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Lu S, Tan Z, Zhang D. Dual D-shaped plastic optical fiber for simultaneous measurement of refractive index and temperature based on specklegram. OPTICS EXPRESS 2024; 32:15166-15176. [PMID: 38859175 DOI: 10.1364/oe.522435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 03/23/2024] [Indexed: 06/12/2024]
Abstract
The refractive index (RI) measurment of the liquid often changes with the sensor's temperature. Accurate RI measurements require simultaneous measurements of the liquid temperature to calibrate the RI measurement. This study proposed what we believe to be a novel dual D-shaped plastic optical fiber sensor capable of simultaneously measuring both RI and temperature. A fluorescent material made of rhodamine B (RhB) is embedded in one of the D-shaped structures of the dual D-shaped fiber, which can be excited by a green laser to produce orange fluorescence. The fluorescence and the input laser of the fiber are superimposed at the output end of the fiber to form a specklegram containing information of two wavelengths. It was found through experiments that the effects of temperature and RI change on the red and green channels of the specklegrams are different, and the neural network can learn this feature to complete the measurement of both RI and temperature parameters. For RI sensing, the maximum error between the average predicted value and the true value of the test set is 0.0005. For temperature sensing, the maximum error between the average predicted value and the true value of the test set is 0.26°C. In addition, because the intensity change of the fluorescence varies linearly with RI and temperature, the sensor also has good stability.
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2
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Jin L, Xie K, Du Y, Li M. Linearization signal conditioning circuit for tri-axial micro-grating MOEMS accelerometer. OPTICS EXPRESS 2024; 32:10241-10251. [PMID: 38571240 DOI: 10.1364/oe.518469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/24/2024] [Indexed: 04/05/2024]
Abstract
This paper proposes what we believe to be a novel linearization signal conditioning circuit for a tri-axial micro-grating micro-opto-electro-mechanical systems (MOEMS) accelerometer. The output of a micro-grating accelerometer varies as a sine/cosine function of the acceleration. The proposed circuit utilizes a subdivision interpolation technique to process these nonlinear intensity variations and render a linear digital output across the full range. Such a linearization circuit was achieved through a 90-degree phase-shift circuit, high-precision DC bias-voltage and subdivision interpolation circuits to reduce the influence of phase, magnitude, and offset errors of the sine-cosine signals on the interpolation factor, improving the resolution and accuracy of acceleration detection. Experimental results demonstrated that the micro-grating MOEMS accelerometer achieves a resolution of sub-mg, cross-axis errors of 3.57%, 1.22% and 0.89% for x-, y- and z-aixs, respectively. The bias instabilities and velocity random walks for the vertical and lateral accelerometer are superior to 26 µg and 38.7 µg/√Hz. The tri-axial micro-grating MOEMS accelerometer exhibits significant potential for applications requiring high sensitivity and large operation ranges, including the automotive industry and military equipment.
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3
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Ghaderi Goran Abad M, Mahmoudi M. Microwave optical limiting via an acoustic field in a diamond mechanical resonator. OPTICS EXPRESS 2024; 32:8249-8261. [PMID: 38439486 DOI: 10.1364/oe.511843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/14/2024] [Indexed: 03/06/2024]
Abstract
We investigate the generation and control of the reverse saturable absorption (RSA) and optical limiting (OL) at microwave (mw) range in high-Q single-crystal diamond mechanical resonator (DMR) embedded with many nitrogen-vacancy (NV) centers. The strain-induced acoustic modes enable mechanical manipulation of NV centers. On the basis of strain-coupling mechanism, it is shown that the saturable absorption (SA) switches to the RSA by applying the acoustic field, leading to induce the OL in the diamond through the cross-Kerr effect. We demonstrate that the OL characteristics such as, threshold, efficiency, and dynamic range can be controlled by changing either the intensity or frequency of the acoustic field. Moreover, we show that this optical limiter can amplify noiselessly the low intensity of the mw field input to the sensors and also attenuate any gain-induced noise and increase in the intensity of the mw field if it exceeds the intensity threshold. In addition, it is shown that by increasing either the number of NV centers or length of the diamond, the optical limiter can be more efficient. The physical mechanism of the OL establishment is explained using the analytical expressions, which are in good agreement with the numerical results. Our proposed acoustic-induced optical limiter can be a scheme for protecting different optical and electronic devices in mw range, remote sensing, navigation, communications, microwave heating and thermo/laser therapy.
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Zhang X, Wang C, Zheng T, Wu H, Wu Q, Wang Y. Wearable Optical Fiber Sensors in Medical Monitoring Applications: A Review. SENSORS (BASEL, SWITZERLAND) 2023; 23:6671. [PMID: 37571457 PMCID: PMC10422468 DOI: 10.3390/s23156671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 08/13/2023]
Abstract
Wearable optical fiber sensors have great potential for development in medical monitoring. With the increasing demand for compactness, comfort, accuracy, and other features in new medical monitoring devices, the development of wearable optical fiber sensors is increasingly meeting these requirements. This paper reviews the latest evolution of wearable optical fiber sensors in the medical field. Three types of wearable optical fiber sensors are analyzed: wearable optical fiber sensors based on Fiber Bragg grating, wearable optical fiber sensors based on light intensity changes, and wearable optical fiber sensors based on Fabry-Perot interferometry. The innovation of wearable optical fiber sensors in respiration and joint monitoring is introduced in detail, and the main principles of three kinds of wearable optical fiber sensors are summarized. In addition, we discuss their advantages, limitations, directions to improve accuracy and the challenges they face. We also look forward to future development prospects, such as the combination of wireless networks which will change how medical services are provided. Wearable optical fiber sensors offer a viable technology for prospective continuous medical surveillance and will change future medical benefits.
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Affiliation(s)
- Xuhui Zhang
- Heilongjiang Province Key Laboratory of Laser Spectroscopy Technology and Application, Harbin University of Science and Technology, Harbin 150080, China; (X.Z.); (C.W.); (H.W.)
| | - Chunyang Wang
- Heilongjiang Province Key Laboratory of Laser Spectroscopy Technology and Application, Harbin University of Science and Technology, Harbin 150080, China; (X.Z.); (C.W.); (H.W.)
| | - Tong Zheng
- School of Artificial Intelligence, Beijing Technology and Business University, Beijing 100048, China;
| | - Haibin Wu
- Heilongjiang Province Key Laboratory of Laser Spectroscopy Technology and Application, Harbin University of Science and Technology, Harbin 150080, China; (X.Z.); (C.W.); (H.W.)
| | - Qing Wu
- Heilongjiang Province Key Laboratory of Laser Spectroscopy Technology and Application, Harbin University of Science and Technology, Harbin 150080, China; (X.Z.); (C.W.); (H.W.)
| | - Yunzheng Wang
- Center for Optics Research and Engineering, Shandong University, Qingdao 266237, China
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Dežman M, Massardi S, Pinto-Fernandez D, Grosu V, Rodriguez-Guerrero C, Babič J, Torricelli D. A mechatronic leg replica to benchmark human-exoskeleton physical interactions. BIOINSPIRATION & BIOMIMETICS 2023; 18. [PMID: 37068491 DOI: 10.1088/1748-3190/accda8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/17/2023] [Indexed: 05/09/2023]
Abstract
Evaluating human-exoskeleton interaction typically requires experiments with human subjects, which raises safety issues and entails time-consuming testing procedures. This paper presents a mechatronic replica of a human leg, which was designed to quantify physical interaction dynamics between exoskeletons and human limbs without the need for human testing. In the first part of this work, we present the mechanical, electronic, sensory system and software solutions integrated in our leg replica prototype. In the second part, we used the leg replica to test its interaction with two types of commercially available wearable devices, i.e. an active full leg exoskeleton and a passive knee orthosis. We ran basic test examples to demonstrate the functioning and benchmarking potential of the leg replica to assess the effects of joint misalignments on force transmission. The integrated force sensors embedded in the leg replica detected higher interaction forces in the misaligned scenario in comparison to the aligned one, in both active and passive modalities. The small standard deviation of force measurements across cycles demonstrates the potential of the leg replica as a standard test method for reproducible studies of human-exoskeleton physical interaction.
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Affiliation(s)
- Miha Dežman
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Stefano Massardi
- Department of Industrial Mechanical Engineering (DIMI), University of Brescia (UNIBS), Brescia, Italy
- Instituto Cajal, Spanish National Research Council (CSIC), Madrid, Spain
| | - David Pinto-Fernandez
- Universidad Politécnica de Madrid, Madrid, Spain
- Instituto Cajal, Spanish National Research Council (CSIC), Madrid, Spain
| | - Victor Grosu
- Department of Mechanical Engineering, Robotics & Multibody Mechanics Research Group (R&MM), and Flanders Make, Vrije Universiteit Brussel, Brussel, Belgium
- Research and Development Department, GROVIXON BV, Vilvoorde, Belgium
| | | | - Jan Babič
- Laboratory for Neuromechanics and Biorobotics, Jožef Stefan Institute, Ljubljana, Slovenia
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Diego Torricelli
- Instituto Cajal, Spanish National Research Council (CSIC), Madrid, Spain
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6
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Influence of UV Radiation on Mechanical Properties of Polymer Optical Fibers. Polymers (Basel) 2022; 14:polym14214496. [DOI: 10.3390/polym14214496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 11/16/2022] Open
Abstract
This paper presents an analysis of the mechanical properties of different polymer optical fibers (POFs) at ultraviolet (UV) radiation conditions. Cyclic transparent optical polymer (CYTOP) and polymethyl methacrylate (PMMA) optical fibers are used in these analyses. In this case, the fiber samples are irradiated at the same wavelength, pulse time and energy conditions for different times, namely, 10 s, 1 min, 2 min and 3 min. The samples are tested in tensile tests and dynamic mechanical thermal analysis (DMTA) to infer the variation in the static and dynamic properties of such fibers as a function of the UV radiation condition. Furthermore, reference samples of each fiber (without UV radiation) are tested for comparison purposes. The results show a lower UV resistance of PMMA fibers, i.e., higher variation in the material features in static conditions (Young’s modulus variation of 0.65 GPa). In addition, CYTOP fiber (material known for its high UV resistance related to its optical properties) also presented Young’s modulus variation of around 0.38 GPa. The reason for this reduction in the moduli is related to possible localized annealing due to thermal effects when the fibers are subjected to UV radiation. The dynamic results also indicated a higher variation in the PMMA fibers storage modulus, which is around 30% higher than the variations in the CYTOP fibers when different radiation conditions are analyzed. However, CYTOP fibers show a smaller operational temperature range and higher variation in the storage modulus as a function of the temperature when compared with PMMA fibers. In contrast, PMMA fibers show higher variations in their material properties when subjected to oscillatory loads at different frequency conditions. Thus, the results obtained in this work can be used as guidelines for the influence of UV radiation in POFs not only for the material choice, but also on the limitations of UV radiation in the fabrication of the grating as well as in sensor applications at UV radiation conditions.
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Pospori A, Ioannou A, Kalli K. Temperature and Humidity Sensitivity of Polymer Optical Fibre Sensors Tuned by Pre-Strain. SENSORS (BASEL, SWITZERLAND) 2022; 22:s22197233. [PMID: 36236332 PMCID: PMC9572418 DOI: 10.3390/s22197233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/17/2022] [Accepted: 09/21/2022] [Indexed: 05/31/2023]
Abstract
Polymer optical fibre Bragg grating (POFBG) sensors are of high interest due to their enhanced fracture toughness, flexibility in bending, and sensitivity in stress and pressure monitoring applications compared to silica-based sensors. The POFBG sensors can also detect humidity due to the hydrophilic nature of some polymers. However, multi-parameter sensing can cause cross-sensitivity issues in certain applications if the temperature and humidity measurements are not adequately compensated. In this work, we demonstrate the possibility of selectively tuning sensors' temperature and humidity sensitivities to the desired level by applying a certain amount of fibre pre-strain. The temperature sensitivity of POFBG sensors fabricated in perfluoropolymers (CYTOP) can be selectively tuned from positive to negative values, having the option for insensitivity in specific temperature ranges depending on the amount of the applied pre-strain. The humidity sensitivity of sensors can also be changed from positive values to insensitivity. The importance of thermal annealing treatment of POFBG sensors for improved repeatability in temperature measurements is also reported. An array of 4 multiplexed POFBGs was fabricated, and each sensor was pre-strained accordingly to demonstrate the possibility of having targeted temperature and humidity sensitivities along the same fibre.
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8
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Massardi S, Rodriguez-Cianca D, Pinto-Fernandez D, Moreno JC, Lancini M, Torricelli D. Characterization and Evaluation of Human–Exoskeleton Interaction Dynamics: A Review. SENSORS 2022; 22:s22113993. [PMID: 35684614 PMCID: PMC9183080 DOI: 10.3390/s22113993] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 02/01/2023]
Abstract
Exoskeletons and exosuits have witnessed unprecedented growth in recent years, especially in the medical and industrial sectors. In order to be successfully integrated into the current society, these devices must comply with several commercialization rules and safety standards. Due to their intrinsic coupling with human limbs, one of the main challenges is to test and prove the quality of physical interaction with humans. However, the study of physical human–exoskeleton interactions (pHEI) has been poorly addressed in the literature. Understanding and identifying the technological ways to assess pHEI is necessary for the future acceptance and large-scale use of these devices. The harmonization of these evaluation processes represents a key factor in building a still missing accepted framework to inform human–device contact safety. In this review, we identify, analyze, and discuss the metrics, testing procedures, and measurement devices used to assess pHEI in the last ten years. Furthermore, we discuss the role of pHEI in safety contact evaluation. We found a very heterogeneous panorama in terms of sensors and testing methods, which are still far from considering realistic conditions and use-cases. We identified the main gaps and drawbacks of current approaches, pointing towards a number of promising research directions. This review aspires to help the wearable robotics community find agreements on interaction quality and safety assessment testing procedures.
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Affiliation(s)
- Stefano Massardi
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28006 Madrid, Spain; (S.M.); (D.R.-C.); (D.P.-F.); (J.C.M.)
- Department of Mechanical and Industrial Engineering (DIMI), University of Brescia, 25100 Brescia, Italy
| | - David Rodriguez-Cianca
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28006 Madrid, Spain; (S.M.); (D.R.-C.); (D.P.-F.); (J.C.M.)
| | - David Pinto-Fernandez
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28006 Madrid, Spain; (S.M.); (D.R.-C.); (D.P.-F.); (J.C.M.)
- Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Juan C. Moreno
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28006 Madrid, Spain; (S.M.); (D.R.-C.); (D.P.-F.); (J.C.M.)
| | - Matteo Lancini
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health (DSMC), University of Brescia, 25100 Brescia, Italy;
| | - Diego Torricelli
- Neural Rehabilitation Group, Cajal Institute, Spanish National Research Council (CSIC), 28006 Madrid, Spain; (S.M.); (D.R.-C.); (D.P.-F.); (J.C.M.)
- Correspondence:
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9
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Shin S, Hur JG, Park JK, Kim DH. Polarization effects on ablation efficiency and microstructure symmetricity in femtosecond laser processing of materials-developing a pattern generation model for laser scanning. OPTICS EXPRESS 2022; 30:18018-18031. [PMID: 36221610 DOI: 10.1364/oe.459377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/23/2022] [Indexed: 06/16/2023]
Abstract
This paper investigated the effects of femtosecond laser beam polarization on ablation efficiency and microstructure symmetricity for 64FeNi alloy (Invar) sheet processing to fabricate fine metal masks. It was found that the ablation efficiency for linear polarization was approximately 15% higher than that for circular polarization due to electric field enhancement induced by low-spatial-frequency laser-induced periodic surface structures (LIPSS). The hole size and sidewall taper angles for the microstructures generated by linear polarization were asymmetric, whereas those generated by circular polarization were symmetric due to non-oriented LIPSS. The asymmetric and symmetric three-dimensional microstructure profiles, measured by using a confocal laser scanning microscope, were verified by employing an analytical model that was derived using the total input fluence and the ablation rates for linear and circular polarizations, respectively.
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Lesiak P, Pogorzelec K, Bochenek A, Sobotka P, Bednarska K, Anuszkiewicz A, Osuch T, Sienkiewicz M, Marek P, Nawotka M, Woliński TR. Three-Dimensional-Printed Mechanical Transmission Element with a Fiber Bragg Grating Sensor Embedded in a Replaceable Measuring Head. SENSORS 2022; 22:s22093381. [PMID: 35591070 PMCID: PMC9103822 DOI: 10.3390/s22093381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/23/2022] [Accepted: 04/24/2022] [Indexed: 12/10/2022]
Abstract
Compliant mechanisms have gained an increasing interest in recent years, especially in relation to the possibility of using 3D printers for their production. These mechanisms typically find applications in precise positioning systems of building robotic devices or in sensing where they can be used to characterize displacement. Three-dimensional printing with PLA materials allows fiber optic-based sensors to be incorporated into the structures of properly designed compliant mechanisms. Therefore, in this paper, an innovative technology is described, of a Fiber Bragg Grating (FBG) sensor embedded in a measuring head which was then inserted into a specially designed mechanical transmission element. The shape of this element is based on clippers that allow to freely modify the amplification of displacement amplitude so that the FBG sensor always works in the most optimal regime without any need to modify its external dimensions. Flexural sensitivity of the replaceable measuring head equal to 1.26 (mε/mm) can be adapted to the needs of the flexure design.
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Affiliation(s)
- Piotr Lesiak
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
- Correspondence:
| | - Konrad Pogorzelec
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
| | - Aleksandra Bochenek
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
| | - Piotr Sobotka
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
| | - Karolina Bednarska
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
| | - Alicja Anuszkiewicz
- Faculty of Electronics and Information Technology, Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland; (A.A.); (T.O.)
- Institute of Microelectronics and Photonics, Lukasiewicz Research Network, al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Tomasz Osuch
- Faculty of Electronics and Information Technology, Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland; (A.A.); (T.O.)
- National Institute of Telecommunications, Szachowa 1, 04-894 Warsaw, Poland
| | - Maksymilian Sienkiewicz
- Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, 00-665 Warsaw, Poland; (M.S.); (P.M.)
| | - Piotr Marek
- Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, 00-665 Warsaw, Poland; (M.S.); (P.M.)
| | - Michał Nawotka
- Central Office of Measures, Elektoralna 2, 00-139 Warsaw, Poland;
| | - Tomasz R. Woliński
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-665 Warsaw, Poland; (K.P.); (A.B.); (P.S.); (K.B.); (T.R.W.)
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Butt AM, Alsaffar H, Alshareef M, Qureshi KK. AI Prediction of Brain Signals for Human Gait Using BCI Device and FBG Based Sensorial Platform for Plantar Pressure Measurements. SENSORS 2022; 22:s22083085. [PMID: 35459070 PMCID: PMC9025845 DOI: 10.3390/s22083085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/30/2022] [Accepted: 04/11/2022] [Indexed: 12/16/2022]
Abstract
Artificial intelligence (AI) in developing modern solutions for biomedical problems such as the prediction of human gait for human rehabilitation is gaining ground. An attempt was made to use plantar pressure information through fiber Bragg grating (FBG) sensors mounted on an in-sole, in tandem with a brain-computer interface (BCI) device to predict brain signals corresponding to sitting, standing and walking postures of a person. Posture classification was attained with an accuracy range between 87–93% from FBG and BCI signals using machine learning models such as K-nearest neighbor (KNN), logistic regression (LR), support vector machine (SVM), and naïve Bayes (NB). These models were used to identify electrodes responding to sitting, standing and walking activities of four users from a 16 channel BCI device. Six electrode positions based on the 10–20 system for electroencephalography (EEG) were identified as the most sensitive to plantar activities and found to be consistent with clinical investigations of the sensorimotor cortex during foot movement. A prediction of brain EEG corresponding to given FBG data with lowest mean square error (MSE) values (0.065–0.109) was made with the selection of a long-short term memory (LSTM) machine learning model when compared to the recurrent neural network (RNN) and gated recurrent unit (GRU) models.
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Affiliation(s)
- Asad Muhammad Butt
- College of Chemicals & Materials, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
- Correspondence: ; Tel.: +966-537651766
| | - Hassan Alsaffar
- Electrical Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia; (H.A.); (M.A.)
- Physics Department, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Muhannad Alshareef
- Electrical Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia; (H.A.); (M.A.)
| | - Khurram Karim Qureshi
- Optical Communications and Sensors Laboratory (OCSL), Electrical Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia;
- Center for Communication Systems & Sensing, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
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12
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Development of a 3D Relative Motion Method for Human-Robot Interaction Assessment. SENSORS 2022; 22:s22062411. [PMID: 35336593 PMCID: PMC8952123 DOI: 10.3390/s22062411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 12/10/2022]
Abstract
Exoskeletons have been assessed by qualitative and quantitative features known as performance indicators. Within these, the ergonomic indicators have been isolated, creating a lack of methodologies to analyze and assess physical interfaces. In this sense, this work presents a three-dimensional relative motion assessment method. This method quantifies the difference of orientation between the user’s limb and the exoskeleton link, providing a deeper understanding of the Human–Robot interaction. To this end, the AGoRA exoskeleton was configured in a resistive mode and assessed using an optoelectronic system. The interaction quantified a difference of orientation considerably at a maximum value of 41.1 degrees along the sagittal plane. It extended the understanding of the Human–Robot Interaction throughout the three principal human planes. Furthermore, the proposed method establishes a performance indicator of the physical interfaces of an exoskeleton.
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13
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Armitage L, Turner S, Sreenivasa M. Human-device interface pressure measurement in prosthetic, orthotic and exoskeleton applications: A systematic review. Med Eng Phys 2021; 97:56-69. [PMID: 34756339 DOI: 10.1016/j.medengphy.2021.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 08/16/2021] [Accepted: 09/20/2021] [Indexed: 02/02/2023]
Abstract
This study aimed to investigate normal and shear load sensor technology that has been characterised and used at the human-device interface in prosthetic, orthotic and exoskeleton applications. In addition to taking a cross-disciplinary view, this study expands on previous reviews by considering recently published papers, clinical translation of sensors, and development of the sensor technology itself. A search of MEDLINE, INSPEC, SCOPUS and Web of Science was performed up to 26 January 2021. A total of 33 studies were assessed for quality and their data extracted. The review found variable quality of published papers, with normal load being most commonly measured, and resistive sensor technology most commonly used. The translation to clinical environments was indicated in most studies, though the study population was not always made up of the target users. Studies could benefit from more direct comparison with clinically relevant load thresholds and by ensuring clinical testing is performed in the most realistic and representative way possible. Additionally, more focus on developing sensors that measure shear loads would enable further insights into conditions at the human-device interface. Finally, all researchers would benefit from better and more widespread anonymous data sharing practices to facilitate further experimentation.
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Affiliation(s)
- Lucy Armitage
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Shruti Turner
- Sackler MSk Laboratory, Department of Surgery and Cancer, Sir Michael Uren Hub, Imperial College London, 86 Wood Ln, London W12 0BZ, United Kingdom.
| | - Manish Sreenivasa
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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14
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Leal-Junior A, Avellar L, Jaimes J, Díaz C, dos Santos W, Siqueira AAG, Pontes MJ, Marques C, Frizera A. Polymer Optical Fiber-Based Integrated Instrumentation in a Robot-Assisted Rehabilitation Smart Environment: A Proof of Concept. SENSORS 2020; 20:s20113199. [PMID: 32512903 PMCID: PMC7313705 DOI: 10.3390/s20113199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/20/2020] [Accepted: 06/01/2020] [Indexed: 11/30/2022]
Abstract
Advances in robotic systems for rehabilitation purposes have led to the development of specialized robot-assisted rehabilitation clinics. In addition, advantageous features of polymer optical fiber (POF) sensors such as light weight, multiplexing capabilities, electromagnetic field immunity and flexibility have resulted in the widespread use of POF sensors in many areas. Considering this background, this paper presents an integrated POF intensity variation-based sensor system for the instrumentation of different devices. We consider different scenarios for physical rehabilitation, resembling a clinic for robot-assisted rehabilitation. Thus, a multiplexing technique for POF intensity variation-based sensors was applied in which an orthosis for flexion/extension movement, a modular exoskeleton for gait assistance and a treadmill were instrumented with POF angle and force sensors, where all the sensors were integrated in the same POF system. In addition, wearable sensors for gait analysis and physiological parameter monitoring were also proposed and applied in gait exercises. The results show the feasibility of the sensors and methods proposed, where, after the characterization of each sensor, the system was implemented with three volunteers: one for the orthosis on the flexion/extension movements, one for the exoskeleton for gait assistance and the other for the free gait analysis using the proposed wearable POF sensors. To the authors’ best knowledge, this is the first time that optical fiber sensors have been used as a multiplexed and integrated solution for the simultaneous assessment of different robotic devices and rehabilitation protocols, where such an approach results in a compact, fully integrated and low-cost system, which can be readily employed in any clinical environment.
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Affiliation(s)
- Arnaldo Leal-Junior
- Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitória 29075-910, Brazil; (L.A.); (C.D.); (M.J.P.); (A.F.)
- Correspondence: (A.L.-J.); (C.M.)
| | - Leticia Avellar
- Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitória 29075-910, Brazil; (L.A.); (C.D.); (M.J.P.); (A.F.)
| | - Jonathan Jaimes
- Department of Mechanical Engineering, Engineering School of São Carlos, University of São Paulo, São Carlos 13566-590, Brazil; (J.J.); (W.d.S.); (A.A.G.S.)
| | - Camilo Díaz
- Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitória 29075-910, Brazil; (L.A.); (C.D.); (M.J.P.); (A.F.)
| | - Wilian dos Santos
- Department of Mechanical Engineering, Engineering School of São Carlos, University of São Paulo, São Carlos 13566-590, Brazil; (J.J.); (W.d.S.); (A.A.G.S.)
| | - Adriano A. G. Siqueira
- Department of Mechanical Engineering, Engineering School of São Carlos, University of São Paulo, São Carlos 13566-590, Brazil; (J.J.); (W.d.S.); (A.A.G.S.)
| | - Maria José Pontes
- Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitória 29075-910, Brazil; (L.A.); (C.D.); (M.J.P.); (A.F.)
| | - Carlos Marques
- I3N & Physics Department, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
- Correspondence: (A.L.-J.); (C.M.)
| | - Anselmo Frizera
- Graduate Program of Electrical Engineering, Federal University of Espirito Santo, Vitória 29075-910, Brazil; (L.A.); (C.D.); (M.J.P.); (A.F.)
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15
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Avellar L, Leal-Junior A, Marques C, Frizera A. Performance Analysis of a Lower Limb Multi Joint Angle Sensor Using CYTOP Fiber: Influence of Light Source Wavelength and Angular Velocity Compensation. SENSORS 2020; 20:s20020326. [PMID: 31935990 PMCID: PMC7013721 DOI: 10.3390/s20020326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 11/16/2022]
Abstract
This paper presents the analysis of an intensity variation polymer optical fiber (POF)-based angle sensor performance, i.e., sensitivity, hysteresis and determination coefficient ( R 2 ), using cyclic transparent optical polymer (CYTOP) fiber. The analysis consisted of two approaches: influence of different light source central wavelengths (430 nm, 530 nm, 660 nm, 870 nm and 950 nm) and influence of different angular velocities ( 0.70 rad/s, 0.87 rad/s, 1.16 rad/s, 1.75 rad/s and 3.49 rad/s). The first approach aimed to select the source which resulted in the most suitable performance regarding highest sensitivity and linearity while maintaining lowest hysteresis, through the figure of merit. Thereafter, the analysis of different angular velocities was performed to evaluate the influence of velocity in the curvature sensor performance. Then, a discrete angular velocity compensation was proposed in order to reduce the root-mean-square error (RMSE) of responses for different angular velocities. Ten tests for each analysis were performed with angular range of 0 ∘ to 50 ∘ , based on knee and ankle angle range during the gait. The curvature sensor was applied in patterns simulating the knee and ankle during the gait. Results show repeatability and the best sensor performance for λ = 950 nm in the first analysis and show high errors for high angular velocities ( w = 3.49 rad/s) in the second analysis, which presented up to 50 % angular error. The uncompensated RMSE was high for all velocities ( 6.45 ∘ to 12.41 ∘ ), whereas the compensated RMSE decreased up to 74 % ( 1.67 ∘ to 3.62 ∘ ). The compensated responses of application tests showed maximum error of 5.52 ∘ and minimum of 1.06 ∘ , presenting a decrease of mean angular error up to 30 ∘ when compared with uncompensated responses.
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Affiliation(s)
- Letícia Avellar
- Graduate Program in Electrical Engineering, Federal University of Espirito Santo, 29075-910 Vitoria, Brazil;
- Correspondence: ; Tel.: +55-27-4009-2644
| | - Arnaldo Leal-Junior
- Mechanical Engineering Department, Federal University of Espirito Santo, 29075-910 Espirito Santo, Brazil;
| | - Carlos Marques
- I3N & Physics Department, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal;
| | - Anselmo Frizera
- Graduate Program in Electrical Engineering, Federal University of Espirito Santo, 29075-910 Vitoria, Brazil;
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3D-Printing Techniques on the Development of Multiparameter Sensors Using One FBG. SENSORS 2019; 19:s19163514. [PMID: 31405237 PMCID: PMC6720728 DOI: 10.3390/s19163514] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 12/01/2022]
Abstract
We report the development of a fiber Bragg grating (FBG) sensor for multiparameter sensing using only one FBG. The FBG was half-embedded in a 3D-printed structure, which resulted in a division of the grating spectrum creating two peaks with different sensitivities with respect to different physical parameters. A numerical analysis of the proposed technique was performed using the coupled-mode theory with modified transfer matrix formulation. Then, experimental analyses were performed as function of temperature, strain and force, where the peaks showed different sensitivities in all analyzed cases. Such results enable the application of a technique for simultaneous measurement of multiple physical parameters using both peaks and the full width half maximum of the FBG embedded in a 3D structure. In the simultaneous multiparameter assessment, the proposed sensor system was able to estimate the three tested parameters (strain, temperature and force) with relative errors as low as 4%.
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Avellar LM, Leal-Junior AG, Diaz CAR, Marques C, Frizera A. POF Smart Carpet: A Multiplexed Polymer Optical Fiber-Embedded Smart Carpet for Gait Analysis. SENSORS 2019; 19:s19153356. [PMID: 31370153 PMCID: PMC6695953 DOI: 10.3390/s19153356] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 07/23/2019] [Accepted: 07/29/2019] [Indexed: 11/16/2022]
Abstract
This paper presents the development of a smart carpet based on polymer optical fiber (POF) for ground reaction force (GRF) and spatio-temporal gait parameter assessment. The proposed carpet has 20 intensity variation-based sensors on one fiber with two photodetectors for acquisition, each one for the response of 10 closer sensors. The used multiplexing technique is based on side-coupling between the light sources and POF lateral sections in which one light-emitting diode (LED) is activated at a time, sequentially. Three tests were performed, two for sensor characterization and one for validation of the smart carpet, where the first test consisted of the application of calibrated weights on the top of each sensor for force characterization. In the second test, the foot was positioned on predefined points distributed on the carpet, where a mean relative error of 2.9% was obtained. Results of the walking tests on the proposed POF-embedded smart carpet showed the possibility of estimating the GRF and spatio-temporal gait parameters (step and stride lengths, cadence, and stance duration). The obtained results make possible the identification of gait events (stance and swing phases) as well as the stance duration and double support periods. The proposed carpet is a low-cost and reliable tool for gait analysis in different applications.
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Affiliation(s)
- Leticia M Avellar
- Graduate Program in Electrical Engineering, Federal University of Espirito Santo, Vitoria 29075-910, Brazil.
| | - Arnaldo G Leal-Junior
- Mechanical Engineering Department, Federal University of Espirito Santo, Espirito Santo 29075-910, Brazil
| | - Camilo A R Diaz
- Graduate Program in Electrical Engineering, Federal University of Espirito Santo, Vitoria 29075-910, Brazil
| | - Carlos Marques
- I3N & Physics Department, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Anselmo Frizera
- Graduate Program in Electrical Engineering, Federal University of Espirito Santo, Vitoria 29075-910, Brazil
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Polymer Optical Fiber Sensors in Healthcare Applications: A Comprehensive Review. SENSORS 2019; 19:s19143156. [PMID: 31323734 PMCID: PMC6679278 DOI: 10.3390/s19143156] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/08/2019] [Accepted: 07/15/2019] [Indexed: 01/15/2023]
Abstract
Advances in medicine and improvements in life quality has led to an increase in the life expectancy of the general population. An ageing world population have placed demands on the use of assistive technology and, in particular, towards novel healthcare devices and sensors. Besides the electromagnetic field immunity, polymer optical fiber (POF) sensors have additional advantages due to their material features such as high flexibility, lower Young’s modulus (enabling high sensitivity for mechanical parameters), higher elastic limits, and impact resistance. Such advantages are well-aligned with the instrumentation requirements of many healthcare devices and in movement analysis. Aiming at these advantages, this review paper presents the state-of-the-art developments of POF sensors for healthcare applications. A plethora of healthcare applications are discussed, which include movement analysis, physiological parameters monitoring, instrumented insoles, as well as instrumentation of healthcare robotic devices such as exoskeletons, smart walkers, actuators, prostheses, and orthosis. This review paper shows the feasibility of using POF sensors in healthcare applications and, due to the aforementioned advantages, it is possible to envisage a further widespread use of such sensors in this research field in the next few years.
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