scholarly journals Validation method for body-mounted sensor attachments

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Katharina Schmidt ◽  
David Hochmann
Keyword(s):  
Evaluation Method ◽  
Tracking System ◽  
The Body ◽  
Exploratory Research ◽  
Body Segment ◽  
Validation Method ◽  
Sensor Position ◽  
Validation Parameters ◽  
Measurement Units ◽  
Soft Tissue Artifact

AbstractSmall sensor devices like inertial measurement units enable mobile movement and gait analysis, whereby existing systems differ in data acquisition, data processing, and gait parameter calculation. Concerning the validation, recent studies focus on the captured motion and the influence of sensor positioning with respect to the accuracy of the computed biomechanical parameters in comparison to a reference system. Although soft tissue artifact is a major source of error for skin-mounted sensors, there are no investigations regarding the relative movement between the body segment and sensor attachment itself. The aim of this study is to find an evaluation method and to determine parameters that allow the validation of various sensor attachment types and different sensor positionings. The analysis includes the comparison between an adhesive and strap attachment variant as well as the frontal and lateral sensor placement. To validate different attachments, an optical marker-based tracking system was used to measure the body segment and sensor position during movement. The distance between these two positions was calculated and analyzed to determine suitable validation parameters. Despite the exploratory research, the results suggest a feasible validation method to detect differences between the attachments, independent of the sensor type. To have representative and statistically validated results, further studies that involve more participants are necessary.

Accuracy of Estimating Hand Location During Lifting Using Five Wearable Motion Sensors

2020 ◽  
Vol 64 (1) ◽  
pp. 1269-1273
Author(s):  
Menekse S. Barim ◽  
Ming-Lun Lu ◽  
Shuo Feng ◽  
Grant Hughes ◽  
Marie Hayden ◽  
...  
Keyword(s):  
The Body ◽  
Motion Sensors ◽  
Body Segment ◽  
Limit Values ◽  
Body Segments ◽  
Motion Data ◽  
Average Accuracy ◽  
Measurement Units ◽  
Using Data ◽  
Wearable Motion Sensors

The purpose of this study was to assess two computation models for estimating the hand locations during lifting tasks using data from five inertial measurement units (IMUs) attached to five body segments. The first model computed the hand location with the IMU gyroscope data and the pre-defined ratios of body segment lengths. The second model used the same gyroscope information and all measured lengths of the body segments. The outcome measure of these models was the estimated hand location in 12 lifting zones defined by the ACGIH Threshold Limit Values (TLVs) for lifting. Motion data was collected with the wearable system and a laboratory-grade motion capture system on ten subjects that performed 12 two- handed lifting tasks representing the lifting zones. By including body segment measurements, the average accuracy of the model improved from 4 to 34%, suggesting that body segment information plays an important role in estimating the lifting zones.

scholarly journals Optimization of IMU Sensor Placement for the Measurement of Lower Limb Joint Kinematics

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 5993
Author(s):  
Wesley Niswander ◽  
Wei Wang ◽  
Kimberly Kontson
Keyword(s):  
Lower Limb ◽  
Sensor Placement ◽  
Joint Kinematics ◽  
The Body ◽  
Timed Up And Go ◽  
Functional Movement ◽  
Sensor Position ◽  
Optical Motion ◽  
Measurement Units ◽  
Optical Motion Capture

There is an increased interest in using wearable inertial measurement units (IMUs) in clinical contexts for the diagnosis and rehabilitation of gait pathologies. Despite this interest, there is a lack of research regarding optimal sensor placement when measuring joint kinematics and few studies which examine functionally relevant motions other than straight level walking. The goal of this clinical measurement research study was to investigate how the location of IMU sensors on the lower body impact the accuracy of IMU-based hip, knee, and ankle angular kinematics. IMUs were placed on 11 different locations on the body to measure lower limb joint angles in seven participants performing the timed-up-and-go (TUG) test. Angles were determined using different combinations of IMUs and the TUG was segmented into different functional movements. Mean bias and root mean square error values were computed using generalized estimating equations comparing IMU-derived angles to a reference optical motion capture system. Bias and RMSE values vary with the sensor position. This effect is partially dependent on the functional movement analyzed and the joint angle measured. However, certain combinations of sensors produce lower bias and RMSE more often than others. The data presented here can inform clinicians and researchers of placement of IMUs on the body that will produce lower error when measuring joint kinematics for multiple functionally relevant motions. Optimization of IMU-based kinematic measurements is important because of increased interest in the use of IMUs to inform diagnose and rehabilitation in clinical settings and at home.

scholarly journals Using Different Combinations of Body-Mounted IMU Sensors to Estimate Speed of Horses—A Machine Learning Approach

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 798
Author(s):  
Hamed Darbandi ◽  
Filipe Serra Bragança ◽  
Berend Jan van der Zwaag ◽  
John Voskamp ◽  
Annik Imogen Gmel ◽  
...  
Keyword(s):  
Machine Learning ◽  
The Body ◽  
Biomechanical Analysis ◽  
Estimation Accuracy ◽  
Speed Estimation ◽  
Motion Patterns ◽  
Positioning Systems ◽  
Machine Learning Approach ◽  
Global Positioning ◽  
Measurement Units

Speed is an essential parameter in biomechanical analysis and general locomotion research. It is possible to estimate the speed using global positioning systems (GPS) or inertial measurement units (IMUs). However, GPS requires a consistent signal connection to satellites, and errors accumulate during IMU signals integration. In an attempt to overcome these issues, we have investigated the possibility of estimating the horse speed by developing machine learning (ML) models using the signals from seven body-mounted IMUs. Since motion patterns extracted from IMU signals are different between breeds and gaits, we trained the models based on data from 40 Icelandic and Franches-Montagnes horses during walk, trot, tölt, pace, and canter. In addition, we studied the estimation accuracy between IMU locations on the body (sacrum, withers, head, and limbs). The models were evaluated per gait and were compared between ML algorithms and IMU location. The model yielded the highest estimation accuracy of speed (RMSE = 0.25 m/s) within equine and most of human speed estimation literature. In conclusion, highly accurate horse speed estimation models, independent of IMU(s) location on-body and gait, were developed using ML.

Influence on Skin Burns by Water Absorbed Station Wear and Underwear in Firefighter Clothing

2013 ◽  
Vol 796 ◽  
pp. 623-629
Author(s):  
Kaoru Wakatsuki ◽  
Norimasa Morii ◽  
Yoshio Ogawa ◽  
Hajime Tsuji
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Evaluation Method ◽  
The Body ◽  
Electric Heater ◽  
Copper Sensor ◽  
Wet Condition ◽  
Transfer Index ◽  
Wear Condition

During firefighting, within firefighter clothing, underwear and station wear gets heavily wet due to firefighting water and moisture from the body. Water has higher thermal conductivity relative to air and it has been expected that heavily wet condition within the firefighter clothing makes faster skin burns. The objective of this study is how the wet condition within a firefighter clothing makes faster heat transfer from feeling pain and to being 2nd degree of skin burns relative to the dry condition in case of routine firefighting operation in a building (up to 20 kW/m2). Aramid station wear and cotton underwear, generally used by a Japanese firefighter, have been selected and cut 0.15 m x 0.15 m to attach an ISO 9151 copper sensor. A cone shape electric heater, which produces 12 kW/m2 to 20 kW/m2, was used to heat the fabrics. Scenario of fabrics are that (1) wet station wear and dry underwear, (2) wet station and wet underwear, (3) dry station wear and wet underwear, and (4) dry station wear and dry underwear. Evaluation method was by a heat transfer index (HTI) by ISO 9151. The time to rise temperature of 12 and 24 °C (HTI12 and HTI24), and heat transfer rate (dT/dt) were investigated for above four scenarios. The result shows that there was significant impact by condition of station wear, but little impact by underwear. In heat transfer rate (dT/dt) analysis, for the situation of feeling pain to the 2nd degree of skin burns (from HTI12 to HTI24), heat transfer rate was about 50% higher relative to the dry station wear condition. This result indicates that it is possible to be 2nd degree of skin burns easily as soon as a firefighter feels the pain, if he/she wears wet station wear.

Servitisation through structural adaptation

2021 ◽  
Vol 31 (3) ◽  
pp. 468-490
Author(s):  
Saad Zighan ◽  
Ziad Alkalha ◽  
David Bamford ◽  
Iain Reid ◽  
Zu'bi M.F. Al-Zu'bi
Keyword(s):  
Service Provision ◽  
Design Theory ◽  
Structural Changes ◽  
Oil And Gas ◽  
Project Managers ◽  
The Body ◽  
Exploratory Research ◽  
Organisational Structure ◽  
Structural Adaptation ◽  
Content Type

PurposeThe purpose of this study is to investigate the structural changes needed for project-based organisations (PBOs) to synthesise their project operations and services following the servitisation strategy. It addresses the question of how PBOs should change their organisational structure fitting with service provision strategy.Design/methodology/approachThis study followed an exploratory research method using a single in-depth case with evidence collected from 51 project managers from five different industry sectors: construction, oil and gas, IT, logistics and health careFindingsCapitalising on organisational design theory, it has been found that successfully extending PBOs' outcomes into a system of both project output and extra services requires an adjustment of organisational structure that creates greater value for both companies and customers. This required adjustment has been divided into five main categories: (1) collaboration cross-project and customers; (2) flexible workflow, (3) decentralised decision-making, (4) wide span of control and (5) project governance. However, the findings indicate that success can only be ensured by particular mutually coordinated organisational designs with a suitable balance of products and servicesPractical implicationsThis study presents vital indicators to PBOs practitioners when deploying servitisation within their operational strategy by adjusting the organisation's design.Social implicationsServitisation could add both economic and social values for a diverse set of project stakeholders. However, the sustainability performance of servitisation in servitised project-based organisations is an outcome of reducing the discrepancy between project operation and service provision activities.Originality/valueThis study contributes to the body of knowledge and proposes a structural alteration process in PBOs to help align project operations and service provision activities. It explains how project-based organisations reconfigure their resources to provide services.

Exploring the effects of studentification on neighbourhoods in Nigeria

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Oluseyi Adebowale ◽  
Fredrick Simpeh
Keyword(s):  
Research Area ◽  
Student Housing ◽  
Research Strategy ◽  
The Body ◽  
Exploratory Research ◽  
Structured Interviews ◽  
Related Factors ◽  
Content Type ◽  
Positive Effects ◽  
Analysis Technique

Purpose The increase in enrolment into higher education and the inadequate student housing in educational institutions has led to the growth of off-campus private student housing in Nigeria. Studentification as a research area has received attention in most countries in the global North, whereas there is dearth of studies on studentification in Nigeria. Therefore, this paper aims to examine the effects of studentification on the residents of selected Nigerian communities. Design/methodology/approach The study adopted an exploratory research strategy. Semi-structured interviews were conducted to gather qualitative data from respondents, who were landlords and indigenous tenants of the host communities of two tertiary institutions. The data collected were analysed by means of the thematic analysis technique. Findings It became evident that studentification has some effects on the communities. Significant positive effects are business patronage and liveliness, while socio-economic-related factors, which include indecent clothing and theft, were noted as the most significant negative factors. Practical implications Implementing the outcomes of this study will contribute to promoting societal ethical values and economic prosperity of the communities. Originality/value The paper contributes to building the body of knowledge on the effect of studentification in the Nigerian context.

scholarly journals A New Radiographic Method for Estimating Tibial Malrotation

2020 ◽  
Vol 7 (3) ◽  
pp. 121-128
Author(s):  
Hamidreza Yazdi ◽  
◽  
Mohammad Taher Ghaderi ◽  
Alireza Yousof Gomrokchi ◽  
Parham Pezeshk ◽  
...  
Keyword(s):  
Lower Limb ◽  
Evaluation Method ◽  
Bone Fractures ◽  
Distal Tibia ◽  
Bone Diseases ◽  
The Body ◽  
University Hospital ◽  
Radiographic Evaluation ◽  
Minor Trauma ◽  
Lower Limb Injury

Background: Diaphyseal tibial fractures are the most frequent bone fractures in the body and are usually treated with intramedullary nailing method. However, this approach is responsible for 41% of the rotational deviation.  Objectives: This study aimed to provide a radiographic evaluation method to determine tibial malrotation in closed fixation of tibia bone fractures during or after the operation. Methods: This study was conducted in a university hospital from May 2015 to March 2016. All patients referring to the hospital with the complaints of minor trauma around the ankle and knee requiring radiographic evaluation of both joints were enrolled in the study. The inclusion criteria included being 20 and 50 years old; having normal axial, sagittal, and coronal lower limb alignment; lacking previous lower limb injury (such as fractures of the tibia or fibula), ankle or knee sprain; not having previous lower limb surgery, metabolic or congenital bone diseases, or malignancy. In all cases, a standard Anteroposterior (AP) radiograph of the knee was taken, and then, without changing the limb position or image setting, an AP radiograph of the ankle was obtained. The overlap between the distal tibia and fibula was measured in the PACS program environment.   Results: Fifty cases were included in this study. The Mean±SD ages of males and females were 29.08±2.49 years and 31.46±2.04 years, respectively. The range of distal tibia-fibula overlap one centimeter above the tibiotalar joint line was 7.81 to 9.09 mm (confidence interval of 95%), and its percentage to the fibula shaft width at the same level was 49.43% to 54.35%. Conclusion: According to the results, distal tibia-fibula overlap when the knee is in the true AP position, regardless of the side and gender, is 7.81 to 9.09 mm or 49.43% to 54.35%.

scholarly journals Determining the musculoskeletal disorders as the most common work-related injuries, especially in the crafts using the OCRA evaluation method

2019 ◽  
Author(s):  
Gh Halvani ◽  
H Fallah ◽  
R Jafari Nodoushan ◽  
A Haji hosseini ◽  
H Fallah zadeh ◽  
...  
Keyword(s):  
Risk Factors ◽  
High Risk ◽  
Musculoskeletal Disorders ◽  
Evaluation Method ◽  
The Body ◽  
Working Environment ◽  
Work Related ◽  
Demographic Questionnaire ◽  
Work Related Musculoskeletal Disorders ◽  
Ergonomic Risk Factors

Introduction: The condition of work in handloom weaving industries cause musculoskeletal (MSDS) disorders which are the most prevailing professional problem among weavers. The aim of this research was to determine ergonomic risk factors in the occurrence of musculoskeletal disorders. Method: The present study was done through descriptive cross-section method to assess the risk factors of work-related musculoskeletal disorders of the weavers. Our data collection tools were: demographic questionnaire, job Nordic questionnaire and body map prevalence of musculoskeletal disorders to decide the rate of symptoms. Then, we took film from handloom weavers while wearing to know the condition of their bodies. After reviewing the films, the posture marks was assigned to each duty using the Ergo Intelligence software. At the end, data were analyzed via one-way ANOVA and T-test using SPSS ver.20. Results: The results showed that the most frequent incidence of pain in different organs of the body during last year belonged to neck and shoulder. The average OCRA was 3.65.This indicated that most of the handloom weavers (64.4%) are at high risk. Conclusion: According to the re According to the results of OCRA indices, weavers are at high risk for musculoskeletal injuries, indicating their poor working environment and working conditions, indicating the need for corrective actions.

scholarly journals Artifact Elimination in Impedance Cardiography using Gradient based Adaptive Signal Enhancement Techniques

2019 ◽  
Vol 8 (2) ◽  
pp. 598-606
Keyword(s):  
Stroke Volume ◽  
Blood Volume ◽  
Impedance Cardiography ◽  
Signal Enhancement ◽  
The Body ◽  
Body Segment ◽  
Volume Changes ◽  
The Real ◽  
Adaptive Techniques ◽  
Adaptive Signal

Impedance Cardiography (ICG) is a noninvasive method for indirect measurement of stroke volume, monitoring the cardiac output and observing the other hemodynamic parameters by the blood volume changes in the body. The blood volume changes inside a certain body segment due to a number of physiological processes are extracted in the form of the impedance variations of the body segment. The ICG analysis provides the heart stroke volume in sudden cardiac arrest. In the clinical environment desired ICG signals are influenced by several physiological and non-physiological artifacts.As these artifacts are not stationary in nature, we proposed adaptive filtering techniques to eliminate the artifacts. In this paper we used Least Mean Square (LMS), Least Mean Fourth (LMF), Median LMS (MLMS), Leaky LMS (LLMS), and Dead Zone (DZLMS) adaptive techniques to eliminate artifacts from the desired signals. Several adaptive signal enhancement units (ASEUs) are developed based on these adaptive techniques, and evaluated on the real ICG signal components. The ability of these algorithms is evaluated by performing the experiments to eliminate the various artifacts such as sinusoidal artifacts (SA), respiration artifacts (RA), muscle artifacts (MA) and electrode artifacts (EA). Among these techniques, the DZLMS based ASEU performs better in the filtering process. The signal to noise ratio improvement (SNRI) for this algorithm is calculated as 11.9140 dB, 7.3657 dB, 10.4060 dB and 10.5125 dB respectively for SA, RA, MA and EA. Hence, the DZLMS based ASEUs are well suitable for ICG filtering in the real time health care monitoring systems.

Sign in / Sign up

Export Citation Format

Share Document