THE INSTRUMENTATION OF A RIDE-ON
CAR TO QUANTITATIVELY ASSESS
PERFORMANCE AND PROGRESS FOR
CHILDREN WITH MOBILITY IMPAIRMENTS
Jesse Schmitz*, Raman Paranjape*, Kim Schaan^, Kent Windsor^
*University of Regina
^Wascana Rehabilitation Center
Modified Ride-On Cars (MROC)
■ Children’s toy cars that have been
retrofitted to be operated by
children with wide variety of
mobility impairments
– Switches/Joystick vs Steering
Wheel and Pedal
– Physical modifications to
seating for support and
stability
Benefits to Power Mobility
■ Lack of mobility can cause cognitive, social, and emotional delays
■ Using power wheelchairs for early mobility can improve cognitive and social
development and visual perception skills [1]
■ MROC becoming more popular in occupational/physical therapy in pediatrics
as an alternative to traditional power mobility
[1] H.-H. Huang and J. C. Galloway, ”Modified Ride-on Toy Cars for Early Power Mobility: A Technical
Report”, Pediatric Physical Therapy, vol. 24, no. 2, pp. 149154, 2012.
MROC vs Traditional Power Mobility
■ Power wheelchairs are costly and government subsidies require competence to
be shown
■ MROC are lower cost than traditional power mobility
■ Size and weight of MROC make them easy to transport and less dangerous
■ Less social stigma
– It’s a toy that other children play with
MROC Research
■ Relatively small amount of research about the effectiveness of MROC
■ Recent review paper found 14 studies dealing with MROCs being used with
children under the age of 6 [2]
– Almost all studies were case studies, many with a single subject
– Observations are made by therapists (no quantitative data collected)
■ Children found to show improvements in one of the following:
– Arm and hand use - Driving Skills
– Self initiated movement - Moving within different locations
– Interpersonal interactions - Communication
[2] D. James, J. Pfaff, and L. M. Jeffries, ”Modified Ride-on Cars as Early Mobility for Children with
Mobility Limitations: A Scoping Review,” Physical and Occupational Therapy In Pediatrics, pp. 118,
2018.
The Zoom Car Project
■ Initiated by staff at Wascana Rehabilitation Center Children's Program
■ Started as an implementation of Go-Baby-Go! project out of University of
Delaware [1]
– Provides a set of instructions for laypersons to make modifications
■ Personnel at University of Regina felt that the project could be taken further
– Three MROC built in previous phases of the project
– New, fully instrumented built especially for this research project
[1] H.-H. Huang and J. C. Galloway, ”Modified Ride-on Toy Cars for Early Power Mobility: A Technical
Report”, Pediatric Physical Therapy, vol. 24, no. 2, pp. 149154, 2012.
Car 1
■ Fully analog
■ Single switch operation
■ Low-Pass filter to allow
for gradual
starting/stopping
Car 2
■ Controlled via Arduino
■ Multi-Button Control
■ Ultrasonic sensors to
prevent collision
■ Encoders to ensure
straight driving
Car 3
■ Arduino controlled
■ Utilizes joystick salvaged
from power wheelchair
■ Intent is to mimic controls
of power wheelchair
Current Phase of the Zoom Project
■ Goal is to develop a MROC that will act as a measurement device to record
quantitative data about how a child is performing/progressing in several areas
■ The car will then be able to be used as both a therapy device, as well as an
evaluation tool
■ Discussion with OT/PT led to identification of various metrics/measurements
that would be useful for evaluating children’s progress
■ Car will be tested starting in June
– Children will use the car several times over a period of ~8 weeks
– Data will be collected and analyzed to determine if the car is able to
measure changes over time and between participants
Data to be Collected
■ IMU data for the car (magnetometer, accelerometer, gyro)
■ Proximity of car to objects surrounding it
■ Interactions with the car’s user inputs
– Time and duration of button presses
– Position of the user joystick
■ Pressure sensors (FSRs) in the seat to measure posture of the child
■ EMG sensors to measure muscle activity as the child drives the car and
responds to obstacles
Design of the New Zoom Car
■ Designed to be as flexible as possible
– 3.5mm sockets to allow up to 4 buttons or joystick to be plugged in
– Indicator LEDs to show what is plugged in
■ EMG and Posture Sensors also wired to 3.5mm cables to allow any number of
those sensors to be used
– Up to 3 channels of EMG data (biceps, triceps, deltoid for this study)
– Up to 7 channels of Posture data (under glutes, behind hips, behind
shoulders, and mid back for this study)
■ XBee Remote (802.15.4) allows therapist to override control of the car
Design of the New Zoom Car
■ External video camera used in conjunction with photogrammetry techniques
used to track the position of the car as it moves around a room.
■ Audio is also recorded, as verbal communication is a crucial part of therapy,
and it may want to be examined afterwards when analyzing other data
Design of the New Zoom Car
Methodology for Testing the New Car
■ Testing of the new car is set to begin in June
■ ~8 children to take part in the testing
■ Between the ages 2-8 with a movement disorder that has restricted or delayed
the child’s mobility skills
■ Each child will have 3 data collecting sessions with the car over the period of
~8 weeks
■ During data collection, children will complete driving tasks using a control
scheme to fit their abilities (single button, multi button, or joystick)
■ Tasks for participant children to complete will be part of a driving course that
will remain consistent throughout testing
Methodology for Testing the New Car
■ Development of the course is based on skills checklist to gauge readiness of
children to be prescribed a power wheelchair
– Drives forward 20 feet with no more than 1 stop for distractions
– Drives down right side of the corridor without hitting walls or obstacles
– Can maneuver turns
– Stops within 2 seconds upon request
– Understands and yields right of way to pedestrians
■ Course therefore includes straightaways at least 20 feet in length, right and
left turns, points where the child will stop, and obstacles (pylons) to avoid
Methodology for Testing the New Car
■ Having children come in multiple times allows for us to test if the system can:
– Distinguish between the various ability levels of the different children
– Measure changes in a single child as they develop skills over time.
■ Once data collection is complete, data will be analyzed to quantify child’s
abilities and progress in the areas of:
– Postural control
– Muscle control
– Driving skills
■ If useful information is able to be extracted from collected data, the new car
will be considered a success
Conclusions and Future Work
■ Zoom car project has already seen much success in helping children with
mobility impairments
■ Existing cars are seen by therapists and caregivers as an extremely positive
part of therapy activities
■ By transforming a MROC into a data-collection system, the impact of these
cars will be able to be better quantified and understood
■ Future studies with this car will almost certainly attempt to make claims
about the quantitative impact and clinical value that these cars have
– Longer study
– More participants
