A 3D printing personalized percutaneous puncture guide access plate for percutaneous nephrolithotomy: a pilot study

Objective CT-Urography combined with 3D printing technology, digital design, construction of individualized PCNL puncture guides, and preliminary analyze their efficacy, safety puncture positioning for PCNL. Methods Twenty-two patients with renal calculi were randomly selected at the affiliated Hospital of Xuzhou Medical University during 2017–2018. We randomly divided the patients into two groups: in 10 experimental groups, we used our 3D printing personalized percutaneous puncture guide access plate for PCNL, and in the control group, 12 patients with standard USG guide PCNL. The accuracy of puncture position, puncture time, and intraoperative blood loss was compared. Results In the experimental group, 10 patients with 3D printing personalized percutaneous puncture guide access plate. The puncture needle was accessed through the guide plate and verified by the color Doppler. The single puncture, needle position, and depth success rate were 100.00% (10/10). The angles were consistent with the preoperative design. In the control group, 12 patients via USG guided PCNL success rate was 75.00% (9/12). The puncture time and amount of hemorrhage was (7.78 ± 0.94) min and (49.31 ± 6.43) mL, and (9.04 ± 1.09) min and (60.08 ± 12.18) mL, respectively. The above data of the two groups were statistically significant (P < 0.05). Conclusion 3D printing personalized percutaneous nephrolithotomy guide plate for PCNL can improve PCNL renal puncture channel positioning accuracy, shorten puncture time, reduce intraoperative blood loss, bleeding-related complications and provide a new method for PCNL renal puncture positioning, which is worthy of further clinical exploration.

Redesign of a fatigue machine guide plate based on topology optimization

Machinery components are subjected to dynamic loads. In particular, the fatigue machines must be designed for these types of conditions. On the other hand, the industry demands that it is sought to consume the least amount of raw material for its construction, that is, to optimize. In general, optimization tasks have been carried out mostly by trial and error. In the present work, a redesign of a guide plate of a fatigue machine was carried out based on Topology Optimization. For this purpose, Static Structural, Topology Optimization, Fatigue and Modal Analysis were carried out. With this, a new design is obtained with a reduction in its raw material of 61%. The component was designed for infinite life so that it will not compromise its structural integrity throughout the life of the equipment operation.

Numerical Study of The Power Plant Surface Condenser to Prevent High Pressure in Critical Areas

A numerical study to reduce the condenser pressure in critical areas of a power plant surface condenser has been carried out. Numerically, effects are considered through a three-dimensional simulation approach. Modifying by adding a guide plate with a three variation of angle, (?) 15?, 30?, 45? in the surface condenser area to reduce the dynamic forces and pressure due to the collision of fluid flow in the critical pipeline without reducing the purpose of the design of shell and tube heat exchanger results in transferring heat. The drag force caused by the interaction of the shear layer with the surface of the body is very undesirable, so that the control of the flow fields is needed, one of which is by optimal angle guide plate of the pipe arrangement in the critical area. This study aims to determine the optimal plate angle to overcome high pressure in the critical area. This research was numerically conducted using 3D CFD ANSYS 14.5 software with a turbulence model using a standard k-? using a pressure-based solution solver. The initial stage takes geometric data on the surface condenser in the design specification as the basis for making the domain and data from before as boundary conditions in the simulation research process. The result is that with the addition of guide plates, the average drag coefficient (Cd) is reduced compared to the average Cd in the baseline conditions and angle variation (?) 15?, 30?, 45? is 0.537; 0.644; 0.446; 0.464. Taking into this aspect, the most optimal plate angle is 30?. The simulation results show that changing the angle of the plate can reduce the Nusselt value than the baseline conditions.

CFD analysis on the oil flow of a gear stage with guide plate

Gearbox housing geometry and oil guide plates strongly influence gearbox oil flow and interaction of oil with machine elements. Guided oil flow can increase gearbox efficiency and improve heat management. Recent research studies have demonstrated the potential of Computational Fluid Dynamics (CFD) simulations to predict the gearbox oil flow and no-load losses. Thereby, the influence of housing geometry and guide plates has rarely been addressed. This study focuses on a CFD analysis on the oil flow of a dip lubricated spur gear stage with a guide plate. Grid-based CFD models with different simulation setups were confronted and evaluated. Results show that the selection of the simulation setup with respect to the acceleration ramp and mesh size needs to address the considered object of investigation and the desired depth of information. An appropriate simulation setup shows great accordance with recordings of the oil distribution by a high-speed camera. A detailed analysis of the simulation results identified the contribution of different gear surface zones to the no-load gear loss torque. For the considered guide plate a strong interaction of oil flow and loss torque due to pressure forces on the tooth flank surface zones and due to shear forces on the front and tip circle surface zones of the gears was determined.

Finite Element Analysis of a Novel Anatomical Locking Guide Plate for Anterior Column and Posterior Hemi-Transverse Acetabular Fractures

Purpose The increasing worldwide prevalence of anterior column-posterior hemi-transverse fracture (ACPHTF) brings formidable challenges to orthopaedic surgeons. Our newly-designed locking plate had previously demonstrated promising effects in ACPHTF, but evidence of their direct comparison with conventional internal fixations remains lacking. In this study, we aimed to compare our novel plate with the traditional devices via finite element analysis. Methods The ACPHTF model was created based on a 48-year-old volunteer’s CT data, and then fixed in three different internal fixations: an anterior column locking plate with posterior column screws, double column locking plates, and our novel anatomical locking plate. These models were next loaded with a downward vertical force of 200 N, 400 N and 600 N, and the stress peaks and displacements of three different sites were recorded and analyzed. Results We first tested the rigidity and found that our newly-designed locking plate as well as its matched screws had a greater stiffness especially when they were under a higher loading force of 600 N. Then we evaluated the displacements of fracture ends after applying these fixations. Both our novel plate and DLP showed significantly smaller displacement than LPPCS at the anterior column fracture line and the pubic branch fracture line, while our novel plate was not obviously inferior to DLP in terms of the displacement. Conclusion This novel plate demonstrates a distinct superiority in the stiffness over LPPCS and DLP and comparable displacements to DLP in ACPHTF, which suggests this novel anatomical locking guide plate should be taken into consideration in ACPHTF.

A 3D Printing Personalized Percutaneous Nephroscope Puncture Guide Plate in Percutaneous Nephrolithotomy: A Pilot Study

Objective Using CTU, combined with 3D printing technology, digital design, the development of individualized PCNL) puncture guides, preliminary discussion of its feasibility for PCNL puncture positioning.Methods Twenty-two patients with renal calculi who underwent PCNL in the hospital of Xuzhou Medical University in 2017-2018, including 10 experimental groups, used 3D printing technology to make guides (puncture guides); simulated punctures in vitro, after clearing the needle angle, PCNL was performed in 10 patients and PCNL in 12 patients in the control group. The accuracy of puncture positioning, puncture time and intraoperative blood loss were compared between the two groups.Results In the experimental group, 10 patients had good puncture guide plate and the patient's skin. The puncture needle was puncture under the guidance of the guide plate and verified by the color Doppler. The 1 needle puncture was successful 100.00% (10/10), the positioning of the needle point, the depth of the puncture. The angles were consistent with the preoperative design. The success rate of 12 cases of color Doppler ultrasound in the control group was 75.00% (9/12). There was no significant difference between the two groups (P>0.05). The amount of hemorrhage was (7.78±0.94) min and (49.31±6.43) mL, respectively. The control group was (9.04±1.09) min and (60.08±12.18) mL, respectively. The two groups were statistically significant (P<0.05). Conclusion 3D printing personalized percutaneous nephrolithotomy guide can improve the accuracy of PCNL renal puncture channel positioning, shorten the puncture time and reduce intraoperative blood loss, and provide a new method for PCNL renal puncture positioning, which is worthy of further clinical exploration.