10 research outputs found

    Spinopelvic Adaptations in Standing and Sitting Positions in Patients With Adult Spinal Deformity

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    Purpose To describe spinopelvic adaptations in the standing and sitting positions in patients with adult spinal deformity (ASD). Methods Ninety-five patients with ASD and 32 controls completed health-related quality of life (HRQOL) questionnaires: short form 36 (SF36), Oswestry Disability Index (ODI), and visual analog scale (VAS) for pain. They underwent biplanar radiography in both standing and sitting positions. Patients with ASD were divided into ASD-front (frontal deformity Cobb > 20°, n = 24), ASD-sag (sagittal vertical axis (SVA) > 50 mm, pelvic tilt (PT) > 25°, or pelvic incidence (PI)-lumbar lordosis (LL) > 10°, n = 40), and ASD-hyper thoracic kyphosis (TK >60°, n = 31) groups. Flexibility was defined as the difference (Δ) in radiographic parameters between the standing and sitting positions. The radiographic parameters were compared between the groups. Correlations between HRQOL scores were evaluated. Results All participants increased their SVA from standing to sitting (ΔSVA<0), except for patients with ASD-sag, who tended to decrease their SVA (78-62 mm) and maximize their pelvic retroversion (27-40° vs 10-34° in controls, p<0.001). They also showed reduced thoracic and lumbar flexibility (ΔLL = 3.4 vs 37.1°; ΔTK = −1.7 vs 9.4° in controls, p<0.001). ASD-hyperTK showed a decreased PT while sitting (28.9 vs 34.4° in controls, p<0.001); they tended to decrease their LL and TK but could not reach values for controls (ΔLL = 22.8 vs 37.1° and ΔTK = 5.2 vs 9.4°, p<0.001). The ASD-front had normal standing and sitting postures. ΔSVA and ΔLL were negatively correlated with the physical component scale (PCS of SF36) and ODI (r = −0.39 and r = −0.46, respectively). Conclusion Patients with ASD present with different spinopelvic postures and adaptations from standing to sitting positions, with those having sagittal malalignment most affected. In addition, changes in standing and sitting postures were related to HRQOL outcomes. Therefore, surgeons should consider patient sitting adaptations in surgical planning and spinal fusion. Future studies on ASD should evaluate whether physical therapy or spinal surgery can improve sitting posture and QOL, especially for those with high SVA or PT

    Functional assessment using 3D movement analysis can better predict health-related quality of life outcomes in patients with adult spinal deformity: a machine learning approach

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    IntroductionAdult spinal deformity (ASD) is classically evaluated by health-related quality of life (HRQoL) questionnaires and static radiographic spino-pelvic and global alignment parameters. Recently, 3D movement analysis (3DMA) was used for functional assessment of ASD to objectively quantify patient's independence during daily life activities. The aim of this study was to determine the role of both static and functional assessments in the prediction of HRQoL outcomes using machine learning methods.MethodsASD patients and controls underwent full-body biplanar low-dose x-rays with 3D reconstruction of skeletal segment as well as 3DMA of gait and filled HRQoL questionnaires: SF-36 physical and mental components (PCS&amp;MCS), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), and visual analog scale (VAS) for pain. A random forest machine learning (ML) model was used to predict HRQoL outcomes based on three simulations: (1) radiographic, (2) kinematic, (3) both radiographic and kinematic parameters. Accuracy of prediction and RMSE of the model were evaluated using 10-fold cross validation in each simulation and compared between simulations. The model was also used to investigate the possibility of predicting HRQoL outcomes in ASD after treatment.ResultsIn total, 173 primary ASD and 57 controls were enrolled; 30 ASD were followed-up after surgical or medical treatment. The first ML simulation had a median accuracy of 83.4%. The second simulation had a median accuracy of 84.7%. The third simulation had a median accuracy of 87%. Simulations 2 and 3 had comparable accuracies of prediction for all HRQoL outcomes and higher predictions compared to Simulation 1 (i.e., accuracy for PCS = 85 ± 5 vs. 88.4 ± 4 and 89.7% ± 4%, for MCS = 83.7 ± 8.3 vs. 86.3 ± 5.6 and 87.7% ± 6.8% for simulations 1, 2 and 3 resp., p &lt; 0.05). Similar results were reported when the 3 simulations were tested on ASD after treatment.DiscussionThis study showed that kinematic parameters can better predict HRQoL outcomes than stand-alone classical radiographic parameters, not only for physical but also for mental scores. Moreover, 3DMA was shown to be a good predictive of HRQoL outcomes for ASD follow-up after medical or surgical treatment. Thus, the assessment of ASD patients should no longer rely on radiographs alone but on movement analysis as well

    Robust segmentation and statistical shape modelling : application to cardiac imaging

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    Cardiac segmentation involves accurate delineation of cardiac anatomy and it is required for deriving both local and global anatomical and functional indices. Consistent, robust and accurate segmentation has become a major bottleneck in standard clinical workflows. Whilst manual segmentation still remains a common practice in many clinical settings, it is getting increasingly impractical due to the large amount of data involved. Thus far, fully automatic techniques still remain difficult due to inconsistent image quality and high degree of morphological variations between different subjects. However, segmentation with active shape and appearance models are amongst popular techniques that are gaining significant clinical interest. These methods exploit a priori knowledge about the geometry and appearance of the anatomical structures, making them appealing for practical applications. For these techniques to be clinical relevant, several limitations need to be carefully addressed. For example, model construction requires establishing valid correspondence between shapes, and the effect of outliers on performance needs to be tackled. The purpose of this thesis is to present a practical and robust segmentation and modelling framework based on active shape models combined with the random walker algorithm and reinforcement learning. For shape modelling, a strategy based on harmonic embedding and the minimum description length is proposed. We also present a general framework for explicit handling of outliers in active shape models by employing deterministic annealing and softassign. The random walker algorithm is used for robust feature extraction based on discrete harmonic functions on graphs. Finally, an interactive framework based on reinforcement learning is developed so as to minimise user interaction when adjusting pre-segmentation results from the proposed model-based approach. Throughout this thesis, the methods proposed have been extensively validated with in vivo data and detailed statistical analysis has been provided for evaluating the accuracy and robustness of different aspects of the proposed techniques.Open acces

    Spinopelvic Adaptations in Standing and Sitting Positions in Patients With Adult Spinal Deformity

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    International audiencePurposeTo describe spinopelvic adaptations in the standing and sitting positions in patients with adult spinal deformity (ASD).MethodsNinety-five patients with ASD and 32 controls completed health-related quality of life (HRQOL) questionnaires: short form 36 (SF36), Oswestry Disability Index (ODI), and visual analog scale (VAS) for pain. They underwent biplanar radiography in both standing and sitting positions. Patients with ASD were divided into ASD-front (frontal deformity Cobb > 20°, n = 24), ASD-sag (sagittal vertical axis (SVA) > 50 mm, pelvic tilt (PT) > 25°, or pelvic incidence (PI)-lumbar lordosis (LL) > 10°, n = 40), and ASD-hyper thoracic kyphosis (TK >60°, n = 31) groups. Flexibility was defined as the difference (Δ) in radiographic parameters between the standing and sitting positions. The radiographic parameters were compared between the groups. Correlations between HRQOL scores were evaluated.ResultsAll participants increased their SVA from standing to sitting (ΔSVA<0), except for patients with ASD-sag, who tended to decrease their SVA (78-62 mm) and maximize their pelvic retroversion (27-40° vs 10-34° in controls, p<0.001). They also showed reduced thoracic and lumbar flexibility (ΔLL = 3.4 vs 37.1°; ΔTK = −1.7 vs 9.4° in controls, p<0.001). ASD-hyperTK showed a decreased PT while sitting (28.9 vs 34.4° in controls, p<0.001); they tended to decrease their LL and TK but could not reach values for controls (ΔLL = 22.8 vs 37.1° and ΔTK = 5.2 vs 9.4°, p<0.001). The ASD-front had normal standing and sitting postures. ΔSVA and ΔLL were negatively correlated with the physical component scale (PCS of SF36) and ODI (r = −0.39 and r = −0.46, respectively).ConclusionPatients with ASD present with different spinopelvic postures and adaptations from standing to sitting positions, with those having sagittal malalignment most affected. In addition, changes in standing and sitting postures were related to HRQOL outcomes. Therefore, surgeons should consider patient sitting adaptations in surgical planning and spinal fusion. Future studies on ASD should evaluate whether physical therapy or spinal surgery can improve sitting posture and QOL, especially for those with high SVA or PT

    Towards Multi-Modal Image-Guided Tumour Identification in Robot-Assisted Partial Nephrectomy

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    Abstract — Tumour identification is a critical step in robotassisted partial nephrectomy (RAPN) during which the surgeon determines the tumour localization and resection margins. To help the surgeon in achieving this step, our research work aims at leveraging both pre- and intra-operative imaging modalities (CT, MRI, laparoscopic US, stereo endoscopic video) to provide an augmented reality view of kidney-tumour boundaries with uncertainty-encoded information. We present herein the progress of this research work including segmentation of preoperative scans, biomechanical simulation of deformations, stereo surface reconstruction from stereo endoscopic camera, pre-operative to intra-operative data registration, and augmented reality visualization. I

    Evaluation of how users interface with holographic augmented reality surgical scenes: Interactive planning MR-Guided prostate biopsies

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    Background User interfaces play a vital role in the planning and execution of an interventional procedure. The objective of this study is to investigate the effect of using different user interfaces for planning transrectal robot-assisted MR-guided prostate biopsy (MRgPBx) in an augmented reality (AR) environment. Method End-user studies were conducted by simulating an MRgPBx system with end- and side-firing modes. The information from the system to the operator was rendered on HoloLens as an output interface. Joystick, mouse/keyboard, and holographic menus were used as input interfaces to the system. Results The studies indicated that using a joystick improved the interactive capacity and enabled operator to plan MRgPBx in less time. It efficiently captures the operator's commands to manipulate the augmented environment representing the state of MRgPBx system. Conclusions The study demonstrates an alternative to conventional input interfaces to interact and manipulate an AR environment within the context of MRgPBx planning

    Evaluation of Hardware Accelerators for Lattice Boltzmann based Aneurysm Blood Flow Measurement

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    Clipping is a potential treatment for ruptured/unruptured brain aneurysm patients. In order to determine the profitable treatment and also clip's location, surgeons need to have the measurements such as velocity and blood pressure in and around the aneurysm.Typically, simulating the blood fluid and finding the corresponding measurements require heavy computation resources. The Lattice Boltzmann (LB) method is the conventional way to simulate the fluid dynamics and HemeLB is an open-source computational suite for 3D fluid dynamics simulations of blood flow in the vasculature of the human body. In this work, we aim to evaluate the hardware acceleration of LB and HemeLB on reconfigurable system on chip (SoC) and high performance computing (HPC) machine using RAAD platform.qscienc

    Global Sagittal Angle and T9-tilt seem to be the most clinically and functionally relevant global alignment parameters in patients with Adult Spinal Deformity

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    Introduction Radiographic analysis is necessary for the assessment and the surgical planning in adults with spinal deformity (ASD). Restoration of global alignment is key to improving patient's quality of life. However, the large number of existing global alignment parameters can be confusing for surgeons. Research question To determine the most clinically and functionally relevant global alignment parameters in ASD. Material and methods ASD and controls underwent full body biplanar X-ray to calculate global alignment parameters: odontoid to hip axis angle (OD-HA), global sagittal angle (GSA), global tilt (GT), SVA, center of auditory meatus to hip axis (CAM-HA), SSA, T1-tilt and T9-tilt. All subjects filled HRQoL questionnaires: ODI, SF-36, VAS for pain and BDI (Beck's Depression Inventory). 3D gait analysis was performed to calculate kinematic and spatio-temporal parameters. A machine learning model predicted gait parameters and HRQoL scores from global alignment parameters. Results 124 primary ASD and 47 controls were enrolled. T9 tilt predicted the most BDI (31%), hip flexion/extension during gait (36%), and double support time (39%). GSA predicted the most ODI (26%), thorax flexion/extension during gait (33%), and cadence (36%). Discussion and conclusion Among all global alignment parameters, GSA, evaluating both trunk shift and knee flexion, and T9 tilt, evaluating the shift of the center of mass, were the best predictors for most of HRQoL scores and gait kinematics. Therefore, we recommend using GSA and T9 tilt in clinical practice when evaluating ASD because they represent the most quality of life and functional kinematic of these patients

    Spermaurin, an La1-like peptide from the venom of the scorpion Scorpio maurus palmatus , improves sperm motility and fertilization in different mammalian species

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    International audienceSTUDY QUESTIONIs it possible to identify original compounds that are able to enhance sperm motility from the venom of the scorpion Scorpio maurus palmatus?SUMMARY ANSWERWe identified a potent disulfide-rich peptide (DRP) of 73 amino acids that significantly improved the motility of fresh and frozen-thawed sperm in different mammalian species, including human, and improved fertilization outcome in mouse IVF experiments.WHAT IS KNOWN ALREADYAny disturbance of sperm motility has a strong impact on fertilization and can lead to subfertility or infertility. Significant efforts have, therefore,  been made to identify pharmacological drugs that might improve sperm motility. Such compounds are particularly useful in azoospermia to improve testicular sperm extraction and in the domain of cryopreservation because the motility of frozen-thawed sperm is reduced.STUDY DESIGN, SIZE, DURATIONThis was a basic science/medical research study aimed at identifying original compounds from a library of venoms able to enhance mammalian sperm motility, including human. We first identified in the venom of a scorpion S. m. palmatus a fraction able to potently activate sperm motility. We next purified and characterized the compound by liquid chromatography, mass spectrometry and peptide synthesis. Finally, the potency and toxicity of both purified and synthetic versions of the identified compound on sperm motility were assessed using different in vitro tests in different mammalian species.PARTICIPANTS/MATERIALS, SETTING, METHODS For human sperm, biological samples were collected from normozoospermic donors and subfertile patients attending a reproduction department for diagnostic semen analysis. Testicular sperm was collected from cynomolgus monkeys (Macaca fascicularis) euthanized for the needs of specific authorized research projects. The peptide was also tested on bovine and mouse epidydimal sperm. We measured different sperm motility parameters with a computer-assisted sperm analysis system in the presence or absence of the peptide.MAIN RESULTS AND THE ROLE OF CHANCESize exclusion chromatography enabled us to isolate a fraction of the venom of S. m. palmatus able to increase sperm motility. By liquid chromatography and mass spectrometry, a peptide comprising 73 amino acids with 4 disulfide bridges was identified as responsible for the biological activity and called ‘spermaurin’. The identity of spermaurin was confirmed by chemical synthesis. We showed that the peptide increased the motility of fresh and frozen-thawed human sperm. We observed that the potency of the peptide was higher on fresh ejaculated spermatozoa with a low motility, achieving a 100% increase of curvilinear velocity in poorly performing sperm. We also demonstrated that peptide is effective on bovine and mouse fresh epididymal, bovine frozen-thawed ejaculated and fresh non-human primate testicular sperm. Finally, in mouse IVF, the production of 2-cell embryos was increased by 24% when sperm were treated with the peptide.LIMITATIONS, REASONS FOR CAUTIONThis work is an in vitro evaluation of the ability of spermaurin to improve sperm motility parameters. Another limitation of this study is the small number of human sperm samples tested with the natural (n = 36) and synthetic (n = 12) peptides. Moreover, the effect of the peptide on IVF outcome was only tested in mouse and further tests with human and bovine gametes are required to confirm and extend this result in other mammalian species.WIDER IMPLICATIONS OF THE FINDINGSThis work confirms our initial study showing that venoms represent an interesting source of molecules that are able to modify sperm physiology. Moreover, this work presents the first demonstrated biological action of a venom peptide from the scorpion S. m. palmatus with sequence similarities to La1 peptide from Liocheles australasiae (Wood scorpion), a widespread family of DRPs.STUDY FUNDING/COMPETING INTEREST(S)This work is part of the project ‘LAB COM-14 LAB7 0004 01-LIPAV’, funded by the program LabCom 2014 from t e French Research Agency (ANR). Dr Arnoult reports grants from IMV Technologies during the conduct of the study. In addition, Drs Arnoult, Martinez, Ray and Schmitt have a patent EP16305642.7 pending containing some of the information presented in this manuscript
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