EXERLEARN BIKE: AN EXERGAMING SYSTEM FOR CHILDREN S EDUCATIONAL AND PHYSICAL WELL-BEING

2012 IEEE International Conference on Multimedia and Expo Workshops EXERLEARN BIKE: AN EXERGAMING SYSTEM FOR CHILDREN S EDUCATIONAL AND PHYSICAL WELL-BEING Rajwa Al-Hrathi, Ali Karime 1, 2, Hussein Al-Osman and Abdulmotaleb El Saddik 1 Multimedia Communication Research Laboratory, University of Ottawa, Canada 2 Division of Engineering, NYUAD, United Arab Emirates {ralha081, akari049, halos072, elsaddik}@ uottawa.ca Abstract Recently, games that incorporate exertion interfaces have emerged and are gaining attention from both academic researchers and commercial companies. Exergaming refers to video games that promote physical activity through playing. Exergames are believed to be a good method of promoting physical activity in children. Such games encourage children to engage in physical activity while enjoying their gaming experience. Nonetheless, we wanted to investigate whether combining exercising and learning modalities could be more beneficial for children's well-being. In this paper, we present our exergaming system called the ExerLearn Bike System, which combines both physical and educational aspects. The ExerLearn Bike System not only engages children in exercising through playing, but also provides them with learning experiences at the same time. We adopted a modular design approach that makes it possible to use any stationary bicycle as an input interface by attaching a number of devices on the bike. Index Terms Exertion user interface, exergaming, serious games 1. INTRODUCTION Physical inactivity and sedentary behavior patterns among children contribute greatly to the prevalence of a wide range of diseases, including obesity, cancer, cardiovascular disease, and diabetes. They are also associated with other important health effects, such as mental health, anxiety, and depression [1][2][3]. Statistics have revealed that obesity is dramatically increasing among children. For instance, the World Health Organization (WHO) [4] reported that the worldwide obesity rate has doubled since 1980 and that approximately 43 million children under the age of five were diagnosed as overweight in 2010. Moreover, the Childhood Obesity Foundation [5] has estimated that more than 26% of Canadian children aged 2 through 17 are currently overweight. This may contribute to type 2 diabetes and high blood pressure in the future based on statements from the Heart and Stroke Foundation of Canada [6], which also reported that encouraging children to be physically active can prevent them from developing such diseases and reduce heart attack risk by 35% to 55%. Researchers have argued that solitary activities, such as playing video games and television viewing, are why children are physically inactive [7][8][9]. The Research Unit in Health and Behavioral Change [10] has pointed out that Canadian children have become addicted to playing video games and that the amount of time they spend engaging in such activity is among the highest in the world. Interestingly, academic studies have recommended promoting health and wellness for children by exposing them to a modified type of video game [11]. Since video games have become a significant and popular mode of entertainment for the younger population, keeping children from such activities is impractical. Instead, it would be highly desirable to exploit the time that children consume playing video games by engaging them in simultaneous physical activity [11][12]. Exergaming is an emerging field that promotes exercising through games by incorporating exertion user interfaces as computer input devices [13]. This new type of interaction has found its way into academic research and commercial companies and has captured the attention of the human-computer interaction community. Exergame was coined from the combination of physical activities and digital gaming; it refers to games that incorporate physical movement as input mechanisms. Exergames can be designed with various objectives and connected with physical, education, and entertainment aspects [14][15]. Exergames can be classified based on their interaction techniques and the input devices used to capture physical movement. Input devices used to interact with video games vary and are not tied to a specific hardware platform. Few studies have been performed to classify exergames so as to understand the differences and similarities among them [16]. It is important to be familiar with all the possible features and hardware elements that can be incorporated into a game s design to determine both its efficiency and the attractiveness of the exertion game. Interaction style is an important feature of exergames, thus marking one difference from traditional input styles such as the keyboard and mouse. Interaction styles are varied and their capabilities are based on the hardware devices used. In [17], the authors defined an exertion interface and proposed taxonomy to distinguish among the existing exergames. Within the study, four categories were presented based on the hardware devices used. Some games used accelerometers to interact with and control the game, such as those for the popular Nintendo Wii [18]. Others used a camera as an input device, such as the PlayStation Eye [19], which captures users movement and position using a computer vision system. In [20], pads with pressure sensors were placed on the floor to sense the user s steps. Exercise equipment, such as the stationary bike, was also used as input devices for PCGameBike [21] games and Fisher Price [22] games, which require users to pedal and steer to control the game. Most exergame designers have focused on incorporating attractive features, paying little attention to the games capability to help children develop cognitive skills and improve their learning process. As a learning objective, a few exergames have provided learning experiences but they have not involved parents or teachers in the design of the children s learning process. Also, with regard to exercise, most exergames only offer new ways to control the games and provide users with entertaining interfaces that are not considered to be true sport alternatives [13]. Moreover, based on 978-0-7695-4729-9/12 $26.00 2012 IEEE DOI 10.1109/ICMEW.2012.91 489

the survey in [16] and [17], available exergames are not modular and have been designed for specific hardware platforms. In this research, we developed an exergaming system for children that differs from the existing systems in the sense that it combines valuable educational aspects, attractive gaming technology, and real physical activity. The game is composed of a stationary bike mounted with appropriate sensors and a number of entertaining software games. We adopted a modular design approach so that any available stationary bike can be used to interact with the system through the handlebars and pedals. The main idea of the game is for children to have fun and learn basic concepts using enticing games with multimedia such as text, sounds, and visual representation and to get effective exercise. The remainder of the paper is organized as follows: Section 2 summarizes closely related studies. In Section 3, we introduce our design of the proposed exergame and explain its features and advantages as compared to related games, while Section 4 presents our implementation and technical details. We examine and evaluate our system in Section 5. Finally, the conclusion and our future vision of the proposed system are provided in Section 6. 2. RELATEDWORKS Equipment-based exergames that use a regular exercise machine as an input device are known to provide a real workout and increase the fitness level of children. Therefore, many exertion systems have been developed based on such equipment, especially the exercise bike [23][24]. Heart Burn [25] is a research prototype game that combines entertainment and physical activity while supporting competition between players. It is a multiplayer exercise game that consists of a stationary bicycle and a wireless game pad connected to a PC. In Heart Burn, players are required to race cars on an onscreen track. They have to reach the end of the track by pedaling the bike and steering with the game pad. The more the players pedal, the faster their cars move. Heart Burn uses real-time heart rate data to determine the game speed and balance game performance to serve different levels of fitness. Frozen Treasure Hunter [26] is another tool that makes use of a stationary bike. The system is composed of a bike, a Wii remote, and Nunchuck controllers that act as input devices to promote physical activity. In this game, two players cooperatively play the game using two different interaction styles. By pedaling a bike and steering via the game pad, the first player controls the movement of the avatar. The second player uses the Wii remote and Nunchuck controllers to swat away harmful snowballs that are thrown at the avatar. Virku [27] is an academic project that integrates exercise features and video game technology. During the project, researchers designed an exergame with a regular fitness bike and 3D virtual environment software for users between the ages of 22 and 41. Players are required to pedal to move through a virtual environment using a stationary bike and handlebars. The software game has different landscapes combined with natural sound effects, such as the sound of birds and the humming noise of the bicycle wheels. The pedaling speed can be increased or decreased based on the game environment. In [28], the authors used a standard commercial CatEye GameBike to develop a modified version that would overcome existing limitations. Since the GameBike heart rate functionality and resistance setting could not be achieved using an external PC interface, the researchers added two connections to Windows PC, one to provide feedback and a second to receive information on the state of the user s heart rate. This modification allowed the control of cycling speed based on the information received. Consequently, the bike became an adaptive version of the regular exergaming bikes. Simple software was developed for evaluation purposes. To achieve a high score, a player must pedal within a specific speed rate range to control a helicopter and collect items along a passageway. The helicopter crashes if the speed rate is not maintained. One limitation of this system, based on the retrieved information, is that the levels of game challenge were not successfully controlled. PCGameBike [21] and Exerbike Pro [29] are commercial exercise bikes that can be used as exertion interfaces with a wide range of PC racing and driving games. They have a customized resistance setting that provides customized resistance based on the player s fitness level. Similar is the GameCycle [30], where players upper body rather than their lower body, is used to control the game. Players are required to pedal using their arms and to tilt the cranks left or right to control game actions. SmartCycle [22] is the most popular educational system commercially produced by FisherPrice. The system targets children between the ages of 3 and 6 and consists of a small stationary bike that can be connected to any TV and a set of software games that enable learning. SmartCycle provides learning, exercise, and entertainment benefits for preschoolers. However, the system is designed exclusively for children aged 3 through 6 and cannot be customized to meet different needs. 3. PROPOSED SYSTEM This section elaborates on the ExerLearn Bike System design by illustrating in detail the hardware components and software modules involved. 3.1 Overview The ExerLearn Bike System is aimed at providing children with educational experience in an enjoyable environment using their physical movement as the system's input mechanism. This is accomplished by encouraging children to interact with the various games by completing a certain number of pedaling cycles to reflect their answers. The system is composed of two customizable edutaining software games that offer different goals and features, plus a set of hardware components. The games are intended to improve and widen children's knowledge in various topics such as mathematics and shapes and to help them strengthen brain memorization capabilities. Two games are incorporated: the Memory Game and the ExerMath game. We adopted a modular hardware design approach by using two sensors that can be mounted on any type of stationary bike without any particular hardware specifications. Knowing that the cognitive and physical abilities of children vary from one to another, we designed the games to be customizable in terms of physical intensity and learning content so that they meet the needs of a wide range of children with various cognitive and physical skills. For instance, parents and teachers can choose the difficulty of math operations in the ExerMath game. On the other hand, they can upload the images of their choice and create their own category sets based on the children s learning levels and needs in the Memory Game. 490

Fig.1. ExerLearn Bike overall system architecture 3.2 System architecture This section provides an overview of the system architecture with the hardware and software modules that comprise the ExerLearn Bike System. Actual prototype implementation and technical details for the ExerLearn Bike System are clarified in Section 4. Figure 1 depicts the overall system architecture, which includes the different hardware components and associated modules. A. Hall-Effect Sensor The Hall-effect sensor is a transducer that varies its output voltage in the presence of a magnetic field within its proximity. We deployed two sensors, one for detecting the number of pedaling cycles in a forward motion and another for reverse. The sensors were positioned on the bike's shroud a few degrees from each other. A circular magnet that produced the required magnetic field was attached to the bike's pedal facing the Hall-effect sensors. This technique enabled us to detect the number of cycles every time the pedal crossed the sensors. A push button that helped in the playing process was mounted on the bike's handlebar. B. Microcontroller Unit The microcontroller unit was used to convert the analog values captured from the sensors and the push button into digital data. In addition, this unit was programmed to translate the raw digital data into a form readable by the game engine module. For example, the microcontroller unit determined the number of cycles by either incrementing or decrementing that number depending on the child's pedaling motion. Moreover, it indicated whether the button was pressed by sending an ON or OFF command to the Game Engine Module. C. The Communication Module The communication module was basically responsible for sending the data from the hardware components to the computer on which the system's software was running. This was accomplished by connecting a Bluetooth chip to the hardware circuitry and a Bluetooth dongle to the computer. D. Game Engine Module After receiving the necessary information from the microcontroller unit, the game engine module translated the data into actions and displayed the customized games based on the user adjustments and actions. The microcontroller unit consisted of two modules that worked together to provide children with personalized games that matched their physical and mental abilities. E. Media Controller Unit This module allowed guardians to choose different types of media to be displayed for a particular child, based on the child s needs. The games were designed with optional media features from which to choose, including text, audio, and visual representation. F. Learning Module The learning module is the most important module in the ExerLearn Bike System; this is the module in which guardians can specify their educational objectives. This module allows guardians to upload their desired learning content either from a personal repository or from a Web service for use in educating children during play. In addition, guardians can customize the difficulty levels of the games. For instance, for the Memory Game, they could increase or decrease the number of cycles required to reveal a picture. 491

G. Graphical User interface The games user interfaces were carefully designed so that users with basic computer skills could easily grasp the functionalities of the system. The games were designed with clear instructions, easy navigation, and cheerful presentation. H. Web Service Layer A mechanism based on Web services was applied to present teachers/guardians and parents with an instrument to remotely monitor data pertaining to a child s exergaming sessions. Every time a child, whether at school or at home, performed one of the exercises, the results of the session were automatically uploaded to a central server. Using a Web interface, parents and teachers/guardians could track the performance of a child regardless of whether the exercises were performed at home or at school. The Memory Game was designed to improve many aspects of children s brains, including focus, attention, and memory. It is a novel game that combines learning features to teach children about new objects and vocabulary. Just like traditional memory games, the participant is required to find matching pairs of pictures. However, since we used a bicycle, we introduced new rules for the game. As we did not make use of a mouse or other traditional input device, the pictures included in the game could be revealed by pedaling a predefined number of times. The number of pedaling cycles required to reveal a picture could be established by a guardian. For instance, we used three cycles per picture in our evaluation. 4. IMPLEMENTATION The hardware unit of the ExerLearn Bike System was implemented using two Parallax Melexis 90217 Hall-effect sensors, an Arduino microcontroller, and a push button. We chose the Hall-effect sensor due to its small size, weight, and price. We considered the push button's bouncing effect by properly filtering the signal glitches received by the microcontroller. For wireless communication, we deployed a BlueSmirf Gold Bluetooth chip transmitting at a Baud rate of 9600 Kb/s. On the software side, the Memory Game and the ExerMath game were developed using Visual Studio 2010 (VB) on a Windows 7 platform. We used the Microsoft Speech Engine's API for verbal spellings and feedback messages. 5. EVALUATION In this section, we report our assessment of children using the ExerLearn Bike System through quantitative and qualitative evaluations. We mainly focused on two aspects: the attractiveness and effectiveness aspects of the exergame inspired by the dual flow model [24] combined with the educational experience: 1. Effectiveness: We concentrated on whether the ExerLearn Bike System could engage children in physical activity and provide them with the recommended exercise intensity level. 2. Attractiveness: We examined whether the ExerLearn Bike System was entertaining for children to perform and whether it could motivate them to learn. The software games designed for the ExerLearn Bike System varied in their goals and the physical intensity required. They consisted of two games: ExerMath and the Memory Game. In the ExerMath game shown in Figure 2, children could sharpen their math skills by answering random questions. The system default presented 10 random questions per session, varying from simple to difficult. To answer these questions, the child had to perform a number of pedaling cycles that equaled the correct answer. For instance, to answer the addition question of 1+3, the child had to perform 4 pedaling cycles. Each cycle was accompanied by verbal spelling and visual presentation of the number. Fig.2. The memory game and the ExerMath User Interfaces In this case, each time the child pedaled four cycles, the next picture was revealed and the previous one hidden. If the participant realized that he/she had previously seen a particular picture, he/she could press the push button to hold the displayed picture and go back over the previous pictures to look for its match. Once the match was found, the participant could hold the match by pressing again on the button. Each picture revealed was associated with its written and verbal presentation, as shown in Figure 2. A. Experimental set up We conducted our experiments at the Multimedia Communication Research Laboratory (MCRLAB). We mounted our hardware on an exercise bike that was positioned in front of a 60-inch TV screen connected to a laptop on which all the required software was installed. B. Participants We conducted our evaluations with 8 children (5 boys, 3 girls) between the ages of 7 and 13 years. All the children who participated in the evaluation were healthy and had no history of heart problems. Before we began our evaluations, we showed the participants a number of demonstrations that explained the overall theme of the games. In addition, we measured the heart rate of each participant at rest ( HR rest ) for later use in our analysis. 492

Table 1. Participants resting and imum heart rates per minute. Participants Age Gender HR rest HR P 1 10 M 86 200 P 2 11 M 90 199 P 3 7 M 81 202 P 4 12 M 89 198.8 P 5 12 F 90 198.8 P 6 13 M 79 198 P 7 9 F 91 201 P 8 12 F 90 199 Table 2. A comparison between participants heart rates during the memory game session and the THR. ID P1 P2 P3 P4 P5 P6 P7 P8 HR child 158 147 128 153 134 153 154 151 50 143 145 141 144 143 139 146 145 THR Zone % 60 % 172 156 154 155 155 150 157 155 C. Quantitative evaluation To evaluate the effectiveness of the ExerLearn Bike System, we wanted to determine the energy expenditure during the gameplay session. We chose the heart rate (HR) as a metric because it is widely considered as a reasonable way to measure the physical effort level due to the correlation between heartbeats and exercise intensity. For this purpose, each child was strapped with a Polar Wear link heart rate transmitter over his/her chest prior to each session. To establish the target heart rate (THR) that each participant should achieve, we used the Karvonen method [30] based on Equation 1: THR = ) + ( HR HRrest Intensity HR rest (1) Here, HRrest is the heart rate of the participant at rest, Intensity is a level that ranges between 50% and 60%, and HR is the imum heart rate that a participant can achieve at a time [32]. It is worth noting that a participant might never achieve HR since this an approximation found using Equation 2: HR = 206.9 (0.67 Age) (2) Table 1 reveals the calculated HR and the measured HR rest of each of the children. The THR was calculated (see Table 2) based on a 50% to 60% physical intensity level, which is considered to be the light to medium exercise intensity level recommended for children s daily routines [33]. D. Results Table 2 reveals the results at the end of the 8 sessions. HR represents the average heart rate each child achieved child during the evaluation session. The THR zone shows the lower 50% and the higher 60% range of physical intensity, depending on the HR previously calculated. As can be seen from Table 2 and Figure 3, the Memory Game increased the children s HR with an average of 60%. Six participants actually achieved a heart rate value that fell within the calculated range. On the other hand, the heart rates of the other two Fig.3. A comparison between children HR at rest and during playing participants (P 3 and P 5) were lower than expected. However, the reason might be related to the level of difficulty of the participant s session or the size of the bike. E. Qualitative evaluation To evaluate the attractiveness and the quality of experience of the system, we asked each child to fill out a simple questionnaire distributed at the end of the evaluation sessions. The questionnaire contained 6 questions, as follows: Q1: Is it fun to play with the ExerLearn Bike System? Q2: How do you feel about controlling the game using the exercise bike? Q3: Was the ExerLearn Bike System easy to play with? Q4: Were you able to focus on the game while exercising? Q5: How was the cycling? Q6: Would you recommend the games to your friends? Almost all of the participants agreed that the games were fun to play and asked to play them again. Seven participants found it easy to control the games. Participant P 3, a girl, responded to the second question by saying that it is a good way to answer questions while getting some exercise instead of writing the answer because a lot of children like to ride bikes. So, this activity makes children enjoy doing math and learning. All of the participants found it easy to play with the system except the youngest child, who said that it was a bit difficult. Six participants answered Q4 with yes and two of them with sometimes. Seven children had a positive feeling while cycling and said that they got good exercise during the play session. Responding to Q6, five children would recommend the Memory Game to their friends in school. 493

Fig.4. A girl playing ExerLearn Bike system Based on our observations, the children were happy and capable of performing the physical movements easily while responding to the game s tasks, as shown in Figure 4. Parents who attended the evaluation sessions with their children were asked to upload the desired categories of pictures using the customized panel. For example, P 3 s mother chose the shapes category and uploaded pictures using the Web service. When we asked her opinion of the game, she reported, It is useful to use the game to introduce new stuff to the child for first time and added that reading the written word and listening to its pronunciation twice while looking at the object picture allows the child to memorize it easily. Another mother expressed her admiration of allowing the children to personalize the content and adjust the game settings. 6. CONCLUSION In this paper, we have presented an exergaming system for children that uses a stationary bike as an input device. The proposed system promotes both education and gaming through physical activity. One of the essential features that the system incorporates is customization. This is because the learning requirements of children might differ from one to another. The results obtained from the evaluation sessions have demonstrated that the ExerLearn Bike System promotes physical activity in children and can provide them with the exercise intensity level that is recommended for their daily exercise. Our future work will include improving the system to an adaptive version by adding new features, such as the ability to control the intensity of the exercise based on heart rate level. In addition, we plan to incorporate multilingual features into the system to enhance children s education. Finally, we would like to add special features for children with special needs to accommodate some types of disability. REFERENCES [1] T. Tanha, P. Wollmer, O. Thorsson, M. K. Karlsson, C. Lindén, L. B. Andersen, and M. 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