Smart Wearable:
Let’s Think Wearable from a New Perspective
Saul Emanuel Delabrida Silva
Ouro Preto
Março de 2018
Saul Emanuel Delabrida Silva
Universidade Federal de Ouro Preto
Tese submetida ao Instituto de Ciˆencias Exatas e Biol´ogicas da Universidade Federal de Ouro Preto como requisito parcial para obten¸c˜ao do t´ıtulo de Doutor em Ciˆencia da Computa¸c˜ao Orientador: Dr. Ricardo Augusto Rabelo Oliveira Ouro Preto, 13 de Mar¸co de 2018
Catalogação: www.sisbin.ufop.br
D331s Delabrida Silva, Saul Emanuel.
Smart Wearable [manuscrito]: let\'s think wearable from a new perspective / Saul Emanuel Delabrida Silva. - 2018.
104f.: il.: grafs; tabs.
Orientador: Prof. Dr. Ricardo Augusto Oliveira Rabelo.
Tese (Doutorado) - Universidade Federal de Ouro Preto. Instituto de Ciências Exatas e Biológicas. Departamento de Computação. Programa de Pós-Graduação em Ciência da Computação.
Área de Concentração: Ciência da Computação.
1. Wearable Computing. 2. Smart Wearable. 3. Wearable Accessory. 4. Passive Sensor Board (PSB). 5. Intelligent Sensor Board (ISB). I. Rabelo, Ricardo Augusto Oliveira. II. Universidade Federal de Ouro Preto. III. Titulo. CDU: 004
This work is dedicated to:
Members of my family who understood my busy days. In particular, my wife and my parents.
The Professors Ricardo Rabelo, Antonio Loureiro, Bruce Thomas and Mark
Billinghurst for having patience with me and give me directions to conclude this work. The colleagues who spent some precious time and weekends contributing to the
development. In particular, Thiago D’Angelo.
To my friends who made my adaptation in Australia easier. There are too many people to cite here...
All persons who imposed barriers and make this work harder. I became stronger learning with you. There are too many people to cite here...
To Helena, my daughter, who will be born after my defense. You encouraged me to conclude this phase of my life...
Smart Wearable: Let’s Think Wearable from a New
Perspective
Abstract
Wearable computing is considered the next big thing. The market represents billions of dollars of investments. Samsung, Google, and other companies aggregate part of this market with the release of new gadgets such as smartwatches and smartglasses. Other startups emerged in the last years and made available devices such as Fitbit and ReconJet. On the other hand, users are losing the interest on wearable devices due to the low quality of applications and the restricted value offered by them. We did a study about the role of wearable devices and its integration. In our findings, the dependency and low processing capabilities of the devices contribute to the scenario. The goal of this work is to introduce a new way to build and design wearable devices and systems. We propose the definition of the terms “Wearable Accessory” and “Smart Wearable” as a new classification of wearable devices, systems, and applications. Our characterization was done by the development of two smart wearable devices. In our methodology, we demonstrate the design until the user experience evaluation to build these devices. Our findings consider some current limitation of these devices and users expectations. Two applications addressed to the ecological scenarios are the secondary contribution of this work. Also, challenges and future work to improve the proposed concept and user experience with wearable devices are discussed.
Declara¸
c˜
ao
Esta tese ´e resultado de meu pr´oprio trabalho, exceto onde referˆencia expl´ıcita ´e feita ao trabalho de outros, e n˜ao foi submetida para outra defesa nesta nem em outra uni-versidade.
Parte deste trabalho j´a foi publicado e este texto ´e uma composi¸c˜ao adaptada de artigos publicados pelo autor. Abaixo listo a rela¸c˜ao de cada artigo publicado at´e a data desta defesa e o conte´udo relacionado a este documento:
• DELABRIDA, SAUL; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A.R. ; LOUREIRO, ANTONIO A.F. . Building Wearables for Geology. Operating Systems Review, v. 50, p. 31-45, 2016.. Os Cap´ıtulos 2 e 3 cont´em trechos deste artigo.
• DELABRIDA, S.; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A. RABELO ; LOUREIRO, A. A. F. . Wearable HUD for Ecological Field Research Applications. Journal on Special Topics in Mobile Networks and Applications, v. 21, p. 1-11, 2016. Os Cap´ıtulos 2 e 3 cont´em texto deste artigo.
• DELABRIDA, SAUL; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A. RABELO. Fast prototyping of an AR HUD based on Google Card-board API. In: the 2015 ACM International Joint Conference, 2015, Osaka. Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers - UbiComp ’15. New York: ACM Press, 2015. p. 1303-1306. Os Cap´ıtulos 2 e 3 cont´em trechos deste artigo.
Computing Systems Engineering, 2015, Foz do Iguacu. V Brazilian Symposium on Computing Systems Engineering, 2015. Os Cap´ıtulos 2 e 3 cont´em trechos deste artigo.
• DELABRIDA, SAUL; BILLINGHURST, MARK ; THOMAS, BRUCE H. ; RABELO, RICARDO A. R. ; RIBEIRO, S´ERVIO P. . Design of a wearable system for 3D data acquisition and reconstruction for tree climbers. In: SIGGRAPH Asia 2017 Mobile Graphics & Interactive Applications, 2017, Bangkok. SIGGRAPH Asia 2017 Mobile Graphics & Interactive Applications on - SA ’17, 2017. p. 1. O Cap´ıtulo 4 cont´em trechos deste artigo.
Saul Emanuel Delabrida Silva
Agradecimentos
Agrade¸co `a UFOP e colegas do Departamento de Computa¸c˜ao pela confian¸ca e lib-era¸c˜ao para capacita¸c˜ao e conclus˜ao deste trabalho.
Agrade¸co `a agencia de fomento CAPES pela oportunidade de desenvolver parte deste trabalho na Austr´alia.
Agrade¸co ao ITV pelo apoio financeiro essencial para do desenvolvimento de parte deste projeto.
Agrade¸co aos professores e t´ecnicos do PPGCC UFOP.
I would like thanks the University of South Australia (UniSA) for my acceptance as a visiting student researcher. I would like to extend this to the UniSA staff who help me on this process (Bruce Thomas by providing the necessary documents, Emily Sellar, Sarah and Linda Burlison for helping me in the visa process).
Aos meus colegas do laborat´orio iMobilis, na UFOP.
To my colleagues from the Wearable Computer and Empathic Computing Labs, in UniSA.
Muito Obrigado! Thank you so much!
Contents
List of Figures xix
List of Tables xxi
Nomenclature xxv
1 Introduction 1
1.1 Research Scope and Goals . . . 3
1.2 Methodology . . . 3
1.3 Contributions . . . 4
1.3.1 Publications . . . 6
1.4 Text Organization . . . 7
2 Wearable Computing 9 2.1 Usual Wearable Architectures . . . 9
2.2 Wearable Communications Architecture . . . 11
2.3 Wearable Operating Systems . . . 12
2.3.1 The Role of Wearable Operating Systems . . . 18
2.3.2 Wearable OS vs. IoT OS . . . 19
2.4 Wearable Market and User Adoption . . . 22
2.7 Smart Wearable Definition . . . 28
2.8 Wearable Accessory X SmartWearable . . . 29
2.9 Concluding Remarks and Lessons Learned . . . 31
3 First Case Study - Smartwearable as an Input Device 33 3.1 Wearable For Geologist . . . 33
3.1.1 HMD Physical Structure Development . . . 35
3.1.2 Passive Sensors Board . . . 36
3.1.3 Intelligent Sensor Board . . . 39
3.1.4 User Interface Module . . . 42
3.1.5 Wearable Components Integration . . . 43
3.2 Wearable Evaluation and OS Events . . . 44
3.2.1 Algorithm Evaluation . . . 45
3.2.2 Operating System Events . . . 48
3.2.3 ISP and PSB Energy Consumption . . . 51
3.2.4 Smartphone HMD Evaluation . . . 53
3.2.5 User Interface Discussion . . . 56
3.3 Final Prototype . . . 56
3.4 This Smart Wearable Requirements . . . 58
3.5 Lessons Learned, Limitations, Challenges and Further Directions . . . 58
3.5.1 Prototype Limitations and Further Development Directions . . . . 58
3.5.2 Challenges . . . 59
4 Second Case Study- Smartwearable as an Output Device 61
4.1 Wearable for Biologist . . . 62
4.1.1 The Role of Leaf Density Identification . . . 63
4.1.2 Tree Climbing Techniques . . . 63
4.1.3 Virtual Cylinder . . . 64
4.1.4 How is the Data Collected Today? . . . 65
4.2 Wearable Devices for Climbing . . . 67
4.3 System Requirements . . . 68
4.4 Platform Description . . . 69
4.4.1 Environment Collector Description . . . 70
4.4.2 Environment Reconstructor Description . . . 71
4.5 Prototype Description . . . 71
4.5.1 Environment Collector . . . 72
4.5.2 Environment Reconstructor . . . 73
4.6 User Study Assessment . . . 77
4.6.1 Experimental Setup . . . 77
4.6.2 System Features . . . 78
4.6.3 Users’ Profile . . . 78
4.6.4 Users’ Task Performing . . . 79
4.6.5 Users’ Perception . . . 83
4.6.6 Specialist Opinion . . . 84
4.7 This Smart Wearable Requirements . . . 85
4.8 Limitation and Discussions . . . 86
4.8.1 3D Scanning Process . . . 86
4.8.2 Crowd and Collaborative Platform . . . 87
4.8.3 The use of 3D Scanning for Academic Purposes . . . 88
4.8.6 Real Time 3D Streaming . . . 89 4.9 Lessons Learned, Challenges and Further Directions for this Prototype . 89 4.10 Smart Wearable Lessons Learned . . . 90
5 Conclusion and Future Work 93
5.1 Closing Remarks . . . 93 5.2 The Future of Smart Wearable . . . 95 5.3 Other Wearable Challenges . . . 96
Bibliography 97
List of Figures
1.1 Research Methodology . . . 4
2.1 Architecture Level 1 . . . 10
2.2 Architecture Level 2 . . . 11
2.3 Architecture Level 3 . . . 11
2.4 Wearable Market in Billion of dollars. . . 23
2.5 Wearable Interest. . . 25
2.6 Users’ Expectation. . . 26
3.1 Example of Image taken by Geologists . . . 34
3.2 Final HMD Physical Structure Design in Autodesk 123D . . . 36
3.3 HMD Internal View (on left) and HUD Front View (on right) . . . 37
3.4 PSB Architecture . . . 37
3.5 PSB Cascade . . . 38
3.6 Station Board for Passive Sensors . . . 39
3.7 Algorithm Stages . . . 40
3.8 AR Cardboard Application . . . 42
3.9 System Architecture . . . 43
3.10 Hits Percentage per Second . . . 46
3.13 Smartphone Battery Discharge Time . . . 54
3.14 Final Prototype Front and Side View . . . 57
3.15 Final Prototype Back View . . . 57
4.1 Climbing Tree Measurements . . . 64
4.2 Climber Counting Leaves . . . 65
4.3 System Overview . . . 70 4.4 HMD Scanning . . . 73 4.5 Tree Example . . . 75 4.6 Virtual Cylinder . . . 75 4.7 Intersection . . . 75 4.8 Final Result . . . 75
4.9 3D Model Reconstruction Steps . . . 75
4.10 Tagged Leaf . . . 76
4.11 Tagged Leaf After Rotation . . . 76
4.12 Leaves Counted by User on Each Scene . . . 79
4.13 Time Spent by Number of Leaves . . . 82
4.14 Users’ Feelings . . . 83
4.15 Users’ Feelings . . . 84
4.16 Users’ Condition Preference . . . 85
4.17 A low Quality Scan Example . . . 87
List of Tables
2.1 Wearable Operating Systems . . . 21
2.2 Comparison Between Categories . . . 30
3.1 CPU Performance . . . 48
3.2 Platforms Events . . . 49
3.3 Experiments Configuration . . . 54
4.1 Measurement Activities . . . 66
4.2 System Requirements and User Perspective . . . 69
4.3 Two-way ANOVA: Factors Tag x Plants - Leaves Counted . . . 80
4.4 Two-way ANOVA: Factors Counter x Plants - Leaves Counted . . . 81
4.5 Two-way ANOVA: Factors Tag x Plants - Time Spent . . . 81
4.6 Two-way ANOVA: Factors Counter x Plants - Time Spent . . . 82
“Seja vocˆe quem for, seja qual for a posi¸c˜ao social que vocˆe tenha na vida, a mais alta ou a mais baixa, tenha sempre como meta muita for¸ca, muita determina¸c˜ao e sempre
fa¸ca tudo com muito amor e com muita f´e em Deus, que um dia vocˆe chega l´a. De alguma maneira vocˆe chega l´a.”
— Ayrton Senna
Nomenclature
AD Analog Digital
API Application Programming Interface AR Augmented Reality
CAD Computer Aided Design DIP Digital Image Processing DoF Degrees of Freedom HMD Head Mounted Display HMI Human Machine Interface HSL Hue, Saturation, Lightness ISB Intelligent Sensor Board OS Operating System PSB Passive Sensor Board
RTOS Real Time Operating System UI User Interface
VC Virtual Cylinder VR Virtual Reality
Chapter 1
Introduction
Wearable computing emerged as a new age of technology in the last years. Thousands of gadgets are released to end users. Smartwatch, Head Mounted Displays (HMDs) are the most popular devices that, usually, play a role of the tool for safety, health and sports applications.
Wearable computing concept has been discussed since 1980’s but gained evidence in the last years due to the release of smartwatches and smartglasses and the advance of technology of hardware miniaturization. The promising wearable market has projections of billions of dollars in the next years. On the other side, users’ expectations have not been met by the current wearable gadgets available.
Some statistics show that most smartwatches’ users lose the interest on their devices after 2 or 3 months. Smartglasses are still not attracting costumers. Users who are mon-itoring their heartbeat want to know a more specialized information. For instance, they desire to receive information about the cardiac risks based on their routines activities instead of the heart frequency. Smartwatches’ users do not see the real value of these devices due to their concerns about privacy and the low quality of applications of these devices.
Wearable devices are considered as accessories or complementary equipment. We attribute this due to two main reasons. First, the current shape of the most common wearable computers available to users (such as bracelets, glasses, watches, and others) are classified as accessories. Second, most equipment are dependent on other platforms, such smartphones or cloud interfaces for data processing. The massive number of de-vices have the function to collect data from user’s body or work as an alternative tool
to smartphones to access e-mail and other functionalities provided by them. Due to this fact, most wearables have the smartphones as a type of base station for data col-lection. Moreover, this dependency leads the engineers to design low power processing capabilities devices. Battery consumption is another reason that contributes to this scenario.
The research question raised on this work is:
How to develop more intelligent wearable computing based on user’s expectations? This research project introduces the terms “Wearable Accessory” and “Smart Wear-able” as a new way to design and categorize wearable devices and wearable systems.
• Wearable Accessory is a device which works for data collection and exhibition. Usually, it can be dependent of other platforms to run their task.
• Smart wearable are devices or a set of devices working together in order to play a specific application.
• A smart wearable system is an on-body system that can be composed of one or more wearable connected or not to other legacy platforms. It can also be composed of wearable accessories.
We believe that this classification can improve the user experience and the wearable development.
The proposal is based on a literature review about wearable devices and how they are designed regarding hardware and software properties. A classification of the main architectures found in the literature was defined, as well as, the requirements for classi-fication of devices into the categories “Wearable Accessory” and “Smart Wearable”. We choose an experimental methodology to evidence the proposed concepts developing and evaluating two smart wearable devices.
After the development of each prototype, we discussed the lessons learned, challenges and further directions the concept, as well as, some specific challenges of each case study.
Introduction 3
1.1
Research Scope and Goals
To formalize the definition of “Wearable Accessories” and “Smart Wearable” and intro-duce and the requirements of a smart wearable device and smart wearable system. The goal of this research is present the concept based on lessons learned by the development of smart wearables. The secondary goals of this research are:
• To develop smart wearable devices as proof-of-the-concept • To create alternatives to design flexible smart wearable devices • To present challenges and future works related to this new concept.
The scientific contribution of this work is the discussion and definition of a new way to classify wearable as smart wearable and wearable devices. Also, this thesis demonstrates our methodology to build smart wearable devices.
Next section describes the methodology for this project development.
1.2
Methodology
This section shows the methodology used for this project development. Figure 1.1 summarizes the development stages. Each stage is described below:
Bibliography and Research review: is a continuous stage of the study of the state-of-the-art. This was the first stage, but it was done during in all next stages. The results of this review is described on the Chapters 2, 3 and 4.
Problem statement: In this stage was done a study of wearable acceptance by the users, discussion of the proposed concept. The results are described in the Chapter 2.
Terms Review: Describes the concepts and lessons learned regarding smart wear-able and wearwear-able accessories. Most of the results are described on Chapter 2.
Requirements for Smart Wearable: Describes the requirements of smart wear-ables for the prototyping. The results are described on Chapter 2.
Smart Wearable Prototyping: This stage describes two smart wearables devel-oped as the proof-of-the-concept of smart wearables. We defined the cases study into
Figure 1.1: Research Methodology
two classes. First, we developed a smart wearable as an input device and the second as a user interaction interface. This decision was made to split the problems into two small problems. We also decided to make both cases related to the ecology scenario to show the case studies that can be done with Internet connection limitation. The first prototype is described on Chapter 3 and the second one in the Chapter 4.
Discussion, Conclusion and Addressed Challenges: We described and dis-cussed the lessons learned, challenges and conclusions of this work. The results are introduced in Chapters 3, 4 and 5.
1.3
Contributions
Introduction 5
In the wearable context:
• A review of the main HW/OS architectures used to build wearable systems: A study and classification of wearable architectures is presented in this work. This classification provides information about when an operating system is used or not for building wearable devices and shows many case studies. This study was done in order to understand the different ways to create wearable devices and give directions for wearable developers. The lessons learned and findings were the baseline to define the smart wearable concept.
• A survey of available wearable operating systems and their features: Af-ter understanding the scenarios where Operating Systems are adequate to build a wearable, a review of the main wearable operating systems available in the market was presented. In this discussion, the real-time and User Interface (UI) character-istics of wearable devices were shown. In fact, both charactercharacter-istics are mutually exclusive considering the current technology available today. In our discussion, we present the challenge to provide Operating Systems which can balance the real-time and UI interface without providing negative influences on the application. • A discussion and presentation of some challenges addressed by the
com-munity about the wearable appliances and wearable accessories: A discus-sion and questions about the role of wearable accessories and wearable appliances are presented. The goal is to understand the impact of the use of the operating systems to provide this feature.
• A methodology for building and evaluating smart wearable appliances: A set of steps for building and evaluating a wearable appliance is presented based on the experiences in the development of a wearable device.
• Two cases studies of the creation of smart wearables: An input prototype was developed using a case study of a geologist. The first case study presents an assessment of the energy consumption of different wearable’s configurations is presented. Also, the impact of a digital image processing algorithm impact on the operating system was done. A second case study is focused to create a support tool for biologists. These cases studies can be used as an example and benchmark for the development of new smart wearables.
1.3.1
Publications
Up to date, this thesis resulted in 6 published papers.
• DELABRIDA, SAUL; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A.R. ; LOUREIRO, ANTONIO A.F. . Building Wearables for Geology. Operating Sys-tems Review, v. 50, p. 31-45, 2016.
• DELABRIDA, S.; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A. RABELO ; LOUREIRO, A. A. F. . Wearable HUD for Ecological Field Research Applications. Journal on Special Topics in Mobile Networks and Applications, v. 21, p. 1-11, 2016.
• DELABRIDA, SAUL; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A. RA-BELO . Fast prototyping of an AR HUD based on Google Cardboard API. In: the 2015 ACM International Joint Conference, 2015, Osaka. Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers - UbiComp ’15. New York: ACM Press, 2015. p. 1303-1306.
• DELABRIDA, S.; OLIVEIRA, RICARDO AUGUSTO RABELO ; D’ANGELO, THIAGO ; LOUREIRO, A. A. F. . Towards to a Wearable Device for Monitoring Ecological Environments. In: V Brazilian Symposium on Computing Systems Engineering, 2015, Foz do Iguacu. V Brazilian Symposium on Computing Systems Engineering, 2015.
• DELABRIDA, SAUL; LOUREIRO, ANTONIO A. F. ; D’ANGELO, THIAGO ; OLIVEIRA, RICARDO A. RABELO ; THOMAS, BRUCE ; CARVALHO, ED-SON ; BILLINGHURST, MARK . A Low Cost Optical See-Through HMD - Do-It-Yourself. In: 2016 IEEE International Symposium on Mixed and Augmented Reality, 2016, Merida. 2016 IEEE International Symposium on Mixed and Aug-mented Reality (ISMAR-Adjunct), 2016. p. 252.
• DELABRIDA, SAUL; BILLINGHURST, MARK ; THOMAS, BRUCE H. ; RA-BELO, RICARDO A. R. ; RIBEIRO, S´ERVIO P. . Design of a wearable system for 3D data acquisition and reconstruction for tree climbers. In: SIGGRAPH Asia 2017 Mobile Graphics & Interactive Applications, 2017, Bangkok. SIGGRAPH Asia 2017 Mobile Graphics & Interactive Applications on - SA ’17, 2017. p. 1.
Introduction 7
Also, a book was edited and published related to wearable applications: DELABRIDA SILVA, SAUL EMANUEL; Oliveira, Ricardo A. R. ; LOUREIRO, A. A. F. . Examining Developments and Applications of Wearable Devices in Modern Society. 1. ed. IGI Global, 2017. v. 1. 330p.
Additionaly, I’m co-author of other papers of other doctoral and master students based on this project that were published in the last years.
1.4
Text Organization
The rest of this work is organized as: Chapter 2 presents the wearable concepts, discus-sion, challenges as well as the proposed concepts of this work. Chapter 3 shows the first case study of smart wearable as an input device. A solution for some users expectations such as more flexible device is presented on this chapter. Chapter 4 describes the second smartwearable case study. It was focused on a output device and the a user experice evaluation was done. Finally, Chapter 5 presents the conclusion and the future work.
Chapter 2
Wearable Computing
This chapter presents an overview of wearable computing concepts. A study of the main wearable architectures was done to classify the most common structure found in the literature. A brief overview of wearable communication architectures is presented, as well as, the wearable operating system features. Challenges are raised and reviewed throughout the chapter. Also, we describe the wearable market and user adoption and propose the “Wearable Acessory” and “Smart Wearable” definition.
2.1
Usual Wearable Architectures
Wearable computing is an emergent research area which uses embedded smart computers on the human body to collect information about the user or the context around users. Smartwatches and the HoloLens head-mounted display (HMD) 1 are two examples of wearable computing systems currently available. Wearable computing plays a relevant role in user daily activities. Users can change their behavior during daily tasks based on feedback received by wearable devices (Vega, Flanagan & Fuks 2013).
A classification of the wearable systems architectures found in literature into two sub-classes was done. The first one is Operating Systems Based Software that describes systems whose design contains operating systems. The power processing and the energy consumption are higher in this kind of system. On the other hand, the integration of cloud services and design of Internet of Things (IoT) systems are more flexible. The second one does not contain OS. This type of system has less demand for processing
1
https://www.microsoft.com/microsoft-hololens/en-us
power and battery consumption consequently has low-cost. Wearable accessories found in the literature were classified into three architectures.
Figure 2.1 shows the first architecture. The first and second layers represent the sensors hardware assembled with an AD converter. A microprocessor receives the result to perfor the data fusion. Commonly user’s smartphones with Android OS are used to develop the HMI. Also, the data extracted can be submitted for an infrastructure network in a private or public cloud (Hardegger, Tr¨oster & Roggen 2013, Senyurek, Hocaoglu, Sezer & Urhan 2011, Mokhlespour, Zobeiri, Narimani, Hoviattalab, Moshiri & Parnianpour 2012, Mayton, Dublon, Palacios & Paradiso 2012, Corbellini, Ferraris & Parvis 2008, Ceccarelli, Bondavalli, Figueiras, Malinowsky, Wakula, Brancati, Dambra & Seminatore 2012, Baron, Cifuentes, Velasquez & Rodriguez 2011, Conjeti, Singh & Banerjee 2012).
Figure 2.1: Architecture Level 1
Figure 2.2 shows the second architecture. Smartphone performs the data fusion role instead of the microcontroller. This procedure gives more flexibility for develop-ers (Starner 2015, Guti, Inform, Luna, Byron, Zaragoza, Guti´errez-G´omez & Guerrero 2013, Osswald, Weiss & Tscheligi 2013, Musu, Popescu & Giusto 2014, M. Hardegger, L-V. Nguyen-Dinh, A. Calatroni, G. Tr¨oster 2014, Hiremath, Yang & Mankodiya 2014, Bonato, Mork, Sherrill & Westgaard 2003).
Finally, the third approach introduces the smart sensors conception. Figure 2.3 shows sensors embedded in smartphones (Lu, Huang, Saha & Nachman 2014, Yau & Buduru 2014, Feese, Arnrich, Tr¨oster, Burtscher, Meyer & Jonas 2013). The advantage of this approach is the abstraction level provided by the operating system for the users (Lim, Seo & Ryu 2007, Matsuda, Uemura, Sakata & Nishida 2012, Tang 2014). Thus, users do not need to concern about the first and second layers. Furthermore, this approach does not limit users to use the conventional sensors. In fact, this is a good strategy when smartphones do not contain all sensors available.
Wearable Computing 11
Figure 2.2: Architecture Level 2
Figure 2.3: Architecture Level 3
Most of the wearable studies found in the literature do not have an operating system in their architectures (Profita, Clawson, Gilliland, Zeagler, Starner, Budd & Do 2013, Sugiyama, Hayashida, Katsuyama, Matsumoto, Ido, Shinagawa & Kado 2013a, Forsyth, Martin, Young-Corbett & Dorsa 2012, Kawamoto, Tanaka & Kuriyama 2014, Zhang, Huang, Huo & Tao 2012, Jackson, Zeagler & Valentin 2013). In this case, researchers develop prototypes using sensors and microcontrollers. Microcontrollers process the data provided by sensors. A Human Interface Machine (HIM) shows the results obtained. Bluetooth and Zigbee are the technologies most used by researchers.
2.2
Wearable Communications Architecture
The communication among sensors on a body is classified as Body Area Network (BAN) (Kim, Lee, Lee & Architecture 2015). (Chen, Gonzalez, Vasilakos, Cao & Leung 2011) intro-duces the terms Intra-BAN Communications and Inter-BAN Communications.
sensors. 2) Communications between body sensors and the portable Processing System (PS). PHY layer usually is composed wired interface (Derogarian, Ferreira & Tavares 2014, Sugiyama, Hayashida, Katsuyama, Matsumoto, Ido, Shinagawa & Kado 2013b), but this is not a hard rule due to user convenience (e.g. smart watch). Otherwise, the use of wireless connection demands investigations to solve some open challenges. For instance, the high density of wireless devices can prejudge the communication (Pyattaev, Johnsson, Andreev, Koucheryavy & Ale 2015). Furthermore, battery consumption is an important concern in wearable systems (Keally, Zhou, Xing & Wu 2013).
Inter-BAN corresponds to the layer that provides the communication among body sensors and an infrastructure of the network. The communication interfaces are ma-ture once the most common radio technologies are: WLan, Bluetooth and Low power Bluetooth, Zigbee and mobile networks.
2.3
Wearable Operating Systems
We describe two main classes of wearable operating systems. A wearable Real Time Operating System (RTOS) is an operating system that supports the real-time operation of sensors, actuators and processes. Both efficient process scheduling and energy man-agement are the main features of this kind of operating system (Cho & Lee 2010, Cho, Lim & Lee 2009, Acquaviva, Benini & Ricc´o 2001). Operating Systems focused on the user interface (UI) prioritize the user experience. The operating system removes back-ground processes of processor or closes them if they are hindering the UI tasks. Android is an example of OS focused on UI with restriction about UI interface. For example, the time spent to update an UI cannot exceed 200ms. This feature is a no functional requirement of the OS. To provide the best user experience Android OS give low priority to the background process to users receive UI update soon as possible. Other challenges proposed by (Lee, Flinn & Noble 2015) describe the prediction of user attention, user interaction demands.
The central question is how to define mechanisms to warn a user about applications’ notifications and how to improve these alerts (Lee, Flinn & Noble 2015). This classifi-cation is necessary because wearable devices have different goals. Systems that monitor user body and contain a set of sensors typically demand an RTOS whereas smartwatches ask for the best user interface the user can get.
Wearable Computing 13
Wearable RTOS
The main goal of an RTOS is to do CPU, I/O, memory and energy management con-sidering the constraints of the applications running on the platform. Safety and critical applications demand RTOS, such as a wearable for firefighters (Futuristic Firefighter Suit Has Sensors, Head-up Display n.d.) that requires real-time sensing, real-time user notification, and may require real-time inter-body communication as well as cloud plat-form communication. An RTOS should be able to provide the best scheduling solutions for these scenarios.
On the other hand, health systems are examples of applications that may not require real-time constraints. (Weekly 2015). However, an RTOS should provide efficient bat-tery consumption techniques and efficient I/O and memory management strategies to maximize the resources usage of a low-power computing platform. In practical terms, this means that, even when an application has no real-time requirements, the inclusion of an RTOS can allow the software to take advantages of the hardware capabilities. Furthermore, a device with computing constraints and with no OS is more restricted regarding functionalities. Therefore, depending on the goal of the hardware/software platform, the inclusion of an RTOS might be the best choice.
Nucleus Wearable OS Nowadays, more than 3 billion devices use Nucleus RTOS. Mentor Graphics designed it for wearable devices (Mentor Graphics Announces Nucleus RTOS for Wearable Devices n.d.) in medical, fitness, security, safety applications, among others. Nucleus OS contains a framework for inter-process communication. Wireless communication and extensive protocol support for cloud connectivity are available to support the main requirements for wearable and IoT devices. Also, Nucleus contains a framework to manage the internal SoC resources. For instance, each core can be switched off during run time to save energy.
Nucleus promises to be an operating system with support for the real-time require-ment and provides user interface features. Qt Framework is available for developers designing advanced UI. Advanced resources to manage the user interface are not present on Nucleus. Due this fact we suggest the Nucleus evaluation under UI requirements perspective.
Nucleus presents some features that allow us to classify it as a wearable OS that covers the typical requirements for such an application, but a more detailed study is
needed to evaluate it for wearable applications. For instance, suppose a designer wants to apply Nucleus RTOS to wearable applications with time constraints. Some of the questions that might arise are:
1. What is the impact of turning on an internal component during runtime based on data collected from sensors?
2. Will component boot-time and sensors’ calibration be done considering possible time restrictions?
3. Is it possible for the OS to predict when is the most appropriate moment to turn off SoC components?
The feature to turn off internal components is already available on Android OS except if some application demands hardware resources. However, this decision is based on UI available to the user and there is no real-time feature on Android OS. Therefore, we need to perform an evaluation of RTOS for wearable devices.
Given the examples above about the difference between operating system focused on real-time applications and operating systems focused on user experience, we can affirm that an RTOS is not compatible with an operating system focused on UI experience. Some consolidated OS such as Android, Tizen and WatchOS are focused on UI experience and cannot ensure RTOS features. Wearable systems demand a quick time response and an evaluation of the best moment to provide alerts and information to users. The Nucleus behavior needs to be evaluated considering these requirements. The use of the Qt framework to provide wearable UI demands more detailed evaluations and, possibly, adaptations to the framework engine.
User Interface of a Wearable OS
The user interface of an operating system aims to provide the most interesting user experience. Besides of the fast UI update some operating systems provide the better user interaction when a user is not interacting with his/her device. (Lee, Flinn & Noble 2015) propose an operating system for this purpose. The operating system responsibility is to predict how the operating system should request a user interaction. Also, the frequent evaluation is proposed to improve the user experience. To decide about the user interface interaction is not a trivial task. For instance, a wearable whose role is to measure the
Wearable Computing 15
activities of the user’s body through several sensors may need to issue a critical alert to the user. In this case, to decide by actions that prioritize the user interface can affect the sensors performance negatively since the operating system prioritize the UI tasks stopping processes in the background. However, to take the decision to prioritize the sensors and does not notify the user about some health risk, may affect his/her health. It is crucial to take consideration that this decision can be dependent of the user context-aware. On this case, the context-aware identification is another feature demand by wearable operating systems.
Android Wear Android Wear is a Google operating system focused on wearable de-vices, released in March 2014, and currently embedded on smartwatches. The OS focuses on the user interface and provides integration with Google’s services such as Google Now. Furthermore, smartwatches have fewer sensors than smartphones. This fact implies lower background processes and reduces the real-time requirement of applications.
Main applications for Android Wear OS are available on Google Play store. Also, it open source feature, makes it a good option for building low cost smartwatches. Although, these facts are viewed as evidence that Android Wear is the most currently used, but the numbers show the opposite. The market expects to grab a 17.4 percent in 2015, that represents 4,1 million devices sold (Wearable tech market bursting at the seams: survey n.d.). Furthermore, 720,000 Android Wear devices were sold in 2014, this number is considered a slow start by specialists (A slow start More than 720,000 Android Wear devices were shipped in 2014, led by the Moto 360 Kernel Description n.d.).
Google’s smartwatch is a peripheral device of an Android smartphone. The smart-watch integration with Google services aims to maintain the user hands free, avoiding the smartphone use. However, smartwatches do not have a good user interface due to their screen size. Because of this, Google released the Google Now service for Android wearables. The Android and Android wearable integration represents the current trend of wearable technology.
Android OS is a based operating system. The main difference to other Linux-based operating systems is it distributed feature. User API provides the same interface to access the resources through either a local URI or a network URL.
Android Wear is based on Android OS. There are not many information available about their kernel differences, but is known that Android Wear has three main features: 1- A time-telling 2- User notify interface and 3-It is prepared to low cost devices (Android
Wear Review n.d.).
Android Wear also demands interface with Android to collect data from Android applications and show to the user. When an app generates a notification, in response to an event, for example, a mail reader receives a new mail
The Android OS convergence to wearable operating systems poses new questions:
• What is the real need to build new wearable operating systems?
• Do we need to design wearable operating systems only for low-cost devices? The questions are addressed in this section and in the discussion describing our experience developing a wearable user view and the corresponding user interface. Some challenges are discussed in Section 3.2.
Tizen OS Tizen is Samsung’s multi-application operating system designed for wear-able, in-vehicles, TV and IoT devices (Tizen n.d.). Samsung follows Apple and Google recipes keeping an app store and a development API for Tizen. Tizen applications’ interface is based on HTLM5, making it available for web integration.
Samsung announces an operating system for upgrading the user experience. Tizen is the operating system of some Samsung smartphones and the adoption by the community was successful. Maybe the main Samsung challenge is to reproduce the Google services and app store success. On the other hand, smartwatch Tizen had a significant number of devices sold on the first day in China (Samsung’s Gear S2 Sees 180,000 Sold In China In 8 Hours n.d.).
Today, Tizen is widely embedded into smartwatches. Samsung is possibly the first company to indicate that smartwatches are not just smartphones’ peripherals because some Samsung Gear devices can provide services without a smartphone integration. Also, a 3G connection is available in some smartwatches.
Pebble Pebble was the first smartwatch device running the Pebble OS (Pebble n.d.). Pebble OS is a custom version of FreeRTOS and was the first smartwatch available to the community. Pebble company invested on the integration of Pebble smartwatches with Android and iPhone devices. Recently Pebble OS has supported Android Wear notifications allowing Android Wear apps to push notifications on Pebble.
Wearable Computing 17
WatchOS Operating system for Apple’s smartwatches. There is not much information about this operating system. It is known that the operating system is based on iOS and is adapted for better energy consumption. This operating system is present on 58% of wearable sold in 2015 (Wearable tech market bursting at the seams: survey n.d.).
Linux Based OS
Linux is a general purpose OS and is the base of several operating systems for different purposes. Android is the most popular OS based on Linux and presents better features than its precursor. For instance, Android has algorithms to schedule process that reduce the battery consumption. Another example is the Android interprocess communication that changes the way of managing the hardware resources such as memory. Linux is an operating system widely used by different hardware manufacturers that runs on several different platforms. It is possible to find different Linux implementations with real-time features and variations of user interfaces. For now, Linux becomes a wearable OS due to Yocto Framework and particular hardware available on the market (Intel’s Edison Brings Yocto Linux to Wearables n.d.).
Other Wearable OS
Other wearable less expressive operating systems are emerging or available on the mar-ket. This section describes some of them.
webOS WebOS belongs to LG (Open webOS n.d.) and nowadays smartTVs and LG smartwatches use this OS. It can work paired with Android devices or standalone with SIM cards (A List of All Operating Systems Running on Smartwatches [Wearables] n.d.). Its interface is based on the web. LG provides a set of applications and services API for the application development that this OS supports. An advantage of this OS is the support to Yocto framework (Porting Open webOS n.d.). This fact eases the operating system portability for different hardware.
Firefox OS Mozilla Company announced the use of FirefoxOS in small wearable de-vices (Mozilla plans Firefox OS for wearables, targets Apple, Google n.d.). Now Fire-foxOS is embedded on Panasonic TVs. Mozilla bets on an OS that pairs and interacts
with different OS. It is compatible with Android from Google and iOS. Mozilla does not declare when it will release the OS for the community.
2.3.1
The Role of Wearable Operating Systems
The absence of an operating system is common in many wearable appliances, mainly in healthcare sensors and log companions. Low energy consumption is the main reason to use this model of the device. Otherwise, an operating system is used in case of integration with advanced user display information or integration with cloud platforms. Also, systems which demand low power processing and memory usually use hardware without an operating system. Today, two fundamental questions are commonly raised:
Are wearable devices’ peripherals designed for smartphones?
Regardless of what the answer is for the questions above, the use of operating systems has directly influenced the kind of desired application.
At first, the response to the question above seems obvious: The operating system has no important role in the solution if the wearable is a smartphone peripheral. But, consid-ering the wearable are not just smartphone peripherals operating systems are necessary because sophisticated algorithms are necessary. Smartwatches are peripheral devices for smartphones and also contain operating systems. The second question commonly raised is:
Why do peripheral devices need operating systems?
There are three main reasons: (i)an attractive user interface that provides infor-mation to several applications demands an operational system; (ii) peripheral devices require operating systems to manage distributed applications; (iii) peripheral devices tend to become a non-peripheral device.
Today, the industrial community poses a question that describes the main challenge for the success of wearable devices.
How does a wearable add value to end user providing information instead of data? To provide the end user with information instead of data in wearable applications is an arduous task that can involve multidisciplinary knowledge. For instance, a hardware that collects your heartbeats gives no useful information if the user is not a doctor or a health professional. Users want to know how the heart behavior during a sportive
Wearable Computing 19
activity or over a day may affect their health, or perhaps to be alerted about health risks in real time. To provide this kind of information through algorithms is a costly task because can demand data mining and machine learning techniques. Furthermore, some applications are dependent on cloud platform integration and interface connection. A cloud platform can aggregate data provided by many users and improve the feedback trough Internet connection. Corporations provide effective services that facilitate the integration of embedded platforms with the cloud platform. For instance, the Microsoft Azure provides an interface for development of distributed machine learning algorithms. But, this data flow depends on the operating systems integration between cloud platform and wearable devices.
The integration of Distributed wearable algorithms and IoT is another way that may be applied to improve the wearable user experience. Devices can enjoy memory and power processing of their neighborhoods as well as their power communication. This feature is not explored in the literature yet. Some challenges such cluster formation, hardware allocation, missing connection are addressed to provide this level of service. In this case, operating system capabilities are crucial for a successful project.
In summary, the most significant concern for a successful wearable is highly dependent on the operating systems. Next section presents a review of wearable, IoT and real-time operating systems.
2.3.2
Wearable OS vs. IoT OS
Before starting this discussion, a definition of wearable and IoT concepts is necessary. Wearable devices are computing elements placed on the user body to collect user or envi-ronment data. The integration of the system components with a user interface becomes necessary in most of the applications because wearable systems have focus on providing some information for the end user. IoT applications are focused on machine to machine (M2M) communication. IoT represents the interaction and adaptation of hardware for an applications purpose. Usually, these applications are focused on hardware automation for industrial and home scenarios. The challenges addressed in both areas are different. While wearable has the focus on giving the user the better experience, IoT applications are focused on hardware communication and system orchestration. To illustrate this affirmation, consider a simple example of household appliances. The system contains a refrigerator able to measure environment temperature and light. The combination of a range of values may mean that the refrigerator is spending more energy to maintain
its correct internal temperature. Considering that the window also contains an IoT hardware with an actuator, the refrigerator may issue a request for the window to close the curtain. This decision could also take into account to turn on the air-conditioner comparing the energy costs. Further examples of industrial scenarios can be found in the literature, but the most important is to notice that the system orchestration has no demand to user notification. The wearables’ application concern in provide information to users instead.
Google announced the Android Things (ATs) on 2016 as an operating system for Internet of Things (IoT). ATs is an evolution of Brillo (Brillo n.d.) lauched on 2015 and based on Android. The use of the well disseminated Android development platforms was integrated to the ATs, this is the basic difference announced by Google between both OS. Android Things is a software focused on embedded hardware and has support for a small number of equipments of Intel and NXP 2.
One question raised about Google’s strategy for its operating systems is:
Why is Google developing Android Wear and Android Things at the same time? The answer can have a relationship with the discussion above. Android Thing OS focuses on IoT applications while Android Wear focuses on wearable devices. This means that Android Thing is concerned about solving drivers, the communication interface and real-time requirements rather than the user interface. IoT applications concern with machine-to-machine communication and wearable operating systems provide focus on the user interface and experience. Two facts reinforce this idea. First one, the Weave protocol is announced together Android Thing that shows the Google aspires to provide the best developer experience on the integration of devices. On the other hand, Android Wear has features such as Google Now with support for intelligent voice recognition questions. Furthermore, Android Thing is designed for low-power computing hardware. At the first glance, wearable can be defined as a subtype of IoT applications. For instance, an application that demands inter-body communication for distributed algo-rithms purposes poses challenges similar to IoT. Another example is the use of a wearable by employees on an industrial production line. In this case, the wearable should be rep-resented as a “Thing” of the system. Although, today this scenario is not usual in the most applications, its use together with wearable RTOS requirements serves to raise questions about wearable and IoT operating systems.
2
Wearable Computing 21
Otherwise, wearable in its essence is not an IoT application. Some smartwatches collect data from user body and show them for the user without communicating with other modules. Furthermore, algorithms for low power processing can be embedded to provide information to the user.
1. What is the real frontier among wearable and IoT operating systems features? 2. Is it possible to converge to an integrated solution that provides correct RTOS
priorities and good user interface at the same time?
3. Considering that the answer to the last question is no, is an efficient solution to use different hardware each one with specifics operating system for its purpose?
This work makes an evaluation of a wearable system with modules composed by OS and no user interface, a user interface composed by OS and a hardware station without OS.
Table 2.1: Wearable Operating Systems
Feature/ Android ATs Tizen Pebble watchOS Linux Nucleus
OS Wear based
Battery Low Good Medium Excellent Excellent Device Excellent
Life feature
Graphics High No High High High Medium Medium
Quality Graphics
Voice Yes No Yes Yes Yes Depends No
recognition of user
Supported Android Android Tizen and Android iOS Any No
devices 4.3+ 4.3+ Android iOS info
UI Yes No Yes Yes Yes Yes/No Yes
RTOS No Yes No Yes No No Yes
Open source Yes No (yet) Yes Yes No Yes No
Wearable operating system has a different focus on each application. For now, most of the wearable devices found in the market are designed for fitness and health purposes.
Academic studies introduce new developments focused on health and safety applications. Due to the features of these cases, RTOS for wearable applications has a lower demand than user interface applications. The main OS manufacturers are concerned to provide the best user experience. This fact makes sense since the main wearable devices are smartphones peripherals.
Table 2.1 summarizes the features of the primary wearable operating systems avail-able on the market. WebOS is a current choice of LG after be tried by Palm and HP. Although they are done making efforts to popularize the OS to the developer commu-nity, we believe that to have a similar successful online app store, such as Google Play and Apple Store, is not a trivial task. On the other hand, Samsung follows the same strategy, but it is the current wearable market leader (A List of All Operating Systems Running on Smartwatches [Wearables] n.d.). This fact simplifies the OS popularization. Up to date, Mozilla only announces the interest in creating a wearable operating system. There are no indications that FirefoxOS is available in wearable devices.
Android, on the other hand, seems to become one of the most used wearable OS. Besides the large devices available with this OS, there are rumors that Pebble will release its smartwatches with Google OS. On this scenario, Google has less popularity compared with watchOS by Apple. One possible reason is the fidelity relationship presented by Apple’s users to other devices in the past. For now, Samsung Tizen plays a significant role in this valuable new market.
A question that is still not clear is the combination of RTOS and User interface features as proposed by NucleusOS. Hardware and software evaluations are necessary to define what the limits and frontiers of the user interface and RTOS requirements are. In this work, we design, prototype, evaluate and discuss the use of different operating systems in a wearable device with real-time and user interface requirements.
2.4
Wearable Market and User Adoption
Wearable devices have gained attention in the last years, in particular with the popu-larization of smartwatches, smartglasses, and other equipment. Most of the wearable devices available on the market are focused on providing health functionalities and act as an accessory to support diary activities of the users. These devices work as an aux-iliary interface for smartphone functionalities and can be used as a view interface or a
Wearable Computing 23
sensing platform. For instance, smartwatches have an interface to notify users a new received message and reading email as well. The same device also can sense user data and behavior for health purposes. This is the case of Samsung Gear which collects data from user body and behavior using sensors connected to the smartwatch. The data is aggregated with other got from the smartphone, and the application can give the user information about the sleep quality.
Wearable market increased in the lasts years and market perspectives are positive as shown in Figure 2.4. On the other hand, experts are discussing the role of wearable devices based on users’ experience and expectations, in particular regarding the value spent and return received by the users. The key point of their argument is related to the decreasing interest of the users by the technology few months after their acquisition.
Figure 2.4: Wearable Market in Billion of dollars.
Source: https://www.statista.com/statistics/302482/wearable-device-market-value/. Accessed in 26/11/2017
Smith (Smith 2016) discuss that the value of the wearable devices is on the data provided by them instead of the hardware. However, users don’t know how to use these data. He also affirms “...the true value comes from interpreting it all...”.
In addition, (England & Neeno 2015) discuss the relation of the value spent in the last years with wearable devices and the benefit given to the end users. Authors affirm that the amount of investments in problems that users don’t have doesn’t justify the investments. “...The value proposition just isn’t there yet to justify spending hundreds of dollars for a problem you don’t have...”.
Wearables are viewed as accessories by designers. The accessory concept brings in association the devices should be low battery consumption, low size, limited resources, as consequence low-level application. In particular, with the use of smartphones or cloud interface as a data processing unit the wearable devices trend to be considered just accessories. This scenario can change with the advance of the hardware miniaturization. More power computer capabilities can be designed on small devices. Also, the invisible computing is a trend. Wearable computing is a technology that can contributes with this context.
Users are not benefiting from this technology, they are losing the interest in wearable devices. According to (Maddox 2014) 50% of users lose interest within a few months. A study conducted by Endeavour Partners shows that some usability features influences this behavior. Some of them are described below:
• They are easy to lose • They break
• They’re not waterproof
• They’re a pain to sync with your smartphone • The battery doesn’t last long enough
• They’re ugly
• They’re uncomfortable to wear • They provide no material benefit
Barries (Danova 2015) summarizes the main reasons which are inhibitors for wearable adoption. Figure 2.5 shows them.
Note that 51% of the users don’t see a persuasive use case for wearable device use. This means that they can not see the value of these devices and this make them lose
Wearable Computing 25
Figure 2.5: Wearable Interest.
Source: http://www.businessinsider.com/wearables-adoption-barriers-what-keeps-people-from-buying-smartwatch-fitness-bands-2015-6. Accessed in 26/11/2017
the interest by this technology. The lack of applications able to work with the wearable hardware is another reason for a low-adoption of wearable devices.
An article released by The Economist (Economist 2014) shows that users are available to spent money with wearables since the technology give them the expected result. Figure 2.6 summarizes the features that increase the wearable usage according to the users when asked about the use of smartwatches.
Most users require more sensors for wearable devices. This means that the applica-tions also should be more flexible to work with the range of sensors connected. Another demand pointed by users is more computing capabilities in order to improve the quality of applications.
(Yang, Yu, Zo & Choi 2016) shows a study of the wearable acceptance. They collected data from 375 survey samples related to the perceived value of wearable devices. The research shows that perceived value is a clear antecedent of adoption intention.
Although the market numbers show a satisfactory demand by wearable devices to the next years, the current state of this technology has the problem for user adoption maintenance. People who have experimented this technology decrease their interest after some months while the number of new users is increasing. The challenge addressed is to
Figure 2.6: Users’ Expectation.
Source: https://www.economist.com/news/business/21646225-smartwatches-and-other-wearable-devices-become-mainstream-products-will-take-more. Accessed in
26/11/2017
provide new applications that can give value and improve the experience of the users. Features such as more sensors, more computing capabilities and more valuable infor-mation are desired for new wearable design. An example of relevant inforinfor-mation can be done by the use of smartwatch for heart frequency collection. Users are not interested in their heartbeat frequency. They would like to know their health condition based on their routine activities and measured data collected from their body. The heartbeat frequency is data that has no significance if not aggregated with other data.
Other components beyond physical sensors should be considered for some applica-tions. The previous example should use a data warehouse infrastructure to improve the accuracy to users. This fact gives evidence of a wearable model whose role is aggregate data from many other sources making it more flexible. For users, it does not matter where the data has been processed. A research question for this scenario is related where the data can be processed. Then, examinations of the integration of wearable devices to
Wearable Computing 27
Fog and Edge architectures should be done.
Based on this discussion, this research project proposes the formalization of the term “Smart wearable” and “Wearable Accessory”. We believe that this is the first step to for further investigations of the role of wearable devices and the users’ experience improvement. Next sections discuss the terms concept and their main differences.
2.5
Wearable and Privacy
Personal privacy is the main user’s concern about wearable devices. Data can be cap-tured by sensors integrated with wearable and shared without user accord. A camera is the most prominent sensor for this question citeWearablePrivacy. For instance, the video and pictures captured by these cameras can be used for planning a stolen. Also, users can record inappropriate data that compromises the third person.
The frontier of self-disclosure and the user privacy concerns is a challenge. This is one of the studies presented by citenewWave. Their findings indicate that there is a positive relationship between social norms and self-disclosure behavior, as well as, a positive relationship between privacy assurance mechanisms and privacy concern. On the other hand, the authors found a negative relationship between perceived ownership of personal data and self-disclosure behavior.
Citemann is bolder in relation to wearable privacy. He believes that wearables can contribute to the creation of a new level of personal privacy because it can be made more personal.
The privacy concern on wearable devices extends to the pervasive computing pri-vacy concern. Usually, users agree in to provide data citeWearablePripri-vacy, newWave as input for big data systems and new information. On the other hand, to avoid threats cause by the data collected and third people exposition is the main challenge. More transparent mechanisms for improving the user confidence with data ownership should be investigated.
2.6
Wearable Accessory Definition
A wearable accessory can be defined as an auxiliary device for dressing that works as a data sensing or a user view interface. Bracelets, watches, glasses are the example of equipment with low computing capabilities classified as wearable accessories.
The term “smart” as a prefix to symbolize an “intelligent” device (E.g., Smartwatch, smartglass, and others), these equipment use the term smart for differentiation of a traditional glass to a glass with an embedded hardware and software, they not necessary have some intelligence and give valuable information to the users. Smartwatches are digital watches with an operating system able to connect to a smartphone and show its application on a different interface. For instance, the user can read his/her email on a smartwatch. Usually, smartwatches can collect the body data such as heartbeat frequency. This wearable should works as an input device or an output device according to user convenience. Nevertheless, these devices use the term smart in our classification it should be categorized as a wearable accessory instead of a smart wearable device.
2.7
Smart Wearable Definition
The term “Smart Wearable” can be found on the literature (Chan, Est`eve, Fourniols, Escriba & Campo 2012, Lymberis 2003a, Appelboom, Camacho, Abraham, Bruce, Du-mont, Zacharia, D’Amico, Slomian, Reginster, Bruy`ere & Connolly 2014, Soh, den Bergh, Xu, Aliakbarian, Farsi, Samal, Vandenbosch, Schreurs & Nauwelaers 2013, Lymberis 2003b) but we did not find a manuscript that differentiates a smart wearable from a non-smart wearable. Also, we find the use of this term in applications designed only for healthcare purposes. This work aims to provide case studies of wearable devices not focused on applications dedicated to health.
The European Commission (COMMISSION 2016) defined smart wearable as:
‘‘Smart wearables are body-borne computational and sensory devices which can sense the person who wears them and/or their environment.
Wearables can communicate either directly
through embedded wireless connectivity or through another device (e.g. a smartphone)."
Wearable Computing 29
In our definition, smart wearable is not only sensing devices. A range of wearable devices for user interaction can be developed. They should be able to perform “intel-ligent” algorithms and be more independent of other devices for data processing and communication.
In our definition, a smart wearable is a device or a set of devices, whose comprises the following requirements:
• A specific purpose: The system should have a specific purpose of solving a specific problem to the user. It is desired that the system gives new values to the user Human-Centered Application: The wearable should be planned considering the human requirements and expectations
• Independence: The wearable should perform the tasks and provides the infor-mation to the user according to the scenario planned without dependency to other equipment not available. Should have an interface for components communication each other.
• Flexibility: The system should be flexible enough to accept new components such as sensors, user interfaces, hardware and software compatible with the application • Transparency: Should be transparent to the user where data has been processing
or coming.
• Improve user experience: The user should have the experience to perform some task improved compared with his previous activities.
A smart wearable can be composed of a set of wearable accessories or make the use of resources which are not placed on the user body. For instance, a smart wearable system can be a smartglasses that show to users their health conditions based on data collected on his body through a smartwatch combined with historical data of other users in which are stored in a cloud interface.
2.8
Wearable Accessory X SmartWearable
In general, we can classify any wearable device into one of these following two categories: (1) smart wearable and (2) wearable accessories (The Future of Wearables: Accessory or
Appliance? n.d.). The smart wearable category consists of wearable devices or system which can perform their task without the aid of another device. Meanwhile, the wearable accessory category consists of wearable devices which need to communicate with another device to full their purpose. In this way, we can classify the previous examples using these concepts: a smartwatch which needs to communicate to a smartphone in order to work properly is classified as an accessory; on the other hand, a smartwatch which works as a stand-alone device is classified as a smart wearable. Microsoft HoloLens AR HMD is a device designed to be classified into the smart wearable category, according to the application developed for it. It does not depend on other devices to work properly.
Generally, smart wearables demand more complex hardware and software features in order to process and deliver to the user all necessary information related to their tasks. Therefore, a smart wearable demands a smart sensor architecture level (Delabrida, D’Angelo, Oliveira & Loureiro 2016), taking advantage of the abstraction level provided by the operating system in order to accomplish its purpose without the aid of another device.
Usually, wearable accessories only need to collect and/or display data, while the pro-cessing function is given to another device, such as in the previous smartwatch and smart-phone example. Therefore, wearable accessories can use any type of architecture, ranging from a simple microcontroller-based architecture to a very most complex smart sensor architecture, depending on the user interface and real-time requirements (Delabrida, D’Angelo, Oliveira & Loureiro 2016).
Table 2.2 shows a comparison of both concepts according to the requirements previ-ously defined.
Table 2.2: Comparison Between Categories
Requirement Acessory SmartWearable
A Specific Purpose No Yes
Independence No Yes
Flexibility Yes Yes
Transparency No Yes
Improve UX No Yes
Wearable Computing 31
are devices for user interaction with routines activities, such as read mail and body data collection. These devices are dependents of smartphones. They are flexible to re-ceive new applications. Most OS installed in these devices has an API for development. Transparency is a requirement that demands the processing power capabilities. Usually, wearable accessories are built on hardware with low power computing capabilities. Fi-nally, the review presented in this chapter demonstrates that wearable accessories are not improving the UX.
2.9
Concluding Remarks and Lessons Learned
This chapter surveys the main architectures for building wearable devices as well as the principal operating systems available for this purpose. Also, a comparison of wearable and IoT systems was introduced.
Although companies such Google and Samsung developed their “wear” operating systems version, is still more usual the adoption of the embedded Linux or Android. Also, wearables can play RTOS, in particular when the goal is sensing data.
Another contribution of this chapter is the definition of the terms wearable acces-sory and smart wearable. A study of wearable market and the main bottlenecks for user adoption and maintenance is presented. Based on the discussion, we proposed the classification of the wearable accessories and smart wearables and the requirements for including a wearable device based on its application.
Next Chapters, we presented two case studies based on the requirements. The pro-totypes are the proof-of-the concept of smartwearables. Chapter 3 introduces a smart wearable as an input device, while Chapter 4 introduces a smart wearable-focused on user interaction. Both cases studies are based on ecological systems and are complemen-tary. But we described two different cases studies due to project decision. We choose to create wearable-focused on the field research applications to avoid the exemplification to of wearable applications for health purposes, as most wearables found o literature. Also, these cases give us the opportunity to develop a system considering some limitations such as Internet access imposed by this kind of application. This is an example of the independence requirement.
