PEP stands for positive expiratory pressure. PEP valve is a treatment that helps to remove mucus from the lungs. It can also prevent lung collapse or open up areas that have collapsed. All these devices are PEP! Got mine from the hospital when I had pneumonia to help open up and clear the crud! If you have a thumping type massage unit hold it gently to your chest and work at deep inhales and pursed lip exhales and attempt coughing.

I have a Portex Acapella You can get these on amazon or shop around. The purpose of this is if you have heavy phlegm in your lungs as you exhale the vibration will help loosen and allow you to cough it up! These are used more for people with chronic bronchitis where as emphysema is a dry type! Hope this helps some!

It does help

Not impressed. I have an air PEP valve device from a Respiratory Therapist that works way better.