Well the patent states that a very small electric current in the scalp and around the follicles inhibits dht binding to the androgen receptors and provokes a wound responce that causes the hair follicle to regenerate. Well they speculate that, they admit they do not fully understand why this happens but they have on average a 10% increase in termal growth in only six weeks!
The electric current is generated by depositing copper and zinc ions in the scalp. Copper and zinc have a high standard electrode potential (
http://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)) just by being close to each other they will produce an electric current, just like a small battery in your scalp. The proper name for a battery like this is a galvanic cell. So the patent is descirbing a way of producing thousands of little galvanic cells on the skin to produce a lasting micro voltage/current in the skin.
The pilox device does something similer by using copper and zinc discs to supply the ions rather than a mix of zinc and copper salts in solution. I believe this patent was made to cover all bases and the stop anyone releasing a similer product to pilox using a different method. The pilox method is far more elegant.