A preliminary study of sleep spindles across non-rapid eye movement sleep stages in children with autism spectrum disorder.

Study Objectives: Sleep spindles play a crucial role in multiple neuronal network functions. Initiation and termination of spindles are regulated by the thalamic reticular nucleus and thalamocortical network, and the spindle can be an index for brain organization. We conducted a preliminary study of the parameters of sleep spindles, focusing on sleep-stage temporal distribution in children with autism spectrum disorder (ASD) with normal intelligence/developmental quotients.

Reference values for a fetal movement acceleration measurement recorder to count fetal movements.

BackgroundA newly developed fetal movement acceleration measurement recorder has made it possible to count gross movements for hours. The purpose of this study was to determine the normal reference values for such movements.MethodsOne hundred and six pregnant women recorded fetal movements by themselves when they slept at home weekly from 28 weeks to term.

Automated Software Analysis of Fetal Movement Recorded during a Pregnant Woman's Sleep at Home.

Fetal movement is an important biological index of fetal well-being. Since 2008, we have been developing an original capacitive acceleration sensor and device that a pregnant woman can easily use to record fetal movement by herself at home during sleep. In this study, we report a newly developed automated software system for analyzing recorded fetal movement.

Association between heart rate variability, blood pressure and autonomic activity in cyclic alternating pattern during sleep.

Study Objectives: Cyclic alternating pattern (CAP) is frequently followed by changes in heart rate (HR) and blood pressure (BP), but the sequential associations between CAP and autonomic nerve activity have not been studied. The study aimed to reveal the precise changes in heart rate variability (HRV) during phase A of the CAP cycle.

Design: Polysomnography was recorded according to the CAP Atlas (Terzano, 2002), and BP and electrocardiogram were simultaneously recorded.

Estimation of parasympathetic nerve function during sleep in patients with obstructive sleep apnea by instantaneous time-frequency analysis.

Background And Objectives: The pathophysiologic aspects of parasympathetic nerve (PN) function during sleep in patients with obstructive sleep apnea (OSA) studied by classical power spectrum analysis on heart rate variability (HRV) are highly controversial. The controversy is attributed to methodologic concerns, such as poor time resolution involved in power spectrum analysis. We aimed to establish the appropriate method for the investigation of PN function in OSA patients with apneas and hypopneas using instantaneous time-frequency analysis with complex demodulation (CD) and sufficient time resolution.

Influence of kappa-rhythm when assessing drowsiness.

Kappa-rhythm appears at the highest amplitude on a bipolar T3-T4 derivation and its frequency range is 7-10 Hz. When a contra-lateral earlobe is used as a reference, the kappa-rhythm causes serious problems in assessing drowsiness. Assessment of drowsiness using contra- and ipsi-lateral earlobes as references in 129 subjects who showed kappa-rhythm was compared.