Physio-Control Inc., a former Medtronic subsidiary in Redmond, Wash., is merging with health information software firm Sansio of Duluth for an undisclosed amount.

Privately owned Physio-Control makes external heart defibrillators, which are designed to shock patients who go into cardiac arrest, and cloud-based patient information systems for emergency medical responders.

Physio-Control is the former Medtronic Emergency Response Systems, which Medtronic sold to Bain Capital, a Boston private investment firm, in 2011 for $487 million in cash.

Sansio, also privately owned, provides medical data gathering software for emergency medical responders and home health care firms.

Under the deal announced Friday, Bain remains the owner of Physio-Control, and Sansio will become a Physio-Control subsidiary, said Kraig Erickson, Sansio's vice president of sales. Sansio has 70 employees, including 57 based in Duluth, and the combined companies will have about 1,300 employees, Erickson said.

The two firms overlap in the emergency medical responder market, Erickson said. Physio-Control makes heart defibrillators and electrocardiogram devices used by emergency medical technicians, and Sansio makes the cloud-based software that collects medical data while a patient is being treated and brought to a hospital by ambulance, Erickson said.

"We are definitely taking Physio-Control further into the data solutions part of the emergency medical services market, which is an area they have decided to expand into," Erickson said. "Physio-Control has been more of a medical device company."

In 2010, the Medtronic operations that later became Physio-Control had 1,000 employees and $425 million in worldwide sales, mainly from external heart defibrillators. The company, founded in 1955 and acquired by Medtronic in 1998, changed its name to Physio-Control in early 2012 after it was sold by Medtronic.

Sansio, founded in 1997 and originally known as ScanHealth, changed its name to Sansio in 2007.