Nobody knows precisely why it works, but doctors have known for decades that the healing process for open wounds can be greatly speeded up by applying negative pressure — that is, suction — under a bandage sealed tightly over the affected area. The speculation is that it helps by drawing bacteria and fluid away from the wound, keeping it cleaner.
For patients, there is a benefit even beyond the speedier healing. Traditional dressings need to be removed and replaced — sometimes painfully — up to three times a day, but with the negative pressure system dressings can be left in place for a few days. But in the developing world, there's a problem: The systems are expensive, and they need to be plugged in or powered by batteries that last only a few hours. In many developing nations, a reliable source of electricity is rarely available.
That's the problem that students in an MIT mechanical engineering class decided to tackle a few years ago. With the help of Dr. Robert Sheridan from Massachusetts General Hospital, the students developed a simple, inexpensive and lightweight version of the system that required no power supply and could be left in place for days. One of those students, Danielle Zurovcik SM '07, continued to work on the project and made it the subject of her master's thesis.
Zurovcik demonstrates here how the negative pressure pump can help seal a wound.