Provides outreach and education for independent inventors who file patent applications without the assistance of a registered patent attorney or The purpose of this guide is to provide you with basic information about filing a utility patent application with the USPTO.Patent ductus arteriosus (PDA) is a heart defect found in the days or weeks after birth. The ductus arteriosus is a normal part of fetal blood circulation. The ductus arteriosus is a hole that allows the blood to skip the circulation to the lungs. Bilateral foraminal stenosis is where both foramina have become narrowed compressing the nerve roots and causing symptoms on both sides.