Laser “tricorder” diagnoses malaria through the skin.

I couldn’t really improve on New Scientist‘s headline there. This device shines a laser through an earlobe or wrist and detects malaria parasites through light absorption:

It works by pulsing energy into a vein in a person’s wrist or earlobe. The laser’s wavelength doesn’t harm human tissue, but is absorbed by hemozoin – waste crystals that are produced by the malaria parasite Plasmodium falciparum when it feeds on blood.

When the crystals absorb this energy, they warm the surrounding blood plasma, making it bubble. An oscilloscope placed on the skin alongside the laser senses these nanoscale bubbles when they start popping, detecting malaria infections in only 20 seconds.

“It’s the first true non-invasive diagnostic,” says Dmitri Lapotko of Rice University in Houston, Texas, whose team used the probe to correctly identify which person had malaria in a test of six individuals. They even managed to use the device to show whether dead mosquitoes were carrying the parasite.

Lapotko says that a single, battery-powered device the size of a shoebox would house everything associated with the small probe, with no other reagents, facilities or specialist personnel required. The team estimates that a single unit would cost around $15,000, but that this could test 200,000 people – potentially bringing the per-person cost of testing down from as much as 50 cents to under 8 cents.

The team is now preparing for trials in Africa.