New device to allow for pain-free blood tests

The size of a pingpong ball, it can extract a small blood sample when held against the skin for two minutes, without causing pain

A new device the size of a pingpong ball can extract a small blood sample when held against the skin for two minutes, allowing for pain-free blood tests, researchers say.

The device is being developed by researchers from the University of Wisconsin-Madison who have formed a company, named Tasso, which aims to make blood sampling less painful and more convenient.

When the device is held against the skin, a slight vacuum in the device enables a small sample of blood to flow into an attached sample tube, which can be mailed or handed to a lab. Users report that the process is almost entirely painless.

The technology relies on the forces that govern the flow of tiny fluid streams, said Ben Casavant, vice president and co-founder.

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

The company has applied for a patent on channels that create capillary action to move blood toward the sample tube.

The company has also received an additional $3 million from the US Defense Advanced Research Projects Agency (DARPA) to advance its product.

The DARPA grant will fund work with companies that make blood preservatives. The goal is to stabilise the blood so it can survive one week at 60 degrees Celsius and still be fit for analysis.

That would enable the invention to be used to sample in a wide range of locations without needing costly cold-chain transportation.

Tasso is also developing a technique for taking samples to diagnose HIV.

Currently, the device can extract about 0.15 of a cubic centimetre, enough to test cholesterol, infection, cancer cells and blood sugar, Casavant said.

Although diabetics must test their blood sugar several times a day, they are not an initial market, Casavant said, as those tests are inexpensive if somewhat painful.

"We see our specialty as people who need to test semi-frequently, or infrequently, to monitor cancer or chronic infectious diseases, for example. Instead of buying a machine or expensive equipment, we ship you this device, you put it on your arm for two minutes and send it back to the lab," he said.

The device could help those who fear blood draws, and avoid time-consuming trips to labs for blood draws.

Casavant expects the device to reach the market next year.