Fluorescence optical imaging techniques have revolutionized the field of cardiac electrophysiology and advanced our understanding of complex electrical activities such as arrhythmias. However, traditional monocular optical mapping systems, despite having high spatial resolution, are restricted to a two-dimensional (2D) field of view. Consequently, tracking complex three-dimensional (3D) electrical waves such as during ventricular fibrillation is challenging as the waves rapidly move in and out of the field of view. This problem has been solved by panoramic imaging which uses multiple cameras to measure the electrical activity from the entire epicardial surface. However, the diverse engineering skill set and substantial resource cost required to design and implement this solution have made it largely inaccessible to the biomedical research community at large. To address this barrier to entry, we present an open source toolkit for building panoramic optical mapping systems which includes the 3D printing of perfusion and imaging hardware, as well as software for data processing and analysis. In this paper, we describe the toolkit and demonstrate it on different mammalian hearts: mouse, rat, and rabbit.

Atherosclerotic diseases of coronary vessels are the main reasons of myocardial ischemia. The value of the fractional flow reserve (FFR) factor is the golden standard for making decision on coronary network surgical treatment. The FFR measurements require expensive endovascular diagnostics. We propose a noninvasive method of the virtual FFR assessment in patient-specific coronary network based on angiography and computer tomography data. Also we analyze sensitivity of the model to the heart stroke volume.

Patient-specific simulations of human physiological processes remain the challenge for many years. Detailed 3D reconstruction of body anatomical parts on the basis of medical images is an important stage of individualized simulations in physiology. In this paper we present and develop the methods and algorithms for construction of patient-specific discrete geometric models. These models are represented by anatomically correct computational meshes. Practical use of these methods is demonstrated for two important medical applications: numerical evaluation of fractional flow reserve in coronary arteries and electrocardiography simulation

An airflow in the first four generations of the tracheobronchial tree was simulated by the 1D model of incompressible fluid flow through the network of the elastic tubes coupled with 0D models of lumped alveolar components, which aggregates parts of the alveolar volume and smaller airways, extended with convective transport model throughout the lung and alveolar components which were combined with the model of oxygen and carbon dioxide transport between the alveolar volume and the averaged blood compartment during pathological respiratory conditions. The novel features of this work are 1D reconstruction of the tracheobronchial tree structure on the basis of 3D segmentation of the computed tomography (CT) data; 1D−0D coupling of the models of 1D bronchial tube and 0D alveolar components; and the alveolar gas exchange model. The results of our simulations include mechanical ventilation, breathing patterns of severely ill patients with the cluster (Biot) and periodic (Cheyne-Stokes) respirations and bronchial asthma attack. The suitability of the proposed mathematical model was validated. Carbon dioxide elimination efficiency was analyzed in all these cases. In the future, these results might be integrated into research and practical studies aimed to design cyberbiological systems for remote real-time monitoring, classification, prediction of breathing patterns and alveolar gas exchange for patients with breathing problems.

Aim.To evaluate the diagnostic accuracy of a noninvasive method of fractional flow reserve (FFR) assessment based on a one-dimensional hemodynamic model build on data obtained from the coronary computed tomography angiography (CCTA).Material and methods.The study enrolled 57 patients: 16 of them underwent 64-slice computed tomography — included retrospectively, 34 — prospectively, with a 640-slice CT scan. Specialists from the Laboratory of Mathematical Modeling processed CT images and evaluated noninvasive FFR. Ischemia was confirmed if FFR <0,80 and disproved if FFR ≥0,80. After that the prospective group of patients was hospitalized for invasive FFR assessment as a reference standard; if ischemia was proved, patients underwent stent implantation. In the retrospective group, patients already had invasive FFR values estimated. Statistical analysis was performed using R programming language packages (cran-r.project.com). Continuous variables are presented as mean values ± standard deviations, order variables are presented as medians with interquartile ranges in parentheses. We used the D’Agostino-Pearson omnibus test for the assessment of normality of distribution; a Q-Q Plot was also constructed. We performed the Bland-Altman analysis and ROC-analysis for comparison of these two methods, and the Pearson’s chi-squared to assess the degree of correlation.Results.During data processing, 3 patients of the retrospective and 34 patients of the prospective group were excluded from the study. The sensitivity of our method was 90,91% (95% CI; 58,72-99,77), specificity — 86,67% (95% CI; 59,54-98,34), P<0,05, accuracy — 88,46 (95% CI; 69,85-97,55) — in per-vessel analysis. In perpatient analysis, the sensitivity was 91,67% (95% CI; 61,52-99,79), specificity — 80% (95% CI; 28,36-99,49), (P<0,05); accuracy 88,24 (95% CI; 63,56-98,54).Conclusion.Our method has quite a high accuracy and can be successfully used in clinical practice in order to enhance the diagnostic efficiency of the CCTA.