This week for senior design, our group finalized a number of design concepts for our car design. Major additions we plan on adding to our car include a 5-point harness, an adjustable seat, and a forearm tray. These additions will make significant improvement towards increasing the vehicle’s adjustability, support, and safety. The implementation method for these designs have been planned out as well in preparation for an initial build session. An amazon order was placed for initial prototype materials, which should be delivered in time for a planned prototype construction meeting this upcoming Saturday.

A number of materials have been ordered and obtained for the prototype build. This includes PVC piping, a start button, a seat adjuster, the 5-point harness, and a speed controller. The PVC piping will serve as a easily manipulatable material to allow for a wide range of customization for our seat. It is currently planned to remove the current seat within the vehicle, and build a new, adjustable seat out of the PVC piping. A fabric material will be attached to the PVC to allow for a hammock-like seat. The seat adjuster will be placed below the seat, and allow adjustability frontwards and backwards within the car. The current prototype will have the seat adjuster attached with velcro. After confirmation that the front and back adjustability work ideally for the car, more work will be done in the upcoming weeks to allow for adjustability in the vertical direction. The speed controller and start button will serve as functional electric modifications to the car. The addition of the speed controller will allow the caretaker to adjust the maximum speed of the vehicle to a condition deemed safe for the child. Furthermore, the start button will replace the pedal as the mechanism for the child to start the vehicle, allowing children without lower body control to use the car. 

After the work is done this upcoming weekend, more work will be done to continue to refine and develop design ideas. It is believed that hands on construction will allow availability to design and implementation insights likely overlooked within the planning phase. Our group will go over both the failed and successful aspects of our prototype, and make adjustments from there to further optimize our upcoming designs. By the end of the month, our group plans to have a fully completed model that can be used by graduate students at the Susan Gray school to begin testing with children.

Before winter break, our group visited the Belmont School of Occupational Therapy to assist in a car-build in order to better contextualize the current equipment and gain some experience in working with the cars. Our main task was working with a Lightning McQueen model car and attaching a controller to the internal circuitry allowing the user to change the speed settings. From a design perspective, this component is critical for implementation in the school and home settings as the initial speeds of the cars are too fast to be used safely.

In order to implement the device, the seat was removed from the Lightning McQueen car and the battery was detached from the motor. Each lead was cut and stripped and the new component was connected between the devices allowing for multiple settings. By working directly with the car and assembling the different components, we found a clearer understanding of the design constraints and the different aspects we would need to consider.

Our project involves the implementation of “lean tools” and “contextualized adaptations” which are terms describing the simplification of existing technologies and the diversion of existing techniques for new purposes, respectively. In the context of our design, we are optimizing mobility devices that already exist in order to be more cost-effective and readily available as well as repurposing existing technologies, motorized toy-cars, to be used in the clinical setting. With these concepts in mind, our group decided to focus primarily on three main aspects to be determined by clearly defining the needs of the patient and the components we deem important. By comparing these two ideas, we can narrow down the three most important design criteria to focus our efforts and create a quality design.