Which measurement is affected by the impedance of the skin?

The measurement affected by the impedance of the skin is electrode voltage. When electrodes are placed on the skin to measure electrical signals, such as those in an EEG or an EKG, the impedance, or resistance, of the skin can influence the voltage that is detected by the electrodes. High skin impedance can lead to poor signal quality and reduced voltage readings, while lower impedance can enhance the clarity and strength of the signal.

For instance, if the skin is not properly prepared or if the electrode material does not have good conductivity, this can increase impedance, leading to weaker signals that may be more prone to noise and interference. Therefore, managing skin impedance is critical to obtaining accurate and reliable measurements in sleep studies and other medical tests.

Other choices, while related to the overall context of signal integrity, do not directly relate to how skin impedance affects voltage measurements specifically. Electromagnetic interference and ambient light interference pertain to external noise influences, while signal amplification refers to the process of increasing signal strength rather than being directly affected by skin impedance.