772 research outputs found
Application of rewriting techniques to verification problems
The goal of the project is to employ techniques from term rewriting to verification problems. The relationship between liveness properties and termination of term rewrite systems (TRSs) is of particular interest. The emphasis is on the investigation of such properties for infinite state space systems where standard model checking techniques fail. Next to developing the necessary underlying theory and performing a case study analysis, the possibility to automate this approach is of great importance. In this paper we discuss the motivation of such work, present the results obtained so far, discuss related work and present plans for the further research
Automatic method for detection of characteristic areas in thermal face images
The use of thermal images of a selected area of the head in screening systems,
which perform fast and accurate analysis of the temperature distribution of individual areas,
requires the use of profiled image analysis methods. There exist methods for automated face
analysis which are used at airports or train stations and are designed to detect people with
fever. However, they do not enable automatic separation of specific areas of the face. This
paper presents an algorithm for image analysis which enables localization of characteristic
areas of the face in thermograms. The algorithm is resistant to subjects’ variability and also to
changes in the position and orientation of the head. In addition, an attempt was made to
eliminate the impact of background and interference caused by hair and hairline. The algorithm
automatically adjusts its operation parameters to suit the prevailing room conditions.
Compared to previous studies (Marzec et al., J Med Inform Tech 16:151–159, 2010), the set
of thermal images was expanded by 34 images. As a result, the research material was a total of
125 patients’ thermograms performed in the Department of Pediatrics and Child and
Adolescent Neurology in Katowice, Poland. The images were taken interchangeably with
several thermal cameras: AGEMA 590 PAL (sensitivity of 0.1 °C), ThermaCam S65
(sensitivity of 0.08 °C), A310 (sensitivity of 0.05 °C), T335 (sensitivity of 0.05 °C) with a
320×240 pixel optical resolution of detectors, maintaining the principles related to taking
thermal images for medical thermography. In comparison to (Marzec et al., J Med Inform Tech
16:151–159, 2010), the approach presented there has been extended and modified. Based on
the comparison with other methods presented in the literature, it was demonstrated that this
method is more complex as it enables to determine the approximate areas of selected parts of the face including anthropometry. As a result of this comparison, better results were obtained
in terms of localization accuracy of the center of the eye sockets and nostrils, giving an
accuracy of 87 % for the eyes and 93 % for the nostrils
First uses of HAART 300 rings for aortic valve repair in Poland – 4 case studies
Introduction: Aortic valve reconstructions using geometric an- nuloplasty rings HAART 300/200 open new era in aortic valve surgery. The HAART technology resizes, reshapes, stabilizes and simplifies aortic valve repair. The HAART aortic repair rings are designed to be implanted directly into aortic annulus (un- der aortic valve leaflets).
Aim: We present first in Poland 4 cases of aortic valve recon- structions using geometric annuloplasty rings HAART 300. Material and methods: Two patients had type IA aortic insuf- ficiency (due to El-Khoury classification) – they were treated by HAART 300 ring insertion and ascending aorta prosthesis implantation. Third patient, Marfan with type IB aortic insuf- ficiency was repaired by HAART 300 ring implantation followed by remodeling (Yacoub) procedure. Fourth patient with type II aortic insufficiency (due to RCC prolapse) was repaired by HAART 300 implantation and cusp plication.
Results: All patients shows good results on 6 months postop- erative 3D TTE examinations. Conclusions: Presented technique is reproducible and simplify aortic valve reconstructions
Comparative study of anterior eye segment measurements with spectral swept-source and time-domain optical coherence tomography in eyes with corneal dystrophies
Purpose. To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT) in eyes with corneal dystrophies (CDs). Methods. Fifty healthy volunteers (50 eyes) and 54 patients (96 eyes) diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes) were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT), anterior chamber depth (ACD), and nasal and temporal trabecular iris angle (nTIA, tTIA) were measured and compared with Bland-Altman plots. Results. Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. Conclusions. Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements
Classification tree to analyze factors connected with post operative complications of cataract surgery in a teaching hospital
Background: Artificial intelligence (AI) is becoming ever more frequently applied in medicine and, consequently, also in ophthalmology to improve both the quality of work for physicians and the quality of care for patients. The aim of this study is to use AI, in particular classification tree, for the evaluation of both ocular and systemic features involved in the onset of complications due to cataract surgery in a teaching hospital. Methods: The charts of 1392 eyes of 1392 patients, with a mean age of 71.3 ± 8.2 years old, were reviewed to collect the ocular and systemic data before, during and after cataract surgery, including post-operative complications. All these data were processed by a classification tree algorithm, producing more than 260 million simulations, aiming to develop a predictive model. Results: Postoperative complications were observed in 168 patients. According to the AI analysis, the pre-operative characteristics involved in the insurgence of complications were: ocular comorbidities, lower visual acuity, higher astigmatism and intra-operative complications. Conclusions: Artificial intelligence application may be an interesting tool in the physician’s hands to develop customized algorithms that can, in advance, define the post-operative complication risk. This may help in improving both the quality and the outcomes of the surgery as well as in preventing patient dissatisfaction
Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies
Purpose. To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT) in eyes with corneal dystrophies (CDs). Methods. Fifty healthy volunteers (50 eyes) and 54 patients (96 eyes) diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes) were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT), anterior chamber depth (ACD), and nasal and temporal trabecular iris angle (nTIA, tTIA) were measured and compared with Bland-Altman plots. Results. Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. Conclusions. Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements
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