Closed-Loop Vibratory Haptic Feedback in Upper-Limb Prosthetic Users

2014 ◽  
Vol 26 (3) ◽  
pp. 120-127 ◽  
Author(s):  
Pravin Chaubey ◽  
Teri Rosenbaum-Chou ◽  
Wayne Daly ◽  
David Boone
Keyword(s):  
Upper Limb ◽  
Closed Loop ◽  
Haptic Feedback

scholarly journals Evaluation of Optimal Vibrotactile Feedback for Force-Controlled Upper Limb Myoelectric Prostheses

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5209 ◽  
Author(s):  
Andrea Gonzalez-Rodriguez ◽  
Jose L. Ramon ◽  
Vicente Morell ◽  
Gabriel J. Garcia ◽  
Jorge Pomares ◽  
...  
Keyword(s):  
Real Time ◽  
Upper Limb ◽  
Closed Loop ◽  
Fine Tuning ◽  
Vibrotactile Feedback ◽  
Loop Control ◽  
Myoelectric Prostheses ◽  
Amplitude Level ◽  
Real Time Application ◽  
Selection Of

The main goal of this study is to evaluate how to optimally select the best vibrotactile pattern to be used in a closed loop control of upper limb myoelectric prostheses as a feedback of the exerted force. To that end, we assessed both the selection of actuation patterns and the effects of the selection of frequency and amplitude parameters to discriminate between different feedback levels. A single vibrotactile actuator has been used to deliver the vibrations to subjects participating in the experiments. The results show no difference between pattern shapes in terms of feedback perception. Similarly, changes in amplitude level do not reflect significant improvement compared to changes in frequency. However, decreasing the number of feedback levels increases the accuracy of feedback perception and subject-specific variations are high for particular participants, showing that a fine-tuning of the parameters is necessary in a real-time application to upper limb prosthetics. In future works, the effects of training, location, and number of actuators will be assessed. This optimized selection will be tested in a real-time proportional myocontrol of a prosthetic hand.

Torque Control of Electrorheological Fluidic Resistive Actuators for Haptic Vehicular Instrument Controls

2005 ◽  
Vol 128 (2) ◽  
pp. 216-226 ◽  
Author(s):  
M. A. Vitrani ◽  
J. Nikitczuk ◽  
G. Morel ◽  
C. Mavroidis ◽  
B. Weinberg
Keyword(s):  
Electric Fields ◽  
Closed Loop ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Control Device ◽  
Torque Control ◽  
Feedback Mechanisms ◽  
Feedforward Loop ◽  
Integral Controller ◽  
Proportional Integral Controller

Force-feedback mechanisms have been designed to simplify and enhance the human-vehicle interface. The increase in secondary controls within vehicle cockpits has created a desire for a simpler, more efficient human-vehicle interface. By consolidating various controls into a single, haptic feedback control device, information can be transmitted to the operator, without requiring the driver’s visual attention. In this paper, the experimental closed loop torque control of electro-rheological fluids (ERF) based resistive actuators for haptic applications is performed. ERFs are liquids that respond mechanically to electric fields by changing their properties, such as viscosity and shear stress electroactively. Using the electrically controlled rheological properties of ERFs, we developed resistive-actuators for haptic devices that can resist human operator forces in a controlled and tunable fashion. In this study, the ERF resistive-actuator analytical model is derived and experimentally verified and accurate closed loop torque control is experimentally achieved using a non-linear proportional integral controller with a feedforward loop.

scholarly journals A Preliminary Study on the Use of Haptic Feedback to Assist Users with Impaired Arm Coordination During Mouse Interactions

2011 ◽  
Vol 8 (1) ◽  
pp. 13-20
Author(s):  
N. G. Tsagarakis ◽  
D. G. Caldwell
Keyword(s):  
Upper Limb ◽  
Haptic Feedback ◽  
Experimental System ◽  
Tracking Tasks ◽  
Central Nervous System Dysfunction ◽  
Erratic Motion ◽  
Impaired User ◽  
Two Degree Of Freedom ◽  
Assistive Robotic ◽  
Motion Suppression

Physical movement impairments caused by central nervous system dysfunction or by muscle spasms generated from other neurological damage or dysfunction can often make it difficult or impossible for affected individuals to interact with computer generated environments using the conventional mouse interfaces. This work investigates the use of a 2 dimensional haptic device as an assistive robotic aid to minimize the effects of the pathological absence of motor control on the upper limb in impaired users while using a mouse interface. The haptic system used in this research is a two degree of freedom (DOF) Pantograph planar device. To detect the intended user motion, the device is equipped with force sensing allowing the monitoring of the user applied loads. Impedance based techniques are used to develop a “clumsy” motion suppression control system. The erratic motion suppression techniques and the experimental system setup are evaluated in two dimensional tracking tasks using a human subject with failure of the gross coordination of the upper limb muscle movements resulting from a disorder called ‘Muscle Ataxia’. The results presented demonstrate the ability of the system to improve the tracking performance of the impaired user while interacting with a simple computer generated 2D space.

scholarly journals Miniaturization of mechanical actuators in skin-integrated electronics for haptic interfaces

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dengfeng Li ◽  
Jiahui He ◽  
Zhen Song ◽  
Kuanming Yao ◽  
Mengge Wu ◽  
...  
Keyword(s):  
Human Body ◽  
Closed Loop ◽  
Haptic Feedback ◽  
Haptic Interfaces ◽  
Accuracy Rate ◽  
Daily Lives ◽  
Integrated Electronics ◽  
Electronic Skin ◽  
Tactile Sensations ◽  
Tactile Enhancement

AbstractSkin-integrated electronics, also known as electronic skin (e-skin), are rapidly developing and are gradually being adopted in biomedical fields as well as in our daily lives. E-skin capable of providing sensitive and high-resolution tactile sensations and haptic feedback to the human body would open a new e-skin paradigm for closed-loop human–machine interfaces. Here, we report a class of materials and mechanical designs for the miniaturization of mechanical actuators and strategies for their integration into thin, soft e-skin for haptic interfaces. The mechanical actuators exhibit small dimensions of 5 mm diameter and 1.45 mm thickness and work in an electromagnetically driven vibrotactile mode with resonance frequency overlapping the most sensitive frequency of human skin. Nine mini actuators can be integrated simultaneously in a small area of 2 cm × 2 cm to form a 3 × 3 haptic feedback array, which is small and compact enough to mount on a thumb tip. Furthermore, the thin, soft haptic interface exhibits good mechanical properties that work properly during stretching, bending, and twisting and therefore can conformally fit onto various parts of the human body to afford programmable tactile enhancement and Braille recognition with an accuracy rate over 85%.

Upper Limb Motion Profile During Small to Medium Time-Limited Reaching Tasks in a VR Based Robotic Training Environment

2007 ◽  
Author(s):  
Evagoras G. Xydas ◽  
Loucas S. Louca
Keyword(s):  
Virtual Environments ◽  
Virtual Environment ◽  
Upper Limb ◽  
Haptic Feedback ◽  
Control Function ◽  
Rehabilitation Robotics ◽  
Working Environment ◽  
Therapeutic Effects ◽  
Robotic Training ◽  
Minimum Jerk

In the area of rehabilitation robotics, many researchers have investigated the therapeutic effects of forces that are proportional to the difference of the user’s hand trajectory with an optimum trajectory that is usually based on the Minimum Jerk Model (MJM). Forces applied in different studies were based on MJM trajectory variables, e.g., velocity, acceleration, position, etc. Consequently, MJM is a key component for upper limb robotic rehabilitation. However, it is critical to establish the validity of this model in the working environment prior of employing it as a reference control function. This work investigates the validity of the MJM under a haptic-virtual environment. The original ‘real’ tests (with no obstacles) that were employed for validating the MJM in planar motion are duplicated in a virtual environment. Haptic feedback is achieved with the use of a Phantom 1.5 High Force haptic interface. Experiments with healthy users are performed to investigate the validity of the MJM in virtual reality conditions. The experiments demonstrated that the MJM is also valid in virtual environments. Nevertheless it was found that in the virtual world, higher time durations are required for completing the tasks than in the real world. The results of this work will be used in the design of haptic-virtual environments for the rehabilitation of upper limbs of people with neuro-disabilities. Therapeutic forces based on the MJM can be applied given that the Minimum Jerk Model is valid in virtual environments.

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