I assume that you will be near the Beilinson branch of the Rabin Medical Center, i.e. on or near Jabotinski St, the main route from Tel-Aviv to Petach Tikva. The hotels near the Diamond Exchange in Ramat Gan are a good choice: a short walk to Jabotinski where you can easily get a bus or sherut to Petach Tikva, and also convenient for going into Tel Aviv in the evening. The same buses & sheruts also go by the Crown Plaza in the Azrieli Center.