WorldWideScience

Sample records for breathing motion compensation

  1. Motion Estimated-Compensated Reconstruction with Preserved-Features in Free-Breathing Cardiac MRI

    CERN Document Server

    Bustin, Aurelien; Janich, Martin A; Burschka, Darius; Felblinger, Jacques; Brau, Anja C S; Odille, Freddy

    2016-01-01

    To develop an efficient motion-compensated reconstruction technique for free-breathing cardiac magnetic resonance imaging (MRI) that allows high-quality images to be reconstructed from multiple undersampled single-shot acquisitions. The proposed method is a joint image reconstruction and motion correction method consisting of several steps, including a non-rigid motion extraction and a motion-compensated reconstruction. The reconstruction includes a denoising with the Beltrami regularization, which offers an ideal compromise between feature preservation and staircasing reduction. Results were assessed in simulation, phantom and volunteer experiments. The proposed joint image reconstruction and motion correction method exhibits visible quality improvement over previous methods while reconstructing sharper edges. Moreover, when the acceleration factor increases, standard methods show blurry results while the proposed method preserves image quality. The method was applied to free-breathing single-shot cardiac MR...

  2. Tracking 'differential organ motion' with a 'breathing' multileaf collimator: magnitude of problem assessed using 4D CT data and a motion-compensation strategy.

    Science.gov (United States)

    McClelland, J R; Webb, S; McQuaid, D; Binnie, D M; Hawkes, D J

    2007-08-21

    Intrafraction tumour (e.g. lung) motion due to breathing can, in principle, be compensated for by applying identical breathing motions to the leaves of a multileaf collimator (MLC) as intensity-modulated radiation therapy is delivered by the dynamic MLC (DMLC) technique. A difficulty arising, however, is that irradiated voxels, which are in line with a bixel at one breathing phase (at which the treatment plan has been made), may move such that they cease to be in line with that breathing bixel at another phase. This is the phenomenon of differential voxel motion and existing tracking solutions have ignored this very real problem. There is absolutely no tracking solution to the problem of compensating for differential voxel motion. However, there is a strategy that can be applied in which the leaf breathing is determined to minimize the geometrical mismatch in a least-squares sense in irradiating differentially-moving voxels. A 1D formulation in very restricted circumstances is already in the literature and has been applied to some model breathing situations which can be studied analytically. These are, however, highly artificial. This paper presents the general 2D formulation of the problem including allowing different importance factors to be applied to planning target volume and organ at risk (or most generally) each voxel. The strategy also extends the literature strategy to the situation where the number of voxels connecting to a bixel is a variable. Additionally the phenomenon of 'cross-leaf-track/channel' voxel motion is formally addressed. The general equations are presented and analytic results are given for some 1D, artificially contrived, motions based on the Lujan equations of breathing motion. Further to this, 3D clinical voxel motion data have been extracted from 4D CT measurements to both assess the magnitude of the problem of 2D motion perpendicular to the beam-delivery axis in clinical practice and also to find the 2D optimum breathing-leaf strategy

  3. Motion compensator for holographic motion picture camera

    Science.gov (United States)

    Kurtz, R. L.

    1973-01-01

    When reference beam strikes target it undergoes Doppler shift dependent upon target velocity. To compensate, object beam is first reflected from rotating cylinder that revolves in direction opposite to target but at same speed. When beam strikes target it is returned to original frequency and is in phase with reference beam. Alternatively this motion compensator may act on reference beam.

  4. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  5. A new strategy for respiration compensation, applied toward 3D free-breathing cardiac MRI.

    Science.gov (United States)

    Madore, Bruno; Farnebäck, Gunnar; Westin, Carl-Fredrik; Durán-Mendicuti, Alejandra

    2006-07-01

    In thorax and abdomen imaging, image quality may be affected by breathing motion. Cardiac MR images are typically obtained while the patient holds his or her breath, to avoid respiration-related artifacts. Although useful, breath-holding imposes constraints on scan duration, which in turn limits the achievable resolution and SNR. Longer scan times would be required to improve image quality, and effective strategies are needed to compensate for respiratory motion. A novel approach at respiratory compensation, targeted toward 3D free-breathing cardiac MRI, is presented here. The method aims at suppressing the negative effects of respiratory-induced cardiac motion while capturing the heart's beating motion. The method is designed so that the acquired data can be reconstructed in two different ways: First, a time series of images is reconstructed to quantify and correct for respiratory motion. Then, the corrected data are reconstructed a final time into a cardiac-phase series of images to capture the heart's beating motion. The method was implemented, and initial results are presented. A cardiac-phase series of 3D images, covering the entire heart, was obtained for two free-breathing volunteers. The present method may prove especially useful in situations where breath-holding is not an option, for example, for very sick, mentally impaired or infant patients.

  6. Lossless Compression of Video using Motion Compensation

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1998-01-01

    We investigate lossless coding of video using predictive coding andmotion compensation. The methods incorporate state-of-the-art lossless techniques such ascontext based prediction and bias cancellation, Golomb coding, high resolution motion field estimation,3d-dimensional predictors, prediction...... using one or multiple previous images, predictor dependent error modelling, and selection of motion field by code length. For slow pan or slow zoom sequences, coding methods that use multiple previous images are up to 20% better than motion compensation using a single previous image and up to 40% better...... than coding that does not utilize motion compensation....

  7. Lossless Compression of Video using Motion Compensation

    DEFF Research Database (Denmark)

    Martins, Bo; Forchhammer, Søren

    1998-01-01

    Summary form only given. We investigate lossless coding of video using predictive coding and motion compensation. The new coding methods combine state-of-the-art lossless techniques as JPEG (context based prediction and bias cancellation, Golomb coding), with high resolution motion field estimation......-predictors and intra-frame predictors as well. As proposed by Ribas-Corbera (see PhD thesis, University of Michigan, 1996), we use bi-linear interpolation in order to achieve sub-pixel precision of the motion field. Using more reference images is another way of achieving higher accuracy of the match. The motion...

  8. Position Control of Motion Compensation Cardiac Catheters

    Science.gov (United States)

    Kesner, Samuel B.; Howe, Robert D.

    2011-01-01

    Robotic catheters have the potential to revolutionize cardiac surgery by enabling minimally invasive structural repairs within the beating heart. This paper presents an actuated catheter system that compensates for the fast motion of cardiac tissue using 3D ultrasound image guidance. We describe the design and operation of the mechanical drive system and catheter module and analyze the catheter performance limitations of friction and backlash in detail. To mitigate these limitations, we propose and evaluate mechanical and control system compensation methods, including inverse and model-based backlash compensation, to improve the system performance. Finally, in vivo results are presented that demonstrate that the catheter can track the cardiac tissue motion with less than 1 mm RMS error. The ultimate goal of this research is to create a fast and dexterous robotic catheter system that can perform surgery on the delicate structures inside of the beating heart. PMID:21874124

  9. Robotic motion compensation for applications in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Christian

    2013-07-22

    Radiation therapy today, on account of improvements in treatment procedures over the last 60 years, allows precise treatment of static tumors inside the human body. However, irradiation of moving tumors is still a challenging task as moving tumors often leave the treatment beam and the radiation dose delivered to the tumor reduces simultaneously increasing that on healthy tissue. This research work aims to push the frontiers of radiation therapy in order to enable precise treatment of moving tumors with focus on research and development of a unique real-time system enabling active motion compensation through robotic means to compensate tumor motion. During treatment, patients lie on a treatment couch which is normally used for static position corrections of patient set-up errors prior to radiation treatment. The treatment couch used, called HexaPOD, is a parallel manipulator with six degrees of freedom which can precisely position heavy loads inside a small region. Despite the HexaPOD not initially built with dynamics in mind, it is used in this work for sustained motion compensation by moving patients such that tumors stay precisely located at the center of the treatment beam during the complete course of treatment. In order to realize real-time tumor motion compensation by means of the HexaPOD, several challenges need to be addressed. Real-time aspects are covered by the adoption of a hard real-time operation system in combination with measurement and estimation of latencies of all physical quantities in the compensation system such as tumor or breathing position measurements. Accurate timing information is respected consistently in the whole system and all software-induced latencies are adaptively compensated for. This requires knowledge of future tumor positions from predictors. Several predictors for breathing and tumor motion predictions are proposed and evaluated in terms of a variety of different performance metrics. Extensions to prediction algorithms are

  10. Video Coding with Motion-Compensated Lifted Wavelet Transforms

    OpenAIRE

    Flierl, M.; Girod, B.

    2004-01-01

    This article explores the efficiency of motion-compensated three-dimensional transform coding, a compression scheme that employs a motion-compensated transform for a group of pictures. We investigate this coding scheme experimentally and theoretically. The practical coding scheme employs in temporal direction a wavelet decomposition with motion-compensated lifting steps. Further, we compare the experimental results to that of a predictive video codec with single-hypothesis motion compensation...

  11. 2-D Tissue Motion Compensation of Synthetic Transmit Aperture Images

    DEFF Research Database (Denmark)

    Gammelmark, Kim Løkke; Jensen, Jørgen Arendt

    2014-01-01

    images recorded using the same emission sequence. The velocity and direction of the motion are found by crosscorrelating short high-resolution lines beamformed along selected angles. The motion acquisition is interleaved with the regular B-mode emissions in STA imaging, and the motion compensation...... be compensated for, and that doing so yields a significant increase in image quality....

  12. Breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises

    Directory of Open Access Journals (Sweden)

    G.M. Tomich

    2007-10-01

    Full Text Available The objective of the present study was to evaluate breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises: diaphragmatic breathing (DB, flow-oriented (Triflo II incentive spirometry and volume-oriented (Voldyne incentive spirometry. Seventeen healthy subjects (12 females, 5 males aged 23 ± 5 years (mean ± SD were studied. Calibrated respiratory inductive plethysmography was used to measure the following variables during rest (baseline and breathing exercises: tidal volume (Vt, respiratory frequency (f, rib cage contribution to Vt (RC/Vt, inspiratory duty cycle (Ti/Ttot, and phase angle (PhAng. Sternocleidomastoid muscle activity was assessed by surface electromyography. Statistical analysis was performed by ANOVA and Tukey or Friedman and Wilcoxon tests, with the level of significance set at P < 0.05. Comparisons between baseline and breathing exercise periods showed a significant increase of Vt and PhAng during all exercises, a significant decrease of f during DB and Voldyne, a significant increase of Ti/Ttot during Voldyne, and no significant difference in RC/Vt. Comparisons among exercises revealed higher f and sternocleidomastoid activity during Triflo II (P < 0.05 with respect to DB and Voldyne, without a significant difference in Vt, Ti/Ttot, PhAng, or RC/Vt. Exercises changed the breathing pattern and increased PhAng, a variable of thoracoabdominal asynchrony, compared to baseline. The only difference between DB and Voldyne was a significant increase of Ti/Ttot compared to baseline. Triflo II was associated with higher f values and electromyographic activity of the sternocleidomastoid. In conclusion, DB and Voldyne showed similar results while Triflo II showed disadvantages compared to the other breathing exercises.

  13. Motion compensation for structured light sensors

    Science.gov (United States)

    Biswas, Debjani; Mertz, Christoph

    2015-05-01

    In order for structured light methods to work outside, the strong background from the sun needs to be suppressed. This can be done with bandpass filters, fast shutters, and background subtraction. In general this last method necessitates the sensor system to be stationary during data taking. The contribution of this paper is a method to compensate for the motion if the system is moving. The key idea is to use video stabilization techniques that work even if the illuminator is switched on and off from one frame to another. We used OpenCV functions and modules to implement a robust and efficient method. We evaluated it under various conditions and tested it on a moving robot outdoors. We will demonstrate that one can not only do 3D reconstruction under strong ambient light, but that it is also possible to observe optical properties of the objects in the environment.

  14. A Hybrid Motion Compensation De-interlacing Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Motion compensation de-interlacing is expected to be better than linear techniques; but all the block-based motion compensation de-interlacing methods cause block artifacts. The algorithm proposed in this paper is concerned with reducing the deficiency of motion-compensated interpolation by using adaptive hybrid de-interlacing methods. A spatio-temporal tensor-based approach is used to get more accurate motion field for de-interlacing. Motion vector is assigned for each position with pixel precision; the block artifact is reduced significantly. To deal with the artifacts introduced by motion-compensation when the motion estimation is incorrect, linear techniques are considered by adaptive weighting. Furthermore, directional filter is adapted to preserve details and the edge discontinuity could be eliminated greatly. Our approach is robust to incorrect motion vector estimation.

  15. Compensating for Quasi-periodic Motion in Robotic Radiosurgery

    CERN Document Server

    Ernst, Floris

    2012-01-01

    Compensating for Quasi-periodic Motion in Robotic Radiosurgery outlines the techniques needed to accurately track and compensate for respiratory and pulsatory motion during robotic radiosurgery. The algorithms presented within the book aid in the treatment of tumors that move during respiration. In Chapters 1 and 2,  the book introduces the concept of stereotactic body radiation therapy, motion compensation strategies and the clinical state-of-the-art. In Chapters 3 through 5, the author describes and evaluates new methods for motion prediction, for correlating external motion to internal organ motion, and for the evaluation of these algorithms’ output based on an unprecedented amount of real clinical data. Finally, Chapter 6 provides a brief introduction into currently investigated, open questions and further fields of research. Compensating for Quasi-periodic Motion in Robotic Radiosurgery targets researchers working in the related fields of surgical oncology, artificial intelligence, robotics and more. ...

  16. A General Method for Motion Compensation in X-ray Computed Tomography

    CERN Document Server

    AUTHOR|(CDS)2067162; Dosanjh, Manjit; Soleimani, Manuchehr

    2017-01-01

    Motion during data acquisition is a known source of error in medical tomography, resulting in blur artefacts in the regions that move. It is critical to reduce these artefacts in applications such as image-guided radiation therapy as a clearer image translates into a more accurate treatment and the sparing of healthy tissue close to a tumour site. Most research in 4D X-ray tomography involving the thorax relies on respiratory phase binning of the acquired data and reconstructing each of a set of images using the limited subset of data per phase. In this work, we demonstrate a motion-compensation method to reconstruct images from the complete dataset taken during breathing without recourse to phase-binning or breath-hold techniques. As long as the motion is sufficiently well known, the new method can accurately reconstruct an image at any time during the acquisition time span. It can be applied to any iterative reconstruction algorithm.

  17. ROBOT'S MOTION ERROR AND ONLINE COMPENSATION BASED ON FORCE SENSOR

    Institute of Scientific and Technical Information of China (English)

    GAN Fangjian; LIU Zhengshi; REN Chuansheng; ZHANG Ping

    2007-01-01

    Robot's dynamic motion error and on-line compensation based on multi-axis force sensor are dealt with. It is revealed that the reasons of the error are formed and the relations of the error are delivered. A motion equation of robot's termination with the error is established, and then, an error matrix and an error compensation matrix of the motion equation are also defined. An on-line error's compensation method is put forward to decrease the displacement error, which is a degree of millimeter, shown by the result of Simulation of PUMA562 robot.

  18. Duplex synthetic aperture imaging with tissue motion compensation

    DEFF Research Database (Denmark)

    Gammelmark, Kim; Jensen, Jørgen Arendt

    2003-01-01

    This paper investigates a method for tissue motion estimation and compensation in synthetic transmits aperture imaging. The approach finds the tissue velocity and the direction of the motion at very tissue region by cross-correlating high resolution lines beamformed along multiple directions...... at each image points. Compensation is applied in the beamformer by tracking the image points using the velocity and angle estimates from the closest estimation point. Simulation results using Field II show nearly perfect motion compensation with no appreciable difference in contrast resolution after...

  19. Image-based iterative compensation of motion artifacts in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schretter, Colas; Rose, Georg; Bertram, Matthias [Philips Research Europe, Weisshausstrasse 2, 52066 Aachen, Germany and Otto-von-Guericke University, Universitaetsplatz 2, 39016 Magdeburg (Germany); Otto-von-Guericke University, Universitaetsplatz 2, 39016 Magdeburg (Germany); Philips Research Europe, Weisshausstrasse 2, 52066 Aachen (Germany)

    2009-11-15

    Purpose: This article presents an iterative method for compensation of motion artifacts for slowly rotating computed tomography (CT) systems. Patient's motion introduces inconsistencies among projections and yields severe reconstruction artifacts for free-breathing acquisitions. Streaks and doubling of structures can appear and the resolution is limited by strong blurring. Methods: The rationale of the proposed motion compensation method is to iteratively correct the reconstructed image by first decomposing the perceived motion in projection space, then reconstructing the motion artifacts in image space, and finally subtracting the artifacts from an initial image. The initial image is reconstructed from the acquired data and might contain motion blur artifacts but, nevertheless, is considered as a reference for estimating the reconstruction artifacts. Results: Qualitative and quantitative figures are shown for experiments based on numerically simulated projections of a sequence of clinical images resulting from a respiratory-gated helical CT acquisition. The border of the diaphragm becomes progressively sharper and the contrast improves for small structures in the lungs. Conclusions: The originality of the technique stems from the fact that the patient motion is not explicitly estimated but the motion artifacts are reconstructed in image space. This approach could provide sharp static anatomical images on interventional C-arm systems or on slowly rotating X-ray equipments in radiotherapy.

  20. Motion error compensation of multi-legged walking robots

    Science.gov (United States)

    Wang, Liangwen; Chen, Xuedong; Wang, Xinjie; Tang, Weigang; Sun, Yi; Pan, Chunmei

    2012-07-01

    Existing errors in the structure and kinematic parameters of multi-legged walking robots, the motion trajectory of robot will diverge from the ideal sports requirements in movement. Since the existing error compensation is usually used for control compensation of manipulator arm, the error compensation of multi-legged robots has seldom been explored. In order to reduce the kinematic error of robots, a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile robot. The locus error of a robot body is measured, when robot moves along a given track. Error of driven joint variables is obtained by error calculation model in terms of the locus error of robot body. Error value is used to compensate driven joint variables and modify control model of robot, which can drive the robots following control model modified. The model of the relation between robot's locus errors and kinematic variables errors is set up to achieve the kinematic error compensation. On the basis of the inverse kinematics of a multi-legged walking robot, the relation between error of the motion trajectory and driven joint variables of robots is discussed. Moreover, the equation set is obtained, which expresses relation among error of driven joint variables, structure parameters and error of robot's locus. Take MiniQuad as an example, when the robot MiniQuad moves following beeline tread, motion error compensation is studied. The actual locus errors of the robot body are measured before and after compensation in the test. According to the test, variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one time. The kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward.

  1. Holographic motion picture camera with Doppler shift compensation

    Science.gov (United States)

    Kurtz, R. L. (Inventor)

    1976-01-01

    A holographic motion picture camera is reported for producing three dimensional images by employing an elliptical optical system. There is provided in one of the beam paths (the object or reference beam path) a motion compensator which enables the camera to photograph faster moving objects.

  2. 3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom.

    Science.gov (United States)

    Mann, P; Witte, M; Moser, T; Lang, C; Runz, A; Johnen, W; Berger, M; Biederer, J; Karger, C P

    2017-01-21

    In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX(™) container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated

  3. 3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom

    Science.gov (United States)

    Mann, P.; Witte, M.; Moser, T.; Lang, C.; Runz, A.; Johnen, W.; Berger, M.; Biederer, J.; Karger, C. P.

    2017-01-01

    In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX™ container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated

  4. Video coding using Karhunen-Loeve transform and motion compensation

    Science.gov (United States)

    Musatenko, Yurij S.; Soloveyko, Olexandr M.; Kurashov, Vitalij N.; Dubikovskiy, Vladislav A.

    1999-07-01

    The paper present a new method for video compression. The discussed techniques consider video frames as a set of correlated images. Common approach to the problem of compression of correlated images is to use some orthogonal transform, for example cosine or wavelet transform, in order to remove the correlation among images and then to compress resolution coefficients using already known compression technique such as JPEG or EZW. However, the most optimal representation for removing of correlation among images is Karhunen-Loeve (KL) transform. In the paper we apply recently proposed Optimal Image Coding using KL transform method (OICKL) based on this approach. In order to take into account the nature of video we use Triangle Motion Compensation to improve correlation among frames. Experimental part compares the performance of plain OICKL codec with OICKL and motion compensation combined. Recommendations concerning using of motion compensation with OICKL technique are worked out.

  5. Three-Axis Motion Compensated Crane Head Control

    OpenAIRE

    Henriksen, Vegard Wie; Røine, Audun Gerhardsen

    2016-01-01

    Offshore operations can be harsh and demanding and set personnel and equipment at risk. Ships will be exposed to the environmental forces of wind, waves and current, which will influence offshore crane operations considerably. This thesis addresses the use of a crane head, a Three Axis Compensator (TAC), constructed as a Delta parallel robot, to compensate for the motions of the ship in three axes. This type of robot has a rigid and accurate structure, and because of its highly nonlinear natu...

  6. Motion-compensated wavelet video coding using adaptive mode selection

    Science.gov (United States)

    Zhai, Fan; Pappas, Thrasyvoulos N.

    2004-01-01

    A motion-compensated wavelet video coder is presented that uses adaptive mode selection (AMS) for each macroblock (MB). The block-based motion estimation is performed in the spatial domain, and an embedded zerotree wavelet coder (EZW) is employed to encode the residue frame. In contrast to other motion-compensated wavelet video coders, where all the MBs are forced to be in INTER mode, we construct the residue frame by combining the prediction residual of the INTER MBs with the coding residual of the INTRA and INTER_ENCODE MBs. Different from INTER MBs that are not coded, the INTRA and INTER_ENCODE MBs are encoded separately by a DCT coder. By adaptively selecting the quantizers of the INTRA and INTER_ENCODE coded MBs, our goal is to equalize the characteristics of the residue frame in order to improve the overall coding efficiency of the wavelet coder. The mode selection is based on the variance of the MB, the variance of the prediction error, and the variance of the neighboring MBs' residual. Simulations show that the proposed motion-compensated wavelet video coder achieves a gain of around 0.7-0.8dB PSNR over MPEG-2 TM5, and a comparable PSNR to other 2D motion-compensated wavelet-based video codecs. It also provides potential visual quality improvement.

  7. Quantitative assessment of tumor angiogenesis using real-time motion-compensated contrast-enhanced ultrasound imaging

    Science.gov (United States)

    Pysz, Marybeth A.; Guracar, Ismayil; Foygel, Kira; Tian, Lu; Willmann, Jürgen K.

    2015-01-01

    Purpose To develop and test a real-time motion compensation algorithm for contrast-enhanced ultrasound imaging of tumor angiogenesis on a clinical ultrasound system. Materials and methods The Administrative Institutional Panel on Laboratory Animal Care approved all experiments. A new motion correction algorithm measuring the sum of absolute differences in pixel displacements within a designated tracking box was implemented in a clinical ultrasound machine. In vivo angiogenesis measurements (expressed as percent contrast area) with and without motion compensated maximum intensity persistence (MIP) ultrasound imaging were analyzed in human colon cancer xenografts (n = 64) in mice. Differences in MIP ultrasound imaging signal with and without motion compensation were compared and correlated with displacements in x- and y-directions. The algorithm was tested in an additional twelve colon cancer xenograft-bearing mice with (n = 6) and without (n = 6) anti-vascular therapy (ASA-404). In vivo MIP percent contrast area measurements were quantitatively correlated with ex vivo microvessel density (MVD) analysis. Results MIP percent contrast area was significantly different (P < 0.001) with and without motion compensation. Differences in percent contrast area correlated significantly (P < 0.001) with x- and y-displacements. MIP percent contrast area measurements were more reproducible with motion compensation (ICC = 0.69) than without (ICC = 0.51) on two consecutive ultrasound scans. Following anti-vascular therapy, motion-compensated MIP percent contrast area significantly (P = 0.03) decreased by 39.4 ± 14.6 % compared to non-treated mice and correlated well with ex vivo MVD analysis (Rho = 0.70; P = 0.05). Conclusion Real-time motion-compensated MIP ultrasound imaging allows reliable and accurate quantification and monitoring of angiogenesis in tumors exposed to breathing-induced motion artifacts. PMID:22535383

  8. Design of motion compensation mechanism of satellite remote sensing camera

    Science.gov (United States)

    Gu, Song; Yan, Yong; Xu, Kai; Jin, Guang

    2011-08-01

    With the development of aerospace remote sensing technology, the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures, the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera, the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera, the compensation method of image motion to space camera is researched. First, the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second, the system adopts 80C31 as controller of drift angle, and adopts stepping motor for actuators, and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced, and it achieve the closed-loop control of the drift angle position. At the last, this paper analyses the transmission precision of the mechanism. Through the experiment, we measured the actual precision of the image motion compensation mechanism, and compared with the theoretical analysis.There are two major contributions in this paper. First, the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism, it will bring adverse effects for the precision and stiffness of mechanism. For this problem, This paper designed a image motion compensation that have some advantages such as small size, light weight at the same time, high precision, stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second

  9. Real-time optical tracking for motion compensated irradiation with scanned particle beams at CNAO

    Energy Technology Data Exchange (ETDEWEB)

    Fattori, G., E-mail: giovanni.fattori@psi.ch [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Seregni, M. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Pella, A. [Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Campeggi 53, 27100 Pavia (Italy); Riboldi, M. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Capasso, L. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125 (Italy); Donetti, M. [Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Campeggi 53, 27100 Pavia (Italy); Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125 (Italy); Ciocca, M. [Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Campeggi 53, 27100 Pavia (Italy); Giordanengo, S. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125 (Italy); Pullia, M. [Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Campeggi 53, 27100 Pavia (Italy); Marchetto, F. [Istituto Nazionale di Fisica Nucleare, Section of Torino, Torino 10125 (Italy); Baroni, G. [Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Campeggi 53, 27100 Pavia (Italy)

    2016-08-11

    Purpose: We describe the interface developed at the National Center for Oncological Hadrontherapy in Pavia to provide the dose delivery systems with real time respiratory motion information captured with an optical tracking system. An experimental study is presented to assess the technical feasibility of the implemented organ motion compensation framework, by analyzing the film response when irradiated with proton beams. Methods: The motion monitoring solution is based on a commercial hardware for motion capture running in-house developed software for respiratory signal processing. As part of the integration, the latency of data transmission to the dose delivery system was experimentally quantified and accounted for by signal time prediction. A respiratory breathing phantom is presented and used to test tumor tracking based either on the optical measurement of the target position or internal-external correlation models and beam gating, as driven by external surrogates. Beam tracking was tested considering the full target motion excursion (25×18 mm), whereas it is limited to 6×2 mm in the gating window. The different motion mitigation strategies were evaluated by comparing the experimental film responses with respect to static irradiation conditions. Dose inhomogeneity (IC) and conformity (CI) are provided as main indexes for dose quality assessment considering the irradiation in static condition as reference. Results: We measured 20.6 ms overall latency for motion signal processing. Dose measurements showed that beam tracking largely preserved dose homogeneity and conformity, showing maximal IC and CI variations limited to +0.10 and −0.01 with respect to the static reference. Gating resulted in slightly larger discrepancies (ΔIC=+0.20, ΔCI=−0.13) due to uncompensated residual motion in the gating window. Conclusions: The preliminary beam tracking and gating results verified the functionality of the prototypal solution for organ motion compensation based on

  10. Multimodal MRI Neuroimaging with Motion Compensation Based on Particle Filtering

    CERN Document Server

    Chen, Yu-Hui; Kim, Boklye; Meyer, Charles; Hero, Alfred

    2015-01-01

    Head movement during scanning impedes activation detection in fMRI studies. Head motion in fMRI acquired using slice-based Echo Planar Imaging (EPI) can be estimated and compensated by aligning the images onto a reference volume through image registration. However, registering EPI images volume to volume fails to consider head motion between slices, which may lead to severely biased head motion estimates. Slice-to-volume registration can be used to estimate motion parameters for each slice by more accurately representing the image acquisition sequence. However, accurate slice to volume mapping is dependent on the information content of the slices: middle slices are information rich, while edge slides are information poor and more prone to distortion. In this work, we propose a Gaussian particle filter based head motion tracking algorithm to reduce the image misregistration errors. The algorithm uses a dynamic state space model of head motion with an observation equation that models continuous slice acquisitio...

  11. Motion compensated beamforming in synthetic aperture vector flow imaging

    DEFF Research Database (Denmark)

    Oddershede, Niels; Jensen, Jørgen Arendt

    2006-01-01

    . Here the SNR is -10 dB compared to the stationary scatterer. A 2D motion compensation method for synthetic aperture vector flow imaging is proposed, where the former vector velocity estimate is used for compensating the beamforming of new data. This method is tested on data from an experimental flow......In synthetic aperture imaging the beamformed data from a number of emissions are summed to create dynamic focusing in transmit. This makes the method susceptible to motion, which is especially the case for the synthetic aperture flow estimation method, where large movements are expected......) of the beamformed response from the scatterer at all velocities is compared to that of a stationary scatterer. For lateral movement, the SNR drops almost linearly with velocity to -4 dB at I m/s, while for axial movement the SNR drop is largest, when the scatterer moves a quarter of a wavelength between emissions...

  12. Video coding with lifted wavelet transforms and complementary motion-compensated signals

    Science.gov (United States)

    Flierl, Markus H.; Vandergheynst, Pierre; Girod, Bernd

    2004-01-01

    This paper investigates video coding with wavelet transforms applied in the temporal direction of a video sequence. The wavelets are implemented with the lifting scheme in order to permit motion compensation between successive pictures. We improve motion compensation in the lifting steps and utilize complementary motion-compensated signals. Similar to superimposed predictive coding with complementary signals, this approach improves compression efficiency. We investigate experimentally and theoretically complementary motion-compensated signals for lifted wavelet transforms. Experimental results with the complementary motion-compensated Haar wavelet and frame-adaptive motion compensation show improvements in coding efficiency of up to 3 dB. The theoretical results demonstrate that the lifted Haar wavelet scheme with complementary motion-compensated signals is able to approach the bound for bit-rate savings of 2 bits per sample and motion-accuracy step when compared to optimum intra-frame coding of the input pictures.

  13. Compensation of motion error in a high accuracy AFM

    Science.gov (United States)

    Cui, Yuguo; Arai, Yoshikazu; He, Gaofa; Asai, Takemi; Gao, Wei

    2008-10-01

    An atomic force microscope (AFM) system is used for large-area measurement with a spiral scanning strategy, which is composed of an air slide, an air spindle and a probe unit. The motion error which is brought from the air slide and the air spindle will increase with the increasing of the measurement area. Then the measurement accuracy will decrease. In order to achieve a high speed and high accuracy measurement, the probe scans along X-direction with constant height mode driven by the air slide, and at the same time, based on the change way of the motion error, it moves along Zdirection conducted by piezoactuator. According to the above method of error compensation, the profile measurement experiment of a micro-structured surface has been carried out. The experimental result shows that this method is effective for eliminating motion error, and it can achieve high speed and precision measurement of micro-structured surface.

  14. Galvanometer control system design of aerial camera motion compensation

    Science.gov (United States)

    Qiao, Mingrui; Cao, Jianzhong; Wang, Huawei; Guo, Yunzeng; Hu, Changchang; Tang, Hong; Niu, Yuefeng

    2015-10-01

    Aerial cameras exist the image motion on the flight. The image motion has seriously affected the image quality, making the image edge blurred and gray scale loss. According to the actual application situation, when high quality and high precision are required, the image motion compensation (IMC) should be adopted. This paper designs galvanometer control system of IMC. The voice coil motor as the actuator has a simple structure, fast dynamic response and high positioning accuracy. Double-loop feedback is also used. PI arithmetic and Hall sensors are used at the current feedback. Fuzzy-PID arithmetic and optical encoder are used at the speed feedback. Compared to conventional PID control arithmetic, the simulation results show that the control system has fast response and high control accuracy.

  15. Vessel, motion platform, method for compensating motions of a vessel and use of a stewart platform

    NARCIS (Netherlands)

    Van der Tempel, J.; Salzmann, D.J.C.; Koch, J.; Gerner. F.; Goebel, A.J.

    2007-01-01

    A vessel (1) with a motion compensation platform (4), which platform is provided with at least one carrier (6) for bearing, moving and/or transferring a load, actuators (5) for moving the carrier relative to the vessel, preferably in six degrees of freedom, a control system for driving the actuators

  16. Scalable video compression using longer motion compensated temporal filters

    Science.gov (United States)

    Golwelkar, Abhijeet V.; Woods, John W.

    2003-06-01

    Three-dimensional (3-D) subband/wavelet coding using a motion compensated temporal filter (MCTF) is emerging as a very effective structure for highly scalable video coding. Most previous work has used two-tap Haar filters for the temporal analysis/synthesis. To make better use of the temporal redundancies, we are proposing an MCTF scheme based on longer biorthogonal filters. We show a lifting based coder capable of subpixel accurate motion compensation. If we retain the fixed size GOP structure of the Haar filter MCTFs, we need to use symmetric extensions at both ends of the GOP. This gives rise to loss of coding efficiency at the GOP boundaries resulting in significant PSNR drops there. This performance can be considerably improved by using a 'sliding window,' in place of the GOP block. We employ the 5/3 filter and its non-orthogonality causes PSNR variation, which can be reduced by employing filter-based weighting coefficients. Overall the longer filters have a higher coding gain than the Haar filters and show significant improvement in average PSNR at high bit rates. However, a doubling in the number of motion vectors to be transmitted, translates to a drop in PSNR at the lower video bit rates.

  17. Motion-compensated non-contact detection of heart rate

    Science.gov (United States)

    Yang, Lei; Liu, Ming; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua

    2015-12-01

    A new non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. This poses a great challenge to compensate the motion artifacts during measurements. In order to circumvent this problem, we have proposed the amplitude spectrum and phase spectrum adaptive filter. Comparing with the time-domain adaptive filter and independent component analysis, the amplitude spectrum and phase spectrum adaptive filter can suppress the interference caused by the two circuit differences and effectively compensate the motion artifacts. To make the device is much compact and portable, a photoelectric probe is designed. The measurement distance is from several centimeters up to several meters. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor.

  18. Optimising rigid motion compensation for small animal brain PET imaging

    Science.gov (United States)

    Spangler-Bickell, Matthew G.; Zhou, Lin; Kyme, Andre Z.; De Laat, Bart; Fulton, Roger R.; Nuyts, Johan

    2016-10-01

    Motion compensation (MC) in PET brain imaging of awake small animals is attracting increased attention in preclinical studies since it avoids the confounding effects of anaesthesia and enables behavioural tests during the scan. A popular MC technique is to use multiple external cameras to track the motion of the animal’s head, which is assumed to be represented by the motion of a marker attached to its forehead. In this study we have explored several methods to improve the experimental setup and the reconstruction procedures of this method: optimising the camera-marker separation; improving the temporal synchronisation between the motion tracker measurements and the list-mode stream; post-acquisition smoothing and interpolation of the motion data; and list-mode reconstruction with appropriately selected subsets. These techniques have been tested and verified on measurements of a moving resolution phantom and brain scans of an awake rat. The proposed techniques improved the reconstructed spatial resolution of the phantom by 27% and of the rat brain by 14%. We suggest a set of optimal parameter values to use for awake animal PET studies and discuss the relative significance of each parameter choice.

  19. Characterization of free breathing patterns with 5D lung motion model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Tianyu; Lu Wei; Yang Deshan; Mutic, Sasa; Noel, Camille E.; Parikh, Parag J.; Bradley, Jeffrey D.; Low, Daniel A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2009-11-15

    Purpose: To determine the quiet respiration breathing motion model parameters for lung cancer and nonlung cancer patients. Methods: 49 free breathing patient 4DCT image datasets (25 scans, cine mode) were collected with simultaneous quantitative spirometry. A cross-correlation registration technique was employed to track the lung tissue motion between scans. The registration results were applied to a lung motion model: X-vector=X-vector{sub 0}+{alpha}-vector{beta}-vector f, where X-vector is the position of a piece of tissue located at reference position X-vector{sub 0} during a reference breathing phase (zero tidal volume v, zero airflow f). {alpha}-vector is a parameter that characterizes the motion due to air filling (motion as a function of tidal volume v) and {beta}-vector is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation that causes lung motion hysteresis (motion as a function of airflow f). The parameters {alpha}-vector and {beta}-vector together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The {alpha}-vector and {beta}-vector distributions were examined for each patient to determine overall general patterns and interpatient pattern variations. Results: For 44 patients, the greatest values of |{alpha}-vector| were observed in the inferior and posterior lungs. For the rest of the patients, |{alpha}-vector| reached its maximum in the anterior lung in three patients and the lateral lung in two patients. The hysteresis motion {beta}-vector had greater variability, but for the majority of patients, |{beta}-vector| was largest in the lateral lungs. Conclusions: This is the first report of the three-dimensional breathing motion model parameters for a large cohort of patients. The model has the potential for noninvasively predicting lung motion. The majority of patients exhibited similar |{alpha}-vector| maps

  20. Comparison of impedance and inductance ventilation sensors on adults during breathing, motion, and simulated airway obstruction.

    Science.gov (United States)

    Cohen, K P; Ladd, W M; Beams, D M; Sheers, W S; Radwin, R G; Tompkins, W J; Webster, J G

    1997-07-01

    The goal of this study was to compare the relative performance of two noninvasive ventilation sensing technologies on adults during artifacts. We recorded changes in transthoracic impedance and cross-sectional area of the abdomen (abd) and rib cage (rc) using impedance pneumography (IP) and respiratory inductance plethysmography (RIP) on ten adult subjects during natural breathing, motion artifact, simulated airway obstruction, yawning, snoring, apnea, and coughing. We used a pneumotachometer to measure air flow and tidal volume as the standard. We calibrated all sensors during natural breathing, and performed measurements during all maneuvers without changing the calibration parameters. No sensor provided the most-accurate measure of tidal volume for all maneuvers. Overall, the combination of inductance sensors [RIP(sum)] calibrated during an isovolume maneuver had a bias (weighted mean difference) as low or lower than all individual sensors and all combinations of sensors. The IP(rc) sensor had a bias as low or lower than any individual sensor. The cross-correlation coefficient between sensors was high during natural breathing, but decreased during artifacts. The cross correlation between sensor pairs was lower during artifacts without breathing than it was during maneuvers with breathing for four different sensor combinations. We tested a simple breath-detection algorithm on all sensors and found that RIP(sum) resulted in the fewest number of false breath detections, with sensitivity of 90.8% and positive predictivity of 93.6%.

  1. Acquisition-related motion compensation for digital subtraction angiography.

    Science.gov (United States)

    Ionasec, Razvan Ioan; Heigl, Benno; Hornegger, Joachim

    2009-06-01

    Subtraction methods in angiography are generally applied in order to enhance the visualization of blood vessels by eliminating bones and surrounding tissues from X-ray images. The main limitation of these methods is the sensitivity to patient movement, which leads to artifacts and reduces the clinical value of the subtraction images. In this paper we present a novel method for rigid motion compensation with primary application to road mapping, frequently used in image-guided interventions. Using the general concept of image-based registration, we optimize the physical position and orientation of the C-arm X-ray device, thought of as the rigid 3D transformation accounting for the patient movement. The registration is carried out using a hierarchical optimization strategy and a similarity measure based on the variance of intensity differences, which has been shown to be most suitable for fluoroscopic images. Performance evaluation demonstrated the capabilities of the proposed approach to compensate for potential intra-operative patient motion, being more resilient to the fundamental problems of pure image-based registration.

  2. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, Laura; O' Brien, Kendall J. [Children' s National Health System, Division of Cardiology, Washington, DC (United States); National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Cross, Russell [Children' s National Health System, Division of Cardiology, Washington, DC (United States); Xue, Hui; Kellman, Peter; Hansen, Michael S. [National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States)

    2016-06-15

    The value of late-gadolinium-enhancement (LGE) imaging in the diagnosis and management of pediatric and congenital heart disease is clear; however current acquisition techniques are susceptible to error and artifacts when performed in children because of children's higher heart rates, higher prevalence of sinus arrhythmia, and inability to breath-hold. Commonly used techniques in pediatric LGE imaging include breath-held segmented FLASH (segFLASH) and steady-state free precession-based (segSSFP) imaging. More recently, single-shot SSFP techniques with respiratory motion-corrected averaging have emerged. This study tested and compared single-shot free-breathing LGE techniques with standard segmented breath-held techniques in children undergoing LGE imaging. Thirty-two consecutive children underwent clinically indicated late-enhancement imaging using intravenous gadobutrol 0.15 mmol/kg. Breath-held segSSFP, breath-held segFLASH, and free-breathing single-shot SSFP LGE sequences were performed in consecutive series in each child. Two blinded reviewers evaluated the quality of the images and rated them on a scale of 1-5 (1 = poor, 5 = superior) based on blood pool-myocardial definition, presence of cardiac motion, presence of respiratory motion artifacts, and image acquisition artifact. We used analysis of variance (ANOVA) to compare groups. Patients ranged in age from 9 months to 18 years, with a mean +/- standard deviation (SD) of 13.3 +/- 4.8 years. R-R interval at the time of acquisition ranged 366-1,265 milliseconds (ms) (47-164 beats per minute [bpm]), mean +/- SD of 843+/-231 ms (72+/-21 bpm). Mean +/- SD quality ratings for long-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.1+/-0.9, 3.4+/-0.9 and 4.0+/-0.9, respectively (P < 0.01 by ANOVA). Mean +/- SD quality ratings for short-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.4+/-1, 3.8+/-0.9 and 4.3+/-0.7, respectively (P < 0.01 by ANOVA). Single-shot late

  3. Importance of motion in motion-compensated temporal discrete wavelet transforms

    Science.gov (United States)

    Konrad, Janusz; Bozinovic, Nikola

    2005-03-01

    Discrete wavelet transforms (DWTs) applied temporally under motion compensation (MC) have recently become a very powerful tool in video compression, especially when implemented through lifting. A recent theoretical analysis has established conditions for perfect reconstruction in the case of transversal MC-DWT, and also for the equivalence of lifted and transversal implementations of MC-DWT. For Haar MC-DWT these conditions state that motion must be invertible, while for higher-order transforms they state that motion composition must be a well-defined operator. Since many popular motion models do not obey these properties, thus inducing errors (prior to compression), it is important to understand what is the impact of motion non-invertibility or quasi-invertibility on the performance of video compression. In this paper, we present new experimental results of a study aiming at a quantitative evaluation of such impact in case of block-based motion. We propose a new metric to measure the degree with which two motion fields are not inverses of each other. Using this metric we investigate several motion inversion schemes, from simple temporal sample-and-hold, through spatial nearest-neighbor, to advanced spline-based inversion, and we compare compression performance of each method to that of independently-estimated forward and backward motion fields. We observe that compression performance monotonically improves with the reduction of the proposed motion inversion error, up to 1-1.5dB for the advanced spline-based inversion. We also generalize the problem of "unconnected" pixels by extending it to both update and prediction steps, as opposed to the update step only used in conventional methods. Initial tests show favorable results compared to previously reported techniques.

  4. Non-contact Breath Motion Monitor ing System in Full Automation.

    Science.gov (United States)

    Sato, Isao; Nakajima, Masato

    2005-01-01

    It is said that sleep apnea syndrome is one of the main causes of airplane, train and car accidents. We have developed a non-contact breathing measurement system which diagnoses not only sleep apnea syndrome but also other sleep disorders. This system calculates the amount of the volume change and makes the movement of the outside of the body by the breath motion visible. If the patient is breathing abnormally, we are able to recognize the appearance of abnormality at a glance and know the amount of the volume change in that location. To verify the amount of the volume change, we compare the amount of ventilation measured with a spirometer to the amount of volume change measured with this system. As a result, there is a high correlation in the amount of the volume change and the amount of ventilation in any sleeping position.

  5. A Novel Method to Compute Breathing Volumes via Motion Capture Systems: Design and Experimental Trials.

    Science.gov (United States)

    Massaroni, Carlo; Cassetta, Eugenio; Silvestri, Sergio

    2017-03-24

    Respiratory assessment can be carried out by using motion capture systems. A geometrical model is mandatory in order to compute the breathing volume as a function of time from the markers trajectories. This study describes a novel model to compute volume changes and calculate respiratory parameters by using a motion capture system. The novel method, i.e. prism-based method, computes the volume enclosed within the chest by defining 82 prisms from the 89 markers attached to the subject chest. Volumes computed with this method are compared to spirometry volumes and to volumes computed by a conventional method based on the tetrahedrons decomposition of the chest wall and integrated in a commercial motion capture system. Eight healthy volunteers were enrolled and 30 seconds quiet breathing collected from each of them. Results show a better agreement between volumes computed by the prism-based method and the spirometry (discrepancy of 2.23%, R(2)=0.94) compared to the agreement between volumes computed by the conventional method and the spirometry (discrepancy of 3.56%, R(2)=0.92). The proposed method also showed better performances in the calculation of respiratory parameters. Our findings open up prospects for the further use of the new method in the breathing assessment via motion capture systems.

  6. Combination of principal component analysis and optical-flow motion compensation for improved cardiac MR thermometry

    Science.gov (United States)

    Toupin, S.; de Senneville, B. Denis; Ozenne, V.; Bour, P.; Lepetit-Coiffe, M.; Boissenin, M.; Jais, P.; Quesson, B.

    2017-02-01

    The use of magnetic resonance (MR) thermometry for the monitoring of thermal ablation is rapidly expanding. However, this technique remains challenging for the monitoring of the treatment of cardiac arrhythmia by radiofrequency ablation due to the heart displacement with respiration and contraction. Recent studies have addressed this problem by compensating in-plane motion in real-time with optical-flow based tracking technique. However, these algorithms are sensitive to local variation of signal intensity on magnitude images associated with tissue heating. In this study, an optical-flow algorithm was combined with a principal component analysis method to reduce the impact of such effects. The proposed method was integrated to a fully automatic cardiac MR thermometry pipeline, compatible with a future clinical workflow. It was evaluated on nine healthy volunteers under free breathing conditions, on a phantom and in vivo on the left ventricle of a sheep. The results showed that local intensity changes in magnitude images had lower impact on motion estimation with the proposed method. Using this strategy, the temperature mapping accuracy was significantly improved.

  7. Friction Effects on Inertia Compensators used for Heliostat Base Motion Isolation.

    Science.gov (United States)

    The base motion isolation of an optical beam deflector with a two-axis gimbal support ( heliostat ) is discussed. The use of an auxiliary inertia...coupled between the elevation gimbal and the heliostat mirror to produce a compensating torque referred to as a gear compensator and a belt compensator

  8. Design and Implementation of the Motion Compensation Module for HDTV Video Decoder

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presented a new solution for motion compensation module in the high definition television (HDTV) video decoder. The overall architecture and the design of the major functional units, such as the motion vector decoder, the predictor , and the mixer, were discussed. Based on the exploitation of the special characteristics inherent in the motion compensation algorithm, the motion compensation module and its functional units adopt various novel architectures in order to allow the module to meet real-time constraints. This solution resolves the problem of high hardware costs, low bus efficiency and complex control schemes in conventional designs.

  9. Global motion compensated visual attention-based video watermarking

    Science.gov (United States)

    Oakes, Matthew; Bhowmik, Deepayan; Abhayaratne, Charith

    2016-11-01

    Imperceptibility and robustness are two key but complementary requirements of any watermarking algorithm. Low-strength watermarking yields high imperceptibility but exhibits poor robustness. High-strength watermarking schemes achieve good robustness but often suffer from embedding distortions resulting in poor visual quality in host media. This paper proposes a unique video watermarking algorithm that offers a fine balance between imperceptibility and robustness using motion compensated wavelet-based visual attention model (VAM). The proposed VAM includes spatial cues for visual saliency as well as temporal cues. The spatial modeling uses the spatial wavelet coefficients while the temporal modeling accounts for both local and global motion to arrive at the spatiotemporal VAM for video. The model is then used to develop a video watermarking algorithm, where a two-level watermarking weighting parameter map is generated from the VAM saliency maps using the saliency model and data are embedded into the host image according to the visual attentiveness of each region. By avoiding higher strength watermarking in the visually attentive region, the resulting watermarked video achieves high perceived visual quality while preserving high robustness. The proposed VAM outperforms the state-of-the-art video visual attention methods in joint saliency detection and low computational complexity performance. For the same embedding distortion, the proposed visual attention-based watermarking achieves up to 39% (nonblind) and 22% (blind) improvement in robustness against H.264/AVC compression, compared to existing watermarking methodology that does not use the VAM. The proposed visual attention-based video watermarking results in visual quality similar to that of low-strength watermarking and a robustness similar to those of high-strength watermarking.

  10. Relative Motion Compensation for Cargo Handling Operations -- Annotated Bibliography

    Science.gov (United States)

    1991-01-01

    4-6 Active Heave Compensation Systems on Board of Vessels and Offshore Rigs ............................................... 4...Herwig, "Active Heave Compensation Systems on Board of Vessels and Offshore Rigs," Marine Technology, pp. 59-61 (May 1986). Active heave compensation systems

  11. TU-F-BRB-01: Resolving and Characterizing Breathing Motion for Radiotherapy with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tryggestad, E. [Mayo Clinic (United States)

    2015-06-15

    The current clinical standard of organ respiratory imaging, 4D-CT, is fundamentally limited by poor soft-tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose-volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft-tissue contrast. MRI-based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR-based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D-MRI and MRI hybrid treatment machines (i.e. MR-linac or MR-Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI-based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR-based motion management methods and technologies, the state-of-the-art concerning MRI development and clinical application and the barriers to more widespread adoption. Learning Objectives: Discuss the need of MR-based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

  12. Five-dimensional motion compensation for respiratory and cardiac motion with cone-beam CT of the thorax region

    Science.gov (United States)

    Sauppe, Sebastian; Hahn, Andreas; Brehm, Marcus; Paysan, Pascal; Seghers, Dieter; Kachelrieß, Marc

    2016-03-01

    We propose an adapted method of our previously published five-dimensional (5D) motion compensation (MoCo) algorithm1, developed for micro-CT imaging of small animals, to provide for the first time motion artifact-free 5D cone-beam CT (CBCT) images from a conventional flat detector-based CBCT scan of clinical patients. Image quality of retrospectively respiratory- and cardiac-gated volumes from flat detector CBCT scans is deteriorated by severe sparse projection artifacts. These artifacts further complicate motion estimation, as it is required for MoCo image reconstruction. For high quality 5D CBCT images at the same x-ray dose and the same number of projections as todays 3D CBCT we developed a double MoCo approach based on motion vector fields (MVFs) for respiratory and cardiac motion. In a first step our already published four-dimensional (4D) artifact-specific cyclic motion-compensation (acMoCo) approach is applied to compensate for the respiratory patient motion. With this information a cyclic phase-gated deformable heart registration algorithm is applied to the respiratory motion-compensated 4D CBCT data, thus resulting in cardiac MVFs. We apply these MVFs on double-gated images and thereby respiratory and cardiac motion-compensated 5D CBCT images are obtained. Our 5D MoCo approach processing patient data acquired with the TrueBeam 4D CBCT system (Varian Medical Systems). Our double MoCo approach turned out to be very efficient and removed nearly all streak artifacts due to making use of 100% of the projection data for each reconstructed frame. The 5D MoCo patient data show fine details and no motion blurring, even in regions close to the heart where motion is fastest.

  13. Image-based motion compensation for high-resolution extremities cone-beam CT

    Science.gov (United States)

    Sisniega, A.; Stayman, J. W.; Cao, Q.; Yorkston, J.; Siewerdsen, J. H.; Zbijewski, W.

    2016-03-01

    Purpose: Cone-beam CT (CBCT) of the extremities provides high spatial resolution, but its quantitative accuracy may be challenged by involuntary sub-mm patient motion that cannot be eliminated with simple means of external immobilization. We investigate a two-step iterative motion compensation based on a multi-component metric of image sharpness. Methods: Motion is considered with respect to locally rigid motion within a particular region of interest, and the method supports application to multiple locally rigid regions. Motion is estimated by maximizing a cost function with three components: a gradient metric encouraging image sharpness, an entropy term that favors high contrast and penalizes streaks, and a penalty term encouraging smooth motion. Motion compensation involved initial coarse estimation of gross motion followed by estimation of fine-scale displacements using high resolution reconstructions. The method was evaluated in simulations with synthetic motion (1-4 mm) applied to a wrist volume obtained on a CMOS-based CBCT testbench. Structural similarity index (SSIM) quantified the agreement between motion-compensated and static data. The algorithm was also tested on a motion contaminated patient scan from dedicated extremities CBCT. Results: Excellent correction was achieved for the investigated range of displacements, indicated by good visual agreement with the static data. 10-15% improvement in SSIM was attained for 2-4 mm motions. The compensation was robust against increasing motion (4% decrease in SSIM across the investigated range, compared to 14% with no compensation). Consistent performance was achieved across a range of noise levels. Significant mitigation of artifacts was shown in patient data. Conclusion: The results indicate feasibility of image-based motion correction in extremities CBCT without the need for a priori motion models, external trackers, or fiducials.

  14. PET Motion Compensation for Radiation Therapy Using a CT-Based Mid-Position Motion Model: Methodology and Clinical Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kruis, Matthijs F.; Kamer, Jeroen B. van de; Houweling, Antonetta C.; Sonke, Jan-Jakob; Belderbos, José S.A.; Herk, Marcel van, E-mail: m.v.herk@nki.nl

    2013-10-01

    Purpose: Four-dimensional positron emission tomography (4D PET) imaging of the thorax produces sharper images with reduced motion artifacts. Current radiation therapy planning systems, however, do not facilitate 4D plan optimization. When images are acquired in a 2-minute time slot, the signal-to-noise ratio of each 4D frame is low, compromising image quality. The purpose of this study was to implement and evaluate the construction of mid-position 3D PET scans, with motion compensated using a 4D computed tomography (CT)-derived motion model. Methods and Materials: All voxels of 4D PET were registered to the time-averaged position by using a motion model derived from the 4D CT frames. After the registration the scans were summed, resulting in a motion-compensated 3D mid-position PET scan. The method was tested with a phantom dataset as well as data from 27 lung cancer patients. Results: PET motion compensation using a CT-based motion model improved image quality of both phantoms and patients in terms of increased maximum SUV (SUV{sub max}) values and decreased apparent volumes. In homogenous phantom data, a strong relationship was found between the amplitude-to-diameter ratio and the effects of the method. In heterogeneous patient data, the effect correlated better with the motion amplitude. In case of large amplitudes, motion compensation may increase SUV{sub max} up to 25% and reduce the diameter of the 50% SUV{sub max} volume by 10%. Conclusions: 4D CT-based motion-compensated mid-position PET scans provide improved quantitative data in terms of uptake values and volumes at the time-averaged position, thereby facilitating more accurate radiation therapy treatment planning of pulmonary lesions.

  15. Flexible three-band motion-compensated temporal filtering for scalable video coding

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-yu; SUN Qu; YUAN Chao-wei

    2009-01-01

    A novel scheme for scalable video coding using three-band lifting-based motion-compensated transform is presented in this article. A series of flexible three-band motion-compensated lifting steps are used to implement the temporal wavelet transform, which provide improved compression performance by selecting specific motion model according to real video sequences, and offer higher temporal scalability flexibility by using three-band lifting steps. The experimental results compared with motion picture expert group (MPEG)-4 codec concerning standard video sequences demonstrate the effectiveness of the method.

  16. SU-E-J-234: Application of a Breathing Motion Model to ViewRay Cine MR Images

    Energy Technology Data Exchange (ETDEWEB)

    O’Connell, D. P.; Thomas, D. H.; Dou, T. H.; Lamb, J. M.; Yang, L.; Low, D. A. [University of California, Los Angeles, Los Angeles, CA (United States)

    2015-06-15

    Purpose: A respiratory motion model previously used to generate breathing-gated CT images was used with cine MR images. Accuracy and predictive ability of the in-plane models were evaluated. Methods: Sagittalplane cine MR images of a patient undergoing treatment on a ViewRay MRI/radiotherapy system were acquired before and during treatment. Images were acquired at 4 frames/second with 3.5 × 3.5 mm resolution and a slice thickness of 5 mm. The first cine frame was deformably registered to following frames. Superior/inferior component of the tumor centroid position was used as a breathing surrogate. Deformation vectors and surrogate measurements were used to determine motion model parameters. Model error was evaluated and subsequent treatment cines were predicted from breathing surrogate data. A simulated CT cine was created by generating breathing-gated volumetric images at 0.25 second intervals along the measured breathing trace, selecting a sagittal slice and downsampling to the resolution of the MR cines. A motion model was built using the first half of the simulated cine data. Model accuracy and error in predicting the remaining frames of the cine were evaluated. Results: Mean difference between model predicted and deformably registered lung tissue positions for the 28 second preview MR cine acquired before treatment was 0.81 +/− 0.30 mm. The model was used to predict two minutes of the subsequent treatment cine with a mean accuracy of 1.59 +/− 0.63 mm. Conclusion: Inplane motion models were built using MR cine images and evaluated for accuracy and ability to predict future respiratory motion from breathing surrogate measurements. Examination of long term predictive ability is ongoing. The technique was applied to simulated CT cines for further validation, and the authors are currently investigating use of in-plane models to update pre-existing volumetric motion models used for generation of breathing-gated CT planning images.

  17. MR-Based Cardiac and Respiratory Motion-Compensation Techniques for PET-MR Imaging.

    Science.gov (United States)

    Munoz, Camila; Kolbitsch, Christoph; Reader, Andrew J; Marsden, Paul; Schaeffter, Tobias; Prieto, Claudia

    2016-04-01

    Cardiac and respiratory motion cause image quality degradation in PET imaging, affecting diagnostic accuracy of the images. Whole-body simultaneous PET-MR scanners allow for using motion information estimated from MR images to correct PET data and produce motion-compensated PET images. This article reviews methods that have been proposed to estimate motion from MR images and different techniques to include this information in PET reconstruction, in order to overcome the problem of cardiac and respiratory motion in PET-MR imaging. MR-based motion correction techniques significantly increase lesion detectability and contrast, and also improve accuracy of uptake values in PET images.

  18. A High-precision Motion Compensation Method for SAR Based on Image Intensity Optimization

    Directory of Open Access Journals (Sweden)

    Hu Ke-bin

    2015-02-01

    Full Text Available Owing to the platform instability and precision limitations of motion sensors, motion errors negatively affect the quality of synthetic aperture radar (SAR images. The autofocus Back Projection (BP algorithm based on the optimization of image sharpness compensates for motion errors through phase error estimation. This method can attain relatively good performance, while assuming the same phase error for all pixels, i.e., it ignores the spatial variance of motion errors. To overcome this drawback, a high-precision motion error compensation method is presented in this study. In the proposed method, the Antenna Phase Centers (APC are estimated via optimization using the criterion of maximum image intensity. Then, the estimated APCs are applied for BP imaging. Because the APC estimation equals the range history estimation for each pixel, high-precision phase compensation for every pixel can be achieved. Point-target simulations and processing of experimental data validate the effectiveness of the proposed method.

  19. Design principle of high-precision flexure mechanisms based on parasitic-motion compensation

    Science.gov (United States)

    Li, Shouzhong; Yu, Jingjun

    2014-07-01

    In design of flexure mechanism, diminishing the parasitic-motion is a key point to improve the accuracy. However, most of existing topics concentrate on improving the accuracy of linear-motion flexure mechanisms via compensating the parasitic error, but few research the multi-dimensional flexure mechanisms. A general design principle and method for high-precision flexure mechanisms based on the parasitic-motion compensation is presented, and the proposed method can compensate the parasitic rotation in company with translation, or the parasitic translation in company with rotation, or both. The crucial step for the method is that the parasitic motion of a flexure mechanism is formulated and evaluated in terms of its compliance. The overall compliance matrix of a general flexure mechanism is formulated by using screw theory firstly, then the criteria for the parasitic motions is introduced by analyzing the characteristics of the resultant compliance matrix as well as with aid of the concept of instantaneous rotation center. Subsequently, a compliance-based compensation approach for reducing parasitic-motion is addressed as the most important part. The design principles and procedure are further discussed to help with improving the accuracy of flexure mechanisms, and case studies are provided to illustrate this method. Finally, an analytical verification is provided to demonstrate that the symmetry design philosophy widely used in flexure design can effectively improve accuracy in terms of the proposed method. The proposed compensation method can be well used to diminish the parasitic-motion of multi-dimensional flexure mechanisms.

  20. A Motion Compensated Lifting Wavelet Codec for 3D Video Coding

    Institute of Scientific and Technical Information of China (English)

    LUO Lin(罗琳); LI Jin(李劲); LI ShiPeng(李世鹏); ZHUANG ZhenQuan(庄镇泉)

    2003-01-01

    A motion compensated lifting (MCLIFT) framework for the 3D wavelet videocoding is proposed in this paper. By using bi-directional motion compensation in each lifting stepof the temporal direction, the video frames are effectively de-correlated. With the proper entropycoding and bit-stream packaging schemes, the MCLIFT wavelet video coder is scalable at framerate and quality level. Experimental results show that the MCLIFT video coder outperforms the3D wavelet video coder without motion by an average of 0.9-1.3dB, and outperforms MPEG-4coder by an average of 0.2-0.6dB.

  1. Clinical evaluation of 4D PET motion compensation strategies for treatment verification in ion beam therapy

    Science.gov (United States)

    Gianoli, Chiara; Kurz, Christopher; Riboldi, Marco; Bauer, Julia; Fontana, Giulia; Baroni, Guido; Debus, Jürgen; Parodi, Katia

    2016-06-01

    A clinical trial named PROMETHEUS is currently ongoing for inoperable hepatocellular carcinoma (HCC) at the Heidelberg Ion Beam Therapy Center (HIT, Germany). In this framework, 4D PET-CT datasets are acquired shortly after the therapeutic treatment to compare the irradiation induced PET image with a Monte Carlo PET prediction resulting from the simulation of treatment delivery. The extremely low count statistics of this measured PET image represents a major limitation of this technique, especially in presence of target motion. The purpose of the study is to investigate two different 4D PET motion compensation strategies towards the recovery of the whole count statistics for improved image quality of the 4D PET-CT datasets for PET-based treatment verification. The well-known 4D-MLEM reconstruction algorithm, embedding the motion compensation in the reconstruction process of 4D PET sinograms, was compared to a recently proposed pre-reconstruction motion compensation strategy, which operates in sinogram domain by applying the motion compensation to the 4D PET sinograms. With reference to phantom and patient datasets, advantages and drawbacks of the two 4D PET motion compensation strategies were identified. The 4D-MLEM algorithm was strongly affected by inverse inconsistency of the motion model but demonstrated the capability to mitigate the noise-break-up effects. Conversely, the pre-reconstruction warping showed less sensitivity to inverse inconsistency but also more noise in the reconstructed images. The comparison was performed by relying on quantification of PET activity and ion range difference, typically yielding similar results. The study demonstrated that treatment verification of moving targets could be accomplished by relying on the whole count statistics image quality, as obtained from the application of 4D PET motion compensation strategies. In particular, the pre-reconstruction warping was shown to represent a promising choice when combined with intra

  2. Verification and compensation of respiratory motion using an ultrasound imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Ho-Chiao, E-mail: hchuang@mail.ntut.edu.tw; Hsu, Hsiao-Yu; Chiu, Wei-Hung; Tien, Der-Chi [Department of Mechanical Engineering, National Taipei University of Technology, Number 1, Section 3, Chung-Hsiao E. Road, Taipei 10608, Taiwan (China); Wu, Ren-Hong; Hsu, Chung-Hsien [Shin Kong Wu Ho-Su Memorial Hospital, Number 95, Wen-Chang Road, Shih-Lin District, Taipei 11101, Taiwan (China)

    2015-03-15

    Purpose: The purpose of this study was to determine if it is feasible to use ultrasound imaging as an aid for moving the treatment couch during diagnosis and treatment procedures associated with radiation therapy, in order to offset organ displacement caused by respiratory motion. A noninvasive ultrasound system was used to replace the C-arm device during diagnosis and treatment with the aims of reducing the x-ray radiation dose on the human body while simultaneously being able to monitor organ displacements. Methods: This study used a proposed respiratory compensating system combined with an ultrasound imaging system to monitor the compensation effect of respiratory motion. The accuracy of the compensation effect was verified by fluoroscopy, which means that fluoroscopy could be replaced so as to reduce unnecessary radiation dose on patients. A respiratory simulation system was used to simulate the respiratory motion of the human abdomen and a strain gauge (respiratory signal acquisition device) was used to capture the simulated respiratory signals. The target displacements could be detected by an ultrasound probe and used as a reference for adjusting the gain value of the respiratory signal used by the respiratory compensating system. This ensured that the amplitude of the respiratory compensation signal was a faithful representation of the target displacement. Results: The results show that performing respiratory compensation with the assistance of the ultrasound images reduced the compensation error of the respiratory compensating system to 0.81–2.92 mm, both for sine-wave input signals with amplitudes of 5, 10, and 15 mm, and human respiratory signals; this represented compensation of the respiratory motion by up to 92.48%. In addition, the respiratory signals of 10 patients were captured in clinical trials, while their diaphragm displacements were observed simultaneously using ultrasound. Using the respiratory compensating system to offset, the diaphragm

  3. Margin selection to compensate for loss of target dose coverage due to target motion during external-beam radiation therapy of the lung.

    Science.gov (United States)

    Foster, W Kyle; Osei, Ernest; Barnett, Rob

    2015-01-08

    The aim of this study is to provide guidelines for the selection of external-beam radiation therapy target margins to compensate for target motion in the lung during treatment planning. A convolution model was employed to predict the effect of target motion on the delivered dose distribution. The accuracy of the model was confirmed with radiochromic film measurements in both static and dynamic phantom modes. 502 unique patient breathing traces were recorded and used to simulate the effect of target motion on a dose distribution. A 1D probability density function (PDF) representing the position of the target throughout the breathing cycle was generated from each breathing trace obtained during 4D CT. Changes in the target D95 (the minimum dose received by 95% of the treatment target) due to target motion were analyzed and shown to correlate with the standard deviation of the PDF. Furthermore, the amount of target D95 recovered per millimeter of increased field width was also shown to correlate with the standard deviation of the PDF. The sensitivity of changes in dose coverage with respect to target size was also determined. Margin selection recommendations that can be used to compensate for loss of target D95 were generated based on the simulation results. These results are discussed in the context of clinical plans. We conclude that, for PDF standard deviations less than 0.4 cm with target sizes greater than 5 cm, little or no additional margins are required. Targets which are smaller than 5 cm with PDF standard deviations larger than 0.4 cm are most susceptible to loss of coverage. The largest additional required margin in this study was determined to be 8 mm.

  4. Motion compensated frame interpolation with a symmetric optical flow constraint

    DEFF Research Database (Denmark)

    Rakêt, Lars Lau; Roholm, Lars; Bruhn, Andrés;

    2012-01-01

    We consider the problem of interpolating frames in an image sequence. For this purpose accurate motion estimation can be very helpful. We propose to move the motion estimation from the surrounding frames directly to the unknown frame by parametrizing the optical flow objective function such that ......We consider the problem of interpolating frames in an image sequence. For this purpose accurate motion estimation can be very helpful. We propose to move the motion estimation from the surrounding frames directly to the unknown frame by parametrizing the optical flow objective function...... such that the interpolation assumption is directly modeled. This reparametrization is a powerful trick that results in a number of appealing properties, in particular the motion estimation becomes more robust to noise and large displacements, and the computational workload is more than halved compared to usual bidirectional...... methods. The proposed reparametrization is generic and can be applied to almost every existing algorithm. In this paper we illustrate its advantages by considering the classic TV-L1 optical flow algorithm as a prototype. We demonstrate that this widely used method can produce results that are competitive...

  5. Phase noise from aircraft motion: Compensation and effect on synthetic aperture radar images

    Science.gov (United States)

    Gabriel, Andrew K.; Goldstein, Richard M.

    1986-01-01

    Image degradation of airborne SAR imagery caused by phase errors introduced in the received signal by aircraft motion is discussed. Mechanical motion has a small bandwidth and does not affect the range signal, where the total echo time is typically 60 microsec. However, since the aperture length can be several seconds, the synthesized azimuth signal can have significant errors of which phase noise is the most important. An inertial navigation system can be used to compensate for these errors when processing the images. Calculations to evaluate how much improvement results from compensation are outlined.

  6. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    Directory of Open Access Journals (Sweden)

    Paolo Domenici

    2014-12-01

    Full Text Available Fast-starts are brief accelerations commonly observed in fish within the context of predator–prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1 which provides a sudden acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming at a prey. Little is known about C-starts outside the context of predator–prey interactions, though recent work has shown that escape response can also be induced by high temperature. Here, we test the hypothesis that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn which re-directs the fish towards the bottom. Using high-speed video in the laboratory, we compared the kinematics of the turn immediately following air-gulping performed by H. littorale in normoxia with those of mechanically-triggered C-start escape responses and with routine (i.e. spontaneous turns. Our results show that air-breathing events overlap considerably with escape responses with a large stage 1 angle in terms of turning rates, distance covered and the relationship between these rates. Therefore, these two behaviours can be considered kinematically comparable, suggesting that air-breathing in this species is followed by escape-like C-start motions, presumably to minimise time at the surface and exposure to avian predators. These findings show that C-starts can occur in a variety of contexts in which fish may need to get away from areas of potential danger.

  7. Motion estimation and compensation in dynamic spiral CT reconstruction; Estimation et compensation de mouvement en reconstruction dynamique de tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Kimdon, J.; Grangeat, P.; Koenig, A.; Bonnet, St

    2004-07-01

    Respiratory and cardiac motion causes blurring in dynamic X-ray Computed Tomography (CT). Fast scans reduce this problem, but they require a higher radiation dose per time period to maintain the signal to noise ratio of the resulting images, thereby magnifying the health risk to the patient. As an alternative to increased radiation, our team has already developed a cone-beam reconstruction algorithm based on a dynamic particle model that estimates, predicts, and compensates for respiratory motion in circular X-ray CT. The current paper presents an extension of this method to spiral CT, applicable to modern multi-slice scanners that take advantage of the speed and dose benefits of helical trajectories. We adapted all three main areas of the algorithm: backprojection, prediction, and compensation/accumulation. In backprojection, we changed the longitudinal re-binning technique, filter direction, and the method of enforcing the data sufficiency requirements. For prediction, we had to be careful of objects appearing and disappearing as the scanner bed advanced. For compensation/accumulation, we controlled the reconstruction time and combined images to cover a greater longitudinal extent for each phase in the respiratory or cardiac cycle. Tests with moving numerical phantoms demonstrate that the algorithm successfully improves the temporal resolution of the images without increasing the dose or reducing the signal-to-noise ratio. (authors)

  8. Local motion-compensated method for high-quality 3D coronary artery reconstruction.

    Science.gov (United States)

    Liu, Bo; Bai, Xiangzhi; Zhou, Fugen

    2016-12-01

    The 3D reconstruction of coronary artery from X-ray angiograms rotationally acquired on C-arm has great clinical value. While cardiac-gated reconstruction has shown promising results, it suffers from the problem of residual motion. This work proposed a new local motion-compensated reconstruction method to handle this issue. An initial image was firstly reconstructed using a regularized iterative reconstruction method. Then a 3D/2D registration method was proposed to estimate the residual vessel motion. Finally, the residual motion was compensated in the final reconstruction using the extended iterative reconstruction method. Through quantitative evaluation, it was found that high-quality 3D reconstruction could be obtained and the result was comparable to state-of-the-art method.

  9. Wave Motion Compensation Scheme and Its Model Tests for the Salvage of An Ancient Sunken Boat

    Institute of Scientific and Technical Information of China (English)

    YE Jia-wei; CHEN Yuan-ming; WANG Dong-jiao; LIU Yue-qin; SONG Xin; HUANG Yuan-tian

    2006-01-01

    The application of the vertical hoisting jack and wave motion compensation techniques to the salvage of an ancient sunken boat is introduced. The boat is wooden, loaded with cultural relics. It has been immersed at the bottom of the South China Sea for more than 800 years. In order to protect the structure of the boat and the cultural relics inside to the largest extent, an open caisson is used to hold the sunken boat and the silts around before they are raised from the seabed all together as a whole. In the paper, first, the seakeeping model test of the system of the salvage barge and the open caisson is done to determine some important wave response parameters. And then a further experimental study of the application of the vertical hoisting jack and wave motion compensation scheme to the salvage of the sunken boat is carried out. In the model tests, the techniques of the integrative mechanic-electronic-hydraulic control, wave motion forecast and wave motion compensation are used to minimize the heave motion of the open caisson. The results of the model tests show that the heave motion of the open caisson can be reduced effectively by the use of the present method.

  10. Evaluation of Rigid-Body Motion Compensation in Cardiac Perfusion SPECT Employing Polar-Map Quantification.

    Science.gov (United States)

    Pretorius, P Hendrik; Johnson, Karen L; King, Michael A

    2016-06-01

    We have recently been successful in the development and testing of rigid-body motion tracking, estimation and compensation for cardiac perfusion SPECT based on a visual tracking system (VTS). The goal of this study was to evaluate in patients the effectiveness of our rigid-body motion compensation strategy. Sixty-four patient volunteers were asked to remain motionless or execute some predefined body motion during an additional second stress perfusion acquisition. Acquisitions were performed using the standard clinical protocol with 64 projections acquired through 180 degrees. All data were reconstructed with an ordered-subsets expectation-maximization (OSEM) algorithm using 4 projections per subset and 5 iterations. All physical degradation factors were addressed (attenuation, scatter, and distance dependent resolution), while a 3-dimensional Gaussian rotator was used during reconstruction to correct for six-degree-of-freedom (6-DOF) rigid-body motion estimated by the VTS. Polar map quantification was employed to evaluate compensation techniques. In 54.7% of the uncorrected second stress studies there was a statistically significant difference in the polar maps, and in 45.3% this made a difference in the interpretation of segmental perfusion. Motion correction reduced the impact of motion such that with it 32.8 % of the polar maps were statistically significantly different, and in 14.1% this difference changed the interpretation of segmental perfusion. The improvement shown in polar map quantitation translated to visually improved uniformity of the SPECT slices.

  11. Motion Compensation With Prediction Error Using Ezw Wavelet Coefficients

    Directory of Open Access Journals (Sweden)

    Gopinath M (M.Tech

    2016-05-01

    Full Text Available The video compression technique is used to represent any video with minimal distortion. In the compression techniques of image processing, DWT is more significant because of its multi-resolution properties. DCT used in video coding often produces undesirability. The main objective of video coding is reduce spatial and temporal redundancies. In this proposed work a new encoder is designed by exploiting the multi – resolution properties of DWT to get the prediction error, using motion estimation technique to avoid the translation invariance.

  12. SU-E-J-175: Comparison of the Treatment Reproducibility of Tumors Affected by Breathing Motion

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, M; Piotrowski, T; Adamczyk, S [Medical Physics Department, Greater Poland Cancer Centre, Poznan (Poland)

    2015-06-15

    Purpose: The aim of the dose distribution simulations was to form a global idea of intensity-modulated radiation therapy (IMRT) realization, by its comparison to three-dimensional conformal radiation therapy (3DCRT) delivery for tumors affected by respiratory motion. Methods: In the group of 10patients both 3DCRT and IMRT plans were prepared.For each field the motion kernel was generated with the largest movement amplitude of 4;6 and 8mm.Additionally,the sets of reference measurements were made in no motion conditions(0 mm).The evaluation of plan delivery,using a diode array placed on moving platform,was based on the Gamma Index analysis with distance to agreement of 3mm and dose difference of 3%. Results: IMRT plans tended to spare doses delivered to lungs compared to 3DCRT.Nonetheless,analyzed volumes showed no significant difference between the static and dynamic techniques,except for the volumes of both lungs receiving 10 and 15Gy.After adding the components associated with the respiratory movement,all IMRT lung parameters evaluated for the ipsilateral,contralateral and both lungs together,revealed considerable differences between the 0vs.6, 0vs.8 and 4vs.8-mm amplitudes.Similar results were obtained for the 3DCRT lung measurements,but without significance between the 0vs.6-mm amplitude.Taking into account the CTV score parameter in 3DCRT and IMRT plans,there was no statistically significant difference between the motion patterns with the smallest amplitudes.The differences were found for the 8-mm amplitude when it was compared both with static conditions and 4-mm amplitude (for 3DCRT) and between 0vs.6, 0vs.8 and 4vs.8-mm amplitudes (for IMRT).All accepted and measured 3DCRT and IMRT doses to spinal cord,esophagus and heart were always below the QUANTEC limits. Conclusion: The application of IMRT technique in lung radiotherapy affords possibilities for reducing the lung doses.For maximal amplitudes of breathing trajectory below 4mm,the disagreement between CTV

  13. Lung Motion Model Validation Experiments, Free-Breathing Tissue Densitometry, and Ventilation Mapping using Fast Helical CT Imaging

    Science.gov (United States)

    Dou, Hsiang-Tai

    The uncertainties due to respiratory motion present significant challenges to accurate characterization of cancerous tissues both in terms of imaging and treatment. Currently available clinical lung imaging techniques are subject to inferior image quality and incorrect motion estimation, with consequences that can systematically impact the downstream treatment delivery and outcome. The main objective of this thesis is the development of the techniques of fast helical computed tomography (CT) imaging and deformable image registration for the radiotherapy applications in accurate breathing motion modeling, lung tissue density modeling and ventilation imaging. Fast helical CT scanning was performed on 64-slice CT scanner using the shortest available gantry rotation time and largest pitch value such that scanning of the thorax region amounts to just two seconds, which is less than typical breathing cycle in humans. The scanning was conducted under free breathing condition. Any portion of the lung anatomy undergoing such scanning protocol would be irradiated for only a quarter second, effectively removing any motion induced image artifacts. The resulting CT data were pristine volumetric images that record the lung tissue position and density in a fraction of the breathing cycle. Following our developed protocol, multiple fast helical CT scans were acquired to sample the tissue positions in different breathing states. To measure the tissue displacement, deformable image registration was performed that registers the non-reference images to the reference one. In modeling breathing motion, external breathing surrogate signal was recorded synchronously with the CT image slices. This allowed for the tissue-specific displacement to be modeled as parametrization of the recorded breathing signal using the 5D lung motion model. To assess the accuracy of the motion model in describing tissue position change, the model was used to simulate the original high-pitch helical CT scan

  14. Adaptive mode decision with residual motion compensation for distributed video coding

    DEFF Research Database (Denmark)

    Luong, Huynh Van; Forchhammer, Søren; Slowack, Jurgen

    2013-01-01

    mode in DVC. The adaptive mode decision is not only based on quality of key frames but also the rate of Wyner-Ziv (WZ) frames. To improve noise distribution estimation for a more accurate mode decision, a residual motion compensation is proposed to estimate a current noise residue based on a previously...

  15. Intrinsic feature-based pose measurement for imaging motion compensation

    Science.gov (United States)

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  16. A breathing thorax phantom with independently programmable 6D tumour motion for dosimetric measurements in radiation therapy

    Science.gov (United States)

    Steidl, P.; Richter, D.; Schuy, C.; Schubert, E.; Haberer, Th; Durante, M.; Bert, C.

    2012-04-01

    Irradiation of moving targets using a scanned ion beam can cause clinically intolerable under- and overdosages within the target volume due to the interplay effect. Several motion mitigation techniques such as gating, beam tracking and rescanning are currently investigated to overcome this restriction. To enable detailed experimental studies of potential mitigation techniques a complex thorax phantom was developed. The phantom consists of an artificial thorax with ribs to introduce density changes. The contraction of the thorax can be controlled by a stepping motor. A robotic driven detector head positioned inside the thorax mimics e.g. a lung tumour. The detector head comprises 20 ionization chambers and 5 radiographic films for target dose measurements. The phantom’s breathing as well as the 6D tumour motion (3D translation, 3D rotation) can be programmed independently and adjusted online. This flexibility allows studying the dosimetric effects of correlation mismatches between internal and external motions, irregular breathing, or baseline drifts to name a few. Commercial motion detection systems, e.g. VisionRT or Anzai belt, can be mounted as they would be mounted in a patient case. They are used to control the 4D treatment delivery and to generate data for 4D dose calculation. To evaluate the phantom’s properties, measurements addressing reproducibility, stability, temporal behaviour and performance of dedicated breathing manoeuvres were performed. In addition, initial dosimetric tests for treatment with a scanned carbon beam are reported.

  17. Transversal versus lifting approach to motion-compensated temporal discrete wavelet transform of image sequences: equivalence and tradeoffs

    Science.gov (United States)

    Konrad, Janusz

    2004-01-01

    Lifting-based implementations of various discrete wavelet transforms applied in the temporal direction under motion compensation have recently become a very powerful tool in video compression research. We present in this paper a theoretical analysis of motion compensation in both transversal and lifted implementations of such transforms. We derive conditions for perfect reconstruction in the case of motion-compensated transversal discrete wavelet transform. We also derive conditions on motion transformation assuring that a motion-compensated lifting scheme is exactly equivalent to its transversal counterpart. In general, these conditions require that motion transformation allow composition and be invertible. Unfortunately, many motion models do not obey these properties, thus inducing subband decomposition errors (prior to compression). We propose an alternative approach to motion compensation in the case of Haar transform. This new approach poses no constraints on motion; motion-compensated lifted Haar transform exactly implements its transversal implementation, and the latter obeys perfect reconstruction, both regardless of motion transformation used. This new approach, however, does not extend to the 5/3 or any higher-order discrete wavelet transform.

  18. Cardiac motion compensation and resolution modeling in simultaneous PET-MR: a cardiac lesion detection study

    Science.gov (United States)

    Petibon, Y.; Ouyang, J.; Zhu, X.; Huang, C.; Reese, T. G.; Chun, S. Y.; Li, Q.; El Fakhri, G.

    2013-04-01

    Cardiac motion and partial volume effects (PVE) are two of the main causes of image degradation in cardiac PET. Motion generates artifacts and blurring while PVE lead to erroneous myocardial activity measurements. Newly available simultaneous PET-MR scanners offer new possibilities in cardiac imaging as MRI can assess wall contractility while collecting PET perfusion data. In this perspective, we develop a list-mode iterative reconstruction framework incorporating both tagged-MR derived non-rigid myocardial wall motion and position dependent detector point spread function (PSF) directly into the PET system matrix. In this manner, our algorithm performs both motion ‘deblurring’ and PSF deconvolution while reconstructing images with all available PET counts. The proposed methods are evaluated in a beating non-rigid cardiac phantom whose hot myocardial compartment contains small transmural and non-transmural cold defects. In order to accelerate imaging time, we investigate collecting full and half k-space tagged MR data to obtain tagged volumes that are registered using non-rigid B-spline registration to yield wall motion information. Our experimental results show that tagged-MR based motion correction yielded an improvement in defect/myocardium contrast recovery of 34-206% as compared to motion uncorrected studies. Likewise, lesion detectability improved by respectively 115-136% and 62-235% with MR-based motion compensation as compared to gating and no motion correction and made it possible to distinguish non-transmural from transmural defects, which has clinical significance given the inherent limitations of current single modality imaging in identifying the amount of residual ischemia. The incorporation of PSF modeling within the framework of MR-based motion compensation significantly improved defect/myocardium contrast recovery (5.1-8.5%, p defect detectability (39-56%, p < 0.01). No statistical difference was found in PET contrast and lesion detectability

  19. Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

    Science.gov (United States)

    Schwemmer, C.; Rohkohl, C.; Lauritsch, G.; Müller, K.; Hornegger, J.

    2013-06-01

    Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D-2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average.

  20. A new motion compensation algorithm of floating lidar system for the assessment of turbulence intensity

    Science.gov (United States)

    Yamaguchi, Atsushi; Ishihara, Takeshi

    2016-09-01

    In this study, a new motion compensation algorithm was proposed and verified by using numerical simulation. Compensated horizontal mean wind speed by using conventional method shows good agreement with reference wind speed regardless of the motion of the floater. However, turbulence intensity is always overestimated. The overestimation is more significant when the maximum pitch angle of the floater motion is larger. When proposed method is used, the overestimation of the turbulent intensity is improved and estimated turbulent intensity shows better agreement with reference value. There still remains underestimation of the turbulence intensity with the bias of -1.1%. This is probably caused by the low sampling frequency in LIDAR measurement and further research is needed to model the high frequency component of the wind speed for LIDAR measurement.

  1. Refraction-compensated motion tracking of unrestrained small animals in positron emission tomography.

    Science.gov (United States)

    Kyme, Andre; Meikle, Steven; Baldock, Clive; Fulton, Roger

    2012-08-01

    Motion-compensated radiotracer imaging of fully conscious rodents represents an important paradigm shift for preclinical investigations. In such studies, if motion tracking is performed through a transparent enclosure containing the awake animal, light refraction at the interface will introduce errors in stereo pose estimation. We have performed a thorough investigation of how this impacts the accuracy of pose estimates and the resulting motion correction, and developed an efficient method to predict and correct for refraction-based error. The refraction model underlying this study was validated using a state-of-the-art motion tracking system. Refraction-based error was shown to be dependent on tracking marker size, working distance, and interface thickness and tilt. Correcting for refraction error improved the spatial resolution and quantitative accuracy of motion-corrected positron emission tomography images. Since the methods are general, they may also be useful in other contexts where data are corrupted by refraction effects.

  2. An Enhanced Intelligent Handheld Instrument with Visual Servo Control for 2-DOF Hand Motion Error Compensation

    Directory of Open Access Journals (Sweden)

    Yan Naing Aye

    2013-10-01

    Full Text Available The intelligent handheld instrument, ITrem2, enhances manual positioning accuracy by cancelling erroneous hand movements and, at the same time, provides automatic micromanipulation functions. Visual data is acquired from a high speed monovision camera attached to the optical surgical microscope and acceleration measurements are acquired from the inertial measurement unit (IMU on board ITrem2. Tremor estimation and canceling is implemented via Band-limited Multiple Fourier Linear Combiner (BMFLC filter. The piezoelectric actuated micromanipulator in ITrem2 generates the 3D motion to compensate erroneous hand motion. Preliminary bench-top 2-DOF experiments have been conducted. The error motions simulated by a motion stage is reduced by 67% for multiple frequency oscillatory motions and 56.16% for pre-conditioned recorded physiological tremor.

  3. RESEARCH ON MOTION COMPENSATION FOR HIGH RESOLUTION PROFILE OF EXTENDED TARGET FOR STEPPED CHIRP RADAR AND DSP IMPLEMENTATION

    Institute of Scientific and Technical Information of China (English)

    Jiang Bin; He Xiang; Wang Hongqiang; Guo Guirong

    2007-01-01

    A discrete model is set up for High Resolution Range Profile (HRRP) of an extended target and the model of echo from an extended target for a Stepped Chirp Radar (SCR) is proposed. The effect of target motion on a range profile is thoroughly analyzed, and based on which precision requirement is developed for motion compensation. By studying the time domain correlation and the rule based on the least burst error, a motion compensation algorithm which satisfies the project requirement is presented, and the cyber-emulation confirms the conclusion. At last the processor is designed by using DSP devices to realize motion compensation and target recognition.

  4. An experimental evaluation of the Agility MLC for motion-compensated VMAT delivery

    Science.gov (United States)

    Davies, G. A.; Clowes, P.; Bedford, J. L.; Evans, P. M.; Webb, S.; Poludniowski, G.

    2013-07-01

    An algorithm for dynamic multileaf-collimator (dMLC) tracking of a target performing a known a priori, rigid-body motion during volumetric modulated arc therapy (VMAT), has been experimentally validated and applied to investigate the potential of the Agility (Elekta AB, Stockholm, Sweden) multileaf-collimator (MLC) for use in motion-compensated VMAT delivery. For five VMAT patients, dosimetric measurements were performed using the Delta4 radiation detector (ScandiDos, Uppsala, Sweden) and the accuracy of dMLC tracking was evaluated using a gamma-analysis, with threshold levels of 3% for dose and 3 mm for distance-to-agreement. For a motion trajectory with components in two orthogonal directions, the mean gamma-analysis pass rate without tracking was found to be 58.0%, 59.0% and 60.9% and was increased to 89.1%, 88.3% and 93.1% with MLC tracking, for time periods of motion of 4 s, 6 s and 10 s respectively. Simulations were performed to compare the efficiency of the Agility MLC with the MLCi MLC when used for motion-compensated VMAT delivery for the same treatment plans and motion trajectories. Delivery time increases from a static-tumour to dMLC-tracking VMAT delivery were observed in the range 0%-20% for the Agility, and 0%-57% with the MLCi, indicating that the increased leaf speed of the Agility MLC is beneficial for MLC tracking during lung radiotherapy.

  5. Error Modeling and Compensation of Circular Motion on a New Circumferential Drilling System

    Directory of Open Access Journals (Sweden)

    Qiang Fang

    2015-01-01

    Full Text Available A new flexible circumferential drilling system is proposed to drill on the fuselage docking area. To analyze the influence of the circular motion error to the drilling accuracy, the nominal forward kinematic model is derived using Denavit-Hartenberg (D-H method and this model is further developed to model the kinematic errors caused by circular positioning error and synchronization error using homogeneous transformation matrices (HTM. A laser tracker is utilized to measure the circular motion error of the two measurement points at both sides. A circular motion compensation experiment is implemented according to the calculated positioning error and synchronization error. Experimental results show that the positioning error and synchronization error were reduced by 65.0% and 58.8%, respectively, due to the adopted compensation, and therefore the circular motion accuracy is substantially improved. Finally, position errors of the two measurement points are analyzed to have little influence on the measurement result and the validity of the proposed compensation method is proved.

  6. SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell

    Directory of Open Access Journals (Sweden)

    Blas-Pablo Dorta-Naranjo

    2008-05-01

    Full Text Available This paper presents an experimental Synthetic Aperture Radar (SAR system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU; and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR. This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar.

  7. SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell.

    Science.gov (United States)

    González-Partida, José-Tomás; Almorox-González, Pablo; Burgos-Garcia, Mateo; Dorta-Naranjo, Blas-Pablo

    2008-05-23

    This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar.

  8. Motion compensation using origin ensembles in awake small animal positron emission tomography

    Science.gov (United States)

    Gillam, John E.; Angelis, Georgios I.; Kyme, Andre Z.; Meikle, Steven R.

    2017-02-01

    In emission tomographic imaging, the stochastic origin ensembles algorithm provides unique information regarding the detected counts given the measured data. Precision in both voxel and region-wise parameters may be determined for a single data set based on the posterior distribution of the count density allowing uncertainty estimates to be allocated to quantitative measures. Uncertainty estimates are of particular importance in awake animal neurological and behavioral studies for which head motion, unique for each acquired data set, perturbs the measured data. Motion compensation can be conducted when rigid head pose is measured during the scan. However, errors in pose measurements used for compensation can degrade the data and hence quantitative outcomes. In this investigation motion compensation and detector resolution models were incorporated into the basic origin ensembles algorithm and an efficient approach to computation was developed. The approach was validated against maximum liklihood—expectation maximisation and tested using simulated data. The resultant algorithm was then used to analyse quantitative uncertainty in regional activity estimates arising from changes in pose measurement precision. Finally, the posterior covariance acquired from a single data set was used to describe correlations between regions of interest providing information about pose measurement precision that may be useful in system analysis and design. The investigation demonstrates the use of origin ensembles as a powerful framework for evaluating statistical uncertainty of voxel and regional estimates. While in this investigation rigid motion was considered in the context of awake animal PET, the extension to arbitrary motion may provide clinical utility where respiratory or cardiac motion perturb the measured data.

  9. Evaluation of a Nonrigid Motion Compensation Technique Based on Spatiotemporal Features for Small Lesion Detection in Breast MRI

    Directory of Open Access Journals (Sweden)

    F. Steinbruecker

    2012-01-01

    the performance of a new nonrigid motion correction algorithm based on the optical flow method. For each of the small lesions, we extracted morphological and dynamical features describing both global and local shape, and kinetics behavior. In this paper, we compare the performance of each extracted feature set under consideration of several 2D or 3D motion compensation parameters for the differential diagnosis of enhancing lesions in breast MRI. Based on several simulation results, we determined the optimal motion compensation parameters. Our results have shown that motion compensation can improve the classification results. The results suggest that the computerized analysis system based on the non-rigid motion compensation technique and spatiotemporal features has the potential to increase the diagnostic accuracy of MRI mammography for small lesions and can be used as a basis for computer-aided diagnosis of breast cancer with MR mammography.

  10. High-frame-rate, motion-compensated 25.4 megapixel image sensor

    Science.gov (United States)

    Kamasz, Stacy R.; Farrier, Michael G.; Ma, Shing-Fat F.; Sabila, Robert W.; Chamberlain, Savvas G.

    1994-05-01

    The applicability of large-area full-frame CCD image sensor technology to large optical format aerial reconnaissance applications has been recently demonstrated. The requirements of low-contrast, high-resolution imaging at high frame rates have generated the need for a manufacturable, multitap, small-pitch, wafer-scale CCD image sensor technology. The added requirement of incorporation of electronic motion compensation at the focal plane has generated the need for multisegmented full-frame area array architectures. Characterization results from the newly developed 5040 X 5040 element, eight-tap, full-frame image sensor with multisegmentation for electronic motion compensation are discussed. Experimental determination of resistive-capacitive time constants for metal strapped vertical clock busses on wafer-scale sensors is discussed.

  11. MULTI-RESOLUTION MOTION ESTIMATION AND COMPENSATION BASED ON ADJACENT PREDICTION OF FRAME DIFFERENCE IN WAVELET DOMAIN

    Institute of Scientific and Technical Information of China (English)

    Tang Guowei; Gu Guochang

    2009-01-01

    Aiming at the higher bit-rate occupation of motion vector encoding and more time load of full-searching strategies,a multi-resolution motion estimation and compensation algorithm based on adjacent prediction of frame difference was proposed.Differential motion detection was employed to image sequences and proper threshold was adopted to identify the connected region.Then the motion region was extracted to carry out motion estimation and motion compensation on it.The experiment results show that the encoding efficiency of motion vector is promoted,the complexity of motion es timation is reduced and the quality of the reconstruction image at the same bit-rate as Multi-Reso lution Motion Estimation (MRME) is improved.

  12. Rapid estimation of 4DCT motion-artifact severity based on 1D breathing-surrogate periodicity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guang, E-mail: lig2@mskcc.org; Caraveo, Marshall [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Wei, Jie [Department of Computer Science, City College of New York, New York, New York 10031 (United States); Rimner, Andreas; Wu, Abraham J.; Goodman, Karyn A. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Yorke, Ellen [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065 (United States)

    2014-11-01

    Purpose: Motion artifacts are common in patient four-dimensional computed tomography (4DCT) images, leading to an ill-defined tumor volume with large variations for radiotherapy treatment and a poor foundation with low imaging fidelity for studying respiratory motion. The authors developed a method to estimate 4DCT image quality by establishing a correlation between the severity of motion artifacts in 4DCT images and the periodicity of the corresponding 1D respiratory waveform (1DRW) used for phase binning in 4DCT reconstruction. Methods: Discrete Fourier transformation (DFT) was applied to analyze 1DRW periodicity. The breathing periodicity index (BPI) was defined as the sum of the largest five Fourier coefficients, ranging from 0 to 1. Distortional motion artifacts (excluding blurring) of cine-scan 4DCT at the junctions of adjacent couch positions around the diaphragm were classified in three categories: incomplete, overlapping, and duplicate anatomies. To quantify these artifacts, discontinuity of the diaphragm at the junctions was measured in distance and averaged along six directions in three orthogonal views. Artifacts per junction (APJ) across the entire diaphragm were calculated in each breathing phase and phase-averaged APJ{sup ¯}, defined as motion-artifact severity (MAS), was obtained for each patient. To make MAS independent of patient-specific motion amplitude, two new MAS quantities were defined: MAS{sup D} is normalized to the maximum diaphragmatic displacement and MAS{sup V} is normalized to the mean diaphragmatic velocity (the breathing period was obtained from DFT analysis of 1DRW). Twenty-six patients’ free-breathing 4DCT images and corresponding 1DRW data were studied. Results: Higher APJ values were found around midventilation and full inhalation while the lowest APJ values were around full exhalation. The distribution of MAS is close to Poisson distribution with a mean of 2.2 mm. The BPI among the 26 patients was calculated with a value

  13. Effects of image noise, respiratory motion, and motion compensation on 3D activity quantification in count-limited PET images

    Science.gov (United States)

    Siman, W.; Mawlawi, O. R.; Mikell, J. K.; Mourtada, F.; Kappadath, S. C.

    2017-01-01

    The aims of this study were to evaluate the effects of noise, motion blur, and motion compensation using quiescent-period gating (QPG) on the activity concentration (AC) distribution—quantified using the cumulative AC volume histogram (ACVH)—in count-limited studies such as 90Y-PET/CT. An International Electrotechnical Commission phantom filled with low 18F activity was used to simulate clinical 90Y-PET images. PET data were acquired using a GE-D690 when the phantom was static and subject to 1-4 cm periodic 1D motion. The static data were down-sampled into shorter durations to determine the effect of noise on ACVH. Motion-degraded PET data were sorted into multiple gates to assess the effect of motion and QPG on ACVH. Errors in ACVH at AC90 (minimum AC that covers 90% of the volume of interest (VOI)), AC80, and ACmean (average AC in the VOI) were characterized as a function of noise and amplitude before and after QPG. Scan-time reduction increased the apparent non-uniformity of sphere doses and the dispersion of ACVH. These effects were more pronounced in smaller spheres. Noise-related errors in ACVH at AC20 to AC70 were smaller (15%). The accuracy of ACmean was largely independent of the total count. Motion decreased the observed AC and skewed the ACVH toward lower values; the severity of this effect depended on motion amplitude and tumor diameter. The errors in AC20 to AC80 for the 17 mm sphere were  -25% and  -55% for motion amplitudes of 2 cm and 4 cm, respectively. With QPG, the errors in AC20 to AC80 of the 17 mm sphere were reduced to  -15% for motion amplitudes  0.5, QPG was effective at reducing errors in ACVH despite increases in image non-uniformity due to increased noise. ACVH is believed to be more relevant than mean or maximum AC to calculate tumor control and normal tissue complication probability. However, caution needs to be exercised when using ACVH in post-therapy 90Y imaging because of its susceptibility to image

  14. High-resolution motion compensated MRA in patients with congenital heart disease using extracellular contrast agent at 3 Tesla

    Directory of Open Access Journals (Sweden)

    Dabir Darius

    2012-10-01

    Full Text Available Abstract Background Using first-pass MRA (FP-MRA spatial resolution is limited by breath-hold duration. In addition, image quality may be hampered by respiratory and cardiac motion artefacts. In order to overcome these limitations an ECG- and navigator-gated high-resolution-MRA sequence (HR-MRA with slow infusion of extracellular contrast agent was implemented at 3 Tesla for the assessment of congenital heart disease and compared to standard first-pass-MRA (FP-MRA. Methods 34 patients (median age: 13 years with congenital heart disease (CHD were prospectively examined on a 3 Tesla system. The CMR-protocol comprised functional imaging, FP- and HR-MRA, and viability imaging. After the acquisition of the FP-MRA sequence using a single dose of extracellular contrast agent the motion compensated HR-MRA sequence with isotropic resolution was acquired while injecting the second single dose, utilizing the timeframe before viability imaging. Qualitative scores for image quality (two independent reviewers as well as quantitative measurements of vessel sharpness and relative contrast were compared using the Wilcoxon signed-rank test. Quantitative measurements of vessel diameters were compared using the Bland-Altman test. Results The mean image quality score revealed significantly better image quality of the HR-MRA sequence compared to the FP-MRA sequence in all vessels of interest (ascending aorta (AA, left pulmonary artery (LPA, left superior pulmonary vein (LSPV, coronary sinus (CS, and coronary ostia (CO; all p  Conclusions An ECG- and navigator-gated HR-MRA-protocol with infusion of extracellular contrast agent at 3 Tesla is feasible. HR-MRA delivers significantly better image quality and vessel sharpness compared to FP-MRA. It may be integrated into a standard CMR-protocol for patients with CHD without the need for additional contrast agent injection and without any additional examination time.

  15. Adaptive update using visual models for lifting-based motion-compensated temporal filtering

    Science.gov (United States)

    Li, Song; Xiong, H. K.; Wu, Feng; Chen, Hong

    2005-03-01

    Motion compensated temporal filtering is a useful framework for fully scalable video compression schemes. However, when supposed motion models cannot represent a real motion perfectly, both the temporal high and the temporal low frequency sub-bands may contain artificial edges, which possibly lead to a decreased coding efficiency, and ghost artifacts appear in the reconstructed video sequence at lower bit rates or in case of temporal scaling. We propose a new technique that is based on utilizing visual models to mitigate ghosting artifacts in the temporal low frequency sub-bands. Specifically, we propose content adaptive update schemes where visual models are used to determine image dependent upper bounds on information to be updated. Experimental results show that the proposed algorithm can significantly improve subjective visual quality of the low-pass temporal frames and at the same time, coding performance can catch or exceed the classical update steps.

  16. Padrão respiratório e movimento toracoabdominal de crianças respiradoras orais Breathing pattern and thoracoabdominal motion in mouth-breathing children

    Directory of Open Access Journals (Sweden)

    TCS Brant

    2008-12-01

    motion of mouth-breathing children aged between eight and ten years and to compare these characteristics with those of nose-breathing children of the same ages. METHODS: This observational study was carried out in a university laboratory. The sample size of 50 subjects was estimated based on the results of a pilot study with ten children in each group (total of 20 children and considering a significance level of 0.05 and statistical power of 0.80. Twenty-six mouth-breathing and 25 nose-breathing children participated. Calibrated respiratory inductive plethysmography was used to analyze the following variables, among others: respiratory frequency (f, rib cage contribution towards tidal volume (%RC/Vt, phase angle (PhAng and the ratio between time taken to reach peak inspiratory flow and total inspiratory time (PifT/Ti. Peripheral oxygen saturation of hemoglobin (SpO2 was measured using pulse oximetry. Statistical analysis was performed using the Student's t test for independent groups or the Mann-Whitney U test, according to the sample distribution of the variables. RESULTS: A total of 4,816 respiratory cycles were analyzed: 2,455 from mouth-breathers and 2,361 from nose-breathers, with a mean of 94 cycles per child. No statistically significant differences were observed between the groups, for the variables studied (f=20.00±2.68 versus 20.73±2.58, p=0.169; %RC/Vt=39.30±11.86 versus 38.36±10.93, p=0.769; PhAng=14.53±7.97 versus 13.31±7.74, p=0.583; PifT/Ti=57.40±7.16 versus 58.35±5.99, p=0.610; SpO2=96.42±1.52% versus 96.88± 1.01%, p=0.208; respectively. CONCLUSIONS: These results suggest that mouth-breathing children show breathing patterns and thoracoabdominal motion that are similar to those of nose-breathing children in the same age group.

  17. Video compression using lapped transforms for motion estimation/compensation and coding

    Science.gov (United States)

    Young, Robert W.; Kingsbury, Nick G.

    1992-11-01

    Many conventional video coding schemes, such as the CCITT H.261 recommendation, are based on the independent processing of non-overlapping image blocks. An important disadvantage with this approach is that blocking artifacts may be visible in the decoded frames. In this paper, we propose a coding scheme based entirely on the processing of overlapping, windowed data blocks, thus eliminating blocking effects. Motion estimation and compensation are both performed in the frequency domain using a complex lapped transform (CLT), which may be viewed as a complex extension of the lapped orthogonal transform (LOT). The motion compensation algorithm is equivalent to overlapped compensation in the spatial domain, but also allows image interpolation for sub-pel displacements and sophisticated loop filters to be conveniently applied in the frequency domain. For inter- and intra-frame coding, we define the modified fast lapped transform (MFLT). This is a modified form of the LOT, which entirely eliminates blocking artifacts in the reconstructed data. The transform is applied in a hierarchical structure, and performs better than the discrete cosine transform (DCT) for both coding modes. The proposed coder is compared with the H.261 scheme, and is found to have significantly improved performance.

  18. Video compression using lapped transforms for motion estimation compensation and coding

    Science.gov (United States)

    Young, Robert W.; Kingsbury, Nick G.

    1993-07-01

    Many conventional video coding schemes, such as the CCITT H.261 recommendation, are based on the independent processing of nonoverlapping image blocks. An important disadvantage with this approach is that blocking artifacts may be visible in the decoded frames. We propose a coding scheme based entirely on the processing of overlapping, windowed data blocks, thus eliminating blocking effects. Motion estimation and, in part, compensation are performed in the frequency domain using a complex lapped transform (CLT), which can be viewed as a complex extension of the lapped orthogonal transform (LOT). The motion compensation algorithm is equivalent to overlapped compensation in the spatial domain, but also allows image interpolation for subpixel displacements and sophisticated loop filters to be conveniently applied in the frequency domain. For inter- and intraframe coding, we define the modified fast lapped transform (MFLT). This is a modified form of the LOT that entirely eliminates blocking artifacts in the reconstructed data. The transform is applied in a hierarchical structure, and performs better than the discrete cosine transform (DCT) for both coding modes. The proposed coder is compared with the H.261 scheme and is found to have significantly improved performance.

  19. Novel automated motion compensation technique for producing cumulative maximum intensity subharmonic images.

    Science.gov (United States)

    Dave, Jaydev K; Forsberg, Flemming

    2009-09-01

    The aim of this study was to develop a novel automated motion compensation algorithm for producing cumulative maximum intensity (CMI) images from subharmonic imaging (SHI) of breast lesions. SHI is a nonlinear contrast-specific ultrasound imaging technique in which pulses are received at half the frequency of the transmitted pulses. A Logiq 9 scanner (GE Healthcare, Milwaukee, WI, USA) was modified to operate in grayscale SHI mode (transmitting/receiving at 4.4/2.2 MHz) and used to scan 14 women with 16 breast lesions. Manual CMI images were reconstructed by temporal maximum-intensity projection of pixels traced from the first frame to the last. In the new automated technique, the user selects a kernel in the first frame and the algorithm then uses the sum of absolute difference (SAD) technique to identify motion-induced displacements in the remaining frames. A reliability parameter was used to estimate the accuracy of the motion tracking based on the ratio of the minimum SAD to the average SAD. Two thresholds (the mean and 85% of the mean reliability parameter) were used to eliminate images plagued by excessive motion and/or noise. The automated algorithm was compared with the manual technique for computational time, correction of motion artifacts, removal of noisy frames and quality of the final image. The automated algorithm compensated for motion artifacts and noisy frames. The computational time was 2 min compared with 60-90 minutes for the manual method. The quality of the motion-compensated CMI-SHI images generated by the automated technique was comparable to the manual method and provided a snapshot of the microvasculature showing interconnections between vessels, which was less evident in the original data. In conclusion, an automated algorithm for producing CMI-SHI images has been developed. It eliminates the need for manual processing and yields reproducible images, thereby increasing the throughput and efficiency of reconstructing CMI-SHI images. The

  20. SU-F-BRB-03: Quantifying Patient Motion During Deep-Inspiration Breath-Hold Using the ABC System with Simultaneous Surface Photogrammetry

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Y; Rahimi, A; Sawant, A [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose: Active breathing control (ABC) has been used to reduce treatment margin due to respiratory organ motion by enforcing temporary breath-holds. However, in practice, even if the ABC device indicates constant lung volume during breath-hold, the patient may still exhibit minor chest motion. Consequently, therapists are given a false sense of security that the patient is immobilized. This study aims at quantifying such motion during ABC breath-holds by monitoring the patient chest motion using a surface photogrammetry system, VisionRT. Methods: A female patient with breast cancer was selected to evaluate chest motion during ABC breath-holds. During the entire course of treatment, the patient’s chest surface was monitored by a surface photogrammetry system, VisionRT. Specifically, a user-defined region-of-interest (ROI) on the chest surface was selected for the system to track at a rate of ∼3Hz. The surface motion was estimated by rigid image registration between the current ROI image captured and a reference image. The translational and rotational displacements computed were saved in a log file. Results: A total of 20 fractions of radiation treatment were monitored by VisionRT. After removing noisy data, we obtained chest motion of 79 breath-hold sessions. Mean chest motion in AP direction during breath-holds is 1.31mm with 0.62mm standard deviation. Of the 79 sessions, the patient exhibited motion ranging from 0–1 mm (30 sessions), 1–2 mm (37 sessions), 2–3 mm (11 sessions) and >3 mm (1 session). Conclusion: Contrary to popular assumptions, the patient is not completely still during ABC breath-hold sessions. In this particular case studied, the patient exhibited chest motion over 2mm in 14 out of 79 breath-holds. Underestimating treatment margin for radiation therapy with ABC could reduce treatment effectiveness due to geometric miss or overdose of critical organs. The senior author receives research funding from NIH, VisionRT, Varian Medical Systems

  1. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.;

    2015-01-01

    that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn...

  2. Effects of residual motion compensation errors on the performance of airborne along-track interferometric SAR

    Institute of Scientific and Technical Information of China (English)

    Hui ZHANG; Jun HONG; Xiao-lan QIU; Ji-chuan LI; Fang-fang LI; Feng MING

    2016-01-01

    Two approximations, center-beam approximation and reference digital elevation model (DEM) approximation, are used in synthetic aperture radar (SAR) motion compensation procedures. They usually introduce residual motion compensation errors for airborne single-antenna SAR imaging and SAR interferometry. In this paper, we investigate the effects of residual uncompensated motion errors, which are caused by the above two approximations, on the performance of airborne along-track interferometric SAR (ATI-SAR). The residual uncompensated errors caused by center-beam approximation in the absence and in the presence of elevation errors are derived, respectively. Airborne simulation parameters are used to verify the correctness of the analysis and to show the impacts of residual uncompensated errors on the interferometric phase errors for ATI-SAR. It is shown that the interferometric phase errors caused by the center-beam approximation with an accurate DEM could be neglected, while the interferometric phase errors caused by the center-beam approximation with an inaccurate DEM cannot be neglected when the elevation errors exceed a threshold. This research provides theoretical bases for the error source analysis and signal processing of airborne ATI-SAR.

  3. Analytic signal phase-based myocardial motion estimation in tagged MRI sequences by a bilinear model and motion compensation.

    Science.gov (United States)

    Wang, Liang; Basarab, Adrian; Girard, Patrick R; Croisille, Pierre; Clarysse, Patrick; Delachartre, Philippe

    2015-08-01

    Different mathematical tools, such as multidimensional analytic signals, allow for the calculation of 2D spatial phases of real-value images. The motion estimation method proposed in this paper is based on two spatial phases of the 2D analytic signal applied to cardiac sequences. By combining the information of these phases issued from analytic signals of two successive frames, we propose an analytical estimator for 2D local displacements. To improve the accuracy of the motion estimation, a local bilinear deformation model is used within an iterative estimation scheme. The main advantages of our method are: (1) The phase-based method allows the displacement to be estimated with subpixel accuracy and is robust to image intensity variation in time; (2) Preliminary filtering is not required due to the bilinear model. The proposed algorithm, integrating phase-based optical flow motion estimation and the combination of global motion compensation with local bilinear transform, allows spatio-temporal cardiac motion analysis, e.g. strain and dense trajectory estimation over the cardiac cycle. Results from 7 realistic simulated tagged magnetic resonance imaging (MRI) sequences show that our method is more accurate compared with state-of-the-art method for cardiac motion analysis and with another differential approach from the literature. The motion estimation errors (end point error) of the proposed method are reduced by about 33% compared with that of the two methods. In our work, the frame-to-frame displacements are further accumulated in time, to allow for the calculation of myocardial Lagrangian cardiac strains and point trajectories. Indeed, from the estimated trajectories in time on 11 in vivo data sets (9 patients and 2 healthy volunteers), the shape of myocardial point trajectories belonging to pathological regions are clearly reduced in magnitude compared with the ones from normal regions. Myocardial point trajectories, estimated from our phase-based analytic

  4. Motion Compensation of Moving Targets for High Range Resolution Stepped-Frequency Radar

    Directory of Open Access Journals (Sweden)

    Xiqin Wang

    2008-05-01

    Full Text Available High range resolution (HRR profiling using stepped-frequency pulse trains suffers from range shift and the attenuation/dispersion of range profiles while the target of interest is moving. To overcome these two drawbacks, a new algorithm based on the maximum likelihood (ML estimation is proposed in this paper. Without altering the conventional stepped-frequency waveform, this algorithm can estimate the target velocity and thereby compensate the phase errors caused by the target’s motion. It is shown that the velocity can be accurately estimated and the range profile can be correctly reconstructed.

  5. Compensation for the intrinsic dynamics of the InMotion2 robot.

    Science.gov (United States)

    Nguyen, Hoi B; Lum, Peter S

    2013-03-30

    The InMotion2 and other similarly designed robots, are commonly used for rehabilitation of neurological injuries and motor adaptation studies. These robots are used to simulate haptic environments; however, anisotropy in end-point impedance due to the intrinsic robot dynamics can compromise these experiments. The goal was to decrease the magnitude and anisotropy of the robot impedance using a dynamic compensation algorithm that reduces the forces normally felt by the user during rapid movements. We tested this algorithm with two different methods for real-time calculation of derivatives, a novel quadratic fit method (CQF) and the commonly used backward derivative method (CBD). Six subjects performed a series of point-to-point movements under three conditions (no compensation, CQF, CBD), in different directions at peak speeds of 50, 100 and 150 cm/s. Without compensation, tangential peak-to-peak forces were as large as 69 N in certain directions at the 150 cm/s speed. Both CQF and CBD significantly reduced tangential forces in all directions and speeds. CQF outperformed CBD in the directions with highest intrinsic impedance, reducing tangential forces by 64% in these directions. Compensation also significantly reduced forces normal to the movement direction, with CQF again outperforming CBD in several cases. Anisotropy was assessed by the range of tangential peak-to-peak forces across movement directions. In the no compensation condition, anisotropy was as high as 52.7 N at the 150 cm/s speed, but an average anisotropy reduction of 74% was achieved with CQF. The CQF method can significantly reduce impedance and anisotropy in this class of robot.

  6. Real-time tumor tracking: Automatic compensation of target motion using the Siemens 160 MLC

    Energy Technology Data Exchange (ETDEWEB)

    Tacke, Martin B.; Nill, Simeon; Krauss, Andreas; Oelfke, Uwe [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany)

    2010-02-15

    Purpose: Advanced high quality radiation therapy techniques such as IMRT require an accurate delivery of precisely modulated radiation fields to the target volume. Interfractional and intrafractional motion of the patient's anatomy, however, may considerably deteriorate the accuracy of the delivered dose to the planned dose distributions. In order to compensate for these potential errors, a dynamic real-time capable MLC control system was designed. Methods: The newly developed adaptive MLC control system contains specialized algorithms which are capable of continuous optimization and correction of the aperture of the MLC according to the motion of the target volume during the dose delivery. The algorithms calculate the new leaf positions based on target information provided online to the system. The algorithms were implemented in a dynamic target tracking control system designed for a Siemens 160 MLC. To assess the quality of the new target tracking system in terms of dosimetric accuracy, experiments with various types of motion patterns using different phantom setups were performed. The phantoms were equipped with radiochromic films placed between solid water slabs. Dosimetric results of exemplary deliveries to moving targets with and without dynamic MLC tracking applied were compared in terms of the gamma criterion to the reference dose delivered to a static phantom. Results: Our measurements indicated that dose errors for clinically relevant two-dimensional target motion can be compensated by the new control system during the dose delivery of open fields. For a clinical IMRT dose distribution, the gamma success rate was increased from 19% to 77% using the new tracking system. Similar improvements were achieved for the delivery of a complete IMRT treatment fraction to a moving lung phantom. However, dosimetric accuracy was limited by the system's latency of 400 ms and the finite leaf width of 5 mm in the isocenter plane. Conclusions: Different

  7. Motion Compensated Ultrasound Imaging Allows Thermometry and Image Guided Drug Delivery Monitoring from Echogenic Liposomes

    Science.gov (United States)

    Ektate, Kalyani; Kapoor, Ankur; Maples, Danny; Tuysuzoglu, Ahmet; VanOsdol, Joshua; Ramasami, Selvarani; Ranjan, Ashish

    2016-01-01

    Ultrasound imaging is widely used both for cancer diagnosis and to assess therapeutic success, but due to its weak tissue contrast and the short half-life of commercially available contrast agents, it is currently not practical for assessing motion compensated contrast-enhanced tumor imaging, or for determining time-resolved absolute tumor temperature while simultaneously reporting on drug delivery. The objectives of this study were to: 1) develop echogenic heat sensitive liposomes (E-LTSL) and non-thermosensitive liposomes (E-NTSL) to enhance half-life of contrast agents, and 2) measure motion compensated temperature induced state changes in acoustic impedance and Laplace pressure of liposomes to monitor temperature and doxorubicin (Dox) delivery to tumors. LTSL and NTSL containing Dox were co-loaded with an US contrast agent (perfluoropentane, PFP) using a one-step sonoporation method to create E-LTSL and E-NTSL. To determine temperature induced intensity variation with respect to the state change of E-LTSL and E-NTSL in mouse colon tumors, cine acquisition of 20 frames/second for about 20 min (or until wash out) at temperatures of 42°C, 39.5°C, and 37°C was performed. A rigid rotation and translation was applied to each of the “key frames” to adjust for any gross motion that arose due to motion of the animal or the transducer. To evaluate the correlation between ultrasound (US) intensity variation and Dox release at various temperatures, treatment (5 mg Dox/kg) was administered via a tail vein once tumors reached a size of 300-400 mm3, and mean intensity within regions of interest (ROIs) defined for each sample was computed over the collected frames and normalized in the range of [0,1]. When the motion compensation technique was applied, a > 2-fold drop in standard deviation in mean image intensity of tumor was observed, enabling a more robust estimation of temporal variations in tumor temperatures for 15-20 min. due to state change of E-LTSL and E

  8. 3D model-based catheter tracking for motion compensation in EP procedures

    Science.gov (United States)

    Brost, Alexander; Liao, Rui; Hornegger, Joachim; Strobel, Norbert

    2010-02-01

    Atrial fibrillation is the most common sustained heart arrhythmia and a leading cause of stroke. Its treatment by radio-frequency catheter ablation, performed using fluoroscopic image guidance, is gaining increasingly more importance. Two-dimensional fluoroscopic navigation can take advantage of overlay images derived from pre-operative 3-D data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of these static overlay images for catheter navigation. We developed an approach for image-based 3-D motion compensation as a solution to this problem. A bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3-D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3-D. This step involves bi-plane fluoroscopy and 2-D/3-D registration. Phantom data and clinical data were used to assess our model-based catheter tracking method. Experiments involving a moving heart phantom yielded an average 2-D tracking error of 1.4 mm and an average 3-D tracking error of 1.1 mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2-D tracking error of 1.0 mm +/- 0.4 mm and an average 3-D tracking error of 0.8 mm +/- 0.5 mm. These results demonstrate that model-based motion-compensation based on 2-D/3-D registration is both feasible and accurate.

  9. Motion-compensated coding and frame rate up-conversion: models and analysis.

    Science.gov (United States)

    Dar, Yehuda; Bruckstein, Alfred M

    2015-07-01

    Block-based motion estimation (ME) and motion compensation (MC) techniques are widely used in modern video processing algorithms and compression systems. The great variety of video applications and devices results in diverse compression specifications, such as frame rates and bit rates. In this paper, we study the effect of frame rate and compression bit rate on block-based ME and MC as commonly utilized in inter-frame coding and frame rate up-conversion (FRUC). This joint examination yields a theoretical foundation for comparing MC procedures in coding and FRUC. First, the video signal is locally modeled as a noisy translational motion of an image. Then, we theoretically model the motion-compensated prediction of available and absent frames as in coding and FRUC applications, respectively. The theoretic MC-prediction error is studied further and its autocorrelation function is calculated, yielding useful separable-simplifications for the coding application. We argue that a linear relation exists between the variance of the MC-prediction error and temporal distance. While the relevant distance in MC coding is between the predicted and reference frames, MC-FRUC is affected by the distance between the frames available for interpolation. We compare our estimates with experimental results and show that the theory explains qualitatively the empirical behavior. Then, we use the models proposed to analyze a system for improving of video coding at low bit rates, using a spatio-temporal scaling. Although this concept is practically employed in various forms, so far it lacked a theoretical justification. We here harness the proposed MC models and present a comprehensive analysis of the system, to qualitatively predict the experimental results.

  10. Research on compensation of motion, Earth curvature and tropospheric delay in GEOSAR

    Science.gov (United States)

    Sheng, Wei; Hobbs, Stephen E.

    2011-06-01

    GEOSAR (synthetic aperture radar on geosynchronous satellite) becomes a potential method of space-borne geoscience remote sensing. Though it has attractive characters such as extra long observing time and very large observing area the unique geometry and relative motion are quite different from straight line required by SAR, and long integration time also causes delay by troposphere and ionosphere. Curvature of the Earth is no long negligible in GEOSAR. Especially, principle of azimuth compression in GEOSAR should be different from that of traditional SAR. In order to fulfill practical GEOSAR such problems should be solved. A new solution of azimuth compression together with motion compensation is presented here by taking the advantages of GEOSAR movement. A new method to overcome the Earth curvature in range compression of EACH footprint is testified. After compensating the Earth curvature traditional methods for range cell migration correction can be used in GEOSAR. Multi-sub-aperture method is applied to eliminate the phase delay caused by troposphere. This modified imaging algorithm makes it possible for GEOSAR to have long integration time and high resolution.

  11. BioWatch: Estimation of Heart and Breathing Rates from Wrist Motions

    Directory of Open Access Journals (Sweden)

    Javier Hernandez

    2015-11-01

    Full Text Available Continued developments of sensor technology including hardware miniaturization and increased sensitivity have enabled the development of less intrusive methods to monitor physiological parameters during daily life. In this work, we present methods to recover cardiac and respiratory parameters using accelerometer and gyroscope sensors on the wrist. We demonstrate accurate measurements in a controlled laboratory study where participants (n = 12 held three different positions (standing up, sitting down and lying down under relaxed and aroused conditions. In particular, we show it is possible to achieve a mean absolute error of 1.27 beats per minute (STD: 3.37 for heart rate and 0.38 breaths per minute (STD: 1.19 for breathing rate when comparing performance with FDA-cleared sensors. Furthermore, we show comparable performance with a state-of-the-art wrist-worn heart rate monitor, and when monitoring heart rate of three individuals during two consecutive nights of in-situ sleep measurements.

  12. Rapid maneuvering of multi-body dynamic systems with optimal motion compensation

    Science.gov (United States)

    Bishop, B.; Gargano, R.; Sears, A.; Karpenko, M.

    2015-12-01

    Rapid maneuvering of multi-body dynamical systems is an important, yet challenging, problem in many applications. Even in the case of rigid bodies, it can be difficult to maintain precise control over nominally stationary links if it is required to move some of the other links quickly because of the various nonlinearities and coupled interactions that occur between the bodies. Typical control concepts treat the multi-body motion control problem in two-stages. First, the nonlinear and coupling terms are treated as disturbances and a trajectory tracking control law is designed in order to attenuate their effects. Next, motion profiles are designed, based on kinematics parameterizations, and these are used as inputs to the closed loop system to move the links. This paper describes an approach for rapid maneuvering of multi-body systems that uses optimal control theory to account for dynamic nonlinearities and coupling as part of the motion trajectory design. Incorporating appropriate operational constraints automatically compensates for these multi-body effects so that motion time can be reduced while simultaneously achieving other objectives such as reducing the excitation of selected links. Since the compensatory effect is embedded within the optimal motion trajectories, the performance improvement can be obtained even when using simple closed-loop architectures for maneuver implementation. Simulation results for minimum time control of a two-axis gimbal system and for rapid maneuvering of a TDRS single-access antenna, wherein it is desired to limit the excitation of the satellite body to which the antenna is attached, are presented to illustrate the concepts.

  13. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.

    2015-01-01

    that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn....... Our results show that air-breathing events overlap considerably with escape responses with a large stage 1 angle in terms of turning rates, distance covered and the relationship between these rates. Therefore, these two behaviours can be considered kinematically comparable, suggesting that air-breathing......Fast-starts are brief accelerations commonly observed in fish within the context of predator–prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1) which provides a sudden...

  14. An anthropomorphic breathing phantom of the thorax for testing new motion mitigation techniques for pencil beam scanning proton therapy

    Science.gov (United States)

    Perrin, R. L.; Zakova, M.; Peroni, M.; Bernatowicz, K.; Bikis, C.; Knopf, A. K.; Safai, S.; Fernandez-Carmona, P.; Tscharner, N.; Weber, D. C.; Parkel, T. C.; Lomax, A. J.

    2017-03-01

    Motion-induced range changes and incorrectly placed dose spots strongly affect the quality of pencil-beam-scanned (PBS) proton therapy, especially in thoracic tumour sites, where density changes are large. Thus motion-mitigation techniques are necessary, which must be validated in a realistic patient-like geometry. We report on the development and characterisation of a dynamic, anthropomorphic, thorax phantom that can realistically mimic thoracic motions and anatomical features for verifications of proton and photon 4D treatments. The presented phantom is of an average thorax size, and consists of inflatable, deformable lungs surrounded by a skeleton and skin. A mobile ‘tumour’ is embedded in the lungs in which dosimetry devices (such as radiochromic films) can be inserted. Motion of the tumour and deformation of the thorax is controlled via a custom made pump system driving air into and out of the lungs. Comprehensive commissioning tests have been performed to evaluate the mechanical performance of the phantom, its visibility on CT and MR imaging and its feasibility for dosimetric validation of 4D proton treatments. The phantom performed well on both regular and irregular pre-programmed breathing curves, reaching peak-to-peak amplitudes in the tumour of  feasible with Gamma Index agreements (4%/4 mm) between film dose and planned dose  >90% in the central planes of the target. The results of this study demonstrate that this anthropomorphic thorax phantom is suitable for imaging and dosimetric studies in a thoracic geometry closely-matched to lung cancer patients under realistic motion conditions.

  15. Evaluation of a motion artifacts removal approach on breath-hold cine-magnetic resonance images of hypertrophic cardiomyopathy subjects

    Science.gov (United States)

    Betancur, Julián.; Simon, Antoine; Schnell, Frédéric; Donal, Erwan; Hernández, Alfredo; Garreau, Mireille

    2013-11-01

    The acquisition of ECG-gated cine magnetic resonance images of the heart is routinely performed in apnea in order to suppress the motion artifacts caused by breathing. However, many factors including the 2D nature of the acquisition and the use of di erent beats to acquire the multiple-view cine images, cause this kind of artifacts to appear. This paper presents the qualitative evaluation of a method aiming to remove motion artifacts in multipleview cine images acquired on patients with hypertrophic cardiomyopathy diagnosis. The approach uses iconic registration to reduce for in-plane artifacts in long-axis-view image stacks and in-plane and out-of-plane motion artifacts in sort-axis-view image stack. Four similarity measures were evaluated: the normalized correlation, the normalized mutual information, the sum of absolute voxel di erences and the Slomka metric proposed by Slomka et al. The qualitative evaluation assessed the misalignment of di erent anatomical structures of the left ventricle as follows: the misalignment of the interventricular septum and the lateral wall for short-axis-view acquisitions and the misalignment between the short-axis-view image and long-axis-view images. Results showed the correction using the normalized correlation as the most appropriated with an 80% of success.

  16. Improved spatio-SNR FGS video coding scheme using motion compensation on enhancement-layer

    Institute of Scientific and Technical Information of China (English)

    Jiang Tao; Zhang Zhaoyang; Ma Ran; Shi Xuli

    2006-01-01

    MPEG-4 fine-granularity-scalable (FGS) technology is an effective solution to resolve the network bandwidth varying because FGS provides very fine granular SNR scalability. However, this scalability is obtained with sacrifice of coding efficiency. An one-loop FGS structure is presented based on motion compensation (MC + FGS) to improve the coding efficiency of base FGS. Then it describes and discusses the hybrid spatial-SNR FGS (FGSS) structure that extends SNR scalability of FGS to spatial scalability (spatio-SNR scalability). FGSS structure inherent the low coding efficiency of FGS structure. Combining MC + FGS structure with FGSS structure, a structure of MC + FGSS structure is obtained which acquires both structures' advantages and counteracts both structures' defects. Experimental results prove the MC + FGSS structure not only obtains fine granular spatio-SNR scalability, but also achieves high coding efficiency.

  17. Active Head Motion Compensation of TMS Robotic System Using Neuro-Fuzzy Estimation

    Directory of Open Access Journals (Sweden)

    Wan Zakaria W.N.

    2016-01-01

    Full Text Available Transcranial Magnetic Stimulation (TMS allows neuroscientist to study human brain behaviour and also become an important technique for changing the activity of brain neurons and the functions they sub serve. However, conventional manual procedure and robotized TMS are currently unable to precisely position the TMS coil because of unconstrained subject’s head movement and excessive contact force between the coil and subject’s head. This paper addressed this challenge by proposing an adaptive neuro-fuzzy force control to enable low contact force with a moving target surface. A learning and adaption mechanism is included in the control scheme to improve position disturbance estimation. The results show the ability of the proposed force control scheme to compensate subject’s head motions while maintaining desired contact force, thus allowing for more accurate and repeatable TMS procedures.

  18. Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.;

    2015-01-01

    acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming at a prey. Little is known about C-starts outside the context of predator–prey interactions, though recent work has shown that escape response can also be induced by high temperature. Here, we test the hypothesis...... that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn...

  19. Friction compensation for low velocity control of hydraulic flight motion simulator: A simple adaptive robust approach

    Institute of Scientific and Technical Information of China (English)

    Yao Jianyong; Jiao Zongxia; Han Songshan

    2013-01-01

    Low-velocity tracking capability is a key performance of flight motion simulator (FMS),which is mainly affected by the nonlinear friction force.Though many compensation schemes with ad hoc friction models have been proposed,this paper deals with low-velocity control without friction model,since it is easy to be implemented in practice.Firstly,a nonlinear model of the FMS middle frame,which is driven by a hydraulic rotary actuator,is built.Noting that in the low velocity region,the unmodeled friction force is mainly characterized by a changing-slowly part,thus a simple adaptive law can be employed to learn this changing-slowly part and compensate it.To guarantee the boundedness of adaptation process,a discontinuous projection is utilized and then a robust scheme is proposed.The controller achieves a prescribed output tracking transient performance and final tracking accuracy in general while obtaining asymptotic output tracking in the absence of modeling errors.In addition,a saturated projection adaptive scheme is proposed to improve the globally learning capability when the velocity becomes large,which might make the previous proposed projection-based adaptive law be unstable.Theoretical and extensive experimental results are obtained to verify the high-performance nature of the proposed adaptive robust control strategy.

  20. Motion-compensated noncontact imaging photoplethysmography to monitor cardiorespiratory status during exercise

    Science.gov (United States)

    Sun, Yu; Hu, Sijung; Azorin-Peris, Vicente; Greenwald, Stephen; Chambers, Jonathon; Zhu, Yisheng

    2011-07-01

    With the advance of computer and photonics technology, imaging photoplethysmography [(PPG), iPPG] can provide comfortable and comprehensive assessment over a wide range of anatomical locations. However, motion artifact is a major drawback in current iPPG systems, particularly in the context of clinical assessment. To overcome this issue, a new artifact-reduction method consisting of planar motion compensation and blind source separation is introduced in this study. The performance of the iPPG system was evaluated through the measurement of cardiac pulse in the hand from 12 subjects before and after 5 min of cycling exercise. Also, a 12-min continuous recording protocol consisting of repeated exercises was taken from a single volunteer. The physiological parameters (i.e., heart rate, respiration rate), derived from the images captured by the iPPG system, exhibit functional characteristics comparable to conventional contact PPG sensors. Continuous recordings from the iPPG system reveal that heart and respiration rates can be successfully tracked with the artifact reduction method even in high-intensity physical exercise situations. The outcome from this study thereby leads to a new avenue for noncontact sensing of vital signs and remote physiological assessment, with clear applications in triage and sports training.

  1. Motion Compensated Abdominal Diffusion Weighted MRI by Simultaneous Image Registration and Model Estimation (SIR-ME).

    Science.gov (United States)

    Kurugol, Sila; Freiman, Moti; Afacan, Onur; Domachevsky, Liran; Perez-Rossello, Jeannette M; Callahan, Michael J; Warfield, Simon K

    2015-01-01

    Non-invasive characterization of water molecule's mobility variations by quantitative analysis of diffusion-weighted MRI (DW-MRI) signal decay in the abdomen has the potential to serve as a biomarker in gastrointestinal and oncological applications. Accurate and reproducible estimation of the signal decay model parameters is challenging due to the presence of respiratory, cardiac, and peristalsis motion. Independent registration of each b-value image to the b-value=0 s/mm(2) image prior to parameter estimation might be sub-optimal because of the low SNR and contrast difference between images of varying b-value. In this work, we introduce a motion-compensated parameter estimation framework that simultaneously solves image registration and model estimation (SIR-ME) problems by utilizing the interdependence of acquired volumes along the diffusion weighting dimension. We evaluated the improvement in model parameters estimation accuracy using 16 in-vivo DW-MRI data sets of Crohn's disease patients by comparing parameter estimates obtained using the SIR-ME model to the parameter estimates obtained by fitting the signal decay model to the acquired DW-MRI images. The proposed SIR-ME model reduced the average root-mean-square error between the observed signal and the fitted model by more than 50%. Moreover, the SIR-ME model estimates discriminate between normal and abnormal bowel loops better than the standard parameter estimates.

  2. The impact of breathing guidance and prospective gating during thoracic 4DCT imaging: an XCAT study utilizing lung cancer patient motion

    Science.gov (United States)

    Pollock, Sean; Kipritidis, John; Lee, Danny; Bernatowicz, Kinga; Keall, Paul

    2016-09-01

    Two interventions to overcome the deleterious impact irregular breathing has on thoracic-abdominal 4D computed tomography (4DCT) are (1) facilitating regular breathing using audiovisual biofeedback (AVB), and (2) prospective respiratory gating of the 4DCT scan based on the real-time respiratory motion. The purpose of this study was to compare the impact of AVB and gating on 4DCT imaging using the 4D eXtended cardiac torso (XCAT) phantom driven by patient breathing patterns. We obtained simultaneous measurements of chest and abdominal walls, thoracic diaphragm, and tumor motion from 6 lung cancer patients under two breathing conditions: (1) AVB, and (2) free breathing. The XCAT phantom was used to simulate 4DCT acquisitions in cine and respiratory gated modes. 4DCT image quality was quantified by artefact detection (NCCdiff), mean square error (MSE), and Dice similarity coefficient of lung and tumor volumes (DSClung, DSCtumor). 4DCT acquisition times and imaging dose were recorded. In cine mode, AVB improved NCCdiff, MSE, DSClung, and DSCtumor by 20% (p  =  0.008), 23% (p  cine acquisitions by 15 s and reduced respiratory gated acquisitions by 31 s. AVB increased imaging dose in cine mode by 10%. This was the first study to quantify the impact of breathing guidance and respiratory gating on 4DCT imaging. With the exception of DSCtumor in respiratory gated mode, AVB significantly improved 4DCT image analysis metrics in both cine and respiratory gated modes over free breathing. The results demonstrate that AVB and respiratory-gating can be beneficial interventions to improve 4DCT for cancer radiation therapy, with the biggest gains achieved when these interventions are used simultaneously.

  3. Processive pectin methylesterases: the role of electrostatic potential, breathing motions and bond cleavage in the rectification of Brownian motions.

    Directory of Open Access Journals (Sweden)

    Davide Mercadante

    Full Text Available Pectin methylesterases (PMEs hydrolyze the methylester groups that are found on the homogalacturonan (HG chains of pectic polysaccharides in the plant cell wall. Plant and bacterial PMEs are especially interesting as the resulting de-methylesterified (carboxylated sugar residues are found to be arranged contiguously, indicating a so-called processive nature of these enzymes. Here we report the results of continuum electrostatics calculations performed along the molecular dynamics trajectory of a PME-HG-decasaccharide complex. In particular it was observed that, when the methylester groups of the decasaccharide were arranged in order to mimic the just-formed carboxylate product of de-methylesterification, a net unidirectional sliding of the model decasaccharide was subsequently observed along the enzyme's binding groove. The changes that occurred in the electrostatic binding energy and protein dynamics during this translocation provide insights into the mechanism by which the enzyme rectifies Brownian motions to achieve processivity. The free energy that drives these molecular motors is thus demonstrated to be incorporated endogenously in the methylesterified groups of the HG chains and is not supplied exogenously.

  4. Effect of hierarchical deformable motion compensation on image enhancement for DSA acquired via C-ARM

    Science.gov (United States)

    Wei, Liyang; Shen, Dinggang; Kumar, Dinesh; Turlapati, Ram; Suri, Jasjit S.

    2008-02-01

    DSA images suffer from challenges like system X-ray noise and artifacts due to patient movement. In this paper, we present a two-step strategy to improve DSA image quality. First, a hierarchical deformable registration algorithm is used to register the mask frame and the bolus frame before subtraction. Second, the resulted DSA image is further enhanced by background diffusion and nonlinear normalization for better visualization. Two major changes are made in the hierarchical deformable registration algorithm for DSA images: 1) B-Spline is used to represent the deformation field in order to produce the smooth deformation field; 2) two features are defined as the attribute vector for each point in the image, i.e., original image intensity and gradient. Also, for speeding up the 2D image registration, the hierarchical motion compensation algorithm is implemented by a multi-resolution framework. The proposed method has been evaluated on a database of 73 subjects by quantitatively measuring signal-to-noise (SNR) ratio. DSA embedded with proposed strategies demonstrates an improvement of 74.1% over conventional DSA in terms of SNR. Our system runs on Eigen's DSA workstation using C++ in Windows environment.

  5. 3D optical imagery for motion compensation in a limb ultrasound system

    Science.gov (United States)

    Ranger, Bryan J.; Feigin, Micha; Zhang, Xiang; Mireault, Al; Raskar, Ramesh; Herr, Hugh M.; Anthony, Brian W.

    2016-04-01

    Conventional processes for prosthetic socket fabrication are heavily subjective, often resulting in an interface to the human body that is neither comfortable nor completely functional. With nearly 100% of amputees reporting that they experience discomfort with the wearing of their prosthetic limb, designing an effective interface to the body can significantly affect quality of life and future health outcomes. Active research in medical imaging and biomechanical tissue modeling of residual limbs has led to significant advances in computer aided prosthetic socket design, demonstrating an interest in moving toward more quantifiable processes that are still patient-specific. In our work, medical ultrasonography is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets while greatly reducing cost compared to an MRI-based framework. This paper presents a prototype limb imaging system that uses a medical ultrasound probe, mounted to a mechanical positioning system and submerged in a water bath. The limb imaging is combined with three-dimensional optical imaging for motion compensation. Images are collected circumferentially around the limb and combined into cross-sectional axial image slices, resulting in a compound image that shows tissue distributions and anatomical boundaries similar to magnetic resonance imaging. In this paper we provide a progress update on our system development, along with preliminary results as we move toward full volumetric imaging of residual limbs for prosthetic socket design. This demonstrates a novel multi-modal approach to residual limb imaging.

  6. SU-D-BRE-01: A Realistic Breathing Phantom of the Thorax for Testing New Motion Mitigation Techniques with Scanning Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, R; Peroni, M; Bernatowicz, K; Zakova, M; Knopf, A; Safai, S [Paul Scherrer Institut, Psi-villigen, Aargau (Switzerland); Parkel, T [CSEM, Swiss Centre of Electronics and Microtechnology, Landquart, Graubunden (Switzerland)

    2014-06-01

    Purpose: A prototype breathing phantom (named LuCa) has been developed which simulates the anatomy and motion of a patient thorax.In this work, we describe the results of the first commissioning tests with LuCa. Methods: The phantom provides a close representation of the human thorax. The lungs,contained within a tissue-equivalent ribcage and skin,are made from a polymer foam,which is inflated and deflated using a custommade ventilator. A tumor is simulated using a wooden ball with cutplanes for placing GafChromic films. The ventilator,controlled with Labview software,simulates a full range of breathing motion types.Commissioning tests were performed to assess its performance using imaging (CT and radiographic) and film dosimetry as follows:i)maximum Tumor excursion at acceptable pressure ranges, ii)tumor Motion repeatability between breathing periods,iii)reproducibility between measurement days,iv)tumor-to-surface motion correlation and v)reproducibility of film positioning in phantom. Results: The phantom can generate repeatable motion patterns with sin{sup 4},sin,breath-hold (tumor amplitude repeatability <0.5mm over 10min),aswell as patient-specific motion types. Maximum excursions of the tumor are 20mm and 14mm for the large and small tumor inserts respectively. Amplitude reproducibility (Coefficient of Variation) averaged at 16% for the workable pressure range over 2 months. Good correlation between tumor and surface motion was found with R{sup 2}=0.92. Reproducibility of film positioning within the thorax was within 0.9mm, and maximum 3° error from the coronal plane. Film measurements revealed that the film repositioning error yields relative errors in the mean dose over the planned target volume (PTV) of up to 2.5% and 4.5% for films at the center and on the edge of the PTV respectively. Conclusion: Commissioning tests have shown that the LuCa phantom can produce tumor motion with excellent repeatability. However,a poorer performance in reproducibility of

  7. Respiratory motion compensated overlay of surface models from cardiac MR on interventional x-ray fluoroscopy for guidance of cardiac resynchronization therapy procedures

    Science.gov (United States)

    Manzke, R.; Bornstedt, A.; Lutz, A.; Schenderlein, M.; Hombach, V.; Binner, L.; Rasche, V.

    2010-02-01

    Various multi-center trials have shown that cardiac resynchronization therapy (CRT) is an effective procedure for patients with end-stage drug invariable heart failure (HF). Despite the encouraging results of CRT, at least 30% of patients do not respond to the treatment. Detailed knowledge of the cardiac anatomy (coronary venous tree, left ventricle), functional parameters (i.e. ventricular synchronicity) is supposed to improve CRT patient selection and interventional lead placement for reduction of the number of non-responders. As a pre-interventional imaging modality, cardiac magnetic resonance (CMR) imaging has the potential to provide all relevant information. With functional information from CMR optimal implantation target sites may be better identified. Pre-operative CMR could also help to determine whether useful vein target segments are available for lead placement. Fused with X-ray, the mainstay interventional modality, improved interventional guidance for lead-placement could further help to increase procedure outcome. In this contribution, we present novel and practicable methods for a) pre-operative functional and anatomical imaging of relevant cardiac structures to CRT using CMR, b) 2D-3D registration of CMR anatomy and functional meshes with X-ray vein angiograms and c) real-time capable breathing motion compensation for improved fluoroscopy mesh overlay during the intervention based on right ventricular pacer lead tracking. With these methods, enhanced interventional guidance for left ventricular lead placement is provided.

  8. The use of a 3D sensor (Kinect) for robot motion compensation : The applicability in relation to medical applications

    OpenAIRE

    Kvalbein, Martin

    2012-01-01

    The use of robotic systems for remote ultrasound diagnostics has emerged over the last years. This thesis looks into the possibility of integrating the Kinect sensor from Microsoft into a semi-autonomous robotic system for ultrasound diagnostics, with the intention to give the robotic system visual feedback to compensate for patient motion. In the first part of this thesis, a series of tests have been performed to explore the Kinect's sensor capabilities, with focus on accuracy, precis...

  9. Compensation of Wave-Induced Motion and Force Phenomena for Ship-Based High Performance Robotic and Human Amplifying Systems

    Energy Technology Data Exchange (ETDEWEB)

    Love, LJL

    2003-09-24

    Learning Controller has little impact due to the variable nature of the wave period. We then introduce a new approach to HAT control, Ship Motion Compensation for Force Control Systems (SMCFCS). This basic approach uses inclinometer and acceleration information from the base of the robot to compensate for ship motion disturbances. Results of the simulation study show over an order of magnitude decrease in the disturbance force reflected back to the operator and an order of magnitude increase in positioning accuracy and resolution.

  10. Local motion compensation in image sequences degraded by atmospheric turbulence: a comparative analysis of optical flow vs. block matching methods

    Science.gov (United States)

    Huebner, Claudia S.

    2016-10-01

    As a consequence of fluctuations in the index of refraction of the air, atmospheric turbulence causes scintillation, spatial and temporal blurring as well as global and local image motion creating geometric distortions. To mitigate these effects many different methods have been proposed. Global as well as local motion compensation in some form or other constitutes an integral part of many software-based approaches. For the estimation of motion vectors between consecutive frames simple methods like block matching are preferable to more complex algorithms like optical flow, at least when challenged with near real-time requirements. However, the processing power of commercially available computers continues to increase rapidly and the more powerful optical flow methods have the potential to outperform standard block matching methods. Therefore, in this paper three standard optical flow algorithms, namely Horn-Schunck (HS), Lucas-Kanade (LK) and Farnebäck (FB), are tested for their suitability to be employed for local motion compensation as part of a turbulence mitigation system. Their qualitative performance is evaluated and compared with that of three standard block matching methods, namely Exhaustive Search (ES), Adaptive Rood Pattern Search (ARPS) and Correlation based Search (CS).

  11. Adaptive robust motion trajectory tracking control of pneumatic cylinders with LuGre model-based friction compensation

    Science.gov (United States)

    Meng, Deyuan; Tao, Guoliang; Liu, Hao; Zhu, Xiaocong

    2014-07-01

    Friction compensation is particularly important for motion trajectory tracking control of pneumatic cylinders at low speed movement. However, most of the existing model-based friction compensation schemes use simple classical models, which are not enough to address applications with high-accuracy position requirements. Furthermore, the friction force in the cylinder is time-varying, and there exist rather severe unmodelled dynamics and unknown disturbances in the pneumatic system. To deal with these problems effectively, an adaptive robust controller with LuGre model-based dynamic friction compensation is constructed. The proposed controller employs on-line recursive least squares estimation (RLSE) to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. In addition, in order to realize LuGre model-based friction compensation, the modified dual-observer structure for estimating immeasurable friction internal state is developed. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology is applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Finally, the proposed controller is tested for tracking sinusoidal trajectories and smooth square trajectory under different loads and sudden disturbance. The testing results demonstrate that the achievable performance of the proposed controller is excellent and is much better than most other studies in literature. Especially when a 0.5 Hz sinusoidal trajectory is tracked, the maximum tracking error is 0.96 mm and the average tracking error is 0.45 mm. This

  12. Shared computational mechanism for tilt compensation accounts for biased verticality percepts in motion and pattern vision

    NARCIS (Netherlands)

    Vrijer, M. de; Medendorp, W.P.; Gisbergen, J.A.M. van

    2008-01-01

    To determine the direction of object motion in external space, the brain must combine retinal motion signals and information about the orientation of the eyes in space. We assessed the accuracy of this process in eight laterally tilted subjects who aligned the motion direction of a random-dot patter

  13. Shared computational mechanism for tilt compensation accounts for biased verticality percepts in motion and pattern vision.

    NARCIS (Netherlands)

    Vrijer, M. de; Medendorp, W.P.; Gisbergen, J.A.M. van

    2008-01-01

    To determine the direction of object motion in external space, the brain must combine retinal motion signals and information about the orientation of the eyes in space. We assessed the accuracy of this process in eight laterally tilted subjects who aligned the motion direction of a random-dot patter

  14. Inferential modeling and predictive feedback control in real-time motion compensation using the treatment couch during radiotherapy.

    Science.gov (United States)

    Qiu, Peng; D'Souza, Warren D; McAvoy, Thomas J; Ray Liu, K J

    2007-10-07

    Tumor motion induced by respiration presents a challenge to the reliable delivery of conformal radiation treatments. Real-time motion compensation represents the technologically most challenging clinical solution but has the potential to overcome the limitations of existing methods. The performance of a real-time couch-based motion compensation system is mainly dependent on two aspects: the ability to infer the internal anatomical position and the performance of the feedback control system. In this paper, we propose two novel methods for the two aspects respectively, and then combine the proposed methods into one system. To accurately estimate the internal tumor position, we present partial-least squares (PLS) regression to predict the position of the diaphragm using skin-based motion surrogates. Four radio-opaque markers were placed on the abdomen of patients who underwent fluoroscopic imaging of the diaphragm. The coordinates of the markers served as input variables and the position of the diaphragm served as the output variable. PLS resulted in lower prediction errors compared with standard multiple linear regression (MLR). The performance of the feedback control system depends on the system dynamics and dead time (delay between the initiation and execution of the control action). While the dynamics of the system can be inverted in a feedback control system, the dead time cannot be inverted. To overcome the dead time of the system, we propose a predictive feedback control system by incorporating forward prediction using least-mean-square (LMS) and recursive least square (RLS) filtering into the couch-based control system. Motion data were obtained using a skin-based marker. The proposed predictive feedback control system was benchmarked against pure feedback control (no forward prediction) and resulted in a significant performance gain. Finally, we combined the PLS inference model and the predictive feedback control to evaluate the overall performance of the

  15. Motion compensation method using dynamic programming for quantification of neovascularization in carotid atherosclerotic plaques with contrast enhanced ultrasound (CEUS)

    Science.gov (United States)

    Akkus, Zeynettin; Hoogi, Assaf; Renaud, Guillaume; ten Kate, Gerrit L.; van den Oord, Stijn C. H.; Schinkel, Arend F. L.; de Jong, Nico; van der Steen, Antonius F. W.; Bosch, Johan G.

    2012-03-01

    Intraplaque neovascularization (IPN) has been linked with progressive atherosclerotic disease and plaque instability in several studies. Quantification of IPN may allow early detection of vulnerable plaques. A dedicated motion compensation method with normalized-cross-correlation (NCC) block matching combined with multidimensional (2D+time) dynamic programming (MDP) was developed for quantification of IPN in small plaques (images of carotid arteries were acquired by a Philips iU22 system with a L9-3 linear array probe. The motion pattern for the plaque region was obtained from the Bmode images with MDP. MDP results were evaluated in-vitro by a phantom and in-vivo by comparing to manual tracking of three experts for multibeat-image-sequences (MIS) of 11 plaques. In the in-vivo images, the absolute error was 72+/-55μm (mean+/-SD) for X (longitudinal) and 34+/-23μm for Y (radial). The method's success rate was visually assessed on 67 MIS. The tracking was considered failed if it deviated >2 pixels (~200μm) from true motion in any frame. Tracking was scored as fully successful in 63 MIS (94%) for MDP vs. 52(78%) for FT. The range of displacement over these 63 was 1045+/-471μm (X) and 395+/-216μm (Y). The tracking sporadically failed in 4 MIS (6%) due to poor image quality, jugular vein proximity and out-of-plane motion. Motion compensation showed improved lumen-plaque contrast separation. In conclusion, the proposed method is sufficiently accurate and successful for in vivo application.

  16. Motion compensation for robotic lung tumour radiotherapy in remote locations: A personalised medicine approach

    Science.gov (United States)

    Ionescu, Clara M.; Copot, Cosmin; Verellen, Dirk

    2017-03-01

    The purpose of this work is to integrate the concept of patient-in-the-closed-loop application with tumour treatment of cancer-diagnosed patients in remote areas. The generic closed loop control objective is effective synchronisation of the radiation focus to the movement of a lung tissue tumour during actual breathing of the patient. This is facilitated by accurate repositioning of a robotic arm manipulator, i.e. we emulate the Cyberknife Robotic Radiosurgery system. Predictive control with disturbance filter is used in this application in a minimalistic model design. Performance of the control structure is validated by means of simulation using real recorded breathing patterns from patients measured in 3D space. Latency in communication protocol is taken into account, given telerobotics involve autonomous operation of a robot interacting with a human being in different location. Our results suggest that the proposed closed loop control structure has practical potential to individualise the treatment and improves accuracy by at least 15%.

  17. Impact of scanning parameters and breathing patterns on image quality and accuracy of tumor motion reconstruction in 4D CBCT: a phantom study.

    Science.gov (United States)

    Lee, Soyoung; Yan, Guanghua; Lu, Bo; Kahler, Darren; Li, Jonathan G; Sanjiv, Samat S

    2015-11-08

    Four-dimensional, cone-beam CT (4D CBCT) substantially reduces respiration-induced motion blurring artifacts in three-dimension (3D) CBCT. However, the image quality of 4D CBCT is significantly degraded which may affect its accuracy in localizing a mobile tumor for high-precision, image-guided radiation therapy (IGRT). The purpose of this study was to investigate the impact of scanning parameters hereinafter collectively referred to as scanning sequence) and breathing patterns on the image quality and the accuracy of computed tumor trajectory for a commercial 4D CBCT system, in preparation for its clinical implementation. We simulated a series of periodic and aperiodic sinusoidal breathing patterns with a respiratory motion phantom. The aperiodic pattern was created by varying the period or amplitude of individual sinusoidal breathing cycles. 4D CBCT scans of the phantom were acquired with a manufacturer-supplied scanning sequence (4D-S-slow) and two in-house modified scanning sequences (4D-M-slow and 4D-M-fast). While 4D-S-slow used small field of view (FOV), partial rotation (200°), and no imaging filter, 4D-M-slow and 4D-M-fast used medium FOV, full rotation, and the F1 filter. The scanning speed was doubled in 4D-M-fast (100°/min gantry rotation). The image quality of the 4D CBCT scans was evaluated using contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and motion blurring ratio (MBR). The trajectory of the moving target was reconstructed by registering each phase of the 4D CBCT with a reference CT. The root-mean-squared-error (RMSE) analysis was used to quantify its accuracy. Significant decrease in CNR and SNR from 3D CBCT to 4D CBCT was observed. The 4D-S-slow and 4D-M-fast scans had comparable image quality, while the 4D-M-slow scans had better performance due to doubled projections. Both CNR and SNR decreased slightly as the breathing period increased, while no dependence on the amplitude was observed. The difference of both CNR and SNR

  18. Mensuração da amplitude de movimento cervical em crianças respiradoras orais Measurement of neck range of motion among mouth-breathing children

    Directory of Open Access Journals (Sweden)

    PD Neiva

    2007-10-01

    Full Text Available INTRODUÇÃO: Por definição clínica, respiradores orais (RO utilizam a boca como maior via de acesso de ar durante a respiração. Isso resulta em alterações na posição da língua e cabeça e pode influenciar a mecânica craniofacial durante o desenvolvimento. A anteriorização da cabeça também é comum em RO, podendo levar a desalinhamentos em segmentos adjacentes do corpo humano. OBJETIVOS: Avaliar a amplitude de movimento (ADM cervical em crianças RO e comparar com crianças respiradoras nasais (RN. MÉTODOS: Dez crianças RO, de ambos os sexos, com idade de 6,90 ± 1,37 anos e dez RN, de ambos os sexos, com idade de 7,70 ± 1,42 anos, participaram do estudo. O Cervical Range of Motion (CROM foi utilizado para medir a ADM de flexão, extensão e protrusão da cabeça. Para a análise estatística foi utilizado o teste t Student para amostras independentes, considerando nível de significância estatística o valor de pINTRODUCTION: By clinical definition, mouth breathers use the mouth as their main air pathway during breathing. This results in modifications to tongue and head positioning and may have an influence on craniofacial mechanics during development. Bringing the head forward is also common among mouth breathers and may lead to misalignments in adjacent segments of the human body. OBJECTIVE: To evaluate neck (cervical range of motion (ROM among mouth-breathing children and compare this with a group of nose-breathing children. METHOD: Ten mouth-breathing children of both sexes aged 6.90 ± 1.37 years and ten nose-breathing children aged 7.70 ± 1.42 years participated in this study. The ROM for neck flexion, extension and protrusion of the head were evaluated. Student's t test for independent samples was used for the statistical analysis, considering p< 0.05 as the statistical significance level. RESULTS: The mouth-breathing children had a significantly smaller ROM for neck extension (59.0º ± 10.79º, compared with the

  19. Compensation of Environment and Motion Error for Accuracy Improvement of Ultra-Precision Lathe

    Science.gov (United States)

    Kwac, Lee-Ku; Kim, Jae-Yeol; Kim, Hong-Gun

    The technological manipulation of the piezo-electric actuator could compensate for the errors of the machining precision during the process of machining which lead to an elevation and enhancement in overall precisions. This manipulation is a very convenient method to advance the precision for nations without the solid knowledge of the ultra-precision machining technology. There were 2 divisions of researches conducted to develop the UPCU for precision enhancement of the current lathe and compensation for the environmental errors as shown below; The first research was designed to measure and real-time correct any deviations in variety of areas to achieve a compensation system through more effective optical fiber laser encoder than the encoder resolution which was currently used in the existing lathe. The deviations for a real-time correction were composed of followings; the surrounding air temperature, the thermal deviations of the machining materials, the thermal deviations in spindles, and the overall thermal deviation occurred due to the machine structure. The second research was to develop the UPCU and to improve the machining precision through the ultra-precision positioning and the real-time operative error compensation. The ultimate goal was to improve the machining precision of the existing lathe through completing the 2 research tasks mentioned above.

  20. Enabling Error-Resilient Internet Broadcasting using Motion Compensated Spatial Partitioning and Packet FEC for the Dirac Video Codec

    Directory of Open Access Journals (Sweden)

    Myo Tun

    2008-06-01

    Full Text Available Video transmission over the wireless or wired network require protection from channel errors since compressed video bitstreams are very sensitive to transmission errors because of the use of predictive coding and variable length coding. In this paper, a simple, low complexity and patent free error-resilient coding is proposed. It is based upon the idea of using spatial partitioning on the motion compensated residual frame without employing the transform coefficient coding. The proposed scheme is intended for open source Dirac video codec in order to enable the codec to be used for Internet broadcasting. By partitioning the wavelet transform coefficients of the motion compensated residual frame into groups and independently processing each group using arithmetic coding and Forward Error Correction (FEC, robustness to transmission errors over the packet erasure wired network could be achieved. Using the Rate Compatibles Punctured Code (RCPC and Turbo Code (TC as the FEC, the proposed technique provides gracefully decreasing perceptual quality over packet loss rates up to 30%. The PSNR performance is much better when compared with the conventional data partitioning only methods. Simulation results show that the use of multiple partitioning of wavelet coefficient in Dirac can achieve up to 8 dB PSNR gain over its existing un-partitioned method.

  1. A Temperature Compensation Method for Piezo-Resistive Pressure Sensor Utilizing Chaotic Ions Motion Algorithm Optimized Hybrid Kernel LSSVM.

    Science.gov (United States)

    Li, Ji; Hu, Guoqing; Zhou, Yonghong; Zou, Chong; Peng, Wei; Alam Sm, Jahangir

    2016-10-14

    A piezo-resistive pressure sensor is made of silicon, the nature of which is considerably influenced by ambient temperature. The effect of temperature should be eliminated during the working period in expectation of linear output. To deal with this issue, an approach consists of a hybrid kernel Least Squares Support Vector Machine (LSSVM) optimized by a chaotic ions motion algorithm presented. To achieve the learning and generalization for excellent performance, a hybrid kernel function, constructed by a local kernel as Radial Basis Function (RBF) kernel, and a global kernel as polynomial kernel is incorporated into the Least Squares Support Vector Machine. The chaotic ions motion algorithm is introduced to find the best hyper-parameters of the Least Squares Support Vector Machine. The temperature data from a calibration experiment is conducted to validate the proposed method. With attention on algorithm robustness and engineering applications, the compensation result shows the proposed scheme outperforms other compared methods on several performance measures as maximum absolute relative error, minimum absolute relative error mean and variance of the averaged value on fifty runs. Furthermore, the proposed temperature compensation approach lays a foundation for more extensive research.

  2. A Temperature Compensation Method for Piezo-Resistive Pressure Sensor Utilizing Chaotic Ions Motion Algorithm Optimized Hybrid Kernel LSSVM

    Directory of Open Access Journals (Sweden)

    Ji Li

    2016-10-01

    Full Text Available A piezo-resistive pressure sensor is made of silicon, the nature of which is considerably influenced by ambient temperature. The effect of temperature should be eliminated during the working period in expectation of linear output. To deal with this issue, an approach consists of a hybrid kernel Least Squares Support Vector Machine (LSSVM optimized by a chaotic ions motion algorithm presented. To achieve the learning and generalization for excellent performance, a hybrid kernel function, constructed by a local kernel as Radial Basis Function (RBF kernel, and a global kernel as polynomial kernel is incorporated into the Least Squares Support Vector Machine. The chaotic ions motion algorithm is introduced to find the best hyper-parameters of the Least Squares Support Vector Machine. The temperature data from a calibration experiment is conducted to validate the proposed method. With attention on algorithm robustness and engineering applications, the compensation result shows the proposed scheme outperforms other compared methods on several performance measures as maximum absolute relative error, minimum absolute relative error mean and variance of the averaged value on fifty runs. Furthermore, the proposed temperature compensation approach lays a foundation for more extensive research.

  3. A Unifying model of perfusion and motion applied to reconstruction of sparsely sampled free-breathing myocardial perfusion MRI

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Ólafsdóttir, Hildur; Larsen, Rasmus;

    2010-01-01

    The clinical potential of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is currently limited by respiratory induced motion of the heart. This paper presents a unifying model of perfusion and motion in which respiratory motion becomes an integral part of myocardial perfusion...... on the underlying theory of the proposed framework, but shows in vivo results of respiratory motion correction and simulation results of reconstructing sparsely sampled data....

  4. Gravity Compensation Method for Combined Accelerometer and Gyro Sensors Used in Cardiac Motion Measurements.

    Science.gov (United States)

    Krogh, Magnus Reinsfelt; Nghiem, Giang M; Halvorsen, Per Steinar; Elle, Ole Jakob; Grymyr, Ole-Johannes; Hoff, Lars; Remme, Espen W

    2017-01-23

    A miniaturized accelerometer fixed to the heart can be used for monitoring of cardiac function. However, an accelerometer cannot differentiate between acceleration caused by motion and acceleration due to gravity. The accuracy of motion measurements is therefore dependent on how well the gravity component can be estimated and filtered from the measured signal. In this study we propose a new method for estimating the gravity, based on strapdown inertial navigation, using a combined accelerometer and gyro. The gyro was used to estimate the orientation of the gravity field and thereby remove it. We compared this method with two previously proposed gravity filtering methods in three experimental models using: (1) in silico computer simulated heart motion; (2) robot mimicked heart motion; and (3) in vivo measured motion on the heart in an animal model. The new method correlated excellently with the reference (r (2) > 0.93) and had a deviation from reference peak systolic displacement (6.3 ± 3.9 mm) below 0.2 ± 0.5 mm for the robot experiment model. The new method performed significantly better than the two previously proposed methods (p high accuracy and performs better than existing methods for filtering the gravity component from the accelerometer signal.

  5. WE-AB-303-05: Breathing Motion of Liver Segments From Fiducial Tracking During Robotic Radiosurgery and Comparison with 4D-CT-Derived Fiducial Motion

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J; Pantarotto, J; Nair, V; Cook, G; Plourde, M; Vandervoort, E [The Ottawa Hospital Cancer Centre, Ottawa, Ontario (Canada)

    2015-06-15

    Purpose: To quantify respiratory-induced motion of liver segments using the positions of implanted fiducials during robotic radiosurgery. This study also compared fiducial motion derived from four-dimensional computed tomography (4D-CT) maximum intensity projections (MIP) with motion derived from imaging during treatment. Methods: Forty-two consecutive liver patients treated with liver ablative radiotherapy were accrued to an ethics approved retrospective study. The liver segment in which each fiducial resided was identified. Fiducial positions throughout each treatment fraction were determined using orthogonal kilovoltage images. Any data due to patient repositioning or motion was removed. Mean fiducial positions were calculated. Fiducial positions beyond two standard deviations of the mean were discarded and remaining positions were fit to a line segment using least squares minimization (LSM). For eight patients, fiducial motion was derived from 4D-CT MIPs by calculating the CT number weighted mean position of the fiducial on each slice and fitting a line segment to these points using LSM. Treatment derived fiducial trajectories were corrected for patient rotation and compared to MIP derived trajectories. Results: The mean total magnitude of fiducial motion across all liver segments in left-right, anteroposterior, and superoinferior (SI) directions were 3.0 ± 0.2 mm, 9.3 ± 0.4 mm, and 20.5 ± 0.5 mm, respectively. Differences in per-segment mean fiducial motion were found with SI motion ranging from 12.6 ± 0.8 mm to 22.6 ± 0.9 mm for segments 3 and 8, respectively. Large, varied differences between treatment and MIP derived motion at simulation were found with the mean difference for SI motion being 2.6 mm (10.8 mm standard deviation). Conclusion: The magnitude of liver fiducial motion was found to differ by liver segment. MIP derived liver fiducial motion differed from motion observed during treatment, implying that 4D-CTs may not accurately capture the

  6. IMPROVED SYNTHETIC APERTURE SONAR MOTION COMPENSATION COMBINED DPCA WITH SUB-APERTURE IMAGE CORRELATION

    Institute of Scientific and Technical Information of China (English)

    Liu Wei; Zhang Chunhua; Liu Jiyuan

    2009-01-01

    Estimation precision of Displaced Phase Center Algorithm (DPCA) is affected by the number of displaced phase center pairs, the bandwidth of transmitting signal and many other factors. Detailed analysis is made on DPCA's estimation precision. Analysis results show that the directional vector estimation precision of DPCA is low, which will produce accumulating errors when phase centers' track is estimated. Because of this reason, DPCA suffers from accumulating errors seriously. To overcome this problem, a method combining DPCA with Sub Aperture Image Correlation (SAIC) is presented. Large synthetic aperture is divided into sub-apertures. Micro errors in sub-aperture are estimated by DPCA and compensated to raw echo data. Bulk errors between sub-apertures are estimated by SAIC and compensated directly to sub-aperture images. After that, sub-aperture images are directly used to generate ultimate SAS image. The method is applied to the lake-trial dataset of a 20 kHz SAS prototype system. Results show the method can successfully remove the accumulating error and produce a better SAS image.

  7. Spatial and Temporal Control of Hyperthermia Using Real Time Ultrasonic Thermal Strain Imaging with Motion Compensation, Phantom Study.

    Directory of Open Access Journals (Sweden)

    Josquin Foiret

    Full Text Available Mild hyperthermia has been successfully employed to induce reversible physiological changes that can directly treat cancer and enhance local drug delivery. In this approach, temperature monitoring is essential to avoid undesirable biological effects that result from thermal damage. For thermal therapies, Magnetic Resonance Imaging (MRI has been employed to control real-time Focused Ultrasound (FUS therapies. However, combined ultrasound imaging and therapy systems offer the benefits of simple, low-cost devices that can be broadly applied. To facilitate such technology, ultrasound thermometry has potential to reliably monitor temperature. Control of mild hyperthermia was previously achieved using a proportional-integral-derivative (PID controller based on thermocouple measurements. Despite accurate temporal control of heating, this method is limited by the single position at which the temperature is measured. Ultrasound thermometry techniques based on exploiting the thermal dependence of acoustic parameters (such as longitudinal velocity can be extended to create thermal maps and allow an accurate monitoring of temperature with good spatial resolution. However, in vivo applications of this technique have not been fully developed due to the high sensitivity to tissue motion. Here, we propose a motion compensation method based on the acquisition of multiple reference frames prior to treatment. The technique was tested in the presence of 2-D and 3-D physiological-scale motion and was found to provide effective real-time temperature monitoring. PID control of mild hyperthermia in presence of motion was then tested with ultrasound thermometry as feedback and temperature was maintained within 0.3°C of the requested value.

  8. The use of anatomical information for molecular image reconstruction algorithms: Attention/Scatter correction, motion compensation, and noise reduction

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Se Young [School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

    2016-03-15

    PET and SPECT are important tools for providing valuable molecular information about patients to clinicians. Advances in nuclear medicine hardware technologies and statistical image reconstruction algorithms enabled significantly improved image quality. Sequentially or simultaneously acquired anatomical images such as CT and MRI from hybrid scanners are also important ingredients for improving the image quality of PET or SPECT further. High-quality anatomical information has been used and investigated for attenuation and scatter corrections, motion compensation, and noise reduction via post-reconstruction filtering and regularization in inverse problems. In this article, we will review works using anatomical information for molecular image reconstruction algorithms for better image quality by describing mathematical models, discussing sources of anatomical information for different cases, and showing some examples.

  9. Motion compensation in a tomographic ultrasound imaging system: Toward volumetric scans of a limb for prosthetic socket design.

    Science.gov (United States)

    Ranger, Bryan J; Feigin, Micha; Pestrov, Nikita; Zhang, Xiang; Lempitsky, Victor; Herr, Hugh M; Anthony, Brian W

    2015-08-01

    Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and repeatable process has not been fully demonstrated. Medical ultrasonography, which has significant potential to expand its clinical applications, is being pursued to acquire data that may quantify and improve the design process and fabrication of prosthetic sockets. This paper presents a new multi-modal imaging approach for acquiring volumetric images of a human limb, specifically focusing on how motion of the limb is compensated for using optical imagery.

  10. SU-C-210-04: Considerable Pancreatic Tumor Motion During Breath-Hold Measured Using Intratumoral Fiducials On Fluoroscopic Movies

    Energy Technology Data Exchange (ETDEWEB)

    Lens, E; Horst, A van der; Versteijne, E; Tienhoven, G van; Bel, A [Academic Medical Center, Amsterdam (Netherlands)

    2015-06-15

    Purpose: Using a breath hold (BH) technique during radiotherapy of pancreatic tumors is expected to reduce intra-fractional motion. The aim of this study was to evaluate the tumor motion during BH. Methods: In this pilot study, we included 8 consecutive pancreatic cancer patients. All had 2– 4 intratumoral gold fiducials. Patients were asked to perform 3 consecutive 30-second end-inhale BHs on day 5, 10 and 15 of their three-week treatment. During BH, airflow through a mouthpiece was measured using a spirometer. Any inadvertent flow of air during BH was monitored for all patients. We measured tumor motion on lateral fluoroscopic movies (57 in total) made during BH. In each movie the fiducials as a group were tracked over time in superior-inferior (SI) and anterior-posterior (AP) direction using 2-D image correlation between consecutive frames. We determined for each patient the range of intra-BH motion over all movies; we also determined the absolute means and standard deviations (SDs) for the entire patient group. Additionally, we investigated the relation between inadvertent airflow during BH and the intra-BH motion. Results: We found intra-BH tumor motion of up to 12.5 mm (range, 1.0–12.5 mm) in SI direction and up to 8.0 mm (range, 1.0–8.0 mm) in AP direction. The absolute mean motion over the patient population was 4.7 (SD: 3.0) mm and 2.8 (SD: 1.2) mm in the SI and AP direction, respectively. Patients were able to perform stable consecutive BHs; during only 20% of the movies we found very small airflows (≤ 65 ml). These were mostly stepwise in nature and could not explain the continuous tumor motions we observed. Conclusion: We found substantial (up to 12.5 mm) pancreatic tumor motion during BHs. We found minimal inadvertent airflow, seen only during a minority of BHs, and this did not explain the obtained results. This work was supported by the foundation Bergh in het Zadel through the Dutch Cancer Society (KWF Kankerbestrijding) project No. UVA 2011-5271.

  11. An integrated bioimpedance—ECG gating technique for respiratory and cardiac motion compensation in cardiac PET

    Science.gov (United States)

    Koivumäki, Tuomas; Nekolla, Stephan G.; Fürst, Sebastian; Loher, Simone; Vauhkonen, Marko; Schwaiger, Markus; Hakulinen, Mikko A.

    2014-10-01

    Respiratory motion may degrade image quality in cardiac PET imaging. Since cardiac PET studies often involve cardiac gating by ECG, a separate respiratory monitoring system is required increasing the logistic complexity of the examination, in case respiratory gating is also needed. Thus, we investigated the simultaneous acquisition of both respiratory and cardiac gating signals using II limb lead mimicking electrode configuration during cardiac PET scans of 11 patients. In addition to conventional static and ECG-gated images, bioimpedance technique was utilized to generate respiratory- and dual-gated images. The ability of the bioimpedance technique to monitor intrathoracic respiratory motion was assessed estimating cardiac displacement between end-inspiration and -expiration. The relevance of dual gating was evaluated in left ventricular volume and myocardial wall thickness measurements. An average 7.6  ±  3.3 mm respiratory motion was observed in the study population. Dual gating showed a small but significant increase (4 ml, p = 0.042) in left ventricular myocardial volume compared to plain cardiac gating. In addition, a thinner myocardial wall was observed in dual-gated images (9.3  ±  1.3 mm) compared to cardiac-gated images (11.3  ±  1.3 mm, p = 0.003). This study shows the feasibility of bioimpedance measurements for dual gating in a clinical setting. The method enables simultaneous acquisition of respiratory and cardiac gating signals using a single device with standard ECG electrodes.

  12. Three-dimensional reconstruction of coronary stents in vivo based on motion compensated X-ray angiography

    Science.gov (United States)

    Schäfer, Dirk; Movassaghi, Babak; Grass, Michael; Schoonenberg, Gert; Florent, Raoul; Wink, Onno; Klein, Andrew J. P.; Chen, James Y.; Garcia, Joel; Messenger, John C.; Carroll, John D.

    2007-03-01

    The complete expansion of the stent during a percutaneous transluminal coronary angioplasty (PTCA) procedure is essential for treatment of a stenotic segment of a coronary artery. Inadequate expansion of the stent is a major predisposing factor to in-stent restenosis and acute thrombosis. Stents are positioned and deployed by fluoroscopic guidance. Although the current generation of stents are made of materials with some degree of radio-opacity to detect their location after deployment, proper stent expansion is hard to asses. In this work, we introduce a new method for the three-dimensional (3D) reconstruction of the coronary stents in-vivo utilizing two-dimensional projection images acquired during rotational angiography (RA). The acquisition protocol consist of a propeller rotation of the X-ray C-arm system of 180°, which ensures sufficient angular coverage for volume reconstruction. The angiographic projections were acquired at 30 frames per second resulting in 180 projections during a 7 second rotational run. The motion of the stent is estimated from the automatically tracked 2D coordinates of the markers on the balloon catheter. This information is used within a motion-compensated reconstruction algorithm. Therefore, projections from different cardiac phases and motion states can be used, resulting in improved signal-to-noise ratio of the stent. Results of 3D reconstructed coronary stents in vivo, with high spatial resolution are presented. The proposed method allows for a comprehensive and unique quantitative 3D assessment of stent expansion that rivals current X-ray and intravascular ultrasound techniques.

  13. Three-directional motion compensation-based novel-look-up-table for video hologram generation of three-dimensional objects freely maneuvering in space.

    Science.gov (United States)

    Dong, Xiao-Bin; Kim, Seung-Cheol; Kim, Eun-Soo

    2014-07-14

    A new three-directional motion compensation-based novel-look-up-table (3DMC-NLUT) based on its shift-invariance and thin-lens properties, is proposed for video hologram generation of three-dimensional (3-D) objects moving with large depth variations in space. The input 3-D video frames are grouped into a set of eight in sequence, where the first and remaining seven frames in each set become the reference frame (RF) and general frames (GFs), respectively. Hence, each 3-D video frame is segmented into a set of depth-sliced object images (DOIs). Then x, y, and z-directional motion vectors are estimated from blocks and DOIs between the RF and each of the GFs, respectively. With these motion vectors, object motions in space are compensated. Then, only the difference images between the 3-directionally motion-compensated RF and each of the GFs are applied to the NLUT for hologram calculation. Experimental results reveal that the average number of calculated object points and the average calculation time of the proposed method have been reduced compared to those of the conventional NLUT, TR-NLUT and MPEG-NLUT by 38.14%, 69.48%, and 67.41% and 35.30%, 66.39%, and 64.46%, respectively.

  14. Fast CT-CT fluoroscopy registration with respiratory motion compensation for image-guided lung intervention

    Science.gov (United States)

    Su, Po; Xue, Zhong; Lu, Kongkuo; Yang, Jianhua; Wong, Stephen T.

    2012-02-01

    CT-fluoroscopy (CTF) is an efficient imaging method for guiding percutaneous lung interventions such as biopsy. During CTF-guided biopsy procedure, four to ten axial sectional images are captured in a very short time period to provide nearly real-time feedback to physicians, so that they can adjust the needle as it is advanced toward the target lesion. Although popularly used in clinics, this traditional CTF-guided intervention procedure may require frequent scans and cause unnecessary radiation exposure to clinicians and patients. In addition, CTF only generates limited slices of images and provides limited anatomical information. It also has limited response to respiratory movements and has narrow local anatomical dynamics. To better utilize CTF guidance, we propose a fast CT-CTF registration algorithm with respiratory motion estimation for image-guided lung intervention using electromagnetic (EM) guidance. With the pre-procedural exhale and inhale CT scans, it would be possible to estimate a series of CT images of the same patient at different respiratory phases. Then, once a CTF image is captured during the intervention, our algorithm can pick the best respiratory phase-matched 3D CT image and performs a fast deformable registration to warp the 3D CT toward the CTF. The new 3D CT image can be used to guide the intervention by superimposing the EM-guided needle location on it. Compared to the traditional repetitive CTF guidance, the registered CT integrates both 3D volumetric patient data and nearly real-time local anatomy for more effective and efficient guidance. In this new system, CTF is used as a nearly real-time sensor to overcome the discrepancies between static pre-procedural CT and the patient's anatomy, so as to provide global guidance that may be supplemented with electromagnetic (EM) tracking and to reduce the number of CTF scans needed. In the experiments, the comparative results showed that our fast CT-CTF algorithm can achieve better registration

  15. 2D-3D rigid registration to compensate for prostate motion during 3D TRUS-guided biopsy

    Science.gov (United States)

    De Silva, Tharindu; Fenster, Aaron; Bax, Jeffrey; Gardi, Lori; Romagnoli, Cesare; Samarabandu, Jagath; Ward, Aaron D.

    2012-02-01

    Prostate biopsy is the clinical standard for prostate cancer diagnosis. To improve the accuracy of targeting suspicious locations, systems have been developed that can plan and record biopsy locations in a 3D TRUS image acquired at the beginning of the procedure. Some systems are designed for maximum compatibility with existing ultrasound equipment and are thus designed around the use of a conventional 2D TRUS probe, using controlled axial rotation of this probe to acquire a 3D TRUS reference image at the start of the biopsy procedure. Prostate motion during the biopsy procedure causes misalignments between the prostate in the live 2D TRUS images and the pre-acquired 3D TRUS image. We present an image-based rigid registration technique that aligns live 2D TRUS images, acquired immediately prior to biopsy needle insertion, with the pre-acquired 3D TRUS image to compensate for this motion. Our method was validated using 33 manually identified intrinsic fiducials in eight subjects and the target registration error was found to be 1.89 mm. We analysed the suitability of two image similarity metrics (normalized cross correlation and mutual information) for this task by plotting these metrics as a function of varying parameters in the six degree-of-freedom transformation space, with the ground truth plane obtained from registration as the starting point for the parameter exploration. We observed a generally convex behaviour of the similarity metrics. This encourages their use for this registration problem, and could assist in the design of a tool for the detection of misalignment, which could trigger the execution of a non-real-time registration, when needed during the procedure.

  16. Breathing Problems

    Science.gov (United States)

    ... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.

  17. Development of a frameless stereotactic radiosurgery system based on real-time 6D position monitoring and adaptive head motion compensation

    Science.gov (United States)

    Wiersma, Rodney D.; Wen, Zhifei; Sadinski, Meredith; Farrey, Karl; Yenice, Kamil M.

    2010-01-01

    Stereotactic radiosurgery delivers radiation with great spatial accuracy. To achieve sub-millimeter accuracy for intracranial SRS, a head ring is rigidly fixated to the skull to create a fixed reference. For some patients, the invasiveness of the ring can be highly uncomfortable and not well tolerated. In addition, placing and removing the ring requires special expertise from a neurosurgeon, and patient setup time for SRS can often be long. To reduce the invasiveness, hardware limitations and setup time, we are developing a system for performing accurate head positioning without the use of a head ring. The proposed method uses real-time 6D optical position feedback for turning on and off the treatment beam (gating) and guiding a motor-controlled 3D head motion compensation stage. The setup consists of a central control computer, an optical patient motion tracking system and a 3D motion compensation stage attached to the front of the LINAC couch. A styrofoam head cast was custom-built for patient support and was mounted on the compensation stage. The motion feedback of the markers was processed by the control computer, and the resulting motion of the target was calculated using a rigid body model. If the target deviated beyond a preset position of 0.2 mm, an automatic position correction was performed with stepper motors to adjust the head position via the couch mount motion platform. In the event the target deviated more than 1 mm, a safety relay switch was activated and the treatment beam was turned off. The feasibility of the concept was tested using five healthy volunteers. Head motion data were acquired with and without the use of motion compensation over treatment times of 15 min. On average, test subjects exceeded the 0.5 mm tolerance 86% of the time and the 1.0 mm tolerance 45% of the time without motion correction. With correction, this percentage was reduced to 5% and 2% for the 0.5 mm and 1.0 mm tolerances, respectively.

  18. Development of a frameless stereotactic radiosurgery system based on real-time 6D position monitoring and adaptive head motion compensation

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, Rodney D; Wen Zhifei; Sadinski, Meredith; Farrey, Karl; Yenice, Kamil M [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637 (United States)], E-mail: rwiersma@uchicago.edu

    2010-01-21

    Stereotactic radiosurgery delivers radiation with great spatial accuracy. To achieve sub-millimeter accuracy for intracranial SRS, a head ring is rigidly fixated to the skull to create a fixed reference. For some patients, the invasiveness of the ring can be highly uncomfortable and not well tolerated. In addition, placing and removing the ring requires special expertise from a neurosurgeon, and patient setup time for SRS can often be long. To reduce the invasiveness, hardware limitations and setup time, we are developing a system for performing accurate head positioning without the use of a head ring. The proposed method uses real-time 6D optical position feedback for turning on and off the treatment beam (gating) and guiding a motor-controlled 3D head motion compensation stage. The setup consists of a central control computer, an optical patient motion tracking system and a 3D motion compensation stage attached to the front of the LINAC couch. A styrofoam head cast was custom-built for patient support and was mounted on the compensation stage. The motion feedback of the markers was processed by the control computer, and the resulting motion of the target was calculated using a rigid body model. If the target deviated beyond a preset position of 0.2 mm, an automatic position correction was performed with stepper motors to adjust the head position via the couch mount motion platform. In the event the target deviated more than 1 mm, a safety relay switch was activated and the treatment beam was turned off. The feasibility of the concept was tested using five healthy volunteers. Head motion data were acquired with and without the use of motion compensation over treatment times of 15 min. On average, test subjects exceeded the 0.5 mm tolerance 86% of the time and the 1.0 mm tolerance 45% of the time without motion correction. With correction, this percentage was reduced to 5% and 2% for the 0.5 mm and 1.0 mm tolerances, respectively.

  19. Setup error and motion during deep inspiration breath-hold breast radiotherapy measured with continuous portal imaging

    DEFF Research Database (Denmark)

    Lutz, Christina Maria; Poulsen, Per Rugaard; Fledelius, Walther;

    2016-01-01

    differences between the groups were found. In a combined analysis, the group mean inter-fraction setup error was M = - 0.1 mm, with random and systematic errors of σ = 1.7 mm and Σ = 1.4 mm. The group mean inter-field shift was M = 0.0 (σ = 1.3 mm and Σ = 1.1 mm) and the group mean standard deviation......). At every third treatment fraction, continuous portal images were acquired. The time-resolved chest wall position during treatment was compared with the planned position to determine the inter-fraction setup errors and the intra-fraction motion of the chest wall. RESULTS: The DIBH compliance was 95% during...... both recruitment periods. A tendency of smaller inter-fraction setup errors and intra-fraction motion was observed for group 2 (medial marker block position). However, apart from a significantly reduced inter-field random shift (σ = 1.7 mm vs. σ = 0.9 mm, p = 0.005), no statistically significant...

  20. Image-based compensation for involuntary motion in weight-bearing C-arm cone-beam CT scanning of knees

    Science.gov (United States)

    Unberath, Mathias; Choi, Jang-Hwan; Berger, Martin; Maier, Andreas; Fahrig, Rebecca

    2015-03-01

    We previously introduced four fiducial marker-based strategies to compensate for involuntary knee-joint motion during weight-bearing C-arm CT scanning of the lower body. 2D methods showed significant reduction of motion- related artifacts, but 3D methods worked best. However, previous methods led to increased examination times and patient discomfort caused by the marker attachment process. Moreover, sub-optimal marker placement may lead to decreased marker detectability and therefore unstable motion estimates. In order to reduce overall patient discomfort, we developed a new image-based 2D projection shifting method. A C-arm cone-beam CT system was used to acquire projection images of five healthy volunteers at various flexion angles. Projection matrices for the horizontal scanning trajectory were calibrated using the Siemens standard PDS-2 phantom. The initial reconstruction was forward projected using maximum-intensity projections (MIP), yielding an estimate of a static scan. This estimate was then used to obtain the 2D projection shifts via registration. For the scan with the most motion, the proposed method reproduced the marker-based results with a mean error of 2.90 mm +/- 1.43 mm (compared to a mean error of 4.10 mm +/- 3.03 mm in the uncorrected case). Bone contour surrounding modeling clay layer was improved. The proposed method is a first step towards automatic image-based, marker-free motion-compensation.

  1. Motion Compensation for Broadband LFM Signal in Airborne PD Radar%机载PD雷达宽带线性调频信号运动补偿

    Institute of Scientific and Technical Information of China (English)

    曹书华; 汪凌艳; 赵鹏; 张建凌; 吴磊

    2015-01-01

    Broadband linearly frequency modulated signal is taken as a common method to promote range resolution and anti-interference performance of radar. However,the relative motion between radar and target consumes partial target echo coherent integration energy,influences the target range and frequency resolution. To solve these problems,a motion compensation method based on the improved match filter is found. This method achieves Broadband LFM signal target motion compensation based on compensating target echo phase error. Experimental and simulation results show the effectiveness of the algorithm.%采用宽带线性调频信号能够显著地提高雷达的距离分辨率和抗干扰能力,然而雷达与目标间的相对运动损耗了部分目标回波相参积累能量,影响目标频率向和距离向分辨力。针对以上问题,提出了一种基于改进匹配滤波函数的运动补偿方法,补偿信号回波中的相位误差,实现宽带线性调频信号目标运动运动补偿。实验与仿真结果证明了该算法的有效性。

  2. Research on new software compensation method of static and quasi-static errors for precision motion controller

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To reduce mechanical vibrations induced by big errors compensation, a new software compensation method based on an improved digital differential analyzer (DDA) interpolator for static and quasi-static errors of machine tools is proposed. Based on principle of traditional DDA interpolator, a DDA interpolator is divided into command generator and command analyzer. There are three types of errors, considering the difference of positions between compensation points and interpolation segments. According to the classification, errors are distributed evenly in data processing and compensated to certain interpolation segments in machining. On-line implementation results show that the proposed approach greatly improves positioning accuracy of computer numerical control (CNC) machine tools.

  3. Motion

    CERN Document Server

    Graybill, George

    2007-01-01

    Take the mystery out of motion. Our resource gives you everything you need to teach young scientists about motion. Students will learn about linear, accelerating, rotating and oscillating motion, and how these relate to everyday life - and even the solar system. Measuring and graphing motion is easy, and the concepts of speed, velocity and acceleration are clearly explained. Reading passages, comprehension questions, color mini posters and lots of hands-on activities all help teach and reinforce key concepts. Vocabulary and language are simplified in our resource to make them accessible to str

  4. First steps towards ultrasound-based motion compensation for imaging and therapy: calibration with an optical system and 4D PET imaging

    Directory of Open Access Journals (Sweden)

    Julia eSchwaab

    2015-11-01

    Full Text Available Target motion, particularly in the abdomen, due to respiration or patient movement is still a challenge in many diagnostic and therapeutic processes. Hence, methods to detect and compensate this motion are required. Diagnostic ultrasound represents a non-invasive and dose-free alternative to fluoroscopy, providing more information about internal target motion than respiration belt or optical tracking.The goal of this project is to develop an ultrasound based motion tracking for real time motion correction in radiation therapy and diagnostic imaging, notably in 4D positron emission tomography (PET. In this work, a workflow is established to enable the transformation of ultrasound tracking data to the coordinates of the treatment delivery or imaging system – even if the ultrasound probe is moving due to respiration. It is shown that the ultrasound tracking signal is equally adequate for 4D PET image reconstruction as the clinically used respiration belt and provides additional opportunities in this concern. Furthermore, it is demonstrated that the ultrasound probe being within the PET field of view generally has no relevant influence on the image quality. The accuracy and precision of all the steps in the calibration workflow for ultrasound tracking based 4D PET imaging are found to be in an acceptable range for clinical implementation. Eventually, we show in vitro that an ultrasound based motion tracking in absolute room coordinates with a moving US-transducer is feasible.

  5. DGPS/SINS INTEGRATED SYSTEM USED IN SAR MOTION COMPENSATION%用于SAR运动补偿的DGPS/SINS组合系统研究

    Institute of Scientific and Technical Information of China (English)

    曹福祥; 保铮; 袁建平; 郑谔

    2001-01-01

    使用考虑位置误差相关项的伪距率观测模型,研究了用于合成孔径雷达运动补偿的差分GPS/SINS伪距率组合系统。结果表明,组合系统的长期位置精度能达到1m左右。GPS数据更新率低于INS,在GPS测量时间间隔内,组合系统的性能仅由INS决定。虽然INS误差随时间积累,在GPS数据更新率为1s的情况下,即使采用中等精度的惯性仪表,其相对位置精度为厘米级(这里相对位置精度指组合系统在GPS测量时间间隔内位置误差的变化范围)。%Nowadays higher resolution image from an airborne Synthetic Aperture Radar (SAR) is needed in both civil and military usage, so more accurate motion compensation should be applied to the radar returns to reduce image degradation caused by spurious motion of antenna phase center (APC). As Global Positioning System (GPS) became practical usage, the SARMCS using the information of GPS has received increasing attention. The main aim using GPS/INS integrated system in navigation is to improve long-term accuracy. For SAR motion compensation, both long-term accuracy and short-term accuracy are important. DGPS technique can dramatically improve the precision of GPS. DGPS/SINS integrated system for SAR motion compensation is studied in this paper. First, the principle of DGPS/SINS pseudo-range and pseudo-range rate integrated system is described, then the state equations and precise measurement model concerning position error is given, and finally the algorithm of integrated system Kalman filter and error propagation of INS are newly described. Simulation results show that even if middle accuracy INS instrument is used, the long-term position error of integrated system is about 1m and relative change of position error in the time interval of GPS measurement is smaller than 1 centimeter. This conclusion is valuable in the practical design of motion compensation systems for airborne SAR.

  6. Multivariate respiratory motion prediction

    Science.gov (United States)

    Dürichen, R.; Wissel, T.; Ernst, F.; Schlaefer, A.; Schweikard, A.

    2014-10-01

    In extracranial robotic radiotherapy, tumour motion is compensated by tracking external and internal surrogates. To compensate system specific time delays, time series prediction of the external optical surrogates is used. We investigate whether the prediction accuracy can be increased by expanding the current clinical setup by an accelerometer, a strain belt and a flow sensor. Four previously published prediction algorithms are adapted to multivariate inputs—normalized least mean squares (nLMS), wavelet-based least mean squares (wLMS), support vector regression (SVR) and relevance vector machines (RVM)—and evaluated for three different prediction horizons. The measurement involves 18 subjects and consists of two phases, focusing on long term trends (M1) and breathing artefacts (M2). To select the most relevant and least redundant sensors, a sequential forward selection (SFS) method is proposed. Using a multivariate setting, the results show that the clinically used nLMS algorithm is susceptible to large outliers. In the case of irregular breathing (M2), the mean root mean square error (RMSE) of a univariate nLMS algorithm is 0.66 mm and can be decreased to 0.46 mm by a multivariate RVM model (best algorithm on average). To investigate the full potential of this approach, the optimal sensor combination was also estimated on the complete test set. The results indicate that a further decrease in RMSE is possible for RVM (to 0.42 mm). This motivates further research about sensor selection methods. Besides the optical surrogates, the sensors most frequently selected by the algorithms are the accelerometer and the strain belt. These sensors could be easily integrated in the current clinical setup and would allow a more precise motion compensation.

  7. Respiratory impact on motion sickness induced by linear motion

    NARCIS (Netherlands)

    Mert, A.; Klöpping-Ketelaars, I.; Bles, W.

    2009-01-01

    Motion sickness incidence (MSI) for vertical sinusoidal motion reaches a maximum at 0.167 Hz. Normal breathing frequency is close to this frequency. There is some evidence for synchronization of breathing with this stimulus frequency. If this enforced breathing takes place over a larger frequency ra

  8. Motion-aware temporal regularization for improved 4D cone-beam computed tomography

    Science.gov (United States)

    Mory, Cyril; Janssens, Guillaume; Rit, Simon

    2016-09-01

    Four-dimensional cone-beam computed tomography (4D-CBCT) of the free-breathing thorax is a valuable tool in image-guided radiation therapy of the thorax and the upper abdomen. It allows the determination of the position of a tumor throughout the breathing cycle, while only its mean position can be extracted from three-dimensional CBCT. The classical approaches are not fully satisfactory: respiration-correlated methods allow one to accurately locate high-contrast structures in any frame, but contain strong streak artifacts unless the acquisition is significantly slowed down. Motion-compensated methods can yield streak-free, but static, reconstructions. This work proposes a 4D-CBCT method that can be seen as a trade-off between respiration-correlated and motion-compensated reconstruction. It builds upon the existing reconstruction using spatial and temporal regularization (ROOSTER) and is called motion-aware ROOSTER (MA-ROOSTER). It performs temporal regularization along curved trajectories, following the motion estimated on a prior 4D CT scan. MA-ROOSTER does not involve motion-compensated forward and back projections: the input motion is used only during temporal regularization. MA-ROOSTER is compared to ROOSTER, motion-compensated Feldkamp-Davis-Kress (MC-FDK), and two respiration-correlated methods, on CBCT acquisitions of one physical phantom and two patients. It yields streak-free reconstructions, visually similar to MC-FDK, and robust information on tumor location throughout the breathing cycle. MA-ROOSTER also allows a variation of the lung tissue density during the breathing cycle, similar to that of planning CT, which is required for quantitative post-processing.

  9. Four-dimensional computed tomography based assessment and analysis of lung tumor motion during free-breathing respiration%基于四维CT影像肺内肿瘤运动度的测量与分析

    Institute of Scientific and Technical Information of China (English)

    王彦; 包勇; 张黎; 樊卫; 邓小武; 陈明

    2010-01-01

    目的 以四维CT(4DCT)影像量化肺内肿瘤因呼吸导致的运动,分析其影响因素,寻找运动度大的肿瘤特征.方法 在平静呼吸状态下接受4DCT扫描的肺内肿瘤患者43例,肺内可测量病灶44个.由同一位医生在4DCT各时相数据集卜勾画肿瘤GTV,分别测量GTV中心点在上下、左右、前后三维方向上的运动幅度.对与运动度可能相关的临床变量和解剖学因素进行统计学分析.以任意方向运动幅度>5 mm作为分界点,分析此类肿瘤特征.结果 肺内肿瘤运动度与T分期、GTV体积、肺内所处上下位置、与固定组织(如胸壁、纵隔、脊柱)粘连程度相关.10例患者肺内肿瘤的运动幅度>5 mm,均位于胸腔下部及后部,上下方向运动度最大,最大值为14.4 mm.95%肺内肿瘤的运动幅度在上下方向<11.8 mm,前后方向<4.6 mm,左右方向<2.7 mm.结论 呼吸导致的肺内肿瘤运动度受肿瘤位置、体积、T分期及粘连程度等因素影响.下叶肺内孤立肿瘤的运动度最大,主要发生在上下方向,上叶后段肿瘤的运动度次之.%Objective To quantify the amplitudes of lung tumor motion during free-breathing using four dimensional computed tomography (4DCT), and seek the characteristics of tumors with large motion. Methods Respiratory-induced tumor motion was analyzed for 44 tumors from 43 patients. All patients un-derwent 4DCT during free-breathing before treatment. Gross tumor volumes (GTV) on ten respiratory phases were contoured by the same doctor. The eentroids of GTVs were autoplaeed with treatment software (ADAC Pinnacle 7.4f), then the amplitudes of tumor motion were assessed. The various clinical and anatomic fac-tors associated with GTV motion were analyzed. The characteristics of tumors with motion greater than 5 mm in any direction were explored. Results The tumor motion was found to be associated with T stage, GTV size, the superior-inferior (SI) tumor location in the lung, and the attachment

  10. Compensation of errors due to incident beam drift in a 3 DOF measurement system for linear guide motion.

    Science.gov (United States)

    Hu, Pengcheng; Mao, Shuai; Tan, Jiu-Bin

    2015-11-01

    A measurement system with three degrees of freedom (3 DOF) that compensates for errors caused by incident beam drift is proposed. The system's measurement model (i.e. its mathematical foundation) is analyzed, and a measurement module (i.e. the designed orientation measurement unit) is developed and adopted to measure simultaneously straightness errors and the incident beam direction; thus, the errors due to incident beam drift can be compensated. The experimental results show that the proposed system has a deviation of 1 μm in the range of 200 mm for distance measurements, and a deviation of 1.3 μm in the range of 2 mm for straightness error measurements.

  11. A motion-compensated image filter for low-dose fluoroscopy in a real-time tumor-tracking radiotherapy system.

    Science.gov (United States)

    Miyamoto, Naoki; Ishikawa, Masayori; Sutherland, Kenneth; Suzuki, Ryusuke; Matsuura, Taeko; Toramatsu, Chie; Takao, Seishin; Nihongi, Hideaki; Shimizu, Shinichi; Umegaki, Kikuo; Shirato, Hiroki

    2015-01-01

    In the real-time tumor-tracking radiotherapy system, a surrogate fiducial marker inserted in or near the tumor is detected by fluoroscopy to realize respiratory-gated radiotherapy. The imaging dose caused by fluoroscopy should be minimized. In this work, an image processing technique is proposed for tracing a moving marker in low-dose imaging. The proposed tracking technique is a combination of a motion-compensated recursive filter and template pattern matching. The proposed image filter can reduce motion artifacts resulting from the recursive process based on the determination of the region of interest for the next frame according to the current marker position in the fluoroscopic images. The effectiveness of the proposed technique and the expected clinical benefit were examined by phantom experimental studies with actual tumor trajectories generated from clinical patient data. It was demonstrated that the marker motion could be traced in low-dose imaging by applying the proposed algorithm with acceptable registration error and high pattern recognition score in all trajectories, although some trajectories were not able to be tracked with the conventional spatial filters or without image filters. The positional accuracy is expected to be kept within ±2 mm. The total computation time required to determine the marker position is a few milliseconds. The proposed image processing technique is applicable for imaging dose reduction.

  12. Respiratory motion compensation for simultaneous PET/MR based on a 3D-2D registration of strongly undersampled radial MR data: a simulation study

    Science.gov (United States)

    Rank, Christopher M.; Heußer, Thorsten; Flach, Barbara; Brehm, Marcus; Kachelrieß, Marc

    2015-03-01

    We propose a new method for PET/MR respiratory motion compensation, which is based on a 3D-2D registration of strongly undersampled MR data and a) runs in parallel with the PET acquisition, b) can be interlaced with clinical MR sequences, and c) requires less than one minute of the total MR acquisition time per bed position. In our simulation study, we applied a 3D encoded radial stack-of-stars sampling scheme with 160 radial spokes per slice and an acquisition time of 38 s. Gated 4D MR images were reconstructed using a 4D iterative reconstruction algorithm. Based on these images, motion vector fields were estimated using our newly-developed 3D-2D registration framework. A 4D PET volume of a patient with eight hot lesions in the lungs and upper abdomen was simulated and MoCo 4D PET images were reconstructed based on the motion vector fields derived from MR. For evaluation, average SUVmean values of the artificial lesions were determined for a 3D, a gated 4D, a MoCo 4D and a reference (with ten-fold measurement time) gated 4D reconstruction. Compared to the reference, 3D reconstructions yielded an underestimation of SUVmean values due to motion blurring. In contrast, gated 4D reconstructions showed the highest variation of SUVmean due to low statistics. MoCo 4D reconstructions were only slightly affected by these two sources of uncertainty resulting in a significant visual and quantitative improvement in terms of SUVmean values. Whereas temporal resolution was comparable to the gated 4D images, signal-to-noise ratio and contrast-to-noise ratio were close to the 3D reconstructions.

  13. Motion-compensated hand-held common-path Fourier-domain optical coherence tomography probe for image-guided intervention

    Science.gov (United States)

    Huang, Yong; Song, Cheol; Liu, Xuan; Kang, Jin U.

    2013-03-01

    A motion-compensated hand-held common-path Fourier-domain optical coherence tomography imaging probe has been developed for image guided intervention during microsurgery. A hand-held prototype instrument was designed and fabricated by integrating an imaging fiber probe inside a stainless steel needle which is attached to the ceramic shaft of a piezoelectric motor housed in an aluminum handle. The fiber probe obtains A-scan images. The distance information was extracted from the A-scans to track the sample surface distance and a fixed distance was maintained by a feedback motor control which effectively compensated hand tremor and target movements in the axial direction. Graphical user interface, real-time data processing, and visualization based on a CPU-GPU hybrid programming architecture were developed and used in the implantation of this system. To validate the system, free-hand optical coherence tomography images using various samples were obtained. The system can be easily integrated into microsurgical tools and robotics for a wide range of clinical applications. Such tools could offer physicians the freedom to easily image sites of interest with reduced risk and higher image quality.

  14. The NACA High-Speed Motion-Picture Camera Optical Compensation at 40,000 Photographs Per Second

    Science.gov (United States)

    Miller, Cearcy D

    1946-01-01

    The principle of operation of the NACA high-speed camera is completely explained. This camera, operating at the rate of 40,000 photographs per second, took the photographs presented in numerous NACA reports concerning combustion, preignition, and knock in the spark-ignition engine. Many design details are presented and discussed, details of an entirely conventional nature are omitted. The inherent aberrations of the camera are discussed and partly evaluated. The focal-plane-shutter effect of the camera is explained. Photographs of the camera are presented. Some high-speed motion pictures of familiar objects -- photoflash bulb, firecrackers, camera shutter -- are reproduced as an illustration of the quality of the photographs taken by the camera.

  15. Assessing and accounting for the impact of respiratory motion on FDG uptake and viable volume for liver lesions in free-breathing PET using respiration-suspended PET images as reference

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guang, E-mail: lig2@mskcc.org; Schmidtlein, C. Ross; Humm, John L. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Burger, Irene A. [Department of Radiology, University Hospital of Zurich, CH-8091 Zurich (Switzerland); Ridge, Carole A.; Solomon, Stephen B. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065 (United States)

    2014-09-15

    Purpose: To assess and account for the impact of respiratory motion on the variability of activity and volume determination of liver tumor in positron emission tomography (PET) through a comparison between free-breathing (FB) and respiration-suspended (RS) PET images. Methods: As part of a PET/computed tomography (CT) guided percutaneous liver ablation procedure performed on a PET/CT scanner, a patient's breathing is suspended on a ventilator, allowing the acquisition of a near-motionless PET and CT reference images of the liver. In this study, baseline RS and FB PET/CT images of 20 patients undergoing thermal ablation were acquired. The RS PET provides near-motionless reference in a human study, and thereby allows a quantitative evaluation of the effect of respiratory motion on PET images obtained under FB conditions. Two methods were applied to calculate tumor activity and volume: (1) threshold-based segmentation (TBS), estimating the total lesion glycolysis (TLG) and the segmented volume and (2) histogram-based estimation (HBE), yielding the background-subtracted lesion (BSL) activity and associated volume. The TBS method employs 50% of the maximum standardized uptake value (SUV{sub max}) as the threshold for tumors with SUV{sub max} ≥ 2× SUV{sub liver-bkg}, and tumor activity above this threshold yields TLG{sub 50%}. The HBE method determines local PET background based on a Gaussian fit of the low SUV peak in a SUV-volume histogram, which is generated within a user-defined and optimized volume of interest containing both local background and lesion uptakes. Voxels with PET intensity above the fitted background were considered to have originated from the tumor and used to calculate the BSL activity and its associated lesion volume. Results: Respiratory motion caused SUV{sub max} to decrease from RS to FB by −15% ± 11% (p = 0.01). Using TBS method, there was also a decrease in SUV{sub mean} (−18% ± 9%, p = 0.01), but an increase in TLG{sub 50%} (18

  16. Breathing In

    Science.gov (United States)

    Mahoney, Daniel P.

    2008-01-01

    Healthful indoor air quality (IAQ) in education facilities can improve the learning environment for students, enhance teacher job satisfaction, and reduce staff complaints. A proactive indoor air quality program helps identify and eliminate conditions that could lead to IAQ complaints, building-related illnesses, and workers' compensation claims.…

  17. 一种激光断面仪运动补偿用IMU/GPS/OD系统%IMU/GPS/OD integrated system for motion compensation of laser profiler

    Institute of Scientific and Technical Information of China (English)

    刘百奇; 康泰钟; 李建利

    2012-01-01

    针对车载激光路面断面仪性能受检测车垂直振动及姿态变化影响的问题,设计并实现了一种车载激光断面仪运动补偿用IMU/GPS/OD组合测量系统,采用低成本IMU结合捷联解算算法计算检测车的三维位置、速度和姿态,通过GPS和里程仪结合最优滤波技术抑制低成本IMU在捷联解算过程中形成的累积误差,并提出了一种基于IMU/GPS/OD组合测量系统的检测车垂直振动位移的计算方法.最后进行了室内实验验证,实验结果表明,该IMU/GPS/OD组合测量系统应用于车载激光断面仪是可行的.%Laser profiler is widely used to measure road pavements; its accuracy depends on the compensation of the profiler vertical vibration and attitude change on tires and suspension. An IMU/GPS/OD integrated system for motion compensation of laser profiler is designed and realized in this paper. In this system, a low cost IMU combined with strapdown inertial algorithm is used to measure the position and attitude of the vehicle, which are corrected with GPS and OD through optimal filter; and a special algorithm based on IMU/GPS/OD is proposed to calculate the vertical vibration distance of the vehicle. Room experiment was carried out to verify the proposed method, and experiment results indicate that the proposed IMU/GPS/OD integrated system can satisfy the requirements of laser profiler.

  18. Non-negative constraint for image-based breathing gating in ultrasound hepatic perfusion data

    Science.gov (United States)

    Wu, Kaizhi; Ding, Mingyue; Chen, Xi; Deng, Wenjie; Zhang, Zhijun

    2015-12-01

    Images acquired during free breathing using contrast enhanced ultrasound hepatic perfusion imaging exhibits a periodic motion pattern. It needs to be compensated for if a further accurate quantification of the hepatic perfusion analysis is to be executed. To reduce the impact of respiratory motion, image-based breathing gating algorithm was used to compensate the respiratory motion in contrast enhanced ultrasound. The algorithm contains three steps of which respiratory kinetics extracted, image subsequences determined and image subsequences registered. The basic performance of the algorithm was to extract the respiratory kinetics of the ultrasound hepatic perfusion image sequences accurately. In this paper, we treated the kinetics extracted model as a non-negative matrix factorization (NMF) problem. We extracted the respiratory kinetics of the ultrasound hepatic perfusion image sequences by non-negative matrix factorization (NMF). The technique involves using the NMF objective function to accurately extract respiratory kinetics. It was tested on simulative phantom and used to analyze 6 liver CEUS hepatic perfusion image sequences. The experimental results show the effectiveness of our proposed method in quantitative and qualitative.

  19. Breath alcohol test

    Science.gov (United States)

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  20. Rapid shallow breathing

    Science.gov (United States)

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking Chronic obstructive ...

  1. Breathing difficulties - first aid

    Science.gov (United States)

    Difficulty breathing - first aid; Dyspnea - first aid; Shortness of breath - first aid ... Breathing difficulty is almost always a medical emergency. An exception is feeling slightly winded from normal activity, ...

  2. Automated analysis of non-mass-enhancing lesions in breast MRI based on morphological, kinetic, and spatio-temporal moments and joint segmentation-motion compensation technique

    Science.gov (United States)

    Hoffmann, Sebastian; Shutler, Jamie D.; Lobbes, Marc; Burgeth, Bernhard; Meyer-Bäse, Anke

    2013-12-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) represents an established method for the detection and diagnosis of breast lesions. While mass-like enhancing lesions can be easily categorized according to the Breast Imaging Reporting and Data System (BI-RADS) MRI lexicon, a majority of diagnostically challenging lesions, the so called non-mass-like enhancing lesions, remain both qualitatively as well as quantitatively difficult to analyze. Thus, the evaluation of kinetic and/or morphological characteristics of non-masses represents a challenging task for an automated analysis and is of crucial importance for advancing current computer-aided diagnosis (CAD) systems. Compared to the well-characterized mass-enhancing lesions, non-masses have no well-defined and blurred tumor borders and a kinetic behavior that is not easily generalizable and thus discriminative for malignant and benign non-masses. To overcome these difficulties and pave the way for novel CAD systems for non-masses, we will evaluate several kinetic and morphological descriptors separately and a novel technique, the Zernike velocity moments, to capture the joint spatio-temporal behavior of these lesions, and additionally consider the impact of non-rigid motion compensation on a correct diagnosis.

  3. Coil concepts for rapid and motion-compensated MR-Imaging of small animals; Spulenkonzepte zur schnellen und bewegungskompensierten MR-Bildgebung von Kleintieren

    Energy Technology Data Exchange (ETDEWEB)

    Korn, Matthias

    2009-05-06

    In this work radiofrequency-coils for the imaging of small animals in clinical whole-body MRI-systems were developed. Therefore in a first step single-channel solenoids were designed and characterized. The solenoids had two and three windings respectively, which were implemented as double wires to increase the homogeneity of the receive profile. These coils allow the acquisition of whole-body images of mice with high signal-to-noise ratio and homogeneity over a distance of at least 6.3 cm. Since many imaging experiments require rapid image acquisition, in the next step a novel coil concept was developed, which, due to its geometry, enables parallel imaging in arbitrary directions. A prototype was assembled and tested on phantom and small-animal experiments. With an accelerating factor of R=2, the difference of the SNR in all directions from the theoretical maximum, was less than 1%. In order to compensate physiological motion by the self-gating technique, in this work a coil is presented for the first time, which selectively amplifies the self-gating signal, while - due to a optical detuning technique - preserving the homogeneous illumination of the image. In vivo experiments on a small animal show an amplification of the self-gating signal by at least 40%. (orig.)

  4. Fast-starting for a breath: Air breathing in Hoplosternum littorale

    DEFF Research Database (Denmark)

    Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.

    by the fall of a prey item on the water surface, and in tapping motions of goldfish, a behaviour that was interpreted to be food-related. Little is known about C-starts being used outside the context of escaping or feeding. Here, we test the hypothesis that air-breathing fish may use C-starts when gulping air...... at the surface. Air breathing is a common behaviour in many fish species when exposed to hypoxia, although certain species perform air-breathing in normoxia to fill their swim bladders for buoyancy control and/or sound transduction. Hoplosternum littorale is an air-breathing freshwater catfish found in South......, with those of mechanically-triggered C-start escape responses. Our results show that these two behaviours overlap considerably in their kinematics (turning rates and distance covered), suggesting that air breathing in this species is performed using escapelike C-start motions. This demonstrates that C...

  5. What Causes Bad Breath?

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness What Causes Bad Breath? KidsHealth > For Teens > What Causes Bad Breath? A A A en español ¿Qué es lo que provoca el mal aliento? Bad breath, or halitosis , can be a major problem, ...

  6. 颈椎单节段融合术后相邻各节段运动补偿的规律研究%Research of the motion compensation after single segmental cervical spine fusion surgery

    Institute of Scientific and Technical Information of China (English)

    张睿; 周文钰; 顾洪生; 刘伟强; 白波; 王大平

    2014-01-01

    目的 了解颈椎单节段融合术后上、下相邻及非相邻节段的运动补偿规律.方法 通过三维运动采集系统,捕捉到6具新鲜人尸体颈椎单节段融合术前后C2~T1各节段的运动角度数据.结果 经过归一化处理后,分析得出颈椎单节段融合术后各节段的运动变化规律,发现融合术后其他各节段运动幅度均有不同程度的增加,尤其是下相邻节段,差异有统计学意义(P<0.05).结论 颈椎单节段融合术后邻近节段的代偿性运动幅度增加是导致其退变的重要原因.%Objective To know the motion compensation regulation of each segments after single segmental cervical spine fusion surgery.Methods With the help of 3D motion information collecting system,the movement angle of each segment was recorded before and after single segmental cervical spine fusion surgery.Results All the statistics are dealed with normalization,we got the statistics of the motion compensation regulation of each segments after single segmental cervical spine fusion surgery,range of motion of each segment increased diversely,especially the lower adjacent segment,with statistical significance(P<0.05).Conclusion Compensatory enhancement of the range of motion of adjacent segments is one of the important reasons lead to the degeneration.

  7. Leveraging respiratory organ motion for non-invasive tumor treatment devices: a feasibility study

    Science.gov (United States)

    Möri, Nadia; Jud, Christoph; Salomir, Rares; Cattin, Philippe C.

    2016-06-01

    In noninvasive abdominal tumor treatment, research has focused on minimizing organ motion either by gating, breath holding or tracking of the target. The paradigm shift proposed in this study takes advantage of the respiratory organ motion to passively scan the tumor. In the proposed self-scanning method, the focal point of the HIFU device is held fixed for a given time, while it passively scans the tumor due to breathing motion. The aim of this paper is to present a treatment planning method for such a system and show by simulation its feasibility. The presented planning method minimizes treatment time and ensures complete tumor ablation under free-breathing. We simulated our method on realistic motion patterns from a patient specific statistical respiratory model. With our method, we achieved a shorter treatment time than with the gold-standard motion-compensation approach. The main advantage of the proposed method is that electrically steering of the focal spot is no longer needed. As a consequence, it is much easier to find an optimal solution for both avoiding near field heating and covering the whole tumor. However, the reduced complexity on the beam forming comes at the price of an increased complexity on the planning side as well as a reduced efficiency in the energy distribution. Although we simulate the approach on HIFU, the idea of self-scanning passes over to other tumor treatment modalities such as proton therapy or classical radiation therapy.

  8. 前馈PID控制器在钻柱运动补偿系统中的应用%Application of feedforward PID control in deep-sea drill string motion compensation system

    Institute of Scientific and Technical Information of China (English)

    张文凡; 廖辉

    2012-01-01

    Aiming at the problem that load of drill string motion compensation system is very heavy in deep-sea, which will take a long response time of system, and the process of compensation movement occurred delaying and oscillating, the feedward PID controller of drill string motion compensation system was put forward, on the basis of the forecast output of the trend of load, a feed forward compensation control method was used to reduce the effects of the changement of the load, improve the respons time of system. Meanwhile, a PID feed back control method was used to reduce the errors which caused by others reason, improve the control accuration of the system. The research results show that this method has some guidance and practical value to the design of controller of high inertia loads of motion compensation device in deep-sea.%针对“深海钻柱运动补偿系统负载大时,钻柱运动补偿系统响应的时间长,使得补偿系统在控制过程中出现滞后、反馈补偿出现振荡”等问题,设计了钻柱运动补偿系统中的前馈PID控制器.根据对负载变化趋势的预测结果,采取前馈补偿的方法来减小补偿系统负载变化对钻压产生的影响,提高了系统的响应速度;同时,引入PID反馈控制消除补偿系统在前馈控制过程中产生的误差,提高了系统跟踪补偿的精度.研究结果表明,该方法对于大惯性负载的运动补偿装置控制器的设计具有一定的借鉴意义和实用价值.

  9. Multivariate regression approaches for surrogate-based diffeomorphic estimation of respiratory motion in radiation therapy

    Science.gov (United States)

    Wilms, M.; Werner, R.; Ehrhardt, J.; Schmidt-Richberg, A.; Schlemmer, H.-P.; Handels, H.

    2014-03-01

    Breathing-induced location uncertainties of internal structures are still a relevant issue in the radiation therapy of thoracic and abdominal tumours. Motion compensation approaches like gating or tumour tracking are usually driven by low-dimensional breathing signals, which are acquired in real-time during the treatment. These signals are only surrogates of the internal motion of target structures and organs at risk, and, consequently, appropriate models are needed to establish correspondence between the acquired signals and the sought internal motion patterns. In this work, we present a diffeomorphic framework for correspondence modelling based on the Log-Euclidean framework and multivariate regression. Within the framework, we systematically compare standard and subspace regression approaches (principal component regression, partial least squares, canonical correlation analysis) for different types of common breathing signals (1D: spirometry, abdominal belt, diaphragm tracking; multi-dimensional: skin surface tracking). Experiments are based on 4D CT and 4D MRI data sets and cover intra- and inter-cycle as well as intra- and inter-session motion variations. Only small differences in internal motion estimation accuracy are observed between the 1D surrogates. Increasing the surrogate dimensionality, however, improved the accuracy significantly; this is shown for both 2D signals, which consist of a common 1D signal and its time derivative, and high-dimensional signals containing the motion of many skin surface points. Eventually, comparing the standard and subspace regression variants when applied to the high-dimensional breathing signals, only small differences in terms of motion estimation accuracy are found.

  10. 吸气式高超声速飞行器纵向运动反演控制器设计%Design of Backstepping Controller for Longitudinal Motion of an Air-Breathing Hypersonic Vehicle

    Institute of Scientific and Technical Information of China (English)

    时建明; 王洁; 王琨; 邵雷

    2013-01-01

    针对气动/推进/结构耦合的吸气式高超声速飞行器纵向平面飞行控制问题,提出了基于反演的鲁棒控制器设计方法.利用曲线拟合模型将控制系统表示为反馈形式,采用反演方法设计虚拟和实际控制器,并引入鲁棒微分器估计虚拟控制量的导数,解决了虚拟控制量求导运算复杂的问题.为增强控制器应对不确定项的鲁棒性,设计了超扭曲滑模干扰观测器,实现了对系统模型不确定项的估计和补偿.对吸气式高超声速飞行器一体化原理模型的速度和高度指令跟踪仿真表明,该控制器对拟合误差和外加干扰等系统不确定项具有鲁棒性,系统状态量能够在指令跟踪过程中趋于平衡状态,从而验证了所提方案的有效性.%A robust controller based on backstepping design procedure is proposed for an air-breathing hypersonic vehicle with aerodynamic, propulsion and structural couplings. Expressing the control system as strict feedback form via the curve-fitted model, virtual and actual controllers are constructed for the velocity and altitude subsystems. To omit analytic calculation of the virtual control law derivatives, which is very difficult to evaluate in the traditional backstepping control, robust differentiators are introduced. Super-twisting sliding mode disturbance observers are designed to compensate uncertainties in the system dynamics. Trajectory tracking simulation performed on the first principle model of the vehicle's longitudinal dynamics shows that the designed controllers are robust to model fitting errors and outside disturbances, and the system states reach trimmed condition asymptotically.

  11. Application of Smoothing Algorithm in SINS/GPS Integrated System for Airborne SAR Real-time Motion Compensation%SINS/GPS组合平滑估计在机载SAR实时运动补偿中的应用

    Institute of Scientific and Technical Information of China (English)

    宫晓琳; 秦婷婷

    2014-01-01

    针对机载合成孔径雷达(SAR)实时成像运动补偿对高精度运动参数的需求,该文提出一种基于捷联惯性导航系统/全球定位系统(SINS/GPS)组合 Rauch-Tung-Striebel (R-T-S)平滑估计的实时运动补偿方案。该方案在实时卡尔曼滤波的基础上,对SAR每一次合成孔径时间段内的滤波结果再进行后向平滑递推,进一步修正滤波结果。仿真试验和飞行成像数据处理结果表明,该方案可以有效提高合成孔径时间段内运动参数的估计精度。%Considering the urgent need of high precision motion parameter for SAR motion compensation in real-time, a motion compensation scheme using the Strapdown Inertial Navigation System/Global Positioning System (SINS/GPS) integrated system based on Rauch-Tung-Striebel (R-T-S) smoothing method is proposed. In this scheme, the Kalman filtering is done firstly and based on this, the backward smoothing iteration is performed for correcting the filter’s results during each synthetic aperture moment. The results of numerical simulation and flight-test data processing show that the scheme can effectively improve the precision of estimates of the motion parameter in the synthetic aperture moment.

  12. Deserved Compensation

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ China's National People's Congress (NPC), the top legislature, recently adopted amendments to the Law on State Compensation, granting citizens greater power to obtain compensation when their rights are violated by the state.

  13. Running and Breathing in Mammals

    Science.gov (United States)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  14. Research on the technology of projectile synchronized photography based on motion compensation for rotating mirror%基于转镜运动补偿的弹丸同步摄影技术研究

    Institute of Scientific and Technical Information of China (English)

    蔡荣立; 陈瑞; 卢岩涛

    2012-01-01

    弹丸的空间飞行姿态是武器性能的一项重要指标.为了使数字摄影相机实现对高速运动弹丸运行轨迹的成像,设计了一种基于转镜运动补偿的弹丸同步摄影装置.在高速数字相机前设置一面反射转镜,当弹丸进入跟踪视场时,利用转镜的旋转补偿弹丸的空间运动,使得由转镜反射到相机像面的弹丸图像偏移在许可范围内,实现同步摄影过程.实验证明该方法能够满足常规弹丸同步摄影的需求.%The flight attitude of projectile in space is a very important performance evaluation indicator of weapons in target range test. In order to obtain images of fast-moving projectiles with a digtial camera, a projectile synchronous camera system is designed based on rotary mirror moving compensation. A reflection rotary mirror is set in front of a high speed digtal camera, and when the projectile passes the field, the camera image obtained from the reflection rotary mirror is appropriated by using rotary mirror to compensate the projectile moving in space controlled by a servo system, and the synchronized photographic process is finally achieved. With this method as the theoretical basis to establish mirror equation of motion, the tracking data discretization mathematical model is obtained through the analysis of the imaging error. The method provides theoretical basis for the system of projectile synchronized photography based on motion compensation for rotating mirror.

  15. From breathing to respiration.

    Science.gov (United States)

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  16. Breathing simulator of workers for respirator performance test.

    Science.gov (United States)

    Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

    2015-01-01

    Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

  17. Intra- and interfraction breathing variations during curative radiotherapy for lung cancer

    DEFF Research Database (Denmark)

    Juhler Nøttrup, Trine; Korreman, Stine Sofia; Pedersen, Anders Navrsted;

    2007-01-01

    BACKGROUND AND PURPOSE: This study aimed at quantifying the breathing variations among lung cancer patients over full courses of fractionated radiotherapy. The intention was to relate these variations to the margins assigned to lung tumours, to account for respiratory motion, in fractionated...... radiotherapy. MATERIALS AND METHODS: Eleven lung cancer patients were included in the study. The patients' chest wall motions were monitored as a surrogate measure for breathing motion during each fraction of radiotherapy by use of an external optical marker. The exhale level variations were evaluated...... with respect to exhale points and fraction-baseline, defined for intra- and interfraction variations respectively. The breathing amplitude was evaluated as breathing cycle amplitudes and fraction-max-amplitudes defined for intra- and interfraction breathing, respectively. RESULTS: The breathing variations over...

  18. Evaluation of breathing patterns for respiratory-gated radiation therapy using the respiration regularity index

    Science.gov (United States)

    Cheong, Kwang-Ho; Lee, MeYeon; Kang, Sei-Kwon; Yoon, Jai-Woong; Park, SoAh; Hwang, Taejin; Kim, Haeyoung; Kim, KyoungJu; Han, Tae Jin; Bae, Hoonsik

    2015-01-01

    Despite the considerable importance of accurately estimating the respiration regularity of a patient in motion compensation treatment, not to mention the necessity of maintaining that regularity through the following sessions, an effective and simply applicable method by which those goals can be accomplished has rarely been reported. The authors herein propose a simple respiration regularity index based on parameters derived from a correspondingly simplified respiration model. In order to simplify a patient's breathing pattern while preserving the data's intrinsic properties, we defined a respiration model as a cos4( ω( t) · t) wave form with a baseline drift. According to this respiration formula, breathing-pattern fluctuation could be explained using four factors: the sample standard deviation of respiration period ( s f ), the sample standard deviation of amplitude ( s a ) and the results of a simple regression of the baseline drift (slope as β, and standard deviation of residuals as σ r ) of a respiration signal. The overall irregularity ( δ) was defined as , where is a variable newly-derived by using principal component analysis (PCA) for the four fluctuation parameters and has two principal components ( ω 1, ω 2). The proposed respiration regularity index was defined as ρ = ln(1 + (1/ δ))/2, a higher ρ indicating a more regular breathing pattern. We investigated its clinical relevance by comparing it with other known parameters. Subsequently, we applied it to 110 respiration signals acquired from five liver and five lung cancer patients by using real-time position management (RPM; Varian Medical Systems, Palo Alto, CA). Correlations between the regularity of the first session and the remaining fractions were investigated using Pearson's correlation coefficient. Additionally, the respiration regularity was compared between the liver and lung cancer patient groups. The respiration regularity was determined based on ρ; patients with ρ 0.7 was

  19. Take a Deep Breath

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Everyone involved in Beijing’s Olympic Games held their breath last week, not because of the city’s famously polluted air , but in anticipation of the results of an experiment that could help to clean it up.

  20. Minimizing Shortness of Breath

    Science.gov (United States)

    ... is also placed on proper use of the abdominal muscles to better control episodes of shortness of breath, ... Treatment & Programs Health Insights Doctors & Departments Research & Science Education & Training Make a Donation Make an Appointment Contact ...

  1. Breathing difficulty - lying down

    Science.gov (United States)

    ... short of breath. Considerations This is a common complaint in people with some types of heart or ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  2. Creative compensation

    Energy Technology Data Exchange (ETDEWEB)

    Coll, D

    1994-09-19

    A discussion is presented of executive compensation in Canada's petroleum industry. Mandatory disclosure of executive compensation and benefits is regulated by the Ontario Securities Commission. Examination of the compensation packages of 80 oilpatch CEOs shows a clear difference in philosophy between large and small companies. Larger companies pay larger salaries, offer pension plans, and reward long-term loyalty. Within smaller companies, compensation tends to be linked with stock performance. Trends in compensation are to lower base salaries with more variables such as bonuses, cash incentives and gain-sharing programs. Increasing shareholder scrutiny is prompting more stringent guidelines on stock option plans. Some companies place performance conditions on stock vesting. Another option is to grant premium priced options to executives, to increase the gains required for the executive to post a profit. Other comapanies are granting stock options to their field personnel, or are granting stock to all employees. Directors are playing an increasing role in executive compensation. 4 tabs.

  3. Adaptation requirements due to anatomical changes in free-breathing and deep-inspiration breath-hold for standard and dose-escalated radiotherapy of lung cancer patients

    DEFF Research Database (Denmark)

    Sibolt, Patrik; Ottosson, Wiviann; Sjöström, David;

    2015-01-01

    Background. Radiotherapy of lung cancer patients is subject to uncertainties related to heterogeneities, anatomical changes and breathing motion. Use of deep-inspiration breath-hold (DIBH) can reduce the treated volume, potentially enabling dose-escalated (DE) treatments. This study was designed...

  4. Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

    Science.gov (United States)

    Bowen, S. R.; Nyflot, M. J.; Herrmann, C.; Groh, C. M.; Meyer, J.; Wollenweber, S. D.; Stearns, C. W.; Kinahan, P. E.; Sandison, G. A.

    2015-05-01

    Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT

  5. Fast-starting for a breath: Air breathing in Hoplosternum littorale

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2012-01-01

    overlap considerably in their kinematics (turning rates and distance covered), suggesting that air breathing in this species is performed using escapelike C-start motions. This demonstrates that C-starts in fish do not need external stimulation and can be spontaneous behaviours used outside the context...... to be food-related. Little is known about C-starts being used outside the context of escaping or feeding. Here, we test the hypothesis that air-breathing fish may use C-starts when gulping air at the surface. Air breathing is a common behaviour in many fish species when exposed to hypoxia, although certain...... of Denmark, Denmark), John F. Steffensen (University of Copenhagen, Denmark), Morten Svendsen (Technical University of Denmark, Denmark) and Augusto Abe (Unlversidade Estadual Paulista, Brazil) Fast starts are brief accelerations commonly observed in fish within the context of predator-prey interactions...

  6. Types of diaphragmatic motion during hepatic angiography.

    Science.gov (United States)

    Katsuda, T; Kuroda, C; Fujita, M

    1997-01-01

    To determine the types and causes of diaphragmatic motion during hepatic angiography, the authors used transarterial cut-film portography (TAP) to study movement of the diaphragm during breath-holding. Thirty-three TAP sequences were studied, and the patients' diaphragmatic motions were classified into four categories according to the distance their diaphragms moved. Results showed that the diaphragm was stationary in 33% of the TAP studies, while perpetual motion occurred in 15% of the studies, early-phase motion occurred in 12% and late-phase motion occurred in 40%. Ten sequences showed diaphragmatic motion of more than 10 mm, with eight sequences showing caudal motion and two showing cranial motion. This article discusses the cause of diaphragmatic motion during breath-holding for hepatic angiography and presents suggestions to reduce motion artifacts during the exam.

  7. Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults

    OpenAIRE

    2013-01-01

    Copyright © 2013 The Cochrane Collaboration. Published by JohnWiley & Sons, Ltd. Background: Dysfunctional breathing/hyperventilation syndrome (DB/HVS) is a respiratory disorder, psychologically or physiologically based, involving breathing too deeply and/or too rapidly (hyperventilation) or erratic breathing interspersed with breath-holding or sighing (DB). DB/HVS can result in significant patient morbidity and an array of symptoms including breathlessness, chest tightness, dizziness, tre...

  8. Surrogate-driven deformable motion model for organ motion tracking in particle radiation therapy

    Science.gov (United States)

    Fassi, Aurora; Seregni, Matteo; Riboldi, Marco; Cerveri, Pietro; Sarrut, David; Battista Ivaldi, Giovanni; Tabarelli de Fatis, Paola; Liotta, Marco; Baroni, Guido

    2015-02-01

    The aim of this study is the development and experimental testing of a tumor tracking method for particle radiation therapy, providing the daily respiratory dynamics of the patient’s thoraco-abdominal anatomy as a function of an external surface surrogate combined with an a priori motion model. The proposed tracking approach is based on a patient-specific breathing motion model, estimated from the four-dimensional (4D) planning computed tomography (CT) through deformable image registration. The model is adapted to the interfraction baseline variations in the patient’s anatomical configuration. The driving amplitude and phase parameters are obtained intrafractionally from a respiratory surrogate signal derived from the external surface displacement. The developed technique was assessed on a dataset of seven lung cancer patients, who underwent two repeated 4D CT scans. The first 4D CT was used to build the respiratory motion model, which was tested on the second scan. The geometric accuracy in localizing lung lesions, mediated over all breathing phases, ranged between 0.6 and 1.7 mm across all patients. Errors in tracking the surrounding organs at risk, such as lungs, trachea and esophagus, were lower than 1.3 mm on average. The median absolute variation in water equivalent path length (WEL) within the target volume did not exceed 1.9 mm-WEL for simulated particle beams. A significant improvement was achieved compared with error compensation based on standard rigid alignment. The present work can be regarded as a feasibility study for the potential extension of tumor tracking techniques in particle treatments. Differently from current tracking methods applied in conventional radiotherapy, the proposed approach allows for the dynamic localization of all anatomical structures scanned in the planning CT, thus providing complete information on density and WEL variations required for particle beam range adaptation.

  9. Questioning Compensation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Transparent management and open information needed for the fund set up to compensate victims of the 2008 Sanlu milk scandal Almost three years after the Sanlu milk scandal that caused thousands of infants in China to develop urinary disease after drinking melamine

  10. The Air We Breathe

    Science.gov (United States)

    Davila, Dina

    2010-01-01

    Topics discussed include NASA mission to pioneer the future in space exploration, scientific discovery and aeronautics research; the role of Earth's atmosphere, atmospheric gases, layers of the Earth's atmosphere, ozone layer, air pollution, effects of air pollution on people, the Greenhouse Effect, and breathing on the International Space Station.

  11. The Breath of Chemistry

    DEFF Research Database (Denmark)

    Josephsen, Jens

    The present preliminary text is a short thematic presentation in biological inorganic chemistry meant to illustrate general and inorganic (especially coordination) chemistry in biochemistry. The emphasis is on molecular models to explain features of the complicated mechanisms essential to breathing...

  12. Breathing Like a Fish

    Science.gov (United States)

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  13. Whole-heart magnetic resonance coronary angiography with multiple breath-holds and automatic breathing-level tracking

    Science.gov (United States)

    Kuhara, Shigehide; Ninomiya, Ayako; Okada, Tomohisa; Kanao, Shotaro; Kamae, Toshikazu; Togashi, Kaori

    2010-05-01

    Whole-heart (WH) magnetic resonance coronary angiography (MRCA) studies are usually performed during free breathing while monitoring the position of the diaphragm with real-time motion correction. However, this results in a long scan time and the patient's breathing pattern may change, causing the study to be aborted. Alternatively, WH MRCA can be performed with multiple breath-holds (mBH). However, one problem in the mBH method is that patients cannot hold their breath at the same position every time, leading to image degradation. We have developed a new WH MRCA imaging method that employs both the mBH method and automatic breathing-level tracking to permit automatic tracking of the changes in breathing or breath-hold levels. Evaluation of its effects on WH MRCA image quality showed that this method can provide high-quality images within a shorter scan time. This proposed method is expected to be very useful in clinical WH MRCA studies.

  14. Polymeric microtubules that breathe: CO2 -driven polymer controlled-self-assembly and shape transformation.

    Science.gov (United States)

    Yan, Qiang; Zhao, Yue

    2013-09-16

    Tubular breathing motion: Polymer tubules self-assembled from a gas-sensitive triblock copolymer can undergo shape evolution. A sequence from microtubes through submicroscopic vesicles to nanosized spherical micelles is modulated by CO2 stimulation levels.

  15. An Ultrasound Image-Based Dynamic Fusion Modeling Method for Predicting the Quantitative Impact of In Vivo Liver Motion on Intraoperative HIFU Therapies: Investigations in a Porcine Model.

    Directory of Open Access Journals (Sweden)

    W Apoutou N'Djin

    Full Text Available Organ motion is a key component in the treatment of abdominal tumors by High Intensity Focused Ultrasound (HIFU, since it may influence the safety, efficacy and treatment time. Here we report the development in a porcine model of an Ultrasound (US image-based dynamic fusion modeling method for predicting the effect of in vivo motion on intraoperative HIFU treatments performed in the liver in conjunction with surgery. A speckle tracking method was used on US images to quantify in vivo liver motions occurring intraoperatively during breathing and apnea. A fusion modeling of HIFU treatments was implemented by merging dynamic in vivo motion data in a numerical modeling of HIFU treatments. Two HIFU strategies were studied: a spherical focusing delivering 49 juxtapositions of 5-second HIFU exposures and a toroidal focusing using 1 single 40-second HIFU exposure. Liver motions during breathing were spatially homogenous and could be approximated to a rigid motion mainly encountered in the cranial-caudal direction (f = 0.20 Hz, magnitude > 13 mm. Elastic liver motions due to cardiovascular activity, although negligible, were detectable near millimeter-wide sus-hepatic veins (f = 0.96 Hz, magnitude 75%. Fusion modeling predictions were preliminarily validated in vivo and showed the potential of using a long-duration toroidal HIFU exposure to accelerate the ablation process during breathing (from 0.5 to 6 cm3 · min(-1. To improve HIFU treatment control, dynamic fusion modeling may be interesting for assessing numerically focusing strategies and motion compensation techniques in more realistic conditions.

  16. Ion dynamics in plasma compensation scheme

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, I.V.; Lotov, K.V. E-mail: lotov@inp.nsk.su

    2002-06-11

    In this paper the ability of a plasma to compensate beam-induced fields at the interaction point of muon colliders is discussed. Among numerous factors that limit beam and plasma parameters for which a given compensation degree can be achieved, one of the most important limitations (the motion of plasma ions) is analyzed in details. It is found that this limitation is determined by an instability of the relative motion of plasma electrons and ions. It is shown that discussed parameters of ultimate muon colliders fall outside the applicability area of plasma compensation.

  17. Breath Figures Formation

    OpenAIRE

    Guadarrama-Cetina, J.; González-Viñas, W

    2013-01-01

    We present experimental observations of Breath Figures (BF) which are formed by the dew of water when it condenses on a cold surface. The experiments were done in specific conditions and configurations of temperature, surfaces and mixes in controlled concentration of miscibles and immiscibles substances like the salt saturated solution, alcohol and silicon oil (C_6H_18O_2Si). The hydrophobic surfaces used on those observations are thin glasses coated with ITO (Indium Tin Oxide), 3M ECG-1700 w...

  18. Learn More Breathe Better

    Centers for Disease Control (CDC) Podcasts

    2011-11-16

    Chronic obstructive pulmonary disease (COPD) is a serious lung disease that makes breathing very difficult and can affect your quality of life. Learn the causes of COPD and what you can do to prevent it.  Created: 11/16/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Adult and Community Health (NCCDPHP, DACH).   Date Released: 11/16/2011.

  19. SU-E-T-622: Planning Technique for Passively-Scattered Involved-Node Proton Therapy of Mediastinal Lymphoma with Consideration of Cardiac Motion

    Energy Technology Data Exchange (ETDEWEB)

    Flampouri, S; Li, Z; Hoppe, B [University of Florida Health Proton Therapy Institute, Jacksonville, FL (United States)

    2015-06-15

    Purpose: To develop a treatment planning method for passively-scattered involved-node proton therapy of mediastinal lymphoma robust to breathing and cardiac motions. Methods: Beam-specific planning treatment volumes (bsPTV) are calculated for each proton field to incorporate pertinent uncertainties. Geometric margins are added laterally to each beam while margins for range uncertainty due to setup errors, breathing, and calibration curve uncertainties are added along each beam. The calculation of breathing motion and deformation effects on proton range includes all 4DCT phases. The anisotropic water equivalent margins are translated to distances on average 4DCT. Treatment plans are designed so each beam adequately covers the corresponding bsPTV. For targets close to the heart, cardiac motion effects on dosemaps are estimated by using a library of anonymous ECG-gated cardiac CTs (cCT). The cCT, originally contrast-enhanced, are partially overridden to allow meaningful proton dose calculations. Targets similar to the treatment targets are drawn on one or more cCT sets matching the anatomy of the patient. Plans based on the average cCT are calculated on individual phases, then deformed to the average and accumulated. When clinically significant dose discrepancies occur between planned and accumulated doses, the patient plan is modified to reduce the cardiac motion effects. Results: We found that bsPTVs as planning targets create dose distributions similar to the conventional proton planning distributions, while they are a valuable tool for visualization of the uncertainties. For large targets with variability in motion and depth, integral dose was reduced because of the anisotropic margins. In most cases, heart motion has a clinically insignificant effect on target coverage. Conclusion: A treatment planning method was developed and used for proton therapy of mediastinal lymphoma. The technique incorporates bsPTVs compensating for all common sources of uncertainties

  20. Remote monitoring of breathing dynamics using infrared thermography

    Science.gov (United States)

    Pereira, Carina Barbosa; Yu, Xinchi; Czaplik, Michael; Rossaint, Rolf; Blazek, Vladimir; Leonhardt, Steffen

    2015-01-01

    An atypical or irregular respiratory frequency is considered to be one of the earliest markers of physiological distress. In addition, monitoring of this vital parameter plays a major role in diagnosis of respiratory disorders, as well as in early detection of sudden infant death syndrome. Nevertheless, the current measurement modalities require attachment of sensors to the patient’s body, leading to discomfort and stress. The current paper presents a new robust algorithm to remotely monitor breathing rate (BR) by using thermal imaging. This approach permits to detect and to track the region of interest (nose) as well as to estimate BR. In order to study the performance of the algorithm, and its robustness against motion and breathing disorders, three different thermal recordings of 11 healthy volunteers were acquired (sequence 1: normal breathing; sequence 2: normal breathing plus arbitrary head movements; and sequence 3: sequence of specific breathing patterns). Thoracic effort (piezoplethysmography) served as “gold standard” for validation of our results. An excellent agreement between estimated BR and ground truth was achieved. Whereas the mean correlation for sequence 1–3 were 0.968, 0.940 and 0.974, the mean absolute BR errors reached 0.33, 0.55 and 0.96 bpm (breaths per minute), respectively. In brief, this work demonstrates that infrared thermography is a promising, clinically relevant alternative for the currently available measuring modalities due to its performance and diverse remarkable advantages. PMID:26601003

  1. Irradiation of hepatocellular carcinoma: Impact of breathing on motions and variations of volume of the tumor, liver and upper abdominal organs; L'irradiation des carcinomes hepatocellulaires: impact de la respiration sur les mouvements et variations de volume de la tumeur, du foie et des organes intra-abdominaux

    Energy Technology Data Exchange (ETDEWEB)

    Kubas, A.; Mornex, F.; D' Hombres, A.; Lorchel, F.; Chapet, O. [Centre hospitalier Lyon-Sud, Service de Radiotherapie-oncologie Rhone-Alpes, 69 - Pierre-Benite (France); Merle, P. [Hopital de l' Hotel-Dieu, Service d' Hepatogastroenterologie, 69 - Lyon (France)

    2008-12-15

    Purpose: To evaluate the amplitude of motion and the variations of volume of the tumor, the liver and upper abdominal organs induced by breathing during the irradiation of hepatocellular carcinoma (H.C.C.). Material and methods: Two scanners were performed in inhale and in exhale not forced in 20 patients with a H.C.C.. The liver (left/right lobes), the tumor, the duodenum, the two kidneys and the pancreas were delineated on each acquisition. The superposition of the two spirals made it possible to measure the displacements and variations of volume of these structures in the cranio caudal (C.C.), lateral (Lat), and anteroposterior (A.P.) directions. Results:The mean displacement of the tumour in C.C., Lat and A.P. was of 19.7 {+-} 8.3 mm, 4.5 {+-} 2.3 mm, and 8.9 {+-} 6.5 mm. The greatest amplitude of movement was obtained in C.C. for the right and left hepatic lobes (19 {+-} 6.5 mm, 10 {+-} 5.6 mm), the duodenum(12.6 {+-} 6.4 mm), the kidneys right and left (15.5 {+-} 6.1 mm, 16.2 {+-} 10 mm) and the pancreas (13.2 {+-} 6 mm). No significant variation of volume was observed for these organs. Conclusion: The movements of the tumour, the liver and the abdominal organs, induced by breathing are significant. The respiratory gating appears essential in particular with the development of new techniques of irradiation such as the intensity-modulated radiotherapy (I.M.R.T.) or the stereotactic body radiation therapy (S.B.R.T.). (authors)

  2. High-pitch coronary CT angiography in dual-source CT during free breathing vs. breath holding in patients with low heart rates

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, Bernhard, E-mail: bernhard.bischoff@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany); Meinel, Felix G. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany); Del Prete, Alessandra [Department of Radiology Magrassi-Lanzara, Second University of Naples, Naples (Italy); Reiser, Maximilian F.; Becker, Hans-Christoph [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany)

    2013-12-01

    Background: Coronary CT angiography (CCTA) is usually performed during breath holding to reduce motion artifacts caused by respiration. However, some patients are not able to follow the breathing commands adequately due to deafness, hearing impairment, agitation or pulmonary diseases. The aim of this study was to evaluate the potential of high-pitch CCTA in free breathing patients when compared to breath holding patients. Methods: In this study we evaluated 40 patients (20 free breathing and 20 breath holding patients) with a heart rate of 60 bpm or below referred for CCTA who were examined on a 2nd generation dual-source CT system. Image quality of each coronary artery segment was rated using a 4-point grading scale (1: non diagnostic–4: excellent). Results: Mean heart rate during image acquisition was 52 ±5 bpm in both groups. There was no significant difference in mean image quality, slightly favoring image acquisition during breath holding (mean image quality score 3.76 ± 0.32 in breath holding patients vs. 3.61 ± 0.45 in free breathing patients; p = 0.411). Due to a smaller amount of injected contrast medium, there was a trend for signal intensity to be slightly lower in free breathing patients, but this was not statistically significant (435 ± 123 HU vs. 473 ± 117 HU; p = 0.648). Conclusion: In patients with a low heart rate who are not able to hold their breath adequately, CCTA can also be acquired during free breathing without substantial loss of image quality when using a high pitch scan mode in 2nd generation dual-source CT.

  3. Patient-specific simulation of tidal breathing

    Science.gov (United States)

    Walters, M.; Wells, A. K.; Jones, I. P.; Hamill, I. S.; Veeckmans, B.; Vos, W.; Lefevre, C.; Fetitia, C.

    2016-03-01

    Patient-specific simulation of air flows in lungs is now straightforward using segmented airways trees from CT scans as the basis for Computational Fluid Dynamics (CFD) simulations. These models generally use static geometries, which do not account for the motion of the lungs and its influence on important clinical indicators, such as airway resistance. This paper is concerned with the simulation of tidal breathing, including the dynamic motion of the lungs, and the required analysis workflow. Geometries are based on CT scans obtained at the extremes of the breathing cycle, Total Lung Capacity (TLC) and Functional Residual Capacity (FRC). It describes how topologically consistent geometries are obtained at TLC and FRC, using a `skeleton' of the network of airway branches. From this a 3D computational mesh which morphs between TLC and FRC is generated. CFD results for a number of patient-specific cases, healthy and asthmatic, are presented. Finally their potential use in evaluation of the progress of the disease is discussed, focusing on an important clinical indicator, the airway resistance.

  4. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Compressed breathing gas and liquefied breathing... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing gas and liquefied breathing gas containers; minimum requirements. (a) Compressed breathing gas...

  5. The effects of reproducibility of apparent diffusion coefficient measurements obtained with respiratory motion compensation techniques%呼吸补偿技术对测量正常肝实质表观扩散系数值可重复性的影响

    Institute of Scientific and Technical Information of China (English)

    钟桂棉; 向之明; 梁倩雯; 艾竹; 梁健科; 郑和旭; 梁长虹

    2016-01-01

    Objective To evaluate the reproducibility of normal liver ADC measurements by different respiratory motion compensation techniques. Methods A total of 31 young healthy volunteers who are 20 to 40 years old without any hepatic diseases were selected to research. Each volunteer underwent liver DWI twice in 24 hours with the same parameters and location. The imaging was performed with free-breath(FB), breathhold(BH), rspiratory-triggered(RT)and navigator-triggered(NT)techniques, and the ADC values of the left hepatic lobe and right hepatic lobe (upper, middle and lower) was acquired with two scans. Analysis the the ADC values of various anatomic locations of liver with two-way analysis of variance of randomized block design. Reproducibility of ADCs was assessed with the Bland-Altman method. Analysis of variance and paired-sample t test was used to assess ADCs from both right and left liver lobe among the four techniques. Result The ADC values acquired from the four techniques were significant differences (P<0.01),and the ADC values of the right lobe were less than the left lobe's(P<0.01). It showed a trend to decrease moving from superior to inferior levels in both left and right lobes, and the ADC values among The middle and lower were significant differences (P<0.01). The limit of agreement of ADC of twice imaging among the four techniques were as follow: the right lobe was less than the left lobes, and the breathhold was less the others. As the result, reproducibility in the right liver lobe was better to that in the left and the reproducibility with breathhold was better than the other respiratory motion compensation techniques. Conclusions Both anatomic location and DWI technique influence the liver ADC measurements and their reproducibility. The reproducibility of BH is the best.%目的:探讨呼吸补偿技术对测量正常肝实质ADC值可重复性的影响。方法前瞻性收集无肝脏疾病的20~40岁健康志愿者31名纳入研究,

  6. Tongue Scrapers Only Slightly Reduce Bad Breath

    Science.gov (United States)

    ... your desktop! more... Tongue Scrapers Only Slightly Reduce Bad Breath Article Chapters Tongue Scrapers Only Slightly Reduce ... oral cavity. Reviewed: January 2012 Related Articles: Halitosis (Bad Breath) Do You Have Traveler's Breath? Does a ...

  7. Thoracic radiotherapy and breath control: current prospects; Radiotherapie thoracique et controle de la respiration: perspectives actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, F.; Mineur, L.; Paoli, J.B.; Bodez, V.; Oozeer, R.; Garcia, R. [Institut Sainte-Catherine, 84 - Avignon (France)

    2002-11-01

    Three-dimensional conformal radiotherapy (3D CRT) is adversely affected by setup error and organ motion. In thoracic 3D CRT, breathing accounts for most of intra-fraction movements, thus impairing treatment quality. Breath control clearly exhibits dosimetric improvement compared to free breathing, leading to various techniques for gated treatments. We review benefits of different breath control methods -i.e. breath-holding or beam gating, with spirometric, isometric or X-ray respiration sensor- and argument the choice of expiration versus inspiration, with consideration to dosimetric concerns. All steps of 3D-CRT can be improved with breath control. Contouring of organs at risk (OAR) and target are easier and more accurate on breath controlled CT-scans. Inter- and intra-fraction target immobilisation allows smaller margins with better coverage. Lung outcome predictors (NTCP, Mean Dose, LV20, LV30) are improved with breath-control. In addition, inspiration breath control facilitates beam arrangement since it widens the distance between OAR and target, and leaves less lung normal tissue within the high dose region. Last, lung density, as of CT scan, is more accurate, improving dosimetry. Our institutions choice is to use spirometry driven, patient controlled high-inspiration breath-hold; this technique gives excellent immobilization results, with high reproducibility, yet it is easy to implement and costs little extra treatment time. Breath control, whatever technique is employed, proves superior to free breathing treatment when using 3D-CRT. Breath control should then be used whenever possible, and is probably mandatory for IMRT. (authors)

  8. 联合运动补偿的逆合成孔径雷达成像方位定标方法%Joint method of motion compensation and cross-range scajing for inverse synthetic aperture radar imaging

    Institute of Scientific and Technical Information of China (English)

    盛佳恋; 张磊; 邢孟道; 徐刚; 贺丽

    2014-01-01

    在雷达识别系统中,确定目标的尺寸对于提高目标识别能力具有重要的意义。针对逆合成孔径雷达(inverse synthetic aperture radar,ISAR)成像的定标问题,考虑了等效转台和残余平动引入的相位误差,提出了一种 ISAR 目标有效转动速度估计的新方法。通过在距离多普勒图像中自适应提取若干目标特征点,对其建立时变自回归模型(time-varying autoregressive,TVAR)。利用多项式拟合极点的多普勒历程,解算有效转动速度与残余相位误差系数。该方法不仅能可靠实现方位定标,残余的相位误差补偿可进一步提高图像的聚焦性能。仿真和实测数据实验验证了所提方法的有效性。%In radar target recognition systems,it is of great significance to determine the target size for im-proving the capability of identification.Considering the phase error induced by the equivalent turntable and re-sidual translation,this paper proposes a new method to estimate effective rotation velocity for inverse synthetic aperture radar (ISAR)cross-range scaling.By extracting some featured scatterers in the range-Doppler image,a time-varying autoregressive (TVAR)model is invoked for the scatterers.After polyfitting the Doppler histories of the poles,effective rotation velocity and residual phase error can be calculated.One contribution of this method lies in that it can reliably implement cross-range scaling.Simultaneously,the motion compensation processing can further improve the target focus.Simulation and real-data experiments verify the effectiveness of this proposal.

  9. Breath in the technoscientific imaginary.

    Science.gov (United States)

    Rose, Arthur

    2016-12-01

    Breath has a realist function in most artistic media. It serves to remind the reader, the viewer or the spectator of the exigencies of the body. In science fiction (SF) literature and films, breath is often a plot device for human encounters with otherness, either with alien peoples, who may not breathe oxygen, or environments, where there may not be oxygen to breathe. But while there is a technoscientific quality to breath in SF, especially in its attention to physiological systems, concentrating on the technoscientific threatens to occlude other, more affective aspects raised by the literature. In order to supplement the tendency to read SF as a succession of technoscientific accounts of bodily experience, this paper recalls how SF texts draw attention to the affective, non-scientific qualities of breath, both as a metonym for life and as a metaphor for anticipation. Through an engagement with diverse examples from SF literature and films, this article considers the tension between technoscientific and affective responses to breath in order to demonstrate breath's co-determinacy in SF's blending of scientific and artistic discourses.

  10. BREATHE to Understand©

    Science.gov (United States)

    Swisa, Maxine

    2015-01-01

    BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

  11. FMWC Radar for Breath Detection

    DEFF Research Database (Denmark)

    Suhr, Lau Frejstrup; Tafur Monroy, Idelfonso; Vegas Olmos, Juan José

    We report on the experimental demonstration of an FMCW radar operating in the 25.7 - 26.6 GHz range with a repetition rate of 500 sweeps per second. The radar is able to track the breathing rate of an adult human from a distance of 1 meter. The experiments have utilized a 50 second recording window...... to accurately track the breathing rate. The radar utilizes a saw tooth modulation format and a low latency receiver. A breath tracking radar is useful both in medical scenarios, diagnosing disorders such as sleep apnea, and for home use where the user can monitor its health. Breathing is a central part of every...... radar chip which, through the use of a simple modulation scheme, is able to measure the breathing rate of an adult human from a distance. A high frequency output makes sure that the radar cannot penetrate solid obstacles which is a wanted feature in private homes where people therefore cannot measure...

  12. SU-E-J-185: A Systematic Review of Breathing Guidance in Radiation Oncology and Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, S; Keall, P [University of Sydney, Sydney (Australia); Keall, R [Hammond Care Palliative and Supportive Care Service, Sydney, NSW (Australia)

    2015-06-15

    Purpose: The advent of image-guided radiation therapy (IGRT) has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion is the use of breathing guidance systems during imaging and treatment. A review of such research had not yet been performed, it was therefore our aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: Results of online database searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with the PRISMAStatement reporting standard (Preferred Reporting Items for Systematic reviews and Meta-Analyses) utilizing the PICOS approach (Participants, Intervention, Comparison, Outcome, Study design). Participants: Cancer patients, healthy volunteers. Intervention: Biofeedback breathing guidance systems. Comparison: No breathing guidance of the same breathing type. Outcome: Regularity of breathing signal and anatomic/tumor motion, medical image quality, radiation treatment margins and coverage, medical imaging and radiation treatment times. Study design: Quantitative and controlled prospective or retrospective trials. Results: The systematic search yielded a total of 479 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. The vast majority of investigated outcomes were significantly positively impacted by the use of breathing guidance; however, this was dependent upon the nature of the breathing guidance system and study design. In 25/27 studies significant improvements from the use of breathing guidance were observed. Conclusion: The results found here indicate that further clinical studies are warranted which quantify more comprehensively the

  13. SU-E-J-67: Evaluation of Breathing Patterns for Respiratory-Gated Radiation Therapy Using Respiration Regularity Index

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, K; Lee, M; Kang, S; Yoon, J; Park, S; Hwang, T; Kim, H; Kim, K; Han, T; Bae, H [Hallym University College of Medicine, Anyang (Korea, Republic of)

    2014-06-01

    Purpose: Despite the importance of accurately estimating the respiration regularity of a patient in motion compensation treatment, an effective and simply applicable method has rarely been reported. The authors propose a simple respiration regularity index based on parameters derived from a correspondingly simplified respiration model. Methods: In order to simplify a patient's breathing pattern while preserving the data's intrinsic properties, we defined a respiration model as a power of cosine form with a baseline drift. According to this respiration formula, breathing-pattern fluctuation could be explained using four factors: sample standard deviation of respiration period, sample standard deviation of amplitude and the results of simple regression of the baseline drift (slope and standard deviation of residuals of a respiration signal. Overall irregularity (δ) was defined as a Euclidean norm of newly derived variable using principal component analysis (PCA) for the four fluctuation parameters. Finally, the proposed respiration regularity index was defined as ρ=ln(1+(1/ δ))/2, a higher ρ indicating a more regular breathing pattern. Subsequently, we applied it to simulated and clinical respiration signals from real-time position management (RPM; Varian Medical Systems, Palo Alto, CA) and investigated respiration regularity. Moreover, correlations between the regularity of the first session and the remaining fractions were investigated using Pearson's correlation coefficient. Results: The respiration regularity was determined based on ρ; patients with ρ<0.3 showed worse regularity than the others, whereas ρ>0.7 was suitable for respiratory-gated radiation therapy (RGRT). Fluctuations in breathing cycle and amplitude were especially determinative of ρ. If the respiration regularity of a patient's first session was known, it could be estimated through subsequent sessions. Conclusions: Respiration regularity could be objectively determined

  14. Influence of image registration on ADC images computed from free-breathing diffusion MRIs of the abdomen

    Science.gov (United States)

    Guyader, Jean-Marie; Bernardin, Livia; Douglas, Naomi H. M.; Poot, Dirk H. J.; Niessen, Wiro J.; Klein, Stefan

    2014-03-01

    The apparent diffusion coefficient (ADC) is an imaging biomarker providing quantitative information on the diffusion of water in biological tissues. This measurement could be of relevance in oncology drug development, but it suffers from a lack of reliability. ADC images are computed by applying a voxelwise exponential fitting to multiple diffusion-weighted MR images (DW-MRIs) acquired with different diffusion gradients. In the abdomen, respiratory motion induces misalignments in the datasets, creating visible artefacts and inducing errors in the ADC maps. We propose a multistep post-acquisition motion compensation pipeline based on 3D non-rigid registrations. It corrects for motion within each image and brings all DW-MRIs to a common image space. The method is evaluated on 10 datasets of free-breathing abdominal DW-MRIs acquired from healthy volunteers. Regions of interest (ROIs) are segmented in the right part of the abdomen and measurements are compared in the three following cases: no image processing, Gaussian blurring of the raw DW-MRIs and registration. Results show that both blurring and registration improve the visual quality of ADC images, but compared to blurring, registration yields visually sharper images. Measurement uncertainty is reduced both by registration and blurring. For homogeneous ROIs, blurring and registration result in similar median ADCs, which are lower than without processing. In a ROI at the interface between liver and kidney, registration and blurring yield different median ADCs, suggesting that uncorrected motion introduces a bias. Our work indicates that averaging procedures on the scanner should be avoided, as they remove the opportunity to perform motion correction.

  15. Design of a breath analysis system for diabetes screening and blood glucose level prediction.

    Science.gov (United States)

    Yan, Ke; Zhang, David; Wu, Darong; Wei, Hua; Lu, Guangming

    2014-11-01

    It has been reported that concentrations of several biomarkers in diabetics' breath show significant difference from those in healthy people's breath. Concentrations of some biomarkers are also correlated with the blood glucose levels (BGLs) of diabetics. Therefore, it is possible to screen for diabetes and predict BGLs by analyzing one's breath. In this paper, we describe the design of a novel breath analysis system for this purpose. The system uses carefully selected chemical sensors to detect biomarkers in breath. Common interferential factors, including humidity and the ratio of alveolar air in breath, are compensated or handled in the algorithm. Considering the intersubject variance of the components in breath, we build subject-specific prediction models to improve the accuracy of BGL prediction. A total of 295 breath samples from healthy subjects and 279 samples from diabetic subjects were collected to evaluate the performance of the system. The sensitivity and specificity of diabetes screening are 91.51% and 90.77%, respectively. The mean relative absolute error for BGL prediction is 21.7%. Experiments show that the system is effective and that the strategies adopted in the system can improve its accuracy. The system potentially provides a noninvasive and convenient method for diabetes screening and BGL monitoring as an adjunct to the standard criteria.

  16. Waldorf Education: Breathing Creativity

    Science.gov (United States)

    Nordlund, Carrie

    2013-01-01

    After 10 years of teaching art in public schools, Carrie Nordlund arrived at a state of query that set in motion her search for alternative approaches to learning. As she was feeling stifled in a seemingly sterile education institution with its overdependence on and pedagogy aimed at standardized tests, she came across a reference to Waldorf…

  17. Correcting for respiratory motion in liver PET/MRI: preliminary evaluation of the utility of bellows and navigated hepatobiliary phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hope, Thomas A. [Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (United States); Department of Radiology, San Francisco VA Medical Center, San Francisco, CA (United States); Verdin, Emily F. [Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (United States); Bergsland, Emily K. [Division of Hematology/Oncology, Department of Medicine, University of California, San Francisco, San Francisco, CA (United States); Ohliger, Michael A. [Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (United States); Department of Radiology, San Francisco General Hospital, San Francisco, CA (United States); Corvera, Carlos University; Nakakura, Eric K. [Division of Surgical Oncology, Department of Surgery, University of California, San Francisco, San Francisco, CA (United States)

    2015-09-18

    The purpose of this study was to evaluate the utility of bellows-based respiratory compensation and navigated hepatobiliary phase imaging to correct for respiratory motion in the setting of dedicated liver PET/MRI. Institutional review board approval and informed consent were obtained. Six patients with metastatic neuroendocrine tumor were imaged using Ga-68 DOTA-TOC PET/MRI. Whole body imaging and a dedicated 15-min liver PET acquisition was performed, in addition to navigated and breath-held hepatobiliary phase (HBP) MRI. Liver PET data was reconstructed three ways: the entire data set (liver PET), gated using respiratory bellows (RC-liver PET), and a non-gated data set reconstructed using the same amount of data used in the RC-liver PET (shortened liver PET). Liver lesions were evaluated using SUV{sub max}, SUV{sub peak}, SUV{sub mean}, and Vol{sub isocontour}. Additionally, the displacement of each lesion between the RC-liver PET images and the navigated and breath-held HBP images was calculated. Respiratory compensation resulted in a 43 % increase in SUVs compared to ungated data (liver vs RC-liver PET SUV{sub max} 26.0 vs 37.3, p < 0.001) and a 25 % increase compared to a non-gated reconstruction using the same amount of data (RC-liver vs shortened liver PET SUV{sub max} 26.0 vs 32.6, p < 0.001). Lesion displacement was minimized using navigated HBP MRI (1.3 ± 1.0 mm) compared to breath-held HBP MRI (23.3 ± 1.0 mm). Respiratory bellows can provide accurate respiratory compensation when imaging liver lesions using PET/MRI, and results in increased SUVs due to a combination of increased image noise and reduced respiratory blurring. Additionally, navigated HBP MRI accurately aligns with respiratory compensated PET data.

  18. Whole left ventricular functional assessment from two minutes free breathing multi-slice CINE acquisition

    Science.gov (United States)

    Usman, M.; Atkinson, D.; Heathfield, E.; Greil, G.; Schaeffter, T.; Prieto, C.

    2015-04-01

    Two major challenges in cardiovascular MRI are long scan times due to slow MR acquisition and motion artefacts due to respiratory motion. Recently, a Motion Corrected-Compressed Sensing (MC-CS) technique has been proposed for free breathing 2D dynamic cardiac MRI that addresses these challenges by simultaneously accelerating MR acquisition and correcting for any arbitrary motion in a compressed sensing reconstruction. In this work, the MC-CS framework is combined with parallel imaging for further acceleration, and is termed Motion Corrected Sparse SENSE (MC-SS). Validation of the MC-SS framework is demonstrated in eight volunteers and three patients for left ventricular functional assessment and results are compared with the breath-hold acquisitions as reference. A non-significant difference (P > 0.05) was observed in the volumetric functional measurements (end diastolic volume, end systolic volume, ejection fraction) and myocardial border sharpness values obtained with the proposed and gold standard methods. The proposed method achieves whole heart multi-slice coverage in 2 min under free breathing acquisition eliminating the time needed between breath-holds for instructions and recovery. This results in two-fold speed up of the total acquisition time in comparison to the breath-hold acquisition.

  19. Faculty Compensation Policies.

    Science.gov (United States)

    Silander, Fred

    1983-01-01

    Faculty compensation policy is seen as one means by which an institution influences the faculty to work toward institutional goals. Among the broad criteria for compensation are worth, equity, need, and market measures. Benefits and issues in compensation including differentials in compensation, merit, part-time instruction, etc. are discussed.…

  20. Method for Analysis of an Offshore Heave Compensator

    Directory of Open Access Journals (Sweden)

    Gwi-Nam Kim

    2016-02-01

    Full Text Available A heave compensation system consists of a drill string compensator (DSC and an active heave compensator (AHC cylinder, which together produce control force over an oil pressure system suitable for transmission of considerable power and compensating for heaving motion of the hull during drilling work. In this study, a heave compensator of an oil pressure system was simulated to draw a conclusion, which was verified by comparison with the result of a test conducted using an actual miniature model. The compensation rate was 95%, based on which the dynamic behaviors of an actual-size heave compensator were presumed. Furthermore, the speed of each cylinder and the acceleration of heave can be determined and used to fabricate an actual-size heave compensator.

  1. Visualizing Breath using Digital Holography

    Science.gov (United States)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  2. Respiratory pattern of diaphragmatic breathing and pilates breathing in COPD subjects

    Directory of Open Access Journals (Sweden)

    Karina M. Cancelliero-Gaiad

    2014-08-01

    Full Text Available BACKGROUND: Diaphragmatic breathing (DB is widely used in pulmonary rehabilitation (PR of patients with chronic obstructive pulmonary disease (COPD, however it has been little studied in the scientific literature. The Pilates breathing (PB method has also been used in the rehabilitation area and has been little studied in the scientific literature and in COPD. OBJECTIVES: To compare ventilatory parameters during DB and PB in COPD patients and healthy adults. METHOD: Fifteen COPD patients (COPD group and fifteen healthy patients (healthy group performed three types of respiration: natural breathing (NB, DB, and PB, with the respiratory pattern being analyzed by respiratory inductive plethysmography. The parameters of time, volume, and thoracoabdominal coordination were evaluated. After the Shapiro-Wilk normality test, ANOVA was applied followed by Tukey's test (intragroup analysis and Student's t-test (intergroup analysis; p<0.05. RESULTS: DB promoted increase in respiratory volumes, times, and SpO2 as well as decrease in respiratory rate in both groups. PB increased respiratory volumes in healthy group, with no additional benefits of respiratory pattern in the COPD group. With respect to thoracoabdominal coordination, both groups presented higher asynchrony during DB, with a greater increase in the healthy group. CONCLUSIONS: DB showed positive effects such as increase in lung volumes, respiratory motion, and SpO2 and reduction in respiratory rate. Although there were no changes in volume and time measurements during PB in COPD, this breathing pattern increased volumes in the healthy subjects and increased oxygenation in both groups. In this context, the acute benefits of DB are emphasized as a supporting treatment in respiratory rehabilitation programs.

  3. SU-E-J-62: Breath Hold for Left-Sided Breast Cancer: Visually Monitored Deep Inspiration Breath Hold Amplitude Evaluated Using Real-Time Position Management

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, L; Quirk, S; Smith, WL [The University of Calgary, Calgary, AB (Canada); Tom Baker Cancer Centre, Calgary, AB (Canada); Yeung, R; Phan, T [The University of Calgary, Calgary, AB (Canada); Hudson, A [Tom Baker Cancer Centre, Calgary, AB (Canada)

    2015-06-15

    Purpose: We used Real-Time Position Management (RPM) to evaluate breath hold amplitude and variability when gating with a visually monitored deep inspiration breath hold technique (VM-DIBH) with retrospective cine image chest wall position verification. Methods: Ten patients with left-sided breast cancer were treated using VM-DIBH. Respiratory motion was passively collected once weekly using RPM with the marker block positioned at the xiphoid process. Cine images on the tangent medial field were acquired on fractions with RPM monitoring for retrospective verification of chest wall position during breath hold. The amplitude and duration of all breath holds on which treatment beams were delivered were extracted from the RPM traces. Breath hold position coverage was evaluated for symmetric RPM gating windows from ± 1 to 5 mm centered on the average breath hold amplitude of the first measured fraction as a baseline. Results: The average (range) breath hold amplitude and duration was 18 mm (3–36 mm) and 19 s (7–34 s). The average (range) of amplitude standard deviation per patient over all breath holds was 2.7 mm (1.2–5.7 mm). With the largest allowable RPM gating window (± 5 mm), 4 of 10 VM-DIBH patients would have had ≥ 10% of their breath hold positions excluded by RPM. Cine verification of the chest wall position during the medial tangent field showed that the chest wall was greater than 5 mm from the baseline in only 1 out of 4 excluded patients. Cine images verify the chest wall/breast position only, whether this variation is acceptable in terms of heart sparing is a subject of future investigation. Conclusion: VM-DIBH allows for greater breath hold amplitude variability than using a 5 mm gating window with RPM, while maintaining chest wall positioning accuracy within 5 mm for the majority of patients.

  4. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    Science.gov (United States)

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  5. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults

    OpenAIRE

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function...

  6. Physiological Motion and Registration of Abnormalities in Liver During Focused Ultrasound Surgery

    Science.gov (United States)

    Chauhan, Sunita; Rh, Abhilash

    Continuous deformation and dislocation of soft tissues in the abdominal and thoracic region presents a major issue for effective targeting of all non-invasive ablative modalities such as radiotherapy/surgery and Focused Ultrasound Surgery. Most significant among these is the movement of the target organs due to physiological processes such as respiration. The movement is found to be most significant for liver and kidneys. We studied movement and compensation strategies with the aim to implement them during ultrasound ablation using our robotic system for targeted FUS dose delivery. The motion pattern of the liver can be assumed to be in a single plane as it closely follows the movement of the diaphragm. However, the movement of kidneys is three dimensional and follows complicated patterns. Kidney motion is highly subject specific and has poor repeatability. In our research, we quantify the relation of liver movement and the breathing pattern so as to achieve real-time movement compensation using a prediction-correlation approach.

  7. Breathing guidance in radiation oncology and radiology: A systematic review of patient and healthy volunteer studies

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Sean, E-mail: sean.pollock@sydney.edu.au; Keall, Paul [Radiation Physics Laboratory, University of Sydney, Sydney 2050 (Australia); Keall, Robyn [Central School of Medicine, University of Sydney, Sydney 2050, Australia and Hammond Care, Palliative Care and Supportive Care Service, Greenwich 2065 (Australia)

    2015-09-15

    Purpose: The advent of image-guided radiation therapy has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion irregularities is the use of breathing guidance systems during imaging and treatment. These systems aim to facilitate regular respiratory motion which in turn improves image quality and radiation treatment accuracy. A review of such research has yet to be performed; it was therefore their aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: From August 1–14, 2014, the following online databases were searched: Medline, Embase, PubMed, and Web of Science. Results of these searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with preferred reporting items for systematic reviews and meta-analyses. Reference lists of included articles, and repeat authors of included articles, were hand-searched. Results: The systematic search yielded a total of 480 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. These 27 articles detailed the intervention of breathing guidance strategies in controlled studies assessing its impact on such outcomes as breathing regularity, image quality, target coverage, and treatment margins, recruiting either healthy adult volunteers or patients with thoracic or abdominal lesions. In 21/27 studies, significant (p < 0.05) improvements from the use of breathing guidance were observed. Conclusions: There is a trend toward the number of breathing guidance studies increasing with time, indicating a growing clinical interest. The results found here indicate that further clinical studies are warranted that quantify the

  8. Evidence for breathing modes in direct current, pulsed, and high power impulse magnetron sputtering plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuchen [State Key Lab for Materials Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Zhou, Xue [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150000 (China); Liu, Jason X. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, Berkeley, California 94720 (United States); Anders, André, E-mail: aanders@lbl.gov [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2016-01-18

    We present evidence for breathing modes in magnetron sputtering plasmas: periodic axial variations of plasma parameters with characteristic frequencies between 10 and 100 kHz. A set of azimuthally distributed probes shows synchronous oscillations of the floating potential. They appear most clearly when considering the intermediate current regime in which the direction of azimuthal spoke motion changes. Breathing oscillations were found to be superimposed on azimuthal spoke motion. Depending on pressure and current, one can also find a regime of chaotic fluctuations and one of stable discharges, the latter at high current. A pressure-current phase diagram for the different situations is proposed.

  9. PCA-derived respiratory motion surrogates from X-ray angiograms for percutaneous coronary interventions

    NARCIS (Netherlands)

    H. Ma (Hua); G. Dibildox (Gerardo); C. Schultz (Carl); E.S. Regar (Eveline); T.W. van Walsum (Theo)

    2015-01-01

    textabstractPurpose: Intraoperative coronary motion modeling with motion surrogates enables prospective motion prediction in X-ray angiograms (XA) for percutaneous coronary interventions. The motion of coronary arteries is mainly affected by patients breathing and heartbeat. Purpose of our work is t

  10. Essays in Executive Compensation

    NARCIS (Netherlands)

    D. Zhang (Dan)

    2012-01-01

    textabstractThis dissertation focuses on how executive compensation is designed and its implications for corporate finance and government regulations. Chapter 2 analyzes several proposals to restrict CEO compensation and calibrates two models of executive compensation that describe how firms would r

  11. Taking a deep breath

    Directory of Open Access Journals (Sweden)

    Carlos Renato Zacharias

    2012-12-01

    be paid to language revision and reference citation. Together with its authors and readers, IJHDR contributes to the development of a kind of knowledge close to the borders of science. Therefore, to establish a valid scientific background, the articles must be clearly written, and based on sound assumptions. High-visibility for articles is a fundamental aspect desired by all authors. As an open and free access journal, IJHDR meets that condition, and we are planning to make our influence and visibility even wider. Inclusion in the major databases has paramount importance in the academic milieu, however, it should be considered as a consequence, rather than a goal. In 2013, IJHDR will chair a collaborative project with several research institutions aiming to deliver information everywhere, increasing the visibility of the published articles. Thus, now it is the time to take a deep breath, relax, and prepare you for the forthcoming work! See you in 2013!

  12. Active Wireline Heave Compensation for Ocean Drilling

    Science.gov (United States)

    Goldberg, D.; Liu, T.; Swain, K.; Furman, C.; Iturrino, G. J.

    2014-12-01

    The up-and-down heave motion of a ship causes a similar motion on any instruments tethered on wireline cable below it. If the amplitude of this motion is greater than a few tens of cm, significant discrepancy in the depth below the ship is introduced, causing uncertainty in the acquired data. Large and irregular cabled motions also increase the risk of damaging tethered instruments, particularly those with relatively delicate sensors. In 2005, Schlumberger and Deep Down, Inc built an active wireline heave compensator (AHC) system for use onboard the JOIDES Resolution to compensate for heave motion on wireline logging tools deployed in scientific drill holes. The goals for the new AHC system were to (1) design a reliable heave compensation system; and (2) devise a robust and quantitative methodology for routine assessment of compensation efficiency (CE) during wireline operations. Software programs were developed to monitor CE and the dynamics of logging tools in real-time, including system performance under variable parameters such as water depth, sea state, cable length, logging speed and direction. We present the CE results from the AHC system on the JOIDES Resolution during a 5-year period of recent IODP operations and compare the results to those from previous compensation systems deployed during ODP and IODP. Based on new data under heave conditions of ±0.2-2.0 m and water depths of 300-4,800 m in open holes, the system reduces 65-80% of downhole tool displacement under stationary conditions and 50-60% during normal logging operations. Moreover, down/up tool motion at low speeds (300-600 m/h) reduces the system's CE values by 15-20%, and logging down at higher speeds (1,000-1,200 m/h) reduces CE values by 55-65%. Furthermore, the system yields slightly lower CE values of 40-50% without tension feedback of the downhole cable while logging. These results indicate that the new system's compensation efficiency is comparable to or better than previous systems

  13. Cardiac output in exercise by impedance cardiography during breath holding and normal breathing.

    Science.gov (United States)

    Du Quesnay, M C; Stoute, G J; Hughson, R L

    1987-01-01

    Estimation of cardiac output by impedance cardiography (QZ) in exercise during normal breathing (NB) has been limited by motion artifact. Our objective was to obtain readable impedance cardiograms on five subjects during upright cycle exercise at 0, 50, 100, 150, and 200 W to permit comparisons of QZ during NB, expiratory breath hold (EXP) and inspiratory breath hold (INSP). Q was also determined using an equilibration CO2 rebreathing method [Q(RB)]. QZ during NB exceeded EXP QZ at 100, 150, and 200 W, and exceeded INSP QZ at 100 W (P less than 0.05). The low EXP QZ values were due to a significantly lower stroke volume at 100, 150, and 200 W (P less than 0.05). For the INSP QZ at 100 W, heart rate was lower than during EXP (P less than 0.05). Regression of QZ (NB) against Q(RB) resulted in a linear relationship (r = 0.93) over the range of Q = 7-26 1/min. The slope of the regression differed significantly from 1.0 (P less than 0.05). We conclude that QZ values obtained during EXP or INSP should not be assumed to represent QZ during NB, at least at work rates greater than 50 W. A consequence of the linear relationship between QZ(NB) and Q(RB) over the range of 0-200 W is that estimates of CO2 rebreathing cardiac output can be obtained by impedance cardiography if QZ is adjusted using an appropriate empirical factor.

  14. 平底刀五轴端铣3D刀补中运动突变的检测算法%A Detection Algorithm of Motion Mutation during 3D Cutter Compensation in Five Axis End Milling with a Flat-bottomed Tool

    Institute of Scientific and Technical Information of China (English)

    王峰; 林浒; 刘峰; 郑飂默; 郑一麟

    2013-01-01

    In the process of five-axis end milling with a flat-bottomed tool,if the 3D cutter compensation function was adopted,the motion of linear axis control point would be unsteady because there would be singular solution during solving the radius compensation vector.To provide the precondition for solving such problem,it was needed to detect positions where motion mutation will happen.The reason that the singular point generated during 3D cutter compensation was analyzed based on building the relationship between coordinates of the cutter contact point and the linear axis control point.For the singular point,the adjacent points of the singular point and the boundary of the singular area,which were three positions where motion mutation would happen,a detected algorithm was advanced,which was based on calculating the angle between the tool axis vector and the normal vector and observing the symbol of the dominant angle of the tool axis posture.A simulation experiment was performed to verify the correctness and the effectiveness of this algorithm.%应用3D刀补功能进行五轴端铣加工时,如果某一点处的刀具半径补偿矢量出现奇异解,会导致直线轴控制点在该位置附近发生运动突变.为了准确检测出发生运动突变的位置,从而为进一步解决该类型突变问题提供前提条件,以平底刀为研究对象,在建立切触点与直线轴控制点空间映射关系的基础上,分析了3D刀补中加工奇异点产生的原因;针对奇异点、奇异点相邻点以及奇异区域边界三处会发生运动突变的位置,给出了基于计算刀轴法矢量夹角与观察刀轴姿态主导角符号的检测算法.仿真实验证明了该算法的正确性与有效性.

  15. Submarines, Spacecraft, and Exhaled Breath

    Science.gov (United States)

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  16. Breath-holding and its breakpoint.

    Science.gov (United States)

    Parkes, M J

    2006-01-01

    This article reviews the basic properties of breath-holding in humans and the possible causes of the breath at breakpoint. The simplest objective measure of breath-holding is its duration, but even this is highly variable. Breath-holding is a voluntary act, but normal subjects appear unable to breath-hold to unconsciousness. A powerful involuntary mechanism normally overrides voluntary breath-holding and causes the breath that defines the breakpoint. The occurrence of the breakpoint breath does not appear to be caused solely by a mechanism involving lung or chest shrinkage, partial pressures of blood gases or the carotid arterial chemoreceptors. This is despite the well-known properties of breath-hold duration being prolonged by large lung inflations, hyperoxia and hypocapnia and being shortened by the converse manoeuvres and by increased metabolic rate. Breath-holding has, however, two much less well-known but important properties. First, the central respiratory rhythm appears to continue throughout breath-holding. Humans cannot therefore stop their central respiratory rhythm voluntarily. Instead, they merely suppress expression of their central respiratory rhythm and voluntarily 'hold' the chest at a chosen volume, possibly assisted by some tonic diaphragm activity. Second, breath-hold duration is prolonged by bilateral paralysis of the phrenic or vagus nerves. Possibly the contribution to the breakpoint from stimulation of diaphragm muscle chemoreceptors is greater than has previously been considered. At present there is no simple explanation for the breakpoint that encompasses all these properties.

  17. Monitoring of Heart and Breathing Rates Using Dual Cameras on a Smartphone.

    Science.gov (United States)

    Nam, Yunyoung; Kong, Youngsun; Reyes, Bersain; Reljin, Natasa; Chon, Ki H

    2016-01-01

    Some smartphones have the capability to process video streams from both the front- and rear-facing cameras simultaneously. This paper proposes a new monitoring method for simultaneous estimation of heart and breathing rates using dual cameras of a smartphone. The proposed approach estimates heart rates using a rear-facing camera, while at the same time breathing rates are estimated using a non-contact front-facing camera. For heart rate estimation, a simple application protocol is used to analyze the varying color signals of a fingertip placed in contact with the rear camera. The breathing rate is estimated from non-contact video recordings from both chest and abdominal motions. Reference breathing rates were measured by a respiration belt placed around the chest and abdomen of a subject; reference heart rates (HR) were determined using the standard electrocardiogram. An automated selection of either the chest or abdominal video signal was determined by choosing the signal with a greater autocorrelation value. The breathing rate was then determined by selecting the dominant peak in the power spectrum. To evaluate the performance of the proposed methods, data were collected from 11 healthy subjects. The breathing ranges spanned both low and high frequencies (6-60 breaths/min), and the results show that the average median errors from the reflectance imaging on the chest and the abdominal walls based on choosing the maximum spectral peak were 1.43% and 1.62%, respectively. Similarly, HR estimates were also found to be accurate.

  18. 4D-CT motion estimation using deformable image registration and 5D respiratory motion modeling

    OpenAIRE

    2008-01-01

    Four-dimensional computed tomography (4D-CT) imaging technology has been developed for radiation therapy to provide tumor and organ images at the different breathing phases. In this work, a procedure is proposed for estimating and modeling the respiratory motion field from acquired 4D-CT imaging data and predicting tissue motion at the different breathing phases. The 4D-CT image data consist of series of multislice CT volume segments acquired in ciné mode. A modified optical flow deformable i...

  19. Neural mechanisms underlying breathing complexity.

    Directory of Open Access Journals (Sweden)

    Agathe Hess

    Full Text Available Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD. COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI, we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL medulla (pre-Bötzinger complex and the caudal VL pons (parafacial group. fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in

  20. 一种将增强层运动补偿与混合时空域的FGS融合的视频编码方案%An improved spatio-temporal-SNR FGS video coding scheme using motion compensation on enhancement layers

    Institute of Scientific and Technical Information of China (English)

    江涛; 张兆扬; 马然; 石旭利

    2006-01-01

    In this paper an effective MC + FGSST structure is explored, which is appropriate for scalable video coding. The structure obtains spatio-temporal-SNR fine granular scalability, and achieves high coding efficiency at the same time. Users can acquire their necessary scalability by choosing and combming them. Then, a high-powered codec solution based on this structure is presented. Subsequently, a focus issue on the right number of bit-planes should be used for motion compensation is discussed, and an algorithm is presented for this issue. The proposed codec saves a lot of hardware expense. Simulation results indicate that the performance of MC + FGSST structure is superior to that of FGSST structure.

  1. Novel lung IMRT planning algorithms with nonuniform dose delivery strategy to account for respiratory motion.

    Science.gov (United States)

    Li, Xiang; Zhang, Pengpeng; Mah, Dennis; Gewanter, Richard; Kutcher, Gerald

    2006-09-01

    To effectively deliver radiation dose to lung tumors, respiratory motion has to be considered in treatment planning. In this paper we first present a new lung IMRT planning algorithm, referred as the dose shaping (DS) method, that shapes the dose distribution according to the probability distribution of the tumor over the breathing cycle to account for respiratory motion. In IMRT planning a dose-based convolution method was generally adopted to compensate for random organ motion by performing 4-D dose calculations using a tumor motion probability density function. We modified the CON-DOSE method to a dose volume histogram based convolution method (CON-DVH) that allows nonuniform dose distribution to account for respiratory motion. We implemented the two new planning algorithms on an in-house IMRT planning system that uses the Eclipse (Varian, Palo Alto, CA) planning workstation as the dose calculation engine. The new algorithms were compared with (1) the conventional margin extension approach in which margin is generated based on the extreme positions of the tumor, (2) the dose-based convolution method, and (3) gating with 3 mm residual motion. Dose volume histogram, tumor control probability, normal tissue complication probability, and mean lung dose were calculated and used to evaluate the relative performance of these approaches at the end-exhale phase of the respiratory cycle. We recruited six patients in our treatment planning study. The study demonstrated that the two new methods could significantly reduce the ipsilateral normal lung dose and outperformed the margin extension method and the dose-based convolution method. Compared with the gated approach that has the best performance in the low dose region, the two methods we proposed have similar potential to escalate tumor dose, but could be more efficient because dose is delivered continuously.

  2. Quantification of myocardial perfusion using free-breathing MRI and prospective slice tracking

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Kelle, Sebastian; Ringgaard, Steffen

    2009-01-01

    Quantification of myocardial perfusion using first-pass magnetic resonance imaging (MRI) is hampered by respiratory motion of the heart. Prospective slice tracking (PST) potentially overcomes this problem, and may provide an attractive alternative or supplement to current breath-hold techniques...

  3. 二级深拖系统的瞬态仿真及升沉补偿%Secondary Deep-sea Towed System's Transient Motion Simulation and Heave Compensation

    Institute of Scientific and Technical Information of China (English)

    裴轶群; 李英辉

    2011-01-01

    The dynamic model of the cable was established by adopting the mass method, and then the numerical analysis to the partial differential equation of second order was done by the means of Rung-Kutta algorithm when the boundary conditions and initial conditions are given. The results demonstrate that the dynamic stabilization exists and the effect of the heave compensation is well.%采用集中质量法建立缆绳动力学模型,在给出边界条件和初始条件后,利用龙格-库塔算法对二阶偏微分方程组进行数值分析,并对缆绳运动进行仿真.结果表明:系统动态稳定存在,二级拖体升沉补偿效果良好.

  4. Real time transit dosimetry for the breath-hold radiotherapy technique: An initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Piermattei, Angelo; Cilla, Savino; Grimaldi, Luca (Istituto di Fisica, Universitagrave Cattolica S. Cuore, Roma (Italy)) (and others)

    2008-08-15

    Introduction. The breath-hold is one of the techniques to obtain the dose escalation for lung tumors. However, the change of the patient's breath pattern can influence the stability of the inhaled air volume, IAV, used in this work as a surrogate parameter to assure the tumor position reproducibility during dose delivery. Materials. and method. In this paper, an Elekta active breathing coordinator has been used for lung tumor irradiation. This device is not an absolute spirometer and the feasibility study here presented developed (i) the possibility to select a specific range epsilon of IAV values comfortable for the patient and (ii) the ability of a transit signal rate, obtained by a small ion-chamber positioned on the portal image device, to supply in real time the in vivo isocenter dose reproducibility. Indeed, while the selection of the IAV range depends on the patient's ability to follow instructions for breath-hold, the monitoring can supply to the radiation therapist a surrogate of the tumor irradiation reproducibility. Results. The detection of the (image) in real time during breath-hold was used to determine the interfraction isocenter dose variations due to the reproducibility of the patient's breathing pattern. The agreement between the reconstructed and planned isocenter dose in breath-hold at the interfraction level was well within 1.5%, while in free breathing a disagreement up to 8% was observed. The standard deviation of the [image omitted] in breath-hold observed at the intrafraction level is a bit higher than the one obtained without the patient and this can be justified by the presence of a small residual tumor motion as heartbeat. Conclusion. The technique is simple and can be implemented for routine use in a busy clinic

  5. Rationalizing vaccine injury compensation.

    Science.gov (United States)

    Mello, Michelle M

    2008-01-01

    Legislation recently adopted by the United States Congress provides producers of pandemic vaccines with near-total immunity from civil lawsuits without making individuals injured by those vaccines eligible for compensation through the Vaccine Injury Compensation Program. The unusual decision not to provide an alternative mechanism for compensation is indicative of a broader problem of inconsistency in the American approach to vaccine-injury compensation policy. Compensation policies have tended to reflect political pressures and economic considerations more than any cognizable set of principles. This article identifies a set of ethical principles bearing on the circumstances in which vaccine injuries should be compensated, both inside and outside public health emergencies. A series of possible bases for compensation rules, some grounded in utilitarianism and some nonconsequentialist, are discussed and evaluated. Principles of fairness and reasonableness are found to constitute the strongest bases. An ethically defensible compensation policy grounded in these principles would make a compensation fund available to all individuals with severe injuries and to individuals with less-severe injuries whenever the vaccination was required by law or professional duty.

  6. [Stahl, Leibniz, Hoffmann and breathing].

    Science.gov (United States)

    Carvallo, Sarah

    2006-01-01

    At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine.

  7. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults.

    Science.gov (United States)

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function.

  8. Breathing Modes in Dusty Plasma

    Institute of Scientific and Technical Information of China (English)

    王晓钢; 王爽; 潘秋惠; 刘悦; 贺明峰

    2003-01-01

    Acoustic breathing modes of dusty plasmas have been investigated in a cylindricalsystem with an axial symmetry. The linear wave solution and a "dispersion" relation were derived.It was found that in an infinite area, the mode is reduced to a "classical" dust acoustic wave inthe region away from the center. If the dusty plasma is confined in a finite region, however, thebreathing (or heart-beating) behavior would be found as observed in many experiments.

  9. Motion-corrected Fourier ptychography

    CERN Document Server

    Bian, Liheng; Guo, Kaikai; Suo, Jinli; Yang, Changhuei; Chen, Feng; Dai, Qionghai

    2016-01-01

    Fourier ptychography (FP) is a recently proposed computational imaging technique for high space-bandwidth product imaging. In real setups such as endoscope and transmission electron microscope, the common sample motion largely degrades the FP reconstruction and limits its practicability. In this paper, we propose a novel FP reconstruction method to efficiently correct for unknown sample motion. Specifically, we adaptively update the sample's Fourier spectrum from low spatial-frequency regions towards high spatial-frequency ones, with an additional motion recovery and phase-offset compensation procedure for each sub-spectrum. Benefiting from the phase retrieval redundancy theory, the required large overlap between adjacent sub-spectra offers an accurate guide for successful motion recovery. Experimental results on both simulated data and real captured data show that the proposed method can correct for unknown sample motion with its standard deviation being up to 10% of the field-of-view scale. We have released...

  10. Cooperation, compensation and transition

    NARCIS (Netherlands)

    Ju, Y.

    2004-01-01

    Cooperation and compensation are two important and well-linked issues in economics. The central question in cooperation is how to share the joint gains among participating players. Compensation is a specific aspect of surplus sharing problems providing incentives for agents to sacrifice their own di

  11. Options in Compensation

    DEFF Research Database (Denmark)

    Flor, Christian Riis; Frimor, Hans; Munk, Claus

    2014-01-01

    We derive the optimal compensation contract in a principal–agent setting in which outcome is used to provide incentives for both effort and risky investments. To motivate investment, optimal compensation entails rewards for high as well as low outcomes, and it is increasing at the mean outcome to...

  12. Climate change and compensation

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint; Flanagan, Tine Bech

    2013-01-01

    This paper presents a case for compensation of actual harm from climate change in the poorest countries. First, it is shown that climate change threatens to reverse the fight to eradicate poverty. Secondly, it is shown how the problems raised in the literature for compensation to some extent...... are based on misconceptions and do not apply to compensation of present actual harm. Finally, two arguments are presented to the effect that, in so far as developed countries accept a major commitment to mitigate climate change, they should also accept a commitment to address or compensate actual harm from...... in the future, then there is also moral reason to address these harms if they materialize now. We argue that these principles are applicable to climate change, and that given the commitment of wealthy countries to a "common but differentiated responsibility," they lead to a commitment to address or compensate...

  13. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  14. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Directory of Open Access Journals (Sweden)

    Wen-Qin Wang

    Full Text Available High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF. The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  15. 29 CFR 541.709 - Motion picture producing industry.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Motion picture producing industry. 541.709 Section 541.709... SALES EMPLOYEES Definitions and Miscellaneous Provisions § 541.709 Motion picture producing industry... motion picture producing industry who is compensated at a base rate of at least $695 a week (exclusive...

  16. SU-E-J-29: Audiovisual Biofeedback Improves Tumor Motion Consistency for Lung Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D; Pollock, S; Makhija, K; Keall, P [The University of Sydney, Camperdown, NSW (Australia); Greer, P [The University of Newcastle, Newcastle, NSW (Australia); Calvary Mater Newcastle Hospital, Newcastle, NSW (Australia); Arm, J; Hunter, P [Calvary Mater Newcastle Hospital, Newcastle, NSW (Australia); Kim, T [The University of Sydney, Camperdown, NSW (Australia); University of Virginia Health System, Charlottesville, VA (United States)

    2014-06-01

    Purpose: To investigate whether the breathing-guidance system: audiovisual (AV) biofeedback improves tumor motion consistency for lung cancer patients. This will minimize respiratory-induced tumor motion variations across cancer imaging and radiotherapy procedues. This is the first study to investigate the impact of respiratory guidance on tumor motion. Methods: Tumor motion consistency was investigated with five lung cancer patients (age: 55 to 64), who underwent a training session to get familiarized with AV biofeedback, followed by two MRI sessions across different dates (pre and mid treatment). During the training session in a CT room, two patient specific breathing patterns were obtained before (Breathing-Pattern-1) and after (Breathing-Pattern-2) training with AV biofeedback. In each MRI session, four MRI scans were performed to obtain 2D coronal and sagittal image datasets in free breathing (FB), and with AV biofeedback utilizing Breathing-Pattern-2. Image pixel values of 2D images after the normalization of 2D images per dataset and Gaussian filter per image were used to extract tumor motion using image pixel values. The tumor motion consistency of the superior-inferior (SI) direction was evaluated in terms of an average tumor motion range and period. Results: Audiovisual biofeedback improved tumor motion consistency by 60% (p value = 0.019) from 1.0±0.6 mm (FB) to 0.4±0.4 mm (AV) in SI motion range, and by 86% (p value < 0.001) from 0.7±0.6 s (FB) to 0.1±0.2 s (AV) in period. Conclusion: This study demonstrated that audiovisual biofeedback improves both breathing pattern and tumor motion consistency for lung cancer patients. These results suggest that AV biofeedback has the potential for facilitating reproducible tumor motion towards achieving more accurate medical imaging and radiation therapy procedures.

  17. Boundary oscillations at Geotail: Windsock, breathing, and wrenching

    Science.gov (United States)

    Shodhan, S.; Siscoe, G. L.; Frank, L. A.; Ackerson, K. L.; Paterson, W. R.

    1996-02-01

    On March 18-19, 1993, when Geotail was beyond 150 RE down the tail, for about 30 hours it frequently transited between magnetosheath-like plasma and lobe-like plasma. The transitions take the form of smooth variation by about a factor of 10 in both density and speed. Some of the transitions are distinctly asymmetric with a fast rise to sheath-like values and a slow decline to lobe-like values. We have suggested that these transitional regions are the plasma mantle, but this raises the question of why the mantle crossed Geotail many times in 30 hours. Three possible causes are flapping of the tail in response to solar wind flow changes (the windsock mechanism), intrinsic expansions and contractions of the tail boundary, perhaps in response to substorm phases (the breathing mechanism), and an IMF-squeezed elliptical tail cross section changing its orientation to follow the IMF (the wrenching mechanism). We test these possibilities here by examining simultaneous solar wind velocity and magnetic field data from IMP 8. For the cases studied, both the windsock and the breathing mechanisms appear to contribute to the motions that cause the transitions, whereas the wrenching mechanism seems less effective. Breathing dominates on a timescale of tens of minutes, and windsock dominates on a scale of hours. Since the windsock mechanism is unavoidable, the important finding here is that the breathing mechanism appears also to operate. We use the windsock variation to estimate the thickness of the mantle at Geotail's position and find that the density drops by a factor of 10 in 9 RE. We model the mantle as a one-dimensional slow-mode expansion fan and use the model to predict the change in plasma parameters that occurs from the outer edge of the mantle to its inner edge. A comparison of the predicted profile with the observed profile shows that the model simulates the observed changes reasonably well.

  18. [Breath-analysis tests in gastroenetrological diagnosis].

    Science.gov (United States)

    Caspary, W F

    1975-12-01

    The introduction of a simple method for analysis of 14CO2 in breath allowed a more widely application of breath-tests in the diagnosis of gastroenterological diseases. During a breath-test a 14C-labelled compound is administered orally and 14CO2 is subsequently measured in breath by discontinuous samplings of 14CO2 by virtue of a trapping solution (hyamine hydroxide). Most helpful tests in gastroenterology are the 14C-glycyl-cholate breath test for detecting increased deconjugation of bile acids due to small intestinal bacterial overgrowth or bile acid malabsorption in ileal resection or Crohn's disease of the ileum, the 14C-lactose breath test in lactase deficiency, whereas the 14C-tripalmitin test seems less helpful in the diagnosis of fat malabsorption. A 14C-aminopyrine breath test may turn out to be a simple and valuable liver function test. Oral loading tests with breath analysis of H2 have shown to be helpful in the diagnosis of carbohydrate malabsorption, determination of intestinal transit time and intestinal gas production. Due to technical reasons (gas-chromatographie analysis) H2-breath analysis is still limited to research centers. Despite low radiation doses after oral administration of 14C-labelled compounds oral loading tests with H2- or 13C-analysis might be preferable in the future.

  19. High capacity for extracellular acid-base regulation in the air-breathing fish Pangasianodon hypophthalmus.

    Science.gov (United States)

    Damsgaard, Christian; Gam, Le Thi Hong; Tuong, Dang Diem; Thinh, Phan Vinh; Huong Thanh, Do Thi; Wang, Tobias; Bayley, Mark

    2015-05-01

    The evolution of accessory air-breathing structures is typically associated with reduction of the gills, although branchial ion transport remains pivotal for acid-base and ion regulation. Therefore, air-breathing fishes are believed to have a low capacity for extracellular pH regulation during a respiratory acidosis. In the present study, we investigated acid-base regulation during hypercapnia in the air-breathing fish Pangasianodon hypophthalmus in normoxic and hypoxic water at 28-30°C. Contrary to previous studies, we show that this air-breathing fish has a pronounced ability to regulate extracellular pH (pHe) during hypercapnia, with complete metabolic compensation of pHe within 72 h of exposure to hypoxic hypercapnia with CO2 levels above 34 mmHg. The high capacity for pHe regulation relies on a pronounced ability to increase levels of HCO3(-) in the plasma. Our study illustrates the diversity in the physiology of air-breathing fishes, such that generalizations across phylogenies may be difficult.

  20. Sleep disordered breathing in pregnancy

    Directory of Open Access Journals (Sweden)

    Bilgay Izci Balserak

    2015-12-01

    Sleep disordered breathing (SDB is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the severity of SDB, the epidemiology and the risk factors of SDB in pregnancy, the association of SDB with adverse pregnancy outcomes, and screening and management options specific for this population.

  1. 42 CFR 84.79 - Breathing gas; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing gas; minimum requirements. 84.79 Section...-Contained Breathing Apparatus § 84.79 Breathing gas; minimum requirements. (a) Breathing gas used to supply... respiratory tract irritating compounds. (c) Compressed, gaseous breathing air shall meet the...

  2. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing apparatus shall be designed and constructed to prevent: (a)...

  3. 42 CFR 84.85 - Breathing bags; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bags; minimum requirements. 84.85 Section...-Contained Breathing Apparatus § 84.85 Breathing bags; minimum requirements. (a) Breathing bags shall have.... (b) Breathing bags shall be constructed of materials which are flexible and resistant to...

  4. ERROR COMPENSATION OF COORDINATE MEASURING MACHINES WITH LOW STIFFNESS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A technique for compensating the errors of coordinate measuring machines (CMMs) with low stiffness is proposed. Some additional it ems related with the force deformation are introduced to the error compensation equations. The research was carried on a moving column horizontal arm CMM. Experimental results show that both the effects of systematic components of error motions and force deformations are greatly reduced, which shows the effectiveness o proposed technique.

  5. Fractional motions

    Energy Technology Data Exchange (ETDEWEB)

    Eliazar, Iddo I., E-mail: eliazar@post.tau.ac.il [Holon Institute of Technology, P.O. Box 305, Holon 58102 (Israel); Shlesinger, Michael F., E-mail: mike.shlesinger@navy.mil [Office of Naval Research, Code 30, 875 N. Randolph St., Arlington, VA 22203 (United States)

    2013-06-10

    Brownian motion is the archetypal model for random transport processes in science and engineering. Brownian motion displays neither wild fluctuations (the “Noah effect”), nor long-range correlations (the “Joseph effect”). The quintessential model for processes displaying the Noah effect is Lévy motion, the quintessential model for processes displaying the Joseph effect is fractional Brownian motion, and the prototypical model for processes displaying both the Noah and Joseph effects is fractional Lévy motion. In this paper we review these four random-motion models–henceforth termed “fractional motions” –via a unified physical setting that is based on Langevin’s equation, the Einstein–Smoluchowski paradigm, and stochastic scaling limits. The unified setting explains the universal macroscopic emergence of fractional motions, and predicts–according to microscopic-level details–which of the four fractional motions will emerge on the macroscopic level. The statistical properties of fractional motions are classified and parametrized by two exponents—a “Noah exponent” governing their fluctuations, and a “Joseph exponent” governing their dispersions and correlations. This self-contained review provides a concise and cohesive introduction to fractional motions.

  6. News from the Breath Analysis Summit 2011.

    Science.gov (United States)

    Corradi, Massimo; Mutti, Antonio

    2012-06-01

    This special section highlights some of the important work presented at the Breath Analysis Summit 2011, which was held in Parma (Italy) from 11 to 14 September 2011. The meeting, which was jointly organized by the International Association for Breath Research and the University of Parma, was attended by more than 250 delegates from 33 countries, and offered 34 invited lectures and 64 unsolicited scientific contributions. The summit was organized to provide a forum to scientists, engineers and clinicians to present their latest findings and to meet industry executives and entrepreneurs to discuss key trends, future directions and technologies available for breath analysis. A major focus was on nitric oxide, exhaled breath condensate, electronic nose, mass spectrometry and newer sensor technologies. Medical applications ranged from asthma and other respiratory diseases to gastrointestinal disease, occupational diseases, critical care and cancer. Most people identify breath tests with breathalysers used by police to estimate ethanol concentration in blood. However, breath testing has far more sophisticated applications. Breath analysis is rapidly evolving as a new frontier in medical testing for disease states in the lung and beyond. Every individual has a breath fingerprint-or 'breathprint'-that can provide useful information about his or her state of health. This breathprint comprises the many thousands of molecules that are expelled with each breath we exhale. Breath research in the past few years has uncovered the scientific and molecular basis for such clinical observations. Relying on mass spectrometry, we have been able to identify many such unique substances in exhaled breath, including gases, such as nitric oxide (NO) and carbon monoxide (CO), and a wide array of volatile organic compounds. Exhaled breath also carries aerosolized droplets that can be collected as an exhaled breath condensate that contains endogenously produced non-volatile compounds. Breath

  7. Protective supplied breathing air garment

    Science.gov (United States)

    Childers, Edward L.; von Hortenau, Erik F.

    1984-07-10

    A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

  8. Workers Compensation Claim Data -

    Data.gov (United States)

    Department of Transportation — This data set contains DOT employee workers compensation claim data for current and past DOT employees. Types of data include claim data consisting of PII data (SSN,...

  9. Climate change and compensation

    DEFF Research Database (Denmark)

    Jensen, Karsten Klint; Flanagan, Tine Bech

    2013-01-01

    This paper presents a case for compensation of actual harm from climate change in the poorest countries. First, it is shown that climate change threatens to reverse the fight to eradicate poverty. Secondly, it is shown how the problems raised in the literature for compensation to some extent...... are based on misconceptions and do not apply to compensation of present actual harm. Finally, two arguments are presented to the effect that, in so far as developed countries accept a major commitment to mitigate climate change, they should also accept a commitment to address or compensate actual harm from...... climate change. The first argument appeals to the principle that if it is an injustice to cause risk of incurring harm in the future, then it is also an injustice to cause a similar harm now. The second argument appeals to the principle that if there is moral reason to reduce the risk of specific harms...

  10. Prediction and classification of respiratory motion

    CERN Document Server

    Lee, Suk Jin

    2014-01-01

    This book describes recent radiotherapy technologies including tools for measuring target position during radiotherapy and tracking-based delivery systems. This book presents a customized prediction of respiratory motion with clustering from multiple patient interactions. The proposed method contributes to the improvement of patient treatments by considering breathing pattern for the accurate dose calculation in radiotherapy systems. Real-time tumor-tracking, where the prediction of irregularities becomes relevant, has yet to be clinically established. The statistical quantitative modeling for irregular breathing classification, in which commercial respiration traces are retrospectively categorized into several classes based on breathing pattern are discussed as well. The proposed statistical classification may provide clinical advantages to adjust the dose rate before and during the external beam radiotherapy for minimizing the safety margin. In the first chapter following the Introduction  to this book, we...

  11. ACTS Rain Fade Compensation

    Science.gov (United States)

    Coney, Thom A.

    1996-01-01

    Performance status of the Adaptive Rain Fade Compensation includes: (1) The rain fade protocol is functional detecting fades, providing an additional 10 dB of margin and seamless transitions to and from coded operation; (2) The stabilization of the link margins and the optimization of rain fade decision thresholds has resulted in improved BER performance; (3) Characterization of the fade compensation algorithm is ongoing.

  12. Dosage compensation in birds

    OpenAIRE

    McQueen, H A; McBride, D; Miele, G; Bird, A.P.; Clinton, M

    2001-01-01

    The Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess "dosage compensation" systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mamma...

  13. Submarines, spacecraft and exhaled breath.

    Science.gov (United States)

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  14. Estimation, transmission, and distribution of motion information in future image communication networks

    Science.gov (United States)

    Chupeau, Bertrand

    1993-10-01

    There is no doubt that in a near future a large number of image processing techniques will be based on motion compensation, making thus very common the cascading of several 'motion compensated' devices in the same image chain. A reference scheme for the optimum use of motion compensation in future image communication networks is presented. Motion estimation is performed once only, at a very early stage of the process chain, then motion information is encoded, transmitted in a separate data channel and distributed to the cascaded motion compensated processes. The distribution scenario must take into consideration the various transformations performed on the image signal since its origination so that the motion information distributed is always consistent with the pictures to process. The problems of the representation of motion relatively to a given source image signal and of its adjustment to new frame rate environments are especially addressed.

  15. ROBUST MOTION SEGMENTATION FOR HIGH DEFINITION VIDEO SEQUENCES USING A FAST MULTI-RESOLUTION MOTION ESTIMATION BASED ON SPATIO-TEMPORAL TUBES

    OpenAIRE

    Brouard, Olivier; Delannay, Fabrice; Ricordel, Vincent; Barba, Dominique

    2007-01-01

    4 pages; International audience; Motion segmentation methods are effective for tracking video objects. However, objects segmentation methods based on motion need to know the global motion of the video in order to back-compensate it before computing the segmentation. In this paper, we propose a method which estimates the global motion of a High Definition (HD) video shot and then segments it using the remaining motion information. First, we develop a fast method for multi-resolution motion est...

  16. 42 CFR 84.141 - Breathing gas; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Respirators § 84.141 Breathing gas; minimum requirements. (a) Breathing gas used to supply supplied-air respirators shall be respirable breathing air and contain no less than 19.5 volume-percent of oxygen....

  17. How Does a Hopping Kangaroo Breathe?

    Science.gov (United States)

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  18. Controlled Frequency Breathing Reduces Inspiratory Muscle Fatigue.

    Science.gov (United States)

    Burtch, Alex R; Ogle, Ben T; Sims, Patrick A; Harms, Craig A; Symons, Thorburn B; Folz, Rodney J; Zavorsky, Gerald S

    2016-08-16

    Controlled frequency breathing (CFB) is a common swim training modality involving holding one's breath for about 7 to 10 strokes before taking another breath. We sought to examine the effects of CFB training on reducing respiratory muscle fatigue. Competitive college swimmers were randomly divided into either the CFB group that breathed every 7 to 10 strokes, or a control group that breathed every 3-4 strokes. Twenty swimmers completed the study. The training intervention included 5-6 weeks (16 sessions) of 12x50-m repetitions with breathing 8-10 breaths per 50m (control group), or 2-3 breaths per 50-m (CFB group). Inspiratory muscle fatigue was defined as the decrease in maximal inspiratory mouth-pressure (MIP) between rest and 46s after a 200 yard free-style swimming race [115s (SD 7)]. Aerobic capacity, pulmonary diffusing capacity, and running economy were also measured pre and post-training. Pooled results demonstrated a 12% decrease in MIP at 46s post-race [-15 (SD 14) cm H2O, Effect size = -0.48, p training, only the CFB group prevented a decline in MIP values pre to 46 s post-race [-2 (13) cm H2O, p > 0.05]. However, swimming performance, aerobic capacity, pulmonary diffusing capacity, and running economy did not improve (p > 0.05) post-training in either group. In conclusion, CFB training appears to prevent inspiratory muscle fatigue yet no difference was found in performance outcomes.

  19. Relationships between hippocampal activity and breathing patterns

    DEFF Research Database (Denmark)

    Harper, R M; Poe, G R; Rector, D M;

    1998-01-01

    Single cell discharge, EEG activity, and optical changes accompanying alterations in breathing patterns, as well as the knowledge that respiratory musculature is heavily involved in movement and other behavioral acts, implicate hippocampal regions in some aspects of breathing control. The control...

  20. Pulse pressure variation to predict fluid responsiveness in spontaneously breathing patients: tidal vs. forced inspiratory breathing.

    Science.gov (United States)

    Hong, D M; Lee, J M; Seo, J H; Min, J J; Jeon, Y; Bahk, J H

    2014-07-01

    We evaluated whether pulse pressure variation can predict fluid responsiveness in spontaneously breathing patients. Fifty-nine elective thoracic surgical patients were studied before induction of general anaesthesia. After volume expansion with hydroxyethyl starch 6 ml.kg(-1) , patients were defined as responders by a ≥ 15% increase in the cardiac index. Haemodynamic variables were measured before and after volume expansion and pulse pressure variations were calculated during tidal breathing and during forced inspiratory breathing. Median (IQR [range]) pulse pressure variation during forced inspiratory breathing was significantly higher in responders (n = 29) than in non-responders (n = 30) before volume expansion (18.2 (IQR 14.7-18.2 [9.3-31.3])% vs. 10.1 (IQR 8.3-12.6 [4.8-21.1])%, respectively, p breathing could predict fluid responsiveness (area under the curve 0.910, p breathing can be used to guide fluid management in spontaneously breathing patients.

  1. Discriminating between Nasal and Mouth Breathing

    CERN Document Server

    Curran, Kevin; Coyle, Damian

    2010-01-01

    The recommendation to change breathing patterns from the mouth to the nose can have a significantly positive impact upon the general well being of the individual. We classify nasal and mouth breathing by using an acoustic sensor and intelligent signal processing techniques. The overall purpose is to investigate the possibility of identifying the differences in patterns between nasal and mouth breathing in order to integrate this information into a decision support system which will form the basis of a patient monitoring and motivational feedback system to recommend the change from mouth to nasal breathing. Our findings show that the breath pattern can be discriminated in certain places of the body both by visual spectrum analysis and with a Back Propagation neural network classifier. The sound file recoded from the sensor placed on the hollow in the neck shows the most promising accuracy which is as high as 90%.

  2. Abortion--the breath of life.

    Science.gov (United States)

    Joling, R J

    1974-01-01

    A scholarly review of medical-legal and biblical authority on the su bject of abortion supports abortion as a woman's right when it is performed before the fetus has had its "breath of life." Based on biblical evidence, a person becomes a living being when the soul, the "breath of life" is breathed into it. Without the "breath of life" no person exists. A fetus less than 28 weeks old is incapable of breathing alone; thus an aborted fetus that age is not truly a living human being capable of surviving independently of its mother's womb. Legal aspects include supreme, local and state court decisions defining abortion. It is ultimately expected that each person will determine what approach to take towards the abortion question. Abortion is still a personal problem regardless of supreme court decisions or ecclesiastical determinants. Religion and moral concepts should be the guiding conscience involved in the question of abortion.

  3. Rapid eye movement sleep in breath holders.

    Science.gov (United States)

    Kohyama, J; Hasegawa, T; Shimohira, M; Fukumizu, M; Iwakawa, Y

    2000-07-01

    One-night polysomnography was performed on seven subjects suffering from breath-holding spells, including one whose death was suggested to be a consequence of a breath-holding spell. The fatal case showed no rapid eye movements (REMs) during REM sleep, although he exhibited REMs during wakefulness. The average numbers of both REMs and bursts of REMs in REM sleep in the other six breath holders were significantly lower than those in age-matched controls. The breath holders showed no airway obstruction, desaturation, or sleep fragmentation. Since the rapid ocular activity in REM sleep is generated in the brain stem, we hypothesized that a functional brainstem disturbance is involved in the occurrence of breath-holding spells.

  4. Time Breath of Psychological Theories

    DEFF Research Database (Denmark)

    Tateo, Luca; Valsiner, Jaan

    2015-01-01

    Psychology as a self-aspiring, ambitious, developmental science faces the crucial limit of time—both theoretically and practically. The issue of time in constructing psychology’s theories is a major unresolved metatheoretical task. This raises several questions about generalization of knowledge......: which is the time length of breath of psychological theories? Which is the temporal dimension of psychological processes? In this article we discuss the role of different axiomatic assumptions about time in the construction of psychological theories. How could different theories include a concept...... of time—or fail to do that? How can they generalize with respect to time? The different conceptions of time often remain implicit, while shaping the concepts used in understanding psychological processes. Any preconception about time in human development will foster the generalizability of theory, as well...

  5. A Pre-compensation Fuzzy Logic Algorithm Designed for the Dynamic Compensation Robotic System

    Directory of Open Access Journals (Sweden)

    Shouren Huang

    2015-01-01

    Full Text Available This paper deals with the issue of non-model-based position regulation for the dynamic compensation robotic system (DCRS, which has been proposed for cooperating with the existing main robotic systems, such as the common serial robotic arms, to accomplish high-speed and accurate manipulations. The dynamic compensation concept is realized by fusing a high-speed & light-weight compensation actuator as well as endpoint closed loop (ECL configured high-speed cameras. Within the context of the DCRS, the coarse motion, which is realized by the main robotic system, usually gives rise to negative dynamic impact on the compensation actuator that is configured to accomplish the fine motion. Through the analysis of a simplified model for the coupled two-plant system, relative velocity information between the two plants is found to play a role in the first order derivative of the displacement error. With the use of the relative position information from high-speed visual feedback, this paper proposes a new pre- compensation fuzzy logic control (PFLC approach for control of the compensation actuator. The PFLC method is model-independent and is realized with a cascade fuzzy inference structure that conveniently integrates the relative velocity term between the two plants into the error regulation, and therefore realizes the partial counteraction of the disturbance from the main robot easily without knowing the explicit mathematical models of the system. Comparison works between the proposed PFLC and approaches that take no consideration of the relative velocity information, such as proportional-derivative (PD control and conventional fuzzy logic control, are conducted. Simulations and experiments show the consistent effectiveness of the proposed approach.

  6. Executive Compensation: A Brief Review

    OpenAIRE

    Bognanno, Michael L.

    2010-01-01

    Chief executive officer (CEO) compensation is defined as the sum of base pay, bonuses, stock grants, stock options, other forms of compensation and benefits. Inflation?adjusted, median total CEO compensation in the United States almost tripled between 1992 and 2000, with grants of stock options evolving to be the largest component of compensation. This article presents the arguments for and against this level and composition of CEO compensation.

  7. Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

    Science.gov (United States)

    Wang, Zhennan; Sun, Meixiu; Chen, Zhuying; Zhao, Xiaomeng; Li, Yingxin; Wang, Chuji

    2016-11-01

    Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (diabetic screening and management under a specifically controlled condition.

  8. Tongue Motion Patterns in Post-Glossectomy and Typical Speakers: A Principal Components Analysis

    Science.gov (United States)

    Stone, Maureen; Langguth, Julie M.; Woo, Jonghye; Chen, Hegang; Prince, Jerry L.

    2014-01-01

    Purpose: In this study, the authors examined changes in tongue motion caused by glossectomy surgery. A speech task that involved subtle changes in tongue-tip positioning (the motion from /i/ to /s/) was measured. The hypothesis was that patients would have limited motion on the tumor (resected) side and would compensate with greater motion on the…

  9. An Ultrasonic Contactless Sensor for Breathing Monitoring

    Directory of Open Access Journals (Sweden)

    Philippe Arlotto

    2014-08-01

    Full Text Available The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569.

  10. Decreased chewing activity during mouth breathing.

    Science.gov (United States)

    Hsu, H-Y; Yamaguchi, K

    2012-08-01

    This study examined the effect of mouth breathing on the strength and duration of vertical effect on the posterior teeth using related functional parameters during 3 min of gum chewing in 39 nasal breathers. A CO(2) sensor was placed over the mouth to detect expiratory airflow. When no airflow was detected from the mouth throughout the recording period, the subject was considered a nasal breather and enrolled in the study. Electromyographic (EMG) activity was recorded during 3 min of gum chewing. The protocol was repeated with the nostrils occluded. The strength of the vertical effect was obtained as integrated masseter muscle EMG activity, and the duration of vertical effect was also obtained as chewing stroke count, chewing cycle variation and EMG activity duration above baseline. Baseline activity was obtained from the isotonic EMG activity during jaw movement at 1.6 Hz without making tooth contact. The duration represented the percentage of the active period above baseline relative to the 3-min chewing period. Paired t-test and repeated analysis of variance were used to compare variables between nasal and mouth breathing. The integrated EMG activity and the duration of EMG activity above baseline, chewing stroke count and chewing cycle significantly decreased during mouth breathing compared with nasal breathing (Pmouth breathing was significantly greater than nasal breathing (PMouth breathing reduces the vertical effect on the posterior teeth, which can affect the vertical position of posterior teeth negatively, leading to malocclusion.

  11. An ultrasonic contactless sensor for breathing monitoring.

    Science.gov (United States)

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-08-20

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569).

  12. Breathing and sleep at high altitude.

    Science.gov (United States)

    Ainslie, Philip N; Lucas, Samuel J E; Burgess, Keith R

    2013-09-15

    We provide an updated review on the current understanding of breathing and sleep at high altitude in humans. We conclude that: (1) progressive changes in pH initiated by the respiratory alkalosis do not underlie early (48 h), complex cellular and neurochemical re-organization occurs both in the peripheral chemoreceptors as well as within the central nervous system. The latter is likely influenced by central acid-base changes secondary to the extent of the initial respiratory responses to initial exposure to high altitude; (3) sleep at high altitude is disturbed by various factors, but principally by periodic breathing; (4) the extent of periodic breathing during sleep at altitude intensifies with duration and severity of exposure; (5) complex interactions between hypoxic-induced enhancement in peripheral and central chemoreflexes and cerebral blood flow--leading to higher loop gain and breathing instability--underpin this development of periodic breathing during sleep; (6) because periodic breathing may elevate rather than reduce mean SaO2 during sleep, this may represent an adaptive rather than maladaptive response; (7) although oral acetazolamide is an effective means to reduce periodic breathing by 50-80%, recent studies using positive airway pressure devices to increase dead space, hyponotics and theophylline are emerging but appear less practical and effective compared to acetazolamide. Finally, we suggest avenues for future research, and discuss implications for understanding sleep pathology.

  13. Power factor compensation

    Energy Technology Data Exchange (ETDEWEB)

    Barra R, Felipe [Schneider Electric Chile (Chile)

    2010-07-01

    Every company is looking for ways to increase productivity as a way to gain a competitive advantage. Energy is a significant element in making any product and so it is important to assess production processes from an energy perspective. This paper discusses the impact of power factor compensation on energy efficiency. The life cycle solution for energy efficiency involves optimization of active energy using automation and regulation. A brief explanation is given of how each component of a company plays a part in this cycle. Examples include simulations and analysis, modeling, performance monitoring facilities, and environmental sustainability. Reactive energy suppliers and the installation of capacitors are also explained. Types of compensation include fixed and automation compensations. Economic advantages include a reduction in the electricity bill and active energy consumption. Technical advantages include reduction in voltage drop and an increase in available power. The power correction factor also improves reliability and contributes to conservation of the environment.

  14. Compensation neurosis rides again.

    Science.gov (United States)

    Levy, A

    1992-01-01

    Compensation neurosis (CN), also known as accident neurosis, has generally not been considered to be a 'real' disorder. In 1961 it was seemingly laid to rest by Henry Miller, a distinguished neurologist, in a sharp article which appeared in the British Medical Journal. Miller's view of patients who presented psychological symptoms following accidents or traumas was suspicious. Compensated or not, his view seemed to be that they should have their legal process finished as quickly as possible and then they will miraculously convalescence. Miller's work, it appeared, was the coup de grâce for this ill-defined diagnosis. Today, however, compensation neurosis seems to ride again. After a prolonged silence in the psychiatric literature, new papers are emerging, strongly suggesting that this vanishing diagnosis be reconsidered. This new trend will be presented.

  15. Manifold learning for image-based breathing gating with application to 4D ultrasound.

    Science.gov (United States)

    Wachinger, Christian; Yigitsoy, Mehmet; Navab, Nassir

    2010-01-01

    Breathing motion leads to a significant displacement and deformation of organs in the abdominal region. This makes the detection of the breathing phase for numerous applications necessary. We propose a new, purely image-based respiratory gating method for ultrasound. Further, we use this technique to provide a solution for breathing affected 4D ultrasound acquisitions with a wobbler probe. We achieve the gating with Laplacian eigenmaps, a manifold learning technique, to determine the low-dimensional manifold embedded in the high-dimensional image space. Since Laplacian eigenmaps assign each ultrasound frame a coordinate in low-dimensional space by respecting the neighborhood relationship, they are well suited for analyzing the breathing cycle. For the 4D application, we perform the manifold learning for each angle, and consecutively, align all the local curves and perform a curve fitting to achieve a globally consistent breathing signal. We performed the image-based gating on several 2D and 3D ultrasound datasets over time, and quantified its very good performance by comparing it to measurements from an external gating system.

  16. Practical recommendations for breathing-adapted radiotherapy; Bonnes pratiques pour la radiotherapie asservie a la respiration

    Energy Technology Data Exchange (ETDEWEB)

    Simon, L.; Giraud, P.; Rosenwald, J.C. [Institut Curie, Dept. d' Oncologie-radiotherapie, 75 - Paris (France); Dumas, J.L.; Lorchel, F. [CHU de Besancon, Hopital Jean-Minjoz, Service Radiotherapie, 25 - Besancon (France); Marre, D. [Institut Claudius-Regaud, Dept. des Radiations, 31 - Toulouse (France); Dupont, S. [Hopital Europeen Georges-Pompidou, Service d' Oncoradiotherapie, 75 - Paris (France); Varmenot, N. [Centre Henri-Becquerel, UnitE de Physique Medicale, 76 - Rouen (France); Ginestet, C. [Centre Leon-Berard, Dept. de Radiotherapie, 69 - Lyon (France); Caron, J. [Institut Bergonie, Dept. de Radiotherapie, 33 - Bordeaux (France); Marchesi, V. [Centre Alexis-Vautrin, Dept. de Radiotherapie, 54 - Vandoeuvre-les-Nancy (France); Ferreira, I. [Institut Gustave-Roussy, Dept. d' Oncologie Radiotherapie, 94 - Villejuif (France); Garcia, R. [Institut Sainte-Catherine, Service de Radiotherapie, 84 - Avignon (France)

    2007-06-15

    Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

  17. A finite state model for respiratory motion analysis in image guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wu Huanmei [College of Computer and Information Science, Northeastern University, Boston, MA 02115 (United States); Sharp, Gregory C [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 (United States); Salzberg, Betty [College of Computer and Information Science, Northeastern University, Boston, MA 02115 (United States); Kaeli, David [Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115 (United States); Shirato, Hiroki [Department of Radiation Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Jiang, Steve B [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 (United States)

    2004-12-07

    Effective image guided radiation treatment of a moving tumour requires adequate information on respiratory motion characteristics. For margin expansion, beam tracking and respiratory gating, the tumour motion must be quantified for pretreatment planning and monitored on-line. We propose a finite state model for respiratory motion analysis that captures our natural understanding of breathing stages. In this model, a regular breathing cycle is represented by three line segments, exhale, end-of-exhale and inhale, while abnormal breathing is represented by an irregular breathing state. In addition, we describe an on-line implementation of this model in one dimension. We found this model can accurately characterize a wide variety of patient breathing patterns. This model was used to describe the respiratory motion for 23 patients with peak-to-peak motion greater than 7 mm. The average root mean square error over all patients was less than 1 mm and no patient has an error worse than 1.5 mm. Our model provides a convenient tool to quantify respiratory motion characteristics, such as patterns of frequency changes and amplitude changes, and can be applied to internal or external motion, including internal tumour position, abdominal surface, diaphragm, spirometry and other surrogates.

  18. Enhanced motion coding in MC-EZBC

    Science.gov (United States)

    Chen, Junhua; Zhang, Wenjun; Wang, Yingkun

    2005-07-01

    Since hierarchical variable size block matching and bidirectional motion compensation are used in the motioncompensated embedded zero block coding (MC-EZBC), the motion information consists of motion vector quadtree map and motion vectors. In the conventional motion coding scheme, the quadtree structure is coded directly, the motion vector modes are coded with Huffman codes, and the motion vector differences are coded by an m-ary arithmetic coder with 0-order models. In this paper we propose a new motion coding scheme which uses an extension of the CABAC algorithm and new context modeling for quadtree structure coding and mode coding. In addition, we use a new scalable motion coding method which scales the motion vector quadtrees according to the rate-distortion slope of the tree nodes. Experimental results show that the new coding scheme increases the efficiency of the motion coding by more than 25%. The performance of the system is improved accordingly, especially in low bit rates. Moreover, with the scalable motion coding, the subjective and objective coding performance is further enhanced in low bit rate scenarios.

  19. Robustness of the Voluntary Breath-Hold Approach for the Treatment of Peripheral Lung Tumors Using Hypofractionated Pencil Beam Scanning Proton Therapy

    DEFF Research Database (Denmark)

    Dueck, Jenny; Knopf, Antje-Christin; Lomax, Antony;

    2016-01-01

    PURPOSE: The safe clinical implementation of pencil beam scanning (PBS) proton therapy for lung tumors is complicated by the delivery uncertainties caused by breathing motion. The purpose of this feasibility study was to investigate whether a voluntary breath-hold technique could limit the delivery...... uncertainties resulting from interfractional motion. METHODS AND MATERIALS: Data from 15 patients with peripheral lung tumors previously treated with stereotactic radiation therapy were included in this study. The patients had 1 computed tomographic (CT) scan in voluntary breath-hold acquired before treatment......=.008) and tumor size (2F, P=.025; 3F, P=.025). Smaller tumors with large baseline shifts were also at risk for reduced V95% (interaction term baseline/size: 2F, P=.005; 3F, P=.002). CONCLUSIONS: The breath-hold approach is a realistic clinical option for treating lung tumors with PBS proton therapy...

  20. 46 CFR 197.456 - Breathing supply hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being...

  1. 21 CFR 862.3080 - Breath nitric oxide test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breath nitric oxide test system. 862.3080 Section... Systems § 862.3080 Breath nitric oxide test system. (a) Identification. A breath nitric oxide test system is a device intended to measure fractional nitric oxide in human breath. Measurement of changes...

  2. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  3. 42 CFR 84.88 - Breathing bag test.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public... RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a) Breathing bags will be tested in an air atmosphere saturated...

  4. A hybrid breath hold and continued respiration-triggered technique for time-resolved 3D MRI perfusion studies in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hintze, C. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Radiologie; Stemmer, A. [Siemens AG (Germany). Healthcare Sector; Bock, M. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (DE). Medizinische Physik in der Radiologie] (and others)

    2010-01-15

    Assessment of lung cancer perfusion is impaired by respiratory motion. Imaging times for contrast agent wash-out studies often exceed breath hold capabilities, and respiration triggering reduces temporal resolution. Temporally resolved volume acquisition of entire tumors is required to assess heterogeneity. Therefore, we developed and evaluated an MR measurement technique that exceeds a single breath hold, and provides a variable temporal resolution during acquisition while suspending breath-dependent motion. 20 patients with suspected lung cancer were subjected to perfusion studies using a spoiled 3D gradient echo sequence after bolus injection of 0.07 mmol/kg body weight of Gd-DTPA. 10 acquisitions in expiratory breath hold were followed by 50 navigator-triggered acquisitions under free breathing. Post-processing allowed for co-registration of the 3D data sets. An ROI-based visualization of the signal-time curves was performed. In all cases motion-suspended, time-resolved volume data sets (40 x 33 x 10 cm{sup 3}, voxel size: 2.1 x 2.1 x 5.0 mm{sup 3}) were generated with a variable, initially high temporal resolution (2.25 sec) that was synchronized with the breath pattern and covered up to 8(1)/(2) min. In 7 / 20 cases a remaining offset could be reduced by rigid co-registration. The tumors showed fast wash-in, followed by rapid signal decay (8 / 20) or a plateau. The feasibility of a perfusion study with hybrid breath hold and navigator-triggered time-resolved 3D MRI which combines high initial temporal resolution during breath hold with a long wash-out period under free breathing was demonstrated. (orig.)

  5. An introduction to the psychophysiology of breathing.

    Science.gov (United States)

    Ley, R

    1994-06-01

    Breathing can be viewed as an independent variable which affects emotion, cognition, and behavior as well as a dependent variable which reflects changes in emotion, cognition, and behavior. This bidirectional interaction is basic to an appreciation of the significance of breathing in terms of its relevance in research and application. The underlying premise of the present article is that since breathing is a behavior that is under voluntary as well as reflexive control, it can be modified according to the principles of both instrumental training (operant conditioning) and Pavlovian (classical) conditioning. The implications of this premise are relevant to theory, diagnosis, and treatment of stress and anxiety-related disorders (e.g., panic disorder, phobias, test anxiety, occupational strain, and related psychosomatic disorders), and to basic and applied research in the psychophysiology of breathing.

  6. Can Breath Test Detect Stomach Cancers Earlier?

    Science.gov (United States)

    ... news/fullstory_163342.html Can Breath Test Detect Stomach Cancers Earlier? New technology may also spot esophageal cancers ... the only way to diagnose esophageal cancer or stomach cancer is with endoscopy. This method is expensive, invasive ...

  7. Breathing exercises for adults with asthma.

    Science.gov (United States)

    2015-11-01

    Asthma is a common long-term condition that remains poorly controlled in many people despite the availability of pharmacological interventions, evidence-based treatment guidelines and care pathways.(1) There is considerable public interest in the use of non-pharmacological approaches for the treatment of asthma.(2) A survey of people with asthma reported that many have used complementary and alternative medicine, often without the knowledge of their clinical team.(3) Such interventions include breathing techniques, herbal products, homeopathy and acupuncture. The role of breathing exercises within the management of asthma has been controversial, partly because early claims of effectiveness were exaggerated.(4) UK national guidance and international guidelines on the management of asthma have included the option of breathing exercise programmes as an adjuvant to pharmacological treatment.(5,6) Here we discuss the types of breathing exercises used and review the evidence for their effectiveness.

  8. Markerless motion tracking of awake animals in positron emission tomography.

    Science.gov (United States)

    Kyme, Andre; Se, Stephen; Meikle, Steven; Angelis, Georgios; Ryder, Will; Popovic, Kata; Yatigammana, Dylan; Fulton, Roger

    2014-11-01

    Noninvasive functional imaging of awake, unrestrained small animals using motion-compensation removes the need for anesthetics and enables an animal's behavioral response to stimuli or administered drugs to be studied concurrently with imaging. While the feasibility of motion-compensated radiotracer imaging of awake rodents using marker-based optical motion tracking has been shown, markerless motion tracking would avoid the risk of marker detachment, streamline the experimental workflow, and potentially provide more accurate pose estimates over a greater range of motion. We have developed a stereoscopic tracking system which relies on native features on the head to estimate motion. Features are detected and matched across multiple camera views to accumulate a database of head landmarks and pose is estimated based on 3D-2D registration of the landmarks to features in each image. Pose estimates of a taxidermal rat head phantom undergoing realistic rat head motion via robot control had a root mean square error of 0.15 and 1.8 mm using markerless and marker-based motion tracking, respectively. Markerless motion tracking also led to an appreciable reduction in motion artifacts in motion-compensated positron emission tomography imaging of a live, unanesthetized rat. The results suggest that further improvements in live subjects are likely if nonrigid features are discriminated robustly and excluded from the pose estimation process.

  9. Fast and Accurate Exhaled Breath Ammonia Measurement

    OpenAIRE

    Solga, Steven F; Mudalel, Matthew L; Spacek, Lisa A.; Risby, Terence H.

    2014-01-01

    This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Toge...

  10. Optoacoustic 13C-breath test analyzer

    Science.gov (United States)

    Harde, Hermann; Helmrich, Günther; Wolff, Marcus

    2010-02-01

    The composition and concentration of exhaled volatile gases reflects the physical ability of a patient. Therefore, a breath analysis allows to recognize an infectious disease in an organ or even to identify a tumor. One of the most prominent breath tests is the 13C-urea-breath test, applied to ascertain the presence of the bacterium helicobacter pylori in the stomach wall as an indication of a gastric ulcer. In this contribution we present a new optical analyzer that employs a compact and simple set-up based on photoacoustic spectroscopy. It consists of two identical photoacoustic cells containing two breath samples, one taken before and one after capturing an isotope-marked substrate, where the most common isotope 12C is replaced to a large extent by 13C. The analyzer measures simultaneously the relative CO2 isotopologue concentrations in both samples by exciting the molecules on specially selected absorption lines with a semiconductor laser operating at a wavelength of 2.744 μm. For a reliable diagnosis changes of the 13CO2 concentration of 1% in the exhaled breath have to be detected at a concentration level of this isotope in the breath of about 500 ppm.

  11. Swimming in air-breathing fishes.

    Science.gov (United States)

    Lefevre, S; Domenici, P; McKenzie, D J

    2014-03-01

    Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise.

  12. Single breath-hold magnetic resonance cine imaging for fast assessment of global and regional left ventricular function in clinical routine

    Energy Technology Data Exchange (ETDEWEB)

    Nassenstein, Kai; Heilmaier, Christina; Schlosser, Thomas [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Eberle, Holger; Jensen, Christoph J.; Bruder, Oliver [Elisabeth Hospital Essen, Department of Cardiology and Angiology, Essen (Germany); Maderwald, Stefan [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany)

    2010-10-15

    To evaluate a TGRAPPA (temporal parallel acquisition technique)-accelerated, single breath-hold multi-slice cine imaging approach for the assessment of left ventricular (LV) function. One hundred eleven patients were examined at 1.5 T. Cine imaging was performed with single-slice breath-hold acquisitions in short-axis orientation using a SSFP (TR 2.63 ms, TE 1.12 ms, FA 72 ) sequence and a TGRAPPA SSFP (TR 2.66 ms, TE 1.11 ms, FA 72 , AF 3) sequence, which covered the entire LV in multiple short-axis slices during a single breath-hold. End-diastolic (EDV), end-systolic (ESV), stroke volumes (SV), ejection fraction (EF), muscle mass (MM) and regional wall motion were assessed for both data sets. Single breath-hold imaging was feasible in 108 patients. Excellent correlations were observed for all volumetric parameters derived from both data sets (all r > 0.97). While EDV and ESV showed marginally lower values for single breath-hold imaging (EDV: -1.6 {+-} 7.9 ml; ESV: -1.8 {+-} 6.0 ml, p < 0.05), no differences were observed for SV, EF, MM and regional wall motion assessment. Single breath-hold imaging required significant shorter acquisition times (28 {+-} 6 s vs. 335 {+-} 87 s). TGRAPPA-accelerated multi-slice SSPF imaging allows for fast and accurate assessment of regional and global LV function within a single breath-hold. (orig.)

  13. Master equation approach to DNA breathing in heteropolymer DNA

    DEFF Research Database (Denmark)

    Ambjörnsson, Tobias; Banik, Suman K; Lomholt, Michael A

    2007-01-01

    After crossing an initial barrier to break the first base-pair (bp) in double-stranded DNA, the disruption of further bps is characterized by free energies up to a few k(B)T. Thermal motion within the DNA double strand therefore causes the opening of intermittent single-stranded denaturation zones......, the DNA bubbles. The unzipping and zipping dynamics of bps at the two zipper forks of a bubble, where the single strand of the denatured zone joins the still intact double strand, can be monitored by single molecule fluorescence or NMR methods. We here establish a dynamic description of this DNA breathing...... in a heteropolymer DNA with given sequence in terms of a master equation that governs the time evolution of the joint probability distribution for the bubble size and position along the sequence. The transfer coefficients are based on the Poland-Scheraga free energy model. We derive the autocorrelation function...

  14. Vortical Structures in CT-based Breathing Lung Models

    Science.gov (United States)

    Choi, Jiwoong; Lee, Changhyun; Hoffman, Eric; Lin, Ching-Long

    2016-11-01

    The 1D-3D coupled computational fluid dynamics (CFD) lung model is applied to study vortical structures in the human airways during normal breathing cycles. During inhalation, small vortical structures form around the turbulent laryngeal jet and Taylor-Gőrtler-like vortices form near the curved walls in the supraglottal region and at airway bifurcations. On exhalation elongated vortical tubes are formed in the left main bronchus, whereas a relatively slower stream is observed in the right main bronchus. These structures result in helical motions in the trachea, producing long lasting high wall shear stress on the wall. The current study elucidates that the correct employment of image-based airway deformation and lung deflation information is crucial for capturing the physiologically consistent regional airflow structures. The pathophysiological implications of these structures in destruction of tracheal wall will be discussed.

  15. Clinical Applications of CO2 and H2 Breath Test

    OpenAIRE

    ZHAO Si-qian; Chen, Bao-Jun; LUO Zhi-fu

    2016-01-01

    Breath test is non-invasive, high sensitivity and high specificity. In this article, CO2 breath test, H2 breath test and their clinical applications were elaborated. The main applications of CO2 breath test include helicobacter pylori test, liver function detection, gastric emptying test, insulin resistance test, pancreatic exocrine secretion test, etc. H2 breath test can be applied in the diagnosis of lactose malabsorption and detecting small intestinal bacterial overgrowth. With further res...

  16. RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS

    Directory of Open Access Journals (Sweden)

    Gabriel BURLACU,

    2011-11-01

    Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator

  17. Research on Positioning Error Compensation for Micro Milling Machine Tool

    Institute of Scientific and Technical Information of China (English)

    Ming-Jun Chen; Wen-Lan Tian; Yong Xiao; Yan Jiang

    2014-01-01

    Micro milling has many advantages in fabricating three⁃dimensional ( 3D) structure in micrometer scale. The micro milling machine tool with high positioning accuracy is of great importance for getting micro structure with high profile precision and good surface quality. Meanwhile, the method of position error compensation is a good way to improve the accuracy of the micro milling machine tools. In this paper, a software method is adopted to compensate the positioning error and improve the positioning accuracy. According to error cancellation theory, the compensation values are generated and compensation tables are built to adjust the positioning error in the NC system based on Industrial Motion and Automation Control ( IMAC) . The positioning accuracy of linear motor is ±0�3μm without backlash after compensation. In order to verify the effectiveness of compensation on the machining performance, concave spherical surfaces are processed on the micro milling machine tool. The experimental results show that the profile radius error of the spherical surface machined with compensation decreases more than 60%.

  18. Stochastic Wheel-Slip Compensation Based Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)

    SIDHARTHAN, R. K.

    2016-05-01

    Full Text Available Wheel slip compensation is vital for building accurate and reliable dead reckoning based robot localization and mapping algorithms. This investigation presents stochastic slip compensation scheme for robot localization and mapping. Main idea of the slip compensation technique is to use wheel-slip data obtained from experiments to model the variations in slip velocity as Gaussian distributions. This leads to a family of models that are switched depending on the input command. To obtain the wheel-slip measurements, experiments are conducted on a wheeled mobile robot and the measurements thus obtained are used to build the Gaussian models. Then the localization and mapping algorithm is tested on an experimental terrain and a new metric called the map spread factor is used to evaluate the ability of the slip compensation technique. Our results clearly indicate that the proposed methodology improves the accuracy by 72.55% for rotation and 66.67% for translation motion as against an uncompensated mapping system. The proposed compensation technique eliminates the need for extro receptive sensors for slip compensation, complex feature extraction and association algorithms. As a result, we obtain a simple slip compensation scheme for localization and mapping.

  19. The influence of respiratory motion on CT image volume definition

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Romero, Ruth, E-mail: rrromero@salud.madrid.org; Castro-Tejero, Pablo, E-mail: pablo.castro@salud.madrid.org [Servicio de Radiofísica y Protección Radiológica, Hospital Universitario Puerta de Hierro Majadahonda, 28222 Madrid (Spain)

    2014-04-15

    Purpose: Radiotherapy treatments are based on geometric and density information acquired from patient CT scans. It is well established that breathing motion during scan acquisition induces motion artifacts in CT images, which can alter the size, shape, and density of a patient's anatomy. The aim of this work is to examine and evaluate the impact of breathing motion on multislice CT imaging with respiratory synchronization (4DCT) and without it (3DCT). Methods: A specific phantom with a movable insert was used. Static and dynamic phantom acquisitions were obtained with a multislice CT. Four sinusoidal breath patterns were simulated to move known geometric structures longitudinally. Respiratory synchronized acquisitions (4DCT) were performed to generate images during inhale, intermediate, and exhale phases using prospective and retrospective techniques. Static phantom data were acquired in helical and sequential mode to define a baseline for each type of respiratory 4DCT technique. Taking into account the fact that respiratory 4DCT is not always available, 3DCT helical image studies were also acquired for several CT rotation periods. To study breath and acquisition coupling when respiratory 4DCT was not performed, the beginning of the CT image acquisition was matched with inhale, intermediate, or exhale respiratory phases, for each breath pattern. Other coupling scenarios were evaluated by simulating different phantom and CT acquisition parameters. Motion induced variations in shape and density were quantified by automatic threshold volume generation and Dice similarity coefficient calculation. The structure mass center positions were also determined to make a comparison with their theoretical expected position. Results: 4DCT acquisitions provided volume and position accuracies within ±3% and ±2 mm for structure dimensions >2 cm, breath amplitude ≤15 mm, and breath period ≥3 s. The smallest object (1 cm diameter) exceeded 5% volume variation for the breath

  20. ISAR Motion Compensation using the Registration-Restoration-Fusion Method

    Science.gov (United States)

    2006-06-01

    diffusion de la cible et donne lieu A une image ISAR bien focalisre. Le concept de base consiste A utiliser la mrthode du voisin le plus proche pour...de restitution, pourrait etre utilis6e pour grnrrer [’image ISAR focalisre. Cette mrthode proposre a &6 appliqure avec succ~s A des donn~es ISAR tant...constitue une option efficace pour r~soudre la bavure de [’image caus~e par le comportement variable dans le temps et donne lieu At une image ISAR bien

  1. Compensation for Unconstrained Catheter Shaft Motion in Cardiac Catheters

    Science.gov (United States)

    Degirmenci, Alperen; Loschak, Paul M.; Tschabrunn, Cory M.; Anter, Elad; Howe, Robert D.

    2016-01-01

    Cardiac catheterization with ultrasound (US) imaging catheters provides real time US imaging from within the heart, but manually navigating a four degree of freedom (DOF) imaging catheter is difficult and requires extensive training. Existing work has demonstrated robotic catheter steering in constrained bench top environments. Closed-loop control in an unconstrained setting, such as patient vasculature, remains a significant challenge due to friction, backlash, and physiological disturbances. In this paper we present a new method for closed-loop control of the catheter tip that can accurately and robustly steer 4-DOF cardiac catheters and other flexible manipulators despite these effects. The performance of the system is demonstrated in a vasculature phantom and an in vivo porcine animal model. During bench top studies the robotic system converged to the desired US imager pose with sub-millimeter and sub-degree-level accuracy. During animal trials the system achieved 2.0 mm and 0.65° accuracy. Accurate and robust robotic navigation of flexible manipulators will enable enhanced visualization and treatment during procedures. PMID:27525170

  2. A statistical approach to motion compensated cone-beam

    DEFF Research Database (Denmark)

    Lyksborg, Mark; Hansen, Mads Fogtmann; Larsen, Rasmus

    One of the problems arising in radiotherapy planning is the quality of CT planning data. In the following attention is giving to the cone-beam scanning geometry where reconstruction of a 3D volume based on 2D projections, using the classic Feldkamp-Davis-Kress (FDK) algorithm requires a large...

  3. Motion compensated iterative reconstruction for cardiac X-ray tomography

    NARCIS (Netherlands)

    A.A. Isola (Alfonso)

    2010-01-01

    textabstractWithin this Ph.D. project, three-dimensional reconstruction methods for moving objects (with a focus on the human heart) from cone-beam X-ray projections using iterative reconstruction algorithms were developed and evaluated. This project was carried in collaboration with the Digital Ima

  4. A Statistical Approach to Motion Compensated Cone Beam Reconstruction

    DEFF Research Database (Denmark)

    Lyksborg, Mark; Hansen, Mads Fogtmann; Larsen, Rasmus

    2010-01-01

    One of the problems arising in radiotherapy planning is the quality of CT planning data. In the following attention is giving to the cone-beam scanning geometry where reconstruction of a 3D volume based on 2D projections, using the classic Feldkamp-Davis-Kress (FDK) algorithm requires a large...

  5. Compensability index for compensation radiotherapy after treatment interruptions

    Directory of Open Access Journals (Sweden)

    Putora Paul

    2012-12-01

    Full Text Available Abstract Background The goal of our work was to develop a simple method to evaluate a compensation treatment after unplanned treatment interruptions with respect to their tumour- and normal tissue effect. Methods We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions. In order to express and visualize the deviations from the originally planned tumour and normal tissue effects we defined the compensability index. Results The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect. An automated tool provides a method for quick evaluation of compensation treatments. Conclusions The compensability index calculation may serve as a decision support system based on existing and established recommendations.

  6. Compensation for Occupational Cancer

    OpenAIRE

    Kim, Inah; Kim, Eun-A; Kim, Jae Young

    2014-01-01

    The legal scope and criteria for occupational cancer in Korea was out of date. The aim of this study was to review the current criteria for occupational cancer and amend the existent criteria on the basis of recent scientific evidence. The scientific evidence and the legal list of occupational cancer were analyzed to identify the causes of occupational cancer on a global scale. The relationship between compensated occupational cancer cases and carcinogen exposure in Korea was examined. The fa...

  7. Video super-resolution using simultaneous motion and intensity calculations

    DEFF Research Database (Denmark)

    Keller, Sune Høgild; Lauze, Francois Bernard; Nielsen, Mads

    2011-01-01

    In this paper we propose an energy based algorithm for motion compensated video super-resolution (VSR) targeted on upscaling of standard definition (SD) video to high definition (HD) video. Since the motion (flow field) of the image sequence is generally unknown, we introduce a formulation...

  8. SU-C-210-03: Impact of Breathing Irregularities On Gated Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Schiuma, D; Arheit, M; Schmelzer, P; Scheib, S [Varian Medical Systems, Imaging Laboratory GmbH, Baden-Daettwil (Switzerland); Buchsbaum, T; Pemler, P [Radioonkologie, Stadtspital Triemli, Zurich (Switzerland)

    2015-06-15

    Purpose: To evaluate the effect of breathing irregularities on target location in gated treatments using amplitude and phase gating. Methods: 111 breathing patterns acquired using RPM system were categorized based on period and amplitude STD as regular (STD period ≤ 0.5 s, STD amplitude ≤ 1.5 mm), medium (0.5 s < STD period ≤ 1 s, 1.5 mm < STD amplitude ≤ 3 mm) and irregular (STD period > 1 s, STD amplitude > 3 mm). One pattern representative of the average defined population was selected per category and corresponding target motion reproduced using Quasar Respiratory Motion Phantom. Phantom in motion underwent 4D-CT scan with phase reconstruction. Gated window was defined at end of exhale and DRRs reconstructed in treatment planning at 40% (beam on) and 60% phase (beam off). Target location uncertainty was assessed by comparing gated kV triggered images continuously acquired at beam on/off on a True Beam 2.0 with corresponding DRRs. Results: Average target uncertainty with amplitude gating was in [0.4 – 1.9] mm range for the different scenarios with maximum STD of 1.2 mm for the irregular pattern. Average target uncertainty with phase gating was [1.1 – 2.2] mm for regular and medium patterns, while it increased to [3.6 – 9.6] mm for the irregular pattern. Live gated motion was stable with amplitude gating, while increasing with phase gating for the irregular pattern. Treatment duration range was [68 – 160] s with amplitude and [70 – 74] s with phase gating. Conclusion: Breathing irregularities were found to affect gated treatments only when using phase gating. For regular and medium patterns no significant difference was found between the two gating strategies. Amplitude gating ensured stable gated motion within the different patterns, thus reducing intra-fraction target location variability for the irregular pattern and resulting in longer treatment duration.

  9. Ecological sounds affect breath duration more than artificial sounds.

    Science.gov (United States)

    Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, Tiziano

    2016-01-01

    Previous research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants' breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants' breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled.

  10. Graph-based retrospective 4D image construction from free-breathing MRI slice acquisitions

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Ciesielski, Krzysztof C.; McDonough, Joseph M.; Mong, Andrew; Campbell, Robert M.

    2014-03-01

    4D or dynamic imaging of the thorax has many potential applications [1, 2]. CT and MRI offer sufficient speed to acquire motion information via 4D imaging. However they have different constraints and requirements. For both modalities both prospective and retrospective respiratory gating and tracking techniques have been developed [3, 4]. For pediatric imaging, x-ray radiation becomes a primary concern and MRI remains as the de facto choice. The pediatric subjects we deal with often suffer from extreme malformations of their chest wall, diaphragm, and/or spine, as such patient cooperation needed by some of the gating and tracking techniques are difficult to realize without causing patient discomfort. Moreover, we are interested in the mechanical function of their thorax in its natural form in tidal breathing. Therefore free-breathing MRI acquisition is the ideal modality of imaging for these patients. In our set up, for each coronal (or sagittal) slice position, slice images are acquired at a rate of about 200-300 ms/slice over several natural breathing cycles. This produces typically several thousands of slices which contain both the anatomic and dynamic information. However, it is not trivial to form a consistent and well defined 4D volume from these data. In this paper, we present a novel graph-based combinatorial optimization solution for constructing the best possible 4D scene from such data entirely in the digital domain. Our proposed method is purely image-based and does not need breath holding or any external surrogates or instruments to record respiratory motion or tidal volume. Both adult and children patients' data are used to illustrate the performance of the proposed method. Experimental results show that the reconstructed 4D scenes are smooth and consistent spatially and temporally, agreeing with known shape and motion of the lungs.

  11. Lung cancer biomarkers in exhaled breath.

    Science.gov (United States)

    Amann, Anton; Corradi, Massimo; Mazzone, Peter; Mutti, Antonio

    2011-03-01

    Lung cancer is the leading cause of cancer-related mortality worldwide. Methods for early detection of lung cancer, such as computerized tomography scanning technology, often discover a large number of small lung nodules, posing a new problem to radiologists and chest physicians. The vast majority of these nodules will be benign, but there is currently no easy way to determine which nodules represent very early lung cancer. Adjuvant testing with PET imaging and nonsurgical biopsies has a low yield for these small indeterminate nodules, carries potential morbidity and is costly. Indeed, purely morphological criteria seem to be insufficient for distinguishing lung cancer from benign nodules at early stages with sufficient confidence, therefore false positives undergoing surgical resection frequently occur. A molecular approach to the diagnosis of lung cancer through the analysis of exhaled breath could greatly improve the specificity of imaging procedures. A biomarker-driven approach to signs or symptoms possibly due to lung cancer would represent a complementary tool aimed at ruling out (with known error probability) rather than diagnosing lung cancer. Volatile and nonvolatile components of the breath are being studied as biomarkers of lung cancer. Breath testing is noninvasive and potentially inexpensive. There is promise that an accurate lung cancer breath biomarker, capable of being applied clinically, will be developed in the near future. In this article, we summarize some of the rationale for breath biomarker development, review the published literature in this field and provide thoughts regarding future directions.

  12. Sudarshan kriya yoga: Breathing for health

    Directory of Open Access Journals (Sweden)

    Sameer A Zope

    2013-01-01

    Full Text Available Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind-body connection, and the benefits of Sudarshan Kriya Yoga (SKY in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders.

  13. Pulse Ejection Presentation System Synchronized with Breathing

    Science.gov (United States)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  14. Retrospective Reconstruction of High Temporal Resolution Cine Images from Real-Time MRI using Iterative Motion Correction

    DEFF Research Database (Denmark)

    Hansen, Michael Schacht; Sørensen, Thomas Sangild; Arai, Andrew

    2012-01-01

    Cardiac function has traditionally been evaluated using breath-hold cine acquisitions. However, there is a great need for free breathing techniques in patients who have difficulty in holding their breath. Real-time cardiac MRI is a valuable alternative to the traditional breath-hold imaging...... approach, but the real-time images are often inferior in spatial and temporal resolution. This article presents a general method for reconstruction of high spatial and temporal resolution cine images from a real-time acquisition acquired over multiple cardiac cycles. The method combines parallel imaging...... and motion correction based on nonrigid registration and can be applied to arbitrary k-space trajectories. The method is demonstrated with real-time Cartesian imaging and Golden Angle radial acquisitions, and the motion-corrected acquisitions are compared with raw real-time images and breath-hold cine...

  15. 38 CFR 3.4 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Compensation. 3.4 Section..., Compensation, and Dependency and Indemnity Compensation General § 3.4 Compensation. (a) Compensation. This term...) Disability compensation. (1) Basic entitlement for a veteran exists if the veteran is disabled as the...

  16. Technologies for Clinical Diagnosis Using Expired Human Breath Analysis

    Directory of Open Access Journals (Sweden)

    Thalakkotur Lazar Mathew

    2015-02-01

    Full Text Available This review elucidates the technologies in the field of exhaled breath analysis. Exhaled breath gas analysis offers an inexpensive, noninvasive and rapid method for detecting a large number of compounds under various conditions for health and disease states. There are various techniques to analyze some exhaled breath gases, including spectrometry, gas chromatography and spectroscopy. This review places emphasis on some of the critical biomarkers present in exhaled human breath, and its related effects. Additionally, various medical monitoring techniques used for breath analysis have been discussed. It also includes the current scenario of breath analysis with nanotechnology-oriented techniques

  17. TU-EF-304-04: A Heart Motion Model for Proton Scanned Beam Chest Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    White, B; Kiely, J Blanco; Lin, L; Freedman, G; Both, S [University of Pennsylvania, Philadelphia, PA (United States); Vennarini, S [Operativa di Protonterapia, Azienda Provinciale per i Servizi Sanitari, Trento, Trento (Italy); Santhanam, A; Low, D [University of California, Los Angeles, Los Angeles, CA (United States)

    2015-06-15

    Purpose: To model fast-moving heart surface motion as a function of cardiac-phase in order to compensate for the lack of cardiac-gating in evaluating accurate dose to coronary structures. Methods: Ten subjects were prospectively imaged with a breath-hold, cardiac-gated MRI protocol to determine heart surface motion. Radial and planar views of the heart were resampled into a 3-dimensional volume representing one heartbeat. A multi-resolution optical flow deformable image registration algorithm determined tissue displacement during the cardiac-cycle. The surface of the heart was modeled as a thin membrane comprised of voxels perpendicular to a pencil beam scanning (PBS) beam. The membrane’s out-of-plane spatial displacement was modeled as a harmonic function with Lame’s equations. Model accuracy was assessed with the root mean squared error (RMSE). The model was applied to a cohort of six chest wall irradiation patients with PBS plans generated on phase-sorted 4DCT. Respiratory motion was separated from the cardiac motion with a previously published technique. Volumetric dose painting was simulated and dose accumulated to validate plan robustness (target coverage variation accepted within 2%). Maximum and mean heart surface dose assessed the dosimetric impact of heart and coronary artery motion. Results: Average and maximum heart surface displacements were 2.54±0.35mm and 3.6mm from the end-diastole phase to the end-systole cardiac-phase respectively. An average RMSE of 0.11±0.04 showed the model to be accurate. Observed errors were greatest between the circumflex artery and mitral valve level of the heart anatomy. Heart surface displacements correspond to a 3.6±1.0% and 5.1±2.3% dosimetric impact on the maximum and mean heart surface DVH indicators respectively. Conclusion: Although heart surface motion parallel to beam’s direction was substantial, its maximum dosimetric impact was 5.1±2.3%. Since PBS delivers low doses to coronary structures relative to

  18. A Fast quarter-pixel motion estimation algorithm for H.264/AVC

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A fast quarter-pixel motion estimation algorithm is proposed in this paper. The proposed algorithm based on mathematical models of the motion compensated prediction errors. Unlike conventional quarter-pixel accurate motion estimation algorithm,proposed algorithm can avoid fractional-pixel interpolation and subsequent fractional-pixel search after integer-precision motion estimation. Experiments show that the proposed algorithm greatly reduces the computational complexity of quarterpixel motion estimation, while keeping the nearly equal quality of the image.

  19. Motion feature extraction scheme for content-based video retrieval

    Science.gov (United States)

    Wu, Chuan; He, Yuwen; Zhao, Li; Zhong, Yuzhuo

    2001-12-01

    This paper proposes the extraction scheme of global motion and object trajectory in a video shot for content-based video retrieval. Motion is the key feature representing temporal information of videos. And it is more objective and consistent compared to other features such as color, texture, etc. Efficient motion feature extraction is an important step for content-based video retrieval. Some approaches have been taken to extract camera motion and motion activity in video sequences. When dealing with the problem of object tracking, algorithms are always proposed on the basis of known object region in the frames. In this paper, a whole picture of the motion information in the video shot has been achieved through analyzing motion of background and foreground respectively and automatically. 6-parameter affine model is utilized as the motion model of background motion, and a fast and robust global motion estimation algorithm is developed to estimate the parameters of the motion model. The object region is obtained by means of global motion compensation between two consecutive frames. Then the center of object region is calculated and tracked to get the object motion trajectory in the video sequence. Global motion and object trajectory are described with MPEG-7 parametric motion and motion trajectory descriptors and valid similar measures are defined for the two descriptors. Experimental results indicate that our proposed scheme is reliable and efficient.

  20. Effect of different breathing patterns in the same patient on stereotactic ablative body radiotherapy dosimetry for primary renal cell carcinoma: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Daniel, E-mail: Daniel.Pham@petermac.org [Radiotherapy Services, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Kron, Tomas [Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Foroudi, Farshad; Siva, Shankar [Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia)

    2013-10-01

    Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26 Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist's discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk.

  1. Effect of different breathing patterns in the same patient on stereotactic ablative body radiotherapy dosimetry for primary renal cell carcinoma: a case study.

    Science.gov (United States)

    Pham, Daniel; Kron, Tomas; Foroudi, Farshad; Siva, Shankar

    2013-01-01

    Stereotactic ablative body radiotherapy (SABR) for primary renal cell carcinoma (RCC) targets requires motion management strategies to verify dose delivery. This case study highlights the effect of a change in patient breathing amplitude on the dosimetry to organs at risk and target structures. A 73-year-old male patient was planned for receiving 26Gy of radiation in 1 fraction of SABR for a left primary RCC. The patient was simulated with four-dimensional computed tomography (4DCT) and the tumor internal target volume (ITV) was delineated using the 4DCT maximum intensity projection. However, the initially planned treatment was abandoned at the radiation oncologist's discretion after pretreatment cone-beam CT (CBCT) motion verification identified a greater than 50% reduction in superior to inferior diaphragm motion as compared with the planning 4DCT. This patient was resimulated with respiratory coaching instructions. To assess the effect of the change in breathing on the dosimetry to the target, each plan was recalculated on the data set representing the change in breathing condition. A change from smaller to larger breathing showed a 46% loss in planning target volume (PTV) coverage, whereas a change from larger breathing to smaller breathing resulted in an 8% decrease in PTV coverage. ITV coverage was similarly reduced by 8% in both scenarios. This case study highlights the importance of tools to verify breathing motion prior to treatment delivery. 4D image guided radiation therapy verification strategies should focus on not only verifying ITV margin coverage but also the effect on the surrounding organs at risk.

  2. Decompression sickness following breath-hold diving.

    Science.gov (United States)

    Schipke, J D; Gams, E; Kallweit, Oliver

    2006-01-01

    Despite convincing evidence of a relationship between breath-hold diving and decompression sickness (DCS), the causal connection is only slowly being accepted. Only the more recent textbooks have acknowledged the risks of repetitive breath-hold diving. We compare four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. Finally, national and international associations (e.g., International Association of Free Drives [IAFD] or Association Internationale pour Le Developpment De L'Apnee [AIDA]) promote free-diving championships including deep diving categories such as constant weight, variable weight, and no limit. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record is presently set at a depth of 171 m. This review presents data found after searching Medline and ISI Web of Science and using appropriate Internet search engines (e.g., Google). We report some 90 cases in which DCS occurred after repetitive breath-hold dives. Even today, the risk of suffering from DCS after repetitive breath-hold diving is often not acknowledged. We strongly suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent, and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. We propose therefore the development of easily manageable

  3. Electrospray ionization of volatiles in breath

    Science.gov (United States)

    Martínez-Lozano, P.; de La Mora, J. Fernández

    2007-08-01

    Recent work by Zenobi and colleagues [H. Chen, A. Wortmann, W. Zhang, R. Zenobi, Angew. Chem. Int. Ed. 46 (2007) 580] reports that human breath charged by contact with an electrospray (ES) cloud yields many mass peaks of species such as urea, glucose, and other ions, some with molecular weights above 1000 Da. All these species are presumed to be involatile, and to originate from breath aerosols by so-called extractive electrospray ionization EESI [H. Chen, A. Venter, R.G. Cooks, Chem. Commun. (2006) 2042]. However, prior work by Fenn and colleagues [C.M. Whitehouse, F. Levin, C.K. Meng, J.B. Fenn, Proceedings of the 34th ASMS Conference on Mass Spectrometry and Allied Topics, Denver, 1986 p. 507; S. Fuerstenau, P. Kiselev, J.B. Fenn, Proceedings of the 47th ASMS Conference on Mass Spectrometry, 1999, Dallas, TX, 1999] and by Hill and colleagues [C. Wu, W.F. Siems, H.H. Hill Jr., Anal. Chem. 72 (2000) 396] have reported the ability of electrospray drops to ionize a variety of low vapor pressure substances directly from the gas phase, without an apparent need for the vapor to be brought into the charging ES in aerosol form. The Ph.D. Thesis of Martínez-Lozano [P. Martínez-Lozano Sinués, Ph.D. Thesis, Department of Thermal and Fluid Engineering, University Carlos III of Madrid; April 5, 2006 (in Spanish); http://hdl.handle.net/10016/655] had also previously argued that the numerous human breath species observed via a similar ES ionization approach were in fact ionized directly from the vapor. Here, we observe that passage of the breath stream through a submicron filter does not eliminate the majority of the breath vapors seen in the absence of the filter. We conclude that direct vapor charging is the leading mechanism in breath ionization by electrospray drops, though aerosol ionization may also play a role.

  4. Breath testing and personal exposure--SIFT-MS detection of breath acetonitrile for exposure monitoring.

    Science.gov (United States)

    Storer, Malina; Curry, Kirsty; Squire, Marie; Kingham, Simon; Epton, Michael

    2015-05-26

    Breath testing has potential for the rapid assessment of the source and impact of exposure to air pollutants. During the development of a breath test for acetonitrile using selected ion flow tube mass spectrometry (SIFT-MS) raised acetonitrile concentrations in the breath of volunteers were observed that could not be explained by known sources of exposure. Workplace/laboratory exposure to acetonitrile was proposed since this was common to the volunteers with increased breath concentrations. SIFT-MS measurements of acetonitrile in breath and air were used to confirm that an academic chemistry laboratory was the source of exposure to acetonitrile, and quantify the changes that occurred to exhaled acetonitrile after exposure. High concentrations of acetonitrile were detected in the air of the chemistry laboratory. However, concentrations in the offices were not significantly different across the campus. There was a significant difference in the exhaled acetonitrile concentrations of people who worked in the chemistry laboratories (exposed) and those who did not (non-exposed). SIFT-MS testing of air and breath made it possible to determine that occupational exposure to acetonitrile in the chemistry laboratory was the cause of increased exhaled acetonitrile. Additionally, the sensitivity was adequate to measure the changes to exhaled amounts and found that breath concentrations increased quickly with short exposure and remained increased even after periods of non-exposure. There is potential to add acetonitrile to a suite of VOCs to investigate source and impact of poor air quality.

  5. An autotuning respiration compensation system based on ultrasound image tracking.

    Science.gov (United States)

    Kuo, Chia-Chun; Chuang, Ho-Chiao; Teng, Kuan-Ting; Hsu, Hsiao-Yu; Tien, Der-Chi; Wu, Chih-Jen; Jeng, Shiu-Chen; Chiou, Jeng-Fong

    2016-11-22

    The purpose of this study was to develop an ultrasound image tracking algorithm (UITA) for extracting the exact displacement of internal organs caused by respiratory motion. The program can track organ displacements in real time, and analyze the displacement signals associated with organ displacements via a respiration compensating system (RCS). The ultrasound imaging system is noninvasive and has a high spatial resolution and a high frame rate (around 32 frames/s), which reduces the radiation doses that patients receive during computed tomography and X-ray observations. This allows for the continuous noninvasive observation and compensation of organ displacements simultaneously during a radiation therapy session.This study designed a UITA for tracking the motion of a specific target, such as the human diaphragm. Simulated diaphragm motion driven by a respiration simulation system was observed with an ultrasound imaging system, and then the induced diaphragm displacements were calculated by our proposed UITA. These signals were used to adjust the gain of the RCS so that the amplitudes of the compensation signals were close to the target movements. The inclination angle of the ultrasound probe with respect to the surface of the abdomen affects the results of ultrasound image displacement tracking. Therefore, the displacement of the phantom was verified by a LINAC with different inclination-angle settings of the ultrasound probe. The experimental results indicate that the best inclination angle of the ultrasound probe is 40 degrees, since this results in the target displacement of the ultrasound images being close to the actual target motion. The displacement signals of the tracking phantom and the opposing displacement signals created by the RCS were compared to assess the positioning accuracy of our proposed ultrasound image tracking technique combined with the RCS.When the ultrasound probe was inclined by 40 degrees in simulated respiration experiments using sine

  6. Medication effects on sleep and breathing.

    Science.gov (United States)

    Seda, Gilbert; Tsai, Sheila; Lee-Chiong, Teofilo

    2014-09-01

    Sleep respiration is regulated by circadian, endocrine, mechanical and chemical factors, and characterized by diminished ventilatory drive and changes in Pao2 and Paco2 thresholds. Hypoxemia and hypercapnia are more pronounced during rapid eye movement. Breathing is influenced by sleep stage and airway muscle tone. Patient factors include medical comorbidities and body habitus. Medications partially improve obstructive sleep apnea and stabilize periodic breathing at altitude. Potential adverse consequences of medications include precipitation or worsening of disorders. Risk factors for adverse medication effects include aging, medical disorders, and use of multiple medications that affect respiration.

  7. Bending and Breathing Modes of the Galactic Disk

    CERN Document Server

    Widrow, Lawrence M; Chequers, Matthew H; Cheng, Edward

    2014-01-01

    We explore the hypothesis that a passing satellite or dark matter subhalo has excited coherent oscillations of the Milky Way's stellar disk in the direction perpendicular to the Galactic midplane. This work is motivated by recent observations of spatially dependent bulk vertical motions within ~ kpc of the Sun. A satellite can transfer a fraction of its orbital energy to the disk stars as it plunges through the Galactic midplane thereby heating and thickening the disk. Bulk motions arise during the early stages of such an event when the disk is still in an unrelaxed state. We present simple toy-model calculations and simulations of disk-satellite interactions, which show that the response of the disk depends on the relative velocity of the satellite. When the component of the satellite's velocity perpendicular to the disk is small compared with that of the stars, the perturbation is predominantly a bending mode. Conversely, breathing and higher order modes are excited when the vertical velocity of the satelli...

  8. Comparison of two devices and two breathing patterns for exhaled breath condensate sampling.

    Directory of Open Access Journals (Sweden)

    Eva-Maria Hüttmann

    Full Text Available Analysis of exhaled breath condensate (EBC is a noninvasive method to access the epithelial lining fluid of the lungs. Due to standardization problems the method has not entered clinical practice. The aim of the study was to assess the comparability for two commercially available devices in healthy controls. In addition, we assessed different breathing patterns in healthy controls with protein markers to analyze the source of the EBC.EBC was collected from ten subjects using the RTube and ECoScreen Turbo in a randomized crossover design, twice with every device--once in tidal breathing and once in hyperventilation. EBC conductivity, pH, surfactant protein A, Clara cell secretory protein and total protein were assessed. Bland-Altman plots were constructed to display the influence of different devices or breathing patterns and the intra-class correlation coefficient (ICC was calculated. The volatile organic compound profile was measured using the electronic nose Cyranose 320. For the analysis of these data, the linear discriminant analysis, the Mahalanobis distances and the cross-validation values (CVV were calculated.Neither the device nor the breathing pattern significantly altered EBC pH or conductivity. ICCs ranged from 0.61 to 0.92 demonstrating moderate to very good agreement. Protein measurements were greatly influenced by breathing pattern, the device used, and the way in which the results were reported. The electronic nose could distinguish between different breathing patterns and devices, resulting in Mahalanobis distances greater than 2 and CVVs ranging from 64% to 87%.EBC pH and (to a lesser extent EBC conductivity are stable parameters that are not influenced by either the device or the breathing patterns. Protein measurements remain uncertain due to problems of standardization. We conclude that the influence of the breathing maneuver translates into the necessity to keep the volume of ventilated air constant in further studies.

  9. Breathing adapted radiotherapy for breast cancer: comparison of free breathing gating with the breath-hold technique

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia; Pedersen, Anders N; Nøttrup, Trine Jakobi;

    2005-01-01

    -hold (EBH). The Varian Real-time Position Management system (RPM) was used to monitor respiratory movement and to gate the scanner. For each breathing phase, a population based internal margin (IM) was estimated based on average chest wall excursion, and incorporated into an individually optimised three...

  10. In vivo proton MRS of normal pancreas metabolites during breath-holding and free-breathing

    Energy Technology Data Exchange (ETDEWEB)

    Su, T.-H. [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China); Jin, E.-H., E-mail: erhujin1@hotmail.com [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China); Shen, H. [GE China Company Ltd, Healthcare, General Electric Company, Beijing (China); Zhang, Y.; He, W. [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 95 Yong-An Road, Beijing (China)

    2012-07-15

    Aim: To characterize normal pancreas metabolites using in vivo proton magnetic resonance spectroscopy ({sup 1}H MRS) at 3 T under conditions of breath-holding and free-breathing. Materials and methods: The pancreases of 32 healthy volunteers were examined using {sup 1}H MRS during breath-holding and free-breathing acquisitions in a single-voxel point-resolved selective spectroscopy sequence (PRESS) technique using a 3 T MRI system. Resonances were compared between paired spectra of the two breathing modes. Furthermore, correlations between lipid (Lip) content and age, body-mass index (BMI), as well as choline (Cho) peak visibility of the normal pancreas were analysed during breath-holding. Results: Twenty-nine pairs of spectra were successfully obtained showing three major resonances, Lip, Cho, cholesterol and the unsaturated parts of the olefinic region of fatty acids (Chol + Unsat). Breath-hold spectra were generally better, with higher signal-to-noise ratios (SNR; Z=-2.646, p = 0.008) and Cho peak visible status (Z=-2.449, p = 0.014). Correlations were significant between spectra acquired by the two breathing modes, especially for Lip height, Lip area, and the area of other peaks at 1.9-4.1 ppm. However, the Lip resonance was significantly different between the spectra of the two breathing modes (p < 0.05). In the breath-holding spectra, there were significant positive correlations between Lip peak height, area, and age (r = 0.491 and 0.521, p = 0.007 and 0.004), but not between Lip peak area and BMI. There was no statistical difference in Cho resonances between males and females. The Lip peak height and area were significantly higher in the Cho peak invisible group than in the Cho peak visible group (t = 2.661 and 2.353, p = 0.030 and 0.043). Conclusion: In vivo{sup 1}H MRS of the normal pancreas at 3 T is technically feasible and can characterize several metabolites. {sup 1}H MRS during breath-holding acquisition is superior to that during free-breathing

  11. Divergence compensation for hardware-in-the-loop simulation of stiffness-varying discrete contact in space

    Science.gov (United States)

    Qi, Chenkun; Zhao, Xianchao; Gao, Feng; Ren, Anye; Hu, Yan

    2016-11-01

    The hardware-in-the-loop (HIL) contact simulation for flying objects in space is challenging due to the divergence caused by the time delay. In this study, a divergence compensation approach is proposed for the stiffness-varying discrete contact. The dynamic response delay of the motion simulator and the force measurement delay are considered. For the force measurement delay, a phase lead based force compensation approach is used. For the dynamic response delay of the motion simulator, a response error based force compensation approach is used, where the compensation force is obtained from the real-time identified contact stiffness and real-time measured position response error. The dynamic response model of the motion simulator is not required. The simulations and experiments show that the simulation divergence can be compensated effectively and satisfactorily by using the proposed approach.

  12. Shape-correlated Deformation Statistics for Respiratory Motion Prediction in 4D Lung

    OpenAIRE

    Liu, Xiaoxiao; Oguz, Ipek; Pizer, Stephen M.; Mageras, Gig S.

    2010-01-01

    4D image-guided radiation therapy (IGRT) for free-breathing lungs is challenging due to the complicated respiratory dynamics. Effective modeling of respiratory motion is crucial to account for the motion affects on the dose to tumors. We propose a shape-correlated statistical model on dense image deformations for patient-specic respiratory motion estimation in 4D lung IGRT. Using the shape deformations of the high-contrast lungs as the surrogate, the statistical model trained from the plannin...

  13. Diaphragm motion characterization using chest motion data for biomechanics-based lung tumor tracking during EBRT

    Science.gov (United States)

    Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas

    2016-03-01

    Despite recent advances in image-guided interventions, lung cancer External Beam Radiation Therapy (EBRT) is still very challenging due to respiration induced tumor motion. Among various proposed methods of tumor motion compensation, real-time tumor tracking is known to be one of the most effective solutions as it allows for maximum normal tissue sparing, less overall radiation exposure and a shorter treatment session. As such, we propose a biomechanics-based real-time tumor tracking method for effective lung cancer radiotherapy. In the proposed algorithm, the required boundary conditions for the lung Finite Element model, including diaphragm motion, are obtained using the chest surface motion as a surrogate signal. The primary objective of this paper is to demonstrate the feasibility of developing a function which is capable of inputting the chest surface motion data and outputting the diaphragm motion in real-time. For this purpose, after quantifying the diaphragm motion with a Principal Component Analysis (PCA) model, correlation coefficient between the model parameters of diaphragm motion and chest motion data was obtained through Partial Least Squares Regression (PLSR). Preliminary results obtained in this study indicate that the PCA coefficients representing the diaphragm motion can be obtained through chest surface motion tracking with high accuracy.

  14. 42 CFR 84.195 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Cartridge Respirators § 84.195 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent: (a) Restriction of free...

  15. 42 CFR 84.132 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... Respirators § 84.132 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with supplied-air respirators shall be designed and constructed to prevent: (a) Restriction of free...

  16. Apolo Ohno: Breathing Easier | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... please turn Javascript on. Feature: Breathing Easier Apolo Ohno: Breathing Easier Past Issues / Fall 2013 Table of ... skating. What does the future hold for Apolo Ohno? Even though I'm no longer skating competitively, ...

  17. Urban agglomeration and CEO compensation

    OpenAIRE

    Francis, Bill; Hasan, Iftekhar; John, Kose; Waisman , Maya

    2012-01-01

    An underlying assumption in the executive compensation literature is that there is a national labor market for CEOs. The urban economics literature, however, documents higher ability among workers in large metropolitans, which results in a real and stable urban wage premium. In this paper, we investigate the link between the spatial clustering of firms in big, central cities (i.e., urban agglomeration) and the level and structure of CEO compensation. Using CEO compensation data for the period...

  18. Measuring breath acetone for monitoring fat loss: Review

    OpenAIRE

    Anderson, Joseph C.

    2015-01-01

    Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in...

  19. Breathing Better with a COPD Diagnosis

    Science.gov (United States)

    Now that you kNow it’s CoPD, here’s how to breathe better. You have taken the important step of being aware of your symptoms, and seeing your doctor ... care provider for testing and a diagnosis. While COPD (Chronic Obstructive Pulmonary Disease) is a serious lung ...

  20. Ineffective breathing pattern related to malnutrition.

    Science.gov (United States)

    Openbrier, D R; Covey, M

    1987-03-01

    This article has highlighted the problem of malnutrition in the stable COPD patient and the critically ill, hypercatabolic patient, and has reviewed resultant mechanisms which influence the alteration of breathing pattern. These complex patients present a challenge for the nurse. Table 1 briefly summarizes the manifestations of malnutrition, goals, interventions and expected outcomes of the nursing diagnosis, ineffective breathing pattern related to malnutrition. The goal of the interventions is to modify the cause (malnutrition) of the nursing diagnosis (altered breathing pattern). The success of the interventions will lead to the achievement of expected outcome As expected outcomes are achieved, relief of signs and symptoms related to the nursing diagnosis will occur. The nurse caring for the patient with actual or potential malnutrition must be knowledgeable about the physiology of malnutrition and effect on breathing pattern. It is essential that the nurse assess and provide appropriate nutritional support and evaluate progress toward expected outcomes. In the event that expected outcomes are not achieved, reassessment with modification of interventions is necessary. Nurses play a key role in the total health care delivery to these complex patients. Further study will strengthen the research base of nursing interventions.

  1. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  2. Fast and accurate exhaled breath ammonia measurement.

    Science.gov (United States)

    Solga, Steven F; Mudalel, Matthew L; Spacek, Lisa A; Risby, Terence H

    2014-06-11

    This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations.

  3. Sleep-disordered breathing in acromegaly

    Directory of Open Access Journals (Sweden)

    L K Dzeranova

    2013-03-01

    Full Text Available Sleep-disordered breathing is higly prevalent in acromegaly, disturbing patients quality of life and increasing the risk of acute cardiovascular compications. Presented clinical case discusses key considerations for timely diagnosis of sleep apnea syndrome and treatment planning. The case of 41 y.o. woman with newly diagnosed acromegaly and concomitant sleep apnea is typical for this disease.

  4. Coordination of breathing with nonrespiratory activities.

    Science.gov (United States)

    Bartlett, Donald; Leiter, James C

    2012-04-01

    Many articles in this section of Comprehensive Physiology are concerned with the development and function of a central pattern generator (CPG) for the control of breathing in vertebrate animals. The action of the respiratory CPG is extensively modified by cortical and other descending influences as well as by feedback from peripheral sensory systems. The central nervous system also incorporates other CPGs, which orchestrate a wide variety of discrete and repetitive, voluntary and involuntary movements. The coordination of breathing with these other activities requires interaction and coordination between the respiratory CPG and those governing the nonrespiratory activities. Most of these interactions are complex and poorly understood. They seem to involve both conventional synaptic crosstalk between groups of neurons and fluid identity of neurons as belonging to one CPG or another: neurons that normally participate in breathing may be temporarily borrowed or hijacked by a competing or interrupting activity. This review explores the control of breathing as it is influenced by many activities that are generally considered to be nonrespiratory. The mechanistic detail varies greatly among topics, reflecting the wide variety of pertinent experiments.

  5. Oral Breathing Challenge in Participants with Vocal Attrition

    Science.gov (United States)

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2003-01-01

    Vocal folds undergo osmotic challenge by mouth breathing during singing, exercising, and loud speaking. Just 15 min of obligatory oral breathing, to dry the vocal folds, increases phonation threshold pressure (P[subscript th]) and expiratory vocal effort in healthy speakers (M. Sivasankar & K. Fisher, 2002). We questioned whether oral breathing is…

  6. Human respiratory deposition of particles during oronasal breathing

    Science.gov (United States)

    Swift, David L.; Proctor, Donald F.

    Deposition of particles in the tracheobronchial and pulmonary airways is computed as a function of particle size, correcting for deposition in the parallel nasal and oral airways with oronasal breathing. Thoracic deposition is lower at all sizes for oronasal breathing than for mouth breathing via tube, and is negligible for aerodynamic equivalent diameters of 10 μm or larger.

  7. 46 CFR 197.340 - Breathing gas supply.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing gas supply. 197.340 Section 197.340 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.340 Breathing gas supply. (a) A primary breathing gas supply for surface-supplied diving must be sufficient to support the following for...

  8. 46 CFR 197.312 - Breathing supply hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.312 Section 197.312 Shipping... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must— (1) Have a maximum working pressure that is equal to or exceeds— (i) The...

  9. 21 CFR 868.5330 - Breathing gas mixer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  10. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  11. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  12. 46 CFR 197.450 - Breathing gas tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing gas tests. 197.450 Section 197.450 Shipping....450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air... or modification. (b) Purchased supplies of breathing mixtures supplied to a diver are checked...

  13. 21 CFR 868.5240 - Anesthesia breathing circuit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia breathing circuit. 868.5240 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5240 Anesthesia breathing circuit. (a) Identification. An anesthesia breathing circuit is a device that is intended to administer medical gases to...

  14. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.115 Section 84.115 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  15. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  16. Effect of slow deep breathing (6 breaths/min) on pulmonary function in healthy volunteers

    OpenAIRE

    Shravya Keerthi G, Hari Krishna Bandi, Suresh M, Mallikarjuna Reddy

    2013-01-01

    We designed this study to test the hypothesis that whether 10 minutes of slow deep breathing have any effect on pulmonary function in healthy volunteers. The main objective was to study the immediate effect of slow deep breathing on Forced vital capacity (FVC), Forced expiratory volume in the first second (FEV1), Forced expiratory volume percent (FEV1/FVC%), Peak expiratory flow rate (PEFR), Forced expiratory flow 25-75%(FEF25-75%), Maximum voluntary ventilation (MVV), Slow vital capacity (SV...

  17. Thermal effects and thermal compensation in the OSIRIS camera

    Science.gov (United States)

    González, J. Jesús; Tejada, Carlos; Farah, Alejandro; Rasilla, Jose L.; Fuentes, F. Javier

    2003-03-01

    Tight stability requirements for the imager/spectrograph OSIRIS (a Day One optical instrument for the GTC telescope) demand a careful treatment of thermal effects within the OSIRIS camera. Mostly due to the thermal response of refraction indices of its glasses (and not so much to curvature, spacing or thickness variations of the lenses), the camera optics alone degrades beyond requirements the image quality and plate scale under the expected ambient temperature variations (about 1.8 °C/hour). Thermal effects and thermal compensator studies of the OSIRIS camera are first summarized, before discussing how the motion (of a few microns per °C) of the 3rd camera doublet, as a sole compensator, practically eliminates thermal influences on both image quality and plate scale. A concept for the passive implementation of the compensator is also discussed.

  18. STEERABLE ANTENNAS MOVEMENT COMPENSATION FOR HIGH ALTITUDE PLATFORM

    Institute of Scientific and Technical Information of China (English)

    Wang Zhenyong; Liu Xiaowei; Li Zhuoshi

    2011-01-01

    High Altitude Platform (HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio (CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.

  19. Electromagnetic organ tracking allows for real-time compensation of tissue shift in image-guided laparoscopic rectal surgery

    DEFF Research Database (Denmark)

    Wagner, Martin; Gondan, Matthias; Zöllner, Christian

    2016-01-01

    and intraoperative electromagnetic tracking(EMT) of the rectum. Methods. Three models were compared and evaluated for the compensation of tissue. deformation. For Model A no compensation was performed. Model B moved the corresponding points rigidly to the motion of the EMT sensor. Model C used five nested linear....... In laparoscopic rectal surgery the combination of electromagnetic organ tracking and preoperative imaging is a promising approach to compensate for intraoperative tissue shift in real-time....

  20. Upper limb kinematic differences between breathing and non-breathing conditions in front crawl sprint swimming.

    Science.gov (United States)

    McCabe, Carla B; Sanders, Ross H; Psycharakis, Stelios G

    2015-11-26

    The purpose of this study was to determine whether the breathing action in front crawl (FC) sprint swimming affects the ipsilateral upper limb kinematics relative to a non-breathing stroke cycle (SC). Ten male competitive swimmers performed two 25m FC sprints: one breathing to their preferred side (Br) and one not breathing (NBr). Both swim trials were performed through a 6.75m(3) calibrated space and recorded by six gen-locked JVC KY32 CCD cameras. A paired t-test was used to assess statistical differences between the trials, with a confidence level of pswim performance is compromised by the inclusion of taking a breath in sprint FC swimming. It was proposed that swimmers aim to orient their ipsilateral shoulder into a stronger position by stretching and rolling the shoulders more in the entry phase whilst preparing to take a breath. Swimmers should focus on lengthening the push phase by extending the elbow more and not accelerating the hand too quickly upwards when preparing to inhale.

  1. Compensation: The Impact of Policy.

    Science.gov (United States)

    Morrell, Louis R.

    1994-01-01

    Complexity of employee compensation policy is examined as it applies to colleges and universities. It is argued that sound compensation policy helps the institution attract and retain qualified, skilled employees. New approaches that shift the focus from job to employee are outlined, and their implications for institutions of higher education are…

  2. Alternative Teacher Compensation: A Primer

    Science.gov (United States)

    Koppich, Julia E.; Rigby, Jessica

    2009-01-01

    This policy primer is designed to provide base-line information about new forms of teacher pay that are emerging around the country, to support the local conversations and negotiations that will lead to the development of innovative compensation systems. It identifies reasons why teacher compensation is high on local, state, and federal policy…

  3. Fast motion vector estimation by using spatiotemporal correlation of motion field

    Science.gov (United States)

    Kim, Sungook; Chalidabhongse, Junavit; Kuo, C.-C. Jay

    1995-04-01

    Motion vector (MV) estimation plays an important role in motion compensated video coding. In this research, we first examine a stochastic MV model which enables us to exploit the strong correlation of MVs in both spatial and temporal domains in a given image sequence. Then, a new fast stochastic block matching algorithm (SBMA) is proposed. The basic idea is to select a set of good MV candidates and choose from them the one which satisfies a certain spatio-temporal correlation rule. The proposed algorithm reduces matching operations to about 2% of that of the full block matching algorithm (FBMA) with only 2% increase of the sum of absolute difference (SAD) in motion compensated residuals. The excellent performance of the new algorithm is supported by extensive experimental results.

  4. Motion Simulator

    Science.gov (United States)

    1993-01-01

    MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.

  5. 38 CFR 3.459 - Death compensation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Death compensation. 3.459..., Compensation, and Dependency and Indemnity Compensation Apportionments § 3.459 Death compensation. (a) Death compensation will be apportioned if the child or children of the deceased veteran are not in the custody of...

  6. Modeling Human Control of Self-Motion Direction With Optic Flow and Vestibular Motion.

    Science.gov (United States)

    Zaal, Peter M T; Nieuwenhuizen, Frank M; van Paassen, Marinus M; Mulder, Max

    2013-04-01

    In this paper, we investigate the effects of visual and motion stimuli on the manual control of one's direction of self-motion. In a flight simulator, subjects conducted an active target-following disturbance-rejection task, using a compensatory display. Simulating a vehicular control task, the direction of vehicular motion was shown on the outside visual display in two ways: an explicit presentation using a symbol and an implicit presentation, namely, through the focus of radial outflow that emerges from optic flow. In addition, the effects of the relative strength of congruent vestibular motion cues were investigated. The dynamic properties of human visual and vestibular motion perception paths were modeled using a control-theoretical approach. As expected, improved tracking performance was found for the configurations that explicitly showed the direction of self-motion. The human visual time delay increased with approximately 150 ms for the optic flow conditions, relative to explicit presentations. Vestibular motion, providing higher order information on the direction of self-motion, allowed subjects to partially compensate for this visual perception delay, improving performance. Parameter estimates of the operator control model show that, with vestibular motion, the visual feedback becomes stronger, indicating that operators are more confident to act on optic flow information when congruent vestibular motion cues are present.

  7. Workers' compensation law: an overview.

    Science.gov (United States)

    Yorker, B

    1994-09-01

    1. The workers' compensation system provides benefits to workers who are injured or made ill in the course of employment or their dependents regardless of fault. 2. The current workers' compensation laws benefit both the employer and the employee; however, workers' compensation is an exclusive remedy which bars recovery through a negligence lawsuit. 3. Workers' compensation regulations interact with other federal statutes such as the Americans With Disabilities Act and the Family Medical Leave Act. 4. Workers' compensation covers occupational injuries and occupational diseases, which may include cumulative trauma and mental stress claims. Nurses may be instrumental in evaluating and planning for an injured employee's return to work and occasionally in detecting fraudulent claims.

  8. A 4D treatment planning tool for the evaluation of motion effects on lung cancer treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ding, M; Newman, F; Kavanagh, B; Stuhr, K; Raben, D [Radiation Oncology Department, University of Colorado at Denver and Health Science Center, Aurora, CO 80010 (United States); Li, J S; Ma, C-M [Radiation Oncology Department, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States); Gaspar, L, E-mail: meisong.ding@uchsc.edu

    2008-02-01

    In this study, a 4D treatment planning tool using an analytical model accounting for breathing motion is investigated to evaluate the motion effect on delivered dose for lung cancer treatments with three-dimensional conformal radiotherapy (3DCRT). The Monte Carlo EGS4/MCDOSE user code is used in the treatment planning dose calculation, and the patient CT data are converted into respective patient geometry files for Monte Carlo dose calculation. The model interpolates CT images at different phases of the breathing cycle from patient CT scans taken at end inspiration and end expiration phases and the chest wall position. Correlation between the voxels in a reference CT dataset and the voxels in the interpolated CT datasets at any breathing phases is established so that the dose to a voxel can be accumulated through the entire breathing cycle. Simulated lung tumors at different locations are used to demonstrate our model in 3DCRT for lung cancer treatments. We demonstrated the use of a 4D treatment planning tool in evaluating the breathing motion effect on delivered dose for different planning margins. Further studies are being conducted to use this tool to study the lung motion effect through large-scale analysis and to implement this useful tool for treatment planning dose calculation and plan evaluation for 4D radiotherapy.

  9. Joint PET-MR respiratory motion models for clinical PET motion correction

    Science.gov (United States)

    Manber, Richard; Thielemans, Kris; Hutton, Brian F.; Wan, Simon; McClelland, Jamie; Barnes, Anna; Arridge, Simon; Ourselin, Sébastien; Atkinson, David

    2016-09-01

    Patient motion due to respiration can lead to artefacts and blurring in positron emission tomography (PET) images, in addition to quantification errors. The integration of PET with magnetic resonance (MR) imaging in PET-MR scanners provides complementary clinical information, and allows the use of high spatial resolution and high contrast MR images to monitor and correct motion-corrupted PET data. In this paper we build on previous work to form a methodology for respiratory motion correction of PET data, and show it can improve PET image quality whilst having minimal impact on clinical PET-MR protocols. We introduce a joint PET-MR motion model, using only 1 min per PET bed position of simultaneously acquired PET and MR data to provide a respiratory motion correspondence model that captures inter-cycle and intra-cycle breathing variations. In the model setup, 2D multi-slice MR provides the dynamic imaging component, and PET data, via low spatial resolution framing and principal component analysis, provides the model surrogate. We evaluate different motion models (1D and 2D linear, and 1D and 2D polynomial) by computing model-fit and model-prediction errors on dynamic MR images on a data set of 45 patients. Finally we apply the motion model methodology to 5 clinical PET-MR oncology patient datasets. Qualitative PET reconstruction improvements and artefact reduction are assessed with visual analysis, and quantitative improvements are calculated using standardised uptake value (SUVpeak and SUVmax) changes in avid lesions. We demonstrate the capability of a joint PET-MR motion model to predict respiratory motion by showing significantly improved image quality of PET data acquired before the motion model data. The method can be used to incorporate motion into the reconstruction of any length of PET acquisition, with only 1 min of extra scan time, and with no external hardware required.

  10. Fourier-based linear systems description of free-breathing pulmonary magnetic resonance imaging

    Science.gov (United States)

    Capaldi, D. P. I.; Svenningsen, S.; Cunningham, I. A.; Parraga, G.

    2015-03-01

    Fourier-decomposition of free-breathing pulmonary magnetic resonance imaging (FDMRI) was recently piloted as a way to provide rapid quantitative pulmonary maps of ventilation and perfusion without the use of exogenous contrast agents. This method exploits fast pulmonary MRI acquisition of free-breathing proton (1H) pulmonary images and non-rigid registration to compensate for changes in position and shape of the thorax associated with breathing. In this way, ventilation imaging using conventional MRI systems can be undertaken but there has been no systematic evaluation of fundamental image quality measurements based on linear systems theory. We investigated the performance of free-breathing pulmonary ventilation imaging using a Fourier-based linear system description of each operation required to generate FDMRI ventilation maps. Twelve subjects with chronic obstructive pulmonary disease (COPD) or bronchiectasis underwent pulmonary function tests and MRI. Non-rigid registration was used to co-register the temporal series of pulmonary images. Pulmonary voxel intensities were aligned along a time axis and discrete Fourier transforms were performed on the periodic signal intensity pattern to generate frequency spectra. We determined the signal-to-noise ratio (SNR) of the FDMRI ventilation maps using a conventional approach (SNRC) and using the Fourier-based description (SNRF). Mean SNR was 4.7 ± 1.3 for subjects with bronchiectasis and 3.4 ± 1.8, for COPD subjects (p>.05). SNRF was significantly different than SNRC (p<.01). SNRF was approximately 50% of SNRC suggesting that the linear system model well-estimates the current approach.

  11. 4D modeling and estimation of respiratory motion for radiation therapy

    CERN Document Server

    Lorenz, Cristian

    2013-01-01

    Respiratory motion causes an important uncertainty in radiotherapy planning of the thorax and upper abdomen. The main objective of radiation therapy is to eradicate or shrink tumor cells without damaging the surrounding tissue by delivering a high radiation dose to the tumor region and a dose as low as possible to healthy organ tissues. Meeting this demand remains a challenge especially in case of lung tumors due to breathing-induced tumor and organ motion where motion amplitudes can measure up to several centimeters. Therefore, modeling of respiratory motion has become increasingly important in radiation therapy. With 4D imaging techniques spatiotemporal image sequences can be acquired to investigate dynamic processes in the patient’s body. Furthermore, image registration enables the estimation of the breathing-induced motion and the description of the temporal change in position and shape of the structures of interest by establishing the correspondence between images acquired at different phases of the br...

  12. Color Data Compensation for Illumination Change

    Institute of Scientific and Technical Information of China (English)

    Pranchalee Rattanasakornchai; Yasushi Hoshino; Chun Weilin

    2004-01-01

    Compensation method for illumination change, which has big influences on the characteristics of imaging system, is studied. On the condition that color chart is placed in the view of camera, the imaging system recognizes the color chart and the signals from the camera are processed by using the color chart data. Concerning the light from the window, and fluorescent light, it is confirmed that color chart is possible to be recognized and the color system is corrected to the expected chart signal within the error 10 % by considering quadratic terms of RGB. This method is considered to improve the accuracy of motion detection and also to better video communication by realizing preferalle color reproduction.

  13. First Breath prenatal smoking cessation pilot study: preliminary findings.

    Science.gov (United States)

    Jehn, Lisette; Lokker, Nicole; Matitz, Debra; Christiansen, Bruce

    2003-01-01

    Despite the many dangers associated with smoking during pregnancy, it remains a salient public health problem for Wisconsin women. The First Breath pilot program was developed in an attempt to reduce rates of smoking during pregnancy among low-income women. Preliminary results suggest that the First Breath counseling-based approach is effective, with a quit rate of 43.8% among First Breath enrollees at 1 month postpartum. Women receiving First Breath cessation counseling also had higher quit rates at every measurement period versus women in a comparison group who were receiving whatever cessation care was available in their county in the absence of First Breath. The First Breath pilot study has demonstrated success in helping pregnant women quit smoking and in creating a model for integration of cessation services into prenatal health care service provision. It is through this success that First Breath is expanding beyond the pilot study stage to a statewide program in 2003.

  14. Information dynamics in cardiorespiratory analyses: application to controlled breathing.

    Science.gov (United States)

    Widjaja, Devy; Faes, Luca; Montalto, Alessandro; Van Diest, Ilse; Marinazzo, Daniele; Van Huffel, Sabine

    2014-01-01

    Voluntary adjustment of the breathing pattern is widely used to deal with stress-related conditions. In this study, effects of slow and fast breathing with a low and high inspiratory to expiratory time on heart rate variability (HRV) are evaluated by means of information dynamics. Information transfer is quantified both as the traditional transfer entropy as well as the cross entropy, where the latter does not condition on the past of HRV, thereby taking the highly unidirectional relation between respiration and heart rate into account. The results show that the cross entropy is more suited to quantify cardiorespiratory information transfer as this measure increases during slow breathing, indicating the increased cardiorespiratory coupling and suggesting the shift towards vagal activation during slow breathing. Additionally we found that controlled breathing, either slow or fast, results as well in an increase in cardiorespiratory coupling, compared to spontaneous breathing, which demonstrates the beneficial effects of instructed breathing.

  15. Study on the feasibility of intensity-modulated treatments with breath control; Estudio sobre la viabilidad de tratamientos de intensidad modulada con control respiratorio

    Energy Technology Data Exchange (ETDEWEB)

    Zucca Aparicio, D.; Perez Moreno, J. M.; Fernandez Leton, P.; Garcia Ruiz-Zorrrilla, J.; Minambres Moro, A.

    2011-07-01

    The present work is to study the feasibility of IMRT treatments, both static and dynamic, with breath control offered by BrainLAB gating system and to quantify how the shadows of the measured dose profiles in case of respiratory motion are distorted for the case of NO movement.

  16. Breath Analysis Using Laser Spectroscopic Techniques: Breath Biomarkers, Spectral Fingerprints, and Detection Limits

    Directory of Open Access Journals (Sweden)

    Peeyush Sahay

    2009-10-01

    Full Text Available Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS, cavity ringdown spectroscopy (CRDS, integrated cavity output spectroscopy (ICOS, cavity enhanced absorption spectroscopy (CEAS, cavity leak-out spectroscopy (CALOS, photoacoustic spectroscopy (PAS, quartz-enhanced photoacoustic spectroscopy (QEPAS, and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS. Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.

  17. Fixman compensating potential for general branched molecules

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Abhinandan, E-mail: Abhi.Jain@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States); Kandel, Saugat; Wagner, Jeffrey; Larsen, Adrien; Vaidehi, Nagarajan, E-mail: nvaidehi@coh.org [Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010 (United States)

    2013-12-28

    The technique of constraining high frequency modes of molecular motion is an effective way to increase simulation time scale and improve conformational sampling in molecular dynamics simulations. However, it has been shown that constraints on higher frequency modes such as bond lengths and bond angles stiffen the molecular model, thereby introducing systematic biases in the statistical behavior of the simulations. Fixman proposed a compensating potential to remove such biases in the thermodynamic and kinetic properties calculated from dynamics simulations. Previous implementations of the Fixman potential have been limited to only short serial chain systems. In this paper, we present a spatial operator algebra based algorithm to calculate the Fixman potential and its gradient within constrained dynamics simulations for branched topology molecules of any size. Our numerical studies on molecules of increasing complexity validate our algorithm by demonstrating recovery of the dihedral angle probability distribution function for systems that range in complexity from serial chains to protein molecules. We observe that the Fixman compensating potential recovers the free energy surface of a serial chain polymer, thus annulling the biases caused by constraining the bond lengths and bond angles. The inclusion of Fixman potential entails only a modest increase in the computational cost in these simulations. We believe that this work represents the first instance where the Fixman potential has been used for general branched systems, and establishes the viability for its use in constrained dynamics simulations of proteins and other macromolecules.

  18. Auditory Motion Elicits a Visual Motion Aftereffect

    Directory of Open Access Journals (Sweden)

    Christopher C. Berger

    2016-12-01

    Full Text Available The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect—an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

  19. Flow-Force Compensation in a Hydraulic Valve

    CERN Document Server

    Lugowski, Jan

    2015-01-01

    Flow-reaction forces acting in hydraulic valves have been studied for many decades. Despite this, they are difficult to account for due to the complexities of the jet flow. This paper focuses only on the reduction, also referred to as compensation, of the flow force as applied to a valve spool featuring a profile of a turbine bucket. Fluid power textbooks explain the compensation taking place on such a profile by applying Newton laws of motion to the profile and deliver an equation for the magnitude and the direction of the flow force. This paper shows that both the magnitude and the direction of the compensating flow force are incorrect if calculated from the textbook equation. A corrected analysis of the dynamic forces is presented that are in agreement with earlier experiments by this author. It follows that the compensating flow force should be calculated from the static-pressure imbalance on the spool profile. That is, not Newton but Pascal law should be applied to calculate the compensating flow force.

  20. Breathing dissipative solitons in optical microresonators

    CERN Document Server

    Lucas, Erwan; Guo, Hairun; Gorodetsky, Michael; Kippenberg, Tobias

    2016-01-01

    Dissipative solitons are self-localized structures resulting from a double balance between dispersion and nonlinearity as well as dissipation and a driving force. They occur in a wide variety of fields ranging from optics, hydrodynamics to chemistry and biology. Recently, significant interest has focused on their temporal realization in driven optical microresonators, known as dissipative Kerr solitons. They provide access to coherent, chip-scale optical frequency combs, which have already been employed in optical metrology, data communication and spectroscopy. Such Kerr resonator systems can exhibit numerous localized intracavity patterns and provide rich insights into nonlinear dynamics. A particular class of solutions consists of breathing dissipative solitons, representing pulses with oscillating amplitude and duration, for which no comprehensive understanding has been presented to date. Here, we observe and study single and multiple breathing dissipative solitons in two different microresonator platforms...

  1. Protective supplied-breathing-air garment

    Science.gov (United States)

    Childers, E.L.; von Hortenau, E.F.

    1982-05-28

    A breathing-air garment for isolating a wearer from hostile environments containing toxins or irritants is disclosed. The garment includes a suit and a separate head-protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air-delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air-delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit sealed with an adhesive sealing flap.

  2. C-130J Breathing Resistance Study

    Science.gov (United States)

    2016-05-01

    flows used in the study . The simulated workloads were: 1) 60 ALPM: Rest; 2) 90 ALPM: Light Work ; 3) 125 ALPM: Moderate Work ; and 4) 150 ALPM...AFRL-RH-WP-TR-2016-0040 C-130J BREATHING RESISTANCE STUDY George W. Miller Air Force Research Laboratory Wright-Patterson Air...ASSIGNED DISTRIBUTION STATEMENT. //signed// //signed// GEORGE W. MILLER SCOTT M. GALSTER Work Unit Manager Chief, Applied

  3. Collective motion

    Science.gov (United States)

    Vicsek, Tamás; Zafeiris, Anna

    2012-08-01

    We review the observations and the basic laws describing the essential aspects of collective motion - being one of the most common and spectacular manifestation of coordinated behavior. Our aim is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, mathematical methods and models for simulations, so that readers with a variety of background could get both the basics and a broader, more detailed picture of the field. The observations we report on include systems consisting of units ranging from macromolecules through metallic rods and robots to groups of animals and people. Some emphasis is put on models that are simple and realistic enough to reproduce the numerous related observations and are useful for developing concepts for a better understanding of the complexity of systems consisting of many simultaneously moving entities. As such, these models allow the establishing of a few fundamental principles of flocking. In particular, it is demonstrated, that in spite of considerable differences, a number of deep analogies exist between equilibrium statistical physics systems and those made of self-propelled (in most cases living) units. In both cases only a few well defined macroscopic/collective states occur and the transitions between these states follow a similar scenario, involving discontinuity and algebraic divergences.

  4. Breath alcohol, multisensor arrays, and electronic noses

    Science.gov (United States)

    Paulsson, Nils; Winquist, Fredrik

    1997-01-01

    The concept behind a volatile compound mapper, or electronic nose, is to use the combination of multiple gas sensors and pattern recognition techniques to detect and quantify substances in gas mixtures. There are several different kinds of sensors which have been developed during recent years of which the base techniques are conducting polymers, piezo electrical crystals and solid state devices. In this work we have used a combination of gas sensitive field effect devices and semiconducting metal oxides. The most useful pattern recognition routine was found to be ANNs, which is a mathematical approximation of the human neural network. The aim of this work is to evaluate the possibility of using electronic noses in field instruments to detect drugs, arson residues, explosives etc. As a test application we have chosen breath alcohol measurements. There are several reasons for this. Breath samples are a quite complex mixture contains between 200 and 300 substances at trace levels. The alcohol level is low but still possible to handle. There are needs for replacing large and heavy mobile instruments with smaller devices. Current instrumentation is rather sensitive to interfering substances. The work so far has dealt with sampling, how to introduce ethanol and other substances in the breath, correlation measurements between the electronic nose and headspace GC, and how to evaluate the sensor signals.

  5. Determination of breath isoprene allows the identification of the expiratory fraction of the propofol breath signal during real-time propofol breath monitoring.

    Science.gov (United States)

    Hornuss, Cyrill; Dolch, Michael E; Janitza, Silke; Souza, Kimberly; Praun, Siegfried; Apfel, Christian C; Schelling, Gustav

    2013-10-01

    Real-time measurement of propofol in the breath may be used for routine clinical monitoring. However, this requires unequivocal identification of the expiratory phase of the respiratory propofol signal as only expiratory propofol reflects propofol blood concentrations. Determination of CO2 breath concentrations is the current gold standard for the identification of expiratory gas but usually requires additional equipment. Human breath also contains isoprene, a volatile organic compound with low inspiratory breath concentration and an expiratory concentration plateau. We investigated whether breath isoprene could be used similarly to CO2 to identify the expiratory fraction of the propofol breath signal. We investigated real-time breath data obtained from 40 study subjects during routine anesthesia. Propofol, isoprene, and CO2 breath concentrations were determined by a combined ion molecule reaction/electron impact mass spectrometry system. The expiratory propofol signal was identified according to breath CO2 and isoprene concentrations and presented as median of intervals of 30 s duration. Bland-Altman analysis was applied to detect differences (bias) in the expiratory propofol signal extracted by the two identification methods. We investigated propofol signals in a total of 3,590 observation intervals of 30 s duration in the 40 study subjects. In 51.4 % of the intervals (1,844/3,590) both methods extracted the same results for expiratory propofol signal. Overall bias between the two data extraction methods was -0.12 ppb. The lower and the upper limits of the 95 % CI were -0.69 and 0.45 ppb. Determination of isoprene breath concentrations allows the identification of the expiratory propofol signal during real-time breath monitoring.

  6. Motion control report

    CERN Document Server

    2013-01-01

    Please note this is a short discount publication. In today's manufacturing environment, Motion Control plays a major role in virtually every project.The Motion Control Report provides a comprehensive overview of the technology of Motion Control:* Design Considerations* Technologies* Methods to Control Motion* Examples of Motion Control in Systems* A Detailed Vendors List

  7. Space optical remote sensor image motion velocity vector computational modeling, error budget and synthesis

    Institute of Scientific and Technical Information of China (English)

    Jiaqi Wang; Ping Yu; Changxiang Yan; Jianyue Ren; Bin He

    2005-01-01

    @@ For space optical remote sensor (SORS) with either film or time delay and integrate charge coupled device (TDI-CCD) imaging, in order to achieve higher resolution it requires more accurate real-time image motion compensation.

  8. The research of moving object detection based on background difference compensation

    Science.gov (United States)

    Song, Yan-bin; Ying, Jie; Lu, Lin-li

    2013-08-01

    Moving object detection was implemented in dynamic background based on background difference compensation. Background differential can effectively segment the moving object in static background. But in moving video, the camera motion causes corresponding movement of the target and background, which makes the prospect moving object hard to separate from the background. In order to detect moving object, we can compensate the movement of the background and transfer the dynamic background to static. Moving object detection in static background image was implemented using a new weights updating method that the weights were updated during a certain period. This method based on classical Gaussian mixture model improved the efficiency of image segmentation greatly. Moving object detection in dynamic background was realized using background differential compensation. The global motion of the background was established according to the affined parameters model. The model parameters were estimated by feature points matching based on the search strategy. Invalid matching points were eliminated using the method of distance consistency. Backward mapping was used to get the motion parameters of the background. After compensation of the background with the global motion parameters, frame difference between the current frame and the background can detect moving objects effectively. Experiments were done on computer with the programming tools of VS2010 and MATLAB. Experimental results showed that the algorithm based on differential compensation was effective.

  9. LCD motion blur: modeling, analysis, and algorithm.

    Science.gov (United States)

    Chan, Stanley H; Nguyen, Truong Q

    2011-08-01

    Liquid crystal display (LCD) devices are well known for their slow responses due to the physical limitations of liquid crystals. Therefore, fast moving objects in a scene are often perceived as blurred. This effect is known as the LCD motion blur. In order to reduce LCD motion blur, an accurate LCD model and an efficient deblurring algorithm are needed. However, existing LCD motion blur models are insufficient to reflect the limitation of human-eye-tracking system. Also, the spatiotemporal equivalence in LCD motion blur models has not been proven directly in the discrete 2-D spatial domain, although it is widely used. There are three main contributions of this paper: modeling, analysis, and algorithm. First, a comprehensive LCD motion blur model is presented, in which human-eye-tracking limits are taken into consideration. Second, a complete analysis of spatiotemporal equivalence is provided and verified using real video sequences. Third, an LCD motion blur reduction algorithm is proposed. The proposed algorithm solves an l(1)-norm regularized least-squares minimization problem using a subgradient projection method. Numerical results show that the proposed algorithm gives higher peak SNR, lower temporal error, and lower spatial error than motion-compensated inverse filtering and Lucy-Richardson deconvolution algorithm, which are two state-of-the-art LCD deblurring algorithms.

  10. Improved motion description for action classification

    Directory of Open Access Journals (Sweden)

    Mihir eJain

    2016-01-01

    Full Text Available Even though the importance of explicitly integrating motion characteristics in video descriptions has been demonstrated by several recent papers on action classification, our current work concludes that adequately decomposing visual motion into dominant and residual motions, i.e.: camera and scene motion, significantly improves action recognition algorithms. This holds true both for the extraction of the space-time trajectories and for computation of descriptors.We designed a new motion descriptor – the DCS descriptor – that captures additional information on local motion patterns enhancing results based on differential motion scalar quantities, divergence, curl and shear features. Finally, applying the recent VLAD coding technique proposed in image retrieval provides a substantial improvement for action recognition. These findings are complementary to each other and they outperformed all previously reported results by a significant margin on three challenging datasets: Hollywood 2, HMDB51 and Olympic Sports as reported in (Jain et al. (2013. These results were further improved by (Oneata et al. (2013; Wang and Schmid (2013; Zhu et al. (2013 through the use of the Fisher vector encoding. We therefore also employ Fisher vector in this paper and we further enhance our approach by combining trajectories from both optical flow and compensated flow. We as well provide additional details of DCS descriptors, including visualization. For extending the evaluation, a novel dataset with 101 action classes, UCF101, was added.

  11. Stock Repurchases and Incentive Compensation

    OpenAIRE

    Christine Jolls

    1998-01-01

    A longstanding puzzle in corporate finance is the rise of stock repurchases as a means of distributing earnings to shareholders. While most attempts to explain repurchase behavior focus on the incentives of firms, this paper focuses on the incentives of the agents who run firms, as determined by those agents' compensation packages. The increased use of repurchases coincided with an increasing reliance on stock options to compensate top managers, and stock options encourage managers to choose ...

  12. Very Low Bit-Rate Video Coding Using Motion ompensated 3-D Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A new motion-compensated 3-D wavelet transform (MC-3DWT) video coding scheme is presented in thispaper. The new coding scheme has a good performance in average PSNR, compression ratio and visual quality of re-constructions compared with the existing 3-D wavelet transform (3DWT) coding methods and motion-compensated2-D wavelet transform (MC-WT) coding method. The new MC-3DWT coding scheme is suitable for very low bit-rate video coding.

  13. Evaluation of breathing interplay effects during VMAT by using 3D gel measurements

    Science.gov (United States)

    Ceberg, S.; Ceberg, C.; Falk, M.; Rosenschöld, P. Munk af; Bäck, S. ÅJ

    2013-06-01

    Respiratory motion during dynamic radiotherapy may affect the absorbed dose distribution both by dose-reducing smoothing and by more complicated interplay effects. In this study we present a novel method to determine the relative importance of these two effects. For the two dynamic deliveries studied in this work, the expected target dose reduction due to the smoothing effect was estimated by measurements convolved by the motion function. Remaining absorbed dose differences were attributed to interplay effects between the motion of the gel phantom and the movement of the modulating MLC leaves during modulated arc radiotherapy. The total dosimetric effect due to breathing motion and dynamic MLC motion during VMAT delivery resulted in an average of about 4% target dose reduction. Comparing with only the smoothing effect, the average difference was decreased to around 1%, and the remaining distribution was attributed to interplay effects. Although the interplay effects were small compared to the smoothing effect, the standard deviations of 1.4-2.3% (1SD) were larger than the narrow distribution for repeated stationary measurement with a standard deviation between 0.5-0.9% (1SD).

  14. RESP-24: a computer program for the investigation of 24-h breathing abnormalities in heart failure patients.

    Science.gov (United States)

    Maestri, R; Pinna, G D; Robbi, E; Varanini, M; Emdin, M; Raciti, M; La Rovere, M T

    2002-05-01

    In this paper, we describe a computer program (RESP-24) specifically devised to assess the prevalence and characteristics of breathing disorders in ambulant chronic heart failure patients during the overall 24 h period. The system works on a single channel respiratory signal (RS) recorded through a Holter-like portable device. In the pre-processing stage RESP-24 removes noise, baseline drift and motion artefacts from the RS using a non-linear filter, enhances respiratory frequency components through high-pass filtering and derives an instantaneous tidal volume (ITV) signal. The core processing is devoted to the identification and classification of the breathing pattern into periodic breathing (PB), normal breathing or non-classifiable breathing using a 60 s segmentation, and to the identification and estimation of apnea and hypopnea events. Sustained episodes of PB are detected by cross analysis of both the spectral content and time behavior of the ITV signal. User-friendly interactive facilities allow all the results of the automatic analysis procedure to be edited. The final report provides a set of standard and non-standard parameters quantifying breathing abnormalities during the 24 h period, the night-time and the day-time, including the apnea/hypopnea index, the apnea index, the total time spent in apnea or in hypopnea and the prevalence of non-apneic and apneic PB. The accuracy of these measurements was appraised on a data set of 14 recordings, by comparing them with those provided by a trained analyst. The mean and standard deviation of the error of the automatic procedure were below respectively 6 and 8% of the reference value for all parameters considered and the mean total classification accuracy was 92%. In most cases, the individual error was <12%. We conclude that measurements provided automatically by the RESP-24 software are suitable for screening purposes and clinical trials, although a preventive check of signal quality should be recommended.

  15. MO-G-18C-05: Real-Time Prediction in Free-Breathing Perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Song, H [Department of Radiology, University of Pittsburgh, Pittsburgh, PA (United States); Liu, W [Department of Bioengineering, UCLA, Los Angeles, CA (United States); Ruan, D [Department of Bioengineering, UCLA, Los Angeles, CA (United States); Department of Radiation Oncology, UCLA, Los Angeles, CA (United States); Jung, S [Department of Statistics, University of Pittsburgh, Pittsburgh, PA (United States); Gach, M [Department of Radiology, University of Pittsburgh, Pittsburgh, PA (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA (United States)

    2014-06-15

    Purpose: The aim is to minimize frame-wise difference errors caused by respiratory motion and eliminate the need for breath-holds in magnetic resonance imaging (MRI) sequences with long acquisitions and repeat times (TRs). The technique is being applied to perfusion MRI using arterial spin labeling (ASL). Methods: Respiratory motion prediction (RMP) using navigator echoes was implemented in ASL. A least-square method was used to extract the respiratory motion information from the 1D navigator. A generalized artificial neutral network (ANN) with three layers was developed to simultaneously predict 10 time points forward in time and correct for respiratory motion during MRI acquisition. During the training phase, the parameters of the ANN were optimized to minimize the aggregated prediction error based on acquired navigator data. During realtime prediction, the trained ANN was applied to the most recent estimated displacement trajectory to determine in real-time the amount of spatial Results: The respiratory motion information extracted from the least-square method can accurately represent the navigator profiles, with a normalized chi-square value of 0.037±0.015 across the training phase. During the 60-second training phase, the ANN successfully learned the respiratory motion pattern from the navigator training data. During real-time prediction, the ANN received displacement estimates and predicted the motion in the continuum of a 1.0 s prediction window. The ANN prediction was able to provide corrections for different respiratory states (i.e., inhalation/exhalation) during real-time scanning with a mean absolute error of < 1.8 mm. Conclusion: A new technique enabling free-breathing acquisition during MRI is being developed. A generalized ANN development has demonstrated its efficacy in predicting a continuum of motion profile for volumetric imaging based on navigator inputs. Future work will enhance the robustness of ANN and verify its effectiveness with human

  16. Ultrafast Imaging of Electronic Motion in Atoms and Molecules

    Science.gov (United States)

    2016-01-12

    AFRL-AFOSR-VA-TR-2016-0045 Ultrafast Imaging of Electronic Motion in Atoms and Molecules Martin Centurion UNIVERSITY OF NEBRSKA Final Report 01/12...Ultrafast Imaging of Electronic Motion in Atoms and Molecules 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-12-1-0149 5c. PROGRAM ELEMENT NUMBER 6...a gaseous target of atoms or molecules . An optical setup was designed and constructed to compensate for the blurring of the temporal resolution due

  17. Apparatus and method for monitoring breath acetone and diabetic diagnostics

    Science.gov (United States)

    Duan, Yixiang; Cao, Wenqing

    2008-08-26

    An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

  18. Development of Techniques for Trace Gas Detection in Breath

    OpenAIRE

    2012-01-01

    This thesis aims to investigate the possibility of developing spectroscopic techniques for trace gas detection, with particular emphasis on their applicability to breath analysis and medical diagnostics. Whilst key breath molecules such as methane and carbon dioxide will feature throughout this work, the focus of the research is on the detection of breath acetone, a molecule strongly linked with the diabetic condition. Preliminary studies into the suitability of cavity enhanced absorption...

  19. Automatic Recognition of Breathing Route During Sleep Using Snoring Sounds

    Science.gov (United States)

    Mikami, Tsuyoshi; Kojima, Yohichiro

    This letter classifies snoring sounds into three breathing routes (oral, nasal, and oronasal) with discriminant analysis of the power spectra and k-nearest neighbor method. It is necessary to recognize breathing route during snoring, because oral snoring is a typical symptom of sleep apnea but we cannot know our own breathing and snoring condition during sleep. As a result, about 98.8% classification rate is obtained by using leave-one-out test for performance evaluation.

  20. Nonrigid retrospective respiratory motion correction in whole-heart coronary MRA.

    Science.gov (United States)

    Schmidt, Johannes F M; Buehrer, Martin; Boesiger, Peter; Kozerke, Sebastian

    2011-12-01

    A nonrigid retrospective respiratory motion correction scheme is presented for whole-heart coronary imaging with interleaved acquisition of motion information. The quasi-periodic nature of breathing is exploited to populate a 3D nonrigid motion model from low-resolution 2D imaging slices acquired interleaved with a segmented 3D whole-heart coronary scan without imposing scan time penalty. Reconstruction and motion correction are based on inversion of a generalized encoding equation. Therein, a forward model describes the transformation from the motion free image to the motion distorted k-space data, which includes nonrigid spatial transformations. The effectiveness of the approach is demonstrated on 10 healthy volunteers using free-breathing coronary whole-heart scans. Although conventional respiratory-gated acquisitions with 5-mm gating window resulted in an average gating efficiency of 51% ± 11%, nonrigid motion correction allowed for gate-free acquisitions, and hence scan time reduction by a factor of two without significant penalty in image quality. Image scores and quantitative image quality measures for the left coronary arteries showed no significant differences between 5-mm gated and gate-free acquisitions with motion correction. For the right coronary artery, slightly reduced image quality in the motion corrected gate-free scan was observed as a result of the close vicinity of anatomical structures with different motion characteristics. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.

  1. Breathing, crawling, budding, and splitting of a liquid droplet under laser heating.

    Science.gov (United States)

    Song, Chaeyeon; Moon, Jong Kyun; Lee, Kyuyong; Kim, Kipom; Pak, Hyuk Kyu

    2014-04-21

    The manipulation of droplets with sizes on the millimetre scale and below has attracted considerable attention over the past few decades for applications in microfluidics, biology, and chemistry. In this paper, we report the response of an oil droplet floating in an aqueous solution to local laser heating. Depending on the laser power, distinct dynamic transitions of the shape and motion of the droplet are observed, namely, breathing, crawling, budding, and splitting. We found that the selection of the dynamic modes is determined by dynamic instabilities due to the interplay between the convection flows and capillary effects. Our findings can be useful for constructing microfluidic devices to control the motion and shape of a small droplet by simply altering the laser power, and for understanding thermal convective systems with fully soft boundaries.

  2. 14 CFR 158.53 - Collection compensation.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Collection compensation. 158.53 Section 158... Collection compensation. (a) As compensation for collecting, handling, and remitting the PFC revenue, the... a new compensation level based on an analysis of the data provided under paragraph (c)(1) of...

  3. 48 CFR 752.7007 - Personnel compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Personnel compensation... Personnel compensation. The following clause shall be used in all USAID cost-reimbursement contracts. Personnel Compensation (JUL 2007) (a) Direct compensation of the Contractor's personnel will be...

  4. 22 CFR 96.34 - Compensation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Compensation. 96.34 Section 96.34 Foreign... Financial and Risk Management § 96.34 Compensation. (a) The agency or person does not compensate any... for compensation within the intercountry adoption community in that country, to the extent that...

  5. 30 CFR 90.103 - Compensation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compensation. 90.103 Section 90.103 Mineral..., Rights of Part 90 Miners § 90.103 Compensation. (a) The operator shall compensate each Part 90 miner at... part. (d) In addition to the compensation required to be paid under paragraphs (a), (b) and (c) of...

  6. 48 CFR 970.2270 - Unemployment compensation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unemployment compensation... Unemployment compensation. (a) Each state has its own unemployment compensation system to provide payments to... unemployment compensation benefits through a payroll tax on employers. Most DOE contractors are subject to...

  7. 43 CFR 4.355 - Omitted compensation.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Omitted compensation. 4.355 Section 4.355... Compensation § 4.355 Omitted compensation. When, subsequent to the issuance of a final order determining heirs under § 4.352, it is found that certain additional compensation had been due the decedent and had...

  8. 7 CFR 930.133 - Compensation rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Compensation rate. 930.133 Section 930.133 Agriculture... Regulations § 930.133 Compensation rate. A compensation rate of $250 per meeting shall be paid to the public member and to the alternate public member when attending Board meetings. Such compensation is a...

  9. 12 CFR 9.15 - Fiduciary compensation.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Fiduciary compensation. 9.15 Section 9.15 Banks... BANKS Regulations § 9.15 Fiduciary compensation. (a) Compensation of bank. If the amount of a national bank's compensation for acting in a fiduciary capacity is not set or governed by applicable law,...

  10. 23 CFR 751.15 - Just compensation.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Just compensation. 751.15 Section 751.15 Highways... AND ACQUISITION § 751.15 Just compensation. (a) Just compensation shall be paid the owner for the... removed, relocated, or disposed of pursuant to 23 U.S.C. 136. (b) No rights to compensation accrue until...

  11. 12 CFR 7.2011 - Compensation plans.

    Science.gov (United States)

    2010-01-01

    ... Corporate Practices § 7.2011 Compensation plans. Consistent with safe and sound banking practices and the compensation provisions of 12 CFR part 30, a national bank may adopt compensation plans, including, among... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Compensation plans. 7.2011 Section 7.2011...

  12. 29 CFR 525.6 - Compensable time.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Compensable time. 525.6 Section 525.6 Labor Regulations... WITH DISABILITIES UNDER SPECIAL CERTIFICATES § 525.6 Compensable time. Individuals employed subject to this part must be compensated for all hours worked. Compensable time includes not only those...

  13. General Anesthesia with Preserved Spontaneous Breathing through an Intubation Tube

    Directory of Open Access Journals (Sweden)

    V. V. Moroz

    2010-01-01

    Full Text Available Objective: to study whether spontaneous patient breathing may be preserved during elective operations under general anesthesia with tracheal intubation. Subjects and methods. One hundred and twelve patients undergoing elective surgeries under general endotracheal anesthesia were randomized into 2 groups: 1 patients who had forced mechanical ventilation in the volume-controlled mode and 2 those who received assisted ventilation as spontaneous breathing with mechanical support. Conclusion. The study shows that spontaneous breathing with mechanical support may be safely used during some surgical interventions in patients with baseline healthy lungs. Key words: Pressure Support, assisted ventilation, spontaneous breathing, general anesthesia, lung function.

  14. Using acoustic sensors to discriminate between nasal and mouth breathing.

    Science.gov (United States)

    Curran, Kevin; Yuan, Peng; Coyle, Damian

    2012-01-01

    The recommendation to change breathing patterns from the mouth to the nose can have a significantly positive impact upon the general well being of the individual. We classify nasal and mouth breathing by using an acoustic sensor and intelligent signal processing techniques. The overall purpose is to investigate the possibility of identifying the differences in patterns between nasal and mouth breathing in order to integrate this information into a decision support system which will form the basis of a patient monitoring and motivational feedback system to recommend the change from mouth to nasal breathing.

  15. A fibre-optic oxygen sensor for monitoring human breathing.

    Science.gov (United States)

    Chen, Rongsheng; Formenti, Federico; Obeid, Andy; Hahn, Clive E W; Farmery, Andrew D

    2013-09-01

    The development and construction of a tapered-tip fibre-optic fluorescence based oxygen sensor is described. The sensor is suitable for fast and real-time monitoring of human breathing. The sensitivity and response time of the oxygen sensor were evaluated in vitro with a gas pressure chamber system, where oxygen partial pressure was rapidly changed between 5 and 15 kPa, and then in vivo in five healthy adult participants who synchronized their breathing to a metronome set at 10, 20, 30, 40, 50, and 60 breaths min(-1). A Datex Ultima medical gas analyser was used to monitor breathing rate as a comparator. The sensor's response time in vitro was less than 150 ms, which allows accurate continuous measurement of inspired and expired oxygen pressure. Measurements of breathing rate by means of our oxygen sensor and of the Datex Ultima were in strong agreement. The results demonstrate that the device can reliably resolve breathing rates up to 60 breaths min(-1), and that it is a suitable cost-effective alternative for monitoring breathing rates and end-tidal oxygen partial pressure in the clinical setting. The rapid response time of the sensor may allow its use for monitoring rapid breathing rates as occur in children and the newborn.

  16. A simple optical fiber interferometer based breathing sensor

    Science.gov (United States)

    Li, Xixi; Liu, Dejun; Kumar, Rahul; Ng, Wai Pang; Fu, Yong-qing; Yuan, Jinhui; Yu, Chongxiu; Wu, Yufeng; Zhou, Guorui; Farrell, Gerald; Semenova, Yuliya; Wu, Qiang

    2017-03-01

    A breathing sensor has been experimentally demonstrated based on a singlemode–multimode–singlemode (SMS) fiber structure which is attached to a thin plastic film in an oxygen mask. By detecting power variations due to the macro bending applied to the SMS section by each inhalation and exhalation process, the breath state can be monitored. The proposed sensor is capable of distinguishing different types of breathing conditions including regular and irregular breath state. The sensor can be used in a strong electric/magnetic field and radioactive testing systems such as magnetic resonance imaging (MRI) systems and computed tomography (CT) examinations where electrical sensors are restricted.

  17. Can resistive breathing injure the lung? Implications for COPD exacerbations

    Directory of Open Access Journals (Sweden)

    Vassilakopoulos T

    2016-09-01

    Full Text Available Theodoros Vassilakopoulos, Dimitrios Toumpanakis Pulmonary and Critical Care Medicine, Medical School, National and Kapodistrian University of Athens, Greece Abstract: In obstructive lung diseases, airway inflammation leads to bronchospasm and thus resistive breathing, especially during exacerbations. This commentary discusses experimental evidence that resistive breathing per se (the mechanical stimulus in the absence of underlying airway inflammation leads to lung injury and inflammation (mechanotransduction. The potential implications of resistive breathing-induced mechanotrasduction in COPD exacerbations are presented along with the available clinical evidence. Keywords: resistive breathing, COPD, mechanotransduction, bronchoconstriction, inflammation

  18. Sports-related lung injury during breath-hold diving

    Directory of Open Access Journals (Sweden)

    Tanja Mijacika

    2016-12-01

    Full Text Available The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise. In this article we focus on the effects of breath-hold diving on pulmonary function. Respiratory symptoms have been reported in almost 25% of breath-hold divers after repetitive diving sessions. Acutely, repetitive breath-hold diving may result in increased transpulmonary capillary pressure, leading to noncardiogenic oedema and/or alveolar haemorrhage. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition. According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage.

  19. Sports-related lung injury during breath-hold diving.

    Science.gov (United States)

    Mijacika, Tanja; Dujic, Zeljko

    2016-12-01

    The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise.In this article we focus on the effects of breath-hold diving on pulmonary function. Respiratory symptoms have been reported in almost 25% of breath-hold divers after repetitive diving sessions. Acutely, repetitive breath-hold diving may result in increased transpulmonary capillary pressure, leading to noncardiogenic oedema and/or alveolar haemorrhage. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition.According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage.

  20. Optimal technique for deep breathing exercises after cardiac surgery.

    Science.gov (United States)

    Westerdahl, E

    2015-06-01

    Cardiac surgery patients often develop a restrictive pulmonary impairment and gas exchange abnormalities in the early postoperative period. Chest physiotherapy is routinely prescribed in order to reduce or prevent these complications. Besides early mobilization, positioning and shoulder girdle exercises, various breathing exercises have been implemented as a major component of postoperative care. A variety of deep breathing maneuvres are recommended to the spontaneously breathing patient to reduce atelectasis and to improve lung function in the early postoperative period. Different breathing exercises are recommended in different parts of the world, and there is no consensus about the most effective breathing technique after cardiac surgery. Arbitrary instructions are given, and recommendations on performance and duration vary between hospitals. Deep breathing exercises are a major part of this therapy, but scientific evidence for the efficacy has been lacking until recently, and there is a lack of trials describing how postoperative breathing exercises actually should be performed. The purpose of this review is to provide a brief overview of postoperative breathing exercises for patients undergoing cardiac surgery via sternotomy, and to discuss and suggest an optimal technique for the performance of deep breathing exercises.

  1. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner

    Science.gov (United States)

    Reichenbach, Jürgen R.

    2016-01-01

    This work’s aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay −0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence. PMID:26975051

  2. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner.

    Science.gov (United States)

    Herrmann, Karl-Heinz; Krämer, Martin; Reichenbach, Jürgen R

    2016-01-01

    This work's aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay -0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence.

  3. Real-time 3D visualization of the thoraco-abdominal surface during breathing with body movement and deformation extraction.

    Science.gov (United States)

    Povšič, K; Jezeršek, M; Možina, J

    2015-07-01

    Real-time 3D visualization of the breathing displacements can be a useful diagnostic tool in order to immediately observe the most active regions on the thoraco-abdominal surface. The developed method is capable of separating non-relevant torso movement and deformations from the deformations that are solely related to breathing. This makes it possible to visualize only the breathing displacements. The system is based on the structured laser triangulation principle, with simultaneous spatial and color data acquisition of the thoraco-abdominal region. Based on the tracking of the attached passive markers, the torso movement and deformation is compensated using rigid and non-rigid transformation models on the three-dimensional (3D) data. The total time of 3D data processing together with visualization equals 20 ms per cycle.In vitro verification of the rigid movement extraction was performed using the iterative closest point algorithm as a reference. Furthermore, a volumetric evaluation on a live subject was performed to establish the accuracy of the rigid and non-rigid model. The root mean square deviation between the measured and the reference volumes shows an error of  ±0.08 dm(3) for rigid movement extraction. Similarly, the error was calculated to be  ±0.02 dm(3) for torsional deformation extraction and  ±0.11 dm(3) for lateral bending deformation extraction. The results confirm that during the torso movement and deformation, the proposed method is sufficiently accurate to visualize only the displacements related to breathing. The method can be used, for example, during the breathing exercise on an indoor bicycle or a treadmill.

  4. Electronic response to nuclear breathing mode

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Hendrik; Ruffini, Remo [ICRANet, P.zza della Repubblica 10, I-65122 Pescara, Italy Dipartimento di Fisica and ICRA, Sapienza Università di Roma P.le Aldo Moro 5, I-00185 Rome (Italy); ICRANet, University of Nice-Sophia Antipolis, 28 Av. de Valrose, 06103 Nice Cedex 2 (France); Xue, She-Sheng [ICRANet, P.zza della Repubblica 10, I-65122 Pescara, Italy Dipartimento di Fisica and ICRA, Sapienza Università di Roma P.le Aldo Moro 5, I-00185 Rome (Italy)

    2015-12-17

    Based on our previous work on stationary oscillation modes of electrons around giant nuclei, we show how to treat a general driving force on the electron gas, such as the one generated by the breathing mode of the nucleus, by means of the spectral method. As an example we demonstrate this method for a system with Z = 10{sup 4} in β-equilibrium with the electrons compressed up to the nuclear radius. In this case the stationary modes can be obtained analytically, which allows for a very speedy numerical calculation of the final result.

  5. Exhaled breath condensate pH assays.

    Science.gov (United States)

    Davis, Michael D; Hunt, John

    2012-08-01

    Airway pH is central to the physiologic function and cellular biology of the airway. The causes of airway acidification include (1) hypopharyngeal gastric acid reflux with or without aspiration through the vocal cords, (2) inhalation of acid fog or gas (such as chlorine), and (3) intrinsic airway acidification caused by altered airway pH homeostasis in infectious and inflammatory disease processes. The recognition that relevant airway pH deviations occur in lung diseases is opening doors to new simple and inexpensive therapies. This recognition has resulted partly from the ability to use exhaled breath condensate as a window on airway acid-base balance.

  6. Exhaled Breath Condensate for Proteomic Biomarker Discovery

    Directory of Open Access Journals (Sweden)

    Sean W. Harshman

    2014-07-01

    Full Text Available Exhaled breath condensate (EBC has been established as a potential source of respiratory biomarkers. Compared to the numerous small molecules identified, the protein content of EBC has remained relatively unstudied due to the methodological and technical difficulties surrounding EBC analysis. In this review, we discuss the proteins identified in EBC, by mass spectrometry, focusing on the significance of those proteins identified. We will also review the limitations surrounding mass spectral EBC protein analysis emphasizing recommendations to enhance EBC protein identifications by mass spectrometry. Finally, we will provide insight into the future directions of the EBC proteomics field.

  7. System of Optoelectronic Sensors for Breath Analysis

    Directory of Open Access Journals (Sweden)

    Mikołajczyk Janusz

    2016-09-01

    Full Text Available The paper describes an integrated laser absorption system as a potential tool for breath analysis for clinical diagnostics, online therapy monitoring and metabolic disorder control. The sensors operate basing on cavity enhanced spectroscopy and multi-pass spectroscopy supported by wavelength modulation spectroscopy. The aspects concerning selection of operational spectral range and minimization of interference are also discussed. Tests results of the constructed devices collected with reference samples of biomarkers are also presented. The obtained data provide an opportunity to analyse applicability of optoelectronic sensors in medical screening.

  8. Extensive Epidermoid Cyst and Breathing Difficulty

    Directory of Open Access Journals (Sweden)

    Ciro Dantas Soares

    2015-01-01

    Full Text Available Epidermoid cysts are common cystic lesions in the skin, ovaries, and testicles, but their occurrence in the oral cavity is uncommon. They consist of cysts delimited by a fibrous capsule without cutaneous annexes and are lined by stratified squamous epithelium. The differential diagnosis includes ranula, dermoid cysts, and lingual thyroid. Despite their benign presentation, these cysts can cause functional limitations, requiring special clinical attention for extensive lesions located in regions that preserve vital structures. This paper aims to report a case of epidermoid cyst in patient with swallowing and breathing difficulty, highlighting the clinical and surgical planning.

  9. A young male with shortness of breath

    Directory of Open Access Journals (Sweden)

    Khan Fahmi

    2008-01-01

    Full Text Available We report a case of primary mediastinal seminoma, which presented initially with shortness of breath and a swelling in upper part of anterior chest wall. The diagnosis of primary mediastinal seminoma was established on the basis of histologic findings and was confirmed by immunohistochemical analysis. Abdominal, pelvis and cerebral CT scan, testicular ultrasound and TC-99 MDP bone scintigraphy were negative. Chemotherapy was initiated with B.E.P. protocol (Bleomycin, Etoposide, Cisplatinum; the patient received four cycles of chemotherapy. After 8 months, the patient was seen in the clinic; he was well.

  10. Extensive Epidermoid Cyst and Breathing Difficulty

    Science.gov (United States)

    Soares, Ciro Dantas; Gurgel, Alberto Costa; de Souza Júnior, Francisco de Assis; de Oliveira, Samila Neres; de Carvalho, Maria Goretti Freire; Oliveira, Hanieri Gustavo

    2015-01-01

    Epidermoid cysts are common cystic lesions in the skin, ovaries, and testicles, but their occurrence in the oral cavity is uncommon. They consist of cysts delimited by a fibrous capsule without cutaneous annexes and are lined by stratified squamous epithelium. The differential diagnosis includes ranula, dermoid cysts, and lingual thyroid. Despite their benign presentation, these cysts can cause functional limitations, requiring special clinical attention for extensive lesions located in regions that preserve vital structures. This paper aims to report a case of epidermoid cyst in patient with swallowing and breathing difficulty, highlighting the clinical and surgical planning. PMID:26180645

  11. Options for assessing and measuring chest wall motion.

    Science.gov (United States)

    Seddon, Paul

    2015-01-01

    Assessing chest wall motion is a basic and vital component in managing the child with respiratory problems, whether these are due to pathology in the lungs, airways, chest wall or muscles. Since the 1960s, clinical assessment has been supplemented with an ever-growing range of technological options for measuring chest wall motion, each with unique advantages and disadvantages. Measurements of chest wall motion can be used to: (1) Assess respiratory airflow and volume change, as a non-invasive alternative to measurement at the airway opening, (2) Monitor breathing over long periods of time, to identify apnoea and other types of sleep-disordered breathing, (3)Identify and quantify patterns of abnormal chest wall movement, whether between ribcage and abdominal components (thoracoabdominal asynchrony) or between different regions of the ribcage (eg in scoliosis and pectus excavatum). Measuring chest wall motion allows us to do things which simply cannot be done by more mainstream respiratory function techniques measuring flow at the airway opening: it allows respiratory airflow to be measured when it would otherwise be impossible, and it tells us how the different parts of the chest wall (eg ribcage vs abdomen, right vs left) are moving in order to generate that airflow. The basis of the different techniques available to assess and measure chest wall motion will be reviewed and compared, and their relevance to paediatric respiratory practice assessed.

  12. Appropriate sample bags and syringes for preserving breath samples in breath odor research : a technical note

    NARCIS (Netherlands)

    Winkel, E. G.; Tangerman, A.

    2008-01-01

    It is now generally accepted that the volatile sulfur compounds (VSCs) hydrogen sulfide, methyl mercaptan and dimethyl sulfide are the main contributors to halitosis when of oropharyngeal origin. The VSCs hydrogen sulfide and methyl mercaptan are the major causes of bad breath in oral malodour where

  13. Tracking lung tumour motion using a dynamically weighted optical flow algorithm and electronic portal imaging device

    Science.gov (United States)

    Teo, P. T.; Crow, R.; Van Nest, S.; Sasaki, D.; Pistorius, S.

    2013-07-01

    This paper investigates the feasibility and accuracy of using a computer vision algorithm and electronic portal images to track the motion of a tumour-like target from a breathing phantom. A multi-resolution optical flow algorithm that incorporates weighting based on the differences between frames was used to obtain a set of vectors corresponding to the motion between two frames. A global value representing the average motion was obtained by computing the average weighted mean from the set of vectors. The tracking accuracy of the optical flow algorithm as a function of the breathing rate and target visibility was investigated. Synthetic images with different contrast-to-noise ratios (CNR) were created, and motions were tracked. The accuracy of the proposed algorithm was compared against potentiometer measurements giving average position errors of 0.6 ± 0.2 mm, 0.2 ± 0.2 mm and 0.1 ± 0.1 mm with average velocity errors of 0.2 ± 0.2 mm s-1, 0.4 ± 0.3 mm s-1 and 0.6 ± 0.5 mm s-1 for 6, 12 and 16 breaths min-1 motions, respectively. The cumulative average position error reduces more rapidly with the greater number of breathing cycles present in higher breathing rates. As the CNR increases from 4.27 to 5.6, the average relative error approaches zero and the errors are less dependent on the velocity. When tracking a tumour on a patient's digitally reconstructed radiograph images, a high correlation was obtained between the dynamically weighted optical flow algorithm, a manual delineation process and a centroid tracking algorithm. While the accuracy of our approach is similar to that of other methods, the benefits are that it does not require manual delineation of the target and can therefore provide accurate real-time motion estimation during treatment.

  14. Manifold learning for image-based breathing gating in ultrasound and MRI.

    Science.gov (United States)

    Wachinger, Christian; Yigitsoy, Mehmet; Rijkhorst, Erik-Jan; Navab, Nassir

    2012-05-01

    Respiratory motion is a challenging factor for image acquisition and image-guided procedures in the abdominal and thoracic region. In order to address the issues arising from respiratory motion, it is often necessary to detect the respiratory signal. In this article, we propose a novel, purely image-based retrospective respiratory gating method for ultrasound and MRI. Further, we apply this technique to acquire breathing-affected 4D ultrasound with a wobbler probe and, similarly, to create 4D MR with a slice stacking approach. We achieve the gating with Laplacian eigenmaps, a manifold learning technique, to determine the low-dimensional manifold embedded in the high-dimensional image space. Since Laplacian eigenmaps assign to each image frame a coordinate in low-dimensional space by respecting the neighborhood relationship, they are well suited for analyzing the breathing cycle. We perform the image-based gating on several 2D and 3D ultrasound datasets over time, and quantify its very good performance by comparing it to measurements from an external gating system. For MRI, we perform the manifold learning on several datasets for various orientations and positions. We achieve very high correlations by a comparison to an alternative gating with diaphragm tracking.

  15. 75 FR 49595 - Performance of Functions; Claims for Compensation Under the Federal Employees' Compensation Act...

    Science.gov (United States)

    2010-08-13

    ... Labor Office of Workers' Compensation Programs 20 CFR Parts 1, 10, and 25 Performance of Functions; Claims for Compensation Under the Federal Employees' Compensation Act; Compensation for Disability and... Workers' Compensation Programs 20 CFR Parts 1, 10, and 25 RIN 1240-AA03 Performance of Functions;...

  16. Respiratory motion correction in 4D-PET by simultaneous motion estimation and image reconstruction (SMEIR)

    Science.gov (United States)

    Kalantari, Faraz; Li, Tianfang; Jin, Mingwu; Wang, Jing

    2016-08-01

    In conventional 4D positron emission tomography (4D-PET), images from different frames are reconstructed individually and aligned by registration methods. Two issues that arise with this approach are as follows: (1) the reconstruction algorithms do not make full use of projection statistics; and (2) the registration between noisy images can result in poor alignment. In this study, we investigated the use of simultaneous motion estimation and image reconstruction (SMEIR) methods for motion estimation/correction in 4D-PET. A modified ordered-subset expectation maximization algorithm coupled with total variation minimization (OSEM-TV) was used to obtain a primary motion-compensated PET (pmc-PET) from all projection data, using Demons derived deformation vector fields (DVFs) as initial motion vectors. A motion model update was performed to obtain an optimal set of DVFs in the pmc-PET and other phases, by matching the forward projection of the deformed pmc-PET with measured projections from other phases. The OSEM-TV image reconstruction was repeated using updated DVFs, and new DVFs were estimated based on updated images. A 4D-XCAT phantom with typical FDG biodistribution was generated to evaluate the performance of the SMEIR algorithm in lung and liver tumors with different contrasts and different diameters (10-40 mm). The image quality of the 4D-PET was greatly improved by the SMEIR algorithm. When all projections were used to reconstruct 3D-PET without motion compensation, motion blurring artifacts were present, leading up to 150% tumor size overestimation and significant quantitative errors, including 50% underestimation of tumor contrast and 59% underestimation of tumor uptake. Errors were reduced to less than 10% in most images by using the SMEIR algorithm, showing its potential in motion estimation/correction in 4D-PET.

  17. Motion in radiotherapy

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia

    2012-01-01

    This review considers the management of motion in photon radiation therapy. An overview is given of magnitudes and variability of motion of various structures and organs, and how the motion affects images by producing artifacts and blurring. Imaging of motion is described, including 4DCT and 4DPET...

  18. Change of amplitude of motion and force of hand for women after a radical mammectomy

    OpenAIRE

    Odinec T.E.

    2009-01-01

    The estimation of dynamometer of brush and amplitude of motion is rotined in a humeral joint for women. The features of remote postprocess period are considered after a radical mammectomy. Close correlation is rotined between amplitude of motion and index of function of the external breathing. The results of goniometer and dynamometer are presented. A hydrokinesitherapy is considered from position of perspective mean of rehabilitation of the functional state of women. The high degree of inter...

  19. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    Science.gov (United States)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  20. Exhaled Breath Condensate: Technical and Diagnostic Aspects

    Directory of Open Access Journals (Sweden)

    Efstathia M. Konstantinidi

    2015-01-01

    Full Text Available Purpose. The aim of this study was to evaluate the 30-year progress of research on exhaled breath condensate in a disease-based approach. Methods. We searched PubMed/Medline, ScienceDirect, and Google Scholar using the following keywords: exhaled breath condensate (EBC, biomarkers, pH, asthma, gastroesophageal reflux (GERD, smoking, COPD, lung cancer, NSCLC, mechanical ventilation, cystic fibrosis, pulmonary arterial hypertension (PAH, idiopathic pulmonary fibrosis, interstitial lung diseases, obstructive sleep apnea (OSA, and drugs. Results. We found 12600 related articles in total in Google Scholar, 1807 in ScienceDirect, and 1081 in PubMed/Medline, published from 1980 to October 2014. 228 original investigation and review articles were eligible. Conclusions. There is rapidly increasing number of innovative articles, covering all the areas of modern respiratory medicine and expanding EBC potential clinical applications to other fields of internal medicine. However, the majority of published papers represent the results of small-scale studies and thus current knowledge must be further evaluated in large cohorts. In regard to the potential clinical use of EBC-analysis, several limitations must be pointed out, including poor reproducibility of biomarkers and absence of large surveys towards determination of reference-normal values. In conclusion, contemporary EBC-analysis is an intriguing achievement, but still in early stage when it comes to its application in clinical practice.

  1. Screening Sleep Disordered Breathing in Stroke Unit

    Directory of Open Access Journals (Sweden)

    Kirsi Väyrynen

    2014-01-01

    Full Text Available In acute stroke, OSA has been found to impair rehabilitation and increase mortality but the effect of central apnea is more unclear. The aim of the present study was to evaluate the feasibility of using limited ambulatory recording system (sleep mattress to evaluate nocturnal breathing and EOG-electrodes for sleep staging in sleep disordered breathing (SDB diagnostics in mild acute cerebral ischemia patients and to discover the prevalence of various SDB-patterns among these patients. 42 patients with mild ischemic stroke or transient ischemic attack were studied. OSA was found in 22 patients (52.4%. Central apnea was found in two patients (4.8% and sustained partial obstruction in only one patient (2.4%. Sleep staging with EOG-electrodes only yielded a similar outcome as scoring with standard rules. OSA was found to be common even after mild stroke. Its early diagnosis and treatment would be favourable in order to improve recovery and reduce mortality. Our results suggest that OSA can be assessed by a limited recording setting with EOG-electrodes, sleep mattress, and pulse oximetry.

  2. Epiglottic movements during breathing in humans

    Science.gov (United States)

    Amis, T C; O'Neill, N; Di Somma, E; Wheatley, J R

    1998-01-01

    Using X-ray fluoroscopy we measured antero-posterior (A–P) and cranio-caudal (C–C) displacements of the epiglottic tip (ET), corniculate cartilage and hyoid bone in seven seated, normal human subjects (age 34 ± 3 years; mean ±s.e.m.; 4 males, 3 females) breathing via a nasal mask or mouthpiece with (RL) and without (UB) a fixed resistive load.During UB, via either mouth or nose, there were no significant A-P ET movements. During RL via the nose the ET at peak expiratory flow was 2.6 ± 1.3 mm cranial to its position at peak inspiratory flow (P <0.05, ANOVA). C–C movements of the ET correlated strongly with C-C movements of the corniculate cartilage and hyoid bone.The ET, corniculate cartilage and hyoid bone (at zero airflow) were situated more caudally during oral UB than for any other condition.When present, epiglottic movements during breathing do not appear to be independent of those of the larynx and hyoid. Furthermore, epiglottic position may be related to the level of upper airway resistance. PMID:9729637

  3. GPU-based video motion magnification

    Science.gov (United States)

    DomŻał, Mariusz; Jedrasiak, Karol; Sobel, Dawid; Ryt, Artur; Nawrat, Aleksander

    2016-06-01

    Video motion magnification (VMM) allows people see otherwise not visible subtle changes in surrounding world. VMM is also capable of hiding them with a modified version of the algorithm. It is possible to magnify motion related to breathing of patients in hospital to observe it or extinguish it and extract other information from stabilized image sequence for example blood flow. In both cases we would like to perform calculations in real time. Unfortunately, the VMM algorithm requires a great amount of computing power. In the article we suggest that VMM algorithm can be parallelized (each thread processes one pixel) and in order to prove that we implemented the algorithm on GPU using CUDA technology. CPU is used only to grab, write, display frame and schedule work for GPU. Each GPU kernel performs spatial decomposition, reconstruction and motion amplification. In this work we presented approach that achieves a significant speedup over existing methods and allow to VMM process video in real-time. This solution can be used as preprocessing for other algorithms in more complex systems or can find application wherever real time motion magnification would be useful. It is worth to mention that the implementation runs on most modern desktops and laptops compatible with CUDA technology.

  4. Compensation for electrical converter nonlinearities

    Science.gov (United States)

    Perisic, Milun; Ransom, Ray M; Kajouke, Lateef A

    2013-11-19

    Systems and methods are provided for delivering energy from an input interface to an output interface. An electrical system includes an input interface, an output interface, an energy conversion module between the input interface and the output interface, an inductive element between the input interface and the energy conversion module, and a control module. The control module determines a compensated duty cycle control value for operating the energy conversion module to produce a desired voltage at the output interface and operates the energy conversion module to deliver energy to the output interface with a duty cycle that is influenced by the compensated duty cycle control value. The compensated duty cycle control value is influenced by the current through the inductive element and accounts for voltage across the switching elements of the energy conversion module.

  5. Robust tracking control design for a flexible air-breathing hypersonic vehicle

    Institute of Scientific and Technical Information of China (English)

    张垚; 鲜斌; 刁琛; 赵勃; 郭建川

    2014-01-01

    A nonlinear robust controller was presented to improve the tracking control performance of a flexible air-breathing hypersonic vehicle (AHV) which is subjected to system parametric uncertainties and unknown additive time-varying disturbances. The longitudinal dynamic model for the flexible AHV was used for the control development. High-gain observers were designed to compensate for the system uncertainties and additive disturbances. Small gain theorem and Lyapunov based stability analysis were utilized to prove the stability of the closed loop system. Locally uniformly ultimately bounded tracking of the vehicle’s velocity, altitude and attack angle were achieved under aeroelastic effects, system parametric uncertainties and unknown additive disturbances. Matlab/Simulink simulation results were provided to validate the robustness of the proposed control design. The simulation results demonstrate that the tracking errors stay in a small region around zero.

  6. Adaptive Neural Back-Stepping Control with Constrains for a Flexible Air-Breathing Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Pengfei Wang

    2015-01-01

    Full Text Available The design of an adaptive neural back-stepping control for a flexible air-breathing hypersonic vehicle (AHV in the presence of input constraint and aerodynamic uncertainty is discussed. Based on functional decomposition, the dynamics can be decomposed into the velocity subsystem and the altitude subsystem. To guarantee the exploited controller’s robustness with respect to parametric uncertainties, neural network (NN is applied to approximate the lumped uncertainty of each subsystem of AHV model. The exceptional contribution is that novel auxiliary systems are introduced to compensate both the tracking errors and desired control laws, based on which the explored controller can still provide effective tracking of velocity and altitude commands when the actuators are saturated. Finally, simulation studies are made to illustrate the effectiveness of the proposed control approach in spite of the flexible effects, system uncertainties, and varying disturbances.

  7. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    Science.gov (United States)

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies.

  8. Measuring Motion-Induced B0-Fluctuations in the Brain Using Field Probes

    DEFF Research Database (Denmark)

    Andersen, Mads; Hanson, Lars G.; Madsen, Kristoffer Hougaard;

    2016-01-01

    Purpose: Fluctuations of the background magnetic field (B0) due to body and breathing motion can lead to significant artifacts in brain imaging at ultrahigh field. Corrections based on real-time sensing using external field probes show great potential. This study evaluates different aspects of fi...

  9. The internal-external respiratory motion correlation is unaffected by audiovisual biofeedback.

    Science.gov (United States)

    Steel, Harry; Pollock, Sean; Lee, Danny; Keall, Paul; Kim, Taeho

    2014-03-01

    This study evaluated if an audiovisual (AV) biofeedback causes variation in the level of external and internal correlation due to its interactive intervention in natural breathing. The internal (diaphragm) and external (abdominal wall) respiratory motion signals of 15 healthy human subjects under AV biofeedback and free breathing (FB) were analyzed and measures of correlation and regularity taken. Regularity metrics (root mean square error and spectral power dispersion metric) were obtained and the correlation between these metrics and the internal and external correlation was investigated. For FB and AV biofeedback assisted breathing the mean correlations found between internal and external respiratory motion were 0.96±0.02 and 0.96±0.03, respectively. This means there is no evidence to suggest (p-value=0.88) any difference in the correlation between internal and external respiratory motion with the use of AV biofeedback. Our results confirmed the hypothesis that the internal-external correlation with AV biofeedback is the same as for free breathing. Should this correlation be maintained for patients, AV biofeedback can be implemented in the clinic with confidence as regularity improvements using AV biofeedback with an external signal will be reflected in increased internal motion regularity.

  10. Wavefront Compensation Segmented Mirror Sensing and Control

    Science.gov (United States)

    Redding, David C.; Lou, John Z.; Kissil, Andrew; Bradford, Charles M.; Woody, David; Padin, Stephen

    2012-01-01

    The primary mirror of very large submillimeter-wave telescopes will necessarily be segmented into many separate mirror panels. These panels must be continuously co-phased to keep the telescope wavefront error less than a small fraction of a wavelength, to ten microns RMS (root mean square) or less. This performance must be maintained continuously across the full aperture of the telescope, in all pointing conditions, and in a variable thermal environment. A wavefront compensation segmented mirror sensing and control system, consisting of optical edge sensors, Wavefront Compensation Estimator/Controller Soft ware, and segment position actuators is proposed. Optical edge sensors are placed two per each segment-to-segment edge to continuously measure changes in segment state. Segment position actuators (three per segment) are used to move the panels. A computer control system uses the edge sensor measurements to estimate the state of all of the segments and to predict the wavefront error; segment actuator commands are computed that minimize the wavefront error. Translational or rotational motions of one segment relative to the other cause lateral displacement of the light beam, which is measured by the imaging sensor. For high accuracy, the collimator uses a shaped mask, such as one or more slits, so that the light beam forms a pattern on the sensor that permits sensing accuracy of better than 0.1 micron in two axes: in the z or local surface normal direction, and in the y direction parallel to the mirror surface and perpendicular to the beam direction. Using a co-aligned pair of sensors, with the location of the detector and collimated light source interchanged, four degrees of freedom can be sensed: transverse x and y displacements, as well as two bending angles (pitch and yaw). In this approach, each optical edge sensor head has a collimator and an imager, placing one sensor head on each side of a segment gap, with two parallel light beams crossing the gap. Two sets

  11. APPROACH TO IMPROVEMENT OF ROBOT TRAJECTORY ACCURACY BY DYNAMIC COMPENSATION

    Institute of Scientific and Technical Information of China (English)

    Wang Gang; Ren Guoli; Yan Xiang'an; Wang Guodong

    2004-01-01

    Some dynamic factors, such as inertial forces and friction, may affect the robot trajectory accuracy. But these effects are not taken into account in robot motion control schemes. Dynamic control methods, on the other hand, require the dynamic model of robot and the implementation of new type controller. A method to improve robot trajectory accuracy by dynamic compensation in robot motion control system is proposed. The dynamic compensation is applied as an additional velocity feedforward and a multilayer neural network is employed to realize the robot inverse dynamics. The complicated dynamic parameter identification problem becomes a learning process of neural network connecting weights under supervision. The finite Fourier series is used to activate each actuator of robot joints for obtaining training samples. Robot control system, consisting of an industrial computer and a digital motion controller, is implemented. The system is of open architecture with velocity feedforward function. The proposed method is not model-based and combines the advantages of close-loop position control and computed torque control. Experimental results have shown that the method is validatities to improve the robot trajectory accuracy.

  12. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  13. Depth Compensated Spectral Domain Optical Coherence Tomography via Digital Compensation

    CERN Document Server

    Boroomand, Ameneh; Shafiee, Mohammad Javad; Bizheva, Kostadinka; Wong, Alexander

    2015-01-01

    Spectral Domain Optical Coherence Tomography (SD-OCT) is a well-known imaging modality which allows for \\textit{in-vivo} visualization of the morphology of different biological tissues at cellular level resolutions. The overall SD-OCT imaging quality in terms of axial resolution and Signal-to-Noise Ratio (SNR) degrades with imaging depth, while the lateral resolution degrades with distance from the focal plane. This image quality degradation is due both to the design of the SD-OCT imaging system and the optical properties of the imaged object. Here, we present a novel Depth Compensated SD-OCT (DC-OCT) system that integrates a Depth Compensating Digital Signal Processing (DC-DSP) module to improve the overall imaging quality via digital compensation. The designed DC-DSP module can be integrated to any SD-OCT system and is able to simultaneously compensate for the depth-dependent loss of axial and lateral resolutions, depth-varying SNR, as well as sidelobe artifact for improved imaging quality. The integrated D...

  14. Joint Motion Estimation and Layer Segmentation in Transparent Image Sequences—Application to Noise Reduction in X-Ray Image Sequences

    Directory of Open Access Journals (Sweden)

    Jean Liénard

    2009-01-01

    Full Text Available This paper is concerned with the estimation of the motions and the segmentation of the spatial supports of the different layers involved in transparent X-ray image sequences. Classical motion estimation methods fail on sequences involving transparent effects since they do not explicitly model this phenomenon. We propose a method that comprises three main steps: initial block-matching for two-layer transparent motion estimation, motion clustering with 3D Hough transform, and joint transparent layer segmentation and parametric motion estimation. It is validated on synthetic and real clinical X-ray image sequences. Secondly, we derive an original transparent motion compensation method compatible with any spatiotemporal filtering technique. A direct transparent motion compensation method is proposed. To overcome its limitations, a novel hybrid filter is introduced which locally selects which type of motion compensation is to be carried out for optimal denoising. Convincing experiments on synthetic and real clinical images are also reported.

  15. Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep

    NARCIS (Netherlands)

    Randerath, Winfried; Verbraecken, Johan; Andreas, Stefan; Arzt, Michael; Bloch, Konrad E; Brack, Thomas; Buyse, Bertien; De Backer, Wilfried; Eckert, Danny Joel; Grote, Ludger; Hagmeyer, Lars; Hedner, Jan; Jennum, Poul; La Rovere, Maria Teresa; Miltz, Carla; McNicholas, Walter T; Montserrat, Josep; Naughton, Matthew; Pepin, Jean-Louis; Pevernagie, Dirk; Sanner, Bernd; Testelmans, Dries; Tonia, Thomy; Vrijsen, Bart; Wijkstra, Peter; Levy, Patrick

    2016-01-01

    The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerg

  16. Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep

    DEFF Research Database (Denmark)

    Randerath, Winfried; Verbraecken, Johan; Andreas, Stefan;

    2017-01-01

    The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can em...

  17. View compensated compression of volume rendered images for remote visualization.

    Science.gov (United States)

    Lalgudi, Hariharan G; Marcellin, Michael W; Bilgin, Ali; Oh, Han; Nadar, Mariappan S

    2009-07-01

    Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images from a server, based on viewpoint requests from a client. For constrained server-client bandwidth, an efficient compression scheme is vital for transmitting high quality rendered images. In this paper, we present a new view compensation scheme that utilizes the geometric relationship between viewpoints to exploit the correlation between successive rendered images. The proposed method obviates motion estimation between rendered images, enabling significant reduction to the complexity of a compressor. Additionally, the view compensation scheme, in conjunction with JPEG2000 performs better than AVC, the state of the art video compression standard.

  18. Controlling chaos based on an adaptive nonlinear compensator mechanism

    Institute of Scientific and Technical Information of China (English)

    Tian Ling-Ling; Li Dong-Hai; Sun Xian-Fang

    2008-01-01

    The control problems of chaotic systems are investigated in the presence of parametric uncertainty and persistent external disturbances based on nonlinear control theory.By using a designed nonlinear compensator mechanism,the system deterministic nonlinearity,parametric uncertainty and disturbance effect can be compensated effectively.The renowned chaotic Lorenz system subjected to parametric variations and external disturbances is studied as an illustrative example.From the Lyapunov stability theory,sufficient conditions for choosing control parameters to guarantee chaos control are derived.Several experiments are carried out,including parameter change experiments,set-point change experiments and disturbance experiments.Simulation results indicate that the chaotic motion can be regulated not only to steady states but also to any desired periodic orbits with great immunity to parametric variations and external disturbances.

  19. Fast 3-Breath-Hold 3-Dimensional Tagging Cardiac Magnetic Resonance in Patients with Hypertrophic Myocardial Diseases: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Yasuo Amano

    2016-01-01

    Full Text Available Tagging CMR has been established as the standard reference for measurement of myocardial strain. The current 2D tagging technique requires multiple breath-holds to cover the whole heart and cannot show the 3D motions of the left ventricle. We performed fast 3-breath-hold 3D tagging with localized tagging preparation and complementary spatial modulation of magnetization in 10 patients with hypertrophic myocardial diseases and 6 normal volunteers. The left wall motion was observed at any view angle, which allowed for the identification of regional and global hypokinesis using the fast 3D tagging. Although a decrease in the circumferential strain and LGE were observed at the basal septum in hypertrophic cardiomyopathy, they were not located together in each patient. In hypertensive heart disease, the decrease in circumferential strain was observed more widely than LGE, and the summed strain of all segments was significantly decreased. The decrease in strain and LGE were observed diffusely in cardiac amyloidosis. In conclusion, fast 3-breath-hold 3D tagging is feasible for the regional and global strain analysis. The location of reduced circumferential strain is not necessarily the same as that of LGE and is related to the global cardiac function in patients with hypertrophic myocardial diseases.

  20. [Prevalence of mouth breathing in children from an elementary school].

    Science.gov (United States)

    Felcar, Josiane Marques; Bueno, Izabele Rafael; Massan, Ana Carolina Silva; Torezan, Roberta Pereira; Cardoso, Jefferson Rosa

    2010-03-01

    The objective of this article is to identify the prevalence of mouth breathing in children from an elementary school. 496 questionnaires were answered by 1st and 4th grade children's parents or sponsors in order to identify mouth-breathing. There were questions about habits, sleeping, behavior, eating, personal care and breathing. Mann-Whitney and the Chi-square tests were used to compare the variables between mouth-breathing and nose-breathing among the groups. To measure the exposure effect of the explanatory variables on mouth breathing, the test of logistic regression was used and its magnitude was calculated through Odds Ratio. The statistical significance was set at 5%, and the rate of returned questionnaires was 84.5%. The prevalence of the mouthbreathing over this population was 56.8%. The average age was 7 years old (6-9). There was no significant statistical difference between genders, considering 49.1% male and 50.9% female. The final model of logistic regression identified the variables dribble, sleeps well (negative association) and snores as factors that predict the occurrence of the mouth-breathing. The prevalence of mouthbreathing was similar to related in the literature. The variables dribble, sleeps well (negative association) and snores may be factors that predict the occurrence of mouth-breathing.