Menon Samir, Brantner Gerald, Aholt Chris, Kay Kendrick, Khatib Oussama
Annu Int Conf IEEE Eng Med Biol Soc. 2013;2013:4137-42. doi: 10.1109/EMBC.2013.6610456.
A challenging problem in motor control neuroimaging studies is the inability to perform complex human motor tasks given the Magnetic Resonance Imaging (MRI) scanner's disruptive magnetic fields and confined workspace. In this paper, we propose a novel experimental platform that combines Functional MRI (fMRI) neuroimaging, haptic virtual simulation environments, and an fMRI-compatible haptic device for real-time haptic interaction across the scanner workspace (above torso ∼ .65×.40×.20m(3)). We implement this Haptic fMRI platform with a novel haptic device, the Haptic fMRI Interface (HFI), and demonstrate its suitability for motor neuroimaging studies. HFI has three degrees-of-freedom (DOF), uses electromagnetic motors to enable high-fidelity haptic rendering (>350Hz), integrates radio frequency (RF) shields to prevent electromagnetic interference with fMRI (temporal SNR >100), and is kinematically designed to minimize currents induced by the MRI scanner's magnetic field during motor displacement (<2cm). HFI possesses uniform inertial and force transmission properties across the workspace, and has low friction (.05-.30N). HFI's RF noise levels, in addition, are within a 3 Tesla fMRI scanner's baseline noise variation (∼.85±.1%). Finally, HFI is haptically transparent and does not interfere with human motor tasks (tested for .4m reaches). By allowing fMRI experiments involving complex three-dimensional manipulation with haptic interaction, Haptic fMRI enables-for the first time-non-invasive neuroscience experiments involving interactive motor tasks, object manipulation, tactile perception, and visuo-motor integration.
在运动控制神经成像研究中，一个具有挑战性的问题是，鉴于磁共振成像（MRI）扫描仪具有干扰性的磁场和有限的工作空间，无法执行复杂的人类运动任务。在本文中，我们提出了一种新颖的实验平台，该平台将功能磁共振成像（fMRI）神经成像、触觉虚拟仿真环境以及一种与fMRI兼容的触觉设备相结合，以实现跨扫描仪工作空间（躯干上方约0.65×0.40×0.20立方米）的实时触觉交互。我们使用一种新颖的触觉设备——触觉fMRI接口（HFI）来实现这个触觉fMRI平台，并证明其适用于运动神经成像研究。HFI具有三个自由度（DOF），使用电磁电机实现高保真触觉渲染（>350Hz），集成射频（RF）屏蔽以防止对fMRI产生电磁干扰（时间信噪比>100），并且在运动学设计上可将电机位移过程中由MRI扫描仪磁场感应产生的电流降至最低（<2cm）。HFI在整个工作空间内具有均匀的惯性和力传递特性，并且摩擦力较低（0.05 - 0.30N）。此外，HFI的射频噪声水平在3特斯拉fMRI扫描仪的基线噪声变化范围内（约0.85±0.1%）。最后，HFI在触觉上是透明的，不会干扰人类运动任务（针对0.4米的伸展进行了测试）。通过允许涉及具有触觉交互的复杂三维操作的fMRI实验，触觉fMRI首次实现了涉及交互式运动任务、物体操作、触觉感知和视觉运动整合的非侵入性神经科学实验。
