This type of stroke is the most common. A blood clot â a clump of blood that sticks together â is usually to blame for ischemic strokes. They can also happen when arteries become narrow and clogged with plaque. Plaque is a mix of cholesterol and other fatty stuff that sticks to the walls of blood vessels.
Premarket Approval (PMA) A PMA submission is used to demonstrate to the FDA that a new or modified device is safe and effective. This standard is higher than is required for 510(k) submissions. Human use data from a formal clinical study is almost always required in addition to laboratory studies.
1 clear the device after reviewing a premarket notification, otherwise known as a 510(k) (named for a section in the Food, Drug, and Cosmetic Act), that has been filed with FDA, or.  2 approve the device after reviewing a premarket approval (PMA) application that has been submitted to FDA.