The Experts below are selected from a list of 2214 Experts worldwide ranked by ideXlab platform
Paul Edward Cuddihy - One of the best experts on this subject based on the ideXlab platform.
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quantitative gait measurement with Pulse Doppler Radar for passive in home gait assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intra-class correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment. Language: en
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Quantitative Gait Measurement With Pulse-Doppler Radar for Passive In-Home Gait Assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intraclass correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13%-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment.
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gait characterization via Pulse Doppler Radar
IEEE International Conference on Pervasive Computing and Communications, 2011Co-Authors: Tarik Yardibi, Marjorie Skubic, Marilyn Rantz, Paul Edward Cuddihy, Sahika Genc, Corey Nicholas Bufi, Calvin E PhillipsAbstract:Falls are a major cause of injury in the elderly with almost 1/3rd of people aged 65 and more falling each year [1]. This work aims to use gait measurements from everyday living environments to estimate risk of falling and enable improved interventions. For this purpose, we consider the use of low-cost Pulse-Doppler range control Radar. These Radars can continuously acquire data during normal activity of a person in night and day conditions and even in the presence of obstructing furniture. A short-time Fourier transform of the Radar data reveals unique Doppler signatures from the torso motion and the leg swings. Two algorithms that can extract these features from the Radar spectrogram are proposed in this study for estimating gait velocity and stride durations. The performance of the proposed Radar system is evaluated with experimental data, which consists of 9 different walk types and a total of 27 separate tests. A high accuracy motion-capture camera system has also been used to acquire data simultaneously with the Radar and provides the ground truth reference. Results indicate that the proposed Radar system is a viable candidate for gait characterization and can be used to accurately track mean gait velocity, mean stride duration and stride duration variability. The gait velocity variability can also be estimated but with relatively larger error levels.
Marilyn Rantz - One of the best experts on this subject based on the ideXlab platform.
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automated in home fall risk assessment and detection sensor system for elders
Gerontologist, 2015Co-Authors: Marilyn Rantz, Marjorie Skubic, Carmen Abbott, Colleen Galambos, Mihail Popescu, James M Keller, Erik E Stone, Jessie Back, Steven J Miller, Gregory F PetroskiAbstract:PURPOSE OF THE STUDY: Falls are a major problem for the elderly people leading to injury, disability, and even death. An unobtrusive, in-home sensor system that continuously monitors older adults for fall risk and detects falls could revolutionize fall prevention and care. DESIGN AND METHODS: A fall risk and detection system was developed and installed in the apartments of 19 older adults at a senior living facility. The system includes Pulse-Doppler Radar, a Microsoft Kinect, and 2 web cameras. To collect data for comparison with sensor data and for algorithm development, stunt actors performed falls in participants' apartments each month for 2 years and participants completed fall risk assessments (FRAs) using clinically valid, standardized instruments. The FRAs were scored by clinicians and recorded by the sensing modalities. Participants' gait parameters were measured as they walked on a GAITRite mat. These data were used as ground truth, objective data to use in algorithm development and to compare with Radar and Kinect generated variables. RESULTS: All FRAs are highly correlated (p Language: en
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quantitative gait measurement with Pulse Doppler Radar for passive in home gait assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intra-class correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment. Language: en
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Quantitative Gait Measurement With Pulse-Doppler Radar for Passive In-Home Gait Assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intraclass correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13%-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment.
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gait characterization via Pulse Doppler Radar
IEEE International Conference on Pervasive Computing and Communications, 2011Co-Authors: Tarik Yardibi, Marjorie Skubic, Marilyn Rantz, Paul Edward Cuddihy, Sahika Genc, Corey Nicholas Bufi, Calvin E PhillipsAbstract:Falls are a major cause of injury in the elderly with almost 1/3rd of people aged 65 and more falling each year [1]. This work aims to use gait measurements from everyday living environments to estimate risk of falling and enable improved interventions. For this purpose, we consider the use of low-cost Pulse-Doppler range control Radar. These Radars can continuously acquire data during normal activity of a person in night and day conditions and even in the presence of obstructing furniture. A short-time Fourier transform of the Radar data reveals unique Doppler signatures from the torso motion and the leg swings. Two algorithms that can extract these features from the Radar spectrogram are proposed in this study for estimating gait velocity and stride durations. The performance of the proposed Radar system is evaluated with experimental data, which consists of 9 different walk types and a total of 27 separate tests. A high accuracy motion-capture camera system has also been used to acquire data simultaneously with the Radar and provides the ground truth reference. Results indicate that the proposed Radar system is a viable candidate for gait characterization and can be used to accurately track mean gait velocity, mean stride duration and stride duration variability. The gait velocity variability can also be estimated but with relatively larger error levels.
Marjorie Skubic - One of the best experts on this subject based on the ideXlab platform.
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automated in home fall risk assessment and detection sensor system for elders
Gerontologist, 2015Co-Authors: Marilyn Rantz, Marjorie Skubic, Carmen Abbott, Colleen Galambos, Mihail Popescu, James M Keller, Erik E Stone, Jessie Back, Steven J Miller, Gregory F PetroskiAbstract:PURPOSE OF THE STUDY: Falls are a major problem for the elderly people leading to injury, disability, and even death. An unobtrusive, in-home sensor system that continuously monitors older adults for fall risk and detects falls could revolutionize fall prevention and care. DESIGN AND METHODS: A fall risk and detection system was developed and installed in the apartments of 19 older adults at a senior living facility. The system includes Pulse-Doppler Radar, a Microsoft Kinect, and 2 web cameras. To collect data for comparison with sensor data and for algorithm development, stunt actors performed falls in participants' apartments each month for 2 years and participants completed fall risk assessments (FRAs) using clinically valid, standardized instruments. The FRAs were scored by clinicians and recorded by the sensing modalities. Participants' gait parameters were measured as they walked on a GAITRite mat. These data were used as ground truth, objective data to use in algorithm development and to compare with Radar and Kinect generated variables. RESULTS: All FRAs are highly correlated (p Language: en
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quantitative gait measurement with Pulse Doppler Radar for passive in home gait assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intra-class correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment. Language: en
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Quantitative Gait Measurement With Pulse-Doppler Radar for Passive In-Home Gait Assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intraclass correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13%-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment.
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gait characterization via Pulse Doppler Radar
IEEE International Conference on Pervasive Computing and Communications, 2011Co-Authors: Tarik Yardibi, Marjorie Skubic, Marilyn Rantz, Paul Edward Cuddihy, Sahika Genc, Corey Nicholas Bufi, Calvin E PhillipsAbstract:Falls are a major cause of injury in the elderly with almost 1/3rd of people aged 65 and more falling each year [1]. This work aims to use gait measurements from everyday living environments to estimate risk of falling and enable improved interventions. For this purpose, we consider the use of low-cost Pulse-Doppler range control Radar. These Radars can continuously acquire data during normal activity of a person in night and day conditions and even in the presence of obstructing furniture. A short-time Fourier transform of the Radar data reveals unique Doppler signatures from the torso motion and the leg swings. Two algorithms that can extract these features from the Radar spectrogram are proposed in this study for estimating gait velocity and stride durations. The performance of the proposed Radar system is evaluated with experimental data, which consists of 9 different walk types and a total of 27 separate tests. A high accuracy motion-capture camera system has also been used to acquire data simultaneously with the Radar and provides the ground truth reference. Results indicate that the proposed Radar system is a viable candidate for gait characterization and can be used to accurately track mean gait velocity, mean stride duration and stride duration variability. The gait velocity variability can also be estimated but with relatively larger error levels.
Fang Wang - One of the best experts on this subject based on the ideXlab platform.
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quantitative gait measurement with Pulse Doppler Radar for passive in home gait assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intra-class correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment. Language: en
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Quantitative Gait Measurement With Pulse-Doppler Radar for Passive In-Home Gait Assessment
IEEE Transactions on Biomedical Engineering, 2014Co-Authors: Fang Wang, Marjorie Skubic, Marilyn Rantz, Paul Edward CuddihyAbstract:In this paper, we propose a Pulse-Doppler Radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler Radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual Radar set up with one Radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intraclass correlation coefficients of 0.97 was found for step time estimation with the foot level Radar. For walking speed, although both Radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the Radar beam. The torso level Radar has a better performance (9% offset on average) in the speed estimation compared to the foot level Radar (13%-18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment.
Zachary Staples - One of the best experts on this subject based on the ideXlab platform.
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analysis of a covert communication method utilizing non coherent dpsk masked by Pulsed Radar interference
International Conference on Acoustics Speech and Signal Processing, 2017Co-Authors: Thomas W Tedesso, Ric A Romero, Zachary StaplesAbstract:In this paper, a covert communication method is proposed that embeds a digital communication signal onto the Radar return of a Pulse Doppler Radar. The interfering Radar signal at the receiver is estimated and coherently subtracted from combined signal prior to demodulation of the communications signal to baseband and symbol detection. The robustness of the communication method to various estimation errors is investigated for several phase shift keying digital communication modulations through Monte Carlo simulations. It is demonstrated that differential encoding systems with non-coherent detection perform best in the presence of frequency estimation errors. However, it was also demonstrated that the system is not very robust to phase estimation errors. The performance of non-coherent differential phase shift keying and differential quaternary phase shift keying are investigated to determine the impact of varying different parameters upon symbol error rate.
