Search within the title, abstract, claims, or full patent document: You can restrict your search to a specific field using field names. A patent foramen ovale (PFO) is a hole in the wall between the heart's two upper chambers (atria).Before birth all babies have this opening. Appeal from the Patent Office Board of Appeals. Before MARKEY, Chief Judge, RICH, BALDWIN and LANE, Associate Judges, and ALMOND, Senior Judge. This page provides information on the types of patents and types of patent applications, and the examination process. The prevalence of PFO in patients with ischemic stroke is significantly higher than in the normal population. Patent Appeal No. 7990. The date shown in the middle column above indicates when each form was last revised. An Ostium secundum atrial septal defect is a type of congenital heart defect called an atrial septal defect (ASD).