Chance invention gives needle-free blood test

By SIMON COLLINS science reporter

New Zealand scientists have accidentally discovered a device that can test blood without taking a sample using a needle.

The scientists at Government-owned HortResearch say the device, originally developed for sheep, has the potential to replace most medical blood tests - a market worth billions of dollars worldwide.

Initial tests on Team New Zealand's America's Cup sailors have boosted their strength by optimising their training, sleep, diet and health supplements.

The hand-held, gun-like device uses sound waves above the limit of human hearing and an electric current to draw chemicals from blood into the skin and then, through a special membrane, into a recording instrument.

"You position it on the forearm of the subject, leave it there for 15 seconds, take it off and you have a sample," said HortResearch scientist Dr Christian Cook.

The system can measure more than 20 factors in the blood, such as the hormones testosterone and cortisol, which measure strength, muscle growth and stress, and creatine kinase, which is a good predictor of muscle breakdown.

Unlike conventional blood tests, the system can take a series of tests without "bleeding the patient dry".

For Team NZ, this has meant sailors could be tested at any point during their daily workout. They need only stop for a few seconds between exercises.

Dr Cook, who works for HortResearch at Ruakura, near Hamilton, discovered the new technique while investigating whether high-frequency sound could be used to measure fat levels in sheep.

"I wanted to see whether putting ultrasound on the skin disrupted some of the cells in the skin," he said.

"Serendipitously, I guess, there was this increase in flux [draw-up of chemicals from the blood to the skin] that I hadn't thought would be present."

He has since found that scientists in the US have discovered the same phenomenon, but nobody had used it to test athletes.

Team NZ fitness trainer David Slyfield told the Pacific Rim Biotechnology Conference yesterday that the system let him measure the effect of training routines.

For example, some individuals did not reach full strength until an hour after starting exercise, and therefore did not get much benefit from one-hour daily workouts.

He gave those individuals extra warm-up exercises, and shifted their heaviest exercises until an hour after they started - and saw dramatic gains in strength.

The system also revealed that some individuals performed best on only seven hours' sleep, while others needed nine.

The system can tell whether people are getting the right amounts of proteins, carbohydrates and water in their diets.

"We have 36 people on our sailing team. Now we can look at each person as an individual and change their diet, training, sleep patterns and supplementation, and actually the whole sailing team will go forward," Mr Slyfield said.

HortResearch is working with Waikato Hospital to test the system on selected patients, and has been in touch with overseas interests about commercialising the technique for medical blood tests.

However, Dr Cook said it might take five to 10 years to complete the trials required for widespread use, and financial returns would need to be shared with partners.

"In a 10-year span, there is the potential to replace many, perhaps most, of the conventional blood tests," he said.

In the meantime, HortResearch hopes to develop the "niche markets" of testing athletes and animals.

Further reading

nzherald.co.nz/health

nzherald.co.nz/americascup