Design Of Retinoscoy With The Ultrasonic Distance Measure Instrument

Objective:The purpose of the project is to design a new retinoscope with the ultrasonic distance measure instrument which can accurately measure the dioptre result of artificial myopia. The result can be displayed on LCD. It can avoid error of measure dioptre caused by measuring distance between optometrist and patient.Method:Energy conversion device of ultrasonic wave transmit ultrasonic wave which occur reflection when meeting cornea of patient. Mono-plate processor reckon time of ultrasonic wave transmitting. The dioptre of artificial myopia is displayed on LCD.Results:Ultrasonic energy conversion device transmit ultrasonic wave of 40 hertz, which is accepted by receptor of ultrasonic energy conversion device after reflecting. Its frequency still is 40 hertz. Break of Mono-plate processor is caused by low voltage impulses which are created by the receptive ultrasonic which being magnified and shaped. Time of ultrasonic wave transmitting is counted. The dioptre of artificial myopia is calculated by related formula. The result is displayed on LCD. User can directly read the dioptre result of artificial myopia.Conclution:Applying the new retinoscope with the ultrasonic distance measure instrument, optometrist can obtain practical dioptre result of patient if only adding the direct dioptre result of artificial myopia to neutral dioptre obtained at roll-back point.