A Wrist and Finger Force Sensor Module for Use During Movements of the Upper Limb in Chronic Hemiparetic Stroke

Finally someone looking at the specific problems with stroke movements.
http://www.arnostienen.net/articles/miller09.pdf
Abstract—Previous studies using robotic devices that focus on
the wrist/fingers following stroke provide an incomplete picture of
movement dysfunction because they do not consider the abnormal
joint torque coupling that occurs during progressive shoulder abduction
loading in the paretic upper limb. This letter introduces a
device designed to measure isometric flexion/extension forces generated
by the fingers, wrist, and thumb during robot-mediated 3-D
dynamic movements of the upper limb. Validation data collected
from eight participants with chronic hemiparetic stroke are presented
in this paper.
Index Terms—Hand, kinetic measurements, robotic rehabilitation,
shoulder loading, stroke, upper extremity.
I. INTRODUCTION
IN RECENT years, the quest for more effective rehabilitation
strategies for the upper limb following hemiparetic stroke has
focused on employing instrumented robotic devices to explore
motor learning, to investigate the effects of treatment intensity,
and to study mechanisms underlying stroke-induced movement
disorders. This letter introduces a device, theWrist/Finger Force
Sensing module (WFFS), which is designed to quantify potential
abnormal joint torque coupling between the shoulder and
wrist/fingers in the paretic upper limb. The WFFS measures
isometric flexion/extension forces generated by the wrist, fingers,
and thumb during 3-D movements of the paretic upper
limb.
In the paretic upper limb of moderately to severely affected
hemiparetic stroke survivors, coupling between shoulder abductors
and elbow, wrist and finger flexors, clinically described
as the flexion synergy [1], [2], frequently occurs. This coupling
could partially explain the hypertonia in the wrist/finger
flexors observed frequently during upper limb movements following
stroke. Robotic assistive devices for the hand, such as
extension-aiding gloves and exoskeletons, have the potential to
improve hand function, as do robot-aided rehabilitation protocols
that can involve sophisticated and precise active or passive
mechanical manipulations of the hand/wrist. However, the expression
of the stroke-induced flexion synergy at the hand must
be better quantified before these technologies can reach their
full potential.
Currently available robot assistive devices or robot-aided rehabilitation
protocols for the hand and wrist are limited because
they have examined the hand and wrist in isolation from the
rest of the upper limb. Devices such as CyberGrasp exoskeleton
(CyberGlove Systems), HandCARE [3], RutgersMasters II [4],
Hand–Wrist Assisting Robotic Device (HWARD) [5], Multiple
User Virtual Environment for Rehabilitation (MUVER) [6],
and other pneumatically controlled or actuated gloves [7], [8]
are generally designed to assist hand opening, increase finger
range of motion, or improve object grasp/release. Other devices,
like the Haptic Knob [9], are designed to improve performance
of functional tasks that require precise fine motor control.