Most devices that treat sleep apnea are in the form of high-tech, oxygenated face masks – but a Minnesota startup is taking a different approach, building an implantable device that treats the common breathing disorder.

Respicardia has raised $25 million, with about $20 million of that coming from the Milan-based Sorin Group. The Italian cardiac devicemaker which has the exclusive right to buy Respicardia and the rights to distribute the device in parts of Europe for the next five years.

The company’s Remede system works a bit like a pacemaker, but it’s implanted in a vein that’s near the phrenic nerves that run between the lung and heart to the diaphragm. It generates small electric pulses that stimulate a response in the diaphragm that regulates breathing – so patients don’t stop breathing, at random, in the middle of the night.

The device has been cleared for sale in Europe starting next year – having received a CE mark in 2010 – and Respicardia’s in the process of winning over U.S. regulatory approval. It’s currently in the midst of an IDE trial.