What is the difference of a monophasic and biphasic defibrillators?

Monophasic defibrillators deliver a single electrical shock in one direction to the heart, while biphasic defibrillators deliver shocks that travel in two directions, typically from one electrode to another and then back again. Biphasic defibrillators are generally more effective at restoring normal heart rhythm with lower energy levels, which reduces the risk of damage to the heart muscle. As a result, biphasic devices have become the standard in modern defibrillation practices.