scholarly journals A structured light laser probe for gastrointestinal polyp size measurement: a preliminary comparative study

2018 ◽  
Vol 06 (05) ◽  
pp. E602-E609 ◽  
Author(s):  
Marco Visentini-Scarzanella ◽  
Hiroshi Kawasaki ◽  
Ryo Furukawa ◽  
Marco Bonino ◽  
Simone Arolfo ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Visual Inspection ◽  
Ex Vivo ◽  
Estimation Error ◽  
Structured Light ◽  
Operating Time ◽  
Visual Assessment ◽  
Reference Points ◽  
Size Measurement ◽  
Polyp Size

Abstract Background and study aims Polyp size measurement is an important diagnostic step during gastrointestinal endoscopy, and is mainly performed by visual inspection. However, lack of depth perception and objective reference points are acknowledged factors contributing to measurement errors in polyp size. In this paper, we describe the proof-of-concept of a polyp measurement device based on structured light technology for future endoscopes. Patients and methods Measurement accuracy, time, user confidence, and satisfaction were evaluated for polyp size assessment by (a) visual inspection, (b) open biopsy forceps of known size, (c) ruled snare, and (d) structured light probe, for a total of 392 independent polyp measurements in ex vivo porcine stomachs. Results Visual assessment resulted in a median estimation error of 2.2 mm, IQR = 2.6 mm. The proposed probe can reduce the error to 1.5 mm, IQR = 1.67 mm (P = 0.002, 95 %CI) and its performance was found to be statistically similar to using forceps for reference (P = 0.81, 95 %CI) or ruled snare (P = 0.99, 95 %CI), while not occluding the tool channel. Timing performance with the probe was measured to be on average 54.75 seconds per polyp. This was significantly slower than visual assessment (20.7 seconds per polyp, P = 0.005, 95 %CI) but not significantly different from using a snare (68.5 seconds per polyp, P = 0.73, 95 %CI). However, the probe’s timing performance was partly due to lens cleaning problems in our preliminary design. Reported average satisfaction on a 0 – 10 range was highest for the proposed probe (7.92), visual assessment (7.01), and reference forceps (7.82), while significantly lower for snare users with a score of 4.42 (P = 0.035, 95 %CI). Conclusions The common practice of visual assessment of polyp size was found to be significantly less accurate than tool-based assessment, but easy to carry out. The proposed technology offers an accuracy on par with using a reference tool or ruled snare with the same satisfaction levels of visual assessment and without occluding the tool channel. Further study will improve the design to reduce the operating time by integrating the probe within the scope tip.

scholarly journals Robotic-assisted cholecystectomy is superior to laparoscopic cholecystectomy in the initial training for surgical novices in an ex vivo porcine model: a randomized crossover study

2021 ◽  
Author(s):  
E. Willuth ◽  
S. F. Hardon ◽  
F. Lang ◽  
C. M. Haney ◽  
E. A. Felinska ◽  
...  
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Crossover Study ◽  
Porcine Model ◽  
Haptic Feedback ◽  
Ex Vivo ◽  
Operating Time ◽  
Surgical Performance ◽  
Robotic Assisted ◽  
Subjective Workload ◽  
Randomized Crossover Study

Abstract Background Robotic-assisted surgery (RAS) potentially reduces workload and shortens the surgical learning curve compared to conventional laparoscopy (CL). The present study aimed to compare robotic-assisted cholecystectomy (RAC) to laparoscopic cholecystectomy (LC) in the initial learning phase for novices. Methods In a randomized crossover study, medical students (n = 40) in their clinical years performed both LC and RAC on a cadaveric porcine model. After standardized instructions and basic skill training, group 1 started with RAC and then performed LC, while group 2 started with LC and then performed RAC. The primary endpoint was surgical performance measured with Objective Structured Assessment of Technical Skills (OSATS) score, secondary endpoints included operating time, complications (liver damage, gallbladder perforations, vessel damage), force applied to tissue, and subjective workload assessment. Results Surgical performance was better for RAC than for LC for total OSATS (RAC = 77.4 ± 7.9 vs. LC = 73.8 ± 9.4; p = 0.025, global OSATS (RAC = 27.2 ± 1.0 vs. LC = 26.5 ± 1.6; p = 0.012, and task specific OSATS score (RAC = 50.5 ± 7.5 vs. LC = 47.1 ± 8.5; p = 0.037). There were less complications with RAC than with LC (10 (25.6%) vs. 26 (65.0%), p = 0.006) but no difference in operating times (RAC = 77.0 ± 15.3 vs. LC = 75.5 ± 15.3 min; p = 0.517). Force applied to tissue was similar. Students found RAC less physical demanding and less frustrating than LC. Conclusions Novices performed their first cholecystectomies with better performance and less complications with RAS than with CL, while operating time showed no differences. Students perceived less subjective workload for RAS than for CL. Unlike our expectations, the lack of haptic feedback on the robotic system did not lead to higher force application during RAC than LC and did not increase tissue damage. These results show potential advantages for RAS over CL for surgical novices while performing their first RAC and LC using an ex vivo cadaveric porcine model. Registration number researchregistry6029 Graphic abstract

scholarly journals Smartphone-Enhanced Training, QA, Monitoring, and Evaluation of a Platform for Secondary Prevention of Cervical Cancer: Opportunities and Challenges to Implementation in Tanzania

2020 ◽  
pp. 1114-1123
Author(s):  
Karen Yeates ◽  
Erica Erwin ◽  
Zac Mtema ◽  
Frank Magoti ◽  
Simoni Nkumbugwa ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Visual Inspection ◽  
Screening Program ◽  
Cervical Screening ◽  
Monitoring And Evaluation ◽  
Visual Assessment ◽  
Cervical Cancer Prevention ◽  
Supportive Supervision ◽  
Health Providers

PURPOSE Until human papillomavirus (HPV)–based cervical screening is more affordable and widely available, visual inspection with acetic acid (VIA) is recommended by the WHO for screening in lower-resource settings. Visual inspection will still be required to assess the cervix for women whose screening is positive for high-risk HPV. However, the quality of VIA can vary widely, and it is difficult to maintain a well-trained cadre of providers. We developed a smartphone-enhanced VIA platform (SEVIA) for real-time secure sharing of cervical images for remote supportive supervision, data monitoring, and evaluation. METHODS We assessed programmatic outcomes so that findings could be translated into routine care in the Tanzania National Cervical Cancer Prevention Program. We compared VIA positivity rates (for HIV-positive and HIV-negative women) before and after implementation. We collected demographic, diagnostic, treatment, and loss-to-follow-up data. RESULTS From July 2016 to June 2017, 10,545 women were screened using SEVIA at 24 health facilities across 5 regions of Tanzania. In the first 6 months of implementation, screening quality increased significantly from the baseline rate in the prior year, with a well-trained cadre of more than 50 health providers who “graduated” from the supportive-supervision training model. However, losses to follow-up for women referred for further evaluation or to a higher level of care were considerable. CONCLUSION The SEVIA platform is a feasible, quality improvement, mobile health intervention that can be integrated into a national cervical screening program. Our model demonstrates potential for scalability. As HPV screening becomes more affordable, the platform can be used for visual assessment of the cervix to determine amenability for same-day ablative therapy and/or as a secondary triage step, if needed.

An endoscopic training model to improve accuracy of colonic polyp size measurement

2010 ◽  
Vol 25 (5) ◽  
pp. 655-660 ◽  
Author(s):  
Chi-Yang Chang ◽  
Han-Mo Chiu ◽  
Hsiu-Po Wang ◽  
Ching-Tai Lee ◽  
John Jen Tai ◽  
...  
Keyword(s):  
Training Model ◽  
Colonic Polyp ◽  
Size Measurement ◽  
Polyp Size ◽  
Endoscopic Training ◽  
Improve Accuracy

469 ASSESSMENT OF PERFUSION OF GASTRIC CONDUIT AND PROXIMAL ESOPHAGEAL STUMP BY INDOCYANINE GREEN FLUORESCENCE IMAGING IN PATIENTS UNDERGOING ESOPHAGECTOMY

2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Subramanyeshwar Rao Thammineedi
Keyword(s):  
Indocyanine Green ◽  
Fluorescence Imaging ◽  
Visual Inspection ◽  
Near Infrared ◽  
Infrared Camera ◽  
Visual Assessment ◽  
Transhiatal Esophagectomy ◽  
Gastric Conduit ◽  
Indocyanine Green Fluorescence ◽  
Laparoscopic Assisted

Abstract   Post esophagectomy anastomotic leakage and stricture are crucial factors in determining morbidity and mortality. Good vascularity of the gastric conduit is essential to avoid this complications. This prospective study assesses the utility of intraoperative indocyanine green (ICG) fluorescence imaging to determine gastric conduit vascularity in patients undergoing esophagectomy. Methods Thirteen consecutive patients who were undergoing esophagectomy for carcinoma middle, lower third esophagus or gastro-esophageal junction from August 2019 to September 2019, were included. Three patients underwent laparoscopic-assisted transhiatal esophagectomy, ten thoraco-laparoscopic assisted esophagectomy. Reconstruction was done by gastric pull up via posterior mediastinal route. Vascularity of gastric conduit was assessed by the near-infrared camera using ICG. Results On visual assessment of perfusion at the tip of gastric conduit, it was dusky in 11 patients, pink in two. Fuorescence imaging showed inadequate perfusion at the tip of conduit in 12 patients, needing revision. In one patient visual inspection showed adequate perfusion, but ICG disclosed poor vascularity requiring revision of the conduit’s tip. Resection of the devitalized portion of the proximal esophageal stump was needed in 5 patients both by visual and ICG assessment. The median time to appearance of blush from the time of injection of dye was 15 seconds (10 to 23 seconds). Conclusion Visual inspection of the gastric conduit vascularity can underestimate perfusion and hence can compromise resection of the devitalized part. ICG fluorescence imaging is more objective and promising means to ascertain the vascularity of gastric conduit during an esophagectomy. It could complement the visual inspection to decide the site of anastomosis.

scholarly journals Practical Fingerprinting Localization for Indoor Positioning System by Using Beacons

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Santosh Subedi ◽  
Jae-Young Pyun
Keyword(s):  
Estimation Error ◽  
Indoor Positioning ◽  
Location Estimation ◽  
Reference Points ◽  
Ultra Wideband ◽  
Positioning System ◽  
Localization Method ◽  
Weighted Centroid Localization ◽  
Time Required ◽  
Indoor Positioning System

Recent developments in the fields of smartphones and wireless communication technologies such as beacons, Wi-Fi, and ultra-wideband have made it possible to realize indoor positioning system (IPS) with a few meters of accuracy. In this paper, an improvement over traditional fingerprinting localization is proposed by combining it with weighted centroid localization (WCL). The proposed localization method reduces the total number of fingerprint reference points over the localization space, thus minimizing both the time required for reading radio frequency signals and the number of reference points needed during the fingerprinting learning process, which eventually makes the process less time-consuming. The proposed positioning has two major steps of operation. In the first step, we have realized fingerprinting that utilizes lightly populated reference points (RPs) and WCL individually. Using the location estimated at the first step, WCL is run again for the final location estimation. The proposed localization technique reduces the number of required fingerprint RPs by more than 40% compared to normal fingerprinting localization method with a similar localization estimation error.

A weighted fusion method with multi-system for improving measurement accuracy of structured light 3D profilometry

2021 ◽  
Author(s):  
Chao Xing ◽  
Junhui Huang ◽  
Zhao Wang ◽  
Jianmin Gao
Keyword(s):  
Measurement Errors ◽  
Measurement Accuracy ◽  
Structured Light ◽  
Profile Measurement ◽  
Complex Surfaces ◽  
3D Profilometry ◽  
Weighted Fusion ◽  
Multiple Measurements ◽  
Geometric Relationship ◽  
3D Profile

Abstract It is a challenge to improve the accuracy of 3D profile measurement based on binary coded structured light for complex surfaces. A new method of weighted fusion with multi-system is presented to reduce the measurement errors due to the stripe grayscale asymmetry, which is based on the analysis of stripe center deviation related to surface normal and the directions of incident and reflected rays. First, the stripe center deviation model is established according to the geometric relationship between the stripe center deviation, the incident and reflected angles at any measured point. The influence of each variable on stripe center deviation is analyzed, and three subsystems are formed by a binocular structured light framework to achieve multiple measurements based on the influence regularity. Then in order to improve the measurement accuracy, different weights are assigned to the measured point in different subsystems according to the stripe center deviation model and its relationship with measurement error, and the weighted data from different subsystems are fused. Experiments are carried out to validate the presented method, and the experimental results demonstrate that it effectively improves the measurement accuracy of complex surfaces and measurement accuracy is improved by about 27% compared with the conventional method.

Performance-based assessment of Nahr Al-Fidar bridge

2019 ◽  
Author(s):  
Nisrine Makhoul
Keyword(s):  
Quality Control ◽  
Service Life ◽  
Performance Indicators ◽  
Visual Inspection ◽  
Visual Assessment ◽  
Economic Losses ◽  
Performance Goals ◽  
Control Plan ◽  
Performance Based Assessment ◽  
Bridge Reconstruction

<p>Nahr Al-Fidar Bridge is in Fidar village, which is located near Byblos City, Lebanon. The bridge reconstruction was carried out swiftly during 2006-2007, due to its importance as a vital commercial artery. Indeed, no traffic disruption is allowed on the bridge, since it leads to great economic losses. At the time being, even though the bridge has only accomplished about 10 years of its service life, it is being overloaded.</p><p>The paper aims to assess the performance of Nahr Al-Fidar bridge. To that purpose, first, the case bridge is introduced, and a visual inspection took place to identify current the state of the bridge. Second, the performance indicators are evaluated for this bridge, by means of the visual assessment, and the key performance indicators are assessed. The aim is to check if the bridge meets the pre-specified performance goals. Finally, a quality control plan is implemented for Nahr Al-Fidar bridge.</p>

scholarly journals Computerized quantification of pain drawings

2019 ◽  
Vol 20 (1) ◽  
pp. 175-189
Author(s):  
Søren O’Neill ◽  
Tue Secher Jensen ◽  
Peter Kent
Keyword(s):  
Visual Inspection ◽  
Principal Component ◽  
Visual Assessment ◽  
Spinal Pain ◽  
Correct Choice ◽  
Significant Degree ◽  
Clinical Registry ◽  
Pain Drawing ◽  
Pain Drawings ◽  
Pain Area

AbstractBackground and aimsUsing a computer algorithm to quantify pain drawings could be useful, especially when large numbers of drawings need to be assessed. Whilst informal visual assessment of pain drawings can give clinicians a quick impression of the extent of pain and its location, formal quantification of pain drawings by computer for research purposes is not necessarily trivial. The current study compared seven different approaches to quantification in a large sample of clinical spinal pain drawings.MethodsA large number (n = 55,720) of pain drawings were extracted from the SpineData database, a clinical registry of spinal pain patients in the Region of Southern Denmark. Drawings were analyzed both as pixel (raster) and vector based images, with different approaches based on the raw pain drawing, simple encircling polygons, convex-hull encircling polygons and discrete anatomical regions. Data were analyzed using principal component analysis, correlation and linear regression, as well as informal visual inspection of outlier pain drawings.ResultsEighty-one percent of the variance could be explained by the first principal component, which we interpreted as the true score variance, i.e. the variance attributable to differences in pain area between individuals. The second principal component explained 10% of the variance and was loaded differentially by polygon-based methods and non-polygon-based methods. Correlations between the different approaches ranged from 0.66 to 1.00. Some approaches correlated so strongly as to be interchangeable, others tended to bias area estimates significantly. Visual inspection of outlier pain drawing indicated that when the different approaches to quantification yielded different results, characteristic patterns could be identified in the style and patterns of those pain drawings.ConclusionsThe different approaches reflected the same underlying construct (pain area), but could not be relied upon to produce the same area estimates and were affected by the interaction between drawing style and quantification approach. To some extend, the “correct” choice of quantification method is specific to and dictated by the style of each pain drawing. A differentiated approach is required in which the results of quantification and the drawing style are considered in combination. We provide suggestions for such differentiated approaches taking into account the nature of the drawing data (raster vs. vector) and the method of analysis (partly vs completely automated).ImplicationsThe chosen method of quantifying pain drawings in combination with the drawing style of the individual patient, can impact the resulting area estimate to a significant degree. These issues should be considered before undertaking computerized area estimation of pain drawings.

Structured light in visual inspection

1998 ◽  
Author(s):  
Constantin Blanaru ◽  
Virgil V. Vasiliu
Keyword(s):  
Visual Inspection ◽  
Structured Light
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