EAGER: Preliminary Investigation of Virtual Tactual Stereognosis

想象一下，你把手伸进口袋，找到并抓住你的车；S的钥匙卡在一堆硬币、钞票和钥匙中，然后找到解锁按钮(不是锁按钮，不是后备箱开锁按钮，特别是紧急按钮)并按下它。这是触觉立体认知(TS)的一个例子，即人们仅通过触摸就能识别熟悉的物品的能力。这是平凡而平淡无奇的。然而，还没有开发出可编程的触觉界面，允许人们使用可能被称为虚拟触觉立体识别(VTS)来识别虚拟对象。创建这样的接口是PI的长期目标。VTS长期以来一直遥不可及，因为它依赖于主动触摸、多指交互和裸露指尖，这些都是现有显示技术难以实现的。PI最近的研究导致了一类新的原型设备(XPad)，它们解决了这些限制。这些设备使用摩擦调制来控制指尖和平板之间的力。基本的TPaD(触觉图案显示)可以创建虚拟纹理、虚拟凹凸和孔洞等效果。更先进的版本，如ShiverPad和SwirlPad，将面内振动与摩擦水平同步，以便在指尖产生主动推力。使用这些设备可以产生许多额外的效果，包括可以用指尖追踪的虚拟边缘。因此，xPad设备似乎非常适合VTS。它们是活动的触控设备，可以裸露指尖工作(换句话说，xPad是固定的，手指在上面滑动)。此外，它们非常紧凑，潜在地使多个面板能够排列在对象的表面上，以便支持多手指接口。在这项研究中，PI将开始探索多xPad界面，通过在由两个相对的ShiverPad组成的界面上执行实验，受试者使用握手(即食指在一个ShiverPaD上，拇指在另一个上)，以演示“绑定”，即手指和拇指知觉的感知融合到一个集成的对象表征中。从客厅到办公室，再到汽车，再到人所在的任何地方，图形显示已经成为一种重要的界面形式。然而，随着图形显示变得越来越普遍，自然的触摸交互似乎变得更加过时。VTS的目标是实现相反的目标，使未来的界面具有复杂的触觉功能，使手和大脑中的感知和感觉机制参与其中。想象一下，一个医生能够同时观察和触摸体内的组织，一个怀孕的母亲能够抚摸她未出生的孩子的超声波图像，一个自闭症儿童能够在建筑任务中与动画角色合作，或者一个司机能够伸手、找到并操作触摸屏控制，而他/她的眼睛不离开道路。VTS将成为盲人新型电子显示器的推动者。它将是一个强大的新工具，可以扩展我们对触觉的基本知识，因为它是自然发生的。

Imagine reaching into your pocket, locating and grasping your car;'s key fob amongst a clutter of coins, bills and keys, then finding the unlock button (not the lock button, not the trunk release, especially not the panic button) and pressing it. This is an example of Tactual Stereognosis (TS), the ability of people to identify familiar items using touch alone. It is commonplace and uneventful. Yet no programmable haptic interface has ever been developed that would allow people to identify virtual objects using what might be termed Virtual Tactual Stereognosis (VTS). Creating such an interface is a long-range goal of the PIs. VTS has long been out of reach because it depends on active touch, multi-finger interaction, and bare fingertips, which are all difficult to achieve with existing display technology. The PIs' recent research has led to a new class of prototype devices (xPaDs), which address each of these limitations. These devices use friction modulation to control forces between the fingertip and a flat plate. The basic TPaD (Tactile Pattern Display) can create effects such as virtual textures, virtual bumps and holes, and more. More advanced versions such as the ShiverPad and SwirlPad synchronize in-plane vibrations to friction levels in order to generate active pushing forces on the fingertip. It is possible to generate many additional effects with these devices, including virtual edges that can be traced with the fingertip. The xPaD devices thus appear to be well suited to VTS. They are active touch devices that work with bare fingertips (in other words, the xPaD is fixed and the finger slides over it). Moreover, they are very compact, potentially enabling multiple panels to be arrayed over the surface of an object in order to support a multi-finger interface. In this study the PIs will begin exploration of a multi-xPaD interface, by performing experiments on an interface consisting of two opposing ShiverPads with subjects employing a pinch grip (that is, index finger on one ShiverPaD, and thumb on the other), in order to demonstrate "binding," the perceptual fusion of the finger and thumb percepts into an integrated object representation.Broader Impacts: Virtual Tactual Stereognosis is an important goal for many reasons. Graphical displays have become an important form of interface in venues ranging from the living room, to the office, to the car, to any place that a person may be. Yet as graphical displays grow more prevalent, natural touch interactions seemingly grow more obsolete. VTS aims to achieve the opposite, to empower future interfaces with sophisticated tactual capabilities that engage perceptual as well as sensory mechanisms in the hand and brain. Imagine a doctor able to simultaneously look at and palpate tissue within the body, a pregnant mother able to caress the ultrasound image of her unborn child, an autistic child able to cooperate with an animated character in a construction task, or a driver able to reach out, find and operate touch screen controls without taking his/her eyes off the road. VTS would be an enabler for new types of electronic displays for the blind. And it would be a powerful new tool to extend our basic knowledge of haptic perception as it occurs naturally.