What does a constant voltage stimulator do?

A constant voltage stimulator functions by adjusting its output to ensure that a predetermined voltage is consistently maintained throughout the stimulation process. This mechanism is essential because it guarantees that the voltage delivered to the tissue is stable, regardless of changes in impedance or other factors that might vary during the monitoring or stimulating process. By varying the current output as needed, the stimulator can uphold the set voltage level effectively, which is critical for accurate neurophysiological assessments during surgery.

This characteristic inherently distinguishes it from other stimulators that may focus on maintaining constant current levels instead of voltage. For instance, other devices might output a steady current but fail to adjust for fluctuations in voltage due to varying tissue resistance. Thus, the ability to maintain a constant voltage effectively underpins the operational principle of a constant voltage stimulator, confirming that the answer is indeed that it varies the current to maintain a preset voltage level.