In fact, scar tissue can restrict many layers of muscle and connective tissue, which can cause varying degrees of pain or discomfort. Scar tissue is weaker, less elastic and more prone to re-injury than normal, healthy tissue, and can lead to chronic pain if it affects the functioning of other structures--especially nerves and blood vessels.
Negative pressure means the pressure in the pipe/duct/room is less so flow would go into the room. These are all gauge pressures, which can be positive or negative since they are merely measuring a relative pressure compared against some constant pressure, typically atmospheric which is about 14.7 psi.
Negative pressure wound therapy is a medical procedure in which a vacuum dressing is used to enhance and promote wound healing in acute, chronic and burn wounds. The therapy involves using a sealed wound dressing attached to a pump to create a negative pressure environment in the wound.he pump that creates the negative pressure is small and portable. Many wounds undergoing negative pressure wound therapy can be treated at home with a visiting home health care provider.