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.
Multiple USB devices can also be connected to each other using a USB hub. A USB hub plugs into one USB port and contains additional ports for other devices to connect subsequently. If using a USB hub, plug a separate cable into each device and connect them to the hub individually.