Mobility assessment using simulated Artificial Human Vision

Medical Imaging 2004: Physiology, Function, and Structure from Medical Images, 2004

This paper investigates methods of processing mobility related static images to enhance the effectiveness of a visual prosthesis system. Eight images were processed into 50x50 pixel binary, greyscale, Sobel and Canny edge detected images. 10 subjects were asked 5 mobility related identification tasks for each (randomly ordered) image. Results indicate that edge detection may be useful at this resolution. However, there was not a significant difference found between the results achieved using the Canny and Sobel algorithms. These results support the development of an adaptive device. A mobility display framework has been proposed to assist in this development. Future work will focus on processing image sequences and the development of a visual prosthesis simulation device.

Active Media Technology, 2006

Electrical stimulation of the human visual system can result in the per- ception of blobs of light, known as phosphenes. Artificial Hu man Vision (AHV or visual prosthesis) systems use this method to provide a visual substitute for the blind. This paper reports on our experiments involving normally sighted partici- pants using a portable AHV simulation. A Virtual Reality Head

Journal of Neural …, 2007

Wayfinding is an important activity that can be performed with limited visual resources, and thus may be an important application of early visual prostheses. In a pair of experiments we explored minimal visual resolution requirements of a simulated retinal electrode array for mobility in real and virtual environments, experienced by normally sighted subjects in video headsets. In experiment 1, inexperienced and experienced subjects traveled similar routes around a suite of offices with simulated implants of 4 × 4, 6 × 10 and 16 × 16 dots. In experiment 2, the effects of adding dynamic noise and removing a subset of 'phosphenes' from a 6 × 10 dot array on the mobility of experienced subjects through a series of different virtual 10-room buildings were determined. Performance was quantified in terms of time and navigation errors in both experiments, and wall contacts in the real environment; a compound score was also computed for trials in experiment 1. In experiment 1, inexperienced subjects required 16 × 16 dots for adequate performance, while experienced subjects reached similar levels with 6 × 10 dots. In experiment 2, dot removal up to 30% led to modest yet significant performance deterioration, and noise addition to slight but non-significant improvement, while practice led to a reduction in travel time by 50% over the 28-trial experiment. Error counts in experiment 2 were fairly high, but largely randomly distributed, and attributable to the high risk of becoming disoriented in the sparse visual environment. Substantial performance level differences were found between subjects, spanning a threefold range even after practice. The findings suggest that a retinal implant with as few as 60 electrodes may provide independent wayfinding abilities to the adventitiously blind, but that substantial practice and supervision will be required in learning this task.

IEEE Transactions on Biomedical Engineering, 1982

An overview of both early and recent developments in artificial aids for blind orientation and mobility is presented. Most aids developed previously fall into the category of "mobility aids" intended to sense obstacles in or near the traveler's immediate path. The more global problem of absolute orientation and navigation has not been well addressed by researchers in electronic aids, but this situation is now changing. A new system for aiding blind orientation, described here, is now advancing beyond the experimental stage.

Assistive Technology, 2020

One of the challenges faced by blind persons to achieve optimal mobility is the detection and avoidance of obstacles located in their travel path. Besides the widely used white cane, alternative or complementary devices have been developed, such as electronic aids that provide feedback about the environment. However, the devices available have been unable to provide an optimal solution with widespread acceptance, motivating the present work. The eBAT (electronic Buzzer for Autonomous Travel) is designed to offer optimal protection and employs the user's own mobile phone for easier use and reduced manufacturing costs. For this work, a group of 25 blind individuals was used to validate the eBAT based on the single-subject with reversal method (ABA study). The results show a significant decrease in the number of involuntary contacts in an unknown travel path between the first phase of the study, which did not involve the eBAT, and the second, where it was used. When the device was again removed in the third phase, the number of contacts rose. We may therefore conclude that the eBAT fills an important gap in mobility aids for blind people, yielding a clear benefit by reducing the participants' feeling of insecurity.

PLOS digital health, 2023

Visual impairment represents a significant health and economic burden affecting 596 million globally. The incidence of visual impairment is expected to double by 2050 as our population ages. Independent navigation is challenging for persons with visual impairment, as they often rely on non-visual sensory signals to find the optimal route. In this context, electronic travel aids are promising solutions that can be used for obstacle detection and/or route guidance. However, electronic travel aids have limitations such as low uptake and limited training that restrict their widespread use. Here, we present a virtual reality platform for testing, refining, and training with electronic travel aids. We demonstrate the viability on an electronic travel aid developed in-house, consist of a wearable haptic feedback device. We designed an experiment in which participants donned the electronic travel aid and performed a virtual task while experiencing a simulation of three different visual impairments: age-related macular degeneration, diabetic retinopathy, and glaucoma. Our experiments indicate that our electronic travel aid significantly improves the completion time for all the three visual impairments and reduces the number of collisions for diabetic retinopathy and glaucoma. Overall, the combination of virtual reality and electronic travel aid may have a beneficial role on mobility rehabilitation of persons with visual impairment, by allowing earlyphase testing of electronic travel aid prototypes in safe, realistic, and controllable settings.

PLoS ONE, 2013

Virtual worlds and environments are becoming an increasingly central part of our lives, yet they are still far from accessible to the blind. This is especially unfortunate as such environments hold great potential for them for uses such as social interaction, online education and especially for use with familiarizing the visually impaired user with a real environment virtually from the comfort and safety of his own home before visiting it in the real world. We have implemented a simple algorithm to improve this situation using single-point depth information, enabling the blind to use a virtual cane, modeled on the "EyeCane" electronic travel aid, within any virtual environment with minimal preprocessing. Use of the Virtual-EyeCane, enables this experience to potentially be later used in real world environments with identical stimuli to those from the virtual environment. We show the fast-learned practical use of this algorithm for navigation in simple environments.

Australian New Zealand Conference on Intelligent Information Systems, 2000

This paper examines intelligent image processing con- straints which may need to be considered for visual pros- thesis development and proposes a display framework which incorporates context, task and alerts related to a scene. A simulation device to investigate this framework is also described. Mobility requirements, assessment, and devices are discussed to identify the functions required by a prosthesis, and

Proc. SPIE, 2005

Simulating mobility tasks in a virtual environment reduces risk for research subjects, and allows for improved experimental control and measurement. We are currently using a simulated shopping mall environment (where subjects walk on a treadmill in front of a large projected video display) to evaluate a number of ophthalmic devices developed at the Schepens Eye Research Institute for people with vision impairment, particularly visual field defects. We have conducted experiments to study subject's perception of "safe passing distance" when walking towards stationary obstacles. The subject's binary responses about potential collisions are analyzed by fitting a psychometric function, which gives an estimate of the subject's perceived safe passing distance, and the variability of subject responses. The system also enables simulations of visual field defects using head and eye tracking, enabling better understanding of the impact of visual field loss. Technical infrastructure for our simulated walking environment includes a custom eye and head tracking system, a gait feedback system to adjust treadmill speed, and a handheld 3-D pointing device. Images are generated by a graphics workstation, which contains a model with photographs of storefronts from an actual shopping mall, where concurrent validation experiments are being conducted. Human Vision and Electronic Imaging X, edited by Bernice E. Rogowitz, Thrasyvoulos N. Pappas, Scott J. Daly, Proc. of SPIE-IS&T Electronic Imaging, SPIE Vol. 5666 © 2005 SPIE and IS&T · 0277-786X/05/$15 424

Lecture Notes in Computer Science, 2007

We discuss requirements surrounding a mobile navigation system for visually impaired people. We describe an initial prototype based on a PDA using GPS location tracking. This prototype has so far failed to provide reliable location detection, due to the use of GPS in built up environments. We discuss how our system may improve detection by switching between a range of different location tracking technologies. However, we conclude that there may still be times when these technologies fail, and more work is needed on how to support the user in such circumstances.

2017

B.E. , Department of Computer Science Engineering, Sinhgad Institute of Technology, Lonavala, Maharashtra ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract In this paper, we have introduced an elaborate assistive mobility aid system for visually impaired individuals. In this system, a visually impaired individual is aided through a networked system comprising mainly an android device and ultrasonic sensors. The phone is placed in the individual’s pocket and the sensors are fitted at the individual’s feet and temple. The visually impaired individual, or ‘user’ for further reference, is guided through the environment through English voice guidance produced by the application as per the current position of the user and the relative position of obstacles in the line of the user’s path. The user can navigate around the app using voice commands. The app is made accessible using aural feedbac...

This article presents an exploratory case study with a mobile application devised to promote social inclusion of visually impaired people through collaborative mapping considering changes in the local environment. General strategies and technological resources used in tools like this provide greater independence and social inclusion for people with disabilities. Test results suggest that this application can support and expand communication and mobility in physical spaces such as schools, public institutions and the community at large.

Restorative neurology and neuroscience, 2014

Independent mobility is one of the most pressing problems facing people who are blind. We present the EyeCane, a new mobility aid aimed at increasing perception of environment beyond what is provided by the traditional White Cane for tasks such as distance estimation, navigation and obstacle detection. The "EyeCane" enhances the traditional White Cane by using tactile and auditory output to increase detectable distance and angles. It circumvents the technical pitfalls of other devices, such as weight, short battery life, complex interface schemes, and slow learning curve. It implements multiple beams to enables detection of obstacles at different heights, and narrow beams to provide active sensing that can potentially increase the user's spatial perception of the environment. Participants were tasked with using the EyeCane for several basic tasks with minimal training. Blind and blindfolded-sighted participants were able to use the EyeCane successfully for distance est...

… of the 7th ACM SIGCHI New …, 2007

Individuals with visual impairments must rely on information from their other senses to provide them with obstacle preview. Although the long cane has become the most common primary device for detecting obstacles on the ground, other systems have gained ...

Proceedings of the 11th IFIP TC 13 international …, 2007

We present a study about the use of current electronic travel aids to help blind people navigate through familiar and unfamiliar environments. We also discuss the main strengths and weaknesses of electronic travel aids and propose guidelines to design and use them adequately. We provide a proposal to develop and use traveling aids. As a result, this can be a first step towards defining major aspects to develop travel aids oriented to assist mobility and orientation of blind people.