There are benefits to getting your own back. Especially if it is blood. The bigger the operation, the more blood gets spilled. In procedures like open heart surgery and major trauma, blood loss can be so great that large quantities need to be replaced. Blood transfusions are often the preferred option. But in a minority of cases there can be adverse reactions. And then there is the cost. As Professor Terry Gourlay puts it: "Blood is not cheap". He is a bioengineer at Strathclyde University in Glasgow, the leader of a team which has produced a new device to recycle blood during major surgery. Recovering a surgical patient's blood and putting it back in the body is not a new idea. But autotransfusion, as it is known, is typically a skilled, time-consuming and costly business. Hemosep, as the Strathclyde process is known, is altogether more straightforward and looks a lot less labour intensive. There is a small, lightweight machine which agitates the blood to stop it settling. But the key to it is the special plastic bag in which the recovered blood is poured. Simply put, it is like a chemical sponge that soaks up the unwanted plasma which has diluted the blood during the operation. The key component is an advanced polycarbonate membrane which lets the plasma through but keeps the important blood components separate. They include important proteins and clotting factors. These concentrated cells can then be returned to the patient. According to Professor Gourlay, the medical benefit of that is straightforward: "It's your blood." Worldwide market Hemosep has already been tested successfully in Turkey where it has been used in more than 100 open heart surgery procedures. The system will now be sold throughout the European Union in a partnership between Strathclyde and the medical device company, Advancis. It has also been approved for sale in Canada. Professor Gourlay says that in some markets the true cost of a unit of blood can touch $1,600 and blood products constitute a multi-billion dollar worldwide market. He explained: "Blood is not free, by any measure, and in fact in North America the latest studies suggest that a unit of blood costs upwards of $1,600." The Strathclyde team and its partners will be contending for a share of that. And if Hemosep is a success they will also save buckets of blood. Literally.