| E/I | expiration/inspiration [ratio] |
|---|---|
| EMR | educable mentally retarded; electromagnetic radiation; electronic medical record; emergency mechanic... |
| ETAR | equivalent tissue air ratio |
| ETR | effective thyroxine ratio; endothelin receptor |
| FEF50/FIF50 | ratio of expiratory flow to inspiratory flow at 50% of forced vital capacity |