Insole Optical Fiber Sensor Architecture for Remote Gait Analysis—An e-Health Solution

Abstract

Abstract-In an era of unprecedented progress in sensing technology and communications, health services are able to evolve towards a close monitoring of patients and elderly citizens, without jeopardizing their daily routines, through health applications on their mobile devices, in what is known as e-Health. Within this field, we propose an optical fiber sensor (OFS) based system for simultaneous monitoring of shear and plantar pressure during gait movement. These parameters are considered to be two key factors in gait analysis which can help in early diagnosis of multiple anomalies, such as diabetic foot ulcerations or in physical rehabilitation scenarios.The proposed solution is a biaxial OFS based on two in-line fiber Bragg gratings (FBGs), which were inscribed in the same optical fiber and placed individually in two adjacent cavities, forming a small sensing cell. Such design presents a more compact and resilient solution with higher accuracy, when compared to the existing electronic systems.The implementation of the proposed elements into an insole is also described, showing the compactness of the sensing cells, which can be easily integrated into a non-invasive mobile e-Health solution for a continuous remote gait analysis of patients and elder citizens. The reported results show that the proposed system outperforms existing solutions, in the sense that it is able to dynamically discriminate shear and plantar pressure during gait.

Wheelchair Pressure Ulcer Prevention Using FBG Based Sensing Devices

“…Thus, the amplitude of the pressure is different for the pressure values registered for the others pressure relief positions. Further, in previous work [22], a similar cork insole was used for the gait analysis, and higher pressures than those reported in this work were measured, which indicates that there is no limitation on the sensitivity. compared with the reference initial Bragg wavelength.…”

“…In the case of the scapulas and ischiatic zones, the cells were glued with a strong double-sided duct tape to the wheelchair, where it contacted with the bony prominence regions of the user. The sensors for heel pressure monitoring were implemented into cork insoles [22] of appropriate size, which were adapted to the user's shoes. In Figure 4b we present a schematic representation of the overall experimental setup, which comprises the multiplexed FBG sensor network attached to the wheelchair and insoles, the optical interrogator, and the computer for data acquisition.…”

“…The information retrieved with the proposed system will allow the monitoring of pressure relief exercises and further to evaluate if the users are performing them properly, and, consequently, to correctly instruct them. The potential connection of this sensing solution to an eHealth architecture [22] will also provide the medical staff with a continuous monitoring of the wheelchair user, offering a constant evaluation of the pressure exerted at the ulceration points. From the pressure results, the breathing rate can also be estimated.…”

A piezoelectric flexible insole system for gait monitoring for the Internet of Health Things

“…Gait is closely associated with many chronic diseases, as well as their progressions (e.g., stroke [1][2], tarsal coalition [3], Parkinson's disease [4][5], and diabetes [6][7]). It is of great significance to monitor gait parameters, such as velocity [8], stride length [9], and plantar pressure distribution accurately and continuously for disease evaluation [4] and efficient rehabilitation [10].…”

“…In [13], a wireless insole system was developed using the four FSRs to analyze how the patient's pressure distribution is affected by abnormalities, fractures, etc. In [6], an insole optical fiber sensor was presented for continuous and remote gait pressure distribution monitoring and to evaluate the evolution of ulcerations for patients of diabetes. However, there are still some challenges that need to be addressed.…”