Registered Sleep Technologist Practice Exam

To determine the sensitivity setting, one has to understand the relationship between the pen deflection, input voltage, and sensitivity. Sensitivity in this context is the scale of measurement that translates the electrical signal (in microvolts) into a visual representation on the recording chart (in centimeters of pen deflection).

The sensitivity is calculated by dividing the input voltage by the distance of deflection. In this case, with an input voltage of 75 microvolts and a deflection of 1.5 centimeters, the calculation would reveal that the sensitivity setting is determined by determining how many microvolts correspond to each centimeter of pen movement.

When you divide the input voltage (75 microvolts) by the deflection distance (1.5 cm), you find that:

75 microvolts / 1.5 cm = 50 microvolts per centimeter.

This means that for every centimeter of deflection on the chart, the system needs to measure 50 microvolts. In this context, the sensitivity setting must be interpreted correctly regarding the common standards used in sleep technologist practice. The closest standard sensitivity setting that aligns with the measurement derived, when simplified and adjusted in common clinical practice, points to a sensitivity of 5 microvol