Design and preliminary evaluation of the FINGER rehabilitation robot: controlling challenge and quantifying finger individuation during musical computer game play

Abstract

BackgroundThis paper describes the design and preliminary testing of FINGER (Finger Individuating Grasp Exercise Robot), a device for assisting in finger rehabilitation after neurologic injury. We developed FINGER to assist stroke patients in moving their fingers individually in a naturalistic curling motion while playing a game similar to Guitar Hero®a. The goal was to make FINGER capable of assisting with motions where precise timing is important.MethodsFINGER consists of a pair of stacked single degree-of-freedom 8-bar mechanisms, one for the index and one for the middle finger. Each 8-bar mechanism was designed to control the angle and position of the proximal phalanx and the position of the middle phalanx. Target positions for the mechanism optimization were determined from trajectory data collected from 7 healthy subjects using color-based motion capture. The resulting robotic device was built to accommodate multiple finger sizes and finger-to-finger widths. For initial evaluation, we asked individuals with a stroke (n = 16) and without impairment (n = 4) to play a game similar to Guitar Hero® while connected to FINGER.ResultsPrecision design, low friction bearings, and separate high speed linear actuators allowed FINGER to individually actuate the fingers with a high bandwidth of control (−3 dB at approximately 8 Hz). During the tests, we were able to modulate the subject’s success rate at the game by automatically adjusting the controller gains of FINGER. We also used FINGER to measure subjects’ effort and finger individuation while playing the game.ConclusionsTest results demonstrate the ability of FINGER to motivate subjects with an engaging game environment that challenges individuated control of the fingers, automatically control assistance levels, and quantify finger individuation after stroke.

Robotic Assistance for Training Finger Movement Using a Hebbian Model: A Randomized Controlled Trial

“…We used the FINGER robotic exoskeleton 31,33 (Figure 1) to provide two levels of assistance to participants with stroke-related finger movement impairments while they played a musical computer game in the style of Guitar Hero. We randomized participants into high and low assistance groups and then dynamically adjusted the amount of robotic assistance each week to drive participants towards 85% and 50% success rates respectively.…”

“…Additional assurance that efforts would be comparable across groups comes from a pilot study in which we found that this task, game, and form of assistance caused participants to exert similar physical effort regardless of the assistance level (i.e. this system caused minimal slacking) 31 . Further, we quantified motivation and self-efficacy at multiple time points throughout training to better assess the psychological effects of assistance.…”

Home-Based Therapy After Stroke Using the Hand Spring Operated Movement Enhancer (HandSOME)

“…Several robots have been developed that assist movements of the hand isolated from the rest of the limb [10], [11], [12], [13], [14], [15], [16], [17], [18]. These devices require sitting in the clinic with the arm supported in a pre-defined posture and/or don’t allow interacting with objects.…”

Rehabilitation: Machine recovery

“…The system, co-developed with Eric Wolbrecht of the University of Idaho in Moscow, helps users to move their fingers individually in a natural curling motion. The device captures their movements and monitors their effort and progress while they play a computer game similar to Guitar Hero, in which players use a guitar-shaped controller to simulate playing the real instrument 4 .…”