Bifurcation Angle Research Articles

Preoperative Morphological Prediction of Early Reoperation Risk After Primary Repair in Tetralogy of Fallot: A Contemporary Analysis of 83 Cases.

This study was conducted to investigate the pulmonary artery (PA) variations in tetralogy of Fallot (TOF) and preoperative morphological predictors for early reoperation. Eighty-three TOF patients and 20 children with normal PA were included. The TOF group was divided into two subsets according to whether or not reoperation was performed within 3 years postoperatively. Clinical information was obtained, along with computed tomography (CT)-based three-dimensional geometry of the PA. Morphological measurements of the length of the main PA branches, the angles between them, and the cross-sectional area of each segment of the PAs were acquired using computer software. Logistic regression and receiver operating characteristic curves were applied to analysis. The TOF group showed a significantly smaller PA size and irregular PA shape, with lower Nakata and McGoon indices, than the control group. The median bifurcation angle (angle-γ) was greater than 100° in the TOF group, as compared to 66.70° in the control group (P < 0.000). Residual obstruction of the infundibulum or PAs was the main reason for early reoperation in this series. The development of the main PA and left PA was poorer in the reoperation subset than in the non-reoperation subset (P ≤ 0.01). The preoperative angle-γ in the reoperation subset was larger than that in the non-reoperation subset (median, 117.8° vs. 112.0°, P = 0.026). Higher weight (OR = 0.372) and McGoon index (OR = 0.122) were protective factors, while larger angle-γ (> 114.8°, OR = 5.040) and angle-γ normalized by body surface area (BSA) (γ/BSA > 297.9, OR = 18.860) were risk factors. This study provides an intuitive perspective of PA anatomical variations in TOF. Larger preoperative PA bifurcation angle and γ/BSA were morphological risk predictors of postoperative reoperation in patients with TOF.

Carotid artery stenosis in correlation with neck and carotid artery anatomy.

The purpose of this study was to examine the relationship between neck anatomy, especially its largest muscle - sternocleidomastoid and carotid space, with carotid artery anatomy and stenosis. We analysed 102 computed tomography carotid angiograms. The study included the measurement of the neck and sternocleidomastoid length, diameter and volume and the size of the carotid space. Analysis of carotid artery geometry, the length, angle and height of carotid artery bifurcation and the direction of the internal carotid artery origin was also included. We found a positive correlation only between the neck and carotid length. There was no correlation between other neck characteristics and a carotid anatomy or internal carotid artery stenosis. Direction of internal carotid artery origin was significantly different (p < 0.01) between the left and right sides. We have not found a correlation between the size of sternocleidomastoid and carotid space and carotid stenosis as a hypothetical factor for atherosclerosis. Also, the degree of carotid artery stenosis did not correlate with other neck and carotid measurements. Neck and carotid anatomy correlated only in their lengths. The left internal carotid artery showed mostly posterolateral origin, and right internal carotid artery had no predominate direction.

Calculation of the Correct Angle of Bifurcation Predicts the Atherosclerotic Lesion Severity More Accurately

Calculation of the Correct Angle of Bifurcation Predicts the Atherosclerotic Lesion Severity More Accurately

A New Occluding Balloon-Facilitated Reversed Guidewire Technique in Successful Percutaneous Coronary Intervention for the Right Coronary Artery Chronic Total Occlusion Involving Distal Bifurcation.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can be challenging when a bifurcation lesion complicates a distal CTO cap.1,2 Baseline wiring into the true lumen at the point of bifurcation is essential to avoid jeopardizing the side branches (SB).1 The angle of bifurcation is occasionally quite large, and the reversed guidewire technique is useful in this clinical scenario.3 A critical step of the technique involves a second guidewire going into the SB far enough to provide good support. Here, we present a case where an occluding balloon technique facilitated the advance of the second guidewire.

Investigation of red blood cell partitioning in an in vitro microvascular bifurcation.

There is a long history of research examining red blood cell (RBC) partitioning in microvasculature bifurcations. These studies commonly report results describing partitioning that exists as either regular partitioning, which occurs when the RBC flux ratio is greater than the bulk fluid flowrate ratio, or reverse partitioning when the RBC flux ratio is less than or equal to that of the bulk fluid flowrate. This paper presents a study of RBC partitioning in a single bifurcating microchannel with dimensions of 6 to 16μm, investigating the effects of hematocrit, channel width, daughter channel flowrate ratio, and bifurcation angle. The erythrocyte flux ratio, N*, manifests itself as either regular or reverse partitioning, and time-dependent partitioning is much more dynamic, occurring as both regular and reverse partitioning. We report a significant reduction in the well-known sigmoidal variation of the erythrocyte flux ratio (N*) versus the volumetric flowrate ratio (Q*), partitioning behavior with increasing hematocrit in microchannels when the channel dimensions are comparable with cell size. RBCs "lingering" or jamming at the bifurcation were also observed and quantified in vitro. Results from trajectory analyses suggest that the RBC position in the feeder channel strongly affects both partitioning and lingering frequency of RBCs, with both being significantly reduced when RBCs flow on streamlines near the edge of the channel as opposed to the center of the channel. Furthermore, our experiments suggest that even at low Reynolds number, partitioning is affected by the bifurcation angle by increasing cell-cell interactions. The presented results provide further insight into RBC partitioning as well as perfusion throughout the microvasculature.

Determination of the dominant arch by computational fluid dynamics analysis using computed tomography images in double aortic arch.

Computational fluid dynamics (CFD) analysis using computed tomography images can reveal the details of the blood flow in cardiovascular disease. In double aortic arch, it is difficult to assess the hemodynamics because of the strong influence of various anatomical features, such as the angle of the aortic bifurcation. In the present study, we reported that CFD analysis is a valuable method for hemodynamic assessment in patients with double aortic arch.

Changes in retinal vascular diameters in senior and geriatric cats in association with variation in systemic blood pressure.

Early diagnosis of arterial hypertension is essential to prevent target organ damage. In humans, retinal arteriolar narrowing predicts hypertension. This blinded prospective observational study investigated the retinal vessel diameters in senior and geriatric cats of varying systolic blood pressure (SBP) status and evaluated retinal vascular changes in hypertensive cats after treatment. Cats with a median age of 14 years (range 9.1-22 years) were categorised into five groups: group 1, healthy normotensive (SBP <140 mmHg; n = 40) cats; group 2, pre-hypertensive (SBP 140-160 mmHg; n = 14) cats; group 3, cats with chronic kidney disease (CKD) and normotensive (n = 26); group 4, cats with CKD and pre-hypertensive (n = 13); and group 5, hypertensive cats (SBP >160 mmHg, n = 15). Colour fundus images (Optibrand ClearView) were assessed for hypertensive lesions. Retinal vascular diameters and bifurcation angles were annotated and calculated using the Vascular Assessment and Measurement Platform for Images of the Retina annotation tool (VAMPIRE-AT). When available, measurements were obtained at 3 and 6 months after amlodipine besylate treatment. Ten hypertensive cats had retinal lesions, most commonly intraretinal haemorrhages and retinal exudates. Arteriole and venule diameters decreased significantly with increasing age (-0.17 ± 0.05 pixels/year [P = 0.0004]; -0.19 ± 0.05 pixels/year). Adjusted means ± SEM for arteriole and venule diameter (pixels) were 6.3 ± 0.2 and 8.9 ± 0.2 (group 1); 7.6 ± 0.3 and 10.1 ± 0.4 (group 2); 6.9 ± 0.2 and 9.5 ± 0.3 (group 3); 7.4 ± 0.3 and 10.0 ± 0.4 (group 4); and 7.0 ± 0.3 and 9.8 ± 0.4 (group 5). Group 1 arteriole and venule diameters were significantly lower than those of groups 2 and 4. Group 2 arteriole bifurcation angle was significantly narrower than those of groups 1 and 3. Post-treatment, vessel diameters decreased significantly at 3 and 6 months in seven hypertensive cats. Increased age was associated with reduced vascular diameters. Longitudinal studies are required to assess if vessel diameters are a risk indicator for hypertension in cats.

Local accumulation of extracellular matrix regulates global morphogenetic patterning in the developing mammary gland

The tree-like pattern of the mammary epithelium is formed during puberty through a process known as branching morphogenesis. Although mammary epithelial branching is stochastic and generates an epithelial tree with a random pattern of branches, the global orientation of the developing epithelium is predictably biased along the long axis of the gland. Here, we combine analysis of pubertal mouse mammary glands, a three-dimensional (3D)-printed engineered tissue model, and computational models of morphogenesis to investigate the origin and the dynamics of the global bias in epithelial orientation during pubertal mammary development. Confocal microscopy analysis revealed that a global bias emerges in the absence of pre-aligned networks of type I collagen in the fat pad and is maintained throughout pubertal development until the widespread formation of lateral branches. Using branching and annihilating random walk simulations, we found that the angle of bifurcation of terminal end buds (TEBs) dictates both the dynamics and the extent of the global bias in epithelial orientation. Our experimental and computational data demonstrate that a local increase in stiffness from the accumulation of extracellular matrix, which constrains the angle of bifurcation of TEBs, is sufficient to pattern the global orientation of the developing mammary epithelium. These data reveal that local mechanical properties regulate the global pattern of mammary epithelial branching and may provide new insight into the global patterning of other branched epithelia.

The study of heat control on PVT modules with a new leaf-like heat exchanger

The photovoltaic/thermal (PVT) collector is an eco-friendly technology that simultaneously converts solar energy into electrical and thermal energy. However, a high solar cell temperature seriously affects the electrical efficiency of the PVT collector, which is an urgent problem that needs to be addressed. Some traditional cooling technologies for PVT collectors were previously investigated, but they were inefficient in heat collecting performance. In addition, a nonuniform solar cell temperature distribution accelerates the aging of PVT modules, and this topic has only rarely been discussed. In the present study, a new leaf-like heat exchanger based on bionics was proposed to improve heat control of the PVT collector. A three-dimensional mathematical model was developed in COMSOL and validated by comparing modeling results with experimental data already available in the literature. The effect of different operating conditions on the performance of the new PVT collector was investigated. The results of this study show that the bifurcation angle of the leaf-like heat exchanger with a symmetrical configuration between 20° and 35° was characterized by a lower and more uniform temperature distribution on solar cells in comparison with conventional heat exchangers. Moreover, the average temperature of the solar cell cooled by the new leaf-like heat exchanger decreased by 5.31 °C, and the pressure drop associated with the leaf-like heat exchanger was only half the value of the pressure drop associated with a conventional heat exchanger at a mass flow rate of 0.0314 kg/s. Finally, the total efficiency of the new PVT collector was 4.36% higher than that of the conventional PVT collector.

Automated segmentation of the individual branches of the carotid arteries in contrast-enhanced MR angiography using DeepMedic

BackgroundNon-invasive imaging is of interest for tracking the progression of atherosclerosis in the carotid bifurcation, and segmenting this region into its constituent branch arteries is necessary for analyses. The purpose of this study was to validate and demonstrate a method for segmenting the carotid bifurcation into the common, internal, and external carotid arteries (CCA, ICA, ECA) in contrast-enhanced MR angiography (CE-MRA) data.MethodsA segmentation pipeline utilizing a convolutional neural network (DeepMedic) was tailored and trained for multi-class segmentation of the carotid arteries in CE-MRA data from the Swedish CardioPulmonsary bioImage Study (SCAPIS). Segmentation quality was quantitatively assessed using the Dice similarity coefficient (DSC), Matthews Correlation Coefficient (MCC), F2, F0.5, and True Positive Ratio (TPR). Segmentations were also assessed qualitatively, by three observers using visual inspection. Finally, geometric descriptions of the carotid bifurcations were generated for each subject to demonstrate the utility of the proposed segmentation method.ResultsBranch-level segmentations scored DSC = 0.80 ± 0.13, MCC = 0.80 ± 0.12, F2 = 0.82 ± 0.14, F0.5 = 0.78 ± 0.13, and TPR = 0.84 ± 0.16, on average in a testing cohort of 46 carotid bifurcations. Qualitatively, 61% of segmentations were judged to be usable for analyses without adjustments in a cohort of 336 carotid bifurcations without ground-truth. Carotid artery geometry showed wide variation within the whole cohort, with CCA diameter 8.6 ± 1.1 mm, ICA 7.5 ± 1.4 mm, ECA 5.7 ± 1.0 mm and bifurcation angle 41 ± 21°.ConclusionThe proposed segmentation method automatically generates branch-level segmentations of the carotid arteries that are suitable for use in further analyses and help enable large-cohort investigations.

Comparing the Electrophysiology and Morphology of Human and Mouse Layer 2/3 Pyramidal Neurons With Bayesian Networks.

Pyramidal neurons are the most common neurons in the cerebral cortex. Understanding how they differ between species is a key challenge in neuroscience. We compared human temporal cortex and mouse visual cortex pyramidal neurons from the Allen Cell Types Database in terms of their electrophysiology and dendritic morphology. We found that, among other differences, human pyramidal neurons had a higher action potential threshold voltage, a lower input resistance, and larger dendritic arbors. We learned Gaussian Bayesian networks from the data in order to identify correlations and conditional independencies between the variables and compare them between the species. We found strong correlations between electrophysiological and morphological variables in both species. In human cells, electrophysiological variables were correlated even with morphological variables that are not directly related to dendritic arbor size or diameter, such as mean bifurcation angle and mean branch tortuosity. Cortical depth was correlated with both electrophysiological and morphological variables in both species, and its effect on electrophysiology could not be explained in terms of the morphological variables. For some variables, the effect of cortical depth was opposite in the two species. Overall, the correlations among the variables differed strikingly between human and mouse neurons. Besides identifying correlations and conditional independencies, the learned Bayesian networks might be useful for probabilistic reasoning regarding the morphology and electrophysiology of pyramidal neurons.

Exploring the Relationships Between Hemodynamic Stresses in the Carotid Arteries.

Background: Atherosclerosis manifests as a focal disease, often affecting areas with complex hemodynamics such as the carotid bifurcation. The magnitude and regularity of the hemodynamic shear stresses acting on the vessel wall are thought to generate risk patterns unique to each patient and play a role in the pathogenesis of atherosclerosis. The involvement of different expressions of shear stress in the pathogenesis of carotid atherosclerosis highlights the need to characterize and compare the differential impact of the various expressions of shear stress in the atherosclerotic carotid bifurcation. Therefore, the aim of this study is to characterize and compare hemodynamic wall shear stresses (WSS) in the carotid arteries of subjects with asymptomatic atherosclerotic plaques. Shear stresses were also compared against vessel diameter and bifurcation angle to examine the relationships with the geometry of the carotid bifurcation.Methods: 4D Flow MRI and contrast-enhanced MRA data were acquired for 245 subjects with atherosclerotic plaques of at least 2.7 mm in conjunction with the Swedish CArdioPulmonary bioImage Study (SCAPIS). Following automatic segmentation and geometric analysis, time-resolved WSS and near-wall turbulent kinetic energy (nwTKE) were derived from the 4D Flow data. Whole-cycle parameters including time-averaged WSS and nwTKE, and the oscillatory shear index (OSI) were calculated. Pairwise Spearman rank-correlation analyses were used to investigate relationships among the hemodynamic as well as geometric parameters.Results: One hundred and seventy nine subjects were successfully segmented using automated tools and subsequently geometric and hemodynamic analyses were performed. Temporally resolved WSS and nwTKE were strongly correlated, ρ = 0.64. Cycle-averaged WSS and nwTKE were moderately correlated, ρ = 0.57. Cycle-average nwTKE was weakly correlated to OSI (ρ = −0.273), revealing that nwTKE provides information about disturbed flow on the vessel wall that OSI does not. In this cohort, there was large inter-individual variation for both WSS and nwTKE. Both WSS and nwTKE varied most within the external carotid artery. WSS, nwTKE, and OSI were weakly correlated to vessel diameter and bifurcation angle.Conclusion: The turbulent and mean component of WSS were examined together in vivo for the first time, and a strong correlation was found between them. nwTKE presents the opportunity to quantify turbulent wall stresses in vivo and gain insight into the effects of disturbed flow on the vessel wall. Neither vessel diameter nor bifurcation angle were found to be strongly correlated to the turbulent or mean component of WSS in this cohort.

Antegrade and retrograde in‐stent tibial artery chronic total occlusion recanalization with double kiss crush (DK crush) stenting of previous stent

Below the knee (BTK) peripheral arterial disease often presents with critical limb ischemia (CLI) clinically with involvement of more than one tibial vessels. Drug eluting stent (DES) technology for treatment of BTK disease has shown promising long-term durable results; however, currently only coronary DESs are available for application in the United States. Although coronary bifurcation stenting techniques are backed by extensive data in literature, there is a scarcity of data for the treatment of tibial bifurcation disease. Bifurcation angles in the tibials are similar to those in the coronaries and therefore the same two stent bifurcation technique can be applied in BTK disease. Double Kiss crush (DK crush) stenting has superior outcomes when compared to provisional or culotte stenting in randomized coronary trials (based on Medina classification). We present a case of BTK CLI with tibial bifurcation chronic total occlusion treated with two stent DK crush technique using coronary DES.

A retrospective longitudinal study of age-related shifts and deformations in the basilar artery bifurcation.

Previous studies have indicated that cerebral arterial morphology is linked to aging and some cerebrovascular diseases. However, the mechanisms of morphological changes remain unclear. This study evaluated age-related positional changes in the basilar artery (BA) bifurcation based on longitudinal computed tomography angiography (CTA) data. This retrospective study evaluated clinical and imaging data from 72 subjects who underwent two CTA scans between July 2011 and August 2019. Three-dimensional (3D) models were reconstructed for each subject based on the two CTA scans with the longest separating interval. Skull landmarks were used to fuse the two models, and the fused model was used to evaluate positional changes in the BA bifurcation. Univariable and multivariable analyses were used to identify variables that were correlated to BA bifurcation shifting. Pearson's correlation test was used to analyze the correlation between the shifting distance and change in the BA bifurcation angle. Significant differences between aneurysm and non-aneurysm cases were observed in terms of sex (p = 0.004), CTA scan interval (p = 0.023), and BA bifurcation shifting distance (p = 0.007). Multivariable linear regression analysis revealed that the BA bifurcation shifting distance was significantly correlated with the CTA scan interval (p = 0.038) and the presence of aneurysms (p < 0.001). Furthermore, the shifting distance was positively correlated with widening of the BA bifurcation angle (p = 0.002). Aging-related widening of the BA bifurcation angle may be related to distal shifting of the BA bifurcation's position, and larger distal shifting of the BA bifurcation may be associated with the risk of aneurysm formation.

Hydraulically Steerable Micro Guidewire Capable of Distal Sharp Steering.

Current steerable catheters or guidewires often cannot advance into small diameter vessels due to their large diameters or lack of sharp steering capacity. This paper proposes a hydraulically steerable guidewire with 400 μm diameter, which can access 1 mm diameter vessels whose branching angle is larger than 90 degrees. The designed steering mechanism consists of a flexible eccentric tube with inner micro patterns, which can bend in two different curvatures when pressurized. Its distal sharp curve of the 2 mm segment allows access to small diameter vessels because it provides a large steering angle even in confinement inside the narrow vessels. Its proximal gradual curve of the 9 mm segment allows access to relatively large diameter vessels because of its large steering distance. Fabrication of the steering mechanism uses a template and does not use adhesion or division. A 3D printed cylindrical template is patterned by stamping and chemically removed after silicone coating. The performance of selective insertion of the proposed guidewire is evaluated in a blood circulatory system specially developed to mimic human arterial environment. It emulates viscosity, pressure, and flow velocity inside the blood vessels as well as bifurcation geometry. Experiment result shows that the proposed guidewire can access 1 mm diameter vessels with 128 degrees of bifurcation angle. The developed guidewire uses only biocompatible materials including driving fluid.

A Computational Study on the Effect of Bifurcation Lesions with Different Structures on Blood Velocity and Temperature

Treating coronary bifurcation stenosis is still a challenging task. Existing procedures still display a relatively small rate of success. This paper aims to investigate numerically the effect of bifurcation lesions with different structures on the dynamics of blood flow and related temperature. The problem geometry is parametrically varied by changing the bifurcation angle and radius. A finite volume method is used to simulate the three-dimensional flow. The effects induced by the structure of the stenosis, the artery bifurcation angle and radius, and the inlet velocity of blood are discussed in terms of flow pattern, pressure distribution, and shear stress at the blood wall. The heat transfer from the solid tissue is also determined for different stenosis configurations. The present study has been conducted with the explicit intention to generate useful data for the development of methods curing the vascular stenosis with thermal ablation.

Segmentation of the Airway Tree From Chest CT Using Tiny Atrous Convolutional Network

The airway tree is one of the most important part in human respiratory system. Airway segmentation plays a crucial role in pulmonary disease diagnosis, localization and surgical navigation. We propose a novel method to improve airway segmentation in thoracic computed tomography(CT) using deep learning. In order to take into account the multi-scale changes of the airway and achieve accurate airway segmentation, we design an end-to-end Tiny Atrous Convolutional Network (TACNet) based on 3D convolution neural network. In view of the difficulty of classification due to the numerous branches of airway, two evaluation factors, namely, the angle of airway bifurcation and the buffer length of airway bifurcation are designed, which are used for airway classification by combining the centerline extraction. We train TACNet on the inspirator thoracic CT scans with ground truth, which are generated by clinicians and evaluate on our own clinical data sets and EXACT'09 data sets. Compared with state-of-the-art airway segmentation algorithms, proposed algorithm in this paper achieve very competitive results in 20 test datasets of the EXACT'09 challenge. The experimental results show that the algorithm proposed in this paper has high robustness and advantages regardless of airway segmentation or airway classification. In 20 test datasets of the EXACT'09 challenge, the average airway tree length detection rate is the best in the public literatures.

Clinical impact of bifurcation angle change between diastole and systole in complex stenting for left main distal bifurcation: The Milan and New-Tokyo (MITO) Registry.

We assessed the impact of pre-percutaneous coronary intervention (PCI) bifurcation angle change (BAC) on clinical outcomes. There are little available data about the impact of BAC in unprotected left main distal bifurcation lesions (ULMD) PCI. We identified consecutive 300 patients with ULMD underwent complex stenting using drug-eluting stent in three high-volume centers (Tokyo and Milan). We measured the widest BA of ULMD at both end-diastole and end-systole before stenting with two-dimensional quantitative coronary angiographic assessment and calculated the BAC value as a difference of two BA value in each lesion. We divided them into small and large BAC group according to the median BAC value (7.2°). The primary endpoint was target lesion failure (TLF), which was defined as a composite of cardiac death, target lesion revascularization (TLR) and myocardial infarction. TLF rate at 3-year was significantly higher in the large BAC group than in the small BAC group (adjusted hazard ratio [HR] 5.85; 95% confidence interval [CI], 3.40-10.1; p< .001). TLR rate for left main (LM) to left anterior descending artery (LAD) and ostial left circumflex artery (LCXos) at 3-year were significantly higher in large BAC group than in small BAC group (adjusted HR 5.91; 95% CI, 2.03-17.2; p= .001 and adjusted HR 10.6; 95% CI, 5.20-21.6; p< .001, respectively). A large BAC before stenting is strongly associated with adverse events after complex stenting for ULMD, mainly driven by repeat PCI for restenosis of the LCXos and of the LM-LAD.

Efficacy of Combination Atherectomy of Orbital Atherectomy System and Rotational Atherectomy for Severely Calcified Nodule

Provisional single drug-eluting stent (DES) strategy remains the standard of care in simple bifurcation lesions which comprise the vast majority of coronary bifurcations. Nevertheless, the presence of complex bifurcations which are defined based on the 1) Side Branch (SB) lesion length of >10 mm and 2) SB ostial diameter stenosis of >70% are approached with a 2-DES strategy upfront. The bifurcation angle will further define the most appropriate technique, with T-stenting more suitable in angulations close to 90°, Culotte and the family of Crush techniques more appropriate for acute angles of <75°. The Crush techniques which are composed of the classic Crush, mini-Crush and double kissing Crush (DK-Crush) share the core principle of protruding the SB DES within the Main Branch (MB) to minimize the risk of ostial SB restenosis, which remains the most prevalent etiology of stent failure during 2-stent approach in bifurcations. Proximal Side Optimization (PSO) is an additional technical consideration to further optimize the protruding SB struts enabling 1) optimal SB strut accommodation to the larger MB vessel diameter, 2) strut enlargement that will further facilitate effortless rewiring for kissing balloon inflation (KBI) avoiding unfavorable guide wire advancement in the peri-ostial SB area.

Investigation on the characteristics of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tubes

In order to deeply understand the overpressure propagation characteristics of explosion shock wave of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tube, this paper makes a comprehensive and in-depth study on the change and distribution law of explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tube by means of experimental research, the results show that: the explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion is all affected by the bifurcation angle of the tube, the larger the bifurcation angle of the tube is, and the greater the explosion shock wave overpressure is. In terms of explosion shock wave overpressure distribution, single-phase gas explosion and gas-coal dust coupling explosion show a similar overall development trend, and the maximum explosion shock wave overpressure is obtained in front of the bifurcation point. The mutation coefficients of explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion before and after the bifurcation point of the tube are all affected by the bifurcation angle of the tube. In the straight tube section, the mutation coefficient of explosion shock wave overpressure increases gradually with the increase of the bifurcation angle of the tube, while the situation in the inclined tube section is just the opposite. Under the condition of the same bifurcation angle, the shock wave overpressure mutation coefficient of gas-coal dust coupling explosion is smaller than that of single-phase gas explosion.