How We Found Our IMU: Guidelines to IMU Selection and a Comparison of Seven IMUs for Pervasive Healthcare Applications.

Lin Zhou,Eric Fischer,Bert Arnrich,Urs Granacher,Cem Ersoy,Clemens Markus Brahms,Can Tunca

doi:10.3390/s20154090

Abstract

Inertial measurement units (IMUs) are commonly used for localization or movement tracking in pervasive healthcare-related studies, and gait analysis is one of the most often studied topics using IMUs. The increasing variety of commercially available IMU devices offers convenience by combining the sensor modalities and simplifies the data collection procedures. However, selecting the most suitable IMU device for a certain use case is increasingly challenging. In this study, guidelines for IMU selection are proposed. In particular, seven IMUs were compared in terms of their specifications, data collection procedures, and raw data quality. Data collected from the IMUs were then analyzed by a gait analysis algorithm. The difference in accuracy of the calculated gait parameters between the IMUs could be used to retrace the issues in raw data, such as acceleration range or sensor calibration. Based on our algorithm, we were able to identify the best-suited IMUs for our needs. This study provides an overview of how to select the IMUs based on the area of study with concrete examples, and gives insights into the features of seven commercial IMUs using real data.

Highlights

Inertial measurement units (IMUs) are electronic devices that typically consist of a 3-axis accelerometer and a 3-axis gyroscope
Almost all IMUs have an acceleration range of ±16 g and a gyroscope range of ±2000 deg/s, except that the default sampling rate that can be configured in Bonsai app is ±4 g, but customization to ±16 g is possible depending on the use case
The current study proposed a guideline for the selection of IMUs for pervasive healthcare-related use cases and compared the specification, data collection procedures, as well as the data quality of seven consumer grade IMUs

Summary

Introduction

Inertial measurement units (IMUs) are electronic devices that typically consist of a 3-axis accelerometer (which measures linear acceleration) and a 3-axis gyroscope (which measures angular velocity). Some IMUs contain a 3-axis magnetometer (measuring magnetic field), which are specified as MIMUs. By fusing information from these sensors, the orientation of the IMU can be estimated [1]. IMUs have been gaining popularity in the past years as a research tool for pervasive healthcare [2,3]. The selection of an IMU suitable for the research topic is increasingly challenging due to the large variety of options. The following paragraphs will provide a brief introduction of the commercially available IMUs, their applications in pervasive healthcare related to gait, and illustrate how the current study can contribute to the knowledge of IMU selection for pervasive healthcare related use cases

Methods

Results

Discussion

Conclusion