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Respiratory Compensation Point

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https://www.readbyqxmd.com/read/28300367/4d-vmat-planning-and-verification-technique-for-dynamic-tracking-using-a-direct-aperture-deformation-dad-method
#1
Yongqian Zhang, Yong Yang, Weihua Fu, Xiang Li, Tianfang Li, Dwight E Heron, M Saiful Huq
We developed a four-dimensional volumetric modulated arc therapy (4D VMAT) planning technique for moving targets using a direct aperture deformation (DAD) method and investigated its feasibility for clinical use. A 3D VMAT plan was generated on a reference phase of a 4D CT dataset. The plan was composed of a set of control points including the beam angle, MLC apertures and weights. To generate the 4D VMAT plan, these control points were assigned to the closest respiratory phases using the temporal information of the gantry angle and respiratory curve...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28271801/pediatric-aerobic-fitness-and-trainability
#2
Neil Armstrong
Three papers which between them raise controversial issues, apply laboratory measures to sport performance, and expose gaps in knowledge were selected for commentary. The first paper (Sports Med. 2016;46:1451-1460) reviews the literature on peak V̇O2 in relation to body size and recommends that peak V̇O2 in youth is best expressed via allometric scaling of lean body mass. The second paper (Pediatr Exerc Sci. 2016;28:456-465) reports that maturity status has no effect on peak V̇O2, respiratory compensation point, or ventilatory threshold in youth soccer players once data have been allometrically normalized by lower limb muscle volume...
February 2017: Pediatric Exercise Science
https://www.readbyqxmd.com/read/28258401/respiratory-motion-compensation-for-the-robot-guided-laser-osteotome
#3
Alina Giger, Christoph Jud, Philippe C Cattin
PURPOSE: The use of a robot-guided laser osteotome for median sternotomy is impeded by prohibiting cutting inaccuracies due to respiration-induced motions of the thorax. With this paper, we advance today's methodologies in sternotomy procedures by introducing the concept of novel 3D functional cuts and a respiratory motion compensation algorithm for the computer-assisted and robot-guided laser osteotome, CARLO(®). METHODS: We present a trajectory planning algorithm for performing 3D functional cuts at a constant cutting velocity...
March 3, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28254143/the-near-infrared-spectroscopy-derived-deoxygenated-haemoglobin-breaking-point-is-a-repeatable-measure-that-demarcates-exercise-intensity-domains
#4
Danilo Iannetta, Ahmad Qahtani, Felipe Mattioni Maturana, Juan Manuel Murias
OBJECTIVES: A breaking-point in the near-infrared spectroscopy (NIRS)-derived deoxygenated haemoglobin ([HHb]) profile towards the end of a ramp incremental (RI) cycling test has been associated to the respiratory compensation point (RCP). Despite the physiological value of this measure, its repeatability remains unknown. The aim was to examine the repeatability of the [HHb] breaking-point ([HHb]BP) and its association to RCP during a RI cycling test. DESIGN: A repeated measures design was performed on 11 males (30...
February 18, 2017: Journal of Science and Medicine in Sport
https://www.readbyqxmd.com/read/28250511/implementation-research-on-community-health-workers-provision-of-maternal-and-child-health-services-in-rural-liberia
#5
Peter W Luckow, Avi Kenny, Emily White, Madeleine Ballard, Lorenzo Dorr, Kirby Erlandson, Benjamin Grant, Alice Johnson, Breanna Lorenzen, Subarna Mukherjee, E John Ly, Abigail McDaniel, Netus Nowine, Vidiya Sathananthan, Gerald A Sechler, John D Kraemer, Mark J Siedner, Rajesh Panjabi
OBJECTIVE: To assess changes in the use of essential maternal and child health services in Konobo, Liberia, after implementation of an enhanced community health worker (CHW) programme. METHODS: The Liberian Ministry of Health partnered with Last Mile Health, a nongovernmental organization, to implement a pilot CHW programme with enhanced recruitment, training, supervision and compensation. To assess changes in maternal and child health-care use, we conducted repeated cross-sectional cluster surveys before (2012) and after (2015) programme implementation...
February 1, 2017: Bulletin of the World Health Organization
https://www.readbyqxmd.com/read/28211607/physiological-motion-modeling-for-organ-mounted-robots
#6
Nathan A Wood, David Schwartzman, Marco A Zenati, Cameron N Riviere
BACKGROUND: Organ-mounted robots passively compensate heartbeat and respiratory motion. In model-guided procedures, this motion can be a significant source of information that can be used to aid in localization or to add dynamic information to static preoperative maps. METHODS: Models for estimating periodic motion are proposed for both position and orientation. These models are then tested on animal data and optimal orders are identified. Finally, methods for online identification are demonstrated...
February 17, 2017: International Journal of Medical Robotics + Computer Assisted Surgery: MRCAS
https://www.readbyqxmd.com/read/28166117/the-respiratory-compensation-point-is-not-a-valid-surrogate-for-critical-power
#7
Jeffrey A Leo, Surendran Sabapathy, Michael J Simmonds, Troy J Cross
PURPOSE: It is unclear whether the respiratory compensation point (RCP) may be used as a valid surrogate for critical power (CP). Accordingly, we sought to determine the measurement agreement between CP and the RCP obtained during incremental cycling of varying ramp slopes. METHODS: Eleven recreationally-active men completed three separate ramp-incremental cycling protocols, where the work rate increment was slow (SR: 15 W[BULLET OPERATOR]min), medium (MR: 30 W[BULLET OPERATOR]min) or fast (FR: 45 W[BULLET OPERATOR]min)...
February 4, 2017: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/28070288/getting-to-the-core-internal-body-temperatures-help-reveal-the-ecological-function-and-thermal-implications-of-the-lions-mane
#8
Paul Trethowan, Andrea Fuller, Anna Haw, Tom Hart, Andrew Markham, Andrew Loveridge, Robyn Hetem, Byron du Preez, David W Macdonald
It has been proposed that there is a thermal cost of the mane to male lions, potentially leading to increased body surface temperatures (Ts), increased sperm abnormalities, and to lower food intake during hot summer months. To test whether a mane imposes thermal costs on males, we measured core body temperature (Tb) continuously for approximately 1 year in 18 free-living lions. There was no difference in the 24-hr maximum Tb of males (n = 12) and females (n = 6), and males had a 24-hr mean Tb that was 0...
January 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28052050/planning-4d-intensity-modulated-arc-therapy-for-tumor-tracking-with-a-multileaf-collimator
#9
Ying Niu, Gregory T Betzel, Xiaocheng Yang, Minzhi Gui, William C Parke, Byongyong Yi, Cedric X Yu
This study introduces a practical four-dimensional (4D) planning scheme of IMAT using 4D computed tomography (4D CT) for planning tumor tracking with dynamic multileaf beam collimation. We assume that patients can breathe regularly, i.e. the same way as during 4D CT with an unchanged period and amplitude, and that the start of 4D-IMAT delivery can be synchronized with a designated respiratory phase. Each control point of the IMAT-delivery process can be associated with an image set of 4D CT at a specified respiratory phase...
February 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27974570/channel-inactivating-mutations-and-their-revertant-mutants-in-the-envelope-protein-of-infectious-bronchitis-virus
#10
Janet To, Wahyu Surya, To Sing Fung, Yan Li, Carmina Verdià-Bàguena, Maria Queralt-Martin, Vicente M Aguilella, Ding Xiang Liu, Jaume Torres
It has been shown previously in the severe acute respiratory syndrome coronavirus (SARS-CoV) that two point mutations, N15A and V25F, in the transmembrane domain (TMD) of the envelope (E) protein abolished channel activity and led to in vivo attenuation. Pathogenicity was recovered in mutants that also regained E protein channel activity. In particular, V25F was rapidly compensated by changes at multiple V25F-facing TMD residues located on a neighboring monomer, consistent with a recovery of oligomerization...
March 1, 2017: Journal of Virology
https://www.readbyqxmd.com/read/27901338/determinant-factors-of-peak-treadmill-speed-in-physically-active-men
#11
Leonardo Alves Pasqua, Mayara V Damasceno, Salomão Bueno, Alessandro M Zagatto, Gustavo G DE Araújo, Adriano E Lima-Silva, Rômulo Bertuzzi
BACKGROUND: The aim of the present study was to determine whether physiological factors and maximal dynamic strength are able to determine the peak treadmill speed (PTS) in physically active individuals. METHODS: One hundred and fifty physically active healthy males voluntarily visit the laboratory on three separate occasions and underwent the following activities: first visit: IPAQ (short version), anthropometric measurements, and a maximal incremental test performed for physiological variables (maximal oxygen uptake ( ) and respiratory compensation point (RCP); second visit: constant speed test for running economy (RE) measurement, and familiarization with the maximum dynamic strength (1RM) test in the leg press exercise; third visit: 1RM test...
November 30, 2016: Journal of Sports Medicine and Physical Fitness
https://www.readbyqxmd.com/read/27887989/quantitative-pet-image-reconstruction-employing-nested-expectation-maximization-deconvolution-for-motion-compensation
#12
Nicolas A Karakatsanis, Charalampos Tsoumpas, Habib Zaidi
Bulk body motion may randomly occur during PET acquisitions introducing blurring, attenuation-emission mismatches and, in dynamic PET, discontinuities in the measured time activity curves between consecutive frames. Meanwhile, dynamic PET scans are longer, thus increasing the probability of bulk motion. In this study, we propose a streamlined 3D PET motion-compensated image reconstruction (3D-MCIR) framework, capable of robustly deconvolving intra-frame motion from a static or dynamic 3D sinogram. The presented 3D-MCIR methods need not partition the data into multiple gates, such as 4D MCIR algorithms, or access list-mode (LM) data, such as LM MCIR methods, both associated with increased computation or memory resources...
November 16, 2016: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
https://www.readbyqxmd.com/read/27854117/treatment-of-neonates-with-respiratory-distress-syndrome-by-proportional-assist-ventilation-plus-synchronized-intermittent-mandatory-ventilation-a-comparison-study
#13
Rong Wu, Zhao F Tian, Xiang Y Kong, Shao D Hua, Jin H Hu, Guo F Zhen
BACKGROUND: The proportion assisted ventilation (PAV) can improve patient-ventilator interaction, reduce the incidence of end-expiratory asynchrony and increase the time of synchrony. PAV could compensate for the leaks by Elastic and resistive unloading and thus is ideal for neonates with uncuffed airways. The aim of this study was to compare the relevant clinical parameters of neonates with respiratory distress syndrome(RDS) who are surported by PAV plus synchronized intermittent mandatory ventilation (SIMV) and SIMV...
November 17, 2016: Minerva Pediatrica
https://www.readbyqxmd.com/read/27745981/a-novel-respiratory-motion-perturbation-model-adaptable-to-patient-breathing-irregularities
#14
Amy Yuan, Jie Wei, Carl P Gaebler, Hailiang Huang, Devin Olek, Guang Li
PURPOSE: To develop a physical, adaptive motion perturbation model to predict tumor motion using feedback from dynamic measurement of breathing conditions to compensate for breathing irregularities. METHODS AND MATERIALS: A novel respiratory motion perturbation (RMP) model was developed to predict tumor motion variations caused by breathing irregularities. This model contained 2 terms: the initial tumor motion trajectory, measured from 4-dimensional computed tomography (4DCT) images, and motion perturbation, calculated from breathing variations in tidal volume (TV) and breathing pattern (BP)...
December 1, 2016: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/27714456/characterizing-cerebral-and-locomotor-muscle-oxygenation-to-incremental-ramp-exercise-in-healthy-children-relationship-with-pulmonary-gas-exchange
#15
Kristof Vandekerckhove, Ilse Coomans, Annelies Moerman, Daniel De Wolf, Jan Boone
AIMS: To characterize the oxygenation responses at cerebral and locomotor muscle level to incremental exercise in children and to assess the interrelationship with the pulmonary gas exchange responses. METHODS: Eighteen children (9 boys, 9 girls) (mean age 10.9 ± 1.0 years) performed incremental cycle ramp exercise to exhaustion. The concentration of cerebral and muscle oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin (by means of near-infrared spectroscopy) and pulmonary gas exchange was recorded...
December 2016: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/27676142/post-exercise-neurovascular-control-in-chronic-heart-failure-patients
#16
T S Nobre, R V Groehs, L F Azevedo, L M Antunes-Correa, D G Martinez, M J N N Alves, C E Negrao
It remains unknown whether or not a reduction in muscle sympathetic nerve activity in heart failure patients is associated over time with the effects of long- or short-term repeated exercise. 10 chronic heart failure patients, age 49±3 years old, functional class I-III NYHA, ejection fraction <40% were randomly submitted to either an acute bout of moderate continuous exercise OR high-intensity interval exercise. Muscle sympathetic nerve activity (microneurography) and forearm blood flow (venous occlusion plethysmography) were evaluated pre- and post-exercise sessions...
December 2016: International Journal of Sports Medicine
https://www.readbyqxmd.com/read/27619627/diffusion-weighted-mr-imaging-of-upper-abdominal-organs-at-different-time-points-apparent-diffusion-coefficient-normalization-using-a-reference-organ
#17
Ji Soo Song, Hyo Sung Kwak, Jung Hee Byon, Gong Yong Jin
PURPOSE: To compare the apparent diffusion coefficient (ADC) of upper abdominal organs acquired at different time points, and to investigate the usefulness of normalization. MATERIALS AND METHODS: We retrospectively evaluated 58 patients who underwent three rounds of magnetic resonance (MR) imaging including diffusion-weighted imaging of the upper abdomen. MR examinations were performed using three different 3.0 Tesla (T) and one 1.5T systems, with variable b value combinations and respiratory motion compensation techniques...
September 13, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27613650/an-integrated-view-on-the-oxygenation-responses-to-incremental-exercise-at-the-brain-the-locomotor-and-respiratory-muscles
#18
REVIEW
Jan Boone, Kristof Vandekerckhove, Ilse Coomans, Fabrice Prieur, Jan G Bourgois
In the past two decades oxygenation responses to incremental ramp exercise, measured non-invasively by means of near-infrared spectroscopy at different locations in the body, have advanced the insights on the underpinning mechanisms of the whole-body pulmonary oxygen uptake ([Formula: see text]) response. In healthy subjects the complex oxygenation responses at the level of locomotor and respiratory muscles, and brain were simplified and quantified by the detection of breakpoints as a deviation in the ongoing response pattern as work rate increases...
December 2016: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/27612051/an-autotuning-respiration-compensation-system-based-on-ultrasound-image-tracking
#19
Chia-Chun Kuo, Ho-Chiao Chuang, Kuan-Ting Teng, Hsiao-Yu Hsu, Der-Chi Tien, Chih-Jen Wu, Shiu-Chen Jeng, Jeng-Fong Chiou
The purpose of this study was to develop an ultrasound image tracking algorithm (UITA) for extracting the exact displacement of internal organs caused by respiratory motion. The program can track organ displacements in real time, and analyze the displacement signals associated with organ displacements via a respiration compensating system (RCS). The ultrasound imaging system is noninvasive and has a high spatial resolution and a high frame rate (around 32 frames/s), which reduces the radiation doses that patients receive during computed tomography and X-ray observations...
November 22, 2016: Journal of X-ray Science and Technology
https://www.readbyqxmd.com/read/27600918/test-retest-reliability-and-four-week-changes-in-cardiopulmonary-fitness-in-stroke-patients-evaluation-using-a-robotics-assisted-tilt-table
#20
Jittima Saengsuwan, Lucia Berger, Corina Schuster-Amft, Tobias Nef, Kenneth J Hunt
BACKGROUND: Exercise testing devices for evaluating cardiopulmonary fitness in patients with severe disability after stroke are lacking, but we have adapted a robotics-assisted tilt table (RATT) for cardiopulmonary exercise testing (CPET). Using the RATT in a sample of patients after stroke, this study aimed to investigate test-retest reliability and repeatability of CPET and to prospectively investigate changes in cardiopulmonary outcomes over a period of four weeks. METHODS: Stroke patients with all degrees of disability underwent 3 separate CPET sessions: 2 tests at baseline (TB1 and TB2) and 1 test at follow up (TF)...
September 6, 2016: BMC Neurology
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