Background: Haptic simulators for training surgeons often are informed by mechanical data that poorly represent the natural movement of a surgeon. Tissue testing often involves controlled robotic ...motion that does not match the freedom present during surgery. The aim of this study was to build and test a device surgeons could use to perform a discectomy procedure naturally while tracking force and position for eventual application in haptic surgical simulators. Methods: Two excised cadaveric lumbar spine segments were subjected to freehand mechanical testing. Two spine neurosurgeons performed a lumbar discectomy using a Depuy Synthes Concorde Clear MIS vacuum curette. The curette was attached to an Entact W3D device to track position and an ATI 6-axis load cell to track force. The surgeons performed multiple passes through the tissue while position and force were tracked to record the resistance of the tissue during testing. The resistance was measured by normalizing the force as the surgeon penetrated the tissue. The total resistance magnitude and resistances off-axis with respect to the tool were compared. Results: Successful testing was performed on all lumbar levels of both spines. Up to 30% of the total linear resistance was off-axis, with an average drop of 7% per 10 N of increasing force. Linear resistance normalized for speed was 0.31 (N.mm)/(mm/s). Statistically significant differences (p < 0.05) were found in linear resistance between surgeons. Conclusion: A significant percentage of the total resistance present during the discectomy was off-axis, meaning it would not have been captured by controlled robotic testing techniques. The amount of off-axis resistance varied with surgeon speed. These off-axis data are integral to the proper replication of surgery in a simulator and these observations expose limitations to the methods that are often used to capture resistance data for building haptic models. The resistances shown here were captured in a method that is more relevant to the operating room experience, which will allow for the development of more accurate training simulators.
Immersion, interaction, and imagination are three features of virtual reality (VR). Existing VR systems possess fairly realistic visual and auditory feedbacks, and however, are poor with haptic ...feedback, by means of which human can perceive the physical world via abundant haptic properties. Haptic display is an interface aiming to enable bilateral signal communications between human and computer, and thus to greatly enhance the immersion and interaction of VR systems. This paper surveys the paradigm shift of haptic display occurred in the past 30 years, which is classified into three stages, including desktop haptics, surface haptics, and wearable haptics. The driving forces, key technologies and typical applications in each stage are critically reviewed. Toward the future high-fidelity VR interaction, research challenges are highlighted concerning handheld haptic device, multimodal haptic device, and high fidelity haptic rendering. In the end, the importance of understanding human haptic perception for designing effective haptic devices is addressed. Keywords: Haptic display, Virtual reality, Desktop haptics, Surface haptics, Wearable haptics, Multimodal haptics
Ultrasound haptics is a contactless haptic technology that enables novel mid-air interactions with rich multisensory feedback. This article surveys recent advances in ultrasound haptic technology. We ...discuss the fundamentals of this haptic technology, how a variety of perceptible sensations are rendered, and how it is currently being used to enable novel interaction techniques. We summarize its strengths, weaknesses, and potential applications across various domains. We conclude with our perspective on key directions for this promising haptic technology.
Wearable haptic devices provide touch feedback to users for applications including virtual reality, prosthetics, and navigation. When these devices are designed for experimental validation in ...research settings, they are often highly specialized and customized to the specific application being studied. As such, it can be difficult to replicate device hardware due to the associated high costs of customized components and the complexity of their design and construction. In this work, we present Snaptics, a simple and modular platform designed for rapid prototyping of fully wearable multi-sensory haptic devices using 3D-printed modules and inexpensive off-the-shelf components accessible to the average hobbyist. We demonstrate the versatility of the modular system and the salience of haptic cues produced by wearables constructed with Snaptics modules in two human subject experiments. First, we report on the identification accuracy of multi-sensory haptic cues delivered by a Snaptics device. Second, we compare the effectiveness of the Snaptics Vibrotactile Bracelet to the Syntacts Bracelet, a high-fidelity wearable vibration feedback bracelet, in assisting participants with a virtual reality sorting task. Results indicate that participant performance was comparable in perceiving cue sets and in completing tasks when interacting with low-cost Snaptics devices as compared to a similar research-grade haptic wearables.
Most haptic devices generate haptic sensation using mechanical actuators. However, the workload and limited workspace handicap the operator from operating freely. Electrical stimulation is an ...alternative approach to generate haptic sensations without using mechanical actuators. The light weight of the electrodes adhering to the body brings no limitations to free motion. Because a real haptic sensation consists of feelings from several areas, mounting the electrodes to several different body areas can make the sensations more realistic. However, simultaneously stimulating multiple electrodes may result in "noise" sensations. Moreover, the operators may feel tingling because of unstable stimulus signals when using the dry electrodes to help develop an easily mounted haptic device using electrical stimulation. In this study, we first determine the appropriate stimulation areas and stimulus signals to generate a real touch sensation on the forearm. Then, we propose a circuit design guideline for generating stable electrical stimulus signals using a voltage divider resistor. Finally, based on the aforementioned results, we develop a wearable haptic glove prototype. This haptic glove allows the user to experience the haptic sensations of touching objects with five different degrees of stiffness.
Traditional technologies for virtual reality (VR) and augmented reality (AR) create human experiences through visual and auditory stimuli that replicate sensations associated with the physical world. ...The most widespread VR and AR systems use head-mounted displays, accelerometers and loudspeakers as the basis for three-dimensional, computer-generated environments that can exist in isolation or as overlays on actual scenery. In comparison to the eyes and the ears, the skin is a relatively underexplored sensory interface for VR and AR technology that could, nevertheless, greatly enhance experiences at a qualitative level, with direct relevance in areas such as communications, entertainment and medicine
. Here we present a wireless, battery-free platform of electronic systems and haptic (that is, touch-based) interfaces capable of softly laminating onto the curved surfaces of the skin to communicate information via spatio-temporally programmable patterns of localized mechanical vibrations. We describe the materials, device structures, power delivery strategies and communication schemes that serve as the foundations for such platforms. The resulting technology creates many opportunities for use where the skin provides an electronically programmable communication and sensory input channel to the body, as demonstrated through applications in social media and personal engagement, prosthetic control and feedback, and gaming and entertainment.
In this article, we present a planning framework that uses a combination of implicit (robot motion) and explicit (visual/audio/haptic feedback) communication during mobile robot navigation. First, we ...developed a model that approximates both continuous movements and discrete behavior modes in human navigation, considering the effects of implicit and explicit communication on human decision-making. The model approximates the human as an optimal agent, with a reward function obtained through inverse reinforcement learning. Second, a planner uses this model to generate communicative actions that maximize the robot's transparency and efficiency. We implemented the planner on a mobile robot, using a wearable haptic device for explicit communication. In a user study of an indoor human-robot pair orthogonal crossing situation, the robot is able to actively communicate its intent to users in order to avoid collisions and facilitate efficient trajectories. Results show that the planner generated plans that are easier to understand, reduce users' effort, and increase users' trust of the robot, compared to simply performing collision avoidance. The key contribution of this article is the integration and analysis of explicit communication (together with implicit communication) for social navigation.
In the last decade, we have witnessed a drastic change in the form factor of audio and vision technologies, from heavy and grounded machines to lightweight devices that naturally fit our bodies. ...However, only recently, haptic systems have started to be designed with wearability in mind. The wearability of haptic systems enables novel forms of communication, cooperation, and integration between humans and machines. Wearable haptic interfaces are capable of communicating with the human wearers during their interaction with the environment they share, in a natural and yet private way. This paper presents a taxonomy and review of wearable haptic systems for the fingertip and the hand, focusing on those systems directly addressing wearability challenges. The paper also discusses the main technological and design challenges for the development of wearable haptic interfaces, and it reports on the future perspectives of the field. Finally, the paper includes two tables summarizing the characteristics and features of the most representative wearable haptic systems for the fingertip and the hand.
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