This week, the ratings of three Medical Devices stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”). This week, Hansen Medical (NASDAQ:HNSN) drops from a D (“sell”) to an F (“strong sell”) rating. Hansen Medical develops and manufactures medical robotics designed for positioning, manipulation, and control of catheters and catheter-based technologies. In Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum, Equity, Cash Flow, and Sales Growth, HNSN also gets F’s. The stock price has fallen 19% over the past month, worse than the 1.2% increase the Nasdaq has seen over the same period of time. As of July 23, 16.5% of outstanding Hansen Medical shares were held short. For a full analysis of HNSN stock, visit Portfolio Grader.