# US 4,392,725 A · Device for blind spot delineation

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- Number: US 4,392,725 A
- Document ID: US4392725A
- Status: Granted
- Kind: A
- Application number: 06/124,101
- Filed: 1980-02-25
- Granted: 1983-07-12
- Earliest claimed: 1978-12-05
- Inventors: Larry A. Sheingorn
- Web page: https://patentgrep.com/patent/US4392725A

## CPC

- A61B 3/024: for determining the visual field, e.g. perimeter types
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A self-contained, solid state device, with no moving parts, that determines visual field defects is disclosed. The device employs a tangent screen containing LEDs which are illuminated in sequence to test the visual field of the patient. The device utilizes a memory unit for recording and displaying the test results.

## Claims

### Claim 1

A self-contained, solid state device, with no moving parts, that determines visual field defects, comprising:
(a) a surface with lamps mounted therein connected to circuitry which automatically turns on the lamps during testing,
(b) a spring return push button switch that the patient depresses upon observing a lighted lamp on said surface connected to circuitry which determines when the patient responds to or does not respond to a lighted lamp and stores the information in memory,
(c) circuitry which reads and processes the stored information connected to circuitry which routes the output when the memory is read to lamps corresponding to the lamps which were presented to the patient, and not responded to by the patient,
(d) circuitry which determines when the test is complete and
(e) a power supply which supplies power to drive the circuitry of the device.

### Claim 2 (depends on 1)

The device of claim 1, further comprising circuitry for resetting the device after the test is complete.

### Claim 3 (depends on 1)

The device of claim 1, further comprising circuitry for signalling the operator when the test is completed.

### Claim 4 (depends on 1)

The device of claim 1, further comprising circuitry for adjusting the intensity of the lamps.