**4.1. Wearable posture training subsystem**

The wearable posture training headset subsystem is a sophisticatedly designed, earhook headset that is equipped with a real-time sensory system to monitor head and neck posture. The sensory system is an embedded system with dedicated hardware of accelerometer functions to detect and transmit the three-axis acceleration values of the device continuously. We adopt a 32-bit ARM Cortex M0 microprocessor [48] as the core of the embedded system. The microprocessor operates at CPU frequencies of 30 MHz and equips with 16kB of flash memory and 4kB of SRAM with AES 128-bit encryption.

A three-axis accelerometer is used in the embedded system to detect the attitude of the posture monitoring hardware, that is, its pitch, roll and yaw. The accelerometer is featured by its ultra-low power, high performance, micro-electro mechanical system (MEMS) motion sensor for lightweight and long-lasting applications and wearable devices. The accelerometer is used to measure the accelerations of three axes of pitch, roll and yaw and generate 16-bit data streams with output rates in hundreds Hertz. The analog readings measured by the accelerometer are first digitalized and then sent to the 32-bit microprocessor through serial communication interfaces of I2C (Inter-Integrated Circuit) or SPI (Serial Peripheral Interface). The received signals are then filtered and calculated to generate the tilt angles of the posture monitoring hardware with Eq. (1).

## **4.2. Social-networked posture training CSPT App subsystem**

The social-networked posture training CSPT App subsystem is the main interface to posture training users and their peers. The CSPT App provides a number of functions including gateway of sensor data, posture data processing, fuzzy logics and posture determination, biofeedback initiating, data feeder to the cloud and presentation or rendering the historical and analytic posture information. The CSPT App is also a social networking graphical user interface (GUI) for posture training and information sharing among individuals and their peers.

As the key element in the CSPT system, the CSPT App executes and manages many tasks, including signal processing, posture determination, biofeedback and data management to cloud computing. It receives, processes and further transmits posture angles. It determines the good posture and decides to notify when biofeedback is needed. The CSPT App renders the analytic data streams from the cloud, manages identity and access control and does encryption/decryption of the data and user ID, as the platform for chatting, messaging and file sharing of social network functions.

The CSPT App is also a notifier for people to receive alerts or warnings so that they can correct the poor posture immediately. When a biofeedback is enabled, the CSPT App plays default or customized sound or music and makes the smartphone vibrate for a short period of time to notify the users to change their bad posture. The smart feature of the CSPT App enables the intelligent detection of wearable devices so that no sound, music or vibration is made when the wearable devices are not attached or out of their operating space like being left on the desk. To avoid annoying, the notification period increases when the bad posture continues.

The friendly GUI of the CSPT App is the core to people. The CSPT App renders the analytic data streams from the CSPT Cloud. People can watch and be aware of the real-time status of their postures and realize how good or poor their head/neck and low back postures are. People can also glance over their peers' posture training performance. Based on the historical data from the cloud, people can explore their analytics, including the percentages of maintaining good postures, total wearing times and average response times. The resolution of time scales spreads from day, week, month, to year. **Figure 5** depicts two screenshots of the CSPT App GUIs for the analytic report in the day (right) and for poor posture (left), respectively.

**4.3. CSPT Cloud Services subsystem**

**Figure 5.** Screenshots of CSPT App (left: poor posture, right: analytics).

very close proximity to each other of the group.

**5. Experiment design**

The CSPT Cloud Services subsystem manages user data, generates the analytics and provides social network services for posture training. Web services with the on-demand computing platform operating from 12 geographical regions across the world are adopted to provide the CSPT cloud services. NoSQL databases are built to manage user data, posture angles and analytics.

Collaborative, Social-Networked Posture Training with Posturing Monitoring and Biofeedback

http://dx.doi.org/10.5772/intechopen.74791

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To validate the effectiveness of the proposed CSPT posture training framework, we design several experiments considering a group of six teens in a middle school in San Jose, California, USA, whose families are similar in their race of Asian Americans, socioeconomic status, occupational status, family size, housing, geographic location, ethics and morals. The six teens denoted as "C," "E," "GC," "GW," "H" and "L," by the first letter(s) of their names, respectively, are all 8th graders in the school and friends to each other. They study, play and chat in

The light speed advance of mobile technologies always makes the smartphone markets and products dazzling. Backward compatibility is a non-negligible issue in developing smartphone apps, especially to the Android platform. Not every smartphone is fresh new and up-to-date. For young kids and teens, some of them may use cheap-but-obsolete styles or their parents' used smartphones. These legacy smartphones usually use old operating system (OS) and supporting interfaces that are even unable to upgrade. In order to maximize the compatibility to most existing smartphones, the development of the CSPT App subsystem has to consider various and many smartphone models from different manufacturers with different OS and software versions. As compared to the development of other subsystems, it is so tedious and challenging.

Collaborative, Social-Networked Posture Training with Posturing Monitoring and Biofeedback http://dx.doi.org/10.5772/intechopen.74791 49

**Figure 5.** Screenshots of CSPT App (left: poor posture, right: analytics).

#### **4.3. CSPT Cloud Services subsystem**

The CSPT Cloud Services subsystem manages user data, generates the analytics and provides social network services for posture training. Web services with the on-demand computing platform operating from 12 geographical regions across the world are adopted to provide the CSPT cloud services. NoSQL databases are built to manage user data, posture angles and analytics.
