Michael Schumacher's wife, Corinna arrives at the Grenoble hospital, French Alps, Friday, Jan. 3, 2014, where former seven-time Formula One champion Schumacher is being treated. Schumacher has been in a medically induced coma since Sunday, when he struck his head on a rock while on a family vacation. (AP Photo/Thibault Camus)

London - A LUCKY amulet that Michael Schumacher took with him on every race has been placed by his hospital bed by his wife Corinna, who is keeping a constant vigil.

Mrs Schumacher has also surrounded her dangerously ill husband with keepsakes from their children and candles as she prays for his recovery.

The news comes as doctors yesterday revealed the seven-time F1 champion was showing slight signs of improvement and had had a second operation. But they said he remains in a critical condition.

Photographs also emerged of the dramatic moment when he was airlifted from a ski run in the French Alps by a rescue helicopter.

Among the lucky charms his 44-year-old wife has placed by his bed at Grenoble University Hospital is the ceramic amulet she gave him after they wed in 1995, inscibed with the initials of family members.

Schumacher is said to have refused to race without it.

Other sentimental tokens arranged around the bed where he lies in a coma include a hairbrush belonging to 16-year-old daughter Gina-Marie and a golden cross from his son Mick, 14.

Of the cross, which stands by his headboard, Mrs Schumacher, 44, has said: ‘Mick discovered it when he was on holiday with his grandma. It has even been blessed.’

Last night, surgeons said Mrs Schumacher and the children were in a ‘state of shock’.

Her husband’s younger brother Ralf, who was also a Formula One driver, and father Rolf also visited the hospital yesterday.

Schumacher, who turns 45 on Friday, was skiing with Mick on Sunday morning when he hit his head on a rock with sufficient force to crack his helmet in two.

He remains in an artificially induced coma at the hospital with Mrs Schumacher and their children at his bedside.

The hospital’s chief anaesthetist, Professor Jean-Francois Payen, said medical literature puts the likelihood of recovery from his injuries at between 40-45 per cent, but added: ‘I don’t work with statistics, I work with patients.’

Yesterday, surgeons said a second operation to remove a blood clot and relieve the pressure on his brain went well.

Jacqueline Hubert, the director general of the hospital, said a scan on Monday showed that there was an opportunity to perform a second operation to remove some of the haematoma, or pooled blood, that was pressing on his brain.

She added: ‘Very late in the evening a brain scan was carried out and we could see there was a slight improvement of the situation. The scan allowed us to suggest to the family that we had a new surgical intervention to reduce the haematoma, and that surgical intervention took place overnight. A new scan was taken this morning and it showed a slight improvement.’

Neurosurgeon Emmanuel Gay, who performed the operation, said: ‘The dangers are still there. We cannot say we have won because there are still some highs and some lows, but it’s better than yesterday.

‘He is still in a very critical condition, this has not changed. And we still cannot tell how he will be, which state he will be in when he does wake up. We cannot speculate on the future because once again it would be too early to do so.’

Schumacher, who amassed an estimated £500million fortune during his racing career and now earns £7million a year as an ambassador for Mercedes, fell in a rocky area between two marked pistes – a red run for intermediate skiers and a blue run for beginners. It is not steep, but a lack of snow cover has made the rocks more of a hazard.

Although the area is not a piste, experienced skiers cross it to enjoy the thrill of precision skiing between the rocky obstacles.

Schumacher was airlifted within minutes of his accident, after being aided by two patrol skiers who found him disorientated but conscious, with his split helmet full of blood. He was flown to nearby Moutiers before being transferred to a specialist trauma unit 80 miles away in Grenoble.