The Experts below are selected from a list of 17046 Experts worldwide ranked by ideXlab platform
Kyoko Shibata - One of the best experts on this subject based on the ideXlab platform.
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a mobile Force Plate and three dimensional motion analysis system for three dimensional gait assessment
IEEE Sensors Journal, 2012Co-Authors: Yoshio Inoue, Kyoko Shibata, Kouzou ShiojimaAbstract:In order to implement an unobstructed assessment of three-dimensional (3-D) gait, we developed a mobile Force Plate and 3-D motion analysis system (M3D) to measure triaxial ground reaction Forces (GRF) and 3-D orientations of feet. Calibration and test experiments were conducted to characterize the sensor developed. To test the accuracy of the new measurement system, validation experiments by using the reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary Force Plate, a motion capture system based on high-speed cameras and a motion track system of XSENS were adopted to analyze human movements. Experimental results supported the proposal that the developed system can be used to measure triaxial GRF and orientations with an acceptable precision during successive walking gait.
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Design and characterization of a mobile Force Plate and three-dimensional motion analysis system
2010 IEEE Sensors, 2010Co-Authors: Yoshio Inoue, Kyoko Shibata, Kouzou ShiojimaAbstract:In order to implement an unobstructed assessment of walking gait, we proposed a mobile Force Plate and three-dimensional motion analysis system (M3D) to measure triaxial ground reaction Forces (GRF) and three-dimensional orientations of feet. To test accuracy of the new measurement system, verification experiments by using reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary Force Plate and a motion capture system based on high-speed cameras are provided to analyse human movements. Experiment results supported that the developed system can be used to measure triaxial GRF with an acceptable precision during successive walking gait. An application trial was implemented to quantitatively analyze normal gaits and paralysis gaits using the M3D. Some quantitative differences between the gaits were analyzed based on results of three components of GRF and medial-lateral directional angular flexions of the feet.
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a wearable Force Plate system for the continuous measurement of triaxial ground reaction Force in biomechanical applications
Measurement Science and Technology, 2010Co-Authors: Yoshio Inoue, Kyoko ShibataAbstract:The ambulatory measurement of ground reaction Force (GRF) and human motion under free-living conditions is convenient, inexpensive and never restricted to gait analysis in a laboratory environment and is therefore much desired by researchers and clinical doctors in biomedical applications. A wearable Force Plate system was developed by integrating small triaxial Force sensors and three-dimensional (3D) inertial sensors for estimating dynamic triaxial GRF in biomechanical applications. The system, in comparison to existent systems, is characterized by being lightweight, thin and easy-to-wear. A six-axial Force sensor (Nitta Co., Japan) was used as a verification measurement device to validate the static accuracy of the developed Force Plate. To evaluate the precision during dynamic gait measurements, we compared the measurements of the triaxial GRF and the center of pressure (CoP) by using the developed system with the reference measurements made using a stationary Force Plate and an optical motion analysis system. The root mean square (RMS) differences of the two transverse components (x- and y-axes) and the vertical component (z-axis) of the GRF were 4.3 ± 0.9 N, 6.0 ± 1.3 N and 12.1 ± 1.1 N, respectively, corresponding to 5.1 ± 1.1% and 6.5 ± 1% of the maximum of each transverse component and 1.3 ± 0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2 ± 0.8 mm, corresponding to 1.2 ± 0.3% of the length of the shoe. Moreover, based on the results of the assessment of the influence of the system on natural gait, we found that gait was almost never affected. Therefore, the wearable system as an alternative device can be a potential solution for measuring CoP and triaxial GRF in non-laboratory environments.
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a wearable Force Plate system to successively measure multi axial ground reaction Force for gait analysis
Robotics and Biomimetics, 2009Co-Authors: Yoshio Inoue, Kyoko ShibataAbstract:A stationary Force Plate can only accurately measure complete ground reaction Force (GRF) during no more than one stride, but the data of a successively measured multi-axial GRF in different environments is desired not only for researchers on gait analysis but also for clinical doctors. A wearable Force Plate system was developed by integrating small triaxial Force sensors and 3D inertial sensors for estimating multi-axial GRF under free-living environments. In order to verify measures of the developed system, we adopted a combination system including a stationary Force Plate and an optical motion analysis system as a reference system that simultaneously measured triaxial GRF and the center of pressure (CoP) when a subject was required to wear the wearable system. The RMS difference and standard deviation of the two transverse components (x-axis and y-axis) and the vertical component (z-axis) of the GRF was 4.3±0.9N, 6.0±1.3N, and 12.1±1.1N respectively, corresponding to 5.1±1.1% and 6.5±1% of the maximum of each transverse component, and to 1.3±0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2±0.8mm, corresponding to 1.2±0.3% of the length of the shoe. Based on the experimental results, we can conclude that the wearable system as an alternative device can be used to measure CoP and triaxial GRF with an acceptable accuracy in non-laboratory environments.
Yoshio Inoue - One of the best experts on this subject based on the ideXlab platform.
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a mobile Force Plate and three dimensional motion analysis system for three dimensional gait assessment
IEEE Sensors Journal, 2012Co-Authors: Yoshio Inoue, Kyoko Shibata, Kouzou ShiojimaAbstract:In order to implement an unobstructed assessment of three-dimensional (3-D) gait, we developed a mobile Force Plate and 3-D motion analysis system (M3D) to measure triaxial ground reaction Forces (GRF) and 3-D orientations of feet. Calibration and test experiments were conducted to characterize the sensor developed. To test the accuracy of the new measurement system, validation experiments by using the reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary Force Plate, a motion capture system based on high-speed cameras and a motion track system of XSENS were adopted to analyze human movements. Experimental results supported the proposal that the developed system can be used to measure triaxial GRF and orientations with an acceptable precision during successive walking gait.
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Design and characterization of a mobile Force Plate and three-dimensional motion analysis system
2010 IEEE Sensors, 2010Co-Authors: Yoshio Inoue, Kyoko Shibata, Kouzou ShiojimaAbstract:In order to implement an unobstructed assessment of walking gait, we proposed a mobile Force Plate and three-dimensional motion analysis system (M3D) to measure triaxial ground reaction Forces (GRF) and three-dimensional orientations of feet. To test accuracy of the new measurement system, verification experiments by using reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary Force Plate and a motion capture system based on high-speed cameras are provided to analyse human movements. Experiment results supported that the developed system can be used to measure triaxial GRF with an acceptable precision during successive walking gait. An application trial was implemented to quantitatively analyze normal gaits and paralysis gaits using the M3D. Some quantitative differences between the gaits were analyzed based on results of three components of GRF and medial-lateral directional angular flexions of the feet.
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a wearable Force Plate system for the continuous measurement of triaxial ground reaction Force in biomechanical applications
Measurement Science and Technology, 2010Co-Authors: Yoshio Inoue, Kyoko ShibataAbstract:The ambulatory measurement of ground reaction Force (GRF) and human motion under free-living conditions is convenient, inexpensive and never restricted to gait analysis in a laboratory environment and is therefore much desired by researchers and clinical doctors in biomedical applications. A wearable Force Plate system was developed by integrating small triaxial Force sensors and three-dimensional (3D) inertial sensors for estimating dynamic triaxial GRF in biomechanical applications. The system, in comparison to existent systems, is characterized by being lightweight, thin and easy-to-wear. A six-axial Force sensor (Nitta Co., Japan) was used as a verification measurement device to validate the static accuracy of the developed Force Plate. To evaluate the precision during dynamic gait measurements, we compared the measurements of the triaxial GRF and the center of pressure (CoP) by using the developed system with the reference measurements made using a stationary Force Plate and an optical motion analysis system. The root mean square (RMS) differences of the two transverse components (x- and y-axes) and the vertical component (z-axis) of the GRF were 4.3 ± 0.9 N, 6.0 ± 1.3 N and 12.1 ± 1.1 N, respectively, corresponding to 5.1 ± 1.1% and 6.5 ± 1% of the maximum of each transverse component and 1.3 ± 0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2 ± 0.8 mm, corresponding to 1.2 ± 0.3% of the length of the shoe. Moreover, based on the results of the assessment of the influence of the system on natural gait, we found that gait was almost never affected. Therefore, the wearable system as an alternative device can be a potential solution for measuring CoP and triaxial GRF in non-laboratory environments.
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a wearable Force Plate system to successively measure multi axial ground reaction Force for gait analysis
Robotics and Biomimetics, 2009Co-Authors: Yoshio Inoue, Kyoko ShibataAbstract:A stationary Force Plate can only accurately measure complete ground reaction Force (GRF) during no more than one stride, but the data of a successively measured multi-axial GRF in different environments is desired not only for researchers on gait analysis but also for clinical doctors. A wearable Force Plate system was developed by integrating small triaxial Force sensors and 3D inertial sensors for estimating multi-axial GRF under free-living environments. In order to verify measures of the developed system, we adopted a combination system including a stationary Force Plate and an optical motion analysis system as a reference system that simultaneously measured triaxial GRF and the center of pressure (CoP) when a subject was required to wear the wearable system. The RMS difference and standard deviation of the two transverse components (x-axis and y-axis) and the vertical component (z-axis) of the GRF was 4.3±0.9N, 6.0±1.3N, and 12.1±1.1N respectively, corresponding to 5.1±1.1% and 6.5±1% of the maximum of each transverse component, and to 1.3±0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2±0.8mm, corresponding to 1.2±0.3% of the length of the shoe. Based on the experimental results, we can conclude that the wearable system as an alternative device can be used to measure CoP and triaxial GRF with an acceptable accuracy in non-laboratory environments.
Bruce F. Walker - One of the best experts on this subject based on the ideXlab platform.
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The validity of a portable clinical Force Plate in assessment of static postural control: concurrent validity study
Chiropractic & Manual Therapies, 2012Co-Authors: Samira Golriz, Jeffrey J. Hebert, K. Bo Foreman, Bruce F. WalkerAbstract:The broad use of Force Plates in clinical settings for postural control assessment suggests the need for instruments that are easy to use, affordable and readily available. In addition, these instruments of measurement should be reliable and valid as adequate reliability and validity are prerequisites to making correct inferences. The aim of this study was to examine the concurrent validity of postural control measures obtained with a clinical Force Plate. Thirty-one healthy adults were recruited. Participants completed 1 set of 5 trials on each Force Plate. Postural control measures (centre of pressure [COP] average velocity and sway area) were collected and compared using the Midot Posture Scale Analyzer (clinical Force Plate) and the Accugait Force Plate (criterion measure). Intra class correlation coefficient (ICC), standard error of measurement , and paired t-tests were calculated and Bland-Altman plots were constructed to compare the Force Plates and assess consistency of measurement and agreement between them. The ICC values (ICC = 0.14-0.60) between the two Force Plates were lower than the acceptable value for both COP average velocity and sway area. There was significant difference (p > 0.05) in COP average velocity and sway area between the Force Plates. Examination of the plots revealed that there is less difference between the Force Plates in lower magnitudes of COP for average velocity and sway area however, the greater the average velocity and sway area, the greater the difference between the measures obtained from the two Force Plates. Findings of this study showed poor concurrent validity of the clinical Force Plate. This clinical Force Plate cannot be a replacement for known reliable and valid Force Plates and consequently measures obtained from this Force Plate should be treated with caution especially in a clinical population.
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the reliability of a portable clinical Force Plate used for the assessment of static postural control repeated measures reliability study
Chiropractic & Manual Therapies, 2012Co-Authors: Samira Golriz, Jeffrey J. Hebert, Bo K Foreman, Bruce F. WalkerAbstract:Background Force Plates are frequently used for postural control assessments but they are expensive and not widely available in most clinical settings. Increasingly, clinicians are using this technology to assess patients, however, the psychometric properties of these less sophisticated Force Plates is frequently unknown. The purposes of the study were to examine the test-retest reliability of a Force Plate commonly used by clinicians and to explore the effect of using the mean value from multiple repetitions on reliability.
Omer T Inan - One of the best experts on this subject based on the ideXlab platform.
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Mitigation of Instrument-Dependent Variability in Ballistocardiogram Morphology: Case Study on Force Plate and Customized Weighing Scale
IEEE Journal of Biomedical and Health Informatics, 2019Co-Authors: Zahra Ghasemi, Hazar Ashouri, Omer T Inan, Mobashir Hasan Shandhi, Lisheng Xu, Ramakrishna Mukkamala, Jin-oh HahnAbstract:The objective of this study was to investigate the measurement instrument-dependent variability in the morphology of the ballistocardiogram (BCG) waveform in human subjects and computational methods to mitigate the variability. The BCG was measured in 22 young healthy subjects using a high-performance Force Plate and a customized commercial weighing scale under upright standing posture. The timing and amplitude features associated with the major I, J, K waves in the BCG waveforms were extracted and quantitatively analyzed. The results indicated that 1) the I, J, K waves associated with the weighing scale BCG exhibited delay in the timings within the cardiac cycle relative to the ECG R wave as well as attenuation in the absolute amplitudes than the respective Force Plate counterparts, whereas 2) the time intervals between the I, J, K waves were comparable. Then, two alternative computational methods were conceived in an attempt to mitigate the discrepancy between Force Plate versus weighing-scale BCG: a transfer function and an amplitude-phase correction. The results suggested that both methods effectively mitigated the discrepancy in the timings and amplitudes associated with the I, J, K waves between the Force Plate and weighing-scale BCG. Hence, signal processing may serve as a viable solution to the mitigation of the instrument-induced morphological variability in the BCG, thereby facilitating the standardized analysis and interpretation of the timing and amplitude features in the BCG across wide-ranging measurement platforms.
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unobtrusive estimation of cardiac contractility and stroke volume changes using ballistocardiogram measurements on a high bandwidth Force Plate
Sensors, 2016Co-Authors: Hazar Ashouri, Lara Orlandic, Omer T InanAbstract:Unobtrusive and inexpensive technologies for monitoring the cardiovascular health of heart failure (HF) patients outside the clinic can potentially improve their continuity of care by enabling therapies to be adjusted dynamically based on the changing needs of the patients. Specifically, cardiac contractility and stroke volume (SV) are two key aspects of cardiovascular health that change significantly for HF patients as their condition worsens, yet these parameters are typically measured only in hospital/clinical settings, or with implantable sensors. In this work, we demonstrate accurate measurement of cardiac contractility (based on pre-ejection period, PEP, timings) and SV changes in subjects using ballistocardiogram (BCG) signals detected via a high bandwidth Force Plate. The measurement is unobtrusive, as it simply requires the subject to stand still on the Force Plate while holding electrodes in the hands for simultaneous electrocardiogram (ECG) detection. Specifically, we aimed to assess whether the high bandwidth Force Plate can provide accuracy beyond what is achieved using modified weighing scales we have developed in prior studies, based on timing intervals, as well as signal-to-noise ratio (SNR) estimates. Our results indicate that the Force Plate BCG measurement provides more accurate timing information and allows for better estimation of PEP than the scale BCG (r2 = 0.85 vs. r2 = 0.81) during resting conditions. This correlation is stronger during recovery after exercise due to more significant changes in PEP (r2 = 0.92). The improvement in accuracy can be attributed to the wider bandwidth of the Force Plate. ∆SV (i.e., changes in stroke volume) estimations from the Force Plate BCG resulted in an average error percentage of 5.3% with a standard deviation of ±4.2% across all subjects. Finally, SNR calculations showed slightly better SNR in the Force Plate measurements among all subjects but the small difference confirmed that SNR is limited by motion artifacts rather than instrumentation.
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improving the accuracy of proximal timing detection from ballistocardiogram signals using a high bandwidth Force Plate
IEEE-EMBS International Conference on Biomedical and Health Informatics, 2016Co-Authors: Hazar Ashouri, Omer T InanAbstract:Ballistocardiography (BCG) is a non-invasive measure of the reactionary Forces of the body to cardiac ejection of blood into the vasculature. BCG signals are currently measured by modified weighing scales, chairs, beds, or wearable tri-axial accelerometers. In this work, we measure the BCG using a high bandwidth multicomponent Force Plate and compare the timing accuracy of our measured signals with a weighing scale BCG that we have developed and verified in prior studies. We also examine the signal-to-noise ratio (SNR) of BCG signals obtained with each of the two instruments. Our results indicate that the Force Plate BCG measurement provides more accurate timing information as it allows for more reliable prediction of the pre-ejection period (PEP) — the time the ventricles spend in isovolumetric contraction — than the scale BCG (r2=0.83 vs r2=0.73). The SNR comparison results were as follows: although the Force Plate BCG has a slightly better SNR, the improvement is not significant and we conclude that SNR is limited by motion artifacts rather than instrumentation.
Samira Golriz - One of the best experts on this subject based on the ideXlab platform.
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The validity of a portable clinical Force Plate in assessment of static postural control: concurrent validity study
Chiropractic & Manual Therapies, 2012Co-Authors: Samira Golriz, Jeffrey J. Hebert, K. Bo Foreman, Bruce F. WalkerAbstract:The broad use of Force Plates in clinical settings for postural control assessment suggests the need for instruments that are easy to use, affordable and readily available. In addition, these instruments of measurement should be reliable and valid as adequate reliability and validity are prerequisites to making correct inferences. The aim of this study was to examine the concurrent validity of postural control measures obtained with a clinical Force Plate. Thirty-one healthy adults were recruited. Participants completed 1 set of 5 trials on each Force Plate. Postural control measures (centre of pressure [COP] average velocity and sway area) were collected and compared using the Midot Posture Scale Analyzer (clinical Force Plate) and the Accugait Force Plate (criterion measure). Intra class correlation coefficient (ICC), standard error of measurement , and paired t-tests were calculated and Bland-Altman plots were constructed to compare the Force Plates and assess consistency of measurement and agreement between them. The ICC values (ICC = 0.14-0.60) between the two Force Plates were lower than the acceptable value for both COP average velocity and sway area. There was significant difference (p > 0.05) in COP average velocity and sway area between the Force Plates. Examination of the plots revealed that there is less difference between the Force Plates in lower magnitudes of COP for average velocity and sway area however, the greater the average velocity and sway area, the greater the difference between the measures obtained from the two Force Plates. Findings of this study showed poor concurrent validity of the clinical Force Plate. This clinical Force Plate cannot be a replacement for known reliable and valid Force Plates and consequently measures obtained from this Force Plate should be treated with caution especially in a clinical population.
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the reliability of a portable clinical Force Plate used for the assessment of static postural control repeated measures reliability study
Chiropractic & Manual Therapies, 2012Co-Authors: Samira Golriz, Jeffrey J. Hebert, Bo K Foreman, Bruce F. WalkerAbstract:Background Force Plates are frequently used for postural control assessments but they are expensive and not widely available in most clinical settings. Increasingly, clinicians are using this technology to assess patients, however, the psychometric properties of these less sophisticated Force Plates is frequently unknown. The purposes of the study were to examine the test-retest reliability of a Force Plate commonly used by clinicians and to explore the effect of using the mean value from multiple repetitions on reliability.
