Staging of sleep based on electroencephalograms and mental electromyograms recorded by a simplified polygraph, MemCalc-Malkin2

OBJECTIVE: To examine the feasibility of MemCalc-Malkin2, a simplified polygraph, for staging of sleep. DESIGN: Electroencephalograms and mentalelectromyograms were recorded in 33 patients with possible obstructive sleep apnea-hypopnea syndrome by a simplified polygraph, MemCalc-Malkin2, and their frequencies were analyzed according to the sleep stage that were determined by a simultaneous conventional polysomnography. RESULTS: Sleep was divided into four stages, i.e., awake(SWake), rapid eye movement phase(SREM), shallow non-REM sleep {S(1+2)}, and deep non-REM sleep {S(3+4)}. The ratio of the amount of beta waves to that of delta waves was significantly different between the four sleep stages (p < 0.05), being highest in SWake and lowest in S(3+4). Mental electromyographic discharges were significantly more active in SWake and S(1+2) than in S(3+4) and SREM. CONCLUSION: A MemCalc-Malkin2 appears promising for staging of sleep.