There are many different IoT application for eHealth, a review study - such as a short survey of such application, could help you narrow your search. I scanned the google scholar, and found this survey, it wont provide you with a specific 'simulator', but it can help you find the type of simulator you are looking for: https://jitm.ut.ac.ir/article_73278_9658.html
PS: I am not associated with that paper, I just found the link with short search on Scholar. There are also a few other recent studies (2019+) which seem to be related to different eHealth simulators, see: https://scholar.google.com/scholar?as_ylo=2019&q=IoT(Internet+of+Things)+simulator+for+eHealth&hl=en&as_sdt=0,5&as_vis=1