SU1393400A1 - Method of localizing objects inside the eye - Google Patents

Abstract

The invention relates to ophthalmology. The purpose of the invention is to increase the measurement accuracy. The source of ultrasonic waves is moved in the contact liquid to the maximum amplitude of the signal reflected from the object under study. The thickness of the contact liquid layer between the source of ultrasonic waves and the eye is determined. According to the difference in the focal distance of the source of ultrasonic waves and the measured thickness of the contact liquid layer, the object is located. The accuracy of determining the depth of the foreign body in the tissues of the eye is increased by averaging the speed of ultrasound in the individual anatomical structures of the eye.

Description

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The invention relates to medical technology and can be used in ophthalmology to diagnose diseases of the eye and orbit.

The purpose of the invention is to improve the measurement accuracy.

The proposed method is implemented as follows.

A speculum tube is inserted into the eye to be examined into which the contact fluid is poured. A transceiver transmitting focusing piezoelectric transducer is placed in the contact liquid, which is fixed in a coordinate device allowing mechanical movement of the transducer. In order to excite the piezoelectric transducer with short electrical pulses from a pulse generator, a focused acoustic wave of pulse signals is introduced into it through a contact liquid. The volume of contact fluid is chosen from the conditions that ensure the mechanical movement of the converter by a coordinate device in the vertical and horizontal plane. The echo pulses reflected from the surface of the examined eye, the boundaries of the transition from one anatomical structure to another or a foreign body, are accepted by the same focusing transducer. Switching the transmit-receive piezoelectric focusing transducer from transmit to receive is performed by a switch. The echo pulses received by the piezoelectric transducer through the switch and amplifier are fed to the input of the control and measurement oscilloscope, which are synchronized with the pulse generator. By moving the transceiver focusing piezoelectric transducer in the contact fluid, the maximum, amplitude of the echo impulse from the surface

Foreign body in the tissues of the eye studied. Using an echogram on an oscilloscope, the transit time in a specific fluid by an acoustic pulse between the piezoelectric transducer () and the contact fluid boundary — the eye under study is measured. At a known value of the ultrasound velocity 19 of the contact fluid, the thickness of the contact fluid between the transceiver focusing piezoelectric transducer and the surface of the eye being studied is determined by the expression

eleven . .one

f u

where "is the focal distance of the focusing piezoelectric transducer;

Ig is the distance between the focusing piezoelectric transducer and the structure layer under study;

1c is the thickness of the contact fluid between the focusing piezoelectric transducer and the surface of the eye under study;

1c. - the distance between the surface of the eye being studied and the anatomical layer or foreign body under study. From the expression

  and

where 1 is the distance between the surface of the eye and the anatomical layer or foreign body under investigation} 1f is the focal length of the piezoelectric transducer; C is the time of passage of the acoustic wave in the contact fluid between the transducer and the contact fluid boundary — the studied

C C - the speed of ultrasound in the contact fluid,

The depth of the foreign body in the tissues of the eye to be examined is determined.

The positive effect is to increase the accuracy of localization by reducing incidence due to the averaging of the speed of ultrasound in individual anatomical structures. eyes.

Claims (1)

Formula invented and The method of localization of objects inside the eye by means of sounding the eye with focused oscillations through a contact fluid, receiving echoes reflected from the object under study and determining the distance to the object, characterized in that. 313934004. in order to increase the accuracy of the localization of the bone between the ultrasound source, the source of ultraduck waves of the waves and the eye and by the difference, they are focused in the contact fluid to the distance of the source of ultrasound and the maximum amplitude of the reflected waves and the measured value the signal, the gaps of the contact liquid layer, determine the thickness of the contact layer, the liquid and the localization of the object.