This article first appeared on BostInno. The latest regulatory filing for CyPhy Works shows that the Danvers-based drone company has raised over $4.5 million in a debt offering. It also reveals that Helen Greiner, the robotics visionary who started CyPhy in 2008 and later switched to the role of CTO, has left the company. CyPhy Works confirmed to BostInno that Greiner left the company in late 2017. Her name was absent from the U.S. Securities and Exchange Commission filing on Wednesday. "Helen...