When your author was in school studying for a degree in clinical research, he created a presentation spelling out the rights (or lack thereof) of our US Military Service members as regards their participation in medical experiments, most specifically the Pridostigmina Bromide & Botulinum Toxoid administered to over 300,000 soldiers in the first Gulf War.
The bottom line: when you sign up, you surrender your right to consent (agree) to be a subject in a trial of an experimental medicine. Only the President can give you a waiver.
The PDF of the presentation is here.