Manual Positioning Research Articles

Fully automated accurate patient positioning in computed tomography using anterior–posterior localizer images and a deep neural network: a dual-center study

ObjectivesThis study aimed to improve patient positioning accuracy by relying on a CT localizer and a deep neural network to optimize image quality and radiation dose.MethodsWe included 5754 chest CT axial and anterior–posterior (AP) images from two different centers, C1 and C2. After pre-processing, images were split into training (80%) and test (20%) datasets. A deep neural network was trained to generate 3D axial images from the AP localizer. The geometric centerlines of patient bodies were indicated by creating a bounding box on the predicted images. The distance between the body centerline, estimated by the deep learning model and ground truth (BCAP), was compared with patient mis-centering during manual positioning (BCMP). We evaluated the performance of our model in terms of distance between the lung centerline estimated by the deep learning model and the ground truth (LCAP).ResultsThe error in terms of BCAP was − 0.75 ± 7.73 mm and 2.06 ± 10.61 mm for C1 and C2, respectively. This error was significantly lower than BCMP, which achieved an error of 9.35 ± 14.94 and 13.98 ± 14.5 mm for C1 and C2, respectively. The absolute BCAP was 5.7 ± 5.26 and 8.26 ± 6.96 mm for C1 and C2, respectively. The LCAP metric was 1.56 ± 10.8 and −0.27 ± 16.29 mm for C1 and C2, respectively. The error in terms of BCAP and LCAP was higher for larger patients (p value < 0.01).ConclusionThe accuracy of the proposed method was comparable to available alternative methods, carrying the advantage of being free from errors related to objects blocking the camera visibility.Key Points• Patient mis-centering in the anterior–posterior direction (AP) is a common problem in clinical practice which can degrade image quality and increase patient radiation dose.• We proposed a deep neural network for automatic patient positioning using only the CT image localizer, achieving a performance comparable to alternative techniques, such as the external 3D visual camera.• The advantage of the proposed method is that it is free from errors related to objects blocking the camera visibility and that it could be implemented on imaging consoles as a patient positioning support tool.

Efficacy comparison of two methods for determining the position of the rebate edge (formed after MDF machining) during automatic monitoring of workpiece delamination

Delamination is one of the most common defects in the processing of wood-based materials. It has a massive impact on the quality of the final product. In order to determine the delamination indicators simply and reliably, the automatic image processing method can be used (Śmietańska et al., 2020). Bator and Śmietańska (2019) proposed a special algorithm to estimate the straight line representing a milling edge. However, this algorithm is quite complicated. The aim of this article is to check whether the aforementioned (complicated) algorithmic way can be replaced by a much simpler idea – the precise manual positioning of the scanned sample on a scanner (using a very simple device installed on the scanner). Special experimental research was carried out to compare the effectiveness of the two different methods. The straight line representing the rebate edge identified by the Bator and Śmietańska (2019) algorithm was usually accurate to 1 pixel (0.02 mm). Based on the assumption that the scanned samples were perfectly positioned on the scanner, the analogue line only sometimes fit just as well. At worst, the distance between these lines is 0.2 mm. Usually, the distance did not exceed 0.16 mm but it was significant and quite random. There was no statistically significant correlation between this parameter (Dmax) and tool condition (VB). It means that the samples were not perfectly positioned. They were placed, more or less, in the same position because of the imperfect stiffness of the frame installed on the scanner and human errors.

168. Comparison of manual positioning Vs wafer positioning for orthognathic surgery, a cohort study

Prior to orthognathic surgery a wafer may be constructed. Its use is well established in orthognathic surgery where it is used for setting the jaws when osteotomies are performed. However, inaccuracies of this technique have been well documented in the literature. Whilst uncommon, in some cases the use of intra-operative wafers is abandoned to achieve optimal outcomes. We aimed to assess outcomes of two techniques that are part of our routine practice; intraoperative positioning of the jaws and teeth relative to one another, in comparison to using an intraoperative wafer.

Chest physiotherapy for mechanically ventilated children: a survey of current UK practice

ObjectivesChest physiotherapy is a treatment option for mechanically ventilated children. However, there is a lack of consensus regarding its value and informal discussions suggest variation in practice. This study describes chest physiotherapy practices for mechanically ventilated children in the UK and explores clinical decision making related to its delivery. DesignCross-sectional study, using an anonymous, electronic survey. ParticipantsQualified physiotherapists working in UK NHS paediatric intensive care units (PICUs). ResultsThe response rate was 61% (72/118), this included physiotherapists from 26/27 (96%) PICUs. All participants reported using manual hyperinflations and position changes ‘always’ or ‘often’. Variation in practice was evident for some techniques, including Metaneb® and percussion. DNase (99%, 71/72) and hypertonic saline (90%, 65/72) were the most frequently used mucoactives: 91% (59/65) of physiotherapists reported only nebulising hypertonic saline and 69% (49/71) use both nebulised and instilled DNase. Use and delivery of N-acetylcysteine was inconsistent (nebulised only 55%, 26/47; instilled only 15%, 7/47; both 30%, 14/47). Chest physiotherapy was most commonly delivered with a nurse (67%, 48/72). Clinical decision making processes were comparable between physiotherapists and encompassed three main elements: individual patient assessment, involvement of the multidisciplinary team, and risk versus benefit analysis. ConclusionsA range of chest physiotherapy treatments and adjuncts were used with ventilated children. Variation was apparent and may be due to individual preferences of those training staff or local policies. Pragmatic, interventional studies are required to determine best practice. Further exploration is necessary to understand the variation in practice and intricacies of decision making.

Crosshair, semi-automated targeting for electron microscopy with a motorised ultramicrotome.

Volume electron microscopy (EM) is a time-consuming process - often requiring weeks or months of continuous acquisition for large samples. In order to compare the ultrastructure of a number of individuals or conditions, acquisition times must therefore be reduced. For resin-embedded samples, one solution is to selectively target smaller regions of interest by trimming with an ultramicrotome. This is a difficult and labour-intensive process, requiring manual positioning of the diamond knife and sample, and much time and training to master. Here, we have developed a semi-automated workflow for targeting with a modified ultramicrotome. We adapted two recent commercial systems to add motors for each rotational axis (and also each translational axis for one system), allowing precise and automated movement. We also developed a user-friendly software to convert X-ray images of resin-embedded samples into angles and cutting depths for the ultramicrotome. This is provided as an open-source Fiji plugin called Crosshair. This workflow is demonstrated by targeting regions of interest in a series of Platynereis dumerilii samples.

A novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) to prevent postoperative leg-length discrepancy for femoral neck fractures in hip arthroplasty.

To determine whether the two lower extremities are of equal length after hip arthroplasty for femoral neck fractures, we developed a novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) in hip arthroplasty. Patients with femoral neck fractures requiring hip arthroplasty from July 2020 to March 2022 in the orthopedic department of Jinjiang Municipal Hospital, Fujian Province, China were recruited. Hip arthroplasty was performed using the proposed "shoulder-to-shoulder" method of manual positioning based on anatomical mark in 52 patients with femoral neck fractures who met the inclusion criteria. "Shoulder-to-shoulder" was achieved by alignment of the marked femoral "shoulder" and the "shoulder" of prosthesis stem. There were 16 male and 36 female patients, with 27 undergoing total hip arthroplasty (THA) and 25 undergoing hip hemiarthroplasty (HA). The fractures were categorized according to the Garden classification: type II, type III, and type IV in 5, 11, and 36 patients, respectively. The vertical distance from the apex of the medial margin of the femoral trochanter to the tear drop line on both sides which was regarded as the length of both limbs were compared via postoperative imaging, and the apex-shoulder distance on the ipsilateral side measured via postoperative imaging was compared with those measured intraoperatively. All patients completed the surgery successfully. The measurement results for the lower extremities after THA were as follows: contralateral group, 43.87 ± 5.59 mm; ipsilateral group, 44.64 ± 5.43 mm. The measurement results for the lower extremities after HA were as follows: contralateral group, 45.18 ± 7.82 mm; ipsilateral group, 45.16 ± 6.43 mm. The measurement results for the lower extremities after all arthroplasties were as follows: contralateral group, 44.50 ± 6.72 mm; ipsilateral group, 44.89 ± 5.90 mm. The results for the apex-shoulder distance were as follows: postoperative imaging, 19.44 ± 3.54 mm; intraoperative apex-shoulder distance, 27.28 ± 2.84 mm. Statistical analysis results indicated no statistically significant difference in the postoperative bilateral lower extremity length after hip arthroplasty (P = 0.75), while a statistically significant difference was found between the intraoperative and postoperative imaging measurements of the apex-shoulder distance (P < 0.01). The novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) for femoral neck fractures in hip arthroplasty is simple and accurate, making it effective for preventing postoperative bilateral leg length discrepancy.

Automated elaborate resection planning for bone tumor surgery

PurposePlanning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of planar cuts in a virtual space. More elaborate cutting approaches may be possible through the use of surgical robots or patient-specific instruments; however, methods for preparing such a resection plan must be developed.MethodsThis work describes an automated approach for generating conformal bone tumor resection plans, where the resection geometry is defined by the convex hull of the tumor, and a focal point. The resection geometry is optimized using particle swarm, where the volume of healthy bone collaterally resected with the tumor is minimized. The approach was compared to manually prepared planar resection plans from an experienced surgeon for 20 tumor cases.ResultsIt was found that algorithm-generated hull-type resections greatly reduced the volume of collaterally resected healthy bone. The hull-type resections resulted in statistically significant improvements compared to the manual approach (paired t test, p < 0.001).ConclusionsThe described approach has potential to improve patient outcomes by reducing the volume of healthy bone collaterally resected with the tumor and preserving nearby critical anatomy.

The Identification Method of the Sources of Radiated Electromagnetic Disturbances on the Basis of Measurements in the Near-Field Zone

The paper presents results of tests of a simple device, consisting in the location of a source of disturbance emission by means of measurements within the near field with manual positioning of the measuring probe. The effectiveness of the source of disturbance location was finally verified by a positive result of the radiated emission tests in the EMC laboratory using a standardised method.

The Method of Creel Positioning Based on Monocular Vision.

Automatic replacement of bobbins on the frame is one of the core problems that must be solved in the textile industry. In the process of changing the bobbin, it is faced with problems such as the position offset of the bobbin, the loosening and deformation of the bobbin, which will lead to the failure of replacing the bobbin. Therefore, it is necessary to initialize the creel coordinates regularly, also considering the labor intensity and poor reliability of manual positioning. This paper proposes an automatic creel positioning method based on monocular vision. Firstly, the industrial camera was installed on the drum changing manipulator controlled by the truss system, and each yarn frame in the yarn area was inspected. Secondly, the end face image of the creel was collected at a reasonable distance, and the collected images were transmitted to the computer in real time through the Ethernet bus. Thirdly, the center coordinates (x, y) and radius r of the creel were marked by the improved Hough circle detection algorithm. Finally, the coordinate deviation of the creel was calculated and transmitted to the system controller to realize deviation correction. Before the test, the creel positioning markers were specially designed and the camera was calibrated. Thus, the influence of image complex background, creel end roughness, reflection and other factors can be reduced, and the image processing speed and positioning accuracy can be improved. The results show that the positioning effect of this method is fine when the distance between the center of the camera lens and the center of the end face of the creel is 170~190 mm. Moreover, when the distance is 190 mm, the positioning effect is the best, with an average error of only 0.51 mm. In addition, the deviation between the center coordinate and the radius of the end face of the marker is also very small, which is better than the requirements of bobbin yarn changing accuracy.

ANALISIS TOKO NEW PELITA MOTOR DALAM PENGELOLAAN PERMINTAAN DAN KAPASITAS PRODUKSI DI KOTA BATAM

The economic crisis that has occurred around the world since the emergence of the Covid-19 pandemic has had a severe impact on the operational costs of a business. With that, the purpose of this research is to assist the New Pelita Motor Store in dissecting the problems that exist in them, especially in managing demand and production capacity. Data collection techniques used are literature studies and interviews with owners and employees at the New Pelita Motor Store. The interview questions discussed how their day-to-day operations were, as well as how their sales progressed from period to period. The results obtained are that the management of demand and capacity of these partners has not been effective in the operation, because New Pelita Motor Store tends to be in a manual or traditional operational position. Therefore, suggestions that can be given are to improve the consumer experience when and after receiving services and balance their demands through promotional media to get optimal production capacity.

Accuracy of a 3D temporal scanning system for gait analysis: Comparative with a marker-based photogrammetry system

BackgroundCombining the accuracy of marker-based stereophotogrammetry and the usability and comfort of markerless human movement analysis is a difficult challenge. 3D temporal scanners are a promising solution, since they provide moving meshes with thousands of vertices that can be used to analyze human movements. Research questionCan a 3D temporal scanner be used as a markerless system for gait analysis with the same accuracy as traditional, marker-based stereophotogrammetry systems? MethodsA comparative study was carried out using a 3D temporal scanner synchronized with a marker-based stereophotogrammetry system. Two gait cycles of twelve healthy adults were measured simultaneously, extracting the positions of key anatomical points from both systems, and using them to analyze the 3D kinematics of the pelvis, right hip and knee joints. Measurement differences of marker positions and joint angles were described by their root mean square. A t-test was performed to rule out instrumental errors, and an F-test to evaluate the amplifications of marker position errors in dynamic conditions. ResultsThe differences in 3D landmark positions were between 1.9 and 2.4 mm in the reference pose. Marker position errors were significantly increased during motion in the medial-lateral and vertical directions. The angle relative errors were between 3% and 43% of the range of motion, with the greatest difference being observed in hip axial rotation. SignificanceThe differences in the results obtained between the 3D temporal scanner and the marker-based system were smaller than the usual errors due to lack of accuracy in the manual positioning of markers on anatomical landmarks and to soft-tissue artefacts. That level of accuracy is greater than other markerless systems, and proves that such technology is a good alternative to traditional, marker-based motion capture.

3D Localization of Hand Acupoints Using Hand Geometry and Landmark Points Based on RGB-D CNN Fusion.

Acupoint stimulation has proven to be of significant importance for rehabilitation and preventive therapy. Moxibustion, a kind of acupoint therapy, has mainly been performed by practitioners relying on manual localization and positioning of acupoints, leading to variance in the accuracy owing to human error. Developments in the automatic detection of acupoints using deep learning techniques have proven to somewhat tackle the problem. But the current methods lack depth-based localization and are thus confined to two-dimensional (2D) localization. In this research, a new approach towards 3D acupoint localization is introduced, based on a fusion of RGB and depth convolutional neural networks (CNN) to guide the manipulator. This research aims to tackle the challenge of real-time 3D acupoint localization in order to provide guidance for robot-controlled moxibustion. In the first step, the 3D sensor (Kinect v1) is calibrated and transformation matrix is computed to project the depth data into the RGB domain. Secondly, a fusion of RGB-CNN and depth-CNN is employed, in order to obtain 3D localization. Lastly, 3D coordinates are fed to the manipulator to perform artificially controlled moxibustion therapy. Furthermore, a 3D acupoint dataset consisting of RGB and depth images of hands, is constructed to train, validate and test the network. The network was able to localize 5 sets of acupoints with an average localization error of less than 0.09. Further experiments prove the efficacy of the approach and lay grounds for development of automatic moxibustion robots.

Android Application Design with MIT App Inventor for Bluetooth Based Mobile Robot Control

In this study, a Bluetooth-based Android application interface is developed to perform a manual and automatic control of a four-wheel-driven mobile robot designed for education, research, health, military, and many other fields. The proposed application with MIT App Inventor consists of three components: the main screen, the manual control screen, and the automatic control screen. The main screen is where the actions of the control preference selection such as manual control and automatic control and the Bluetooth connection between the mobile robot and Android phone occur. When the robot is operated manually for calibration or manual positioning purposes, the manual control screen is employed to adjust the desired robot movement and speed by hand. In the case of the need for automatic motion control, the desired robot position and speed data are inserted into the mobile robot processor through the automatic control screen. At the first stage of the work, the proposed Android application is developed with the design and block editors of the MIT App Inventor. The compiled application is then installed on the Android phone. Next, the communication between the Arduino microcontroller used for the robot control with the Bluetooth protocol and the Android application is established. The accuracy of the data dispatched to the Arduino is tested on the serial connection screen. It is validated that the data from the Android application is transferred to Arduino smoothly. At the end of this study, the manual and automatic controls of the proposed mobile robot are performed experimentally and success of the coordination between the Android application and the mobile robot are demonstrated.

Spatial-data-driven layouting for brain network visualization

Recent advances in neuro-imaging enable scientists to create brain network data that can lead to novel insights into neurocircuitry, and a better understanding of the brain’s organization. These networks inherently involve a spatial component, depicting which brain regions are structurally, functionally or genetically related. Their visualization in 3D suffers from occlusion and clutter, especially with increasing number of nodes and connections, while 2D representations such as connectograms, connectivity matrices, and node-link diagrams neglect the spatio-anatomical context. Approaches to arrange 2D-graphs manually are tedious, species-dependent, and require the knowledge of domain experts.In this paper, we present a spatial-data-driven approach for layouting 3D brain networks in 2D node-link diagrams, while maintaining their spatial organization. The produced graphs do not need manual positioning of nodes, are consistent (even for sub-graphs), and provide a perspective-dependent arrangement for orientation. Furthermore, we provide a visual design for highlighting anatomical context, including the shape of the brain, and the size of brain regions. We present in several case-studies the applicability of our approach for different neuroscience-relevant species, including the mouse, human, and Drosophila larvae. In a user study conducted with several domain experts, we demonstrate its relevance and validity, as well as its potential for neuroscientific publications, presentations, and education.

Automated assessment of hyoid movement during normal swallow using ultrasound.

BackgroundThe potential for using ultrasound by speech and language therapists (SLTs) as an adjunct clinical tool to assess swallowing function has received increased attention during the COVID‐19 pandemic, with a recent review highlighting the need for further research on normative data, objective measurement, elicitation protocol and training. The dynamic movement of the hyoid, visible in ultrasound, is crucial in facilitating bolus transition and protection of the airway during a swallow and has shown promise as a biomarker of swallowing function.AimsTo examine the kinematics of the hyoid during a swallow using ultrasound imaging and to relate the patterns to the different stages of a normal swallow. To evaluate the accuracy and robustness of two different automatic hyoid tracking methods relative to manual hyoid position estimation.Methods & ProceduresUltrasound data recorded from 15 healthy participants swallowing a 10 ml water bolus delivered by cup or spoon were analysed. The movement of the hyoid was tracked using manually marked frame‐to‐frame positions, automated hyoid shadow tracking and deep neural net (DNN) tracking. Hyoid displacement along the horizontal image axis (HxD) was charted throughout a swallow, and the maximum horizontal displacement (HxD max) and maximum hyoid velocity (HxV max) along the same axis were automatically calculated.Outcomes & ResultsThe HxD and HxV of 10 ml swallows are similar to values reported in the literature. The trajectory of the hyoid movement and its location at significant swallow event time points showed increased hyoid displacement towards the peak of the swallow. Using an interclass correlation coefficient, HxD max and HxV max values derived from the DNN tracker and shadow tracker are shown to be in high agreement and moderate agreement, respectively, when compared with values derived from manual tracking.Conclusions & ImplicationsThe similarity of the hyoid tracking results using ultrasound to previous reports based on different instrumental tools supports the possibility of using hyoid movement as a measure of swallowing function in ultrasound. The use of machine learning to automatically track the hyoid movement potentially provides a reliable and efficient way to quantify swallowing function. These findings contribute towards improving the clinical utility of ultrasound as a swallowing assessment tool. Further research on both normative and clinical populations is needed to validate hyoid movement metrics as a means of differentiating normal and abnormal swallows and to verify the reliability of automatic tracking.WHAT THIS PAPER ADDSWhat is already known on this subject There is growing interest in the use of ultrasound as an adjunct tool for assessing swallowing function. However, there is currently insufficient knowledge about the patterning and timing of lingual and hyoid movement in a typical swallow. We know that movement of the hyoid plays an essential role in bolus transition and airway protection. However, manual tracking of hyoid movement is time‐consuming and restricts the extent of large‐scale normative studies. What this study adds We show that hyoid movement can be tracked automatically, providing measurable continuous positional data. Measurements derived from this objective data are comparable with similar measures previously reported using videofluoroscopy and of the two automatic trackers assessed, the DNN approach demonstrates better robustness and higher agreement with manually derived measures. Using this kinematic data, hyoid movement can be related to different stages of swallowing. Clinical implications of this study This study contributes towards our understanding of the kinematics of a typical swallow by evaluating an automated hyoid tracking method, paving the way for future studies of typical and disordered swallow. The challenges of image acquisition highlight issues to be considered when establishing clinical protocols. The application of machine learning enhances the utility of ultrasound swallowing assessment by reducing the labour required and permitting a wider range of hyoid measurements. Further research in normative and clinical populations is facilitated by automatic data extraction allowing the validity of prospective hyoid measures in differentiating different types of swallows to be rigorously assessed.

Intraoperative condylar positioning techniques on mandible in orthognathic surgery.

The surgical condylar displacement often resulted in relapse and serious symptoms of temporomandibular joint disorders (TMD) after orthognathic surgery. To minimize the displacement, numerous techniques have been proposed. To verify their accuracy in positioning and effectiveness in preventing post-operative TMD and relapse, we reviewed the literature related to intraoperative condylar positioning techniques on the mandible in this study. The literature on condylar positioning techniques was reviewed with two charts, including the non-computer-assisted and the computer-assisted positioning methods. The pre- and post-operative alterations of condyles, the post-operative temporomandibular joint (TMJ) function and surgical relapse were analysed regarding the techniques. The clinical usage and characteristics were reviewed as well. A total of 22 articles, including 907 patients, have been reported since 2001. Nearly all methods reach a considerable positioning accuracy within the range of 1-2mm and 1-2° from the pre-operative position. We ranked the accuracy of the methods from high to low: CAD/CAM CPDs > CAD/CAM titanium plate positioning > manual positioning > computer-assisted navigation systems > imaging positioning systems. Most skeletal class II and class III patients achieved great occlusion and had no TMJ dysfunction or relapse after condylar positioning. Both the non-computer-assisted and computer-assisted condylar positioning techniques reach considerable accuracy in locating the pre-operative condyle position and preventing TMJ dysfunction and surgical relapse. Different levels of surgeons and cases can benefit from multiple suggested positioning methods. Further research with large samples and long-term follow-up is worth looking forward to upgrading the current methods, improving the clinical utility and developing new positioning techniques.

Corneal Strain Induced by Intracorneal Ring Segment Implantation Visualized With Optical Coherence Elastography.

To record the axial strain field in the cornea directly after creating a stromal tunnel and implanting an intracorneal ring segment (ICRS). Freshly enucleated porcine eyes were obtained and assigned to either ICRS implantation, tunnel creation only, or virgin control groups. Immediately after manual tunnel creation and ICRS positioning, the entire eye globe was mounted on a customized holder and intraocular pressure (IOP) was adjusted to 15 mm Hg. Then, IOP was inreased to 20 mm Hg, in steps of 1 mm Hg. At each step, an optical coherence tomography volume scan was recorded. Displacements between subsequent scans were retrieved using a vector-based phase difference method. The induced corneal strain direction was determined by taking the axial gradient. In addition, corneal surface was detected and sagittal curvature maps computed. Corneal tissue presented a localized compressive strain in the direct vicinity of the stromal tunnel, which was independent of IOP change. The central and peripheral (exterior to the ICRS) cornea demonstrated compressive strains on IOP increase, and tensile strains on IOP decrease. ICRS implantation induced an annular-shaped tensile strain at its inner border, particularly during IOP increase. The compressive strains close to the tunnel remained after ICRS implantation. Corneal curvature changes were concentrated on regions where strain was induced. ICRS implantation induces localized strains in the regions subjected to refractive changes, suggesting that corneal strain and curvature are directly related. Studying corneal strain in response to surgical intervention may provide new insights on underlying working principles. [J Refract Surg. 2022;38(3):210-216.].

An Evidence-Based Protocol for Manual Prone Positioning of Patients With ARDS.

Manual prone positioning has been shown to reduce mortality among patients with moderate to severe acute respiratory distress syndrome, but it is associated with a high incidence of pressure injuries and unplanned extubations. This study investigated the feasibility of safely implementing a manual prone positioning protocol that uses a dedicated device. A search of CINAHL and Medline identified multiple randomized controlled trials and meta-analyses that demonstrated both the reduction of mortality when prone positioning is used for more than 12 hours per day in patients with acute respiratory distress syndrome and the most common complications of this treatment. An existing safe patient-handling device was modified to enable staff to safely perform manual prone positioning with few complications for patients receiving mechanical ventilation. All staff received training on the protocol and use of the device before implementation. This study included 36 consecutive patients who were admitted to the medical intensive care unit at a large academic medical center because of hypoxemic respiratory failure/acute respiratory distress syndrome and received mechanical ventilation and prone positioning. Data were collected on clinical presentation, interventions, and complications. Using the robust protocol and the low-cost device, staff can safely perform a low-volume, high-risk maneuver. This method provides cost savings compared with other prone positioning methods. Implementing a prone positioning protocol with a dedicated device is feasible, with fewer complications and lower costs than anticipated.

The Ratio of Stress to Nonstress Anterior Talofibular Ligament Length on Ultrasonography: Normative Values.

Background:Stress ultrasonography (US) has been shown to be a valid procedure for evaluating chronic anterior talofibular ligament (ATFL) injury. The ratio of stress/nonstress ATFL length (ATFL ratio) as measured on US is clinically useful; however, there are no published normative data concerning this ratio.Purpose:To report a normative value of the ATFL ratio on US and evaluate the relationships between sex, generalized joint laxity (GJL), and the grade of anterior drawer test (ADT).Study Design:Cross-sectional study; Level of evidence, 3.Methods:The ATFL lengths were prospectively measured in the stress and nonstress positions (manual maximal anterior drawer position) for participants with noninjured ankles from March 2020 to March 2021. GJL was defined as a Beighton score ≥4. A manual ADT was also performed. The ATFL ratio was calculated, and the relationships between sex, GJL, and ADT grade were evaluated.Results:A total of 333 ankles in 184 participants (mean age, 24.5 ± 2.7 years; range, 20-33 years) were eligible for the analysis. GJL was found in 69 ankles (20.7%). The mean ATFL ratio was 1.08 ± 0.04 (95% CI, 1.08-1.09; range, 1.01-1.24), and there was a significant difference between male (1.07 ± 0.04; 95% CI, 1.07-1.08; range, 1.02-1.23) and female (1.09 ± 0.04; 95% CI, 1.08-1.10; range, 1.01-1.24) ankles (P = .001). In male ankles, the ATFL ratio was significantly greater in participants with GJL (1.11 ± 0.06 vs 1.07 ± 0.03; P = .02) or a higher grade of ADT (grade 2 vs grade 1: 1.11 ± 0.06 vs 1.07 ± 0.03, P = .002). These findings were not observed in female ankles.Conclusion:The normative value of the ATFL ratio on stress US was 1.07 ± 0.04 in men and 1.09 ± 0.04 in women. The ATFL ratio was affected by the presence of GJL in men but not in women. These findings will be useful for future studies seeking to establish the cutoff value of the ATFL ratio for diagnosing chronic lateral ankle stability on stress US.

Automated resection planning for bone tumor surgery.

Planning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of cutting planes (CPs). This work describes an automated approach for generating bone tumor resection plans, where the volume of healthy bone collaterally resected with the tumor is minimized through optimized placement of CPs. Particle swarm optimization calculates the optimal position and orientation of the CPs by introducing a single new CP to an existing resection, then optimizing all CPs to find the global minima. The bone bounded by all CPs is collaterally resected with the tumor. The approach was compared to manual resection plans from an experienced surgeon for 20 tumor cases. It was found that a greater number of CPs reduce the collaterally resected healthy bone, with diminishing returns on this improvement after five CPs. The algorithm-generated resection plan with equivalent number of CPs resulted in a statistically significant improvement over manual plans (paired t-test, p<0.001). The described approach has potential to improve patient outcomes by reducing loss of healthy bone in tumor surgery while offering a surgeon multiple resection plan options.