For biomedical what you mean by ENG and EEG

EEG

Electroencephalography (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain  EEG is most often used to diagnose epilepsy, which causes obvious abnormalities in EEG readings.[2] It is also used to diagnose sleep disorders, coma, encephalopathies, and brain death. EEG used to be a first-line method of diagnosis for tumors, stroke and other focal brain disorders,[3] but this use has decreased with the advent of high-resolution anatomical imaging techniques such as MRI and CT. Despite limited spatial resolution, EEG continues to be a valuable tool for research and diagnosis, especially when millisecond-range temporal resolution (not possible with CT or MRI) is required.   ENG electronystagmogram (ENG) measures normal eye movement and involuntary rapid eye movements called nystagmus. It also checks the muscles that control eye movements. ENG checks how well the eyes, inner ears , and brain help you keep your balance and position (such as when you change from lying down to standing).   ENG is done to help see whether there is damage or a problem in how the inner ear, brain, or nerves connecting them work. These problems may cause dizziness, vertigo, or loss of balance.   Nystagmus occurs normally when the head is moved. But nystagmus without moving your head or nystagmus that does not go away may be caused by conditions that affect the inner ear, brain, or the nerves connecting them.   During ENG, electrodes are attached to the face near the eyes to record eye movements. The movements are recorded on graph paper. A series of recordings is done.