Topic 6 Ultrasound Flashcards
What is ultrasound
Sabbath frequencies higher than 20,000 Hz
What can electrical devices be made to produce
Electrical oscillations over a range of frequencies
Please can easily be converted into mechanical vibrations to produce sound waves be on the range of human hearing
What is partial reflection
When a wave passes from one medium to another some of the ray is reflected off a Boundry And some is transmitted and reflected
What happens to ultrasounds at boundaries
They get partially reflective
How can partially reflected raise be able to detect how far away are boundaries
You can point of course of ultrasound at an object and wherever there are boundaries between one substance and another some of the ultrasound gets reflected back
this can be measured to see how far away it is
How is ultrasound used in medical imaging for prenatal scanning of the fetus
Ultrasound can pass through the body whenever they reach a boundary between two different media like fluid in the womb and the skin of a fetus some of the weight is reflected back undetected
The exact timing distribution of these echoes are processed by a computer to produce a video image of a fetus
How old is unsafe for prenatal scanning
No one knows for sure but x-rays would definitely be more dangerous
How are ultrasounds used an industrial imaging e.g. finding flaws in materials
Ultrasound can also be used to find flaws in objects such as pipes material such as wood or metal
Ultrasound waves entering a material will usually be reflected by the far side of the material
If there is a floor such as a crack inside the object the wave will be reflected sooner
What is Eco sounding
Uses high frequency sound waves e.g. ultrasounds used by boats and submarines to find out the depth of water they are in or locate objects in deep water
