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.
A USB hub can help connect USB devices to computers with different types of connectors. USB 3.0, with its SuperSpeed connection, is shaped differently than previous ports. Memory card readers connect to a computer via USB. MP3 players often use USB cords to connect to a computer.