The Experts below are selected from a list of 585 Experts worldwide ranked by ideXlab platform
Michael A Hunt - One of the best experts on this subject based on the ideXlab platform.
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validity of the microsoft kinect for providing lateral trunk lean feedback during gait retraining
Gait & Posture, 2013Co-Authors: Ross A Clark, Adam L Bryant, Michael A HuntAbstract:Abstract Gait retraining programs are prescribed to assist in the rehabilitation process of many clinical conditions. Using lateral trunk lean modification as the model, the aim of this study was to assess the concurrent validity of kinematic data recorded using a marker-based 3D motion analysis (3DMA) system and a low-cost alternative, the Microsoft Kinect™ (Kinect), during a gait retraining session. Twenty healthy adults were trained to modify their gait to obtain a lateral trunk lean angle of 10°. Real-time biofeedback of the lateral trunk lean angle was provided on a computer screen in front of the subject using data extracted from the Kinect skeletal tracking algorithm. Marker coordinate data were concurrently recorded using the 3DMA system, and the similarity and equivalency of the trunk lean angle data from each system were compared. The lateral trunk lean angle data obtained from the Kinect system without any form of calibration resulted in errors of a high (>2°) magnitude (mean error = 3.2 ± 2.2°). Performing global and individualized calibration significantly ( P
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validity of the microsoft kinect for providing lateral trunk lean feedback during gait retraining
Gait & Posture, 2013Co-Authors: Ross A Clark, Adam L Bryant, Yonghao Pua, Michael A HuntAbstract:Gait retraining programs are prescribed to assist in the rehabilitation process of many clinical conditions. Using lateral trunk lean modification as the model, the aim of this study was to assess the concurrent validity of kinematic data recorded using a marker-based 3D motion analysis (3DMA) system and a low-cost alternative, the Microsoft Kinect™ (Kinect), during a gait retraining session. Twenty healthy adults were trained to modify their gait to obtain a lateral trunk lean angle of 10°. Real-time biofeedback of the lateral trunk lean angle was provided on a computer screen in front of the subject using data extracted from the Kinect skeletal tracking algorithm. Marker coordinate data were concurrently recorded using the 3DMA system, and the similarity and equivalency of the trunk lean angle data from each system were compared. The lateral trunk lean angle data obtained from the Kinect system without any form of calibration resulted in errors of a high (>2°) magnitude (mean error = 3.2 ± 2.2°). Performing global and individualized calibration significantly (P < 0.001) improved this error to 1.7 ± 1.5° and 0.8 ± 0.8° respectively. With the addition of a simple calibration the anatomical position coordinates of the Kinect can be used to create a real-time biofeedback system for gait retraining. Given that this system is low-cost, portable and does not require any sensors to be attached to the body, it could provide numerous advantages when compared to laboratory-based gait retraining systems.
Scott R. Obach - One of the best experts on this subject based on the ideXlab platform.
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a comparison of 2 phenyl 2 1 piperidinyl propane ppp 1 1 1 phosphinothioylidynetrisaziridine thiotepa clopidogrel and ticlopidine as selective inactivators of human cytochrome p450 2b6
Drug Metabolism and Disposition, 2007Co-Authors: Robert L. Walsky, Scott R. ObachAbstract:The use of selective chemical inhibitors of human cytochrome P450 (P450) enzymes represents a powerful method by which the relative contributions of various human P450 enzymes to the metabolism of drugs can be determined. However, the identification of CYP2B6 in the metabolism of drugs has been more challenging because of the lack of a well established inhibitor of this enzyme. In this report, we describe the selectivity of 2-phenyl-2-(1-piperidinyl)propane (PPP) as an inactivator of CYP2B6 and compare this selectivity versus other CYP2B6 inactivators: 1,1′,1″-phosphinothioylidynetrisaziridine (thioTEPA), clopidogrel, and ticlopidine. Values of KI and Kinact for PPP were 5.6 μM and 0.13/min for bupropion hydroxylase catalyzed by pooled human liver microsomes, and values for thioTEPA were similar (4.8 μM and 0.20/min, respectively). Intrinsic inactivation capability was considerably greater for clopidogrel because of a greater Kinact value (1.9/min). Ticlopidine was potent with KI and Kinact values of 0.32 μM and 0.43/min, respectively. The selectivity of these four agents for CYP2B6 was determined by testing their effects on other human P450 enzyme activities using conditions that yield ∼90% inactivation of CYP2B6 activity. The results showed that preincubation of human liver microsomes with PPP at 30 μM for 30 min provided more selective inhibition for CYP2B6 than thioTEPA, clopidogrel, and ticlopidine. Furthermore, the use of clopidogrel is complicated by the observation that this agent is not stable in the presence of human liver microsomes, even without addition of NADPH. Therefore, PPP can serve as a selective chemical inactivator of CYP2B6 and be used to define the role of CYP2B6 in the metabolism of drugs.
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Ticlopidine as Selective Inactivators of Human Cytochrome P450 2B6
2007Co-Authors: Robert L. Walsky, Scott R. ObachAbstract:The use of selective chemical inhibitors of human cytochrome P450 (P450) enzymes represents a powerful method by which the relative contributions of various human P450 enzymes to the me-tabolism of drugs can be determined. However, the identification of CYP2B6 in the metabolism of drugs has been more challenging because of the lack of a well established inhibitor of this enzyme. In this report, we describe the selectivity of 2-phenyl-2-(1-piperidi-nyl)propane (PPP) as an inactivator of CYP2B6 and compare this selectivity versus other CYP2B6 inactivators: 1,1,1-phosphino-thioylidynetrisaziridine (thioTEPA), clopidogrel, and ticlopidine. Values of KI and Kinact for PPP were 5.6 M and 0.13/min for bupropion hydroxylase catalyzed by pooled human liver micro-somes, and values for thioTEPA were similar (4.8 M and 0.20/min, respectively). Intrinsic inactivation capability was considerably greater for clopidogrel because of a greater Kinact value (1.9/min)
David A Rodrigues - One of the best experts on this subject based on the ideXlab platform.
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mechanism based inhibition of human liver microsomal cytochrome p450 1a2 by zileuton a 5 lipoxygenase inhibitor
Drug Metabolism and Disposition, 2003Co-Authors: Ping Lu, Donald E Slaughter, Conrad E Raab, Michael L. Schrag, Magang Shou, David A RodriguesAbstract:Zileuton, a 5-lipoxygenase inhibitor, was evaluated as an inhibitor of cytochrome P450 activity in human liver microsomes. In the absence of preincubation, the racemate was found to be a weak inhibitor (IC50 > 100 μM) of phenacetin O-deethylation (POD) (CYP1A2), paclitaxel 6α-hydroxylation (CYP2C8), diclofenac 4′-hydroxylation (CYP2C9), (S)-mephenytoin 4′-hydroxylation (CYP2C19), bufuralol 1′-hydroxylation (CYP2D6), testosterone 6β-hydroxylation (CYP3A4), chlorzoxazone 6-hydroxylation (CYP2E1), and bupropion hydroxylation (CYP2B6). When preincubated with NADPH-fortified human liver microsomes in the absence of substrate, zileuton (racemate) was shown to inhibit POD. The effect was NADPH-, time-, and concentration-dependent, and was characterized by a Kinact (maximal rate of enzyme inactivation) and apparent KI(inhibitor concentration that supports half the maximal rate of inactivation) of 0.035 min-1 and 117 μM, respectively (Kinact/KIratio of 0.0003 min-1 μM-1). Preincubation-dependent inhibition of POD activity was also observed with the individual (S)-(-)- and (R)-(+)-enantiomers of zileuton [(S)-(-)-zileuton; Kinact, 0.037 min-1, KI, 98.2 μM, Kinact/KIratio, 0.0004 min-1 μM-1; (R)-(+)-zileuton; Kinact, 0.012 min-1, KI, 66.6 μM, Kinact/KIratio, 0.0002 min-1 μM-1]. In addition, the inhibition of CYP1A2 was not reversed in the presence of reduced glutathione, catalase, and superoxide dismutase and was refractory to dialysis. Therefore, zileuton was characterized as a mechanism-based inhibitor of human liver microsomal CYP1A2. Mechanism-based inhibition of CYP1A2 may explain why zileuton decreases the oral clearance of antipyrine, propranolol, (R)-warfarin, and theophylline, at doses that have a minimal effect on the pharmacokinetics of (S)-warfarin, phenytoin, and terfenadine.
Ivan Tashev - One of the best experts on this subject based on the ideXlab platform.
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kinect development kit a toolkit for gesture and speech based human machine interaction
Signal Processing Magazine, 2013Co-Authors: Ivan TashevAbstract:Kinect is a device for human-machine interaction, which adds two more input modalities to the palette of the user interface designer: gestures and speech. Kinect is transforming how people interact with computers, kiosks, and other motion-controlled devices from fun applications like playing a virtual violin, to applications in health care and physical therapy, retail, education, and training. The Kinect for Windows SDK and toolkit contain drivers, tools, APIs, device interfaces, and code samples to simplify development of applications with Kinect. The KDK has integrated skeletal and facial tracking and gesture recognition. Voice recognition adds an additional dimension of human comprehension, while Kinect Fusion reconstructs data into 3D models.
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Kinect Development Kit: A Toolkit for Gesture- and Speech-Based Human-Machine Interaction [Best of the Web]
IEEE Signal Processing Magazine, 2013Co-Authors: Ivan TashevAbstract:Kinect is a device for human?machine interaction, which adds two more input modalities to the palette of the user interface designer: gestures and speech. Kinect is transforming how people interact with computers, kiosks, and other motion-controlled devices from fun applications like playing a virtual violin, to applications in health care and physical therapy, retail, education, and training.
Ross A Clark - One of the best experts on this subject based on the ideXlab platform.
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validity of the microsoft kinect for providing lateral trunk lean feedback during gait retraining
Gait & Posture, 2013Co-Authors: Ross A Clark, Adam L Bryant, Michael A HuntAbstract:Abstract Gait retraining programs are prescribed to assist in the rehabilitation process of many clinical conditions. Using lateral trunk lean modification as the model, the aim of this study was to assess the concurrent validity of kinematic data recorded using a marker-based 3D motion analysis (3DMA) system and a low-cost alternative, the Microsoft Kinect™ (Kinect), during a gait retraining session. Twenty healthy adults were trained to modify their gait to obtain a lateral trunk lean angle of 10°. Real-time biofeedback of the lateral trunk lean angle was provided on a computer screen in front of the subject using data extracted from the Kinect skeletal tracking algorithm. Marker coordinate data were concurrently recorded using the 3DMA system, and the similarity and equivalency of the trunk lean angle data from each system were compared. The lateral trunk lean angle data obtained from the Kinect system without any form of calibration resulted in errors of a high (>2°) magnitude (mean error = 3.2 ± 2.2°). Performing global and individualized calibration significantly ( P
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validity of the microsoft kinect for providing lateral trunk lean feedback during gait retraining
Gait & Posture, 2013Co-Authors: Ross A Clark, Adam L Bryant, Yonghao Pua, Michael A HuntAbstract:Gait retraining programs are prescribed to assist in the rehabilitation process of many clinical conditions. Using lateral trunk lean modification as the model, the aim of this study was to assess the concurrent validity of kinematic data recorded using a marker-based 3D motion analysis (3DMA) system and a low-cost alternative, the Microsoft Kinect™ (Kinect), during a gait retraining session. Twenty healthy adults were trained to modify their gait to obtain a lateral trunk lean angle of 10°. Real-time biofeedback of the lateral trunk lean angle was provided on a computer screen in front of the subject using data extracted from the Kinect skeletal tracking algorithm. Marker coordinate data were concurrently recorded using the 3DMA system, and the similarity and equivalency of the trunk lean angle data from each system were compared. The lateral trunk lean angle data obtained from the Kinect system without any form of calibration resulted in errors of a high (>2°) magnitude (mean error = 3.2 ± 2.2°). Performing global and individualized calibration significantly (P < 0.001) improved this error to 1.7 ± 1.5° and 0.8 ± 0.8° respectively. With the addition of a simple calibration the anatomical position coordinates of the Kinect can be used to create a real-time biofeedback system for gait retraining. Given that this system is low-cost, portable and does not require any sensors to be attached to the body, it could provide numerous advantages when compared to laboratory-based gait retraining systems.
