Patent No. EP1906883 (titled "A Non-Cylindrical Prosthetic Valve System For Transluminal Delivery") was filed by Corevalve on May 24, 2006. The application was issued on Jan 27, 2021.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.