Insertion Method Research Articles

Intra-aortic Balloon Pump Securement.

Intra-aortic Balloon Pump Securement.

Modeling and simulation for transient thermal analyses using a voltage-in-current latency insertion method

This article presents a modeling and simulation method for transient thermal analyses of integrated circuits (ICs) using the original and voltage-in-current (VinC) latency insertion method (LIM). LIM-based algorithms are a set of fast transient simulation methods that solve electrical circuits in a leapfrog updating manner without relying on large matrix operations used in conventional Simulation Program with Integrated Circuit Emphasis (SPICE)-based methods which can significantly slow down the solution process. The conversion from the thermal to electrical model is performed first by using the analogy between heat and electrical conduction. Since electrical inductance has no thermal equivalence, a modified VinC LIM formulation is presented which removes the requirement of the insertion of fictitious inductors. Numerical examples are presented which show that the modified VinC LIM formulation outperforms the basic LIM formulation, both in terms of stability and accuracy in the transient thermal simulation of ICs.

Collaborative scheduling of production resources and spare parts inventory for distributed equipment with feedback guidance and minimum capacity loss

Previous studies on production scheduling have neglected the impact of the supply mode of inventory allocation on the arrangement of production resources and guiding significance of delivery information to the demand side. To fill these gaps, this study investigates a collaborative scheduling model of production resources and spare parts inventory to satisfy the spare parts requirements of demand-side distributed equipment, and we propose feedback guidance based on delivery information to reduce the negative impact of delayed spare parts. The feedback guidance adopts an optimal operating strategy to reduce the capacity loss of the equipment corresponding to the delayed spare parts. An optimization objective, referred to as the total capacity loss of all distributed equipment, is introduced to visually display the effect of the scheduling scheme on the demand side. Another objective is to minimize the total service cost of the service provider, including the inventory, transportation, and tardiness costs. A modified restarted iterated Pareto greedy algorithm is proposed to solve the model. Based on the problem characteristics, certain effective operators, including two problem-dependent local-search operators and a modified idle-time insertion method, are designed to improve the search performance. Extensive experiments are conducted to demonstrate the effectiveness of the algorithm, including the feedback guidance and proposed operators. Finally, the impact of different inventory levels on the service provider and demand side is analyzed, and the results indicate that the collaborative mode can effectively reduce inventory.

TALI: An Update-Distribution-Aware Learned Index for Social Media Data

In the growing mass of social media data, how to efficiently extract the collection of interested concerns has become a research hotspot. Due to the large size and regularity of social media data, traditional indexing techniques are not applicable. Our “Learned Index”, which is a part of social media intelligence solutions, uses mathematical principles to summarize the laws from the data. It predicts the location of the data by learning the mathematical properties of the data distribution to build the model. Although existing methods over single dimension and multi-dimension such as setting gaps are proposed to further optimize the performance of index, they do not consider the update-distribution of data. In this paper, we propose an update-distribution-aware learned index for social media data (TALI) to support update operations and handle the data sliding. In TALI, underlying data are learned through machine learning models, and a recursive hierarchical model is built. It also learns the update-distribution of data to adjust the size of each leaf node. Thus, it can more effectively support all kinds of operations in databases due to the decrease of the leaf nodes’ sliding. In addition, TALI uses the model-based insertion method for bulkload and query, resulting in a small prediction error. Thus, exponential search is used to perform secondary lookup to improve query efficiency. Experiments were tested and compared on four realistic and synthetic social media datasets. Through extensive experiments, TALI performed better than the existing state-of-the-art learned index with less space occupancy on four realistic and synthetic social media datasets.

The Role of Carbonic Anhydrase αCA4 in Photosynthetic Reactions in Arabidopsis thaliana Studied, Using the Cas9 and T-DNA Induced Mutations in Its Gene

An homozygous mutant line of Arabidopsis thaliana with a knocked out At4g20990 gene encoding thylakoid carbonic anhydrase αCA4 was created using a CRISPR/Cas9 genome editing system. The effects of the mutation were compared with those in two mutant lines obtained by the T-DNA insertion method. In αCA4 knockouts of all three lines, non-photochemical quenching of chlorophyll a fluorescence was lower than in the wild type (WT) plants due to a decrease in its energy-dependent component. The αCA4 knockout also affected the level of expression of the genes encoding all proteins of the PSII light harvesting antennae, the genes encoding cytoplasmic and thylakoid CAs and the genes induced by plant immune signals. The production level of starch synthesis during the light period, as well as the level of its utilization during the darkness, were significantly higher in these mutants than in WT plants. These data confirm that the previously observed differences between insertional mutants and WT plants were not the result of the negative effects of T-DNA insertion transgenesis but the results of αCA4 gene knockout. Overall, the data indicate the involvement of αCA4 in the photosynthetic reactions in the thylakoid membrane, in particular in processes associated with the protection of higher plants' photosynthetic apparatus from photoinhibition.

A Comparison Between the Complications of Laparoscopic and Open Gastrostomy Tube Insertions: A Single-Center Study From Riyadh, Saudi Arabia.

Background and objective Gastrostomy is a procedure that involves placing a feeding tubethrough the abdominal wall into the stomachto provide nutritional support. There are several modes of gastrostomy tube insertion including laparoscopic-assisted gastrostomy (LAG), percutaneous endoscopic gastrostomy (PEG), and open gastrostomy(OG) procedure, among others. Although it is a widely performed procedure, limited data is available regarding gastrostomy inSaudi Arabia, specifically among the pediatric population. This study aimed to shed more light on different aspects of surgical gastrostomy procedures among pediatric patients at the King Abdullah Specialist Children's Hospital (KASCH) in Riyadh, Saudi Arabia. The main objective of our study was to report the indications and complications of both LAG and OGinsertions in the pediatric population. Methods A retrospective cross-sectional study was conducted at KASCH to analyze the different parameters related to LAG and OG insertions, and to evaluate for any association between these modes of insertion and their complications. Pertinent data on children from birth to 14 years of age were collected through consecutive sampling using a chart review. A total of 107 pediatric patients who underwent the procedurefrom 2016 to 2020 were evaluated. Results Demographically, the majority (58%) of gastrostomies were performed in infants (less than a year old).Additionally, our study showed a significantly increased association between LAG andcomplications such as discharge, (27.12%), skin manifestations (27.12%), and bleeding (10.17%) when compared to OG. Conclusion Based on our findings, LAG showed less favorable outcomes in contrast to OG. Further studies should be conducted to validate our findings and ensure consistent results and outcomes among different methods of gastrostomy tube insertion.

Analysis of Post‐Blast Residues in Soil Sample by 1H qNMR Spectroscopy

AbstractAnalysing active chemical components of explosives, propellants and post‐blast residues have been challenging as it involves massive complexity. The increased use of energetics in various activities like military conflicts, terrorist's activities, and accidental explosions has made the task even more difficult for forensic scientists and environmentalists to analyse post‐blast debris. The present studies reported the quantitative analysis of energetic materials present in post‐blast soil by 1H qNMR. The three methods have been used for quantitative studies, i. e. calibration curve method, co‐axial stem insert method, and ERETIC method (Electronic to Access In Vivo Concentration). All three methods have been compared with the studies of post‐blast residues of explosives such as PETN, Tetryl and TNT. The technique is selective, sensitive, rapid, reliable, and reproduce the result with good accuracy. The study merely requires a nuclear magnetic resonance spectrometer (400 MHz or 500 MHz) as an instrument.

Concentric-ring arrays for forward-viewing ultrasound imaging.

Current ultrasound (US)-image-guided needle insertions often require an expertized technique for clinicians because the performance of tasks in a three-dimensional space using two-dimensional images requires operators to cognitively maintain the spatial relationships between the US probe, the needle, and the lesion. This work presents forward-viewing US imaging with a ring array configuration to enable needle interventions without requiring the registration between tools and targets. The center-open ring array configuration allows the needle to be inserted from the center of the visualized US image, providing simple and intuitive guidance. To establish the feasibility of the ring array configuration, the design parameters causing the image quality, including the radius of the center hole and the number of ring layers and transducer elements, were investigated. Experimental results showed successful visualization, even with a hole in the transducer elements, and the target visibility was improved by increasing the number of ring layers and the number of transducer elements in each ring layer. Reducing the hole radius improved the region's image quality at a shallow depth. Forward-viewing US imaging with a ring array configuration has the potential to be a viable alternative to conventional US image-guided needle insertion methods.

Ultrasound-guided versus traditional method for peripheral venous access: an umbrella review

BackgroundShort peripheral catheters (SPC) insertion technique has a high failure rate, one of the reasons why the ultrasound (US)-guided method has been proposed as a valid alternative to traditional technique in SPC insertion. This umbrella review aims to synthesize the available evidence comparing the US-guided method with the traditional method on SPC insertion in terms of effectiveness, safety and patient satisfaction.MethodsAn umbrella review addressing the comparison between US-guided versus traditional method for SPC insertion in which only systematic reviews of all comparative study designs were eligible was carried out. Previous systematic reviews and meta-analyses were systematically searched in MEDLINE, EMBASE, Web of Science and Cochrane Library. Methodological quality was assessed with AMSTAR-2 tool. The quality of evidence per association was assessed using the GRADE criteria and was stablished as high, moderate, low and very low.ResultsTwelve systematic reviews with a range of 75–1860 patients were included. Moderate certainty evidence supports the positive effect of US-guided method on first-attempt success rate and number of attempts. There is moderate certainty evidence that US-guided method does not reduce the time spent in SPC insertion. Low certainty evidence supports that US-guided method improves both overall success rates and patient satisfaction. Emergency department was the main hospital department where these findings were reported.ConclusionsThe best current evidence indicates that US-guided method for SPC insertion is postulated as a valid alternative for both adult and pediatric population, especially in patients with difficult venous access and in hospital departments where optimal vascular access in the shortest time possible is critical.Trial registrationPROSPERO: CRD42021290824.

Data-constrained MHD Simulation for the Eruption of a Filament–Sigmoid System in Solar Active Region 11520

The separation of a filament and sigmoid is observed during an X1.4 flare on 2012 July 12 in solar active region 11520, but the corresponding change in magnetic field is not clear. We construct a data-constrained magnetohydrodynamic simulation of the filament–sigmoid system with the flux rope insertion method and magnetic flux eruption code, which produces a magnetic field evolution that may explain the separation of the low-lying filament and high-lying hot channel (sigmoid). The initial state of the magnetic model contains a magnetic flux rope with a hyperbolic flux tube, a null-point structure, and overlying confining magnetic fields. We find that the magnetic reconnections at the null point make the right footpoint of the sigmoid move from one positive magnetic polarity (P1) to another (P3). The tether-cutting reconnection at the hyperbolic flux tube occurs and quickly cuts off the connection of the low-lying filament and high-lying sigmoid. In the end, the high-lying sigmoid erupts and grows into a coronal mass ejection, while the low-lying filament remains stable. The observed double J-shaped flare ribbons, semicircular ribbon, and brightenings of several loops are reproduced in the simulation, where the eruption of the magnetic flux rope includes the impulsive acceleration and propagation phases.

Imaging Evaluation of Insertion Point Accuracy in Retrograde Intramedullary Femoral Nailing.

When compared with visual retrograde intramedullary nail placement in the femur, fluoroscopic retrograde intramedullary nail placement in the femur improved the accuracy of insertion. Ninety-six patients treated with retrograde intramedullary nailing of the femur for femoral fracture were included in this retrospective case-control study, including 48 patients treated with nailing under direct vision and 48 patients treated with nailing under fluoroscopy. Influencing factors potentially associated with the deviation of the needle insertion point on the coronal and sagittal planes (including the needle insertion method, use of limited open reduction, side, intramedullary nail diameter, mechanism of injury, and fracture classification) were analyzed univariately; then, the variables with a p value < 0.20 on univariate analysis were included in the linear regression equation to assess the independent factors associated with needle insertion point deviation. On the coronal plane, the insertion point deviation in the visual nail placement group (1.11 ± 4.08 mm) was not significantly different (p = 0.13) from that in the fluoroscopic nail placement group (-0.44 ± 3.48 mm); on the sagittal plane, the insertion point deviation in the visual nail placement group (4.91 ± 4.67 mm) was significantly greater than that in the fluoroscopic nail placement group (2.08 ± 2.97 mm) (p < 0.01). Visual nail placement was a risk factor for insertion point deviation on the sagittal plane compared with fluoroscopic nail placement (β = -0.84, p < 0.01). Compared with visual nail placement, fluoroscopic nail placement improves the accuracy of insertion on the sagittal plane, with no difference between the two methods on the coronal plane. These findings indicate that surgeons should exercise more caution when placing nails under direct vision.

Investigation of the New Advantages of Colonoscope Insertion with an Endoscopic Position Detection Unit.

The use of an endoscopic position detection unit (UPD) enables better and more objective understanding of the shape and position of the colonoscope. Here, we investigated the reproducibility of the insertion of a colonoscope with UPD. Study participants were 122 patients who received a colonoscopy with UPD twice for the purpose of large bowel screening and surveillance. The mean age of participants was 69.7 ± 10.4 years, and the male-to-female ratio was 9.2:1. The colonoscope insertion technique was primarily based on the shaft-holding, shortening insertion method. The cecal intubation time was recorded; the method used for passing through the sigmoid/descending colon junction (SDJ) and the hepatic flexure. The mean cecal intubation time was 990 ± 511 s. The cecal intubation time and the patterns for passing through the SDJ and hepatic flexure were significantly correlated between the first and second colonoscopies. Use of a UPD revealed good reproducibility of colonoscope insertion. This is the first time we have proved that both time and pattern are inserted in much the same way for the first and second times. In patients' conducted UPD combination TCS after the second time, it was suggested that individual tailor-made insertions are possible based on the information from the first time.

A new path planning method for bevel-tip flexible needle insertion in 3D space with multiple targets and obstacles

A new path planning method for bevel-tip flexible needle insertion in 3D space with multiple targets and obstacles

Performance Improvement of Lithium Metal Anode All-Solid-State Batteries By High-Speed Blowing of Abrasive Grains

All-solid-state lithium metal batteries (ASSLiMBs) are one of the candidates for a next-generation automotive battery. In particular, oxide-based SEs have relatively high electrochemical stability against lithium metal. Thus, ASSLiMB with oxide SE is expected to be long life and high energy density battery.Poor contact between the lithium metal and oxide SE is an issue to realize ASSLiMB with oxide SE. This poor contact causes high overvoltage at the SE-Li interface, and lithium dendrite grows into the SE, and it reaches to the cathode, then causing a short circuit at high-speed charging that exceeds critical current density (CCD). Several methods (e.g., thin-film insertion method, interface structure modification methods) are proposed to suppress the interface resistance and enhance the CCD; however, more low interface resistance and high CCD is required to achieve high-speed charging by ASSLiMB with oxide SE.In this study, we propose a thin surface structure control method by shot peening (S.P.) to suppress the interface resistance and increase the CCD of ASSLiMB with oxide SE. S.P. is a surface treatment method by blowing abrasive grains with high-pressure air. S.P. has the effect of imparting an uneven surface and compressive residual stresses to the surface. The uneven shape is expected to increase the interfacial stress and improve the contact property as the SE bites into the Li. The compressive residual stresses suppress crack initiation on the SE surface. It has been reported that Li dendrites grow with cracks, and suppression of cracks is expected to improve CCD . The S.P. has above two effects that can improve the lithium metal anode performance, so, we investigated the influence of the S.P. on the lithium metal anode performance. We also investigated the influence of the grain size on the electrode performance because the size of the surface roughness and the compressive residual stresses can be changed by the change of the grain size used in S.P.Pellets of oxide SE (Li6.25Ga0.25La3Zr2O12) synthesized by the solid phase reaction method were processed by S.P. with abrasive grain of Al2O3 powder. After the S.P., the surface of the pellet is coated with gold by gold sputtering. Three experiments with three abrasive gain sizes (50 µm,100 µm,300 µm) and the SE without S.P. were carried out to check the influence of the S.P.. Li metal was attached to both sides of the SE layer to construct a symmetric cell, and CCD measurements and electrochemical impedance spectroscopy measurements were performed. Surface characteristics were measured by surface three-dimensional scanning electron microscopy (surface 3DSEM) and indentation.Fig. 1 shows the CCD and interfaces resistance without S.P. and S.P. using each abrasive grain. As shown in the figure, higher CCD and low interface resistance are achieved for the samples with S.P. with 50 µm, and 100 µm grain size than non S.P. processed samples. On the other hand, the CCD of S.P. with 300 µm grain is almost the same as the non S.P. processed samples and the interface resistance is high. These results indicate that the S.P. can improve electrode performance, and there is an optimum S.P. grain size. From indentation, the fracture toughness of S.P. processed samples were higher than a sample without S.P., and the fracture toughness increased with increasing in grain diameter. This increase in fracture toughness may have suppressed the growth of Li dendrites into the SE, leading to an increase in CCD. The surface 3DSEM showed that the S.P. creates an uneven pattern on the SE pellet and the structure size is several µm. The structure size increases with the increase in the abrasive grain size. This unevenness improves the contact between SE and Li and suppresses the interface resistance. This interface resistance suppression depends on the structure size, and the lowest interface resistance is achieved for the S.P. with the smallest grain size of 50 µm. As a result of the balance between high compressive residual stress by small size grain and the low interface resistance by large size grain, the highest CCD is obtained by middle size grain of 100 µm.This study shows that S.P. can decrease the interfacial resistance of ASSLiMB and improve CCD. The unevenness caused by S.P. is on the order of several micrometers, and it can be said that S.P. can be applied to separators thinner than 100 micrometers. Figure 1

Topological Evolution of an Unwinding Blowout Jet

We investigate the topological evolution of coronal jet containing a sigmoid-like flux rope using a nonlinear force-free field model obtained with the flux-rope insertion method and magnetofrictional relaxation. We examine the topological evolution predicted by the unstable model with respect to observations from Solar Dynamic Observatory’s Atmospheric Imaging Array. We also calculate the squeezing factor, an approximation for sharp discontinuities in the magnetic field, and the coiling rate, an approximation for the amount of twist in the field. We identify at least two topological features where magnetic reconnection is likely taking place: an internal anemone-like region, near the filament, and an external region between the closed dome of the coronal jet and the ambient field. We also find evidence of reconnection below the filament, but it is not clear if the two inner regions are the same. We find that the internal region inflates the jet dome into the external region, which in turn initiates the fast eruption, allowing the inner region to unwind and the filament to escape. Finally, we examine the thermal evolution of the jet and trace the regions of enhanced emission-measure-weighted temperature (T EM) to the location of the expected reconnection regions. We find that magnetic field lines associated with the internal reconnection region are tied to increased T EM and emission in extreme-UV observations, indicative of heating. We identify this eruption as an untwisting jet, where unwinding magnetic field lines impart energy along the magnetic field forming the observed features of the coronal jet.

Comparative analysis of intaglio surface trueness of cement-retained implant-supported prostheses generated by a cast-free digital workflow and a three-dimensionally printed cast workflow

Statement of problemComparative analysis of the accuracy of the prostheses produced by a cast-free digital workflow and 3-dimensional (3D) printing cast workflow is lacking. PurposeThe purpose of the present investigation was to compare the intaglio surface trueness of implant-supported prostheses fabricated by using 3 different digital workflows: cast-free computer-aided design (CAD), 3D printed cast CAD (direct insert), and 3D printed cast CAD (indirect insert). Material and methodsThe laboratory data of 11 partially edentulous arches for prosthetic implant treatment were obtained. Three different workflows were tested to produce the cement-retained prostheses: cast-free CAD (Group CF), 3D printed cast CAD with direct insert (Group PD), and 3D printed cast CAD with indirect insert (Group PI). The intaglio surfaces of the prosthesis CAD data from Groups CF, PD, and PI were superimposed with 3D printed prosthesis scan data from Group CF to measure 3D surface deviation. Using the prosthesis CAD data from Group CF as a reference, those from Groups PD and PI were compared by superimposition analysis. The root mean square (RMS) estimates, positive average deviations, and negative average deviations were measured. The Kruskal-Wallis test and Dunn test with Bonferroni correction, and the Wilcoxon rank sum test were used for statistical analyses (α=.05). ResultsSignificant differences were found among the 3 groups when the 3D printed prosthesis scan data were referenced (P<.05). Group CF showed the lowest RMS, positive average deviation, and negative deviation values, while Group PI showed the highest values. Significant differences in the RMS, positive average deviation, and negative average deviation values were found between Groups PD and PI when the prosthesis CAD data (Group CF) were referenced (P<.05). ConclusionsAmong the 3 different workflows tested, the prostheses generated from the cast-free CAD flow showed significantly lower intaglio surface deviation than those generated from the 3D printed cast CAD flows, regardless of the insertion method of the implant replicas.

Efficacy of haptic sutured in-the-bag intraocular lens for intraocular lens-capsule complex stability: a comparison of three insertion methods.

To evaluate the efficacy and stability of haptic sutured in-the-bag intraocular lens (IOL) in eyes with zonular instability. A total 60 eyes of 60 patients were included in this retrospective cohort study. Postoperative stability in three groups [haptic sutured IOL in the bag, IOL in the bag insertion with haptics oriented toward areas of zonulysis, IOL with capsular tension ring (CTR) in the bag insertion] were compared according to the IOL insertion methods. To evaluate the IOL stability, the changes of anterior chamber depth (ACD), refraction, contraction of anterior continuous curvilinear capsulotomy (CCC) area, and tilt of IOL were compared. There was no significant difference in change of ACD (-0.04±0.01 mm in group of haptic sutured IOL, -0.07±0.01 mm in group of CTR insertion) and refraction (0.05±0.05 D in group of haptic sutured IOL, 0.37±015 D in group of CTR insertion) between the group of haptic sutured IOL in the bag and CTR insertion group. But in comparison of CCC contraction and IOL tilt, CTR insertion group showed less contraction (1.00%±0.52%) and less IOL tilt (2.66°±0.11°) than the group of haptic sutured IOL in the bag (6.32%±1.36%, 3.47°±0.11°, respectively). The CTR insertion group showed the least CCC contraction and the least tilt. In eyes with zonular instability, the method of haptic sutured IOL in-the-bag shows comparable stability in ACD and refraction in comparison with IOL with CTR in the bag insertion. The method of IOL only in-the-bag insertion shows the largest contraction of CCC and the largest tilt of IOL.

Stereoselective ZnCl2-Catalyzed B-H Bond Insertion of Vinyl Carbenes Generated from Cyclopropenes for the Synthesis of Allylboranes.

Zinc-catalyzed insertion of vinyl carbenes generated from cyclopropenes into the B-H bonds of Lewis base-borane adducts for concise and efficient access to allylboranes has been developed. This protocol represents the first zinc-catalyzed B-H bond insertion of carbenes for organoborane compounds. In this protocol, inexpensive ZnCl2, with low toxicity, is used as the catalyst. This simple ligand-free catalytic system affords allylboranes in yields up to 92%, with E/Z ratios of >20:1. Besides, this new protocol offers a broad scope of Lewis base-borane adducts, which are not easily obtained by other catalytic methods for metal carbene insertion into B-H bonds. The potential synthetic applicability of this new methodology is exemplified by a gram-scale experiment and synthetic transformation of the products.

An improved simulation modelling on the heat transfer process of wire-feeding spheroidization in iron melt

ABSTRACT The wire-feeding spheroidization treatment is important research and how to realize visual control of the process is an unsolved problem all along. In this work, an improved model of cored wire-feeding spheroidization coupled with more proper boundary conditions was developed, in which both the heat transfer effect of Mg-core and steel shell are considered. In our simulation, an implicit time integration scheme was given in the framework of FVM to ensure the convergence of calculations. The reliability performance of the presented model was verified by comparing it with the test of the artificial insertion method. Particularly, the relationship among the temperature of the iron melt, the speed of wire-feeding and melt-explosion depth of cored wire was investigated using our model. In addition, we also study the temperature variation rules at different positions of the cross-section of cored wire, and the effects of parameters on the microstructures and properties of ductile iron could provide theoretical guidance for industrial production.

Study of the surgical needle and biological soft tissue interaction phenomenon during insertion process for medical application: A Survey.

The insertion of the surgical needle in soft tissue has involved significant interest in the current time because of its purpose in minimally invasive surgery (MIS) and percutaneous events like biopsies, PCNL, and brachytherapy. This study represents a review of the existing condition of investigation on insertion of a surgical needle in biological living soft tissue material. As observes the issue from numerous phases, like, analysis of the cutting forces modeling (insertion), tissue material deformation, analysis of the needle deflection for the period of the needle insertion, and the robot-controlled insertion procedures. All analysis confirms that the total needle insertion force is the total of dissimilar forces spread sideways the shaft of the insertion needle for example cutting force, stiffness force, and frictional force. Various investigations have analyzed all these kinds of forces during the needle insertion process. The force data in several measures are applied for recognizing the biological tissue materials as the needle is penetrated or for path planning. The deflection of the needle during insertion and tissue material deformation is the main trouble for defined needle placing and efforts have been prepared to model them. Applying existing models numerous insertion methods are established that are discussed in this review.