Читать книгу The Physics and Technology of Diagnostic Ultrasound: A Practitioner's Guide - Robert Gill - Страница 7

Physics deals with concepts that help us to understand the physical world – concepts such as mass, force, velocity, temperature and pressure. Most importantly, it also deals with the relationships between these quantities. These relationships are normally expressed using mathematical equations, since any other way of expressing them would be very cumbersome and difficult to use.

You will therefore need to be able to understand equations and what they say about the relationships between quantities. For example, the simple equation λ = c/f says that the wavelength of the ultrasound (λ) can be calculated by dividing the ultrasound propagation speed (c) by the ultrasound frequency (f). It also tells us that the wavelength is inversely proportional to frequency; thus, for example, if the frequency was doubled then the wavelength would be halved.

You have very likely forgotten at least some of the mathematics that you will need in studying ultrasound physics. The following section provides a brief review of relevant aspects, including decibel notation, and some examples for you to try.

You are strongly urged to work through it. You will also need to do calculations using the various equations introduced. You will therefore need to have a scientific calculator and be familiar with its use.