An Asian airline has become the first in the world to use a revolutionary Irish-made aircraft cushion, which reduces the risk of travellers developing potentially fatal blood clots on long-distance flights.

The Taiwan-based China Airlines has confirmed the cushion, developed by Co Cork-based Longhaul Technologies, features in its multi-million dollar Airbus A340-300 aircraft, introduced two weeks ago.

It is understood Longhaul is on the verge of signing deals for its cushion with other Asian airlines and is talking to a major European airline.

Research published in the Lancet last week shows that up to one in 10 long-haul travellers show evidence of symptomless clotting in their legs. While most clots will resolve spontaneously, some will not.

So-called "economy-class syndrome", where passengers develop deep vein thrombosis from sitting for hours in cramped conditions, has caused concern following a number of deaths in recent months. The Longhaul cushion consists of two airbags and moulds to the passenger's body to reduce seat pressure points, thereby allowing better blood circulation. It enables passengers to stretch their legs for exercise with comfort. This compares with conventional seats, which put pressure on veins during such exercises. In March, representatives of the world's largest airline carriers met to look at measures to reduce the incidence of deep vein thrombosis. A Japanese doctor has claimed that 25 people including a pilot have died in the past eight years at Tokyo's Narita airport due to blood clots caused by cramped seating.

Mr Morgan Connolly, managing director of Longhaul, said airlines were beginning to realise just how serious an issue this was and were acting accordingly. He said the new cushions would soon undergo tests to establish their medical benefit.

"For 30 years, there has been virtually no movement away from the solid, traditional airline seat but that's all going to change now as concern about blood clots increases," he added.