Kinderklinik Tuebingen, Abteilung III Neuropaediatrie, Tuebingen, Germany.
IEEE Trans Biomed Eng. 2012 Oct;59(10):2852-8. doi: 10.1109/TBME.2012.2212191. Epub 2012 Aug 7.
Electric stimulation of the peripheral nerves is well established as a diagnostic and research tool to analyze the somatosensory system. However, electric stimulation has some disadvantages. Electric stimulation of the median nerve triggers action potentials in all fiber populations of the nerve. Electric stimulation further creates artifacts and courses discomfort which is usually not well tolerated in the awake child. Therefore, the development of a more specific stimulation has constantly been a goal in recent years. There have been several approaches in the past to deliver somatic stimulation. However, all of them failed short in some aspects. In this study, a new type of somatosensory stimulator device was developed and compared against the gold standard of electric stimulation. The stimulation is achieved by repetitive tactile stimulation of the index finger using a blunt needle. In contrast to all previous approaches, we use a hydraulic system to move the needle up and downward. Given that water is very well suited to conduct pressure pulses it is possible to place the tactile stimulator device holding the needle close to the subject and the hydraulic driving system outside a critical area. Using a phantom, we showed that our stimulator is capable of delivering a stimulus precise on the submillisecond time scale. In addition, we test our stimulator on a healthy adult and compare the results against the electric stimulation. We can show the feasibility of measuring the electric responses of the peripheral nerve and while using MEG also the response of the primary somatosensory cortex. The tactile stimulation showed a more spatial focuses activation of the primary somatosensory cortex when compared against the electric stimulation. The proposed high-precision tactile stimulator will make it possible to analyze the somatosensory system noninvasively in children in the future.
电刺激外周神经作为一种诊断和研究工具，已被广泛应用于分析躯体感觉系统。然而，电刺激存在一些缺点。电刺激正中神经会在神经的所有纤维群中引发动作电位。电刺激还会产生伪迹，并引起不适，在清醒的儿童中通常难以耐受。因此，近年来，开发一种更具特异性的刺激一直是一个目标。过去有几种方法可以进行躯体刺激。然而，它们在某些方面都存在缺陷。在这项研究中，开发了一种新型的躯体感觉刺激器设备，并与电刺激的金标准进行了比较。刺激是通过使用钝针反复刺激食指来实现的。与以往所有方法不同的是，我们使用液压系统来上下移动针。由于水非常适合传导压力脉冲，因此可以将带有针的触觉刺激器设备放置在靠近受试者的地方，而将液压驱动系统放置在关键区域之外。我们使用一个模型表明，我们的刺激器能够在亚毫秒级的时间尺度上精确地传递刺激。此外，我们在健康成年人身上测试了我们的刺激器，并将结果与电刺激进行了比较。我们可以证明测量外周神经的电反应的可行性，同时使用 MEG 还可以证明初级躯体感觉皮层的反应。与电刺激相比，触觉刺激显示出初级躯体感觉皮层更具空间聚焦的激活。所提出的高精度触觉刺激器将使未来能够在儿童中进行非侵入性的躯体感觉系统分析成为可能。
