Physics Essay Ultrasound

Name: Vineet Baldwa

Grade: 9C

Introduction

When we first hear the word 'Ultrasound', the first thing that comes in our mind is a contraption which is used to see a developing fetus inside a pregnant lady's womb. This is not a definition of ultrasound, it is just the most common use of it but in order to properly understand that use, we have to know how and why it works. This is an essay written for you to understand the true mystery behind ultrasound. Hopefully by the end of this essay, you will have understood it.

Ultrasound

Ultrasound is the term used to describe a sound wave which is over the frequency of 20,000 Hz (The human audibility limit). The reason its frequency is so high is so that it does not damage the human ear. However you will be surprised to know that even nature uses ultrasound.

Sound Spectrum of a Humpback Whale (Megaptera nova...

English: Example of a digital screengrab of dual f...

English: Diagram showing basic principle of single...

Ultrasound is similar to the echolocation used by bats, whales and dolphins. Here's how it works:

The device send out an ultrasound wave

The wave strikes an object and bounces back. Using the speed in different mediums, the distance to the object is calculated using this formula: v = (2d/t).

Ultrasound Machine

An ultrasound machine is a machine that sends out ultrasound waves. In a typical ultrasound machine, millions of pulses and echoes are sent and received each second. A basic ultrasound machine has the following parts:

Transducer probe - probe that sends and receives the sound waves

Central processing unit (CPU) - computer that does all of the calculations and contains the electrical power supplies for itself and the transducer probe

Transducer pulse controls - changes the amplitude, frequency and duration of the pulses emitted from the transducer probe

Display - displays the image from the ultrasound data...