by: Jason Mick
Scientists are conquering some of the greatest challenges in the field of vision
Previously, DailyTech reported on Second Sight Vision's efforts to bring partial vision to the blind through wireless retinal implants. The company has a strong competitor, though. Researchers at
Aachen University Clinic and the Fraunhofer Institute for Microelectronic Circuits in Germany are pursuing a similar line of research and have also been experiencing strong results.
The Institute's EPI-RET project has been running for 12 years and has sought to find ways to offer relief to the over 30 million people suffering from retinal diseases. In September 2007, during a clinical study with six patients, it was shown that the group's completely implantable vision prosthesis both was feasible and allowed patients to perceive visual images.
Dr. Hoc Khiem Trieu from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg comments, "For normally sighted people that may not seem much, but for the Blind, it is a major step. After years of blindness, the patients were able to see spots of light or geometric patterns, depending on how the nerve cells were stimulated."
The project has been funded by the German Ministry of Education and Research. Dr. Trieu worked closely with colleagues Dr. Ingo Krisch and Dipl.-Ing. Michael Görtz and medical professionals to translating medical specifications into an engineered implant.
The researchers state that the major breakthrough is making the system's communication wireless. Says Dr. Ingo Krisch, "A milestone was reached when the prosthetic system finally operated wirelessly and remotely controlled. A great deal of detailed work was necessary before the implant could be activated without any external cable connections."
Colleague Görtz adds, "The designs became smaller and smaller, the materials more flexible, more robust and higher in performance, so that the implant now fits comfortably in the eye."
Similar to the Second Sight Vision implant, the EPI-RET implant utilizes a CMOS camera in glasses frames to capture images. This image is then transferred to the implant wirelessly, which stimulates retinal cells. The implant consists of an array of 25 electrodes (5x5) connected to ganglion cells. This falls somewhere between Second Sight Vision's original model used in clinical tests, which used a 4x4 grid of electrodes, and its current model, which has an asymmetric 10x6 grid.
The EPI-RET project team hopes to up the number of electrodes in the finished project. Their Institute has created a spin-off EPI-RET GmbH, which seeks to market the technology. After another round of clinical trials, the implants are expected to be offered commercially within three years, according to researchers. While some might dismiss this team's parallel efforts, it promises to make the field of ocular implants more competitive.
And that’s not the only vision advance that the Germans are cooking up. Researchers at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena are working on developing an ultra thin imaging sensor, which acts as a compound eye and is modeled after insect eyes in nature. Researcher Andreas Brückner is leading the effort to look at ways to dramatically improve the accuracy of existing imaging sensors by adopting compound eye algorithms, allow the sensors to be potential shrunk, while keeping equivalent accuracy.
Insect eyes, while not high resolution, perceive the world in great detail. This is due to a phenomenon known as hyperacuity. As the visual fields of adjacent facets overlap, the eyes see more than the resolution itself. The result is a higher effective resolution than the physical resolution when the images are processed. Andreas Brückner is working to mimic the phenomena in a man-made imaging system.
Andreas Brückner states, "The aim was to develop micro-optical compound eyes which contain numerous parallel imaging channels and which are also extremely compact, thinner than 0.5 millimeters"
After creating a multifaceted sensor, Brückner analyzed the angular sensitivity of the facets. By overlapping, based on this analysis, the sensor is able to determine positions from 2D images much more accurately than its resolution would otherwise allow. In a comparison a 50 x 50 pixel image sensor set up as a compound eye could detect spatial relations equivalent to a traditional 625 x 625 pixel sensor.
The improved resolution will allow sensors to be shrunk. It will also offer better object recognition, size and position analysis, and movement tracking. All of these are invaluable advances to industrial and robotics applications.
According to the institute commercialization is well underway. It states that current tracks include "solar altitude sensors in automobiles, for recognizing traffic lanes in driver assistance systems, and in machine vision."
With the exciting groundbreaking efforts in vision research in the U.S., Germany, and elsewhere, it seems that many sight related diseases are approaching partial cures, and that sighted applications like robotics will undergo dramatic improvements, implementing new designs.
