Solar-powered Sterile Box sterilizes medical tools anywhere

HOUSTON, March 23 (UPI) -- Patients are nine times more likely develop surgical site infections in low-resource areas, and researchers at Rice University looking to mitigate the problem designed a low-power, mobile facility to sterilize medical tools for reuse.

The Sterile Box is a full, solar-powered sterilization facility built into a standard 20-foot steel shipping container that can be set up anywhere, researchers said in a press release.

"Infection control in the surgical suite really is a big challenge in the developing world," said Maria Oden, director of the Oshman Engineering Design Kitchen at Rice University. "I was shocked to learn how many surgeries end up with patients developing some manner of infection."

The researchers had previously worked on a standalone device to sterilize tools, but started thinking bigger because of the lack of facilities in rural and developing areas.

In designing the portable facility, the researchers worked to consider water and energy requirements and availability, and wanted to make it easy to avoid human error in construction or use.

"The box looks at the problem from a complete system level and makes it easy to implement," Oden said. "It's not just a simple device to clean and sterilize the tools, but a way to manage the process."

The box, a standard 20-foot steel shipping container, is separated by a small foyer into four areas for decontamination, preparation, sterilization and drying and storage, all of which are partitioned off by a half-wall.

Power for the unit is generated by solar panels on the roof, and water is supplied by a 55-gallon receiving tank on the ground and 50-gallon tank on the roof. A non-electric, gravity steam sterilizer, heated with a custom-designed 750-watt hotplate, is used to sterilize instruments.

In a study, published in the journal PLOS ONE, the researchers report instruments were properly decontaminated and sterilized in 61 trials of the Sterile Box between May and August 2015 for a failure rate of 0 percent.

"We tried to really think hard about social context," said Douglas Schuler, an associate professor of business and public policy at Rice. "We laid out the elements to minimize human error and water and energy requirements to the extent that we can. I really like that about our design."

The researchers are working with researchers at the Baylor College of Medicine to incorporate their design into a mobile surgical suite expected to be sent to the Malawi capital of Lilongwe in 2017 to see how it performs in the field.