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Wm. H. Dobelle, Ph.D.

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Wm. Dobelle, Joao Lobo Antunes, Domingos Coiteiro, John Girvin

We report eight patients, from six countries, implanted with the first commercially-available artificial vision systems. This system depends on implants on the visual cortex. Results are preliminary, but include thresholds, visual fields, color, and performance of electrode arrays implanted simultaneously on both hemispheres. Efforts are focusing on the use of pre-processing (edge detection) for a variety of endeavors, including driving a car.

Jens Driving Car

Backing the car was difficult because the rear mirrors did not provide enough resolution. Jen's solution-simply stick your head out the window

  1. 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

  2. All eight (8) patients had an uncomplicated hospital course after implantation in April, 2002. There have been no infections.
  3. All sixteen (16) electrode arrays, implanted on both hemispheres of each patient, produced good phosphenes.
  4. All efforts to stimulate phosphenes were complicated by patients' inability to fixate. the eye musculature, in most cases, was weak or absent.
  5. Phosphene thresholds are uniformly low (e.g. below 16 miliamps).
  6. 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.
  7. 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).
  8. Four of the eight patients report colored phosphenes. They are the first blind patients to report color.
  9. 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.
  10. 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.
  11. 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.

  1. Dobelle,W.H., Artificial Vision for Blind by Connecting a Television Camera to a Visual Cortex, ASAIO Journal 2000; 46:3-9.
  2. Sobel l: Camera models and machine perception. AIM-21, Stanford Artificial Intelligence Laboratory, Palo Alto, California, 1970.

From The Dobelle Institute (Portugal) Lda.

Submitted June 13th 2002

Reprint Requests to:
Wm. H. Dobelle
Avenida Infante Santo, 34
Lisboa, 1350-179

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