Design of a Wearable 3-DOF Forearm Exoskeleton for Rehabilitation and Assistive Purposes

2017 ◽  
Author(s):  
Junghee Lee ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Degrees Of Freedom ◽  
Human Hand ◽  
Direct Drive ◽  
Wrist Flexion ◽  
Ulnar Deviation ◽  
System A ◽  
Arm Rehabilitation ◽  
Dynamic Analyses ◽  
Three Degrees Of Freedom ◽  
Flexion And Extension

This paper presents the design and analysis of a portable forearm exoskeleton designed for rehabilitation and assistive purposes (FE.RAP). The design uses a direct-drive mechanism to actuate three degrees of freedom (DOFs) of the wrist, including: (1) wrist flexion and extension, (2) wrist radial and ulnar deviation, and (3) forearm supination and pronation. In recent decades, automated at-home recovery therapies have emerged as popular alternatives to hospital-based rehabilitation. Often in the case of lower arm rehabilitation, however, existing exoskeletons are not practical to use as home rehabilitation devices due to being non-transportable, bulky in size, and heavy in weight. In addition, compact sized exoskeletons often lack sufficient DOFs to mirror the natural movements of the hand. This paper proposes a design that addresses the drawbacks of current exoskeletons. The FE.RAP is designed to be portable and lightweight, while maintaining sufficient DOFs to help patients recover the range of motion needed by the wrist and forearm to support activities of daily living (ADL). Along with the design, the paper presents an analysis used to optimize the workspace for each DOF of the system. A kinematic analysis is performed to validate and compare the workspace of the system, as well as the coupling relationship between the DOFs, to that of the human hand and wrist. Finally, the torque required to support most ADLs is determined using static and dynamic analyses.

Assessment of Muscle Activity and Joint Angles in Small-Handed Pianists: A Pilot Study on the 7/8-Sized Keyboard versus the Full-Sized Keyboard

2006 ◽  
Vol 21 (1) ◽  
pp. 3-9
Author(s):  
B G Wristen ◽  
M C Jung ◽  
A K G Wismer ◽  
M S Hallbeck
Keyword(s):  
Pilot Study ◽  
Research Question ◽  
Wrist Flexion ◽  
Joint Angles ◽  
Ulnar Deviation ◽  
Surface Electrodes ◽  
Musical Excerpt ◽  
Muscle Loading ◽  
Maximal Angle ◽  
Flexion And Extension

This pilot study examined whether the use of a 7/8 keyboard contributed to the physical ease of small-handed pianists as compared with the conventional piano keyboard. A secondary research question focused on the progression of physical ease in pianists making the transition from one keyboard to the other. For the purposes of this study, a hand span of 8 inches or less was used to define a “small-handed” pianist. The goal was to measure muscle loading and hand span during performance of a specified musical excerpt. For data collection, each of the two participants was connected to an 8-channel electromyography system via surface electrodes, which were attached to the upper back/shoulder, parts of the hand and arm, and masseter muscle of the jaw. Subjects also were fitted with electrogoniometers to capture how the span from the first metacarpophalangeal (MCP) joint to the fifth MCP joint moves according to performance demands, as well as wrist flexion and extension and radial and ulnar deviation. We found that small-handed pianists preferred the smaller keyboard and were able to transition between it and the conventional keyboard. The maximal angle of hand span while playing a difficult piece was about 5º smaller radially and 10º smaller ulnarly for the 7/8 keyboard, leading to perceived ease and better performance as rated by the pianists.

scholarly journals Real-Time Posture Control for a Robotic Manipulator Using Natural Human–Computer Interaction

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 31
Author(s):  
Guillaume Plouffe ◽  
Pierre Payeur ◽  
Ana-Maria Cretu
Keyword(s):  
Real Time ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Robotic Arm ◽  
Human Hand ◽  
Graphical Interface ◽  
Left Hand ◽  
Human Control ◽  
Depth Data ◽  
Three Degrees Of Freedom

In this paper, we propose a vision-based recognition approach to control the posture of a robotic arm with three degrees of freedom (DOF) using static and dynamic human hand gestures. Two different methods are investigated to intuitively control a robotic arm posture in real-time using depth data collected by a Kinect sensor. In the first method, the user’s right index fingertip position is mapped to compute the inverse kinematics on the robot. Using the Forward And Backward Reaching Inverse Kinematics (FABRIK) algorithm, the inverse kinematics (IK) solutions are displayed in a graphical interface. Using this interface and his left hand, the user can intuitively browse and select a desired robotic arm posture. In the second method, the user’s left index position and direction are respectively used to determine the end-effector position and an attraction point position. The latter enables the control of the robotic arm posture. The performance of these real-time natural human control approaches is evaluated for precision and speed against static and dynamic obstacles.

scholarly journals The Effect of Locking out Wrist Flexion and Extension with an Upper Body Exoskeleton on Handgun Training

2017 ◽  
Vol 61 (1) ◽  
pp. 1499-1503 ◽  
Author(s):  
Thomas M. Schnieders ◽  
Richard T. Stone ◽  
Erik Danford-Klein ◽  
Tyler Oviatt
Keyword(s):  
Law Enforcement ◽  
Upper Body ◽  
The Arctic ◽  
Control Group ◽  
Robotic Control ◽  
Wrist Flexion ◽  
Ulnar Deviation ◽  
Arctic Lawe ◽  
Experimental Group ◽  
Flexion And Extension

The second version of The Armed Robotic Control for Training in Civilian Law Enforcement, or ARCTiC LawE is presented in this paper. The ARCTiC LawE is an upper body exoskeleton designed to assist in training civilians, military, and law enforcement personnel. This second iteration tests the effect of locking out wrist flexion and extension for handgun training in addition to locking out the radial and ulnar deviation from the first version of The ARCTiC LawE. The experimental group scored significantly higher than the control group at 21 feet and 45 feet over a two-week period. The training occurred in week one and testing occurred in week two. This study lays the groundwork for continued research on transfer of training effectiveness with the ARCTiC LawE.

Muscular Forces and Joint Angles in Small-Handed Pianists: A Pilot Study on the 7/8 Size Keyboard versus the Full Size Keyboard

2005 ◽  
Vol 49 (18) ◽  
pp. 1752-1756
Author(s):  
B.G. Wristen ◽  
A.K.G. Wismer ◽  
M.-C Jung ◽  
M.S. Hallbeck
Keyword(s):  
Pilot Study ◽  
Masseter Muscle ◽  
Research Question ◽  
Wrist Flexion ◽  
Joint Angles ◽  
Ulnar Deviation ◽  
Surface Electrodes ◽  
Muscle Loading ◽  
Maximal Angle ◽  
Flexion And Extension

This pilot study examined whether the use of a 7/8 keyboard contributed to the physical ease of small-handed pianists in comparison with the conventional piano keyboard. A secondary research question focused on the transition from one keyboard to the other. For the purposes of this study, we adopted David Steinbuhler's postulated hand span of 8 inches or less as defining a “small-handed' pianist. The goal was to measure muscle loading and hand span during performance of the excerpt. Data collection included each participant being monitored using electromyography via surface electrodes, which were attached to the upper back/shoulder, parts of the hand and arm, and the masseter muscle of the jaw. Subjects were also fitted with electrogoniometers to capture how the span from the first metacarpophalangeal (MCP) joint to the fifth MCP joint moved according to performance demands, as well as recording wrist flexion and extension, radial and ulnar deviation. The findings were that small-handed pianists preferred the smaller keyboard and were able to transition smoothly between it and the conventional keyboard. The maximal angle of hand span while playing a difficult piece averaged about 5° smaller on the radial side and 10° smaller on the ulnar side for the 7/8 keyboard, leading to perceived comfort (ease) and better performance as rated by the subjects.

scholarly journals SMA Actuated Finger Exoskeleton Device for Rehabilitation of Acute Paresis Patient

2015 ◽  
Vol 773-774 ◽  
pp. 883-887 ◽  
Author(s):  
Abdul Hakim Ab. Rahim ◽  
Andreas Lachmann ◽  
Cheng Yee Low ◽  
Adam Tan Mohd Amin
Keyword(s):  
High Temperature ◽  
Daily Living ◽  
Degrees Of Freedom ◽  
Room Temperature ◽  
Robotic Rehabilitation ◽  
Optimum Range ◽  
Finger Flexion ◽  
Exoskeleton Device ◽  
Three Degrees Of Freedom ◽  
Flexion And Extension

Functional recovery of upper limb after stroke is crucial to restore the ability to perform activities of daily living (ADL). This paper presents a robotic rehabilitation approach based on repetitive exercise aimed to help stroke survivors relearn the skills of finger flexion and extension at the comfort of their home. The finger rehabilitation device deploysShape Memory Alloy(SMA) wires as an actuation approach to deliver three degrees of freedom per finger module. The advantages and challenges of using SMA wires rather than conventional actuators are discussed. A prototype of the finger rehabilitation device was built using PLA material and experiments have been conducted for the purposes of feasibility study. Tests conducted on the wires suggest that it has to have sufficient weight and also has to be stretching at high temperature rather than room temperature in order to have an optimum range of recovery.

Improved performance for robot manipulators via transmission re-design: the SPRINTA

Robotica ◽  
2000 ◽  
Vol 18 (2) ◽  
pp. 195-200
Author(s):  
P.J. Turner ◽  
P. Nigrowsky ◽  
G. Vines
Keyword(s):  
Degrees Of Freedom ◽  
Robot Manipulators ◽  
Tracking Error ◽  
Reduction Ratio ◽  
Practical Implementation ◽  
Gravity Compensation ◽  
Direct Drive ◽  
Dynamic Decoupling ◽  
Improved Performance ◽  
Three Degrees Of Freedom

A new design philosophy for the transmission of robot manipulators is proposed and an example of a practical implementation is presented. The philosophy combines the advantages of conventional geared robots in terms of relocating the actuators away from the joints and the alternative direct-drive approach. The gimbal drive is an example of a non-linear transmission where there is negligible friction, no backlash or compliance and which provides a varying reduction ratio for gravity compensation and for some dynamic decoupling. The gimbal drive is implemented on the three degrees of freedom SPRINTA prototype. Static repeatability, as well as tracking error and dynamic repeatability for the industrial goalpost test are measured. The performance demonstrates the potential of such a type of robot.

Partially conforming plate bending elements for static and dynamic analyses

1973 ◽  
Vol 8 (4) ◽  
pp. 260-263 ◽  
Author(s):  
C T F Ross
Keyword(s):  
Degrees Of Freedom ◽  
Natural Frequencies ◽  
Virtual Work ◽  
Plate Bending ◽  
Principle Of Virtual Work ◽  
Displacement Method ◽  
Dynamic Analyses ◽  
The Matrix ◽  
Three Degrees Of Freedom ◽  
General Convergence

Two partially conforming flat-plate bending elements have been developed for static and dynamic analyses through the principle of virtual work. One of these elements is triangular and the other quadrilateral and both have corner nodes only, with three degrees of freedom per node. By use of these elements in the matrix displacement method, the natural frequencies of vibration of a square cantilevered plate have been calculated; these calculated results have been compared with experimental results. Agreement has been found to be good, and in general, convergence appears to take place.

Analysis of wrist bone motion before and after SL-ligament resection

2016 ◽  
Vol 61 (3) ◽  
pp. 345-357 ◽  
Author(s):  
Jörg Eschweiler ◽  
Jan Philipp Stromps ◽  
Björn Rath ◽  
Norbert Pallua ◽  
Klaus Radermacher
Keyword(s):  
Degrees Of Freedom ◽  
Wrist Joint ◽  
Tracking System ◽  
Longitudinal Axis ◽  
Ligament Injury ◽  
Scaphoid Bone ◽  
Electromagnetic Tracking ◽  
Ulnar Deviation ◽  
Flexion And Extension

Abstract The analysis of the three-dimensional motion of wrist joint components in the physiological and injured wrist is of high clinical interest. Therefore, the purpose of this in vitro study was to compare the motion of scaphoid, lunate and triquetrum during physiological wrist motion in flexion and extension, and in radial- and ulnar-deviation, with those motion patterns after complete resection of the scapho-lunate-ligament. Eight fresh frozen cadaver wrists were carefully thawed and prepared for the investigation with an electromagnetic tracking system by implantation of measurement coils with 6 degrees of freedom. Electromagnetic tracking enabled the motion analysis of the scaphoid, lunate, and triquetrum bones with respect to the fixed radius in three planes of passive motion. After scapho-lunate-ligament injury changes in the translational and rotational motion pattern especially of the scaphoid bone occurred in dorsal-volar directions during flexion and extension, radial- and ulnar-deviation, and during rotation around the radio-ulnar- and longitudinal-axis of the wrist.

scholarly journals Development of an armored upper limb exoskeleton

2019 ◽  
pp. 109-117
Author(s):  
Santiago López-Méndez ◽  
Hader Vladimir Martínez-Tejada ◽  
Marco Fidel Valencia-García
Keyword(s):  
Upper Limb ◽  
Metal Matrix ◽  
Degrees Of Freedom ◽  
New Technologies ◽  
Personal Safety ◽  
Critical Aspect ◽  
Upper Limb Exoskeleton ◽  
The Military ◽  
Three Degrees Of Freedom ◽  
Flexion And Extension

Personal safety is a critical aspect of daily life, but also in the military. Active soldiers often have to carry heavy gear during missions, which puts pressure on their backs. Therefore, the military must come up with new technologies that allow both protection and movement. In this paper, it is explaining the development of an armored upper limb exoskeleton with three degrees of freedom. To ensure portability, it is used battery-fed DC actuators. The system was encased in a metal matrix that doubles up as a protective plate. The exoskeleton, the control system, the actuators, and the plate are integrated so that they offer protection while supporting the flexion and extension of the upper limb.

Sign in / Sign up

Export Citation Format

Share Document