Yes, MBBS Doctors can become perfusionist. After MBBS one must appear for the national eligibility entrance examination for postgraduate. According to the ranking, he/she has to choose Clinical Perfusion as the Specialization subject. For 2 years the doctor has to operate the cardio pulmonary bypass machine during cardiac surgery and other surgery that require cardio pulmonary bypass to manage the patients physiological status and master the subject. Thank you. Good Luck.