Pointing Device Usage Guidelines for People With Quadriplegia: A Simulation
  and Validation Study Utilizing an Integrated Pointing Device Apparatus
From: IEEE Transactions on Neural Systems and Rehabilitation Engineering -
  June 2009 - page 279
By: Chen, H.-C.; Chen, C.-L.; Lu, C.-C.; Wu, C.-Y.

Abstract: This study undertakes a simulation and validation experiment to
provide guidelines regarding pointing device usage for quadriplegic
individuals assisted by a newly developed integrated pointing device
apparatus (IPDA). The simulation experiment involving 30 normal subjects
whose upper limb movement was restricted by splints. Another 15 subjects with
high level cervical spinal cord injury (SCI) were recruited for the
validation study. All normal subjects employed six control modes for
target-acquisition and drag-and-drop tasks using an IPDA to integrate common
pointing devices. A previously designed software was used to evaluate the
operational efficiency (OE), expressed as "able performance" (%AP), of the
subjects. The experimental results indicated that the OE of normal subjects
for controlling the pointing devices were dominated first by using the
unilateral hand (69 - 100 %AP), then by using the wrist/hand (65 - 73 %AP),
and finally by using either bilateral body parts or the combination of limb
and chin (45 - 53 %AP). The OE for operating an orientation-rotated mouse
using the dominant wrist/hand via IPDA in both tasks was equivalent to that
for operating a trackball using the dominant hand. The experimental results
obtained by subjects with SCI also demonstrated similar findings, although
the OEs in each control mode were lower than in normal subjects. Results of
this study provide valuable guidelines for selecting and integrating common
pointing devices using IPDA for quadriplegic individuals. The priority for
selecting which body part should control the pointing devices was as follows:
unilateral hands, unilateral wrist/hands, and either bilateral body parts or
a limb and chin/head/neck in combination.  

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