We present the polysamnogram assay (PSGA), a new representation format for the polysomnogram (PSG), designed to assist in the interpretation of overnight PSG studies. The technique condenses the PSG record by a factor...
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We present the polysamnogram assay (PSGA), a new representation format for the polysomnogram (PSG), designed to assist in the interpretation of overnight PSG studies. The technique condenses the PSG record by a factor of 30 while preserving the ability to portray PSG features of diagnostic relevance, including sleep architecture, arousals, movement, leg jerks, cyclic alternating pattern, and increased breathing effort. The PSGA patterns associated with these events are described and illustrated by examples. The new format considerably reduces the effort required to evaluate sleep quality and continuity, making it more practicable for the polysomnographer to interpret the entire overnight PSG study. The compressed time scale also facilitates analysis of relatively long PSG episodes and allows assessment of signal activity surrounding critical PSG events. The PSGA appears capable of improving identification of arousals, leg jerks, and upper airway resistance, and may be especially amenable for automatic analysis of PSG data (C) 2000 Academic Press.
A nonstationary signal analysis technique is introduced, which regards an oscillatory physiological signal as a sum of its fragments, presented in the form of a fragmentary decomposition (FD). The Virtue of FD is that...
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A nonstationary signal analysis technique is introduced, which regards an oscillatory physiological signal as a sum of its fragments, presented in the form of a fragmentary decomposition (FD). The Virtue of FD is that it is free of the necessity to choose a priori the basis functions intended for signal analysis or synthesis. FD uses an unchanged signal fragment between adjacent zero-crossings, as a natural basis function called the half-wave function (HWF). To show that such a function is a physically meaningful object, Fourier transform methods were employed, supported by the similar basis function (SBF) algorithm, which provides the means for numerical Fourier transform spectroscopy of separate half-waves and their frequency domain description in terms of both amplitude and phase. The application of this method to parameter identification of 751 EMG half-waves from the eye blink EMG records of ten normal subjects showed that HWF's frequency domain image represents a Gaussian distribution, which applies over a defined range of relative frequencies. This empirical evidence shows that HWFs are produced by a specific system of first-order nonlinear differential equations, whose dependency on a. number of random factors is characteristic of deterministic chaos. The particular form of solutions indicates that statistical regularities relevant to the central limit theorem are likely to underlie the genesis of the mass potentials studied. FD shows potential utility in a range of nonstationary physiological signals.
Three kinds of blinks, spontaneous, reflex, and voluntary, were measured fur 11 men using electromyogram (EMG) at the orbicularis oculi muscle on the right side and electro-oculogram (EOG) in the vertical direction to...
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Three kinds of blinks, spontaneous, reflex, and voluntary, were measured fur 11 men using electromyogram (EMG) at the orbicularis oculi muscle on the right side and electro-oculogram (EOG) in the vertical direction to the right eyelid. The amplitude and the duration time were defined here from the raw waves of the EMG and the: EOG for the three kinds of blinks. The amplitude of the EMG indicated that the mean value for the spontaneous blinks was significantly smaller than that of the voluntary blinks and the mean duration of die EMG shows the value for the spontaneous blinks was smaller than that for the reflex and the voluntary blinks. The EMG for the spontaneous blinks had a smaller amplitude and a shorter duration time than the other blinks. The LOG amplitude indicated that the mean value for the spontaneous blinks uas significantly smaller than that for the voluntary blinks, but there was no significant difference between the spontaneous blinks and the other blinks for the duration of the EGG. The amplitude and the duration for both the EMG and the LOG discriminated any two types of blinks from three blinks by statistical rest. Those values for the EMG and the EOG are effective indices for the evaluation of blinks. Moreover, the coefficients of variation of the amplitude and durations of EMG and EOG for three kinds of blinks denote their characteristics. Multiple discriminant analysis distinguished the types of blinks simultaneously: The resultant maximum correct rare for the three blinks reaches to be 81.8%. So far, it has been difficult to discriminate the blinks quantitatively, but the procedures present ed here are able to solve the difficulty.
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