Simulating Vision through Retinal Prothesis: Difference between revisions
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= Introduction = | = Introduction = | ||
Retinal degenerative diseases such as age-related macular degeneration or retinitis pigmentosa are among the leading causes of blindness in the developed world. These diseases lead to a loss of photoreceptors, while the inner retinal neurons survive to a large extent. Electrical stimulation of the surviving retinal neurons has been achieved either epiretinally, in which case the primary targets of stimulation are the retinal ganglion cells (RGCs), or subretinally to bypass the degenerated photoreceptors and use neurons in the inner nuclear layer (bipolar, amacrine and horizontal cells) as primary targets. Other fully optical approaches to restoration of sight include optogenetics, in which retinal neurons are transfected to express light-sensitive Na and Cl channels, small- molecule photoswitches which bind to K channels and make them light sensitive [22] or photovoltaic implants based on thin-film polymers. | Retinal degenerative diseases such as age-related macular degeneration or retinitis pigmentosa are among the leading causes of blindness in the developed world. These diseases lead to a loss of photoreceptors, while the inner retinal neurons survive to a large extent. Electrical stimulation of the surviving retinal neurons has been achieved either epiretinally, in which case the primary targets of stimulation are the retinal ganglion cells (RGCs), or subretinally to bypass the degenerated photoreceptors and use neurons in the inner nuclear layer (bipolar, amacrine and horizontal cells) as primary targets. Other fully optical approaches to restoration of sight include optogenetics, in which retinal neurons are transfected to express light-sensitive Na and Cl channels, small- molecule photoswitches which bind to K channels and make them light sensitive [22] or photovoltaic implants based on thin-film polymers. | ||
Recent clinical studies with epiretinal and subretinal prosthetic systems have demonstrated improvements of the visual function in certain tasks, with some patients being able to identify letters with equivalent visual acuity of up to 20/550. Despite progress in improving visual acuity, normal vision at this resolution lacks much functionality. Simulating vision through retinal prothesis, as well as processing the image through various means could determine better methods in transferring information through the retina at this limited bandwidth. | Recent clinical studies with epiretinal and subretinal prosthetic systems have demonstrated improvements of the visual function in certain tasks, with some patients being able to identify letters with equivalent visual acuity of up to 20/550. Despite progress in improving visual acuity, normal vision at this resolution lacks much functionality. Simulating vision through retinal prothesis, as well as processing the image through various means could determine better methods in transferring information through the retina at this limited bandwidth. | ||
== What Has Been Done in the Past == | == What Has Been Done in the Past == | ||
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=== Project Xense === | === Project Xense === | ||
Developed at the Entertainment Technology Center at Carnegie Mellon University, Project Xense is a collection of three musuem exhibits about medical implants and prostheses technology. One of these exhibits simulate vision through a retinal implant. Guests wear a head-mounted display equipped with a camera; the display will show video from the camera that has been processed in real-time to resemble the low-resolution vision afforded by retinal implants. | Developed at the Entertainment Technology Center at Carnegie Mellon University, Project Xense is a collection of three musuem exhibits about medical implants and prostheses technology. One of these exhibits simulate vision through a retinal implant. Guests wear a head-mounted display equipped with a camera; the display will show video from the camera that has been processed in real-time to resemble the low-resolution vision afforded by retinal implants. | ||
[[File:Xense1.png|800px|center]] | |||
When guests put on the head-mounted display, their field of vision will be blocked out and replaced by small screens that show processed live video from a camera mounted on the headset. The processed video reduces images into a black-and-white grid based on brightness; the resolution of the grid directly corresponds to different important historical and theoretical milestones in retinal implant technology. If guests press the control buttons, they can scan through these various resolutions to experience what it would be like to have the corresponding retinal implant. | When guests put on the head-mounted display, their field of vision will be blocked out and replaced by small screens that show processed live video from a camera mounted on the headset. The processed video reduces images into a black-and-white grid based on brightness; the resolution of the grid directly corresponds to different important historical and theoretical milestones in retinal implant technology. If guests press the control buttons, they can scan through these various resolutions to experience what it would be like to have the corresponding retinal implant. | ||
[[File:Xense2.png|800px|center]] | [[File:Xense2.png|800px|center]] | ||
== What We Intend to Do == | == What We Intend to Do == | ||
Revision as of 06:26, 18 March 2014
Group Members: Alex Martinez
Back to Psych 221 Projects 2014
Introduction
Retinal degenerative diseases such as age-related macular degeneration or retinitis pigmentosa are among the leading causes of blindness in the developed world. These diseases lead to a loss of photoreceptors, while the inner retinal neurons survive to a large extent. Electrical stimulation of the surviving retinal neurons has been achieved either epiretinally, in which case the primary targets of stimulation are the retinal ganglion cells (RGCs), or subretinally to bypass the degenerated photoreceptors and use neurons in the inner nuclear layer (bipolar, amacrine and horizontal cells) as primary targets. Other fully optical approaches to restoration of sight include optogenetics, in which retinal neurons are transfected to express light-sensitive Na and Cl channels, small- molecule photoswitches which bind to K channels and make them light sensitive [22] or photovoltaic implants based on thin-film polymers.
Recent clinical studies with epiretinal and subretinal prosthetic systems have demonstrated improvements of the visual function in certain tasks, with some patients being able to identify letters with equivalent visual acuity of up to 20/550. Despite progress in improving visual acuity, normal vision at this resolution lacks much functionality. Simulating vision through retinal prothesis, as well as processing the image through various means could determine better methods in transferring information through the retina at this limited bandwidth.
What Has Been Done in the Past
Our group investigated prior simulations and descriptions given by patients about their restored vision.
Project Xense
Developed at the Entertainment Technology Center at Carnegie Mellon University, Project Xense is a collection of three musuem exhibits about medical implants and prostheses technology. One of these exhibits simulate vision through a retinal implant. Guests wear a head-mounted display equipped with a camera; the display will show video from the camera that has been processed in real-time to resemble the low-resolution vision afforded by retinal implants.
When guests put on the head-mounted display, their field of vision will be blocked out and replaced by small screens that show processed live video from a camera mounted on the headset. The processed video reduces images into a black-and-white grid based on brightness; the resolution of the grid directly corresponds to different important historical and theoretical milestones in retinal implant technology. If guests press the control buttons, they can scan through these various resolutions to experience what it would be like to have the corresponding retinal implant.
What We Intend to Do
Develop a Simulation that incorporates computer vision, such a facial recognition, in enhancing what information is sent to the patient.
Background
Methods
Results
Conclusions and Future Work
References - Resources and related work
References
[1] "Project Xense Retinal Implant Simulation" etc.cmu.edu. Carnegie Mellon University, 2012. Web. 14 Mar 2014. <http://www.etc.cmu.edu/projects/tatrc>.
[2] "Photo to colored dot patterns with OpenCV" opencv-code.com OpenCV Code, Feb 13, 2013. Web. 3 Mar 2014 <https://opencv-code.com/tutorials/photo-to-colored-dot-patterns-with-opencv>.
[3] "Introduction to OpenCV" opencv-python-tutroals.readthedocs.org. OpenCV-Python Tutorials, 18 Feb 2014. Web. 15 Mar 2014. <http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_setup/py_table_of_contents_setup/py_table_of_contents_setup.html>
[4] Brian A. Wandell, Foundations of Vision, Chapter 9. https://www.stanford.edu/group/vista/cgi-bin/FOV/chapter-9-color/#Linear_Models
Software
Image Systems Engineering Toolbox http://imageval.com/
Python OpenCV http://http://opencv.org/
Appendix I - Code and Data
In the belief that the techniques used may be illustrated best by example, the Python code used to perform the image processing is available below.
Code
All code was written in Python 2.7.5 for Mac OSX, Mavericks. External dependencies include the OpenCV and NumPy
Presentation
This project was given as a 5-minute presentation to the PSYCH221 Winter 2013 class at Stanford. The presentation files used are linked below.