Performance Study Involving a Force-Reflecting Joystick for Spastic Individuals Performing two Types of Tracking Tasks

1995 ◽  
Vol 81 (2) ◽  
pp. 561-562 ◽  
Author(s):  
D. W. Repperger ◽  
C. A. Phillips ◽  
T. L. Chelette
Keyword(s):  
Upper Extremity ◽  
Continuous Time ◽  
Normal Subjects ◽  
Tracking Task ◽  
Performance Study ◽  
Fitts Law ◽  
Spatial Sense ◽  
Tracking Tasks ◽  
Acquisition Task ◽  
Force Reflection

10 upper-extremity spastic subjects and 10 normal subjects were studied with a force-reflecting joystick in the performance of a continuous time-tracking task as well as an acquisition task termed, “Fitts’ Law.” Certain force-reflection paradigms, in a spatial sense, allowed the spastic subjects to obtain performance proficiency near levels of the normal subjects as measured by a capacity metric.

Development of a Control Theoretic Alternative to Fitts’ Law With Application to In-Vehicle Touchscreen Interface

2015 ◽  
Author(s):  
Chao Wang ◽  
Bahram Ravani
Keyword(s):  
Physical Interpretation ◽  
Model Identification ◽  
Human Operator ◽  
Target Acquisition ◽  
Relative Movement ◽  
Brief Treatment ◽  
Fitts Law ◽  
Proposed Model ◽  
Acquisition Task

A control theoretic alternative to Fitts’ Law based on a modified crossover model is proposed. A physical interpretation of the model offers the unification of various different formulations of Fitts’ Law. Model identification and validation is carried out for a target acquisition task using a touchscreen. A brief treatment of noise generated by random relative movement between the human operator and the touchscreen (such as in-vehicle touchscreen based devices) is considered using the proposed model.

Effects of Intermittency of Feedback on a Compensatory Tracking Task

1976 ◽  
Vol 43 (3_suppl) ◽  
pp. 1339-1345 ◽  
Author(s):  
Henry S. R. Kao
Keyword(s):  
Tracking System ◽  
Wave Pattern ◽  
Open Loop ◽  
Tracking Task ◽  
Target Display ◽  
Random Wave ◽  
Tracking Tasks ◽  
The Difference ◽  
Effects Of Feedback ◽  
Task Efficiency

Target intermittence in tracking has been studied as frequency of target presentation at various time intervals. Task efficiency increased as a function of increased frequency of target display in open-loop tracking tasks, where the steady state of presentation resulted in the best performance. The present study examined effects of feedback intermittency in compensatory tracking as a major source of disruption of the motor-sensory feedback process in the closed-loop tracking system. Feedback intermittency is defined as the feedback of momentary sampling of the difference between target movements and the operator's control motion for specified time lengths before being displayed to him in a continuous tracking task. With a random wave pattern of 9.76 cpm, 7 magnitudes of 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.5 sec. were used to represent various levels of feedback intermittency. Task efficiency decreased as a function of increased magnitudes of intermittency. Results are discussed relative to the difference between target intermittence and feedback intermittency and their effects on different tracking tasks. The findings also establish the concept of feedback intermittency as a disturbing factor in compensatory tracking in degrading the operator's performance.

Effect of altering limb position on blood flow, O2 uptake, and skin temperature

1962 ◽  
Vol 17 (2) ◽  
pp. 191-194 ◽  
Author(s):  
David I. Abramson ◽  
Samuel Tuck ◽  
Agenor M. Zayas ◽  
Roscoe E. Mitchell
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Skin Temperature ◽  
Upper Extremity ◽  
Normal Subjects ◽  
Local Blood Flow ◽  
O2 Uptake ◽  
Limb Position ◽  
Cutaneous Temperature ◽  
Consistent Change

The effect of altering the position of the upper extremity on local blood flow, oxygen uptake and tissue temperatures was studied in a group of 19 normal subjects. In each instance the limb was placed in three positions: 1) horizontally, at the level of the heart; 2) with the elbow at this level, but with the forearm and hand dependent and forming an angle of 34°with the horizontal; and 3) with the forearm and hand elevated and forming an angle of 34°with the horizontal. No consistent change in blood flow or O2 uptake was noted when the limb was placed in dependency. In the elevated position there was a small, but significant, reduction in blood flow and O2 uptake. Cutaneous temperature of the forearm was not affected by either position, while a definite fall in skin temperature was noted in the hand in dependency. These results suggest that variations in position of the upper extremity elicit compensatory vascular mechanisms which tend to counteract the hydrostatic effect on local blood flow and O2 uptake. Submitted on June 19, 1961

A Foot Operated Pc Pointer Positioning Device

1993 ◽  
Vol 37 (4) ◽  
pp. 314-317
Author(s):  
Nancy S. Anderson ◽  
Blake Sobiloff ◽  
Patricia White ◽  
Glenn Pearson
Keyword(s):  
Second Generation ◽  
Tracking Task ◽  
Input Device ◽  
Font Size ◽  
The Third ◽  
Tracking Tasks ◽  
Towers Of Hanoi ◽  
Practice Performance ◽  
Positioning Device

The “mole” is a foot-operated input device for a computer which emulates a mouse in functionality. It is used to control the position of the pointer on a PC screen. The “mole” device studied in the present research is the second-generation version of the device which was developed by Pearson (1988). In Pearson's previous studies, (Pearson and Weiser 1988), he demonstrated that individuals unfamiliar with the “mole” could learn to use the device to hit small on-screen targets comparable in size to small font size characters. The present studies were designed to provide data for evaluation of both the second-generation device and its software. The first study tested the use of the “mole” in controlling the pointer to solve the problem of the Towers of Hanoi. The second study involved a short (60 second) tracking task at each of three different target sizes and three different target speeds. In the third study, six individuals each practiced for four hours using the foot control and the mouse in the same tracking tasks. The results thus far are encouraging in providing data that shows increases in performance over short (one hour) and long (four hour) periods of practice. After the short amount of practice, performance on the tracking tasks was as high as 89% and 90%; after long practice as high as 95%.

A Model of the Upper Extremity Using FES for Stroke Rehabilitation

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Chris T. Freeman ◽  
Ann-Marie Hughes ◽  
Jane H. Burridge ◽  
Paul H. Chappell ◽  
Paul L. Lewin ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Electrical Stimulation ◽  
Upper Extremity ◽  
Stroke Rehabilitation ◽  
Horizontal Plane ◽  
Stroke Patients ◽  
Unknown Parameters ◽  
Triceps Muscle ◽  
Tracking Tasks ◽  
Short Period

A model of the upper extremity is developed in which the forearm is constrained to lie in a horizontal plane and electrical stimulation is applied to the triceps muscle. Identification procedures are described to estimate the unknown parameters using tests that can be performed in a short period of time. Examples of identified parameters obtained experimentally are presented for both stroke patients and unimpaired subjects. A discussion concerning the identification’s repeatability, together with results confirming the accuracy of the overall representation, is given. The model has been used during clinical trials in which electrical stimulation is applied to the triceps muscle of a number of stroke patients for the purpose of improving both their performance at reaching tasks and their level of voluntary control over their impaired arm. Its purpose in this context is threefold: Firstly, changes occurring in the levels of stiffness and spasticity in each subject’s arm can be monitored by comparing frictional components of models identified at different times during treatment. Secondly, the model is used to calculate the moments applied during tracking tasks that are due to a patient’s voluntary effort, and it therefore constitutes a useful tool with which to analyze their performance. Thirdly, the model is used to derive the advanced controllers that govern the level of stimulation applied to subjects over the course of the treatment. Details are provided to show how the model is applied in each case, and sample results are shown.

scholarly journals Design and Preliminary Evaluation of a Tongue-Operated Exoskeleton System for Upper Limb Rehabilitation

2021 ◽  
Vol 18 (16) ◽  
pp. 8708
Author(s):  
Zhenxuan Zhang ◽  
Boris I. Prilutsky ◽  
Andrew J. Butler ◽  
Minoru Shinohara ◽  
Maysam Ghovanloo
Keyword(s):  
Upper Extremity ◽  
Upper Limb ◽  
Assistive Device ◽  
Preliminary Evaluation ◽  
Upper Limb Rehabilitation ◽  
Upper Limb Function ◽  
Tracking Tasks ◽  
Arm Reaching ◽  
Upper Extremity Impairment ◽  
Limb Rehabilitation

Stroke is a devastating condition that may cause upper limb paralysis. Robotic rehabilitation with self-initiated and assisted movements is a promising technology that could help restore upper limb function. Previous studies have established that the tongue motion can be used to communicate human intent and control a rehabilitation robot/assistive device. The goal of this study was to evaluate a tongue-operated exoskeleton system (TDS-KA), which we have developed for upper limb rehabilitation. We adopted a tongue-operated assistive technology, called the tongue drive system (TDS), and interfaced it with the exoskeleton KINARM. We also developed arm reaching and tracking tasks, controlled by different tongue operation modes, for training and evaluation of arm motor function. Arm reaching and tracking tasks were tested in 10 healthy participants (seven males and three females, 23–60 years) and two female stroke survivors with upper extremity impairment (32 and 58 years). All healthy and two stroke participants successfully performed the tasks. One stroke subject demonstrated a clinically significant improvement in Fugl-Meyer upper extremity score after practicing the tasks in six 3-h sessions. We conclude that the TDS-KA system can accurately translate tongue commands to exoskeleton arm movements, quantify the function of the arm, and perform rehabilitation training.

Comparison of Six Cursor Control Devices Based on Fitts' Law Models

1986 ◽  
Vol 30 (4) ◽  
pp. 327-331 ◽  
Author(s):  
Brian W. Epps
Keyword(s):  
Regression Analysis ◽  
Movement Time ◽  
Performance Data ◽  
Target Acquisition ◽  
Acquisition Performance ◽  
Cursor Control ◽  
Fitts Law ◽  
Acquisition Task ◽  
Control Devices ◽  
Best Fit

Six cursor control devices were compared on a target acquisition task which required subjects to move a cursor into square targets of varying sizes and at various screen distances. The target acquisition performance data were fitted to movement time models proposed by Fitts, Jagacinski, and Kvalseth. Regression analysis results indicated good predictions of target acquisition performance for the six cursor devices. The best fit was obtained with the trackball across the three models.

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