The Aurora Funds is among the investors in a $21.5 million Series C venture capital firm for medical device firm CardioFocus.

CardioFocus, which is based in Boston, is developing catheters for use in combating atrial fibrillation, or abnormal heart rhythm.

Chris Kroeger, a principal for Durham-based Aurora, will join the CardioFocus board.

Leading the round were HIG Ventures and KBL Healthcare Ventures. Aurora is a new investor in CardioFocus. Other investors include Accuitive Medical Ventures, Oxford Bioscience Partners and SV Life Sciences.

Aurora Funds: