Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 st., 02-109 Warsaw, Poland.
Int J Neural Syst. 2020 Mar;30(3):2050003. doi: 10.1142/S0129065720500033. Epub 2020 Jan 23.
We evaluated the properties of oscillations in the Mayer waves (MW) frequency range (Hz) detected in blood pressure, heart rate variability, cerebral blood oxygenation changes and evolution of electroencephalographic (EEG) rhythms to elucidate the mechanisms of MW generation. We examined the persistence of MW in different signals and stability of their oscillations on the level of individual MW waveforms, which was achieved by applying matching pursuit (MP). MP yields adaptive time-frequency approximation of signal's structures in terms of frequency, amplitude, time occurrence, and time-span. The number of waveforms contributing to 95% of the energy of the signals was vastly different for the time series, but the average number of waveforms conforming to the MW criteria was almost the same ( per 120s epoch). In all the investigated signals, MW had the same distributions of frequency and the number of cycles. We show that the MW energy ratios in different signals varied strongly, . The highest percentage of MW energy was observed in blood pressure signals, heart rate variability, and reduced hemoglobin, in contrast to brain signals and oxygenated hemoglobin. The percentage of MW energy was related to the strength of causal influence exerted by them on the other signals. Our results indicate existence of a common mechanism of MW generation and support the hypothesis of MW generation in the baroreflex loop; however, they do not exclude the action of a central pacemaker.
我们评估了在血压、心率变异性、脑血氧变化和脑电图（EEG）节律演变中检测到的 Mayer 波（MW）频率范围内（Hz）的振荡特性，以阐明 MW 产生的机制。我们研究了不同信号中 MW 的持久性及其在单个 MW 波形水平上的振荡稳定性，这是通过应用匹配追踪（MP）来实现的。MP 以频率、幅度、时间发生和时间跨度的方式对信号结构进行自适应时频逼近。对信号能量贡献 95%的波形数量在时间序列中差异很大，但符合 MW 标准的平均波形数量几乎相同（每个 120 秒的时程）。在所有研究的信号中，MW 的频率和周期数分布相同。我们表明，不同信号中的 MW 能量比差异很大，。在血压信号、心率变异性和还原血红蛋白中观察到 MW 能量的百分比最高，而在脑信号和氧合血红蛋白中则较低。MW 能量的百分比与它们对其他信号施加的因果影响的强度有关。我们的结果表明存在 MW 产生的共同机制，并支持 MW 在压力反射环中产生的假设；然而，它们并不排除中央起搏器的作用。
