Machines for Heart Surgery Gibbon’s Oxygenated and Diabetes
Gibbon’s extracorporeal oxygenator consisted of two pumps, one pushing blood through the artificial lung, the other through the body’s arteries. The oxygenator (also known as the film oxygenator) was an arrangement of stainless steel layers that made up a large surface area over which oxygen was blown. The blood was pumped over these screens, where it could pick up oxygen to transport to the arteries while releasing carbon dioxide – its main waste product – at the same time.
Once in the arteries, the pumped blood had, of course, to flow freely but without being squeezed, which would have damaged the structure of the blood cells, while in the machine there was the added problem of blood sticking to the various pipes and junctions and clogging up the smooth mechanism. Gibbon managed to resolve these difficulties in the laboratory and in the last years used his machine to aid him in an operation on an 18-year-old girl suffering from an atrial septal defect.
She was connected up to it for 45 minutes, for 25 of which the mechanical device completely took over the function of the heart. Open-heart surgery with the heart-lung machine had taken its fin decisive step. At the same time as artificial extra-corporeal cardiorespiratory systems were in their infancy, another time-seeking technique was being developed.
Instead of passing the blood of the patient through a machine, why not use another human circulatory system – a biological life-support method that avoided all the problems associated with man-made pumps, valves, pipes, and tubes? Animal experiments by Anthony Anderson in the UK had demonstrated that such a cross-circulation arrangement could work: the functioning of one animal’s heart and lungs could temporarily be taken over by the second animal, then restored, without harming either borrower or lender.
There are really no big distinctions between sugars and starches in either nutritional terms or in the G.I. sense. Some sugars such as fructose or fruit sugar have a low G.I. factor. Others, such as glucose, have a high G.I. factor. The most common sugar in our diet, ordinary table sugar (sucrose), has an intermediate G.I. factor.
Starches can fall into both the high and low G.I. categories too, depending on the type of starch and what treatment it has received during cooking and processing. Most modern starchy foods, like bread, potatoes, and breakfast cereals, contain high G.I. carbohydrates. What research has shown is that people with diabetes can eat the same amount of sugar as the average person, without compromising diabetes control.
However, it is important to remember that sugar alone won’t keep the engine running smoothly, so don’t overdo it. Studies have shown that diets containing moderate amounts of refined sugars are perfectly healthy (10 to 12 percent of kilojoule intake) and the sugar helps to make many of the other nutritious foods in the diet more palatable.