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Ventriloquist illusion, the change in perceived location of an auditory stimulus when a synchronously presented but spatially discordant visual stimulus is added, has been previously shown in young healthy populations to be a robust paradigm that mainly relies on automatic processes. Here, we propose ventriloquist illusion as a potential simple test to assess audiovisual (AV) integration in young and older individuals. We used a modified version of the illusion paradigm that was adaptive, nearly bias-free, relied on binaural stimulus representation using generic head-related transfer functions (HRTFs) instead of multiple loudspeakers, and tested with synchronous and asynchronous presentation of AV stimuli (both tone and speech). The minimum audible angle (MAA), the smallest perceptible difference in angle between two sound sources, was compared with or without the visual stimuli in young and older adults with no or minimal sensory deficits. The illusion effect, measured by means of MAAs implemented with HRTFs, was observed with both synchronous and asynchronous visual stimulus, but only with tone and not speech stimulus. The patterns were similar between young and older individuals, indicating the versatility of the modified ventriloquist illusion paradigm.

Real-life, adverse listening conditions involve a great deal of speech variability, including variability in speaking style. Depending on the speaking context, talkers may use a more casual, reduced speaking style or a more formal, careful speaking style. Attending to fine-grained acoustic-phonetic details characterizing different speaking styles facilitates the perception of the speaking style used by the talker. These acoustic-phonetic cues are poorly encoded in cochlear implants (CIs), potentially rendering the discrimination of speaking style difficult. As a first step to characterizing CI perception of real-life speech forms, the present study investigated the perception of different speaking styles in normal-hearing (NH) listeners with and without CI simulation. The discrimination of three speaking styles (conversational reduced speech, speech from retold stories, and carefully read speech) was assessed using a speaking style discrimination task in two experiments. NH listeners classified sentence-length utterances, produced in one of the three styles, as either formal (careful) or informal (conversational). Utterances were presented with unmodified speaking rates in experiment 1 (31 NH, young adult Dutch speakers) and with modified speaking rates set to the average rate across all utterances in experiment 2 (28 NH, young adult Dutch speakers). In both experiments, acoustic noise-vocoder simulations of CIs were used to produce 12-channel (CI-12) and 4-channel (CI-4) vocoder simulation conditions, in addition to a no-simulation condition without CI simulation. In both experiments 1 and 2, NH listeners were able to reliably discriminate the speaking styles without CI simulation. However, this ability was reduced under CI simulation. In experiment 1, participants showed poor discrimination of speaking styles under CI simulation. Listeners used speaking rate as a cue to make their judgements, even though it was not a reliable cue to speaking style in the study materials. In experiment 2, without differences in speaking rate among speaking styles, listeners showed better discrimination of speaking styles under CI simulation, using additional cues to complete the task. The findings from the present study demonstrate that perceiving differences in three speaking styles under CI simulation is a difficult task because some important cues to speaking style are not fully available in these conditions. While some cues like speaking rate are available, this information alone may not always be a reliable indicator of a particular speaking style. Some other reliable speaking styles cues, such as degraded acoustic-phonetic information and variability in speaking rate within an utterance, may be available but less salient. However, as in experiment 2, listeners’ perception of speaking styles may be modified if they are constrained or trained to use these additional cues, which were more reliable in the context of the present study. Taken together, these results suggest that dealing with speech variability in real-life listening conditions may be a challenge for CI users. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

International audience; This article addresses output feedback stabilization of continuous-time nonlinear systems by choosing control actions from a finite set. Working under the assumption that the system under consideration is passive and large-time norm observable, we propose a static feedback mapping, from the output space to the finite set of control actions, which is shown to be practically stabilizing if the convex hull of certain control actions (in the chosen finite set) contains the origin in its interior. Consequently, to construct this stabilizing feedback, it suffices to have, in addition to a zero symbol, another m + 1 elements in the control set which form an m-simplex in R m (the input, and output space).

Technical design features for improving the way a passive elastic filament produces propulsive thrust can be understood by analyzing the deformation of sperm‐templated microrobots with segmented magnetization. Magnetic nanoparticles are electrostatically self‐assembled on bovine sperm cells with nonuniform surface charge, producing different categories of sperm‐templated microrobots. Depending on the amount and location of the nanoparticles on each cellular segment, magnetoelastic and viscous forces determine the wave pattern of each category during flagellar motion. Passively propagating waves are induced along the length of these microrobots using external rotating magnetic fields and the resultant wave patterns are measured. The response of the microrobots to the external field reveals distinct flow fields, propulsive thrust, and frequency responses during flagellar propulsion. This work allows predictions for optimizing the design and propulsion of flexible magnetic microrobots with segmented magnetization., Sperm‐templated flexible magnetic microrobots are categorized based on the location and combination of their magnetic segments. The different magnetization profiles lead to distinct wave patterns once exposed to rotating 3D magnetic fields. This results in a variety of frequency responses, flow fields surrounding the microrobots and propulsive thrust force. The article gives indications for the design of flexible magnetic microrobots.

In the past decade, remote actuation through magnetic fields has been used for position and orientation control of continuum manipulators (CMs) with a single magnet at the distal tip. By leveraging multiple points of actuation along the length of the CM it is possible to achieve increasingly complex shapes, which could be of interest in complex navigation tasks, for example, in minimally invasive surgery. In this study we present an approach for multi-point orientation control of discretely magnetized CMs. The approach is demonstrated with a manipulator that contains two permanent magnets, which are each actuated inside a non-homogeneous magnetic field. We formulate an accurate field model that conforms to Maxwell's equations and apply this to the available actuation system. Furthermore, Cosserat rod theory is used to model the manipulator deformation under external wrenches, and is utilized to numerically compute a Jacobian necessary to calculate the actuation inputs. During experiments, a stereo vision setup is used for manipulator shape feedback. Target orientations are manually provided as input to show independent orientation control of the two permanent magnets. Additionally, simulations with an extended virtual clone of the electromagnetic system are performed to show the capability of achieving more complex manipulator shapes. In both scenarios, it is observed that the algorithm is able to independently control the orientation of two interconnected magnets in a non-uniform magnetic field.

Purpose: To investigate aortic remodeling of the supra- and infrarenal aorta from preoperative to 1 month and midterm follow-up after endovascular aneurysm repair (EVAR) by analyzing changes in angulation and curvature in patients with vs without late type Ia endoleak or device migration. Materials and Methods: From a multicenter database, 35 patients (mean age 76±5 years; 31 men) were identified with late (>1 year) type Ia endoleak or endograft migration (≥10 mm) and defined as the complication group. The control group consisted of 53 patients (mean age 75±7 years; 48 men) with >1-year computed tomography angiography (CTA) follow-up and no evidence of endoleaks. Suprarenal and infrarenal angles were measured on centerline reconstructions of the preoperative, 1-month, and midterm CTA scans. The value and location relative to baseline of maximum suprarenal and infrarenal curvature were determined semiautomatically using dedicated software. Changes were determined at 1 month compared with the preoperative CTA and at midterm compared with 1 month. Results: Preoperative suprarenal angulation was significantly greater in the complication group compared to the controls (34°±18° vs 24°±17°, p=0.008). It decreased significantly at 1 month in the complication group (29°±16°, p=0.011) and at midterm follow-up in the controls (20°±19°, p−1 vs 29±25 m−1, p=0.115). This variable increased significantly through midterm follow-up in the complication group (44±22 m−1) but remained constant in the controls (28±22 m−1). Preoperative infrarenal curvature was significantly greater in the complication group (77±29 m−1 vs 65±28 m−1, p=0.047) and decreased significantly in both groups during midterm follow-up (50±17 m−1 vs 41±19 m−1 p=0.033). The location of the maximum curvature with regard to baseline shifted significantly distally in the complication group (54±43 to 72±41 mm, pConclusion: At midterm follow-up, significant differences in supra- and infrarenal angulation and curvature were observed between patients with vs without type Ia endoleak or migration. The location of the maximum curvature shifted distally in patients with complications. The aortic morphology is more stable during midterm follow-up in the patients without endoleaks.

Purpose To evaluate the effect of three-dimensional virtual pre-operative planning (3DVP) on the incidence of dorsal screw penetration after volar plating of distal radius fractures. Methods A cross-sectional diagnostic imaging study was performed. Twenty out of 50 patients were randomly selected from our index prospective cohort (IPC): a prior study evaluating dorsal tangential views (DTVs) in reducing dorsal screw penetration in internal fixation of intra-articular distal radius fractures using post-operative CT scans to quantify screw protrusion. Pre-operative CTs from this cohort were now used for 3DVP by three experienced orthopaedic trauma surgeons (supplementary video). 3DVP was compared with the corresponding post-operative CT for assessing screw lengths and incidence of dorsal penetration. The Wilcoxon Signed Ranks test was used to compare screw lengths and the Fishers’ exact for incidence of penetration. Results Three surgeons performed 3DVP for 20 distal radius fractures and virtually applied 60 volar plates and 273 screws. Median screw length was shorter in the 3DVP when compared to IPC: 18 mm (range, 12–22) versus 20 mm (range, 14–26) (p p = 0.047). Corresponding to a reduction in incidence of at least one dorsally penetrating screw in 40% of patients in the IPC group, to 18% in the 3DVP group (p = 0.069). Conclusion Three-Dimensional Virtual Pre-Operative Planning (3DVP) may reduce the incidence of dorsally penetrating screws in patients treated with volar plating for intra-articular distal radius fractures. Level of evidence II, diagnostic imaging study.

Background Anastomotic leakage in patients undergoing colorectal surgery is associated with morbidity and mortality. Although multiple risk factors have been identified, the underlying mechanisms are mainly unknown. The aim of this study was to perform a transcriptome analysis of genes underlying the development of anastomotic leakage. Methods A set of human samples from the anastomotic site collected during stapled colorectal anastomosis were used in the study. Transcriptomic profiles were generated for patients who developing anastomotic leakage and case-matched controls with normal anastomotic healing to identify genes and biological processes associated with the development of anastomotic leakage. Results The analysis included 22 patients with and 69 without anastomotic leakage. Differential expression analysis showed that 44 genes had adjusted P < 0.050, consisting of two upregulated and 42 downregulated genes. Co-functionality analysis of the 150 most upregulated and 150 most downregulated genes using the GenetICA framework showed formation of clusters of genes with different enrichment for biological pathways. The enriched pathways for the downregulated genes are involved in immune response, angiogenesis, protein metabolism, and collagen cross-linking. The enriched pathways for upregulated genes are involved in cell division. Conclusion These data indicate that patients who develop anastomotic leakage start the healing process with an error at the level of gene regulation at the time of surgery. Despite normal macroscopic appearance during surgery, the transcriptome data identified several differences in gene expression between patients who developed anastomotic leakage and those who did not. The expressed genes and enriched processes are involved in the different stages of wound healing. These provide therapeutic and diagnostic targets for patients at risk of anastomotic leakage.

This paper introduces and validates a real-time dynamic predictive model based on a neural network approach for soft continuum manipulators. The presented model provides a real-time prediction framework using neural-network-based strategies and continuum mechanics principles. A time-space integration scheme is employed to discretize the continuous dynamics and decouple the dynamic equations for translation and rotation for each node of a soft continuum manipulator. Then the resulting architecture is used to develop distributed prediction algorithms using recurrent neural networks. The proposed RNN-based parallel predictive scheme does not rely on computationally intensive algorithms; therefore, it is useful in real-time applications. Furthermore, simulations are shown to illustrate the approach performance on soft continuum elastica, and the approach is also validated through an experiment on a magnetically-actuated soft continuum manipulator. The results demonstrate that the presented model can outperform classical modeling approaches such as the Cosserat rod model while also shows possibilities for being used in practice.

Background: Differences in patient demographics and disease burden can influence comparison of hospital performances. This study aimed to provide a case-mix model to compare short-term postoperative outcomes for patients undergoing liver resection for colorectal liver metastases (CRLM).Methods: This retrospective, population-based study included all patients who underwent liver resection for CRLM between 2014 and 2018 in the Netherlands. Variation in case-mix variables between hospitals and influence on postoperative outcomes was assessed using multivariable logistic regression. Primary outcomes were 30-day major morbidity and 30-day mortality. Validation of results was performed on the data from 2019.Results: In total, 4639 patients were included in 28 hospitals. Major morbidity was 6.2% and mortality was 1.4%. Uncorrected major morbidity ranged from 3.3% to 13.7% and mortality ranged from 0.0% to 5.0%. between hospitals. Significant differences between hospitals were observed for age higher than 80 (0.0%-17.1%, p < 0.001), ASA 3 or higher (3.3%-36.3%, p < 0.001), histopathological parenchymal liver disease (0.0%-47.1%, p < 0.001), history of liver resection (8.1%-36.3%, p < 0.001), major liver resection (6.7%-38.0%, p < 0.001) and synchronous metastases (35.5%-62.1%, p < 0.001). Expected 30-day major morbidity between hospitals ranged from 6.4% to 11.9% and expected 30-day mortality ranged from 0.6% to 2.9%. After case-mix correction no significant outliers concerning major morbidity and mortality remained. Validation on patients who underwent liver resection for CRLM in 2019 affirmed these outcomes.Conclusion: Case-mix adjustment is a prerequisite to allow for institutional comparison of short-term postoperative outcomes after liver resection for CRLM. (C) 2020 University Medical Center Groningen. Published by Elsevier Ltd.

Flow sensors found in animals often feature soft and slender structures (e.g. fish neuromasts, insect hairs, mammalian stereociliary bundles, etc) that bend in response to the slightest flow disturbances in their surroundings and heighten the animal’s vigilance with respect to prey and/or predators. However, fabrication of bioinspired flow sensors that mimic the material properties (e.g. low elastic modulus) and geometries (e.g. high-aspect ratio (HAR) structures) of their biological counterparts remains a challenge. In this work, we develop a facile and low-cost method of fabricating HAR cantilever flow sensors inspired by the mechanotransductory flow sensing principles found in nature. The proposed workflow entails high-resolution 3D printing to fabricate the master mould, replica moulding to create HAR polydimethylsiloxane (PDMS) cantilevers (thickness = 0.5–1 mm, width = 3 mm, aspect ratio = 20) with microfluidic channel (150 μm wide × 90 μm deep) imprints, and finally graphene nanoplatelet ink drop-casting into the microfluidic channels to create a piezoresistive strain gauge near the cantilever’s fixed end. The piezoresistive flow sensors were tested in controlled airflow (0–9 m s−1) inside a wind tunnel where they displayed high sensitivities of up to 5.8 kΩ m s−1, low hysteresis (11% of full-scale deflection), and good repeatability. The sensor output showed a second order dependence on airflow velocity and agreed well with analytical and finite element model predictions. Further, the sensor was also excited inside a water tank using an oscillating dipole where it was able to sense oscillatory flow velocities as low as 16–30 μm s−1 at an excitation frequency of 15 Hz. The methods presented in this work can enable facile and rapid prototyping of flexible HAR structures that can find applications as functional biomimetic flow sensors and/or physical models which can be used to explain biological phenomena.

Purpose The purpose of this paper is to present and validate a new semi-automated 3D surface mesh segmentation approach that optimizes the laborious individual human vertebrae separation in the spinal virtual surgical planning workflow and make a direct accuracy and segmentation time comparison with current standard segmentation method. Methods The proposed semi-automatic method uses the 3D bone surface derived from CT image data for seed point-based 3D mesh partitioning. The accuracy of the proposed method was evaluated on a representative patient dataset. In addition, the influence of the number of used seed points was studied. The investigators analyzed whether there was a reduction in segmentation time when compared to manual segmentation. Surface-to-surface accuracy measurements were applied to assess the concordance with the manual segmentation. Results The results demonstrated a statically significant reduction in segmentation time, while maintaining a high accuracy compared to the manual segmentation. A considerably smaller error was found when increasing the number of seed points. Anatomical regions that include articulating areas tend to show the highest errors, while the posterior laminar surface yielded an almost negligible error. Conclusion A novel seed point initiated surface based segmentation method for the laborious individual human vertebrae separation was presented. This proof-of-principle study demonstrated the accuracy of the proposed method on a clinical CT image dataset and its feasibility for spinal virtual surgical planning applications.

Magnetically-driven screws operating in softtissue environments could be used to deploy localized therapy or achieve minimally invasive interventions. In this work, we characterize the closed-loop behavior of magnetic screws inan agar gel tissue phantom using a permanent magnet-based robotic system with an open-configuration. Our closed-loop control strategy capitalizes on an analytical calculation of the swimming speed of the screw in viscoelastic fluids and the magnetic point-dipole approximation of magnetic fields. Theanalytical solution is based on the Stokes/Oldroyd-B equations and its predictions are compared to experimental results at different actuation frequencies of the screw. Our measurements matches the theoretical prediction of the analytical model before the step-out frequency of the screw owing to the linearity of the analytical model. We demonstrate open-loop control intwo-dimensional space, and point-to-point closed-loop motion control of the screw (length and diameter of 6 mm and 2 mm, respectively) with maximum positioning error of 1.8 mm.

Earlier studies have shown that musically trained individuals may have a benefit in adverse listening situations when compared to non-musicians, especially in speech-on-speech perception. However, the literature provides mostly conflicting results. In the current study, by employing different measures of spoken language processing, we aimed to test whether we could capture potential differences between musicians and non-musicians in speech-on-speech processing. We used an offline measure of speech perception (sentence recall task), which reveals a post-task response, and online measures of real time spoken language processing: gaze-tracking and pupillometry. We used stimuli of comparable complexity across both paradigms and tested the same groups of participants. In the sentence recall task, musicians recalled more words correctly than non-musicians. In the eye-tracking experiment, both groups showed reduced fixations to the target and competitor words’ images as the level of speech maskers increased. The time course of gaze fixations to the competitor did not differ between groups in the speech-in-quiet condition, while the time course dynamics did differ between groups as the two-talker masker was added to the target signal. As the level of two-talker masker increased, musicians showed reduced lexical competition as indicated by the gaze fixations to the competitor. The pupil dilation data showed differences mainly in one target-to-masker ratio. This does not allow to draw conclusions regarding potential differences in the use of cognitive resources between groups. Overall, the eye-tracking measure enabled us to observe that musicians may be using a different strategy than non-musicians to attain spoken word recognition as the noise level increased. However, further investigation with more fine-grained alignment between the processes captured by online and offline measures is necessary to establish whether musicians differ due to better cognitive control or sound processing.

Using recent results on the incremental stability analysis via contraction and on internal model principle, we revisit the pinning synchronization problem in nonlinear multi-agent systems (MAS). We provide sufficient and necessary conditions for both the pinned agents as well as the rest of the agents to guarantee the state synchronization. For the non-pinned agents, we present a distributed control framework based only on the relative local state measurement and we give sufficient conditions for the contractivity of the individual virtual systems in order to achieve pinning synchronization. Numerical simulation is given to illustrate the main results.

Image vectorisation methods proposed in the past have not seen wide adoption due to performance, quality, controllability, and/or generality issues.We present a vectorisation method that uses mesh colours as a vector primitive for image vectorisation. We show that mesh colours have clear benefits for rendering performance and texture detail. Due to their flexibility, they also enable a simplified and more efficient generation of meshes of curved triangular patches, which are in our case constrained by our image feature extraction algorithm. The proposed method follows a standard pipeline where each step is efficient and controllable, leading to results that compare favourably with those from previous work. We show results over a variety of input images including photos, drawings, paintings, designs, and cartoons and also devise a user-guided vectorisation variant.

In this letter, we investigate the formation control problem of mobile robots moving in the plane where, instead of assuming robots to be simple points, each robot is assumed to have the form of a disk with equal radius. Based on interior angle measurements of the neighboring robots' disk, which can be obtained from low-cost vision sensors, we propose a gradient-based distributed control law and show the exponential convergence property of the associated error system. By construction, the proposed control law has the appealing property of ensuring collision avoidance between neighboring robots. We also present simulation results for {a team} of four circular mobile robots forming a rectangular shape., 6 pages, submitted to the 59th IEEE Conf. Dec. Control and IEEE Control Systems Letters

Objectives:Speech intelligibility in the presence of a competing talker (speech-on-speech; SoS) presents more difficulties for cochlear implant (CI) users compared with normal-hearing listeners. A recent study implied that these difficulties may be related to CI users' low sensitivity to two fundamental voice cues, namely, the fundamental frequency (F0) and the vocal tract length (VTL) of the speaker. Because of the limited spectral resolution in the implant, important spectral cues carrying F0 and VTL information are expected to be distorted. This study aims to address two questions: (1) whether spectral contrast enhancement (SCE), previously shown to enhance CI users' speech intelligibility in the presence of steady state background noise, could also improve CI users' SoS intelligibility, and (2) whether such improvements in SoS from SCE processing are due to enhancements in CI users' sensitivity to F0 and VTL differences between the competing talkers.Design:The effect of SCE on SoS intelligibility and comprehension was measured in two separate tasks in a sample of 14 CI users with Cochlear devices. In the first task, the CI users were asked to repeat the sentence spoken by the target speaker in the presence of a single competing talker. The competing talker was the same target speaker whose F0 and VTL were parametrically manipulated to obtain the different experimental conditions. SoS intelligibility, in terms of the percentage of correctly repeated words from the target sentence, was assessed using the standard advanced combination encoder (ACE) strategy and SCE for each voice condition. In the second task, SoS comprehension accuracy and response times were measured using the same experimental setup as in the first task, but with a different corpus. In the final task, CI users' sensitivity to F0 and VTL differences were measured for the ACE and SCE strategies. The benefit in F0 and VTL discrimination from SCE processing was evaluated with respect to the improvement in SoS perception from SCE.Results:While SCE demonstrated the potential of improving SoS intelligibility in CI users, this effect appeared to stem from SCE improving the overall signal to noise ratio in SoS rather than improving the sensitivity to the underlying F0 and VTL differences. A second key finding of this study was that, contrary to what has been observed in a previous study for childlike voice manipulations, F0 and VTL manipulations of a reference female speaker (target speaker) toward male-like voices provided a small but significant release from masking for the CI users tested.Conclusions:The present findings, together with those previously reported in the literature, indicate that SCE could serve as a possible background-noise-reduction strategy in commercial CI speech processors that could enhance speech intelligibility especially in the presence of background talkers that have longer VTLs compared with the target speaker.

Objectives: Aim of this work was to investigate precision of deployment and conformability of a new generation GORE EXCLUDER Conformable Endoprosthesis with active control system (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) by analyzing aortic neck coverage and curvature. Methods: All consecutive elective patients affected by abdominal aortic aneurysm or aortoiliac aneurysm treated at our institution between November 2018 and June 2019 with the new CEXC Device were enrolled. Validated software was adopted to determine the available apposition surface area into the aortic neck, apposition of the endograft to the aortic wall, shortest apposition length (SAL), shortest distance between the endograft fabric and the lowest renal arteries (SFD) and between the endograft fabric and the contralateral renal artery (CFD). Pointwise centerline curvature was also computed. Results: Twelve patients (10 men, median age 78 years (71.75, 81.0)) with available pre- and postoperative computed tomography angiography (CTA) were included. Technical success was obtained in all the cases. Preoperative median length of the proximal aortic neck was 16.1 mm (10.7, 21.7) and suprarenal (α) and infrarenal (β) neck angulation were, respectively, 28.9° (15.7°, 47.5°) and 75.0° (66.9°, 81.4°). Postoperative median apposition surface coverage was 79% (69.25%, 90.75%) of the available apposition surface. SFD and CFD were 1.5 mm (0.75, 5.25) and 7 mm (4.5, 21.5), respectively. Average curvature over the infrarenal aorta decreased from 25 m−1 (21.75, 29.0) to 22.5 m−1 (18.75, 24.5) postoperatively (p=0.02). Maximum curvature did not decrease significantly from 64.5 m−1 (54.25, 92.0) to 62 m−1 (41.75, 71.5) (p=0.1). Conclusions: Our early experience showed that deployment of the CEXC Device is safe and effective for patients with challenging proximal aortic necks. Absence of significant changes between pre- and postoperative proximal aortic neck angulations and curvature confirms the high conformability of this endograft.

We present the design of H_inf Fault Detection Filter (FDF) for Discrete-time Markov Jump Lur'e Systems with bounded sector condition based on the use of Linear Matrix Inequality (LMI). A numerical example is presented to illustrate the effectiveness of the proposed approach.

Contains fulltext : 239393.pdf (Publisher’s version ) (Open Access) The assessment of gaps and steps in acetabular fractures is challenging. Data from various imaging techniques to enable accurate quantification of acetabular fracture displacement are limited. The aim of this study was to assess the accuracy of pelvic radiographs, intraoperative fluoroscopy, and computed tomography (CT) in detecting gaps and step-offs in acetabular fractures. Sixty patients, surgically treated for acetabular fractures, were included. Five observers (5400 measurements) measured the gaps and step-offs on radiographs and CT scans. Intraoperative fluoroscopy images were reassessed for the presence of gaps and/or step-offs. Preoperatively, 25% of the gaps and 40% of the step-offs were undetected on radiographs compared to CT. Postoperatively, 52% of the gaps and 80% of the step-offs were missed on radiographs compared to CT. Radiograph analysis led to a significantly smaller gap and step-off compared to the CT measurements, an underestimation by a factor of two. Approximately 70% of the residual gaps and step-offs was not detected using intraoperative fluoroscopy. Gaps and step-offs that exceed the critical cut-off indicating worse prognosis often remained undetected on radiographs compared to CT scans. Less-experienced observers tend to overestimate gaps and step-offs compared to the more-experienced observers. In acetabular fracture treatment, gaps and step-offs were often undetected and underestimated on radiographs and intraoperative fluoroscopy in comparison with CT scans. This means that CT is superior to radiographs in detecting acetabular fracture displacement, which is clinically relevant for patient counselling regarding treatment decisions and prognosis.

Since emotion recognition involves integration of the visual and auditory signals, it is likely that sensory impairments worsen emotion recognition. In emotion recognition, young adults can compensate for unimodal sensory degradations if the other modality is intact. However, most sensory impairments occur in the elderly population and it is unknown whether older adults are similarly capable of compensating for signal degradations. As a step towards studying potential effects of real sensory impairments, this study examined how degraded signals affect emotion recognition in older adults with normal hearing and vision. The degradations were designed to approximate some aspects of sensory impairments. Besides emotion recognition accuracy, we recorded eye movements to capture perceptual strategies for emotion recognition. Overall, older adults were as good as younger adults at integrating auditory and visual information and at compensating for degraded signals. However, accuracy was lower overall for older adults, indicating that aging leads to a general decrease in emotion recognition. In addition to decreased accuracy, older adults showed smaller adaptations of perceptual strategies in response to video degradations. Concluding, this study showed that emotion recognition declines with age, but that integration and compensation abilities are retained. In addition, we speculate that the reduced ability of older adults to adapt their perceptual strategies may be related to the increased time it takes them to direct their attention to scene aspects that are relatively far away from fixation.

International audience; Perception tasks that require long and frequent testing can result in a loss of attention and focus, contributing to erroneous and inconsistent data. To maintain engagement and improve reliability of data, a more interactive interface could be used. This study aims to investigate if a humanoid NAO robot could provide such an interface to improve or maintain engagement during testing. More specifically, human-robot interaction (HRI) will be explored when performing various auditory perception tasks, played in the form of games, on the NAO robot. Evaluation of the HRI will be performed using questionnaires derived from the system usability, Godspeed, and similarityattraction scales, as well as through video analysis. Future research will extend the evaluation of the HRI to children and aim to further improve the engagement and social acceptability of the NAO robot as a game interface.

Medial descriptors offer a promising way for representing, simplifying, manipulating, and compressing images. However, to date, these have been applied in a global manner that is oblivious to salient features. In this paper, we adapt medial descriptors to use the information provided by saliency maps to selectively simplify and encode an image while preserving its salient regions. This allows us to improve the trade-off between compression ratio and image quality as compared to the standard dense-skeleton method while keeping perceptually salient features, in a focus-and-context manner. We show how our method can be combined with JPEG to increase overall compression rates at the cost of a slightly lower image quality. We demonstrate our method on a benchmark composed of a broad set of images.

Background The optimal timing of resection after decompression of left-sided obstructive colon cancer is unknown. Revised expert-based guideline recommendations have shifted from an interval of 5 – 10 days to approximately 2 weeks following self-expandable metal stent (SEMS) placement, and recommendations after decompressing stoma are lacking. We aimed to evaluate the recommended bridging intervals after SEMS and explore the timing of resection after decompressing stoma. Methods This nationwide study included patients registered between 2009 and 2016 in the prospective, mandatory Dutch ColoRectal Audit. Additional data were collected through patient records in 75 hospitals. Only patients who underwent either SEMS placement or decompressing stoma as a bridge to surgery were selected. Technical SEMS failure and unsuccessful decompression within 48 hours were exclusion criteria. Results 510 patients were included (182 SEMS, 328 decompressing stoma). Median bridging interval was 23 days (interquartile range [IQR] 13 – 31) for SEMS and 36 days (IQR 22 – 65) for decompressing stoma. Following SEMS placement, no significant differences in post-resection complications, hospital stay, or laparoscopic resections were observed with resection after 11 – 17 days compared with 5 – 10 days. Of SEMS-related complications, 48 % occurred in patients operated on beyond 17 days. Compared with resection within 14 days, an interval of 14 – 28 days following decompressing stoma resulted in significantly more laparoscopic resections, more primary anastomoses, and shorter hospital stays. No impact of bridging interval on mortality, disease-free survival, or overall survival was demonstrated. Conclusions Based on an overview of the data with balancing of surgical outcomes and timing of adverse events, a bridging interval of approximately 2 weeks seems appropriate after SEMS placement, while waiting 2 – 4 weeks after decompressing stoma further optimizes surgical conditions for laparoscopic resection with restoration of bowel continuity.

We tackle the fault accommodation control (FAC) in the Markovian jump linear system (MJLS) framework for the discrete-time domain, under the assumption that it is not possible to access the Markov chain mode. This premise brings some challenges since the controllers are no longer allowed to depend on the Markov chain, meaning that there is an asynchronism between the system and the controller modes. To tackle this issue, a hidden Markov chain ((Formula presented.), (Formula presented.)) is used where θ(k) denotes the Markov chain mode, and (Formula presented.) denotes the estimated mode. The main novelty of this work is the design of H∞ and H2 FAC under the MJLS framework considering partial observation of the Markov chain. Both designs are obtained via bilinear matrix inequalities optimization problems, which are solved using coordinate descent algorithm. As secondary results, we present simulations using a two-degree of freedom serial flexible joint robot to illustrate the viability of the proposed approach.

Background Currently, there is no consensus regarding the best treatment option in recurrent haemorrhoidal disease (HD), due to a lack of solid evidence. The Napoleon trial aims to provide high-level evidence on the comparative effectiveness and cost-effectiveness of repeat rubber band ligation (RBL) versus sutured mucopexy versus haemorrhoidectomy in patients with recurrent HD. Methods This is a multicentre randomized controlled trial. Patients with recurrent HD grade II and III, ≥18 years of age and who had at least two RBL treatments in the last three years are eligible for inclusion. Exclusion criteria include previous rectal or anal surgery, rectal radiation, pre-existing sphincter injury or otherwise pathologies of the colon and rectum, pregnancy, presence of hypercoagulability disorders, and medically unfit for surgery (ASA > III). Between June 2020 and May 2022, 558 patients will be randomized to receive either: (1) RBL, (2) sutured mucopexy, or (3) haemorrhoidectomy. The primary outcomes are recurrence after 52 weeks and patient-reported symptoms measured by the PROM-HISS. Secondary outcomes are impact on daily life, treatment satisfaction, early and late complication rates, health-related quality of life, costs and cost-effectiveness, and budget impact. Cost-effectiveness will be expressed in societal costs per Quality Adjusted Life Year (QALY) (based on EQ-5D-5L), and healthcare costs per recurrence avoided. Discussion The best treatment option for recurrent HD remains unknown. The comparison of three generally accepted treatment strategies in a randomized controlled trial will provide high-level evidence on the most (cost-) effective treatment. Trial registration ClinicalTrials.gov identifier: NCT04101773

Continuum robots have the potential to form an effective interface between the patient and surgeon in minimally invasive procedures. Magnetic actuation has the potential for accurate catheter steering, reducing tissue trauma and decreasing radiation exposure. In this paper, a new design of a monolithic metallic compliant continuum manipulator is presented, with flexures for precise motion. Contactless actuation is achieved using time-varying magnetic fields generated by an array of electromagnetic coils. The motion of the manipulator under magnetic actuation for planar deflection is studied. The mean errors of the theoretical model compared to experiments over three designs are found to be 1.9 mm and 5.1 deg in estimating the in-plane position and orientation of the tip of the manipulator, respectively, and 1.2 mm for the whole shape of the manipulator. Maneuverability of the manipulator is demonstrated by steering it along a path of known curvature and also through a gelatin phantom, which is visualized in real time using ultrasound imaging, substantiating its application as a steerable surgical manipulator.

Much of the costs and dangers of exposure therapy in phobia treatment can be removed through virtual reality (VR). Exposing people to heights, for instance, might sound easy, but it still involves time and money investments to reach a tall building, mountain or bridge. People suffering from milder forms of acrophobia might not even be treated at all, the cost not being worth it. This paper presents a prototype that allows exposure therapy to be done in a controlled environment, in a more comfortable, quick and cheaper way. By applying acrophobia questionnaires, collecting biophysical data and developing a virtual reality game, we can expose volunteers to heights and analyze if there is any change in their fear and anxiety levels. This way, regardless of the initial anxiety level and phobia severity, we can check if there is any post-therapy improvement and verify if virtual reality is a viable alternative to real-world exposure.

Speech intelligibility in multitalker settings is challenging for most cochlear implant (CI) users. One possibility for this limitation is the suboptimal representation of vocal cues in implant processing, such as the fundamental frequency (F0), and the vocal tract length (VTL). Previous studies suggested that while F0 perception depends on spectrotemporal cues, VTL perception relies largely on spectral cues. To investigate how spectral smearing in CIs affects vocal cue perception in speech-on-speech (SoS) settings, adjacent electrodes were simultaneously stimulated using current steering in 12 Advanced Bionics users to simulate channel interaction. In current steering, two adjacent electrodes are simultaneously stimulated forming a channel of parallel stimulation. Three such stimulation patterns were used: Sequential (one current steering channel), Paired (two channels), and Triplet stimulation (three channels). F0 and VTL just-noticeable differences (JNDs; Task 1), in addition to SoS intelligibility (Task 2) and comprehension (Task 3), were measured for each stimulation strategy. In Tasks 2 and 3, four maskers were used: the same female talker, a male voice obtained by manipulating both F0 and VTL (F0+VTL) of the original female speaker, a voice where only F0 was manipulated, and a voice where only VTL was manipulated. JNDs were measured relative to the original voice for the F0, VTL, and F0+VTL manipulations. When spectral smearing was increased from Sequential to Triplet, a significant deterioration in performance was observed for Tasks 1 and 2, with no differences between Sequential and Paired stimulation. Data from Task 3 were inconclusive. These results imply that CI users may tolerate certain amounts of channel interaction without significant reduction in performance on tasks relying on voice perception. This points to possibilities for using parallel stimulation in CIs for reducing power consumption.

International audience; We study the relationship between the global exponential stability of an invariant manifold and the existence of a semi-definite positive Riemannian metric which is contracted by the flow. In particular, we investigate how the following properties are related to each other (in the global case): i). A manifold is globally ‘‘transversally’' exponentially stable; ii). The corresponding variational system (c.f. (8) in Section II) admits the same property; iii). There exists a degenerate Riemannian metric which is contracted by the flow and can be used to construct a Lyapunov function. We show that the transverse contraction rate being larger than the expansion of the shadow on the manifold is a sufficient condition for the existence of such a Lyapunov function. An illustration of these tools is given in the context of global full-order observer design.

After infrainguinal endovascular treatment for peripheral arterial disease (PAD), it is uncertain whether single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT) should be preferred. This study investigated major adverse limb events (MALE) and major adverse cardiovascular events (MACE) between patients receiving SAPT and DAPT. Patient data from three centers in the Netherlands were retrospectively collected and analyzed. All patients treated for PAD by endovascular revascularization of the superficial femoral, popliteal, or below-the-knee (BTK) arteries and who were prescribed acetylsalicylic acid or clopidogrel, were included. End points were 1-, 3-, and 12-month MALE and MACE, and bleeding complications. In total, 237 patients (258 limbs treated) were included, with 149 patients receiving SAPT (63%) and 88 DAPT (37%). No significant differences were found after univariate and multivariate analyses between SAPT and DAPT on 1-, 3-, and 12-month MALE and MACE, or bleeding outcomes. Subgroup analyses of patients with BTK treatment showed a significantly lower 12-month MALE rate when treated with DAPT (hazard ratio 0.33, 95% confidence interval 0.12&ndash, 0.95, p = 0.04). In conclusion, although patient numbers were small, no differences were found between SAPT and DAPT regarding MALE, MACE, or bleeding complications. DAPT should, however, be considered over SAPT for the subgroup of patients with below-the-knee endovascular treatment.

Ultra-high vacuum chemical vapor deposition is a thin film deposition process that features excellent film purity, but is sensitive to the processing variations (such as, the precursors and their dispensers, the reactor’s initial condition, etc.). In this paper, we present the design of a ultra-high vacuum chemical vapor deposition reactor with in situ partial pressure atomic absorption spectroscopy measurement that improves reproducibility and observability of such a process. Our main contributions are: (i) a conceptual control systems design of ultra-high vacuum chemical vapor deposition; (ii) atomic absorption spectroscopy based sensor design for the real-time in situ partial pressure measurements; (iii) a flux dynamical model; (iv) experimental reactor design; and (v) experimental validation of model components and the atomic absorption spectroscopy measurement technique. Our results show that the proposed sensor systems are able to provide real-time measurements of the partial pressure inside the reactor and our proposed flux dynamical model agrees with the measured partial pressure. The latter allows us to use it in the design of model-based output feedback control of the partial pressure.

Advancements in medical microrobotics have given rise to an abundance of agents capable of localised interaction with human body in small scales. Nevertheless, clinically-relevant applications of this technology are still limited by the auxiliary infrastructure required for actuation of micro-agents. In this letter, we approach this challenge. Using finite-element analysis, we show that miniaturization of electromagnets can be used to create systems capable of providing magnetic forces adequate for micro-agent steering, while retaining small footprint and power consumption. We use these observations to create MILiMAC (Microrobotic Infrastructure Loaded into Magnetically-Actuated Catheter). MILiMAC is a flexible catheter employing three miniaturized electromagnets to provide localized magnetic actuation at the deeply-seated microsurgery site. We test our approach in a proof-of-concept study deploying MILiMAC inside a test platform to deliver and steer a 600 [\boldsymbol{\mu }m] ferromagnetic microbead. The bead is steered along a set of user-defined trajectories using closed-loop position control. Across all trajectories the best performance metrics are the mean error of 0.41 [mm] and the steady-state error of 0.27 [mm].

We propose a generalised B-spline construction that extends uniform bicubic B-splines to multisided regions spanned over extraordinary vertices in quadrilateral meshes. We show how the structure of the generalised Bezier patch introduced by Varady et al. can be adjusted to work with B-spline basis functions. We create ribbon surfaces based on B-splines using special basis functions. The resulting multisided surfaces are C-2 continuous internally and connect with G(2) continuity to adjacent regular and other multisided B-splines patches. We visually assess the quality of these surfaces and compare them to Catmull-Clark limit surfaces on several challenging geometrical configurations. (C) 2020 The Author(s). Published by Elsevier Ltd.

Lindenmayer systems (L-systems) have been developed to model plant growth by repeatedly applying production rules to an initial axiom, and serve as a model for genetically driven growth processes found in nature. A simulation method is proposed to evolve their phenotypic representations through competition in a heterogeneous environment to further expand on this biological analogy. The resulting simulations demonstrate evolution driven by competition, resulting in agents employing strategies similar to those found in nature.

Accurate navigation of flexible medical instruments like catheters require the knowledge of its pose, that is its position and orientation. In this paper multi-core fibers inscribed with fiber Bragg gratings (FBG) are utilized as sensors to measure the pose of a multi-segment catheter. A reconstruction technique that provides the pose of such a fiber is presented. First, the measurement from the Bragg gratings are converted to strain then the curvature is deduced based on those strain calculations. Next, the curvature and the Bishop frame equations are used to reconstruct the fiber. This technique is validated through experiments where the mean error in position and orientation is observed to be less than 4.69 mm and 6.48 degrees, respectively. The main contributions of the paper are the use of Bishop frames in the reconstruction and the experimental validation of the acquired pose.

The rapid spread of COVID-19 has changed the global surgical care. Patients infected with COVID-19 may present without typical symptoms, and such asymptomatic patients may potentially trigger in-hospital outbreaks by transmitting the disease to health care providers and other hospitalized patients. Further, asymptomatic COVID-19 patients have worse postop- erative outcomes with an unexpectedly high morbidity and mortality, reaching 20⋅5 per cent deaths. However, we do not have objective global data on this issue. In an attempt to clarify the current global surgical practice under the COVID-19 pandemic particularly focusing on the preoperative screening of asymptomatic COVID-19 patients, we conducted a cross-sectional online survey on surgical practice. The survey was administered to surgeons worldwide through international surgical societies, social media and personal contacts dur- ing 2 April to 8 April. The results were analyzed by country’s cumulative deaths number by 8 April, 2020 (high risk, >5000; intermediate risk, 100-5000; low risk

BACKGROUND Long-term data on robot-assisted sacrocolporectopexy for the treatment of multicompartment pelvic organ prolapse are scarce. With the rising prevalence of prolapse and increasing surgical repair, it is essential to evaluate long-term results. OBJECTIVE This study aimed to evaluate long-term functional and anatomic outcomes after sacrocolporectopexy. DESIGN This is a prospective, observational cohort study. SETTINGS This study was conducted at a teaching hospital with tertiary referral function for patients with gynecological/rectal prolapse. PATIENTS All patients undergoing robot-assisted sacrocolporectopexy from 2011 to 2012 were included. INTERVENTION Robot-assisted sacrocolporectopexy was performed. MAIN OUTCOME MEASURES The primary outcome was the anatomic cure rate after 1 and 4 years, defined as simplified pelvic organ prolapse quantification stage 1 vaginal apical prolapse and no external rectal prolapse or internal rectal prolapse present. Kaplan-Meier curves were used for determination of recurrence-free intervals. Secondary outcomes were functional pelvic floor symptoms (symptoms of bulge, obstructed defecation, fecal incontinence, urogenital distress inventory) and quality of life (Pelvic Floor Impact Questionnaire). RESULTS Fifty-three patients were included. After 12 and 48 months, the recurrence-free intervals based on Kaplan-Meier estimates were 100% and 90%. In total, there were 10 recurrences: 2 apical and 8 internal rectal prolapses. Symptoms of bulge (94%-12%; p < 0.0005), fecal incontinence (62%-32%; p < 0.0005), obstructed defecation (59%-24%; p = 0.008), and median Pelvic Floor Impact Questionnaire scores (124-5; p = 0.022) improved significantly at final follow-up. Median urogenital distress inventory scores showed improvement after 1 year (30-13; p = 0.021). LIMITATIONS This was an observational, single-center study with selective postoperative imaging. CONCLUSIONS Ninety percent of patients were recurrence free 48 months after robot-assisted sacrocolporectopexy. Symptoms of vaginal bulge, quality of life, constipation, and fecal incontinence improved significantly. However, a subgroup of patients showed persistent bowel complaints that underlie the complexity of multicompartment prolapse. See Video Abstract at http://links.lww.com/DCR/B265. RESULTADOS ANATOMICOS Y FUNCIONALES A LARGO PLAZO DE LA CIRUGIA DE PISO PELVICO ASISTIDA POR ROBOT EN EL TRATAMIENTO DEL PROLAPSO MULTICOMPARTIMENTAL: UN ESTUDIO PROSPECTIVO: Los datos a largo plazo sobre la sacrocolporectopexia asistida por robot para el tratamiento del prolapso multicompartimental de organos pelvicos son escasos. Con el aumento de la prevalencia del prolapso y el aumento de la reparacion quirurgica, es esencial evaluar los resultados a largo plazo.Evaluar los resultados funcionales y anatomicos a largo plazo despues de la sacrocolporectopexia.Estudio prospectivo observacional de cohorte.Hospital de ensenanza con funcion de referencia terciaria para pacientes con prolapso ginecologico/rectal.Todos los pacientes sometidos a sacrocolporectopexia asistida por robot en 2011-2012.Sacrocolporectopexia asistida por robot.El resultado primario fue la tasa de curacion anatomica a uno y cuatro anos, definida como etapa 1 de prolapso apical vaginal en la cuantificacion del prolapso de organos pelvicos simplificado, y sin prolapso rectal externo o prolapso rectal interno presentes. Se utilizaron curvas de Kaplan Meier para determinar los intervalos libres de recurrencia. Los resultados secundarios fueron sintomas funcionales del piso pelvico (sintomas de abultamiento, obstruccion defecatoria, incontinencia fecal, inventario de molestias urogenitales) y calidad de vida (cuestionario de impacto del piso pelvico).Se incluyeron 53 pacientes. Despues de 12 y 48 meses, el intervalo libre de recurrencia basado en las estimaciones con metodo Kaplan Meier fue del 100% y 90%, respectivamente. En total hubo diez recurrencias: dos apicales y ocho prolapsos rectales internos. Los sintomas de abultamiento (94% a 12%; p

Introduction: Definitions regarding resectability and hence indications for preoperative chemotherapy vary. Use of preoperative chemotherapy may influence postoperative outcomes. This study aimed to assess the variation in use of preoperative chemotherapy for CRLM and related postoperative outcomes in the Netherlands.Materials and methods: All patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were included from a national database. Case-mix factors contributing to the use of preoperative chemotherapy, hospital variation and postoperative outcomes were assessed using multivariable logistic regression. Postoperative outcomes were postoperative complicated course (PCC), 30day morbidity and 30-day mortality.Results: In total, 4469 patients were included of whom 1314 patients received preoperative chemotherapy and 3155 patients did not. Patients receiving chemotherapy were significantly younger (mean age (+SD) 66.3 (10.4) versus 63.2 (10.2) p < 0.001) and had less comorbidity (Charlson scores 2+ (24% versus 29%, p = 0.010). Unadjusted hospital variation concerning administration of preoperative chemotherapy ranged between 2% and 55%. After adjusting for case-mix factors, three hospitals administered significantly more preoperative chemotherapy than expected and six administered significantly less preoperative chemotherapy than expected. PCC was 12.1%, 30-day morbidity was 8.8% and 30-day mortality was 1.5%. No association between preoperative chemotherapy and PCC (OR 1.24, 0.98-1.55, p = 0.065), 30-day morbidity (OR 1.05, 0.81-1.39, p = 0.703) or with 30-day mortality (OR 1.22, 0.75-2.09, p = 0.467) was found.Conclusion: Significant hospital variation in the use of preoperative chemotherapy for CRLM was present in the Netherlands. No association between postoperative outcomes and use of preoperative chemotherapy was found. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Percutaneous deep venous arterialization (pDVA) is a developing technique for limb salvage in patients with chronic limb-threatening ischemia by creating an arteriovenous (AV) circuit. After pDVA, patency of the AV circuit is evaluated using duplex ultrasound (DUS) imaging. Peak systolic velocity (PSV) and volume flow (VF) values for maintaining a patent AV circuit are undefined, therefore, guidance about when a reintervention should be performed is lacking. The objective of this study was to interpret post-pDVA PSV and VF values in relation to AV circuit preservation. This was performed by analyzing DUS results of 22 post-pDVA patients. A total of 670 PSV and 623 VF measurements were collected. A PSV value of &le, 55 cm/s and a VF value of &le, 195 mL/min were found predictive for failure. The reliability of PSV and VF measurements in patent AV-circuits was good (intraclass correlation coefficient, PSV, 0.85, VF, 0.88). In conclusion, this study is the first to analyze DUS measurements in post-pDVA patients and showed that DUS can be used to anticipate for failure. The thresholds found can be used to help interpret DUS measurements in post-pDVA patients. More research in a larger patient population is needed to prospectively validate these thresholds.

We present the conceptual design and initial development of the Hysteretic Deformable Mirror (HDM). The HDM is a completely new approach to the design and operation of deformable mirrors for wavefront correction in advanced imaging systems. The key technology breakthrough is the application of highly hysteretic piezoelectric material in combination with a simple electrode layout to efficiently define single actuator pixels. The set-and-forget nature of the HDM, which is based on the large remnant deformation of the newly developed piezo material, facilitates the use of time division multiplexing (TDM) to address the single pixels without the need for high update frequencies to avoid pixel drift. This, in combination with the simple electrode layout, paves the way for upscaling to extremely high pixel numbers ($\geq 128\times 128$) and pixel density ($100/mm^2$) deformable mirrors (DMs), which is of great importance for high spatial frequency wavefront correction in some of the most advanced imaging systems in the world.

Background Accurate detection of patients with minimal residual disease (MRD) after surgery for stage II colon cancer (CC) remains an urgent unmet clinical need to improve selection of patients who might benefit form adjuvant chemotherapy (ACT). Presence of circulating tumor DNA (ctDNA) is indicative for MRD and has high predictive value for recurrent disease. The MEDOCC-CrEATE trial investigates how many stage II CC patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces the risk of recurrence in these patients. Methods/design MEDOCC-CrEATE follows the ‘trial within cohorts’ (TwiCs) design. Patients with colorectal cancer (CRC) are included in the Prospective Dutch ColoRectal Cancer cohort (PLCRC) and give informed consent for collection of clinical data, tissue and blood samples, and consent for future randomization. MEDOCC-CrEATE is a subcohort within PLCRC consisting of 1320 stage II CC patients without indication for ACT according to current guidelines, who are randomized 1:1 into an experimental and a control arm. In the experimental arm, post-surgery blood samples and tissue are analyzed for tissue-informed detection of plasma ctDNA, using the PGDx elio™ platform. Patients with detectable ctDNA will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin while patients without detectable ctDNA and patients in the control group will standard follow-up according to guideline. The primary endpoint is the proportion of patients receiving ACT when ctDNA is detectable after resection. The main secondary outcome is 2-year recurrence rate (RR), but also includes 5-year RR, disease free survival, overall survival, time to recurrence, quality of life and cost-effectiveness. Data will be analyzed by intention to treat. Discussion The MEDOCC-CrEATE trial will provide insight into the willingness of stage II CC patients to be treated with ACT guided by ctDNA biomarker testing and whether ACT will prevent recurrences in a high-risk population. Use of the TwiCs design provides the opportunity to randomize patients before ctDNA measurement, avoiding ethical dilemmas of ctDNA status disclosure in the control group. Trial registration Netherlands Trial Register: NL6281/NTR6455. Registered 18 May 2017, https://www.trialregister.nl/trial/6281

We present co-skeletons, a new method that computes consistent curve skeletons for 3D shapes from a given family. We compute co-skeletons in terms of sampling density and semantic relevance, while preserving the desired characteristics of traditional, per-shape curve skeletonization approaches. We take the curve skeletons extracted by traditional approaches for all shapes from a family as input, and compute semantic correlation information of individual skeleton branches to guide an edge-pruning process via skeleton-based descriptors, clustering, and a voting algorithm. Our approach achieves more concise and family-consistent skeletons when compared to traditional per-shape methods. We show the utility of our method by using co-skeletons for shape segmentation and shape blending on real-world data.

A rotating two-tailed soft microrobot induces a frequency dependent flow-field in low Reynolds number fluids. We use this flow-field to achieve noncontact manipulation of nonmagnetic microbeads with average diameter of 30 $\mu {\rm m}$ in 2-D space. Our noncontact manipulation strategy capitalizes on exerting a rotational magnetic torque on the magnetic dipole of the microrobot. The induced flow-field enables microbeads in the surrounding fluid to orbit the microrobot along a sprocketlike trajectory due to a periodic and asymmetric flow-field caused by the two tails. A hydrodynamic model of the two-tailed microrobot and the orbiting microbeads is developed based on the method of regularized Stokeslets for computing Stokes flows. The relations between the angular velocity of the orbiting microbeads and the rotation frequency of the microrobot, their proximity ( $\mathbf {p}$ ), and tail length ratio of the microrobots are studied theoretically and experimentally. Our simulations and experimental results show that the angular velocity of the orbiting microbeads decreases nearly as $\mid \mathbf {p}\mid ^{-2}$ with the distance to the microrobot and its tail length ratio. We also demonstrate closed-loop control of the microbeads toward target positions along sprocketlike trajectories with an average position error of $23.1\pm 9.1$ $\mu {\rm m}$ ( $n=10$ ), and show the ability to swim away without affecting the positioning accuracy after manipulation.

In this paper, we present our novel concept of deformable mirror which enables a high density 2D actuation array through multiplexing. We investigate the resulting electrical coupling effect in the neighboring actuators through finite element analysis. These insights are used to consider the behavior within the least-square fitting performed to achieve wavefront error corrections.