The use of a vacuum pump is considered because it is a device that will be going to draw a gas molecule from a sealed volume to leave behind a partial vacuum. It will generate a relative vacuum capacity within a capacity. Moreover, in hospitals, it has a negative pressure which is used for suctioning patients and anesthetics gas scavenging system as well. For the sake of convenience now claw vacuum pumps also are in use. https://medicaltestin.livejournal.com/436.html