Acoustic Field of an Ultrasound Device for Differential Diagnosis of Human Hearing

Abstract

In this paper analyzes the relevance and novelty of using a multielement array in an electroacoustic transducer for differential diagnosis of human inner ear coagulation by changing the pulse duration and direction of radiation. Today the clinical applications of ultrasound are numerous and diverse, and ultrasound diagnostics is one of the most rapidly developing methods in medicine. In recent years the effect of focused ultrasound on the human auditory system has been actively studied. The structure of the human inner ear is in the middle of a system of spaces and channels of bony labyrinths. It is known that the most successful way to the auricular labyrinth is the one with the shortest distance and with the least tissue loss. In order for the width of the scanning ultrasound beam to remain constant throughout the entire length of probing, the mode of dynamic focusing of the ultrasound beam was considered. The ultrasonic beam in the scanners is formed using a linear multielement array with individual element dimensions of several wavelengths by introducing between the electrical signals sent or received from the elements such delays that ensure that the fields are focused at a given point on the beam axis, and additionally by using acoustic lenses. In practice, the problem is solved by successive focusing of the beam at several fixed distances from the working surface. Calculations of the geometric dimensions and the study of the acoustic field for the cylindrical wave front created by a linear multielement array of piezoelements are performed. Calculations of the acoustic field distribution in depth at varying pulse duration and at changing the angle of deflection from the axis, with the focal distance unchanged.  It is concluded that it is reasonable to use this type of electroacoustic transducer for differential diagnosis of human hearing. From the obtained graphs it was found that an increase in the pulse attenuation coefficient leads to a decrease in the values of the diffraction maximum. It is also shown that the relative amplitude of the diffraction maximum can be reduced by reducing the pulse duration and increasing the number of piezoelectric elements in the working group.    This type of piezoelectric transducer will allow, by changing the angle, to affect all parts of the cochlea of a person, as it is known that each part of the cochlea is responsible for a certain frequency of perception, pick up a certain duration for safe exposure. And it will also be possible to perform acoustic influence on the cochlea to confirm the functioning of the auditory nerves before cochlear implantation.