Lechambers9150

To quantitatively analyze the impact of intrahepatic venovenous shunt (IHVS) on hepatic venous pressure gradient (HVPG) measurement.

From 2015 to 2019, 222 HVPG measurements performed during transjugular intrahepatic portosystemic shunt creation were eligible for this study. Digital subtraction angiography (DSA) software color-coded each pixel of a two-dimensional DSA series by time-intensity curve to classify IHVS. Different degrees of IHVS were found in 36.5% of patients (81/222). Mild IHVS was found in 10.8% of patients (24/222), moderate IHVS was found in 10.8% of patients (24/222), and severe IVHS was found in 14.9% of patients (33/222).

Mean wedged hepatic vein pressure (WHVP) and HVPG were significantly lower in patients with IHVS compared with patients without IHVS (WHVP 17.78 mm Hg ± 7.00 vs 24.89 mm Hg ± 8.69, P= .001; HVPG 11.93 mm Hg ± 5.76 vs 18.6 mm Hg ± 6.85, P < .001). Mild IHVS had little effect on WHVP and HVPG. Mean WHVP and HVPG were 11 mm Hg lower in patients with moderate IHVS (WHVP 20.38 mm Hg ± 8.38 vs 31.5 mm Hg ± 9.39, P= .026; HVPG 13.88 mm Hg ± 6.33 vs 25.00 mm Hg ± 9.81, P < .001) and 15 mm Hg lower in patients with severe IHVS (WHVP 13.45 mm Hg ± 5.28 vs 28.64 mm Hg ± 6.38, P= .017; HVPG 8.27 mm Hg ± 3.85 vs 23.45 mm Hg ± 6.95, P < .001) than mean portal vein pressure and portal vein gradient.

For patients with moderate or severe IHVS, HVPG might greatly underestimate the actual value of portal vein pressure, and the portal vein should be catheterized to measure portal pressure.

For patients with moderate or severe IHVS, HVPG might greatly underestimate the actual value of portal vein pressure, and the portal vein should be catheterized to measure portal pressure.In this paper the biomechanical response of a novel dental preparation technique, referred to as the Anatomic-Functional-Geometry treatment (AFG), is investigated through a 3D nonlinear finite-element modelling approach. A comparative investigation against a standard technique employed in dental clinical practice is carried out, by simulating typical experimental mechanical tests and physiological functional conditions. Failure mechanisms of treated tooth models are investigated through a progressive damage formulation implemented via a displacement-driven incremental approach. Computational results clearly show that AFG-treated teeth, as a consequence of a more conservative morphological preparation of the tooth, are characterized by more effective crown-dentin loading transfer mechanisms, higher fracture strength levels and more homogeneous stress patterns than the standard-treated ones, thereby opening towards widespread clinical application.The fields of Minimally Invasive Surgery (MIS) and Natural Orifices Transluminal Endoscopic Surgery (NOTES) strive to reduce the level of invasiveness by entering the body through smaller incisions and natural orifices. Selleckchem Tetramisole Hyper-redundant snake-like instruments can help in this pursuit of reducing invasiveness. Such instruments can pass along multi-curved pathways through the body without any support or guidance from its anatomical environment. In this way, the width of the surgical pathway and thus the invasiveness of the procedure can be reduced significantly. This is referred to as Follow-the-Leader (FTL) motion. Generally, surgical instruments intended for FTL-motion are robotic systems that require medical grade actuators, sensors, and controllers, driving up costs and increasing their footprint in the operation room. Our goal was to discard the need for these elements and develop a non-robotic instrument capable of FTL-motion along pre-determined paths. A proof of concept prototype called MemoFlex II was developed, consisting of a cable-driven hyper-redundant shaft that is controlled via four physical tracks. The MemoFlex II was able to perform 3D FTL-motion along pre-determined paths. Among other things, this study reports on a Ø8 mm shaft containing seven segments and 14 degrees of freedom (DOFs) following several multi-curved paths with an average maximal footprint between 11.0 and 17.1 mm.Sigmoid sinus diverticulum (SSD) is a common pathophysiology of pulsatile tinnitus (PT) and mainly treated by SSD reconstruction surgery. The degree of reconstruction is an important indicator of SSD reconstruction surgery, but its impact on the effect of SSD reconstruction is unclear. This study aimed to clarify the effect of the degree of SSD reconstruction on diverticulum reconstruction surgical treatment. One patient-specific case (control subject) was reconstructed based on the computed tomography angiography (CTA) images of patients with PT. The SSD reconstruction degree was used as a new index in this study. And the case of 30% (case 1), 60% (case 2), and 100% (case 3) of the diverticulum reconstruction degree of control subject were constructed. Transient-state computational fluid dynamics was performed. Wall pressure distribution, wall average pressure (Pavg) of SSD, flow pattern (velocity streamlines and velocity vector), wall shear stress (WSS) and averaged WSS (WSSavg) were calculated and used in change in the diverticulum is small, and the PT may have remained. SSD may be caused by high-speed blood flow.Mechanical properties and microstructural modifications of vessel tissues are strongly linked, as established in the state of the art of cardiovascular diseases. Techniques to obtain both mechanical and structural information are reported, but the possibility to obtain real-time microstructural and macrostructural data correlated is still lacking. An experimental approach to characterize the aortic tissue is presented. A setup integrating biaxial traction and Small Angle Light Scattering (SALS) analysis is described. The system was adopted to test ex-vivo aorta specimens from healthy and aneusymatic (aTAA) cases. A significant variation of the fiber dispersion with respect to the unloaded state was encountered during the material traction. The corresponding microstructural and mechanical data were successfully used to fit a given anisotropic constitutive model, with satisfactory R2 values (0.97±0.11 and 0.96±0.17, for aTAA and healthy population, respectively) and fiber dispersion parameters variations between the aTAA and healthy populations (0.39±0.23 and 0.15±0.10). The method integrating the biaxial/SALS technique was validated, allowing for real-time synchronization between mechanical and microstructural analysis of anisotropic biological tissues.The biological effects of a light-emitting diode (LED) light therapy device are determined by irradiation parameters, mainly wavelength and power density. However, using a battery to provide power causes a problem in the variation of LED power density during battery discharge. As a result, maintaining a stable LED power density, along with extending battery life and operating time, are the primary concerns in designing a LED light therapy device. The present study aims to introduce a LED light therapy device design with different LED color power density control. A Fuzzy logic, based on the relationship between LED power density and operating time, was proposed to control constant power density in this design. The experimental results demonstrate that by using the designed controller, the LED light therapy device's power density (40 mW/cm2, 50 mW/cm2, 60 mW/cm2 for red, blue, and green light, respectively) can be controlled. The newly designed LED light therapy device could be considered an advanced version with energy savings and stabilized LED power emitting property under a broad range voltage variation.The helical axis of motion (HAM), which describes the simultaneous multiplanar translations and rotations that occur within a joint, has been proposed as a single measure to characterize dynamic joint function. The objective of this study was to determine the tibiofemoral HAM during 5 discrete phases of gait. Thirty-nine knees from 20 healthy adults were imaged using high-speed biplane radiography during treadmill walking. The primary outcome measures were the intersection of the HAM with the sagittal plane of the femur, and the direction of the HAM. The intersection point translated an average of 12.7 ± 5.5% of femur condyle depth in the anterior-posterior direction and 28.6 ± 13.3% of femur condyle height in the proximal-distal direction during gait. The anterior/posterior and proximal/distal components of the HAM vector were greater during stance (5.6°±3.8° and 11.1°±5.0°, respectively) than during swing (2.0°±1.1° and 6.4°±3.8°, respectively) (p less then 0.001) reflecting greater coupled rotations during stance. No significant side-to-side differences in intersection point location or HAM orientation were found during any of the 5 phases of gait (max difference 4.1 ± 3.4% of femur condyle depth and 13.1 ± 16.7% of femur condyle height; 12.7°±12.3° proximal/distal and 4.2°±4.5° anterior/posterior direction). Loading significantly affected HAM location and orientation (p less then 0.001). Knowledge of healthy knee HAM and typical side-to-side differences during gait can serve as a baseline for evaluating knee motion after clinical interventions.Intra-stent thrombosis is one of the major failure modes of popliteal aneurysm endovascular repair, especially when the diseased arterial segment is long and requires overlapping stent-grafts having different nominal diameters in order to accommodate the native arterial tapering. However, the interplay between stent sizing, post-operative arterial tortuosity, luminal diameter, local hemodynamics, and thrombosis onset is not elucidated, yet. In the present study, a popliteal aneurysm was treated with endovascular deployment of two overlapped stent-grafts, showing intra-stent thrombosis at one-year follow-up examination. Patient-specific computational fluid-dynamics analyses including straight- and bent-leg position were performed. The computational fluid-dynamics analysis showed that the overlapping of the stent-grafts induces a severe discontinuity of lumen, dividing the stented artery in two regions the proximal part, affected by thrombosis, is characterized by larger diameter, low tortuosity, low flow velocity, low helicity, and low wall shear stress; the distal part presents higher tortuosity and smaller lumen diameter promoting higher flow velocity, higher helicity, and higher wall shear stress. Moreover, leg bending induces an overall increase of arterial tortuosity and reduces flow velocity promoting furtherly the luminal area exposed to low wall shear stress.Spinal cord injury (SCI) often results in loss of the ability to keep the trunk erect and stable while seated. Functional neuromuscular stimulation (FNS) can cause muscles paralyzed by SCI to contract and assist with trunk stability. We have extended the results of a previously reported threshold-based controller for restoring upright posture using FNS in the sagittal plane to more challenging displacements of the trunk in the coronal plane. The system was applied to five individuals with mid-thoracic or higher SCI, and in all cases the control system successfully restored upright sitting. The potential of the control system to maintain posture in forward-sideways (diagonal) directions was also tested in three of the subjects. In all cases, the controller successfully restored posture to erect. Clinically, these results imply that a simple, threshold based control scheme can restore upright sitting from forward, lateral or diagonal leaning without a chest strap; and that removal of barriers to upper extremity interaction with the surrounding environment could potentially allow objects to be more readily retrieved from around the wheelchair.