Squid: Exercise Effectiveness and. Muscular Activation Tracking

Transcription

1 1 Squid: Exercise Effectiveness and Muscular Activation Tracking Design Team Trevor Lorden, Adam Morgan, Kyle Peters, Joseph Sheehan, Thomas Wilbur Interactive Media Alexandra Aas, Alexandra Moran, Amy Schaeffer Design Advisors Prof. Constantinos Mavroidis, PhD, Mark Sivak Abstract The rise of mobile media is changing the way people interact with each other and the world. The team is particularly interested in its potential applications as a physical fitness tool. Smartphone products geared towards training in the endurance exercises (e.g. running and cycling) have been enormously popular; the run tracking application Nike+ alone has grown to a user base of 1.2 million runners. The success of these products is due to the fact that they offer 3 major benefits to users: (1) motivation, (2) convenience, and (3) social connection. With the aim of providing these benefits, the team has designed a system geared specifically towards weightlifting; the 2 nd most popular mode of exercise in the United States. Strategically placed EMG (electromyography) sensors embedded on a compression shirt will monitor a user s muscle activation during a weightlifting regiment. Real-time biofeedback from a Smartphone application will optimize the effectiveness of workouts. All workouts will be stored on a web database that allows for the integration of a goal-reward structure, providing motivation and tracking progress over time.

2 2 The Need for Project There is an opportunity for Smartphone integration in the weightlifting field. The increasing popularity of Smartphones has provided an accessible avenue towards monitoring one s physical activity. Using wearable sensors along with a Smartphone interface, can further enhance an individual s ability to set goals, track progress, evaluate performance, and optimize the effectiveness of their exercise routine. A product targeted toward the 45.5 million American health club members offering these benefits has the potential to experience similar successes to those demonstrated by the integration of Smartphone technology and endurance training. Figure 1: Wahoo Fitness Run Pack The Design Project Objectives and Requirements The objective of this design project is to create a low cost, home-based, sensorized device with Smartphone integration to monitor weightlifting, provide real-time feedback, and track progress. Objectives The main objective of this project is to create a sensorized apparatus integrated with a Smartphone to record and transmit physical fitness data. Using a web-based platform, this data can be accessed and reviewed via the internet by users and fitness professionals. To be viable, this product must promote convenience and motivation for users. In large degree, sensorized monitoring of physical fitness has been restricted to clinical settings, where high-cost, tethered systems are the norm. This design aims for a conveniently portable, low-cost system capable of collecting and analyzing similar data. Design Requirements To determine design requirements, experts in the field including personal trainers, athletic trainers and exercise physiologists were consulted. These experts considered an ability to provide the user with real-time biofeedback to be the most important characteristic of the design. Biofeedback is the main function of a personal trainer; it ensures that exercises are performed properly and with maximum effectiveness. A design providing this feedback helps the user improve their exercise performance and efficiency. Additionally, the design must be portable, unobtrusive, untethered, have a 4+ hour battery life, and provide reliable data.

3 3 Design Concepts considered Four design concepts were During brainstorming sessions, 4 concepts were generated that would initially considered; one concept satisfy the team s design requirements: (1) The form tracker is a formfitting garment sensorized with embedded inertial measurement units in particular best fulfilled design requirements. (IMUs). An IMU is able to track acceleration, position, and rotation in 3 axes. Placing these IMUs at key locations on the body would allow for monitoring of the user s motion and speed. This data is used to track form and rhythm, ensuring exercises are performed properly. (2) The muscle activation tracker is similarly a form-fitting garment. Instead of embedded IMUs, electromyography sensors (EMGs) are placed on key muscles. EMG sensors monitor muscle activation which is directly related to muscle recruitment and exercise effectiveness. Feedback from Figure 2: Smart Gym Concept this data can encourage users to engage in greater muscle activation, providing motivation and increasing workout efficiency. (3) The team tracker also is based on a sensorized garment. The design measures heart rate and sweat loss of athletes during practice sessions. Athletic trainers can use this information to monitor and evaluate workout intensity levels and ensure proper hydration among all of athletes. (4) Finally, a smart gym concept departs from user-wearable sensors, Figure 3: Muscle Activation instead placing them on gym equipment. IMUs embedded in weights Tracker and machines are coupled with wireless data transmission activated by a Smartphone scan. This allows for tracking of weights, repetitions, and pace. The partnered Smartphone application can be used to track workout programs and progress over time. Recommended Design Concept Design Description A compression shirt will be In a design analysis, the muscle activation tracker concept was equipped with embedded EMG selected as the most viable. Muscle activation is monitored by the use of electrodes to measure muscular EMG electrodes placed on targeted muscle groups, measuring voltage activation, vibrators to provide across muscle fibers. A proof of concept prototype will focus on the tactile biofeedback, and a heart upper body only. Holes cut into a compression shirt allow for direct rate monitor to track exertion. A electrode skin-contact and ensure repeatable sensor placement on 3 microcontroller will interface these major muscle groups in the upper body; the pectoralis majors (chest), sensors with a Smartphone medial deltoids (shoulders), and latissimus dorsi (back). Electrode application specially designed to placement was determined in conjunction with an exercise physiologist. track and interpret this data over 2 electrodes are required per muscle for a differential voltage

4 4 time. Figure 4: EMG Patches Figure 5: Raw EMG Signal Figure 6: Clean EMG Signal Figure 7: Polar OEM Heart Rate Monitor measurement, totaling 12 electrodes to monitor the 6 target muscles. Patches have been designed to attach to the shirt over the holes guiding proper sensor placement by the user. The patches attach to embedded wires on the shirt, which carry the raw signal to filtering circuits. A microcontroller transmits filtered EMG data and data from a heart rate monitor to a Smartphone. The microcontroller also controls vibrators that are embedded in the shirt over each muscle to provide real-time tactile feedback. A specially designed Smartphone application records the data and transmits it to a website where the user will be able to view past workouts and track their progress over time. Analytical Investigations Analyzing and understanding the characteristics of a raw EMG signal produced by muscle contraction is critical to the design. For the team s purposes the raw EMG signal must be converted into a signal envelope for easy measurement. This conversion is achieved by a combination of filtering and amplification circuitry. Overall, the voltage signal must be amplified by a factor of about 500 and filtered so that only voltage changes from muscle contractions are measured. Individual filtering circuits for each muscle feature adjustable amplification so that meaningful data can be collected from all target muscles. Experimental Investigations Placement of the EMG sensors is important for collecting reliable, repeatable data. Positioning and acceptable placement error for sensors on target muscles has been determined by testing performed at the Clinical Exercise Physiology Laboratory of Northeastern University using a traditional tethered EMG machine. Subsystem testing of filtering and microcontroller circuitry has also been successfully performed; collecting single-muscle data during sample exercises. Future experimental investigations will be performed to confirm sensor placement repeatability and demonstrate full-system integration of the design. Key Advantages of Recommended Concept Typically, EMG measurements are performed only in clinical settings using expensive, tethered machines. As a result, the average gym user has been unable to achieve benefits associated with real-time tracking of muscle activation. With this device, users can increase their exercise performance and effectiveness, conveniently track progress over time, and benefit from the motivation provided by goal setting

5 5 features and social connections. Software Created for Concept The Interactive Media team developed a Smartphone application and corresponding website to track and store exercise data. The application walks the user through the workout, monitoring exercise, repetitions, and heart rate. The data will initially be stored on the phone; however, after the workout it will be to the website. The website indexes data by date so users can access data from both individual workouts and the long term. Workouts can also be created and an interactive goal-reward structure provides additional motivation. In the future users will be able to interact will each other to share workout routines, goals, progress, and Figure 8: Smartphone Application Financial Issues encouragement. The current cost of the prototype is The initial prototype cost for this device is about $340. This cost can about $340; cost reducing be reduced significantly by simplification and miniaturization of measures could result in an end microcontroller and filtering circuitry, which currently make up the product marketable well over majority of the prototype cost. With additional cost reductions, the team $100. anticipates the final cost of the product to be roughly $100. Given the price range for less-capable available products, the final market price of the product could range much higher than $100. The product will be geared towards an athletic male seeking to further enhance their gym experience. On top of that, this product can also be marketed towards high-level athletic teams that wish to track the physical activity of their players. Recommended Improvements Key design improvements include targeting more muscles for activation tracking and reducing cost through hardware simplification and miniaturization. Recommended design improvements focus on the inclusion of a greater number of muscles to be tracked for activation. The same data acquisition techniques can be applied to the other muscles of the upper body as well as the lower body muscles. Ideally, this type of system could track muscular activation for all muscles targeted by an exercise routine. Cost reductions are also a main focus for improvement to ensure that this product is marketable to the everyday user; these efforts will center on simplifying and miniaturizing microcontroller and filtering circuitry. In the future, more sophisticated processing software may be developed to eliminate the need for some of the design s filtering and amplification hardware.