Edwards Lifesciences ( EW) provides products and technologies that treat advanced cardiovascular disease. EW was bought by one insider during the past month. On Nov. 29, Barbara McNeil purchased 158 shares at $63.78. Now the stock is trading at $70.22 per share, returning over 10% since November 29. Louis Navellier also invested $31 million in EW. Columbus Circle Investors had $37 million in EW at the end of September. Boston Scientific ( BSX) develops, manufactures and markets medical devices globally. BSX was bought by three insiders during the past month. On Nov. 29, Nj Nicholas purchased 10,000 shares at $5.56. BSX is currently trading at $5.26 per share, slightly lower than the price Nicholas bought at. Nicholas also purchased 30,000 shares of the stock in total at around $6.67 per share in May. BSX was trading above $7.25 per share in July. On Nov. 28, Ernest Mario and Katharine Bartlett bought 100,000 shares and 8,000 shares respectively at around $5.40 per share. Mario also bought 25,000 shares at $5.30 on Nov. 21 and 5,0000 shares in total at around $5.50 per share in October. Like Nicholas, Mario bought the stock in May as well. He purchased 2,500 shares at $6.72 in mid-May. Insider purchases in BSX sends "strong buy" signals and outsiders can imitate insiders without paying a premium in this case. Omega Advisors had nearly $100 million in BSX at the end of the third quarter. Other healthcare stocks insiders are buying during the past month include United Therapeutics ( UTHR), Techne ( TECH) and Sirona Dental Systems ( SIRO). The strongest buy signal comes from SIRO as four insiders purchased shares during the past 30 days. Investors should also keep in mind that insider trading in smaller companies are generally more profitable. Nevertheless, they have to research these names carefully as sometimes insiders try to trick the investors by making coordinated small purchases. >>To see these stocks in action, visit the 8 Health Care Stocks Insiders Are Bullish on portfolio on Stockpickr.