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 is a neurological disease characterized by recurrent moderate to severe headaches often in association with a number of autonomic nervous system symptoms. The word is derived from the Greek á¼¡Î¼Î¹ÎºÏÎ±Î½Î¯Î± (hemikrania), pain on one side of the head, from á¼¡Î¼Î¹- (hemi-), half, and ÎºÏÎ±Î½Î¯Î¿Î½ (kranion), skull. Chronic migraine is a complication of migraines, and is a headache that fulfills diagnostic criteria for migraine headache and occurs for a greater time interval. 2  Specifically, greater or equal to 15 days/month for longer than 3 months.