Hong Kong's best-known quadriplegic, Tang Siu-pun, has hailed the potential benefits of the latest hi-tech equipment for people like him but bemoaned the fact that few could afford it. He said his own wheelchair - a gift from Canto-pop singer Jacky Cheung Hok-yau - cost as much as a car and was well beyond the reach of the average disabled person. Mr Tang, popularly known as Ah Bun, was speaking yesterday at the introduction of three new pieces of medical engineering - a computer operated by eye movement, a robotic rehabilitation system and a fluid that hardens to help heal bone fractures. 'The computer controlled by eyeball movement costs about HK$70,000 to HK$80,000,' Mr Tang said. 'To an unproductive man who is living on social security, it is impossible for him to buy a computer like that.' He said he hoped universities that developed the technology would offer the disabled a free trial of equipment so they could make an informed choice. He said his own wheelchair, which he can move by touching a joystick with his chin, cost about HK$200,000. 'My special wheelchair is as expensive as a car. Actually it is not very special, but it can let me move while lying down.' The equipment, developed at two local universities, was put on show by the Hong Kong Institution of Engineers. Eric Tam Wing-cheung, assistant professor of health technology and informatics at Polytechnic University - which developed the computer and the PolyJbot rehabilitation system - said it was inevitable that equipment for the handicapped would be expensive. Materials had to be imported and the equipment was produced in small numbers, which meant it was expensive, he said. The PolyJbot is a robotic device that helps the elderly and disabled people with limb problems by monitoring muscle activities and generating training regimes with various combinations of forces. The University of Hong Kong invented the bioactive bone fluid, which hardens to help heal bone fractures. The fluid is injected into fractures to hold them together while they heal.