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Respiratory Compensation Point

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)...
September 3, 2016: International Journal of Radiation Oncology, Biology, Physics
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...
October 6, 2016: European Journal of Applied Physiology
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...
September 27, 2016: International Journal of Sports Medicine
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
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...
September 9, 2016: European Journal of Applied Physiology
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...
September 9, 2016: Journal of X-ray Science and Technology
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)...
2016: BMC Neurology
Jeffery A Leo, Troy J Cross, Michael J Simmonds, Surendran Sabapathy
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Nadia Möri, Christoph Jud, Rares Salomir, Philippe C Cattin
In noninvasive abdominal tumor treatment, research has focused on minimizing organ motion either by gating, breath holding or tracking of the target. The paradigm shift proposed in this study takes advantage of the respiratory organ motion to passively scan the tumor. In the proposed self-scanning method, the focal point of the HIFU device is held fixed for a given time, while it passively scans the tumor due to breathing motion. The aim of this paper is to present a treatment planning method for such a system and show by simulation its feasibility...
June 7, 2016: Physics in Medicine and Biology
Kevin Thomas, Marc Elmeua, Glyn Howatson, Stuart Goodall
PURPOSE: We tested the hypothesis that central and peripheral fatigue after constant-load cycling exercise would vary with exercise intensity and duration. METHODS: Twelve well-trained male cyclists (V˙O2max, 4.49 ± 0.35 L·min) completed three constant-load cycling trials to the limit of tolerance in a randomized crossover design. Exercise intensities were set according to the respiratory responses to a preliminary ramp test to elicit cardiorespiratory and metabolic responses consistent with exercise in the severe and heavy exercise domains: 1) at power at V˙O2max (S+, 379 ± 31 W), 2) at 60% of the difference between gas exchange threshold and V˙O2max (S-, 305 ± 23 W), and 3) at the respiratory compensation point (RCP, 254 ± 26 W)...
September 2016: Medicine and Science in Sports and Exercise
Mark S Smyczynski, Howard C Gifford, Andre Lehovich, Joseph E McNamara, W Paul Segars, Eric A Hoffman, Benjamin M W Tsui, Michael A King
The objectives of this investigation were to model the respiratory motion of solitary pulmonary nodules (SPN) and then use this model to determine the impact of respiratory motion on the localization and detection of small SPN in SPECT imaging for four reconstruction strategies. The respiratory motion of SPN was based on that of normal anatomic structures in the lungs determined from breath-held CT images of a volunteer acquired at two different stages of respiration. End-expiration (EE) and time-averaged (Frame Av) non-uniform-B-spline cardiac torso (NCAT) digital-anthropomorphic phantoms were created using this information for respiratory motion within the lungs...
February 2016: IEEE Transactions on Nuclear Science
Arthur Henrique Bossi, Pedro Lima, Jorge Perrout de Lima, James Hopker
This study aimed to assess the relationship between an uphill time-trial (TT) performance and both aerobic and anaerobic parameters obtained from laboratory tests. Fifteen cyclists performed a Wingate anaerobic test, a graded exercise test (GXT) and a field-based 20-min TT with 2.7% mean gradient. After a 5-week non-supervised training period, 10 of them performed a second TT for analysis of pacing reproducibility. Stepwise multiple regressions demonstrated that 91% of TT mean power output variation (W kg(-1)) could be explained by peak oxygen uptake (ml kg(-1...
May 7, 2016: Journal of Sports Sciences
Tobias Engeroff, Andreas Bernardi, Daniel Niederer, Jan Wilke, Lutz Vogt, Winfried Banzer
BACKGROUND: Running economy (RE) is often described as a key demand of running performance. The variety of currently used assessment methods with different running intensities and outcomes restricts interindividual comparability of RE in recreational level runners. The purpose of this study was to compare the influence of RE, assessed as Oxygen cost (OC) and Caloric unit cost (CUC), on running speed at individual physiological thresholds. METHODS: Eighteen recreational runners performed 1) A graded exercise test to estimate first ventilatory threshold (VT1), respiratory compensation point (RCP) and maximal oxygen uptake (VO2max), 2) Discontinuous RE assessment to determine relative OC in millilitres per kilogram per kilometre (ml/kg/km) and CUC in kilocalories per kilogram per kilometre (kcal/kg/km) at three different running intensities: VT1, RCP and at a third standardized reference point (TP) in between...
May 3, 2016: Journal of Sports Medicine and Physical Fitness
Magdalena Wiecek, Marcin Maciejczyk, Jadwiga Szymura, Zbigniew Szygula
OBJECTIVES: The aim of this study was to test the hypotheses: (1) there is a negative correlation between protein and lipid oxidative damage following maximal-intensity exercise, and oxygen uptake and work intensity (%VO2max) at the respiratory compensation point (RCP) in women and men; (2) nitro-oxidative stress following maximal-intensity exercise results from the intensification of anaerobic processes and muscle fibre micro-damage. METHODS: Study participants comprised 20 women (21...
April 14, 2016: Redox Report: Communications in Free Radical Research
Cyril Brechbuhl, Olivier Girard, Grégoire P Millet, Laurent Schmitt
PURPOSE: We aimed to a) introduce a new Test to Exhaustion Specific to Tennis (TEST) and compare performance (test duration) and physiological responses to those obtained during the 20-m multistage shuttle test (MSST), and b) determine to which extent those variables correlate with performance level (tennis competitive ranking) for both test procedures. METHODS: Twenty-seven junior players (8 males, 19 females) members of the national teams of the French Tennis Federation completed MSST and TEST, including elements of the game (ball hitting, intermittent activity, lateral displacement), in a randomized order...
2016: PloS One
Virginie Maes, Stéphane Betoulle, Ali Jaffal, Odile Dedourge-Geffard, Laurence Delahaut, Alain Geffard, Olivier Palluel, Wilfried Sanchez, Séverine Paris-Palacios, Aurélie Vettier, Elise David
This study aims to determine the potential impairment of cell energy synthesis processes (glycolysis and respiratory chain pathways) by copper in juvenile roach at different regulation levels by using a multi-marker approach. Juvenile roach were exposed to 0, 10, 50, and 100 µg/L of copper for 7 days in laboratory conditions. The glycolysis pathway was assessed by measuring the relative expression levels of 4 genes encoding glycolysis enzymes. The respiratory chain was studied by assessing the electron transport system and cytochrome c oxidase gene expression...
July 2016: Ecotoxicology
Victor José Bastos-Silva, Alan de Albuquerque Melo, Adriano Eduardo Lima-Silva, Felipe Arruda Moura, Rômulo Bertuzzi, Gustavo Gomes de Araujo
The aim was to investigate the influence of a carbohydrate (CHO) mouth rinse on the vastus lateralis (VL) and rectus femoris (RF) electromyographic activity (EMG) and time to exhaustion (TE) during moderate (MIE) and high-intensity cycling exercise (HIE). Thirteen participants cycled at 80% of their respiratory compensation point and at 110% of their peak power output to the point of exhaustion. Before the trials and every 15 min during MIE, participants rinsed with the CHO or Placebo (PLA) solutions. The root mean square was calculated...
March 2016: Nutrients
J Budjan, S O Schoenberg, P Riffel
UNLABELLED: Abdominal imaging is the driving force that necessitates the development of numerous techniques for accelerated image acquisition in magnetic resonance imaging (MRI). Today, numerous techniques are available that enable rapid, high spatial resolution acquisition for both T1 and T2 weighted images. These techniques open new opportunities in the detection and classification of numerous pathologies in the abdomen. However, there is still ongoing progress in the development of fast and ultrafast sequences and promising techniques are currently close to clinical application...
June 2016: RöFo: Fortschritte Auf Dem Gebiete der Röntgenstrahlen und der Nuklearmedizin
Ian E Klein, Jason B White, Sharon R Rana
A novel outdoor elliptical bicycle has been designed to elicit running-similar physiological adaptations while reducing the impact forces that commonly lead to injury. Various cross-training methods have been utilized to reduce injury risk, restore or maintain fitness, and prevent detraining. The purpose of this study was to compare 4-weeks of elliptical bicycle-only training to run-only training on maximal oxygen consumption, ventilatory threshold, respiratory compensation point, running economy, and 5,000 m time trial times...
March 3, 2016: Journal of Strength and Conditioning Research
Kohei Osada, Yoshio Sakurai, Masanori Tamura
Pediatric advanced life support (PALS) is the global standard of pediatric emergency medicine. It depends on the consensus of ILCOR which has been revised every 5 years by the experts worldwide. The concept of PALS is to treat the sick and injured children based on the systematic approach of the evaluation and classification in terms of the respiratory and circulatory status. On the other hand, point of care ultrasound (POCU) has been getting popular worldwide in the field of the emergency and critical care medicine...
February 2016: Nihon Rinsho. Japanese Journal of Clinical Medicine
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