Automated visual assessment system with steady state visual evoked potential stimulator and product detector

A visual testing apparatus, comprising:

• control means for stimulating the visual system of patient with a test image at a stimulus frequency during a selected one of refractometry, acuity, astigmatism, contrast and color vision tests;
• sensing means for detecting evoked potentials produced by the test image in the patient's brain at the stimulus frequency during the selected test, said sensing means comprising:
• self-preparing electrodes attachable to the patient's head for detecting evoked potentials;
• and
• a product detector, operatively connected to said electrodes and said analysis means, for detecting the amplitude of the evoked potentials at the stimulus frequency;
• and
• analysis means for analyzing the evoked potentials produced by the patient during the selected test and displaying the results of the selected test.

A visual testing apparatus, comprising:

• control means for stimulating the visual system of a patient with a test image at a stimulus frequency during a selected one of refractometry, acuity, astigmatism, contrast and color vision tests;
• sensing means for detecting evoked potentials produced by the test image in the patient's brain at the stimulus frequency during the selected test, said sensing means comprising:
• self-preparing electrodes attachable to the patient's head for detecting evoked potentials;
• and
• a product detector, operatively connected to said electrodes, for detecting the amplitude of the evoked potentials at the stimulus frequency;
• analysis means for analyzing the evoked potentials produced by the patient during the selected test and displaying the results of the selected test;
• and
• a reference product detector for detecting brain wave activity at a frequency other than the stimulus frequency, the amplitude detected by said product detector is adjusted by aid analysis means using the brain wave activity detected by said reference product detector.

A visual testing apparatus, comprising:

• control means for stimulating the visual system of a patient with a test image at a stimulus frequency during a selected one of refractometry, acuity, astigmatism, contrast and color vision tests;
• sensing means for detecting evoked potentials produced by the test image in the patient's brain at the stimulus frequency during the selected test;
• and
• analysis means for analyzing the evoked potentials produce by the patient during the selected test and displaying the results of the selected test, said analysis means comprising a computer that filters the evoked potentials, produces result curves, and produces results values based on the result curves.

A stimulus generator for a patient, comprising:

• first and second light sources each having red, green and blue light sources;
• a patterned mirror, the first light source producing light that passes through the mirror to the patient, the second light source producing light reflected off the mirror to the patient;
• and
• light control means for changing activation times of the red, green and blue sources.

A stimulus generator for a patient, comprising:

• first and second light sources;
• a patterned mirror, the first light source producing light that passes through the mirror to the patient, the second light source producing light reflected off the mirror to the patient;
• a third light source washing out light from the mirror, said first through third light sources producing continuous light;
• first polarizing means for polarizing the light from the first and second sources in a first direction;
• second polarizing means for polarizing the light from the third source in a second direction perpendicular to the first direction;
• and
• a rotatable polarizer through which the light from the mirror and the third source pass.

An apparatus for determining a display to which an observer is paying attention, said apparatus comprising:

• display means simultaneously producing images that flicker at different frequencies, the observer viewing said display means;
• detection means, coupled to the observer by electrode means for contacting the observer's head, for detecting the amplitude of evoked potentials produced in the observer's brain at the different frequencies;
• and
• comparison means, operatively connected to said detection means and including means for storing amplitudes, for determining which amplitude is the largest, the largest amplitude indicating which of said display means is receiving the greatest amount of attention.