Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
1.
Sensors (Basel) ; 24(9)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38732810

RESUMEN

With neutron diffraction, the local stress and texture of metallic components can be analyzed non-destructively. For both, highly accurate positioning of the sample is essential, requiring the measurement at the same sample location from different directions. Current sample-positioning systems in neutron diffraction instruments combine XYZ tables and Eulerian cradles to enable the accurate six-degree-of-freedom (6DoF) handling of samples. However, these systems are not flexible enough. The choice of the rotation center and their range of motion are limited. Industrial six-axis robots have the necessary flexibility, but they lack the required absolute accuracy. This paper proposes a visual servoing system consisting of an industrial six-axis robot enhanced with a high-precision multi-camera tracking system. Its goal is to achieve an absolute positioning accuracy of better than 50µm. A digital twin integrates various data sources from the instrument and the sample in order to enable a fully automatic measurement procedure. This system is also highly relevant for other kinds of processes that require the accurate and flexible handling of objects and tools, e.g., robotic surgery or industrial printing on 3D surfaces.

2.
Biomimetics (Basel) ; 9(4)2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38667248

RESUMEN

The load-adaptive behavior of the muscles in the human musculoskeletal system offers great potential for minimizing resource and energy requirements in many technical systems, especially in drive technology and robotics. However, the lack of knowledge about suitable technical linear actuators that can reproduce the load-adaptive behavior of biological muscles in technology is a major reason for the lack of successful implementation of this biological principle. In this paper, therefore, the different types of linear actuators are investigated. The focus is particularly on artificial muscles and rope pulls. The study is based on literature, on the one hand, and on two physical demonstrators in the form of articulated robots, on the other hand. The studies show that ropes are currently the best way to imitate the load-adaptive behavior of the biological model in technology. This is especially illustrated in the context of this paper by the discussion of different advantages and disadvantages of the technical linear actuators, where ropes, among other things, have a good mechanical and control behavior, which is very advantageous for use in an adaptive system. Finally, the next steps for future research are outlined to conclude how ropes can be used as linear actuators to transfer load-adaptive lightweight design into technical applications.

3.
Sci Data ; 11(1): 309, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38519557

RESUMEN

Data quality is of crucial importance in the field of automated or digitally assisted assembly. This paper presents a comprehensive data set of triangle meshes representing electrical and electronic components obtained by scraping Computer Aided Design (CAD) models from the Internet. Consisting of a total of 234 triangle meshes with labelled vertices, this data set was specifically created for segmentation tasks. Its versatility for multimodal tasks is underscored by the presence of various labels, including vertex labels, categories, and subcategories. This paper presents the data set and provides a thorough statistical analysis, including measures of shape, size, distribution, and inter-rater reliability. In addition, the paper suggests several approaches for using the data set, considering its multimodal characteristics. The data set and related findings presented in this paper are intended to encourage further research and advancement in the field of manufacturing automation, specifically spatial assembly.

4.
World Neurosurg ; 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38310950

RESUMEN

BACKGROUND: The optimal configuration for spinopelvic fixation during multilevel spine fusion surgery for adult spine deformity remains unclear. Postoperative sacroiliac (SI) joint pain, S2AI screw loosening and implant breakage could be related to continued motion of the SI joint with use of only a single point of fixation across the SI joint. METHODS: Prospective, international, multicenter randomized controlled trial of 222 patients with adult spine deformity scheduled for multilevel (4 or more levels) spine fusion surgery with pelvic fixation. Subjects were randomized to sacroalar (S2) iliac (S2AI) screws alone for pelvic fixation or S2AI + triangular titanium implants placed cephalad to S2AI screws. Quad rod techniques were not allowed or used. Baseline spinal deformity measures were read by an independent radiologist. Site-reported perioperative adverse events were reviewed by a clinical events committee. Quality of life questionnaires and other clinical outcomes are in process with planned 2-year follow-up. RESULTS: One hundred thirteen participants were assigned to S2AI and 109 to S2AI + titanium triangular implants (TTI). 35/222 (16%) of all subjects had a history of SI joint pain or were diagnosed with SI joint pain during preoperative workup. Three-month follow-up was available in all but 4 subjects. TTI placement was successful in 106 of 109 (98%) subjects assigned to TTI. In 2 cases, TTI could not be placed due to anatomical considerations. Three TTI ventral iliac breaches were observed, all of which were managed non-surgically. One TTI subject had a transverse sacral fracture and 1 TTI subject had malposition of the implant requiring removal. CONCLUSIONS: SI joint pain is common in patients with adult spinal deformity who are candidates for multilevel spine fusion surgery. Concurrent placement of TTI parallel to S2AI screws during multilevel spine fusion surgery is feasible and safe. Further follow-up will help to determine the clinical value of this approach to augment pelvic fixation.

5.
Sci Data ; 11(1): 36, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38182596

RESUMEN

The Modern Era Reanalysis (ModE-RA) is a global monthly paleo-reanalysis covering the period between 1421 and 2008. To reconstruct past climate fields an offline data assimilation approach is used, blending together information from an ensemble of transient atmospheric model simulations and observations. In the early period, ModE-RA utilizes natural proxies and documentary data, while from the 17th century onward instrumental measurements are also assimilated. The impact of each observation on the reconstruction is stored in the observation feedback archive, which provides additional information on the input data such as preprocessing steps and the regression-based forward models. The monthly resolved reconstructions include estimates of the most important climate fields. Furthermore, we provide a reconstruction, ModE-RAclim, which together with ModE-RA and the model simulations allows to disentangle the role of observations and model forcings. ModE-RA is best suited to study intra-annual to multi-decadal climate variability and to analyze the causes and mechanisms of past extreme climate events.

6.
Artículo en Inglés | MEDLINE | ID: mdl-38082850

RESUMEN

Impaired mobility have far-reaching consequences for handicapped persons and their relatives. Mobile robotic technologies enable intelligent wheelchairs to regain mobility for those affected. Multiple research projects address human aware navigation and the task of following a person for assistive robots. But just a few projects focus on accompanying a person to enable social interaction. Therefore, we present a navigation system for indoor navigation in dynamic and cluttered environments as well as a novel algorithm for accompanying a person.First, we developed an autonomous driving wheelchair for indoor navigation based on the robot operating system (ROS). Thereby, a multi sensor setup using cameras and laser scanner enables localization within a map. People are detected by the same sensors and tracked by a Kalman filter. Afterwards we propose a novel algorithm to achieve a dynamic accompanying behaviour. An attractiveness distribution is introduced to evaluate the possible accompanying positions next to the manually selected target person regarding social interaction. The resulting two-dimensional optimization problem is solved by a novel multimodal extension of the A* algorithm.The proposed intelligent wheelchair is able to navigate in indoor environments and to accompany any person. In addition it allows social interaction while walking to relieve relatives or nursing staff, which otherwise need to push the wheelchair. The aim is to increase participation in everyday life for those affected.


Asunto(s)
Personas con Discapacidad , Robótica , Silla de Ruedas , Humanos , Algoritmos , Programas Informáticos
7.
Artículo en Inglés | MEDLINE | ID: mdl-38083008

RESUMEN

Stress urinary incontinence is the involuntary leakage of urine during increased abdominal pressure, such as coughing, sneezing, laughing, or exercising. It can have a significant negative impact on a person's quality of life and can result in decreased physical activity and social isolation. The presented closure mechanism for a mechatronic intraurethral artificial urinary sphincter is designed to be inserted minimally invasive into the urethra. The device consists of a solid shell, which serves as a housing for the electronics and is designed to enable fixation in the urethra. During micturition, the urine flows through the system, where it is guided through an elastic silicone-tube that, on the one hand, enables closure by a squeezing mechanism and, on the other hand, prevents biofilm growth by oscillation at a frequency of 22.5 Hz. The squeezing mechanism consists of a pinch valve system actuated by a piezo motor. The system has been tested under urodynamic conditions and the results show that it is able to close the urethra effectively to restore continence. The device is able to withstand sudden loads and shows good performance in terms of biofilm prevention during first experiments with artificial urine. The results show that the mechatronic intraurethral artificial urinary sphincter has the potential to be an effective and minimally invasive alternative to current treatment options for stress urinary incontinence.Clinical Relevance- This novel concept of a mechatronic intraurethral artificial urinary sphincter presents a promising alternative treatment option for patients suffering from stress urinary incontinence. As it is designed to be inserted minimally invasive, it reduces the impact and complications associated with current treatment options. The future development and testing of the device could lead to a safe and effective option for clinicians to offer their patients with stress urinary incontinence, which can improve their quality of life, and decrease costs for society and healthcare systems.


Asunto(s)
Incontinencia Urinaria de Esfuerzo , Esfínter Urinario Artificial , Humanos , Incontinencia Urinaria de Esfuerzo/cirugía , Calidad de Vida , Uretra/cirugía , Micción
8.
Brain Spine ; 3: 102688, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38020998

RESUMEN

Introduction: The purpose is to report on the fourth set of recommendations developed by SPINE20 to advocate for evidence-based spine care globally under the theme of "One Earth, One Family, One Future WITHOUT Spine DISABILITY". Research question: Not applicable. Material and methods: Recommendations were developed and refined through two modified Delphi processes with international, multi-professional panels. Results: Seven recommendations were delivered to the G20 countries calling them to:-establish, prioritize and implement accessible National Spine Care Programs to improve spine care and health outcomes.-eliminate structural barriers to accessing timely rehabilitation for spinal disorders to reduce poverty.-implement cost-effective, evidence-based practice for digital transformation in spine care, to deliver self-management and prevention, evaluate practice and measure outcomes.-monitor and reduce safety lapses in primary care including missed diagnoses of serious spine pathologies and risk factors for spinal disability and chronicity.-develop, implement and evaluate standardization processes for spine care delivery systems tailored to individual and population health needs.-ensure accessible and affordable quality care to persons with spine disorders, injuries and related disabilities throughout the lifespan.-promote and facilitate healthy lifestyle choices (including physical activity, nutrition, smoking cessation) to improve spine wellness and health. Discussion and conclusion: SPINE20 proposes that focusing on the recommendations would facilitate equitable access to health systems, affordable spine care delivered by a competent healthcare workforce, and education of persons with spine disorders, which will contribute to reducing spine disability, associated poverty, and increase productivity of the G20 nations.

9.
Stud Health Technol Inform ; 301: 69-70, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37172155

RESUMEN

In this paper we outline a cost-effective design for the improvement of telemedicine applications through a two components concept. A normal smartphone is equipped with a small device containing different filter options, which provide particular spectral information for the identification of skin lesions. By merging the measured spectra, a higher data density and more information can be obtained using an ANN to improve an early diagnosis of skin lesions through telemedicine applications in remote areas.


Asunto(s)
Aplicaciones Móviles , Telemedicina , Teléfono Inteligente , Imágenes Hiperespectrales , Diagnóstico Precoz , Telemedicina/métodos
10.
Spine J ; 23(10): 1494-1505, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37236367

RESUMEN

BACKGROUND CONTEXT: Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSE: To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGN: Prospective, multicenter, international, observational cohort study. PATIENT SAMPLE: Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURES: Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODS: Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTS: Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONS: Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.


Asunto(s)
Fusión Vertebral , Espondilolistesis , Humanos , Espondilolistesis/cirugía , Espondilolistesis/etiología , Estudios Prospectivos , Estudios de Seguimiento , Vértebras Lumbares/cirugía , Constricción Patológica , Calidad de Vida , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Dolor de Espalda/etiología , Resultado del Tratamiento , Estudios Retrospectivos
11.
Front Med (Lausanne) ; 10: 1147907, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37215712

RESUMEN

Introduction: Activities of daily living, such as walking, are impaired in chronic low back pain (CLBP) patients compared to healthy individuals. Thereby, pain intensity, psychosocial factors, cognitive functioning and prefrontal cortex (PFC) activity during walking might be related to gait performance during single and dual task walking (STW, DTW). However, to the best of our knowledge, these associations have not yet been explored in a large sample of CLBP patients. Method: Gait kinematics (inertial measurement units) and PFC activity (functional near-infrared spectroscopy) during STW and DTW were measured in 108 CLBP patients (79 females, 29 males). Additionally, pain intensity, kinesiophobia, pain coping strategies, depression and executive functioning were quantified and correlation coefficients were calculated to determine the associations between parameters. Results: The gait parameters showed small correlations with acute pain intensity, pain coping strategies and depression. Stride length and velocity during STW and DTW were (slightly to moderately) positively correlated with executive function test performance. Specific small to moderate correlations were found between the gait parameters and dorsolateral PFC activity during STW and DTW. Conclusion: Patients with higher acute pain intensity and better coping skills demonstrated slower and less variable gait, which might reflect a pain minimization strategy. Psychosocial factors seem to play no or only a minor role, while good executive functions might be a prerequisite for a better gait performance in CLBP patients. The specific associations between gait parameters and PFC activity during walking indicate that the availability and utilization of brain resources are crucial for a good gait performance.

12.
Polymers (Basel) ; 15(5)2023 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-36904405

RESUMEN

The expanding demand for electro mobility in general and specifically for electrified vehicles requires the expansion of electro mobility technology with respect to variations in the requirements of the process and the application. Within the stator, the electrical insulation system has a high impact on the application properties. So far, limitations, such as the identification of suitable materials for the stator insulation or high costs in the processes, have hindered the implementation of new applications. Therefore, a new technology that allows integrated fabrication via the injection molding of thermosets is founded in order to expand the applications of stators. The possibility of the integrated fabrication of insulation systems to meet the demands of the application can be improved by the processing conditions and the slot design. Within this paper, two epoxy (EP) types with different fillers are investigated to show the impact of the fabrication process in terms of different parameters; these include the holding pressure or the temperature setup, as well as the slot design and with that the flow conditions. To evaluate the improvement in the insulation system of electric drives, a single slot sample, consisting of two parallel copper wires, was used. Then, the two parameters of the average partial discharge (PD) and the partial discharge extinction voltage (PDEV), as well as the full encapsulation detected by microscopy images, were analyzed. It was shown that both characteristics (electric properties-PD and PDEV; full encapsulation) could be improved in terms of an increase in the holding pressure (up to 600 bar) or a reduction in the heating time (around 40 s), as well as the injection speed (down to 15 mm/s). Further, an improvement in the properties can be reached by increasing the space between the wires, as well as the wire and the stack, due to a higher slot depth or by implementing flow-improving grooves that have a positive effect on the flow conditions. With that, the optimization of the integrated fabrication of insulation systems in electric drives via the injection molding of thermosets was enabled with respect to the process conditions and the slot design.

14.
J Colloid Interface Sci ; 635: 12-22, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36577351

RESUMEN

HYPOTHESIS: Recently, the anomalous shrinkage of surface-supported hyaluronate/poly-l-lysine (HA/PLL) microgels (µ-gels), which exceeds that reported for any other multilayer-based systems, has been reported [1]. The current study investigates the capability of these unique µ-gels for the encapsulation and retention of macromolecules, and proposes the shrinkage-driven assembly of biopolymer-based µ-gels as a novel tool for one-step surface biofunctionalization. EXPERIMENTS: A set of dextrans (DEX) and their charged derivatives - carboxymethyl (CM)-DEX and diethylaminoethyl (DEAE)-DEX - has been utilized to evaluate the effects of macromolecular mass and net charge on µ-gel shrinkage and macromolecule entrapment. µ-gels formation on the surface of silicone catheters exemplifies their potential to tailor biointerfaces. FINDINGS: Shrinkage-driven µ-gel formation strongly depends on the net charge and mass content of encapsulated macromolecules. Inclusion of neutral DEX decreases the degree of shrinkage several times, whilst charged DEXs adopt to the backbone of oppositely charged polyelectrolytes, resulting in shrinkage comparable to that of non-loaded µ-gels. Retention of CM-DEX in µ-gels is significantly higher compared to DEAE-DEX. These insights into the mechanisms of macromolecular entrapment into biopolymer-based µ-gels promotes fundamental understanding of molecular dynamics within the multilayer assemblies. Organization of biodegradable µ-gels at biomaterial surfaces opens avenues for their further exploitation in a diverse array of bioapplications.


Asunto(s)
Microgeles , Geles
15.
Polymers (Basel) ; 14(24)2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36559719

RESUMEN

Due to the increasing demand for electro mobility and specifically for electrified vehicles, the demand for electric drive technology is expanding significantly with changing requirements in terms of the process and the application. The electrical insulation system of the stator is an essential part of the fabrication process with a high impact on the application properties. Due to limitations-for example, in terms of suitable materials for the stator insulation-a new technology of integrated fabrication by injection molding of thermosets has been founded. In this study, two epoxy (EP) types with different fillers were investigated to prove their suitability in terms of the material properties in the fabrication process and the application. A general realization of the integrated fabrication of insulation systems in electrical engineering by injection molding was proved. Further, the differences regarding the suitability of the two materials are portrayed. It was demonstrated that mainly the filler material influences the fabrication process and the properties in the application, leading to differing suitability in terms of the EP 3162 EMG within the fabrication process and in terms of XW 6640-1 within the application properties of the thermal conductivity and the thermal linear expansion. It was further shown that the filler within the material system is required to increase the thermal conductivity needed for the application. The inclusion of the filler influences the reaction kinetics and the viscosity behavior. A fabrication of the material with fillers is however still possible.

16.
Front Surg ; 9: 1000238, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36406358

RESUMEN

Objective: Nonsteroidal anti-inflammatory drugs (NSAID) are essential in surgeons' armamentarium for pain relief and antiphlogistic effects. However, spine surgeons are concerned about the drugs' impact on coagulation, fearing hemodynamic instability due to blood loss and neurological complications due to postoperative hematoma. Furthermore, there are no clear guidelines for the use of these drugs. Materials and methods: In this retrospective subgroup analysis of a prospective observational study, we investigated 181 patients who underwent minimally invasive spinal fusions in degenerative lumbar spine pathologies. 83 patients were given NSAID perioperatively, 54 of which were female and 29 male. Of these patients who took NSAID, 39 were on NSAID until at least one day before surgery or perioperatively, whilst the others discontinued their NSAID medication at least three days before surgery. Differences in perioperative blood loss, as well as complication rates between patients with and without NSAID treatment, were investigated. Results: A significantly higher amount of blood loss during surgery and the monitoring period was encountered in patients whose spine was fused in more than one level, regardless of whether NSAID medication was taken or not and up until what point. Furthermore, it was found that taking NSAID medication had no effect on the incidence of postoperative epidural hematomas. Conclusion: Perioperatively taking NSAID medication does not increase blood loss or the incidence of postoperative hematoma in patients undergoing minimally invasive lumbar spinal fusion surgery.

17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 2479-2482, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36085608

RESUMEN

A new patient-friendly and discrete approach to build a unidirectional communication path with active implants based on deliberately produced human body signals is presented. The application for which this approach is intended is an artificial urinary sphincter implant, the closure mechanism of which is wirelessly actuated in the event of micturition need. Conventional implant communication methods can be associated with limitations regarding technological implementation and usability, and are used by medical professionals only. In order to enable patients to discretely and directly communicate with their implant without the need for an external handheld device, the feasibility of a communication approach based on manually applied 'knocking' signals on abdominal tissue is examined in the presented work. A gelatin-based phantom model is used to mimic vibro-acoustic properties of human soft tissue in vitro. A piezoelectric element and an electret microphone are applied as sensors for signal detection at the implantation site and are investigated with respect to their suitability for the intended application. Clinical Relevance- The presented implant communication method can contribute to urinary incontinence therapy by enabling patients to discretely and user-friendly actuate their artificial sphincter implant and can provide a basis for future research into new implant communication technologies.


Asunto(s)
Comunicación , Cuerpo Humano , Acústica , Humanos , Prótesis e Implantes , Tecnología
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 4269-4273, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36085946

RESUMEN

Orientation and mobility of visually impaired people usually requires intensive training with mobility aids (e.g. white canes). Assistance systems capture information from the environment, process sensor data and provide the results to the impaired user. The paper presents an approach for efficient segmentation of obstacles in low-structured outdoor environments using encoder-decoder deep learning architectures and depth images. Therefore, an efficient method for generating training data using the v-disparity method is presented. Based on an extensive dataset of RGB and depth images and the corresponding binary label images, different state-of-the-art encoder-decoder architectures are evaluated on a mobile computing unit with respect to accuracy and efficiency. Besides pure depth-based architectures, RGB-D fused architectures are evaluated, too. The quantitative results show some limitations, but an additional qualitative evaluation proves the applicability of the approach to support the navigation of VIP by mapping the position of surrounding obstacles. Thus, an efficient combination of classical image processing, the integration of knowledge about the physical nature of the environment and deep learning can be made. Clinical Relevance- The approach supports the navigation of visually impaired people, which enables a more self-sufficient life related to higher quality of life.


Asunto(s)
Calidad de Vida , Personas con Daño Visual , Humanos , Procesamiento de Imagen Asistido por Computador/métodos
19.
Geosci Data J ; 9(1): 89-107, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35873191

RESUMEN

Data assimilation techniques are becoming increasingly popular for climate reconstruction. They benefit from estimating past climate states from both observation information and from model simulations. The first monthly global paleo-reanalysis (EKF400) was generated over the 1600 and 2005 time period, and it provides estimates of several atmospheric fields. Here we present a new, considerably improved version of EKF400 (EKF400v2). EKF400v2 uses atmospheric-only general circulation model simulations with a greatly extended observational network of early instrumental temperature and pressure data, documentary evidences and tree-ring width and density proxy records. Furthermore, new observation types such as monthly precipitation amounts, number of wet days and coral proxy records were also included in the assimilation. In the version 2 system, the assimilation process has undergone methodological improvements such as the background-error covariance matrix is estimated with a blending technique of a time-dependent and a climatological covariance matrices. In general, the applied modifications resulted in enhanced reconstruction skill compared to version 1, especially in precipitation, sea-level pressure and other variables beside the mostly assimilated temperature data, which already had high quality in the previous version. Additionally, two case studies are presented to demonstrate the applicability of EKF400v2 to analyse past climate variations and extreme events, as well as to investigate large-scale climate dynamics.

20.
Eur Spine J ; 31(8): 1943-1951, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35796837

RESUMEN

PURPOSE: Sagittal balance (SB) plays an important role in the surgical treatment of spinal disorders. The aim of this research study is to provide a detailed evaluation of a new, fully automated algorithm based on artificial intelligence (AI) for the determination of SB parameters on a large number of patients with and without instrumentation. METHODS: Pre- and postoperative sagittal full body radiographs of 170 patients were measured by two human raters, twice by one rater and by the AI algorithm which determined: pelvic incidence, pelvic tilt, sacral slope, L1-S1 lordosis, T4-T12 thoracic kyphosis (TK) and the spino-sacral angle (SSA). To evaluate the agreement between human raters and AI, the mean error (95% confidence interval (CI)), standard deviation and an intra- and inter-rater reliability was conducted using intra-class correlation (ICC) coefficients. RESULTS: ICC values for the assessment of the intra- (range: 0.88-0.97) and inter-rater (0.86-0.97) reliability of human raters are excellent. The algorithm is able to determine all parameters in 95% of all pre- and in 91% of all postoperative images with excellent ICC values (PreOP-range: 0.83-0.91, PostOP: 0.72-0.89). Mean errors are smallest for the SSA (PreOP: -0.1° (95%-CI: -0.9°-0.6°); PostOP: -0.5° (-1.4°-0.4°)) and largest for TK (7.0° (6.1°-7.8°); 7.1° (6.1°-8.1°)). CONCLUSION: A new, fully automated algorithm that determines SB parameters has excellent reliability and agreement with human raters, particularly on preoperative full spine images. The presented solution will relieve physicians from time-consuming routine work of measuring SB parameters and allow the analysis of large databases efficiently.


Asunto(s)
Cifosis , Lordosis , Médicos , Inteligencia Artificial , Humanos , Cifosis/diagnóstico por imagen , Cifosis/cirugía , Lordosis/cirugía , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sacro , Columna Vertebral/diagnóstico por imagen , Columna Vertebral/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...