A smart insole for monitoring plantar pressure based on the fiber Bragg grating sensing technique

2019 ◽  
Vol 89 (17) ◽  
pp. 3433-3446 ◽  
Author(s):  
Rafique Ahmed Lakho ◽  
Zhang Yi-Fan ◽  
Jiang Jin-Hua ◽  
Hong Cheng-Yu ◽  
Zamir Ahmed Abro
Keyword(s):  
Optical Fiber ◽  
Pressure Distribution ◽  
Fiber Bragg Grating ◽  
Plantar Pressure ◽  
Bragg Grating ◽  
Body Postures ◽  
Plantar Pressure Distribution ◽  
The Subject ◽  
Fbg Sensors ◽  
Smart Insole

The analysis of plantar pressure distribution is essential in the field of biomedical and sports-related applications. In this study, a smart insole was developed for the measurement of plantar pressure distribution and the evaluation of body postures using optical fiber Bragg grating (FBG) sensing technology. Four FBG sensors characterized by four different center Bragg wavelengths, 1528 ± 0.3, 1532 ± 0.3, 1535 ± 0.3 and 1539 ± 0.3 nm, were located at the first metatarsus, third metatarsus, fifth metatarsus and heel position, respectively. The measurement sensitivity of all the FBG sensors was 0.000412 nm/kPa, approximately. Silica gel material of modulus = 10 MPa was selected to incorporate the FBG sensors. All FBG sensors were multiplexed together with one optical fiber cable. The performance and functional properties of all FBG-based pressure sensors were calibrated in the laboratory to evaluate plantar pressure distribution. A male subject was selected for performing four tasks, namely standing in an upright position, leaning forward, squat position and forward fold. During standing tests, plantar pressure observed at the heel position was around 57% higher than that at the first and third metatarsus, while the pressure of the fifth metatarsus position presents minimal pressure, which is only 37% that of the pressure of the heel position. When the subject performs leaning forward, the squat position and forward fold posture, the first and third metatarsi show maximum pressure, while the pressure decreases at the fifth metatarsus position. However, almost zero pressure is observed at the heel position when the subject changes the body postures of leaning forward, squat and forward fold posture. The extreme pressure of the forward fold posture was 1750 kPa acquired at the first metatarsus, which is 52% and 62% higher than those at the fifth and third metatarsi, respectively. Therefore, the smart insole successfully recorded both plantar pressure distribution and body posture changes regarding the wavelength values collected by the FBG sensors.

Embedding optical Fiber Bragg Grating (FBG) sensors in 3D printed casings

2019 ◽  
Vol 53 ◽  
pp. 102015 ◽  
Author(s):  
Natalia Reggiani Manzo ◽  
Gabriel T. Callado ◽  
Cristiano M.B. Cordeiro ◽  
Luiz Carlos M. Vieira Jr.
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
3D Printed ◽  
Fbg Sensors ◽  
Optical Fiber Bragg Grating

STRAIN MEASUREMENT AT CANTILEVER BEAM WITH FIBER BRAGG GRATING SENSORS AND COLLIMATORS AND ITS CORRECTION METHOD

2012 ◽  
Vol 06 ◽  
pp. 576-582
Author(s):  
Seung Min Tak ◽  
Min Kyu Kang ◽  
Dong Jin Park ◽  
Seok Soon Lee
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Cantilever Beam ◽  
Strain Measurement ◽  
Wave Length ◽  
Correction Method ◽  
The Other ◽  
Bragg Grating ◽  
Fiber Bragg Grating Sensors ◽  
Fbg Sensors

Recently, Fiber Bragg Grating(FBG) sensors are being used in various fields. However, it has difficulty to measure at the place where it is not possible to connect fibers each other physically. In this study, using FBG a collimator, we have measured strains with a single optical fiber with many FBG sensors where FBG sensors on one optical fiber line is installed on the beam and the other optical fiber line is connected with an optical interrogator installed at stationary side. The optical fiber lines between an optical fiber line with FBG sensors on the beam and the other optical fiber line on the stationary part are connected by the collimator which makes the use of light's unique characteristic - light travels through space. The experiment showed that the wave length of the light were changed to be linear as strains increased, and the accurate strains were measured by applying the collimator collection factor, which was proposed in this paper.

scholarly journals Investigation on Low Cost Optical Fiber Sensor Interrogator

2021 ◽  
Vol 64 (5) ◽  
pp. 765-767
Author(s):  
Yandong Gong ◽  
Ke Li ◽  
Zhuo Zhang
Keyword(s):  
Structural Health Monitoring ◽  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Health Monitoring ◽  
Lower Cost ◽  
Low Cost ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Bragg Grating ◽  
Fbg Sensors

Abstract— Optical fiber sensor is attracting more attention in the structural health monitoring of civil applications. A general interrogator which can be used for both SOFO and fiber Bragg grating (FBG) sensors has been proposed, it has a lower cost with a much simpler design. Its accuracy can reach up to ~2.5 με, it has a niche market where it can compete with the conventional sensors.

The Use of Fiber Bragg Grating Sensors during the Static Load Test of a Composite Wing Structure

2013 ◽  
Vol 486 ◽  
pp. 102-105 ◽  
Author(s):  
Milan Dvorak ◽  
Miroslav Kabrt ◽  
Milan Růžička
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Static Load ◽  
Load Test ◽  
Bragg Grating ◽  
Strain Gages ◽  
Hydraulic Actuator ◽  
Fbg Sensors ◽  
Wing Structure ◽  
Composite Wing

The article describes process of implementation of optical Fiber Bragg Grating (FBG) sensors into the composite wing structure and their behavior during the strength test. The wing is of all-composite construction. The upper and lower skins are made of glass/epoxy composite. The spar caps are made of carbon/epoxy unidirectional composite. Optical fibers were integrated directly into the spar caps and into the adhesive joints. They were oriented in parallel with the main spar axis. The first optical fiber with chain of multiple FBG sensors was integrated into the structure of upper spar cap. Another FBG chain of FBG sensors was located in the adhesive joint of lower spar cap and shear web. The wing was instrumented with strain gages as well. Strain gages were glued to the sides of the spar caps. Static load was produced by a hydraulic actuator. Experimental results from strain gages and FBG sensors were compared with the results of the analytical analysis of the wing.

Measurement of pile load transfer using the Fiber Bragg Grating sensor system

2004 ◽  
Vol 41 (6) ◽  
pp. 1222-1232 ◽  
Author(s):  
Woojin Lee ◽  
Won-Je Lee ◽  
Sang-Bae Lee ◽  
Rodrigo Salgado
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Axial Load ◽  
Load Transfer ◽  
Optical Fiber Sensor ◽  
Sensor System ◽  
Fiber Sensor ◽  
Bragg Grating ◽  
Fbg Sensors ◽  
Bragg Grating Sensor

A series of laboratory and field tests were performed to evaluate the applicability of an optical fiber sensor system in the instrumentation of piles. A multiplexed sensor system, constructed by arranging several Fiber Bragg Grating (FBG) sensors along a single line of optical fiber, is capable of measuring local axial strains as a function of wavelength shifts. The distributions of axial load in three model piles and a field test pile evaluated from the strains measured by FBG sensors are found to be comparable, in terms of both magnitude and trend, with those obtained from conventional strain gauges. This suggests that the FBG sensor system is an effective tool for the analysis of the axial load transfer in piles. The successful instrumentation of a soil–cement injected precast (SIP) pile using FBG sensors suggests that the use of these sensors in drilled shafts and other types of cast in situ concrete piles is feasible. With the rapid advance of optical fiber sensor technology, the economics of the use of optical fiber sensors in this type of instrumentation is expected to improve significantly in coming years.Key words: pile foundation, load transfer, fiber optic sensor, Fiber Bragg Grating sensor.

scholarly journals The Design and Simulation of a 16-Sensors Plantar Pressure Insole Layout for Different Applications: From Sports to Clinics, a Pilot Study

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1450
Author(s):  
Alfredo Ciniglio ◽  
Annamaria Guiotto ◽  
Fabiola Spolaor ◽  
Zimi Sawacha
Keyword(s):  
Pressure Distribution ◽  
Plantar Pressure ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Weight Lifting ◽  
Lower Limbs ◽  
Plantar Pressure Distribution ◽  
Drop Landing ◽  
Mean Pressure ◽  
Footwear Design

The quantification of plantar pressure distribution is widely done in the diagnosis of lower limbs deformities, gait analysis, footwear design, and sport applications. To date, a number of pressure insole layouts have been proposed, with different configurations according to their applications. The goal of this study is to assess the validity of a 16-sensors (1.5 × 1.5 cm) pressure insole to detect plantar pressure distribution during different tasks in the clinic and sport domains. The data of 39 healthy adults, acquired with a Pedar-X® system (Novel GmbH, Munich, Germany) during walking, weight lifting, and drop landing, were used to simulate the insole. The sensors were distributed by considering the location of the peak pressure on all trials: 4 on the hindfoot, 3 on the midfoot, and 9 on the forefoot. The following variables were computed with both systems and compared by estimating the Root Mean Square Error (RMSE): Peak/Mean Pressure, Ground Reaction Force (GRF), Center of Pressure (COP), the distance between COP and the origin, the Contact Area. The lowest (0.61%) and highest (82.4%) RMSE values were detected during gait on the medial-lateral COP and the GRF, respectively. This approach could be used for testing different layouts on various applications prior to production.

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