University of Leeds, Leeds Institute of Health Science, Leeds, UK; Leeds Teaching Hospitals NHS Trust, UK.
Loughborough University, Department of Computer Science, Loughborough, UK.
J Clin Neurosci. 2020 Nov;81:101-104. doi: 10.1016/j.jocn.2020.09.046. Epub 2020 Oct 2.
Eulerian magnification amplifies very small movements in video, revealing otherwise invisible motion. This raises the possibility that it could enable clinician visualisation of subclinical tremor using a standard camera. We tested whether Eulerian magnification of apparently atremulous hands reveals a Parkinsonian tremor more frequently in Parkinson's than in controls.
We applied Eulerian magnification to smartphone video of 48 hands that appeared atremulous during recording (22 hands from 11 control participants, 26 hands from 17 idiopathic Parkinson's participants). Videos were rated for Parkinsonian tremor appearance (yes/no) before and after Eulerian magnification by three movement disorder specialist neurologists.
The proportion of hands correctly classified as Parkinsonian or not by clinicians was significantly higher after Eulerian magnification (OR = 2.67; CI = [1.39, 5.17]; p < 0.003). Parkinsonian-appearance tremors were seen after magnification in a number of control hands, but the proportion was greater in the Parkinson's hands.
Eulerian magnification slightly improves clinician ability to identify apparently atremulous hands as Parkinsonian. This suggests that some of the apparent tremor revealed may be subclinical Parkinson's (pathological) tremor, and Eulerian magnification may represent a first step towards contactless visualisation of such tremor. However, the technique also reveals apparent tremor in control hands. Therefore, our method needs additional elaboration and would not be of direct clinical use in its current iteration.
Eulerian 放大可以放大视频中的微小运动，揭示出原本不可见的运动。这就提出了一种可能性，即它可以使临床医生使用标准摄像机观察到亚临床震颤。我们测试了使用智能手机对看似震颤的手进行 Eulerian 放大，是否能更频繁地在帕金森病患者中发现帕金森震颤，而不是在对照组中。
我们对在记录过程中显得震颤的 48 只手的智能手机视频（对照组 11 名参与者的 22 只手，特发性帕金森病参与者的 26 只手）应用了 Eulerian 放大。在应用 Eulerian 放大前后，三位运动障碍专家神经病学家对手部视频的帕金森震颤外观（有/无）进行了评估。
经过 Eulerian 放大后，临床医生正确分类为帕金森或非帕金森的手的比例显著提高（OR = 2.67；CI = [1.39, 5.17]；p < 0.003）。在放大后，一些对照组的手中出现了帕金森震颤，但帕金森组中的比例更大。
Eulerian 放大略微提高了临床医生识别看似震颤的手为帕金森病的能力。这表明，一些明显的震颤可能是亚临床帕金森病（病理性）震颤，而 Eulerian 放大可能是接触式可视化这种震颤的第一步。然而，该技术也会在对照组的手中揭示出明显的震颤。因此，我们的方法需要进一步细化，在其当前迭代中无法直接用于临床。
