hey birdie I also have first hand experience with microsleeps.
YOU CANNOT PREDICT WHEN THEY WILL OCCUR.
change your lifestyle!
hire an assistant and cut back the hours.
learn to delegate or just let some things slip.
get more sleep or you will kill yourself.
worse still you will kill someone else by accident.
stop reading to understand it. you need more sleep. simple.
your brain is shutting down because the circuitry is exhausted.
on a positive note I made all such changes and dont suffer microsleeps any more. it isnt a permanent condition. like a hangover you sleep it off.