This paper proposes a Van der Pol (VDP) oscillator screening for peripheral arterial disease (PAD) in patients with diabetes mellitus. The long-term elevated blood sugar levels produce a high risk of peripheral neurop...This paper proposes a Van der Pol (VDP) oscillator screening for peripheral arterial disease (PAD) in patients with diabetes mellitus. The long-term elevated blood sugar levels produce a high risk of peripheral neuropathy and peripheral vascular disease, especially in the foot of a diabetic. Early detection is important, in order to prevent foot problems for diabetic patients with PAD. Photoplethysmography (PPG) is a non-invasive method for the detection of blood volume changes in peripheral arteries. Because of changes in the resistance-compliance, the rise time and transit time for the PPG signals increase and change in their shape are highly correlated with PAD severity. In this study, the Burg autoregressive (AR) method is used to determine the characteristic frequencies of the right-and left-side PPG signals. For bilateral frequency spectra, the VDP oscillator uses asynchronous signals. This produces damped sinusoidal responses and the oscillation overshoot (OS) is an approximating function only of the damped factor. This index is used to estimate the degree of PAD, including normal the condition and diabetic patients with PAD. The results show that the proposed method is efficient and more accurate in the estimation of PAD.展开更多
并不是每个人都有波澜壮阔的人生经历,也许每个人在小时候都曾经幻想自己在不太遥远的将来可以大权在握、富可敌国、万众瞩目、功成名就,但在成长的过程中这些幻想渐渐被现实冲散。我们发现活着就好,能吃饱就好,有点小积蓄就好,生活开...并不是每个人都有波澜壮阔的人生经历,也许每个人在小时候都曾经幻想自己在不太遥远的将来可以大权在握、富可敌国、万众瞩目、功成名就,但在成长的过程中这些幻想渐渐被现实冲散。我们发现活着就好,能吃饱就好,有点小积蓄就好,生活开始变得有些漫无目标,只是闷头走稳每一步。比起名人们被聚光灯围绕的生活,更"平凡"一些的人生别有一种美感,像一个无名的艺术家用一生时间去雕刻一件举世无双的艺术品。比之于酒,大多数人的人生像日常餐酒(VDT vin de table),不甚名贵却又不可不喝;不禁细品却又有滋有味。"我还不算成功人士吧?大成功是没有的,说小成功的话还差不多",接受采访时李善顺女士这么说。"小成功",不妨称之为地区餐酒(VDP,vin de pays)吧,虽然逊于AOC,却又好过VDT。展开更多
This study aims to determine the phenomenological bifurcation(P-bifurcation)occur-ring in the van der Pol(VDP)neuronal model of burst neurons with a random signal.We observe the P-bifurcation under an intense noise st...This study aims to determine the phenomenological bifurcation(P-bifurcation)occur-ring in the van der Pol(VDP)neuronal model of burst neurons with a random signal.We observe the P-bifurcation under an intense noise stimulus which would become chaotic transitions.Bursting and spiking simulations are used to describe the causes of chaotic transitions between two periodic phases that are the reason for the neuronal activities.Ran-domness plays a crucial role in detecting the P-bifurcation.To determine the equilibrium points,stability or instability of the stochastic VDP equation,and bifurcation,we use the stochastic averaging method and some related theorems.Apart from theoretical methods,we also examine numerical simulations in the particular case of that stochastic equation that illustrates the outcome of theorems for various noise types.The most striking part of our theoretical findings is that these results are also valid for the Izhikevich-FitzHugh model,Bonhoeffer-van der Pol oscillator in dynamical systems of neuroscience.Finally,we will discuss some applications of the VDP equation in neuronal activity.展开更多
文摘This paper proposes a Van der Pol (VDP) oscillator screening for peripheral arterial disease (PAD) in patients with diabetes mellitus. The long-term elevated blood sugar levels produce a high risk of peripheral neuropathy and peripheral vascular disease, especially in the foot of a diabetic. Early detection is important, in order to prevent foot problems for diabetic patients with PAD. Photoplethysmography (PPG) is a non-invasive method for the detection of blood volume changes in peripheral arteries. Because of changes in the resistance-compliance, the rise time and transit time for the PPG signals increase and change in their shape are highly correlated with PAD severity. In this study, the Burg autoregressive (AR) method is used to determine the characteristic frequencies of the right-and left-side PPG signals. For bilateral frequency spectra, the VDP oscillator uses asynchronous signals. This produces damped sinusoidal responses and the oscillation overshoot (OS) is an approximating function only of the damped factor. This index is used to estimate the degree of PAD, including normal the condition and diabetic patients with PAD. The results show that the proposed method is efficient and more accurate in the estimation of PAD.
文摘并不是每个人都有波澜壮阔的人生经历,也许每个人在小时候都曾经幻想自己在不太遥远的将来可以大权在握、富可敌国、万众瞩目、功成名就,但在成长的过程中这些幻想渐渐被现实冲散。我们发现活着就好,能吃饱就好,有点小积蓄就好,生活开始变得有些漫无目标,只是闷头走稳每一步。比起名人们被聚光灯围绕的生活,更"平凡"一些的人生别有一种美感,像一个无名的艺术家用一生时间去雕刻一件举世无双的艺术品。比之于酒,大多数人的人生像日常餐酒(VDT vin de table),不甚名贵却又不可不喝;不禁细品却又有滋有味。"我还不算成功人士吧?大成功是没有的,说小成功的话还差不多",接受采访时李善顺女士这么说。"小成功",不妨称之为地区餐酒(VDP,vin de pays)吧,虽然逊于AOC,却又好过VDT。
文摘This study aims to determine the phenomenological bifurcation(P-bifurcation)occur-ring in the van der Pol(VDP)neuronal model of burst neurons with a random signal.We observe the P-bifurcation under an intense noise stimulus which would become chaotic transitions.Bursting and spiking simulations are used to describe the causes of chaotic transitions between two periodic phases that are the reason for the neuronal activities.Ran-domness plays a crucial role in detecting the P-bifurcation.To determine the equilibrium points,stability or instability of the stochastic VDP equation,and bifurcation,we use the stochastic averaging method and some related theorems.Apart from theoretical methods,we also examine numerical simulations in the particular case of that stochastic equation that illustrates the outcome of theorems for various noise types.The most striking part of our theoretical findings is that these results are also valid for the Izhikevich-FitzHugh model,Bonhoeffer-van der Pol oscillator in dynamical systems of neuroscience.Finally,we will discuss some applications of the VDP equation in neuronal activity.
