Elements of a Real-Time Vital Signs Monitoring System for Players during a Football Game Shinsuke Hara (1) , TetsuoTsujioka (1) , Takunori Shimazaki (1) , Kouhei Tezuka (1) , Masayuki Ichikawa (1) , Masato Ariga (1) , Hajime Nakamura (2) , Takashi Kawabata (3) , Kenji Watanabe (4) , Masanao Ise (4) , Noa Arime (4) , and Hiroyuki Okuhata (4) (1) Graduate School of Engineering, Osaka City University, E-mail: {hara@, tsujioka@, shimazaki@c., tezuka@c., ichikawa@c., ariga@c.}info.eng.osaka-cu.ac.jp (2) Graduate School of Medicine, Osaka City University, E-mail: nhajime@med.osaka-cu.ac.jp (3) School of Health and Well-being, Kansai University, E-mail: takakaw@kansai-u.ac.jp (4) Synthesis Corporation, E-mail: {watanabe, ise, arime, okuhata}@synthsis.co.jp Abstract—We have developed a real-time vital signs monitoring system for two years in 2012 and 2013. Just by putting a single vital sensor node to the back waist position of each player and placing four data collection nodes around a field, the system can monitor at a note PC heart rate (HR), energy expenditure (EE) and body temperature (BT) for all players during a football game in real-time, periodically and reliably. The system is based on novel vital sensing technique and wireless data transmission technique. This paper introduces the two techniques in the system, presents some problems encountered in the system development and discusses solutions for them. Keywords—vital signs; real-time monitoring; sensing technique; wireless data transmission technique I. INTRODUCTION From the view-points of sport physiology and healthcare, it is important to monitor in real-time vital signs such as heart rate (HR), energy expenditure (EE) and body temperature (BT) for athletes in training. For example, the Karvonen formula gives adequate HR for athlete during training [1]: adequate EE depends on the age, weight and sex of athlete: BT should be below 37 o C before training and cannot go beyond 40 o C even during training. In this way, for effective training and injury/disease prevention, real-time HR, EE and BT monitoring is essential, and training based on feeling, experience and intuition has been gone; now it is the time of training based on scientific evidence using vital data. However, it has been common that data are once stored in the memory of vital sensor put to each athlete during training, and after training, by checking the log, a coach or trainer can understand the today’s physical condition of the athlete. This is useful only for scheduling tomorrow’s training menu. If real- time vital signs collection and analysis is possible in a field, the coach or trainer can adaptively control today’s training menu personalized for each athlete in a field by feed-backing his real- time vital data. On the other hand, an unhappy incident happened in Japan in 2011 that Naoki Matsuda, a former defender of Japanese national football team, collapsed during training due to a cardiac arrest after finishing a 15-minute warmup run, and two days later he died at the age of 34 [2]. The main reason of disturbing real-time vital signs collection and monitoring from athletes during training is the lack of adequate vital sensing technique and wireless data transmission technique. First, training is hostile to sensing of vital signs. To sense a vital sign, we need to put a sensor close to a body and keep the sensing condition and environment stable. However, the motion of athlete during training makes the condition and environment unstable. Furthermore, a vital sign has an adequate position to be sensed. For instance, HR sensor should be put closer to the heart, and tri-accelerometer should be put to the lower part of body. However, putting several vital sensors to different positions of body is prohibitive. Second, training is also hostile to wireless transmission of vital data. During training, athletes spread in a large field, randomly in one time and with a coordinated mobility in another time. The unlicensed 2.4GHz industrial scientific and medical (ISM) band is now commonly used in various wireless applications over the world. However, the wireless signal of typical data transmission tools in the frequency band has a relatively short transmittable range and is easily blocked by an obstacle such as another athlete. We have developed a vital signs monitoring system for two years in 2012 and 2013 [3-7]. It can collect and monitor vital signs such as HR, EE and BT from all (twenty two) players during a football game in real-time, periodically and reliably. The reason of selecting football game is that the condition and environment are very hostile to vital signs sensing and wireless data transmission; many vital sensor wearers (footballers) spread in a large field and take vigorous exercises such as running, sprint, jumping, tackling and sliding. In this paper, we introduce the system based on novel vital sensing and wireless data transmission techniques and show the results obtained in in-house experiments and field experiments. We have solved a lot of problems encountered in the experiments and have selected best-suited techniques. However, unfortunately, several problems have remained unsolved. In this paper, we mention some unsolved problems and discuss promising solutions for them. This paper is organized as follows. Section II explains the elements of the developed systems. Section III presents the developed vital signs sensing technique, and Section IV presents the developed wireless data transmission technique. 2014 IEEE 16th International Conference on e-Health Networking, Applications and Services (Healthcom) 978-1-4799-6644-8/14/$31.00 ©2014 IEEE 384