Julian: Fiberoptics and Proximities for Independent Driving!
Background:
Julian is a young adult and busy college student. He has places to go and things to do! Julian also has spinal muscular atrophy (SMA), type I, which leads to profound muscle weakness. He started using a ventilator at about 1 year of age and has been driving a power wheelchair since he was 3.
Julian’s needs have changed over the years as his muscle weakness progresses. As a result, his seating and access have also changed. Julian requires a custom molded seating system to support his orthopedic asymmetries and provide adequate postural support. Julian has never been able to use any type of joystick, but he has been able to drive with switches since a very young age.
Evaluation – age 11
At age 11, Julian was re-evaluated to determine his best driving method, as he was having difficulty driving. He was able to drive his power wheelchair using the following combination of switches:
- Forward and Reset: Fiberoptic switches for Forward and Reset were placed under the right index finger and thumb, mounted in the handpad of his armtrough (see Figure 1).
- Left: a Proximity switch by the left side of his head was used for Left directional control and mounted in the left lateral pad of his head support.
- Right: a mechanical Microlite switch was used by the right medial knee for Right directional control, mounted with an L bracket to a Gatlin mount to swing out of the way for transfers (see Figure 2).
He was also able to control his power tilt, Reverse, Speeds, and his computer through the driving method, using the Reset switch. He used his power wheelchair at school, home, and in the community.
fiberoptic switches 
microlite switch by medial knee
Evaluation – age 17
By age 17, progressing muscle weakness had resulted in Julian no longer being able to drive his power wheelchair. We re-evaluated him, once again, to identify potential switch sites for Forward, Left, Right, and Reset.
- Forward: Julian’s strongest movement was now moving his head to his left. He already was using a Proximity switch in this location for Left turns. We now assigned this switch to be Forward as most drivers activate and sustain contact with Forward more than any other direction (see Figure 3). The Proximity switch was mounted in the left lateral pad of a Stealth Products Pro Series iDrive Head Array.
- Right: Julian was no longer able to move his leg to access a switch by his medial knee for Right turns. A Proximity switch was placed in the right lateral pad of the iDrive Head Array for Right directional control (see Figure 4).
Proximity switch for forward 
Proximity switch for right
- Left: Julian’s strongest finger movement was at the left middle finger if his fingers extended slightly beyond the edge of the armtrough hand pad. He could then flex this finger toward the distal edge of the hand pad (see Figure 5). Finger movement is often easier if the fingers are already flexed. A Fiberoptic switch was mounted in this location to capture this movement and serve as Left directional control. The switch was mounted under the armtrough on a gooseneck mount which allowed precise positioning and is hollow to contain the Fiberoptic cables. This switch was then connected to the iDrive system.
- Reset: Julian previously controlled both Forward and Reset with Fiberoptic switches by his right thumb and forefinger. He could now only move his right index finger from a flexed position, though had difficulty sustaining this movement (see Figure 6). Reset does not require a sustained activation, and so this switch site worked for this function. This switch was also connected to the iDrive system.
location for fiberoptic mount (left) 
location for fiberoptic mount (reset)
After submitting paperwork and obtaining approval, Julian received his new power wheelchair and driving method. Although using new switches in new locations, Julian drove well immediately and was very excited to be independent in his mobility, and other chair functions, once again!
Michelle is an occupational therapist in private practice, Access to Independence. She is a well-respected lecturer and author. She is the co-editor of Seating and Wheeled Mobility: a clinical resource guide, editor of Fundamentals in Assistive Technology, 4th ed., NRRTS Continuing Education Curriculum Coordinator and Clinical Editor of Directions magazine. Michelle is a member of the Clinician Task Force. Michelle is a RESNA Fellow, certified ATP, certified SMS and is a Senior Disability Analyst of the ABDA.