Attention graph convolutional nets for esophageal contraction pattern recognition in high-resolution manometries

2021 ◽  
Vol 68 ◽  
pp. 102734
Author(s):  
Zheng Wang ◽  
Lu Yan ◽  
Yuzhuo Dai ◽  
Fanggen Lu ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
High Resolution ◽  
Contraction Pattern ◽  
Esophageal Contraction

Photogrammetric Investigation of the Flying Shape of Spinnakers in a Twisted Flow Wind Tunnel

2009 ◽  
Author(s):  
Kai Graf ◽  
Olaf Müller
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
High Resolution ◽  
Wind Tunnel ◽  
Wind Velocity ◽  
Digital Cameras ◽  
Pattern Recognition Methods ◽  
Twisted Flow ◽  
High Resolution Images ◽  
The Impact

This paper describes a method for the acquisition of the flying shape of spinnakers in a twisted flow wind tunnel. The method is based on photogrammetry. A set of digital cameras is used to obtain high resolution images of the spinnaker from different viewing angles. The images are post-processed using image-processing tools, pattern recognition methods and finally the photogrammetry algorithm. Results are shown comparing design versus flying shape of the spinnaker and the impact of wind velocity and wind twist on the flying shape. Finally some common rules for optimum spinnaker trimming are investigated and examined.

scholarly journals Classification of High-Resolution Manometry Data According to Videofluoroscopic Parameters Using Pattern Recognition

2013 ◽  
Vol 149 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Matthew R. Hoffman ◽  
Corinne A. Jones ◽  
Zhixian Geng ◽  
Suzan M. Abelhalim ◽  
Chelsea C. Walczak ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
High Resolution ◽  
High Resolution Manometry

Quantum Dimension Reduction for Pattern Recognition in High-Resolution Spatio-Spectral Data

2020 ◽  
pp. 1-1
Author(s):  
Naveed Mahmud ◽  
Bennett Haase-Divine ◽  
Andrew MacGillivray ◽  
Esam El-Araby
Keyword(s):  
Pattern Recognition ◽  
High Resolution ◽  
Dimension Reduction ◽  
Spectral Data

What Are Present Limits of Quantitative High Resolution Tem?

1997 ◽  
Vol 3 (S2) ◽  
pp. 935-936
Author(s):  
Christian Kisielowski
Keyword(s):  
Pattern Recognition ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Chemical Imaging ◽  
Atomic Scale ◽  
Lattice Image ◽  
Recognition Procedure ◽  
Unit Cells ◽  
High Resolution Tem ◽  
Lattice Images

In recent years quantitative high resolution electron microscopy (HREM) became a reliable tool to investigate physical processes at an atomic scale. Certainly, there is no unique approach to quantify the information content from lattice images. However, specific methods like Chemical Imaging^ and QUANTITEM were established that allow to investigate the atomic structure of crystalline solids quantitatively and almost routinely.Nevertheless, there are limits to the application of these methods and they are of principle and of practical nature. Obviously, the resolution of quantitative HRTEM is limited by the point resolution of modern microscopes that has reached 0.1 mn. However, the quantification of the information from lattice images requires two important steps, namely, the application of a pattern recognition procedure and the extraction of changes of the electron scattering potential from the lattice images. The application of the pattern recognition procedure influences the lateral resolution of the method because a lattice image has to be broken up into unit cells of identical size (figure 1).

scholarly journals Topographical plots of esophageal distension and contraction: effects of posture on esophageal peristalsis and bolus transport

2019 ◽  
Vol 316 (4) ◽  
pp. G519-G526 ◽  
Author(s):  
Ali Zifan ◽  
Hyun Joo Song ◽  
Young-Hoon Youn ◽  
Xinhuan Qiu ◽  
Melissa Ledgerwood-Lee ◽  
...  
Keyword(s):  
High Resolution ◽  
Healthy Subjects ◽  
Temporal Relationship ◽  
Entire Length ◽  
Esophageal Peristalsis ◽  
Descending Inhibition ◽  
Position Change ◽  
Trendelenburg Position ◽  
High Resolution Manometry ◽  
Esophageal Contraction

Each swallow induces a wave of inhibition followed by contraction in the esophagus. Unlike contraction, which can easily be measured in humans using high-resolution manometry (HRM), inhibition is difficult to measure. Luminal distension is a surrogate of the esophageal inhibition. The aim of this study was to determine the effect of posture on the temporal and quantitative relationship between distension and contraction along the entire length of the esophagus in normal healthy subjects by using concurrent HRM, HRM impedance (HRMZ), and intraluminal ultrasound (US). Studies were conducted in 15 normal healthy subjects in the supine and Trendelenburg positions. Both manual and automated methods were used to extract quantitative pressure and impedance-derived features from the HRMZ recordings. Topographical plots of distension and contraction were visualized along the entire length of the esophagus. Distension was also measured from the US images during 10-ml swallows at 5 cm above the lower esophageal sphincter. Each swallow was associated with luminal distension followed by contraction, both of which traversed the esophagus in a sequential/peristaltic fashion. Luminal distension (US) and esophageal contraction amplitude were greater in the Trendelenburg compared with the supine position. Length of esophageal breaks (in the transition zone) were reduced in the Trendelenburg position. Change in posture altered the temporal relationship between distension and contraction, and bolus traveled closer to the esophageal contraction in the Trendelenburg position. Topographical contraction-distension plots derived from HRMZ recordings is a novel way to visualize esophageal peristalsis. Future studies should investigate if abnormalities of esophageal distension are the cause of functional dysphagia. NEW & NOTEWORTHY Ascending contraction and descending inhibition are two important components of peristalsis. High-resolution manometry only measures the contraction phase of peristalsis. We measured esophageal distension from intraluminal impedance recordings and developed novel contraction-distension topographical plots to prove that similar to contraction, distension also travels in a peristaltic fashion. Change in posture from the supine to the Trendelenburg position also increased the amplitude of esophageal distension and contraction and altered the temporal relationship between distension and contraction.

Esophageal contractile segment impedance from high-resolution impedance manometry correlates with mean nocturnal baseline impedance and acid exposure time from 24-hour pH-impedance monitoring

2020 ◽  
Vol 33 (12) ◽  
Author(s):  
Anthony Horton ◽  
Shai Posner ◽  
Brian Sullivan ◽  
Jennifer Cornejo ◽  
Andrea Davis ◽  
...  
Keyword(s):  
High Resolution ◽  
Exposure Time ◽  
Acid Exposure ◽  
Presenting Symptoms ◽  
Impedance Monitoring ◽  
Esophageal Sphincter ◽  
Acid Exposure Time ◽  
Gerd Symptoms ◽  
Ambulatory Ph ◽  
Esophageal Contraction

Summary Esophageal baseline impedance (BI) acquired during esophageal contraction (contractile segment impedance [CSI]) is proposed to improve BI accuracy in gastroesophageal reflux disease (GERD). We evaluated associations between CSI and conventional and novel GERD metrics. We analyzed high-resolution impedance manometry (HRIM) and ambulatory pH-impedance studies from 51 patients (58.6 ± 1.5 years; 26% F) with GERD symptoms studied off antisecretory therapy. Patients with achalasia or absent contractility were excluded. CSI (averaged across 10 swallows) and BI-HRIM (from the resting landmark phase) were acquired from the distal impedance sensors (distal sensor and 5 cm above the lower esophageal sphincter). Acid exposure time (AET) and mean nocturnal baseline impedance (MNBI) were calculated. Associations between CSI, BI-HRIM, MNBI, and AET were evaluated using correlation (Pearson) and receiver operating characteristic (ROC) analysis. Presenting symptoms included heartburn (67%), regurgitation (12%), cough (12%), and chest pain (10%). CSI-distal and CSI-5 each correlated with BI-HRIM, AET, and distal MNBI. Associations with AET were numerically stronger for CSI-distal (r = −0.46) and BI-HRIM-distal (r = −0.44) than CSI-5 (r = −0.33), BI-HRIM-5 (r = −0.28), or distal MNBI (r < −0.36). When compared to AET <4%, patients with AET >6% had significantly lower CSI-distal and BI-HRIM-distal values but not CSI-5, BI-HRIM-5, or MNBI. ROC areas under the curve for AET >6% were numerically higher for CSI-distal (0.81) than BI-HRIM-distal (0.77), distal MNBI (0.68–0.75), CSI-5 (0.68), or BI-HRIM-5 (0.68). CSI from HRIM studies inversely correlates with pathologic AET and has potential to augment the evaluation of GERD.

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