The Biopsy Urobot will help doctors by delivering needles more

accurately, cutting down on human error.

In a prostate biopsy, small samples of prostate tissue are removed for examination, under a microscope, for signs of prostate cancer. With 230 cases detected annually, prostate cancer is the fifth most common cancer among men here.

Doctors use a spring-driven, needle-tipped device to collect between 10 and 16 tissue samples from areas of the prostate where cancerous growths are likely to be.

But though the location of these spots is identified using computer algorithms, the marks are not always hit: The doctors must manually manipulate the needle based on blurry ultrasound images.

Said one of the lead researchers, Dr Christopher Cheng, head of SGH's urology department: "It's like shooting an arrow from the bow but not knowing where the arrow will go."

"So on a good day, the doctor might be able to hit 90 per cent of all the spots, but if he hasn't slept the night before, the results could be affected.''

Using the same computer algorithms, however, the robot can deliver the needle to within 1.5mm of each intended target spot ? significantly better than what a human can consistently achieve.

Said the other lead investigator, Associate Professor Ng Wan Sing of NTU's School of Mechanical and Production Engineering: "This means it will be accurate and consistent. So each time you aim to go to Toa Payoh, at worst you will end up in Bishan, but not Pasir Ris.''

The team of 15 researchers spent over two years and about $500,000 in grants working on this project.

They have filed a provisional patent in the United States and are in talks with a few international medical instrumentation firms about refining and commercialising the invention.

It will be least another two to four years before the Biopsy Urobot is available commercially.

Added Dr Cheng: "In future, it could even be adapted to implant radioactive seeds accurately within the prostate to cure cancer.''