Definition - What does Phased Array Technology mean? Ultrasound beams are used in phased array (PA) ultrasonic equipment, which is considered an advanced method of ultrasonic testing. This technology finds applications in medical science and non-destructive testing. This method is more accurate at finding flaws in manufactured materials such as welds.
A migraine is a medical condition which usually causes a pounding, throbbing headache on one side of the head. The pain may be very bad and hurt so much that a person may have a hard time doing anything. While most people who have migraines get a headache, not everyone does.
Migraine headache definition and facts. 1  Migraine headache is a result of specific changes within the brain. It causes severe head pain that is often accompanied by sensitivity to light, sound, or smells. 2  Common symptoms include: Eye pain. Sensitivity to light or sound.