In this video from Tuesday's Market Checkup, Motley Fool health care analyst David Williamson takes investors through the biggest investing stories in the health care space today.

Shares of Hansen Medical (NASDAQ: HNSN) shot up 20% today, on news that the company received FDA approval for a new robotic catheter, the Magellan 6Fr. Hansen also named Chris Lowe as its new CEO, to replace outgoing Bruce Barclay. While investors are hoping that approval of the Magellan 6Fr will keep the momentum going for the robotic catheter maker, sales were very light for Hansen in 2013. Q1 2013 sales came in at $2 million, increasing to more than $5 million last quarter, but David sees the company as needing to do much more to justify its valuation. With its current cash burn rate and relatively low cash position, investors could be risking exposure to a dilutive event here.