Design of a Wearable Haptic Device for Hand Palm Cutaneous Feedback

Abstract

This study describes the main design and prototyping steps of a novel haptic device for cutaneous stimulus of a hand palm. This part of the hand is fundamental in several grasping and manipulation tasks, but is still less exploited in haptics applications than other parts of the hand, as for instance the fingertips. The proposed device has a parallel tendon-based mechanical structure and is actuated by three motors positioned on the hand’s back. The device is able to apply both normal and tangential forces and to render the contact with surfaces with different slopes. The end-effector can be easily changed to simulate the contact with different surface curvatures. The design is inspired by a smaller device previously developed for the fingertips; however, in the device presented in this study, there are significant differences due to the wider size, the different form-factor, and the structure of hand palm. The hand palm represents the support for the fingers and is connected to the arm through the wrist. The device has to be developed taking into account fingers’ and wrist’s motions, and this requirement constrains the number of actuators and the features of the transmission system. The larger size of the palm and the higher forces challenge the device from a structural point of view. Since tendons can apply only tensile forces, a spring-based support has been developed to keep the end-effector separated from the palm when the device is not actuated or when the force to be rendered is null. The study presents the main design guidelines and the main features of the proposed device. A prototype has been realized for the preliminary tests, and an application scenario with a VR environment is introduced.

PalmEx: Adding Palmar Force-Feedback for 3D Manipulation With Haptic Exoskeleton Gloves

“…Handheld devices stimulating the users' palms in VR have therefore been designed in these regards. Palmar contact enables size, shape and stiffness renderings, which can be simulated by 1.5D tangible interfaces [10], inflatable proxies [11], shape-changing handhelds [12] or wearables [13], [14], [15]. Their main limitation is that they are required to be held continuously within the hand.…”

A 4-DoF wearable hand device for haptic rendering of surfaces and edges

“…Wearables are attracting great attention in the mechatronics field, as they provide human users with an intuitive, comfortable, and elegant way to interact with nowadays technology. Haptics technology is no exception, with wearable haptics systems being successfully employed in various scenarios [1], including rehabilitation [2,3,4], Virtual and Augmented Reality (VR/AR) [5,6,7,8,9,10,11,12,13,14,15], and robotic teleoperation [16,5,17,18]. Wearable haptic devices have been proposed for different parts of the body, providing kinesthetic [2,3,16,19], pressure [5,6,7,16,10,11,12,13,14], skin stretch [8,9,17,10,13,15], and vibration [6,4,16] stimuli to the fingers [5,7,8,9,6,4], palm…”

“…With respect to other wearable haptic solutions for the palm, such as [10,11,12,13,14,15], the proposed device is able to provide a broader range of stimuli, i.e., slanted surfaces, edges, and variable curvature sensations. Moreover, it is accompanied by an in-depth mechanical analysis and evaluation which is missing in the aforementioned works.…”

“…Trinitatova and Tsetserukou [12,11] used a 3-DoF inverted delta mechanism consisting of three identical kinematic limbs to move a pin-like end-effector across the palm. Similarly, Dragusanu et al [14] used a 3-DoF parallel tendon-based mechanical structure to actuate an interchangeable palmar end-effector. Guzererler et al [21] designed a handheld haptic device applying palm skin stretch via an actuated tactor, offering richer feedback than fingertip devices.…”

HAPP: a Haptic Portable Pad for Hand Disease Manual Treatment

“…In this paper, leveraging our expertise in hand stimulation by haptic devices [29], [30] and robotic systems for reha- bilitation [31], [32], [33], we present HAPP (see Fig. 1), a haptic device for preclinical investigation on correlation between CRPS-I symptoms reduction and MT, and also for clinical treatment of CRPS-I and other diseases of carpus and metacarpus, by mimicking traditional mechanical and rhythmic stimulations proper of manual treatments.…”