In the high-tech mechatronics world, aluminum and steel are well known materials, while carbon fiber is often neglected. In the RAAK project 'Composites in Mechatronics', the use of carbon fiber composites in mechatronics is investigated.
We report on the calibration and testing of a fiber Bragg grating (FBG)-based 2D-shape sensing strip for real-time monitoring of the position and orientation of the human spine during gait. The strip is evaluated for its use as an input for control of an exoskeleton for patients with spinal cord injury. By measuring the torsion and bending of the back, walking movements can be reconstructed. The 3D-printed strip has nine embedded fiber Bragg gratings that are located at specific places with respect to the vertebral column. Three FBGs are placed opposite to the thoracic vertebrae T6–T9, these FBGs are sensitive for measuring the bending of the spine during the gait cycle. Torsion is measured at two locations: at thoracic vertebra, T3 and at lumbar vertebra, L3. At these locations, the width of the strip is reduced to have a larger sensitivity for torsion. The strain at each FBG is measured using an interrogator. This leads to the radius of curvature and torsion as a function of time. The Frenet-Serret formulae are used to calculate the shape of the strip during the gait cycle. We have calibrated this FBG strip for curvature by bending it at known radius of different curvatures. We found a linear dependence between the strain and curvature. For torsion calibration we have rotated the strip with a stepper motor at different angles and monitored the strain. We, again, found a linear dependence with a small hysteresis. We mounted the strip on a healthy test subject and monitored their gait cycle. The FBG strip shows similar results when compared to a motion capture system based on multiple cameras. Although the fixation of the strip to a garment or on the back directly strongly influences the measured response, it does show a periodic and reproducible signal during the gait cycle.
This investigation is undertaken based on the indicated improvements for fabric simulations, defined during the panel discussion “Driving the Uniformity of Material Measurements for Accurate Virtual Simulation” at the Product Innovation Apparel Conference (PI Apparel) in Berlin 2017, by experts from industry and academia. According to the expert panel, there is no coherency between methods used to measure the fabric properties and the simulated results of the same fabric among the different software packages. In praxis, fashion brands use different 3D software packages and need to measure a fabric with different methods to obtain the same fabric properties. In addition to the time investment, the simulated results for the same fabric vary significantly between the different software packages. The experts indicated the lack of standardization in material measurements, the lack of correlation between the data of the different measurement systems, and the lack of correlation between the simulated results of the different software packages for the same material. The contributions of the panel were followed up during the next edition of PI Apparel in the United States and resulted in the 3D Retail Coalition (RC) innovation committee to work on the indicated areas to improve the efficiency of material measurements. Moreover, this topic was further discussed during the PI Apparel Conference at Lago Maggiore in 2019 within the panel discussion "How Can We Collectively Achieve the Standardisation of Fabric Measurements for Digital Materials?"This paper investigates, on the one hand, the suitability of the current available measurement technologies for retrieving fabric parameters for precise virtual fabric and garment simulations. The focus is on the main properties required by the software packages—bending, shear, tensile and friction—aiming to identify and specify the most suitable methods to retrieve mechanical fabric properties and to start a standardization process for fabric measurements for virtual simulations.Seven fabric measurement methods and their output data are reviewed, namely the Kawabata Evaluation System (KES), the Fabric Assurance by Simple Testing (FAST), the Fabric Touch Tester (FTT), the CLO Fabric Kit 2.0, the Fabric Analyser by Browzwear (FAB), the Optitex Mark 10, and the cantilever principle. A set of fabrics with different mechanical behavior and physical drape has been tested with the FAB method. Other measurement methods have been discussed with expert users. In addition, fabrics have been tested with ZwickRoell’s (ZwickRoell) measuring systems applying various standard measurement methods, developed for similar materials. This publication will give for each property an overview of the different measurement methods, as well as recommendations based on their accuracy. Further, a SWOT analysis is provided. The outcome of this research can be used to pave the foundation for further work on the standardization of the fabric measurement.
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Low back pain is the leading cause of disability worldwide and a significant contributor to work incapacity. Although effective therapeutic options are scarce, exercises supervised by a physiotherapist have shown to be effective. However, the effects found in research studies tend to be small, likely due to the heterogeneous nature of patients' complaints and movement limitations. Personalized treatment is necessary as a 'one-size-fits-all' approach is not sufficient. High-tech solutions consisting of motions sensors supported by artificial intelligence will facilitate physiotherapists to achieve this goal. To date, physiotherapists use questionnaires and physical examinations, which provide subjective results and therefore limited support for treatment decisions. Objective measurement data obtained by motion sensors can help to determine abnormal movement patterns. This information may be crucial in evaluating the prognosis and designing the physiotherapy treatment plan. The proposed study is a small cohort study (n=30) that involves low back pain patients visiting a physiotherapist and performing simple movement tasks such as walking and repeated forward bending. The movements will be recorded using sensors that estimate orientation from accelerations, angular velocities and magnetometer data. Participants complete questionnaires about their pain and functioning before and after treatment. Artificial analysis techniques will be used to link the sensor and questionnaire data to identify clinically relevant subgroups based on movement patterns, and to determine if there are differences in prognosis between these subgroups that serve as a starting point of personalized treatments. This pilot study aims to investigate the potential benefits of using motion sensors to personalize the treatment of low back pain. It serves as a foundation for future research into the use of motion sensors in the treatment of low back pain and other musculoskeletal or neurological movement disorders.
In order to decrease the environmental impact caused by the construction sector, biobased materials need to be further developed to allow better integration and acceptance in the market. Mycelium composites are innovative products, with intrinsic properties which rise the attention of architects, designers and industrial companies. Both mycelium foam and board material have the potential to substitute conventional toxic materials. The mechanical properties of these products are influenced by their production process. For example, bending and tensile strengths have shown to be higher in heat pressed samples (F. V.W. Appels, 2019). The heat press process related to mycelium boards, needs further development in terms of process timing and of parameters, as temperature, pressure and duration of pressing. It is the need to research mycelium boards which drove the partner companies to approach the Centre of Expertise BioBased Economy (CoEBBE). The project partners are the following: KNN Cellulose BV, Fungalogic and V8 Architects. The interest of each partner is focused on different aspects of mycelium boards, which can be summarised in the following questions: • Is it possible to use cellulose to produce mycelium composites? (KNN Cellulose) • What are the different production parameters and how can these be optimized? (V8 Architects, Fungalogic) • What are the mechanical material properties and (how) can mycelium boards be used for interior or construction purposes? (V8 Architects, Fungalogic) These questions merge together in the research question: is it possible to create a mycelium board with cellulose biomass that can be used as a substitution of conventional board materials? The developed research will bring specific knowledge to each involved partner. In particular, KNN Cellulose will have a new application for their product; Fungalogic will acquire knowledge on board materials and have a potential new product; V8 Architects will gain specific knowledge on mycelium products.
