Question

Please do not Quote from another writter. handwitten work much preferred.(3 pages needed)
Describe how an ultrasound transducer works? Include a discussion of the energy form used to create images and how that interacts with tissues in the body.

Answer 1

Ultrasound is a medical imaging and diagnostic technique that uses high frequency sound waves and their echoes to form 2-D images from which any particular property/characteristic can be interpreted.

The ultrasound machine consists of parts: Transducer probe, CPU (Central Processing Unit), transducer pulse control, display, disk storage, keyboard and printer.

Transducer: It is the most essential component of the ultrasound machine. It consists of a probe that sends the sound waves and receive the echoes. It is based on the principle of piezoelectric (pressure electricity) effect. The probe consists of one quartz crystal called as piezoelectric crystals whose shape changes rapidly as soon as the electric current is applied to it. This results in the production of sound waves through the vibrations of the crystals and the sound waves travel outward. The probe also consists of a sound absorbing substance which absorbs the deflected sound waves and convert them into electrical signals. These probes comes in various shapes which determines the field of view and the frequency of emitted sound waves determines how deep the sound waves penetrate and the resolution of the image.

Ultrasound energy is a type of mechanical energy which involves sound waves characterized by vibrating or moving particles within a medium. The energy generally travels through the medium in the form of a wave due to  which particles are deformed and then re-established after the energy passes.

Interaction of the Ultrasound waves with tissues:

The transducer generates the sound waves in the form of pulses which travels through the different medium in the body i.e skin, chest, pericardium, etc. With the increase in the distance and transition between each medium the amplitude of the waves reduces due to the reflection of these sound waves by the tissues.As the reflected soundwaves reaches the piezoelectric crystals they vibrate and generate electric currents which are then transmitted to the machine for the image generation. The difference in the amplitude of the emitted and the reflected sound waves result in the image generation.