Unitedâs iPhone App â How to Change Your Flight for Free. All airlines need to model their mobile app after Unitedâs iPhone App and offer to change your flight for free1. When you need a United Airlines flight change, there is no better way than to use Unitedâs Mobile App. It is one of the most useful travel tools I haveâ¦when I am flying on United that is.
English-born physicist John Wild (1914â2009) first used ultrasound to assess the thickness of bowel tissue as early as 1949; he has been described as the father of medical ultrasound. Subsequent advances in the field took place concurrently in several countries.
2. 1  a. The use of ultrasonic waves for diagnostic or therapeutic purposes, specifically to image an internal body structure, monitor a developing fetus, or generate localized deep heat to the tissues. 2  b. An image produced by ultrasound.