US Patent 7249604 - Magnetic nanoparticles for blood flow control

http://www.freepatentsonline.com/7249604.html

This patent from VASMO, Inc. teaches a fairly interesting application of microparticles or nanoparticles in medicine. Basically the particles are used to form configurable valves based on external magnetic fields to control blood flow. Claim 1 reads:

1. A method for occluding or controlling blood flow wherein: (a) magnetic microparticles, magnetic nanoparticles, or magnetic colloids are administered in the form of a dispersion or suspension into a blood vessel that flows through the vessel in the bloodstream, and (b) an external magnetic field source is placed or held at the desired site near or above the path of the blood stream, and (c) a plug or blockade is formed within said blood vessel as a result of acts (a) and (b) that occludes or controls blood flow through the vessel.