Ventilation Graphics Publications (151)

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Ventilation Graphics Publications

2016Dec
Clin. Chest Med.
Clin Chest Med 2016 Dec 14;37(4):669-681. Epub 2016 Oct 14.
Respiratory Care Services, Duke University Hospital, Box 3911 Duke North, Erwin Road, Durham, NC 27710, USA.

Ventilatory muscle fatigue is a reversible loss of the ability to generate force or velocity of contraction in response to increased elastic and resistive loads. Mechanical ventilation should provide support without imposing additional loads from the ventilator (dys-synchrony). Interactive breaths optimize this relationship but require that patient effort and the ventilator response be synchronous during breath initiation, flow delivery, and termination. Read More

Proper delivery considers all 3 phases and uses clinical data, ventilator graphics, and sometimes a trial-and-error approach to optimize patient-ventilator interactions. Newer modes optimize interactions but await good clinical outcome data before routine use.

2016Dec
Minerva Pediatr.
Minerva Pediatr 2016 Dec 8;68(6):456-469. Epub 2016 Jul 8.
Section of Critical Care, Department of Pediatrics, University of Alabama, Birmingham, AL, USA -
2015Nov
Int. J. Radiat. Oncol. Biol. Phys.
Int J Radiat Oncol Biol Phys 2015 Nov 18;93(3):547-56. Epub 2015 Jun 18.
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
2015Jun
J Cardiovasc Magn Reson
J Cardiovasc Magn Reson 2015 Jun 11;17:47. Epub 2015 Jun 11.
Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland.

Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration.
To develop a time-efficient single breath-hold 3D CMR acquisition and reconstruction method to precisely measure LA volumes and function. Read More


A highly accelerated compressed-sensing multi-slice cine sequence (CS-cineCMR) was combined with a non-model-based 3D reconstruction method to measure LA volumes with high temporal and spatial resolution during a single breath-hold. This approach was validated in LA phantoms of different shapes and applied in 3 patients. In addition, the influence of slice orientations on accuracy was evaluated in the LA phantoms for the new approach in comparison with a conventional model-based biplane area-length reconstruction. As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR-CMR) was acquired during mid-diastole to yield accurate LA volumes.
Phantom studies. LA volumes were accurately measured by CS-cineCMR with a mean difference of -4.73 ± 1.75 ml (-8.67 ± 3.54%, r2 = 0.94). For the new method the calculated volumes were not significantly different when different orientations of the CS-cineCMR slices were applied to cover the LA phantoms. Long-axis "aligned" vs "not aligned" with the phantom long-axis yielded similar differences vs the reference volume (-4.87 ± 1.73 ml vs. -4.45 ± 1.97 ml, p = 0.67) and short-axis "perpendicular" vs. "not-perpendicular" with the LA long-axis (-4.72 ± 1.66 ml vs. -4.75 ± 2.13 ml; p = 0.98). The conventional bi-plane area-length method was susceptible for slice orientations (p = 0.0085 for the interaction of "slice orientation" and "reconstruction technique", 2-way ANOVA for repeated measures). To use the 3D-HR-CMR as the reference for LA volumes in patients, it was validated in the LA phantoms (mean difference: -1.37 ± 1.35 ml, -2.38 ± 2.44%, r2 = 0.97). Patient study: The CS-cineCMR LA volumes of the mid-diastolic frame matched closely with the reference LA volume (measured by 3D-HR-CMR) with a difference of -2.66 ± 6.5 ml (3.0% underestimation; true LA volumes: 63 ml, 62 ml, and 395 ml). Finally, a high intra- and inter-observer agreement for maximal and minimal LA volume measurement is also shown.
The proposed method combines a highly accelerated single-breathhold compressed-sensing multi-slice CMR technique with a non-model-based 3D reconstruction to accurately and reproducibly measure LA volumes and function.

2015Jul
Med Image Anal
Med Image Anal 2015 Jul 17;23(1):43-55. Epub 2015 Apr 17.
Robarts Research Institute, The University of Western Ontario, London, ON, Canada; Graduate Program in Biomedical Engineering, The University of Western Ontario, London, ON, Canada; Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada. Electronic address:

Pulmonary imaging using hyperpolarized (3)He/(129)Xe gas is emerging as a new way to understand the regional nature of pulmonary ventilation abnormalities in obstructive lung diseases. However, the quantitative information derived is completely dependent on robust methods to segment both functional and structural/anatomical data. Here, we propose an approach to jointly segment the lung cavity from (1)H and (3)He pulmonary magnetic resonance images (MRI) by constraining the spatial consistency of the two segmentation regions, which simultaneously employs the image features from both modalities. Read More

We formulated the proposed co-segmentation problem as a coupled continuous min-cut model and showed that this combinatorial optimization problem can be solved globally and exactly by means of convex relaxation. In particular, we introduced a dual coupled continuous max-flow model to study the convex relaxed coupled continuous min-cut model under a primal and dual perspective. This gave rise to an efficient duality-based convex optimization algorithm. We implemented the proposed algorithm in parallel using general-purpose programming on graphics processing unit (GPGPU), which substantially increased its computational efficiency. Our experiments explored a clinical dataset of 25 subjects with chronic obstructive pulmonary disease (COPD) across a wide range of disease severity. The results showed that the proposed co-segmentation approach yielded superior performance compared to single-channel image segmentation in terms of precision, accuracy and robustness.

2015Apr
BMC Bioinformatics
BMC Bioinformatics 2015 Apr 29;16:134. Epub 2015 Apr 29.
Oregon Clinical and Translational Research Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd97239, Portland, Oregon, US.

Characterization of respiratory phenotypes can enhance complex trait and genomic studies involving allergic/autoimmune and infectious diseases. Many aspects of respiration can be measured using devices known as plethysmographs that can measure thoracic movement. One such approach (the Buxco platform) performs unrestrained whole body plethysmography on mice which infers thoracic movements from pressure differences from the act of inhalation and exhalation. Read More

While proprietary software is available to perform basic statistical analysis as part of machine's bundled software, it is desirable to be able to incorporate these analyses into high-throughput pipelines and integrate them with other data types, as well as leverage the wealth of analytic and visualization approaches provided by the R statistical computing environment.
This manuscript describes the plethy package which is an R/Bioconductor framework for pre-processing and analysis of plethysmography data with emphasis on larger scale longitudinal experiments. The plethy package was designed to facilitate quality control and exploratory data analysis. We provide a demonstration of the features of plethy using a dataset assessing the respiratory effects over time of SARS and Influenza infection in mice.
The plethy package provides functionality for users to import, perform quality assessment and exploratory data analysis in a manner that allows interoperability with existing modelling tools. Our package is implemented in R and is freely available as part of the Bioconductor project http://www.bioconductor.org/packages/release/bioc/html/plethy.html .

2015Jun
Semin Fetal Neonatal Med
Semin Fetal Neonatal Med 2015 Jun 7;20(3):181-91. Epub 2015 Feb 7.
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, C.S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI, USA.

Real-time pulmonary graphics now enable clinicians to view lung mechanics and patient-ventilator interactions on a breath-to-breath basis. Displays of pressure, volume, and flow waveforms, pressure-volume and flow-volume loops, and trend screens enable clinicians to customize ventilator settings based on the underlying pathophysiology and responses of the individual patient. This article reviews the basic concepts of pulmonary graphics and demonstrates how they contribute to our understanding of respiratory physiology and the management of neonatal respiratory failure. Read More

2014Oct
Med Image Comput Comput Assist Interv
Med Image Comput Comput Assist Interv 2014 ;17(Pt 1):423-31

Augmented reality for soft tissue laparoscopic surgery is a growing topic of interest in the medical community and has potential application in intra-operative planning and image guidance. Delivery of such systems to the operating room remains complex with theoretical challenges related to tissue deformation and the practical limitations of imaging equipment. Current research in this area generally only solves part of the registration pipeline or relies on fiducials, manual model alignment or assumes that tissue is static. Read More

This paper proposes a novel augmented reality framework for intra-operative planning: the approach co-registers pre-operative CT with stereo laparoscopic images using cone beam CT and fluoroscopy as bridging modalities. It does not require fiducials or manual alignment and compensates for tissue deformation from insufflation and respiration while allowing the laparoscope to be navigated. The paper's theoretical and practical contributions are validated using simulated, phantom, ex vivo, in vivo and non medical data.

2014Jul
Niger Med J
Niger Med J 2014 Jul;55(4):359-61
Department of Neuroanesthesia and Neurocritical Care, All India Institute of Medical Sciences, New Delhi, India.

The importance of ventilator graphics cannot be over emphasized that provide the useful information about airway, ventilation, compliance and lung mechanics. Some bizarre forms of graphics are usually overlooked in view of artifacts, but sometimes these tracings may in fact predict some relevant information. Read More