Design of a Wearable Fingertip Haptic Device for Remote Palpation: Characterisation and Interface with a Virtual Environment

Abstract

This paper presents the development of a wearable Fingertip Haptic Device (FHD) that can provide cutaneous feedback via a Variable Compliance Platform (VCP). The FHD includes an inertial measurement unit, which tracks the motion of the user's finger while its haptic functionality relies on two parameters: pressure in the VCP and its linear displacement towards the fingertip. The combination of these two features results in various conditions of the FHD, which emulate the remote object or surface stiffness properties. Such a device can be used in tele-operation, including virtual reality applications, where rendering the level of stiffness of different physical or virtual materials could provide a more realistic haptic perception to the user. The FHD stiffness representation is characterised in terms of resulting pressure and force applied to the fingertip created through the relationship of the two functional parameters -pressure and displacement of the VCP. The FHD was tested in a series of user studies to assess its potential to create a user perception of the object's variable stiffness. The viability of the FHD as a haptic device has been further confirmed by interfacing the users with a virtual environment. The developed virtual environment task required the users to follow a virtual path, identify objects of different hardness on the path and navigate away from "no-go" zones. The task was performed with and without the use of the variable compliance on the FHD. The results showed improved performance with the presence of the variable compliance provided by the FHD in all assessed categories and particularly in the ability to identify correctly between objects of different hardness.

Development of a wearable force-feedback mechanism for free-range haptic immersive experience

“…One of the subsystems comprises an inertial measurement unit that tracks the motion of user's finger and controls linear displacement of a pad towards one's fingertip. The other subsystem controls pressure in a variable compliance platform through a motorized syringe to simulate the stiffness of a touched surface (Tzemanaki et al, 2018).…”

Face mediated human–robot interaction for remote medical examination

“…Consequently, several high-fidelity haptic feedback 26 devices have been developed for use in conjunction with remote surgical systems. One simple format is a stimulation device that can be placed directly on top of the fingertip or wrapped around the control joystick 27 and delivers a local vibration or compression 28 . In contrast, the most elaborate devices morph 2D surfaces to deliver tactile feedback by changing the surface’s geometry 29 – 31 .…”

An Abdominal Phantom With Tunable Stiffness Nodules and Force Sensing Capability for Palpation Training

“…Magneto-Rheological (MR) fluid [16] and phase-change material [17] have the advantages of physical simulation accuracy but need complex control conditions. Pneumatic inflation, on the other hand, is compact in control and flexible to be integrated into diverse systems [18]. However, the elastomeric material is prone to exhibit non-linear deformation when stiffness is controlled [19].…”