Willem Kolff invented the first 'artificial kidney' during the Nazi occupation of the Netherlands using sausage casings, beverage cans, and a washing machine motor. The machine filters a patient's blood to remove waste products and excess water when the kidneys can no longer function. This process, called hemodialysis, turned a previously certain death sentence for those with kidney failure into a manageable chronic condition. Kolff is considered the 'father of artificial organs,' and his work led to the development of modern dialysis centers and eventually the first artificial heart.