Tip Position Research Articles

Initial needle tracking with the first standalone combined infrared camera - CT system for brachytherapy-analysis of tracking accuracy and uncertainties.

Aprototype infrared camera - cone-beam computed tomography (CBCT) system for tracking in brachytherapy has recently been developed. We evaluated for the first time the corresponding tracking accuracy and uncertainties, and implemented atracking-based prediction of needles on CBCT scans. Amarker tool rigidly attached to needles was 3D printed. The precision and accuracy of tool tracking was then evaluated for both static and dynamic scenarios. Euclidean distances between the tracked and CBCT-derived markers were assessed as well. To implement needle tracking, ground truth models of the tool attached to 200 mm and 160 mm needles were matched to the tracked positions in order to project the needles into CBCT scans. Deviations between projected and actual needle tips were measured. Finally, we put our results into perspective with simulations of the system's tracking uncertainties. For the stationary scenario and dynamic movements, we achieved tool-tracking precision and accuracy of 0.04 ± 0.06 mm and 0.16 ± 0.18 mm, respectively. The tracked marker positions differed by 0.52 ± 0.18 mm from the positions determined via CBCT. In addition, the predicted needle tips in air deviated from the actual tip positions by only 1.62 ± 0.68 mm (200 mm needle) and 1.49 ± 0.62 mm (160 mm needle). The simulated tracking uncertainties resulted in tip variations of 1.58 ± 0.91 mm and 1.31 ± 0.69 mm for the 200 mm and 160 mm needles, respectively. With the innovative system it was possible to achieve ahigh tracking and prediction accuracy of marker tool and needles. The system shows high potential for applicator tracking in brachytherapy.

Optimal positioning of central venous catheters using intracavitary electrocardiogram: A narrative review

Central venous catheters (CVCs), either inserted centrally or peripherally (PICCs), are an essential therapeutic assist tool within and beyond critical care. The correct position of the tip of the CVC is important as suboptimal positioning may lead to complications. Chest X-ray remains the mainstay for tip position confirmation for the vast majority of CVCs. Intracavitary electrocardiogram (IC-ECG) is a validated method that can be utilized for this purpose. It is an accurate, easy-to-use, safer technique without radiation exposure. Its routine adoption in clinical practice is not universal. This narrative review discusses the techniques used for IC-ECG and their clinical implications.

Crack Tip Localization in Adhesively Bonded CFRP-CFRP Joints subjected to Mode II Fatigue Loading

The use of resin-based composite materials in place of metals has gained prominence across various industries. Such composites offer a superior strength-to-weight ratio, addressing the increasing demand for lightweight structures to reduce emissions. As such, structural joining of composite materials is of growing importance. Traditional fasteners, however, not only compromise weight savings, but also introduce weak points within the structure. Adhesive bonding emerges as the most promising joining technology, balancing weight efficiency and performance. However, its broader adoption for primary structural joints is hindered by a lack of standardization of quality control and non-destructive inspection techniques and concerns about long-term reliability. To address this challenge, the “CERTBOND” COST Action initiative (CA18120) was established to investigate adhesive bonding and develop a reliable certification roadmap for bonded primary structures. As part of this initiative, a Mode II fatigue loading Round Robin study was conducted on adhesively bonded CFRP-CFRP End-Notched Flexure specimens. While conducting the fatigue tests, supplementary techniques for estimating the crack tip position were employed. The selected techniques included visual testing (employing two different methods), ultrasonic phased array testing, distributed strain sensing using optical backscatter reflectometry, digital image correlation, and localization by acoustic emission. The present study describes, compares and discusses the results obtained by the cited localization techniques.

Comparison of Transesophageal Echocardiography Probe as Surface Probe with Vascular Probe During Right Internal Jugular Vein Catheterization in Cardiac Surgeries.

USG vascular probe and TEE probe can help during central venous catheterization (CVC) and can confirm the location of guide wire in the neck vessels. We proposed this study, as there are only few studies comparing between TEE probe as surface probe and USG vascular probe for right IJV cannulation. To compare the TEE probe as a surface probe and USG vascular probe during right IJV catheterization in cardiac surgeries. Prospective, comparative study. One twenty-four patients of either sex posted for major elective cardiac surgery were included in this study. Patients were divided into two groups (TEE group and USG group) of 62 by assigning the study participants alternatively to each group. The goal of this study was to compare the puncture time, visualization of IJV to first successful puncture, quality of the imaging with needle tip positioning, and catheter positioning using both TEE probe and vascular probe. The primary outcome was comparison of time from visualization of the IJV to successful puncture using both TEE probe as a surface probe and vascular probe. Secondary outcome was to compare the quality of image with respect to needle tip positioning and compare quality of image with respect to catheter position using both probes. Statistical analyses were performed by using a statistical software package SPSS, version 20.0. The observation and results of our study clearly show the feasibility of TEE as surface probe for guiding central venous catheter in right IJV just like the vascular linear probe. There was no significant difference between the two groups (P > 0.05). No statistical differences were found in the puncture time, image quality, needle tip positioning, wire positioning, and catheter positioning between the two groups. All the P values were greater than 0.05. The TEE probe can be used as an alternative method to guide IJV puncturing and catheterization when the vascular probe is not available. It is feasible especially in cardiac surgeries where the TEE monitoring machine is a must in modern anesthesia and readily available than an ultrasound machine.

Monitoring Crack Tip Position in Adhesively Bonded Joints Under Mixed I+II Mode Loading

The use of adhesive joints has gained favour in recent years, due to their capacity for weight reduction, improved stress distribution, and enhanced fatigue resistance. However, the widespread use of adhesive joints in structural applications is hindered, because reliable and mature inspection and defect detection techniques are not yet available. Adhesive joints in structural applications are subject to fatigue loading, during which debonds can initiate and propagate, ultimately leading to potential failure. In the majority of cases, joints operate under mixed-mode loading conditions. In this work, steel Cracked Lap Shear specimens were tested to investigate the crack growth behaviour of adhesive joints under mixed I+II mode loading. To address the challenge of monitoring these joints, a range of experimental techniques was employed. These techniques included Visual testing, Digital Image Correlation, Optical Backscatter Reflectometry, and localization by Acoustic Emission. The different methods were evaluated and compared to determine their effectiveness in locating the crack tip within the joints during fatigue propagation.

Accuracy of pH strip testing and pH liquid testing versus standard pH meter of gastric contents in critically ill patients: a diagnostic accuracy study

ObjectiveThe utilisation of pH level measurements from gastric contents may indicate the preferred tip position of a nasogastric tube or monitor the efficacy of stress ulcer prophylaxis in critically ill...

A surgical instrument motion measurement system for skill evaluation in practical laparoscopic surgery training.

This study developed and validated a surgical instrument motion measurement system for skill evaluation during practical laparoscopic surgery training. Owing to the various advantages of laparoscopic surgery including minimal invasiveness, this technique has been widely used. However, expert surgeons have insufficient time for providing training to beginners due to the shortage of surgeons and limited working hours. Skill transfer efficiency has to be improved for which there is an urgent need to develop objective surgical skill evaluation methods. Therefore, a simple motion capture-based surgical instrument motion measurement system that could be easily installed in an operating room for skill assessment during practical surgical training was developed. The tip positions and orientations of the instruments were calculated based on the marker positions attached to the root of the instrument. Because the patterns of these markers are individual, this system can track multiple instruments simultaneously and detect exchanges. However due to the many obstacles in the operating room, the measurement data included noise and outliers. In this study, the effect of this decrease in measurement accuracy on feature calculation was determined. Accuracy verification experiments were conducted during wet-lab training to demonstrate the capability of this system to measure the motion of surgical instruments with practical accuracy. A surgical training experiment on a cadaver was conducted, and the motions of six surgical instruments were measured in 36 cases of laparoscopic radical nephrectomy. Outlier removal and smoothing methods were also developed and applied to remove the noise and outliers in the obtained data. The questionnaire survey conducted during the experiment confirmed that the measurement system did not interfere with the surgical operation. Thus, the proposed system was capable of making reliable measurements with minimal impact on surgery. The system will facilitate surgical education by enabling the evaluation of skill transfer of surgical skills.

Study on the impact of heat loss on premixed hydrogen/air deflagration in closed pipelines

This study developed a one-step chemical reaction model for hydrogen combustion and investigated the effect of heat loss on premixed hydrogen/air deflagration in closed pipelines using numerical simulations with the CFD code GASFLOW-MPI. The simulation results were compared and verified with experimental data. The numerical simulations accurately predicted the flame front structure, pressure, and flame tip position during the deflagration of premixed hydrogen/air. Furthermore, a comparison of adiabatic simulation and heat transfer simulation results revealed that large-scale vortices within the turbulent flow were closely linked to heat loss during the tulip flame stage. Simultaneously, heat loss reduced pressure and flame tip position by diminishing the flame wrinkling factor caused by thermodiffusive instability. Finally, convective heat transfer identified as the most critical factor contributing to heat loss during the deflagration of premixed hydrogen/air in closed pipelines. Specifically, during the tulip flame stage, heat loss was mainly due to convective heat transfer (73.8%∼76.3%), with radiation playing a minor role (23.7%∼26.2%). Therefore, accurate prediction of characteristic parameters during the deflagration of premixed hydrogen/air requires numerical simulations that account for both convective and radiative heat transfer.

Different distances between central venous catheter tips can affect antibiotic clearance during continuous renal replacement therapy

BackgroundThe aim of this experimental study was to elucidate whether different distances between central venous catheter tips can affect drug clearance during continuous renal replacement therapy (CRRT). Central venous catheters (CVCs) are widely used in intensive care patients for drug infusion. If a patient receives CRRT, a second central dialysis catheter (CDC) is required. Where to insert CVCs is directed by guidelines, but recommendations regarding how to place multiple catheters are scarce. There are indications that a drug infused in a CVC with the tip close to the tip of the CDC, could be directly aspirated into the dialysis machine, with a risk of increased clearance. However, studies on whether clearance is affected by different CVC and CDC tip positions, when the two catheters are in the same vessel, are few.MethodsIn this model with 18 piglets, gentamicin (GM) and vancomycin (VM) were infused through a CVC during CRRT. The CVC tip was placed in different positions in relation to the CDC tip from caudal, i.e., proximal to the heart, to cranial, i.e., distal to the heart. Serum and dialysate concentrations were sampled after approximately 30 min of CRRT at four different positions: when the CVC tip was 2 cm caudally (+ 2), at the same level (0), and at 2 (− 2) and 4 (− 4) cm cranially of the tip of the CDC. Clearance was calculated. A mixed linear model was performed, and level of significance was set to p < 0.05.ResultsClearance of GM had median values at + 2 cm, 0 cm, − 2 cm and − 4 cm of 17.3 (5.2), 18.6 (7.4), 20.0 (16.2) and 26.2 (12.2) ml/min, respectively (p = 0.04). Clearance of VM had median values at + 2 cm, 0 cm, − 2 cm and − 4 cm of 16.2 (4.5), 14.7 (4.9), 19.0 (10.2) and 21.2 (11.4) ml/min, respectively (p = 0.02).ConclusionsThe distance between CVC and CDC tips can affect drug clearance during CRRT. A cranial versus a caudal tip position of the CVC in relation to the tip of the CDC led to the highest clearance.

A Randomized Study Comparing Ultrasound-Guided Internal Jugular Vein Cannulation Using Two Techniques: Short-Axis Out-of-Plane With Dynamic Needle Tip Positioning Versus Long-Axis In-Plane.

Introduction Internal jugular vein (IJV) cannulation is a routine procedure in operating rooms, critical care units, and perioperative settings. Ultrasound guidance has notably increased the success rates of IJV cannulation. A modified ultrasound technique known as the short-axis out-of-plane method with dynamic needle tip positioning (DNTP) allows for continuous visualization of the needle tip throughout the procedure. This study aims to compare the first-pass success rate of IJV cannulation using the DNTP and long-axis in-plane (LAIP) approaches. Methods One hundred patients between 18 and 70 years undergoing elective surgery requiring IJV cannulation were recruited.Patients were assigned randomly to the DNTP group (n = 50) or the LAIP group (n = 50). We recorded the first-pass success rate, time to achieve successful cannulation, number of skin punctures, overall success rate within five minutes, and potential complications such as pneumothorax and hematoma. Results The first pass success rate was higher in the DNTP group (48/50, 96%) as compared to the LAIP group (38/50, 76%, relative risk, 1.67; 95% confidence interval, 0.039-0.707; p = 0.008). The cannulation time was shorter in DNTP (116.98 ± 22.90 seconds) versus the LAIP group (213.04 ± 52.08 seconds; p < 0.001). No complications like pneumothorax or hematoma were noted in both groups. Conclusion We conclude that the ultrasound-guided DNTP technique for IJV cannulation, as compared with the LAIP technique, may significantly improve the first attempt cannulation, number of attempts, and cannulation time.

Real-Time Ultrasound Tip Location Reduces Malposition and Radiation Exposure during Umbilical Venous Catheter Placement in Neonates: A Retrospective, Observational Study

Introduction: The umbilical venous catheter is a vital access device in neonatal intensive care units for preterm and critically ill infants. Correct positioning is crucial, as malpositioning can lead to severe complications. According to international guidelines, the position of the umbilical venous catheter tip must be assessed in real time; traditionally, the catheter is visualized with a thoracoabdominal X-ray, but one of the most effective and safest methods is therefore real-time ultrasound. Methods: This study compares real-time ultrasound and traditional X-ray methods for assessing umbilical venous catheter tip location in 461 cases. The rate of tip malposition was analyzed retrospectively. The secondary aim was to assess indwelling time of umbilical venous catheters and reasons of removal. Results: Real-time ultrasound tip location, found to be more reliable and efficient, demonstrated a significantly lower incidence of primary malpositioning compared to X-ray assessments (9.6 vs. 75.9%). The study also highlighted the association of real-time ultrasound with reduced catheter manipulation, fewer radiographs, and higher indwelling times of umbilical venous catheter. The multiple logistic regression showed a high probability of the central safe position of the umbilical venous catheter tip using real-time ultrasound tip location (odds ratio 29.5, 95% confidence interval: 17.4–49.4). Conclusion: The findings support the adoption of real-time ultrasound in clinical settings to enhance umbilical venous catheter placement accuracy and minimize associated risks. A minimal training investment is needed to attain the proficiency to visualize the umbilical venous catheters, offering a substantial advantage in terms of both cost-effectiveness for the procedure and enhanced patient safety.

An iterative crack tip correction algorithm discovered by physical deep symbolic regression

Digital image correlation is a widely used technique in the field of experimental mechanics. In fracture mechanics, determining the precise location of the crack tip is crucial. In this paper, we introduce a novel crack tip detection algorithm based on displacement and strain fields obtained by digital image correlation. Iterative crack tip correction formulas are discovered by applying deep symbolic regression guided by physical unit constraints to a dataset of simulated cracks under mode I, II and mixed-mode conditions with variable T-stress. For the training dataset, we fit the Williams series expansion with super-singular terms to the simulated displacement fields at randomly chosen origins around the actual crack tip. We analyse the discovered formulas and apply the most promising one to digital image correlation data obtained from uniaxial and biaxial fatigue crack growth experiments of AA2024-T3 sheet material. Throughout the experiments, the crack tip positions are reliably detected leading to improved stability of the crack propagation curves.

Cost comparison of four venous catheters: Short peripheral catheter, Long peripheral line, Midline, and PICC for peripheral infusion

Introduction: The use of midline catheters for patients requiring a peripheral IV infusion is sometimes limited by their cost. Although decision trees allow them to be positioned in relation to short peripheral cannulas (SPC), Midlines, and PICCs, their economic impact has not yet been evaluated. A study was conducted to estimate and compare the actual costs of using the three types of catheters for durations of 7, 14, and 21 days. Methods: A budget impact analysis compared midlines or mini-midlines/long peripheral cannulas (LPCs) with SPCs and PICCs for typical medical indications excluding indications requiring central line (infusion of irritant or vesicant drugs): treatment of peritonitis over 7 days, cystic fibrosis infection over 14 days, and meningitis over 21 days. A micro-costing study identified resources used during catheter care procedures (consumables, medical/nursing care, examinations, mechanical complications). The cost of remote systemic complications was estimated from the French national cost study. Literature review compared data based on published complication frequencies. Results: Midline is more economic than the SPC (saving of 39€ over 7 days and 174€ over 14 days), and than the PICC (saving of 102€ over 14 days and 95€ over 21 days). Discussion: Despite a much higher acquisition cost of the Midline than a SPC, the cost of using a Midline is lower. Although this approach cannot be the only argument for choosing a medical device, it can contribute to it in a tense economic context. The micro-costing has been performed in a center placing PICCline using fluoroscopy for catheter tip positioning. The implantation of a PICC with ECG technique does not require an interventional radiology facility and involves significantly lower logistical and personnel costs. This factor is a limitation in this study. However, even with the use of EGC, the cost difference is in favor of Midline.

MAM-STM: A software for autonomous control of single moieties towards specific surface positions

In this publication we introduce MAM-STM, a software to autonomously manipulate arbitrary moieties towards specific positions on a metal surface utilizing the tip of a scanning tunneling microscope (STM). Finding the optimal manipulation parameters for a specific moiety is challenging and time consuming, even for human experts. MAM-STM combines autonomous data acquisition with a sophisticated Q-learning implementation to determine the optimal bias voltage, the z-approach distance, and the tip position relative to the moiety. This then allows to arrange single molecules and atoms at will. In this work, we provide a tutorial based on a simulated response to offer a comprehensive explanation on how to use and customize MAM-STM. Additionally, we assess the performance of the machine learning algorithm by benchmarking it within a simulated stochastic environment. PROGRAM SUMMARYProgram title: MAM-STMCPC Library link to program files: https://doi.org/10.17632/gtf3bt4v47.1Developer's repository link: https://gitlab.tugraz.at/software_public/mam_stm.gitLicensing provisions: GNU General Public License 3 (GPL)Programming language: Python 3Nature of problem: Achieving precise control over the arrangement of individual molecules on surfaces is essential for advancing nanofabrication and understanding molecular interaction processes. While self-assembly offers a method for forming nanostructures, achieving arbitrary arrangements of moieties remains difficult. Current approaches, such as scanning probe microscopy (SPM), require extensive manual intervention and precise control is difficult to achieve consistently due to the stochastic nature of quantum mechanical systems at the nanoscale. Thus, learning to manipulate several moieties in order to build even relatively small structures is challenging and time consuming and the automation through conventional expert systems is hindered by the lack of prior knowledge about the surface-moiety interaction processes.Solution method: This scenario is ideal for machine learning algorithms, like reinforcement learning (RL), which do not require an underlying model but are able to autonomously learn the optimal manipulation parameters by performing manipulations directly at the machine. Introducing MAM-STM, which stands for Molecular and Atomic Manipulation via Scanning Tunneling Microscopy. MAM-STM allows to control molecules and atoms by learning the manipulation parameters for either vertical or lateral manipulations. However, the vast number of manipulation parameter combinations and the inefficient learning procedure of RL agents exhibit several challenges. MAM-STM overcomes these challenges with an autonomous masking routine that eliminates manipulation parameters that induce structural changes to the moiety or lift it off the surface. Additionally, a sophisticated Q-learning approach is developed that speeds up the learning procedure, enabling molecular manipulations within one day of training.

Investigation of Effective Fracture Height Using Strain Responses in a Vertical Monitoring Well during a Well Interference Test

Summary Understanding and characterizing the effective hydraulic fracture height are critical for optimizing completion design and well performance in unconventional reservoirs. Rayleigh frequency shift distributed strain sensing (RFS-DSS) data provide crucial information about the fracture geometry by measuring the strain change along the fiber. Recently, the strain data from the vertical monitoring well [VMW; Boxwood 5 Pilot Hole (B5PH)] at Hydraulic Fracture Test Site 2 (HFTS-2) was collected during a well interference test conducted on two neighboring horizontal wells [Boxwood 3H (B3H) and Boxwood 4H (B4H)] in September 2020. However, this data set was overlooked and not comprehensively analyzed. Consequently, the valuable information that this data may provide remains unexplored. The objective of this study is to determine how to interpret this vertical strain data and assess its potential to provide insights into the effective fracture height generated in the horizontal wells. To understand the measured strain data, we have developed a coupled fluid flow and geomechanics model to simulate the vertical strain responses observed during production and the well interference test. The characteristics of the strain responses are thoroughly analyzed to establish guidelines for identifying the upper and lower tips of the effective fracture in different fracture geometry scenarios. In addition, field-measured data are examined, and a history-matching process is conducted by comparing the numerical matching results with the observed data to identify the effective fracture height. Furthermore, the pressure gauge data are analyzed and compared with the strain data results to further validate the findings. The study has demonstrated that vertical strain measurements obtained from a VMW can be used to determine the effective fracture height. Large strain responses, characterized by both negative and positive peaks, are observed near the tips of the effective fractures. The upper and lower tips of the effective fracture can be identified by examining the locations of zero-strain change. The magnitude of strain response is affected by the distance between the fracture and the fiber. It is worth noting that the locations where the absolute value of the derivative of fracture conductivity changes abruptly correspond to the positions of the fracture tips. Furthermore, we study and history match the field-measured vertical strain change in HFTS-2 data sets. The pressure gauge data are analyzed to further validate our findings. The effective fracture height determined from the strain measurements falls within the range of 11,360–11,616 ft, which is consistent with the values obtained from pressure gauges (11,360–11,635 ft). Specifically, for B4H, the effective fracture height was determined to be 256 ft at a distance of 330 ft away at the time of data acquisition. Overall, the strain measurements provide valuable, time-dependent insights into the effective fracture height and the active drainage interval.

Assessment of Central Catheter Tip Position in Neonates by Ultrasonography Versus X-ray

Assessment of Central Catheter Tip Position in Neonates by Ultrasonography Versus X-ray

Blind versus endoscopy-guided postpyloric feeding tube placement in adults with ischemic stroke: A retrospective cohort study.

This study compared the one-time success rate of blind and endoscopy-guided postpyloric feeding tube placement after implementing a comprehensive nursing scheme of intestinal blind placement for patients with ischemic stroke. This retrospective cohort study included 179 patients with blind bedside placement and 118 with endoscopy-guided placement. The primary outcome was the one-time success rate of radiologically confirmed postpyloric placement. The secondary endpoints included the position of the tube tip, length of insertion, time of placement, and expenses. The safety endpoints were the incidence of complications caused by placement. The results showed that the method of tube placement did not significantly affect the outcome of the first tube placement (odds ratio [OR] = 0.41; 95% CI = 0.137-1.207; P = 0.105). Compared with endoscopy-guided placement, blind placement was half the cost. We also found that a history of abdominal surgery (OR = 0.003; 95% CI = 0.000-0.059; P < 0.001) and longer intensive care unit (ICU) days (OR = 0.94; 95% CI = 0.903-0.981; P = 0.004) were inversely associated with the one-time success rate. Our study suggested that blind intestinal feeding tube placement has an equivalent one-time success rate compared with endoscopy-guided placement in hospitalized patients with ischemic stroke if operators can be trained well. However, the expenses of endoscopy-guided placement were twice those of blind bedside methods. We also found that patients with abdominal surgery history and longer ICU stay were more likely to fail at the first placement. Further research is needed to replicate our single-center observations in a larger population of patients.

Nasal profile changes after LeFort I osteotomy (maxillary advancement) with and without ANS reduction in class III skeletal patients: a study protocol for a randomized clinical trial

BackgroundDentofacial malformation is a common condition that affects a significant portion of the population, resulting in functional and aesthetic defects. Orthognathic surgeries, such as LeFort I osteotomy, are performed to correct these abnormalities. However, the impact of these surgeries on nasal profile changes remains unclear. Additionally, the role of anterior nasal spine (ANS) reduction in maxillary advancement surgeries of 3–5 mm range is yet to be determined. This study aims to investigate the effect of ANS reduction on soft tissue profile changes following LeFort I osteotomy with a maxillary advancement range of 3–5 mm in class III skeletal patients. The hypothesis is that the changes in nasolabial angle and upper lip length will not significantly differ between patients who undergo LeFort I osteotomy with and without ANS reduction.Method and designThis study is designed as a randomized controlled trial. A total of 26 class III skeletal patients with maxillofacial abnormalities will be recruited from the maxillofacial clinic of Bu-Ali and Farahikhtegan Hospitals in Tehran, Iran. Patients meeting the inclusion criteria will be randomly assigned to two groups: one group will undergo LeFort I osteotomy with ANS reduction, and the other group will undergo LeFort I osteotomy without ANS reduction. The soft tissue profile changes, specifically the nasolabial angle and upper lip length, will be evaluated and compared between the two groups.DiscussionAchieving facial harmony through orthognathic surgery requires careful planning and consideration of the impact on surrounding soft tissue. The primary objective is to predict and plan for the effects on the nasolabial region. LeFort I osteotomy is a common procedure used to correct dentofacial deformities, particularly in class III patients. Maxillary advancement during this surgery can lead to changes in nasal tip position, width, and rotation, potentially due to repositioning of the anterior nasal spine and soft tissue dissection. In this study, soft tissue changes will be assessed in non-growing class III patients using cephalometric radiographs. The impact of reducing the anterior nasal spine (ANS) on nasal profile changes will be investigated for maxillary advancements of 3–5 mm. Objective measurements and patient-reported outcomes will be evaluated to gain insights into the aesthetic outcomes of orthognathic surgery. The findings will provide valuable guidance for treatment decisions and alternative options based on expected nasal profile changes.Trial registrationThis project was registered at The Iranian Registry of Clinical Trials (Identifier No. IRCT20210928052625N1, Website: https://www.irct.ir/trial/59171) and Open Science Framework (OSF) (Registration https://doi.org/10.17605/OSF.IO/X3HD4). 2021-06-09.

Vision-based algorithm for online TIG welding deviation detection of stainless steel welded pipes

Tungsten inert gas (TIG) welding is the main welding process in the production of stainless steel welded pipe. According to the morphological characteristics of the welding molten pool image during the TIG welding process of stainless steel welded pipes, the exact position of the tungsten needle tip is calculated using image moments. Extract the weld region in the contour of the molten pool, interpolate the contour curve based on the cubic B-spline curve interpolation method, utilize the characteristics of the S-G filter, remove the interference coordinates in the contour curve through the detrending of the contour curve, extract the weld feature points, and realize the accurate identification of weld seams. The experimental results show that the method can accurately calculate the welding deviation in the welding process.

A temporal enhanced semi-supervised training framework for needle segmentation in 3D ultrasound images

Objective. Automated biopsy needle segmentation in 3D ultrasound images can be used for biopsy navigation, but it is quite challenging due to the low ultrasound image resolution and interference similar to the needle appearance. For 3D medical image segmentation, such deep learning networks as convolutional neural network and transformer have been investigated. However, these segmentation methods require numerous labeled data for training, have difficulty in meeting the real-time segmentation requirement and involve high memory consumption. Approach. In this paper, we have proposed the temporal information-based semi-supervised training framework for fast and accurate needle segmentation. Firstly, a novel circle transformer module based on the static and dynamic features has been designed after the encoders for extracting and fusing the temporal information. Then, the consistency constraints of the outputs before and after combining temporal information are proposed to provide the semi-supervision for the unlabeled volume. Finally, the model is trained using the loss function which combines the cross-entropy and Dice similarity coefficient (DSC) based segmentation loss with mean square error based consistency loss. The trained model with the single ultrasound volume input is applied to realize the needle segmentation in ultrasound volume. Main results. Experimental results on three needle ultrasound datasets acquired during the beagle biopsy show that our approach is superior to the most competitive mainstream temporal segmentation model and semi-supervised method by providing higher DSC (77.1% versus 76.5%), smaller needle tip position (1.28 mm versus 1.87 mm) and length (1.78 mm versus 2.19 mm) errors on the kidney dataset as well as DSC (78.5% versus 76.9%), needle tip position (0.86 mm versus 1.12 mm) and length (1.01 mm versus 1.26 mm) errors on the prostate dataset. Significance. The proposed method can significantly enhance needle segmentation accuracy by training with sequential images at no additional cost. This enhancement may further improve the effectiveness of biopsy navigation systems.