Construction of haptic display system in virtual space by using measured parameters from MR Elastography

我们的研究目的是在虚拟空间中构建一个触觉显示系统，通过使用磁共振弹性成像（MRE）的测量参数。该系统可以为虚拟现实（VR）nMedicine做出贡献。研究期间取得的主要成果如下：1.关于从MRE图像估计粘弹性参数的过程，我们（1）建立了精确估计参数的过程，（2）评估了减少MRE图像中反射波影响的过程。我们还（3）利用（1）的方法观察到骨骼肌等组织中存在各向异性弹性。为了测量力反馈在真实的空间中的分布，我们构造了（1）利用力传感器和触觉装置测量来自真实的物体的力反馈的系统，（2）利用距离传感器测量物体的形状的系统，（3）利用机械臂进行力反馈自动测量的系统。根据测量数据的插值估计力反馈的分布的过程，以及（5）根据分布（4）以真实的时间显示触觉信息的过程。通过心理物理学评估，我们证实了通过引入适当的弹性参数，可以在虚拟空间中表现出真实的物体的力反馈特性.我们已经发现，在主动触摸中的位置和力的转变之间的关系可能包含感知物体的形状的重要信息。

The purpose of our research is to construct a haptic display system in virtual space, by using measured parameters from Magnetic Resonance Elastography (MRE). This system can contribute to the Virtual Reality (VR) nMedicine. The results in the research period are as follows:1. About the procedure to estimate viscoelastic parameters from MRE images, we have (1) established a procedure to estimate the parameters accurately, and (2) evaluated the procedure to reduce the influence of reflection waves in MRE images. We have also (3) observed the existence of anisotropic elasticity in tissues such as skeletal muscle, utilizing procedure (1).2. In order to measure the distributions of force feedback in real space, we have constructed (1) a system to measure the force feedback from real objects utilizing force sensor and haptic device, (2) a system to measure the shapes of objects by range sensor, and (3) a system for automated measurement of force feedback utilizing robot arm. We have also proposed (4) a procedure to estimate the distribution of force feedback from the interpolation of the measured data, and (5) a procedure to display the haptic information from the distribution (4) in real time.3. We have confirmed from psychophysical evaluation that the characteristics of force feedback of real object can be represented in virtual space by introducing proper elastic parameters.4. We have found that the relationship among the transitions of position and force in active touch may include the significant information to perceive shapes of objects.