I found the following sentence: Participant has should be refractory, i.e., having documented failures on more than one AED"
I wonder "has should be" is a mistake, it should be "should be" or "should have been"....
has should be is not grammatical. What is the sentence trying to say?
My guess is that there is a study for a new treatment. The choice criterion for participants is "The Participant should be refractory, i.e. non-responsive to ordinary treatment, showing documented failures on more than one automated defibrillator."