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.
USB is the most common connection found on computers. There are three main types of connectors: USB-A which is used to connect flash drives, external hard drives, MP3 players, mice, keyboards, and printers to your computer. The second type of connector is USB-B which is commonly found on USB printers and some external hard drives.