Millionaire inventor James Dyson  has donated £4 million towards a pioneering cancer care unit at the Royal United Hospital in Bath.

The largest donation in the hospital’s history, it means the Forever Friends Appeal has surpassed its £5.5m minimum target by £3 million and will now be able to include state-of-the-art medical equipment and dedicated research facilities, as well as art and pastoral gardens.

Mr Dyson, who began his empire in Chippenham, has a strong personal motivation for the donation, having lost both his parents to cancer.

He was sent to boarding school when his father Alec passed away with liver cancer when he was just nine.

Half a million people in Bath, West Wiltshire and Northeast Somerset are set to benefit from the new cancer centre, which is expected to open in 2017.

Mr Dyson’s gift has also been prompted by the success of the 2011 £3.1 million neonatal intensive care unit at the RUH, which Dyson also contributed to.

New research funded by the James Dyson Foundation has shown the health of premature babies has been improved by the healing environment created by a well-designed building.

Ninety per cent of babies recuperating in the new build are going home breast feeding, compared to 64 per cent before, according to consultant neonatologist and paediatrician Dr Bernie Marden.

And babies are better rested – sleeping on average for 22 per cent longer. Their respiratory and sleep patterns were measured without invasive tubing and tangled wires by accelerometers, which are also used to measure speed and movement in aircraft, smartphones and by Bath Rugby Club on the pitch.

Infrared tracking technology was used to track staff movements and showed nurses now spend 20 per cent more of their time with the babies in the clinical rooms.

Mr Dyson said: “We have been hugely impressed by the outcomes of the Dyson Centre for Neonatal Care. The new cancer centre will use cutting edge technology and well considered design to improve the health of its patients too.”

He said the new building would remove sources of noise and use natural light to give relaxing and spacious interiors. It would provide space for relatives and carers to stay overnight, and provide flexible, private spaces to sit and be quiet or have private conversations. Inpatient rooms would be placed at the top so patients to benefit from the best views over surrounding countryside.

John Cullum, chairman of the Forever Friends appeal and father of jazz musician Jamie, said: “James Dyson’s donation is providing a massive boost and allowing us to expand the campaign.

"It will enable us to vastly improve cancer care in the region, in the same way that the Dyson Centre for neonatal care has already done for premature babies.”