The insulated gate bipolar transistor (IGBT) is used in the power supplies for medical diagnostic equipment such as X-ray machines and CT scanners. The quality of the images is enhanced by the excellent regulation of the voltage delivered to the X-ray tube by the IGBT-based power supply. It is used to drive the gradient coils in the MRI machines to obtain sectional images of the body. It drives the transducers in ultrasound machines used for neonatal care. The power supplies for lasers used for LASIK surgery utilize IGBTs. It enabled the creation of portable defibrillators for resuscitation of victims of cardiac arrest. The biphasic voltage waveform applied to the victim is controlled by the IGBT.