If you are medical student, this is easy as everyone assumes you are learning all the time and you don’t have all the answers. Take every opportunity to grab the machine and practice on patients, volunteers, your friends etc. Practice at lunchtime, before work, after work. I guarantee you, the portable machine will be available most of the time. Start with the easy stuff then, when you are comfortable with that, move on. Practice, practice, practice, day in, day out. It all adds up in the end.
If you are a qualified physician, it’s a tad more difficult. Patients might expect you to give them answers. Explain that you are still learning and adopt the attitude that although it might give you positive useful information, but it also might not. In the grand scheme of things, no opportunity to learn is ever wasted.