PSG 211 Terminology Week 9 Questions and Answers updated 2024

PSG 211 Terminology Week 9 Questions and Answers updated 2024 Artifact Unwanted signals on the recording that can arise from the body, the environment or the recording circuit itself. Salt bridge Formed when a conductive material, such as sweat or an electrode paste or cream, communicates between two electrodes. Artifact isolation Distinguishing artifact from physiologic activity Electrode popping Occurs with an abrupt shift in impedance. this can be due to a loosened electrode making intermittent contact with the skin, a fractured electrode wire, or a break anywhere in the recording circuit that occasionally loses contact. ECG artifact Occurs when the R wave of the ECG complex is seen on channels recording biopotentials, usually the EEG. Muscle artifact Unintentional 20-200Hz signals that contaminate recorded data as the result of patient tension, body rocking, grinding of the teeth, or pressure being applied to the offending electrode, or when muscles are activated for any reason. Slow frequency artifact Artifact with very high amplitude, may be 1-2 Hz or slower in frequency and may have the appearance in the EEG as N3 sleep. Sweat artifact A slow frequency artifact caused by perspiration loosening the electrode connection to the skin or diluting the conductive material between the electrode and the skin. Respiratory artifact A slow frequency artifact that is aligned with the patient's breathing. Pulse artifact When slow frequency signals are in perfect alignment with the R wave of the ECG channel. A result of electrode placement over a pulsating blood vessel. Cardioballistic artifact Artifact that that is present in the respiratory channels that represents the intrathoracic pressure changes related to the changing volume of the beating heart. The slow waves are aligned with the R wave of the QRS complex but are not related to electrical conduction. Channel blocking artifact When amplifier gain or sensitivity control is set too high, or slow wave or electrode popping artifact is extreme, the positive and negative extremes of the signal may be "chopped off" for a flat appearance. Airflow signal artifact When a thermal sensor falls out of the direct path of airflow or comes in contact with the skin, the relative change in temperature from which the signal is derived will be dampened, causing signal degradation or complete loss.