Technology in Motion (TIM): Unobtrusive assessment of motor (dys)function

The prevalence of disorders that affect motor function, including neurovascular
diseases (e.g., stroke), neurodegenerative diseases (e.g., Parkinson*s disease
[PD]) and musculoskeletal pain conditions (e.g., osteoarthritis), is high and
will further increase as a result of an ageing society, since the incidence of
these disorders increases with age. Along with the foreseeable future shortage
of healthcare supply, this raises the need for effective means to diagnose,
monitor and treat disorders associated with motor dysfunction. A uniform
evaluation of motor function that is efficient, patient-friendly,
cost-effective, and that can be carried out on a large scale is currently not
available. Emerging ICT technologies offer the required breakthrough
opportunities (i.e., unobtrusive motion tracking and flexible task- and
environmental manipulations) to address the shortcomings of traditional
evaluations of motor dysfunction.

The overall objective of this study is to develop patient friendly and
unobtrusive techniques to characterize motor function. In this context we will
use video cameras combined with depth sensors (RGB-D sensors, such as Microsoft
KinectTM) and modern computer-vision techniques to perform accurate markerless
tracking of the motion of patients to construct a *motion phenogram* that
captures all key properties of the patient*s motions. Moreover, we will develop
virtual and augmented reality techniques for examination of motor function
during systematic manipulation of task- and environmental conditions in order
to challenge the patient*s adaptive ability, which may provide a more sensitive
indicator of problems experienced in daily life. The specific objectives are:
1) to evaluate the usability and sensitivity of the markerless motion tracking
devices for 3D-kinematic measurements of a) reaching and grasping movements of
the upper limb and b) gait and balance in PD patients, stroke patients and
controls, and for 3D-kinematic measurements of tremor of the arm and/or hand,
in comparison to reference motion capture systems; 2) to compare unobtrusive
motion outcome measures of stroke patients, PD patients, and healthy controls
to establish whether expected differences between groups (based on
physiological models of the diseases) can be detected; 3) to examine the
association between unobtrusive motion parameters and corresponding (sub)scores
on clinical tests, and to overall severity of motor dysfunction and disability;
4) to identify the set of (motor, sensory and/or cognitive) parameters that can
best account for variance in clinical phenotype within each patient group.

Observational, cross-sectional study in which motion parameters of upper limb
function and motion parameters of gait and balance function are collected in
two groups of patients (PD and stroke) and healthy controls. These patient
groups are included as demonstrator cases.

Besides administration of standard clinical tests, the study will consist of
two experiments: one to evaluate reaching and grasping and one to evaluate gait
and balance. Subjects will participate in one or both experiments, depending on
whether the in- and exclusion criteria for the specific experiments are met.
For a subject participating in both experiments, the two experiments will
either be separated by a 10-15 min break, or will be conducted on separate days
if the total duration of the first experiment (including clinical tests)
exceeds 2 hours. In both experiments, the protocol consists of measurements at
rest, followed by a set of active measurements, starting with assessment of
basic motor functions and ending with a challenging task to evaluate the
functional integration of motor, sensory and cognitive functions in various
contexts.

In the *reaching and grasping* experiment, unrestricted movements of the arm
and hand are recorded with a markerless motion capture device (complemented
with an accelerometer and/or electromyography for validation purposes). The
participants will be seated in a chair 2 m in front of a 60* flatscreen LED TV
in normal upright sitting posture with their feet supported. The LED screen
will be used for presenting task instructions, setting targets in a visual
environment, and/or providing real-time visual feedback on a subject*s
performance. An optical see-through head-mounted device will be used to display
static as well as dynamic three-dimensional content in the subject*s
environment to evaluate reaching and grasping under changing task- and
environmental conditions. To optimize the augmented reality techniques for the
"reaching and grasping" experiment, user experiences and usability will be
evaluated in a small pilot study. In the *gait and balance* experiment,
full-body motions are recorded with markerless motion capture sensors while
participants walk on a 10-meter walkway or while balance tests are performed on
a 3-meter treadmill that includes force plates, which also allows for recording
of shifts in center of pressure. Gait-dependent projections on the walkway are
used to test gait adaptability under changing task- and environmental
conditions (e.g., targeted stepping and obstacle avoidance).

In addition, tremor parameters will be collected in patients with tremor of the
arm and/or hand. This "visual tremor assessment" will be combined with a
scheduled appointment for tremor analysis at the Clinical Neurophysiology
outpatient clinic.

The TIM protocol will align with current clinical practice (i.e., will not
interfere with clinical decision making). TIM will add extra measurements of
motor function using a markerless tracking device for assessment of
unrestricted arm movements, gait, and balance, combined with augmented reality
to evaluate these components in various contexts. When possible, measurements
are performed during regular visits to the outpatient clinic, such that no
extra visits of the patients are required. Depending on the patient*s
preference, clinical tests and experiments will either be performed during a
single visit or in two or three separate visits within one week. Measurements
are non-invasive and bear minimal risks. Active participation of the subjects
is required, but tasks will mostly involve submaximal effort. Actual
measurement time per experiment does not exceed 90 minutes (excluding the
clinical tests) and additional rest periods will be offered if necessary. For
the *gait and balance* experiment, subjects will be asked to register their
falls during a 6-month follow-up period. Travel costs to the hospital will be
compensated on the basis of public transport (2nd class) or travel distance (¤
0.19 per km). Additionally, participants will receive a VVV-voucher to the
value of ¤20 for their participation.