Greatbatch Inc., which makes components used to make medical devices, said Tuesday it has agreed to acquire Quan Emerteq LLC for about $55 million in cash to expand its presence in the vascular market. Blaine, Minn.-based Quan Emerteq makes single-use medical device products for the vascular, cardiac rhythm management and neurostimulation markets. The company is expected to have annual sales in the range of $20 million to $24 million this year, Greatbatch said.