Search results for " Contact pressure"

showing 4 items of 4 documents

A preliminary investigation of the effect of contact pressure on the accuracy of heart rate monitoring by wearable PPG wrist band

2019

The increase of safety and health monitor of workers has become a crucial objective to prevent excessive physical workloads, injuries, accidents and errors. Heart rate (HR) is a very important physiological indicator which could properly describe the workers’ physical status. Recently, wearable photoplethysmographic (PPG) wristband trackers have been utilized to measure HR without hindering normal gesture of workers. However, the quality of PPG signals is highly affected by human physical motions, resulting in a poor reliable HR estimation. Specifically, during different activities and gestures, PPG sensor contact pressures may have an impact on the quality of the heart rate signal. To appr…

Computer sciencePhotoplethysmography wearable sensor PPG sensor contact pressureWearable computerSettore ING-IND/34 - Bioingegneria IndustrialeWristSignalLoad cellSettore ING-IND/14 - Progettazione Meccanica E Costruzione Di Macchinemedicine.anatomical_structureHeart rate monitoringHeart ratemedicineSettore ING-IND/12 - Misure Meccaniche E TermicheHeart rate variabilitysense organsContact pressureBiomedical engineering
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A new quasi-static multi-degree of freedom tapered roller bearing model to accurately consider non-Hertzian contact pressures in time-domain simulati…

2014

The accuracy of the fatigue life calculations in rolling bearing simulations is highly dependent on the precision of the roller-raceway contact simulations and the ability to accurately include structural deflections of the supporting structure. Several different methods exist to simulate the pressure distributions, and in time-domain bearing simulations, where many contacts need evaluation, the simple and time efficient methods are more popular. These methods underestimate the fatigue life reduction due to roller end effects, overload and misalignments. Furthermore, existing time-domain rolling bearing models assume that the bearing rings remain circular, which can be a poor approximation…

EngineeringBearing (mechanical)business.industryNon-Hertzian contact pressureTapered roller bearingMechanical EngineeringStiffnessStructural engineeringCondensed Matter PhysicsMulti degree of freedomlaw.inventionFlexible supportContact mechanicsTapered roller bearinglawmedicineFatigue lifeTime domainmedicine.symptombusinessReduction (mathematics)Quasistatic processProceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics
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A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements

2020

Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo

Future studies0206 medical engineeringheart rate (HR)Physical activityPhysical exercise02 engineering and technologylcsh:Chemical technology01 natural sciencesBiochemistrySignalContact force Contact pressure Heart rate (HR) Heart rate reliability Heart rate signal Photoplethysmography (PPG) PPG accuracy PPG sensor WearablesArticleAnalytical ChemistryPPG accuracysymbols.namesakeWearable Electronic Devicesphotoplethysmography (PPG)Heart RateHeart rateSettore ING-IND/12 - Misure Meccaniche E TermicheMedicineheart rate reliabilityHumanslcsh:TP1-1185Electrical and Electronic EngineeringPhotoplethysmographyInstrumentationExercisecontact pressureheart rate signalbusiness.industry010401 analytical chemistrySignal Processing Computer-Assisted020601 biomedical engineeringAtomic and Molecular Physics and OpticsPearson product-moment correlation coefficient0104 chemical sciencesIntensity (physics)PPG sensorwearablessymbolssense organsbusinesscontact forceContact pressureBiomedical engineering
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3D Data Acquisition and Numerical Analysis of a Footwear in Walking

2004

The aim of the paper is to set a procedure to study the load history of a footwear during a step with non-linear FE analysis. The geometric model tested was reconstructed from a real shoe by means of Reverse Engineering process, starting from dense point clouds acquired by non-contact scanning system. For each phase of the walk, the pressure values are obtained by a pressure distribution platform when tester is walking along the platform. The Finite Element model is easily generated by Hypermesh software using the CAD model. Ansys software is used to perform non-linear analyses. The procedure can be employed for improving the product performance in terms of durability, flexibility and comfo…

Reverse Engineering Contact pressure acquisition Finite Element Analysis Transient Non-linear Analysis CAD
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