One of the risks of undergoing a surgical procedure is getting an on-site infection, which leads to longer periods in hospital and even death, especially when bacteria is resistant to current drugs. In developing countries the problem is bigger as hospitals often lack staple sterilization instruments such as an autoclave. In order to tackle this issue, a team of Rice University students and their mentors are developing a solar-powered sterilization unit that could be a life-saver in regions with little or no access to this type of equipment.

Called Sterile Box, the unit is held inside a 20-foot (6-m) shipping container. It includes the whole range of necessary equipment to leave surgical tools ready for the next job, including a water system for decontamination and a solar-powered autoclave for steam sterilization.

The project is the culmination of a long-standing search for a method to sterilize surgical instruments with sunlight as the source of power.

At first, the researchers deployed a solar thermal collector frame they named Capteurs Soleil, which tapped sunlight to heat a stand-alone autoclave. They wanted a more complex and efficient solution, however, so they added solar panels and electrical storage to the container. They also added water distribution from two tanks, one of which stays on the ground and features a hand pump to send water to a 50-gallon (189-liter) tank on the roof.

Inside, the container features a foyer that separates the sterile processing area from external elements, and a main area with a small window for the carrying of instruments in and out of the Box.

The sterilization process takes place in four steps. The first one is the decontamination in a sink. Once debris is removed, the instruments are soaked in enzymatic detergent, scrubbed and rinsed. The next step is the sterilization per se, which is done with the steam autoclave heated with an electric hotplate. Once sterilized, the instruments are put to dry on wire racks and finally moved to a storage cabinet, ready for the next surgery.

The designers of the Box also had comfort and practicality in mind. A radiant barrier and reflective paint insulate the unit, while mesh screens over the door and windows, floor vents and ceiling fans ensure proper ventilation and airflow. The Box also includes a battery pack connected with the solar panels from which fans and cell phones can be charged.

The team now is planning to test the Sterile Box in a real-life setting. For that, they have teamed up Baylor Global Initiatives at Baylor College of Medicine in Houston so the Box can be incorporated into the initiative's mobile surgical unit called Smart Pod, which is also a re-purposed shipping container. Baylor expects to test the Pod near the capital of Malawi, Lilongwe, in 2017.

The Rice team appears in the video below introducing the Sterile Box.

Source: Rice University