientation of the joint line, thus changing the position and orientation of the F-E and LR axes and consequently the kinematics of the knee. However, the extent to which TKA changes these axes is unknown. An instrument that can measure the locations of and any changes to these axes is an instrumented spatial linkage (ISL), a series of six instrumented revolute joints that can measure the six degrees of freedom of motion (DOF) between two rigid bodies without constraining motion. Previously, we computationally determined how best to design and use an ISL such that rotational and translational errors in locating the F-E and LR axes were minimized [3]. However, this ISL was not constructed and therefore its ability to measure changes in the axes has not been validated. Therefore the objective was to construct the ISL and quantify the errors in measuring changes in position and orientation of the F-E axis.

scholarly journals Acetylcholinesterase Inhibitors Assay Using Colorimetric pH Sensitive Strips and Image Analysis by a Smartphone

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Adam Kostelnik ◽  
Alexander Cegan ◽  
Miroslav Pohanka
Keyword(s):  
Color Change ◽  
Acetylcholinesterase Inhibitors ◽  
Measurement Procedure ◽  
Acid Base ◽  
Ache Inhibitors ◽  
Detection Tool ◽  
Trained Personnel ◽  
Simple Detection ◽  
3D Printed ◽  
Practical Performance

Smartphones are widely spread and their usage does not require any trained personnel. Recently, smartphones were successfully used in analytical chemistry as a simple detection tool in some applications. This paper focuses on immobilization of acetylcholinesterase (AChE) onto commercially available pH strips with stabilization in the gelatin membrane. AChE degrades acetylcholine into choline and acetic acid which causes color change of acid-base indicator. Smartphone served as a tool for measurement of indicator color change from red to orange while inhibitors blocked this process. AChE inhibitors were measured with limits of detection, 149 nM and 22.3 nM for galanthamine and donepezil, respectively. Organic solvents were measured for method interferences. Measurement procedure was performed on 3D printed holder and digital photography was evaluated using red-green-blue (RGB) channels. The invented assay was validated to the standard Ellman’s test and verified on murine plasma samples spiked with inhibitors. We consider that the assay is fully suitable for practical performance.

Design of a Novel Statically Balanced Mechanism for Laparoscope Holders With Decoupled Positioning and Orientating Manipulation

2014 ◽  
Author(s):  
Chin-Hsing Kuo ◽  
Shao-Jung Lai
Keyword(s):  
Parallel Mechanism ◽  
Design Procedure ◽  
Static Balance ◽  
Cad Model ◽  
End Effector ◽  
Surgical Incision ◽  
Physical Prototype ◽  
Position And Orientation ◽  
Insertion Length ◽  
Kinematic Properties

This paper presents a novel mechanism concept of laparoscope holders used for minimally invasive surgery (MIS). The mechanism is made of a parallelogram linkage and a parallel mechanism, which respectively serve as a robotic positioning arm and an orientating wrist of the holder. Due to its special geometry, the mechanism possesses several interesting kinematic properties. First, the laparoscope, which is held by the end-effector, can illustrate a remote center-of-motion (RCM) kinematics at the surgical incision point. Second, the position of the RCM point is solely defined by the parallelogram, whereas the orientation and insertion length of the laparoscope are governed by the parallel mechanism. Such an arrangement suggests a decoupled positioning and orientating manipulation for the holder, which is clinically helpful in laparoscopic MIS. Third, the overall mechanism including the parallelogram linkage and the parallel mechanism can be perfectly statically balanced at any configuration within the workspaces by using common linear springs. In other words, no electrical actuation or mechanical locks are required for making the laparoscope rest at any position and orientation. The design procedure for static balancing is detailed in the paper, and the theoretically perfect static balance of the mechanism is verified by a numerical example and computer simulation. Furthermore, a CAD model of the holder is constructed for evaluating its workspaces and a physical prototype is built up and tested. As a result, the prototyped holder is fully statically balanced within a sufficient workspace for practical MIS environment.

Design of a Novel Statically Balanced Mechanism for Laparoscope Holders With Decoupled Positioning and Orientating Manipulation

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Chin-Hsing Kuo ◽  
Shao-Jung Lai
Keyword(s):  
Computer Aided Design ◽  
Parallel Mechanism ◽  
Design Procedure ◽  
Theoretical Formulation ◽  
Surgical Incision ◽  
Total Potential ◽  
Physical Prototype ◽  
Aided Design ◽  
Insertion Length ◽  
Kinematic Properties

This paper presents a novel mechanism concept of laparoscope holders used for minimally invasive surgery (MIS). The mechanism is made of a parallelogram linkage and a parallel mechanism, which, respectively, serve as a robotic positioning arm and an orientating wrist of the holder. Due to its special geometry, the mechanism possesses several interesting kinematic properties. First, the laparoscope, which is held by the end-effector, can illustrate a remote center-of-motion (RCM) kinematics at the surgical incision point. Second, the position of the RCM point is solely defined by the parallelogram, whereas the orientation and insertion length of the laparoscope are governed by the parallel mechanism. Such an arrangement suggests a decoupled positioning and orientating manipulation for the holder, which is clinically helpful in laparoscopic MIS. Third, the overall mechanism including the parallelogram linkage and the parallel mechanism can be statically balanced at any configuration within the workspaces by using common linear springs. In other words, no electrical actuation or mechanical locks are required for making the laparoscope rest at any position and orientation. The design procedure for static balancing is detailed in the paper, and the theoretical formulation of the statically balanced mechanism is verified by a numerical example and computer simulation. The computer-aided design (CAD) model of the holder is constructed for evaluating its workspace and a physical prototype using commercial springs is built up and tested. It shows that the prototype that uses nonideal (commercial) springs can be statically balanced within the overall workspace, since the shortage/overshoot of the potential energy in the positioning mechanism and orientating mechanism, which are theoretically 6.8% and 5.1% of their total potential energies in maximum, are fully compensated by the friction effect.

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