Many organs for transplant need oxygen and will deteriorate rapidly outside the donor's body. Known as hypoxia, the longest a heart can survive outside the body is about four to six hours.

As time progresses the organ deteriorates because of the lack of oxygen and could be unsuitable for transplant if not delivered in time. Hypoxia creates a very narrow window of opportunity for people who need organ transplants. Patients and surgeons have to be available when an organ is available. 

Now, a revolutionary technology keeps the human heart beating outside the body. Developed Transmedics, the device is known as the Organ Care System uses the company's warm blood perfusion technology that maintains organs in a functioning state. Vessels leading to the heart are plumbed in and receive oxygenated and nutrient-rich blood, which is warmed to just below normal body temperature.

The Organ Care System makes it possible for surgeons to perform living organ transplant that could increase the number of organ transplants by as much as 50-100% each year. If you're not squeamish, you can see the Organ Care System in action (yeah, with an actual human heart) here.