Theoretical considerations on canal-otolith interaction and an observer model
Theoretical considerations on canal-otolith interaction and an observer model
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DOI：
10.1007/s00422-001-0289-7
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发表时间：
2002-03-01
影响因子：
1.9
通讯作者：
Bles, W
中科院分区：
文献类型：
--
作者：
Bos, JE;Bles, W
主观的垂直方向、眼睛和身体的运动以及晕动病都取决于我们的中枢神经系统处理重力-惯性力分辨问题的方式：如何区分运动引起的加速度和重力引起的加速度，尽管这些加速度在物理上是无法区分的。为了控制身体或眼睛的运动，应该明确地知道由于运动而产生的加速度。因此，重力应该以某种方式从耳石所感知的特定力或重力惯性加速度（GIA，两种加速度的总和）中过滤出来，耳石是内耳中的线性加速度计。由于当头部旋转时，GIA在头部固定的参考系中也会发生变化，因此还应考虑由内耳中的半规管感测到的角运动。我们在这里提出了一个理论方法来解决这个问题，并表明，运河耳石相互作用的数学描述实际上是一个三维的二维描述梅恩在1974年给出的等价。一个简单的低通滤波器用于将GIA分为运动和重力分量。结果表明，离心过程中伴随的角运动延迟了体重力效应。此外，我们展示了耳道耳石相互作用如何在观察者模型的框架内描述主观的垂直方向，眼球运动和晕动病特征。例如，为了预测疾病严重程度的频率峰值，有必要明确地包括在传感器传入和内部模型中操作的Mayne方程。从离心和水平振荡的倾斜和平移数据，以及从晕动病数据，我们得出结论，低通滤波器的时间常数是在秒的数量级，而不是几十秒之前假设的。另外还讨论了几个推论。
Subjective vertical orientation, eye and body movements, and motion sickness all depend on the way our central nervous system deals with the gravito-inertial force resolution problem: how to discern accelerations due to motion from those due to gravity, despite these accelerations being physically indistinguishable. To control body or eye movements, the accelerations due to motion should be known explicitly. Hence, somehow gravity should be filtered out of the specific force or gravito-inertial acceleration (GIA, the sum of both accelerations) as sensed by the otoliths, which are the linear accelerometers in the inner ear. As the GIA also changes in a head-fixed frame of reference when the head is rotated, angular motion as sensed by the semicircular canals in the inner ear should also be considered. We present here a theoretical approach to this problem, and show that the mathematical description of canal-otolith interaction is in fact a three-dimensional equivalent of the two-dimensional description given by Mayne in 1974. A simple low-pass filter is used to divide the GIA into a motion and a gravity component. The retardation of the somatogravic effect by concomitant angular motion during centrifugation is shown as a result. Furthermore we show how the canal-otolith interaction fits within the framework of an observer model to describe subjective vertical orientation, eye movement and motion sickness characteristics. To predict a frequency peak in sickness severity, for example, it is necessary to explicitly include the Mayne equation operating both on sensor afferents and in the internal model. From tilt and translation data from centrifugation and horizontal oscillation, as well as from motion sickness data, we conclude that the time constant of the low-pass filter is in the order of seconds instead of tens of seconds as assumed before. Several corollaries are additionally discussed as a result.