Complex sentence: Experiments with the first intravenous blood transfusions began at the start of the 16th century, and in the last 50 years the field of transfusion medicine has progressed remarkably bringing with it an increase in the use of blood and blood product.
Split into simpler sentences: Experiments with the first intravenous blood transfusions began at the start of the 16th century. In the last 50 years, the field of transfusion medicine has progressed remarkably, bringing with it an increase in the use of blood and blood product.