The fictional memory-viewing machine in the Assassin's Creed series is called the Animus.
The Animus allows a modern user to experience genetic memories inherited from ancestors. In the first game, Desmond Miles enters an Animus operated by Abstergo Industries and relives the memories of Altaïr Ibn-La'Ahad. This device provides the series with its recurring link between modern-day characters and historical settings.
The Animus does not literally send someone into the past. It reconstructs ancestral experiences from genetic information, a science-fiction premise that frames the historical adventures. Later games introduce related systems, including Abstergo's Helix entertainment platform and portable or modified Animus technology. Those are connected products or interfaces, but the core machine is the Animus.