| EAR | Foam earplugs the most comfortable available but not as good as wax ones. They are little foam cylinders that are rolled up into a thin core which then slowly expands after insertion into the ear canal. Like all earplugs they take two or three nights to get used to. Available from most chemists. |
| EDS | Excessive Daytime Sleepiness |
| EEG | Electroencephalogram |
| EEG | ElectroEncephaloGram. A graphic record of the electrical activity of the brain. The brain waves are recorded by electrodes that are placed on the head. Different types of brain waves occur during the various sleep stages. Each type of brain wave has a different frequency. |
| EH | Essential Hypersomnia |
| EKG | Electrocardiogram |
| EKG | ElectroCardioGraph. Also ECG. A graphic record of the electrical activity of the heart. Electrodes are placed below the collarbone and on the ribcage. Episodes of apnea can cause repeated changes in heart rate and blood pressure. |
| Electrocardiography (EKG) | A method of measuring the electrical activity of the heart. |
| Electrodes | Small devices transmitting biological electrical activity from subject to polygraph. |
| ELECTRO-ENCEPHALOGRAM | (EEG most people only use the abbreviation). Recording of brain waves required for sleep staging. |
| Electroencephalogram (EEG) | Recording through the scalp of electrical potentials from the brain and the changes in these potentials. The EEG is one of the three basic variables (along with the EOG & EMG) used to score sleep stages and waking. Surface electrodes are used to record sleep in humans recording potential differences between brain regions and a neutral reference point or between brain regions. |
| Electromyogram (EMG) | Recording of electrical activity from the muscular system; in sleep recording synonymous with resting muscle activity or potential. The chin EMG along with EEG and EOG is one of the three basic variables used to score sleep stages and waking. Surface electrodes are used to record sleep in humans measuring activity from the submental or masseter muscles. These reflect the changes in resting muscle activity. During REM sleep the chin/cheek EMG is tonically inhibited. |
| ELECTRO-MYOGRAM (EMG) | Recording of muscle activity. Used as part of sleep staging. |
| Electro-oculogram (EOG) | Recording of voltage changes resulting from shifts in position of the eyeball-possible because each globe is a positive (anterior) and negative (posterior) dipole; along with the EEG and the EMG one of the three basic variables used to score sleep stages and waking. Human sleep recordings utilize surface electrodes placed near the eyes to record the movement of the eyeballs. Rapid eye movements in sleep indicate a certain stage of sleep (usually REM sleep). |
| ELECTRO-OCULOGRAM (EOG) | Recording of eye movements required for sleep staging to define rapid eye movement sleep (or dreaming sleep). |
| EMG | Electromyogram |
| EMG | ElectroMyoGram. A graphic record of muscle movements. Electrodes are placed on the chin and the legs. Muscles relax during the transition from wake to sleep. Then your brain paralyzes many of your muscles during the stage of R sleep (REM sleep) although muscle twitches may occur. Leg movements may be a sign that you have restless legs syndrome or periodic limb movements. |
| ENT | Ear nose and throat |
| ENT - Ear, Nose and Throat | A doctor specializing in diseases of the Ear Nose and Throat. These specialists often do surgery as well and may be referred to as an ENT surgeon. |
| EOG | Electro-oculogram |
| EOG | ElectroOculoGram. A graphic record of eye movements. An electrode is placed on the face near each eye. Slow rolling eye movements occur during the transition from wake to sleep. Brief rapid movements occur during the stage of R sleep (REM sleep). |
| EPAP | Expiratory Positive Airway Pressure |
| EPAP - Expiratory Positive Airway Pressure | Pressure prescribed for the expiratory (breathing out) phase of an individual on Bi-level CPAP therapy for OSA (obstructive sleep apnea). |
| Epidemiology | Scientific discipline studying the incidence distribution and control of disease in a population. Includes the study of factors affecting the progress of an illness and in the case of many chronic diseases their natural history. |
| Epoch | A standard 30 second duration of the sleep recording that is assigned a sleep stage designation; for special purposes occasionally longer or shorter epochs are scored. |
| Epworth Sleepiness Scale | Index of sleep propensity during the day as perceived by patients and derived from the answers to 8 questions. |
| EPWORTH SLEEPINESS SCALE | Eight questions asking about tendency to drop off at inappropriate times used to guage how sleepy someone is. |
| Esophageal Pressure | Measurement used to determine respiratory effort and by inference airway resistance. Considered an invasive measure generally used only in polysomnographic testing conducted in sleep disorders centers. |
| Excessive daytime sleepiness or somnolence (EDS) | Subjective report of difficulty in staying awake accompanied by a ready entrance into sleep when the individual is sedentary |
| Expiratory Phase | Air is expelled during this phase of the breathing cycle |
