The Blind Shall See, the Deaf Shall Hear
For centuries the idea of curing the blind or deaf was considered miraculous or even biblical. However, recent advances in biomedical technologies have made these ideas a reality. Scientists have been using neural implants to convert natural signals the brain receives from the sensory organs and converts them into electronic input channels. Even though the researchers do not understand every detail of the brain's function, they are understanding the neural codes which the sensory organs (such as the eyes, ears, nose, etc.) give off.
These devices researchers and engineers have created are know as Digital Signal Processors, or DSP's. These DSPs use a variety of microphones, video cameras, pheromone detectors, and pressure sensors to give off sensory input, which is then encoded into neural spike-train and sent to the brain.
One example of this technology is implants for the deaf. In the ear, the cochlea transduces the sound waves vibrating the eardrum, the send a spike train down the nerves and into the brain where it is processed. Those who have hearing problems or are completely deaf usually suffer from damage or some other problem concerning the cochlea. Therefore, these people are in need of artificial cochleas. Physicians can implant a small encased device that connects to the nerve and send aural pulses to the brain. These devices communicate with an electronic ear clip with a microphone, a radio frequency transmitter, and a DSP transmitter. These devices have successfully allowed previously deaf people to hear again, thanks to a combination of medical researchers and engineers.
Another example of these DSPs are the creation of the artificial retina. Artificial retinas have been inserted into patients suffering from retinitis pigmentosa and macular degeneration. These devices consist of mostly an analog chip, roughly 3mm^2, that stimulate the ganglion cells, which are prewired to the optic nerve, resulting in a new stimulation of the visual cortex. After a couple of weeks of adaptation, the user will be able to see very blurringly, but see nonetheless.
This design consists of a video camera mounted on a pair of glasses which sends a mega-pixel scene to a pack worn on the belt, where the DSP and the microcontroller encode the image into a pulse train similar to a natural retina. From there a high radio frequency transmits the information to the implanted artificial retina, which then stimulates ganglion cells.
As of right now the artificial retina far from behaving like a natural retina. Unlike natural retinas that contain millions of neurons in the eye, the artificial retina prototypes of today have a grand total of 16 electrodes. Nonetheless, patients that have had the artificial retina implanted were able to distinguish between two objects after several weeks.
The series of prototypes will consist of greater numbers of pixels, ranging from 64 to 100 pixels. Scientists hope that by the third stage of development, they will be able to use a chip containing 1064 electrodes, but hardware problems such as trying to fit that many electrodes on one chip may prove difficult.
http://www.eetimes.com/story/OEG20030923S0053
These devices researchers and engineers have created are know as Digital Signal Processors, or DSP's. These DSPs use a variety of microphones, video cameras, pheromone detectors, and pressure sensors to give off sensory input, which is then encoded into neural spike-train and sent to the brain.
One example of this technology is implants for the deaf. In the ear, the cochlea transduces the sound waves vibrating the eardrum, the send a spike train down the nerves and into the brain where it is processed. Those who have hearing problems or are completely deaf usually suffer from damage or some other problem concerning the cochlea. Therefore, these people are in need of artificial cochleas. Physicians can implant a small encased device that connects to the nerve and send aural pulses to the brain. These devices communicate with an electronic ear clip with a microphone, a radio frequency transmitter, and a DSP transmitter. These devices have successfully allowed previously deaf people to hear again, thanks to a combination of medical researchers and engineers.
Another example of these DSPs are the creation of the artificial retina. Artificial retinas have been inserted into patients suffering from retinitis pigmentosa and macular degeneration. These devices consist of mostly an analog chip, roughly 3mm^2, that stimulate the ganglion cells, which are prewired to the optic nerve, resulting in a new stimulation of the visual cortex. After a couple of weeks of adaptation, the user will be able to see very blurringly, but see nonetheless.
This design consists of a video camera mounted on a pair of glasses which sends a mega-pixel scene to a pack worn on the belt, where the DSP and the microcontroller encode the image into a pulse train similar to a natural retina. From there a high radio frequency transmits the information to the implanted artificial retina, which then stimulates ganglion cells.
As of right now the artificial retina far from behaving like a natural retina. Unlike natural retinas that contain millions of neurons in the eye, the artificial retina prototypes of today have a grand total of 16 electrodes. Nonetheless, patients that have had the artificial retina implanted were able to distinguish between two objects after several weeks.
The series of prototypes will consist of greater numbers of pixels, ranging from 64 to 100 pixels. Scientists hope that by the third stage of development, they will be able to use a chip containing 1064 electrodes, but hardware problems such as trying to fit that many electrodes on one chip may prove difficult.
http://www.eetimes.com/story/OEG20030923S0053
posted by Andrew Moorman at 2:23 PM
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Thank you for providing such a valuable information and thanks for sharing this matter.
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