For some reason, and nobody knows exactly why, the healing process for open wounds can be sped up by applying suction to them under a tightly-sealed bandage. The negative pressure this creates has been benefiting patients for decades but because mechanical pumps are expensive and they need a constant electricity supply the technology is not readily available, often where it is needed most – in the developing world. Students at a Massachusetts Institute of Technology (MIT) engineering class have been able to develop a basic negative pressure pump that doesn’t require electricity, is cheap to manufacture, lightweight to transport and can be left in place for days.

Doctors speculate that negative pressure helps draw bacteria and fluid away from a wound, keeping it cleaner and hence, encouraging faster healing. Negative pressure dressings can also be left in place much longer than traditional dressings which need to be removed and replaced - sometimes painfully – often multiple times per day. But with the negative pressure system dressings can be left in place for a few days.

Under the guidance of Dr Robert Sheridan from Massachusetts General Hospital, the MIT students developed their simple solution as part of a design project in a mechanical design class taught by Prof Alexander Slocum.

Student Danielle Zurovcik recently field-tested the pumps – which cost a meager US$3 each as opposed to US$100 per day to rent a traditional pump plus power or batteries – in Haiti, after an invitation by non-profit healthcare organization Partners in Health. She arrived with 50 devices to take part in earthquake relief efforts in Haiti.

The cylindrical device with its accordion-like folds is squeezed to create the suction, and then left in place, connected to the underside of the wound dressing by a thin plastic tube.

"It holds its pressure for as long as there's not an air leak," Zurovcik told MIT News, hence the need for suitable air-tight dressings as well.

Reportedly, the Haitian patients who received the treatment were pleased with the results. However, many more pumps are needed as Dr Robert Riviello of the Division of Trauma, Burn and Surgical Critical Care at Brigham and Women's Hospital in Boston, believes that between 50 million and 60 million people in low-income countries suffer from acute and chronic wounds, many of whom would benefit from negative-pressure wound therapy.

He said the student-created device has world-wide potential.

MIT News reports that a newer, improved model of the pump that can be manufactured locally has been developed and an initial supply is now in production.

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