I am an electrician, and I want to learn medical equipment maintenance for work reasons. What is the basis I need to master?

Circuit theory, analog electronic technology, digital electronic technology, power electronic technology, automatic control theory, signal and system, digital signal processing, communication principle and system, single chip microcomputer principle and application, computer control technology, electronic circuit CAD, computer communication network, electrical testing technology, power engineering foundation, intelligent instrument design and other professional basic courses and professional direction courses.