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Kartha A, Sadeghi R, Bradley C, Livingston B, Tran C, Gee W, Dagnelie G. Measuring visually guided motor performance in ultra low vision using virtual reality. Front Neurosci 2023; 17:1251935. [PMID: 38178831 PMCID: PMC10765526 DOI: 10.3389/fnins.2023.1251935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/29/2023] [Indexed: 01/06/2024] Open
Abstract
Introduction Ultra low vision (ULV) refers to profound visual impairment where an individual cannot read even the top line of letters on an ETDRS chart from a distance of 0.5 m. There are limited tools available to assess visual ability in ULV. The aim of this study was to develop and calibrate a new performance test, Wilmer VRH, to assess hand-eye coordination in individuals with ULV. Methods A set of 55 activities was developed for presentation in a virtual reality (VR) headset. Activities were grouped into 2-step and 5-step items. Participants performed a range of tasks involving reaching and grasping, stacking, sorting, pointing, throwing, and cutting. Data were collected from 20 healthy volunteers under normal vision (NV) and simulated ULV (sULV) conditions, and from 33 participants with ULV. Data were analyzed using the method of successive dichotomizations (MSD), a polytomous Rasch model, to estimate item (difficulty) and person (ability) measures. MSD was applied separately to 2-step and 5-step performance data, then merged to a single equal interval scale. Results The mean ± SD of completion rates were 98.6 ± 1.8%, 78.2 ± 12.5% and 61.1 ± 34.2% for NV, sULV and ULV, respectively. Item measures ranged from -1.09 to 5.7 logits and - 4.3 to 4.08 logits and person measures ranged from -0.03 to 4.2 logits and -3.5 to 5.2 logits in sULV and ULV groups, respectively. Ninety percent of item infits were within the desired range of [0.5,1.5], and 97% of person infits were within that range. Together with item and person reliabilities of 0.94 and 0.91 respectively, this demonstrates unidimensionality of Wilmer VRH. A Person Item map showed that the items were well-targeted to the sample of individuals with ULV in the study. Discussion We present the development of a calibrated set of activities in VR that can be used to assess hand-eye coordination in individuals with ULV. This helps bridge a gap in the field by providing a validated outcome measure that can be used in vision restoration trials that recruit people with ULV, and to assess rehabilitation outcomes in people with ULV.
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Affiliation(s)
- Arathy Kartha
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, United States
| | - Roksana Sadeghi
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, United States
| | - Chris Bradley
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Brittnee Livingston
- Central Association for the Blind and Visually Impaired, Utica, NY, United States
| | - Chau Tran
- BMORE VIRTUAL LLC, Baltimore, MD, United States
| | - Will Gee
- BMORE VIRTUAL LLC, Baltimore, MD, United States
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD, United States
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Chew LA, Iannaccone A. Gene-agnostic approaches to treating inherited retinal degenerations. Front Cell Dev Biol 2023; 11:1177838. [PMID: 37123404 PMCID: PMC10133473 DOI: 10.3389/fcell.2023.1177838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/31/2023] [Indexed: 05/02/2023] Open
Abstract
Most patients with inherited retinal degenerations (IRDs) have been waiting for treatments that are "just around the corner" for decades, with only a handful of seminal breakthroughs happening in recent years. Highlighting the difficulties in the quest for curative therapeutics, Luxturna required 16 years of development before finally obtaining United States Food and Drug Administration (FDA) approval and its international equivalents. IRDs are both genetically and phenotypically heterogeneous. While this diversity offers many opportunities for gene-by-gene precision medicine-based approaches, it also poses a significant challenge. For this reason, alternative (or parallel) strategies to identify more comprehensive, across-the-board therapeutics for the genetically and phenotypically diverse IRD patient population are very appealing. Even when gene-specific approaches may be available and become approved for use, many patients may have reached a disease stage whereby these approaches may no longer be viable. Thus, alternate visual preservation or restoration therapeutic approaches are needed at these stages. In this review, we underscore several gene-agnostic approaches that are being developed as therapeutics for IRDs. From retinal supplementation to stem cell transplantation, optogenetic therapy and retinal prosthetics, these strategies would bypass at least in part the need for treating every individual gene or mutation or provide an invaluable complement to them. By considering the diverse patient population and treatment strategies suited for different stages and patterns of retinal degeneration, gene agnostic approaches are very well poised to impact favorably outcomes and prognosis for IRD patients.
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Affiliation(s)
- Lindsey A. Chew
- Duke Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC, United States
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, United States
| | - Alessandro Iannaccone
- Duke Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC, United States
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Pamir Z, Jung JH, Peli E. Preparing participants for the use of the tongue visual sensory substitution device. Disabil Rehabil Assist Technol 2022; 17:888-896. [PMID: 32997554 PMCID: PMC8007668 DOI: 10.1080/17483107.2020.1821102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/04/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Visual sensory substitution devices (SSDs) convey visual information to a blind person through another sensory modality. Using a visual SSD in various daily activities requires training prior to use the device independently. Yet, there is limited literature about procedures and outcomes of the training conducted for preparing users for practical use of SSDs in daily activities. METHODS We trained 29 blind adults (9 with congenital and 20 with acquired blindness) in the use of a commercially available electro-tactile SSD, BrainPort. We describe a structured training protocol adapted from the previous studies, responses of participants, and we present retrospective qualitative data on the progress of participants during the training. RESULTS The length of the training was not a critical factor in reaching an advanced stage. Though performance in the first two sessions seems to be a good indicator of participants' ability to progress in the training protocol, there are large individual differences in how far and how fast each participant can progress in the training protocol. There are differences between congenital blind users and those blinded later in life. CONCLUSIONS The information on the training progression would be of interest to researchers preparing studies, and to eye care professionals, who may advise patients to use SSDs.IMPLICATIONS FOR REHABILITATIONThere are large individual differences in how far and how fast each participant can learn to use a visual-to-tactile sensory substitution device for a variety of tasks.Recognition is mainly achieved through top-down processing with prior knowledge about the possible responses. Therefore, the generalizability is still questionable.Users develop different strategies in order to succeed in training tasks.
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Affiliation(s)
- Zahide Pamir
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA
| | - Jae-Hyun Jung
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA
| | - Eli Peli
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA
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Hamilton-Fletcher G, Chan KC. Auditory Scene Analysis Principles Improve Image Reconstruction Abilities of Novice Vision-to-Audio Sensory Substitution Users. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:5868-5871. [PMID: 34892454 PMCID: PMC9352562 DOI: 10.1109/embc46164.2021.9630296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sensory substitution devices (SSDs) such as the 'vOICe' preserve visual information in sound by turning visual height, brightness, and laterality into auditory pitch, volume, and panning/time respectively. However, users have difficulty identifying or tracking multiple simultaneously presented tones - a skill necessary to discriminate the upper and lower edges of object shapes. We explore how these deficits can be addressed by using image-sonifications inspired by auditory scene analysis (ASA). Here, sighted subjects (N=25) of varying musical experience listened to, and then reconstructed, complex shapes consisting of simultaneously presented upper and lower lines. Complex shapes were sonified using the vOICe, with either the upper and lower lines varying only in pitch (i.e. the vOICe's 'unaltered' default settings), or with one line degraded to alter its auditory timbre or volume. Results found that overall performance increased with subjects' years of prior musical experience. ANOVAs revealed that both sonification style and musical experience significantly affected performance, but with no interaction effect between them. Compared to the vOICe's 'unaltered' pitch-height mapping, subjects had significantly better image-reconstruction abilities when the lower line was altered via timbre or volume-modulation. By contrast, altering the upper line only helped users identify the unaltered lower line. In conclusion, adding ASA principles to vision-to-audio SSDs boosts subjects' image-reconstruction abilities, even if this also reduces total task-relevant information. Future SSDs should seek to exploit these findings to enhance both novice user abilities and the use of SSDs as visual rehabilitation tools.
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Ptito M, Bleau M, Djerourou I, Paré S, Schneider FC, Chebat DR. Brain-Machine Interfaces to Assist the Blind. Front Hum Neurosci 2021; 15:638887. [PMID: 33633557 PMCID: PMC7901898 DOI: 10.3389/fnhum.2021.638887] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/19/2021] [Indexed: 12/31/2022] Open
Abstract
The loss or absence of vision is probably one of the most incapacitating events that can befall a human being. The importance of vision for humans is also reflected in brain anatomy as approximately one third of the human brain is devoted to vision. It is therefore unsurprising that throughout history many attempts have been undertaken to develop devices aiming at substituting for a missing visual capacity. In this review, we present two concepts that have been prevalent over the last two decades. The first concept is sensory substitution, which refers to the use of another sensory modality to perform a task that is normally primarily sub-served by the lost sense. The second concept is cross-modal plasticity, which occurs when loss of input in one sensory modality leads to reorganization in brain representation of other sensory modalities. Both phenomena are training-dependent. We also briefly describe the history of blindness from ancient times to modernity, and then proceed to address the means that have been used to help blind individuals, with an emphasis on modern technologies, invasive (various type of surgical implants) and non-invasive devices. With the advent of brain imaging, it has become possible to peer into the neural substrates of sensory substitution and highlight the magnitude of the plastic processes that lead to a rewired brain. Finally, we will address the important question of the value and practicality of the available technologies and future directions.
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Affiliation(s)
- Maurice Ptito
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
- Department of Nuclear Medicine, University of Southern Denmark, Odense, Denmark
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Maxime Bleau
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Ismaël Djerourou
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Samuel Paré
- École d’Optométrie, Université de Montréal, Montréal, QC, Canada
| | - Fabien C. Schneider
- TAPE EA7423 University of Lyon-Saint Etienne, Saint Etienne, France
- Neuroradiology Unit, University Hospital of Saint-Etienne, Saint-Etienne, France
| | - Daniel-Robert Chebat
- Visual and Cognitive Neuroscience Laboratory (VCN Lab), Department of Psychology, Faculty of Social Sciences and Humanities, Ariel University, Ariel, Israël
- Navigation and Accessibility Research Center of Ariel University (NARCA), Ariel, Israël
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Lloyd-Esenkaya T, Lloyd-Esenkaya V, O'Neill E, Proulx MJ. Multisensory inclusive design with sensory substitution. COGNITIVE RESEARCH-PRINCIPLES AND IMPLICATIONS 2020; 5:37. [PMID: 32770416 PMCID: PMC7415050 DOI: 10.1186/s41235-020-00240-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 07/13/2020] [Indexed: 11/10/2022]
Abstract
Sensory substitution techniques are perceptual and cognitive phenomena used to represent one sensory form with an alternative. Current applications of sensory substitution techniques are typically focused on the development of assistive technologies whereby visually impaired users can acquire visual information via auditory and tactile cross-modal feedback. But despite their evident success in scientific research and furthering theory development in cognition, sensory substitution techniques have not yet gained widespread adoption within sensory-impaired populations. Here we argue that shifting the focus from assistive to mainstream applications may resolve some of the current issues regarding the use of sensory substitution devices to improve outcomes for those with disabilities. This article provides a tutorial guide on how to use research into multisensory processing and sensory substitution techniques from the cognitive sciences to design new inclusive cross-modal displays. A greater focus on developing inclusive mainstream applications could lead to innovative technologies that could be enjoyed by every person.
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Affiliation(s)
- Tayfun Lloyd-Esenkaya
- Crossmodal Cognition Lab, University of Bath, Bath, BA2 7AY, UK.,Department of Computer Science, University of Bath, Bath, UK
| | | | - Eamonn O'Neill
- Department of Computer Science, University of Bath, Bath, UK
| | - Michael J Proulx
- Crossmodal Cognition Lab, University of Bath, Bath, BA2 7AY, UK. .,Department of Psychology, University of Bath, Bath, UK.
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Rachitskaya A, Yuan A, Davidson S, Streicher M, DeBenedictis M, Rosenfeldt AB, Alberts J. Computer-Assisted Immersive Visual Rehabilitation in Argus II Retinal Prosthesis Recipients. Ophthalmol Retina 2020; 4:613-619. [PMID: 31937474 DOI: 10.1016/j.oret.2019.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE The field of retinal prostheses is expanding. However, the best approach to training and assessing the functional benefit of postoperative vision has not been established. The purpose of this single-center prospective interventional case series was to evaluate the feasibility and effectiveness of using the Computer Assisted Rehabilitation Environment (CAREN) system as a visual rehabilitation tool in Argus II patients. DESIGN Single-center prospective interventional case series (clinicaltrials.gov identifier, NCT03444961). PARTICIPANTS Four Argus II recipients (3 men and 1 woman). METHODS Eight visual rehabilitation sessions using the CAREN system (twice weekly for 4 weeks). MAIN OUTCOME MEASURES Baseline and postintervention assessments consisted of visual function, mobility, and balance tests. RESULTS All patients successfully completed training on the CAREN system. While the Argus II device was active, walking speed increased from baseline to immediately after the intervention on flat and undulating surfaces and while localizing objects by 20%, 10%, and 18%, respectively. An improved ability to complete the timed up and go test successfully was observed. CONCLUSIONS Novel methods of visual rehabilitation for retinal prostheses recipients, such the CAREN system, are feasible and may result in improved ability to use the Argus II while performing functional tasks. Immersive technology may provide a solution for the standardization of effective rehabilitation approaches to augment retinal prosthesis performance. Heterogeneity of results indicates that a larger sample size would be beneficial.
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Affiliation(s)
- Aleksandra Rachitskaya
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio.
| | - Alex Yuan
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Sara Davidson
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Matthew Streicher
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Meghan DeBenedictis
- Cole Eye Institute, Department of Ophthalmology, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Anson B Rosenfeldt
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Jay Alberts
- Neurological Institute, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, Ohio; Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, Ohio; Office of Clinical Transformation, Cleveland Clinic Foundation, Cleveland, Ohio
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Richardson M, Thar J, Alvarez J, Borchers J, Ward J, Hamilton-Fletcher G. How Much Spatial Information Is Lost in the Sensory Substitution Process? Comparing Visual, Tactile, and Auditory Approaches. Perception 2019; 48:1079-1103. [PMID: 31547778 DOI: 10.1177/0301006619873194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sensory substitution devices (SSDs) can convey visuospatial information through spatialised auditory or tactile stimulation using wearable technology. However, the level of information loss associated with this transformation is unknown. In this study, novice users discriminated the location of two objects at 1.2 m using devices that transformed a 16 × 8-depth map into spatially distributed patterns of light, sound, or touch on the abdomen. Results showed that through active sensing, participants could discriminate the vertical position of objects to a visual angle of 1°, 14°, and 21°, and their distance to 2 cm, 8 cm, and 29 cm using these visual, auditory, and haptic SSDs, respectively. Visual SSDs significantly outperformed auditory and tactile SSDs on vertical localisation, whereas for depth perception, all devices significantly differed from one another (visual > auditory > haptic). Our findings highlight the high level of acuity possible for SSDs even with low spatial resolutions (e.g., 16 × 8) and quantify the level of information loss attributable to this transformation for the SSD user. Finally, we discuss ways of closing this “modality gap” found in SSDs and conclude that this process is best benchmarked against performance with SSDs that return to their primary modality (e.g., visuospatial into visual).
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Affiliation(s)
| | - Jan Thar
- Media Computing Group, RWTH Aachen University, Germany
| | - James Alvarez
- Department of Psychology, University of Sussex, Brighton, UK
| | - Jan Borchers
- Media Computing Group, RWTH Aachen University, Germany
| | - Jamie Ward
- Department of Psychology, University of Sussex, Brighton, UK; Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Giles Hamilton-Fletcher
- Department of Psychology, University of Sussex, Brighton, UK; Neuroimaging and Visual Science Laboratory, New York University Langone Health, NY, USA
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Stronks HC. MacPherson, F. (Ed.). Sensory Substitution and Augmentation. Perception 2019. [DOI: 10.1177/0301006619865349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Exploring User Perception Challenges in Vibrotactile Haptic Display Using Resonant Microbeams under Contact with Skin. MULTIMODAL TECHNOLOGIES AND INTERACTION 2019. [DOI: 10.3390/mti3020038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Resonant vibrotactile microbeams use the concept of resonance to excite the vibration of cantilever beams, which correspond to pixels of an image. The primary benefit of this type of tactile display is its potential for high resolution. This paper presents the concept of the proposed system and human skin contact experiments to explore user perception challenges related to beam vibration during skin contact. The human skin contact experiments can be described in five phases: dried skin contact to metal beam tips, wet and soaped skin contact to metal beam tips, skin contact with a constraint, normal force measurement, and skin contact to the tips of silicone rubber beams attached to metal beam tips. Experimental results are analyzed to determine in what cases of skin contact the beams stop vibrating. It is found that the addition of silicone rubber beams allows the primary metal beams to continue vibrating while in contact with skin. Thus, the vibration response of a metal beam with silicone rubber beams is investigated for the better understanding of the effect of silicone rubber beams on the metal beam vibration.
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Qiu C, Lee KR, Jung JH, Goldstein R, Peli E. Motion Parallax Improves Object Recognition in the Presence of Clutter in Simulated Prosthetic Vision. Transl Vis Sci Technol 2018; 7:29. [PMID: 30386681 PMCID: PMC6205682 DOI: 10.1167/tvst.7.5.29] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/31/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose Efficacy of current visual prostheses in object recognition is limited. Among various limitations to be addressed, such as low resolution and low dynamic range, here we focus on reducing the impact of background clutter on object recognition. We have proposed the use of motion parallax via head-mounted camera lateral scanning and computationally stabilizing the object of interest (OI) to support neural background decluttering. Simulations in head-mounted displays (HMD), mimicking the proposed effect, were used to test object recognition in normally sighted subjects. Methods Images (24° field of view) were captured from multiple viewpoints and presented at a low resolution (20 × 20). All viewpoints were centered on the OI. Experimental conditions (2 × 3) included clutter (with or without) × head scanning (single viewpoint, 9 coherent viewpoints corresponding to subjects' head positions, and 9 randomly associated viewpoints). Subjects used lateral head movements to view OIs in the HMD. Each object was displayed only once for each subject. Results The median recognition rate without clutter was 40% for all head scanning conditions. Performance with synthetic background clutter dropped to 10% in the static condition, but it was improved to 20% with the coherent and random head scanning (corrected P = 0.005 and P = 0.049, respectively). Conclusions Background decluttering using motion parallax cues but not the coherent multiple views of the OI improved object recognition in low-resolution images. The improvement did not fully eliminate the impact of background. Translational Relevance Motion parallax is an effective but incomplete decluttering solution for object recognition with visual prostheses.
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Affiliation(s)
- Cheng Qiu
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Department of Psychology, University of Pennsylvania Philadelphia, PA, USA
| | - Kassandra R Lee
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Jae-Hyun Jung
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Robert Goldstein
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Eli Peli
- The Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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Han S, Qiu C, Lee KR, Jung JH, Peli E. Word recognition: re-thinking prosthetic vision evaluation. J Neural Eng 2018; 15:055003. [PMID: 29781807 DOI: 10.1088/1741-2552/aac663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Evaluations of vision prostheses and sensory substitution devices have frequently relied on repeated training and then testing with the same small set of items. These multiple forced-choice tasks produced above chance performance in blind users, but it is unclear if the observed performance represents restoration of vision that transfers to novel, untrained items. APPROACH Here, we tested the generalizability of the forced-choice paradigm on discrimination of low-resolution word images. Extensive visual training was conducted with the same 10 words used in previous BrainPort tongue stimulation studies. The performance on these 10 words and an additional 50 words was measured before and after the training sessions. MAIN RESULTS The results revealed minimal performance improvement with the untrained words, demonstrating instead pattern discrimination limited mostly to the trained words. SIGNIFICANCE These findings highlight the need to reconsider current evaluation practices, in particular, the use of forced-choice paradigms with a few highly trained items. While appropriate for measuring the performance thresholds in acuity or contrast sensitivity of a functioning visual system, performance on such tasks cannot be taken to indicate restored spatial pattern vision.
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Affiliation(s)
- Shui'Er Han
- Department of Ophthalmology, The Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114-2500, United States of America. School of Psychology, University of Sydney, Sydney, Australia
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13
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Buchs G, Simon N, Maidenbaum S, Amedi A. Waist-up protection for blind individuals using the EyeCane as a primary and secondary mobility aid. Restor Neurol Neurosci 2018; 35:225-235. [PMID: 28157111 PMCID: PMC5366249 DOI: 10.3233/rnn-160686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background: One of the most stirring statistics in relation to the mobility of blind individuals is the high rate of upper body injuries, even when using the white-cane. Objective: We here addressed a rehabilitation- oriented challenge of providing a reliable tool for blind people to avoid waist-up obstacles, namely one of the impediments to their successful mobility using currently available methods (e.g., white-cane). Methods: We used the EyeCane, a device we developed which translates distances from several angles to haptic and auditory cues in an intuitive and unobtrusive manner, serving both as a primary and secondary mobility aid. We investigated the rehabilitation potential of such a device in facilitating visionless waist-up body protection. Results: After ∼5 minutes of training with the EyeCane blind participants were able to successfully detect and avoid obstacles waist-high and up. This was significantly higher than their success when using the white-cane alone. As avoidance of obstacles required participants to perform an additional cognitive process after their detection, the avoidance rate was significantly lower than the detection rate. Conclusion: Our work has demonstrated that the EyeCane has the potential to extend the sensory world of blind individuals by expanding their currently accessible inputs, and has offered them a new practical rehabilitation tool.
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Affiliation(s)
- Galit Buchs
- Department of Cognitive Science, Faculty of Humanities, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
| | - Noa Simon
- The Edmond and Lily Safra Center for Brain Research, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
| | - Shachar Maidenbaum
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
| | - Amir Amedi
- Department of Cognitive Science, Faculty of Humanities, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel.,The Edmond and Lily Safra Center for Brain Research, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel.,Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel.,Sorbonne Universités UPMC Univ Paris 06, Institut de la Vision, Paris, France
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Deverell L, Meyer D, Lau BT, Al Mahmud A, Sukunesan S, Bhowmik J, Chai A, McCarthy C, Zheng P, Pipingas A, Islam FMA. Optimising technology to measure functional vision, mobility and service outcomes for people with low vision or blindness: protocol for a prospective cohort study in Australia and Malaysia. BMJ Open 2017; 7:e018140. [PMID: 29273657 PMCID: PMC5770903 DOI: 10.1136/bmjopen-2017-018140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION Orientation and mobility (O&M) specialists assess the functional vision and O&M skills of people with mobility problems, usually relating to low vision or blindness. There are numerous O&M assessment checklists but no measures that reduce qualitative assessment data to a single comparable score suitable for assessing any O&M client, of any age or ability, in any location. Functional measures are needed internationally to align O&M assessment practices, guide referrals, profile O&M clients, plan appropriate services and evaluate outcomes from O&M programmes (eg, long cane training), assistive technology (eg, hazard sensors) and medical interventions (eg, retinal implants). This study aims to validate two new measures of functional performance vision-related outcomes in orientation and mobility (VROOM) and orientation and mobility outcomes (OMO) in the context of ordinary O&M assessments in Australia, with cultural comparisons in Malaysia, also developing phone apps and online training to streamline professional assessment practices. METHODS AND ANALYSIS This multiphase observational study will employ embedded mixed methods with a qualitative/quantitative priority: corating functional vision and O&M during social inquiry. Australian O&M agencies (n=15) provide the sampling frame. O&M specialists will use quota sampling to generate cross-sectional assessment data (n=400) before investigating selected cohorts in outcome studies. Cultural relevance of the VROOM and OMO tools will be investigated in Malaysia, where the tools will inform the design of assistive devices and evaluate prototypes. Exploratory and confirmatory factor analysis, Rasch modelling, cluster analysis and analysis of variance will be undertaken along with descriptive analysis of measurement data. Qualitative findings will be used to interpret VROOM and OMO scores, filter statistically significant results, warrant their generalisability and identify additional relevant constructs that could also be measured. ETHICS AND DISSEMINATION Ethical approval has been granted by the Human Research Ethics Committee at Swinburne University (SHR Project 2016/316). Dissemination of results will be via agency reports, journal articles and conference presentations.
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Affiliation(s)
- Lil Deverell
- Department of Statistics, Data Science and Epidemiology, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
- Client Services, Guide Dogs Victoria, Kew, Australia
| | - Denny Meyer
- Department of Statistics, Data Science and Epidemiology, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
| | - Bee Theng Lau
- Department of Computing, Faculty of Engineering, Computing and Science, Swinburne University of Technology, Kuching, Malaysia
| | - Abdullah Al Mahmud
- Centre for Design Innovation, School of Design, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
| | - Suku Sukunesan
- Faculty of Business and Law, Swinburne Business School, Swinburne University of Technology, Hawthorn, Australia
| | - Jahar Bhowmik
- Department of Statistics, Data Science and Epidemiology, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
| | - Almon Chai
- Robotics and Mechatronics Engineering, Faculty of Engineering, Computing and Science, Swinburne University of Technology, Kuching, Malaysia
| | - Chris McCarthy
- School of Software and Electrical Engineering, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Australia
| | - Pan Zheng
- Department of Computing, Faculty of Engineering, Computing and Science, Swinburne University of Technology, Kuching, Malaysia
| | - Andrew Pipingas
- Department of Psychological Sciences, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
| | - Fakir M Amirul Islam
- Department of Statistics, Data Science and Epidemiology, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Australia
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Stronks HC, Walker J, Parker DJ, Barnes N. Training Improves Vibrotactile Spatial Acuity and Intensity Discrimination on the Lower Back Using Coin Motors. Artif Organs 2017; 41:1059-1070. [DOI: 10.1111/aor.12882] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 08/10/2016] [Accepted: 09/21/2016] [Indexed: 11/27/2022]
Affiliation(s)
- H. Christiaan Stronks
- NICTAComputer Vision Research GroupCanberra Australia
- Department of Neuroscience, The John Curtin School of Medical ResearchAustralian National UniversityCanberra Australia
| | - Janine Walker
- NICTAComputer Vision Research GroupCanberra Australia
- Centre for Mental Health ResearchAustralian National UniversityCanberra Australia
| | | | - Nick Barnes
- NICTAComputer Vision Research GroupCanberra Australia
- College of Engineering and Computer ScienceAustralian National UniversityCanberra Australia
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Adeyemo O, Jeter PE, Rozanski C, Arnold E, Dalvin LA, Swenor B, Dagnelie G. Living with Ultra-Low Vision: An Inventory of Self-Reported Visually Guided Activities by Individuals with Profound Visual Impairment. Transl Vis Sci Technol 2017; 6:10. [PMID: 28573074 PMCID: PMC5450922 DOI: 10.1167/tvst.6.3.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/12/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose To understand how individuals with profound visual impairment (ultra-low vision, ULV) use their remaining vision. Methods Forty-six participants with ULV (visual acuity ≤ 200/500 in the better seeing eye) were divided into nine focus groups (4–6 individuals per group) and met either in person (n = 2) or over the phone (n = 7). Discussions were guided by the Massof Activity Inventory. Audio recordings were transcribed and analyzed for visual activities that were then classified along two visual categorizations – functional domains and visual aspects. The latter was based on a Grounded Theory classification of participants' descriptions. Results Seven hundred sixty activities were reported. By functional domain they were classified as reading/shape recognition (10%), mobility (17%), visual motor (24%), and visual information gathering (49%). By visual aspects, they were classified as contrast (43%), luminance (17%), environmental lighting (9%), familiarity (3%), motion perception (5%), distance (7%), size (9%), eccentricity (5%), depth perception (1%), and other/miscellaneous (1%). More than one visual aspect may be critical for an activity: participants reported that contrast plays a role in 68% of visual activities, followed by luminance (27%), environmental lighting (14%), and size (14%). Conclusions Visual aspects, primarily contrast, were found to be critical factors enabling ULV individuals to perform visual activities. Translational Relevance This inventory, part of the Prosthetic Low Vision Rehabilitation (PLoVR) curriculum development study, provides a unique perspective into the visual world of the nearly blind, and can be used in the development of a Visual Functioning Questionnaire (VFQ) and visual performance measures suited for ULV populations.
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Affiliation(s)
- Olukemi Adeyemo
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pamela E Jeter
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Collin Rozanski
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Lauren A Dalvin
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
| | - Bonnielin Swenor
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gislin Dagnelie
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Jeter PE, Rozanski C, Massof R, Adeyemo O, Dagnelie G. Development of the Ultra-Low Vision Visual Functioning Questionnaire (ULV-VFQ). Transl Vis Sci Technol 2017; 6:11. [PMID: 28573075 PMCID: PMC5450923 DOI: 10.1167/tvst.6.3.11] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 01/27/2017] [Indexed: 11/30/2022] Open
Abstract
Purpose To develop and psychometrically evaluate a visual functioning questionnaire (VFQ) in an ultra-low vision (ULV) population. Methods Questionnaire items, based on visual activities self-reported by a ULV population, were categorized by functional visual domain (e.g., mobility) and visual aspect (e.g., contrast) to ensure a representative distribution. In Round 1, an initial set of 149 items was generated and administered to 90 participants with ULV (visual acuity [VA] ≤ 20/500; mean [SD] age 61 [15] years), including six patients with a retinal implant. Psychometric properties were evaluated through Rasch analysis and a revised set (150 items) was administered to 80 participants in Round 2. Results In Round 1, the person measure distribution (range, 8.6 logits) was centered at −1.50 logits relative to the item measures. In Round 2, the person measure distribution (range, 9.5 logits) was centered at −0.86 relative to the item mean. The reliability index in both rounds was 0.97 for Items and 0.99 for Persons. Infit analysis showed four underfit items in Round 1, five underfit items in Round 2 with a z-score greater than 4 cutoff. Principal component analysis on the residuals found 69.9% explained variance; the largest component in the unexplained variance was less than 3%. Conclusions The ULV-VFQ, developed with content generated from a ULV population, showed excellent psychometric properties as well as superior measurement validity in a ULV population. Translational Relevance The ULV-VFQ, part of the Prosthetic Low Vision Rehabilitation (PLoVR) development program, is a new VFQ developed for assessment of functional vision in ULV populations.
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Affiliation(s)
- Pamela E Jeter
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Collin Rozanski
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert Massof
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Olukemi Adeyemo
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gislin Dagnelie
- Lions Vision Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Jung JH, Pu T, Peli E. Comparing object recognition from binary and bipolar edge images for visual prostheses. JOURNAL OF ELECTRONIC IMAGING 2016; 25:061619. [PMID: 28458481 PMCID: PMC5407304 DOI: 10.1117/1.jei.25.6.061619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Visual prostheses require an effective representation method due to the limited display condition which has only 2 or 3 levels of grayscale in low resolution. Edges derived from abrupt luminance changes in images carry essential information for object recognition. Typical binary (black and white) edge images have been used to represent features to convey essential information. However, in scenes with a complex cluttered background, the recognition rate of the binary edge images by human observers is limited and additional information is required. The polarity of edges and cusps (black or white features on a gray background) carries important additional information; the polarity may provide shape from shading information missing in the binary edge image. This depth information may be restored by using bipolar edges. We compared object recognition rates from 16 binary edge images and bipolar edge images by 26 subjects to determine the possible impact of bipolar filtering in visual prostheses with 3 or more levels of grayscale. Recognition rates were higher with bipolar edge images and the improvement was significant in scenes with complex backgrounds. The results also suggest that erroneous shape from shading interpretation of bipolar edges resulting from pigment rather than boundaries of shape may confound the recognition.
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Affiliation(s)
- Jae-Hyun Jung
- Harvard Medical School, Massachusetts Eye and Ear, Department of Ophthalmology, Schepens Eye Research Institute, 20 Staniford Street, Boston, Massachusetts 02114, United States
| | - Tian Pu
- Harvard Medical School, Massachusetts Eye and Ear, Department of Ophthalmology, Schepens Eye Research Institute, 20 Staniford Street, Boston, Massachusetts 02114, United States
- University of Electronic Science and Technology of China, School of Optoelectronic Information, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China
| | - Eli Peli
- Harvard Medical School, Massachusetts Eye and Ear, Department of Ophthalmology, Schepens Eye Research Institute, 20 Staniford Street, Boston, Massachusetts 02114, United States
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Stronks HC, Mitchell EB, Nau AC, Barnes N. Visual task performance in the blind with the BrainPort V100 Vision Aid. Expert Rev Med Devices 2016; 13:919-931. [DOI: 10.1080/17434440.2016.1237287] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- H. Christiaan Stronks
- Department of Otorhinolaryngology, Leiden University Medical Centre, Leiden, The Netherlands
- Smart Vision Systems Research Group, Data61, CSIRO, Canberra, Australia
- Department of Neuroscience, The John Curtin School of Medical Research, Australian National University, Canberra, Australia
| | - Ellen B. Mitchell
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | | | - Nick Barnes
- Smart Vision Systems Research Group, Data61, CSIRO, Canberra, Australia
- Research School of Engineering, College of Engineering and Computer Science, Australian National University, Canberra, Australia
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Abstract
Low vision is any type of visual impairment that affects activities of daily living. In the context of low vision, we define plasticity as changes in brain or perceptual behavior that follow the onset of visual impairment and that are not directly due to the underlying pathology. An important goal of low-vision research is to determine how plasticity affects visual performance of everyday activities. In this review, we consider the levels of the visual system at which plasticity occurs, the impact of age and visual experience on plasticity, and whether plastic changes are spontaneous or require explicit training. We also discuss how plasticity may affect low-vision rehabilitation. Developments in retinal imaging, noninvasive brain imaging, and eye tracking have supplemented traditional clinical and psychophysical methods for assessing how the visual system adapts to visual impairment. Findings from contemporary research are providing tools to guide people with low vision in adopting appropriate rehabilitation strategies.
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Affiliation(s)
- Gordon E Legge
- Department of Psychology, University of Minnesota, Minneapolis, Minnesota 55455;
| | - Susana T L Chung
- School of Optometry, University of California, Berkeley, California 94720;
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Brandli A, Luu CD, Guymer RH, Ayton LN. Progress in the clinical development and utilization of vision prostheses: an update. Eye Brain 2016; 8:15-25. [PMID: 28539798 PMCID: PMC5398739 DOI: 10.2147/eb.s70822] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Vision prostheses, or "bionic eyes", are implantable medical bionic devices with the potential to restore rudimentary sight to people with profound vision loss or blindness. In the past two decades, this field has rapidly progressed, and there are now two commercially available retinal prostheses in the US and Europe, and a number of next-generation devices in development. This review provides an update on the development of these devices and a discussion on the future directions for the field.
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Affiliation(s)
- Alice Brandli
- Centre for Eye Research Australia, Department of Surgery (Ophthalmology), The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Chi D Luu
- Centre for Eye Research Australia, Department of Surgery (Ophthalmology), The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Department of Surgery (Ophthalmology), The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Lauren N Ayton
- Centre for Eye Research Australia, Department of Surgery (Ophthalmology), The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
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Barnes N, Scott AF, Lieby P, Petoe MA, McCarthy C, Stacey A, Ayton LN, Sinclair NC, Shivdasani MN, Lovell NH, McDermott HJ, Walker JG. Vision function testing for a suprachoroidal retinal prosthesis: effects of image filtering. J Neural Eng 2016; 13:036013. [DOI: 10.1088/1741-2560/13/3/036013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Grant P, Spencer L, Arnoldussen A, Hogle R, Nau A, Szlyk J, Nussdorf J, Fletcher DC, Gordon K, Seiple W. The Functional Performance of the BrainPort V100 Device in Persons who Are Profoundly Blind. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2016. [DOI: 10.1177/0145482x1611000202] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Introduction This study was conducted to evaluate the functional performance of the BrainPort V100 device, an FDA-cleared sensory-substitution system, in persons who are profoundly blind (that is, have some or no light perception). Methods This was a prospective, single-arm, multicenter clinical investigation. Participants received 10 hours of device training and were required to use the device in their everyday environments for 1 year. Functional performance measures of object identification, orientation and mobility (O&M), and word identification were assessed at baseline, in post-device training, and at the 3-, 6-, 9-, and 12-month time points. Results Fifty-seven participants completed the study and used the device for 1 year. No device-related serious adverse events were reported, demonstrating that the risks associated with the BrainPort are minimal. Participants performed object recognition (91.2% success rate) and O&M (57.9% success rate) tasks beyond chance level. Discussion This study demonstrates that the BrainPort can be used safely and independently by persons who are blind. Participants with profound blindness can accomplish a set of tasks more successfully by using the BrainPort than without the device. Following initial training, performance on these tasks was maintained or improved over the course of 1 year. Implications for practitioners The BrainPort is a noninvasive and nonsurgical device that heightens functional independence for persons who are blind. The device presents users with more information about their environment than conventional assistive devices, and can enhance independence in performing activities of daily living.
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Affiliation(s)
- Patricia Grant
- Director of clinical research, Wicab, Inc., 8313 Greenway Boulevard, Suite 100, Middleton, WI 53562
| | - Lindsey Spencer
- Program manager, McPherson Eye Research Institute, University of Wisconsin–Madison, 1111 Highland Avenue, Madison, WI 53705
| | - Aimee Arnoldussen
- Technology assessment program manager, UW Health, McPherson Eye Research Institute, University of Wisconsin–Madison, 600 Highland Ave, Madison, WI 53792; and scientific consultant, Wicab, Inc., Middleton, WI
| | - Rich Hogle
- Vice president and director of product development, Wicab, Inc., Middleton, WI
| | - Amy Nau
- Optometrist, Korb & Associates, 400 Commonwealth Avenue, Suite 2, Boston, MA 02215
| | - Janet Szlyk
- President and CEO, Chicago Lighthouse for People Who Are Blind or Visually Impaired; professor, University of Illinois at Chicago; research health scientist, Jesse Brown VA Medical Center, Chicago, IL
| | - Jonathan Nussdorf
- Chairman, Department of Ophthalmology, Ochsner Health System, 1514 Jefferson Highway, New Orleans, LA 70121; associate professor, University of Queensland School of Medicine, Queensland, Australia
| | - Donald C. Fletcher
- Medical director, Envision Low Vision Rehabilitation Center, 610 North Main Street, 2nd Floor, Wichita, KS 67203
| | - Keith Gordon
- Vice president, research, Canadian National Institute for the Blind, 1929 Bayview Avenue, Toronto, Ontario, Canada M4G 3E8
| | - William Seiple
- Vice president of research, Lighthouse Guild International, 111 East 59th Street, New York, NY 10023; professor, Department of Ophthalmology, New York University School of Medicine, New York, NY; research biologist, Jesse Brown VA Medical Center, Chicago, IL; invited professor, University Pierre & Marie Curie, Paris, France
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Vincent M, Tang H, Khoo W, Zhu Z, Ro T. Shape Discrimination Using the Tongue: Implications for a Visual-to-Tactile Sensory Substitution Device. Multisens Res 2016. [DOI: 10.1163/22134808-00002542] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Sensory substitution devices have the potential to provide individuals with visual impairments with more information about their environments, which may help them recognize objects and achieve more independence in their daily lives. However, many of these devices may require extensive training and might be limited in the amount of information that they can convey. We tested the effectiveness and assessed some of the limitations of the BrainPort device, which provides stimulation through a 20 × 20 electrode grid array on the tongue. Across five experiments, including one with blind individuals, we found that subjects were unable to accurately discriminate between simple shapes as well as different line orientations that were briefly presented on the tongue, even after 300 trials of practice with the device. These experiments indicate that such a minimal training regimen with the BrainPort is not sufficient for object recognition, raising serious concerns about the usability of this device without extensive training.
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Affiliation(s)
- Margaret Vincent
- The City College and Graduate Center of the City University of New York, 365 Fifth Ave., New York, NY 10016, USA
| | - Hao Tang
- The City College and Graduate Center of the City University of New York, 365 Fifth Ave., New York, NY 10016, USA
| | - Wai Khoo
- The City College and Graduate Center of the City University of New York, 365 Fifth Ave., New York, NY 10016, USA
| | - Zhigang Zhu
- The City College and Graduate Center of the City University of New York, 365 Fifth Ave., New York, NY 10016, USA
| | - Tony Ro
- The City College and Graduate Center of the City University of New York, 365 Fifth Ave., New York, NY 10016, USA
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Buchs G, Maidenbaum S, Levy-Tzedek S, Amedi A. Integration and binding in rehabilitative sensory substitution: Increasing resolution using a new Zooming-in approach. Restor Neurol Neurosci 2016; 34:97-105. [PMID: 26518671 PMCID: PMC4927841 DOI: 10.3233/rnn-150592] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To visually perceive our surroundings we constantly move our eyes and focus on particular details, and then integrate them into a combined whole. Current visual rehabilitation methods, both invasive, like bionic-eyes and non-invasive, like Sensory Substitution Devices (SSDs), down-sample visual stimuli into low-resolution images. Zooming-in to sub-parts of the scene could potentially improve detail perception. Can congenitally blind individuals integrate a 'visual' scene when offered this information via different sensory modalities, such as audition? Can they integrate visual information -perceived in parts - into larger percepts despite never having had any visual experience? METHODS We explored these questions using a zooming-in functionality embedded in the EyeMusic visual-to-auditory SSD. Eight blind participants were tasked with identifying cartoon faces by integrating their individual components recognized via the EyeMusic's zooming mechanism. RESULTS After specialized training of just 6-10 hours, blind participants successfully and actively integrated facial features into cartooned identities in 79±18% of the trials in a highly significant manner, (chance level 10% ; rank-sum P < 1.55E-04). CONCLUSIONS These findings show that even users who lacked any previous visual experience whatsoever can indeed integrate this visual information with increased resolution. This potentially has important practical visual rehabilitation implications for both invasive and non-invasive methods.
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Affiliation(s)
- Galit Buchs
- Department of Cognitive Science, Faculty of Humanities, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
- The Edmond and Lily Safra Center for Brain Research, Hebrew University of Jerusalem Hadassah Ein-Kerem, Jerusalem, Israel
| | - Shachar Maidenbaum
- The Edmond and Lily Safra Center for Brain Research, Hebrew University of Jerusalem Hadassah Ein-Kerem, Jerusalem, Israel
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
| | - Shelly Levy-Tzedek
- Recanati School for Community Health Professions, Department of Physical Therapy, Ben Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Amir Amedi
- Department of Cognitive Science, Faculty of Humanities, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
- The Edmond and Lily Safra Center for Brain Research, Hebrew University of Jerusalem Hadassah Ein-Kerem, Jerusalem, Israel
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Ein-Kerem, Jerusalem, Israel
- Sorbonne Universités UPMC Univ Paris 06, Institut de la Vision Paris, France
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Murphy MC, Nau AC, Fisher C, Kim SG, Schuman JS, Chan KC. Top-down influence on the visual cortex of the blind during sensory substitution. Neuroimage 2015; 125:932-940. [PMID: 26584776 DOI: 10.1016/j.neuroimage.2015.11.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/07/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022] Open
Abstract
Visual sensory substitution devices provide a non-surgical and flexible approach to vision rehabilitation in the blind. These devices convert images taken by a camera into cross-modal sensory signals that are presented as a surrogate for direct visual input. While previous work has demonstrated that the visual cortex of blind subjects is recruited during sensory substitution, the cognitive basis of this activation remains incompletely understood. To test the hypothesis that top-down input provides a significant contribution to this activation, we performed functional MRI scanning in 11 blind (7 acquired and 4 congenital) and 11 sighted subjects under two conditions: passive listening of image-encoded soundscapes before sensory substitution training and active interpretation of the same auditory sensory substitution signals after a 10-minute training session. We found that the modulation of visual cortex activity due to active interpretation was significantly stronger in the blind over sighted subjects. In addition, congenitally blind subjects showed stronger task-induced modulation in the visual cortex than acquired blind subjects. In a parallel experiment, we scanned 18 blind (11 acquired and 7 congenital) and 18 sighted subjects at rest to investigate alterations in functional connectivity due to visual deprivation. The results demonstrated that visual cortex connectivity of the blind shifted away from sensory networks and toward known areas of top-down input. Taken together, our data support the model of the brain, including the visual system, as a highly flexible task-based and not sensory-based machine.
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Affiliation(s)
- Matthew C Murphy
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; Sensory Substitution Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Louis J. Fox Center for Vision Restoration, University of Pittsburgh and UPMC, Pittsburgh, PA, USA
| | - Amy C Nau
- Sensory Substitution Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Louis J. Fox Center for Vision Restoration, University of Pittsburgh and UPMC, Pittsburgh, PA, USA
| | - Christopher Fisher
- Sensory Substitution Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seong-Gi Kim
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, USA; Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Republic of Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Republic of Korea; Department of Biological Sciences, Sungkyunkwan University, Suwon, Republic of Korea
| | - Joel S Schuman
- Sensory Substitution Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Louis J. Fox Center for Vision Restoration, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, USA
| | - Kevin C Chan
- NeuroImaging Laboratory, University of Pittsburgh, Pittsburgh, PA, USA; UPMC Eye Center, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Louis J. Fox Center for Vision Restoration, University of Pittsburgh and UPMC, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, PA, USA.
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Stronks HC, Nau AC, Ibbotson MR, Barnes N. The role of visual deprivation and experience on the performance of sensory substitution devices. Brain Res 2015; 1624:140-152. [DOI: 10.1016/j.brainres.2015.06.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 06/15/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
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Roman AJ, Cideciyan AV, Matsui R, Sheplock R, Schwartz SB, Jacobson SG. Outcome measure for the treatment of cone photoreceptor diseases: orientation to a scene with cone-only contrast. BMC Ophthalmol 2015; 15:98. [PMID: 26253563 PMCID: PMC4528808 DOI: 10.1186/s12886-015-0085-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 07/22/2015] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Inherited retinal degenerations (IRDs) preferentially affecting cone photoreceptor function are being considered for treatment trials aiming to improve day vision. The purpose of the current work was to develop cone-specific visual orientation outcomes that can differentiate day vision improvement in the presence of retained night vision. METHODS A lighted wall (1.4 m wide, 2 m high) resembling a beaded curtain was formed with 900 individually addressable red, blue and green LED triplets placed in 15 vertical strips hanging 0.1 m apart. Under computer control, different combination of colors and intensities were used to produce the appearance of a door on the wall. Scotopically-matched trials were designed to be perceptible to the cone-, but not rod-, photoreceptor based visual systems. Unmatched control trials were interleaved at each luminance level to determine the existence of any vision available for orientation. Testing started with dark-adapted eyes and a scene luminance attenuated 8 log units from the maximum attainable, and continued with progressively increasing levels of luminance. Testing was performed with a three-alternative forced choice method in healthy subjects and patients with Leber congenital amaurosis (LCA) caused by mutations in GUCY2D, the gene that encodes retinal guanylate cyclase-1. RESULTS Normal subjects could perform the orientation task using cone vision at 5 log attenuation and brighter luminance levels. Most GUCY2D-LCA patients failed to perform the orientation task with scotopically-matched test trials at any luminance level even though they were able to perform correctly with unmatched control trials. These results were consistent with a lack of cone system vision and use of the rod system under ambient conditions normally associated with cone system activity. Two GUCY2D-LCA patients demonstrated remnant cone vision but at a luminance level 2 log brighter than normal. CONCLUSIONS The newly developed device can probe the existence or emergence of cone-based vision in patients for an orientation task involving the identification of a door on the wall under free-viewing conditions. This key advance represents progress toward developing an appropriate outcome measure for a clinical trial to treat currently incurable eye diseases severely affecting cone vision despite retained rod vision.
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Affiliation(s)
- Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
| | - Rodrigo Matsui
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
| | - Sharon B Schwartz
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, 51 North 39th St., Philadelphia, PA, 19104, USA.
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29
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O'Modhrain S, Giudice NA, Gardner JA, Legge GE. Designing Media for Visually-Impaired Users of Refreshable Touch Displays: Possibilities and Pitfalls. IEEE TRANSACTIONS ON HAPTICS 2015; 8:248-257. [PMID: 26276998 DOI: 10.1109/toh.2015.2466231] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper discusses issues of importance to designers of media for visually impaired users. The paper considers the influence of human factors on the effectiveness of presentation as well as the strengths and weaknesses of tactile, vibrotactile, haptic, and multimodal methods of rendering maps, graphs, and models. The authors, all of whom are visually impaired researchers in this domain, present findings from their own work and work of many others who have contributed to the current understanding of how to prepare and render images for both hard-copy and technology-mediated presentation of Braille and tangible graphics.
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Stingl K, Bartz-Schmidt KU, Besch D, Chee CK, Cottriall CL, Gekeler F, Groppe M, Jackson TL, MacLaren RE, Koitschev A, Kusnyerik A, Neffendorf J, Nemeth J, Naeem MAN, Peters T, Ramsden JD, Sachs H, Simpson A, Singh MS, Wilhelm B, Wong D, Zrenner E. Subretinal Visual Implant Alpha IMS--Clinical trial interim report. Vision Res 2015; 111:149-60. [PMID: 25812924 DOI: 10.1016/j.visres.2015.03.001] [Citation(s) in RCA: 224] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 02/18/2015] [Accepted: 03/02/2015] [Indexed: 11/27/2022]
Abstract
A subretinal visual implant (Alpha IMS, Retina Implant AG, Reutlingen, Germany) was implanted in 29 blind participants with outer retinal degeneration in an international multicenter clinical trial. Primary efficacy endpoints of the study protocol were a significant improvement of activities of daily living and mobility to be assessed by activities of daily living tasks, recognition tasks, mobility, or a combination thereof. Secondary efficacy endpoints were a significant improvement of visual acuity/light perception and/or object recognition (clinicaltrials.gov, NCT01024803). During up to 12 months observation time twenty-one participants (72%) reached the primary endpoints, of which thirteen participants (45%) reported restoration of visual function which they use in daily life. Additionally, detection, localization, and identification of objects were significantly better with the implant power switched on in the first 3 months. Twenty-five participants (86%) reached the secondary endpoints. Measurable grating acuity was up to 3.3 cycles per degree, visual acuities using standardized Landolt C-rings were 20/2000, 20/2000, 20/606 and 20/546. Maximal correct motion perception ranged from 3 to 35 degrees per second. These results show that subretinal implants can restore very-low-vision or low vision in blind (light perception or less) patients with end-stage hereditary retinal degenerations.
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Affiliation(s)
- Katarina Stingl
- Centre for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany
| | | | - Dorothea Besch
- Centre for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany
| | - Caroline K Chee
- Department of Ophthalmology, National University Health System, 1E Kent Ridge Road, Singapore 119228, Singapore
| | - Charles L Cottriall
- Oxford Eye Hospital and Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Florian Gekeler
- Centre for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany; Klinikum Stuttgart - Katharinenhospital, Eye Clinic, Kriegsbergstraße 60, 70174 Stuttgart, Germany(1)
| | - Markus Groppe
- Oxford Eye Hospital and Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Timothy L Jackson
- King's College Hospital and King's College London, Denmark Hill, London SE5 9RS, United Kingdom
| | - Robert E MacLaren
- Oxford Eye Hospital and Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Assen Koitschev
- Klinikum Stuttgart - Olgahospital, ORL-Department, Pediatric Otorhinolaryngology and Otology, Kriegsbergstr. 62, 70176 Stuttgart, Germany
| | - Akos Kusnyerik
- Department of Ophthalmology, Semmelweis University, Maria utca 39, H-1085 Budapest, Hungary
| | - James Neffendorf
- King's College Hospital and King's College London, Denmark Hill, London SE5 9RS, United Kingdom
| | - Janos Nemeth
- Department of Ophthalmology, Semmelweis University, Maria utca 39, H-1085 Budapest, Hungary
| | - Mohamed Adheem Naser Naeem
- Department of Ophthalmology, National University Health System, 1E Kent Ridge Road, Singapore 119228, Singapore
| | - Tobias Peters
- STZ Eyetrial, Center for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany
| | - James D Ramsden
- Department of Otolaryngology, Oxford University Hospitals NHS Trust, Oxford OX3 9DU, United Kingdom
| | - Helmut Sachs
- Klinikum Dresden Friedrichstadt, Univ. Teaching Hospital, Eye Clinic, Friedrichstr. 41, 01067 Dresden, Germany
| | - Andrew Simpson
- King's College Hospital and King's College London, Denmark Hill, London SE5 9RS, United Kingdom
| | - Mandeep S Singh
- Department of Ophthalmology, National University Health System, 1E Kent Ridge Road, Singapore 119228, Singapore
| | - Barbara Wilhelm
- STZ Eyetrial, Center for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany
| | - David Wong
- Li Ka Shing Faculty of Medicine, University of Hong Kong, 301 Block B, Cyberport 4, Hong Kong
| | - Eberhart Zrenner
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany; Centre for Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany.
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31
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Caspi A, Zivotofsky AZ. Assessing the utility of visual acuity measures in visual prostheses. Vision Res 2015; 108:77-84. [DOI: 10.1016/j.visres.2015.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 01/14/2015] [Accepted: 01/18/2015] [Indexed: 11/28/2022]
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Stronks HC, Parker DJ, Walker J, Lieby P, Barnes N. The Feasibility of Coin Motors for Use in a Vibrotactile Display for the Blind. Artif Organs 2015; 39:480-91. [DOI: 10.1111/aor.12414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- H. Christiaan Stronks
- Computer Vision Research Group; NICTA; Canberra ACT Australia
- Department of Neuroscience; the John Curtin School of Medical Research; Australian National University; Canberra ACT Australia
| | | | - Janine Walker
- Computer Vision Research Group; NICTA; Canberra ACT Australia
- Centre for Mental Health Research; Australian National University; Canberra ACT Australia
| | - Paulette Lieby
- College of Engineering and Computer Science; Australian National University; Canberra ACT Australia
| | - Nick Barnes
- Computer Vision Research Group; NICTA; Canberra ACT Australia
- College of Engineering and Computer Science; Australian National University; Canberra ACT Australia
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Nau AC, Pintar C, Arnoldussen A, Fisher C. Acquisition of Visual Perception in Blind Adults Using the BrainPort Artificial Vision Device. Am J Occup Ther 2015; 69:6901290010p1-8. [PMID: 25553750 PMCID: PMC4281706 DOI: 10.5014/ajot.2015.011809] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
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.
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Affiliation(s)
- Amy C Nau
- Amy C. Nau, OD, is Assistant Professor, University of Pittsburgh Medical Center Eye Center; McGowan Institute for Regenerative Medicine; and Fox Center for Vision Restoration, Korb & Associates, Boston MA;
| | - Christine Pintar
- Christine Pintar, MS, is Clinical Research Coordinator, Fox Center for Vision Restoration, Pittsburgh, PA
| | - Aimee Arnoldussen
- Aimee Arnoldussen, PhD, is Technology Assessment Program Manager, University of Wisconsin, Madison
| | - Christopher Fisher
- Christopher Fisher is Research Assistant, Fox Center for Vision Restoration, Sensory Substitution Laboratory, Pittsburgh, PA
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Jung JH, Aloni D, Yitzhaky Y, Peli E. Active confocal imaging for visual prostheses. Vision Res 2014; 111:182-96. [PMID: 25448710 DOI: 10.1016/j.visres.2014.10.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 10/14/2014] [Accepted: 10/25/2014] [Indexed: 11/26/2022]
Abstract
There are encouraging advances in prosthetic vision for the blind, including retinal and cortical implants, and other "sensory substitution devices" that use tactile or electrical stimulation. However, they all have low resolution, limited visual field, and can display only few gray levels (limited dynamic range), severely restricting their utility. To overcome these limitations, image processing or the imaging system could emphasize objects of interest and suppress the background clutter. We propose an active confocal imaging system based on light-field technology that will enable a blind user of any visual prosthesis to efficiently scan, focus on, and "see" only an object of interest while suppressing interference from background clutter. The system captures three-dimensional scene information using a light-field sensor and displays only an in-focused plane with objects in it. After capturing a confocal image, a de-cluttering process removes the clutter based on blur difference. In preliminary experiments we verified the positive impact of confocal-based background clutter removal on recognition of objects in low resolution and limited dynamic range simulated phosphene images. Using a custom-made multiple-camera system based on light-field imaging, we confirmed that the concept of a confocal de-cluttered image can be realized effectively.
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Affiliation(s)
- Jae-Hyun Jung
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Doron Aloni
- Department of Electro-Optics Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Yitzhak Yitzhaky
- Department of Electro-Optics Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Eli Peli
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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35
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Lee VK, Nau AC, Laymon C, Chan KC, Rosario BL, Fisher C. Successful tactile based visual sensory substitution use functions independently of visual pathway integrity. Front Hum Neurosci 2014; 8:291. [PMID: 24860473 PMCID: PMC4026734 DOI: 10.3389/fnhum.2014.00291] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 04/18/2014] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Neuronal reorganization after blindness is of critical interest because it has implications for the rational prescription of artificial vision devices. The purpose of this study was to distinguish the microstructural differences between perinatally blind (PB), acquired blind (AB), and normally sighted controls (SCs) and relate these differences to performance on functional tasks using a sensory substitution device (BrainPort). METHODS We enrolled 52 subjects (PB n = 11; AB n = 35; SC n = 6). All subjects spent 15 h undergoing BrainPort device training. Outcomes of light perception, motion, direction, temporal resolution, grating, and acuity were tested at baseline and after training. Twenty-six of the subjects were scanned with a three Tesla MRI scanner for diffusion tensor imaging (DTI), and with a positron emission tomography (PET) scanner for mapping regional brain glucose consumption during sensory substitution function. Non-parametric models were used to analyze fractional anisotropy (FA; a DTI measure of microstructural integrity) of the brain via region-of-interest (ROI) analysis and tract-based spatial statistics (TBSS). RESULTS At baseline, all subjects performed all tasks at chance level. After training, light perception, time resolution, location and grating acuity tasks improved significantly for all subject groups. ROI and TBSS analyses of FA maps show areas of statistically significant differences (p ≤ 0.025) in the bilateral optic radiations and some visual association connections between all three groups. No relationship was found between FA and functional performance with the BrainPort. DISCUSSION All subjects showed performance improvements using the BrainPort irrespective of nature and duration of blindness. Definite brain areas with significant microstructural integrity changes exist among PB, AB, and NC, and these variations are most pronounced in the visual pathways. However, the use of sensory substitution devices is feasible irrespective of microstructural integrity of the primary visual pathways between the eye and the brain. Therefore, tongue based devices devices may be usable for a broad array of non-sighted patients.
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Affiliation(s)
- Vincent K Lee
- Department of Radiology, University of Pittsburgh Pittsburgh, PA, USA
| | - Amy C Nau
- Sensory Substitution Laboratory, Department of Ophthalmology, Eye and Ear Institute, University of Pittsburgh Pittsburgh, PA, USA ; Department of Ophthalmology, University of Pittsburgh Medical Center Pittsburgh, PA, USA ; McGowan Institute for Regenerative Medicine, University of Pittsburgh Pittsburgh, PA, USA ; Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh Pittsburgh, PA, USA
| | - Charles Laymon
- Department of Radiology, University of Pittsburgh Pittsburgh, PA, USA
| | - Kevin C Chan
- Department of Ophthalmology, University of Pittsburgh Medical Center Pittsburgh, PA, USA ; McGowan Institute for Regenerative Medicine, University of Pittsburgh Pittsburgh, PA, USA ; Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh Pittsburgh, PA, USA ; Department of Bioengineering, University of Pittsburgh Pittsburgh, PA, USA ; Center for the Neural Basis of Cognition, University of Pittsburgh-Carnegie Mellon University Pittsburgh, PA, USA
| | - Bedda L Rosario
- Department of Radiology, University of Pittsburgh Pittsburgh, PA, USA
| | - Chris Fisher
- Sensory Substitution Laboratory, Department of Ophthalmology, Eye and Ear Institute, University of Pittsburgh Pittsburgh, PA, USA
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