The Buzzer Beater (Duke University)

The Buzzer Beater Game Console

Figure 1. The Buzzer Beater

Halsey Friedel, Jordan Cirocco, Sharmila Yadav Palani, and Arlens Zeqollari. 


Our client is a young boy with a mitochondrial disease that limits his motor control and dexterity, preventing him from independently performing essential tasks such as lifting, reaching, and holding. The goal of this project is to design a device that encourages the client to participate in therapeutic recreation to improve arm control and reaction time. The Buzzer Beater is a desktop game console that promotes functional arm movement by incorporating six entertainment features that require specific arm actions, such as pushing, spinning, and pulling, and a bonus basketball shot. Each successful action results in visual and auditory rewards to stimulate the user and promote cause-and-effect recognition. The Buzzer Beater game console provides a safe, effective, and entertaining method for our client to develop the arm control needed for daily tasks.


Our client is a young boy who loves sports and toys that spin. However, he has a mitochondrial disease manifesting as Cerebral Palsy that significantly limits his play. The mitochondrial disease is caused by failure of mitochondria within cells to produce sufficient energy for proper cell function, resulting in cell injury and cell death.  Mitochondrial disease affects various systems in the body, leaving a patient with the disease severely compromised. Between 1,000 and 4,000 children are born each year in the United States with some manifestation of a mitochondrial disease and it can manifest in over 50 different ways.[1] Genetic factors seem to be the largest cause of most mitochondrial diseases, although mtDNA or nDNA mutations can sometimes induce the disease in individuals.[2] However, not all mitochondrial diseases are the same, even if the same mutation occurs, and are sometimes not tissue-specific. In our client this disease manifests with the symptoms of limited arm control, lack of reflex reaction, lack of verbal communication, and restricted extension of elbow.

Currently, the therapists use a toy with spinning blocks to motivate the client to stretch his arms. This toy is limited in that it must be held in different positions to motivate the client to change his direction of arm extension. Additionally, the toy does not enhance his cognitive development, an additional feature the therapists desire during sessions. Therefore, a new therapeutic device that helps the client improve motor control while promoting cognitive development will allow him to become more functionally independent.


Problem Statement

Our goal is to provide a safe and child-friendly device that encourages our client to complete essential daily tasks. This device will provide a therapeutic environment that helps improve his overall cognitive and motor function, as well as his functional independence and understanding of cause and effect relationships.



The original inspiration for this device came from the Bop It electronic game, where one attempts to complete simple tasks at an increasingly rapid pace to achieve a new high score. These simple tasks are perfect for young children, and the responses make the game very exciting. However, to fit the parameters of the client, the game itself had to be expanded and modified.

The most important factors to consider were what functions to include that would be both therapeutically helpful to the client and fun to perform, in addition to ensuring that the client will understand the results of his actions. This process consisted of both performing research on patented devices for children with similar conditions, such as Cerebral Palsy, as well as discussing the client’s interest with his therapist and teacher.

Before we finalized our design, we built an ideological prototype with ten different operations we felt would be useful to the client. After collaborating with the teacher and therapist, we created a final design with the following six tasks: a spinning wheel, a joystick, a pull-down mechanism, a pick up mechanism, a push handle, and a button. In addition to these six functional tasks, the design included a basketball hoop with a chute to return the ball to the user.

We then began development on our first functioning prototype, which afforded us the ability to determine the correct dimensions for our client, and sensors to assess completion of a task. This process consisted of determining the sensing mechanism with the optimal sensitivity and cost for each functional task. Additionally, we restructured our mechanical designs to work more robustly with the electrical components. The end product of this prototype was a wooden structure with the components embedded into the device and external lights that would activate upon completion from the task. Overall, this prototype showed us the need for increased sensitivity and unique reward mechanisms in our final design.

With the functional tasks working, we needed to develop more appropriate reward mechanisms. We discussed the interests of the client with the teacher and therapist and established that the mechanisms need to be multisensory and include the themes of sports and cars.


Front Panel of the Buzzer Beater with all six functional tasks and basketball shot.

Figure 2. Front Panel of the Buzzer Beater


The Back Panel of Buzzer Beater with the chute, LCD screen and keypad

Figure 3. The Back Panel of the Buzzer Beater


Final Design

The Buzzer Beater consists of a console, a basketball bonus shot, six entertainment features, and six reward mechanisms, all of which are explained below.

The Acrylic console houses all of the electrical circuits and sensing mechanisms for each of the entertainment features and response mechanisms. The top panel of the console contains custom cuts based on the dimensions of the individual entertainment features. The top panel also features a track consisting of three wooden blocks bolted to the panel, each covered in rubber padding, which prevents the basketball from falling off the device on a missed bonus shot. Additional rubber padding is secured to the front edge of the console to provide a comfortable armrest while engaging the entertainment features. Two support legs are screwed into the bottom panel to orient the console to allow for full access to the top panel. Within the console is the Arduino microcontroller, which is responsible for sensing the completion of tasks and initiating responses.

The basketball bonus shot consists of a hoop and return chute to enable continuous shooting. The return chute supports an infrared sensor that detects a successfully made basket. The return chute wraps around the back of the device and leads to a PVC cap that catches the ball in front of the user.

“The spin” is a commercial wheel that contains a rare earth magnet to interact with a Hall effect sensor within the console, causing a change in voltage based on the proximity of the magnets. A full revolution of the wheel triggers the reward response.

“The joystick” is a commercial device bolted to the top panel, allowing movement in any direction to trigger a response. The joystick utilizes a series of switches that when pushed in any direction activates a response.

“The pull-down” consists of a curved metal pipe, which houses a rope-spring system connected to a ring. When the ring is pulled, interior magnets produce a magnetic flux change that activates the sensor which translates it into voltage change. The spring allows the system to return to its original state when the ring is disengaged.

“The pick-up” is a hollow metal tube with plastic end caps that fits into two distinct holes in the top panel. When the tube is placed correctly on the capacitive touch sensor it activates the response mechanism.

“The push” consists of a metal handlebar with plastic end caps attached to a PVC shaft anchored within the console. The PVC shaft is attached to a spring that returns the handlebar to the starting position when disengaged. An interior magnet produces a change in voltage when the feature is pushed toward the Hall effect sensor that activates a response.

“The button” is a commercial product attached to the top panel with a screw-in bolt provided. The button utilizes a switch that when pushed activates a response.

The LED strip is a commercial product that has been programmed to produce different colors at the completion of a task. The color is specific for each task.

The rotating cars are commercial products with holes drilled into the bottom and connected to motors. These motors spin when the user completes a task causing the car to rotate for three seconds.

The recording module is a commercial product on which we recorded two child-friendly songs and activates upon completion of a task.

The levitating confetti tube is an enclosed acrylic cylinder with a fan, operated by a motor, and small pieces of confetti. Upon completion of a functional task, the fan activates resulting in the confetti floating into the air within the tubing.




We realized our goal of creating a device targeted at improving our client’s arm extension, as the client showed great enthusiasm while using the device and was sufficiently motivated to successfully perform the different tasks. Though there was an initial learning curve associated with the device, as he would only use the spin and button features independently, with practice our client has shown great strides in arm control and strength. According to his therapists, he has moved on to the basketball and the push features, which have significantly contributed to improving his arm mobility. Cognitively, the audio-visual stimuli are helping him learn the cause and effect relationship of his actions. Other children in his class who have similar motor difficulties have also been benefiting from using the device. This highlights its wide scope of applicability for helping children with similar manifestations of disease.  In addition to its therapeutic application, the device can be used for diagnostic purposes for children exhibiting similar disability in their upper extremities. Traditionally, diagnosing children with motor dysfunction requires multiple hospital visits and the child’s compliance. The closely monitored environment is not conducive to invoke a natural response from the child. Our device could facilitate the child’s play and create a soothing recreational setup for the child to interact with. Further, since our device models on various physical tasks commonly encountered, it has the capacity of functioning as a single test equipment with which to gauge the extent of a child’s disability. Overall, the buzzer beater has shown to help individuals in therapeutic manner.



The overall cost of creating the buzzer beater was $699.17. However, this total number includes prototyping costs ($31.05) and replacement costs ($122.33). This means the overall development of the buzzer beater cost $545.79, with the most expensive components being the acrylic used for construction of the overall structure, and the arduino used to control the overall system.


Future Direction

One potential extension to our device would be to incorporate a guided game play mode, where the user must perform certain actions based on a prompt from the device. This would coincide with a scoring system to track the progress of the user in terms of correctness of performed tasks and speed at which the tasks are performed. Additionally, new measures could be added to quantitatively assess the client’s arm extension. For example, an accelerometer placed at chest level that receives feedback from sensors attached to the client’s hands can help collect data pertaining to the magnitude and directionality of his arm extensions.



We would like to thank Dr. Bohs, Dr. Palmeri, Matt Brown, Steve Earp, and Greg Bumpass of the Duke University Engineering Department, who were integral to us completing our design.

We would also like to thank our teaching assistant, Costi Shami, and our project advisors, Matt Ball, Michael Atkins, and Evan Schwartz, who all offered tremendous support throughout the process.

Finally, we would like to thank Jane Davis and Victoria Guthrie for their patience in working with us and creative ideas they came up with.



[1] “Specializing in Mitochondrial Disease Treatment and Research.” The Mitochondrial and Metabolic Disease Center. <>.

[2] “What is Mitochondrial Disease?” United Mitochondrial Disease Foundation. <>.



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