What are likely sources of 60-Hz activity in polysomnography recordings?

The correct answer highlights that electrical devices located too close to the equipment are likely sources of 60-Hz activity in polysomnography recordings. This frequency, known as line frequency, often originates from the electrical power supply in North America, which operates at 60 Hz. When electrical devices such as computers, lights, or medical equipment are situated near the polysomnography setup, they can introduce electromagnetic interference. This interference might be recorded as artifacts in the data, typically seen as periodic activity at the 60-Hz frequency.

Understanding this phenomenon is crucial for technologists because identifying and minimizing these sources of interference can lead to cleaner, more accurate sleep recordings. Effective troubleshooting might involve repositioning equipment, using grounding techniques, and ensuring proper shielding to mitigate noise from electrical sources.