Developers: Amy Cheng and Alex Guevara
Supervising Professor: Kevin Caves
ABSTRACT
Children with disabilities are often unable to participate in classroom art activities due to the barriers that typical classroom equipment pose. This project was intended to facilitate art engagement in a pre-kindergarten classroom in downtown Durham. The final device is a fully adjustable and portable easel that provides sensory feedback when a student is drawing on it. The classroom teacher and physical therapist have expressed great enthusiasm about the product and suggested it is capable of engaging every student in the classroom.
INTRODUCTION AND BACKGROUND
Cerebral palsy (CP) is a group of neurological disorders that impair body movement and muscle tone. The subtypes of CP are classified by limbs affected and muscle state [1]. Our client has spastic quadriplegic cerebral palsy – meaning the muscles in her limbs and head are stiff and lack fine motor control. She has patterned movements that affect her ability to move, grasp, and reach. Her therapists also suspect that she has some vision impairment.
PROJECT GOALSOur client is currently enrolled in pre-kindergarten at a local school. Her classroom is designated as special needs and serves 6 children with a variety of physical and cognitive disabilities. The teacher and physical therapist (PT) have noted that the client is not currently motivated to participate in classroom art activities. Art is critical for early life education, as it provides a means of visual communication preceding writing. It builds the fine motor skills required for many functions in our modern world [2]. However, while enjoying other classroom activities, our client is not motivated to do art. Currently, the classroom is equipped with a stand-alone easel along a wall (Fig. 1) and a chair with an angle-adjustable tray (Fig. 2). The client is unable to use the standalone easel due to the angle. Sitting in her wheelchair, her torso is too far from the drawing surface. The chair with the adjustable tray is more ergonomic, but the PT has expressed concerns that the client’s limited head control prevents her from looking down at the drawing surface. The two largest physical barriers to her art engagement are (1) placement of drawing surface and (2) drawing utensil grip. Currently, the client’s occupational therapist (OT) is working with her to provide solutions for the latter. Beyond these barriers, the client’s teacher and PT believe that she requires supplementary sensory feedback from art activities in the form of sound and lights. By addressing the physical limitations and coupling those solutions with sensory “rewards,” they hope to facilitate art engagement for both the client and any future children in the classroom.
The objective of this project is to develop a system that will allow for and encourage children in this pre-K classroom to engage in art activities. Our client will be used as the model; to expand the system to multiple children, it will have to adapt to differing sizes and geometries while addressing placement of drawing surface. In addition, it will have to provide a variety of sensory stimuli to effectively reinforce art engagement. Our client is highly motivated by colorful lights and music, so our final design should incorporate these elements. The system will have to be stored in a busy classroom, so it should require minimal setup and supervision.
DESIGN AND DEVELOPMENT
Overall: The Sensory Studio consists of an adjustable mount connected to a wooden frame fitted with electronics. The mount provides customizable angles in all directions and can be used in space-limited areas of the classroom. The frame and polycarbonate surface are the interface at which the client interacts with the device. On the back of the box are two 3D printed housings, one for an AC to DC power supply, and another for a custom printed circuit board (PCB) and Arduino Uno. In order to use the Sensory Studio, one must use a writing utensil with one of the included magnetic grips. The device must also be used on wall power.
Board: The board is a “shadow box” built from several pine 2x3s glued together and nailed to a plywood backing (dimensions in Fig. 2). These boards have a 1/8”-wide dado cut to fit a polycarbonate sheet. Polycarbonate is a clear and strong plastic that will facilitate visual feedback without the risk of fracturing. Within the box there are 4 Hall Effect sensors [4], a Dexter Industries mini speaker [5], and 4 WS2812 LED light strips [6]. The Hall Effect sensors detect user interaction and the speaker and light strips provide audio and localized visual feedback behind the polycarbonate. The sensory feedback is modeled after current practices in the classroom but are integrated into an automated system to reduce teacher intervention. These are intended to motivate the user’s consistent engagement with the Sensory Studio.Mount: The Sensory Studio is composed of a VIVO Single Monitor Desk Mount [3] attached to a wooden frame containing mounted electronics. This assembly is shown in Fig. 3 before electronics are placed on it. The VIVO mount uses a “C-style” clamp to attach to tables and surfaces of varying widths. The metal arm of the VIVO mount can be lowered, bent, and rotated around the main pole. Resistance is variable at most attachments using an included 6mm Allen key. The board is mounted to a 4” metal plate on the back that allows for rotation and tilting of the interactive surface. This mount makes the device accessible to different users with varying wheelchair and stander configurations. This plate is fastened to the board with 4 lock nuts and is not intended to be removed or replaced.
Electronics: Attached to these electronics, on the back, is a 3D-printed housing holding an Arduino Uno microprocessor [7], a PCB, and a DFPlayer MP3 Player Shield [8]. The Arduino takes real-time data from the Hall Effect sensors, processes the information, and drives the appropriate audio and visual feedback. The MP3 shield interfaces with the Arduino Uno and is required to play mp3 files on a microSD card. The shield outputs to the mini speaker.
All electronics use a shared AC to DC power supply [9] that is also mounted on the back of the board and plugs into a wall outlet. This power supply outputs 5V DC and 12A max, which is more than sufficient for the power consumption of the Sensory Studio.
Grips: Separate from this entire assembly is a set of 3 3D-printed grips, each custom printed for the most common utensil sizes in the classroom. Embedded in each grip are 24 grade-52 Neodymium magnets (10mm x 2mm) [10]. The function of the grip is to produce a magnetic field that, when close enough, triggers a Hall Effect sensor to output a digital signal. Users must fit a provided grip to their writing utensil and interact with the board surface in order to activate the Sensory Studio and receive sensory feedback.
EVALUATION
The device was evaluated for several performance criteria including: simple assembly, stability, ability to generate visual and auditory feedback, and angle adjustability. Verification and validation were assessed for each design specification.
The final device is easy to set up (defined as <10 minutes by no more than two people). This criterion is significant because the classroom staff are extremely busy and cannot afford to expend extra time on a labor-intensive assembly. Ease of assembly was verified by timing a peer in the lab, and then validated by surveying the client post-testing. In verification testing, the user who had never been exposed to the device was instructed in assembly, and then timed without supervision. The user clamped the mount, powered it, placed a grip on a marker, and was able to use the device within 5 minutes. In validation testing, the classroom staff rated all fields at least a 4 out of 5 (passing by our criteria).
Next, we wanted to show the device to be stably mounted, or able to support an 11lb load. Stability and safety are significant in this project, as falling items could pose a hazard to students using the device. Stability of the mounting system was verified by bench testing with a 11lb load in the lab, and validated by soliciting client feedback in a survey. In verification testing, the device was able to support the 11lb load without any obvious buckling or excessive stresses. In validation testing, the classroom staff rated all fields 5 out of 5 (passing by our criteria).
The device’s ability to provide stimulating visual and audio feedback was assessed on a user-defined scale and also additional client feedback via survey. Verification was performed by confirming that able-bodied peers could see and hear the feedback. In validation, the user-defined scale when testing with one student was: visual feedback 4/4, while the user-defined scale for audio feedback was a 3/4. A 3 or higher is considered passing on that scale. In addition, the classroom staff rated the feedback as 5/5 in all aspects.
The final product has been shown to satisfy all performance criteria in both verification and validation. The evaluation of the device is described in further detail in Appendix C.
DISCUSSION AND CONCLUSIONS
The components of our device come together to produce an engaging and accessible easel that fully complies with all design constraints and criteria. Altogether, we chose pieces that provide maximal angle and height adjustability, tailored sensory feedback, and feasible portability and size for a classroom setting. This design provides our client with an innovative teaching tool that overcomes many of the issues of the preexisting classroom easel and trays. Upon delivery for final testing, the device energized all of her students to participate in art activities. The final price of the device’s parts came to approximately $175, which fell within our budget of $300 and is reasonable given the unmet need and the impact that our device has on the students. The design is easily customizable to an end user’s preferences for colors, light patterns, and audio clips. Throughout the design process, we observed that students in the vicinity of the device were soothed and/or distracted from destructive behavior, even though they were not directly using it. The classroom staff and therapists expressed enthusiasm about the device’s potential to increase art engagement in the classroom and develop cognitive and motor acuity.
ACKNOWLEDGEMENTS
Thank you to the Duke University BME Department, who afforded us the opportunities to pursue this project.
Thank you Professor Kevin Caves, for your time and effort spent in teaching and guiding us.
Thank you Matt Brown, for your time and effort in helping our project come to life.
Thank you Anastacia Newton and Barbara Tapper, for your feedback and encouragement.
CONTACT INFORMATION
For any questions, comments, or concerns, please contact:
Amy Cheng
5346 Woodlot Road
Columbia, MD 21044
(410)-497-2434