According to the 2016 ACNS guidelines, a minimum CMRR is recommended to be:

The correct answer, which is 90 dB, aligns with the 2016 American Clinical Neurophysiology Society (ACNS) guidelines regarding the calibration of electroencephalography (EEG) equipment. The CMRR, or Common Mode Rejection Ratio, is a critical parameter that measures the ability of the EEG system to reject common noise signals present in the electrodes, thus ensuring the accuracy and fidelity of the recorded brain signals. A higher CMRR indicates greater capability to filter out interference from electrical noise and improve the signal quality of the EEG recordings.

Recommending a minimum CMRR of 90 dB highlights the importance of maintaining high standards in EEG practice to ensure reliable and interpretable results. This threshold helps clinicians to minimize artifacts and enhance the visibility of true brain activity, crucial for accurate diagnosis and treatment planning in neurology.

In contrast, lower CMRR values, such as those indicated by the other choices of 80 dB, 70 dB, or 100 dB, either do not meet the recommended standards or exceed current guidelines, making them less appropriate for ensuring the desired performance of EEG systems. The choice of 90 dB strikes a balance between performance adequacy and practical application in clinical settings