1 Echocardiography (echo) is a painless test that uses sound waves to create pictures of your heart.  This test gives your doctor information about the size and shape of your heart and how well your heart's chambers and valves are working.
USB was designed to standardize the connection of computer peripherals (including keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters) to personal computers, both to communicate and to supply electric power.
Universal Serial Bus (USB) is an industry standard developed in the mid-1990s to standardize the connection of computer peripherals to computers. It replaced a number of earlier interfaces and is now the most popular connector type for consumer devices. But it can be somewhat complicated to wrap your head around.