A US high school student has won an award for his invention that allows the blind to navigate by using the Global Positioning System (GPS).

Teenager Ameen Abdulrasool recently won a $66,000 bonanza at the International Science and Engineering Fair in Phoenix, Arizona, for the invention.

He has also been awarded an all expense paid trip to attend the International Youth Science seminar in Stockholm during the Nobel Prize ceremonies in December.

Abdulrasool's prototype allows visually impaired individuals to navigate a pre-programmed route via GPS. The prototype has a headset, two bracelets, a personal digital assistant (PDA) and a control box.

Abdulrasool told IANS he was inspired to build the prototype because he wanted to help the visually impaired he had grown up with.

Abdulrasool, whose parents migrated to the US from Karachi, seems unaffected by his achievements and fame.

"His greatest asset is his humility," said Antoinette LoBosco, assistant principal of his school. "He is always kind to his fellow students. We are very proud of him."

Building the prototype took three years - Abdulrasool had to make the parts on his own as the prototype is the first of its kind.

"The PDA was the most expensive part. The rest I could scavenge from old computers and radios," he said.

Elder brother Saleem, who is studying computers in the University of Illinois at Urbana Champaign, helped in the project.

The gadget's accuracy, Abdulrasool said, depends on the number of satellites it can connect to. "In tests, I have found the prototype to be most accurate in the suburbs. In downtown Chicago, there could be a problem because of the tall buildings," he said.

The gadget gives turn-by-turn verbal directions too. "In addition, the user wears braces on both hands. If one has to take a left turn, the brace on the left hand will vibrate. An infrared sensor helps the machine detect obstacles. A beep, the volume of which will depend on the obstacle's distance, alerts the user," Abdulrasool said.

It cost Abdulrasool about $1,200 to build the prototype. "If I get support from some companies, it will be easier for me to distribute the final product," he said.

Abdulrasool plans to attend the University of Illinois this fall to study electrical engineering, biomedical technology and business management.

His hobbies include tennis and football and listening to techno music, pop and occasionally Bach.