Still River Systems Inc. tapped an electrical engineer and serial entrepreneur, Joseph Jachinowski, as its new CEO and named him to its board of directors.

Jachinowski, who replaces Mark Buntaine in the Littleton, Mass.-based company’s corner office, got his start with Varian Medical Systems in 1981, before co-founding protective relays maker SEL Products in 1983. He went back to Varian in 1985, where he led the design team for its medical linear accelerator.

In 1990, he co-founded IMPAC Medical Systems which makes clinical and administrative information management systems for cancer care. After taking the company public in 2002, Jachinowski sold it to Swedish medical device manufacturer Elekta AB in 2005.

Still River Systems, which drummed up a $33 million venture capital round in March from Caxton Health Holdings, Venrock Associates and CHL Medical Partners, is pushing to bring a new radiation-based cancer treatment to market call the Monarch250 proton beam system.

The company said former CEO Buntaine, like Jachinowski a Varian alumnus, was named president and chief commercial officer and co-founder Kenneth Gall was named chief technology officer.

The company said former CEO Buntaine, like Jachinowski a Varian and Elekta alumnus, was named president and chief commercial officer and co-founder Kenneth Gall was named chief technology officer.

Lionel Bouchet, director of product management, told MassDevice the changes in the executive suite are aimed at capitalizing on the relative strengths of Buntaine and Jachinowski, who both hold similar pedigrees.

“Joe is coming to work with Mark and help the next stage [develop] at Still River Systems,” Bouchet told us. “It’s a great move for Still River.”