Doximity, which provides a professional network for physicians, has raised US$17 million in series B financing led by Morgenthaler Ventures with support from existing backers Emergence Capital Partners and InterWest Partners.

Since securing its series A funding 17 months ago, the company says it has grown fifteen-fold to a point where it claims that more than one in seven US physicians are now signed up with it.

Physicians can use their iPhone and Android handsets, as well as PC, to connect with their peers via Proximity to collaborate on patient care or find the right medical expert for a patient.  Doximity provides HIPAA-complaint communications. HIPAA laws protect patient information and restrict physicians from using SMS, email or social networks to discuss their patients.