Valery Spiridonov attends a news conference in Vladimir, Russia, June 25, 2015.[Photo/Agencies]

Human head transplants have raised ethical concerns among people in the field.

Ren disagrees with the opinion that norms come after behavior.

"In medical history, every innovation has been realized before psychologists and ethicists establish norms for it. For human head transplants, since it has not been achieved clincally, there are no norms for it", said Ren.

He cited a professor from Harvard University by saying that it is unreasonable to hamper its development if it is approved by the government and related legal departments.

Three Chinese volunteered for operation

The volunteer for the first human head transplant is Valery Spiridonov, a Russian computer scientist, who suffers from a muscle-wasting condition known as Werdnig-Hoffmann disease. Spiridonov hopes that the procedure will give him a second chance.

Three Chinese also volunteered for such an operation, according to Ren.

Many patients who heard the news begged Ren to consider them for the operation, only to get an explanation that it could not be achieved in the short term.

Many patients, who suffer from terminal cancer,paraplegia or some congenital diseases, have a perfectly healthy head but a dead body. Some of them die without any treatment. Modern science had no way to improve their condition, said Ren.

"As a medical scientist, what's your responsibility and duty? Whether you save these patients' lives or not? In the US, someone questions it on ethical grounds. Spiridonov asked the questioner whether he would oppose if he were in his condition", he said.

What is a head transplant?