Painless blood tests coming soon

A device the size of a ping-pong ball that extracts blood when held against the skin might soon replace needles, according to representatives from Tasso Inc., a company that is working closely with the University of Wisconsin-Madison on the project.

Rather than pulling the blood from veins, which are closed channels, the device pulls it from the open channels in which blood flows through many microscopic vessels called capillaries.

During the two minutes it takes to collect the blood, a delicate vacuum creates capillary action, beckoning blood to flow into an attached container that's lab-ready.

The patient should feel no pain, according to reports.

Called microfluidics, the technology springboards on the forces that govern the flow of tiny fluid streams, according to Ben Casavant, vice president and co-founder of Tasso, Inc.

"At these scales, surface tension dominates over gravity, and that keeps the blood in the channel no matter how you hold the device," says Casavant.

At present, the device is able to pull 0.15 of a cubic centimeter, which makes it practical for testing cholesterol, infection, cancer cells and blood sugar, although diabetes is not an initial market due to the frequency of tests needed.

A technique for taking samples to diagnose HIV is in the works, according to the company.

The disposable device needs only six injection-molded plastic parts, says Casavant, noting this will simplify manufacturing and cut costs compared with conventional hypodermic needles.

Tasso Inc. recently received $3 million in funding from the Defense Advanced Research Projects Agency (DARPA) for their project.

With the money they plan to embark on blood preservatives in the goal of stabilizing blood so it can survive one week at 140 degrees Fahrenheit, thereby eliminating a costly step in the process.

Currently, blood is stored and handled by means of an unbroken cold-chain, meaning that every step of the process is carefully orchestrated to keep the blood at the same temperature.

Without the need for cold chain transportation, individuals could draw their own blood at home and mail the sample to the lab at their leisure, according to a company press release.