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.
One of these is a USB port. A USB port allows computer owners to extend the functionality of their system by connecting USB-compatible devices. USB ports are used to share and transfer files, connect peripherals like a printer, speaker, or mouse, and to charge devices such as an iPad or smartphones.