Unlike most medical equipment inventors whose creations are meant to save lives, Yang Hui created a device that ends lives, albeit quickly and as painlessly as possible.

Yang, 39, is the inventor of a high-speed lethal-injection pump and the sole supplier of the device to local intermediate courts since 1998.

It's an invention he isn't very proud of, for ironically, he is against capital punishment.

"If there comes a day when capital punishment is abolished, it will be a step forward in terms of the protection of criminals' rights," he said.

Lethal injections were thrust back into the spotlight after the method was used to execute Wen Qiang, the former director of the municipal judicial bureau of Southwest China's Chongqing municipality, on July 7, following his conviction of taking bribes and protecting mafia-style gangs.

Beijing and Liaoning province in Northeast China also made headlines when they stopped using firing squads to execute death-row convicts.

Yang hasn't had any medical training. He majored in electronics engineering from the University of Electronic Science and Technology in Hangzhou, capital of East China's Zhejiang province.

In 1998, while he was running a medical-equipment company in Hangzhou, Yang, then 27, applied for a Chinese government program to invent the lethal injection device.

The year before, the code of criminal procedure was revised in China and lethal injection was written into the law as one of two means of capital punishment, along with firing squad. Criminals were not given notice of the way they would be executed.

In China's first use of the lethal injection, four drug dealers were executed in Kunming, Southwest China, in November 1997. The injections were administered with a simple syringe.

Yang took up the program partly because of what happened when he was 6 years old.

He had witnessed the execution of a friend's father in his hometown in South China's Guangxi Zhuang autonomous region. The 30-year-old farmer had been convicted of killing a man who had an affair with his wife.