A neurosurgeon planning to carry out the first human head transplant has unveiled a virtual reality system that will "prepare patients for life in a new body".

Professor Sergio Canavero wants to carry out the operation next year and believes it could lead to people paralysed from the neck down being able to walk again.

Russian wheelchair user Valery Spiridonov has volunteered to take part in the first operation, which would see his head "frozen" to stop brain cells from dying and tubes connected to support key arteries and veins.

The spinal cord would then be cut, repaired and fused on to a donor body and the skin stitched back together.

If successful the process could still lead to "unexpected psychological reactions" from the patient as they get used to their new life, so a virtual reality world to prepare them for a different body is being developed.

Created by US firm Inventum Bioengineering Technologies, patients would take part in sessions for months before an operation.

Inventum chief executive Alexander Pavlovcik said: "In preparing the patient of Heaven (Head Anastomosis Venture) to transition into a new body, virtual reality training will be used before the surgical procedure to prevent the occurrence of unexpected psychological reactions.

"We are combining the latest advancements in virtual reality to develop the world's first protocol for preparing the patient for bodily freedom after the transplantation procedure."

Prospective patient Mr Spiridonov said: "Virtual reality simulations are extremely important as this kind of systems allow to get involved into action and learn fast and efficiently.

"As a computer scientist I am extremely certain that it is an essential technology for the Heaven project."

Prof Canavero showcased the latest "milestone" during a conference at the Royal College of Physicians and Surgeons of Glasgow on Friday.

He said: "This virtual reality system prepares the patient in the best possible way for a new world that he will be facing with his new body.

"A world in which he will be able to walk again."

The procedure for cutting the spinal cord is said to be so delicate with the need to avoid nerves that a knife that can control cuts to a micrometre (one millionth of a metre) has been developed by Farid Amirouche at the University of Illinois.

Prof Canavero said: "Prof Amirouche has developed probably the sharpest and most precise blade in the world which will allow a clear cut of the spinal cord with a minimal impact on the nerves, a cutting system that is innovative and very inventive.

"It is another milestone on the journey to make the first human head transplant possible."