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.
The National Headache Foundation says most migraines last 4 to 72 hours. âBut some people have migraines for a shorter time and some people have them for longer â itâs very individual,â Dr. Mauskop says. Migraine duration also depends on the type of migraine you have: 1  An optical migraine causes visual disturbances such as zigzags or blind spots or blurred vision often in one eye, but no headache pain; it typically lasts an hour or two.