Universal Haptic Drive: A Robot for Arm and Wrist Rehabilitation

Abstract

In this paper we present a universal haptic drive (UHD), a device that enables rehabilitation of either arm ("ARM" mode) or wrist ("WRIST" mode) movement in two degrees-of-freedom. The mode of training depends on the selected mechanical configuration, which depends on locking/unlocking of a passive universal joint. Actuation of the device is accomplished by utilizing a series elastic actuation principle, which enables use of off-the-shelf mechanical and actuation components. A proportional force control scheme, needed for implementation of impedance control based movement training, was implemented. The device performance in terms of achievable lower and upper bound of viable impedance range was evaluated through adequately chosen sinusoidal movement in eight directions of a planar movement for the "ARM" mode and in eight directions of a combined wrist flexion/extension and forearm pronation/supination movement for the "WRIST" mode. Additionally, suitability of the universal haptic drive for movement training was tested in a series of training sessions conducted with a chronic stroke subject. The results have shown that reliable and repeatable performance can be achieved in both modes of operation for all tested directions.

Estimation of Finger Joint Angles from sEMG Using a Neural Network Including Time Delay Factor and Recurrent Structure

“…The human hand has many joints and performs important functions; therefore, injury to or loss of fingers is a serious problem. Prosthetic hands [7][8][9][10][11][12] and robotic devices that assist rehabilitation [13][14][15][16][17][18][19][20][21][22][23][24][25][26] are being developed in many institutes, and some prosthetic hands are available in the world market [7][8][9]. Robotic devices that assist rehabilitation are helpful in achieving an early recovery for injured patients.…”

“…Robotic devices that assist rehabilitation are helpful in achieving an early recovery for injured patients. Devices that target the upper limb (shoulder or elbow, without hand) are currently being researched [13][14][15][16][17][18][19], while other work focuses on hand and finger function [20][21][22][23][24][25][26]. While research on prosthetic hardware has achieved a certain level, the next step must focus on how to control these devices.…”

Variable structure pantograph mechanism with spring suspension system for comprehensive upper-limb haptic movement training

“…When the handle is oriented horizontally, the second DOF is extension/flexion (Figure 6(d) and 6(e)), and when the handle is oriented vertically, the second DOF is radial/ulnar deviation (Figure 6(f) and 6(g)), respectively. Comparisons between achievable ROM of the UHP in Wrist mode and the human wrist have been previously shown [27]. Note that in this mode, a change in length of the segment below universal joint lock A occurs because of the fixed position of the wrist gimbal.…”

“…While the UHP uses the same series elastic actuators (SEAs) as used in the UHD (SEA also described by Oblak et al [27]), the modification can be found in a pantograph mechanism and system of configurable joint locks that can more efficiently transition between five distinct modes of operation with minimal effort by the therapist.…”

“…Reflecting these results, the UHD (a low-cost configurable system) was previously developed (Figure 1(a)) and tested for training both the upper arm and wrist separately with the same 2 controlled DOFs for each configuration [27]. The system used a configurable joint lock to allow the 2 actuated DOFs to be used selectively in one of two modes: (1) Arm mode, for quasiplanar arm positioning tasks, or (2) Wrist mode, for exercising wrist pronosupination, flexion-extension, or radial-ulnar deviation.…”