A Parallel Elastic Haptic Thimble for Wide Bandwidth Cutaneous Feedback.

Design of wearable fingertip haptic devices is often a compromise between conflicting features: lightness and compactness, against rich and neat haptic feedback. On one side direct drive actuators (i.e. voice coils) provide a clean haptic feedback with high dynamics, with limited maximum output forces. On the other side mechanical transmissions with reduction can increase output force of micro sized motors, at the cost of slower and often noisy output signals. In this work we present a compact fingertip haptic device based on a parallel elastic mechanism: it merges the output of two differently designed actuators in a single, wide bandwidth haptic feedback. Each actuator is designed with a different role: one for rendering fast, high frequency force components, the other for rendering constant to low frequency components. In the work we present design and implementation of the device, followed by experimental characterization of its performance in terms of frequency response and rendering capabilities

Wearable haptic systems for the fingertip and the hand: taxonomy, review and perspectives

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

A Shared-Control Teleoperation Architecture for Nonprehensile Object Transportation

This article proposes a shared-control teleoperation architecture for robot manipulators transporting an object on a tray. Differently from many existing studies about remotely operated robots with firm grasping capabilities, we consider the case in which, in principle, the object can break its contact with the robot end-effector. The proposed shared-control approach automatically regulates the remote robot motion commanded by the user and the end-effector orientation to prevent the object from sliding over the tray. Furthermore, the human operator is provided with haptic cues informing about the discrepancy between the commanded and executed robot motion, which assist the operator throughout the task execution. We carried out trajectory tracking experiments employing an autonomous 7-degree-of-freedom (DoF) manipulator and compared the results obtained using the proposed approach with two different control schemes (i.e., constant tray orientation and no motion adjustment). We also carried out a human-subjects study involving 18 participants in which a 3-DoF haptic device was used to teleoperate the robot linear motion and display haptic cues to the operator. In all experiments, the results clearly show that our control approach outperforms the other solutions in terms of sliding prevention, robustness, commands tracking, and user’s preference

Rendering of Pressure and Textures Using Wearable Haptics in Immersive VR Environments

Haptic systems have only recently started to be designed with wearability in mind. Compact, unobtrusive, inexpensive, easy-to-wear, and lightweight haptic devices enable researchers to provide compelling touch sensations to multiple parts of the body, significantly increasing the applicability of haptics in many fields, such as robotics, rehabilitation, gaming, and immersive systems. In this respect, wearable haptics has a great potential in the fields of virtual and augmented reality. Being able to touch virtual objects in a wearable and unobtrusive way may indeed open new exciting avenues for the fields of haptics and VR. This work presents a novel wearable haptic system for immersive virtual reality experiences. It conveys the sensation of touching objects made of different materials, rendering pressure and texture stimuli through a moving platform and a vibrotactile abbrv-doi-hyperref-narrowmotor. The device is composed of two platforms: one placed on the nail side of the finger and one in contact with the finger pad, connected by three cables. One small servomotor controls the length of the cables, moving the platform towards or away from the fingertip. One voice coil actuator, embedded in the platform, provides vibrotactile stimuli to the user

A robotic microsurgical forceps for transoral laser microsurgery

Purpose: In transoral laser microsurgery (TLM), the close curved cylindrical structure of the laryngeal region offers functional challenges to surgeons who operate on its malignancies with rigid, single degree-of-freedom (DOF) forceps. These challenges include surgeon hand tremors, poor reachability, poor tissue surface perception, and reduced ergonomy in design. The integrated robotic microsurgical forceps presented here is capable of addressing the above challenges through tele-operated tissue manipulation in TLM. Methods: The proposed device is designed in compliance with the spatial constraints in TLM. It incorporates a novel 2-DOF motorized microsurgical forceps end-effector, which is integrated with a commercial 6-DOF serial robotic manipulator. The integrated device is tele-operated through the haptic master interface, Omega.7. The device is augmented with a force sensor to measure tissue gripping force. The device is called RMF-2F, i.e. robotic microsurgical forceps with 2-DOF end-effector and force sensing. RMF-2F is evaluated through validation trials and pick-n-place experiments with subjects. Furthermore, the device is trialled with expert surgeons through preliminary tasks in a simulated surgical scenario. Results: RMF-2F shows a motion tracking error of less than 400 μm. User trials demonstrate the device’s accuracy in task completion and ease of manoeuvrability using the Omega.7 through improved trajectory following and execution times. The tissue gripping force shows better regulation with haptic feedback (1.624 N) than without haptic feedback (2.116 N). Surgeons positively evaluated the device with appreciation for improved access in the larynx and gripping force feedback. Conclusions: RMF-2F offers an ergonomic and intuitive interface for intraoperative tissue manipulation in TLM. The device performance, usability, and haptic feedback capability were positively evaluated by users as well as expert surgeons. RMF-2F introduces the benefits of robotic teleoperation including, (i) overcoming hand tremors and wrist excursions, (ii) improved reachability and accuracy, and (iii) tissue gripping feedback for safe tissue manipulation

Modulation of LDL receptor expression and promoter methylation in HepG2 cells treated with a Corylus avellana L. extract

Abstract The aim of our study was to evaluate the impact of an ethanolic extract of C. avellana on the molecular pathway(s) regulating the low-density lipoprotein receptor (LDLR) in HepG2 cells, mainly in terms of epigenetics. We demonstrated that viability, proliferation and cell cycle distribution were not affected up to 72 h of treatment, whereas LDLR expression was stimulated as early as 24 h following administration (

Evaluation of Passing Distance for Social Robots

(c) 2006 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The 15th IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN06); Hatfield, UK; September 6-8, 2006.Digital Object Identifier : 10.1109/ROMAN.2006.314436Casual encounters with mobile robots for nonexperts can be a challenge due to lack of an interaction model. The present work is based on the rules from proxemics which are used to design a passing strategy. In narrow corridors the lateral distance of passage is a key parameter to consider. An implemented system has been used in a small study to verify the basic parametric design for such a system. In total 10 subjects evaluated variations in proxemics for encounters with a robot in a corridor setting. The user feedback indicates that entering the intimate sphere of people is less comfortable, however a too significant avoidance is also considered unnecessary. Adequate signaling of avoidance is a behaviour that must be carefully tuned

cytotoxicity genotoxicity and gene expression changes elicited by exposure of human hepatic cells to ginkgo biloba leaf extract

Abstract The use of Ginkgo biloba leaf extract as nutraceutical is becoming increasingly common. As a consequence, the definition of a reliable toxicological profile is a priority for its safe utilization. Recently, contrasting data have been reported on the carcinogenic potential of Ginkgo biloba extract in rodent liver. We measured viability, Reactive Oxygen Species (ROS), apoptosis, colony-forming efficiency, genotoxicity by comet assay, and gene expression changes associated with hepato-carcinogenicity in human cells of hepatic origin (HepG2 and THLE-2) treated with different concentrations (0.0005–1.2 mg/mL) of Ginkgoselect ® Plus. Our analyses highlighted a decrease of cell viability, not due to apoptosis, after treatment with high doses of the extract, which was likely due to ROS generation by a chemical reaction between extract polyphenols and some components of the culture medium. Comet assay did not detect genotoxic effect at any extract concentration. Finally, the array analysis detected a slight decrease in the expression of only one gene (IGFBP3) in Ginkgo-treated THLE-2 cells as opposed to changes in 28 genes in Aflatoxin B1 treated-cells. In conclusion, our results did not detect any significant genotoxic or biologically relevant cytotoxic effects and gross changes in gene expression using the Ginkgo extract in the hepatic cells tested