Rob Harris

London - After missing out on the Beijing Olympics, double-amputee sprinter Oscar Pistorius is determined to qualify for this year's world championships and prove himself against able-bodied runners on the road to the 2012 London Games.

The 22-year-old South African has fought his legal battles to win approval of his carbon-fibre prosthetic racing blades and is no longer in conflict with the sport's administrators.

"If I run a good time it's not about prosthetic legs having an advantage, and when I run in bad times (hopefully) people will say Oscar isn't fit - he's not concentrating," Pistorius said. "I enjoy being criticized."

Pistorius' detractors had claimed his blades gave him a competitive advantage. The Court of Arbitration for Sport ruled in his favour last year, meaning Pistorius no longer needs to justify his place on the track.

An IAAF ban was overturned in time for the Beijing Olympics, but he missed the 400m qualifying time of 45.55 seconds. He still managed to clock a personal best 46.25 while consumed by the draining legal struggles.

Pistorius won three gold medals in the 100, 200 and 400m at the Beijing Paralympics.

"I woke up on January 1 this year and it felt like a huge burden had been lifted from my shoulders ... 2008 had extreme highs and extreme lows," Pistorius told The Associated Press in an interview. "It was a great end to the year with three golds at the Paralympics, but maybe the good thing was going through all the tests that needed to be done using the best scientists. Nobody can say they are wrong.

"I can do my job to educate people about Paralympic sports as regards to prosthetics, but my job is not to win over as many hearts of those who think the prosthetics legs give advantage ... or carry on debating whether it's right or wrong."

Pistorius hopes to compete in the 400 at the worlds in Berlin from Aug. 15-23. Already 4kg lighter this year - his lightest in four years - Pistorius figures he will need to run 45.95 to qualify.

"At the moment, I can't see any reason why I won't. As long as I'm running personal bests and not letting my talent go to waste I'm really happy about that," he said. "Let's be realistic about it, my performance up to now lands me capable of achieving second round in the Olympics, but then I'll aim for the third round and higher and higher."

Pistorius plans to compete in South Africa in February and March before returning to Europe for the Paralympic World Cup in Manchester, which unveiled British Telecom as its new sponsor to replace Visa on Thursday - and then focus on qualifying for Berlin.