The invention relates to a blood filter that is to be positioned within a blood vessel to trap blood clots. The filter includes a head to which there are attached and from which there extend several legs comprising at least one elongated element having two opposite ends. The legs are radially movable...http://www.google.com.au/patents/US5968071?utm_source=gb-gplus-sharePatent US5968071 - Blood filtering device having improved permeability
