Mr Kweh, 47, intends to traverse city streets and forest trails over three days from April 21 to 23 on a motorised four-wheel drive wheelchair.

He is on an Adventure200 quest to raise $200,000 for the Spastic Children's Association of Singapore (SCAS) to set up a clinic to teach children to use gadgets for the disabled, such as speech devices for those with speech difficulty, and machines that let the disabled use computers.

Mr Kweh was born with a rare genetic condition called Morguio-Brailsford, which caused him to develop very weak lungs. He was forced to use a wheelchair because of spinal sclerosis, and lost his sight in his left eye because of glaucoma.

He said he was inspired to help SCAS after he met some cerebral palsy sufferers there who regained confidence in themselves when they learnt to use the devices in their everyday lives.

'It's also one way to personally challenge myself by getting out of my comfort zone,' said Mr Kweh, who said he had tried to sign up for marathons before but was rejected due to health and safety concerns.

Mr Kweh will be accompanied by a team of eight volunteers and friends on his journey through places like Orchard Road and the MacRitchie forest trails. They will clear the way for him.

He has received support from the National Library Board which will publicise his fundraising efforts at their 22 public libraries.