Boston Scientific closed its acquisition of Apama Medical, a developer of a radiofrequency balloon catheter for the treatment of atrial fibrillation. While the device maker forked over $175 million in cash up front, Apama stands to earn up to $125 million in milestone payments.

Apama will collect follow-on payments for achieving clinical and regulatory milestones from 2018 to 2020, according to a statement. Boston Sci announced the deal earlier this month.

Last November, Apama raised $13 million in series C financing. The Campbell, California-based startup is developing a catheter ablation system for afib that combines the best of two major approaches used to treat the condition—single-point radiofrequency ablation and balloon catheter ablation.

Single-point RF ablation is used to treat multiple types of afib, but the procedure takes a long time, while balloon catheter ablation is quicker but is limited to a few afib types.

"The Apama RF Balloon Catheter System is an innovative solution that addresses the gaps in existing catheter ablation technologies," said Dr. Amin Al-Ahmad of the Texas Cardiac Arrhythmia Institute, when Apama announced its series C round.  "The multipoint RF system enables single shot, customizable ablation geometries for improved efficiency and versatility. In addition, built-in cameras enable real-time visualization that allows for enhanced navigation and feedback on electrode contact."

Apama is the third company out of medtech incubator Shifamed to be acquired. The other two were Kalila Medical, snatched up by Abbott last year and Maya Medical, sold off to Covidien in 2012.

"Shifamed was formed out of my passion for engineering in the medical field and the ability to work alongside and enable others to develop innovative solutions that make a positive impact on patient lives," said Amr Salahieh, who founded Shifamed in 2009. "We are thrilled to collaborate with companies like Boston Scientific that excel at bringing advanced solutions to the patients and care providers we serve."