Smart Insole: A Wearable Sensor Device for Unobtrusive Gait Monitoring in Daily Life

Abstract

Gait analysis is an important medical diagnostic process and has many applications in healthcare, rehabilitation, therapy, and exercise training. However, typical gait analysis has to be performed in a gait laboratory, which is inaccessible for a large population and cannot provide natural gait measures. In this paper, we present a novel sensor device, namely, Smart Insole, to tackle the challenge of efficient gait monitoring in real life. An array of electronic textile (eTextile) based pressure sensors are integrated in the insole to fully measure the plantar pressure. Smart Insole is also equipped with a low-cost inertial measurement unit including a 3-axis accelerometer, a 3-axis gyroscope, and a 3axis magnetometer to capture the gait characteristics in motion. Smart Insole can offer precise acquisition of gait information. Meanwhile, it is lightweight, thin, and comfortable to wear, providing an unobtrusive way to perform the gait monitoring. Furthermore, a smartphone graphic user interface is developed to display the sensor data in real-time via Bluetooth low energy. We perform a set of experiments in four real-life scenes including hallway walking, ascending/descending stairs, and slope walking, where gait parameters and features are extracted. Finally, the limitation and improvement, wearability and usability, further work, and healthcare-related potential applications are discussed.

Estimation of Foot Plantar Center of Pressure Trajectories with Low-Cost Instrumented Insoles Using an Individual-Specific Nonlinear Model

“…Similarly, wearable sensors (including those integrated in smart phones) were reported to be useful for fall risk assessment [ 20 , 21 , 22 , 23 ]. Many low-cost instrumented insole systems have also been developed [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Among the existing low-cost insole systems, different sensor technologies were implemented, such as force sensitive resistors (FSRs) [ 25 , 33 ], fabric or textile pressure sensing arrays [ 28 ], or piezoelectric sensors [ 32 ], etc.…”

A survey on smart shoe insole systems

“…Specifically, Smart Insole can measure step counts, step pace, swing time, and center of pressure (COP) shifting velocity, which can further infer the walking balance status and potential fall risk in real life. [19] According to Wenyao et al, [18], there are three important subsystems as shown in Figure 3 . The first subsystem is low cost sensors for gait characterization, including 48 pressure sensors, 3-axis accelerometer, 3-axis gyroscope and 3-axis compass.…”

Gray-box Soft Sensors in Process Industry: Current Practice, and Future Prospects in Era of Big Data

“…Smart sensors are sensing devices that are equipped with digital features for data processing, storage and efficient transformation of data [10][11][12]. Smart sensors automatized the zero correction, calibration, and scaling of the measured signals by using microprocessors, in contrast to meticulous design, testing, and debugging faced by the conventional analog sensors [13][14][15][16]. The sensing platform of a smartphone is the best example of smart sensing environment; it integrates multiple sensors and…”