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In Nicaragua, using sunlight to sterilize medical equipment

Posting in Design

The Little Devices group at MIT has designed a solar concentrating system that can sterilize surgical tools without using any fuel or power.

Like an autoclave, the SolarClave is a chamber that uses heat and pressure to kill microbes. Since it's designed for use in remote clinics, the system can be built and repaired using locally available parts and costs less than existing fuel- and electrically-powered devices. MIT News reports.

Under a clear sky, the system takes 45 to 60 minutes to heat up to a sterilizing temperature (250 degrees Fahrenheit) and then 20 minutes to carry out the sterilization cycle.

The design reflects feedback from users at health posts in Nicaragua -- where a mostly rural population of six million is served by some 11 hospitals, dozens of health centers, and some 1,300 health posts that provide emergency care, obstetric services, and the occasional baby delivery.

Most of these posts, staffed by nurse practitioners, either lack equipment to sterilize surgical tools and bandages or have kerosene-powered autoclaves. Often, nurses resort to boiling tools or swabbing them with alcohol, or must travel long distances for proper sterilization at larger centers or hospitals.

An early prototype used a boiler suspended over a foil-covered reflector, and tubing carried steam from the boiler to a sterilizing vessel several feet away. But pilot tests in Nicaragua revealed problems with that setup.

  • In the newer, more robust system, the tools and materials to be sterilized are contained in an ordinary pressure cooker.
  • The cooker is insulated in a bucket and suspended directly over the reflector (pictured).
  • The reflector is now an array of 140 pocket-sized mirrors, readily available and less prone to damage. (If a rock drops, a single mirror breaks and not the whole array.)

The upgraded system is now being tested at three locations in Nicaragua; by this summer, the team plans to put several more units in use in other areas in Central America and Africa.

The system meets sterilization standards set by the U.S. Centers for Disease Control. The next step is to work with local companies to manufacture and sell the devices.

[Via MIT News]

Image Anna Young and José Gómez-Márquez via MIT News Office

— By on March 1, 2013, 3:40 AM PST

Janet Fang

Contributing Editor

Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York. Follow her on Twitter. Disclosure