The ratings of three Medical Devices stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Hansen Medical‘s (NASDAQ:HNSN) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). 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. As of Sept. 10, 16.1% of outstanding Hansen Medical shares were held short. For a full analysis of HNSN stock, visit Portfolio Grader.

The rating of AtriCure (NASDAQ:ATRC) slips from a D to an F. AtriCure engages in developing, manufacturing, and selling cardiac surgical ablation systems designed to create precise lesions or scars in cardiac tissue in the United States and internationally. The stock also gets an F in Equity. The stock price has dropped 11% over the past month, worse than the 3.9% increase the Nasdaq has seen over the same period of time. To get an in-depth look at ATRC, get Portfolio Grader’s complete analysis of ATRC stock.

Cutera (NASDAQ:CUTR) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. Cutera is a global provider of laser and other light-based aesthetic systems for practitioners worldwide. The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of CUTR stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.