FIGURE 1.

EEG Analyzer software as a real-time monitor of the Poincaré plot. The EEG Analyzer (downloadable for free use from the blog site Science to Medicine, EEG Analyzer ver. 54_GP, http://www.anesth-kpum.org/blog_ts/?p=3169) was developed using the open-source Processing 3.5 software package with the Apache Commons Mathematics Library (version 3.6.1, Apache Software Foundation, Forrest Hill, MD, United States) and a Java Virtual Machine (Oracle, Redwood Shores, CA, United States) with Java class libraries (javax.swing, java.AWT, and java.io packages). (A) Flow chart of on-line Poincaré plot analysis of processed EEG data. EEG waves obtained from the BIS VISTA A-3000 were passed through six bandpass filters for fast Fourier transform frequency analysis. Then, processed EEG data at each filtered range was subjected to Poincaré plot analysis during general anesthesia management. (B) The EEG Analyzer (connected to a VISTA A-3000 BIS monitor to collect EEG packets through an RS-232 interface) displays BIS, SEF₉₅, total power, frequency spectrum, and the Poincaré plot of bandpass-filtered EEG data. Digitized EEG packets with a sampling frequency of 128 Hz were obtained through the serial output of the BIS monitor. Eight seconds of EEG analysis yields 1,024 data points, resulting in a Poincaré plot with 1,024 data points. The Fc-PIS shown on the screen was not yet optimized. BIS, bispectral index; EEG, electroencephalogram; Fc-PIS, frequency analysis-cooperated Poincaré plot-integrated score; SEF₉₅, spectral edge frequency below 95% of the power of a given signal is located.