scholarly journals Extending assistive devices: using the existing interface versus using a new interface

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Nirit Yuviler-Gavish ◽  
Eitan Kribu ◽  
Avi Weiss ◽  
Uri Ben-Hanan

AbstractThe current research examined whether or not the interface of an extender attached to an assistive device should be identical to the interface of the assistive device. Given the profile of assistive devices such as wheelchairs and the need to extend them in special cases such when maneuvering over rough terrain or obstacles such as stairs and steep inclines, the interface design of these extenders (attached to existing assistive devices) should be evaluated. We have simulated a carrying platform for a wheelchair that is larger than the user’s regular wheelchair. We have examined whether participants used to handling their wheelchair, when asked to operate the carrying platform, handle the latter’s interface better or worse than their wheelchair’s interface. Participants (61) were assigned to one of two between-participants groups. Both groups were trained to navigate a wheelchair using the wheelchair’s interface and then operated the carrying platform. The Familiar Interface group navigated the carrying platform using the wheelchair’s interface, and the New Interface group navigated it with a new interface. The results demonstrated that the Familiar Interface group took longer to perform the task and collided more often with obstacles, compared to the New Interface group. The greater number of collisions can be linked directly to an erroneous mental model of the carrying platform’s size. The insights we reach can be linked to both extenders attached to an assistive device and other technological extenders.

Author(s):  
Akbar Hojjati Najafabadi ◽  
Saeid Amini ◽  
Farzam Farahmand

The majority of the people with incomplete spinal cord injury lose their walking ability, due to the weakness of their muscle motors in providing torque. As a result, developing assistive devices to improve their conditionis of great importance. In this study, a combined application of the saddle-assistive device (S-AD) and mechanical medial linkage or thosis was evaluated to improve the walking ability in patients with spinal cord injury in the gait laboratory. This mobile assistive device is called the saddle-assistive device equipped with medial linkage or thosis (S-ADEM). In this device, a mechanical orthosis was used in a wheeled walker as previously done in the literature. Initially, for evaluation of the proposed assistive device, the experimental results related to the forces and torques exerted on the feet and upper limbs of a person with the incomplete Spinal Cord Injury (SCI) during walking usingthe standard walker were compared with an those obtained from using the S-ADEM on an able-bodied subject. It was found that using this combination of assistive devices decreases the vertical force and torque on the foot at the time of walking by 53% and 48%, respectively compared to a standard walker. Moreover, the hand-reaction force on the upper limb was negligible instanding and walking positions usingthe introduced device. The findings of this study revealed that the walking ability of the patients with incomplete SCI was improved using the proposed device, which is due to the bodyweight support and the motion technology used in it.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 705
Author(s):  
Fatemeh Rasouli ◽  
Kyle B. Reed

Dynamic models, such as double pendulums, can generate similar dynamics as human limbs. They are versatile tools for simulating and analyzing the human walking cycle and performance under various conditions. They include multiple links, hinges, and masses that represent physical parameters of a limb or an assistive device. This study develops a mathematical model of dissimilar double pendulums that mimics human walking with unilateral gait impairment and establishes identical dynamics between asymmetric limbs. It introduces new coefficients that create biomechanical equivalence between two sides of an asymmetric gait. The numerical solution demonstrates that dissimilar double pendulums can have symmetric kinematic and kinetic outcomes. Parallel solutions with different physical parameters but similar biomechanical coefficients enable interchangeable designs that could be incorporated into gait rehabilitation treatments or alternative prosthetic and ambulatory assistive devices.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4515
Author(s):  
Rinku Roy ◽  
Manjunatha Mahadevappa ◽  
Kianoush Nazarpour

Humans typically fixate on objects before moving their arm to grasp the object. Patients with ALS disorder can also select the object with their intact eye movement, but are unable to move their limb due to the loss of voluntary muscle control. Though several research works have already achieved success in generating the correct grasp type from their brain measurement, we are still searching for fine controll over an object with a grasp assistive device (orthosis/exoskeleton/robotic arm). Object orientation and object width are two important parameters for controlling the wrist angle and the grasp aperture of the assistive device to replicate a human-like stable grasp. Vision systems are already evolved to measure the geometrical attributes of the object to control the grasp with a prosthetic hand. However, most of the existing vision systems are integrated with electromyography and require some amount of voluntary muscle movement to control the vision system. Due to that reason, those systems are not beneficial for the users with brain-controlled assistive devices. Here, we implemented a vision system which can be controlled through the human gaze. We measured the vertical and horizontal electrooculogram signals and controlled the pan and tilt of a cap-mounted webcam to keep the object of interest in focus and at the centre of the picture. A simple ‘signature’ extraction procedure was also utilized to reduce the algorithmic complexity and system storage capacity. The developed device has been tested with ten healthy participants. We approximated the object orientation and the size of the object and determined an appropriate wrist orientation angle and the grasp aperture size within 22 ms. The combined accuracy exceeded 75%. The integration of the proposed system with the brain-controlled grasp assistive device and increasing the number of grasps can offer more natural manoeuvring in grasp for ALS patients.


Author(s):  
Huaiqiang Zhang ◽  
Qiang Xue ◽  
Shuo Yang ◽  
Tongtong Wang ◽  
Binwei Zhou

Background: Completing the transition from a sitting position to a standing position is a basic skill in people’s daily lives and is crucial for independent living. Lower limb dysfunction will bring many inconveniences into a person’s life and greatly affect their quality of life. Patients with lower limb dysfunction are a specialized group, and nursing problems for this group are becoming increasingly serious. Helping patients with lower limb dysfunction restore their lower limb mobility or assisting them to walk is a social problem necessary to be solved. Objective: : To review the recent sit-to-stand assistive devices based on hip support, classify them systematically and introduce their characteristics, including the mechanisms and the types of patients for which such mechanisms are applicable; to help patients with lower limb dysfunction or doctors (therapists) understand and choose a reasonable sit-to-stand assist device based on hip support. Methods: This paper summarizes literatures and patents about sit-to-stand assistive devices. From the aspects of structural characteristics, drive type and support modes based on the hip and applications situation, the advantages and disadvantages of the typical sit-to-stand assist devices are represented. Results: Current and future development trends on the structural characteristics, drive type and support modes based on the hip and applications situation of sit-to-stand assist devices are discussed to improve the humanization, modularization and applicability of sit-to-stand assist devices. Conclusion: Sit-to-stand assistive devices based on hip support can help patients improve the quality of their life, assist patients carrying out rehabilitation training, and delay the decline of lower limb function. However, the existing sit-to-stand assistive devices based on hip support need further improvement in the aspects of motion mechanism, new technology application and ergonomics design.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0049
Author(s):  
Alicia Unangst ◽  
Kevin Martin ◽  
Anthony Mustovich ◽  
Jaime Chisholm

Category: Ankle Introduction/Purpose: Following lower extremity surgery patients are often required to utilize assistive devices in order to perform activities of daily living. As technology and assistive devices continue to improve, providers are faced with selecting a device that is safe while providing high patient satisfaction and a quick return to actives. The purpose of the current study was to compare physical exertion and subject preference between a hands-free single crutch and standard axillary crutches in foot and ankle patients. Methods: A prospective, randomized crossover study was performed using 35 orthopedic foot and ankle patients from within one treatment facility. Each participant had demographic data and heart rate recorded. The patients were then randomized to an assistive device. All participants completed a 6-minute walk test (6MWT); immediately following each 6MWT heart rate, self-selected walking velocity (SSWV), perceived exertion using OMNI Rating of Perceived Exertion (OMNI-RPE) and perceived dyspnea using Modified Borg Dyspnea Scale was obtained. The patients then completed another 6MWT using the other assistive device and was asked the same questions. After completing both 6MWTs participants were asked which assistive device they would prefer to use. Results: A total of 35 patients were included with a median age of 32-year-old. The hands-free crutch was preferred by 86% of participants. Regression analysis was used to test if factors such as gender, height, weight, BMI predicted patient preference of iWalk vs. Crutch. None of these factors were found to be significant. Student t-tests and ANOVAs were performed separately for dyspnea, fatigue ratings, distance (meters) and heart rate between iWalk and crutch all were found to be significant (p<0.05, p=1.13e-11, p=2.29e-13, p=5.21e-05, respectively). The axillary crutch group had higher SSWV (0.8 vs 0.77m/s) but was not found to be significant. Neither group had any falls, however, 58% of axillary participants complained of axillary/hand pain while the hands-free group had 14% complain of proximal strap discomfort. Conclusion: Patients preferred the hands-free crutch while reporting lower perceived dyspnea and fatigue. The hands-free group demonstrated lower physiologic demand, which correlated with patient perception.


Author(s):  
P. Geethanjali

Most of the assistive devices are of user contact based control like body-powered prosthetic hand, joystick control of wheelchair, sip-and-puff, etc. and have a limited number of control movements. The performance of these assistive devices improves using bio-signals/gesture based control embedded in the processor. Gesture based control is widely used in wheelchair navigation control, communication with external world for neuromuscular impaired subjects. On the other hand, bio-signals are used widely in prosthetic devices, wheelchair control, orthotic devices, etc. with pattern recognition based control strategy. The choice and number of features used in pattern recognition for accurate control of assistive device is crucial. Further, these features performance also varies with the classifier. The appropriate selection of combination of pattern recognition will enhance the accuracy. This chapter focuses on bio-inspired techniques in selection of features and classification for the pattern recognition based assistive device control.


Author(s):  
Yiannis Koumpouros

The ageing of the population is one of the major societal and financial problems. The prevalence of disability increases dramatically by age. The loss of mobility can be devastating to the elderly. Mobility aids are a one-way street to maintain independent mobility. The performance of daily activities is restrained by a series of factors related to the assistive device limitations, or the ones emerged from environmental causes. A literature review reveals minimal tools for assessing mobility assistive devices able to capture users' satisfaction. The chapter presents an assessment methodology in order to investigate assistive mobility devices' limitations, dissatisfaction reasons, and identifies the most appropriate tools to study such limitations and conclude in valid outcomes. One of the valuable characteristics of the study presented in its generalizability since it is not disease oriented. A summary of the results from both the literature review and the real case study on a mixed group of end users are presented in the chapter.


2022 ◽  
pp. 240-271
Author(s):  
Dmytro Zubov

Smart assistive devices for blind and visually impaired (B&VI) people are of high interest today since wearable IoT hardware became available for a wide range of users. In the first project, the Raspberry Pi 3 B board measures a distance to the nearest obstacle via ultrasonic sensor HC-SR04 and recognizes human faces by Pi camera, OpenCV library, and Adam Geitgey module. Objects are found by Bluetooth devices of classes 1-3 and iBeacons. Intelligent eHealth agents cooperate with one another in a smart city mesh network via MQTT and BLE protocols. In the second project, B&VIs are supported to play golf. Golf flagsticks have sound marking devices with a buzzer, NodeMcu Lua ESP8266 ESP-12 WiFi board, and WiFi remote control. In the third project, an assistive device supports the orientation of B&VIs by measuring the distance to obstacles via Arduino Uno and HC-SR04. The distance is pronounced through headphones. In the fourth project, the soft-/hardware complex uses Raspberry Pi 3 B and Bytereal iBeacon fingerprinting to uniquely identify the B&VI location at industrial facilities.


Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 4 ◽  
Author(s):  
Junghoon Park ◽  
Pilwon Heo ◽  
Jung Kim ◽  
Youngjin Na

This paper presents a fingertip grip force sensor based on custom capacitive sensors for glove-type assistive devices with an open-pad structure. The design of the sensor allows using human tactile sensations during grasping and manipulating an object. The proposed sensor can be attached on both sides of the fingertip and measure the force caused by the expansion of the fingertip tissue when a grasping force is applied to the fingertip. The number of measurable degrees of freedom (DoFs) are the two DoFs (flexion and adduction) for the thumb and one DoF (flexion) for the index and middle fingers. The proposed sensor allows the combination with a glove-type assistive device to measure the fingertip force. Calibration was performed for each finger joint angle because the variations in the expansion of the fingertip tissue depend on the joint angles. The root mean square error (RMSE) for fingertip force estimation ranged from 3.75% to 9.71% after calibration, regardless of the finger joint angles or finger posture.


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