Suitability of smartphone inertial sensors for real-time biofeedback applications

Kos, Anton (author), Tomažič, Sašo (author), Umek, Anton (author)

This article studies the suitability of smartphones with built-in inertial sensors for biofeedback applications. Biofeedback systems use various sensors to measure body functions and parameters. These sensor data are analyzed, and the results are communicated back to the user, who then tries to act on the feedback signals. Smartphone inertial sensors can be used to capture body movements in biomechanical biofeedback systems. These sensors exhibit various inaccuracies that induce significant angular and positional errors. We studied deterministic and random errors of smartphone accelerometers and gyroscopes, primarily focusing on their biases. Based on extensive measurements, we determined accelerometer and gyroscope noise models and bias variation ranges. Then, we compiled a table of predicted positional and angular errors under various biofeedback system operation conditions. We suggest several bias compensation options that are suitable for various examples of use in real-time biofeedback applications. Measurements within the developed experimental biofeedback application show that under certain conditions, even uncompensated sensors can be used for real-time biofeedback. For general use, especially for more demanding biofeedback applications, sensor biases should be compensated. We are convinced that real-time biofeedback systems based on smartphone inertial sensors are applicable to many similar examples in sports, healthcare, and other areas.

• Language: English
• Keywords: biofeedback system, smartphone sensors, MEMS sensors, sensor noise, Allan variance, bias error, bias compensation, real-time biofeedback application
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2016
• Number of pages: 21 str.
• Numbering: Vol. 16, iss. 3, art. 301
• PID: 20.500.12556/RUL-130317
• UDC: 621.39
• ISSN on article: 1424-8220
• DOI: 10.3390/s16030301
• COBISS.SI-ID: 11297876
• Publication date in RUL: 13.09.2021

Record is a part of a journal

• Title: Sensors
• Shortened title: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• COBISS.SI-ID: 10176278

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.03.2016

Secondary language

• Language: Slovenian
• Keywords: sistem z biološko povratno zanko, senzorji pametnih telefonov, MEMS senzorji, šum senzorjev, Allan varianca, napaka ničelne vrednosti, kompenzacija ničelne vrednosti, aplikacija z biološko povratno vezavo v realnem času

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0246
• Name: Algoritmi in optimizacijski postopki v telekomunikacijah

• Funder: ARRS - Slovenian Research Agency
• Project number: L2-5481
• Name: Uporaba brezžičnih senzorskih naprav za spremljanje gibanja in biološko povratno vezavo