BACKGROUND AND PURPOSE
Breathing exercises are used extensively within a range of patient populations for prophylactic care and treatment of respiratory complications. Incentive spirometry (IS) offers visual feedback for patients while performing breathing exercises. Incentive spirometry is a widely used, accepted technique for the prevention and treatment of respiratory complications in a range of patient populations, including postoperative, spinal cord injury,1,2 chronic obstructive pulmonary disease,3 and cystic fibrosis.4 However, several publications have questioned the effectiveness of IS and its use is a topic of much debate in the clinical setting and in the literature.5-13 Evidence supporting the use of breathing exercises and IS is controversial due to varied methodologies and treatment protocols.13 One major difficulty with assessing the efficiency of this type of exercise program is patient adherence.14-18 Specific levels of adherence with IS exercise programs have not been reported; however, poor patient adherence with exercise programs and home-based tasks is a widely accepted issue in physical therapy. In their review of studies using IS, Overend et al13 and Guimaraes et al14 discussed the potential confounding outcomes that could result from the lack of measurement of patient adherence. The lack of consistent findings within IS outcome studies could be the result of poor patient adherence, lack of treatment consistency, poor patient performance, or the reliance on subjective recordings of treatment sessions.
Video games are becoming widely used across the general population. More than 65% of all households play computer or video games.19 The use of computer and video games for health education, assessment, and treatment has rapidly become a focus within the academic and clinical areas of psychology and physical and occupational therapy. Video and computer games can allow for consistent delivery of treatment procedures that can also be modulated in a specific rule-based fashion dependent on the dynamic changes that occur in the patient's performance in real time as well as across treatment sessions. This form of consistent, yet adaptive task delivery can target rehabilitation within relevant and engaging contexts. Video games allow for the creation of computer-generated 2D or 3D simulations, in which hierarchical task-relevant challenges can be delivered and titrated across a range of difficulty levels.19 In this way, a patient's plan of care can be customized to begin at a challenge level that is attainable and comfortable for them, and then proceed with a gradual progression of challenge that is determined by the patient's performance in real time. Furthermore, game-based environments allow for the presentation of more interesting and motivating stimuli. By designing video game environments that stimulate interest and focus attention on a task, patients might be more likely to perform exercises in situations where pain and/or boredom may inhibit treatment adherence. Video game technology also supports precise and detailed capture and analysis of user responses for tracking progress and improvement within and between sessions, a valuable feature for patients and therapists.
The use of a video game for breathing exercises has a number of potential benefits. Video games can provide therapists and patients with an individualized and easily altered level of challenge. Patients might be unlikely to perform breathing exercises if they are too difficult or alternatively, if they are not challenging enough. Patients may be more likely to perform exercises if the level of challenge was accommodated to their individual needs. Video games have the potential to motivate patients to perform and maintain adherence with exercise programs. Patients might be unlikely to perform breathing exercises due to pain, lack of motivation, or poor understanding of the task. A video game could help focus the patient's attention on the game-related task, rather than the “chore” of performing the breathing exercises. Furthermore, patients and therapists can monitor progress and adherence through the quantitative data gathered and stored during game play. The time, date, session length, and performance metrics can be recorded and saved to track progress and adherence, allowing patients and therapists to monitor the exercise program and visualize changes. This provides researchers and therapists with the tools to measure adherence, reducing the unknown variable of patient adherence as a potential confounder in treatment outcomes. Access to session data can be used to set therapy goals, demonstrate improvement over time, and provide patient education regarding respiratory exercise and care.
METHOD DESCRIPTION AND EVALUATION
Informal interviews were performed with physical therapists, occupational therapists, researchers, and key patient populations to explore the need for, and determine key development features of, a computer-based game for breathing exercises. All stakeholder groups supported the concept and provided specific needs and requirements, including the option to change the level of air inspiration or expiration for different patients, the ability to record data from the interaction, and a motivating and fun game that encourages the accurate execution of a range of different breathing patterns. A focus group was undertaken with a sample of 10 participants with spinal cord injury. The group was asked to discuss their experiences with breathing exercises. The majority of participants described breathing exercises as boring and many described maintaining a regular exercise regime as difficult because they could not motivate themselves to do the exercises unless they were experiencing respiratory complications. The game concept was then described and the group provided input on the use of a game as part of a breathing exercise regime and gave specific input on the game ideas themselves. The group agreed that the use of a game where they could collect points and save scores would be more interesting than existing breathing exercise tasks. The group agreed on the following requirements for a successful computer-based breathing exercise program: an easy installation process, the ability to save software on individual's personal computer, only basic computer knowledge needed to install or use the program, and the game would be fun to use. The group agreed that they did not need the games to be realistic, provided they were not condescending or attempting to hide or reduce the focus on the breathing mechanic. Scoring, leader boards, and the ability to track progress were important system features.
The development of an interface that would allow breathing as a method of controlling a video game was the first crucial step in the process of developing a game to motivate breathing exercises. A spirometer is an apparatus for measuring the volume of air inspired and expired by the lungs. The spirometer records the amount of air and the rate of air that is breathed in and out over a specified time. Incentive spirometry is designed to mimic natural sighing or yawning by encouraging the patient to take long, slow, deep breaths.20 The IS device (Figure 1) provides patients with visual feedback when they inhale at a predetermined flow rate or volume and sustain the inflation for a predetermined period. The objectives of this procedure are to increase transpulmonary pressure and inspiratory volumes, improve inspiratory muscle performance, and re-establish or simulate the normal pattern of pulmonary hyperinflation.21-23 A number of electronic spirometry devices were explored for use prior to the decision upon the current input device. The current input device uses airflow measured from a spirometer and the Vernier LabPro® system to interact with the computer-based video game environment. The spirometer records the amount of air and the rate of air that is breathed in and out over a specified time. When attached to the spirometer, the LabPro system can be used to measure the airflow from the spirometer and present the data in graphical format on a computer screen. The prototype interaction device developed for this project was programmed to use the airflow measured from a spirometer via a LabPro system as an input device to interact with games developed using Microsoft's XNA Game Studio in C# programming language. Using the spirometer as the input device eliminates the need for a keyboard or joystick; instead, the user breathes through the spirometer device in order to control tasks within the game environment.
Iterative Design Process
The iterative game design process was used to develop the game content. Iterative design is a process-based design research methodology24,25 in which designers create and test games in various basic forms prior to completing a full prototype. The designers become participants in order to critique their designs and the game play mechanics. Within these procedures of investigation and experimentation, a special form of research takes place: “The process of iteration, of design through play, is a way of discovering the answers to questions you didn't even know were there. And that makes it a powerful and important form of design research.”24(p19)
The first step in the process is brainstorming. Brainstorming for game development involves defining the problem.25 Once the initial brainstorming is completed, the next session involves critically discussing and refining the ideas.25 The process is repeated (brainstorming, expanding, and refining) until the team agrees upon the most appropriate idea. This is the idea that can be prototyped and further explored.
Rapid prototyping of game mechanics and core game play concepts can be performed in 2 ways: using physical props or using software.25 Regardless of the format, rapid prototyping provides the designers and the player with the ability to play the game in a simplified form in order to determine: (1) if the rules make sense and hold up during play, (2) if the game mechanics work, (3) how scoring works, and (4) if the game will be enjoyable to play.
Fullerton et al25 suggest a range of levels of playtest participants. Designers should perform the initial playtests to determine if the first prototype works the way they anticipated. Following the initial playtest and redesign stage, peers are suggested as the second level of playtest participants. Once the game is playable with a clearly defined set of rules and refined game play mechanics, the game should be playtested by participants from the target audience for the game.
During the playtests, the researchers follow a script in order to allow the playtester to play without receiving too much information about the game.25 Playtesters are encouraged to talk aloud as they play. Following completion of the playtest, the playtesters are asked to complete a series of questionnaires, and the researchers ask a series of open-ended questions about specific aspects of the game. Both quantitative and qualitative measures are recorded during the playtests. Overall, the iterative design process involves cycles of design, prototyping, and playtesting to develop and evaluate the key components of play prior to beginning the actual software development. Once playtesting and prototyping cycles are completed, the game can be developed in the intended format and evaluated in a larger trial to determine: (1) if the game is fun, (2) if the graphics are appropriate and entertaining, (3) if the game is still engaging, and perhaps most importantly, (4) if the game performs the required therapy goals. The game development has followed this process, and is currently being playtested by users from the intended audience.
To date, 6 basic game prototypes have been developed for initial playtesting and user feedback. A method was developed to provide the therapist with control over the settings of the game in order to individualize treatment goals and level of challenge. Once the spirometer device is connected to the computer, the therapist or user can open a program that allows for individual calibration and storage of individualized data for use within the game. The user interface is simple and easy to use. Once opened, the screen displays a white background with a red line visualizing inspiration and expiration using the device. The user is instructed to perform the appropriate breathing pattern (eg, 1 deep breath, followed by 3 relaxed breaths; or 2 quick breaths in, followed by a hold and a breath out). Once completed, the breathing pattern is labeled and the user is prompted to confirm and save the output (Figure 2). When starting the game, the user is prompted to select the appropriate breath file (labeled with a unique patient number identifier). The game uses the selected data file as the threshold level for game play. The time, date, session length, and game performance metrics can be recorded and saved at the end of each session. The performance data from the spirometer is saved during each session; however, reliability testing of this data is still required before it can be used to compare lung function between sessions. However, within-session performance is tracked and saved in a file.
The 6 game prototypes were developed by graduate students of electrical engineering and computer science as part of a semester-long research class. The students were involved in expanding the game concept, designing the interaction, programming the games, and integrating the hardware interface.
Frog Jump. The game requires the user to control a frog with their breath. By breathing in, the user can control the length of the frog's jump. If the user's inspiration is performed at the correct rate and depth, the frog will gradually increase in size and change color. The change in color provides a visual cue to the user to breath out. Upon expiration, the frog will jump forward. If the user does not perform a deep enough breath in, or if the breath is taken too slowly, the frog will not increase in size and will not change color. If the user takes a breath that is too fast or too deep, based on individual user settings, the frog will change color to red and do a small vertical jump in the air without moving forward.
Bird's Journey. The game requires the user to control a flying bird using their breath. The bird must be maneuvered to follow a series of targets. When the user breathes in, the bird will fly higher. When the user breathes out, the bird will fly lower, enabling the user to collect items. The targets were placed along a curve to provide a clear visual indication of the pace and depth of the breathing. The pace of the game is set to music.
Tank Targets. The game requires the user to control a plane using their breath. The plane must be maneuvered over a landscape. When the user breathes in, the plane flies higher, enabling the user to collect tokens. When the user breathes out, the plane flies lower, and attacks tanks traveling along a road.
Fish Feeding. The game requires the user to control the release of fish food with their breath. Fish are arranged in a fish tank, moving around the tank at various speeds and patterns. Fish food moves across the top of the tank on a conveyer belt. The user can control the release of fish food using their breath. Upon inspiration, the conveyor belt stops. Upon expiration, the food will drop into the tank.
River Crossing. The game requires the user to control the character, a camel, with their breath. The goal of this game is to help the camel cross the river. Logs float across the river, between the 2 riverbanks (Figure 3). When the user breathes in, the camel jumps onto a log. If the user's breath is too deep, the camel will overshoot the log. If the user's breath is too shallow, the camel will not reach the log. When the camel does not reach the log, it splashes into the water and the game returns the camel back to the riverbank. This game was developed to encourage breath stacking, therefore, the breathing pattern is 2 inspirations followed by expiration, or 3 consecutive inspirations followed by expiration. The number of logs in the river can be set before starting the game to reflect the required breathing pattern.
Magic Carpet. The game requires the user to control a magic carpet with their breath. The user must breathe in to fly over buildings and breathe out to fly under bridges (Figures 4 and 5). If the user's breath is too shallow, the magic carpet will hover in front of the building.
The game prototypes have undergone a series of iterative playtesting and refinement cycles. Initial iterative playtesting series with a sample of 19 healthy participants indicated that the game play and interaction were intuitive and players found the spirometry device easy to use. Users liked the feel and responsiveness of the controller. The controller was intuitive and fun to use, and game play was satisfying. Some initial issues identified by playtesters were the use of ambiguous in structions and directions. The development of clearer instructions or visual demonstrations was suggested. The addition of a more goal-oriented task was suggested, along with clearer instruction as to the pattern of breathing required. Seven users suggested the use of music to provide a beat or tempo to guide the pace of breathing. Nine users suggested the use of different collectable targets and more feedback on correct and incorrect breathing patterns. Revisions were made to the game play based on the feedback from the playtesting session.
The most recent round of playtesting was performed on the River Crossing and Magic Carpet games. Six therapists and 6 patients with prior experience in using IS playtested the games. All participants played the River Crossing game. Three therapists and 2 patients also played the Magic Carpet game. Participants were asked open-ended questions about look and feel of the game and the potential use of the game to perform breathing exercises. Therapists and patients agreed that the games were fun to play, visually interesting, and provided useful visual and auditory feedback of results. The use of individualized files for game play difficulty was described as a unique asset of the games, allowing the user to work at their own level of challenge. Two therapists suggested other breathing exercises that would be useful for their patients. These exercises, along with suggestions from the participants about visual assets, feedback, and game play, will be incorporated into the next version of the games.
Maintaining adherence with breathing exercises can be a matter of life and death. The proper use of IS can have an impact on lung function following disease or surgery, however, the impact is directly related to adherence. Measuring adherence is difficult and often not reported directly in the literature.13,14 Since IS is low cost and it is often performed without the supervision of a practicing clinician, having a clinician supervise all IS activity to ensure adherence would be cost prohibitive. The development of a motivating, cost-saving, objective-reporting, and adherence-regulating IS device will help to ensure objective health outcomes after disease or surgery affecting lung function.
The individuals surveyed for this preliminary study indicate that they would enjoy using such a device, and the clinicians indicate that they can see the potential clinical benefit from such a device. The device and breathing program that we intend to develop further includes the spirometry device, which can be purchased for $295.00, and $3.00 for an attachable bacterial filter. We foresee that each patient using their own device while in the hospital, and depending on the objective data delivered from the device, a unit could be rented for home use. However, if the device indicates low adherence or typical lung function, a device for home would be unnecessary. Other devices and techniques to incorporate respiratory muscle strengthening are currently being explored. Furthermore, we intend to design more breathing games to ensure interest over time. Games will be developed in which the clinician will have more complete control over game parameters. Once refined, the device will be assessed for effectiveness in improving patient adherence and reducing pulmonary complications compared to standard treatment techniques for a range of patient populations (eg, postoperative, spinal cord injury, chronic obstructive pulmonary disease, cystic fibrosis). The first 2 studies will focus on postoperative in-patients following surgery and patients with spinal cord injury as part of a home-based exercise routine.
The integration of medical devices with video game technologies offers great potential to improve assessment, and to collect objective data regarding patient adherence and lung function. The implementation of existing game-design models and user-centered iterative design offers a platform for the development of game-based rehabilitation tools.
The authors would like to thank individuals with spinal cord injury for their generosity of time and feedback; clinicians at Precision Rehabilitation in Long Beach, CA, for their important feedback regarding clinical use; and graduate students Chao Wang, Qijun (Sophia) Guo, Ajit Singh Sirohi, Wenli Huang, Jingming Huang, Jasmeet Singh and Hao Tan for their hard work in the prototype development. This research was partially funded from a Gaming and Computer Science Grant from Microsoft Research.
1. Reines D, Harris R. Pulmonary Complications of Acute Spinal Cord Injuries. Neurosurgery
2. Derrickson J, Ciesla N, Simpson N, Cristina IP. A comparison of two breathing exercise programs for patients with quadriplegia. Phys Ther
3. Scherer T, Spengler C, Owassapian D, Imhof E, Boutellier URS. Respiratary muscle endurance training in chronic obstructive pulmonary disease. Am J Respir Crit Care Med
4. Hall JC, Harris J, Tarala R, Tapper J, Christiansen K. Incentive spirometry versus routine chest physiotherapy for prevention of pulmonary complications after abdominal surgery. Lancet
5. Jenkins SC, Soutar SA, Loukota JM, Johnson LC, Moxham J. Physiotherapy after coronary artery surgery: are breathing exercises necessary? Thorax
6. Chuter TM, Weissman C, Mathews DM, Starker PM. Diaphragmatic breathing maneuvers and movement of the diaphragm after cholecystectomy. Chest
7. Matte P, Jacquet L, Van Dyck V, Goenen M. Effects of conventional physiotherapy, continuous positive airway pressure and non-invasive ventilatory support with bilevel positive airway pressure after coronary artery bypass grafting. Acta Anaesthesiologica Scandinavica.
8. Oikkonen M, Karjalainen K, Kahara V, Kuosa R, Schavikin L. Comparison of incentive spirometry and intermittent positive pressure breathing after coronary artery bypass graft. Chest.
9. Dull JL, Dull Wl. Are maximal inspiratory breathing exercises or incentive spirometry better than early mobilization after cardiopulmonary bypass? Phys Ther
10. Gale GD, Sanders DE. Incentive spirometry: its value after cardiac surgery. Can Anaesth Soc J.
11. Oulton JL, Hobbs GM, Hicken P. Incentive breathing devices and chest physiotherapy: a controlled therapy. Can J Surg.
12. Stock MC, Dows JB, Cooper RB, Lebenson IM, Cleveland J, Weaver DE. Comparison of continuous positive airway pressure, incentive spirometry, and conservative therapy after cardiac operations. Crit Care Med
13. Overend TJ, Anderson CM, Lucy SD, Bhatia C, Jonsson BI, Timmermans C. The effect of incentive spirometry on postoperative pulmonary complications: a systematic review. Chest
. 2001;120: 971-978.
14. Guimaraes MM, El Dib R, Smith AF, Matos D. Insentive spirometry for prevention of postoperative pulmonary complications in upper abdominal surgey. Chochrane Database Syst Rev
. 2009;8(3): CD006058. BMC Public HealthJ Cystic FibrosisClin Rehabil. OnlineFirst.Respir Med
19. Rizzo AA, Schultheis M, Kerns KA, Mateer C. Analysis of Assets for Virtual Reality Applications in Neuropsychology. Neuropsychological Rehabil
20. Scuderi J, Olsen GN. Respiratory therapy in the management of postoperative complications. Respir Care
21. illing L, Bakow E, Fink J, Kelly C, Sobush D, Southorn PA. AARC (American Association for Respiratory Care) clinical practice guideline. Incentive spirometry. Respir Care.
22. Darin J. Effectiveness of hyperinflation therapies for the prevention and treatment of postoperative atelectasis. Curr Rev Respir Ther.
23. Jenkins SC, Soutar SA, Loukota JM, Johnson LC, Moxham J. A comparison of breathing exercises, incentive spirometry andmobilization after coronary artery surgery. Physiotherapy Theory Pract.
24. Salen K, Zimmerman E. Rules of Play: Game Design Fundamentals.
Cambridge, MA: The MIT Press; 2004.
25. Fullerton T, Swain C, Hoffman S. Game Design Workshop: Designing, Prototyping, and Playtesting Games.
San Francisco, CA: CMP Books; 2004.