MIT Student Invents $3 Negative Pressure Pump for Impoverished Countries
A negative pressure pump is a wound therapy device common to nations with advanced medical care. They normally cost $100 a day to rent, which is far too expensive for many patients and hospitals in developing nations....
https://www.neatorama.com/2010/03/19/mit-student-invents-3-negative-pressure-pump-for-impoverished-countries/