The effect of extended sensory range via the EyeCane sensory substitution device on the characteristics of visionless virtual navigation

Mobility training programs for helping the blind navigate through unknown places with a White-Cane significantly improve their mobility. However, what is the effect of new assistive technologies, offering more information to the blind user, on the underlying premises of these programs such as navigation patterns? We developed the virtual-EyeCane, a minimalistic sensory substitution device translating single-point-distance into auditory cues identical to the EyeCane's in the real world. We compared performance in virtual environments when using the virtual-EyeCane, a virtual-White-Cane, no device and visual navigation. We show that the characteristics of virtual-EyeCane navigation differ from navigation with a virtual-White-Cane or no device, and that virtual-EyeCane users complete more levels successfully, taking shorter paths and with less collisions than these groups, and we demonstrate the relative similarity of virtual-EyeCane and visual navigation patterns. This suggests that additional distance information indeed changes navigation patterns from virtual-White-Cane use, and brings them closer to visual navigation.

Is there a future for sensory substitution outside academic laboratories?

Sensory substitution devices (SSDs) have been developed with the ultimate purpose of supporting sensory deprived individuals in their daily activities. However, more than forty years after their first appearance in the scientific literature, SSDs still remain more common in research laboratories than in the daily life of people with sensory deprivation. Here, we seek to identify the reasons behind the limited diffusion of SSDs among the blind community by discussing the ergonomic, neurocognitive and psychosocial issues potentially associated with the use of these systems. We stress that these issues should be considered together when developing future devices or improving existing ones. We provide some examples of how to achieve this by adopting a multidisciplinary and participatory approach. These efforts would contribute not solely to address fundamental theoretical research questions, but also to better understand the everyday needs of blind people and eventually promote the use of SSDs outside laboratories.

Visual objects in the auditory system in sensory substitution: how much information do we need?

Sensory substitution devices such as The vOICe convert visual imagery into auditory soundscapes and can provide a basic 'visual' percept to those with visual impairment. However, it is not known whether technical or perceptual limits dominate the practical efficacy of such systems. By manipulating the resolution of sonified images and asking naïve sighted participants to identify visual objects through a six-alternative forced-choice procedure (6AFC) we demonstrate a 'ceiling effect' at 8 x 8 pixels, in both visual and tactile conditions, that is well below the theoretical limits of the technology. We discuss our results in the context of auditory neural limits on the representation of 'auditory' objects in a cortical hierarchy and how perceptual training may be used to circumvent these limitations.

Intra-session test-retest reliability of magnitude and structure of center of pressure from the Nintendo Wii Balance Board™ for a visually impaired and normally sighted population

Individuals with visual impairment (VI) have irreparable damage to one of the input streams contributing to postural stability. Here, we evaluated the intra-session test-retest reliability of the Wii Balance Board (WBB) for measuring Center of Pressure (COP) magnitude and structure, i.e. approximate entropy (ApEn) in fourteen legally blind participants and 21 participants with corrected-to-normal vision. Participants completed a validated balance protocol which included four sensory conditions: double-leg standing on a firm surface with eyes open (EO-firm); a firm surface with eyes closed (EC-firm); a foam surface with EO (EO-foam); and a foam surface with EC (EC-foam). Participants performed the full balance protocol twice during the session, separated by a period of 15min, to determine the intraclass correlation coefficient (ICC). Absolute reliability was determined by the standard error of measurement (SEM). The minimal difference (MD) was estimated to determine clinical significance for future studies. COP measures were derived from data sent by the WBB to a laptop via Bluetooth. COP scores increased with the difficulty of sensory condition indicating WBB sensitivity (all p<0.01). ICCs in the VI group ranged from 0.73 to 0.95, indicating high to very high correlations, and the normal group showed moderate to very high ICCs (0.62-0.94). The SEM was comparable between groups regardless of between-subject variability. The reliability of the WBB makes it practical to screen for balance impairment among VI persons.

Seeking a reading machine for the blind and discovering the speech code

A machine that can read printed material to the blind became a priority at the end of World War II with the appointment of a U.S. Government committee to instigate research on sensory aids to improve the lot of blinded veterans. The committee chose Haskins Laboratories to lead a multisite research program. Initially, Haskins researchers overestimated the capacities of users to learn an acoustic code based on the letters of a text, resulting in unsuitable designs. Progress was slow because the researchers clung to a mistaken view that speech is a sound alphabet and because of persisting gaps in man-machine technology. The tortuous route to a practical reading machine transformed the scientific understanding of speech perception and reading at Haskins Labs and elsewhere, leading to novel lines of basic research and new technologies. Research at Haskins Laboratories made valuable contributions in clarifying the physical basis of speech. Researchers recognized that coarticulatory overlap eliminated the possibility of alphabet-like discrete acoustic segments in speech. This work advanced the study of speech perception and contributed to our understanding of the relation of speech perception to production. Basic findings on speech enabled the development of speech synthesis, part science and part technology, essential for development of a reading machine, which has found many applications. Findings on the nature of speech further stimulated a new understanding of word recognition in reading across languages and scripts and contributed to our understanding of reading development and reading disabilities.

PERCEPT-II: smartphone based indoor navigation system for the blind

In this paper we introduce PERCEPT-II, a low cost and user friendly indoor navigation system for blind and visually impaired users. Using an Android Smartphone that runs PERCEPT-II application with accessibility features, the blind user obtains navigation instructions to the chosen destination when touching specific landmarks tagged with Near Field Communication tags. The system was deployed and tested in a large building at the University of Massachusetts at Amherst.

Proposal for SVG2DOT: - An Interoperable Tactile Graphics Creation System Using SVG outputs from Inkscape

For this study, I developed a software that converts SVG outputs from Inkscape to tactile graphics. Inkscape is easy to learn because it can be manipulated like any other typical drawing application and has a layer function which is enables robust support in the creation of tactile graphics In a simple evaluation, it is confirmed that the method of drawing a master in Inkscape and converting it with SVG2DOT was nearly as efficient as using a conventional tactile graphics drawing application.

Real-time Pedestrian Crossing Recognition for Assistive Outdoor Navigation

Navigation in urban environments can be difficult for people who are blind or visually impaired. In this project, we present a system and algorithms for recognizing pedestrian crossings in outdoor environments. Our goal is to provide navigation cues for crossing the street and reaching an island or sidewalk safely. Using a state-of-the-art Multisense S7S sensor, we collected 3D pointcloud data for real-time detection of pedestrian crossing and generation of directional guidance. We demonstrate improvements to a baseline, monocular-camera-based system by integrating 3D spatial prior information extracted from the pointcloud. Our system's parameters can be set to the actual dimensions of real-world settings, which enables robustness of occlusion and perspective transformation. The system works especially well in non-occlusion situations, and is reasonably accurate under different kind of conditions. As well, our large dataset of pedestrian crossings, organized by different types and situations of pedestrian crossings in order to reflect real-word environments, is publicly available in a commonly used format (ROS bagfiles) for further research.

BrailleEasy: One-handed Braille Keyboard for Smartphones

The evolution of mobile technology is moving at a very fast pace. Smartphones are currently considered a primary communication platform where people exchange voice calls, text messages and emails. The human-smartphone interaction, however, is generally optimized for sighted people through the use of visual cues on the touchscreen, e.g., typing text by tapping on a visual keyboard. Unfortunately, this interaction scheme renders smartphone technology largely inaccessible to visually impaired people as it results in slow typing and higher error rates. Apple and some third party applications provide solutions specific to blind people which enables them to use Braille on smartphones. These applications usually require both hands for typing. However, Brailling with both hands while holding the phone is not very comfortable. Furthermore, two-handed Brailling is not possible on smartwatches, which will be used more pervasively in the future. Therefore, we develop a platform for one-handed Brailing consisting of a custom keyboard called BrailleEasy to input Arabic or English Braille codes within any application, and a BrailleTutor application for practicing. Our platform currently supports Braille grade 1, and will be extended to support contractions, spelling correction, and more languages. Preliminary analysis of user studies for blind participants showed that after less than two hours of practice, participants were able to type significantly faster with the BrailleEasy keyboard than with the standard QWERTY keyboard.

Acquisition of Visual Perception in Blind Adults Using the BrainPort Artificial Vision Device

OBJECTIVE

We sought to determine whether intensive low vision rehabilitation would confer any functional improvement in a sample of blind adults using the BrainPort artificial vision device.

METHOD

Eighteen adults ages 28-69 yr (n=10 men and n=8 women) who had light perception only or worse vision bilaterally spent up to 6 hr per day for 1 wk undergoing structured rehabilitation interventions. The functional outcomes of object identification and word recognition were tested at baseline and after rehabilitation training.

RESULTS

At baseline, participants were unable to complete the two functional assessments. After participation in the 1-wk training protocol, participants were able to use the BrainPort device to complete the two tasks with moderate success.

CONCLUSION

Without training, participants were not able to perform above chance level using the BrainPort device. As artificial vision technologies become available, occupational therapy practitioners can play a key role in clients' success or failure in using these devices.

Observing the use of tactile schedules

This article explores the use of tactile schedules in a heterogeneous sample of children with congenital blindness and varying degrees of additional disabilities. Basic conditions for the use of tactile schedules are proposed and discussed. Child behaviour indicative of some particular functions that can be attained with the use of tactile schedules, such as sense of agency and increased predictability and communication, is described and discussed. The role of the teacher is emphasized throughout the article.

Perception of tactile graphics: embossings versus cutouts

Graphical information, such as illustrations, graphs, and diagrams, are an essential complement to text for conveying knowledge about the world. Although graphics can be communicated well via the visual modality, conveying this information via touch has proven to be challenging. The lack of easily comprehensible tactile graphics poses a problem for the blind. In this paper, we advance a hypothesis for the limited effectiveness of tactile graphics. The hypothesis contends that conventional graphics that rely upon embossings on two-dimensional surfaces do not allow the deployment of tactile exploratory procedures that are crucial for assessing global shape. Besides potentially accounting for some of the shortcomings of current approaches, this hypothesis also serves a prescriptive purpose by suggesting a different strategy for conveying graphical information via touch, one based on cutouts. We describe experiments demonstrating the greater effectiveness of this approach for conveying shape and identity information. These results hold the potential for creating more comprehensible tactile drawings for the visually impaired while also providing insights into shape estimation processes in the tactile modality.

Results of late surgical intervention in children with early-onset bilateral cataracts

BACKGROUND

Cataracts are a major cause of childhood blindness globally. Although surgically treatable, it is unclear whether children would benefit from such interventions beyond the first few years of life, which are believed to constitute 'critical' periods for visual development.

AIMS

To study visual acuity outcomes after late treatment of early-onset cataracts and also to determine whether there are longitudinal changes in postoperative acuity.

METHODS

We identified 53 children with dense cataracts with an onset within the first half-year after birth through a survey of over 20,000 rural children in India. All had accompanying nystagmus and were older than 8 years of age at the time of treatment. They underwent bilateral cataract surgery and intraocular lens implantation. We then assessed their best-corrected visual acuity 6 weeks and 6 months after surgery.

RESULTS

48 children from the pool of 53 showed improvement in their visual acuity after surgery. Our longitudinal assessments demonstrated further improvements in visual acuity for the majority of these children proceeding from the 6-week to 6-month assessment. Interestingly, older children in our subject pool did not differ significantly from the younger ones in the extent of improvement they exhibit.

CONCLUSIONS AND RELEVANCE

Our results demonstrate that not only can significant vision be acquired until late in childhood, but that neural processes underlying even basic aspects of vision like resolution acuity remain malleable until at least adolescence. These data argue for the provision of cataract treatment to all children, irrespective of their age.

Performance of photovoltaic arrays in-vivo and characteristics of prosthetic vision in animals with retinal degeneration

Loss of photoreceptors during retinal degeneration leads to blindness, but information can be reintroduced into the visual system using electrical stimulation of the remaining retinal neurons. Subretinal photovoltaic arrays convert pulsed illumination into pulsed electric current to stimulate the inner retinal neurons. Since required irradiance exceeds the natural luminance levels, an invisible near-infrared (915 nm) light is used to avoid photophobic effects. We characterized the thresholds and dynamic range of cortical responses to prosthetic stimulation with arrays of various pixel sizes and with different number of photodiodes. Stimulation thresholds for devices with 140 μm pixels were approximately half those of 70 μm pixels, and with both pixel sizes, thresholds were lower with 2 diodes than with 3 diodes per pixel. In all cases these thresholds were more than two orders of magnitude below the ocular safety limit. At high stimulation frequencies (>20 Hz), the cortical response exhibited flicker fusion. Over one order of magnitude of dynamic range could be achieved by varying either pulse duration or irradiance. However, contrast sensitivity was very limited. Cortical responses could be detected even with only a few illuminated pixels. Finally, we demonstrate that recording of the corneal electric potential in response to patterned illumination of the subretinal arrays allows monitoring the current produced by each pixel, and thereby assessing the changes in the implant performance over time.

Department of Veterans Affairs. Special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. Final rule

The Department of Veterans Affairs (VA) is issuing a final rule to amend its adjudication regulations regarding special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. This regulatory amendment is necessary to conform the regulations to changes mandated in the Honoring America's Veterans and Caring for Camp Lejeune Families Act of 2012.

Navigation within buildings: novel movement detection algorithms supporting people with visual impairments

This study aimed at finding simple algorithms to identify three different movements registered by accelerometer and to detect differences in the acceleration signals of people with and without visual impairments. The Tactile Acoustical Navigation and Information Assistant (TANIA) is construed to provide persons suffering from visual impairments support for an independent navigation indoors and outdoors. Attaining this goal, TANIA uses vertical acceleration signal extrema to assess its user's walking distance. This study investigated first the sit-to-stand movement, stumbling and walking up- and down stairs of 25 subjects with visual impairments using TANIA sensor system. The objective was to improve the user's movement detection using sensors to get valid and reliable data. In a second step of the study it was investigated if there is a difference between the above-mentioned movements in people with or without visual impairments (n=10). The acceleration signals of the subjects were compared. Three simple algorithms were found, which are able to separate the movement signals based on accelerometers of the respective daily movements. The second step analysis revealed a detectable difference in the second phase of stumbling (p=.034), where the subjects had to get back into walking forward. No differences in the other acceleration signals were found.

Microswitch-aided programs to support physical exercise or adequate ambulation in persons with multiple disabilities

Three microswitch-aided programs were assessed in three single-case studies to enhance physical exercise or ambulation in participants with multiple disabilities. Study I was aimed at helping a woman who tended to have the head bending forward and the arms down to exercise a combination of appropriate head and arms movements. Study II was aimed at promoting ambulation continuity with a man who tended to have ambulation breaks. Study III was aimed at promoting ambulation with appropriate foot position in a girl who usually showed toe walking. The experimental designs of the studies consisted of a multiple probe across responses (Study I), an ABAB sequence (Study II), and an ABABB(1) sequence (Study III). The last phase of each study was followed by a post-intervention check. The microswitches monitored the target responses selected for the participants and triggered a computer system to provide preferred stimuli contingent on those responses during the intervention phases of the studies. Data showed that the programs were effective with each of the participants who learned to exercise head and arms movements, increased ambulation continuity, and acquired high levels of appropriate foot position during ambulation, respectively. The positive performance levels were retained during the post-intervention checks. The discussion focused on (a) the potential of technology-aided programs for persons with multiple disabilities and (b) the need of replication studies to extend the evidence available in the area.

Stereo camera based virtual cane system with identifiable distance tactile feedback for the blind

In this paper, we propose a new haptic-assisted virtual cane system operated by a simple finger pointing gesture. The system is developed by two stages: development of visual information delivery assistant (VIDA) with a stereo camera and adding a tactile feedback interface with dual actuators for guidance and distance feedbacks. In the first stage, user's pointing finger is automatically detected using color and disparity data from stereo images and then a 3D pointing direction of the finger is estimated with its geometric and textural features. Finally, any object within the estimated pointing trajectory in 3D space is detected and the distance is then estimated in real time. For the second stage, identifiable tactile signals are designed through a series of identification experiments, and an identifiable tactile feedback interface is developed and integrated into the VIDA system. Our approach differs in that navigation guidance is provided by a simple finger pointing gesture and tactile distance feedbacks are perfectly identifiable to the blind.

People with multiple disabilities learn to engage in occupation and work activities with the support of technology-aided programs

These two studies were aimed at assessing technology-aided programs to help persons with multiple disabilities engage in basic occupation or work activities. Specifically, Study I focused on teaching two participants (an adolescent and an adult) with low vision or total blindness, severe/profound intellectual disabilities, and minimal object interaction to engage in constructive object-manipulation responses. The technology monitored their responses and followed them with brief stimulation periods automatically. Study II focused on teaching three adults with deafness, severe visual impairment, and profound intellectual disabilities to perform a complex activity, that is, to assemble a five-component water pipe. The technology regulated (a) light cues to guide the participants through the workstations containing single pipe components and the carton for completed pipes and (b) stimulation events. The results of both studies were positive. The participants of Study I showed consistent and independent engagement in object-manipulation responses. The participants of Study II showed consistent and independent pipe assembling performance. General implications of the two programs and the related technology packages for intervention with persons with multiple disabilities are discussed.

Design, development, and clinical evaluation of the electronic mobility cane for vision rehabilitation

This paper proposes a new electronic mobility cane (EMC) for providing obstacle detection and way-finding assistance to the visually impaired people. The main feature of this cane is that it constructs the logical map of the surrounding environment to deduce the priority information. It provides a simplified representation of the surrounding environment without causing any information overload. It conveys this priority information to the subject by using intuitive vibration, audio or voice feedback. The other novel features of the EMC are staircase detection and nonformal distance scaling scheme. It also provides information about the floor status. It consists of a low power embedded system with ultrasonic sensors and safety indicators. The EMC was subjected to series of clinical evaluations in order to verify its design and to assess its ability to assist the subjects in their daily-life mobility. Clinical evaluations were performed with 16 totally blind and four low vision subjects. All subjects walked controlled and the real-world test environments with the EMC and the traditional white cane. The evaluation results and significant scores of subjective measurements have shown the usefulness of the EMC in vision rehabilitation services.

Enhancing activity by means of tactile symbols: a study of a heterogeneous group of pupils with congenital blindness, intellectual disability and autism spectrum disorder

This study investigates responses to verbal versus tactile requests in children with congenital blindness, intellectual disability and autism spectrum disorder (ASD). Observation was conducted on two occasions. At T1, requests were given verbally, and at T2, tactile requests were given. All pupils perceived tactile symbols to be explicit requests to perform the act referred to by the symbols. The children seldom or never followed verbal requests. All children followed more tactile than verbal requests. Individual differences in verbal skills, motivations and the complexity of the activity are discussed. The availability of tactile symbols for individuals with congenital blindness, intellectual disability and ASD seems to increase their level of activity and their participation in school.

Vision rehabilitation in the case of blindness

This article examines the various vision rehabilitation procedures that are available for early and late blindness. Depending on the pathology involved, several vision rehabilitation procedures exist, or are in development. Visual aids are available for low vision individuals, as are sensory aids for blind persons. Most noninvasive sensory substitution prostheses as well as implanted visual prostheses in development are reviewed. Issues dealing with vision rehabilitation are also discussed, such as problems of biocompatibility, electrical safety, psychosocial aspects, and ethics. Basic studies devoted to vision rehabilitation such as simulation in mathematical models and simulation of artificial vision are also presented. Finally, the importance of accurate rehabilitation assessment is addressed, and tentative market figures are given.

Artificial human vision

Can vision be restored to the blind? As early as 1929 it was discovered that stimulating the visual cortex of an individual led to the perception of spots of light, known as phosphenes [1] . The aim of artificial human vision systems is to attempt to utilize the perception of phosphenes to provide a useful substitute for normal vision. Currently, four locations for electrical stimulation are being investigated; behind the retina (subretinal), in front of the retina (epiretinal), the optic nerve and the visual cortex (using intra- and surface electrodes). This review discusses artificial human vision technology and requirements, and reviews the current development projects.

[PASSIVE TACTILE STIMULATION AS A WAY OF SPATIAL RECOGNITION IN SUBJECTS WITH SEVERE VISUAL IMPAIRMENT OR BLINDNESS]

Regular tactile passive stimulation increases the lasting activation of a greater number of synaptic connections (neuroplasticity) in posterior cortical areas in subjects with blidness with duration and permanence of the neuroplasticity process. Assuming that the lack of stimulation logically involves a deficit due to the cerebral hypofunctionality; in the case of blind subjects such deficit should be more pronounced in the occipital lobe responsible of human vision. We found, after long period of táctile stimulation, that the occipital lobe was activated while having at the same time a visual "qualia" subjective sensation using transcranial magnetic stimulation occipital lobe inhibition decreases visual response.

A necklace sonar with adjustable scope range for assisting the visually impaired

A sonar based device with tactile feedback was developed to improve the mobility and independence of visually impaired individuals. It features a transceiver/receiver, a potentiometer, a microcontroller, a rechargeable polymer lithium ion battery, and a Nokia Cell phone vibrator. All components are commercially available and housed in a custom acrylic package with 86 mm × 34 mm × 12 mm in dimension, and 120 grms in weight. Additionally, the device features an adjustable detection scheme for user customization of distance range, and a tactile feedback system that avoids interference with auditory sensory information. The device was tested for its navigational efficacy in an artificial indoor environment, and in a live outdoor setting. Ten subjects (9 males and 1 female), with a mean age of 35 years-old (range: 17 to 52) were presented with a series of navigational tasks resulting in considerable reduction of head, shoulder, chest, and arms collisions during their locomotion. We conclude that this device greatly improves the mobility and safety of visually impaired individuals.

Holographic display system for restoration of sight to the blind

OBJECTIVE

We present a holographic near-the-eye display system enabling optical approaches for sight restoration to the blind, such as photovoltaic retinal prosthesis, optogenetic and other photoactivation techniques. We compare it with conventional liquid crystal displays (LCD) or digital light processing (DLP)-based displays in terms of image quality, field of view, optical efficiency and safety.

APPROACH

We detail the optical configuration of the holographic display system and its characterization using a phase-only spatial light modulator.

MAIN RESULTS

We describe approaches to controlling the zero diffraction order and speckle related issues in holographic display systems and assess the image quality of such systems. We show that holographic techniques offer significant advantages in terms of peak irradiance and power efficiency, and enable designs that are inherently safer than LCD or DLP-based systems. We demonstrate the performance of our holographic display system in the assessment of cortical response to alternating gratings projected onto the retinas of rats.

SIGNIFICANCE

We address the issues associated with the design of high brightness, near-the-eye display systems and propose solutions to the efficiency and safety challenges with an optical design which could be miniaturized and mounted onto goggles.

Gross motor skill performance in children with and without visual impairments--research to practice

The aim of this study was to provide an empirical basis for teaching gross motor skills in children with visual impairments. For this purpose, gross motor skill performance of 23, 6-12 year old, boys and girls who are blind (ICD-10 H54.0) and 28 sighted controls with comparable age and gender characteristics was compared on six locomotor and six object control tasks using the Test of Gross Motor Development-Second Edition. Results indicate that children who are blind perform significantly (p<.05) worse in all assessed locomotor and object control skills, whereby running, leaping, kicking and catching are the most affected skills, and corresponding differences are related to most running, leaping, kicking and catching component. Practical implications are provided.

Establishing a conditional signal for assistance in teenagers with blindness

Five teenagers with severe intellectual impairments and no discernible communication skills were enrolled in training to teach a conditional request for assistance using a speech-generating device (SGD). All were either blind or severely visually impaired since birth. All learned to operate an adaptive switch to control sensory outcomes, next showed preferences among sensory outcomes, and then demonstrated the ability to use their switch to signal for assistance with an SGD when the sensory outcome was remotely disabled. During the signaling phase, or subsequent attempts to generalize its use outside the laboratory, three participants began vocalizing. Most notably, they began imitation of the word "song" or the word "help" emitted by the SGD. The potential role of cause-and-effect training with adaptive switches is discussed.

Determinants of inclusive education of 8-12 year-old children with cerebral palsy in 9 European regions

The principle of inclusive education has been increasingly recognised over recent decades and most countries officially support schooling of children with disabilities in mainstream settings. The SPARCLE study offers the opportunity to report on the schooling practices for children with cerebral palsy according to the nature and severity of their impairments and the schooling policy in European regions. The aim of this paper is to describe the type of schooling of children with cerebral palsy in various European regions after controlling for relevant individual factors. Children aged 8-12 years with cerebral palsy from 9 European regions and their families were interviewed. Our findings support the hypothesis that between-region variations in the type of schooling are still significant after adjustment for individual factors; and that motor function and intellectual ability have different effects on inclusion in mainstream school, depending on the region.

Two women with multiple disabilities communicate with distant partners via a special text messaging system

This study extended the research on a special text messaging system, which allows persons with multiple disabilities to (a) write and send messages to distant partners and (b) have messages from those partners read out to them. The study involved two women with multiple disabilities (including blindness or minimal residual vision). The system comprised a net-book computer, a mobile communication modem, and an input microswitch, and relied on special keyboards (not used before) to allow the women to write their messages. One of the keyboards included (a) two rows of 10 and 11 keys, respectively, reporting the 21 basic letters of the Italian alphabet arranged in alphabetical order and marked with Braille labels and (b) a space bar and an enlarged back/erase key. The other keyboard had Braille cues on the initial, central, and final keys of the letter rows. Moreover, most function keys were covered (cut out from the usable space). Both women learned to use the messaging system with the special keyboards successfully (i.e., to write their messages, to send them out, and to listen to incoming messages). These findings are analyzed in relation to preliminary data with the system and the need to adapt the writing technology to the participants' characteristics.

Prosthetic eye rehabilitation and management of completely blind patients

Facial prostheses aim to restore the appearance, contours, and esthetics of the face while consequently enhancing patients' self-esteem and reintegration into social life. Restoring unilateral missing ocular and orbital tissues is a challenging task that requires great skill from the clinician (anaplastologist) to accurately mimic the opposing natural tissues. Bilateral defects present additional technical and clinical challenges for clinicians and patients alike. This article presents two cases involving restoration of the ocular and orbital components of bilaterally blind patients. The first case comprised the construction of indwelling scleral eye shells for both eyes, while the second comprised left orbital (implant-retained) and right indwelling eye shell prostheses. Custom-made bilaterally indwelling eyes are more esthetically pleasing than stock options and show better fit and comfort following conventional impression techniques. Clinical challenges include impression taking, prosthesis fabrication, identification of the correct orientation into the socket, communication with the patient, and satisfaction of patient expectations. Since both patients were blind, their families played a vital role in describing their prostheses and thus in improving the patients' self-esteem and satisfaction with treatment.

Future trends in global blindness

The objective of this review is to discuss the available data on the prevalence and causes of global blindness, and some of the associated trends and limitations seen. A literature search was conducted using the terms "global AND blindness" and "global AND vision AND impairment", resulting in seven appropriate articles for this review. Since 1990 the estimate of global prevalence of blindness has gradually decreased when considering the best corrected visual acuity definition: 0.71% in 1990, 0.59% in 2002, and 0.55% in 2010, corresponding to a 0.73% reduction per year over the 2002-2010 period. Significant limitations were found in the comparability between the global estimates in prevalence or causes of blindness or visual impairment. These limitations arise from various factors such as uncertainties about the true cause of the impairment, the use of different definitions and methods, and the absence of data from a number of geographical areas, leading to various extrapolation methods, which in turn seriously limit comparability. Seminal to this discussion on limitations in the comparability of studies and data, is that blindness has historically been defined using best corrected visual acuity.

Braille use among Norwegian children from 1967 to 2007: trends in the underlying causes

PURPOSE

The aim of the study was to estimate the occurrence, diagnoses and time trends among Norwegian children that have received education in braille from 1967 to 2007.

METHODS

We used a retrospective population-based study design. The health care system is free for all inhabitants in Norway. We included all children that had received braille education the last four decades. From each student's record, we abstracted year born, country of birth, gender, year diagnosed, diagnosis, classification of visual impairment and type of reading media.

RESULTS

We identified 287 children (137 girls and 150 boys) that had received braille education over the last 40 years. Of these, 262 (91.3%) children were born in Norway, 145 (53.7%) were diagnosed within the first year of life and 59 (20.6%) from age of one to five. The most frequent diagnoses were Retinopathy of Prematurity (ROP), Juvenile Ceroid Lipofuscinoses (JNCL), Lebers Congenital Amaurosis (LCA) and Retinitis Pigmentosa (RP). Among the children, 63% (N = 170) used braille only, 9% (N = 25) braille and print, but priority braille, and 27% (N = 73) braille and print, priority print. The number of children with ROP using braille had a peak in 1977, then the number declined. The number diagnosed with LCA increased from 1987 to 1992. The number of braille users among children diagnosed with JNCL tended to increase substantially after 1992.

CONCLUSION

Braille education seemed to be dependent of trends in diagnoses as well as trends in recommendations from professional educators.

[Research on and design of visual prosthesis based on visual information processing]

Induced by a variety of retinopathy, visual loss has become the most serious form of disability, which influences the quality of human life. With the rapid development and crossing among the information science, microelectronics, material science and biomedical disciplines, the visual prosthesis makes reparation possible for the visual blindness caused by retinitis pigmentosa, age-related macular degeneration, and other eye, retina, optic nerve and visual cortex lesions. With technology innovation, the prosthesis design, manufacturing and surgical technique are no longer the biggest obstacles to the future development of the visual prosthesis, but how to construct effective transmission of information between the brain and the prosthesis. However, due to the complex structure of the human visual system, the visual prosthesis manufacturing and visual information signal mapping are facing some difficulties. Thus, we can only study the representation strategy of image information and micro-electrode array stimulation basing on limited pixels of simulated prosthesis visual information. By studying the visual information processing of the visual prosthesis, we propose a visual prosthesis design which is based on biological, mechanical, and electronic integration.

Association of vision loss in glaucoma and age-related macular degeneration with IADL disability

PURPOSE

To determine if glaucoma and/or age-related macular degeneration (AMD) are associated with disability in instrumental activities of daily living (IADLs).

METHODS

Glaucoma subjects (n = 84) with bilateral visual field (VF) loss and AMD subjects (n = 47) with bilateral or severe unilateral visual acuity (VA) loss were compared with 60 subjects with normal vision (controls). Subjects completed a standard IADL disability questionnaire, with disability defined as an inability to perform one or more IADLs unassisted.

RESULTS

Disability in one or more IADLs was present in 18.3% of controls as compared with 25.0% of glaucoma subjects (P = 0.34) and 44.7% of AMD subjects (P = 0.003). The specific IADL disabilities occurring more frequently in both AMD and glaucoma subjects were preparing meals, grocery shopping, and out-of-home travelling (P < 0.05 for both). In multivariate logistic regression models run adjusting for age, sex, mental status, comorbidity, and years of education, AMD (odds ratio [OR] = 3.4, P = 0.02) but not glaucoma (OR = 1.4, P = 0.45) was associated with IADL disability. However, among glaucoma and control patients, the odds of IADL disability increased 1.6-fold with every 5 dB of VF loss in the better-seeing eye (P = 0.001). Additionally, severe glaucoma subjects (better-eye MD worse than -13.5 dB) had higher odds of IADL disability (OR = 4.2, P = 0.02). Among AMD and control subjects, every Early Treatment of Diabetic Retinopathy Study line of worse acuity was associated with a greater likelihood of IADL disability (OR = 1.3).

CONCLUSIONS

VA loss in AMD and severe VF loss in glaucoma are associated with self-reported difficulties with IADLs. These limitations become more likely with increasing magnitude of VA or VF loss.

Causes of visual impairment in Thai diabetic patients in the visual rehabilitation clinic

BACKGROUND

Visual disability from diabetic retinopathy is one of many public health problems. Knowing the causes of blindness and low vision in diabetic patients will help in policy planning in order to reduce diabetic complications and prevent blindness.

OBJECTIVE

To study the causes of visual impairment, blindness and related factors in diabetic patients who registered at the visual rehabilitation clinic, Siriraj Hospital, Mahidol University, Bangkok.

MATERIAL AND METHOD

A retrospective study of 133 diabetic patients who registered at the visual rehabilitation clinic between January 2007 and December 2010 was conducted. The patients were divided into 2 groups: a low vision group (VA in the better eye < 6/18-3/60) and a blindness group (VA in the better eye < 3/60--No light perception). The history of diabetic mellitus, associated systemic diseases, laboratory investigations, ocular changes and treatment were recorded. The causes of visual impairment and blindness were collected and analyzed.

RESULTS

Of a total of 133 diabetic patients, 93 cases (69.9%) were in a low vision group and 40 cases (30.1%) were in a blindness group. The causes of visual impairment were proliferative diabetic retinopathy (84.6%), retinal detachment (37.2%), macular edema and scar (25.9%), optic atrophy (143%), neovascular glaucoma (11.7%) and vitreous hemorrhage (4.9%). Tractional retinal detachment (p-value < 0.001) and optic atrophy (p-value = 0.021) were the associated factors causing blindness in visual disability patients with statistical significance. Optic atrophy (38 eyes) occurred post vitrectomy in 19 eyes.

CONCLUSION

Visual disability in diabetic patients is caused by the complications of diabetic retinopathy and its management. The prevention of disease progression, especially macular edema and proliferative diabetic retinopathy, will decrease the rate of visual impairment and blindness.

Retinal implants: emergence of a multidisciplinary field

PURPOSE OF REVIEW

This review summarizes the current status of retinal prostheses, recent accomplishments, and major remaining research, engineering, and rehabilitation challenges.

RECENT FINDINGS

Retinal research, materials and biocompatibility studies, and clinical trials in patients blind from retinitis pigmentosa are representative of an emerging field with considerable promise and sobering challenges. A summary of progress in dozens of laboratories, companies, and clinics around the world is presented through a synopsis of relevant studies, not only to summarize the progress but also to convey the remarkable increase in interest, effort, and outside funding this field has enjoyed.

SUMMARY

At present, clinical applications of retinal implant technology are dominated by one or two groups/companies, but the field is wide open for others to take the lead through novel approaches in technology, tissue interfacing, information transfer paradigms, and rehabilitation. Where the field will go in the next few years is almost anybody's guess, but that it will move forward is a certainty.

Technology-based programs to promote walking fluency or improve foot-ground contact during walking: two case studies of adults with multiple disabilities

These two case studies assessed technology-based programs for promoting walking fluency and improving foot-ground contact during walking with a man and a woman with multiple disabilities, respectively. The man showed breaks during walking and the woman presented with toe walking. The technology used in the studies included a microprocessor with specific software, an MP3 with the recordings of preferred stimulus items, and optic sensors. Both studies were carried out according to an ABAB design. In Study I, the optic sensors were activated when the man crossed small marks distributed along the travel routes. At each sensor's activation, the man received a brief period of preferred stimulation. In Study II, the woman received preferred stimulation when the sensors at the toe and the heel of her shoes were activated in close time proximity. The man walked virtually without breaks and improved his mood (with an increase in indices of happiness) during the intervention phases of the study. The woman largely increased her percentages of steps with adequate foot-ground contact, which reached a mean of about 80 during the second intervention phase. The results were discussed in terms of rehabilitation implications and technology demands.

Development of independent locomotion in children with a severe visual impairment

Locomotion of children and adults with a visual impairment (ages 1-44, n = 28) was compared to that of age-related individuals with normal vision (n = 60). Participants walked barefoot at preferred speed while their gait was recorded by a Vicon(®) system. Walking speed, heading angle, step frequency, stride length, step width, stance phase duration and double support time were determined. Differences between groups, relationships with age and possible interaction effects were investigated. With increasing age overall improvements in gait parameters are observed. Differences between groups were a slower walking speed, a shorter stride length, a prolonged duration of stance and of double support in the individuals with a visual impairment. These may be considered either as adaptations to balance problems or as strategies to allow to foot to probe the ground.

A verbal-instruction system to help persons with multiple disabilities perform complex food- and drink-preparation tasks independently

In a recent single-case study, we showed that a new verbal-instruction system, ensuring the automatic presentation of step instructions, was beneficial for promoting the task performance of a woman with multiple disabilities (including blindness). The present study was aimed at replicating and extending the aforementioned investigation with three adults with multiple disabilities. During Part I of the study, the new instruction system was compared with a system requiring the participants to seek instructions on their own. Two tasks were used, one per system. During Part II of the study, the new system was applied with two additional tasks. The results of Part I showed that (a) the participants had a better performance (i.e., in terms of correct steps or task execution time) on the task carried out with the new system than on the task carried out with the comparison/control system, and (b) the performance of this latter task improved rapidly when the new system was used with it. The results of Part II showed satisfactory performance with each of the two tasks carried out directly with the new system. The implications of these data were discussed.

A technology-aided stimulus choice program for two adults with multiple disabilities: choice responses and mood

This study was aimed at replicating and extending early research on technology-aided stimulus choice with two adults with multiple disabilities. The technology-aided program involved (a) a computer-aided system presenting the participants samples of different environmental stimuli and (b) a microswitch device allowing them to choose among those samples and to access the related stimuli for preset periods of time. The system also allowed the participants opportunities to request the continuation/repetition of any stimulus. The program was successful in promoting the participants' selection of preferred stimuli and their requests for continuation/repetition of those stimuli. Data also showed that the intervention sessions largely improved the participants' mood (i.e., increased their indices of happiness). Theoretical and practical relevance of the findings were discussed.

Two adults with multiple disabilities use a computer-aided telephone system to make phone calls independently

This study extended the assessment of a newly developed computer-aided telephone system with two participants (adults) who presented with blindness or severe visual impairment and motor or motor and intellectual disabilities. For each participant, the study was carried out according to an ABAB design, in which the A represented baseline phases and the B represented intervention phases, during which the special telephone system was available. The system involved among others a net-book computer provided with specific software, a global system for mobile communication modem, and a microswitch. Both participants learned to use the system very rapidly and managed to make phone calls independently to a variety of partners such as family members, friends and staff personnel. The results were discussed in terms of the technology under investigation (its advantages, drawbacks, and need of improvement) and the social-communication impact it can make for persons with multiple disabilities.

Effects of video-feedback interaction training for professional caregivers of children and adults with visual and intellectual disabilities

BACKGROUND

Individuals in group homes may experience poor quality of social interaction with their professional caregivers, limiting their quality of life. The video-based Contact programme may help caregivers to improve their interaction with clients.

METHOD

Seventy-two caregivers of 12 individuals with visual and intellectual disabilities received a training programme and four individual video-feedback sessions. Quality of interaction was independently measured in an AB-design across subjects with two baseline and three intervention observations, using a time sampling coding system for interactive behaviour as well as a rating for affective mutuality.

RESULTS

From baseline to intervention, significant increases were found for the frequency with which caregivers confirmed the signals of clients, for the proportion of initiatives taken by clients that were responded to by the caregivers, and the affective mutuality as a quality of the interaction. No significant increase in client responsiveness was observed. Caregivers evaluated the intervention as useful and feasible.

CONCLUSIONS

The start of the Contact programme coincided with improved quality of interaction between professional caregivers and clients with visual and intellectual disabilities in group homes. Further research is necessary regarding the generalisability, long-term effects and effects on quality of life.

Angiographic findings following tack fixation of a wireless epiretinal retina implant device in blind RP patients

BACKGROUND

The fixation of polyimide stimulator foils as the basic substrate of epiretinal prostheses by using retinal tacks may cause retinal or choroidal alterations such as retinal proliferations or choroidal neovascularizations. During the prospective trial for the semichronical testing of a wireless intraocular retinal implant (EPIRET3) we investigated alterations in angiographic findings during implantation and after explantation of the device, to detect potential vascular pathologies at the fixation site or elsewhere.

METHODS

As the final step of the implantation surgery in six blind patients, the stimulator was placed on the retinal surface using retinal tacks. For the detection of possible morphological or vascular alterations committed by the implant fluorescein angiography (FA) was performed 1 day before and 4 weeks after implantation surgery, as well as at the final visit 5 months after explantation.

RESULTS

Following implantation surgery funduscopy and FA did not reveal any evidence of either vascular pathologies or choroidal neovascularisations (CNV), in addition, no cystoid macular edema (CME) occurred after 4 weeks. At the 6-month follow-up visit, we found a mild epiretinal gliosis formation in four patients. In one patient a retinal break occurred during explantation, requiring a temporary silicone-oil endotamponade. At the final visit, we observed a focal proliferative vitreoretinopathy (PVR) reaction without activity, while there was no evidence for a CNV formation in that area.

CONCLUSIONS

The FA findings confirm our previous results on the safety of the EPIRET3 system, which was tolerated in all patients but revealed a certain risk profile in regard to the stimulator fixation. While there was no evidence for newly occurred CME or CNV during the follow-up visits, nevertheless gliosis or even PVR reaction at the tack's fixation site suggests the need to develop alternative fixation procedures of epiretinal stimulators.