US Patent 7393181 Expandable impeller pump

An impeller according to an example of the present invention comprises a hub, and at least one blade supported by the hub. The impeller has a deployed configuration in which the blade extends away from the hub, and a stored configuration in which the impeller is radially compressed, for example by folding the blade towards the hub. The impeller may comprise a plurality of blades, arranged in blade rows, to facilitate radial compression of the blades. The outer edge of a blade may have a winglet, and the base of the blade may have an associated indentation to facilitate folding of the blade.