Hospitals in Scotland are to trial "fresh air machines" which are having dramatic success in the battle against hospital super bugs.

The air disinfection (AD) machines have been developed by AIM-listed technology group Mid-States, where investor Dermot Desmond has a 15% stake, and which has signed a distribution deal with the Sunlight group.

The machines reduced almost to zero the incidence this year of the c.diff infection in a north-east of England hospital ward which reported 31 cases last year. The three cases compare directly with 16 in an identical ward at the hospital without the machines.

Sunderland Royal Hospital has said the results are "extremely impressive and certainly suggest that the AD devices are significantly reducing airborne micro-organisms".

Hospitals in Edinburgh and Dumfries & Galloway could become the first in Scotland to trial the technology, with the Scottish Government com- mitted to cutting hospital c.diff cases by 30%. The Prime Minister has claimed a 57% reduction in hospital MRSA since 2004, following his party con- ference promise a year ago of a "deep clean" for every hospital.

But the MRSA Action lobby group says official figures show that more than half of NHS trusts have made no improvement at all, while hospital insiders say a "deep clean" has no lasting impact, and can even spread infection when patients are evacuated from wards.

The technology developed by formerly Scottish-based entrepreneur David Macdonald has undergone rigorous testing and prototyping for seven years, with the support of leading scientists including Aberdeen University's Professor Hugh Pennington who advises the company.

Macdonald, a scientist who built Alpha Machine Technologies at East Kilbride from start-up to £8m of turnover in two years in the 1990s before the business ran into cash problems, told The Herald in 2004: "The way we fought tuberculosis 70 years ago was to keep patients out in the fresh, clean, healthy air, and getting that air into our wards will beat the superbug."

Hospital-acquired infections make up 12% of all hospital illness, and patients have an 11% likelihood of infection once their stay exceeds four days.

In 2006, Macdonald backed his business into cash shell Mid-States, which took over established healthcare firm Innov8 technologies.

Macdonald, chief scientist of Mid-States and a 21% shareholder, commented last week: "I probably personally spent close to £1.5m before we did anything with it." But he said the Sunderland results were critical. "The drop from 16 cases to three is essentially because we are cleaning the air. That means the technology which would more than meet government targets is in existence, available and affordable."

Air testing found that for 95% of the time, the air in the ward was cleaner than in an operating theatre during an operation.