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.
Most headaches in women are caused by hormones. At least 5 million women experience hormone headaches each month, say researchers. According to Dr Anne MacGregor, formerly of the National Migraine Centre, more than half of women who get migraines notice a link with their periods. These so-called menstrual migraines tend to be particularly severe.