WorldWideScience

Sample records for pulse contour cardiac

  1. Pulse contour-derived cardiac output in hemodialysis patients

    DEFF Research Database (Denmark)

    Cordtz, Joakim; Ladefoged, Soeren D

    2010-01-01

    Reliable methods for cardiac output determination are essential for studying the pathophysiology of intradialytic hypotension. Use of the current gold standard, the Transonic monitor, requires an arteriovenous fistula. We wished to verify the accuracy of a method based on finger pulse contour...

  2. Pulse contour-derived cardiac output in hemodialysis patients

    DEFF Research Database (Denmark)

    Cordtz, Joakim; Ladefoged, Soeren D

    2010-01-01

    Reliable methods for cardiac output determination are essential for studying the pathophysiology of intradialytic hypotension. Use of the current gold standard, the Transonic monitor, requires an arteriovenous fistula. We wished to verify the accuracy of a method based on finger pulse contour...... analysis, namely the Finometer monitor (FNM) for further use on patients dialyzing on a central vascular catheter. Fifty simultaneous cardiac output measurements were obtained during hemodialysis sessions in 25 patients. The internal variability of the FNM measurements was assessed by comparing 24 pairs...

  3. Kredsløbsmonitorering af kritisk syge patienter med "pulse contour cardiac output"-systemet

    DEFF Research Database (Denmark)

    Afshari, Arash; Perner, Anders; Bonde, Jan

    2006-01-01

    The Pulse Contour Cardiac Output (PiCCO) monitoring system measures cardiac output with high precision and accuracy. The system may replace the pulmonary artery catheter in most critically ill patients because the rate of serious complications may be lower. Whether the use of dynamic or static fl...... fluid monitoring by PiCCO will result in better outcomes should be assessed by studies using clinically relevant end points....

  4. Accuracy of Cardiac Output by Nine Different Pulse Contour Algorithms in Cardiac Surgery Patients: A Comparison with Transpulmonary Thermodilution

    Science.gov (United States)

    Bein, Berthold; Gruenewald, Matthias; Masing, Sarah; Huenges, Katharina; Haneya, Assad; Steinfath, Markus; Renner, Jochen

    2016-01-01

    Objective. Today, there exist several different pulse contour algorithms for calculation of cardiac output (CO). The aim of the present study was to compare the accuracy of nine different pulse contour algorithms with transpulmonary thermodilution before and after cardiopulmonary bypass (CPB). Methods. Thirty patients scheduled for elective coronary surgery were studied before and after CPB. A passive leg raising maneuver was also performed. Measurements included CO obtained by transpulmonary thermodilution (COTPTD) and by nine pulse contour algorithms (COX1–9). Calibration of pulse contour algorithms was performed by esophageal Doppler ultrasound after induction of anesthesia and 15 min after CPB. Correlations, Bland-Altman analysis, four-quadrant, and polar analysis were also calculated. Results. There was only a poor correlation between COTPTD and COX1–9 during passive leg raising and in the period before and after CPB. Percentage error exceeded the required 30% limit. Four-quadrant and polar analysis revealed poor trending ability for most algorithms before and after CPB. The Liljestrand-Zander algorithm revealed the best reliability. Conclusions. Estimation of CO by nine different pulse contour algorithms revealed poor accuracy compared with transpulmonary thermodilution. Furthermore, the less-invasive algorithms showed an insufficient capability for trending hemodynamic changes before and after CPB. The Liljestrand-Zander algorithm demonstrated the highest reliability. This trial is registered with NCT02438228 (ClinicalTrials.gov).

  5. Noninvasive cardiac output determination using applanation tonometry-derived radial artery pulse contour analysis in critically ill patients

    DEFF Research Database (Denmark)

    Compton, Friederike; Wittrock, Marc; Schaefer, Juergen-Heiner

    2008-01-01

    Conventional thermodilution cardiac output (CO) monitoring is limited mainly to intensive care units and operating rooms because it requires the use of invasive techniques. To reduce the potential for complications and to broaden the applicability of hemodynamic monitoring, noninvasive methods...... for CO determination are being sought. Applanation tonometry allows noninvasive CO estimation through pulse contour analysis, but the method has not been evaluated in critically ill patients. We therefore performed noninvasive radial artery applanation tonometry in 49 critically ill medical intensive...... care unit patients and compared CO estimates to invasive CO measurements obtained using a pulmonary artery catheter or the PiCCO transpulmonary thermodilution system. One-hundred-sixteen measurements were performed, and patients were receiving vasopressor support during 78 measurements. When the data...

  6. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, C.M.; Lansdorp, B.; Hoeven, J.G. van der; Scheffer, G.J.; Lemson, J.

    2014-01-01

    INTRODUCTION: Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting

  7. Validation of noninvasive pulse contour cardiac output using finger arterial pressure in cardiac surgery patients requiring fluid therapy

    NARCIS (Netherlands)

    Hofhuizen, Charlotte; Lansdorp, Benno; van der Hoeven, Johannes G.; Scheffer, Gert-Jan; Lemson, Joris

    2014-01-01

    Introduction Nexfin (Edwards Lifesciences, Irvine, CA) allows for noninvasive continuous monitoring of blood pressure (ABPNI) and cardiac output (CONI) by measuring finger arterial pressure (FAP). To evaluate the accuracy of FAP in measuring ABPNI and CONI as well as the adequacy of detecting

  8. Noninvasive cardiac output monitoring during exercise testing: Nexfin pulse contour analysis compared to an inert gas rebreathing method and respired gas analysis.

    Science.gov (United States)

    Bartels, Sebastiaan A; Stok, Wim J; Bezemer, Rick; Boksem, Remco J; van Goudoever, Jeroen; Cherpanath, Thomas G V; van Lieshout, Johannes J; Westerhof, Berend E; Karemaker, John M; Ince, Can

    2011-10-01

    Exercise testing is often used to assess cardiac function during physical exertion to obtain diagnostic information. However, this procedure is limited to measuring the electrical activity of the heart using electrocardiography and intermittent blood pressure (BP) measurements and does not involve the continuous assessment of heart functioning. In this study, we compared continuous beat-to-beat pulse contour analysis to monitor noninvasive cardiac output (CO) during exercise with inert gas rebreathing and respired gas analysis. Nineteen healthy male volunteers were subjected to bicycle ergometry testing with increasing workloads. Cardiac output was deter- mined noninvasively by continuous beat-to-beat pulse contour analysis (Nexfin) and by inert gas rebreathing, and estimated using the respired gas analysis method. The effects of the rebreathing maneuver on heart rate (HR), stroke volume (SV), and CO were evaluated. The CO values derived from the Nexfin- and inert gas rebreathing methods were well correlated (r = 0.88, P gas analysis-derived CO values correlated even better (r = 0.94, P < 0.01) and the limits of agreement were 21.5% with a measurement bias of -0.70 ± 1.6 L/min. At rest, the rebreathing maneuver increased HR by 13 beats/min (P < 0.01), SV remained unaffected (P = 0.7), while CO increased by 1.0 L/min (P < 0.01). Rebreathing did not affect these parameters during exercise. Nexfin continuous beat-to-beat pulse contour analysis is an appropriate method for noninvasive assessment of CO during exercise.

  9. Importance of re-calibration time on pulse contour analysis agreement with thermodilution measurements of cardiac output: a retrospective analysis of intensive care unit patients.

    Science.gov (United States)

    Scully, Christopher G; Gomatam, Shanti; Forrest, Shawn; Strauss, David G

    2016-10-01

    We assessed the effect of re-calibration time on cardiac output estimation and trending performance in a retrospective analysis of an intensive care unit patient population using error grid analyses. Paired thermodilution and arterial blood pressure waveform measurements (N = 2141) from 222 patient records were extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database. Pulse contour analysis was performed by implementing a previously reported algorithm at calibration times of 1, 2, 8 and 24 h. Cardiac output estimation agreement was assessed using Bland-Altman and error grid analyses. Trending was assessed by concordance and a 4-Quadrant error grid analysis. Error between pulse contour and thermodilution increased with longer calibration times. Limits of agreement were -1.85 to 1.66 L/min for 1 h maximum calibration time compared to -2.70 to 2.41 L/min for 24 h. Error grid analysis resulted in 74.2 % of points bounded by 20 % error limits of thermodilution measurements for 1 h calibration time compared to 65 % for 24 h. 4-Quadrant error grid analysis showed analysis method and thermodilution showed poor agreement to monitor changes in cardiac output.

  10. Cardiac output measurement by bioimpedance and noninvasive pulse contour analysis compared with the continuous pulmonary artery thermodilution technique

    NARCIS (Netherlands)

    Maass, Saskia W. M. C.; Roekaerts, Paul M. H. J.; Lance, Marcus D.

    2014-01-01

    Objective: The aim of the present study was to compare 2 noninvasive cardiac output measurement methods with the continuous cardiac output thermodilution (CCO-TD) method. Design: A single-center prospective design. Setting: A university hospital. Participants: Fifty-three consecutive patients schedu

  11. Application of pulse contour cardiac output monitoring technique in hemodynamic monitoring in critical patients%脉搏轮廓心排血量监测技术在危重病患者血流动力学监测中的应用

    Institute of Scientific and Technical Information of China (English)

    房贺; 郑兴锋; 夏照帆

    2014-01-01

    Pulse contour cardiac output (PiCCO) monitoring is a new type of invasive hemodynamic monitoring technology,which is more and more often applied in perioperative period and the patients suffering from multiple injuries,septic shock,and extensive burn.With PiCCO one is able to monitor patients' hemodynamic indexes safely,timely,accurately,and continuously to provide reference for judgment of patients' condition and proper quality and quantity of fluid administration.This technique has a good prospect in clinical application.

  12. Autonomic Nervous System Responses to Concussion: Arterial Pulse Contour Analysis

    Directory of Open Access Journals (Sweden)

    Michael F La Fountaine

    2016-02-01

    Full Text Available The arterial pulse wave (APW has a distinct morphology whose contours reflect dynamics in cardiac function and peripheral vascular tone as a result of sympathetic nervous system (SNS control. With a transition from rest to increased metabolic demand, the expected augmentation of SNS outflow will not only affect arterial blood pressure and heart rate, it will also induce changes to the contours of the APW. Following a sports concussion, a transient state cardiovascular autonomic dysfunction is present. How this state affects the APW, has yet to be described. A prospective, parallel-group study on cardiovascular autonomic control (i.e., digital electrocardiogram and continuous beat-to-beat blood pressure was performed in the seated upright position in ten athletes with concussion and 7 non-injured control athletes. Changes in APW were compared at rest and during the first 60 seconds (F60 of an isometric handgrip test (IHGT in concussed athletes and non-injured controls within 48 hours (48hr and 1 week (1wk of injury. The concussion group was further separated by the length of time until they were permitted to return to play (RTP>1wk; RTP≤1wk. SysSlope, an indirect measurement of stroke volume, was significantly lower in the concussion group at rest and during F60 at 48hr and 1wk; a paradoxical decline in SysSlope occurred at each visit during the transition from rest to IHGT F60. The RTP>1wk group had lower SysSlope (405±200; 420±88; 454±236 mmHg/s, respectively at rest 48hr compared to the RTP≤1wk and controls. Similarly at 48hr rest, several measurements of arterial stiffness were abnormal in RTP>1wk compared to RTP≤1wk and controls: Peak-to-Notch Latency (0.12±0.04; 0.16±0.02; 0.17±0.05, respectively, Notch Relative Amplitude (0.70±0.03; 0.71±0.04; 0.66±0.14, respectively and Stiffness Index (6.4±0.2; 5.7±0.4; 5.8±0.5, respectively. Use of APW revealed that concussed athletes have a transient increase in peripheral artery

  13. SU-E-J-129: Atlas Development for Cardiac Automatic Contouring Using Multi-Atlas Segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, R; Yang, J; Pan, T; Milgrom, S; Pinnix, C; Shi, A; Yang, J; Liu, Y; Nguyen, Q; Gomez, D; Dabaja, B; Balter, P; Court, L; Liao, Z [MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To develop a set of atlases for automatic contouring of cardiac structures to determine heart radiation dose and the associated toxicity. Methods: Six thoracic cancer patients with both contrast and non-contrast CT images were acquired for this study. Eight radiation oncologists manually and independently delineated cardiac contours on the non-contrast CT by referring to the fused contrast CT and following the RTOG 1106 atlas contouring guideline. Fifteen regions of interest (ROIs) were delineated, including heart, four chambers, four coronary arteries, pulmonary artery and vein, inferior and superior vena cava, and ascending and descending aorta. Individual expert contours were fused using the simultaneous truth and performance level estimation (STAPLE) algorithm for each ROI and each patient. The fused contours became atlases for an in-house multi-atlas segmentation. Using leave-one-out test, we generated auto-segmented contours for each ROI and each patient. The auto-segmented contours were compared with the fused contours using the Dice similarity coefficient (DSC) and the mean surface distance (MSD). Results: Inter-observer variability was not obvious for heart, chambers, and aorta but was large for other structures that were not clearly distinguishable on CT image. The average DSC between individual expert contours and the fused contours were less than 50% for coronary arteries and pulmonary vein, and the average MSD were greater than 4.0 mm. The largest MSD of expert contours deviating from the fused contours was 2.5 cm. The mean DSC and MSD of auto-segmented contours were within one standard deviation of expert contouring variability except the right coronary artery. The coronary arteries, vena cava, and pulmonary vein had DSC<70% and MSD>3.0 mm. Conclusion: A set of cardiac atlases was created for cardiac automatic contouring, the accuracy of which was comparable to the variability in expert contouring. However, substantial modification may need

  14. Radiographic changes in cardiac contours following heart transplantation; Clarification by MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Murayama, S.; Ikezoe, J.; Godwin, J.D.; Allen, M.D. (Washington Univ. Medical Center, Seattle, WA (USA). Dept. of Radiology Washington Univ. Medical Center, Seattle, WA (USA). Dept. of Surgery)

    1991-03-01

    Chest radiographs of 46 patients who had undergone heart transplantation were reviewed with special attention to abnormalities of the cardiac contours. MR imaging in 3 such patients revealed 3 types of double right cardiac contours: the recipient right atrium combined with the donor right atrium; the donor right atrium combined with the recipient left atrium; and a cardiac fat pad combined with the right atrium. A prominent main pulmonary artery was shown by MR imaging to result from leftward displacement of the main pulmonary artery caused by clockwise rotation and transverse position of the transplanted heart. Recognition of these unique radiographic appearances is of value in assessing transplanted hearts and in avoiding misdiagnosis. (orig.).

  15. An active contour framework based on the Hermite transform for shape segmentation of cardiac MR images

    Science.gov (United States)

    Barba-J, Leiner; Escalante-Ramírez, Boris

    2016-04-01

    Early detection of cardiac affections is fundamental to address a correct treatment that allows preserving the patient's life. Since heart disease is one of the main causes of death in most countries, analysis of cardiac images is of great value for cardiac assessment. Cardiac MR has become essential for heart evaluation. In this work we present a segmentation framework for shape analysis in cardiac magnetic resonance (MR) images. The method consists of an active contour model which is guided by the spectral coefficients obtained from the Hermite transform (HT) of the data. The HT is used as model to code image features of the analyzed images. Region and boundary based energies are coded using the zero and first order coefficients. An additional shape constraint based on an elliptical function is used for controlling the active contour deformations. The proposed framework is applied to the segmentation of the endocardial and epicardial boundaries of the left ventricle using MR images with short axis view. The segmentation is sequential for both regions: the endocardium is segmented followed by the epicardium. The algorithm is evaluated with several MR images at different phases of the cardiac cycle demonstrating the effectiveness of the proposed method. Several metrics are used for performance evaluation.

  16. Reconstructing patient-specific cardiac models from contours via Delaunay triangulation and graph-cuts.

    Science.gov (United States)

    Wan, Min; Lim, Calvin; Zhang, Junmei; Su, Yi; Yeo, Si Yong; Wang, Desheng; Tan, Ru San; Zhong, Liang

    2013-01-01

    This study proposes a novel method to reconstruct the left cardiac structure from contours. Given the contours representing left ventricle (LV), left atrium (LA), and aorta (AO), re-orientation, contour matching, extrapolation, and interpolation are performed sequentially. The processed data are then reconstructed via a variational method. The weighted minimal surface model is revised to handle the multi-phase cases, which happens at the LV-LA-AO junction. A Delaunay-based tetrahedral mesh is generated to discretize the domain while the max-flow/min-cut algorithm is utilized as the minimization tool. The reconstructed model including LV, LA, and AO structure is extracted from the mesh and post-processed further. Numerical examples show the robustness and effectiveness of the proposed method.

  17. Non-Contact Cardiac Activity Monitoring using Pulsed Laser Vibrometer

    Directory of Open Access Journals (Sweden)

    Chen Chia WANG

    2014-01-01

    Full Text Available We demonstrate experimentally the detection of detailed human cardiac mechanical activity in a remote, non-contacting, and non-ionizing manner using a pulsed laser vibrometer. The highly sensitive pulsed laser vibrometer allows the detection of the temporally-phased mechanical events occurring in individual cardiac cycles even from the surface of clothing-covered extremities of the subjects. Fine structures of the detected cardiac traces are identified with their meanings assigned and corroborated using accelerometer and electrocardiogram measurements obtained concurrently with the pulsed laser vibrometer studies.

  18. Pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus ® for the perioperative management of a caesarean section in a patient with severe cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Nicolas Brogly

    2016-06-01

    Full Text Available ABSTRACT BACKGROUND: The delivery of cardiac patients is a challenge for the anaesthesiologist, to whom the welfare of both the mother and the foetus is a main issue. In case of caesarean section, advanced monitoring allows to optimize haemodynamic condition and to improve morbidity and mortality. OBJECTIVE: To describe the use of pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus® for the perioperative management of a caesarean section in a patient with severe cardiomyopathy. CASE REPORT: We describe the case of a 28-year-old woman with a congenital heart disease who was submitted to a caesarean section under general anaesthesia for maternal pathology and foetal breech presentation. Intra- and post-operative management was optimized by advanced haemodynamic monitorization obtained by pulse contour wave analysis and thermodilution calibration (Picco Plus® monitor. The information about preload, myocardial contractility and postcharge was useful in guiding the fluid therapy and the use of vasoactive drugs. CONCLUSION: This case report illustrates the importance of advanced haemodynamic monitoring with an acceptably invasive device in obstetric patients with high cardiac risk. The increasing experience in advanced haemodynamic management will probably permit to decrease morbidity and mortality of obstetric patients in the future.

  19. Automatic 4D reconstruction of patient-specific cardiac mesh with 1-to-1 vertex correspondence from segmented contours lines.

    Directory of Open Access Journals (Sweden)

    Chi Wan Lim

    Full Text Available We propose an automatic algorithm for the reconstruction of patient-specific cardiac mesh models with 1-to-1 vertex correspondence. In this framework, a series of 3D meshes depicting the endocardial surface of the heart at each time step is constructed, based on a set of border delineated magnetic resonance imaging (MRI data of the whole cardiac cycle. The key contribution in this work involves a novel reconstruction technique to generate a 4D (i.e., spatial-temporal model of the heart with 1-to-1 vertex mapping throughout the time frames. The reconstructed 3D model from the first time step is used as a base template model and then deformed to fit the segmented contours from the subsequent time steps. A method to determine a tree-based connectivity relationship is proposed to ensure robust mapping during mesh deformation. The novel feature is the ability to handle intra- and inter-frame 2D topology changes of the contours, which manifests as a series of merging and splitting of contours when the images are viewed either in a spatial or temporal sequence. Our algorithm has been tested on five acquisitions of cardiac MRI and can successfully reconstruct the full 4D heart model in around 30 minutes per subject. The generated 4D heart model conforms very well with the input segmented contours and the mesh element shape is of reasonably good quality. The work is important in the support of downstream computational simulation activities.

  20. The effect of variable arterial transducer level on the accuracy of pulse contour waveform-derived measurements in critically ill patients.

    Science.gov (United States)

    He, Huai-Wu; Liu, Da-Wei; Long, Yun; Wang, Xiao-Ting; Zhao, Mei-Ling; Lai, Xiao-Li

    2016-10-01

    We know that a 10 cm departure from the reference level of pressure transducer position is equal to a 7.5 mmHg change of invasive hemodynamic pressure monitoring in a fluid-filled system. However, the relationship between the site level of a variable arterial pressure transducer and the pulse contour-derived parameters has yet to be established in critically ill patients. Moreover, the related quantitative analysis has never been investigated. Forty-two critically ill patients requiring PiCCO-Plus cardiac output monitoring were prospectively studied. The phlebostatic axis was defined as the zero reference level; the arterial pressure transducer was then vertically adjusted to different positions (+5, +10, +15, +20, -20, -15, -10, -5 cm) of departure from the zero reference site. The pulse contour waveform-derived parameters were recorded at each position. Elevation of the pressure transducer caused significantly positive changes in the continuous cardiac index (+CCI), stroke volume index (+SVI), and stroke volume variation (+SVV), and negative changes in the rate of left ventricular pressure rise during systole (-dP/dtmax), the systemic vascular resistance index (-SVRI), and vice versa. At the 5 cm position, the SVRI changes reached statistical significance with error. At the 10 cm position, the changes in CCI and dP/dtmax reached statistical significance with error, while the change in SVV reached statistical significance at 15 cm. The change rate of CCI was more than 5 % at the 15 cm position and approximately 10 % at the 20 cm position. On average, for every centimeter change of the transducer, there was a corresponding 0.014 L/min/m(2) CCI change and 0.36 % change rate, a 1.41 mmHg/s dP/dtmax change and 0.13 % change rate, and a 25 dyne/s/cm(5) SVRI change and 1.2 % change rate. The variation of arterial transducer position can result in inaccurate measurement of pulse contour waveform-derived parameters, especially when the transducer

  1. Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

    Directory of Open Access Journals (Sweden)

    Grus Franz-H

    2004-03-01

    Full Text Available Abstract Background The new Ocular Dynamic Contour Tonometer (DCT, investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland allows simultaneous recording of intraocular pressure (IOP and ocular pulse amplitude (OPA. It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens®, a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland. Methods Nineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens®, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens®. Results No difference (P = 0.09 was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg. The IOP values of SmartLens® (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg were significantly higher (P = 0.0008 both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg were significantly lower (P = 0.0003 than those obtained by SmartLens® (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg. Conclusions DCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens® (contact lens tonometry gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens® provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

  2. A melodic contour repeatedly experienced by human near-term fetuses elicits a profound cardiac reaction one month after birth.

    Directory of Open Access Journals (Sweden)

    Carolyn Granier-Deferre

    Full Text Available BACKGROUND: Human hearing develops progressively during the last trimester of gestation. Near-term fetuses can discriminate acoustic features, such as frequencies and spectra, and process complex auditory streams. Fetal and neonatal studies show that they can remember frequently recurring sounds. However, existing data can only show retention intervals up to several days after birth. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that auditory memories can last at least six weeks. Experimental fetuses were given precisely controlled exposure to a descending piano melody twice daily during the 35(th, 36(th, and 37(th weeks of gestation. Six weeks later we assessed the cardiac responses of 25 exposed infants and 25 naive control infants, while in quiet sleep, to the descending melody and to an ascending control piano melody. The melodies had precisely inverse contours, but similar spectra, identical duration, tempo and rhythm, thus, almost identical amplitude envelopes. All infants displayed a significant heart rate change. In exposed infants, the descending melody evoked a cardiac deceleration that was twice larger than the decelerations elicited by the ascending melody and by both melodies in control infants. CONCLUSIONS/SIGNIFICANCE: Thus, 3-weeks of prenatal exposure to a specific melodic contour affects infants 'auditory processing' or perception, i.e., impacts the autonomic nervous system at least six weeks later, when infants are 1-month old. Our results extend the retention interval over which a prenatally acquired memory of a specific sound stream can be observed from 3-4 days to six weeks. The long-term memory for the descending melody is interpreted in terms of enduring neurophysiological tuning and its significance for the developmental psychobiology of attention and perception, including early speech perception, is discussed.

  3. Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

    Directory of Open Access Journals (Sweden)

    Shinsuke Nakayama

    Full Text Available This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG. The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

  4. Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

    Science.gov (United States)

    Nakayama, Shinsuke; Sawamura, Kenta; Mohri, Kaneo; Uchiyama, Tsuyoshi

    2011-01-01

    This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI) sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT) level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG). The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

  5. SU-E-J-134: Optimizing Technical Parameters for Using Atlas Based Automatic Segmentation for Evaluation of Contour Accuracy Experience with Cardiac Structures From NRG Oncology/RTOG 0617

    Energy Technology Data Exchange (ETDEWEB)

    Yu, J; Gong, Y; Bar-Ad, V; Giaddui, T; Galvin, J; Xiao, Y [Thomas Jefferson University, Philadelphia, PA (United States); Hu, C [NRG oncology, Philadelphia, PA (United States); Gore, E; Wheatley, M [Medical College of Wisconsin, Milwaukee, WI (United States); Witt, J; Robinson, C; Bradley, J [Washington University in St. Louis School of Medicine, St. Louis, MO (United States); Kong, F [Georgia Regents University, Augusta, GA (Georgia)

    2015-06-15

    Purpose: Accurate contour delineation is crucial for radiotherapy. Atlas based automatic segmentation tools can be used to increase the efficiency of contour accuracy evaluation. This study aims to optimize technical parameters utilized in the tool by exploring the impact of library size and atlas number on the accuracy of cardiac contour evaluation. Methods: Patient CT DICOMs from RTOG 0617 were used for this study. Five experienced physicians delineated the cardiac structures including pericardium, atria and ventricles following an atlas guideline. The consistency of cardiac structured delineation using the atlas guideline was verified by a study with four observers and seventeen patients. The CT and cardiac structure DICOM files were then used for the ABAS technique.To study the impact of library size (LS) and atlas number (AN) on automatic contour accuracy, automatic contours were generated with varied technique parameters for five randomly selected patients. Three LS (20, 60, and 100) were studied using commercially available software. The AN was four, recommended by the manufacturer. Using the manual contour as the gold standard, Dice Similarity Coefficient (DSC) was calculated between the manual and automatic contours. Five-patient averaged DSCs were calculated for comparison for each cardiac structure.In order to study the impact of AN, the LS was set 100, and AN was tested from one to five. The five-patient averaged DSCs were also calculated for each cardiac structure. Results: DSC values are highest when LS is 100 and AN is four. The DSC is 0.90±0.02 for pericardium, 0.75±0.06 for atria, and 0.86±0.02 for ventricles. Conclusion: By comparing DSC values, the combination AN=4 and LS=100 gives the best performance. This project was supported by NCI grants U24CA12014, U24CA180803, U10CA180868, U10CA180822, PA CURE grant and Bristol-Myers Squibb and Eli Lilly.

  6. Successful resuscitation of a patient who developed cardiac arrest from pulsed saline bacitracin lavage during thoracic laminectomy and fusion.

    Science.gov (United States)

    Greenberg, Steven B; Deshur, Mark; Khavkin, Yevgeniy; Karaikovic, Elden; Vender, Jeffery

    2008-06-01

    A patient with a history of T12 burst fracture caused by a fall, and with progressive weakness and sensory loss in the left leg, survived a cardiac arrest after pulsed saline bacitracin lavage irrigation during a posterior spinal fusion.

  7. Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD.

    Science.gov (United States)

    Vassaux, C; Torre-Bouscoulet, L; Zeineldine, S; Cortopassi, F; Paz-Díaz, H; Celli, B R; Pinto-Plata, V M

    2008-11-01

    A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL x kg(-1) x min(-1)) and oxygen pulse (mL x beat(-1))) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3-4) and 46 controls. The patients were divided into those with IC/TLC > 25% or 25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC 25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.

  8. Effects of Synchronization between Cardiac and Locomotor Rhythms on Oxygen Pulse during Walking.

    Science.gov (United States)

    Takeuchi, Shinta; Nishida, Yusuke; Mizushima, Takashi

    2014-12-01

    The oObjective of the study was to investigate whether the occurrence of cardiac-locomotor synchronization (CLS) affects oxygen pulse (O2 pulse, mL/beat) during walking. Twelve healthy men were studied under two treadmill protocols. The CLS protocol involved subjects walking at a frequency of their heart rate (HR) to induce CLS. The free protocol (reference) involved subjects walking at a self-selected cadence. The treadmill load was equal between the two protocols and was adjusted so that the subject's HR was maintained at approximately 120 bpm. Electrocardiographic signals, foot switch signals, and oxygen consumption (VO2) were measured continuously for 10 min after the heart rate reached a steady state. VO2, O2 pulse, and mean HR were calculated. VO2 and O2 pulse were significantly higher in subjects in the CLS protocol compared to those in the free protocol. However, mean HR was not different between the two groups. The synchronization strength was significantly related to the increase in O2 pulse in subjects in the CLS protocol compared with those in the free protocol. These results suggest that the occurrence of CLS enhances O2 pulse by increasing the strength of CLS during walking. Key PointsTwelve healthy men walked at a frequency of their heart rate (CLS protocol) and at a self-selected cadence (free protocol).Walking at the frequency of heart rate would induce the CLS by entrainment.Oxygen pulse was significantly higher in subjects in the CLS protocol compared to those in the free protocol.The occurrence of CLS enhances oxygen pulse by increasing the strength of CLS during walking.

  9. Cardiac gating with a pulse oximeter for dual-energy imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shkumat, N A; Siewerdsen, J H [Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Dhanantwari, A C; Williams, D B [Ontario Cancer Institute, Princess Margaret Hospital, 610 University Ave., Toronto, Ontario, M5G 2M9 (Canada); Paul, N S [Department of Medical Imaging, University Health Network, Toronto, Ontario, M5G 2M9 (Canada); Yorkston, J; Van Metter, R [Carestream Health Inc., Rochester, NY 14650 (United States)], E-mail: jeff.siewerdsen@uhn.on.ca

    2008-11-07

    The development and evaluation of a prototype cardiac gating system for double-shot dual-energy (DE) imaging is described. By acquiring both low- and high-kVp images during the resting phase of the cardiac cycle (diastole), heart misalignment between images can be reduced, thereby decreasing the magnitude of cardiac motion artifacts. For this initial implementation, a fingertip pulse oximeter was employed to measure the peripheral pulse waveform ('plethysmogram'), offering potential logistic, cost and workflow advantages compared to an electrocardiogram. A gating method was developed that accommodates temporal delays due to physiological pulse propagation, oximeter waveform processing and the imaging system (software, filter-wheel, anti-scatter Bucky-grid and flat-panel detector). Modeling the diastolic period allowed the calculation of an implemented delay, t{sub imp}, required to trigger correctly during diastole at any patient heart rate (HR). The model suggests a triggering scheme characterized by two HR regimes, separated by a threshold, HR{sub thresh}. For rates at or below HR{sub thresh}, sufficient time exists to expose on the same heartbeat as the plethysmogram pulse [t{sub imp}(HR) = 0]. Above HR{sub thresh}, a characteristic t{sub imp}(HR) delays exposure to the subsequent heartbeat, accounting for all fixed and variable system delays. Performance was evaluated in terms of accuracy and precision of diastole-trigger coincidence and quantitative evaluation of artifact severity in gated and ungated DE images. Initial implementation indicated 85% accuracy in diastole-trigger coincidence. Through the identification of an improved HR estimation method (modified temporal smoothing of the oximeter waveform), trigger accuracy of 100% could be achieved with improved precision. To quantify the effect of the gating system on DE image quality, human observer tests were conducted to measure the magnitude of cardiac artifact under conditions of successful and

  10. Cardiac gating with a pulse oximeter for dual-energy imaging

    Science.gov (United States)

    Shkumat, N. A.; Siewerdsen, J. H.; Dhanantwari, A. C.; Williams, D. B.; Paul, N. S.; Yorkston, J.; Van Metter, R.

    2008-11-01

    The development and evaluation of a prototype cardiac gating system for double-shot dual-energy (DE) imaging is described. By acquiring both low- and high-kVp images during the resting phase of the cardiac cycle (diastole), heart misalignment between images can be reduced, thereby decreasing the magnitude of cardiac motion artifacts. For this initial implementation, a fingertip pulse oximeter was employed to measure the peripheral pulse waveform ('plethysmogram'), offering potential logistic, cost and workflow advantages compared to an electrocardiogram. A gating method was developed that accommodates temporal delays due to physiological pulse propagation, oximeter waveform processing and the imaging system (software, filter-wheel, anti-scatter Bucky-grid and flat-panel detector). Modeling the diastolic period allowed the calculation of an implemented delay, timp, required to trigger correctly during diastole at any patient heart rate (HR). The model suggests a triggering scheme characterized by two HR regimes, separated by a threshold, HRthresh. For rates at or below HRthresh, sufficient time exists to expose on the same heartbeat as the plethysmogram pulse [timp(HR) = 0]. Above HRthresh, a characteristic timp(HR) delays exposure to the subsequent heartbeat, accounting for all fixed and variable system delays. Performance was evaluated in terms of accuracy and precision of diastole-trigger coincidence and quantitative evaluation of artifact severity in gated and ungated DE images. Initial implementation indicated 85% accuracy in diastole-trigger coincidence. Through the identification of an improved HR estimation method (modified temporal smoothing of the oximeter waveform), trigger accuracy of 100% could be achieved with improved precision. To quantify the effect of the gating system on DE image quality, human observer tests were conducted to measure the magnitude of cardiac artifact under conditions of successful and unsuccessful diastolic gating. Six observers

  11. Contour Tones.

    Science.gov (United States)

    Yip, Moira

    1989-01-01

    Argues that contour tones in East Asian languages behave as melodic units consisting of a root node [upper] dominating a branching specification. It is also argued that, with upper as the tonal root node, no more than two rising or falling tones will contrast underlying. (49 references) (JL)

  12. The Comparison of Pulse Oximetry and Cardiac Catheterization in Managing the Treatment of Children with Congenital Heart Disease

    Directory of Open Access Journals (Sweden)

    R Abbasi

    2015-03-01

    Full Text Available Bachground & aim: Pulse oximetry and cardiac catheterization are concerned in the treatment of children with congenital heart disease. Diagnosis of arterial oxygen saturation in patients with congenital heart disease (CHD can be used to assess and manage their effecacy. The purpose of this study was to compare pulse oximetry and cardiac catheterizations in treatment manage of children with congenital heart disease. Methods: In the present cross sectional study, 110 patients with cyanic and non syani heart disease were studied undergoing right and left heart catheterization by pulse oximetry of index finger and simultaneously, oxygen saturation was measured by cardiac catheterization. Data were analyzed with SPSS software by using Pearson correlation and linear regression. Results: A significant correlation was seen between arterial oxygen saturation measured by pulse oximetry and arterial oxygen saturation (p<0.0001 as well as heart rate, electrocardiogram and pulse oximetry (p<0.0001 respectively. Furthermore, the presence of cyanosis (p=0.001, digital clubbing of the fingers ((p=0.001, low oxygen saturation in the superior vena cava and right atrium (p=0.002 can reduce the accuracy of pulse oximetry for detection of arterial oxygen saturation. The mean right atrial pressure can effect on accuracy of pulse oximetry to detect heartbeat (p=0.034. Maximum sensitivity and specificity for detection of pulse oximetry oxygen saturation was 88 % and 88 heart rate per minute. Conclusion: Pulse oximetric is a useful tool for estimating the arterial oxygen saturation and heart rate in children with congenital heart disease (CHD and is a non-invasive method in comparison with cardiac catheterization. Key words: Pulse oximeter, Congenital Heart Disease, Cardiac Catheterization

  13. Pilot Study: Estimation of Stroke Volume and Cardiac Output from Pulse Wave Velocity.

    Science.gov (United States)

    Obata, Yurie; Mizogami, Maki; Nyhan, Daniel; Berkowitz, Dan E; Steppan, Jochen; Barodka, Viachaslau

    2017-01-01

    Transesophageal echocardiography (TEE) is increasingly replacing thermodilution pulmonary artery catheters to assess hemodynamics in patients at high risk for cardiovascular morbidity. However, one of the drawbacks of TEE compared to pulmonary artery catheters is the inability to measure real time stroke volume (SV) and cardiac output (CO) continuously. The aim of the present proof of concept study was to validate a novel method of SV estimation, based on pulse wave velocity (PWV) in patients undergoing cardiac surgery. This is a retrospective observational study. We measured pulse transit time by superimposing the radial arterial waveform onto the continuous wave Doppler waveform of the left ventricular outflow tract, and calculated SV (SVPWV) using the transformed Bramwell-Hill equation. The SV measured by TEE (SVTEE) was used as a reference. A total of 190 paired SV were measured from 28 patients. A strong correlation was observed between SVPWV and SVTEE with the coefficient of determination (R2) of 0.71. A mean difference between the two (bias) was 3.70 ml with the limits of agreement ranging from -20.33 to 27.73 ml and a percentage error of 27.4% based on a Bland-Altman analysis. The concordance rate of two methods was 85.0% based on a four-quadrant plot. The angular concordance rate was 85.9% with radial limits of agreement (the radial sector that contained 95% of the data points) of ± 41.5 degrees based on a polar plot. PWV based SV estimation yields reasonable agreement with SV measured by TEE. Further studies are required to assess its utility in different clinical situations.

  14. Arterial pulse cardiac output agreement with thermodilution in patients in hyperdynamic conditions.

    Science.gov (United States)

    Della Rocca, Giorgio; Costa, Maria Gabriella; Chiarandini, Paolo; Bertossi, Gaia; Lugano, Manuela; Pompei, Livia; Coccia, Cecilia; Sainz-Barriga, Mauricio; Pietropaoli, Paolo

    2008-10-01

    This study aimed to compare continuous cardiac output (CCO) obtained using the arterial pulse wave (APCO) measurement with a simultaneous measurement of the intermittent cardiac output (ICO) and CCO obtained with a pulmonary artery catheter (PAC) in liver transplant patients. A prospective, single-center evaluation. A university hospital intensive care unit. Eighteen patients after liver transplantation. Pulmonary artery catheters were placed in all patients, and ICO and CCO were determined using thermodilution. APCO measurements were made with the Vigileo System (Edwards Lifesciences, Irvine, CA). The authors obtained 126 data pairs of ICO and APCO and 864 pairs of CCO and APCO. ICO data were collected after intensive care unit admission and every 8 hours until the 48th postoperative hour. CCO and APCO data were collected every hour from admission until the 48th postoperative hour. Bias and precision were 0.95 +/- 1.41 L/min for ICO versus APCO and 1.29 +/- 1.28 L/min for CCO and APCO. Bias and precision for cardiac output (CO) data pairs less than 8 L/min were 0.32 +/- 1.14 L/min between ICO and APCO and 0.71 +/- 0.98 L/min between CCO and APCO. For CO data pairs higher than 8 L/min, bias and precision were 1.79 +/- 1.54 L/min between ICO and APCO and 2.25 +/- 1.14 L/min between CCO and APCO. APCO enables the assessment of CO with clinically acceptable bias and precision. At higher CO levels, APCO underestimates PAC measurements and it is not as reliable as thermodilution in hyperdynamic liver transplant patients.

  15. Effect of Twisted Fiber Anisotropy in Cardiac Tissue on Ablation with Pulsed Electric Fields

    Science.gov (United States)

    Xie, Fei; Zemlin, Christian W.

    2016-01-01

    Background Ablation of cardiac tissue with pulsed electric fields is a promising alternative to current thermal ablation methods, and it critically depends on the electric field distribution in the heart. Methods We developed a model that incorporates the twisted anisotropy of cardiac tissue and computed the electric field distribution in the tissue. We also performed experiments in rabbit ventricles to validate our model. We find that the model agrees well with the experimentally determined ablation volume if we assume that all tissue that is exposed to a field greater than 3 kV/cm is ablated. In our numerical analysis, we considered how tissue thickness, degree of anisotropy, and electrode configuration affect the geometry of the ablated volume. We considered two electrode configurations: two parallel needles inserted into the myocardium (“penetrating needles” configuration) and one circular electrode each on epi- and endocardium, opposing each other (“epi-endo” configuration). Results For thick tissues (10 mm) and moderate anisotropy ratio (a = 2), we find that the geometry of the ablated volume is almost unaffected by twisted anisotropy, i.e. it is approximately translationally symmetric from epi- to endocardium, for both electrode configurations. Higher anisotropy ratio (a = 10) leads to substantial variation in ablation width across the wall; these variations were more pronounced for the penetrating needle configuration than for the epi-endo configuration. For thinner tissues (4 mm, typical for human atria) and higher anisotropy ratio (a = 10), the epi-endo configuration yielded approximately translationally symmetric ablation volumes, while the penetrating electrodes configuration was much more sensitive to fiber twist. Conclusions These results suggest that the epi-endo configuration will be reliable for ablation of atrial fibrillation, independently of fiber orientation, while the penetrating electrode configuration may experience problems when the

  16. Simplifying Massive Contour Maps

    DEFF Research Database (Denmark)

    Arge, Lars; Deleuran, Lasse Kosetski; Mølhave, Thomas;

    2012-01-01

    We present a simple, efficient and practical algorithm for constructing and subsequently simplifying contour maps from massive high-resolution DEMs, under some practically realistic assumptions on the DEM and contours.......We present a simple, efficient and practical algorithm for constructing and subsequently simplifying contour maps from massive high-resolution DEMs, under some practically realistic assumptions on the DEM and contours....

  17. Pulse Wave Velocity and Cardiac Output vs. Heart Rate in Patients with an Implanted Pacemaker Based on Electric Impedance Method Measurement

    Science.gov (United States)

    Soukup, Ladislav; Vondra, Vlastimil; Viščor, Ivo; Jurák, Pavel; Halámek, Josef

    2013-04-01

    The methods and device for estimation of cardiac output and measurement of pulse wave velocity simultaneously is presented here. The beat-to-beat cardiac output as well as pulse wave velocity measurement is based on application of electrical impedance method on the thorax and calf. The results are demonstrated in a study of 24 subjects. The dependence of pulse wave velocity and cardiac output on heart rate during rest in patients with an implanted pacemaker was evaluated. The heart rate was changed by pacemaker programming while neither exercise nor drugs were applied. The most important result is that the pulse wave velocity, cardiac output and blood pressure do not depend significantly on heart rate, while the stroke volume is reciprocal proportionally to the heart rate.

  18. Cardiac output monitoring

    Directory of Open Access Journals (Sweden)

    Mathews Lailu

    2008-01-01

    Full Text Available Minimally invasive and non-invasive methods of estimation of cardiac output (CO were developed to overcome the limitations of invasive nature of pulmonary artery catheterization (PAC and direct Fick method used for the measurement of stroke volume (SV. The important minimally invasive techniques available are: oesophageal Doppler monitoring (ODM, the derivative Fick method (using partial carbon dioxide (CO 2 breathing, transpulmonary thermodilution, lithium indicator dilution, pulse contour and pulse power analysis. Impedance cardiography is probably the only non-invasive technique in true sense. It provides information about haemodynamic status without the risk, cost and skill associated with the other invasive or minimally invasive techniques. It is important to understand what is really being measured and what assumptions and calculations have been incorporated with respect to a monitoring device. Understanding the basic principles of the above techniques as well as their advantages and limitations may be useful. In addition, the clinical validation of new techniques is necessary to convince that these new tools provide reliable measurements. In this review the physics behind the working of ODM, partial CO 2 breathing, transpulmonary thermodilution and lithium dilution techniques are dealt with. The physical and the physiological aspects underlying the pulse contour and pulse power analyses, various pulse contour techniques, their development, advantages and limitations are also covered. The principle of thoracic bioimpedance along with computation of CO from changes in thoracic impedance is explained. The purpose of the review is to help us minimize the dogmatic nature of practice favouring one technique or the other.

  19. Automated cardiopulmonary resuscitation using a load-distributing band external cardiac support device for in-hospital cardiac arrest: a single centre experience of AutoPulse-CPR.

    Science.gov (United States)

    Spiro, J R; White, S; Quinn, N; Gubran, C J; Ludman, P F; Townend, J N; Doshi, S N

    2015-02-01

    Poor quality cardiopulmonary resuscitation (CPR) predicts adverse outcome. During invasive cardiac procedures automated-CPR (A-CPR) may help maintain effective resuscitation. The use of A-CPR following in-hospital cardiac arrest (IHCA) remains poorly described. Firstly, we aimed to assess the efficiency of healthcare staff using A-CPR in a cardiac arrest scenario at baseline, following re-training and over time (Scenario-based training). Secondly, we studied our clinical experience of A-CPR at our institution over a 2-year period, with particular emphasis on the details of invasive cardiac procedures performed, problems encountered, resuscitation rates and in-hospital outcome (AutoPulse-CPR Registry). Scenario-based training: Forty healthcare professionals were assessed. At baseline, time-to-position device was slow (mean 59 (±24) s (range 15-96s)), with the majority (57%) unable to mode-switch. Following re-training time-to-position reduced (28 (±9) s, pCPR Registry: 285 patients suffered IHCA, 25 received A-CPR. Survival to hospital discharge following conventional CPR was 28/260 (11%) and 7/25 (28%) following A-CPR. A-CPR supported invasive procedures in 9 patients, 2 of whom had A-CPR dependant circulation during transfer to the catheter lab. A-CPR may provide excellent haemodynamic support and facilitate simultaneous invasive cardiac procedures. A significant learning curve exists when integrating A-CPR into clinical practice. Further studies are required to better define the role and effectiveness of A-CPR following IHCA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  1. Tagged Vector Contour (TVC)

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas Tagged Vector Contour (TVC) dataset consists of digitized contours from the 7.5 minute topographic quadrangle maps. Coverage for the state is incomplete....

  2. Fairfax County Contours

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This layer contains contours that were derived from the digital terrain model made up of irregularly spaced mass points and breaklines. The contours are 5 foot...

  3. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  4. Finger arterial versus intrabrachial pressure and continuous cardiac output during head-up tilt testing in healthy subjects

    NARCIS (Netherlands)

    Jellema, W.T.; Imholz, B.P.M.; Goudoever, J. van; Wesseling, K.H.; Lieshout, J.J. van

    1996-01-01

    1. The aims of this study were to determine the clinical feasibility of continuous, non-invasive Finapres recordings as a replacement for intrabrachial pressure during a 30 min head-up tilt, and the reliability of continuous cardiac output computation by pulse contour analysis from the finger arteri

  5. Pulse

    Science.gov (United States)

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the person's heart is pumping. Pulse ... rate gives information about your fitness level and health.

  6. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di erent problems that rely on contour trees can be solved in parallel with minimal communication.

  7. Effects of Synchronization between Cardiac and Locomotor Rhythms on Oxygen Pulse during Walking

    Directory of Open Access Journals (Sweden)

    Shinta Takeuchi

    2014-12-01

    Full Text Available The oObjective of the study was to investigate whether the occurrence of cardiac–locomotor synchronization (CLS affects oxygen pulse (O2 pulse, mL/beat during walking. Twelve healthy men were studied under two treadmill protocols. The CLS protocol involved subjects walking at a frequency of their heart rate (HR to induce CLS. The free protocol (reference involved subjects walking at a self-selected cadence. The treadmill load was equal between the two protocols and was adjusted so that the subject’s HR was maintained at approximately 120 bpm. Electrocardiographic signals, foot switch signals, and oxygen consumption (VO2 were measured continuously for 10 min after the heart rate reached a steady state. VO2, O2 pulse, and mean HR were calculated. VO2 and O2 pulse were significantly higher in subjects in the CLS protocol compared to those in the free protocol. However, mean HR was not different between the two groups. The synchronization strength was significantly related to the increase in O2 pulse in subjects in the CLS protocol compared with those in the free protocol. These results suggest that the occurrence of CLS enhances O2 pulse by increasing the strength of CLS during walking.

  8. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixt

  9. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results

  10. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixt

  11. Long-range non-contact imaging photoplethysmography: cardiac pulse wave sensing at a distance

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.; Piasecki, Alyssa M.; Bowers, Margaret A.; Klosterman, Samantha L.

    2016-03-01

    Non-contact, imaging photoplethysmography uses photo-optical sensors to measure variations in light absorption, caused by blood volume pulsations, to assess cardiopulmonary parameters including pulse rate, pulse rate variability, and respiration rate. Recently, researchers have studied the applications and methodology of imaging photoplethysmography. Basic research has examined some of the variables affecting data quality and accuracy of imaging photoplethysmography including signal processing, imager parameters (e.g. frame rate and resolution), lighting conditions, subject motion, and subject skin tone. This technology may be beneficial for long term or continuous monitoring where contact measurements may be harmful (e.g. skin sensitivities) or where imperceptible or unobtrusive measurements are desirable. Using previously validated signal processing methods, we examined the effects of imager-to-subject distance on one-minute, windowed estimates of pulse rate. High-resolution video of 22, stationary participants was collected using an enthusiast-grade, mirrorless, digital camera equipped with a fully-manual, super-telephoto lens at distances of 25, 50, and 100 meters with simultaneous contact measurements of electrocardiography, and fingertip photoplethysmography. By comparison, previous studies have usually been conducted with imager-to-subject distances of up to only a few meters. Mean absolute error for one-minute, windowed, pulse rate estimates (compared to those derived from gold-standard electrocardiography) were 2.0, 4.1, and 10.9 beats per minute at distances of 25, 50, and 100 meters, respectively. Long-range imaging presents several unique challenges among which include decreased, observed light reflectance and smaller regions of interest. Nevertheless, these results demonstrate that accurate pulse rate measurements can be obtained from over long imager-to-participant distances given these constraints.

  12. Prenatal exposure to dexamethasone in the mouse alters cardiac growth patterns and increases pulse pressure in aged male offspring.

    Science.gov (United States)

    O'Sullivan, Lee; Cuffe, James S M; Paravicini, Tamara M; Campbell, Sally; Dickinson, Hayley; Singh, Reetu R; Gezmish, Oksan; Black, M Jane; Moritz, Karen M

    2013-01-01

    Exposure to synthetic glucocorticoids during development can result in later cardiovascular and renal disease in sheep and rats. Although prenatal glucocorticoid exposure is associated with impaired renal development, less is known about effects on the developing heart. This study aimed to examine the effects of a short-term exposure to dexamethasone (60 hours from embryonic day 12.5) on the developing mouse heart, and cardiovascular function in adult male offspring. Dexamethasone (DEX) exposed fetuses were growth restricted compared to saline treated controls (SAL) at E14.5, but there was no difference between groups at E17.5. Heart weights of the DEX fetuses also tended to be smaller at E14.5, but not different at E17.5. Cardiac AT1aR, Bax, and IGF-1 mRNA expression was significantly increased by DEX compared to SAL at E17.5. In 12-month-old offspring DEX exposure caused an increase in basal blood pressure of ~3 mmHg. In addition, DEX exposed mice had a widened pulse pressure compared to SAL. DEX exposed males at 12 months had an approximate 25% reduction in nephron number compared to SAL, but no difference in cardiomyocyte number. Exposure to DEX in utero appears to adversely impact on nephrogenesis and heart growth but is not associated with a cardiomyocyte deficit in male mice in adulthood, possibly due to compensatory growth of the myocardium following the initial insult. However, the widened pulse pressure may be indicative of altered vascular compliance.

  13. Cardiac output during exercise

    DEFF Research Database (Denmark)

    Siebenmann, C; Rasmussen, P.; Sørensen, H.

    2015-01-01

    Several techniques assessing cardiac output (Q) during exercise are available. The extent to which the measurements obtained from each respective technique compares to one another, however, is unclear. We quantified Q simultaneously using four methods: the Fick method with blood obtained from...... the right atrium (Q(Fick-M)), Innocor (inert gas rebreathing; Q(Inn)), Physioflow (impedance cardiography; Q(Phys)), and Nexfin (pulse contour analysis; Q(Pulse)) in 12 male subjects during incremental cycling exercise to exhaustion in normoxia and hypoxia (FiO2  = 12%). While all four methods reported...... a progressive increase in Q with exercise intensity, the slopes of the Q/oxygen uptake (VO2) relationship differed by up to 50% between methods in both normoxia [4.9 ± 0.3, 3.9 ± 0.2, 6.0 ± 0.4, 4.8 ± 0.2 L/min per L/min (mean ± SE) for Q(Fick-M), Q(Inn), QP hys and Q(Pulse), respectively; P = 0...

  14. Nanosecond pulsed platelet-rich plasma (nsPRP) improves mechanical and electrical cardiac function following myocardial reperfusion injury.

    Science.gov (United States)

    Hargrave, Barbara; Varghese, Frency; Barabutis, Nektarios; Catravas, John; Zemlin, Christian

    2016-02-01

    Ischemia and reperfusion (I/R) of the heart is associated with biochemical and ionic changes that result in cardiac contractile and electrical dysfunction. In rabbits, platelet-rich plasma activated using nanosecond pulsed electric fields (nsPRP) has been shown to improve left ventricular pumping. Here, we demonstrate that nsPRP causes a similar improvement in mouse left ventricular function. We also show that nsPRP injection recovers electrical activity even before reperfusion begins. To uncover the mechanism of nsPRP action, we studied whether the enhanced left ventricular function in nsPRP rabbit and mouse hearts was associated with increased expression of heat-shock proteins and altered mitochondrial function under conditions of oxidative stress. Mouse hearts underwent 30 min of global ischemia and 1 h of reperfusion in situ. Rabbit hearts underwent 30 min of ischemia in vivo and were reperfused for 14 days. Hearts treated with nsPRP expressed significantly higher levels of Hsp27 and Hsp70 compared to hearts treated with vehicle. Also, pretreatment of cultured H9c2 cells with nsPRP significantly enhanced the "spare respiratory capacity (SRC)" also referred to as "respiratory reserve capacity" and ATP production in response to the uncoupler FCCP. These results suggest a cardioprotective effect of nsPRP on the ischemic heart during reperfusion.

  15. Applications of pulsed Doppler flow mapping to left sided cardiac valvular lesions.

    Science.gov (United States)

    Kalmanson, D; Veyrat, C; Gourtchiglouian, C; Bas, S; Abitbol, G

    The flow mapping procedure has been developed in parallel to the standard pulsed Doppler procedure. It has a different purpose--picking up flow signals at the site of lesions rather than calibrating velocities--and has its own methodology, developed within the last six years. On the basis of invasive correlations performed in 267 cases of valvular heart disease, we review the three-fold purpose of the flow mapping technique: diagnosing lesions, relying on the presence of flow anomalies; assessing their severity, relying on the spatial spreading of these flow signals; and identifying the site of the lesion, which is a specific advantage, relying on the anatomical location of these flow signals and/or on the direction of the jets. For example, using this technique, it is now possible to easily differentiate a cusp tear from a leak of a bioprosthesis, to measure the size of the leaks, and to reconstruct the image of aortic or mitral stenotic areas. These optimal results are only obtained using an appropriate methodology which mainly includes a) the selection of adequate two-dimensional short axis planes in order to explore the diseased valve in its entirety, because of frequent assymetrical orifices, and to pick up the jets at their starting point, b) measurements of the abnormal areas, c) when jets are studied, a three dimensional approach is required in order to cope with the three dimensional nature of the jet and to make available the calculation of three dimensional indices of severity.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Visualization of Uncertain Contour Trees

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Contour trees can represent the topology of large volume data sets in a relatively compact, discrete data structure. However, the resulting trees often contain many thousands of nodes; thus, many graph drawing techniques fail to produce satisfactory results. Therefore, several visualization methods...... were proposed recently for the visualization of contour trees. Unfortunately, none of these techniques is able to handle uncertain contour trees although any uncertainty of the volume data inevitably results in partially uncertain contour trees. In this work, we visualize uncertain contour trees...... by combining the contour trees of two morphologically filtered versions of a volume data set, which represent the range of uncertainty. These two contour trees are combined and visualized within a single image such that a range of potential contour trees is represented by the resulting visualization. Thus...

  17. Ultrasound-guided femoral arterial access in pediatric cardiac catheterizations: A prospective evaluation of the prevalence, risk factors, and mechanism for acute loss of arterial pulse.

    Science.gov (United States)

    Alexander, John; Yohannan, Thomas; Abutineh, Iman; Agrawal, Vijaykumar; Lloyd, Hannah; Zurakowski, David; Waller, B Rush; Sathanandam, Shyam

    2016-12-01

    The objectives of this study were to describe the prevalence, mechanisms, and identify risk factors for acute loss of arterial pulse (LOP) in children who had ultrasound-guided femoral arterial access (UGFAA) during cardiac catheterization. LOP is a known complication in children following femoral arterial (FA) access for cardiac catheterization. The prevalence of LOP requiring treatment ranges between 4% and 8%. A prospective study was performed including 486 cardiac catheterizations using UGFAA in children ≤18 years over a 3 years period. Ultrasound and Doppler evaluations were performed prior to and at the end of the procedure. LOP was identified in 33 cases (6.8%) with 23 (4.7%) requiring treatment. For children ≤6 months, the prevalence of LOP requiring treatment was 13.6%. FA diameter LOP (OR: 8.44, 95% CI: 2.07-34.5, P LOP had a greater percentage decrease in vessel diameter (median 62% vs 18%, P LOP. FA thrombus was diagnosed only in 9 patients (27% of those with LOP). The prevalence of LOP requiring treatment is 4.7% when UGFAA is used during pediatric cardiac catheterizations. Arterial spasm was more common than thrombus as a cause of LOP. FA diameter LOP in this carefully designed prospective study. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Image Demosaicking with Contour Stencils

    Directory of Open Access Journals (Sweden)

    Pascal Getreuer

    2012-03-01

    Full Text Available Demosaicking (or demosaicing is the problem of interpolating full color information on an image where only one color component is known at each pixel. Most demosaicking methods involve some kind of estimation of the underlying image structure, for example, choosing adaptively between interpolating in the horizontal or vertical direction. This article discusses the implementation details of the method introduced in Getreuer, “Color Demosaicing with Contour Stencils,” 2011. Mosaicked contour stencils first estimate the image contour orientations directly from the mosaicked data. The mosaicked contour stencils are then used to guide a simple demosaicking method based on graph regularization.

  19. Contours - MO 2012 Greene County 5ft Contours (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — 5ft cartographic contour file for Greene County, Missouri. This file was created using the elevation data from the 2011 LiDAR flight. It includes indexes for 10, 25,...

  20. Contours - MO 2012 Greene County 5ft Contours (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 5ft cartographic contour file for Greene County, Missouri. This file was created using the elevation data from the 2011 LiDAR flight. It includes indexes for 10, 25,...

  1. Contours - MO 2012 Greene County NW 1ft Contours (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 1ft contour file for the northwest portion of Greene County, Missouri. This file was created using the USGS corrected elevation data from the 2011 LiDAR flight. It...

  2. Contours - MO 2012 Greene County SE 1ft Contours (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 1ft contour file for the southeast portion of Greene County, Missouri. This file was created using the USGS corrected elevation data from the 2011 LiDAR flight. It...

  3. Contours - MO 2012 Greene County SW 1ft Contours (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 1ft contour file for the southwest portion of Greene County, Missouri. This file was created using the USGS corrected elevation data from the 2011 LiDAR flight. It...

  4. Contours - MO 2012 Greene County NE 1ft Contours (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 1ft contour file for the northeast portion of Greene County, Missouri. This file was created using the USGS corrected elevation data from the 2011 LiDAR flight. It...

  5. Pulse Densitometer Indocyanine Green Dilution Curves : A Simple Applicable and Accurate Method for Determination of Cardiac Shunts

    NARCIS (Netherlands)

    Bergstra, Arend; Hoendermis, Elke S.; Talsma, Melle D.; Mook, Gerrit A.; Zijlstra, Willem G.; Berger, Rolf M. F.

    2009-01-01

    Objective. Adequate hemodynamic evaluation is crucial in the management of patients with congenital heart disease. Although non-invasive diagnostic tools have reduced the need for invasive procedures, cardiac catheterization is still mandatory for absolute quantification of pressures, flows and vasc

  6. Wavelet Representation of Contour Sets

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, M; Laney, D E; Duchaineau, M A; Hansen, C D; Hamann, B; Joy, K I

    2001-07-19

    We present a new wavelet compression and multiresolution modeling approach for sets of contours (level sets). In contrast to previous wavelet schemes, our algorithm creates a parametrization of a scalar field induced by its contoum and compactly stores this parametrization rather than function values sampled on a regular grid. Our representation is based on hierarchical polygon meshes with subdivision connectivity whose vertices are transformed into wavelet coefficients. From this sparse set of coefficients, every set of contours can be efficiently reconstructed at multiple levels of resolution. When applying lossy compression, introducing high quantization errors, our method preserves contour topology, in contrast to compression methods applied to the corresponding field function. We provide numerical results for scalar fields defined on planar domains. Our approach generalizes to volumetric domains, time-varying contours, and level sets of vector fields.

  7. Visualizing Contour Trees within Histograms

    DEFF Research Database (Denmark)

    Kraus, Martin

    2010-01-01

    Many of the topological features of the isosurfaces of a scalar volume field can be compactly represented by its contour tree. Unfortunately, the contour trees of most real-world volume data sets are too complex to be visualized by dot-and-line diagrams. Therefore, we propose a new visualization...... that is suitable for large contour trees and efficiently conveys the topological structure of the most important isosurface components. This visualization is integrated into a histogram of the volume data; thus, it offers strictly more information than a traditional histogram. We present algorithms...... to automatically compute the graph layout and to calculate appropriate approximations of the contour tree and the surface area of the relevant isosurface components. The benefits of this new visualization are demonstrated with the help of several publicly available volume data sets....

  8. Contours--Offshore Monterey, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents bathymetric contours for several seafloor maps of the Monterey Canyon and Vicinity map area, California. The raster data file is...

  9. Contours--Offshore Aptos, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Aptos map area, California. The vector data file is...

  10. Contours--Offshore Aptos, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Aptos map area, California. The vector data file is...

  11. Contours--Offshore Monterey, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents bathymetric contours for several seafloor maps of the Monterey Canyon and Vicinity map area, California. The raster data file is...

  12. Optimality of human contour integration.

    Directory of Open Access Journals (Sweden)

    Udo A Ernst

    Full Text Available For processing and segmenting visual scenes, the brain is required to combine a multitude of features and sensory channels. It is neither known if these complex tasks involve optimal integration of information, nor according to which objectives computations might be performed. Here, we investigate if optimal inference can explain contour integration in human subjects. We performed experiments where observers detected contours of curvilinearly aligned edge configurations embedded into randomly oriented distractors. The key feature of our framework is to use a generative process for creating the contours, for which it is possible to derive a class of ideal detection models. This allowed us to compare human detection for contours with different statistical properties to the corresponding ideal detection models for the same stimuli. We then subjected the detection models to realistic constraints and required them to reproduce human decisions for every stimulus as well as possible. By independently varying the four model parameters, we identify a single detection model which quantitatively captures all correlations of human decision behaviour for more than 2000 stimuli from 42 contour ensembles with greatly varying statistical properties. This model reveals specific interactions between edges closely matching independent findings from physiology and psychophysics. These interactions imply a statistics of contours for which edge stimuli are indeed optimally integrated by the visual system, with the objective of inferring the presence of contours in cluttered scenes. The recurrent algorithm of our model makes testable predictions about the temporal dynamics of neuronal populations engaged in contour integration, and it suggests a strong directionality of the underlying functional anatomy.

  13. Medical Image Segmentation through Bat-Active Contour Algorithm

    Directory of Open Access Journals (Sweden)

    Rabiu O. Isah

    2017-01-01

    Full Text Available In this research work, an improved active contour method called Bat-Active Contour Method (BAACM using bat algorithm has been developed. The bat algorithm is incorporated in order to escape local minima entrapped into by the classical active contour method, stabilize contour (snake movement and accurately, reach boundary concavity. Then, the developed Bat-Active Contour Method was applied to a dataset of medical images of the human heart, bone of knee and vertebra which were obtained from Auckland MRI Research Group (Cardiac Atlas Website, University of Auckland. Set of similarity metrics, including Jaccard index and Dice similarity measures were adopted to evaluate the performance of the developed algorithm. Jaccard index values of 0.9310, 0.9234 and 0.8947 and Dice similarity values of 0.8341, 0.8616 and 0.9138 were obtained from the human heart, vertebra and bone of knee images respectively. The results obtained show high similarity measures between BA-ACM algorithm and expert segmented images. Moreso, traditional ACM produced Jaccard index values 0.5873, 0.5601, 0.6009 and Dice similarity values of 0.5974, 0.6079, 0.6102 in the human heart, vertebra and bone of knee images respectively. The results obtained for traditional ACM show low similarity measures between it and expertly segmented images. It is evident from the results obtained that the developed algorithm performed better compared to the traditional ACM

  14. Inter-beat intervals of cardiac-cell aggregates during exposure to 2.45 GHz CW, pulsed, and square-wave-modulated microwaves.

    Science.gov (United States)

    Seaman, R L; DeHaan, R L

    1993-01-01

    Inter-beat intervals of aggregated cardiac cells from chicken embryos were studied during 190 s exposures to 2.45 GHz microwaves in an open-ended coaxial device. Averaged specific-absorption rates (SARs) and modulation conditions were 1.2-86.9 W/kg continuous-wave (CW), 1.2-12.2 W/kg pulse modulation (PW, duty cycle approximately 11%), and 12.0-43.5 W/kg square-wave modulation (duty cycle = 50%). The inter-beat interval decreased during microwave exposures at 42.0 W/kg and higher when CW or square-wave modulation was used, which is consistent with established effects of elevated temperatures. However, increases in the inter-beat interval during CW exposures at 1.2-12.2 W/kg, and decreases in the inter-beat interval after PW exposures at 8.4-12.2 W/kg, are not consistent with simple thermal effects. Analysis of variance indicated that SAR, modulation, and the modulation-SAR interaction were all significant factors in altering the inter-beat interval. The latter two factors indicated that the cardiac cells were affected by athermal as well as thermal effects of microwave exposure.

  15. Impact of changes in systemic vascular resistance on a novel non-invasive continuous cardiac output measurement system based on pulse wave transit time: a report of two cases.

    Science.gov (United States)

    Ishihara, Hironori; Tsutsui, Masato

    2014-08-01

    The inaccuracy of arterial waveform analysis for measuring continuos cardiac output (CCO) associated with changes in systemic vascular resistance (SVR) has been well documented. A new non-invasive continuous cardiac output monitoring system (esCCO) mainly utilizing pulse wave transit time (PWTT) in place of arterial waveform analysis has been developed. However, the trending ability of esCCO to measure cardiac output during changes in SVR remains unclear. After a previous multicenter study on esCCO measurement, we retrospectively identified two cases in which apparent changes in SVR developed in a short period during data collection. In each case, the trending ability of esCCO to measure cardiac output and time component of PWTT were analyzed. Recorded data suggest that the time component of PWTT may have a significant impact on the accuracy of estimating stroke volume during changes in SVR. However, further prospective clinical studies are required to test this hypothesis.

  16. The impact of left ventricular preload reduction on cardiac pulsed doppler indices during hemodialysis and its relation to intra-dialysis hypotension: A pulsed doppler study

    Directory of Open Access Journals (Sweden)

    Alarrayed Sameer

    2009-01-01

    Full Text Available Fluid status in the body plays an important role on left ventricular (LV filling in patients with end-stage renal disease (ESRD on regular hemodialysis (HD, and plays a role in intra-dialysis hemo-dynamic derangement. Fifty-two patients with ESRD on regular HD, including 34 males with a mean age of 45.5 ± 13 years (range 18-72 years, were studied. All patients underwent Echo-pulsed Doppler study before and immediately after a HD session. The Echo Doppler indices noted were: LV cavity dimension and wall thickness, LV ejection fraction (LVEF%, trans-mitral early diastolic filling velocity (E wave, atrial filling diastolic velocity (A wave, E/A ratio, Deceleration Time (DT of E wave, Isovolumic relaxation time (IVRT, Aortic Velocity Integral (AVI and Inferior Vena Cava Diameter (VCD at expiration. Patients were divided into two groups according to the amount of net ultra filtrate loss after HD. Group I comprised of 25 patients with fluid loss of < 2 liters, and Group II had 27 patients with fluid loss > 2 liters. During the HD session, each patient was observed for the development of acute clinical events such as arterial hypotension (systolic BP less than 90 mmHg, chest pain and arrhythmias. There was a significant difference between the two groups in the mean values, pre- and post- HD, of reduction of E wave velocity (p< 0.01, the reduction of E/A ratio (p< 0.05, the increment in DT of E wave (p< 0.05, the reduction in AVI (p< 0.01 and the reduction of VCD (p< 0.05. There was no significant difference between the groups in the reduction of A wave velocity and the reduction of IVRT. Among the study patients, 11 (21% developed systolic hypo-tension during HD. The pre-dialysis mean values of E/A ratio and DT of E wave in patients who developed hypotension compared to those who did not was 0.7 ± 0.2 vs 1.1 ± 0.2.1 (p< 0.001 and 246 ± 40 vs 224 ± 34 msec (p< 0.05, respectively. Our study suggests that preload reduction in patients with ESRD on

  17. Effects of cardiac timing and peripheral resistance on measurement of pulse wave velocity for assessment of arterial stiffness.

    Science.gov (United States)

    Xiao, Hanguang; Butlin, Mark; Tan, Isabella; Avolio, Alberto

    2017-07-20

    To investigate the effects of heart rate (HR), left ventricular ejection time (LVET) and wave reflection on arterial stiffness as assessed by pulse wave velocity (PWV), a pulse wave propagation simulation system (PWPSim) based on the transmission line model of the arterial tree was developed and was applied to investigate pulse wave propagation. HR, LVET, arterial elastic modulus and peripheral resistance were increased from 60 to 100 beats per minute (bpm), 0.1 to 0.45 seconds, 0.5 to 1.5 times and 0.5 to 1.5 times of the normal value, respectively. Carotid-femoral PWV (cfPWV) and brachial-ankle PWV (baPWV) were calculated by intersecting tangent method (cfPWVtan and baPWVtan), maximum slope (cfPWVmax and baPWVmax), and using the Moens-Korteweg equation ([Formula: see text] and [Formula: see text]). Results showed cfPWV and baPWV increased significantly with arterial elastic modulus but did not increase with HR when using a constant elastic modulus. However there were significant LVET dependencies of cfPWVtan and baPWVtan (0.17 ± 0.13 and 0.17 ± 0.08 m/s per 50 ms), and low peripheral resistance dependencies of cfPWVtan, cfPWVmax, baPWVtan and baPWVmax (0.04 ± 0.01, 0.06 ± 0.04, 0.06 ± 0.03 and 0.09 ± 0.07 m/s per 10% peripheral resistance), respectively. This study demonstrated that LVET dominates the effect on calculated PWV compared to HR and peripheral resistance when arterial elastic modulus is constant.

  18. Topological Cacti: Visualizing Contour-based Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Gunther H.; Bremer, Peer-Timo; Pascucci, Valerio

    2011-05-26

    Contours, the connected components of level sets, play an important role in understanding the global structure of a scalar field. In particular their nestingbehavior and topology-often represented in form of a contour tree-have been used extensively for visualization and analysis. However, traditional contour trees onlyencode structural properties like number of contours or the nesting of contours, but little quantitative information such as volume or other statistics. Here we use thesegmentation implied by a contour tree to compute a large number of per-contour (interval) based statistics of both the function defining the contour tree as well asother co-located functions. We introduce a new visual metaphor for contour trees, called topological cacti, that extends the traditional toporrery display of acontour tree to display additional quantitative information as width of the cactus trunk and length of its spikes. We apply the new technique to scalar fields ofvarying dimension and different measures to demonstrate the effectiveness of the approach.

  19. The added value of cardiac index and pulse pressure variation monitoring to mean arterial pressure-guided volume therapy in moderate-risk abdominal surgery (COGUIDE): a pragmatic multicentre randomised controlled trial.

    Science.gov (United States)

    Stens, J; Hering, J-P; van der Hoeven, C W P; Boom, A; Traast, H S; Garmers, L E; Loer, S A; Boer, C

    2017-09-01

    There is disagreement regarding the benefits of goal-directed therapy in moderate-risk abdominal surgery. Therefore, we tested the hypothesis that the addition of non-invasive cardiac index and pulse pressure variation monitoring to mean arterial pressure-based goal-directed therapy would reduce the incidence of postoperative complications in patients having moderate-risk abdominal surgery. In this pragmatic multicentre randomised controlled trial, we randomly allocated 244 patients by envelope drawing in a 1:1 fashion, stratified per centre. All patients had mean arterial pressure, cardiac index and pulse pressure variation measured continuously. In one group, healthcare professionals were blinded to cardiac index and pulse pressure variation values and were asked to guide haemodynamic therapy only based on mean arterial pressure (control group). In the second group, cardiac index and pulse pressure variation values were displayed and kept within target ranges following a pre-defined algorithm (CI-PPV group). The primary endpoint was the incidence of postoperative complications within 30 days. One hundred and seventy-five patients were eligible for final analysis. Overall complication rates were similar (42/94 (44.7%) vs. 38/81 (46.9%) in the control and CI-PPV groups, respectively; p = 0.95). The CI-PPV group had lower mean (SD) pulse pressure variation values (9.5 (2.0)% vs. 11.9 (4.6)%; p = 0.003) and higher mean (SD) cardiac indices (2.76 (0.62) l min(-1) .m(-2) vs. 2.53 (0.66) l min(-1) .m(-2) ; p = 0.004) than the control group. In moderate-risk abdominal surgery, we observed no additional value of cardiac index and pulse pressure variation-guided haemodynamic therapy to mean arterial pressure-guided volume therapy with regard to postoperative complications. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  20. Illusory contour formation survives crowding.

    Science.gov (United States)

    Lau, Jonathan Siu Fung; Cheung, Sing-Hang

    2012-06-12

    Flanked objects are difficult to identify using peripheral vision due to visual crowding, which limits conscious access to target identity. Nonetheless, certain types of visual information have been shown to survive crowding. Such resilience to crowding provides valuable information about the underlying neural mechanism of crowding. Here we ask whether illusory contour formation survives crowding of the inducers. We manipulated the presence of illusory contours through the (mis)alignment of the four inducers of a Kanizsa square. In the inducer-aligned condition, the observers judged the perceived shape (thin vs. fat) of the illusory Kanizsa square, manipulated by small rotations of the inducers. In the inducer-misaligned condition, three of the four inducers (all except the upper-left) were rotated 90°. The observers judged the orientation of the upper-left inducer. Crowding of the inducers worsened observers' performance significantly only in the inducer-misaligned condition. Our findings suggest that information for illusory contour formation survives crowding of the inducers. Crowding happens at a stage where the low-level featural information is integrated for inducer orientation discrimination, but not at a stage where the same information is used for illusory contour formation.

  1. Towards Stabilizing Parametric Active Contours

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Søren Ingvor;

    2014-01-01

    Numerical instability often occurs in evolving of parametric active contours. This is mainly due to the undesired change of parametrization during evolution. In this paper, we propose a new tangential diffusion term to compensate this undesired change. As a result, the parametrization will converge...

  2. Contour Detection by CORF Operator

    NARCIS (Netherlands)

    Azzopardi, George; Petkov, Nicolai

    2012-01-01

    We propose a contour operator, called CORF, inspired by the properties of simple cells in visual cortex. It combines, by a weighted geometric mean, the blurred responses of difference-of-Gaussian operators that model cells in the lateral geniculate nucleus (LGN). An operator that has gained

  3. Region-based active contour with noise and shape priors

    CERN Document Server

    Lecellier, François; Fadili, Jalal; Aubert, Gilles; Revenu, Marinette; Saloux, Eric

    2008-01-01

    In this paper, we propose to combine formally noise and shape priors in region-based active contours. On the one hand, we use the general framework of exponential family as a prior model for noise. On the other hand, translation and scale invariant Legendre moments are considered to incorporate the shape prior (e.g. fidelity to a reference shape). The combination of the two prior terms in the active contour functional yields the final evolution equation whose evolution speed is rigorously derived using shape derivative tools. Experimental results on both synthetic images and real life cardiac echography data clearly demonstrate the robustness to initialization and noise, flexibility and large potential applicability of our segmentation algorithm.

  4. Gulf of Mexico Deepwater Bathymetry Contours

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — Gulf of Mexico Depth Contours derived from NOAA's NGDC bathymetric grids and from BOEM's seismic grid compilation. Both NOAA and BOEM contours are shown in meters or...

  5. From Inpainting to Active Contours

    DEFF Research Database (Denmark)

    Lauze, Francois Bernard; Nielsen, Mads

    2008-01-01

    image and a guess on the location of the object to be segmented via variational inpainting method. A numerical evaluation of this reconstruction provides a "disocclusion measure" and the correct foreground segmentation region is expected to maximize this measure. This formulation is in fact an optimal...... control problem, where controls are shapes/regions and states are the corresponding inpaintings. Optimization of the disocclusion measure leads formally to a coupled contour evolution equation, an inpainting equation (the state equation) as well as a linear PDE depending on the inpainting (the adjoint...... state equation). The contour evolution is implemented in the framework of level sets. Finally, the proposed method is validated on various examples. We focus among others in the segmentation of calcified plaques observed in radiographs from human lumbar aortic regions. Keywords  Segmentation - Inpainting...

  6. Grouping by proximity in haptic contour detection.

    Directory of Open Access Journals (Sweden)

    Krista E Overvliet

    Full Text Available We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots, relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection.

  7. Active Contour with A Tangential Component

    CERN Document Server

    Wang, Junyan

    2012-01-01

    Conventional edge-based active contours often require the normal component of an edge indicator function on the optimal contours to approximate zero, while the tangential component can still be significant. In real images, the full gradients of the edge indicator function along the object boundaries are often small. Hence, the curve evolution of edge-based active contours can terminate early before converging to the object boundaries with a careless contour initialization. We propose a novel Geodesic Snakes (GeoSnakes) active contour that requires the full gradients of the edge indicator to vanish at the optimal solution. Besides, the conventional curve evolution approach for minimizing active contour energy cannot fully solve the Euler-Lagrange (EL) equation of our GeoSnakes active contour, causing a Pseudo Stationary Phenomenon (PSP). To address the PSP problem, we propose an auxiliary curve evolution equation, named the equilibrium flow (EF) equation. Based on the EF and the conventional curve evolution, w...

  8. Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy

    Science.gov (United States)

    Urbanek, Bożena; Ruta, Jan; Kudryński, Krzysztof; Ptaszyński, Paweł; Klimczak, Artur; Wranicz, Jerzy Krzysztof

    2016-01-01

    Background The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). Material/Methods Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. Results Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. Conclusions During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead. PMID:27305349

  9. A strategic approach for cardiac MR left ventricle segmentation.

    Science.gov (United States)

    Dakua, Sarada Prasad; Sahambi, J S

    2010-09-01

    Quantitative evaluation of cardiac function from cardiac magnetic resonance (CMR) images requires the identification of the myocardial walls. This generally requires the clinician to view the image and interactively trace the contours. Especially, detection of myocardial walls of left ventricle is a difficult task in CMR images that are obtained from subjects having serious diseases. An approach to automated outlining the left ventricular contour is proposed. In order to segment the left ventricle, in this paper, a combination of two approaches is suggested. Difference of Gaussian weighting function (DoG) is newly introduced in random walk approach for blood pool (inner contour) extraction. The myocardial wall (outer contour) is segmented out by a modified active contour method that takes blood pool boundary as the initial contour. Promising experimental results in CMR images demonstrate the potentials of our approach.

  10. Pulse wave velocity and digital volume pulse as indirect estimators of blood pressure: pilot study on healthy volunteers.

    Science.gov (United States)

    Padilla, Juan M; Berjano, Enrique J; Sáiz, Javier; Rodriguez, Rafael; Fácila, Lorenzo

    2009-09-01

    The purpose of the study was to asses the potential use of pulse wave velocity (PWV) and digital volume pulse (DVP) as estimators of systolic (SBP) and diastolic (DPB) blood pressure. Single and multiple correlation studies were conducted, including biometric parameters and risk factors. Brachial-ankle PWV (baPWV) and DVP signals were obtained from a Pulse Trace PWV and Pulse Trace PCA (pulse contour analysis), respectively. The DVP (obtained by photoplethysmography), allowed stiffness (SI) and reflection indexes (RI) to be derived. The first study on 47 healthy volunteers showed that both SBP and DPB correlated significantly both with baPWV and SI. Multiple regression models of the baPWV and the waist-to-hip ratio (WHR) allowed SBP and DBP to be modeled with r = 0.838 and r = 0.673, respectively. SI results also employed WHR and modeled SBP and DBP with r = 0.852 and r = 0.663, respectively. RI did not correlate either with SBP or DBP. In order to avoid the use of ultrasound techniques to measure PWV, we then developed a custom-built system to measure PWV by photoplethysmography and validated it against the Pulse Trace. With the same equipment we conducted a second pilot study with ten healthy volunteers. The best SBP multiple regression model for SBP achieved r = 0.997 by considering the heart-finger PWV (hfPWV measured between R-wave and index finger), WHR and heart rate. Only WHR was significant in the DBP model. Our findings suggest that the hfPWV photoplethysmography signal could be a reliable estimator of approximate SBP and could be used, for example, to monitor cardiac patients during physical exercise sessions in cardiac rehabilitation.

  11. Brightness Alteration with Interweaving Contours

    Directory of Open Access Journals (Sweden)

    Sergio Roncato

    2012-12-01

    Full Text Available Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation or when lines of different colours are collinear (neon effect or adjacent (watercolour to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread. The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975 and Kanizsa (1979 in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.

  12. Contours, 2 Ft. Contours, Published in 2006, North Georgia College and State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, was produced all or in part from LIDAR information as of 2006. It is described as '2 Ft. Contours'. Data by this publisher are often provided...

  13. NY_GOME_CONTOURS: New York Bight and Gulf of Maine bathymetric contours

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This bathymetric shapefile contains 10 m contours for the continental shelf and 100 m beyond the 200 m shelf edge. The contours have been derived from the National...

  14. NY_GOME_CONTOURS: New York Bight and Gulf of Maine bathymetric contours

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This bathymetric shapefile contains 10 m contours for the continental shelf and 100 m beyond the 200 m shelf edge. The contours have been derived from the National...

  15. Contours, Two Foot Contours, Published in 2007, Not Applicable scale, Dunn County, WI.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at Not Applicable scale, was produced all or in part from LIDAR information as of 2007. It is described as 'Two Foot Contours'....

  16. Velocity and depth contours with a mode-locked pulse

    Energy Technology Data Exchange (ETDEWEB)

    Mallick, S.; Malacara, D.

    1976-05-01

    An expression is derived for the intensity in the reconstructed image of a three-dimensional object in motion. The particular cases of (1) a stationary three-dimensional object and (2) a moving object with exact path matching are treated separately. The displacement of the object during the exposure is assumed to be insignificant in comparison with the coherence length of a single subpulse. (MHR)

  17. Contour extracting networks in early extrastriate cortex

    NARCIS (Netherlands)

    Dumoulin, Serge O.; Hess, Robert F.; May, Keith A.; Harvey, Ben M.; Rokers, Bas; Barendregt, Martijn

    2014-01-01

    Neurons in the visual cortex process a local region of visual space, but in order to adequately analyze natural images, neurons need to interact. The notion of an ''association field'' proposes that neurons interact to extract extended contours. Here, we identify the site and properties of contour

  18. RFP for the Comet Nuclei Tour (CONTOUR)

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Madsen, Peter Buch; Betto, Maurizio

    1999-01-01

    This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program.......This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program....

  19. Contour extracting networks in early extrastriate cortex

    NARCIS (Netherlands)

    Dumoulin, Serge O.; Hess, Robert F.; May, Keith A.; Harvey, Ben M.; Rokers, Bas; Barendregt, Martijn

    2014-01-01

    Neurons in the visual cortex process a local region of visual space, but in order to adequately analyze natural images, neurons need to interact. The notion of an ''association field'' proposes that neurons interact to extract extended contours. Here, we identify the site and properties of contour i

  20. Contours--Offshore of Santa Barbara, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3281 presents data for the bathymetric contours for several seafloor maps (see sheets 1, 2, 3, 7, 10, SIM 3281) of the Offshore of Santa Barbara...

  1. Contours--Offshore Coal Oil Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3302 presents bathymetric contours for several seafloor maps of Offshore Coal Oil Point, California (vector data file is included in...

  2. Transgressive Contours--Bolinas to Pescadero, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the transgressive contours for the Bolinas to Pescadero, California, region. The vector file is included in...

  3. Contours-Offshore of Bodega Head, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Bodega Head map area, California. The vector data file is...

  4. Contours--Offshore of Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Pacifica map area, California. The vector data file is...

  5. Contours--Drakes Bay and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Drakes Bay and Vicinity map area, California. The vector data file is...

  6. Contours--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents bathymetric contours for several seafloor maps of the Monterey Canyon and Vicinity map area, California. The raster data file is...

  7. An Active Contour for Range Image Segmentation

    OpenAIRE

    Khaldi Amine; Merouani Hayet Farida

    2012-01-01

    In this paper a new classification of range image segmentation method is proposed according to the criterion of homogeneity which obeys the segmentation, then, a deformable model-type active contour “Snake” is applied to segment range images.

  8. Contours--Offshore Refugio Beach, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3319 presents bathymetric contours for several seafloor maps of Offshore Refugio Beach, California (vector data file is included in...

  9. Contours-Offshore of Bodega Head, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Bodega Head map area, California. The vector data file is...

  10. Water-table contours of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of water-table contours for Nevada. These data were created as part of an effort to provide statewide information on water table and depth to...

  11. Contours--Offshore of Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Pacifica map area, California. The vector data file is...

  12. Contours--Offshore of Fort Ross, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Fort Ross map area, California. The vector data file is...

  13. Contours Offshore of Tomales Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Tomales Point map area, California. The vector data file...

  14. Contours--Offshore Santa Cruz, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Santa Cruz map area, California. The vector data file is...

  15. Contours--Offshore Pigeon Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Pigeon Point map area, California. The vector data file is...

  16. Contours--Offshore of Fort Ross, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Fort Ross map area, California. The vector data file is...

  17. Contours--Offshore Scott Creek, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Scott Creek map area, California. The vector data file is...

  18. Contours--Offshore of San Francisco, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of San Francisco map area, California. The vector data file...

  19. Transgressive Contours--Bolinas to Pescadero, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the transgressive contours for the Bolinas to Pescadero, California, region. The vector file is included in...

  20. Contours--Offshore Scott Creek, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Scott Creek map area, California. The vector data file is...

  1. Contours--Offshore Santa Cruz, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Santa Cruz map area, California. The vector data file is...

  2. Contours--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents bathymetric contours for several seafloor maps of the Monterey Canyon and Vicinity map area, California. The raster data file is...

  3. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  4. Decoupled active contour (DAC) for boundary detection.

    Science.gov (United States)

    Mishra, Akshaya Kumar; Fieguth, Paul W; Clausi, David A

    2011-02-01

    The accurate detection of object boundaries via active contours is an ongoing research topic in computer vision. Most active contours converge toward some desired contour by minimizing a sum of internal (prior) and external (image measurement) energy terms. Such an approach is elegant, but suffers from a slow convergence rate and frequently misconverges in the presence of noise or complex contours. To address these limitations, a decoupled active contour (DAC) is developed which applies the two energy terms separately. Essentially, the DAC consists of a measurement update step, employing a Hidden Markov Model (HMM) and Viterbi search, and then a separate prior step, which modifies the updated curve based on the relative strengths of the measurement uncertainty and the nonstationary prior. By separating the measurement and prior steps, the algorithm is less likely to misconverge; furthermore, the use of a Viterbi optimizer allows the method to converge far more rapidly than energy-based iterative solvers. The results clearly demonstrate that the proposed approach is robust to noise, can capture regions of very high curvature, and exhibits limited dependence on contour initialization or parameter settings. Compared to five other published methods and across many image sets, the DAC is found to be faster with better or comparable segmentation accuracy.

  5. Isolating contour information from arbitrary images

    Science.gov (United States)

    Jobson, Daniel J.

    1989-01-01

    Aspects of natural vision (physiological and perceptual) serve as a basis for attempting the development of a general processing scheme for contour extraction. Contour information is assumed to be central to visual recognition skills. While the scheme must be regarded as highly preliminary, initial results do compare favorably with the visual perception of structure. The scheme pays special attention to the construction of a smallest scale circular difference-of-Gaussian (DOG) convolution, calibration of multiscale edge detection thresholds with the visual perception of grayscale boundaries, and contour/texture discrimination methods derived from fundamental assumptions of connectivity and the characteristics of printed text. Contour information is required to fall between a minimum connectivity limit and maximum regional spatial density limit at each scale. Results support the idea that contour information, in images possessing good image quality, is (centered at about 10 cyc/deg and 30 cyc/deg). Further, lower spatial frequency channels appear to play a major role only in contour extraction from images with serious global image defects.

  6. Perception of illusory contours enhanced in motion

    Institute of Scientific and Technical Information of China (English)

    倪睿; 王志宏; 吴新年; 汪云九; 李东光

    2003-01-01

    Investigation on illusory contours is important for understanding the mechanisms un-derlying the object recognition of human visual system. Numerous researches have shown that illusory contours formed in motion and stereopsis are generated by the unmatched features. Here we conduct three psychophysical experiments to test if Kanizsa illusory contours are also caused by unmatched information. Different types of motion (including horizontal translation, radial ex-panding and shrinking) are utilized in the experiments. The results show that no matter under what kind of motion, when figures or background move separately illusory contours are perceived stronger, and there is no significant difference between the perceived strength in these two types of motion. However, no such enhancement of perceived strength is found when figures and background move together. It is found that the strengthened unmatched features generate the enhancement effect of illusory contour perception in motion. Thus the results suggest that the process of unmatched information in visual system is a critical step in the formation of illusory contours.

  7. Variation in contour and cancer of stomach

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hong; Hwang, Seon Moon [Asan Medical Center, Asan (Korea, Republic of); Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    1999-04-01

    There were four types of stomach contour included eutonic, hypotonic, steerhorn, and cascade. The aim of this study is to clarify relationship between incidence of stomach cancer and contour variation of the stomach. Double- contrast upper gastrointestinal study was performed in 1,546 patients, who had dyspepsia or other gastrointestinal tract symptoms. The radiographs were classified into the four types including eutonic, hypotonic, steerhorn, and cascade according to stomach contour in relation to body build. We also reviewed pathologic reports on endoscopic biopsy or surgical specimen. We studied the presence of relationship between incidence of stomach cancer and variation of stomach contour. We also examined the incidence of gastritis and gastric ulcer to the stomach contour variation. Of total 1,546 patients, eutonic stomach were 438(28.3%), hypotonic 911(58.9%), steerhorn 102(6.5%) and cascade 95(6.2%). Stomach cancer was found in 139(31.7%) of 438 eutonic stomachs, in 135(14.8%) of 911 hypotonic, in 42(41.2%) of 102 steerhorn, and in 24(36.9%) of 95 cascade (P=0.001). In hypotonic stomach, the incidence of stomach cancer was lower compared to the other three types significantly (p<0.05). Gastritis or gastric ulcer was found in 146(33.3%) of eutonic stomach, in 293(32.1%) of hypotonic, in 36(35.2%) of steerhorn, and in 26(27.3%) of cascade (p=0.640). In conclusion, gastric contour variation seems to be a factor affecting development of stomach cancer. The patients with hypotonic stomach may have lower incidence of stomach cancer than that of the other types. There was no relationship between the contour and gastric ulcer.

  8. Contoured-gap coaxial guns for imploding plasma liner experiments

    Science.gov (United States)

    Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.

    2014-10-01

    Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

  9. Pulse on Pulse

    DEFF Research Database (Denmark)

    Schmidt, Ulrik; Carlson, Merete

    2012-01-01

    Pulse on Pulse” investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006-) by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy...... and pulsating ‘room’. Hence, the visitors in Pulse Room are invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic ‘rhythm of life’) and instants of pure material processuality...... a multilayered sense of time and space that is central to the sensory experience of Pulse Room as a whole. Pulse Room is, at the very same time, an anthropomorfized archive of a past intimacy and an all-encompassing immersive environment modulating continuously in real space-time....

  10. Minimization and Mitigation of Wire EDM Cutting Errors in the Application of the Contour Method of Residual Stress Measurement

    Science.gov (United States)

    Ahmad, Bilal; Fitzpatrick, Michael E.

    2016-01-01

    The contour method of residual stress measurement relies on the careful application of wire electro-discharge machining (WEDM) for the cutting stage. Changes in material removal rates during the cut lead to errors in the final calculated values of residual stress. In this study, WEDM cutting parameters have been explored to identify the optimum conditions for contour method residual stress measurements. The influence of machine parameters on the surface roughness and cutting artifacts in the contour cut is discussed. It has been identified that the critical parameter in improving the surface finish is the spark pulse duration. A typical cutting artifact and its impact on measured stress values have been identified and demonstrated for a contour cut in a welded marine steel. A procedure is presented to correct contour displacement data from the influence of WEDM cutting artifacts, and is demonstrated on the correction of a measured weld residual stress. The corrected contour method improved the residual stress magnitude up to 150 MPa. The corrected contour method results were validated by X-ray diffraction, incremental center hole drilling, and neutron diffraction.

  11. A FUZZY FILTERING MODEL FOR CONTOUR DETECTION

    Directory of Open Access Journals (Sweden)

    T.C. Rajakumar

    2011-04-01

    Full Text Available Contour detection is the basic property of image processing. Fuzzy Filtering technique is proposed to generate thick edges in two dimensional gray images. Fuzzy logic is applied to extract value for an image and is used for object contour detection. Fuzzy based pixel selection can reduce the drawbacks of conventional methods(Prewitt, Robert. In the traditional methods, filter mask is used for all kinds of images. It may succeed in one kind of image but fail in another one. In this frame work the threshold parameter values are obtained from the fuzzy histogram of the input image. The Fuzzy inference method selects the complete information about the border of the object and the resultant image has less impulse noise and the contrast of the edge is increased. The extracted object contour is thicker than the existing methods. The performance of the algorithm is tested with Peak Signal Noise Ratio(PSNR and Complex Wavelet Structural Similarity Metrics(CWSSIM.

  12. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars; Mølhave, Thomas

    We consider maintaining the contour tree T of a piecewise-linear triangulation M that is the graph of a time varying height function h:R2→R. We carefully describe the combinatorial change in T that happen as h varies over time and how these changes relate to topological changes in M. We present...... a kinetic data structure that maintains the contour tree of h over time. Our data structure maintains certificates that fail only when h(v)=h(u) for two adjacent vertices v and u in M, or when two saddle vertices lie on the same contour of M. A certificate failure is handled in O(log(n)) time. We also show...

  13. Coding Long Contour Shapes of Binary Objects

    Science.gov (United States)

    Sánchez-Cruz, Hermilo; Rodríguez-Díaz, Mario A.

    This is an extension of the paper appeared in [15]. This time, we compare four methods: Arithmetic coding applied to 3OT chain code (Arith-3OT), Arithmetic coding applied to DFCCE (Arith-DFCCE), Huffman coding applied to DFCCE chain code (Huff-DFCCE), and, to measure the efficiency of the chain codes, we propose to compare the methods with JBIG, which constitutes an international standard. In the aim to look for a suitable and better representation of contour shapes, our probes suggest that a sound method to represent contour shapes is 3OT, because Arithmetic coding applied to it gives the best results regarding JBIG, independently of the perimeter of the contour shapes.

  14. Conversion of contours to cartesian grids

    Energy Technology Data Exchange (ETDEWEB)

    Mann, J.; Broe, B. Riget

    2006-07-15

    A robust and efficient method of calculating a cartesian grid of heights or roughnesses from contour line maps is developed. The purpose of the grids is to serve as input for atmospheric flow solvers such as WAsP Engineering or EllipSys3D. The method builds on Delaunay triangulation constrained to include all contour segments in the triangulation. It is furthermore refined to avoid spurious flat areas produced by the Delaunay triangulation. Robust ways to extrapolate beyond the convex hull of the map points are provided. (au)

  15. Conversion of contours to cartesian grids

    DEFF Research Database (Denmark)

    Mann, Jakob; Broe, Brian Riget

    A robust and efficient method of calculating a cartesian grid of heights or roughnesses from contour line maps is developed. The purpose of the grids is to serve as input for atmospheric flow solvers such as WAsP Engineering or EllipSys3D. The method builds on Delaunay triangulation constrained t...... to include all contour segments in the triangulation. It is furthermore refined to avoid spurious flat areas produced by the Delaunay triangulation. Robust ways to extrapolate beyond the convex hull of the map points are provided....

  16. Cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Andreja Möller Petrun

    2014-02-01

    Full Text Available In recent years, developments in the measuring of cardiac output and other haemodynamic variables are focused on the so-called minimally invasive methods. The aim of these methods is to simplify the management of high-risk and haemodynamically unstable patients. Due to the need of invasive approach and the possibility of serious complications the use of pulmonary artery catheter has decreased. This article describes the methods for measuring cardiac output, which are based on volume measurement (Fick method, indicator dilution method, pulse wave analysis, Doppler effect, and electrical bioimpedance.

  17. Pulse on Pulse

    DEFF Research Database (Denmark)

    Schmidt, Ulrik; Carlson, Merete

    2012-01-01

    and pulsating ‘room’. Hence, the visitors in Pulse Room are invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic ‘rhythm of life’) and instants of pure material processuality......“Pulse on Pulse” investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006-) by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy...... of the visitor’s beating heart to the blink of a fragile light bulb, thereby transforming each light bulb into a register of individual life. But at the same time the blinking light bulbs together produce a chaotically flickering light environment composed by various layers of repetitive rhythms, a vibrant...

  18. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception studie

  19. Contours--Offshore of Carpinteria, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3261 presents data for the bathymetric contours for several seafloor maps (see sheets 1, 2, 3, 5 [in figs. 1, 2, 3], 7, 10, SIM 3261) of the...

  20. Contours--Offshore of Santa Barbara, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3281 presents data for the bathymetric contours for several seafloor maps (see sheets 1, 2, 3, 7, 10, SIM 3281) of the Offshore of Santa Barbara map...

  1. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars; Mølhave, Thomas

    We consider maintaining the contour tree T of a piecewise-linear triangulation M that is the graph of a time varying height function h:R2→R. We carefully describe the combinatorial change in T that happen as h varies over time and how these changes relate to topological changes in M. We present...

  2. An Active Contour for Range Image Segmentation

    Directory of Open Access Journals (Sweden)

    Khaldi Amine

    2012-06-01

    Full Text Available In this paper a new classification of range image segmentation method is proposed according to the criterion of homogeneity which obeys the segmentation, then, a deformable model-type active contour “Snake” is applied to segment range images.

  3. Regression Model With Elliptically Contoured Errors

    CERN Document Server

    Arashi, M; Tabatabaey, S M M

    2012-01-01

    For the regression model where the errors follow the elliptically contoured distribution (ECD), we consider the least squares (LS), restricted LS (RLS), preliminary test (PT), Stein-type shrinkage (S) and positive-rule shrinkage (PRS) estimators for the regression parameters. We compare the quadratic risks of the estimators to determine the relative dominance properties of the five estimators.

  4. Contours--Offshore of Carpinteria, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3261 presents data for the bathymetric contours for several seafloor maps (see sheets 1, 2, 3, 5 [in figs. 1, 2, 3], 7, 10, SIM 3261) of the...

  5. Automatic contour welder incorporates speed control system

    Science.gov (United States)

    Wall, W. A., Jr.

    1968-01-01

    Speed control system maintains the welding torch of an automatic welder at a substantially constant speed. The system is particularly useful when welding contoured or unusually shaped surfaces, which cause the distance from the work surface to the weld carriage to vary in a random manner.

  6. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Mølhave, Thomas; Revsbæk, Morten;

    2015-01-01

    We study the problem of maintaining the contour tree T of a terrain Sigma, represented as a triangulated xy-monotone surface, as the heights of its vertices vary continuously with time. We characterize the combinatorial changes in T and how they relate to topological changes in Sigma. We present ...

  7. Contours--Offshore of San Gregorio, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3306 presents data for the bathymetric contours for several seafloor maps (see sheets 1, 2, 3, 7, 10, SIM 3306) of the Offshore of San Gregorio map...

  8. Analysis of CVC roll contour and determination of roll crown

    Institute of Scientific and Technical Information of China (English)

    Guang Xu; Xianjun Liu; Jiarong Zhao; Junwei Xiong

    2007-01-01

    Mathematical analysis of continuous variable crown (CVC) roll contour used in CSP production line was conducted and the roll contour function of CVC roll was obtained. The validation with actual CVC roll contour shows that the calculation values of the roll contour function and the actual roll contour parameters given by equipment provider are the same, which proves that the roll contour function of CVC rolls given in this article is correct. The nonlinear relationship between the roll crown of CVC rolls and roll shift amounts was deduced. The concept of crown extremum was given.

  9. Contour tracking in echocardiographic sequences via sparse representation and dictionary learning.

    Science.gov (United States)

    Huang, Xiaojie; Dione, Donald P; Compas, Colin B; Papademetris, Xenophon; Lin, Ben A; Bregasi, Alda; Sinusas, Albert J; Staib, Lawrence H; Duncan, James S

    2014-02-01

    This paper presents a dynamical appearance model based on sparse representation and dictionary learning for tracking both endocardial and epicardial contours of the left ventricle in echocardiographic sequences. Instead of learning offline spatiotemporal priors from databases, we exploit the inherent spatiotemporal coherence of individual data to constraint cardiac contour estimation. The contour tracker is initialized with a manual tracing of the first frame. It employs multiscale sparse representation of local image appearance and learns online multiscale appearance dictionaries in a boosting framework as the image sequence is segmented frame-by-frame sequentially. The weights of multiscale appearance dictionaries are optimized automatically. Our region-based level set segmentation integrates a spectrum of complementary multilevel information including intensity, multiscale local appearance, and dynamical shape prediction. The approach is validated on twenty-six 4D canine echocardiographic images acquired from both healthy and post-infarct canines. The segmentation results agree well with expert manual tracings. The ejection fraction estimates also show good agreement with manual results. Advantages of our approach are demonstrated by comparisons with a conventional pure intensity model, a registration-based contour tracker, and a state-of-the-art database-dependent offline dynamical shape model. We also demonstrate the feasibility of clinical application by applying the method to four 4D human data sets.

  10. Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours

    Data.gov (United States)

    Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

  11. Goal-Directed Fluid Therapy Guided by Cardiac Monitoring During High-Risk Abdominal Surgery in Adult Patients: Cost-Effectiveness Analysis of Esophageal Doppler and Arterial Pulse Pressure Waveform Analysis.

    Science.gov (United States)

    Legrand, Guillaume; Ruscio, Laura; Benhamou, Dan; Pelletier-Fleury, Nathalie

    2015-07-01

    Several minimally invasive techniques for cardiac output monitoring such as the esophageal Doppler (ED) and arterial pulse pressure waveform analysis (APPWA) have been shown to improve surgical outcomes compared with conventional clinical assessment (CCA). To evaluate the cost-effectiveness of these techniques in high-risk abdominal surgery from the perspective of the French public health insurance fund. An analytical decision model was constructed to compare the cost-effectiveness of ED, APPWA, and CCA. Effectiveness data were defined from meta-analyses of randomized clinical trials. The clinical end points were avoidance of hospital mortality and avoidance of major complications. Hospital costs were estimated by the cost of corresponding diagnosis-related groups. Both goal-directed therapy strategies evaluated were more effective and less costly than CCA. Perioperative mortality and the rate of major complications were reduced by the use of ED and APPWA. Cost reduction was mainly due to the decrease in the rate of major complications. APPWA was dominant compared with ED in 71.6% and 27.6% and dominated in 23.8% and 20.8% of the cases when the end point considered was "major complications avoided" and "death avoided," respectively. Regarding cost per death avoided, APPWA was more likely to be cost-effective than ED in a wide range of willingness to pay. Cardiac output monitoring during high-risk abdominal surgery is cost-effective and is associated with a reduced rate of hospital mortality and major complications, whatever the device used. The two devices evaluated had negligible costs compared with the observed reduction in hospital costs. Our comparative studies suggest a larger effect with APPWA that needs to be confirmed by further studies. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  12. USGS Elevation Contours Overlay Map Service from The National Map

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Elevation Contours service from The National Map (TNM) consists of contours generated for the conterminous United States from 1- and 1/3 arc-second...

  13. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  14. Automatic liver contouring for radiotherapy treatment planning

    Science.gov (United States)

    Li, Dengwang; Liu, Li; Kapp, Daniel S.; Xing, Lei

    2015-09-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems. The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours. The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  15. [External contour acquisition system for radiotherapy: an original solution].

    Science.gov (United States)

    Létourneau, D; Brochet, F; Bohémier, R; Gagnon, J

    2000-01-01

    A contour acquisition system has been designed in radiotherapy at the Sagamie Hospital complex (Chicoutimi, Québec) to measure the external contours of the patients who do not need a CT exam. This measuring system can produce transversal, sagittal or coronal patient contours in the treatment position. The absolute accuracy of the system is +/- 1 mm. The contours produced by this equipment can be transferred electronically or on paper to the planning system.

  16. Edge and line oriented contour detection : State of the art

    NARCIS (Netherlands)

    Papari, Giuseppe; Petkov, Nicolai

    We present an overview of various edge and line oriented approaches to contour detection that have been proposed in the last two decades. By edge and line oriented we mean methods that do not rely on segmentation. Distinction is made between edges and contours. Contour detectors are divided in local

  17. Edge and line oriented contour detection : State of the art

    NARCIS (Netherlands)

    Papari, Giuseppe; Petkov, Nicolai

    2011-01-01

    We present an overview of various edge and line oriented approaches to contour detection that have been proposed in the last two decades. By edge and line oriented we mean methods that do not rely on segmentation. Distinction is made between edges and contours. Contour detectors are divided in local

  18. Human Lips-Contour Recognition and Tracing

    Directory of Open Access Journals (Sweden)

    Md. Hasan Tareque

    2014-01-01

    Full Text Available Human-lip detection is an important criterion for many automated modern system in present day. Like computerized speech reading, face recognition etc. system can work more precisely if human-lip can detect accurately. There are many processes for detecting human-lip. In this paper an approach is developed so that the region of a human-lip can be detected, we called it lip contour. For this a region-based Active Contour Model (ACM is introduced with watershed segmentation. In this model we used global energy terms instead of local energy terms because, global energy gives better convergence rate for malicious environment. At the time of ACM initialization by using H8 based on Lyapunov stability theory, the system gives more accurate and stable result.

  19. Maintaining Contour Trees of Dynamic Terrains

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Mølhave, Thomas; Revsbæk, Morten

    2015-01-01

    We study the problem of maintaining the contour tree T of a terrain Sigma, represented as a triangulated xy-monotone surface, as the heights of its vertices vary continuously with time. We characterize the combinatorial changes in T and how they relate to topological changes in Sigma. We present...... a kinetic data structure (KDS) for maintaining T efficiently. It maintains certificates that fail, i.e., an event occurs, only when the heights of two adjacent vertices become equal or two saddle vertices appear on the same contour. Assuming that the heights of two vertices of Sigma become equal only O(1......) times and these instances can be computed in O(1) time, the KDS processes O(kappa + n) events, where n is the number of vertices in Sigma and kappa is the number of events at which the combinatorial structure of T changes, and processes each event in O(log n) time. The KDS can be extended to maintain...

  20. Contours, contours 500 ft, Published in 2008, 1:24000 (1in=2000ft) scale, Box Elder County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2008. It is described as 'contours 500 ft'....

  1. Contours, ft 10 NED contours 2, Published in 2008, 1:24000 (1in=2000ft) scale, Box Elder County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2008. It is described as 'ft 10 NED contours...

  2. Contours, contours 100 ft, Published in 2008, 1:24000 (1in=2000ft) scale, Box Elder County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2008. It is described as 'contours 100 ft'....

  3. Contours, contours_2ft, Published in 2007, 1:1200 (1in=100ft) scale, Dodge County, Wisconsin.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from LIDAR information as of 2007. It is described as 'contours_2ft'. Data...

  4. Contours, ft 10 NED contours 1, Published in 2008, 1:24000 (1in=2000ft) scale, Box Elder County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2008. It is described as 'ft 10 NED contours...

  5. Contours, Tagged Vector Contours obtained from DASC, Published in 2003, 1:24000 (1in=2000ft) scale, Reno County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale as of 2003. It is described as 'Tagged Vector Contours obtained from DASC'. Data by this publisher...

  6. Contours, contour 500 ft, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'contour 500 ft'....

  7. Contours, contour 50 ft, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'contour 50 ft'....

  8. Contours, contour 10 ft, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'contour 10 ft'....

  9. Body Image and Body Contouring Procedures.

    Science.gov (United States)

    Sarwer, David B; Polonsky, Heather M

    2016-10-01

    Dissatisfaction with physical appearance and body image is a common psychological phenomena in Western society. Body image dissatisfaction is frequently reported by those who have excess body weight, but also is seen in those of normal body weight. For both groups of individuals, this dissatisfaction impacts self-esteem and quality of life. Furthermore, it is believed to be the motivational catalyst to a range of appearance-enhancing behaviors, including weight loss efforts and physical activity. Body image dissatisfaction is also believed to play a role in the decision to seek the wide range of body contouring procedures offered by aesthetic physicians. Individuals who seek these procedures typically report increased body image dissatisfaction, focus on the feature they wish to alter with treatment, and often experience improvement in body image following treatment. At the same time, extreme body image dissatisfaction is a symptom of a number of recognized psychiatric disorders. These include anorexia nervosa, bulimia nervosa, and body dysmorphic disorder (BDD), all of which can contraindicate aesthetic treatment. This special topic review paper provides an overview of the relationship between body image dissatisfaction and aesthetic procedures designed to improve body contouring. The review specifically focuses on the relationship of body image and body weight, as well as the presentation of body image psychopathology that would contraindicate aesthetic surgery. The overall goal of the paper is to highlight the clinical implications of the existing research and provide suggestions for future research on the psychological aspects of body contouring procedures.

  10. Contour Estimation by Array Processing Methods

    Directory of Open Access Journals (Sweden)

    Bourennane Salah

    2006-01-01

    Full Text Available This work is devoted to the estimation of rectilinear and distorted contours in images by high-resolution methods. In the case of rectilinear contours, it has been shown that it is possible to transpose this image processing problem to an array processing problem. The existing straight line characterization method called subspace-based line detection (SLIDE leads to models with orientations and offsets of straight lines as the desired parameters. Firstly, a high-resolution method of array processing leads to the orientation of the lines. Secondly, their offset can be estimated by either the well-known method of extension of the Hough transform or another method, namely, the variable speed propagation scheme, that belongs to the array processing applications field. We associate it with the method called "modified forward-backward linear prediction" (MFBLP. The signal generation process devoted to straight lines retrieval is retained for the case of distorted contours estimation. This issue is handled for the first time thanks to an inverse problem formulation and a phase model determination. The proposed method is initialized by means of the SLIDE algorithm.

  11. Dynamic Active Contours for Visual Tracking.

    Science.gov (United States)

    Niethammer, Marc; Tannenbaum, Allen; Angenent, Sigurd

    2006-01-01

    Visual tracking using active contours is usually set in a static framework. The active contour tracks the object of interest in a given frame of an image sequence. A subsequent prediction step ensures good initial placement for the next frame. This approach is unnatural; the curve evolution gets decoupled from the actual dynamics of the objects to be tracked. True dynamical approaches exist, all being marker particle based and thus prone to the shortcomings of such particle-based implementations. In particular, topological changes are not handled naturally in this framework. The now classical level set approach is tailored for evolutions of manifolds of codimension one. However, dynamic curve evolution is at least a codimension two problem. We propose an efficient, level set based approach for dynamic curve evolution, which addresses the artificial separation of segmentation and prediction while retaining all the desirable properties of the level set formulation. It is based on a new energy minimization functional which, for the first time, puts dynamics into the geodesic active contour framework.

  12. VT 10 ft Contour Lines generated from bare earth lidar - Chittenden

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ElevationContours_CN10T (10ft contours) was extracted from ElevationContours_CN2T (2ft contours), which was generated by USGS from the 2004...

  13. Context modulates the ERP signature of contour integration.

    Directory of Open Access Journals (Sweden)

    Bart Machilsen

    Full Text Available We investigated how the electrophysiological signature of contour integration is changed by the context in which a contour is embedded. Specifically, we manipulated the orientations of Gabor elements surrounding an embedded shape outline. The amplitudes of early visual components over posterior scalp regions were changed by the presence of a contour, and by the orientation of elements surrounding the contour. Differences in context type had an effect on the early P1 and N1 components, but not on the later P2 component. The presence of a contour had an effect on the N1 and P2 components, but not on the earlier P1 component. A modulatory effect of context on contour integration was observed on the N1 component. These results highlight the importance of the context in which contour integration takes place.

  14. Incorporating Prior Shape into Geometric Active Contours for Face Contour Detection

    Institute of Scientific and Technical Information of China (English)

    HUANGFuzhen; SUJianbo; XIYugeng

    2004-01-01

    In this paper a new method that incorporates prior shape information into geometric active contours for face contour detection is proposed. As in general a human face can be treated as an ellipse with a little shape variation, the prior face shape is represented as an elliptical curve. By combining the prior face shape with the powerful geometric active model proposed by Chan and Vese, the improved geometric active model can retain all the advantage of the Chan-Vese model and can detect face contours in images with complex backgrounds accurately even if the image is noisy. Moreover, by implementing the new model in a variational level set framework, automatic topological changes of the model can be achieved naturally and the transformation parameters that map the face boundary to the prior shape can be roughly estimated simultaneously. The experimental results show our procedure to be eiTicient.

  15. 21 CFR 870.5550 - External transcutaneous cardiac pacemaker (noninvasive).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External transcutaneous cardiac pacemaker... § 870.5550 External transcutaneous cardiac pacemaker (noninvasive). (a) Identification. An external transcutaneous cardiac pacemaker (noninvasive) is a device used to supply a periodic electrical pulse intended to...

  16. Three-dimensional adult male head and skull contours.

    Science.gov (United States)

    Lee, Calvin; Loyd, Andre M; Nightingale, Roger; Myers, Barry S; Damon, Andrew; Bass, Cameron R

    2014-01-01

    Traumatic brain injury (TBI) is a major public health issue, affecting millions of people annually. Anthropomorphic test devices (ATDs) and finite element models (FEMs) provide a means of understanding factors leading to TBI, potentially reducing the occurrence. Thus, there is a need to ensure that these tools accurately model humans. For example, the Hybrid III was not based on 3-dimensional human head shape data. The objective of this study is to produce average head and skull contours for an average U.S. male that can be used for ATDs and FEMs. Computed tomography (CT) scans of adult male heads were obtained from a database provided by the University of Virginia Center for Applied Biomechanics. An orthographic viewer was used to extract head and skull contours from the CT scans. Landmarks were measured graphically using HyperMesh (Altair, HyperWorks). To determine the head occipital condyle (OC) centroid, surface meshes of the OCs were made and the centroid of the surfaces was calculated. The Hybrid III contour was obtained using a MicroScribe Digitizer (Solution Technologies, Inc., Oella, MD). Comparisons of the average male and ATD contours were performed using 2 methods: (1) the midsagittal and midcoronal ATD contours relative to the OC centroid were compared to the corresponding 1 SD range of the average male contours; (2) the ATD sagittal contour was translated relative to the average male sagittal contour to minimize the area between the 2 contours. Average male head and skull contours were created. Landmark measurements were made for the dorsum sellae, nasion skin, nasion bone, infraorbital foramen, and external auditory meatus, all relative to the OC centroid. The Hybrid III midsagittal contour was outside the 1 SD range for 15.2 percent of the average male head contour but only by a maximum distance of 1.5 mm, whereas the Hybrid III midcoronal head contour was outside the 1 SD range for 12.2 percent of the average male head contour by a maximum distance

  17. Automated Contour Detection for Intravascular Ultrasound Image Sequences Based on Fast Active Contour Algorithm

    Institute of Scientific and Technical Information of China (English)

    DONG Hai-yan; WANG Hui-nan

    2006-01-01

    Intravascular ultrasound can provide high-resolution real-time crosssectional images about lumen, plaque and tissue. Traditionally, the luminal border and medial-adventitial border are traced manually. This process is extremely timeconsuming and the subjective difference would be large. In this paper, a new automated contour detection method is introduced based on fast active contour model.Experimental results found that lumen and vessel area measurements after automated detection showed good agreement with manual tracings with high correlation coefficients (0.94 and 0.95, respectively) and small system difference ( -0.32 and 0.56, respectively). So it can be a reliable and accurate diagnostic tool.

  18. Minimally invasive measurement of cardiac output during surgery and critical care: a meta-analysis of accuracy and precision.

    Science.gov (United States)

    Peyton, Philip J; Chong, Simon W

    2010-11-01

    When assessing the accuracy and precision of a new technique for cardiac output measurement, the commonly quoted criterion for acceptability of agreement with a reference standard is that the percentage error (95% limits of agreement/mean cardiac output) should be 30% or less. We reviewed published data on four different minimally invasive methods adapted for use during surgery and critical care: pulse contour techniques, esophageal Doppler, partial carbon dioxide rebreathing, and transthoracic bioimpedance, to assess their bias, precision, and percentage error in agreement with thermodilution. An English language literature search identified published papers since 2000 which examined the agreement in adult patients between bolus thermodilution and each method. For each method a meta-analysis was done using studies in which the first measurement point for each patient could be identified, to obtain a pooled mean bias, precision, and percentage error weighted according to the number of measurements in each study. Forty-seven studies were identified as suitable for inclusion: N studies, n measurements: mean weighted bias [precision, percentage error] were: pulse contour N = 24, n = 714: -0.00 l/min [1.22 l/min, 41.3%]; esophageal Doppler N = 2, n = 57: -0.77 l/min [1.07 l/min, 42.1%]; partial carbon dioxide rebreathing N = 8, n = 167: -0.05 l/min [1.12 l/min, 44.5%]; transthoracic bioimpedance N = 13, n = 435: -0.10 l/min [1.14 l/min, 42.9%]. None of the four methods has achieved agreement with bolus thermodilution which meets the expected 30% limits. The relevance in clinical practice of these arbitrary limits should be reassessed.

  19. Hybrid antenna synthesis for reconfigurable contoured beams

    Science.gov (United States)

    Searle, A. D.; Westcott, B. S.

    1993-08-01

    A reflector illuminated by a small phased array is an attractive antenna configuration for systems requiring reconfigurable contoured beams. The use of a shaped reflector can provide control of the feed power distribution and antenna geometry. A systematic reflector synthesis technique based on geometric optics is formulated, using complex coordinate notation and illustrated by application to a simple design requirement. Results demonstrate that geometric shaping can be successfully applied to systems with distributed sources, and that significant beam reconfiguration can be achieved by phase-only control of the feed array.

  20. Cardiac Sarcoidosis.

    Science.gov (United States)

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  1. Validation of the pulse decomposition analysis algorithm using central arterial blood pressure.

    Science.gov (United States)

    Baruch, Martin C; Kalantari, Kambiz; Gerdt, David W; Adkins, Charles M

    2014-07-08

    There is a significant need for continuous noninvasive blood pressure (cNIBP) monitoring, especially for anesthetized surgery and ICU recovery. cNIBP systems could lower costs and expand the use of continuous blood pressure monitoring, lowering risk and improving outcomes.The test system examined here is the CareTaker® and a pulse contour analysis algorithm, Pulse Decomposition Analysis (PDA). PDA's premise is that the peripheral arterial pressure pulse is a superposition of five individual component pressure pulses that are due to the left ventricular ejection and reflections and re-reflections from only two reflection sites within the central arteries.The hypothesis examined here is that the model's principal parameters P2P1 and T13 can be correlated with, respectively, systolic and pulse pressures. Central arterial blood pressures of patients (38 m/25 f, mean age: 62.7 y, SD: 11.5 y, mean height: 172.3 cm, SD: 9.7 cm, mean weight: 86.8 kg, SD: 20.1 kg) undergoing cardiac catheterization were monitored using central line catheters while the PDA parameters were extracted from the arterial pulse signal obtained non-invasively using CareTaker system. Qualitative validation of the model was achieved with the direct observation of the five component pressure pulses in the central arteries using central line catheters. Statistically significant correlations between P2P1 and systole and T13 and pulse pressure were established (systole: R square: 0.92 (p pressures obtained through the conversion of PDA parameters to blood pressures of non-invasively obtained pulse signatures with catheter-obtained blood pressures fell within the trend guidelines of the Association for the Advancement of Medical Instrumentation SP-10 standard (standard deviation: 8 mmHg(systole: 5.87 mmHg, diastole: 5.69 mmHg)). The results indicate that arterial blood pressure can be accurately measured and tracked noninvasively and continuously using the CareTaker system and the PDA algorithm. The

  2. Alar Contour Grafts in Rhinoplasty: A Safe and Reproducible Way to Refine Alar Contour Aesthetics.

    Science.gov (United States)

    Unger, Jacob G; Roostaeian, Jason; Small, Kevin H; Pezeshk, Ronnie A; Lee, Michael R; Harris, Ryan; Rohrich, Rod J

    2016-01-01

    Alar rim deformities such as retraction, notching, collapse, and asymmetry are common problems in rhinoplasty patients. Although alar rim deformities may be improved through rhinoplasty, this area is prone to late changes because of scarring of the soft triangles and a paucity of native structural support. The purpose of this study was to analyze the effect of alar contour grafts on primary rhinoplasty. Fifty consecutive primary rhinoplasty patients with preoperative and postoperative photographs who received alar contour grafts were evaluated for alar aesthetics; 50 consecutive primary rhinoplasty patients without such grafts served as controls. Differences among alar retraction, notching, collapse, and asymmetry from anterior, lateral, and basal views were evaluated. Follow-up ranged from 1 to 4 years and was graded on a four-point scale. The average difference between the two groups' aggregate preoperative scores was 0.21 (p = 0.24). The average preoperative and postoperative scores in the nongraft group were significant for worsening retraction, notching, and collapse but insignificant for asymmetry. The preoperative and postoperative scores for the graft group were insignificant for retraction but improved significantly for notching, collapse, and asymmetry. Postoperatively, the aggregate average of the scores in the nongroup was 0.32 points worse (p Alar contour grafts have a clear and important impact on cosmetic results of primary rhinoplasty. Use of alar contour grafts has been shown to improve aesthetics, whereas there is a worsening of the measured parameters postoperatively without use of these grafts. Therapeutic, III.

  3. What is in a contour map? A region-based logical formalization of contour semantics

    Science.gov (United States)

    Usery, E. Lynn; Hahmann, Torsten

    2015-01-01

    Contours maps (such as topographic maps) compress the information of a function over a two-dimensional area into a discrete set of closed lines that connect points of equal value (isolines), striking a fine balance between expressiveness and cognitive simplicity. They allow humans to perform many common sense reasoning tasks about the underlying function (e.g. elevation).

  4. Automatic Detection of Adenocarcinoma using Active Contours

    Directory of Open Access Journals (Sweden)

    NeelapalaAnilKumar

    2013-09-01

    Full Text Available CT scan is the one of the image representation for abdomen, where the tumour to be located and specified effectively with clarity, by the medical expert. This role can be hold by using one of the image processing techniques called segmentation. Image segmentation is the technique which isolates the image into different regions to simplify the image and identify the Tumour easily. Image segmentation has been extensively studied by various approaches. This work, focus on the one of the image segmentation technique with a new regularization term that yields an unsupervised segmentation model which identifies different Tumour locations in a given CT image. Active contours form a boundary around a particular part of the image based on an energy function. The energy function may include intensity values of pixels or gradient values. Chen-Vase method of active contour algorithm is adopted for image segmentation. The segmentation is done after properly masking of CT scan image. The cancer prone area is generalized prior to the masking of the image. Effected abdomen cancer can be identified for better analysis of medical experts using image processing MATLAB tools. This paper describes a new method to detect and extract the features in CT scan images, which shows good performance in detection of difficult features. And the developed technique makes use of major image processing methods and fundamentals to detect the cancer with minimum possible human interaction.

  5. Wound Image Analysis Using Contour Evolution

    Directory of Open Access Journals (Sweden)

    K. Sundeep Kumar

    2014-05-01

    Full Text Available The aim of the algorithm described in this paper is to segment wound images from the normal and classify them according to the types of the wound. The segmentation of wounds extravagates color representation, which has been followed by an algorithm of grayscale segmentation based on the stack mathematical approach. Accurate classification of wounds and analyzing wound healing process is a critical task for patient care and health cost reduction at hospital. The tissue uniformity and flatness leads to a simplified approach but requires multispectral imaging for enhanced wound delineation. Contour Evolution method which uses multispectral imaging replaces more complex tools such as, SVM supervised classification, as no training step is required. In Contour Evolution, classification can be done by clustering color information, with differential quantization algorithm, the color centroids of small squares taken from segmented part of the wound image in (C1,C2 plane. Where C1, C2 are two chrominance components. Wound healing is identified by measuring the size of the wound through various means like contact and noncontact methods of wound. The wound tissues proportion is also estimated by a qualitative visual assessment based on the red-yellow-black code. Moreover, involving all the spectral response of the tissue and not only RGB components provides a higher discrimination for separating healed epithelial tissue from granulation tissue.

  6. Study fidelity spatial contours of industrial robots

    Directory of Open Access Journals (Sweden)

    A. V. Ivanova

    2014-01-01

    Full Text Available The purpose of this paper to identify deviations fidelity spatial contours of industrial robots, determine the error pattern detected, and define the ways to solve the problem.The paper presents the research results of fidelity spatial contours done by Fanuc M- 710iC/50 industrial robot when moving along a predetermined path. The proposed method uses a QC20-W ballbar wireless system of Renishaw company, designed to diagnose the state of the measurement and playback linear and angular displacements of the CNC.The solutions to adapt the QC20-W ballbar system to the constructive peculiarities of industrial robots with five or more independently controlled axes are given. The stages of the preparation of diagnostic systems and software robot movements are described.According to study results of errors that arise while playing back the programmed motions of a fixed point of robot capture in three mutually perpendicular planes its practical accuracy has been defined when performing movements in a given region of the working area, thereby allowing us, eventually, to draw a conclusion on the possibility to use a robot in one technological process or another.The study has resulted in emerging the guidelines for the operation of industrial robots with five or more independently controlled axes. Using these guidelines enables us to increase the playback accuracy of the industrial robot to 0.01 mm.

  7. Evaluation of dose to cardiac structures during breast irradiation

    DEFF Research Database (Denmark)

    Aznar, M C; Korreman, S-S; Pedersen, A N

    2011-01-01

    OBJECTIVE: Adjuvant radiotherapy for breast cancer can lead to late cardiac complications. The highest radiation doses are likely to be to the anterior portion of the heart, including the left anterior descending coronary artery (LAD). The purpose of this work was to assess the radiation doses...... and the whole LAD were contoured. The radiation doses to all three cardiac structures were evaluated. RESULTS: For 13 patients, the plans were acceptable based on the criteria set for all 3 contours. For seven patients, the volume of heart irradiated was well below the set clinical threshold whereas a high dose...... was still being delivered to the LAD. In 1 case, the dose to the LAD was low while 19% of the contoured heart volume received over 20 Gy. In five patients, the dose to the arch LAD was relatively low while the dose to the whole LAD was considerably higher. CONCLUSION: This study indicates...

  8. Cardiac Malpositions

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Shi Joon; Im, Chung Gie; Yeon, Kyung Mo; Hasn, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    Cardiac Malposition refers to any position of the heart other than a left-sided heart in a situs solitus individual. Associated cardiac malformations are so complex that even angiocardiographic and autopsy studies may not afford an accurate information. Although the terms and classifications used to describe the internal cardiac anatomy and their arterial connections in cardiac malpositions differ and tend to be confusing, common agreement exists on the need for a segmental approach to diagnosis. Authors present 18 cases of cardiac malpositions in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between 1971 and 1979. Authors analyzed the clinical, radiographic, operative and autopsy findings with the emphasis on the angiocardiographic findings. The results are as follows: 1. Among 18 cases with cardiac malpositions, 6 cases had dextrocardia with situs inversus, 9 cases had dextrocardia with situs solitus and 3 cases had levocardia with situs inversus. 2. There was no genuine exception to visceroatrial concordance rule. 3. Associated cardiac malpositions were variable and complex with a tendency of high association of transposition and double outlet varieties with dextrocardia in situs solitus and levocardia in situs inversus. Only one in 6 cases of dextrocardia with situs inversus had pure transposition. 4. In two cases associated pulmonary atresia was found at surgery which was not predicted by angiocardiography. 5. Because many of the associated complex lesions can be corrected surgically provided the diagnosis is accurate, the selective biplane angiocardiography with or without cineradiography is essential.

  9. Haemodynamics and cardiac function during robotic-assisted laparoscopic prostatectomy in steep Trendelenburg position.

    Science.gov (United States)

    Haas, Sebastian; Haese, Alexander; Goetz, Alwin E; Kubitz, Jens C

    2011-12-01

    Robotic-assisted laparoscopic prostatectomy (RALP) is usually performed in steep Trendelenburg position, which can be associated with cardiac impairment due to positioning and capnoperitoneum. This study investigated haemodynamic consequences and cardiac function in this type of surgery and evaluated the hypothesis that steep Trendelenburg position and capnoperitoneum results in haemodynamic and ventricular impairment. 10 patients (ASA I-III) scheduled for RALP in steep Trendelenburg position with capnoperitoneum were prospectively studied. Heart rate (HR), mean arterial pressure (MAP) and central venous pressure (CVP) were recorded. Stroke volume variation (SVV) and cardiac output (CO) were measured using pulse-contour analysis. Further, cardiac function was assessed using trans-oesophageal echocardiography before positioning (T1) and 10 min (T2) and 60 min (T3) after implementation of steep Trendelenburg position and capnoperitoneum. HR did not change statistically. MAP (T1, 69.7 ± 1.55; T2, 82.9 ± 3.05; T3, 79.4 ± 2.18 mmHg), CVP (T1, 7.7 ± 1.3; T2, 17.3 ± 2.01; T3, 16.9 ± 1.66 mmHg) and CO (T1, 4.0 ± 0.15; T2, 4.9 ± 0.26; T3, 4.9 ± 0.36 l/min) increased significantly at T2 and T3. Echocardiography showed no deterioration of left or right ventricular function. In one patient with pre-existing mitral valve insufficiency (I°) an aggravation of the insufficiency (III°) was observed. No other valve dysfunctions were observed. The steep Trendelenburg position may improve haemodynamic function and does not deteriorate left or right ventricular function during RALP. However, mitral valve insufficiency may be aggravated by positioning and capnoperitoneum. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Predictive Modeling of Complex Contoured Composite Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The existing HDWLT (pictured) contoured composite structure design, its analyses and manufacturing tools, will be used to validate key analyses inputs through...

  11. A new algorithm of brain volume contours segmentation

    Institute of Scientific and Technical Information of China (English)

    吴建明; 施鹏飞

    2003-01-01

    This paper explores brain CT slices segmentation technique and some related problems, including contours segmentation algorithms, edge detector, algorithm evaluation and experimental results. This article describes a method for contour-based segmentation of anatomical structures in 3D medical data sets. With this method, the user manually traces one or more 2D contours of an anatomical structure of interest on parallel planes arbitrarily cutting the data set. The experimental results showes the segmentation based on 3D brain volume and 2D CT slices. The main creative contributions in this paper are: (1) contours segmentation algorithm; (2) edge detector; (3) algorithm evaluation.

  12. Probabilistic contour extraction based on shape prior model

    Institute of Scientific and Technical Information of China (English)

    FAN Xin; LIANG De-qun

    2005-01-01

    Statistical shape prior model is employed to construct the dynamics in probabilistic contour estimation.By applying principal component analysis,plausible shape samples are efficiently generated to predict contour samples.Based on the shape-dependent dynamics and probabilistic image model,a particle filter is used to estimate the contour with a specific shape.Compared with the deterministic approach with shape information,the proposed method is simple yet more effective in extracting contours from images with shape variations and occlusion.

  13. Effects of Spatial Frequency Similarity and Dissimilarity on Contour Integration.

    Directory of Open Access Journals (Sweden)

    Malte Persike

    Full Text Available We examined the effects of spatial frequency similarity and dissimilarity on human contour integration under various conditions of uncertainty. Participants performed a temporal 2AFC contour detection task. Spatial frequency jitter up to 3.0 octaves was applied either to background elements, or to contour and background elements, or to none of both. Results converge on four major findings. (1 Contours defined by spatial frequency similarity alone are only scarcely visible, suggesting the absence of specialized cortical routines for shape detection based on spatial frequency similarity. (2 When orientation collinearity and spatial frequency similarity are combined along a contour, performance amplifies far beyond probability summation when compared to the fully heterogenous condition but only to a margin compatible with probability summation when compared to the fully homogenous case. (3 Psychometric functions are steeper but not shifted for homogenous contours in heterogenous backgrounds indicating an advantageous signal-to-noise ratio. The additional similarity cue therefore not so much improves contour detection performance but primarily reduces observer uncertainty about whether a potential candidate is a contour or just a false positive. (4 Contour integration is a broadband mechanism which is only moderately impaired by spatial frequency dissimilarity.

  14. India-Pakistan: Contours of Relationship

    Directory of Open Access Journals (Sweden)

    Devika Mittal

    2016-06-01

    Full Text Available Even after about 70 years of separation, India and Pakistan continue to live in the prison of the past. The rhetoric of partition is still alive in the memory of the people of both the countries. They have constructed fixed, unchanging and competing images for each other. While Pakistan became an Islamic Republic, India adopted secularism, thereby, negating the two-nation theory. The ‘differences’ along with memories of partition has made Indian and Pakistani to remain in permanent hostile situation. The leaders of the two countries try to settle their disputes but fails because of lack of support from their social and political institutions. Since its coming into power in 2014, the NDA government under the Indian Prime Minister, Mr. Narendra Modi has managed to engage the Pakistani establishment, despite many problems between the two countries. This article tries to highlight upon the contours of relationships post-2014.

  15. Automatic Contour Extraction from 2D Image

    Directory of Open Access Journals (Sweden)

    Panagiotis GIOANNIS

    2011-03-01

    Full Text Available Aim: To develop a method for automatic contour extraction from a 2D image. Material and Method: The method is divided in two basic parts where the user initially chooses the starting point and the threshold. Finally the method is applied to computed tomography of bone images. Results: An interesting method is developed which can lead to a successful boundary extraction of 2D images. Specifically data extracted from a computed tomography images can be used for 2D bone reconstruction. Conclusions: We believe that such an algorithm or part of it can be applied on several other applications for shape feature extraction in medical image analysis and generally at computer graphics.

  16. CMOS image sensor with contour enhancement

    Science.gov (United States)

    Meng, Liya; Lai, Xiaofeng; Chen, Kun; Yuan, Xianghui

    2010-10-01

    Imitating the signal acquisition and processing of vertebrate retina, a CMOS image sensor with bionic pre-processing circuit is designed. Integration of signal-process circuit on-chip can reduce the requirement of bandwidth and precision of the subsequent interface circuit, and simplify the design of the computer-vision system. This signal pre-processing circuit consists of adaptive photoreceptor, spatial filtering resistive network and Op-Amp calculation circuit. The adaptive photoreceptor unit with a dynamic range of approximately 100 dB has a good self-adaptability for the transient changes in light intensity instead of intensity level itself. Spatial low-pass filtering resistive network used to mimic the function of horizontal cell, is composed of the horizontal resistor (HRES) circuit and OTA (Operational Transconductance Amplifier) circuit. HRES circuit, imitating dendrite of the neuron cell, comprises of two series MOS transistors operated in weak inversion region. Appending two diode-connected n-channel transistors to a simple transconductance amplifier forms the OTA Op-Amp circuit, which provides stable bias voltage for the gate of MOS transistors in HRES circuit, while serves as an OTA voltage follower to provide input voltage for the network nodes. The Op-Amp calculation circuit with a simple two-stage Op-Amp achieves the image contour enhancing. By adjusting the bias voltage of the resistive network, the smoothing effect can be tuned to change the effect of image's contour enhancement. Simulations of cell circuit and 16×16 2D circuit array are implemented using CSMC 0.5μm DPTM CMOS process.

  17. Automatic brain cropping enhancement using active contours initialized by a PCNN

    Science.gov (United States)

    Swathanthira Kumar, Murali Murugavel; Sullivan, John M., Jr.

    2009-02-01

    Active contours are a popular medical image segmentation strategy. However in practice, its accuracy is dependent on the initialization of the process. The PCNN (Pulse Coupled Neural Network) algorithm developed by Eckhorn to model the observed synchronization of neural assemblies in small mammals such as cats allows for segmenting regions of similar intensity but it lacks a convergence criterion. In this paper we report a novel PCNN based strategy to initialize the zero level contour for automatic brain cropping of T2 weighted MRI image volumes of Long-Evans rats. Individual 2D anatomy slices of the rat brain volume were processed by means of a PCNN and a surrogate image 'signature' was constructed for each slice. By employing a previously trained artificial neural network (ANN) an approximate PCNN iteration (binary mask) was selected. This mask was then used to initialize a region based active contour model to crop the brain region. We tested this hybrid algorithm on 30 rat brain (256*256*12) volumes and compared the results against manually cropped gold standard. The Dice and Jaccard similarity indices were used for numerical evaluation of the proposed hybrid model. The highly successful system yielded an average of 0.97 and 0.94 respectively.

  18. 32 CFR 707.5 - Underway replenishment contour lights.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Underway replenishment contour lights. 707.5... RULES WITH RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.5 Underway replenishment contour lights... underway replenishment operations, either red or blue lights at delivery-ship-deck-edge extremities....

  19. A bit-level systolic array for digital contour smoothing

    NARCIS (Netherlands)

    Petkov, Nikolai; Sloboda, Fridrich

    1989-01-01

    Linear operators for digital contour smoothing are described. These operators are defined by circulant Toeplitz matrices and allow to smooth digital contours in the least-squares sense. They minimize the undersampling, digitizing and quantizing error and allow to calculate invariants, such as curvat

  20. Compressing industrial computed tomography images by means of contour coding

    Science.gov (United States)

    Jiang, Haina; Zeng, Li

    2013-10-01

    An improved method for compressing industrial computed tomography (CT) images is presented. To have higher resolution and precision, the amount of industrial CT data has become larger and larger. Considering that industrial CT images are approximately piece-wise constant, we develop a compression method based on contour coding. The traditional contour-based method for compressing gray images usually needs two steps. The first is contour extraction and then compression, which is negative for compression efficiency. So we merge the Freeman encoding idea into an improved method for two-dimensional contours extraction (2-D-IMCE) to improve the compression efficiency. By exploiting the continuity and logical linking, preliminary contour codes are directly obtained simultaneously with the contour extraction. By that, the two steps of the traditional contour-based compression method are simplified into only one. Finally, Huffman coding is employed to further losslessly compress preliminary contour codes. Experimental results show that this method can obtain a good compression ratio as well as keeping satisfactory quality of compressed images.

  1. Influence of Endwall Contouring on the Secondary Flow in Turbine Nozzle Guide Vane

    Institute of Scientific and Technical Information of China (English)

    SUN Da-wei; QIAO Wei-yang; XU Kai-fu

    2009-01-01

    Numerical simulations are carried out to investigate the effect of the endwall contouring on the secondary flow in turbine nozzle guide vane. The three contoured cascades with the same contouring profile and the different positions where the contoured profile locates at are researched. The results show that the contouring configuration can reduce the aerodynamic losses of the cascade. The flat side takes advantage of a stronger decrease of the losses, compared to the contoured side. The contouring configuration can also inhibit the secondary flow. The contoured cascade in which the contouring profile starts upstream of the airfoil, ends at the middle of the airfoil has the best effect of improving secondary flow.

  2. Contour polygonal approximation using shortest path in networks

    CERN Document Server

    Backes, André Ricardo; Bruno, Odemir Martinez

    2013-01-01

    Contour polygonal approximation is a simplified representation of a contour by line segments, so that the main characteristics of the contour remain in a small number of line segments. This paper presents a novel method for polygonal approximation based on the Complex Networks theory. We convert each point of the contour into a vertex, so that we model a regular network. Then we transform this network into a Small-World Complex Network by applying some transformations over its edges. By analyzing of network properties, especially the geodesic path, we compute the polygonal approximation. The paper presents the main characteristics of the method, as well as its functionality. We evaluate the proposed method using benchmark contours, and compare its results with other polygonal approximation methods.

  3. Tensor-SIFT based Earth Mover's Distance for Contour Tracking

    CERN Document Server

    Li, Peihua

    2010-01-01

    Contour tracking in adverse environments is a challenging problem due to cluttered background, illumination variation, occlusion, and noise, among others. This paper presents a robust contour tracking method by contributing to some of the key issues involved, including (a) a region functional formulation and its optimization; (b) design of a robust and effective feature; and (c) development of an integrated tracking algorithm. First, we formulate a region functional based on robust Earth Mover's distance (EMD) with kernel density for distribution modeling, and propose a two-phase method for its optimization. In the first phase, letting the candidate contour be fixed, we express EMD as the transportation problem and solve it by the simplex algorithm. Next, using the theory of shape derivative, we make a perturbation analysis of the contour around the best solution to the transportation problem. This leads to a partial differential equation (PDE) that governs the contour evolution. Second, we design a novel and...

  4. Contour-Based Surface Reconstruction using MPU Implicit Models.

    Science.gov (United States)

    Braude, Ilya; Marker, Jeffrey; Museth, Ken; Nissanov, Jonathan; Breen, David

    2007-03-01

    This paper presents a technique for creating a smooth, closed surface from a set of 2D contours, which have been extracted from a 3D scan. The technique interprets the pixels that make up the contours as points in ℝ(3) and employs Multi-level Partition of Unity (MPU) implicit models to create a surface that approximately fits to the 3D points. Since MPU implicit models additionally require surface normal information at each point, an algorithm that estimates normals from the contour data is also described. Contour data frequently contains noise from the scanning and delineation process. MPU implicit models provide a superior approach to the problem of contour-based surface reconstruction, especially in the presence of noise, because they are based on adaptive implicit functions that locally approximate the points within a controllable error bound. We demonstrate the effectiveness of our technique with a number of example datasets, providing images and error statistics generated from our results.

  5. Contour integration and segmentation with a new lateral connections model

    Science.gov (United States)

    Cai, Chao

    2011-11-01

    Automatically target contour detection from cluttered scenes is a very difficult task for computer vision. Humans, however, have a much better background suppress ability. The preceding models could not implement such a task very well. In this letter, an effective contour integration method based on human visual perception mechanism is proposed. The algorithm combines the properties of primary visual cortex and psychology researching results to simulate the contour perception of the V1 cortex. The new lateral connection based computational model have a better texture suppress ability, while, target's contour is enhanced. Compared with traditional methods, experiments show that the new method implement a more reasonable simulation of the V1 function structure, availably enhance the target's contour while suppress the cluttered background, obtain a balance between over and lose detection, besides, it has better accuracy with less computational complexity and time-consuming.

  6. Cardiac cameras.

    Science.gov (United States)

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  7. Directed random polymers via nested contour integrals

    Science.gov (United States)

    Borodin, Alexei; Bufetov, Alexey; Corwin, Ivan

    2016-05-01

    We study the partition function of two versions of the continuum directed polymer in 1 + 1 dimension. In the full-space version, the polymer starts at the origin and is free to move transversally in R, and in the half-space version, the polymer starts at the origin but is reflected at the origin and stays in R-. The partition functions solve the stochastic heat equation in full-space or half-space with mixed boundary condition at the origin; or equivalently the free energy satisfies the Kardar-Parisi-Zhang equation. We derive exact formulas for the Laplace transforms of the partition functions. In the full-space this is expressed as a Fredholm determinant while in the half-space this is expressed as a Fredholm Pfaffian. Taking long-time asymptotics we show that the limiting free energy fluctuations scale with exponent 1 / 3 and are given by the GUE and GSE Tracy-Widom distributions. These formulas come from summing divergent moment generating functions, hence are not mathematically justified. The primary purpose of this work is to present a mathematical perspective on the polymer replica method which is used to derive these results. In contrast to other replica method work, we do not appeal directly to the Bethe ansatz for the Lieb-Liniger model but rather utilize nested contour integral formulas for moments as well as their residue expansions.

  8. Refined contour analysis of giant unilamellar vesicles

    Science.gov (United States)

    Pécréaux, J.; Döbereiner, H.-G.; Prost, J.; Joanny, J.-F.; Bassereau, P.

    2004-03-01

    The fluctuation spectrum of giant unilamellar vesicles is measured using a high-resolution contour detection technique. An analysis at higher q vectors than previously achievable is now possible due to technical improvements of the experimental setup and of the detection algorithm. The global fluctuation spectrum is directly fitted to deduce the membrane tension and the bending modulus of lipid membranes. Moreover, we show that the planar analysis of fluctuations is valid for spherical objects, even at low wave vectors. Corrections due to the integration time of the video camera and to the section of a 3D object by the observation plane are introduced. A precise calculation of the error bars has been done in order to provide reliable error estimate. Eventually, using this technique, we have measured bending moduli for EPC, SOPC and \\chem{SOPC:CHOL} membranes confirming previously published values. An interesting application of this technique can be the measurement of the fluctuation spectra for non-equilibrium membranes, such as “active membranes”.

  9. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  10. Hybrid Parallel Contour Trees, Version 1.0

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-03

    A common operation in scientific visualization is to compute and render a contour of a data set. Given a function of the form f : R^d -> R, a level set is defined as an inverse image f^-1(h) for an isovalue h, and a contour is a single connected component of a level set. The Reeb graph can then be defined to be the result of contracting each contour to a single point, and is well defined for Euclidean spaces or for general manifolds. For simple domains, the graph is guaranteed to be a tree, and is called the contour tree. Analysis can then be performed on the contour tree in order to identify isovalues of particular interest, based on various metrics, and render the corresponding contours, without having to know such isovalues a priori. This code is intended to be the first data-parallel algorithm for computing contour trees. Our implementation will use the portable data-parallel primitives provided by Nvidia’s Thrust library, allowing us to compile our same code for both GPUs and multi-core CPUs. Native OpenMP and purely serial versions of the code will likely also be included. It will also be extended to provide a hybrid data-parallel / distributed algorithm, allowing scaling beyond a single GPU or CPU.

  11. The prevalence of body contouring surgery after gastric bypass surgery.

    Science.gov (United States)

    Kitzinger, Hugo B; Abayev, Sara; Pittermann, Anna; Karle, Birgit; Kubiena, Harald; Bohdjalian, Arthur; Langer, Felix B; Prager, Gerhard; Frey, Manfred

    2012-01-01

    As bariatric surgery has become more popular, more patients are undergoing body contouring surgery after massive weight loss. Many of the surgical procedures performed on the massive weight loss patient are complex and labor-intensive. Therefore, the plastic surgery unit needs to be prepared for a patient's demand. Little literature is available on how frequently patients who have undergone gastric bypass surgery receive body contouring surgery. Two hundred fifty-two subjects (out of 425 who were mailed the questionnaire) who had undergone gastric bypass surgery between 2003 and 2009 completed the questionnaire, which obtained information on body image satisfaction and frequency of body contouring surgery after massive weight loss. Of all patients, 74% desire a body contouring surgery after gastric bypass surgery. Fifty-three patients (21%) have undergone a total of 61 body contouring procedures. The most common were abdominoplasties (59%), followed by lower body lifts (20%). In contrast to a positive judgment of the general aspect of the body image satisfaction after massive weight loss, both genders are unsatisfied with body areas like abdomen/waist, breast, and thighs. Paralleling the increasing use of bariatric surgery, there is a high demand for body contouring surgery. A huge disparity exists between the number of subjects who desire a body contouring surgery and those who actually received it.

  12. GPU based contouring method on grid DEM data

    Science.gov (United States)

    Tan, Liheng; Wan, Gang; Li, Feng; Chen, Xiaohui; Du, Wenlong

    2017-08-01

    This paper presents a novel method to generate contour lines from grid DEM data based on the programmable GPU pipeline. The previous contouring approaches often use CPU to construct a finite element mesh from the raw DEM data, and then extract contour segments from the elements. They also need a tracing or sorting strategy to generate the final continuous contours. These approaches can be heavily CPU-costing and time-consuming. Meanwhile the generated contours would be unsmooth if the raw data is sparsely distributed. Unlike the CPU approaches, we employ the GPU's vertex shader to generate a triangular mesh with arbitrary user-defined density, in which the height of each vertex is calculated through a third-order Cardinal spline function. Then in the same frame, segments are extracted from the triangles by the geometry shader, and translated to the CPU-side with an internal order in the GPU's transform feedback stage. Finally we propose a ;Grid Sorting; algorithm to achieve the continuous contour lines by travelling the segments only once. Our method makes use of multiple stages of GPU pipeline for computation, which can generate smooth contour lines, and is significantly faster than the previous CPU approaches. The algorithm can be easily implemented with OpenGL 3.3 API or higher on consumer-level PCs.

  13. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  14. Adaptive Contour Model for Real-Time Foreground Detection

    Institute of Scientific and Technical Information of China (English)

    HUANG Ying; DING Xiaoqing

    2005-01-01

    A multiscale foreground detection method was developed to segment moving objects from a stationary background. The algorithm is based on a fixed-mesh-based contour model, which starts at the bounding box of the difference map between an input image and its background and ends at a final contour. An adaptive algorithm was developed to calculate an appropriate energy threshold to control the contours to identify the foreground silhouettes. Experiments show that this method more successfully ignores the negative influence of image noise to obtain an accurate foreground map than other foreground detection algorithms. Most shadow pixels are also eliminated by this method.

  15. Details of Side Load Test Data and Analysis for a Truncated Ideal Contour Nozzle and a Parabolic Contour Nozzle

    Science.gov (United States)

    Ruf, Joseph H.; McDaniels, David M.; Brown, Andrew M.

    2010-01-01

    Two cold flow subscale nozzles were tested for side load characteristics during simulated nozzle start transients. The two test article contours were a truncated ideal and a parabolic. The current paper is an extension of a 2009 AIAA JPC paper on the test results for the same two nozzle test articles. The side load moments were measured with the strain tube approach in MSFC s Nozzle Test Facility. The processing techniques implemented to convert the strain gage signals into side load moment data are explained. Nozzle wall pressure profiles for separated nozzle flow at many NPRs are presented and discussed in detail. The effect of the test cell diffuser inlet on the parabolic nozzle s wall pressure profiles for separated flow is shown. The maximum measured side load moments for the two contours are compared. The truncated ideal contour s peak side load moment was 45% of that of the parabolic contour. The calculated side load moments, via mean-plus-three-standard-deviations at each nozzle pressure ratio, reproduced the characteristics and absolute values of measured maximums for both contours. The effect of facility vibration on the measured side load moments is quantified and the effect on uncertainty is calculated. The nozzle contour designs are discussed and the impact of a minor fabrication flaw in the nozzle contours is explained.

  16. Estimation of cardiac output in patients with congestive heart failure by analysis of right ventricular pressure waveforms

    Directory of Open Access Journals (Sweden)

    Linde Cecilia

    2011-05-01

    Full Text Available Abstract Background Cardiac output (CO is an important determinant of the hemodynamic state in patients with congestive heart failure (CHF. We tested the hypothesis that CO can be estimated from the right ventricular (RV pressure waveform in CHF patients using a pulse contour cardiac output algorithm that considers constant but patient specific RV outflow tract characteristic impedance. Method In 12 patients with CHF, breath-by-breath Fick CO and RV pressure waveforms were recorded utilizing an implantable hemodynamic monitor during a bicycle exercise protocol. These data were analyzed retrospectively to assess changes in characteristic impedance of the RV outflow tract during exercise. Four patients that were implanted with an implantable cardiac defibrillator (ICD implementing the algorithm were studied prospectively. During a two staged sub-maximal bicycle exercise test conducted at 4 and 16 weeks of implant, COs measured by direct Fick technique and estimated by the ICD were recorded and compared. Results At rest the total pulmonary arterial resistance and the characteristic impedance were 675 ± 345 and 48 ± 18 dyn.s.cm-5, respectively. During sub-maximal exercise, the total pulmonary arterial resistance decreased (Δ 91 ± 159 dyn.s.cm-5, p -5, NS. The algorithm derived cardiac output estimates correlated with Fick CO (7.6 ± 2.5 L/min, R2 = 0.92 with a limit of agreement of 1.7 L/min and tracked changes in Fick CO (R2 = 0.73. Conclusions The analysis of right ventricular pressure waveforms continuously recorded by an implantable hemodynamic monitor provides an estimate of CO and may prove useful in guiding treatment in patients with CHF.

  17. Bathymetric Contours for Prairie Rose Lake, Shelby County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Prairie Rose Lake in Shelby Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of...

  18. Bathymetric Contours for Lake Minnewashta, Dickinson County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Lake Minnewashta in Dickinson Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of Lake...

  19. Bathymetric Contours for Littlefield Lake, Audubon County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Littlefield Lake in Audubon Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of...

  20. Bathymetric Contours for Nine Eagles Lake, Decatur County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Nine Eagles Lake in Decatur Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of Nine...

  1. Transgressive Contours--Salt Point to Drakes Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the transgressive contours for the Salt Point to Drakes Bay, California, region. The vector file is included in...

  2. Contours--Offshore of Salt Point Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Salt Point map area, California. The vector data file is...

  3. Transgressive Contours--Pigeon Point to South Monterey Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the transgressive contours for the Pigeon Point to South Monterey Bay, California, region. The vector file is included in...

  4. Contours--Offshore of Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Half Moon map area, California. The vector data file is...

  5. Shape reconstruction from apparent contours theory and algorithms

    CERN Document Server

    Bellettini, Giovanni; Paolini, Maurizio

    2015-01-01

    Motivated by a variational model concerning the depth of the objects in a picture and the problem of hidden and illusory contours, this book investigates one of the central problems of computer vision: the topological and algorithmic reconstruction of a smooth three dimensional scene starting from the visible part of an apparent contour. The authors focus their attention on the manipulation of apparent contours using a finite set of elementary moves, which correspond to diffeomorphic deformations of three dimensional scenes. A large part of the book is devoted to the algorithmic part, with implementations, experiments, and computed examples. The book is intended also as a user's guide to the software code appcontour, written for the manipulation of apparent contours and their invariants. This book is addressed to theoretical and applied scientists working in the field of mathematical models of image segmentation.

  6. MAP Estimation of Chin and Cheek Contours in Video Sequences

    Directory of Open Access Journals (Sweden)

    Kampmann Markus

    2004-01-01

    Full Text Available An algorithm for the estimation of chin and cheek contours in video sequences is proposed. This algorithm exploits a priori knowledge about shape and position of chin and cheek contours in images. Exploiting knowledge about the shape, a parametric 2D model representing chin and cheek contours is introduced. Exploiting knowledge about the position, a MAP estimator is developed taking into account the observed luminance gradient as well as a priori probabilities of chin and cheek contours positions. The proposed algorithm was tested with head and shoulder video sequences (image resolution CIF. In nearly 70% of all investigated video frames, a subjectively error free estimation could be achieved. The 2D estimate error is measured as on average between 2.4 and .

  7. Bathymetric Contours for Upper Gar Lake, Dickinson County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Upper Gar Lake in Dickinson Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of Upper...

  8. Bathymetric Contours for Lake Darling, Washington County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of digital bathymetry contours for Lake Darling in Washington Co., Iowa. The U.S. Geological Survey conducted a bathymetric survey of Lake...

  9. Contours Offshore of Point Reyes Map Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Point Reyes map area, California. The vector data file is...

  10. Transgressive Contours--Pigeon Point to South Monterey Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the transgressive contours for the Pigeon Point to South Monterey Bay, California, region. The vector file is included in...

  11. Using mathematical morphology to determine left ventricular contours

    Energy Technology Data Exchange (ETDEWEB)

    Pladellorens, J. (Universitat Politecnica de Catalunya (Spain). Dept. d' Optica i Optometria); Serrat, J. (Universitat Autonoma de Barcelona (Spain). Dept. d' Informatica); Castell, A. (Hospital de la Vall d' Hebro, Barcelona (Spain). Dept. de Medicina Nuclear); Yzuel, M.J. (Universitat Autonoma de Barcelona (Spain). Dept. de Fisica)

    1993-12-01

    Mathematical morphology is used for the determination of left ventricular contours in scintigraphic images using multigated radionuclide angiography. The authors developed a completely automatic method that first restores the image with a Wiener filter, then finds the region where the left ventricle is contained, and finally segments the left ventricle contour and a background zone. The contours depend on the values of the parameters that appear in the mathematical morphology method, which are related to the height and the slope of the count distribution. Results obtained with this method are compared with the contours and the background zones outlined by experts on the basis of the number of counts, and the authors study the values of the parameters with which optimum correlation is obtained. (author).

  12. A Combined Random Forests and Active Contour Model Approach for Fully Automatic Segmentation of the Left Atrium in Volumetric MRI

    Directory of Open Access Journals (Sweden)

    Chao Ma

    2017-01-01

    Full Text Available Segmentation of the left atrium (LA from cardiac magnetic resonance imaging (MRI datasets is of great importance for image guided atrial fibrillation ablation, LA fibrosis quantification, and cardiac biophysical modelling. However, automated LA segmentation from cardiac MRI is challenging due to limited image resolution, considerable variability in anatomical structures across subjects, and dynamic motion of the heart. In this work, we propose a combined random forests (RFs and active contour model (ACM approach for fully automatic segmentation of the LA from cardiac volumetric MRI. Specifically, we employ the RFs within an autocontext scheme to effectively integrate contextual and appearance information from multisource images together for LA shape inferring. The inferred shape is then incorporated into a volume-scalable ACM for further improving the segmentation accuracy. We validated the proposed method on the cardiac volumetric MRI datasets from the STACOM 2013 and HVSMR 2016 databases and showed that it outperforms other latest automated LA segmentation methods. Validation metrics, average Dice coefficient (DC and average surface-to-surface distance (S2S, were computed as 0.9227±0.0598 and 1.14±1.205 mm, versus those of 0.6222–0.878 and 1.34–8.72 mm, obtained by other methods, respectively.

  13. A Combined Random Forests and Active Contour Model Approach for Fully Automatic Segmentation of the Left Atrium in Volumetric MRI

    Science.gov (United States)

    Luo, Gongning

    2017-01-01

    Segmentation of the left atrium (LA) from cardiac magnetic resonance imaging (MRI) datasets is of great importance for image guided atrial fibrillation ablation, LA fibrosis quantification, and cardiac biophysical modelling. However, automated LA segmentation from cardiac MRI is challenging due to limited image resolution, considerable variability in anatomical structures across subjects, and dynamic motion of the heart. In this work, we propose a combined random forests (RFs) and active contour model (ACM) approach for fully automatic segmentation of the LA from cardiac volumetric MRI. Specifically, we employ the RFs within an autocontext scheme to effectively integrate contextual and appearance information from multisource images together for LA shape inferring. The inferred shape is then incorporated into a volume-scalable ACM for further improving the segmentation accuracy. We validated the proposed method on the cardiac volumetric MRI datasets from the STACOM 2013 and HVSMR 2016 databases and showed that it outperforms other latest automated LA segmentation methods. Validation metrics, average Dice coefficient (DC) and average surface-to-surface distance (S2S), were computed as 0.9227 ± 0.0598 and 1.14 ± 1.205 mm, versus those of 0.6222–0.878 and 1.34–8.72 mm, obtained by other methods, respectively. PMID:28316992

  14. Cardiac Rehabilitation

    Science.gov (United States)

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  15. A historical note on illusory contours in shadow writing.

    Science.gov (United States)

    Vezzani, Stefano; Marino, Barbara F M

    2009-01-01

    It is widely accepted that illusory contours have been first displayed and discussed by Schumann (1900, Zeitschrift für Psychologie und Physiologie der Sinnesorgane 23 1-32). Here we show that, before him, Jastrow (1899, Popular Science Monthly 54 299-312) produced illusory contours consisting of a shadow word. A brief history of shadow writing in psychological literature from Jastrow to Brunswik is presented, in which the contributions of Pillsbury, Warren, Koffka, and Benussi are examined.

  16. Contour Detection Using Cost-Sensitive Convolutional Neural Networks

    OpenAIRE

    Hwang, Jyh-Jing; Liu, Tyng-Luh

    2014-01-01

    We address the problem of contour detection via per-pixel classifications of edge point. To facilitate the process, the proposed approach leverages with DenseNet, an efficient implementation of multiscale convolutional neural networks (CNNs), to extract an informative feature vector for each pixel and uses an SVM classifier to accomplish contour detection. The main challenge lies in adapting a pre-trained per-image CNN model for yielding per-pixel image features. We propose to base on the Den...

  17. Upper Arm Contouring with Brachioplasty after Massive Weight Loss

    Directory of Open Access Journals (Sweden)

    Hyun Ho Han

    2014-05-01

    Full Text Available Background As the obese population increases in Korea, the number of patients who are trying to lose weight has been increasing steadily. In these patients, skin laxity and deformation of the body contour occurs, which could possibly be corrected by various body contouring surgeries. Here, we introduce the brachioplasty method and our experience of various body contouring surgeries performed in our center. Methods From November 2009 to August 2011, five cases of brachioplasty were performed. When the patient presented with sagging of the lateral inframammary crease and bat wing deformity in the axilla, extended brachioplasty was performed; in this case, the deformation of the axilla and lateral chest was corrected at the same time. A traditional brachioplasty was performed when contouring was needed only for skin laxity in the upper arm. Results Complications, such as hematomas or nerve injuries, were not evident. Some patients experienced partial wound dehiscence due to tension or hypertrophic scars found during the follow-up. In general, all of the patients were satisfied with the improvement in their upper arm contour. Conclusions Given the demands for body contouring surgery, the number of brachioplasty surgical procedures is expected to increase significantly, with abdominoplasty comprising a large portion of these surgeries. For the brachioplasty procedure, preparation and preoperative consultation regarding design of the surgery by experienced surgeons was important to prevent complications such as nerve damage or hematoma formation.

  18. The Development of Contour Processing: Evidence from Physiology and Psychophysics

    Directory of Open Access Journals (Sweden)

    Gemma eTaylor

    2014-07-01

    Full Text Available Object perception and pattern vision depend fundamentally upon the extraction of contours from the visual environment. In adulthood, contour or edge-level processing is supported by the Gestalt heuristics of proximity, collinearity and closure. Less is known, however, about the developmental trajectory of contour detection and contour integration. Within the physiology of the visual system, long-range horizontal connections in V1 and V2 are the likely candidates for implementing these heuristics. While post-mortem anatomical studies of human infants suggest that horizontal interconnections reach maturity by the second year of life, psychophysical research with infants and children suggests a considerably more protracted development. In the present review, data from infancy to adulthood will be discussed in order to track the development of contour detection and integration. The goal of this review is thus to integrate the development of contour detection and integration with research regarding the development of underlying neural circuitry. We conclude that the ontogeny of this system is best characterized as a developmentally extended period of associative acquisition whereby horizontal connectivity becomes functional over longer and longer distances, thus becoming able to effectively integrate over greater spans of visual space.

  19. A fast contour descriptor algorithm for supernova imageclassification

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Aragon, David Bradburn

    2006-07-16

    We describe a fast contour descriptor algorithm and its application to a distributed supernova detection system (the Nearby Supernova Factory) that processes 600,000 candidate objects in 80 GB of image data per night. Our shape-detection algorithm reduced the number of false positives generated by the supernova search pipeline by 41% while producing no measurable impact on running time. Fourier descriptors are an established method of numerically describing the shapes of object contours, but transform-based techniques are ordinarily avoided in this type of application due to their computational cost. We devised a fast contour descriptor implementation for supernova candidates that meets the tight processing budget of the application. Using the lowest-order descriptors (F{sub 1} and F{sub -1}) and the total variance in the contour, we obtain one feature representing the eccentricity of the object and another denoting its irregularity. Because the number of Fourier terms to be calculated is fixed and small, the algorithm runs in linear time, rather than the O(n log n) time of an FFT. Constraints on object size allow further optimizations so that the total cost of producing the required contour descriptors is about 4n addition/subtraction operations, where n is the length of the contour.

  20. Visual search of illusory contours: Shape and orientation effects

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije

    2008-01-01

    Full Text Available Illusory contours are specific class of visual stimuli that represent stimuli configurations perceived as integral irrespective of the fact that they are given in fragmented uncompleted wholes. Due to their specific features, illusory contours gained much attention in last decade representing prototype of stimuli used in investigations focused on binding problem. On the other side, investigations of illusory contours are related to problem of the level of their visual processing. Neurophysiologic studies show that processing of illusory contours proceed relatively early, on the V2 level, on the other hand most of experimental studies claim that illusory contours are perceived with engagement of visual attention, binding their elements to whole percept. This research is focused on two experiments in which visual search of illusory contours are based on shape and orientation. The main experimental procedure evolved the task proposed by Bravo and Nakayama where instead of detection, subjects were performing identification of one among two possible targets. In the first experiment subjects detected the presence of illusory square or illusory triangle, while in the second experiment subject were detecting two different orientations of illusory triangle. The results are interpreted in terms of visual search and feature integration theory. Beside the type of visual search task, search type proved to be dependent of specific features of illusory shapes which further complicate theoretical interpretation of the level of their perception.

  1. A possible analogy between contours in mathematics--as exemplified by Cauchy's integral formula--and contours in the arts.

    Science.gov (United States)

    Gerr, S

    1982-01-01

    An attempt is made to draw an analogy between contour drawing and a particular mathematical theorem. The analogy is seen to depend on the fact that both methods use definite values along a contour to imply a totality of values within the contour; thus, the use of a part to suggest the whole, by way of a hypothetical 'gestalt-like integration' in the case of the art contour, and the usual process of mathematical integration in the case of Cauchy's formula. Examples illustrating the analogy are drawn from a wide range of artistic work: a modern American drawing, a Cro-Magnon cave painting, and two Chinese works. The traditional Chinese philosophy of painting is invoked in support of the analogy because of its explicit emphasis on the primacy of outline drawing in Chinese painting. Some speculations are offered on further development and application of the analogy.

  2. Contours, Cherokee County Contours, Published in unknown, 1:2400 (1in=200ft) scale, City of Woodstock.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from LIDAR information as of unknown. It is described as 'Cherokee County...

  3. Contours - CONTOURS_24K_USGS_ADRIAN: Elevation Contours from 7.5-Minute Topographic Quadrangle Maps, Grouped into the 30' x 1째 Adrian Quadrangle, Indiana, Michigan, and Ohio (United States Geological Survey, 1:24,000, Line Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — CONTOURS_24K_USGS_ADRIAN is a shapefile containing elevation contours produced at a scale of 1:24,000, grouped into a 30' x 1째 quadrangle block. Elevation values are...

  4. 低频脉冲磁场对大鼠心肌微血管内皮细胞的影响%Effects of low frequency pulsed magnetic fields on cardiac microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    郭影; 李飞; 郭文怡; 孙冬冬; 路晓艳; 张荣庆

    2010-01-01

    Objective To investigate the effects of low frequency pulsed magnetic fields (LF-PMFs) on the proliferation of cardiac microvascular endothelial cells (CMECs) and their ultrastructure,migration and angiogenic potential. Methods CMECs from rats were exposed in vitro to low frequency square wave pulsed magnetic fields (15 Hz) 2 h/d for 5 d.The cells were randomly divided into 4 groups (control,1.0 mT,1.4 mT and 1.8 mT).After 5 days of exposure,proliferation was detected in terms of the cells' growth curves,their cycle was detected with flow cytometry,and their ultrastructure was observed using transmission electric microscopy. A scratch assay was used to evaluate the CMECs migration,and their angiogenic potential was measured using a tube formation assay.Results There was no significant effect of a 1.0 mT magnetic field on the ceils' growth curve,cell cycle or ultrastructure.The 1.4 mT magnetic field did,however,accelerate the CMECs' proliferation.The peak of the cells'growth curve was higher and moved forward,and the percentage of cells in the S phase increased significantly compared with the control group.The effects of a 1.8 mT magnetic field on S phase development were similar to those of the 1.4 mT field,but the peak of the cells' growth curve was not moved forward.After exposure to a 1.4 mT or 1.8 mT magnetic field,the CMECs' ultrastructure changed and they appeared more viable and powerful.Their nucleoil became bigger and clearer than those of the control group.There were cavernous nucleoli or two nucleoli.The number of mitochondria increased.The endoplasmic reticulum was richer and full of protein secretions inside with many microvilli on the surface.The magnetic fields facilitated migration and tube formation in the CMECs significantly,and these effects were correlated with the magnetic field intensity (1.4 mT> 1.8 mT > 1.0 mT).The cell migratory percentage in the 1.4 mT group was 86.1% ,while in the control group it was only 45.3%.When the CMECs were

  5. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  6. Brightness/darkness induction and the genesis of a contour.

    Science.gov (United States)

    Roncato, Sergio

    2014-01-01

    Visual contours often result from the integration or interpolation of fragmented edges. The strength of the completion increases when the edges share the same contrast polarity (CP). Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP). The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different gray shades. These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in is blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this "solution" by the visual system.

  7. Brightness/darkness induction and the genesis of a contour

    Directory of Open Access Journals (Sweden)

    Sergio eRoncato

    2014-10-01

    Full Text Available Visual contours often result from the integration or interpolation of fragmented edges.The strength of the completion increases when the edges share the same contrast polarity (CP. Here we demonstrate that the appearance in the perceptual field of this integrated unit, or contour of invariant CP, is concomitant with a vivid brightness alteration of the surfaces at its opposite sides. To observe this effect requires some stratagems because the formation in the visual field of a contour of invariant CP normally engenders the formation of a second contour and then the rise of two streams of induction signals that interfere in different ways. Particular configurations have been introduced that allow us to observe the induction effects of one contour taken in isolation. I documented these effects by phenomenological observations and psychophysical measurement of the brightness alteration in relation to luminance contrast. When the edges of the same CP complete to form a contour, the background of homogeneous luminance appears to dim at one side and to brighten at the opposite side (in accord with the CP. The strength of the phenomenon is proportional to the local luminance contrast. This effect weakens or nulls when the contour of the invariant CP separates surfaces filled with different grey shades.These conflicting results stimulate a deeper exploration of the induction phenomena and their role in the computation of brightness contrast. An alternative perspective is offered to account for some brightness illusions and their relation to the phenomenal transparency. The main assumption asserts that, when in the same region induction signals of opposite CP overlap, the filling-in are blocked unless the image is stratified into different layers, one for each signal of the same polarity. Phenomenological observations document this solution by the visual system

  8. Development of a contour meter; Desarrollo de un contornimetro

    Energy Technology Data Exchange (ETDEWEB)

    Andrada C, F.A. [Autoridad Regulatoria Nuclear, Av. Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina); Sanz, D.E. [Fundacion Escuela de Medicina Nuclear, Garibaldi 405, Capital, Mendoza (Argentina)]. e-mail: andrada@argentina.com

    2006-07-01

    The dosimetric calculation in patients that receive radiotherapy treatment it requires the one knowledge of the geometry of some anatomical portions, which differs from a patient to another. Making reference to the specific case of mammary neoplasia, one of the measurements that is carried out on the patient is the acquisition of the contour of the breast, which is determined from a point marked on the breastbone until another point marked on the lateral of the thorax, below the armpit, with the patient located in the irradiation position. This measurement is carried out with the help of a mechanical contour meter that is a device conformed by a series of wires with a polymeric coating, which support on the breast of the patient and it reproduces its form. Then it is transported in the more careful possible form on a paper and the contour is traced with a tracer one. The geometric error associated to this procedure is of {+-}1 cm, which is sensitive of being reduced. The present work finds its motivation in the patient's radiological protection radiotherapy. The maximum error in dose allowed in radiotherapeutic treatments is 5%. It would be increase the precision and with it to optimize the treatment received by the patient, reducing the error in the acquisition process of the mammary contour. With this objective, a digital device is designed whose operation is based in the application of a spatial transformation on a picture of the mammary contour, which corrects the geometric distortion introduced in the process of the photographic acquisition. An algorithm that allows to obtain a front image (without distortion) of the plane of the contour was developed. A software tool especially developed carries out the processing of the digital images. The maximum geometric error detected in the validation process is 2 mm located on a small portion of the contour. (Author)

  9. Application of pulse index continuous cardiac output monitoring to improve efficiency of acute heart failure care%应用脉搏指数连续心输出量监测提升急性心力衰竭护理效果

    Institute of Scientific and Technical Information of China (English)

    孙秀月; 张领; 赵书琴

    2015-01-01

    Objective To ihvestigate the effect of pulse index continuous cardiac output (PiCCO) monitoring to nursing care of acute heart failure care.Methods The clinical data of 43 acute heart failure patients were retrospectively analyzed,patients were given pulse index continuous cardiac output monitoring and care,the patient' s nursing outcomes were observed,and the intrathoracic blood volume,cardiac output and oxygen consumption before and after the intervention were compared.Results After the implementation of PiCCO and nursing intervention,43 patients had no serious complications,improved 42 cases discharged,the other 1 patient in critical condition due to old age and heart function improvement sustained no automatic discharge.Oxygen consumption,cardiac output and intrathoracic blood volume were improved after the intervention,there was a significant difference (P < 0.05) compared to the previous indicators and intervention after intervention.Conclusions Application of pulse index continuous cardiac output can effectively improve patient's clinical parameters such as cardiac output,through the implementation of appropriate care can improve symptoms and reduce complications.%目的 探讨急性心力衰竭患者护理中应用脉搏指数连续心输出量监测(PiCCO)的效果.方法 选取平顶山市第二人民医院收治的43例急性心力衰竭患者作为研究对象,收集患者的临床资料并对其做回顾性分析,对患者实施脉搏指数连续心输出量监测和护理,对患者的护理效果进行观察,并对其干预前后的胸腔内血容量、心排血量与氧耗量进行对比观察.结果 实施PiCCO和护理干预,本研究43例患者均无严重并发症产生,42例好转出院,1例由于病情危重、高龄及心功能持续无改善自动出院.患者干预后的氧耗量、心排血量与胸腔内血容量均有所改善,干预后各项指标与干预前比较差异有统计学意义(P<0.05).结论 应用脉搏指数连续心

  10. Physics of Cardiac Arrhythmogenesis

    Science.gov (United States)

    Karma, Alain

    2013-04-01

    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  11. Contours, 2' Contours for Iredell County provided by 2003 NC Floodplain Mapping Program data, Published in 2007, 1:4800 (1in=400ft) scale, Iredell County GIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from LIDAR information as of 2007. It is described as '2' Contours for...

  12. Contours, Contour layer with some elevation information for the northern half of the County., Published in 2000, 1:2400 (1in=200ft) scale, Walworth County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2000. It is described as 'Contour layer...

  13. Contours, Two-foot contours for Oconee County, Georgia, Published in 2006, 1:12000 (1in=1000ft) scale, Northeast Georgia Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from LIDAR information as of 2006. It is described as 'Two-foot contours...

  14. Contours, Two-foot contours for Athens-Clarke County, Georgia, Published in 2005, 1:12000 (1in=1000ft) scale, Northeast Georgia Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:12000 (1in=1000ft) scale, was produced all or in part from LIDAR information as of 2005. It is described as 'Two-foot contours...

  15. The HyperV Full-Scale Contoured-Gap Coaxial Plasma Railgun

    Science.gov (United States)

    Brockington, Samuel; Case, Andrew; Messer, Sarah; Bomgardner, Richard; Elton, Raymond; Wu, Linchun; Witherspoon, F. Douglas

    2009-11-01

    HyperV has been developing pulsed plasma injected coaxial railguns with a contoured gap profile designed to mitigate the blowby instability. Previous work using half-scale guns has been successful in launching 150 μg plasmas at 90 km/s [1]. In order to meet the original goal of 200 μg at 200 km/s the full-scale coaxial plasma gun has been constructed, and initial testing is beginning. This new plasma gun consists of two machined aluminum electrodes and a UHMW polyethylene breech insulator. The gun is breech fed by 64 ablative polyethylene capillary discharge units identical to the half-scale gun units. Maximum accelerator energy storage has also been increased 50%. Refractory coatings may be necessary to allow full current (˜800 kA) operation. The outer electrode includes 24 small diagnostic ports for optical and magnetic probe access to the plasma inside the gun to allow direct measurement of the plasma armature dynamics. Initial test data from the full-scale coax gun will be presented along with plans for future testing. Work supported by the U.S. DOE Office of Fusion Energy Sciences.[4pt] [1] F. D. Witherspoon, A. Case, S. Messer, R. Bomgardner, M. Phillips, S. Brockington, R. Elton, ``Contoured Gap Coaxial Plasma Gun with Injected Plasma Armature'' Rev. Sci. Instr. submitted (2009)

  16. Robust segmentation of 4D cardiac MRI-tagged images via spatio-temporal propagation

    Science.gov (United States)

    Qian, Zhen; Huang, Xiaolei; Metaxas, Dimitris N.; Axel, Leon

    2005-04-01

    In this paper we present a robust method for segmenting and tracking cardiac contours and tags in 4D cardiac MRI tagged images via spatio-temporal propagation. Our method is based on two main techniques: the Metamorphs Segmentation for robust boundary estimation, and the tunable Gabor filter bank for tagging lines enhancement, removal and myocardium tracking. We have developed a prototype system based on the integration of these two techniques, and achieved efficient, robust segmentation and tracking with minimal human interaction.

  17. Parallel peak pruning for scalable SMP contour tree computation

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Hamish A. [Univ. of Leeds (United Kingdom); Weber, Gunther H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Davis, CA (United States); Sewell, Christopher M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahrens, James P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-09

    As data sets grow to exascale, automated data analysis and visualisation are increasingly important, to intermediate human understanding and to reduce demands on disk storage via in situ analysis. Trends in architecture of high performance computing systems necessitate analysis algorithms to make effective use of combinations of massively multicore and distributed systems. One of the principal analytic tools is the contour tree, which analyses relationships between contours to identify features of more than local importance. Unfortunately, the predominant algorithms for computing the contour tree are explicitly serial, and founded on serial metaphors, which has limited the scalability of this form of analysis. While there is some work on distributed contour tree computation, and separately on hybrid GPU-CPU computation, there is no efficient algorithm with strong formal guarantees on performance allied with fast practical performance. Here in this paper, we report the first shared SMP algorithm for fully parallel contour tree computation, withfor-mal guarantees of O(lgnlgt) parallel steps and O(n lgn) work, and implementations with up to 10x parallel speed up in OpenMP and up to 50x speed up in NVIDIA Thrust.

  18. Active contour model based on force field analysis

    Institute of Scientific and Technical Information of China (English)

    HOU Zhi-qiang; HAN Chong-zhao

    2006-01-01

    The traditional snake initial contour should be close to the true boundary of an object of interest in an image;otherwise,an incorrect result will be obtained.Next,active contours have difficulties progressing into boundary concavities.Moreover,the traditional snake as well as almost all of its improved methods can be easily obtained from the local minimum because snake models are nonconvex.An active contour model based on force field analysis (FFA),namely,FFA snake model,is presented in this paper.Based on analyzing force distribution rules of the distance potential force field,a standard is introduced here to distinguish the false one from contour points.The result is not considered as the final solution when the snake energy is minimal.Furthermore,estimation and calculation should be made according to the established standard;only then can the result be considered final.Thus,the snake is prevented from running into the local minimum.The simulation results show that the FFA snake model has a large capture range and can move a snake into the boundary concavities,and that it is able to obtain the object of interest's contour precisely.Compared with the gradient vector flow snake,this new model has a low computational cost.

  19. After massive weight loss: patients' expectations of body contouring surgery.

    Science.gov (United States)

    Kitzinger, Hugo B; Abayev, Sara; Pittermann, Anna; Karle, Birgit; Bohdjalian, Arthur; Langer, Felix B; Prager, Gerhard; Frey, Manfred

    2012-04-01

    Massive weight loss following bariatric surgery leads to excess skin with functional and aesthetic impairments. Surplus skin can then contribute to problems with additional weight loss or gain. The aims of the current study were to evaluate the frequency of massive soft tissue development in gastric bypass patients, to determine whether males and females experience similar post-bypass body changes, and to learn about the expectations and impairments related to body contouring surgery. A questionnaire addressing information on the satisfaction of body image, quality of life, and expectation of body contouring surgery following massive weight loss was mailed to 425 patients who had undergone gastric bypass surgery between 2003 and 2009. Of these 425 individuals, 252 (59%) patients completed the survey. Ninety percent of women and 88% of men surveyed rated their appearance following massive weight loss as satisfactory, good, or very good. However, 96% of all patients developed surplus skin, which caused intertriginous dermatitis and itching. In addition, patients reported problems with physical activity (playing sports) and finding clothing that fit appropriately. Moreover, 75% of female and 68% of male patients reported desiring body contouring surgery. The most important expectation of body contouring surgery was improved appearance, followed by improved self-confidence and quality of life. Surplus skin resulting from gastric bypass surgery is a common issue that causes functional and aesthetic impairments in patients. Consequently, this increases the desire for body contouring surgery with high expectations for the aesthetic outcome as well as improved life satisfaction.

  20. Incorporating Stream Features into Groundwater Contouring Tools Within GIS.

    Science.gov (United States)

    Bannister, Roger; Kennelly, Patrick

    2016-03-01

    Hydrogeologists often are called upon to estimate surfaces from discrete, sparse data points. This estimation is often accomplished by manually drawing contours on maps using interpolation methods between points of known value while accounting for features known to influence the water table's surface. By contrast, geographic information systems (GIS) are good at creating smooth continuous surfaces from limited data points and allowing the user to represent the resulting surface resulting with contours, but these automated methods often fail to meet the expectations of many hydrogeologists because they do not include knowledge of other influences on the water table. In this study, we seek to fill this gap in the GIS-based methodology for hydrogeologists through an interactive tool that shapes an interpolated surface based on additional knowledge of the water table inferred from gaining or losing streams. The modified surface is reflected in water table contours that, for example, "V" upstream for gaining streams, and can be interactively adjusted to fit the user's expectations. By modifying not only the contours but also the associated interpolated surface, additional contours will follow the same trend, and the modified surface can be used for other analyses like calculating average gradients and flow paths. The tool leverages Esri's ArcGIS Desktop software, building upon a robust suite of mapping tools. We see this as a prototype for other tools that could be developed for hydrogeologists to account for variations in the water table inferred from local topographic trends, pumping or injection wells, and other hydrogeologic features.

  1. Image automatic mosaics based on contour phase correlation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; HU Zhiping; LIU Zhitai; OU Zongying

    2007-01-01

    The image planar mosaics is studied,and an image automatic mosaics algorithm on the basis of contour phase correlation is proposed in this paper.To begin with,by taking into account mere translations and rotations between images,a contour phase correlation algorithm is used to realize the preliminary alignments of images,and the initial projective transformation matrices are obtained.Then,an optimization algorithm is used to optimize the initial projective transformation matrices,and complete the precise image mosaics.The contour phase correlation is an improvement on the conventional phase correlation in two aspects:First,the contours of images are extracted,and the phase correlation is applied to the contours of images instead of the whole original images;Second,when there are multiple peak values approximate to the maximum peak value in the δ function array,their corresponding translations can be regarded as candidate translations and calculated separately,and the best translation can be determined by the optimization of conformability of two images in the overlapping area.The running results show that the proposed algorithm can consistently yield high-quality mosaics,even in the cases of poor or differential lighting conditions,existences of minor rotations,and other complicated displacements between images.

  2. Passive leg-raising and end-expiratory occlusion tests perform better than pulse pressure variation in patients with low respiratory system compliance.

    Science.gov (United States)

    Monnet, Xavier; Bleibtreu, Alexandre; Ferré, Alexis; Dres, Martin; Gharbi, Rim; Richard, Christian; Teboul, Jean-Louis

    2012-01-01

    We tested whether the poor ability of pulse pressure variation to predict fluid responsiveness in cases of acute respiratory distress syndrome was related to low lung compliance. We also tested whether the changes in cardiac index induced by passive leg-raising and by an end-expiratory occlusion test were better than pulse pressure variation at predicting fluid responsiveness in acute respiratory distress syndrome patients. Prospective study. Medical intensive care unit. We included 54 patients with circulatory shock (63 ± 13 yrs; Simplified Acute Physiology Score II, 63 ± 24). Twenty-seven patients had acute respiratory distress syndrome (compliance of the respiratory system, 22 ± 3 mL/cm H2O). In nonacute respiratory distress syndrome patients, the compliance of the respiratory system was 45 ± 9 mL/cm H2O. We measured the response of cardiac index (transpulmonary thermodilution) to fluid administration (500 mL saline). Before fluid administration, we recorded pulse pressure variation and the changes in pulse contour analysis-derived cardiac index induced by passive leg-raising and end-expiratory occlusion. Fluid increased cardiac index ≥ 15% (44% ± 39%) in 30 "responders." Pulse pressure variation was significantly correlated with compliance of the respiratory system (r = .58), but not with tidal volume. The higher the compliance of the respiratory system, the better the prediction of fluid responsiveness by pulse pressure variation. A compliance of the respiratory system of 30 mL/cm H2O was the best cut-off for discriminating patients regarding the ability of pulse pressure variation to predict fluid responsiveness. If compliance of the respiratory system was >30 mL/cm H2O, then the area under the receiver-operating characteristics curve for predicting fluid responsiveness was not different for pulse pressure variation and the passive leg-raising and end-expiratory occlusion tests (0.98 ± 0.03, 0.91 ± 0.06, and 0.97 ± 0.03, respectively). By contrast

  3. Layering-based Breakpoint Handling in Contour Line Extraction

    Institute of Scientific and Technical Information of China (English)

    CHEN Dan; LONG Yi; CAI Jinhua

    2003-01-01

    This paper deals withthe automatic connection of contourlines extracted from a scanned browngeographical map. For the variety oftopographical elements contained on amap, the factors causing the interrup-tion of contour line are also multiform,which make the connection task verydifficult. On the basis of separatingthose elements always making the con-tours break and regarding them as ref-erent layers, a layering-based methodis presented. The purpose is to takeinto account property information (likeinclination and configuration) of con-tour lines when they come across otherdifferent symbols, such as gully, cliff,dry land and elevation annotation etc.In this paper, the authors propose thatit should be far more effective and di-rect to adopt different algorithmic op-erators to different factors than usingsingle one operator to all.

  4. A Robust Algorithm of Contour Extraction for Vehicle Tracking

    Institute of Scientific and Technical Information of China (English)

    FANZhimin; ZHOUJie; GAODashan

    2003-01-01

    Contour extraction of moving vehicle is an important and challenging issue in traffic surveillance. In this paper, a robust algorithm is proposed for contour ex-traction and moving vehicle tracking. First, we establish a modified snake model and utilize the directional infor-mation of the edge map to guide the snaxels' behavior.Then an adaptive shape restriction is embedded into the algorithm to govern the scope of the snake's motion, and Kalman filter is employed to estimate spatio-temporal rela-tionship between successive frames. In addition~ multiple refinements are suggested to compensate for the snake's vulnerability to fake edges. All of them contribute to a ro-bust overall performance in contour extraction and vehicle tracking. Experimental results in real traffic scene prove the effectiveness of our algorithm.The comparison with conventional snakes is also provided.

  5. The perception of 3D shape from planar cut contours.

    Science.gov (United States)

    Egan, Eric J L; Todd, James T; Phillips, Flip

    2011-10-01

    A new computational analysis is described for estimating 3D shapes from orthographic images of surfaces that are textured with planar cut contours. For any given contour pattern, this model provides a family of possible interpretations that are all related by affine scaling and shearing transformations in depth, depending on the specific values of its free parameters that are used to compute the shape estimate. Two psychophysical experiments were performed in an effort to compare the model predictions with observers' judgments of 3D shape for developable and non-developable surfaces. The results reveal that observers' perceptions can be systematically distorted by affine scaling and shearing transformations in depth and that the magnitude and direction of these distortions vary systematically with the 3D orientations of the contour planes.

  6. The TICTOP nozzle: a new nozzle contouring concept

    Science.gov (United States)

    Frey, Manuel; Makowka, Konrad; Aichner, Thomas

    2016-10-01

    Currently, mainly two types of nozzle contouring methods are applied in space propulsion: the truncated ideal contour (TIC) and the thrust-optimized parabola (TOP). This article presents a new nozzle contouring method called TICTOP, combining elements of TIC and TOP design. The resulting nozzle is shock-free as the TIC and therefore does not induce restricted shock separation leading to excessive side-loads. Simultaneously, the TICTOP nozzle will allow higher nozzle wall exit pressures and hence give a better separation margin than is the case for a TIC. Hence, this new nozzle type combines the good properties of TIC and TOP nozzles and eliminates their drawbacks. It is especially suited for first stage application in launchers where flow separation and side-loads are design drivers.

  7. Scattering Suppression and Absorption Enhancement in Contour Nanoantennas

    CERN Document Server

    Onal, E Doruk

    2015-01-01

    The expanding application spectrum of plasmonic nanoantennas demand versatile design approaches to tailor the antenna properties for specific requirements. The design efforts primarily concentrate on shifting the operation wavelength or enhancing the local fields by manipulating the size and shape of the nanoantenna. Here, we propose a design path to control the absorption and scattering characteristics of a dipole nanoantenna by introducing a hollow region inside the nanostructure. The resulting contour geometry can significantly suppress the scattering of the dipole nanoantenna and enhance its absorption simultaneously. Both the dipole and the contour dipole nanoantenna couple to equivalent amount of the incident radiation. The dipole nanoantenna scatters 84% of the coupled power (absorbs the remaining 16%) whereas the contour dipole structure scatters only 28% of the coupled power (absorbs the remaining 72%). This constitutes the transformation from scatter to absorber nanoantenna. The scattering of a cont...

  8. Automatic segmentation of leg bones by using active contours.

    Science.gov (United States)

    Kim, Sunhee; Kim, Youngjun; Park, Sehyung; Lee, Deukhee

    2014-01-01

    In this paper, we present a new active contours model to segment human leg bones in computed tomography images that is based on a variable-weighted combination of local and global intensity. This model can split an object surrounded by both weak and strong boundaries, and also distinguish very adjacent objects with those boundaries. The ability of this model is required for segmentation in medical images, e.g., human leg bones, which are usually composed of highly inhomogeneous objects and where the distances among organs are very close. We developed an evolution equation of a level set function whose zero level set represents a contour. An initial contour is automatically obtained by applying a histogram based multiphase segmentation method. We experimented with computed tomography images from three patients, and demonstrate the efficiency of the proposed method in experimental results.

  9. Contour extraction of echocardiographic images based on pre-processing

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Zinah Rajab; Rahmat, Rahmita Wirza; Abdullah, Lili Nurliyana [Department of Multimedia, Faculty of Computer Science and Information Technology, Department of Computer and Communication Systems Engineering, Faculty of Engineering University Putra Malaysia 43400 Serdang, Selangor (Malaysia); Zamrin, D M [Department of Surgery, Faculty of Medicine, National University of Malaysia, 56000 Cheras, Kuala Lumpur (Malaysia); Saripan, M Iqbal

    2011-02-15

    In this work we present a technique to extract the heart contours from noisy echocardiograph images. Our technique is based on improving the image before applying contours detection to reduce heavy noise and get better image quality. To perform that, we combine many pre-processing techniques (filtering, morphological operations, and contrast adjustment) to avoid unclear edges and enhance low contrast of echocardiograph images, after implementing these techniques we can get legible detection for heart boundaries and valves movement by traditional edge detection methods.

  10. Complications following body contouring surgery after massive weight loss

    DEFF Research Database (Denmark)

    Hasanbegovic, Emir; Sørensen, Jens Ahm

    2014-01-01

    Bariatric surgery is a way to achieve lasting weight loss in the obese. Body contouring surgery seeks to alleviate some of the discomfort caused by the excessive loose skin following massive weight loss. Higher complication rates are described in this type of surgery when done post......-bariatric. The purpose of this article is to compare complication rates of body contouring surgery when performed on patients with weight loss due to bariatric surgery compared to patients who lost weight due to dietary changes and/or exercise....

  11. Wilson loops at strong coupling for curved contours with cusps

    CERN Document Server

    Dorn, Harald

    2015-01-01

    We construct the minimal surface in AdS, relevant for the strong coupling behaviour of local supersymmetric Wilson loops in N=4 SYM for a closed contour formed out of segments of two intersecting circles. Its regularised area is calculated including all divergent parts and the finite renormalised term. Furthermore we prove, that for generic planar curved contours with cusps the cusp anomalous dimensions are functions of the respective cusp angles alone. They do not depend on other local data of the cusps.

  12. Motion estimation of elastic articulated objects from image contours

    Institute of Scientific and Technical Information of China (English)

    PAN Hai-lang; DAI Yue-wei; SHI Lei

    2008-01-01

    A new method of elastic articulated objects (human bodies) modeling was presented based on a new conic curve. The model includes 3D object deform able curves which can represent the deformation of human occluding contours. The deformation of human occluding contour can be represented by adjusting only four de-formation parameters for each limb. Then, the 3D deformation parameters are determined by corresponding 2Dcontours from a sequence of stereo images. The algorithm presented in this paper includes deform able conic curve parameters determination and the plane, 3D conic curve lying on, parameter determination.

  13. McCON - A General Contouring Program for Personal Computers.

    Science.gov (United States)

    1992-09-01

    contourable values in the vicinity of the given data sets. The recent advent of high quality graphics capabilities on personal computers and workstations... quality than screen plots. Contouring Nonconvex Areas By Composite Fragments 29. The triangle mesh generation criteria will always result in the data...7 RC.N.OL3N.O 7704 CON IN~i 7705 COL4=COLOR B2 IFFIFNME.EO’ M’ G’O 10 7777 ý ý9ýFILE=FNME,STATU$:’OLD’ ,ERR=567’i 567 INDOO 568 C ONTI NUý R AD 9,1

  14. [Development of a Software for Automatically Generated Contours in Eclipse TPS].

    Science.gov (United States)

    Xie, Zhao; Hu, Jinyou; Zou, Lian; Zhang, Weisha; Zou, Yuxin; Luo, Kelin; Liu, Xiangxiang; Yu, Luxin

    2015-03-01

    The automatic generation of planning targets and auxiliary contours have achieved in Eclipse TPS 11.0. The scripting language autohotkey was used to develop a software for automatically generated contours in Eclipse TPS. This software is named Contour Auto Margin (CAM), which is composed of operational functions of contours, script generated visualization and script file operations. RESULTS Ten cases in different cancers have separately selected, in Eclipse TPS 11.0 scripts generated by the software could not only automatically generate contours but also do contour post-processing. For different cancers, there was no difference between automatically generated contours and manually created contours. The CAM is a user-friendly and powerful software, and can automatically generated contours fast in Eclipse TPS 11.0. With the help of CAM, it greatly save plan preparation time and improve working efficiency of radiation therapy physicists.

  15. Pulse Voltammetry.

    Science.gov (United States)

    Osteryoung, Janet

    1983-01-01

    Discusses the nature of pulse voltammetry, indicating that its widespread use arises from good sensitivity and detection limits and from ease of application and low cost. Provides analytical and mechanistic applications of the procedure. (JN)

  16. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  17. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    Science.gov (United States)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  18. Theory on the molecular characteristic contour(Ⅰ)——A new approach to defining molecular characteristic contour

    Institute of Scientific and Technical Information of China (English)

    赵东霞; 杨忠志

    1999-01-01

    Based on the classical turning point of electron movement in a molecule, a model for defining the molecular characteristic boundary contour is advanced. By using an accurate ab initio MELD program and an auxiliary program, some electron parameters in a molecule, such as the potential felt by an electron, have been evaluated. According to our model and definition, the molecular characteristic contour of the equilibrium geometry configuration is drawn and a vivid intuitive picture for describing the forming or breaking of a chemical bond is displayed.

  19. Organization of contour from motion processing in primate visual cortex

    NARCIS (Netherlands)

    Lamme, V.A.F.; van Dijk, B.W.; Spekreijse, H.

    1994-01-01

    Investigated where contour from motion processing occurs by recording visual evoked potential (VEP) to a stimulus designed to signal the presence of relative motion-sensitive mechanisms. Two human Ss and 3 monkeys participated in the study and had VEP measured on the scalp and intracortically, respe

  20. Design of a Vibrotactile Vest for Contour Perception

    Directory of Open Access Journals (Sweden)

    Juan Wu

    2012-11-01

    Full Text Available A vibrotactile array is a promising human computer interface which could display graphical information to users in a tactile form. This paper presents the design and testing of an image contour display system with a vibrotactile array. The tactile image display system is attached to the back of the user. It converts visual graphics into 2D tactile images and allows subjects to feel the contours of objects through vibration stimulus. The system consists of a USB camera, 48 (6×8 vibrating motors and an embedded control system. The image is captured by the camera and the 2D contour is extracted and transformed into vibrotactile stimuli using a temporal-spatial dynamic coding method. Preliminary experiments were carried out and the optimal parameters of the vibrating time and duration were explored. To evaluate the feasibility and robustness of this vibration mode, letters were also tactilely displayed and the recognition rate about the alphabet letter display was investigated. It was shown that under the condition of no pre-training for the subjects, the recognition rate was 82%. Such a recognition rate is higher than that of the scanning mode (47.5% and the improved handwriting mode (76.8%. The results indicated that the proposed method was efficient in conveying the contour information to the visually impaired by means of vibrations.

  1. DEVELOPMENT OF VISUALLY GUIDED BEHAVIOR REQUIRES ORIENTED CONTOURS

    NARCIS (Netherlands)

    BRENNER, E; CORNELISSEN, FW

    1992-01-01

    Kittens do not learn to use visual information to guide their behaviour if they are deprived of the optic flow that accompanies their own movements. We show that the optic flow that is required for developing visually guided behaviour is derived from changes in contour orientations, rather than from

  2. Large-scale Optimization of Contoured Beam Reflectors and Reflectarrays

    DEFF Research Database (Denmark)

    Borries, Oscar; Sørensen, Stig B.; Jørgensen, Erik;

    2016-01-01

    Designing a contoured beam reflector or performing a direct optimization of a reflectarray requires a mathematical optimization procedure to determine the optimum design of the antenna. A popular approach, used in the market-leading TICRA software POS, can result in computation times on the order...

  3. Design of a Vibrotactile Vest for Contour Perception

    Directory of Open Access Journals (Sweden)

    Juan Wu

    2012-11-01

    Full Text Available A vibrotactile array is a promising human computer interface which could display graphical information to users in a tactile form. This paper presents the design and testing of an image contour display system with a vibrotactile array. The tactile image display system is attached to the back of the user. It converts visual graphics into 2D tactile images and allows subjects to feel the contours of objects through vibration stimulus. The system consists of a USB camera, 48 (6×8 vibrating motors and an embedded control system. The image is captured by the camera and the 2D contour is extracted and transformed into vibrotactile stimuli using a temporal‐spatial dynamic coding method. Preliminary experiments were carried out and the optimal parameters of the vibrating time and duration were explored. To evaluate the feasibility and robustness of this vibration mode, letters were also tactilely displayed and the recognition rate about the alphabet letter display was investigated. It was shown that under the condition of no pre‐training for the subjects, the recognition rate was 82%. Such a recognition rate is higher than that of the scanning mode (47.5% and the improved handwriting mode (76.8%. The results indicated that the proposed method was efficient in conveying the contour information to the visually impaired by means of vibrations.

  4. Surface Perception from Local Analysis of Texture and Contour.

    Science.gov (United States)

    1980-02-01

    Gibson, 1971; Kennedy, 19741 or a learned skill of interpretation analogous to reading, subject to cultural convention (e.g., [ Arnheim , 19541...contours, highlights, and shading edges tell us of the local Gaussian curvature in some cases. 4 t . SStevens I102 References REFERENCES Arnheim . R

  5. Use of rapidly hardening hydroxyapatite cement for facial contouring surgery.

    Science.gov (United States)

    Lee, Dong Won; Kim, Ji Ye; Lew, Dae Hyun

    2010-07-01

    Hydroxyapatite cement is an ideal alloplastic material to replace the autogenous bone grafts in craniofacial surgery. Hydroxyapatite cement is advantageous because it can be easily molded by hand unlike other alloplastic materials such as silicone and high-density polyethylene. For aesthetic applications of hydroxyapatite cement, we evaluated the efficacy and safety of the rapidly hardening hydroxyapatite cement used in facial contour augmentation, especially for the forehead and the malar area. A total of 18 cases of facial skeleton augmentation or contouring surgery using rapidly hardening hydroxyapatite cement (Mimix; Biomet, Warsaw, IN) were examined, and the long-term cosmetic results and any complications were also analyzed. The aims of facial contouring surgeries were to correct the following conditions: hemifacial microsomia, craniosynostosis, posttraumatic facial deformity, deformity after tumor resection, dentofacial deformity, and Romberg disease. The application sites of hydroxyapatite cement were the forehead, malar area, chin, and paranasal area. A mean of 16 g (range, 5-50 g) of the hydroxyapatite cement was used. Postoperative infection, seroma, and migration of the implant were not observed during the follow-up period of 23 months. Rapidly hardening hydroxyapatite cement, Mimix, is easy to manipulate, promptly sclerotized, and can be replaced by living bone tissue, with a low complication rate. Therefore, it can be an optimal treatment that can be used instead of other conventional types of alloplastic materials used in facial contouring surgery.

  6. Automatic Image Segmentation Using Active Contours with Univariate Marginal Distribution

    Directory of Open Access Journals (Sweden)

    I. Cruz-Aceves

    2013-01-01

    Full Text Available This paper presents a novel automatic image segmentation method based on the theory of active contour models and estimation of distribution algorithms. The proposed method uses the univariate marginal distribution model to infer statistical dependencies between the control points on different active contours. These contours have been generated through an alignment process of reference shape priors, in order to increase the exploration and exploitation capabilities regarding different interactive segmentation techniques. This proposed method is applied in the segmentation of the hollow core in microscopic images of photonic crystal fibers and it is also used to segment the human heart and ventricular areas from datasets of computed tomography and magnetic resonance images, respectively. Moreover, to evaluate the performance of the medical image segmentations compared to regions outlined by experts, a set of similarity measures has been adopted. The experimental results suggest that the proposed image segmentation method outperforms the traditional active contour model and the interactive Tseng method in terms of segmentation accuracy and stability.

  7. Integrability and Wilson loops: the wavy line contour

    CERN Document Server

    Cagnazzo, A

    2013-01-01

    The Wilson loop with a wavy line contour is studied using integrable methods. The auxiliary problem is solved and the Lax operator is built to first order in perturbation theory, considering a small perturbation from the straight line. Finally the spectral curve of the solution is considered.

  8. The role of non-CRF inhibition in contour detection

    NARCIS (Netherlands)

    Grigorescu, Cosmin; Petkov, Nicolai; Westenberg, Michel A.; Skala,

    2003-01-01

    We propose a biologically motivated computational step, called non-classical receptive field (non-CRF) inhibition, to improve the performance of contour detectors. Non-CRF inhibition is exhibited by 80% of the orientation selective neurons in the primary visual cortex of macaque monkeys and has been

  9. Active contours for localizing polyps in colonoscopic NBI image data

    Science.gov (United States)

    Breier, Matthias; Gross, Sebastian; Behrens, Alexander; Stehle, Thomas; Aach, Til

    2011-03-01

    Colon cancer is the third most common type of cancer in the United States of America. Every year about 140,000 people are newly diagnosed with colon cancer. Early detection is crucial for a successful therapy. The standard screening procedure is called colonoscopy. Using this endoscopic examination physicians can find colon polyps and remove them if necessary. Adenomatous colon polyps are deemed a preliminary stage of colon cancer. The removal of a polyp, though, can lead to complications like severe bleedings or colon perforation. Thus, only polyps diagnosed as adenomatous should be removed. To decide whether a polyp is adenomatous the polyp's surface structure including vascular patterns has to be inspected. Narrow-Band imaging (NBI) is a new tool to improve visibility of vascular patterns of the polyps. The first step for an automatic polyp classification system is the localization of the polyp. We investigate active contours for the localization of colon polyps in NBI image data. The shape of polyps, though roughly approximated by an elliptic form, is highly variable. Active contours offer the flexibility to adapt to polyp variation well. To avoid clustering of contour polygon points we propose the application of active rays. The quality of the results was evaluated based on manually segmented polyps as ground truth data. The results were compared to a template matching approach and to the Generalized Hough Transform. Active contours are superior to the Hough transform and perform equally well as the template matching approach.

  10. Luminance contours can gate afterimage colors and 'real' colors

    NARCIS (Netherlands)

    Anstis, S.; Vergeer, M.L.T.; Lier, R.J. van

    2012-01-01

    It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The c

  11. Applying manifold learning to plotting approximate contour trees.

    Science.gov (United States)

    Takahashi, Shigeo; Fujishiro, Issei; Okada, Masato

    2009-01-01

    A contour tree is a powerful tool for delineating the topological evolution of isosurfaces of a single-valued function, and thus has been frequently used as a means of extracting features from volumes and their time-varying behaviors. Several sophisticated algorithms have been proposed for constructing contour trees while they often complicate the software implementation especially for higher-dimensional cases such as time-varying volumes. This paper presents a simple yet effective approach to plotting in 3D space, approximate contour trees from a set of scattered samples embedded in the high-dimensional space. Our main idea is to take advantage of manifold learning so that we can elongate the distribution of high-dimensional data samples to embed it into a low-dimensional space while respecting its local proximity of sample points. The contribution of this paper lies in the introduction of new distance metrics to manifold learning, which allows us to reformulate existing algorithms as a variant of currently available dimensionality reduction scheme. Efficient reduction of data sizes together with segmentation capability is also developed to equip our approach with a coarse-to-fine analysis even for large-scale datasets. Examples are provided to demonstrate that our proposed scheme can successfully traverse the features of volumes and their temporal behaviors through the constructed contour trees.

  12. A contoured continuum surface force model for particle methods

    Science.gov (United States)

    Duan, Guangtao; Koshizuka, Seiichi; Chen, Bin

    2015-10-01

    A surface tension model is essential to simulate multiphase flows with deformed interfaces. This study develops a contoured continuum surface force (CCSF) model for particle methods. A color function that varies sharply across the interface to mark different fluid phases is smoothed in the transition region, where the local contour curvature can be regarded as the interface curvature. The local contour passing through each reference particle in the transition region is extracted from the local profile of the smoothed color function. The local contour curvature is calculated based on the Taylor series expansion of the smoothed color function, whose derivatives are calculated accurately according to the definition of the smoothed color function. Two schemes are proposed to specify the smooth radius: fixed scheme, where 2 ×re (re = particle interaction radius) is assigned to all particles in the transition region; and varied scheme, where re and 2 ×re are assigned to the central and edged particles in the transition region respectively. Numerical examples, including curvature calculation for static circle and ellipse interfaces, deformation of square droplet to a circle (2D and 3D), droplet deformation in shear flow, and droplet coalescence, are simulated to verify the CCSF model and compare its performance with those of other methods. The CCSF model with the fixed scheme is proven to produce the most accurate curvature and lowest parasitic currents among the tested methods.

  13. Topology Optimization - Improved Checker-Board Filtering With Sharp Contours

    DEFF Research Database (Denmark)

    Pedersen, Christian Gejl; Lund, Jeppe Jessen; Damkilde, Lars

    2006-01-01

    In topology optimization it is mandatory to use a filtering technique in order to prevent checker-boarder solutions. The paper examines a new filtering principle and demonstrates an improved sharpness in the contours. This was not realized in the original proposal of the filter. Furthermore...

  14. Hybrid measurement to achieve satisfactory precision in perioperative cardiac output monitoring.

    Science.gov (United States)

    Peyton, P

    2014-05-01

    Advanced haemodynamic monitoring employing minimally invasive cardiac output measurement may lead to significant improvements in patient outcomes in major surgery. However, the precision (scatter) of measurement of available generic technologies has been shown to be unsatisfactory with percentage error of agreement with bolus thermodilution (% error) of 40% to 50%. Simultaneous measurement and averaging by two or more technologies may reduce random measurement scatter and improve precision. This concept, called the hybrid method, was tested by comparing accuracy and precision of measurement relative to bolus thermodilution using combinations of three component methods. Thirty patients scheduled for either elective cardiac surgery or liver transplantation were studied. Agreement with simultaneous bolus thermodilution of hybrid combinations of continuous thermodilution (QtCCO) or Vigeleo™/FloTrac™ pulse contour measurement (QtFT) with pulmonary Capnotracking (QtCO2) was assessed pre- and post-cardiopulmonary bypass or pre- and post-reperfusion of the donor liver and compared with that of the component methods alone. Hybridisation of QtCO2 (% error 42.2) and QtCCO (% error 51.3) achieved significantly better precision (% error 31.3) than the component methods (P=0.0004) and (P=0.0195). Due to poor inherent precision of QtFT (% error 82.8), hybrid combination of QtFT with QtCO2 did not result in better precision than QtCO2 alone. Hybrid measurement can approach a 30% error, which is recommended as the upper limit for acceptability. This is a practical option where at least one component method, such as Capnotracking, is automated and does not increase the cost or complexity of the measurement process.

  15. A method of dealing polygon's self-intersection contour in SLA

    Institute of Scientific and Technical Information of China (English)

    GAO Yong-qiang; MO Jian-hua; HUANG Shu-huai

    2007-01-01

    The contour of the slices of SLA parts is composed of a great deal of small lines. When offsetting the contour to compensate for the radius of laser spot, many self-intersection contours come into being, which decrease the precision of formed parts. A new lemma to judge the local self-intersection contour and the global self-intersection contour separately is put forward, according to which self-intersection contour can be removed reliably. Meanwhile, a new beam offsetting algorithm for SLA parts is described, which brings about good results in the practical manufacturing process.

  16. The role of "contrast enhancement" in the detection and appearance of visual contours.

    Science.gov (United States)

    Hess, R F; Dakin, S C; Field, D J

    1998-03-01

    We test the proposition that the appearance and detection of visual contours is based on an increase in the perceived contrast of contour elements. First we show that detection of contours is quite possible in the presence of very high levels of variability in contrast. Second we show that inclusion in a contour does not induce Gabor patches to appear to be of higher contrast than patches outside of a contour. These results suggest that, contrary to a number of current models, contrast or its assumed physiological correlate (the mean firing rate of early cortical neurons) is not the determining information for identifying the contour.

  17. Ladder contours are undetectable in the periphery: a crowding effect?

    Science.gov (United States)

    May, Keith A; Hess, Robert F

    2007-10-29

    We studied the perceptual integration of contours consisting of Gabor elements positioned along a smooth path, embedded among distractor elements. Contour elements either formed tangents to the path ("snakes") or were perpendicular to it ("ladders"). Perfectly straight snakes and ladders were easily detected in the fovea but, at an eccentricity of 6 degrees , only the snakes were detectable. The disproportionate impairment of peripheral ladder detection remained when we brought foveal performance away from ceiling by jittering the orientations of the elements. We propose that the failure to detect peripheral ladders is a form of crowding, the phenomenon observed when identification of peripherally located letters is disrupted by flanking letters. D. G. Pelli, M. Palomares, and N. J. Majaj (2004) outlined a model in which simple feature detectors are followed by integration fields, which are involved in tasks, such as letter identification, that require the outputs of several detectors. They proposed that crowding occurs because small integration fields are absent from the periphery, leading to inappropriate feature integration by large peripheral integration fields. We argue that the "association field," which has been proposed to mediate contour integration (D. J. Field, A. Hayes, & R. F. Hess, 1993), is a type of integration field. Our data are explained by an elaboration of Pelli et al.'s model, in which weak ladder integration competes with strong snake integration. In the fovea, the association fields were small, and the model integrated snakes and ladders with little interference. In the periphery, the association fields were large, and integration of ladders was severely disrupted by interference from spurious snake contours. In contrast, the model easily detected snake contours in the periphery. In a further demonstration of the possible link between contour integration and crowding, we ran our contour integration model on groups of three-letter stimuli

  18. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  19. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  20. Fast Contour-Tracing Algorithm Based on a Pixel-Following Method for Image Sensors.

    Science.gov (United States)

    Seo, Jonghoon; Chae, Seungho; Shim, Jinwook; Kim, Dongchul; Cheong, Cheolho; Han, Tack-Don

    2016-03-09

    Contour pixels distinguish objects from the background. Tracing and extracting contour pixels are widely used for smart/wearable image sensor devices, because these are simple and useful for detecting objects. In this paper, we present a novel contour-tracing algorithm for fast and accurate contour following. The proposed algorithm classifies the type of contour pixel, based on its local pattern. Then, it traces the next contour using the previous pixel's type. Therefore, it can classify the type of contour pixels as a straight line, inner corner, outer corner and inner-outer corner, and it can extract pixels of a specific contour type. Moreover, it can trace contour pixels rapidly because it can determine the local minimal path using the contour case. In addition, the proposed algorithm is capable of the compressing data of contour pixels using the representative points and inner-outer corner points, and it can accurately restore the contour image from the data. To compare the performance of the proposed algorithm to that of conventional techniques, we measure their processing time and accuracy. In the experimental results, the proposed algorithm shows better performance compared to the others. Furthermore, it can provide the compressed data of contour pixels and restore them accurately, including the inner-outer corner, which cannot be restored using conventional algorithms.

  1. Fast Contour-Tracing Algorithm Based on a Pixel-Following Method for Image Sensors

    Directory of Open Access Journals (Sweden)

    Jonghoon Seo

    2016-03-01

    Full Text Available Contour pixels distinguish objects from the background. Tracing and extracting contour pixels are widely used for smart/wearable image sensor devices, because these are simple and useful for detecting objects. In this paper, we present a novel contour-tracing algorithm for fast and accurate contour following. The proposed algorithm classifies the type of contour pixel, based on its local pattern. Then, it traces the next contour using the previous pixel’s type. Therefore, it can classify the type of contour pixels as a straight line, inner corner, outer corner and inner-outer corner, and it can extract pixels of a specific contour type. Moreover, it can trace contour pixels rapidly because it can determine the local minimal path using the contour case. In addition, the proposed algorithm is capable of the compressing data of contour pixels using the representative points and inner-outer corner points, and it can accurately restore the contour image from the data. To compare the performance of the proposed algorithm to that of conventional techniques, we measure their processing time and accuracy. In the experimental results, the proposed algorithm shows better performance compared to the others. Furthermore, it can provide the compressed data of contour pixels and restore them accurately, including the inner-outer corner, which cannot be restored using conventional algorithms.

  2. Recognizing the authenticity of emotional expressions: F0 contour matters when you need to know.

    Science.gov (United States)

    Drolet, Matthis; Schubotz, Ricarda I; Fischer, Julia

    2014-01-01

    Authenticity of vocal emotion expression affects emotion recognition and brain activity in the so-called Theory of Mind (ToM) network, which is implied in the ability to explain and predict behavior by attributing mental states to other individuals. Exploiting the variability of the fundamental frequency (F0 contour), which varies more (higher contour) in play-acted expressions than authentic ones, we examined whether contour biases explicit categorization toward a particular authenticity or emotion category. Moreover, we tested whether contour modulates blood-oxygen-level dependent (BOLD) response in the ToM network and explored the role of task as a top-down modulator. The effects of contour on BOLD signal were analyzed by contrasting high and low contour stimuli within two previous fMRI studies that implemented emotion and authenticity rating tasks. Participants preferentially categorized higher contour stimuli as play-acted and lower contour stimuli as sad. Higher contour was found to up-regulate activation task-independently in the primary auditory cortex. Stimulus contour and task were found to interact in a network including medial prefrontal cortex, with an increase in BOLD signal for low-contour stimuli during explicit perception of authenticity and an increase for high-contour stimuli during explicit perception of emotion. Contour-induced BOLD effects appear to be purely stimulus-driven in early auditory and intonation perception, while being strongly task-dependent in regions involved in higher cognition.

  3. Pulse plating

    CERN Document Server

    Hansal, Wolfgang E G; Green, Todd; Leisner, Peter; Reichenbach, Andreas

    2012-01-01

    The electrodeposition of metals using pulsed current has achieved practical importance in recent years. Although it has long been known that changes in potential, with or without polarity reversal, can significantly affect the deposition process, the practical application of this has been slow to be adopted. This can largely be explained in terms of the complex relationship between the current regime and its effect on the electrodeposition process. In order to harness these effects, an understanding of the anodic and cathodic electrochemical processes is necessary, together with the effects of polarity reversal and the rate of such reversals. In this new monograph, the basics of metal electrodeposition from solution are laid out in great detail in seven distinct chapters. With this knowledge, the reader is able to predict how a given pulse train profile can be adopted to achieve a desired outcome. Equally important is the choice of a suitable rectifier and the ancillary control circuits to enable pulse platin...

  4. U.S. Atlantic East Coast bathymetry contours (EGLORIA_CNT)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The bathymetric contours, which comprise this GIS data layer, contains contours for the U.S. Atlantic East Coast. The dataset was created for use with the USGS...

  5. Comprehensive contour prediction model of work rolls in hot wide strip mill

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Wang; Quan Yang; Anrui He; Renzhong Wang

    2007-01-01

    The predictive calculation of comprehensive contour of work rolls in the on-line strip shape control model during hot rolling consists of two important parts of wear contour calculation and thermal contour calculation, which have a direct influence on the accuracy of shape control. A statistical wear model and a finite difference thermal contour model of work rolls were described. The comprehensive contour is the equivalence treatment of the sum of grinding, wear, and thermal contours. This comprehensive contour calculation model has been applied successfully in the real on-line strip shape control model. Its high precision has been proved through the large amounts of actual roll profile measurements and theoretical analyses. The hit rates (percent of shape index satisfying requirement) of crown and head flatness of the strips rolled, by using the shape control model, which includes the comprehensive contour calculation model, have about 16% and 10% increase respectively, compared to those of strips rolled by using manual operation.

  6. Calf Contouring with Endoscopic Fascial Release, Calf Implant, and Structural Fat Grafting

    Directory of Open Access Journals (Sweden)

    Ercan Karacaoglu, MD

    2013-08-01

    Conclusions: A novel endoscopic approach for lower leg contouring is discussed. Endoscopic fasciotomy technique with calf implant and structural fat grafting for improved lower leg aesthetics is a simple, effective, reliable, and predictable technique for calf contouring.

  7. U.S. Atlantic East Coast bathymetry contours (EGLORIA_CNT)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The bathymetric contours, which comprise this GIS data layer, contains contours for the U.S. Atlantic East Coast. The dataset was created for use with the USGS...

  8. Neural Correlates of the Poggendorff Illusion Driven by Illusory Contour: An fMRI Study

    OpenAIRE

    Qi Chen; Li Li

    2011-01-01

    The Poggendorff illusion is a well-documented geometric illusion that involves the brain's perception of the interaction between oblique lines and object contours: an oblique line is apparently misaligned once interrupted by two parallel contours. This illusion occurs even when the parallel contours are defined subjectively or illusorily. In this fMRI study, we adopted a 4 (type of stimuli: Poggendorff illusion under real contour and its corresponding control condition; Poggendorff illusion u...

  9. Research on Constructing Contours from Regular Terrain Grids Containing Invalid Data

    Institute of Scientific and Technical Information of China (English)

    SU Wei-min; WU Fan

    2004-01-01

    A new method for constructing contours from complicated terrain elevation grids containing invalid data is put forward. By using this method, the topological consistency of contours in groups can be maintained effectively and the contours can be drawn smoothly based on boundaries pre-searching and local correction. An experimental example is given to demonstrate that the contours constructed by this method are of good quality.

  10. The effect of contouring variability on dosimetric parameters for brain metastases treated with stereotactic radiosurgery.

    Science.gov (United States)

    Stanley, Julia; Dunscombe, Peter; Lau, Harold; Burns, Paul; Lim, Gerald; Liu, Hong-Wei; Nordal, Robert; Starreveld, Yves; Valev, Boris; Voroney, Jon-Paul; Spencer, David P

    2013-12-01

    To quantify the effect of contouring variation on stereotactic radiosurgery plan quality metrics for brain metastases. Fourteen metastases, each contoured by 8 physicians, formed the basis of this study. A template-based dynamic conformal 5-arc dose distribution was developed for each of the 112 contours, and each dose distribution was applied to the 7 other contours in each patient set. Radiation Therapy Oncology Group (RTOG) plan quality metrics and the Paddick conformity index were calculated for each of the 896 combinations of dose distributions and contours. The ratio of largest to smallest contour volume for each metastasis varied from 1.25 to 4.47, with a median value of 1.68 (n=8). The median absolute difference in RTOG conformity index between the value for the reference contour and the values for the alternative contours was 0.35. The variation of the range of conformity index for all contours for a given tumor varied with the tumor size. The high degree of interobserver contouring variation strongly suggests that peer review or consultation should be adopted to standardize tumor volume prescription. Observer confidence was not reflected in contouring consistency. The impact of contouring variability on plan quality metrics, used as criteria for clinical trial protocol compliance, was such that the category of compliance was robust to interobserver effects only 70% of the time. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Fast Graph Partitioning Active Contours for Image Segmentation Using Histograms

    Directory of Open Access Journals (Sweden)

    Nath SumitK

    2009-01-01

    Full Text Available Abstract We present a method to improve the accuracy and speed, as well as significantly reduce the memory requirements, for the recently proposed Graph Partitioning Active Contours (GPACs algorithm for image segmentation in the work of Sumengen and Manjunath (2006. Instead of computing an approximate but still expensive dissimilarity matrix of quadratic size, , for a 2D image of size and regular image tiles of size , we use fixed length histograms and an intensity-based symmetric-centrosymmetric extensor matrix to jointly compute terms associated with the complete dissimilarity matrix. This computationally efficient reformulation of GPAC using a very small memory footprint offers two distinct advantages over the original implementation. It speeds up convergence of the evolving active contour and seamlessly extends performance of GPAC to multidimensional images.

  12. Segmentation of Coronal Holes Using Active Contours Without Edges

    CERN Document Server

    Boucheron, L E; McAteer, R T J

    2016-01-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. As the source of the fast solar wind, the detection and characterization of these regions is important for both testing theories of their formation and evolution and from a space weather perspective. Coronal holes are detected in full disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind ...

  13. BABEL - A method for digitization and restoration of contour maps

    Science.gov (United States)

    Westphalen, Gernot

    1995-03-01

    We have developed BABEL as a method for digitization and restoration of contour maps. The results of the comparison between restoration and template are encouraging and first applications are proving very useful. The restoration method is now quite flexible and fast. The result is available as a standard fits file, so that the restored map can be transferred into various coordinate systems and projections and can be used for further digital processing, e.g. for comparison of older radio data with new infrared or X-ray data. So far we have digitized various HI line and 11.1 cm continuum contour maps, for which we know that the original digital data were lost or did never exist in a machine readable format.

  14. Diffusion tensor driven contour closing for cell microinjection targeting.

    Science.gov (United States)

    Becattini, Gabriele; Mattos, Leonardo S; Caldwell, Darwin G

    2010-01-01

    This article introduces a novel approach to robust automatic detection of unstained living cells in bright-field (BF) microscope images with the goal of producing a target list for an automated microinjection system. The overall image analysis process is described and includes: preprocessing, ridge enhancement, image segmentation, shape analysis and injection point definition. The developed algorithm implements a new version of anisotropic contour completion (ACC) based on the partial differential equation (PDE) for heat diffusion which improves the cell segmentation process by elongating the edges only along their tangent direction. The developed ACC algorithm is equivalent to a dilation of the binary edge image with a continuous elliptic structural element that takes into account local orientation of the contours preventing extension towards normal direction. Experiments carried out on real images of 10 to 50 microm CHO-K1 adherent cells show a remarkable reliability in the algorithm along with up to 85% success for cell detection and injection point definition.

  15. Effects of Contoured Pallets on AMC Mission Efficiency

    Science.gov (United States)

    2011-06-01

    airlines. It postulated that national security would benefit from keeping commercial airlines as a viable source of airlift (Donovan, 2011). After the...Research Project, AFIT/ GMO /ENS/04I-01, Air Force Institute of Technology, Wright-Patterson AFB, OH McNabb, Duncan J. (2009). Statement of General Duncan...analysis of the benefits in producing more contoured pallets AMC and USTRANSCOM can increase the efficiency of channel airlift while boosting civilian

  16. Yet another method for triangulation and contouring for automated cartography

    Science.gov (United States)

    De Floriani, L.; Falcidieno, B.; Nasy, G.; Pienovi, C.

    1982-01-01

    An algorithm is presented for hierarchical subdivision of a set of three-dimensional surface observations. The data structure used for obtaining the desired triangulation is also singularly appropriate for extracting contours. Some examples are presented, and the results obtained are compared with those given by Delaunay triangulation. The data points selected by the algorithm provide a better approximation to the desired surface than do randomly selected points.

  17. Contour classification in thermographic images for detection of breast cancer

    Science.gov (United States)

    Okuniewski, Rafał; Nowak, Robert M.; Cichosz, Paweł; Jagodziński, Dariusz; Matysiewicz, Mateusz; Neumann, Łukasz; Oleszkiewicz, Witold

    2016-09-01

    Thermographic images of breast taken by the Braster device are uploaded into web application which uses different classification algorithms to automatically decide whether a patient should be more thoroughly examined. This article presents the approach to the task of classifying contours visible on thermographic images of breast taken by the Braster device in order to make the decision about the existence of cancerous tumors in breast. It presents the results of the researches conducted on the different classification algorithms.

  18. Visual search of illusory contours: an attempt of automatization

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije

    2008-01-01

    Full Text Available Laboratory of Experimental Psychology, University of Belgrade Recent research, which was mostly focused on assessing the types of visual search of illusory contours, showed that visual search is dependent on factors like target configuration and task type. Some experimental research supports the theory of parallel search while other research supports the theory of serial search of illusory contours. The inconsistency is most likely due to the fact that various types of illusory contour configurations were used in set creation. Up to this point, our research indicated that the serial search is used in most cases. Some exceptions of search type have been proven in some modification of task type but nevertheless the search profile remained serial. In this article, we are reporting on two visual search experiments. The first experiment was an investigation of a specific feature of a Kanisza type illusory triangle, orientation. The validity of the profile defined in the first experiment was tested in our second experiment with an attempt to automatize the visual search by the multiplication of the initial experimental trials. Our results confirmed that, regardless of the number of experimental trials, the visual search profile remains serial.

  19. Practical contour segmentation algorithm for small animal digital radiography image

    Science.gov (United States)

    Zheng, Fang; Hui, Gong

    2008-12-01

    In this paper a practical, automated contour segmentation technique for digital radiography image is described. Digital radiography is an imaging mode based on the penetrability of x-ray. Unlike reflection imaging mode such as visible light camera, the pixel brightness represents the summation of the attenuations on the photon thoroughfare. It is not chromophotograph but gray scale picture. Contour extraction is of great importance in medical applications, especially in non-destructive inspection. Manual segmentation techniques include pixel selection, geometrical boundary selection and tracing. But it relies heavily on the experience of the operators, and is time-consuming. Some researchers try to find contours from the intensity jumping characters around them. However these characters also exist in the juncture of bone and soft tissue. The practical way is back to the primordial threshold algorithm. This research emphasizes on how to find the optimal threshold. A high resolution digital radiography system is used to provide the oriental gray scale image. A mouse is applied as the sample of this paper to show the feasibility of the algorithm.

  20. e-Health prototype system for cardiac telemonitoring.

    Science.gov (United States)

    Vargas Escobar, Laura Juliana; Salinas, Sergio Alexander

    2016-08-01

    This paper presents the approach of an e-health system for cardiac telemonitoring which uses the development board LinkIt ONE as a monitoring system. Such board was adapted to measure the cardiac pulse, analyze it and determine whether a person is having a cardiac arrhythmia or not. When an arrhythmia appears, the prototype activates an alarm in order to report the patient's condition and its location to a caregiver or a close healthcare center. The data of the cardiac pulse is originated in an e-health sensor platform connected to an Arduino. Location data comes from a GPS module in the aforementioned board which is connected by WiFi with the virtual platform UBIDOTS. It provides visual information about the variables measured, the patient's location and the alarms; keeping the patient's caregiver or the healthcare center constantly informed.

  1. Time contour expression of limited range phenomena on stack chart; Jugo chart jo deno kyokuchi gensho jikan contour

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T.

    1997-05-27

    Time contour expression of limited range phenomena on stack chart is examined for further improvement on the result of the ultimate interpretation in the seismic reflection survey. The policy is made clear from the beginning that local phenomena are to be discussed, and data prior CMP stacking is interpreted in detail. For this purpose, it is effective to make use of the time contour expression in the midpoint-offset plane simultaneously with the CMP and COP panels. For the review of data prior to CMP stacking, it is convenient to use the CMP (CDP) stacking chart in which the data is arranged methodically. In this chart, all the channels which are crude data prior to stacking are plotted on midpoint-offset coordinates, which plane is called the MOD (Midpoint Offset Domain) panel. Various panels can be chosen unrestrictedly, and their mutual relations can be easily grasped. When data points are given a time axis, they can be expressed in a time contour. Studies are conducted about the underground structure, multiple reflection paths divided by it, and characteristics of detour reflection attributable to faults. 4 refs., 9 figs.

  2. Pulsed thermoelectricity

    Science.gov (United States)

    Apostol, M.; Nedelcu, M.

    2010-07-01

    A special mechanism of thermoelectric transport is described, consisting of pulses of charge carriers which "fly" periodically through the external circuit from the hot end of the sample to the cold end, with a determined duration of the "on" and "off" times of the electric contacts, while maintaining continuously the thermal contacts. It is shown that such a "resonant" ideal thermogenerator may work cyclically, with the same efficiency quotient as the ideal efficiency quotient of the thermoelectric devices operated in the usual stationary transport regime but the electric flow and power are increased, as a consequence of the concentration of the charge carriers on pulses of small spatial extent. The process is reversible, in the sense that it can be operated either as a thermoelectric generator or as an electrothermal cooler.

  3. A Contour-Guided Deformable Image Registration Algorithm for Adaptive Radiotherapy

    CERN Document Server

    Gu, Xuejun; Wang, Jing; Yordy, John; Mell, Loren; Jia, Xun; Jiang, Steve B

    2013-01-01

    In adaptive radiotherapy, deformable image registration is often conducted between the planning CT and treatment CT (or cone beam CT) to generate a deformation vector field (DVF) for dose accumulation and contour propagation. The auto propagated contours on the treatment CT may contain relatively large errors, especially in low contrast regions. A clinician inspection and editing of the propagated contours are frequently needed. The edited contours are able to meet the clinical requirement for adaptive therapy; however, the DVF is still inaccurate and inconsistent with the edited contours. The purpose of this work is to develop a contour-guided deformable image registration (CG-DIR) algorithm to improve the accuracy and consistency of the DVF for adaptive radiotherapy. Incorporation of the edited contours into the registration algorithm is realized by regularizing the objective function of the original demons algorithm with a term of intensity matching between the delineated structures set pairs. The CG-DIR a...

  4. RBF neural network and active circles based algorithm for contours extraction

    Institute of Scientific and Technical Information of China (English)

    Zhou Zhiheng; Zeng Delu; Xie Shengli

    2007-01-01

    For the contours extraction from the images, active contour model and self-organizing map based approach are popular nowadays. But they are still confronted with the problems that the optimization of energy function will trap in local minimums and the contour evolutions greatly depend on the initial contour selection. Addressing to these problems, a contours extraction algorithm based on RBF neural network is proposed here. A series of circles with adaptive radius and center is firstly used to search image feature points that are scattered enough. After the feature points are clustered, a group of radial basis functions are constructed. Using the pixels' intensities and gradients as the input vector, the final object contour can be obtained by the predicting ability of the neural network. The RBF neural network based algorithm is tested on three kinds of images, such as changing topology, complicated background, and blurring or noisy boundary. Simulation results show that the proposed algorithm performs contours extraction greatly.

  5. What Is Cardiac Rehabilitation?

    Science.gov (United States)

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  6. Cardiac tamponade (image)

    Science.gov (United States)

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  7. Cardiac Procedures and Surgeries

    Science.gov (United States)

    ... Procedure Learn more about cardiac medications , including dual antiplatelet therapy, that you may need to take after your ... Procedure Learn more about cardiac medications , including dual antiplatelet therapy, that you may need to take after your ...

  8. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    Amin, A.S.; Asghari-Roodsari, A.; Tan, H.L.

    2010-01-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  9. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    Amin, A.S.; Asghari-Roodsari, A.; Tan, H.L.

    2010-01-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  10. The hydrological impact of contour trenching in Vietnam

    Science.gov (United States)

    Pramana, K. E. R.; Ertsen, M. W.; Uhlenbrook, S.; de Laat, P.; Nonner, J.

    2009-04-01

    At the foothill in the driest rural area in Vietnam, at Ninh Thuan province, poor farmers cultivate up-land crops during the wet season. The area is about 9 hectares of deforested land with a slope up to 8% and has a geology surface of crusted sands and gravels. Water is scarce during the dry season and runs off rapidly during the wet season. Hence, to provide sustainable water resources and support crop growth, a project started in 2007 aiming introducing contour trenching. The main purpose of contour trenching is to trap run off, increase soil moisture for vegetation growth and recharge the groundwater. In order to investigate the impact of the trenches, a field monitoring program was initiated measuring rainfall, soil moisture content, surface water levels and groundwater levels. Recorded annual rainfall reached 600 mm. The groundwater levels are relatively deep and constant at -8 and -10 meters. The soil moisture content ranged from 3% at the driest condition to 37% below the trench at ponding. Water levels in trenches differed from uphill to downhill with higher levels at the first trench uphill. After ponding, water in the trenches infiltrates within a period of days. In this contribution, available field measurements are analyzed in two ways. First, runoff is analyzed. Immediately after significant rainfall events, the observed ponding levels in the trenches with defined uphill runoff areas can be related to the rainfall. The results show reduction of runoff coefficients per trench in downhill direction. Second, the two dimension numerical saturated-unsaturated model Hydrus 2-D was used to simulate the soil moisture content measurements. Model results confirm that infiltration is a quick process in this area with its loamy sand soils. Based on these analyzes, potential of contour trenches for local water retention and groundwater recharge will be discussed.

  11. Cryolipolysis for noninvasive body contouring: clinical efficacy and patient satisfaction

    Directory of Open Access Journals (Sweden)

    Krueger N

    2014-06-01

    Full Text Available Nils Krueger,1 Sophia V Mai,2 Stefanie Luebberding,1 Neil S Sadick3 1Rosenpark Research, Darmstadt, Germany; 2Department of Dermatology, Louisiana State University, New Orleans, LA, 3Department of Dermatology, Weill Cornell Medical College, New York, NY, USA Abstract: In recent years, a number of modalities have become available for the noninvasive reduction of adipose tissue, including cryolipolysis, radiofrequency, low-level laser, and high-intensity focused ultrasound. Each technology employs a different mechanism of action to cause apoptosis or necrosis of the targeted adipocytes. Among these technologies, cryolipolysis has not only been commercially available for the longest time, but has also been best researched including in vitro and animal models and randomized controlled clinical trials in humans. The principle behind cryolipolysis exploits the premise that adipocytes are more susceptible to cooling than other skin cells. The precise application of cold temperatures triggers apoptosis of the adipocytes, which invokes an inflammatory response and leads to slow digestion by surrounding macrophages. In clinical studies, cryolipolysis was shown to reduce subcutaneous fat at the treatment site by up to 25% after one treatment. Improvements were seen in 86% of treated subjects. At 73%, the patient satisfaction rate is higher than with other technologies used for noninvasive lipolysis. Cryolipolysis has been proven to be a very safe method for body contouring, and is accomplished with only minimal discomfort. Expected side effects are temporary erythema, bruising, and transient numbness that usually resolve within 14 days after treatment. With a prevalence of 0.1%, the most common complaint is late-onset pain, occurring 2 weeks post-procedure, which resolves without intervention. Although no procedure has been accepted as the gold standard for noninvasive body contouring as yet, cryolipolysis is considered to be both safe and efficient with a

  12. Terrain Contour Matching (TERCOM): A Cruise Missile Guidance Aid

    Science.gov (United States)

    Golden, Joe P.

    1980-12-01

    The Cruise Missile is guided by an inertial guidance system aided by an updating technique called Terrain Contour Matching (TERCOM). Chance-Vought first proposed the terrain correlation technique in the late 1950's. Since that time TERCOM has evolved into a reliable, accurate, all weather, day and night method of position fixing and updating for cruise missiles. A brief history of TERCOM development will be presented giving results where possible. A description of TERCOM and how is works will be discussed. A snapshot of the present TERCOM status and future planned developments will be addressed.

  13. Laser Welding Of Contoured Thin-Wall Housings

    Science.gov (United States)

    Spiegel, Lyle B.; Oleksiak, Carl E.

    1991-01-01

    Superalloy parts joined with less distortion. Carbon dioxide laser beam directed by optics in numerically controlled robot arm welds shell-type turbopump housings having complicated shapes. 5-kW laser, following single programmed three-dimensional pass, produces high-quality, full-penetration weld pass in age-hardenable nickel superalloy. Operator easily programs robot by using teaching pendant to track weld joint and keeps laser focused on workpiece while following contour of shell. Shells welded in rapid succession, with minimal change in setup for each.

  14. Control of Open Contour Formations of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Uwe Zimmer

    2008-11-01

    Full Text Available In this paper, we propose a distributed elastic behaviour for a deformable chain-like formation of small autonomous underwater vehicles with the task of forming special shapes which have been explicitly defined or are defined by some iso-contour of an environmental concentration field. In the latter case, the formation has to move in such a way as to meet certain formation parameters as well as adapt to the iso-line. We base our controller on our previous models (for manually controlled end points using general curve evolution theory but will also propose appropriate motions for the end robots of an open chain.

  15. SOl-based radial-contour-mode micromechanical disk resonator

    Institute of Scientific and Technical Information of China (English)

    Jia Yingqian; Zhao Zhengping; Yang Yongjun; Hu Xiaodong; Li Qian

    2011-01-01

    This paper reports a radial-contour-mode micromechanical disk resonator for radio frequency applications.This disk resonator with a gold plated layer as the electrodes,was prepared on a silicon-on-insulator wafer,which is supported by an anchor on another silicon wafer through Au-Au thermo-compression bonding.The gap between the disk and the surrounding gold electrodes is 100 nm.The radius of the disk is 20 μm and the thickness is 4.5μm.In results,the resonator shows a resonant frequency of 143 MHz and a quality factor of 5600 in vacuum.

  16. Contour tracking and corner detection in a logic programming environment

    DEFF Research Database (Denmark)

    Bell, Benjamin; Pau, L. F.

    1990-01-01

    The added functionality such as contour tracking and corner detection which logic programming lends to standard image operators is described. An environment for implementing low-level imaging operations with Prolog predicates is considered. Within this environment, higher-level image predicates...... has been very good in many more complex images, as it allows for feedback both ways between sensor input and symbolic models. More important is the parameter selection capability in a dynamic version where background properties change. The authors present examples of Prolog predicates for performing...

  17. Differences in Radiotherapy Delivery and Outcome Due to Contouring Variation

    DEFF Research Database (Denmark)

    Hollensen, Christian; Persson, Gitte; Højgaard, Liselotte;

    2012-01-01

    segmentation methods also produce different results. There is no consensus on how to account for the contouring uncertainty, but has been suggested to incorporate it into the planning target volume (PTV) margin. Current recipes for the PTV margin are based on normal distribution assumptions and are more......Gross tumor volume (GTV) delineation is central for radiotherapy planning. It provides the basis of the clinical target volume and, ultimately, the planning target volume which is used for dose optimization. Manual GTV delineations are prone to intra- and inter-observer variation and automatic...

  18. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  19. The Effect of Local Orientation Change on the Detection of Contours Defined by Constant Curvature: Psychophysics and Image Statistics

    Science.gov (United States)

    Khuu, Sieu K.; Cham, Joey; Hayes, Anthony

    2017-01-01

    In the present study, we investigated the detection of contours defined by constant curvature and the statistics of curved contours in natural scenes. In Experiment 1, we examined the degree to which human sensitivity to contours is affected by changing the curvature angle and disrupting contour curvature continuity by varying the orientation of end elements. We find that (1) changing the angle of contour curvature decreased detection performance, while (2) end elements oriented in the direction (i.e., clockwise) of curvature facilitated contour detection regardless of the curvature angle of the contour. In Experiment 2 we further established that the relative effect of end—element orientation on contour detection was not only dependent on their orientation (collinear or cocircular), but also their spatial separation from the contour, and whether the contour shape was curved or not (i.e., C-shaped or S-shaped). Increasing the spatial separation of end-elements reduced contour detection performance regardless of their orientation or the contour shape. However, at small separations, cocircular end-elements facilitated the detection of C-shaped contours, but not S-shaped contours. The opposite result was observed for collinear end-elements, which improved the detection of S- shaped, but not C-shaped contours. These dissociative results confirmed that the visual system specifically codes contour curvature, but the association of contour elements occurs locally. Finally, we undertook an analysis of natural images that mapped contours with a constant angular change and determined the frequency of occurrence of end elements with different orientations. Analogous to our behavioral data, this image analysis revealed that the mapped end elements of constantly curved contours are likely to be oriented clockwise to the angle of curvature. Our findings indicate that the visual system is selectively sensitive to contours defined by constant curvature and that this might

  20. The Poggendorff illusion driven by real and illusory contour: Behavioral and neural mechanisms.

    Science.gov (United States)

    Shen, Lu; Zhang, Ming; Chen, Qi

    2016-05-01

    The Poggendorff illusion refers to the phenomenon that the human brain misperceives a diagonal line as being apparently misaligned once the diagonal line is interrupted by two parallel edges, and the size of illusion is negatively correlated with the angle of interception of the oblique, i.e. the sharper the oblique angle, the larger the illusion. This optical illusion can be produced by both real and illusory contour. In this fMRI study, by parametrically varying the oblique angle, we investigated the shared and specific neural mechanisms underlying the Poggendorff illusion induced by real and illusory contour. At the behavioral level, not only the real but also the illusory contours were capable of inducing significant Poggendorff illusion. The size of illusion induced by the real contour, however, was larger than that induced by the illusory contour. At the neural level, real and illusory contours commonly activated more dorsal visual areas, and the real contours specifically activated more ventral visual areas. More importantly, examinations on the parametric modulation effects of the size of illusion revealed the specific neural mechanisms underlying the Poggendorff illusion induced by the real and the illusory contours, respectively. Left precentral gyrus and right middle occipital cortex were specifically involved in the Poggendorff illusion induced by the real contour. On the other hand, bilateral intraparietal sulcus (IPS) and right lateral occipital complex (LOC) were specifically involved in the Poggendorff illusion induced by the illusory contour. Functional implications of the above findings were further discussed.

  1. An automated workflow for patient-specific quality control of contour propagation

    Science.gov (United States)

    Beasley, William J.; McWilliam, Alan; Slevin, Nicholas J.; Mackay, Ranald I.; van Herk, Marcel

    2016-12-01

    Contour propagation is an essential component of adaptive radiotherapy, but current contour propagation algorithms are not yet sufficiently accurate to be used without manual supervision. Manual review of propagated contours is time-consuming, making routine implementation of real-time adaptive radiotherapy unrealistic. Automated methods of monitoring the performance of contour propagation algorithms are therefore required. We have developed an automated workflow for patient-specific quality control of contour propagation and validated it on a cohort of head and neck patients, on which parotids were outlined by two observers. Two types of error were simulated—mislabelling of contours and introducing noise in the scans before propagation. The ability of the workflow to correctly predict the occurrence of errors was tested, taking both sets of observer contours as ground truth, using receiver operator characteristic analysis. The area under the curve was 0.90 and 0.85 for the observers, indicating good ability to predict the occurrence of errors. This tool could potentially be used to identify propagated contours that are likely to be incorrect, acting as a flag for manual review of these contours. This would make contour propagation more efficient, facilitating the routine implementation of adaptive radiotherapy.

  2. An automated workflow for patient-specific quality control of contour propagation.

    Science.gov (United States)

    Beasley, William J; McWilliam, Alan; Slevin, Nicholas J; Mackay, Ranald I; van Herk, Marcel

    2016-12-21

    Contour propagation is an essential component of adaptive radiotherapy, but current contour propagation algorithms are not yet sufficiently accurate to be used without manual supervision. Manual review of propagated contours is time-consuming, making routine implementation of real-time adaptive radiotherapy unrealistic. Automated methods of monitoring the performance of contour propagation algorithms are therefore required. We have developed an automated workflow for patient-specific quality control of contour propagation and validated it on a cohort of head and neck patients, on which parotids were outlined by two observers. Two types of error were simulated-mislabelling of contours and introducing noise in the scans before propagation. The ability of the workflow to correctly predict the occurrence of errors was tested, taking both sets of observer contours as ground truth, using receiver operator characteristic analysis. The area under the curve was 0.90 and 0.85 for the observers, indicating good ability to predict the occurrence of errors. This tool could potentially be used to identify propagated contours that are likely to be incorrect, acting as a flag for manual review of these contours. This would make contour propagation more efficient, facilitating the routine implementation of adaptive radiotherapy.

  3. Body contouring after obesity surgery is associated with a weight loss benefit among patients.

    Science.gov (United States)

    Agarwal, Shailesh; Shenaq, Deana; Teven, Chad M; Prachand, Vivek; Roughton, Michelle; Zachary, Lawrence

    2017-09-01

    Patients who undergo obesity surgery often require body contouring procedures to eliminate excess skin. Recent studies suggest that body contouring surgery may provide psychological benefits to patients after obesity surgery. However, it remains unclear how body contouring may affect weight loss maintenance after obesity surgery. This is a retrospective review of patients who underwent obesity surgery with or without body contouring at a single institution from 2000 to 2005. Charts were reviewed for demographic, medical, and surgical information. The primary outcome of interest was the difference in weight loss maintenance among patients who underwent body contouring versus those who did not. A total of 318 patients were included for analysis in this study, of which 70 underwent obesity surgery with body contouring and 248 underwent obesity surgery without body contouring. The mean change in BMI among patients who did not undergo body contouring was 19.7 kg/m(2). The mean change in BMI among patients who underwent body contouring was 22.1 kg/m(2). Among patients who underwent body contouring surgery, 2.9% (2/70) of patients did not maintain at least a 20% decrease in body weight during the entire follow-up period (mean follow-up time 92.2 months). Among patients who did not undergo body contouring surgery, 10% (25/248) of patients did not maintain at least a 20% decrease in body weight during the entire follow-up period (mean follow-up time 39.0 months) (χ(2) = 3.67, p = 0.055). Body contouring surgery may have a positive effect on weight loss maintenance after body contouring determined from the mean weight change and on percentage of patients who maintain at least a 20% decrease in body weight. Copyright © 2017. Published by Elsevier Ltd.

  4. Mechanisms of cardiac pain.

    Science.gov (United States)

    Foreman, Robert D; Garrett, Kennon M; Blair, Robert W

    2015-04-01

    Angina pectoris is cardiac pain that typically is manifested as referred pain to the chest and upper left arm. Atypical pain to describe localization of the perception, generally experienced more by women, is referred to the back, neck, and/or jaw. This article summarizes the neurophysiological and pharmacological mechanisms for referred cardiac pain. Spinal cardiac afferent fibers mediate typical anginal pain via pathways from the spinal cord to the thalamus and ultimately cerebral cortex. Spinal neurotransmission involves substance P, glutamate, and transient receptor potential vanilloid-1 (TRPV1) receptors; release of neurokinins such as nuclear factor kappa b (NF-kb) in the spinal cord can modulate neurotransmission. Vagal cardiac afferent fibers likely mediate atypical anginal pain and contribute to cardiac ischemia without accompanying pain via relays through the nucleus of the solitary tract and the C1-C2 spinal segments. The psychological state of an individual can modulate cardiac nociception via pathways involving the amygdala. Descending pathways originating from nucleus raphe magnus and the pons also can modulate cardiac nociception. Sensory input from other visceral organs can mimic cardiac pain due to convergence of this input with cardiac input onto spinothalamic tract neurons. Reduction of converging nociceptive input from the gallbladder and gastrointestinal tract can diminish cardiac pain. Much work remains to be performed to discern the interactions among complex neural pathways that ultimately produce or do not produce the sensations associated with cardiac pain.

  5. Kredsløbsmonitorering med lithium dilution cardiac output-systemet

    DEFF Research Database (Denmark)

    Christiansen, Christian; Hostrup, Anette; Tønnesen, Else

    2008-01-01

    The lithium dilution cardiac output (LiDCO) system measures cardiac output beat-to-beat with high precision. The system is based on an arterial pulse power analysis which is calibrated every eight hours with a small non-pharmacological dose of lithium. The system is minimally invasive; it requires...

  6. Cardiac tumours in children

    Directory of Open Access Journals (Sweden)

    Parsons Jonathan M

    2007-03-01

    Full Text Available Abstract Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT and Magnetic Resonance Imaging (MRI of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

  7. Theory on the molecular characteristic contour (II)--Molecular intrinsic characteristic contours of several typical organic molecules

    Institute of Scientific and Technical Information of China (English)

    GONG; Lidong; ZHAO; Dongxia; YANG; Zhongzhi

    2005-01-01

    The molecular intrinsic characteristic contour (MICC) is defined based on the classical turning point of electron movement in a molecule. Three typical organic molecules, I.e. Methane, methanol and formic acid, were employed as examples for detailed introduction of our method. Investigations on the cross-sections of MICC provide important information about atomic size changing in the process of forming molecules. The electron density distributions on the MICCs of these molecules were calculated and shown for the first time. Results showed that the electron density distribution on the MICC correlates closely with molecular chemical properties, and it provides a new insight into molecular boundary.

  8. RESEARCH OF BASIFACIAL CONTOURING SCULPTURE BY MANDIBULAR ANGLE OSTECTOMY

    Institute of Scientific and Technical Information of China (English)

    FANG Jian-lin; DAI Chuan-chang; ZHU Guo-xian; ZHANG Ying; JIN Yu-qing; WANG Wei; QI Chuan-liang

    2006-01-01

    Objective Mandibular angle ostectomy is usually applied to the facial contouring sculpture.We evaluated the various techniques in order to enhance the precision and avoid unnecessary damage. Methods Before operation the area and quantity resected bone were designed according to facial measurement, mandible pantomography and orthophoria and lateral localized radiograph of skull. The Incises of mandibular angle ostectomy included intraoral, retroauricular or intraoral associated with retroauricular. Howerer, the sagittal resection of mandible outer table was necessary in all intraoral incise. Results Single mandibular angle ostectomy was not satisfactory for the patients having mandible hypertrophy with over-width basifacial contouring. Mandibular angle ostectomy combined with the sagittal resection of outer table of mandibular angle were required. Good symmetry and ap pearance were gained in 206 cases. One case had facial paralysis. Two patients occured mandibular fracture during the operation. Three cases complicated angled deformity at mandible body. Conclusion Reduction mandibuloplasty should be selected depends on varied types of mandibular angle hypertrophy before operation.

  9. Pupil segmentation using active contour with shape prior

    Science.gov (United States)

    Ukpai, Charles O.; Dlay, Satnam S.; Woo, Wai L.

    2015-03-01

    Iris segmentation is the process of defining the valid part of the eye image used for further processing (feature extraction, matching and decision making). Segmentation of the iris mostly starts with pupil boundary segmentation. Most pupil segmentation techniques are based on the assumption that the pupil is circular shape. In this paper, we propose a new pupil segmentation technique which combines shape, location and spatial information for accurate and efficient segmentation of the pupil. Initially, the pupil's position and radius is estimated using a statistical approach and circular Hough transform. In order to segment the irregular boundary of the pupil, an active contour model is initialized close to the estimated boundary using information from the first step and segmentation is achieved using energy minimization based active contour. Pre-processing and post-processing were carried out to remove noise and occlusions respectively. Experimental results on CASIA V1.0 and 4.0 shows that the proposed method is highly effective at segmenting irregular boundaries of the pupil.

  10. Fast Virtual Stenting with Active Contour Models in Intracranical Aneurysm.

    Science.gov (United States)

    Zhong, Jingru; Long, Yunling; Yan, Huagang; Meng, Qianqian; Zhao, Jing; Zhang, Ying; Yang, Xinjian; Li, Haiyun

    2016-02-15

    Intracranial stents are becoming increasingly a useful option in the treatment of intracranial aneurysms (IAs). Image simulation of the releasing stent configuration together with computational fluid dynamics (CFD) simulation prior to intervention will help surgeons optimize intervention scheme. This paper proposed a fast virtual stenting of IAs based on active contour model (ACM) which was able to virtually release stents within any patient-specific shaped vessel and aneurysm models built on real medical image data. In this method, an initial stent mesh was generated along the centerline of the parent artery without the need for registration between the stent contour and the vessel. Additionally, the diameter of the initial stent volumetric mesh was set to the maximum inscribed sphere diameter of the parent artery to improve the stenting accuracy and save computational cost. At last, a novel criterion for terminating virtual stent expanding that was based on the collision detection of the axis aligned bounding boxes was applied, making the stent expansion free of edge effect. The experiment results of the virtual stenting and the corresponding CFD simulations exhibited the efficacy and accuracy of the ACM based method, which are valuable to intervention scheme selection and therapy plan confirmation.

  11. The contour method cutting assumption: error minimization and correction

    Energy Technology Data Exchange (ETDEWEB)

    Prime, Michael B [Los Alamos National Laboratory; Kastengren, Alan L [ANL

    2010-01-01

    The recently developed contour method can measure 2-D, cross-sectional residual-stress map. A part is cut in two using a precise and low-stress cutting technique such as electric discharge machining. The contours of the new surfaces created by the cut, which will not be flat if residual stresses are relaxed by the cutting, are then measured and used to calculate the original residual stresses. The precise nature of the assumption about the cut is presented theoretically and is evaluated experimentally. Simply assuming a flat cut is overly restrictive and misleading. The critical assumption is that the width of the cut, when measured in the original, undeformed configuration of the body is constant. Stresses at the cut tip during cutting cause the material to deform, which causes errors. The effect of such cutting errors on the measured stresses is presented. The important parameters are quantified. Experimental procedures for minimizing these errors are presented. An iterative finite element procedure to correct for the errors is also presented. The correction procedure is demonstrated on experimental data from a steel beam that was plastically bent to put in a known profile of residual stresses.

  12. A NOVEL FAST MOVING OBJECT CONTOUR TRACKING ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    An Guocheng; Yang Hao; Wu Zhenyang

    2009-01-01

    If a somewhat fast moving object exists in a complicated tracking environment, snake's nodes may fall into the inaccurate local minima. We propose a mean shift snake algorithm to solve this problem. However, if the object goes beyond the limits of mean shift snake module operation in successive sequences, mean shift snake's nodes may also fall into the local minima in their moving to the new object position. This paper presents a motion compensation strategy by using particle filter; therefore a new Particle Filter Mean Shift Snake (PFMSS) algorithm is proposed which combines particle filter with mean shift snake to fulfill the estimation of the fast moving object contour. Firstly, the fast moving object is tracked by particle filter to create a coarse position which is used to initialize the mean shift algorithm. Secondly, the whole relevant motion information is used to compensate the snake's node positions. Finally, snake algorithm is used to extract the exact object contour and the useful information of the object is fed back. Some real world sequences are tested and the results show that the novel tracking method have a good performance with high accuracy in solving the fast moving problems in cluttered background.

  13. Contouring error compensation on a micro coordinate measuring machine

    Science.gov (United States)

    Fan, Kuang-Chao; Wang, Hung-Yu; Ye, Jyun-Kuan

    2011-12-01

    In recent years, three-dimensional measurements of nano-technology researches have received a great attention in the world. Based on the high accuracy demand, the error compensation of measurement machine is very important. In this study, a high precision Micro-CMM (coordinate measuring machine) has been developed which is composed of a coplanar stage for reducing the Abbé error in the vertical direction, the linear diffraction grating interferometer (LDGI) as the position feedback sensor in nanometer resolution, and ultrasonic motors for position control. This paper presents the error compensation strategy including "Home accuracy" and "Position accuracy" in both axes. For the home error compensation, we utilize a commercial DVD pick-up head and its S-curve principle to accurately search the origin of each axis. For the positioning error compensation, the absolute positions relative to the home are calibrated by laser interferometer and the error budget table is stored for feed forward error compensation. Contouring error can thus be compensated if both the compensation of both X and Y positioning errors are applied. Experiments show the contouring accuracy can be controlled to within 50nm after compensation.

  14. Evaluation of solar mirror figure by moire contouring

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, J.W.; Lind, M.A.

    1980-06-01

    Moire topography is applied to the figure assessment of solar mirrors. The technique is demonstrated on component facets of a six-meter diameter, four-meter focal length, parabolic dish collector. The relative ease of experimental implementation and subsequent data analysis suggests distinct advantages over the more established laser ray trace or BCS/ICS technique for many applications. The theoretical and experimental considerations necessary to fully implement moire topography on mirror surfaces are detailed. A procedure to de-specularize the mirror is demonstrated which conserves the surface morphology without damaging the reflective surface. The moire fringe patterns observed for the actual mirror facets are compared with theoretical contours generated for representative dish facets using a computer simulation algorithm. A method for evaluating the figure error of the real facet is presented in which the error parameter takes the form of an average absolute deviation of the surface slope from theoretical. The experimental measurement system used for this study employs a 200 line/inch Ronchi transmission grating. The mirror surface is illuminated by a collimated beam at 60/sup 0/. The fringe observation is performed normal to the grating. These parameters yield contour intervals for the fringe patterns of 0.073 mm. The practical considerations for extending the techniques to higher resolution are discussed.

  15. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

    Boucheron, L. E.; Valluri, M.; McAteer, R. T. J.

    2016-10-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. The detection and characterization of these regions is important for testing theories of their formation and evolution, and also from a space weather perspective because they are the source of the fast solar wind. Coronal holes are detected in full-disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than the surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. The means to identify a coronal hole without specifying a final intensity threshold may allow this algorithm to be more robust across multiple datasets, regardless of data type, resolution, and quality.

  16. Lateral lower face and neck contouring following burn injury.

    Directory of Open Access Journals (Sweden)

    Sadrollah Motamed

    2015-04-01

    Full Text Available The neck is normally a concave and highly mobile structure. Facial and cervical skin is prone to burn scar contracture because of its thin nature. The goal of treatment is to reconstruct this region to achieve a good aesthetic outcome and also normal neck and chin mobilization. This study was conducted to compare the effect of one row of suture and three rows of suture in critical points of the neck to recreate cervicomandibular angle for better contouring of the neck. A cross-sectional study was performed from July 2006 until August 2010. A total of 65 patients underwent lower lateral face and neck burn scar contracture reconstruction. The mean age of participants was 25.5 years old. After designing a local flap, in 31 patients we applied one row of suture. In 34 patients, we used three rows of suture on each side of the neck incorporation with  the recipient bed and the flap dermis or capsule to recreate a natural lower lateral face and neck contour (P<0.001. The standard deviation in hospitalization was 7 ± 2 days for group A and 6 ± 1 days for group B. In a two years follow-up, no blunting of cervicomandibular angle occurred and three rows of suture were superior according to present findings.

  17. The Contour Mapping Program for Prompt Environmental Radiation Distribution Display

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uk Jae; Yoo, Dong Han; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2013-10-15

    For prompt response and consequent measure at the environmental radiation emergency of nuclear installations which include nuclear power plants, needed is rapid and movable monitoring system which can display and analyze distribution of overall environmental radiation around surrounding area. At occurrence of the nuclear emergency including the disastrous accident like the Fukushima Nuclear Power Plants accident or detected radiation in the public city environment, the comprehensive understanding of rapid radiation distribution, which has measurement error, is essential for the quick measuring on the public protection in the surrounding area. For that, 2D and 3D contour mapping method are developed for the distribution of natural radiation, major artificial radiation ({sup 137}Cs, {sup 131}I), and total radiation, which is based on the information which is auto-recognized and interpolated for virtually measured radiation data by using random number generation. Especially, the radiation contour is displayed on the map image of the measured area so that the radiation distribution can be understood at a glance. 2D and 3D mapping programming for the distribution of radiation on the simulated measured radiation data was carried out by using MATLAB language. It showed the operation time of a few ten seconds which was more than 100 times faster than conventional technique. It was thought that the present study could be directly employed for the understanding of rapid and comprehensive radiation distribution on the public environment at the nuclear or radiation emergency.

  18. Segmentation of Coronal Holes Using Active Contours Without Edges

    Science.gov (United States)

    Boucheron, L. E.; Valluri, M.; McAteer, R. T. J.

    2016-09-01

    An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. The detection and characterization of these regions is important for testing theories of their formation and evolution, and also from a space weather perspective because they are the source of the fast solar wind. Coronal holes are detected in full-disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than the surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. The means to identify a coronal hole without specifying a final intensity threshold may allow this algorithm to be more robust across multiple datasets, regardless of data type, resolution, and quality.

  19. Tight focusing of femtosecond elliptically polarised vortex light pulses

    Institute of Scientific and Technical Information of China (English)

    Hua Li-Min; Chen Bao-Suan; Chen Zi-Yang; Pu Ji-Xiong

    2011-01-01

    This paper studies the tight focusing properties of femtosecond elliptically polarised vortex light pulses. Based on Richards-Wolf vectorial diffraction integral, the expressions for the electric field, the velocity of the femtosecond light pulse and the total angular momentum of focused pluses are derived. The numerical calculations are also given to illustrate the intensity distribution, phase contour, the group velocity variation and the total angular momentum near the focus. It finds that near the focus the femtosecond elliptically polarised vortex light pulse can travel at various group speeds, that is, slower or faster than light speed in vacuum, depending on the numerical aperture of the focusing objective system. Moreover, it also studies the influence of the numerical aperture of the focusing objective and the time duration of the elliptically polarised vortex light pulse on the total angular momentum distribution in the focused field.

  20. Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

    Science.gov (United States)

    van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

    2015-01-01

    Non-invasive electrocardiographic imaging (ECGI) of the cardiac muscle can help the pre-procedure planning of the ablation of ventricular arrhythmias by reducing the time to localize the origin. Our non-invasive ECGI system, the cardiac isochrone positioning system (CIPS), requires non-intersecting meshes of the heart, lungs and torso. However, software to reconstruct the meshes of the heart, lungs and torso with the capability to check and prevent these intersections is currently lacking. Consequently the reconstruction of a patient specific model with realistic atrial and ventricular wall thickness and incorporating blood cavities, lungs and torso usually requires additional several days of manual work. Therefore new software was developed that checks and prevents any intersections, and thus enables the use of accurate reconstructed anatomical models within CIPS. In this preliminary study we investigated the accuracy of the created patient specific anatomical models from MRI or CT. During the manual segmentation of the MRI data the boundaries of the relevant tissues are determined. The resulting contour lines are used to automatically morph reference meshes of the heart, lungs or torso to match the boundaries of the morphed tissue. Five patients were included in the study; models of the heart, lungs and torso were reconstructed from standard cardiac MRI images. The accuracy was determined by computing the distance between the segmentation contours and the morphed meshes. The average accuracy of the reconstructed cardiac geometry was within 2mm with respect to the manual segmentation contours on the MRI images. Derived wall volumes and left ventricular wall thickness were within the range reported in literature. For each reconstructed heart model the anatomical heart axis was computed using the automatically determined anatomical landmarks of the left apex and the mitral valve. The accuracy of the reconstructed heart models was well within the accuracy of the used

  1. Right ventricle segmentation from cardiac MRI: a collation study.

    Science.gov (United States)

    Petitjean, Caroline; Zuluaga, Maria A; Bai, Wenjia; Dacher, Jean-Nicolas; Grosgeorge, Damien; Caudron, Jérôme; Ruan, Su; Ayed, Ismail Ben; Cardoso, M Jorge; Chen, Hsiang-Chou; Jimenez-Carretero, Daniel; Ledesma-Carbayo, Maria J; Davatzikos, Christos; Doshi, Jimit; Erus, Guray; Maier, Oskar M O; Nambakhsh, Cyrus M S; Ou, Yangming; Ourselin, Sébastien; Peng, Chun-Wei; Peters, Nicholas S; Peters, Terry M; Rajchl, Martin; Rueckert, Daniel; Santos, Andres; Shi, Wenzhe; Wang, Ching-Wei; Wang, Haiyan; Yuan, Jing

    2015-01-01

    Magnetic Resonance Imaging (MRI), a reference examination for cardiac morphology and function in humans, allows to image the cardiac right ventricle (RV) with high spatial resolution. The segmentation of the RV is a difficult task due to the variable shape of the RV and its ill-defined borders in these images. The aim of this paper is to evaluate several RV segmentation algorithms on common data. More precisely, we report here the results of the Right Ventricle Segmentation Challenge (RVSC), concretized during the MICCAI'12 Conference with an on-site competition. Seven automated and semi-automated methods have been considered, along them three atlas-based methods, two prior based methods, and two prior-free, image-driven methods that make use of cardiac motion. The obtained contours were compared against a manual tracing by an expert cardiac radiologist, taken as a reference, using Dice metric and Hausdorff distance. We herein describe the cardiac data composed of 48 patients, the evaluation protocol and the results. Best results show that an average 80% Dice accuracy and a 1cm Hausdorff distance can be expected from semi-automated algorithms for this challenging task on the datasets, and that an automated algorithm can reach similar performance, at the expense of a high computational burden. Data are now publicly available and the website remains open for new submissions (http://www.litislab.eu/rvsc/).

  2. Ups and Downs in Auditory Development: Preschoolers' Sensitivity to Pitch Contour and Timbre.

    Science.gov (United States)

    Creel, Sarah C

    2016-03-01

    Much research has explored developing sound representations in language, but less work addresses developing representations of other sound patterns. This study examined preschool children's musical representations using two different tasks: discrimination and sound-picture association. Melodic contour--a musically relevant property--and instrumental timbre, which is (arguably) less musically relevant, were tested. In Experiment 1, children failed to associate cartoon characters to melodies with maximally different pitch contours, with no advantage for melody preexposure. Experiment 2 also used different-contour melodies and found good discrimination, whereas association was at chance. Experiment 3 replicated Experiment 2, but with a large timbre change instead of a contour change. Here, discrimination and association were both excellent. Preschool-aged children may have stronger or more durable representations of timbre than contour, particularly in more difficult tasks. Reasons for weaker association of contour than timbre information are discussed, along with implications for auditory development. Copyright © 2015 Cognitive Science Society, Inc.

  3. Visually-salient contour detection using a V1 neural model with horizontal connections

    CERN Document Server

    Loxley, P N

    2011-01-01

    A convolution model which accounts for neural activity dynamics in the primary visual cortex is derived and used to detect visually salient contours in images. Image inputs to the model are modulated by long-range horizontal connections, allowing contextual effects in the image to determine visual saliency, i.e. line segments arranged in a closed contour elicit a larger neural response than line segments forming background clutter. The model is tested on 3 types of contour, including a line, a circular closed contour, and a non-circular closed contour. Using a modified association field to describe horizontal connections the model is found to perform well for different parameter values. For each type of contour a different facilitation mechanism is found. Operating as a feed-forward network, the model assigns saliency by increasing the neural activity of line segments facilitated by the horizontal connections. Alternatively, operating as a feedback network, the model can achieve further improvement over sever...

  4. COMPARISON OF THREE DIFFERENT IMAGE FORCES FOR ACTIVE CONTOURS ON ABDOMINAL IMAGE BOUNDARY DETECTION

    Directory of Open Access Journals (Sweden)

    Cherry Galatia Ballangan

    2005-01-01

    Full Text Available Active contour, or snake, is an energy minimizing spline that is useful in image boundary detection. Active contours are stimulated by internal forces, image forces and external forces which maintain the shape of the contours while attract the contours to some desired features, usually edges. Problems in implementing active contours such as convergence and initialization have motivated researchers to modify image forces of the active contours. This paper presents a comparative study among three different image forces: traditional snakes, balloon and gradient vector flow (GVF. The study is validated by experiments on abdominal image boundaries detection. These lead to the conclusion that GVF gives the most appropriate results among the other approaches.

  5. Fully automated contour detection algorithm the preliminary step for scatter and attenuation compensation in SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Younes, R.B.; Mas, J.; Bidet, R.

    1988-12-01

    Contour detection is an important step in information extraction from nuclear medicine images. In order to perform accurate quantitative studies in single photon emission computed tomography (SPECT) a new procedure is described which can rapidly derive the best fit contour of an attenuated medium. Some authors evaluate the influence of the detected contour on the reconstructed images with various attenuation correction techniques. Most of the methods are strongly affected by inaccurately detected contours. This approach uses the Compton window to redetermine the convex contour: It seems to be simpler and more practical in clinical SPECT studies. The main advantages of this procedure are the high speed of computation, the accuracy of the contour found and the programme's automation. Results obtained using computer simulated and real phantoms or clinical studies demonstrate the reliability of the present algorithm.

  6. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  7. Joint Denoising / Compression of Image Contours via Shape Prior and Context Tree

    OpenAIRE

    Zheng, Amin; Cheung, Gene; Florencio, Dinei

    2017-01-01

    With the advent of depth sensing technologies, the extraction of object contours in images---a common and important pre-processing step for later higher-level computer vision tasks like object detection and human action recognition---has become easier. However, acquisition noise in captured depth images means that detected contours suffer from unavoidable errors. In this paper, we propose to jointly denoise and compress detected contours in an image for bandwidth-constrained transmission to a...

  8. Persistence length of human cardiac α-tropomyosin measured by single molecule direct probe microscopy.

    Directory of Open Access Journals (Sweden)

    Campion K P Loong

    Full Text Available α-Tropomyosin (αTm is the predominant tropomyosin isoform in adult human heart and constitutes a major component in Ca²+-regulated systolic contraction of cardiac muscle. We present here the first direct probe images of WT human cardiac αTm by atomic force microscopy, and quantify its mechanical flexibility with three independent analysis methods. Single molecules of bacterially-expressed human cardiac αTm were imaged on poly-lysine coated mica and their contours were analyzed. Analysis of tangent-angle (θ(s correlation along molecular contours, second moment of tangent angles (, and end-to-end length (L(e-e distributions respectively yielded values of persistence length (L(p of 41-46 nm, 40-45 nm, and 42-52 nm, corresponding to 1-1.3 molecular contour lengths (L(c. We also demonstrate that a sufficiently large population, with at least 100 molecules, is required for a reliable L(p measurement of αTm in single molecule studies. Our estimate that L(p for αTm is only slightly longer than L(c is consistent with a previous study showing there is little spread of cooperative activation into near-neighbor regulatory units of cardiac thin filaments. The L(p determined here for human cardiac αTm perhaps represents an evolutionarily tuned optimum between Ca²+ sensitivity and cooperativity in cardiac thin filaments and likely constitutes an essential parameter for normal function in the human heart.

  9. Parallel development of contour integration and visual contrast sensitivity at low spatial frequencies

    DEFF Research Database (Denmark)

    Benedek, Krisztina; Janáky, Márta; Braunitzer, Gábor;

    2010-01-01

    and contour integration in 152 healthy volunteers aged between 5 and 30 years. The results revealed a significant maturation of contrast sensitivity at low spatial frequencies (0.5, 1.2, and 1.9 cycles/degree) and contour integration. The largest developmental step was observed for both contrast sensitivity...... and contour integration tasks when the 5-8-year olds were compared with the 9-11-year olds. There was a significant correlation between the development of low spatial frequency contrast sensitivity and contour integration. These results raise the possibility that the development of low spatial frequency...

  10. Active contours extension and similarity indicators for improved 3D segmentation of thyroid ultrasound images

    Science.gov (United States)

    Poudel, P.; Illanes, A.; Arens, C.; Hansen, C.; Friebe, M.

    2017-03-01

    Thyroid segmentation in tracked 2D ultrasound (US) using active contours has a low segmentation accuracy mainly due to the fact that smaller structures cannot be efficiently recognized and segmented. To address this issue, we propose a new similarity indicator with the main objective to provide information to the active contour algorithm concerning the regions that the active contour should continue to expand or should stop. First, a preprocessing step is carried out in order to attenuate the noise present in the US image and to increase its contrast, using histogram equalization and a median filter. In the second step, active contours are used to segment the thyroid in each 2D image of the dataset. After performing a first segmentation, two similarity indicators (ratio of mean square error, MSE and correlation between histograms) are computed at each contour point of the initial segmented thyroid between rectangles located inside and outside the obtained contour. A threshold is used on a final indicator computed from the other two indicators to find the probable regions for further segmentation using active contours. This process is repeated until no new segmentation region is identified. Finally, all the segmented thyroid images passed through a 3D reconstruction algorithm to obtain a 3D volume segmented thyroid. The results showed that including similarity indicators based on histogram equalization and MSE between inside and outside regions of the contour can help to segment difficult areas that active contours have problem to segment.

  11. Parallel development of contour integration and visual contrast sensitivity at low spatial frequencies

    DEFF Research Database (Denmark)

    Benedek, Krisztina; Janáky, Márta; Braunitzer, Gábor

    2010-01-01

    and contour integration in 152 healthy volunteers aged between 5 and 30 years. The results revealed a significant maturation of contrast sensitivity at low spatial frequencies (0.5, 1.2, and 1.9 cycles/degree) and contour integration. The largest developmental step was observed for both contrast sensitivity...... processing may affect attentional mechanisms, which may have an impact on early contour integration.......It has been suggested that visual contrast sensitivity and contour integration functions exhibit a late maturation during adolescence. However, the relationship between these functions has not been investigated. The aim of this study was to assess the development of visual contrast sensitivity...

  12. Cardiac sodium channelopathies.

    Science.gov (United States)

    Amin, Ahmad S; Asghari-Roodsari, Alaleh; Tan, Hanno L

    2010-07-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (INa) during phase 0 of the cardiac action potential. The importance of INa for normal cardiac electrical activity is reflected by the high incidence of arrhythmias in cardiac sodium channelopathies, i.e., arrhythmogenic diseases in patients with mutations in SCN5A, the gene responsible for the pore-forming ion-conducting alpha-subunit, or in genes that encode the ancillary beta-subunits or regulatory proteins of the cardiac sodium channel. While clinical and genetic studies have laid the foundation for our understanding of cardiac sodium channelopathies by establishing links between arrhythmogenic diseases and mutations in genes that encode various subunits of the cardiac sodium channel, biophysical studies (particularly in heterologous expression systems and transgenic mouse models) have provided insights into the mechanisms by which INa dysfunction causes disease in such channelopathies. It is now recognized that mutations that increase INa delay cardiac repolarization, prolong action potential duration, and cause long QT syndrome, while mutations that reduce INa decrease cardiac excitability, reduce electrical conduction velocity, and induce Brugada syndrome, progressive cardiac conduction disease, sick sinus syndrome, or combinations thereof. Recently, mutation-induced INa dysfunction was also linked to dilated cardiomyopathy, atrial fibrillation, and sudden infant death syndrome. This review describes the structure and function of the cardiac sodium channel and its various subunits, summarizes major cardiac sodium channelopathies and the current knowledge concerning their genetic background and underlying molecular mechanisms, and discusses recent advances in the discovery of mutation-specific therapies in the management of these channelopathies.

  13. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  14. Cardiac event monitors

    Science.gov (United States)

    ... ECG) - ambulatory; Continuous electrocardiograms (EKGs); Holter monitors; Transtelephonic event monitors ... attached. You can carry or wear a cardiac event monitor up to 30 days. You carry the ...

  15. Cardiac stem cell niches

    Directory of Open Access Journals (Sweden)

    Annarosa Leri

    2014-11-01

    Full Text Available The critical role that stem cell niches have in cardiac homeostasis and myocardial repair following injury is the focus of this review. Cardiac niches represent specialized microdomains where the quiescent and activated state of resident stem cells is regulated. Alterations in niche function with aging and cardiac diseases result in abnormal sites of cardiomyogenesis and inadequate myocyte formation. The relevance of Notch1 signaling, gap-junction formation, HIF-1α and metabolic state in the regulation of stem cell growth and differentiation within the cardiac niches are discussed.

  16. Excimer Laser Pulse Compress With Pulse Feedback

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>To attain a shorter laser pulse, a compressing technique called pulse feedback was developed from the saturation gain switch applied to the amplification in a discharge pumping excimer laser cavity. It can

  17. Statistical region-based active contours with exponential family observations

    CERN Document Server

    Lecellier, François; Fadili, Jalal; Aubert, Gilles; Revenu, Marinette

    2008-01-01

    In this paper, we focus on statistical region-based active contour models where image features (e.g. intensity) are random variables whose distribution belongs to some parametric family (e.g. exponential) rather than confining ourselves to the special Gaussian case. Using shape derivation tools, our effort focuses on constructing a general expression for the derivative of the energy (with respect to a domain) and derive the corresponding evolution speed. A general result is stated within the framework of multi-parameter exponential family. More particularly, when using Maximum Likelihood estimators, the evolution speed has a closed-form expression that depends simply on the probability density function, while complicating additive terms appear when using other estimators, e.g. moments method. Experimental results on both synthesized and real images demonstrate the applicability of our approach.

  18. Equivalence of Two Contour Prescriptions in Superstring Perturbation Theory

    CERN Document Server

    Sen, Ashoke

    2016-01-01

    Conventional superstring perturbation theory based on the world-sheet approach gives divergent results for the S-matrix whenever the total center of mass energy of the incoming particles exceeds the threshold of production of any final state consistent with conservation laws. Two systematic approaches have been suggested for dealing with this difficulty. The first one involves deforming the integration cycles over the moduli space of punctured Riemann surfaces into complexified moduli space. The second one treats the amplitude as a sum of superstring field theory Feynman diagrams and deforms the integration contours over loop energies of the Feynman diagram into the complex plane. In this paper we establish the equivalence of the two prescriptions to all orders in perturbation theory. Since the second approach is known to lead to unitary amplitudes, this establishes the consistency of the first prescription with unitarity.

  19. Hough Transform and Active Contour for Enhanced Iris Segmentation

    Directory of Open Access Journals (Sweden)

    Alaa Hilal

    2012-11-01

    Full Text Available Iris segmentation is considered as the most difficult and fundamental step in an iris recognition system. While iris boundaries are largely approximated by two circles or ellipses, other methods define more accurately the iris resulting in better recognition results. In this paper we propose an iris segmentation method using Hough transform and active contour to detect a circular approximation of the outer iris boundary and to accurately segment the inner boundary in its real shape motivated by the fact that richer iris textures are closer to the pupil than to the sclera. Normalization, encoding and matching are implemented according to Daugmans method. The method, tested on CASIA-V3 iris images database is compared to Daugmans iris recognition system. Recognition performance is measured in terms of decidability, accuracy at the equal error rate and ROC curves. Improved recognition performance is obtained using our segmentation model proposing its use for better iris recognition system.

  20. Reconfigurable contour beam generation using a smart subreflector antenna system

    Science.gov (United States)

    Yoon, Hwan-Sik; Washington, Gregory N.; Theunissen, Wilhelmus H.

    2000-06-01

    A novel way to design, synthesize and adjust the reconfigurable dual offset contour beam reflector antenna employing an adjustable subreflector is presented. The work also presents a graphical user interface based computer code that connects the electro-magnetic effects to the mechanical surface deflections. The subreflector surface is described by using the finite element method and the far-field radiation pattern is calculated by reflector diffraction synthesis. The reflector surface shape is adjusted using a set of linear piezoelectric point actuators attached to its back surface, from which the diffraction synthesis code calculates the radiation pattern. An example of this method applied to the contiguous US is also presented. As a future work, a software package will be built where the finite element code and the diffraction synthesis code are combined, and it will be used for advanced actuator placement and reflector design problem.

  1. New method of 2-dimensional metrology using mask contouring

    Science.gov (United States)

    Matsuoka, Ryoichi; Yamagata, Yoshikazu; Sugiyama, Akiyuki; Toyoda, Yasutaka

    2008-10-01

    We have developed a new method of accurately profiling and measuring of a mask shape by utilizing a Mask CD-SEM. The method is intended to realize high accuracy, stability and reproducibility of the Mask CD-SEM adopting an edge detection algorithm as the key technology used in CD-SEM for high accuracy CD measurement. In comparison with a conventional image processing method for contour profiling, this edge detection method is possible to create the profiles with much higher accuracy which is comparable with CD-SEM for semiconductor device CD measurement. This method realizes two-dimensional metrology for refined pattern that had been difficult to measure conventionally by utilizing high precision contour profile. In this report, we will introduce the algorithm in general, the experimental results and the application in practice. As shrinkage of design rule for semiconductor device has further advanced, an aggressive OPC (Optical Proximity Correction) is indispensable in RET (Resolution Enhancement Technology). From the view point of DFM (Design for Manufacturability), a dramatic increase of data processing cost for advanced MDP (Mask Data Preparation) for instance and surge of mask making cost have become a big concern to the device manufacturers. This is to say, demands for quality is becoming strenuous because of enormous quantity of data growth with increasing of refined pattern on photo mask manufacture. In the result, massive amount of simulated error occurs on mask inspection that causes lengthening of mask production and inspection period, cost increasing, and long delivery time. In a sense, it is a trade-off between the high accuracy RET and the mask production cost, while it gives a significant impact on the semiconductor market centered around the mask business. To cope with the problem, we propose the best method of a DFM solution using two-dimensional metrology for refined pattern.

  2. Contours, Hawaii (Big Island) Hypsography - 40 ft Contour Interval, Published in 2004, 1:24000 (1in=2000ft) scale, U.S. Geological Survey.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Orthoimagery information as of 2004. It is described as 'Hawaii (Big...

  3. Bathymetric Contours - LAKE_BATHYMETRY_IDNR_IN: Bathymetric Contours for Selected Lakes in Indiana (Indiana Department of Natural Resources, Polygon Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — LAKE_BATHYMETRY_IDNR_IN.SHP provides bathymetric contours for the following 85 lakes in Indiana, with depths calculated from the average shoreline of each lake:...

  4. Contours, 2 and 5 foot contours, Published in 2007, 1:1200 (1in=100ft) scale, Mississippi Department of Environmental Quality.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Field Observation information as of 2007. It is described as '2 and 5...

  5. Retroperitoneal Sarcoma Target Volume and Organ at Risk Contour Delineation Agreement Among NRG Sarcoma Radiation Oncologists

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, Elizabeth H., E-mail: ebaldini@partners.org [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Abrams, Ross A. [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States); Bosch, Walter [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Roberge, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Haas, Rick L.M. [Department of Radiotherapy, Netherlands Cancer Institute, Amsterdam (Netherlands); Catton, Charles N. [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Indelicato, Daniel J. [Department of Radiation Oncology, University of Florida Medical Center, Jacksonville, Florida (United States); Olsen, Jeffrey R. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Deville, Curtiland [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Chen, Yen-Lin [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Finkelstein, Steven E. [Translational Research Consortium, 21st Century Oncology, Scottsdale, Arizona (United States); DeLaney, Thomas F. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Wang, Dian [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States)

    2015-08-01

    Purpose: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials: Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions: For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed.

  6. Pulsed Optics

    Science.gov (United States)

    Hirlimann, C.

    Optics is the field of physics which comprises knowledge on the interaction between light and matter. When the superposition principle can be applied to electromagnetic waves or when the properties of matter do not depend on the intensity of light, one speaks of linear optics. This situation occurs with regular light sources such as light bulbs, low-intensity light-emitting diodes and the sun. With such low-intensity sources the reaction of matter to light can be characterized by a set of parameters such as the index of refraction, the absorption and reflection coefficients and the orientation of the medium with respect to the polarization of the light. These parameters depend only on the nature of the medium. The situation changed dramatically after the development of lasers in the early sixties, which allowed the generation of light intensities larger than a kilowatt per square centimeter. Actual large-scale short-pulse lasers can generate peak powers in the petawatt regime. In that large-intensity regime the optical parameters of a material become functions of the intensity of the impinging light. In 1818 Fresnel wrote a letter to the French Academy of Sciences in which he noted that the proportionality between the vibration of the light and the subsequent vibration of matter was only true because no high intensities were available. The intensity dependence of the material response is what usually defines nonlinear optics.

  7. 脉搏指示连续心排血量监测技术在骨盆骨折合并失血性休克患者中的应用及护理%Nursing of pulse-indicated continuous cardiac output technique in pelvic fracture patients with hemorrhagic shock

    Institute of Scientific and Technical Information of China (English)

    赵文静; 程人佳; 张庆红; 赵文州

    2015-01-01

    Objective To investigate the clinical nursing methods of pulse-indicated con-tinuous cardiac output(PICCO)system in pelvic fracture patients with hemorrhagic shock.Methods The clinical data of 82 pelvic fracture patients with hemorrhagic shock treated in emergency inten-sive care unit (EICU)were retrospectively analyzed.Results In 82 patients,74 improved patients transferred to other departments or discharged and 8 patients died including 6 patients with acute re-nal failure.Conclusion Pelvic fracture patients with hemorrhagic shock using PICCO technology can accurately reflect the volume state.The PICCO management and PICCO safety is the key to en-sure successful treatment.%目的:探讨脉搏指示连续心排血量监测技术(PICCO)在骨盆骨折合并失血性休克患者中的应用及护理方法。方法对急诊重症监护室(EICU)收治的82例骨盆骨折合并失血性休克患者的临床及护理资料进行回顾性分析。结果82例患者中,病情好转转科或出院74例,死亡8例,其中并发急性肾衰竭6例。结论骨盆骨折合并失血性休克患者采用 PICCO技术能精准反映患者的容量状态,在 PICCO 的管理和观察中保证 PICCO 监测安全有效是救治成功的关键。

  8. Pulse Indicator Continuous Cardiac Output for Hemodynamics Monitoring in Patients with Septic Shock%脉搏指示连续心排血量监测(PiCCO)在脓毒症休克患者血流动力学监测中的临床价值

    Institute of Scientific and Technical Information of China (English)

    伊敏; 么改琦; 朱曦; 郭向阳

    2013-01-01

    目的 探讨脉搏指示连续心排血量监测技术(pulse indicator continuous cardiac output,PiCCO)在脓毒症休克患者血流动力学监测中的临床价值. 方法 2012年1~8月,前瞻性队列研究比较常规监测(n=12)与PiCCO监测(n=19)脓毒症休克患者的血流动力学,应用PiCCO监测指导脓毒症休克患者的液体复苏、血管收缩药和正性肌力药物的使用. 结果 2组脓毒症休克患者性别、年龄、原发病、既往病史、多器官功能不全综合征(MODS)的发生和发生MODS器官数、急性生理学及慢性健康状况评分系统(APACHE)Ⅱ、脓毒症相关器官衰竭评分(SOFA)、应用去甲肾上腺素剂量和入ICU后7天总的输液量差异均无显著性,PiCCO组初始平均动脉压(MAP)明显低于常规组[(52.00±5.00)mm Hg vs.(59.58±3.42)mm Hg,t=4.603,P=0.000],而对于PiCCO组存在心功能损害的患者应用正性肌力药治疗后达到与常规组相同的MAP达标值[(68.00±2.43)mm Hg vs.(68.58±2.88)mm Hg,t=0.607,P=0.549],2组MAP达标值差异无显著性. 结论 在PiCCO监测指导下,可以对于存在心功能损害的患者应用正性肌力药物,而不是仅应用血管收缩药升高血压.%Objective To investigate the clinical value of pulse indicator continuous cardiac output ( PiCCO) in hemodynamics monitoring for patients with septic shock. Methods A prospective cohort study comparing routine hemodynamics monitoring (n = 12) and PiCCO (n = 19) for patients with septic shock were carried out from January to August 2012. The PiCCO monitor provided a continuous assessment of fluid resuscitation, vasopressors and inotropes infusion in septic shock patients. Results There were no significant difference between the two groups in sex, age, etiology of critical illness, medical history, incidence of MODS, number of MODS involved organ, APACHE Ⅱ and SOFA scores, usage of noradrenaline, and total volume of fluid infusion in a week. In the PiCCO group, the original MAP

  9. Automatic diatom identification using contour analysis by morphological curvature scale spaces

    NARCIS (Netherlands)

    Jalba, Andrei C.; Wilkinson, Michael H.F.; Roerdink, Jos B.T.M.; Bayer, Micha M.; Juggins, Stephen

    2005-01-01

    A method for automatic identification of diatoms (single-celled algae with silica shells) based on extraction of features on the contour of the cells by multi-scale mathematical morphology is presented. After extracting the contour of the cell, it is smoothed adaptively, encoded using Freeman chain

  10. Contour Extraction in Prostate Ultrasound Images Using the Wavelet Transform and Snakes

    Science.gov (United States)

    2007-11-02

    signal noise levels. In this paper we present a semi-automatic prostate contour extraction scheme, which is based on the wavelet transform and active...contour models, or snakes. The ultrasound image is first decomposed into edge naps at different resolutions via the wavelet transform . Seed points are

  11. Hemagglutinin outer contour detection methods based on regular hexagon bar template

    Science.gov (United States)

    Tian, Miaomiao; Jing, Wenbo; Duan, Jin; Wang, Xiaoman

    2014-11-01

    In order to extract hemagglutinin outer contour accurately in the hemagglutinin image, analyzes the hemagglutinin protein content by the size of detected contour, presents a regular hexagon bar circle detection algorithm which uses regular hexagon bar detection template to detect outer contour of the hemagglutinin. Firstly, the hemagglutinin image thresholded by using OTSU adaptive thresholding method; and then using regular hexagon bar detection template method to rough align hemagglutinin after thresholded, intersection of detection template and the hemagglutinin contour area is attained, the noise near hemagglutinin contour is reduced by using the standardization relationship of the hexagon bars, so the hemagglutinin pixels are accurately obtained; finally the hemagglutinin outer contour information is gained by the geometric relationship of pixels, the hemagglutinin position is achieved precisely. The experimental results show that: the contour detection error due to the density uneven and the edge unclearly of hemagglutinin image protein is better reduced, the detection accuracy is increased by a factor of 0.47, detection speed is increased by a factor of 0.56.The hemagglutinin contour can be dected stablely, fastly, accurately and the is significant to the study of the hemagglutinin protein content.

  12. Patient-Reported Outcomes in Weight Loss and Body Contouring Surgery

    DEFF Research Database (Denmark)

    Poulsen, Lotte; Klassen, Anne; Rose, Michael

    2017-01-01

    to the post-body contouring surgery period. Data were collected using REDCap, and analyzed using SPSS software. RESULTS: For all appearance and health-related quality-of-life scales, the mean score was significantly lower in the pre-bariatric surgery group compared with the post-body contouring group...

  13. Dilated contour extraction and component labeling algorithm for object vector representation

    Science.gov (United States)

    Skourikhine, Alexei N.

    2005-08-01

    Object boundary extraction from binary images is important for many applications, e.g., image vectorization, automatic interpretation of images containing segmentation results, printed and handwritten documents and drawings, maps, and AutoCAD drawings. Efficient and reliable contour extraction is also important for pattern recognition due to its impact on shape-based object characterization and recognition. The presented contour tracing and component labeling algorithm produces dilated (sub-pixel) contours associated with corresponding regions. The algorithm has the following features: (1) it always produces non-intersecting, non-degenerate contours, including the case of one-pixel wide objects; (2) it associates the outer and inner (i.e., around hole) contours with the corresponding regions during the process of contour tracing in a single pass over the image; (3) it maintains desired connectivity of object regions as specified by 8-neighbor or 4-neighbor connectivity of adjacent pixels; (4) it avoids degenerate regions in both background and foreground; (5) it allows an easy augmentation that will provide information about the containment relations among regions; (6) it has a time complexity that is dominantly linear in the number of contour points. This early component labeling (contour-region association) enables subsequent efficient object-based processing of the image information.

  14. The Role of Tone Height, Melodic Contour, and Tone Chroma in Melody Recognition.

    Science.gov (United States)

    Massaro, Dominic W.; And Others

    1980-01-01

    Relationships among tone height, melodic contour, tone chroma, and recognition of recently learned melodies were investigated. Results replicated previous studies using familiar folk songs, providing evidence that melodic contour, tone chroma, and tone height contribute to recognition of both highly familiar and recently learned melodies.…

  15. Fourier Descriptor Analysis and Unification of Voice Range Profile Contours: Method and Applications

    Science.gov (United States)

    Pabon, Peter; Ternstrom, Sten; Lamarche, Anick

    2011-01-01

    Purpose: To describe a method for unified description, statistical modeling, and comparison of voice range profile (VRP) contours, even from diverse sources. Method: A morphologic modeling technique, which is based on Fourier descriptors (FDs), is applied to the VRP contour. The technique, which essentially involves resampling of the curve of the…

  16. Contour Propagation Using Feature-Based Deformable Registration for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yuhan Yang

    2013-01-01

    Full Text Available Accurate target delineation of CT image is a critical step in radiotherapy treatment planning. This paper describes a novel strategy for automatic contour propagation, based on deformable registration, for CT images of lung cancer. The proposed strategy starts with a manual-delineated contour in one slice of a 3D CT image. By means of feature-based deformable registration, the initial contour in other slices of the image can be propagated automatically, and then refined by active contour approach. Three algorithms are employed in the strategy: the Speeded-Up Robust Features (SURF, Thin-Plate Spline (TPS, and an adapted active contour (Snake, used to refine and modify the initial contours. Five pulmonary cancer cases with about 400 slices and 1000 contours have been used to verify the proposed strategy. Experiments demonstrate that the proposed strategy can improve the segmentation performance in the pulmonary CT images. Jaccard similarity (JS mean is about 0.88 and the maximum of Hausdorff distance (HD is about 90%. In addition, delineation time has been considerably reduced. The proposed feature-based deformable registration method in the automatic contour propagation improves the delineation efficiency significantly.

  17. Fourier Descriptor Analysis and Unification of Voice Range Profile Contours: Method and Applications

    Science.gov (United States)

    Pabon, Peter; Ternstrom, Sten; Lamarche, Anick

    2011-01-01

    Purpose: To describe a method for unified description, statistical modeling, and comparison of voice range profile (VRP) contours, even from diverse sources. Method: A morphologic modeling technique, which is based on Fourier descriptors (FDs), is applied to the VRP contour. The technique, which essentially involves resampling of the curve of the…

  18. [Advances in cardiac pacing].

    Science.gov (United States)

    de Carranza, María-José Sancho-Tello; Fidalgo-Andrés, María Luisa; Ferrer, José Martínez; Mateas, Francisco Ruiz

    2012-01-01

    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed.

  19. Measuring temporal resolution of cardiac CT reconstructions

    Science.gov (United States)

    Matthews, David; Heuscher, Dominic

    2005-04-01

    Multi-slice CT today is capable of imaging the heart with excellent temporal resolution. Algorithms have been developed to perform reconstructions combining data from multiple cardiac cycles. This paper presents a simulation phantom that enables a direct measurement of the actual temporal resolution achieved by these algorithms. This is not only useful for assessing the temporal resolution but also for validating the algorithms themselves. A simulation phantom was developed that consists of a 20 cm. diameter water phantom containing an array of cylinders whose intensities are pulsed for various durations ranging from 10 msec. to 250 msec. The intensity varied between the background value of water (0 HU) and 800 HU. By measuring the nominal attenuation value at the center of each cylinder, a curve can be derived representing the response over the given temporal range. A temporal resolution representing the FWHM value is determined based on the half-max value of this curve. Reconstructions were performed using a multi-cycle cardiac algorithm described previously in the literature. The measured FWHM values agree quite well to the temporal resolution predicted by the cardiac algorithm itself. Even the variation along the longitudinal axis can be accounted for by the predicted values. A simulated phantom can be used to accurately assess the temporal resolution of cardiac reconstruction algorithms. Excellent agreement was achieved between the predicted and measured temporal resolution values for the multi-cycle algorithm used in this study.

  20. Coronal loop detection and salient contour group extraction from solar images

    Science.gov (United States)

    Durak, Nurcan

    2011-01-01

    This dissertation addresses two different problems: 1) coronal loop detection from solar images: and 2) salient contour group extraction from cluttered images. In the first part, we propose two different solutions to the coronal loop detection problem. The first solution is a block-based coronal loop mining method that detects coronal loops from solar images by dividing the solar image into fixed sized blocks, labeling the blocks as "Loop" or "Non-Loop", extracting features from the labeled blocks, and finally training classifiers to generate learning models that can classify new image blocks. The block-based approach achieves 64% accuracy in 10-fold cross validation experiments. To improve the accuracy and scalability, we propose a contour-based coronal loop detection method that extracts contours from cluttered regions, then labels the contours as "Loop" and "Non-Loop", and extracts geometric features from the labeled contours. The contour-based approach achieves 85% accuracy in 10-fold cross validation experiments, which is a 20% increase compared to the block-based approach. In the second part, we propose a method to extract semi-elliptical open curves from cluttered regions. Our method consists of the following steps: obtaining individual smooth contours along with their saliency measures; then starting from the most salient contour, searching for possible grouping options for each contour; and continuing the grouping until an optimum solution is reached. Our work involved the design and development of a complete system for coronal loop mining in solar images, which required the formulation of new Gestalt perceptual rules and a systematic methodology to select and combine them in a fully automated judicious manner using machine learning techniques that eliminate the need to manually set various weight and threshold values to define an effective cost function. After finding salient contour groups, we close the gaps within the contours in each group and perform

  1. Mathematical cardiac electrophysiology

    CERN Document Server

    Colli Franzone, Piero; Scacchi, Simone

    2014-01-01

    This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

  2. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  3. Sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Neeraj Parakh

    2015-01-01

    Full Text Available Sudden cardiac death is one of the most common cause of mortality worldwide. Despite significant advances in the medical science, there is little improvement in the sudden cardiac death related mortality. Coronary artery disease is the most common etiology behind sudden cardiac death, in the above 40 years population. Even in the apparently healthy population, there is a small percentage of patients dying from sudden cardiac death. Given the large denominator, this small percentage contributes to the largest burden of sudden cardiac death. Identification of this at risk group among the apparently healthy individual is a great challenge for the medical fraternity. This article looks into the causes and methods of preventing SCD and at some of the Indian data. Details of Brugada syndrome, Long QT syndrome, Genetics of SCD are discussed. Recent guidelines on many of these causes are summarised.

  4. Optical contouring of an acrylic surface for non-intrusive diagnostics in pipe-flow investigations

    Science.gov (United States)

    de Witt, Benjamin J.; Coronado-Diaz, Haydee; Hugo, Ronald J.

    2008-07-01

    In this work, an acrylic surface was optically contoured to correct for the optical distortion caused by a transparent pipe wall. This method can be applied to non-invasive viewing/imaging techniques for fluid flow experiments. Software tools were developed to aid in the design of an optically contoured acrylic test section for pipe-flow experiments. Numerical models were computed for a standard acrylic pipe, inner diameter 57.15 mm, with water enclosed. An optical contour prototype was machined on a 5-axis CNC machine, and polished with 1-15 μm diamond paste, alleviating any surface imperfections without significantly altering the contoured surface. Experiments were then performed to measure the emerging optical wavefront and was found to emerge planar when utilizing the optical contour. It was determined that the wavefront was corrected to within ten wavelengths of a Helium-Neon (He-Ne) laser beam.

  5. Parallel algorithm for real-time contouring from grid DEM on modern GPUs

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A real-time algorithm for constructing contour maps from grid DEM data is pre-sented.It runs completely within the programmable 3D visualization pipeline.The interpolation is paralleled by rasterizer units in the graphics card,and contour line extraction is paralleled by pixel shader.During each frame of the rendering,we first make an elevation gradient map out of original terrain vertex data,then figure out the final contour lines with image-space processing,and directly blend the results on the original scene to obtain a final scene with contour map using alpha-blending.We implement this method in our global 3D-digitalearth system with Direct3D?9.0c API and tested on some consumer level PC platforms.For arbitrary scene with certain LOD level,the process takes less than 10 ms,giving topologically correct,anti-aliased contour lines.

  6. Expert Consensus Contouring Guidelines for Intensity Modulated Radiation Therapy in Esophageal and Gastroesophageal Junction Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Abraham J., E-mail: wua@mskcc.org [Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Bosch, Walter R. [Washington University, St. Louis, Missouri (United States); Chang, Daniel T. [Stanford Cancer Institute, Stanford, California (United States); Hong, Theodore S. [Massachusetts General Hospital, Boston, Massachusetts (United States); Jabbour, Salma K. [Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey (United States); Kleinberg, Lawrence R. [Johns Hopkins Medical Center, Baltimore, Maryland (United States); Mamon, Harvey J. [Brigham and Women' s Hospital, Boston, Massachusetts (United States); Thomas, Charles R. [Knight Cancer Institute, Oregon Health & Sciences University, Portland, Oregon (United States); Goodman, Karyn A. [Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2015-07-15

    Purpose/Objective(s): Current guidelines for esophageal cancer contouring are derived from traditional 2-dimensional fields based on bony landmarks, and they do not provide sufficient anatomic detail to ensure consistent contouring for more conformal radiation therapy techniques such as intensity modulated radiation therapy (IMRT). Therefore, we convened an expert panel with the specific aim to derive contouring guidelines and generate an atlas for the clinical target volume (CTV) in esophageal or gastroesophageal junction (GEJ) cancer. Methods and Materials: Eight expert academically based gastrointestinal radiation oncologists participated. Three sample cases were chosen: a GEJ cancer, a distal esophageal cancer, and a mid-upper esophageal cancer. Uniform computed tomographic (CT) simulation datasets and accompanying diagnostic positron emission tomographic/CT images were distributed to each expert, and the expert was instructed to generate gross tumor volume (GTV) and CTV contours for each case. All contours were aggregated and subjected to quantitative analysis to assess the degree of concordance between experts and to generate draft consensus contours. The panel then refined these contours to generate the contouring atlas. Results: The κ statistics indicated substantial agreement between panelists for each of the 3 test cases. A consensus CTV atlas was generated for the 3 test cases, each representing common anatomic presentations of esophageal cancer. The panel agreed on guidelines and principles to facilitate the generalizability of the atlas to individual cases. Conclusions: This expert panel successfully reached agreement on contouring guidelines for esophageal and GEJ IMRT and generated a reference CTV atlas. This atlas will serve as a reference for IMRT contours for clinical practice and prospective trial design. Subsequent patterns of failure analyses of clinical datasets using these guidelines may require modification in the future.

  7. Expert consensus contouring guidelines for IMRT in esophageal and gastroesophageal junction cancer

    Science.gov (United States)

    Wu, Abraham J.; Bosch, Walter R.; Chang, Daniel T.; Hong, Theodore S.; Jabbour, Salma K.; Kleinberg, Lawrence R.; Mamon, Harvey J.; Thomas, Charles R.; Goodman, Karyn A.

    2015-01-01

    Purpose/Objective(s) Current guidelines for esophageal cancer contouring are derived from traditional two-dimensional fields based on bony landmarks, and do not provide sufficient anatomical detail to ensure consistent contouring for more conformal radiotherapy techniques such as intensity-modulated radiation therapy (IMRT). Therefore, we convened an expert panel with the specific aim to derive contouring guidelines and generate an atlas for the clinical target volume (CTV) in esophageal or gastroesophageal junction (GEJ) cancer. Methods and Materials Eight expert academically-based gastrointestinal radiation oncologists participated. Three sample cases were chosen: a GEJ cancer, a distal esophageal cancer, and a mid-upper esophageal cancer. Uniform CT simulation datasets and an accompanying diagnostic PET-CT were distributed to each expert, and he/she was instructed to generate gross tumor volume (GTV) and CTV contours for each case. All contours were aggregated and subjected to quantitative analysis to assess the degree of concordance between experts and generate draft consensus contours. The panel then refined these contours to generate the contouring atlas. Results Kappa statistics indicated substantial agreement between panelists for each of the three test cases. A consensus CTV atlas was generated for the three test cases, each representing common anatomic presentations of esophageal cancer. The panel agreed on guidelines and principles to facilitate the generalizability of the atlas to individual cases. Conclusions This expert panel successfully reached agreement on contouring guidelines for esophageal and GEJ IMRT and generated a reference CTV atlas. This atlas will serve as a reference for IMRT contours for clinical practice and prospective trial design. Subsequent patterns of failure analyses of clinical datasets utilizing these guidelines may require modification in the future. PMID:26104943

  8. An evaluation of the contouring abilities of medical dosimetry students for the anatomy of a prostate cancer patient

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Kevin S., E-mail: kscollin@siu.edu [School of Allied Health, College of Applied Sciences and Arts, Southern Illinois University Carbondale, Carbondale, IL (United States)

    2012-10-01

    Prostate cancer is one of the most common diseases treated in a radiation oncology department. One of the major predictors of the treatment outcome and patient side effects is the accuracy of the anatomical contours for the treatment plan. Therefore, the purpose of this study was to determine which anatomical structures are most often contoured correctly and incorrectly by medical dosimetry students. The author also wanted to discover whether a review of the contouring rules would increase contouring accuracy. To achieve this, a male computed tomography dataset consisting of 72 transverse slices was sent to students for contouring. The students were instructed to import this dataset into their treatment planning system and contour the following structures: skin, bladder, rectum, prostate, penile bulb, seminal vesicles, left femoral head, and right femoral head. Upon completion of the contours, the contour file was evaluated against a 'gold standard' contour set using StructSure software (Standard Imaging, Inc). A review of the initial contour results was conducted and then students were instructed to contour the dataset a second time. The results of this study showed significant differences between contouring sessions. These results and the standardization of contouring rules should benefit all individuals who participate in the treatment planning of cancer patients.

  9. Contours, 2 foot contours from LiDAR flown under the LAR-IAC project, Published in 2006, 1:600 (1in=50ft) scale, County of Los Angeles.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from LIDAR information as of 2006. It is described as '2 foot contours from...

  10. Contours, Contours created by processing hillshade TIF files derived from the U.S. Geological Survey National Elevation Dataset. Available in 50',100, 250', and 500' intervals., Published in 2004, Arizona State Land Department.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset as of 2004. It is described as 'Contours created by processing hillshade TIF files derived from the U.S. Geological Survey National Elevation...

  11. Contours, 2' contours do not cover the entire county, although most of the Green Bay Metro area and villages are complete, Published in 2000, 1:2400 (1in=200ft) scale, Brown County, WI.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Orthoimagery information as of 2000. It is described as '2' contours...

  12. Contours, Elevation contour data are a fundamental base map layer for large scale mapping and GIS analysis., Published in 2001, 1:24000 (1in=2000ft) scale, Louisiana State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:24000 (1in=2000ft) scale as of 2001. It is described as 'Elevation contour data are a fundamental base map layer for large...

  13. Programmable pulse generator

    CERN Document Server

    Xue Zhi Hua; Duan Xiao Hui

    2002-01-01

    The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

  14. Goldmann Applanation Tonometry versus Dynamic Contour Tonometry after Vitrectomy with Silicone Oil Endotamponade.

    Science.gov (United States)

    Fuest, Matthias; Mamas, Nikolaos; Walter, Peter; Mazinani, Babac E; Roessler, Gemot; Plange, Niklas

    2017-07-01

    To evaluate the agreement of intraocular pressure (IOP) measurements using dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in eyes after vitrectomy with silicone oil endotamponade and controls. In this prospective comparative study, IOP was measured with GAT and DCT in 30 eyes with oil endotamponade 1-3 days after vitrectomy and 40 untreated controls. In addition, ocular pulse amplitude (OPA), corneal pachymetry (CCT), and axial length (AL) were measured. GAT values in the oil group were significantly higher compared to control eyes (mean GAT oil 13.6 ± 5.1 mmHg; mean GAT control 10.8 ± 2.1 mmHg; p = 0.003). There was no significant difference in DCT measurements (mean DCT oil 12.0 ± 4.1 mmHg; mean DCT control 11.9 ± 2.9 mmHg; p = 0.9). This led to a significant difference of GAT-DCT between the oil and control group (mean difference of GAT-DCT oil 1.6 ± 4.7 mmHg; mean difference of GAT-DCT control -1.1 ± 2.6 mmHg; p = 0.004). The difference between GAT and DCT was negatively correlated with the mean IOP measured by both methods (r = -0.36, p = 0.02) and positively correlated with CCT only in the control group (r = 0.36, p = 0.02), as well as to AL only in the oil group (r = 0.46, p = 0.01). The OPA did not differ significantly between groups. GAT and DCT showed a good agreement in control eyes. The difference of GAT and DCT is significantly changed in eyes after vitrectomy with silicone oil endotamponade. Our findings suggest that GAT overestimates IOP in this situation.

  15. Statistical Modeling Approach to Quantitative Analysis of Interobserver Variability in Breast Contouring

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jinzhong, E-mail: jyang4@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A.; Reed, Valerie K.; Strom, Eric A.; Perkins, George H.; Tereffe, Welela; Buchholz, Thomas A. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang, Lifei; Balter, Peter; Court, Laurence E. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Dong, Lei [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Scripps Proton Therapy Center, San Diego, California (United States)

    2014-05-01

    Purpose: To develop a new approach for interobserver variability analysis. Methods and Materials: Eight radiation oncologists specializing in breast cancer radiation therapy delineated a patient's left breast “from scratch” and from a template that was generated using deformable image registration. Three of the radiation oncologists had previously received training in Radiation Therapy Oncology Group consensus contouring for breast cancer atlas. The simultaneous truth and performance level estimation algorithm was applied to the 8 contours delineated “from scratch” to produce a group consensus contour. Individual Jaccard scores were fitted to a beta distribution model. We also applied this analysis to 2 or more patients, which were contoured by 9 breast radiation oncologists from 8 institutions. Results: The beta distribution model had a mean of 86.2%, standard deviation (SD) of ±5.9%, a skewness of −0.7, and excess kurtosis of 0.55, exemplifying broad interobserver variability. The 3 RTOG-trained physicians had higher agreement scores than average, indicating that their contours were close to the group consensus contour. One physician had high sensitivity but lower specificity than the others, which implies that this physician tended to contour a structure larger than those of the others. Two other physicians had low sensitivity but specificity similar to the others, which implies that they tended to contour a structure smaller than the others. With this information, they could adjust their contouring practice to be more consistent with others if desired. When contouring from the template, the beta distribution model had a mean of 92.3%, SD ± 3.4%, skewness of −0.79, and excess kurtosis of 0.83, which indicated a much better consistency among individual contours. Similar results were obtained for the analysis of 2 additional patients. Conclusions: The proposed statistical approach was able to measure interobserver variability quantitatively

  16. Cardiac tumors: echo assessment.

    Science.gov (United States)

    Mankad, Rekha; Herrmann, Joerg

    2016-12-01

    Cardiac tumors are exceedingly rare (0.001-0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  17. Cardiac tumors: echo assessment

    Directory of Open Access Journals (Sweden)

    Rekha Mankad MD

    2016-12-01

    Full Text Available Cardiac tumors are exceedingly rare (0.001–0.03% in most autopsy series. They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1 thrombus or vegetations are the most likely etiology, (2 cardiac tumors are mostly secondary and (3 primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  18. A review: aluminum nitride MEMS contour-mode resonator

    Science.gov (United States)

    Yunhong, Hou; Meng, Zhang; Guowei, Han; Chaowei, Si; Yongmei, Zhao; Jin, Ning

    2016-10-01

    Over the past several decades, the technology of micro-electromechanical system (MEMS) has advanced. A clear need of miniaturization and integration of electronics components has had new solutions for the next generation of wireless communications. The aluminum nitride (AlN) MEMS contour-mode resonator (CMR) has emerged and become promising and competitive due to the advantages of the small size, high quality factor and frequency, low resistance, compatibility with integrated circuit (IC) technology, and the ability of integrating multi-frequency devices on a single chip. In this article, a comprehensive review of AlN MEMS CMR technology will be presented, including its basic working principle, main structures, fabrication processes, and methods of performance optimization. Among these, the deposition and etching process of the AlN film will be specially emphasized and recent advances in various performance optimization methods of the CMR will be given through specific examples which are mainly focused on temperature compensation and reducing anchor losses. This review will conclude with an assessment of the challenges and future trends of the CMR. Project supported by National Natural Science Foundation (Nos. 61274001, 61234007, 61504130), the Nurturing and Development Special Projects of Beijing Science and Technology Innovation Base's Financial Support (No. Z131103002813070), and the National Defense Science and Technology Innovation Fund of CAS (No. CXJJ-14-M32).

  19. Multiplatform GPGPU implementation of the active contours without edges algorithm

    Science.gov (United States)

    Zavala-Romero, Olmo; Meyer-Baese, Anke; Meyer-Baese, Uwe

    2012-05-01

    An OpenCL implementation of the Active Contours Without Edges algorithm is presented. The proposed algorithm uses the General Purpose Computing on Graphics Processing Units (GPGPU) to accelerate the original model by parallelizing the two main steps of the segmentation process, the computation of the Signed Distance Function (SDF) and the evolution of the segmented curve. The proposed scheme for the computation of the SDF is based on the iterative construction of partial Voronoi diagrams of a reduced dimension and obtains the exact Euclidean distance in a time of order O(N/p), where N is the number of pixels and p the number of processors. With high resolution images the segmentation algorithm runs 10 times faster than its equivalent sequential implementation. This work is being done as an open source software that, being programmed in OpenCL, can be used in dierent platforms allowing a broad number of nal users and can be applied in dierent areas of computer vision, like medical imaging, tracking, robotics, etc. This work uses OpenGL to visualize the algorithm results in real time.

  20. Patterns in biofilms: From contour undulations to fold focussing

    Science.gov (United States)

    Ben Amar, Martine; Wu, Min

    2014-11-01

    Morphologies of soft materials in growth, swelling or drying have been extensively studied recently. Shape modifications occur as the size varies transforming ordinary spheres, cylinders and thin plates into more or less complex objects. Here we consider the genesis of biofilm patterns when a simple disc containing initially bacteria with moderate adhesion to a rigid substrate grows according to very simple rules. The initial circular geometry is lost during the growth expansion, contour undulations and buckling appear, ultimately a rather regular periodic focussing of folds repartition emerges. We theoretically predict these morphological instabilities as bifurcations of solutions in elasticity, characterized by typical driving parameters established here. The substrate plays a critical role limiting the geometry of the possible modes of instabilities and anisotropic growth, adhesion and toughness compete to eventually give rise to wrinkling, buckling or both. Additionally, due to the substrate, we show that the ordinary buckling modes, vertical deviation of thin films, are not observed in practice and a competitive pattern with self-focussing of folds can be found analytically. These patterns are reminiscent of the blisters of delamination in material sciences and explain recent observations of bacteria biofilms. The model presented here is purely analytical, is based on a neo-Hookean elastic energy, and can be extended without difficulties and applied to polymer materials.

  1. Contour Detection of Leukocyte Cell Nucleus Using Morphological Image

    Science.gov (United States)

    Supriyanti, R.; Satrio, G. P.; Ramadhani, Y.; Siswandari, W.

    2017-04-01

    Leukocytes are blood cells that do not contain color pigments. Leukocyte function to the tool body’s defenses. Abnormal forms of leukocytes can be a sign of serious diseases such example is leukemia. Most laboratories still use cell morphology examination to assist the diagnosis of illness associated with white blood cells such example is leukemia because of limited resources, both infrastructure, and human resources as happens in developing nations, such as Indonesia. This examination is less expensive and quicker process. However, morphological review requires the expertise of a specialist clinical pathology were limited. This process is sometimes less valid cause in some cases trying to differentiate morphology blast cells into the type of myoblasts, lymphoblast, monoblast, or erythroblast thus potentially misdiagnosis. The goal of this research is to develop a detection device types of blood cells automatically as lower-priced, easy to use and accurate so that the tool can be distributed across all units in existing health services throughout Indonesia and in particular for remote areas. However, because the variables used in the identification of abnormal leukocytes are very complex, in this paper, we emphasize on the contour detection of leukocyte cell nucleus using the morphological image. The results show that this method is promising for further development.

  2. Cardiac Tamponade Revisited

    Science.gov (United States)

    Ariyarajah, Vignendra; Spodick, David H.

    2007-01-01

    Cardiac tamponade is a life-threatening clinical syndrome that requires timely diagnosis. Herein, we present an instructive case of a patient who had cardiac tamponade. The condition went undiagnosed and resulted in the patient's death because almost all of the pathognomonic clinical findings of tamponade were unrecognized or not manifest. To better prepare health care professionals for similar challenges, we discuss the symptoms and clinical signs typical of cardiac tamponade, review the medical literature, and highlight current investigative methods that enable quick, efficient diagnosis and treatment. PMID:17948086

  3. Dominant point detecting based non-uniform B-spline approximation for grain contour

    Institute of Scientific and Technical Information of China (English)

    ZHAO XiuYang; YIN YanSheng; YANG Bo

    2007-01-01

    Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural geometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw contours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best estimated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

  4. Dominant point detecting based non-uniform B-spline approximation for grain contour

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural ge-ometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw con-tours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best es-timated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

  5. A shape-based inter-layer contours correspondence method for ICT-based reverse engineering.

    Science.gov (United States)

    Duan, Liming; Yang, Shangpeng; Zhang, Gui; Feng, Fei; Gu, Minghui

    2017-01-01

    The correspondence of a stack of planar contours in ICT (industrial computed tomography)-based reverse engineering, a key step in surface reconstruction, is difficult when the contours or topology of the object are complex. Given the regularity of industrial parts and similarity of the inter-layer contours, a specialized shape-based inter-layer contours correspondence method for ICT-based reverse engineering was presented to solve the above problem based on the vectorized contours. In this paper, the vectorized contours extracted from the slices consist of three graphical primitives: circles, arcs and segments. First, the correspondence of the inter-layer primitives is conducted based on the characteristics of the primitives. Second, based on the corresponded primitives, the inter-layer contours correspond with each other using the proximity rules and exhaustive search. The proposed method can make full use of the shape information to handle industrial parts with complex structures. The feasibility and superiority of this method have been demonstrated via the related experiments. This method can play an instructive role in practice and provide a reference for the related research.

  6. Performance of visual search tasks from various types of contour information.

    Science.gov (United States)

    Itan, Liron; Yitzhaky, Yitzhak

    2013-03-01

    A recently proposed visual aid for patients with a restricted visual field (tunnel vision) combines a see-through head-mounted display and a simultaneous minified contour view of the wide-field image of the environment. Such a widening of the effective visual field is helpful for tasks, such as visual search, mobility, and orientation. The sufficiency of image contours for performing everyday visual tasks is of major importance for this application, as well as for other applications, and for basic understanding of human vision. This research aims is to examine and compare the use of different types of automatically created contours, and contour representations, for practical everyday visual operations using commonly observed images. The visual operations include visual searching for items, such as cutlery, housewares, etc. Considering different recognition levels, identification of an object is distinguished from mere detection (when the object is not necessarily identified). Some nonconventional visual-based contour representations were developed for this purpose. Experiments were performed with normal-vision subjects by superposing contours of the wide field of the scene over a narrow field (see-through) background. From the results, it appears that about 85% success is obtained for searched object identification when the best contour versions are employed. Pilot experiments with video simulations are reported at the end of the paper.

  7. Prevalence and desire for body contouring surgery in postbariatric patients in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Saleh M Aldaqal

    2012-01-01

    Full Text Available Background: Morbid obesity has become a common problem worldwide and as a result the demand for bariatric surgery has increased as well. Most patients develop skin redundancy and sagging at many body parts after major weight loss procedures which increased the demand for body contouring procedures. Aims : The study was to address the prevalence and patient′s desire for body contouring procedures. Materials and Methods: A cross-sectional study targeting the postbariatric patients from April 2011 to October 2011 was conducted at our hospital. Questionnaire was administered in order to measure frequency and patients desire to undergo body contouring surgery after massive weight loss. Results: The total number of patients was 128 patients. The mean age of our patients was 37-year old (range 18-56 year. The percentage of the desire for body contouring surgery after bariatric surgery was 78.1%. There was very pronounced desire to body contouring surgery after those who underwent gastric bypass surgery with P-value 0.001. Only 18 patients (14% have underwent body contouring surgery, with a total of 29 procedures, in which abdominoplasty considered the most commonly procedure performed (57%. Conclusion : With the increasing number of weight loss surgery, there is higher number of patients that desire a body contouring surgery, which create huge disparity between demand and accessibility.

  8. Dynamic Maintenance of Half-Space Depth for Points and Contours

    CERN Document Server

    Burr, Michael A; Souvaine, Diane L

    2011-01-01

    Half-space depth (also called Tukey depth or location depth) is one of the most commonly studied data depth measures because it possesses many desirable properties for data depth functions. The data depth contours bound regions of increasing depth. For the sample case, there are two competing definitions of contours: the rank-based contours and the cover-based contours. In this paper, we present three dynamic algorithms for maintaining the half-space depth of points and contours: The first maintains the half-space depth of a single point in a data set in $O(\\log n)$ time per update (insertion/deletion) and overall linear space. By maintaining such a data structure for each data point, we present an algorithm for dynamically maintaining the rank-based contours in $O(n\\cdot\\log n)$ time per update and overall quadratic space. The third dynamic algorithm maintains the cover-based contours in $O(n\\cdot \\log^2 n)$ time per update and overall quadratic space. We also augment our first algorithm to maintain the loca...

  9. Brain MR image segmentation using local and global intensity fitting active contours/surfaces.

    Science.gov (United States)

    Wang, Li; Li, Chunming; Sun, Quansen; Xia, Deshen; Kao, Chiu-Yen

    2008-01-01

    In this paper, we present an improved region-based active contour/surface model for 2D/3D brain MR image segmentation. Our model combines the advantages of both local and global intensity information, which enable the model to cope with intensity inhomogeneity. We define an energy functional with a local intensity fitting term and an auxiliary global intensity fitting term. In the associated curve evolution, the motion of the contour is driven by a local intensity fitting force and a global intensity fitting force, induced by the local and global terms in the proposed energy functional, respectively. The influence of these two forces on the curve evolution is complementary. When the contour is close to object boundaries, the local intensity fitting force became dominant, which attracts the contour toward object boundaries and finally stops the contour there. The global intensity fitting force is dominant when the contour is far away from object boundaries, and it allows more flexible initialization of contours by using global image information. The proposed model has been applied to both 2D and 3D brain MR image segmentation with promising results.

  10. Contours, 2 foot contours automatically generated from 2008 LIDAR for the purpose of supporting FEMA floodplain mapping. Limited manual editing, breaklines for waterbodies greater than 5 acres created and use.10' index contours labeled., Published in 2008, 1:1200 (1in=100ft) scale, CITY OF PORTAGE.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from LIDAR information as of 2008. It is described as '2 foot contours...

  11. Molecular Basis of Cardiac Myxomas

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2014-01-01

    Full Text Available Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

  12. Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

    Energy Technology Data Exchange (ETDEWEB)

    Gay, Hiram A., E-mail: hgay@radonc.wustl.edu [Washington University School of Medicine, St Louis, MO (United States); Barthold, H. Joseph [Commonwealth Hematology and Oncology, Weymouth, MA (United States); Beth Israel Deaconess Medical Center, Boston, MA (Israel); O' Meara, Elizabeth [Radiation Therapy Oncology Group, Philadelphia, PA (United States); Bosch, Walter R. [Washington University School of Medicine, St Louis, MO (United States); El Naqa, Issam [Department of Radiation Oncology, McGill University Health Center, Montreal, Quebec (Canada); Al-Lozi, Rawan [Washington University School of Medicine, St Louis, MO (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); Lawton, Colleen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lee, W. Robert [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Sandler, Howard [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Zietman, Anthony [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Myerson, Robert [Washington University School of Medicine, St Louis, MO (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Willett, Christopher [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, MA (United States); Jhingran, Anuja [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Portelance, Lorraine [University of Miami, Miami, FL (United States); Ryu, Janice [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States); and others

    2012-07-01

    Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.

  13. Variations in the Contouring of Organs at Risk: Test Case From a Patient With Oropharyngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E., E-mail: alpha@canislupusllc.com [Canis Lupus LLC, Merrimac, WI (United States); Tome, Wolfgang A. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Robinson, Greg [Radiation Oncology Resources, Goshen, IN (United States); Wheeler, James [Department of Radiation Oncology, Goshen Health System Goshen, IN (United States)

    2012-01-01

    Purpose: Anatomy contouring is critical in radiation therapy. Inaccuracy and variation in defining critical volumes will affect everything downstream: treatment planning, dose-volume histogram analysis, and contour-based visual guidance used in image-guided radiation therapy. This study quantified: (1) variation in the contouring of organs at risk (OAR) in a clinical test case and (2) corresponding effects on dosimetric metrics of highly conformal plans. Methods and Materials: A common CT data set with predefined targets from a patient with oropharyngeal cancer was provided to a population of clinics, which were asked to (1) contour OARs and (2) design an intensity-modulated radiation therapy plan. Thirty-two acceptable plans were submitted as DICOM RT data sets, each generated by a different clinical team. Using those data sets, we quantified: (1) the OAR contouring variation and (2) the impact this variation has on dosimetric metrics. New technologies were employed, including a software tool to quantify three-dimensional structure comparisons. Results: There was significant interclinician variation in OAR contouring. The degree of variation is organ-dependent. We found substantial dose differences resulting strictly from contouring variation (differences ranging from -289% to 56% for mean OAR dose; -22% to 35% for maximum dose). However, there appears to be a threshold in the OAR comparison metric beyond which the dose differences stabilize. Conclusions: The effects of interclinician variation in contouring organs-at-risk in the head and neck can be large and are organ-specific. Physicians need to be aware of the effect that variation in OAR contouring can play on the final treatment plan and not restrict their focus only to the target volumes.

  14. Expansion/De-expansion Tool to Quantify the Accuracy of Prostate Contours

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eugene; Stenmark, Matthew H. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Evans, Cheryl [Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States); Narayana, Vrinda [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States); McLaughlin, Patrick W., E-mail: mclaughb@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States)

    2012-05-01

    Purpose: Accurate delineation of the prostate gland on computed tomography (CT) remains a persistent challenge and continues to introduce geometric uncertainty into the planning and delivery of external beam radiotherapy. We, therefore, developed an expansion/de-expansion tool to quantify the contour errors and determine the location of the deviations. Methods and Materials: A planning CT scan and magnetic resonance imaging scan were prospectively acquired for 10 patients with prostate cancer. The prostate glands were contoured by 3 independent observers using the CT data sets with instructions to contour the prostate without underestimation but to minimize overestimation. The standard prostate for each patient was defined using magnetic resonance imaging and CT on multiple planes. After registration of the CT and magnetic resonance imaging data sets, the CT-defined prostates were scored for accuracy. The contours were defined as ideal if they were within a 2.5-mm expansion of the standard without underestimation, acceptable if they were within a 5.0-mm expansion and a 2.5-mm de-expansion, and unacceptable if they extended >5.0 mm or underestimated the prostate by >2.5 mm. Results: A total of 636 CT slices were individually analyzed, with the vast majority scored as ideal or acceptable. However, none of the 30 prostate contour sets had all the contours scored as ideal or acceptable. For all 3 observers, the unacceptable contours were more likely from underestimation than overestimation of the prostate. The errors were more common at the base and apex than the mid-gland. Conclusions: The expansion/de-expansion tool allows for directed feedback on the location of contour deviations, as well as the determination of over- or underestimation of the prostate. This metric might help improve the accuracy of prostate contours.

  15. Speech intonation and melodic contour recognition in children with cochlear implants and with normal hearing.

    Science.gov (United States)

    See, Rachel L; Driscoll, Virginia D; Gfeller, Kate; Kliethermes, Stephanie; Oleson, Jacob

    2013-04-01

    Cochlear implant (CI) users have difficulty perceiving some intonation cues in speech and melodic contours because of poor frequency selectivity in the cochlear implant signal. To assess perceptual accuracy of normal hearing (NH) children and pediatric CI users on speech intonation (prosody), melodic contour, and pitch ranking, and to determine potential predictors of outcomes. Does perceptual accuracy for speech intonation or melodic contour differ as a function of auditory status (NH, CI), perceptual category (falling versus rising intonation/contour), pitch perception, or individual differences (e.g., age, hearing history)? NH and CI groups were tested on recognition of falling intonation/contour versus rising intonation/contour presented in both spoken and melodic (sung) conditions. Pitch ranking was also tested. Outcomes were correlated with variables of age, hearing history, HINT, and CNC scores. The CI group was significantly less accurate than the NH group in spoken (CI, M = 63.1%; NH, M = 82.1%) and melodic (CI, M = 61.6%; NH, M = 84.2%) conditions. The CI group was more accurate in recognizing rising contour in the melodic condition compared with rising intonation in the spoken condition. Pitch ranking was a significant predictor of outcome for both groups in falling intonation and rising melodic contour; age at testing and hearing history variables were not predictive of outcomes. Children with CIs were less accurate than NH children in perception of speech intonation, melodic contour, and pitch ranking. However, the larger pitch excursions of the melodic condition may assist in recognition of the rising inflection associated with the interrogative form.

  16. Hybrid OPC modeling with SEM contour technique for 10nm node process

    Science.gov (United States)

    Hitomi, Keiichiro; Halle, Scott; Miller, Marshal; Graur, Ioana; Saulnier, Nicole; Dunn, Derren; Okai, Nobuhiro; Hotta, Shoji; Yamaguchi, Atsuko; Komuro, Hitoshi; Ishimoto, Toru; Koshihara, Shunsuke; Hojo, Yutaka

    2014-03-01

    Hybrid OPC modeling is investigated using both CDs from 1D and simple 2D structures and contours extracted from complex 2D structures, which are obtained by a Critical Dimension-Scanning Electron Microscope (CD-SEM). Recent studies have addressed some of key issues needed for the implementation of contour extraction, including an edge detection algorithm consistent with conventional CD measurements, contour averaging and contour alignment. Firstly, pattern contours obtained from CD-SEM images were used to complement traditional site driven CD metrology for the calibration of OPC models for both metal and contact layers of 10 nm-node logic device, developed in Albany Nano-Tech. The accuracy of hybrid OPC model was compared with that of conventional OPC model, which was created with only CD data. Accuracy of the model, defined as total error root-mean-square (RMS), was improved by 23% with the use of hybrid OPC modeling for contact layer and 18% for metal layer, respectively. Pattern specific benefit of hybrid modeling was also examined. Resist shrink correction was applied to contours extracted from CD-SEM images in order to improve accuracy of the contours, and shrink corrected contours were used for OPC modeling. The accuracy of OPC model with shrink correction was compared with that without shrink correction, and total error RMS was decreased by 0.2nm (12%) with shrink correction technique. Variation of model accuracy among 8 modeling runs with different model calibration patterns was reduced by applying shrink correction. The shrink correction of contours can improve accuracy and stability of OPC model.

  17. 脓毒性休克患者血浆脑钠肽与 PiCCO 相关指标的关系%The correlation between plasma brain natriuretic peptide (BNP)levels and parameters of pulse -indicated continuous cardiac output(PiCCO)in patients with septic shock

    Institute of Scientific and Technical Information of China (English)

    吴翔; 陶飞; 胡桂芳; 邓烈华; 姚华国

    2016-01-01

    Objective To investigate the relationship between plasma brain natriuretic peptide (BNP)levels and the monito-ring indicators of pulse -indicated continuous cardiac output (PiCCO)in patients with sepstic shock.Methods 48 patients with septic shock according to the criteria of sepsis set by SC-CN /ESICM/ACCP /ATS /SIS were selected.Clinical and laboratory data including BNP were collected on the 1 d,3rd and 5 th day after admittion.The hemodynamics of the patients was monitored using PiCCO technology,and the heart function indexs were recorded,incluing CI,CFI,GEF and dP /dPmax.Acute Physiology and Chronic Health Evaluation (APACHEⅡ)and Sepsis -related Organ Failure Assessment (SOFA)score were determined.The correlation between BNP levels and the above indexs was analyzed.Results The levels of plasma BNP had negative correlation with CI,CFI,GEF (r =-0.339, -0.250, -0.241 ,P 0.05 ).The levels of plasma BNP had significant positive correlation with APACHEII scores and SOFA scores (r =0.509,0.565 ,P <0.05 ). Conclusion The cardiac function could not be reflected by BNP levels in septic shock patients.Plasma BNP levels can re-flect the severity of septic shock in certain degree,and might be considered as a valuable prognostic factor for patients with septic shock.%目的:通过监测脓毒性休克患者血浆脑钠肽(BNP)水平以及脉搏指示连续心排血量(PiCCO)相关指标的变化,探讨脓毒性休克患者脑钠肽水平与心功能的关系。方法选取48例脓毒性休克患者为研究对象,检测患者入 ICU第1、3、5天血浆 BNP 水平,通过 PiCCO 技术对患者进行血流动力学监测,记录反应心功能指标的 CI、CFI、GEF 和 dP/dP-max,并进行 APACHEⅡ、SOFA 评分,分析 BNP 与上述指标的相关性。结果脓毒性休克患者血浆 BNP 水平与 CI 、CFI、GE 呈负相关(r =-0.339、-0.25、-0.241,P <0.05),与 dP/dPmax 无显著相关性(P >0.05

  18. Cardiac Tumors; Tumeurs cardiaques

    Energy Technology Data Exchange (ETDEWEB)

    Laissy, J.P.; Fernandez, P. [Centre Hospitalier Universitaire Bichat Claude Bernard, Service d' Imagerie, 76 - Rouen (France); Mousseaux, E. [Hopital Europeen Georges Pompidou (HEGP), Service de Radiologie Cardio Vasculaire et Interventionnelle, 75 - Paris (France); Dacher, J.N. [Centre Hospitalier Universitaire Charles Nicolle, 75 - Rouen (France); Crochet, D. [Centre Hospitalier Universitaire, Hopital Laennec, Centre Hemodynamique, Radiologie Thoracique et Vasculaire, 44 - Nantes (France)

    2004-04-01

    Metastases are the most frequent tumors of the heart even though they seldom are recognized. Most primary cardiac tumors are benign. The main role of imaging is to differentiate a cardiac tumor from thrombus and rare pseudo-tumors: tuberculoma, hydatid cyst. Echocardiography is the fist line imaging technique to detect cardiac tumors, but CT and MRl arc useful for further characterization and differential diagnosis. Myxoma of the left atrium is the most frequent benign cardiac tumor. It usually is pedunculated and sometimes calcified. Sarcoma is the most frequent primary malignant tumor and usually presents as a sessile infiltrative tumor. Lymphoma and metastases are usually recognized by the presence of known tumor elsewhere of by characteristic direct contiguous involvement. Diagnosing primary and secondary pericardial tumors often is difficult. Imaging is valuable for diagnosis, characterization, pre-surgical evaluation and follow-up. (author)

  19. Socially differentiated cardiac rehabilitation

    DEFF Research Database (Denmark)

    Meillier, Lucette Kirsten; Nielsen, Kirsten Melgaard; Larsen, Finn Breinholt;

    2012-01-01

    to a standard rehabilitation programme (SRP). If patients were identified as socially vulnerable, they were offered an extended version of the rehabilitation programme (ERP). Excluded patients were offered home visits by a cardiac nurse. Concordance principles were used in the individualised programme elements......%. Patients were equally distributed to the SRP and the ERP. No inequality was found in attendance and adherence among referred patients. Conclusions: It seems possible to overcome unequal referral, attendance, and adherence in cardiac rehabilitation by organisation of systematic screening and social......Aim: The comprehensive cardiac rehabilitation (CR) programme after myocardial infarction (MI) improves quality of life and results in reduced cardiac mortality and recurrence of MI. Hospitals worldwide face problems with low participation rates in rehabilitation programmes. Inequality...

  20. Transvenous Temporary Cardiac Pacing

    National Research Council Canada - National Science Library

    Emmanouil Poulidakis; Antonis S Manolis

    2014-01-01

      Transvenous temporary cardiac pacing is a rather old but still contemporary life-saving technique, with a unique value in the treatment of critically ill patients suffering from rhythm disturbances...

  1. Contouring a guide to the analysis and display of spatial data

    CERN Document Server

    Watson, Debbie

    2013-01-01

    This unique book is the key to computer contouring, exploring in detail the practice and principles using a personal computer. Contouring allows a three dimensional view in two dimensions and is a fundamental technique to represent spatial data. All aspects of this type of representation are covered including data preparation, selecting contour intervals, interpolation and griding, computing volumes and output and display. Formulated for both the novice and the experienced user, this book initially conducts the reader through a step by step explanation of PC software and its application to per

  2. Polar-direct-drive experiments with contoured-shell targets on OMEGA

    Science.gov (United States)

    Marshall, F. J.; Radha, P. B.; Bonino, M. J.; Delettrez, J. A.; Epstein, R.; Glebov, V. Yu.; Harding, D. R.; Stoeckl, C.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Zylstra, A.; Giraldez, E.

    2016-01-01

    Polar-driven direct-drive experiments recently performed on the OMEGA Laser System have demonstrated the efficacy of using a target with a contoured shell with varying thickness to improve the symmetry and fusion performance of the implosion. The polar-driven contoured-shell implosions have substantially reduced low mode perturbations compared to polar-driven spherical-shell implosions as diagnosed by x-ray radiographs up to shell stagnation. Fusion yields were increased by more than a factor of ˜2 without increasing the energy of the laser by the use of contoured shells.

  3. Polar-direct-drive experiments with contoured-shell targets on OMEGA

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, F. J.; Radha, P. B.; Bonino, M. J.; Delettrez, J. A.; Epstein, R.; Glebov, V. Yu.; Harding, D. R.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Zylstra, A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Giraldez, E. [General Atomics, San Diego, California 92121 (United States)

    2016-01-15

    Polar-driven direct-drive experiments recently performed on the OMEGA Laser System have demonstrated the efficacy of using a target with a contoured shell with varying thickness to improve the symmetry and fusion performance of the implosion. The polar-driven contoured-shell implosions have substantially reduced low mode perturbations compared to polar-driven spherical-shell implosions as diagnosed by x-ray radiographs up to shell stagnation. Fusion yields were increased by more than a factor of ∼2 without increasing the energy of the laser by the use of contoured shells.

  4. Subcortical neural representation to Mandarin pitch contours in American and Chinese newborns.

    Science.gov (United States)

    Jeng, Fuh-Cherng; Lin, Chia-Der; Wang, Tang-Chuan

    2016-06-01

    Voice pitch carries important information for speech understanding. This study examines the neural representation of voice pitch at the subcortical level, as reflected by the scalp-recorded frequency-following responses from ten American and ten Chinese newborns. By utilizing a set of four distinctive Mandarin pitch contours that mimic the English vowel /yi/, the results indicate that the rising and dipping pitch contours produce significantly better tracking accuracy and larger response amplitudes than the falling pitch contour. This finding suggests a hierarchy of potential stimuli when testing neonates who are born in a tonal or non-tonal linguistic environment.

  5. Cardiac arrest - cardiopulmonary resuscitation

    Institute of Scientific and Technical Information of China (English)

    Basri Lenjani; Besnik Elshani; Nehat Baftiu; Kelmend Pallaska; Kadir Hyseni; Njazi Gashi; Nexhbedin Karemani; Ilaz Bunjaku; Taxhidin Zaimi; Arianit Jakupi

    2014-01-01

    Objective:To investigate application of cardiopulmonary resuscitation(CPR) measures within the golden minutes inEurope.Methods:The material was taken from theUniversityClinical Center ofKosovo -EmergencyCentre inPristina, during the two(2) year period(2010-2011).The collected date belong to the patients with cardiac arrest have been recorded in the patients' log book protocol at the emergency clinic.Results:During the2010 to2011 in the emergency center of theCUCK inPristina have been treated a total of269 patients with cardiac arrest, of whom159 or59.1% have been treated in2010, and110 patients or40.9% in2011.Of the269 patients treated in the emergency centre,93 or34.6% have exited lethally in the emergency centre, and176 or 65.4% have been transferred to other clinics.In the total number of patients with cardiac arrest, males have dominated with186 cases, or69.1%.The average age of patients included in the survey was56.7 year oldSD±16.0 years.Of the269 patients with cardiac arrest, defibrillation has been applied for93 or34.6% of patients.In the outpatient settings defibrillation has been applied for3 or3.2% of patients.Patients were defibrillated with application of one to four shocks. Of27 cases with who have survived cardiac arrest, none of them have suffered cardiac arrest at home,3 or11.1% of them have suffered cardiac arrest on the street, and24 or88.9% of them have suffered cardiac arrest in the hospital.5 out of27 patients survived have ended with neurological impairment.Cardiac arrest cases were present during all days of the week, but frequently most reported cases have been onMonday with32.0% of cases, and onFriday with24.5% of cases. Conclusions:All survivors from cardiac arrest have received appropriate medical assistance within10 min from attack, which implies that if cardiac arrest occurs near an institution health care(with an opportunity to provide the emergent health care) the rate of survival is higher.

  6. Cardiac imaging in adults

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  7. Autonomic cardiac innervation

    OpenAIRE

    Hasan, Wohaib

    2013-01-01

    Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targe...

  8. Port Access Cardiac Surgery.

    Science.gov (United States)

    Viganó, Mario; Minzioni, Gaetano; Spreafico, Patrizio; Rinaldi, Mauro; Pasquino, Stefano; Ceriana, Piero; Locatelli, Alessandro

    2000-10-01

    The port-access technique for cardiac surgery was recently developed at Stanford University in California as a less invasive method to perform some cardiac operations. The port-access system has been described in detail elsewhere. It is based on femoral arterial and venous access for cardiopulmonary bypass (CPB) and on the adoption of a specially designed triple-lumen catheter described originally by Peters, and subsequently modified and developed in the definitive configuration called the endoaortic clamp.

  9. Awareness in cardiac anesthesia.

    LENUS (Irish Health Repository)

    Serfontein, Leon

    2010-02-01

    Cardiac surgery represents a sub-group of patients at significantly increased risk of intraoperative awareness. Relatively few recent publications have targeted the topic of awareness in this group. The aim of this review is to identify areas of awareness research that may equally be extrapolated to cardiac anesthesia in the attempt to increase understanding of the nature and significance of this scenario and how to reduce it.

  10. Post cardiac injury syndrome

    DEFF Research Database (Denmark)

    Nielsen, S L; Nielsen, F E

    1991-01-01

    The post-pericardiotomy syndrome is a symptom complex which is similar in many respects to the post-myocardial infarction syndrome and these are summarized under the diagnosis of the Post Cardiac Injury Syndrome (PCIS). This condition, which is observed most frequently after open heart surgery, i...... on the coronary vessels, with cardiac tamponade and chronic pericardial exudate. In the lighter cases, PCIS may be treated with NSAID and, in the more severe cases, with systemic glucocorticoid which has a prompt effect....

  11. Infected cardiac hydatid cyst

    OpenAIRE

    Ceviz, M; Becit, N; Kocak, H.

    2001-01-01

    A 24 year old woman presented with chest pain and palpitation. The presence of a semisolid mass—an echinococcal cyst or tumour—in the left ventricular apex was diagnosed by echocardiography, computed tomography, and magnetic resonance imaging. The infected cyst was seen at surgery. The cyst was removed successfully by using cardiopulmonary bypass with cross clamp.


Keywords: cardiac hydatid cyst; infected cardiac hydatid cyst

  12. Pulse Indicator Continuous Cardiac Output for Hemodynamics Monitoring in Patients with Septic Shock%脉搏指示连续心排血量监测(PiCCO)在脓毒症休克患者血流动力学监测中的临床价值

    Institute of Scientific and Technical Information of China (English)

    陈涛

    2015-01-01

    Objective To observe and analyze patients with septic shock pulse wave indicates continuous cardiac output monitoring (Picco) clinical value, to provide a reference for future clinical use. Methods January 2013—2014 in March during outpatient sep-sis patients admitted to 40 cases for the study, depending on the admission of hemodynamic monitoring methods divided into two groups, the study group and the control group 20 cases. Two were used for routine monitoring (control group), Picco monitoring (study group) to guide clinical treatment (fluid resuscitation, inotropic drugs, vasoconstrictor drugs, etc.). Results The mean arterial pressure in the two groups of patients after treatment of the initial value and compare, P 0.05). Conclusion Picco be monitored in patients with septic shock hemodynamic parameters with good results, it is worth further study in late.%目的:观察脓毒症休克患者采用脉波指示连续心排血量监测(PiCCO)的效果,并分析其临床应用价值。方法将医院2012年1月—2014年3月期间门诊收入的脓毒症50例患者选为研究对象,按照患者就诊时血动力指标的监测方式不同分成两组:研究组25例,对照组25例。两组分别采用常规监测(对照组)、PiCCO监测(研究组)指导临床治疗(液体复苏、正性肌力药物、血管收缩药物等)。结果两组患者的平均动脉压在初始值比较(P<0.01);研究组患者入院3 d内不同时点GEDI、PPV、SVV检测值比较,组间差异有统计学意义(P<0.05)。组间在去甲肾上腺素和就诊1周输液量比较,差异无统计学意义(P>0.05)。结论脓毒症休克患者予以PiCCO监测血流动力学指标具有良好效果,值得在后期进一步研究。

  13. Cardiac applications of optogenetics.

    Science.gov (United States)

    Ambrosi, Christina M; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia

    2014-08-01

    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics.

  14. Perceived Blur in Naturally-Contoured Images Depends on Phase

    Directory of Open Access Journals (Sweden)

    Stephanie Murray

    2010-12-01

    Full Text Available Perceived blur is an important measure of image quality and clinical visual function. The magnitude of image blur varies across space and time under natural viewing conditions owing to changes in pupil size and accommodation. Blur is frequently studied in the laboratory with a variety of digital filters, without comparing how the choice of filter affects blur perception. We examine the perception of image blur in synthetic images composed of contours whose orientation and curvature spatial properties matched those of natural images but whose blur could be directly controlled. The images were blurred by manipulating the slope of the amplitude spectrum, Gaussian low-pass filtering or filtering with a Sinc function, which, unlike slope or Gaussian filtering, introduces periodic phase reversals similar to those in optically blurred images. For slope-filtered images, blur discrimination thresholds for over-sharpened images were extremely high and perceived blur could not be matched with either Gaussian or Sinc filtered images, suggesting that directly manipulating image slope does not simulate the perception of blur. For Gaussian and Sinc blurred images, blur discrimination thresholds were dipper-shaped and were well-fit with a simple variance discrimination model and with a contrast detection threshold model, but the latter required different contrast sensitivity functions for different types of blur. Blur matches between Gaussian and Sinc blurred images were used to test several models of blur perception and were in good agreement with models based on luminance slope, but not with spatial frequency based models. Collectively, these results show that the relative phases of image components, in addition to their relative amplitudes, determines perceived blur.

  15. New method of contour-based mask-shape compiler

    Science.gov (United States)

    Matsuoka, Ryoichi; Sugiyama, Akiyuki; Onizawa, Akira; Sato, Hidetoshi; Toyoda, Yasutaka

    2007-10-01

    We have developed a new method of accurately profiling a mask shape by utilizing a Mask CD-SEM. The method is intended to realize high accuracy, stability and reproducibility of the Mask CD-SEM adopting an edge detection algorithm as the key technology used in CD-SEM for high accuracy CD measurement. In comparison with a conventional image processing method for contour profiling, it is possible to create the profiles with much higher accuracy which is comparable with CD-SEM for semiconductor device CD measurement. In this report, we will introduce the algorithm in general, the experimental results and the application in practice. As shrinkage of design rule for semiconductor device has further advanced, an aggressive OPC (Optical Proximity Correction) is indispensable in RET (Resolution Enhancement Technology). From the view point of DFM (Design for Manufacturability), a dramatic increase of data processing cost for advanced MDP (Mask Data Preparation) for instance and surge of mask making cost have become a big concern to the device manufacturers. In a sense, it is a trade-off between the high accuracy RET and the mask production cost, while it gives a significant impact on the semiconductor market centered around the mask business. To cope with the problem, we propose the best method for a DFM solution in which two dimensional data are extracted for an error free practical simulation by precise reproduction of a real mask shape in addition to the mask data simulation. The flow centering around the design data is fully automated and provides an environment where optimization and verification for fully automated model calibration with much less error is available. It also allows complete consolidation of input and output functions with an EDA system by constructing a design data oriented system structure. This method therefore is regarded as a strategic DFM approach in the semiconductor metrology.

  16. Intramyocardial strain estimation from cardiac cine MRI.

    Science.gov (United States)

    Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman

    2015-08-01

    Functional strain is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional strain parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional strain parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the strain evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional strain parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic strain change and 0.29 % (per unit time) for indexing systolic and diastolic strain rates. The method was feasible for in vivo extraction of functional strain parameters. Strain indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the

  17. Assessment of cardiac output changes using a modified FloTrac/Vigileo algorithm in cardiac surgery patients.

    Science.gov (United States)

    Senn, Alban; Button, Danny; Zollinger, Andreas; Hofer, Christoph K

    2009-01-01

    The FloTrac/Vigileo (Edwards Lifesciences, Irvine, CA, USA) allows pulse pressure-derived cardiac output measurement without external calibration. Software modifications were performed in order to eliminate initially observed deficits. The aim of this study was to assess changes in cardiac output determined by the FloTrac/Vigileo system (FCO) with an initially released (FCOA) and a modified (FCOB) software version, as well as changes in cardiac output from the PiCCOplus system (PCO; Pulsion Medical Systems, Munich, Germany). Both devices were compared with cardiac output measured by intermittent thermodilution (ICO). Cardiac output measurements were performed in patients after elective cardiac surgery. Two sets of data (A and B) were obtained using FCOA and FCOB in 50 patients. After calibration of the PiCCOplus system, triplicate FCO and PCO values were recorded and ICO was determined in the supine position and cardiac output changes due to body positioning were recorded 15 minutes later (30 degrees head-up, 30 degrees head-down, supine). Student's t test, analysis of variance and Bland-Altman analysis were calculated. Significant changes of FCO, PCO and ICO induced by body positioning were observed in both data sets. For set A, DeltaFCOA was significantly larger than DeltaICO induced by positioning the head down. For set B, there were no significant differences between DeltaFCOB and DeltaICO. For set A, increased limits of agreement were found for FCOA-ICO when compared with PCO-ICO. For set B, mean bias and limits of agreement were comparable for FCOB-ICO and PCO-ICO. The modification of the FloTrac/Vigileo system resulted in an improved performance in order to reliably assess cardiac output and track the related changes in patients after cardiac surgery.

  18. Feed-forward active contour analysis for improved brachial artery reactivity testing.

    Science.gov (United States)

    Pugliese, Daniel N; Sehgal, Chandra M; Sultan, Laith R; Reamer, Courtney B; Mohler, Emile R

    2016-08-01

    The object of this study was to utilize a novel feed-forward active contour (FFAC) algorithm to find a reproducible technique for analysis of brachial artery reactivity. Flow-mediated dilation (FMD) is an important marker of vascular endothelial function but has not been adopted for widespread clinical use given its technical limitations, including inter-observer variability and differences in technique across clinical sites. We developed a novel FFAC algorithm with the goal of validating a more reliable standard. Forty-six healthy volunteers underwent FMD measurement according to the standard technique. Ultrasound videos lasting 5-10 seconds each were obtained pre-cuff inflation and at minutes 1 through 5 post-cuff deflation in longitudinal and transverse views. Automated segmentation using the FFAC algorithm with initial boundary definition from three different observers was used to analyze the images to measure diameter/cross-sectional area over the cardiac cycle. The %FMD was calculated for average, minimum, and maximum diameters/areas. Using the FFAC algorithm, the population-specific coefficient of variation (CV) at end-diastole was 3.24% for transverse compared to 9.96% for longitudinal measurements; the subject-specific CV was 15.03% compared to 57.41%, respectively. For longitudinal measurements made via the conventional method, the population-specific CV was 4.77% and subject-specific CV was 117.79%. The intraclass correlation coefficient (ICC) for transverse measurements was 0.97 (95% CI: 0.95-0.98) compared to 0.90 (95% CI: 0.84-0.94) for longitudinal measurements with FFAC and 0.72 (95% CI: 0.51-0.84) for conventional measurements. In conclusion, transverse views using the novel FFAC method provide less inter-observer variability than traditional longitudinal views. Improved reproducibility may allow adoption of FMD testing in a clinical setting. The FFAC algorithm is a robust technique that should be evaluated further for its ability to replace the

  19. Structural contours of the Hauterivian Qezeltash formation of northern Afghanistan (qezeldpafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains polylines that describe structural contours (subsea elevation) of the Hauterivian Qezeltash formation in northern Afghanistan. Hauterivian...

  20. bathy_500m - 500m Bathy Contours Derived from ETOPO2 Global 2' Elevations

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This bathymetry contour data is in ESRI shapefile format and was derived from a National Oceanic Atmospheric Administration (NOAA), National Geophysical Data Center...

  1. Scale and Contour: Two Components of a Theory of Memory for Melodies.

    Science.gov (United States)

    Dowling, W. Jay

    1978-01-01

    The author concentrates on two components of memory which contribute to the reproduction and recognition of melodies, namely, melodic contour and musical scale. A new experiment is reported that shows the interdependence of both components. (Author/RK)

  2. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Maturation Contours

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The maturation contours show vitrinite reflectance trends and ranges for five key petroleum system horizons within the Uinta-Piceance Province. The horizons are the...

  3. Structural contours of the Upper Campanian through Paleocene Ghory formation of northern Afghanistan (ghorydpafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains polylines that describe structural contours of subsea elevation of the top of the Upper Campanian through Paleocene Ghory formation in...

  4. VT 1 ft Contour Lines generated from bare earth lidar - 60% of VT

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to contours derived from Quality Level 2 (QL2) Lidar "collections" with a resolution (RESCLASS) of 0.7m. For an overview of...

  5. Mahogany Ledge Digital Structure Contour Lines of the Piceance Basin, Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Mahogany ledge structure contour lines were needed to perform overburden calculations in the Piceance Basin, Colorado as part of a 2009 National Oil Shale...

  6. Structure Contour of the Top of the Lower Miocene 2 Sequence, Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The structure contours were created using biostratigraphic data in the Paleo-Data, Inc., Tenroc Regional Geologic Database. The depths of the microfossil locations...

  7. Age-related changes in visual contour integration: implications for physiology from psychophysics.

    Science.gov (United States)

    Hipp, D; Dickerson, K; Moser, A; Gerhardstein, Peter

    2014-09-01

    Visual contour detection is enhanced by grouping principles, such as proximity and collinearity, which appear to rely on horizontal connectivity in visual cortex. Previous experiments suggest that children require greater proximity to detect contours and that, unlike adults, collinearity does not compensate for their proximity limitation. Over two experiments we test whether closure, a global property known to facilitate contour detection, compensates for this limitation. Adults and children (3-9 years old) performed a 2AFC task; one panel contained an illusory contour (closed or open) in visual noise, and one only noise. The experiments were identical except proximity was doubled in Exp. 2, enabling shorter-range spatial integration. Results suggest children are limited by proximity, and that closure did not reliably improve their performance as it did for adults. We conclude that perceptual maturity lags behind anatomy within this system, and suggest that slow statistical learning of long-range orientation correlations controls this disparity. © 2014 Wiley Periodicals, Inc.

  8. USGS Small-scale Dataset - 1:1,000,000-Scale Contours of Alaska 201404 Shapefile

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows elevation contour lines for Alaska. The map layer was derived from the 100-meter resolution elevation data set which is published by the...

  9. Sensitivity adjustable contouring by digital holography and a virtual reference wavefront

    Science.gov (United States)

    Cai, L. Z.; Liu, Q.; Yang, X. L.; Wang, Y. R.

    2003-06-01

    A new method of contouring using digital holography and a virtual reference wavefront is reported. In this method, an object wave is first recorded and then digitally reconstructed. At the same time, a reference wave is digitally introduced to interfere with the reconstructed object wave to form a contour pattern. Since the form or curvature of the reference wave can be arbitrarily designed and artificially generated by a computer, the contouring sensitivity (the depth interval) can be easily adjusted for different purpose. The effectiveness of this method has been verified by computer simulations with both the conventional off-axis hologram and the phase-shifting hologram. The simplicity of optical setup and the unique ability of changing contouring sensitivity in this technique make it attractive potential in practical measurements.

  10. Active Contour Model Coupling with Higher Order Diffusion for Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    Guodong Wang

    2014-01-01

    Full Text Available Active contour models are very popular in image segmentation. Different features such as mean gray and variance are selected for different purpose. But for image with intensity inhomogeneities, there are no features for segmentation using the active contour model. The images with intensity inhomogeneities often occurred in real world especially in medical images. To deal with the difficulties raised in image segmentation with intensity inhomogeneities, a new active contour model with higher-order diffusion method is proposed. With the addition of gradient and Laplace information, the active contour model can converge to the edge of the image even with the intensity inhomogeneities. Because of the introduction of Laplace information, the difference scheme becomes more difficult. To enhance the efficiency of the segmentation, the fast Split Bregman algorithm is designed for the segmentation implementation. The performance of our method is demonstrated through numerical experiments of some medical image segmentations with intensity inhomogeneities.

  11. VT 100 ft Contour Lines generated from USGS 30 meter NED DEM

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This data layers consists of 100 foot contours intervals interpolated from the USGS NED. USGS NED (National Elevation Dataset) data are described...

  12. 1:1,000,000-Scale Contours of the Conterminous United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows elevation contour lines for the conterminous United States. The map layer was derived from the 100-meter resolution elevation data set which is...

  13. USGS Small-scale Dataset - 1:1,000,000-Scale Contours of Hawaii 201404 Shapefile

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows elevation contour lines for Hawaii. The map layer was derived from the 100-meter resolution elevation data set which is published by the...

  14. A multi-scale approach to mass segmentation using active contour models

    Science.gov (United States)

    Yu, Hongwei; Li, Lihua; Xu, Weidong; Liu, Wei

    2010-03-01

    As an important step of mass classification, mass segmentation plays an important role in computer-aided diagnosis (CAD). In this paper, we propose a novel scheme for breast mass segmentation in mammograms, which is based on level set method and multi-scale analysis. Mammogram is firstly decomposed by Gaussian pyramid into a sequence of images from fine to coarse, the C-V model is then applied at the coarse scale, and the obtained rough contour is used as the initial contour for segmentation at the fine scale. A local active contour (LAC) model based on image local information is utilized to refine the rough contour locally at the fine scale. In addition, the feature of area and gray level extracted from coarse segmentation is used to set the parameters of LAC model automatically to improve the adaptivity of our method. The results show the higher accuracy and robustness of the proposed multi-scale segmentation method than the conventional ones.

  15. A multiresolution framework for ultrasound image segmentation by combinative active contours.

    Science.gov (United States)

    Wang, Weiming; Qin, Jing; Chui, Yim-Pan; Heng, Pheng-Ann

    2013-01-01

    We propose a novel multiresolution framework for ultrasound image segmentation in this paper. The framework exploits both local intensity and local phase information to tackle the degradations of ultrasound images. First, multiresolution scheme is adopted to build a Gaussian pyramid for each speckled image. Speckle noise is gradually smoothed out at higher levels of the pyramid. Then local intensity-driven active contours are employed to locate the coarse contour of the target from the coarsest image, followed by local phase-based geodesic active contours to further refine the contour in finer images. Compared with traditional gradient-based methods, phase-based methods are more suitable for ultrasound images because they are invariant to variations in image contrast. Experimental results on left ventricle segmentation from echocardiographic images demonstrate the advantages of the proposed model.

  16. Potentiometric water-level altitude contours of Dixie Valley, west-central Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains the potentiometric water-level altitude contours representing the 2009 potentiometric surface of the basin fill groundwater system of Dixie...

  17. Depth Contours for select locations across the U.S. Pacific Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are depth contours (isobaths) derived at 50 meters for most islands and reefs in the Mariana Archipelago, American Samoa, and the Pacific Remote Island...

  18. VT 50 foot contours generated from USGS 30 meter NED DEM

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This data layers consists of 50 foot contours intervals interpolated from the USGS NED. USGS NED (National Elevation Dataset) data are described...

  19. A new approach of drawing airport noise contours on computer based on Surfer

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bang-jun; GUO Chun-yan; Di Guo-qing

    2004-01-01

    Noise contours are used to describe the extent of airport noise pollution and to plan land use around airports. The LwEcPN (weighted equivalent continuous perceive noise level) recommended by ICAO(International Civil Aviation Organization ) is adopted as airport noise rating parameter in this paper. With the help of various mathematical models in the software Surfer, noise contours can be drawn automatically by the completed program in Visual C++ Code. Corrections for thrust, velocity, atmospheric temperature, humidity and lateral ground attenuation are also considered in the new method, which can improve the efficiency of drawing contours. An example of its use for drawing noise contours of an airport in Zhejiang Province of China is proposed and the predictions and the measurements show agreements well.

  20. 1:1,000,000-Scale Contours of Alaska - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows elevation contour lines for Alaska. The map layer was derived from the 100-meter resolution elevation data set which is published by the...

  1. Contours, Published in 1995, 1:4800 (1in=400ft) scale, Greenwood County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Contours dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Orthoimagery information as of 1995. Data by this publisher are often...

  2. bathy_500m - 500m Bathy Contours Derived from ETOPO2 Global 2' Elevations

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This bathymetry contour data is in ESRI shapefile format and was derived from a National Oceanic Atmospheric Administration (NOAA), National Geophysical Data Center...

  3. CCALBATC - bathymetric contours for the central California region between Point Arena and Point Sur.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — CCALBATC consists of bathymetric contours at 10-m and 50-m intervals for the area offshore of central California between Point Arena to the north and Point Sur to...

  4. Depth to ground water contours of hydrographic area 153, Diamond Valley, Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of depth to ground water contours for hydrographic-area (HA) 153, Diamond Valley, Nevada. These data represent static ground-water levels...

  5. The center of lateral iso-density contours for inclined cosmic air showers

    CERN Document Server

    Montanus, J M C

    2015-01-01

    The lateral density of a cosmic air shower with a non-zero zenith angle is azimuthally asymmetric. The azimuthal asymmetry consist of a stretching of the iso-density contours to ellipses and to a shift of the center of the elliptic contours with respect to the core of the shower. The aim of the paper is to investigate the shift of the center of the elliptic iso-density contours for different zenith angles . On the basis of a model a qualitative equation is derived for the iso-density contours of inclined showers including the shift. to obtain a quantitative equation MC densities are investigated. The shift can be incorporated in an analytic expression of the azimuthal asymmetry of the lateral density as a function of the polar coordinates and parameterized by the zenith angle. Its predictions for asymmetric lateral densities are compared with densities obtained with MC simulations.

  6. Stellwagen Bank bathymetry - Percent slope derived from 5-meter bathymetric contour lines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Percent slope of Stellwagen Bank bathymetry. Raster derived from 5-meter bathymetric contour lines (Quads 1-18). Collected on surveys carried out in 4 cruises 1994 -...

  7. Stellwagen Bank bathymetry - Degree slope derived from 5-meter bathymetric contour lines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Degree slope of Stellwagen Bank bathymetry. Raster derived from 5-meter bathymetric contour lines (Quads 1-18). Collected on surveys carried out in 4 cruises 1994 -...

  8. Ten-Foot Contour Intervals at Pipe Spring National Monument, Arizona (pisp_cntr10ft)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an Arc/Info coverage consisting of 22 arcs that represent the 10 foot contour intervals as determined by a 1958 map found in a report - ask Tom. They were...

  9. Road Bridges and Culverts, 2006 2' contours; autocad dwg, Published in unknown, Washoe County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Bridges and Culverts dataset as of unknown. It is described as '2006 2' contours; autocad dwg'. Data by this publisher are often provided in State Plane...

  10. Structure Contour of the Top of the Upper Miocene Sequence, Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The structure contours were created using biostratigraphic data in the Paleo-Data, Inc., Tenroc Regional Geologic Database. The depths of the microfossil locations...

  11. Emotion identification using extremely low frequency components of speech feature contours.

    Science.gov (United States)

    Lin, Chang-Hong; Liao, Wei-Kai; Hsieh, Wen-Chi; Liao, Wei-Jiun; Wang, Jia-Ching

    2014-01-01

    The investigations of emotional speech identification can be divided into two main parts, features and classifiers. In this paper, how to extract an effective speech feature set for the emotional speech identification is addressed. In our speech feature set, we use not only statistical analysis of frame-based acoustical features, but also the approximated speech feature contours, which are obtained by extracting extremely low frequency components to speech feature contours. Furthermore, principal component analysis (PCA) is applied to the approximated speech feature contours so that an efficient representation of approximated contours can be derived. The proposed speech feature set is fed into support vector machines (SVMs) to perform multiclass emotion identification. The experimental results demonstrate the performance of the proposed system with 82.26% identification rate.

  12. Structure Contour of the Top of the Lower Miocene 1 Sequence, Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The structure contours were created using biostratigraphic data in the Paleo-Data, Inc., Tenroc Regional Geologic Database. The depths of the microfossil locations...

  13. Structure Contour of the Top of the Middle Miocene Sequence, Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The structure contours were created using biostratigraphic data in the Paleo-Data, Inc., Tenroc Regional Geologic Database. The depths of the microfossil locations...

  14. Radial pulse (image)

    Science.gov (United States)

    ... heart. The arteries are the vessels with the "pulse", a rhythmic pushing of the blood in the ... a refilling of the heart chamber. To determine heart rate, one feels the beats at a pulse point ...

  15. Wrist pulse (image)

    Science.gov (United States)

    To measure the pulse at the wrist, place the index and middle finger over the underside of the opposite wrist, below the base ... firmly with flat fingers until you feel the pulse in the radial artery.

  16. Inner and outer coronary vessel wall segmentation from CCTA using an active contour model with machine learning-based 3D voxel context-aware image force

    Science.gov (United States)

    Sivalingam, Udhayaraj; Wels, Michael; Rempfler, Markus; Grosskopf, Stefan; Suehling, Michael; Menze, Bjoern H.

    2016-03-01

    In this paper, we present a fully automated approach to coronary vessel segmentation, which involves calcification or soft plaque delineation in addition to accurate lumen delineation, from 3D Cardiac Computed Tomography Angiography data. Adequately virtualizing the coronary lumen plays a crucial role for simulating blood ow by means of fluid dynamics while additionally identifying the outer vessel wall in the case of arteriosclerosis is a prerequisite for further plaque compartment analysis. Our method is a hybrid approach complementing Active Contour Model-based segmentation with an external image force that relies on a Random Forest Regression model generated off-line. The regression model provides a strong estimate of the distance to the true vessel surface for every surface candidate point taking into account 3D wavelet-encoded contextual image features, which are aligned with the current surface hypothesis. The associated external image force is integrated in the objective function of the active contour model, such that the overall segmentation approach benefits from the advantages associated with snakes and from the ones associated with machine learning-based regression alike. This yields an integrated approach achieving competitive results on a publicly available benchmark data collection (Rotterdam segmentation challenge).

  17. [Psychosomatic aspects of cardiac arrhythmias].

    Science.gov (United States)

    Siepmann, Martin; Kirch, Wilhelm

    2010-07-01

    Emotional stress facilitates the occurrence of cardiac arrhythmias including sudden cardiac death. The prevalence of anxiety and depression is increased in cardiac patients as compared to the normal population. The risk of cardiovascular mortality is enhanced in patients suffering from depression. Comorbid anxiety disorders worsen the course of cardiac arrhythmias. Disturbance of neurocardiac regulation with predominance of the sympathetic tone is hypothesized to be causative for this. The emotional reaction to cardiac arrhythmias is differing to a large extent between individuals. Emotional stress may result from coping with treatment of cardiac arrhythmias. Emotional stress and cardiac arrhythmias may influence each other in the sense of a vicious circle. Somatoform cardiac arrhythmias are predominantly of psychogenic origin. Instrumental measures and frequent contacts between physicians and patients may facilitate disease chronification. The present review is dealing with the multifaceted relationships between cardiac arrhythmias and emotional stress. The underlying mechanisms and corresponding treatment modalities are discussed.

  18. Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model

    Directory of Open Access Journals (Sweden)

    Jen-Hsou Lin

    2010-01-01

    Full Text Available The usefulness of acupuncture (AP as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI, an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA at bilateral acupoint Neiguan (PC6 on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI, including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology.

  19. 脉搏指示连续心排血量监测技术救治重症胰腺炎并发急性呼吸窘迫综合征患儿二例%Pulse indicator continuous cardiac output measurement-guided treatment aids two pediatric patients with severe acute pancreatitis complicated with acute respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    颜卫源; 王丽杰

    2014-01-01

    Objective To evaluate the clinical value of the pulse indicator continuous cardiac output (PiCCO) system in patients with severe acute pancreatitis (SAP) complicated with acute respiratory distress syndrome (ARDS).Method Two cases of SAP with ARDS were monitored using PiCCO during comprehensive management in the Pediatric Intensive Care Unit (PICU) of Shengjing Hospital,China Medical University.To guide fluid management,the cardiac index (CI) was measured to assess cardiac function,the global end-diastolic volume index (GEDVI) was used to evaluate cardiac preload,and the extravascular lung water index (EVLWI) was used to evaluate the pulmonary edema.Result Case 1 was diagnosed with type L2 acute lymphoblastic leukemia (intermediate risk) and received the sixth maintenance phases of chemotherapy this time.After a 1-week dosage of chemotherapeutic drugs (pegaspargase and mitoxantrone),he suffered SAP combined with ARDS.Except comprehensive treatment (life supporting,antibiotic,etc.) and applying continuous veno-venous hemodiafiltration (CVVHDF) to remove inflammatory mediators.PiCCO monitor was utilized to guide fluid management.During the early stage of PiCCO monitoring,the patient showed no significant manifestations of pulmonary edema in the bedside chest X-ray (bedside ultrasound showed left pleural effusion),and had an oxygenation index 223 mmHg (1 mmHg =0.133 kPa),GEDVI 450 ml/m2,and ELVWI 7 ml/kg.We increased cardiac output to increase tissue perfusion and dehydration speed of CVVHDF was set at 70 ml/h.Two hours later,GEDVI significantly increased to 600 ml/m2 and ELVWI significantly increased to 10 ml/kg,the oxygenation index declined to 155 mmHg,the bedside chest X-ray showed a significant decrease of permeability (right lung) and PEEP was adjusted to 5 cmH2O (1 cmH2O =0.098 kPa),indicating circulating overload.ARDS subsequently occurred,upon which the fluid infusion was halted,the dehydration rate of CVVHDF raised (adjusted to 100-200 ml/h).On day 3 in the

  20. AN IMPROVED SNAKE MODEL FOR REFINEMENT OF LIDAR-DERIVED BUILDING ROOF CONTOURS USING AERIAL IMAGES

    Directory of Open Access Journals (Sweden)

    Q. Chen

    2016-06-01

    Full Text Available Building roof contours are considered as very important geometric data, which have been widely applied in many fields, including but not limited to urban planning, land investigation, change detection and military reconnaissance. Currently, the demand on building contours at a finer scale (especially in urban areas has been raised in a growing number of studies such as urban environment quality assessment, urban sprawl monitoring and urban air pollution modelling. LiDAR is known as an effective means of acquiring 3D roof points with high elevation accuracy. However, the precision of the building contour obtained from LiDAR data is restricted by its relatively low scanning resolution. With the use of the texture information from high-resolution imagery, the precision can be improved. In this study, an improved snake model is proposed to refine the initial building contours extracted from LiDAR. First, an improved snake model is constructed with the constraints of the deviation angle, image gradient, and area. Then, the nodes of the contour are moved in a certain range to find the best optimized result using greedy algorithm. Considering both precision and efficiency, the candidate shift positions of the contour nodes are constrained, and the searching strategy for the candidate nodes is explicitly designed. The experiments on three datasets indicate that the proposed method for building contour refinement is effective and feasible. The average quality index is improved from 91.66% to 93.34%. The statistics of the evaluation results for every single building demonstrated that 77.0% of the total number of contours is updated with higher quality index.