| A | B |
|---|
| Impedance | A measure of how much of a signal is lost when a sinusoidal wave form is passed through a circuit. |
| K complex | A waveform used in scoring N2. |
| Limb movement | A burst of EMG activity in the leg channel with duration between 0.5 and 10 seconds. |
| Low amplitude | Background EEG activity during sleep with a mixture of frequencies with most waves be- |
| Low chin EMG tone | No amplitude measure is given for low chin EMG tone. |
| Major body | Artifact from movement and muscle activity that makes it impossible to determine the sleep stage |
| Mixed apnea | A type of apnea that begins as a central apnea and includes a portion with airway obstruction and respiratory effort. |
| Nadir | The lowest point or trough of a waveform. |
| Narrow complex | A series of at least 3 heart beats at a frequency of at least 100 beats per minute and with a QRS |
| Nasal pressure | A measure of airflow based on changes in the pressure in tubing that is placed in or near the |
| Obstructive apnea | A type of apnea with no airflow but continued effort to breathe. |
| Periodic breathing | At least 3 central apneas separated by no more than 20 seconds of normal breathing. |
| Phasic | A short-lasting part of a recording arising from a tonic (long-lasting) background. |
| PLM series | At least 4 limb movements each separated from the previous movement by at least 5 seconds but no more than 90 seconds. |
| Posterior slow waves of youth (PSW) | Waveforms usually mixed in with the dominant posterior rhythm in children. |
| Pulse oximeter | A device that uses changes in the wavelength of blood in the capillaries to estimate the amount |
