Blinden kunnen weer zien


Middels een techniek ontwikkelt door Dobelle kunnen mensen die blind waren weer zien.Dobelle heeft 8 patienten onderzocht. Hieronder een samenvatting:
# Patients are summarized in Table 1.

Jens 39 Canada Metal Penetration 18 years
Dennis 27 USA Auto Accident 6 years
Gerald 77 USA Mortar Shell 57 years
Kenneth 70 England Alkaline Burns 4 years
Marina 41 Italy Auto Accident 22 years
Edmundo 51 Argentina Auto Accident 29 years
Keith 42 USA Anesthesia Accident 2 years
Klaus 51 Germany Right, Since Birth
Left, From Infection
5 years

# All eight (8) patients had an uncomplicated hospital course after implantation in April, 2002. There have been no infections.
# All sixteen (16) electrode arrays, implanted on both hemispheres of each patient, produced good phosphenes.
# All efforts to stimulate phosphenes were complicated by patients’ inability to fixate. the eye musculature, in most cases, was weak or absent.
# Phosphene thresholds are uniformly low (e.g. below 16 miliamps).
# Mapping was conducted using relationships among the phosphenes by stimulating two or more phosphenes and getting a description. Efforts to achieve an absolute map were complicated by eye movements.
# Visual fields vary. At arms length they are approximately 22 inches by 14 inches (as compared to 8 inches by 3 inches in Jerry the prototype patient).
# Four of the eight patients report colored phosphenes. They are the first blind patients to report color.
# One patient, who was 20 years old when he lost his vision in a WW II mortar explosion, saw good phosphenes 57 years later. One of our earlier patients (1) lost his sight at age five and was implanted at age 68. He never saw anything and this may be related to the fact that he was blinded in childhood before the visual cortex fully developed.
# One patient lost his first eye at infancy and his second at age 45 due to an infection. He saw good phosphenes, as did another patient who lost his eyes in separate accidents at ages 19 and 22. This suggests that the time course of blindness, at least if blinded as an adult, has little effect on phosphenes.
# Using Sobel edge detection algorhythms (2) patients were able to detect people in light colored clothing, whether they are stretching out their arms or not. They also detect straight edges, including a cane and even a pencil. Both could drive a car, albeit slowly and entirely on private property. A third patient exhibited similar skills within ten minutes after the camera was connected, but other patients may require a period of training similar to that required by cochlear implant patients.

Het lijkt dus een veelbelovende techniek.
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