Due to the complexity of the original EEG waveforms, previous anesthesia depth monitoring systems only calculated a single index, such as Bispectral index (BIS) or patient state index (PSI), to determine the state under anesthesia. However, a single numerical change may not reflect the true state under anesthesia. By analyzing the original EEG waveforms, more information can be obtained, such as density spectral array (DSA) and power spectral density, which can quantify the energy distribution at various brain wave frequencies. This allows anesthesiologists to determine the effects of medication on brain waves and the effects of surgical stimulation on brain waves during surgery.~After obtaining the signed informed consent form, before inducing general anesthesia in the patient entering the operating room, an anesthesia depth monitoring patch is attached to the forehead, and EEG data during anesthesia is collected using the currently used anesthesia depth monitoring device. The monitoring process starts from the beginning of general anesthesia until the end of the surgery, and the EEG recording is stopped only when the patient wakes up from general anesthesia and leaves the operating room.~By using the original EEG during anesthesia depth monitoring to conduct spectral analysis and combining it with common post-anesthesia adverse symptoms such as pain, nausea and vomiting, delirium, and restlessness, a correlation analysis is conducted between the quantified EEG values and postoperative symptoms. This verifies whether intraoperative EEG spectral analysis can predict the occurrence of postoperative complications.
Using data from electroencephalogram (EEG) obtained through intraoperative depth of anesthesia monitoring devices, combined with clinical symptoms such as postoperative pain and delirium, investigate their correlation and verify whether intraoperative EEG spectral analysis can predict the occurrence of postoperative pain, nausea and vomiting, restlessness, or delirium in patients undergoing surgery.