Design Day is one week away! We have completed our poster as shown below.

We were able to test our device at a GoBabyGo build where 7 children were fitted for their individual toy cars. We were able to have 4 children ranging from ages 20 months to 4 years, all with different diagnoses and substantially different abilities, successfully use it, and speculate that 6 out of the 7 children would be able to efficaciously use our adjustable design. The data is presented in the poster, in which the children were scored on a scale of 1-5 in 5 categories of use in both their own, individualized car, and our adjustable car. We have shown improved benefit in our design as compared to the previous design, as well as proved ability to be used in multiple children. Parents and occupational therapists were very impressed with our design, noting that a car like ours would be more beneficial than the GoBabyGo car for their children as they grow and develop. Here are some photos from that day:

We are excited to get this car into the Susan Gray School where we anticipate that around 6 children will be able to benefit from it. See you at Design Day!

This week we were able to finalize the wiring of the button, allowing the car to be accelerated via the steering wheel instead of a foot pedal. This accommodates children with lower body limitations or low muscle tone. We were also able to make significant progress on our final presentation poster in preparation for design day in just over 3 weeks.

Next steps from a design standpoint include purchasing Plastidip in order to coat exposed metal pieces with plastic. This is necessary for the safety of the toy, as the exposed metal pieces on the steering wheel and seat can pose a potential safety hazard. We also need to move the dial adjusting the speed to a more accessible location for easy adjustment by a therapist, teacher, or parent. This dial works by adjusting the current passing through to the motor by increasing or decreasing the resistance of the speed controller.

Once these final modifications are complete, we will work on getting the car into the Susan Gray School ASAP. Without IRB approval, we won’t be able to conduct research and collect quantitative data, but the occupational therapists at the school will be able to asses the functionality of the toy. As we have kept in mind throughout the project, we define success by utility of the toy in any capacity, as previous adapted toy designs have just collected dust in a closet. If our design is easy, accessible, and fun enough for a child to actually use on a regular basis, we have succeeded in our design goals.

Future long term directions of the project are to develop a fully customizable kit in which parents or therapists can purchase online with the specific parts they deem to be most applicable to their child. This requires the manufacturing capability to standardize dimensions and parts to be implementable in a variety of toy cars, instead of only a single Lightning McQueen. Parts in the kit would include not only our designs we have used on our car, but also additional designs such as a tray, neck support, other types of steering handles, and more.

This past Wednesday we had our 4th design build. In this build we accomplished many goals, including installing the kickboard seats. To do this, we measured placements for cutouts in the styrofoam in which the PVC connectors can be placed in a male-female connector fashion. The circular cutouts in the styrofoam were cut using a box cutter at a slightly smaller diameter of the PVC connector such that the seat can have a tight, secure, and safe fit. The kickboard was installed and showed to be very sturdy, necessary for the safety of our design. A speed controller was also installed successfully. (photos attached)

For our next build, we need to finalize the back rest and finish the wire connections between the button and motor such that the car’s acceleration can be achieved via the button on the steering wheel. We have collectively decided that initial plans to install a tray and an external battery charging port will not be necessary for the success of the design.

Additionally, we had originally planned to collaborate with Alyssa Harding, a Belmont School of Occupational Therapy Graduate student, who is researching these devices for her graduate project. She intended to collect data on the vehicle after implementation in to the Susan Gray school, however, due to IRB approval delay and thus delayed progression of her project, she had to withdraw in order to pursue a different project to fulfill her semester requirements. We still plan on giving the finished product to the Susan Gray School and receiving feedback from the therapists and students. Although, we will not be able to receive the quantitate data Alyssa’s research could have provided, we will have substantial qualitative feedback on the design for future direction and modification improvements.

In addition to finalizing the design and implementing it into the Susan Gray School, we also are beginning to put together our poster for design day. The poster will lay out our research model and design progression, including background, needs assessment, methods, results, conclusions, and figures.

On February 20th, the team met to complete the third car build. Here, we were able to finish the novel steering design and finalize the design for the seat frame. The final steering wheel is compressible against two foam blocks to account for limited muscle tone in the arm and bracketed by two U-Brackets to allow for control of steering. The seat frame is coupled to a seat adjuster allowing for forwards and backward motion and a five-point harness is connected directly to the frame to increase safety and adjustability. Below are images of the design schematic and the final products in the car.

An image of a toy car modified to be used by small children with physical and mobile limitations to aid in early cognitive development. This design depicts A)a five-point harness, B)a novel steering and acceleration mechanism and C)a fully adjustable seat frame. All modifications not shown.

From this point moving forward, our team will be aiming to complete the car the week after Spring Break by doing a final car build. Here, we plan to implement the speed controller, insert kickboards with later support foam into the seat frame, and finish the wiring for the button. In addition, we want to move the battery port to the outside of the car so it’s easier to access for the parent. For the seat design, we would ultimately like to implement a mechanism for tilt, although we have not decided on a final design. So far, the leading idea is to have cutouts in the attached kickboard to allow for PVC pipe inserts on either the front end or the back end which would provide tilt and height adjustability. These design ideas can be finalized at the next build.

Our contact from Belmont has informed us that the IRB approval for the Susan Gray School is still in progress and we aim to have the car in the school around the third week of March.

This week, we hosted a building session for our team so that we were able to implement many of the previously described design criteria. This build session included the addition of the speed controller, the removal of the doors of the vehicle, the introduction of an acceleration button on the steering wheel, and a total redesigned steering system.

The speed controller was introduced so that the therapist would be able to alter the speed of the car according the needs of each child. This device allows the car to operate at a full range of speeds, from maximum speed to an almost unnoticeable crawl. The speed controller works by introducing a variable resistor into the circuitry of the car, and the knob of the potentiometer changes the amount of voltage applied to the motor. The speed controller device was placed underneath the seat alongside the battery for safety purposes, while the adjustment knob was placed outside of the vehicle for easy access.

The doors were removed from the vehicle to allow easy access for students as they entered and exited the vehicle. The doors were found not to be integral to the structure of the vehicle, and could be added back at a later date if deemed necessary by a therapist.

The acceleration button on the steering wheel was necessary for students who may not have the motor control abilities in their legs necessary. A hole was drilled out of the steering wheel so that a large, round button could be inserted. Next, the wires from the button were introduced into the existing circuitry of the car so that either the hand button or the floor pedal could act as the switch to accelerate the vehicle.

The redesigned steering system addressed two needs. First it allows easier steering through a “handlebar” approach rather than the typical small steering wheel. Next, it but be able to be pushed so that it activates the hand pedal. The design accomplishes both of these needs by attaching a length of PVC pipe above the existing steering wheel and hand button using compressible foam. Therefore, when the handlebar is pressed, it also compresses onto the hand pedal, accelerating the car. This system will be fortified using metal U-brackets to ensure proper steering and durability.

Also, we met with an occupational therapist student at Belmont named Alyssa wo gave us many ideas on the design for the seat of the vehicle. She recommended that we use an adjustable frame built with PVC so that ample structure support would be provided for the kids, while adjustability could be maintained. She also mentioned the need for lateral support, which could be accomplished though robust sidewalls on the vehicle. Finally, she stressed the importance of maintaining a proper length for the distance from the seat to the steering wheel so that students would be able to reach the steering wheel without straining. She is excited about the opportunity to use our vehicle with the students and report back to us the efficacy of our design.
We received another shipment of parts this week. We received our 5-point harness, the forearm tray, and the parts required to build the adjustable tray. We are hosting another build session this week, and will report the success of the implementation of these parts at a later date.

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.

On Thursday, November 8th, our group visited the Susan Gray School at Vanderbilt to learn more about the patients our mobility devices would be deployed to and understand their needs. Heather Winters, an occupational therapist at the school, was able to take some time to walk us through the school and talk to use about the patient needs. We began by looking at the devices that were already in use, and an old GoBabyGo car to understand why it wasn’t being used.

Major issues with the current GoBabyGo car included that the charger was missing, the user had a difficult time putting a child into the car and that it was bulky and heavy. It was used for a child who exhibited self-injurious behaviour and was only used once in a therapy session.

Next, we went to observe the specific children that our cars would be used by and asked about their particularly limitations and what they would require. We were able to observe two students directly with the following limitations.

• Student 1: 3 year old with fluctuating athetoid cerebral palsy. Specific mobility restrictions includes little muscle tone in arms, and lack of fine motor control, limited communication and lack of fluid movement. Currently uses a Riftch Activity Chair, a weight bearing stander and a gait trainer. Need to address problems with communication, social interactions and muscle control.
• Student 2: 3 year old with spina bifida. Strong upper arm movement and head control with no control below the waist. Limited vision. Currently uses a wheelchair and a stander.

Heather noted that there are two other students that would potentially be able to use our devices but they were not available for us to observe at that time.

On the tour we were also able to see the specific areas that the cars would be used in. Primarily the cars would be used by children on either of two playgrounds at the school. Some important considerations for the playgrounds is that they do include water play areas, have stairs and metal equipment and are not completely covered. The cars would primarily be used on the playground floor and not near the stairs or the metal structure.

Further, some use would be in the gym which included tile floors and blue raised mats. In this area the students would interact with other students and be encouraged to socialize and design considerations should be made for this type of social environment.

Finally, Heather talked to us about some final design aspects that she would want to ideally see. Her suggestions included the following:

• A component of the car that allowed the children to make simple choices to help with communication
• A door that opened
• Secure harnesses
• Increases in resistance as the muscle develops
• Multiple speed levels
• Removable floor for children with some use of their legs
• Removable handle for a parent
• Velcro on pedals if applicable
• A design that is lightweight

During our research, we found a few sources particularly helpful. Our design is largely based on work done previously by the Go Baby Go foundation operated out of the University of Delaware, and there are specific projects on the mobility devices as they relate to Cerebral Palsy, as found below.

• https://sites.udel.edu/gobabygo/
• http://yourcpf.org/cpproduct/go-baby-go-the-ultimate-toy-hack/

Further, on Thursday we were able to visit the Susan Gray school and directly observe the patients that our devices would be helping. Understanding the purpose of the Susan Gray School and its efforts was vital in our research.

• https://peabody.vanderbilt.edu/admin-offices/sgs/index.php
• https://news.vanderbilt.edu/2014/07/10/susan-gray-school/

Finally, understanding the clinical relevance of our project was important to address the cognitive developmental impairments in children. We referenced the literature to characterize these problems and aid in our design development.

• https://www.tandfonline.com/doi/full/10.1080/10400435.2017.1415575
• https://journals.sagepub.com/doi/abs/10.1177/0956797613479974
• https://www.frontiersin.org/articles/10.3389/frobt.2017.00007/full

This week for our design project, we spoke on the phone with one of the pediatric occupational therapists at the Susan Gray School, Heather Winters. On this call, we spoke about some of the current equipment available at the school. Heather went into depth about which pieces of equipment seemed especially useful for the children, as well as what pieces of equipment they felt could potentially be improved. As for the toy cars, there were many design aspects Heather mentioned that she felt would be useful for both the development of individual children and the range of children for each individual car could be used. Talking to an occupational therapist was extremely helpful, since some of Heather’s design insights were ideas that one without her specific knowledge likely wouldn’t come up with. Some of these examples include a 5-point harness and the ability to tilt the car seat at various angles.

In addition to this, we talked to Dr. Teresa Plummer from the Belmont School of Occupational Therapy about next steps moving forward with the Susan Gray School. She solidified the ideas that we came up with after speaking with Heather and mentioned that moving forward in the Susan Gray school may require some extensive protocols for approval. Luckily, Dr. Plummer has a new graduate student starting at the Susan Gray School in January of next year and if we are able to get a prototype working before then we would be able to work alongside her graduate student in studying the development of children with mobility issues. The paperwork would be accounted for and we would be able to test our design in a controlled environment.

Moving forward, we have established a timeline for some key stage gates moving forward. First we will be visiting the Susan Gray School this upcoming Thursday in order to talk to Heather Winters about the needs of the children as well as seem what kinds of design aspects we feel are most important. Working with the children and observing them in the setting which they would use the mobility devices will help us understand all of the needs of the design. We are then meeting as a group at the Wond’ry to be trained and learn about the manufacturing equipment that we have at our disposal. With the manufacturing capabilities in mind, our designs will be more streamlined and cost effective. Next, we will gather all the information from our conference calls, and visit to the Susan Gray school to develop an extremely well defined set of design requirements. We have set a meeting with our advisor to discuss our progress of these milestones, and set out a productive path moving forward.