Modern medicine has come with lifesaving devices that decrease mortality in patients suffering from acute cardiac conditions like arrhythmias and heart attacks.  An automatic external defibrillator is common in many ERs, doctor’s clinics and ambulances all across the US and the world.  This device is used primarily to bring an abnormal heart rhythm back to its normal state.  The term biphasic refers to the method by which the device transmits the electrical current to the affected heart.


According to Philips HeartStart AED packages experts, Dr. Claude Beck performed the very first successful case of human defibrillation back in 1947.  At the time, the process was performed directly to the heart during heart surgery. The early machines used alternating current until advances in technology allowed for the use of direct current. Developed in the waning years of the 1950s, direct current defibrillators utilized what is called a Lown waveform where the machines provided a uniphasic or one way current from one paddle to its partner.  This approach was considered standard for three decades until biphasic waveform was introduced.


biphasic defibrillatorBiphasic defibrillators utilize current that travels in a single direction from paddle to paddle and then back. The energy level that is delivered can be different over the course of the delivery, which is essentially a bit longer than the old uniphasic variants.  Biphasic defibrillators offer the advantage of using lesser energy to restore the heart to its normal rhythm, which reduces the risk of electrical burns as well as heart damage.

External Defibrillators

The use of biphasic defibrillators has provided a higher success rate for restoring heart rhythms, which led to its widespread use. It has now become the standard in AEDs or automatic external defibrillators for quite some time already. Its ability to use lesser energy means it the design can be small enough for it to be easily transportable in emergency vehicles.

Another example where biphasic defibrillation is used is in implantable cardioverter defibrillators or ICDs.  This device was developed as a treatment option for those that are at high risk for life-threatening cardiac events.

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