Journal articles: 'Vision prosthesis'

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Kirpichnikov, M. P., and М. А. Оstrovsky. "Optogenetics and vision." Вестник Российской академии наук 89, no. 2 (March 20, 2019): 125–30. http://dx.doi.org/10.31857/s0869-5873892125-130.

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In this article the authors discuss electronic and optogenetic approaches for degenerative (blind) retina prosthesis as the main strategies for the restoration of vision to blind people. Primary attention is devoted to the prospects of developing retinal prostheses for the blind using modern optogenetic methods, and rhodopsins, which are photosensitive retinal-binding proteins, are examined as potential tools for such prostheses. The authors consider the question of which particular cells of the degenerative retina for which rhodopsins can be prosthetic as well as ways of delivering the rhodopsin genes to these cells. In conclusion, the authors elucidate the main provisions and tasks related to optogenetic prosthetics for degenerative retina.

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Lin, Xiangli. "Neurophysiology Based on Deep Neural Network under Artificial Prosthesis Vision." Journal of Physics: Conference Series 2074, no. 1 (November 1, 2021): 012083. http://dx.doi.org/10.1088/1742-6596/2074/1/012083.

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Abstract With the vigorous development of electronic technology and computer technology, as well as the continuous advancement of research in the fields of neurophysiology, bionics and medicine, the artificial visual prosthesis has brought hope to the blind to restore their vision. Artificial optical prosthesis research has confirmed that prosthetic vision can restore part of the visual function of patients with non-congenital blindness, but the mechanism of early prosthetic image processing still needs to be clarified through neurophysiological research. The purpose of this article is to study neurophysiology based on deep neural networks under simulated prosthetic vision. This article uses neurophysiological experiments and mathematical statistical methods to study the vision of simulated prostheses, and test and improve the image processing strategies used to simulate the visual design of prostheses. In this paper, based on the low-pixel image recognition of the simulating irregular phantom view point array, the deep neural network is used in the image processing strategy of prosthetic vision, and the effect of the image processing method on object image recognition is evaluated by the recognition rate. The experimental results show that the recognition rate of the two low-pixel segmentation and low-pixel background reduction methods proposed by the deep neural network under simulated prosthetic vision is about 70%, which can significantly increase the impact of object recognition, thereby improving the overall recognition ability of visual guidance.

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Wang, Jing, Rongfeng Zhao, Peitong Li, Zhiqiang Fang, Qianqian Li, Yanling Han, Ruyan Zhou, and Yun Zhang. "Clinical Progress and Optimization of Information Processing in Artificial Visual Prostheses." Sensors 22, no. 17 (August 30, 2022): 6544. http://dx.doi.org/10.3390/s22176544.

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Visual prostheses, used to assist in restoring functional vision to the visually impaired, convert captured external images into corresponding electrical stimulation patterns that are stimulated by implanted microelectrodes to induce phosphenes and eventually visual perception. Detecting and providing useful visual information to the prosthesis wearer under limited artificial vision has been an important concern in the field of visual prosthesis. Along with the development of prosthetic device design and stimulus encoding methods, researchers have explored the possibility of the application of computer vision by simulating visual perception under prosthetic vision. Effective image processing in computer vision is performed to optimize artificial visual information and improve the ability to restore various important visual functions in implant recipients, allowing them to better achieve their daily demands. This paper first reviews the recent clinical implantation of different types of visual prostheses, summarizes the artificial visual perception of implant recipients, and especially focuses on its irregularities, such as dropout and distorted phosphenes. Then, the important aspects of computer vision in the optimization of visual information processing are reviewed, and the possibilities and shortcomings of these solutions are discussed. Ultimately, the development direction and emphasis issues for improving the performance of visual prosthesis devices are summarized.

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Kanathila, Dr Hema, and Dr Ashwin M Pangi. "Adhesive Retained Ocular Prosthesis - “Correcting Defects Providing Quality Life”: Clinical Case Series." International Journal of Science and Healthcare Research 7, no. 2 (June 30, 2022): 338–43. http://dx.doi.org/10.52403/ijshr.20220446.

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Ocular defects are usually due to maxillofacial trauma. This causes an alteration of facial appearance and aesthetics. Apart from psychological trauma to the patient, it interferes with the normal life. Hence correcting such defects with prostheses can get back the individual to normal social life. A prosthetic eye is an answer for these defects. It can help in improving the appearance of the defective eye socket Even though it cannot restore vision, it gives normal appearance for the patient and mental support to a great extent. Adjusting to the ocular prosthesis can be really challenging both mentally as well as physically. This article describes the fabrication of custom-made ocular prostheses retained by adhesives in a series of cases where patients have lost their eyes due to trauma. Keywords: Eye prosthesis, Ocular Prosthesis, Custom eye prosthesis, Adhesive retention.

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Prasad, Raghavendra, Ritika Bhambhani, and Shalini Joshi. "Esthetic Problem: Prosthetic Solution for an Ocular Defect." World Journal of Dentistry 3, no. 3 (2012): 269–72. http://dx.doi.org/10.5005/jp-journals-10015-1171.

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ABSTRACT Anophthalmia (The loss an eye) not only impairs patient's vision but also create a noticeable deformity on facial appearance and esthetics. The condition is a psychological distress for the patient interrupting his routine work. 'sarvendriyanam nayanam pradhanum’ states vision to be the supreme among all the senses. A prosthodontist as an integral member of the craniofacial rehabilitation team can help raise the spirits and ease the mind of the affected. Among various approaches, customized ocular prosthesis achieves better comfort and function between prosthesis and orbital tissues. This is a case report of a female patient of age 22 years had lost her eye as a child due to trauma and the above mentioned prosthesis was planned and fabricated to enhance appearance and boost her confidence. Getting eyesight back is not always possible, but maxillofacial prosthetics can help to reduce the pain of psychological embarrassment. Artistic skills are needed in providing a natural look to the prosthesis; this technique may help in a naturally appearing prosthesis with lesser artistic skills. How to cite this article Prasad R, Bhambhani R, Joshi S. Esthetic Problem: Prosthetic Solution for an Ocular Defect. World J Dent 2012;3(3):269-272.

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Boshlyakov, Andrew A., and Alexander S. Ermakov. "Development of a Vision System for an Intelligent Robotic Hand Prosthesis Using Neural Network Technology." ITM Web of Conferences 35 (2020): 04006. http://dx.doi.org/10.1051/itmconf/20203504006.

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A brief review of the existing auxiliary prosthetic control systems was carried out. The concept of an intelligent prosthesis is proposed, which will expand the possibilities of application and simplify the use of the prosthesis. The required actions of the vision system in automatic and manual capture modes are considered. The sequence of operation of the subsystems of the technical vision system is determined. The possibility of implementing a prosthesis vision system based on neural network technology is shown. The method of using a ready-made neural network for recognition of objects by a prosthesis is considered. The possibilities of using the considered neural network technologies in the mathematical education of engineers are presented. A version of the prosthesis design is proposed. The possibility of constructing the described prosthesis is shown.

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Lyu, Qing, Zhuofan Lu, Heng Li, Shirong Qiu, Jiahui Guo, Xiaohong Sui, Pengcheng Sun, Liming Li, Xinyu Chai, and Nigel H. Lovell. "A Three-Dimensional Microelectrode Array to Generate Virtual Electrodes for Epiretinal Prosthesis Based on a Modeling Study." International Journal of Neural Systems 30, no. 03 (February 18, 2020): 2050006. http://dx.doi.org/10.1142/s0129065720500069.

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Despite many advances in the development of retinal prostheses, clinical reports show that current retinal prosthesis subjects can only perceive prosthetic vision with poor visual acuity. A possible approach for improving visual acuity is to produce virtual electrodes (VEs) through electric field modulation. Generating controllable and localized VEs is a crucial factor in effectively improving the perceptive resolution of the retinal prostheses. In this paper, we aimed to design a microelectrode array (MEA) that can produce converged and controllable VEs by current steering stimulation strategies. Through computational modeling, we designed a three-dimensional concentric ring–disc MEA and evaluated its performance with different stimulation strategies. Our simulation results showed that electrode–retina distance (ERD) and inter-electrode distance (IED) can dramatically affect the distribution of electric field. Also the converged VEs could be produced when the parameters of the three-dimensional MEA were appropriately set. VE sites can be controlled by manipulating the proportion of current on each adjacent electrode in a current steering group (CSG). In addition, spatial localization of electrical stimulation can be greatly improved under quasi-monopolar (QMP) stimulation. This study may provide support for future application of VEs in epiretinal prosthesis for potentially increasing the visual acuity of prosthetic vision.

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Bernal-Torres, Mario G., Hugo I. Medellín-Castillo, and Juan C. Arellano-González. "Design and Control of a New Biomimetic Transfemoral Knee Prosthesis Using an Echo-Control Scheme." Journal of Healthcare Engineering 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/8783642.

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Passive knee prostheses require a significant amount of additional metabolic energy to carry out a gait cycle, therefore affecting the natural human walk performance. Current active knee prostheses are still limited because they do not reply with accuracy of the natural human knee movement, and the time response is relatively large. This paper presents the design and control of a new biomimetic-controlled transfemoral knee prosthesis based on a polycentric-type mechanism. The aim was to develop a knee prosthesis able to provide additional power and to mimic with accuracy of the natural human knee movement using a stable control strategy. The design of the knee mechanism was obtained from the body-guidance kinematics synthesis based on real human walking patterns obtained from computer vision and 3D reconstruction. A biomechanical evaluation of the synthesized prosthesis was then carried out. For the activation and control of the prosthesis, an echo-control strategy was proposed and developed. In this echo-control strategy, the sound side leg is sensed and synchronized with the activation of the knee prosthesis. An experimental prototype was built and evaluated in a test rig. The results revealed that the prosthetic knee is able to mimic the biomechanics of the human knee.

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Nazari, Hossein, Paulo Falabella, Lan Yue, James Weiland, and Mark S. Humayun. "Retinal Prostheses." Journal of VitreoRetinal Diseases 1, no. 3 (April 20, 2017): 204–13. http://dx.doi.org/10.1177/2474126417702067.

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Artificial vision is restoring sight by electrical stimulation of the visual system at the level of retina, optic nerve, lateral geniculate body, or occipital cortex. The development of artificial vision began with occipital cortex prosthesis; however, retinal prosthesis has advanced faster in recent years. Currently, multiple efforts are focused on finding the optimal approach for restoring vision through an implantable retinal microelectrode array system. Retinal prostheses function by stimulating the inner retinal neurons that survive retinal degeneration. In these devices, the visual information, gathered by a light detector, is transformed into controlled patterns of electrical pulses, which are in turn delivered to the surviving retinal neurons by an electrode array. Retinal prostheses are classified based on where the stimulating array is implanted (ie, epiretinal, subretinal, suprachoroidal, or episcleral). Recent regulatory approval of 2 retinal prostheses has greatly escalated interest in the potential of these devices to treat blindness secondary to outer retinal degeneration. This review will focus on the technical and operational features and functional outcomes of clinically tested retinal prostheses. We will discuss the major barriers and some of the more promising solutions to improve the outcomes of restoring vision with electrical retinal stimulation.

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Banarji, A., VS Gurunadh, S. Patyal, TS Ahluwalia, DP Vats, and M. Bhadauria. "Visual Prosthesis: Artificial Vision." Medical Journal Armed Forces India 65, no. 4 (October 2009): 348–52. http://dx.doi.org/10.1016/s0377-1237(09)80098-1.

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Rao, V. Bhujanga, P. Seetharamaiah, and Nukapeyi Sharmili. "Design of a Prototype for Vision Prosthesis." International Journal of Biomedical and Clinical Engineering 7, no. 2 (July 2018): 1–13. http://dx.doi.org/10.4018/ijbce.2018070101.

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This article describes how the field of vision prostheses is currently being developed around the world to restore useful vision for people suffering from retinal degenerative diseases. The vision prosthesis system (VPS) maps visual images to electrical pulses and stimulates the surviving healthy parts in the retina of the eye, i.e. ganglion cells, using electric pulses applied through an electrode array. The retinal neurons send visual information to the brain. This article presents the design of a prototype vision prosthesis system which converts images/video into biphasic electric stimulation pulses for the excitation of electrodes simulated by an LED array. The proposed prototype laboratory model has been developed for the design of flexible high-resolution 1024-electrode VPS, using an embedded computer-based efficient control algorithm for better visual prediction. The prototype design for the VPS is verified visually through a video display on an LCD/LED array. The experimental results of VPS are enumerated for the test objects, such as, palm, human face and large font characters. The results were found to be satisfactory.

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Guo, Fei, Yuan Yang, and Yong Gao. "Optimization of Visual Information Presentation for Visual Prosthesis." International Journal of Biomedical Imaging 2018 (2018): 1–12. http://dx.doi.org/10.1155/2018/3198342.

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Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis.

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Buss, Stephanie. "From Visual Plasticity to the Bionic Eye." Einstein Journal of Biology and Medicine 27, no. 1 (March 2, 2016): 10. http://dx.doi.org/10.23861/ejbm20112725.

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While visual plasticity is strongest in early infancy, new studies show that plasticity is maintained well into adult life.This possibility is compellingly demonstrated by one patient, SK, who gained vision for the first time in adult life andsignificantly improved his ability to see the world around him. The persistence of visual plasticity in adults is promisingnews for the developing field of visual prosthesis.In recent years, there has been an explosion of research on prosthetic devices for the brain. While memory-enhancingbrain chips are still science fiction, cochlear implants, which stimulate the inner ear with tiny electrodes, now allowpeople who were once deaf to hear with increasing accuracy. Although there is not yet any visual equivalent to thecochlear implant, in recent years vision researchers have started to experiment with similar prosthetic techniques totreat blindness.The goal of visual prosthesis is to allow functional restoration of vision and to improve quality of life for blindpatients. In order to achieve these goals, the prosthetic devices must tap into the brain’s plasticity. Plasticity is howthe brain adapts to new environmental stimuli. It enables all forms of learning, including memorizing facts, playingthe piano, and learning to see. Specifically, plasticity is how neural networks in the brain reorganize in response tonew experiences. Understanding plasticity furthers insight into the brain mechanisms active in visual prostheses, andmay help scientists develop new approaches for future devices.

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Girvin, John P. "Current Status of Artificial Vision by Electrocortical Stimulation." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 15, no. 1 (February 1988): 58–62. http://dx.doi.org/10.1017/s0317167100027207.

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ABSTRACT:The history of the provision of artificial vision by electrocortical stimulation has its origin in observations over 50 years ago. However, the realistic modern stimulation of human visual cortex is only 20-years-old. No useful device has been devised as yet and it therefore remains purely experimental. The primary objective of such a prosthetic device is that of independent mobility. This would require the appreciation of half-tone pictures, the detection of depth and discontinuities in outlines, and a significant quality of resolution. Some of the problems which threaten resolution in such a device and the factors which must be overcome in order to achieve a useful visual prosthesis are discussed.

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Wong, Y. T., N. Dommel, P. Preston, L. E. Hallum, T. Lehmann, N. H. Lovell, and G. J. Suaning. "Retinal Neurostimulator for a Multifocal Vision Prosthesis." IEEE Transactions on Neural Systems and Rehabilitation Engineering 15, no. 3 (September 2007): 425–34. http://dx.doi.org/10.1109/tnsre.2007.903958.

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Stieglitz, Thomas. "Development of a micromachined epiretinal vision prosthesis." Journal of Neural Engineering 6, no. 6 (October 23, 2009): 065005. http://dx.doi.org/10.1088/1741-2560/6/6/065005.

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McGrath, Michael, Laura A. Gray, Beata Rek, Kate C. Davies, Zoe Savage, Jane McLean, Alison Stenson, and Saeed Zahedi. "Can microprocessor knees reduce the disparity in trips and falls risks between above and below knee prosthesis users?" PLOS ONE 17, no. 9 (September 2, 2022): e0271315. http://dx.doi.org/10.1371/journal.pone.0271315.

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While all lower limb prosthesis walkers have a high risk of tripping and/or falling, above knee prosthesis users are reported to fall more frequently. Recognising this, engineers designed microprocessor knees (MPK) to help mitigate these risks, but to what extent these devices reduce this disparity between above and below knee users is unclear. A service review was carried out in a prosthetic limb centre regarding the frequency of trips and falls in the previous four weeks. Data from unilateral, community ambulators were extracted. Ordered logistic regressions were applied to investigate whether MPKs mitigated the increased risk of trips and falls for prosthetic knee users, compared to below knee prosthesis users. Socio-demographics (sex, age), prosthesis (prosthesis type, years of use), health (comorbidities, vision, contralateral limb status, medication), and physical function (use of additional walking aids, activity level) were included as covariates. Of the 315 participants in the analysis, 57.5% reported tripping and 20.3% reported falling. Non-microprocessor prosthetic knee (non-MPK) users were shown to trip significantly more than below knee prosthesis users (OR = 1.96, 95% CI = 1.17–3.28). Other covariates showing a significant association included contralateral limb injuries (OR = 1.91, 95% CI = 1.15–3.18) and using an additional walking aid (OR = 1.99, 95% CI = 1.13–3.50). Non-MPK users were also shown to fall significantly more than below knee prosthesis users (OR = 3.34, 95% CI = 1.73–6.45), with no other covariates showing a significant association. MPK users did not show an increased frequency of trips (OR = 0.74, 95% CI = 0.33–1.64) or falls (OR = 0.34, 95% CI = 0.18–2.62), compared to below knee prosthesis users. Of those who tripped at least once in the previous four weeks, those using a non-MPK (OR = 2.73, 95% CI = 1.30–5.74) presented an increased frequency of falling. These findings provide evidence to suggest that the use of MPKs reduces the difference in falls risk between above knee and below knee prosthesis users, providing justification for their provision.

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KIEN, TRAN TRUNG, TOMAS MAUL, and ANDRZEJ BARGIELA. "A REVIEW OF RETINAL PROSTHESIS APPROACHES." International Journal of Modern Physics: Conference Series 09 (January 2012): 209–31. http://dx.doi.org/10.1142/s2010194512005272.

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Age-related macular degeneration and retinitis pigmentosa are two of the most common diseases that cause degeneration in the outer retina, which can lead to several visual impairments up to blindness. Vision restoration is an important goal for which several different research approaches are currently being pursued. We are concerned with restoration via retinal prosthetic devices. Prostheses can be implemented intraocularly and extraocularly, which leads to different categories of devices. Cortical Prostheses and Optic Nerve Prostheses are examples of extraocular solutions while Epiretinal Prostheses and Subretinal Prostheses are examples of intraocular solutions. Some of the prostheses that are successfully implanted and tested in animals as well as humans can restore basic visual functions but still have limitations. This paper will give an overview of the current state of art of Retinal Prostheses and compare the advantages and limitations of each type. The purpose of this review is thus to summarize the current technologies and approaches used in developing Retinal Prostheses and therefore to lay a foundation for future designs and research directions.

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Krausz, Nili E., Blair H. Hu, and Levi J. Hargrove. "Subject- and Environment-Based Sensor Variability for Wearable Lower-Limb Assistive Devices." Sensors 19, no. 22 (November 8, 2019): 4887. http://dx.doi.org/10.3390/s19224887.

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Significant research effort has gone towards the development of powered lower limb prostheses that control power during gait. These devices use forward prediction based on electromyography (EMG), kinetics and kinematics to command the prosthesis which locomotion activity is desired. Unfortunately these predictions can have substantial errors, which can potentially lead to trips or falls. It is hypothesized that one reason for the significant prediction errors in the current control systems for powered lower-limb prostheses is due to the inter- and intra-subject variability of the data sources used for prediction. Environmental data, recorded from a depth sensor worn on a belt, should have less variability across trials and subjects as compared to kinetics, kinematics and EMG data, and thus its addition is proposed. The variability of each data source was analyzed, once normalized, to determine the intra-activity and intra-subject variability for each sensor modality. Then measures of separability, repeatability, clustering and overall desirability were computed. Results showed that combining Vision, EMG, IMU (inertial measurement unit), and Goniometer features yielded the best separability, repeatability, clustering and desirability across subjects and activities. This will likely be useful for future application in a forward predictor, which will incorporate Vision-based environmental data into a forward predictor for powered lower-limb prosthesis and exoskeletons.

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Philip, Jacob Mathew, CJ Venkatakrishnan, Ashish R. Jain, R. Pradeep, and M. Narasimman. "Prosthetic Rehabilitation of Patient with Ocular Defect using Acrylic Stock Eyes." International Journal of Prosthodontics and Restorative Dentistry 3, no. 4 (2013): 143–47. http://dx.doi.org/10.5005/jp-journals-10019-1094.

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ABSTRACT The science and art employed in the profession of dentistry can play an important role in the fabrication of an orbital prosthesis. Anophthalmia (the loss of an eye) not only impairs patient's vision but also create a noticeable deformity on facial appearance and esthetics. The condition is a psychological distress for the patient interrupting his routine work. A prosthodontist as an integral member of the craniofacial rehabilitation team can help raise the spirits and ease the mind of the affected. Mutilation of a portion of a face can cause a heavy impact on the self image and personality of an individual. Acceptable cosmetic results usually can be obtained with a orbital prosthesis. This paper describes prosthetic rehabilitation of a 30-year-old female patient having a left and right ocular defect. A technique to modify stock eye with heat polymerizing polymethyl methacrylate is illustrated. The resultant prosthesis was structurally durable and esthetically acceptable with satisfactory retention. The importance of meticulous treatment planning to tackle the challenges faced in fabricating an ocular prosthesis is explained with the relevant literature. How to cite this article Venkatakrishnan CJ, Jain AR, Pradeep R, Philip JM, Narasimman M. Prosthetic Rehabilitation of Patient with Ocular Defect using Acrylic Stock Eyes. Int J Prosthodont Restor Dent 2013;3(4):143-147.

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Barreto, Marco A., Jorge Perez-Gonzalez, Hugh M. Herr, and Joel C. Huegel. "ARACAM: A RGB-D Multi-View Photogrammetry System for Lower Limb 3D Reconstruction Applications." Sensors 22, no. 7 (March 22, 2022): 2443. http://dx.doi.org/10.3390/s22072443.

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In the world, there is a growing need for lower limb prostheses due to a rising number of amputations caused primarily, by diabetic foot. Researchers enable functional and comfortable prostheses through prosthetic design by integrating new technologies applied to the traditional handcrafted method for prosthesis fabrication that is still current. That is why computer vision shows to be a promising tool for the integration of 3D reconstruction that may be useful for prosthetic design. This work has the objective to design, prototype, and test a functional system to scan plaster cast molds, which may serve as a platform for future technologies for lower limb reconstruction applications. The image capture system comprises 5 stereoscopic color and depth cameras, each with 4 DOF mountings on an enveloping frame, as well as algorithms for calibration, segmentation, registration, and surface reconstruction. The segmentation metrics of dice coefficient and Hausdorff distance (HD) show strong visual similarity with an average similarity of 87% and average error of 6.40 mm, respectively. Moving forward, the system was tested on a known 3D printed model obtained from a computer tomography scan to which comparison results via HD show an average error of ≤1.93 mm thereby making the system competitive against the systems reviewed from the state-of-the-art.

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Wang, Jing, Haiyi Zhu, Jianyun Liu, Heng Li, Yanling Han, Ruyan Zhou, and Yun Zhang. "The application of computer vision to visual prosthesis." Artificial Organs 45, no. 10 (July 27, 2021): 1141–54. http://dx.doi.org/10.1111/aor.14022.

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Normann, Richard A., Edwin M. Maynard, Patrick J. Rousche, and David J. Warren. "A neural interface for a cortical vision prosthesis." Vision Research 39, no. 15 (July 1999): 2577–87. http://dx.doi.org/10.1016/s0042-6989(99)00040-1.

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Došen, Strahinja, and Dejan B. Popović. "Transradial Prosthesis: Artificial Vision for Control of Prehension." Artificial Organs 35, no. 1 (January 2011): 37–48. http://dx.doi.org/10.1111/j.1525-1594.2010.01040.x.

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Weinberg, Marc S., Conrad Wall, Jimmy Robertsson, Edward O’Neil, Kathleen Sienko, and Robert Fields. "Tilt Determination in MEMS Inertial Vestibular Prosthesis." Journal of Biomechanical Engineering 128, no. 6 (May 8, 2006): 943–56. http://dx.doi.org/10.1115/1.2378922.

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Background: There is a clear need for a prosthesis that improves postural stability in the balance impaired. Such a device would be used as a temporary aid during recovery from ablative inner-ear surgery, a postural monitor during rehabilitation (for example, hip surgery), and as a permanent prosthesis for those elderly prone to falls. Method of approach: Recently developed, small instruments have enabled wearable prostheses to augment or replace vestibular functions. The current prosthesis communicates by vibrators mounted on the subject’s trunk. In this paper we emphasize the unique algorithms that enable tilt indication with modestly performing micromachined gyroscopes and accelerometers. Results: For large angles and multiple axes, gyro drift and unwanted lateral accelerations are successfully rejected. In single-axis tests, the most dramatic results were obtained in standard operating tests where balance-impaired subjects were deprived of vision and proprioceptive inputs. Balance-impaired subjects who fell (into safety restraints) when not aided were able to stand with the prosthesis. Initial multiaxis tests with healthy subjects have shown that sway is reduced in both forward-back and sideward directions. Conclusions: Positive results in initial testing and a sound theoretical basis for the hardware warrant continued development and testing, which is being conducted at three sites.

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Limbu, Indra Kumar, Bishal Babu Basnet, and Sandhya Paudel. "Prosthetic rehabilitation of enucleated eye with semi-customized ocular prosthesis: A case report." Medical Journal of Pokhara Academy of Health Sciences 2, no. 3 (October 25, 2019): 169–72. http://dx.doi.org/10.3126/mjpahs.v2i3.26114.

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Eye is a vital organ not only for vision but it is also important component of facial expression. The disfigurement associated with loss of eye can cause significant physical and emotional problem. There are several techniques documented in the literature for fabricating the artificial eye. This is a case report of fabricating ocular prosthesis with stock iris and custom made sclera to provide aesthetically satisfactory result and better fit.

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Sharma, Prabal, and Bhumika Sharma. "Unconventional Dentures: A Manifestation of New Vision in Prosthesis Construction." Journal of Advanced Oral Research 11, no. 1 (May 2020): 101–8. http://dx.doi.org/10.1177/2320206820918738.

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Removable prosthesis, that is, complete and/or partial dentures cannot function as a substitute for natural dentition, but they have been and will remain the staple treatment for edentulous patients. An edentulous patient is found to be satisfied if prosthodontic rehabilitation restores his/her function with superior esthetics. However, not every case of edentulism, either complete or partial, can be treated with conventional methods of denture fabrication. When a patient is clinically presented with complications such as severely resorbed ridge, microstomia, hyperplastic and/or flabby tissue, xerostomia, osteoma, bruxism, and labially inclined premaxilla, then it becomes difficult for the dentist to fulfill the patient’s desire for both esthetics and function. There is a need for slight modification in the regular clinical procedures by altering the impression technique or the design of the prosthesis so as to achieve best results in compromised cases, commonly known as unconventional approaches. This article intends to highlight the unconventional approaches for the fabrication of complete denture prosthesis that can be kept in mind when such cases are encountered in our daily practice.

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Ferguson, Stewart, and Sherry Devereaux Ferguson. "High Resolution Vision Prosthesis Systems: Research after 15 Years." Journal of Visual Impairment & Blindness 80, no. 1 (January 1986): 523–27. http://dx.doi.org/10.1177/0145482x8608000102.

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Using an article by R. Fish, published a decade ago, as a point of departure, the authors propose that no significant advances in high resolution devices in vision substitution systems have been made since then. They claim that this lack of progress is a consequence of researchers failing to exploit the implications in certain of the theoretical insights on perception. They suggest alternative theoretical approaches which may help to move the work forward, as well as presenting new design criteria. Tactile substitution systems are proposed in preference to cortical implant work, and electrocutaneous transfer is offered in preference to vibrotactile techniques, which are seen as the major reason for the very limited resolution achieved by existing approaches.

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AL-SAJI, ALIA. "WHEN THINKING HESITATES: PHILOSOPHY AS PROSTHESIS AND TRANSFORMATIVE VISION." Southern Journal of Philosophy 50, no. 2 (June 2012): 351–61. http://dx.doi.org/10.1111/j.2041-6962.2012.00095.x.

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Bilteanu, Liviu, Ovidiu I. Geicu, Loredana Stanca, Aurelia M. Pisoschi, Florea Serban, Andreea I. Serban, and Valentin Calu. "Human Eye Optics within a Non-Euclidian Geometrical Approach and Some Implications in Vision Prosthetics Design." Biomolecules 11, no. 2 (February 4, 2021): 215. http://dx.doi.org/10.3390/biom11020215.

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An analogy with our previously published theory on the ionospheric auroral gyroscope provides a new perspective in human eye optics. Based on cone cells’ real distribution, we model the human eye macula as a pseudospherical surface. This allows the rigorous description of the photoreceptor cell densities in the parafoveal zones modeled further by an optimized paving method. The hexagonal photoreceptors’ distribution has been optimally projected on the elliptical pseudosphere, thus designing a prosthetic array counting almost 7000 pixel points. Thanks to the high morphological similarities to a normal human retina, the visual prosthesis performance in camera-free systems might be significantly improved.

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LUNDBORG, G., B. ROSÉN, K. LINDSTRÖM, and S. LINDBERG. "Artificial Sensibility Based on the Use of Piezoresistive Sensors." Journal of Hand Surgery 23, no. 5 (October 1998): 620–26. http://dx.doi.org/10.1016/s0266-7681(98)80016-8.

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Piezoresistive sensors, applied to the fingertips of non-sensate fingers, were used for the detection of touch and pressure in four patients with recent median nerve repairs, and in one patient using a myoelectric prosthesis. The signals from the sensors, produced by the tactile stimuli, were processed and transposed as electrical stimuli to sensate skin of the ipsi- or contralateral arm by the use of skin electrodes. With this setup the test subjects could rapidly learn to differentiate between tactile stimuli applied to different fingers, thereby regaining spatial, resolution in the hand. All five patients rapidly improved their ability to regulate the power of pinch grip without the help of vision. The patient with a hand prosthesis rapidly learned to discriminate between four different levels of pressure, applied to the thumb by four different Semmes-Weinstein monofilaments (75, 125, 280 and 450 g). These results indicate that the system is of potential value for patients lacking sensibility or using prostheses.

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Constandinou, Timothy G., Julius Georgiou, and Chris Toumazou. "Towards an Integrated, Fully-Implantable Vestibular Prosthesis for Balance Restoration." Advances in Science and Technology 57 (September 2008): 210–15. http://dx.doi.org/10.4028/www.scientific.net/ast.57.210.

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Neuroprosthetics is a relatively new topic but it has already shown its potential. Since the application of this science, it has already significantly improved the quality of life of over 60,000 individuals who previously suffered from severely impaired hearing or total deafness. Today, through use of cochlear implants, children born totally deaf can enjoy going to regular schools and communicating normally. Individuals suffering from dizziness and balance disorders can also benefit from the progress made in cochlear prosthetics. The inner ear's vestibular system provides cues about self-motion and help stabilise vision during movement. Damage to this system can result in dizziness, imbalance, blurred vision and instability in locomotion, a leading cause of death in the elderly. We propose a hybrid CMOS/MEMS platform for bypassing a dysfunctional pathway in individuals that suffer from balance-related disorders. Combining MEMS-based inertia sensing with CMOS-based neural monitoring and processing electronics, this prosthesis aims to deliver a corrective artificial stimulus to the vestibulocochlear (VIII) nerve. We describe a novel system outlining the architectural aspects and implementation methodology used in the design.

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Nino-de-Rivera y Oyarzabal, Luis, Alejandra Alcala D, Miguel Cruz Irisson, and Vladimir Il'ich Ponomarev. "A Biocompatible PMMA Encapsulated Vision Prosthesis Case for Silicon Retina." Telecommunications and Radio Engineering 64, no. 12 (2005): 1047–56. http://dx.doi.org/10.1615/telecomradeng.v64.i12.70.

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34

Belafsky, Peter C., Gregory N. Postma, and James A. Koufman. "Replacement of a Failed Tracheoesophageal Puncture Prosthesis under Direct Vision." Ear, Nose & Throat Journal 80, no. 12 (December 2001): 862. http://dx.doi.org/10.1177/014556130108001207.

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35

Degenaar, Patrick, Nir Grossman, Muhammad Ali Memon, Juan Burrone, Martin Dawson, Emmanuel Drakakis, Mark Neil, and Konstantin Nikolic. "Optobionic vision—a new genetically enhanced light on retinal prosthesis." Journal of Neural Engineering 6, no. 3 (May 20, 2009): 035007. http://dx.doi.org/10.1088/1741-2560/6/3/035007.

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Ohta, Jun, Norikatsu Yoshida, Keiichiro Kagawa, and Masahiro Nunoshita. "Proposal of Application of Pulsed Vision Chip for Retinal Prosthesis." Japanese Journal of Applied Physics 41, Part 1, No. 4B (April 30, 2002): 2322–25. http://dx.doi.org/10.1143/jjap.41.2322.

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Tsai, D., J. W. Morley, G. J. Suaning, and N. H. Lovell. "A wearable real-time image processor for a vision prosthesis." Computer Methods and Programs in Biomedicine 95, no. 3 (September 2009): 258–69. http://dx.doi.org/10.1016/j.cmpb.2009.03.009.

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Leow, Michael E. L., Richard K. K. Ow, Man Hang Lee, Chan Yiong Huak, and Robert W. H. Pho. "Assessment of Colour Differences in Silicone Hand and Digit Prostheses: Perceptible and Acceptable Thresholds for Fair and Dark Skin Shades." Prosthetics and Orthotics International 30, no. 1 (April 2006): 5–16. http://dx.doi.org/10.1080/03093640500465096.

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This study addresses the dilemma of initial clinical and social acceptance of a newly fabricated silicone prosthesis in relation to its colour match to the natural skin. This was achieved by derivation of specific colour difference thresholds defining perceptible and acceptable levels of colour sensitivity. Two separate sets of 10 fair and dark shade digit prosthesis samples were each fabricated with a stepped increase in colour difference (Δ E) against the baseline hand prosthesis. Ninety individuals with normal colour vision scores were selected as colour assessors. The colour difference of each prosthesis in the two series was evaluated visually against the baseline by the assessors, using defined scores. The thresholds for perceptible and acceptable colour difference determined in this study were Δ E = 0.8 and Δ E = 1.8 for the fair series and Δ E = 1.3 and Δ E = 2.6 for the dark series, respectively. The acceptable threshold values differed from the perceptible threshold values by Δ E = 1.0 for the fair-shade samples and Δ E = 1.3 for the dark-shade samples. This study demonstrated that subjective visual assessment is positively correlated with Δ E values computed from colorimetric measurements for both fair and dark-shade silicone samples (p<0.001). This results shows that human subjects with normal colour vision are capable of accurately assessing colour differences. These observations emphasize the importance of subjective feedback on colour by the patient, provided the latter has perfect colour-tested vision. The study also showed that human subjects were less sensitive to perceived colour differences in darker-shade than fairer-shade samples (p<0.001). This finding seems relevant in a clinical setting involving a multi-ethnic patient population.

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Singh, Tanuja, Suraj Ram Bhakta Mathema, and Pratik Manandhar. "Conventional Approach for Fabrication of Orbital Prosthesis: A Case Report." Birat Journal of Health Sciences 3, no. 2 (September 5, 2018): 495–99. http://dx.doi.org/10.3126/bjhs.v3i2.20969.

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Facial defect rehabilitation is a very critical task which requires personalized design of the prosthesis for each patient. Eyes are vital organ not only for vision but also for the facial expression. Disfigurement due to loss of an eye and associated structures may cause physical and psychological distress to the patient. Rehabilitating such patient with a removable orbital prosthesis is an economical and patient-friendly procedure which restores the patient's social as well as the cosmetic value. The present article describes a conventional technique for the fabrication of a spectacle retained acrylic resin orbital prosthesis providing accurate and effective rehabilitation. BJHS 2018;3(2)6:495-499.

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BARRETT, JOHN MARTIN, ROLANDO BERLINGUER-PALMINI, and PATRICK DEGENAAR. "Optogenetic approaches to retinal prosthesis." Visual Neuroscience 31, no. 4-5 (August 6, 2014): 345–54. http://dx.doi.org/10.1017/s0952523814000212.

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AbstractThe concept of visual restoration via retinal prosthesis arguably started in 1992 with the discovery that some of the retinal cells were still intact in those with the retinitis pigmentosa disease. Two decades later, the first commercially available devices have the capability to allow users to identify basic shapes. Such devices are still very far from returning vision beyond the legal blindness. Thus, there is considerable continued development of electrode materials, and structures and electronic control mechanisms to increase both resolution and contrast. In parallel, the field of optogenetics—the genetic photosensitization of neural tissue holds particular promise for new approaches. Given that the eye is transparent, photosensitizing remaining neural layers of the eye and illuminating from the outside could prove to be less invasive, cheaper, and more effective than present approaches. As we move toward human trials in the coming years, this review explores the core technological and biological challenges related to the gene therapy and the high radiance optical stimulation requirement.

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Markowitz, Michelle, Mark Rankin, Mohamed Mongy, Beatrice E. Patino, Joshua Manusow, Robert G. Devenyi, and Samuel N. Markowitz. "Rehabilitation of lost functional vision with the Argus II retinal prosthesis." Canadian Journal of Ophthalmology 53, no. 1 (February 2018): 14–22. http://dx.doi.org/10.1016/j.jcjo.2017.12.001.

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Bellapianta, Alessandro, Ana Cetkovic, Matthias Bolz, and Ahmad Salti. "Retinal Organoids and Retinal Prostheses: An Overview." International Journal of Molecular Sciences 23, no. 6 (March 8, 2022): 2922. http://dx.doi.org/10.3390/ijms23062922.

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Despite the progress of modern medicine in the last decades, millions of people diagnosed with retinal dystrophies (RDs), such as retinitis pigmentosa, or age-related diseases, such as age-related macular degeneration, are suffering from severe visual impairment or even legal blindness. On the one hand, the reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) and the progress of three-dimensional (3D) retinal organoids (ROs) technology provide a great opportunity to study, understand, and even treat retinal diseases. On the other hand, research advances in the field of electronic retinal prosthesis using inorganic photovoltaic polymers and the emergence of organic semiconductors represent an encouraging therapeutical strategy to restore vision to patients at the late onset of the disease. This review will provide an overview of the latest advancement in both fields. We first describe the retina and the photoreceptors, briefly mention the most used RD animal models, then focus on the latest RO differentiation protocols, carry out an overview of the current technology on inorganic and organic retinal prostheses to restore vision, and finally summarize the potential utility and applications of ROs.

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Abouelseoud, Gehan, Yasmine Abouelseoud, Amin Shoukry, Nour Ismail, and Jaidaa Mekky. "A mixed integer linear programming framework for improving cortical vision prosthesis designs." Biomedical Signal Processing and Control 80 (February 2023): 104253. http://dx.doi.org/10.1016/j.bspc.2022.104253.

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Plaza, Paula, Isabel Cuevas, Cécile Grandin, Anne G. De Volder, and Laurent Renier. "Looking into Task-Specific Activation Using a Prosthesis Substituting Vision with Audition." ISRN Rehabilitation 2012 (February 6, 2012): 1–15. http://dx.doi.org/10.5402/2012/490950.

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A visual-to-auditory sensory substitution device initially developed for the blind is known to allow visual-like perception through sequential exploratory strategies. Here we used functional magnetic resonance imaging (fMRI) to test whether processing the location versus the orientation of simple (elementary) “visual” stimuli encoded into sounds using the device modulates the brain activity within the dorsal visual stream in the absence of sequential exploration of these stimuli. Location and orientation detection with the device induced a similar recruitment of frontoparietal brain areas in blindfolded sighted subjects as the corresponding tasks using the same stimuli in the same subjects in vision. We observed a similar preference of the right superior parietal lobule for spatial localization over orientation processing in both sensory modalities. This provides evidence that the parietal cortex activation during the use of the prosthesis is task related and further indicates the multisensory recruitment of the dorsal visual pathway in spatial processing.

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Christie, Breanne P., Kari R. Ashmont, Paul A. House, and Bradley Greger. "Approaches to a cortical vision prosthesis: implications of electrode size and placement." Journal of Neural Engineering 13, no. 2 (February 23, 2016): 025003. http://dx.doi.org/10.1088/1741-2560/13/2/025003.

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Barnes, Nick, Adele F. Scott, Paulette Lieby, Matthew A. Petoe, Chris McCarthy, Ashley Stacey, Lauren N. Ayton, et al. "Vision function testing for a suprachoroidal retinal prosthesis: effects of image filtering." Journal of Neural Engineering 13, no. 3 (April 25, 2016): 036013. http://dx.doi.org/10.1088/1741-2560/13/3/036013.

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Lo, Pei-An, Kyana Huang, Qifa Zhou, Mark S. Humayun, and Lan Yue. "Ultrasonic Retinal Neuromodulation and Acoustic Retinal Prosthesis." Micromachines 11, no. 10 (October 13, 2020): 929. http://dx.doi.org/10.3390/mi11100929.

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Ultrasound is an emerging method for non-invasive neuromodulation. Studies in the past have demonstrated that ultrasound can reversibly activate and inhibit neural activities in the brain. Recent research shows the possibility of using ultrasound ranging from 0.5 to 43 MHz in acoustic frequency to activate the retinal neurons without causing detectable damages to the cells. This review recapitulates pilot studies that explored retinal responses to the ultrasound exposure, discusses the advantages and limitations of the ultrasonic stimulation, and offers an overview of engineering perspectives in developing an acoustic retinal prosthesis. For comparison, this article also presents studies in the ultrasonic stimulation of the visual cortex. Despite that, the summarized research is still in an early stage; ultrasonic retinal stimulation appears to be a viable technology that exhibits enormous therapeutic potential for non-invasive vision restoration.

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Akano, Theddeus Tochukwu. "Numerical Study of Prosthetic Knee Replacement Using Finite Element Analysis." Journal of Biomimetics, Biomaterials and Biomedical Engineering 44 (February 2020): 9–26. http://dx.doi.org/10.4028/www.scientific.net/jbbbe.44.9.

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The knee at times undergoes a surgical process to substitute the weight-bearing surfaces of the knee joint. This procedure relieves the pain and disability around the knee joint. This research paper studied the knee arthroplasty, also referred to as knee replacement. This work was aided with computer vision for visual and accuracy. Autodesk fusion 360 and the stl files were used to generate cemented, posterior stabilised knee prosthesis and imported into the COMSOL Multiphysics software. Then, the three-dimensional models of the total knee arthroplasty (TKA) prosthetic structure are produced. The prosthetic components are modelled as linear isotropic elastic materials. Finite element (FE) simulations using COMSOL Multiphysics on a CAD model of a knee are effectuated to show the effect of several loads and strains on the knee. FE analysis of the model indicates that the orthotropic model depicts a more realistic stress distribution of the knee as it reveals the detailed anatomy of the entire knee structure. The computational results of this work displayed a fair agreement with experimental information from the literature.

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Kerdraon, Yves A., John A. Downie, Gregg J. Suaning, Malcolm R. Capon, Minas T. Coroneo, and Nigel H. Lovell. "Development and surgical implantation of a vision prosthesis model into the ovine eye." Clinical & Experimental Ophthalmology 30, no. 1 (February 2002): 36–40. http://dx.doi.org/10.1046/j.1442-9071.2002.00485.x.

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Vander, J. F. "Feasibility Study of a Retinal Prosthesis: Spatial Vision With a 16-Electrode Implant." Yearbook of Ophthalmology 2010 (January 2010): 150–51. http://dx.doi.org/10.1016/s0084-392x(09)79189-0.

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Journal articles on the topic 'Vision prosthesis'

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