Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
J Cancer Res Clin Oncol ; 150(5): 235, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38710956

RESUMO

PURPOSE: Transarterial chemoembolization (TACE) has become the standard of care for the treatment of intermediate-stage hepatocellular carcinoma (HCC). However, current clinical practice guidelines lack consensus on the best selection of a specific TACE technique. This study aims to compare safety, tumor response, and progression-free survival (PFS) of conventional TACE (cTACE), drug-eluting bead TACE (DEB-TACE), and degradable starch microsphere TACE (DSM-TACE). METHODS: This retrospective study included n = 192 patients with HCC who underwent first TACE with unbiased follow-up at 4-6 weeks at our center between 2008 and 2021. Eligibility for TACE was BCLC intermediate stage B, bridging/down-staging (B/D) to liver transplantation (LT), or any other stage when patients were not suitable for resection, LT, local ablation, or systemic therapy. Patients were grouped into three cohorts (n = 45 cTACE, n = 84 DEB-TACE, n = 63 DSM-TACE), and further categorized by TACE indication (B/D or palliative). Liver function and adverse events, response assessed by the modified response evaluation criteria in solid tumors (mRECIST) 4-6 weeks post-TACE and PFS were analyzed. RESULTS: There were no significant differences in age, gender distribution, BCLC stage, or etiology of liver disease among the three TACE groups, even in the B/D or palliative subgroups. DEB-TACE induced slight increases in bilirubin in the palliative subgroup and in lactate dehydrogenase in the entire cohort 4-6 weeks post-TACE, and more adverse events in the palliative subgroup. DEB-TACE and DSM-TACE showed significantly higher disease control rates (complete and partial response, stable disease) compared to cTACE, especially in the B/D setting (p < 0.05). There was no significant difference in PFS between the groups [median PFS (months): cTACE, 10.0 vs. DEB, 7.0 vs. DSM, 10.0; p = 0.436]. CONCLUSION: Our study provides valuable perspectives in the decision-making for a specific TACE technique: DEB-TACE and DSM-TACE showed improved tumor response. DEB-TACE showed a prolonged impact on liver function and more side effects, so patients with impaired liver function should be more strictly selected, especially in the palliative subgroup.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Quimioembolização Terapêutica/métodos , Quimioembolização Terapêutica/efeitos adversos , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/mortalidade , Masculino , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/mortalidade , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Adulto
2.
Cardiovasc Intervent Radiol ; 47(4): 462-471, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38416178

RESUMO

PURPOSE: To evaluate the benefit of a contrast-enhanced computed tomography (CT) radiomics-based model for predicting response and survival in patients with colorectal liver metastases treated with transarterial Yttrium-90 radioembolization (TARE). MATERIALS AND METHODS: Fifty-one patients who underwent TARE were included in this single-center retrospective study. Response to treatment was assessed using the Response Evaluation Criteria in Solid Tumors (RECIST 1.1) at 3-month follow-up. Patients were stratified as responders (complete/partial response and stable disease, n = 24) or non-responders (progressive disease, n = 27). Radiomic features (RF) were extracted from pre-TARE CT after segmentation of the liver tumor volume. A model was built based on a radiomic signature consisting of reliable RFs that allowed classification of response using multivariate logistic regression. Patients were assigned to high- or low-risk groups for disease progression after TARE according to a cutoff defined in the model. Kaplan-Meier analysis was performed to analyze survival between high- and low-risk groups. RESULTS: Two independent RF [Energy, Maximal Correlation Coefficient (MCC)], reflecting tumor heterogeneity, discriminated well between responders and non-responders. In particular, patients with higher magnitude of voxel values in an image (Energy), and texture complexity (MCC), were more likely to fail TARE. For predicting treatment response, the area under the receiver operating characteristic curve of the radiomics-based model was 0.75 (95% CI 0.48-1). The high-risk group had a shorter overall survival than the low-risk group (3.4 vs. 6.4 months, p < 0.001). CONCLUSION: Our CT radiomics model may predict the response and survival outcome by quantifying tumor heterogeneity in patients treated with TARE for colorectal liver metastases.


Assuntos
Neoplasias do Colo , Neoplasias Hepáticas , Neoplasias Retais , Humanos , Estudos Retrospectivos , Radiômica , Radioisótopos de Ítrio/uso terapêutico , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/radioterapia
3.
Front Neurol ; 14: 1256365, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38046595

RESUMO

Objective: Mechanical thrombectomy (MT) has become the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO). First-pass (FP) reperfusion of the occluded vessel and fewer passes with stent retrievers show improvement in functional outcomes in stroke patients, while higher numbers of passes are associated with higher complication rates and worse outcomes. Studies indicate that a larger size of the stent-retriever is associated with a higher rate of first-pass reperfusion and improved clinical outcomes. In this retrospective study, we investigated the clinical performance of a recently developed and one of the largest stent-retrievers available in the treatment of LVO (pRESET 6-50, phenox GmbH, Bochum). Materials and methods: All consecutive patients with ischemic stroke due to proximal large vessel occlusion treated with MT using the pRESET 6-50 stent-retriever in two tertiary stroke centers between 09/2021 and 07/2022 were included in this study. The reperfusion rate after MT was quantified by the modified thrombolysis in cerebral infarction (mTICI) score, and functional neurological outcome was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score and the major early neurological recovery (mENR) rate after 24 h. Successful FP reperfusion was defined as mTICI ≥ 2b. Successful and complete reperfusion were defined as mTICI ≥ 2b and mTICI ≥ 2c, respectively. Results: In total, 98 patients (52 men and 46 women) with a median age of 75 (range 25-95 years) were included. A total of 70 (72%) patients presented with an occlusion of the middle cerebral artery (MCA) in the M1 segment, 6 (6%) patients with an occlusion of the M2 segment, 17 (17%) patients with an occlusion of the internal carotid artery (ICA), and 5 (5%) patients with an occlusion of the obstructed basilar artery (BA). Successful FP reperfusion was achieved in 58 patients (62%). Successful and complete reperfusion were achieved in 95 (97%) and 82 (83%) patients, respectively. The median National Institutes of Health Stroke Scale (NIHSS) in all treated patients improved from 17 to 7.5. Major early neurological recovery (mENR) was observed in 34 patients (35.1%). Conclusion: MT with the pRESET 6-50 stent-retriever achieves high successful first-pass and final reperfusion rates in patients with AIS and LVO. The results of this study support the thesis to use large-format stent-retriever in proximal vessel occlusion MT whenever feasible in order to improve high FP and final reperfusion rate, which are known predictors of good clinical outcome.

4.
Neuroradiology ; 65(12): 1777-1785, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37878032

RESUMO

PURPOSE: This study aimed to evaluate the effectiveness and safety of the NeVaTM stent retriever as first- and second-line device for mechanical thrombectomy in acute ischemic stroke. METHODS: In this retrospective single-center study, all consecutive patients that underwent mechanical thrombectomy with NeVaTM stent retriever as first- or second-line device due to intracranial vessel occlusion with acute ischemic stroke between March and November 2022 were included. RESULTS: Thirty-nine patients (m=18, f=21) with a mean age of 69.9 ± 13.3 years were treated with the NeVaTM stent retriever. NeVaTM stent retriever was used as first-line device in 24 (61.5%) of patients and in 15 (38.5%) as second-line device. First-pass rate (≥mTICI 2c) of NeVaTM stent retriever was both 66.7% when used as first- or second-line device. Final recanalization rate including rescue strategies was 92.3% for ≥mTICI2c and 94.9% for ≥mTICI2b. No device-related minor or major adverse events were observed. A hemorrhage was detected in 33.3% of patients at 24h post-thrombectomy dual-energy CT, of which none was classified as symptomatic intracerebral hemorrhage. NIHSS and mRS improved significantly at discharge compared to admission (p<0.05). CONCLUSION: The NeVaTM stent retriever has a high effectivity and good safety profile as first- and second-line device for mechanical thrombectomy in acute ischemic stroke.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Acidente Vascular Cerebral/etiologia , AVC Isquêmico/etiologia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Trombectomia , Stents
5.
Sensors (Basel) ; 23(17)2023 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-37688083

RESUMO

Nitrate (NO3) pollution in groundwater, caused by various factors both natural and synthetic, contributes to the decline of human health and well-being. Current techniques used for nitrate detection include spectroscopic, electrochemical, chromatography, and capillary electrophoresis. It is highly desired to develop a simple cost-effective alternative to these complex methods for nitrate detection. Therefore, a real-time poly (3,4-ethylenedioxythiophene) (PEDOT)-based sensor for nitrate ion detection via electrical property change is introduced in this study. Vapor phase polymerization (VPP) is used to create a polymer thin film. Variations in specific parameters during the process are tested and compared to develop new insights into PEDOT sensitivity towards nitrate ions. Through this study, the optimal fabrication parameters that produce a sensor with the highest sensitivity toward nitrate ions are determined. With the optimized parameters, the electrical resistance response of the sensor to 1000 ppm nitrate solution is 41.79%. Furthermore, the sensors can detect nitrate ranging from 1 ppm to 1000 ppm. The proposed sensor demonstrates excellent potential to detect the overabundance of nitrate ions in aqueous solutions in real time.

6.
Ann Surg Oncol ; 30(13): 7976-7985, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37670120

RESUMO

BACKGROUND: Portal vein embolization (PVE) is used to induce remnant liver hypertrophy prior to major hepatectomy. The purpose of this study was to evaluate the predictive value of baseline computed tomography (CT) data for future remnant liver (FRL) hypertrophy after PVE. METHODS: In this retrospective study, all consecutive patients undergoing right-sided PVE with or without hepatic vein embolization between 2018 and 2021 were included. CT volumetry was performed before and after PVE to assess standardized FRL volume (sFRLV). Radiomic features were extracted from baseline CT after segmenting liver (without tumor), spleen and bone marrow. For selecting features that allow classification of response (hypertrophy ≥ 1.33), a stepwise dimension reduction was performed. Logistic regression models were fitted and selected features were tested for their predictive value. Decision curve analysis was performed on the test dataset. RESULTS: A total of 53 patients with liver tumor were included in this study. sFRLV increased significantly after PVE, with a mean hypertrophy of FRL of 1.5 ± 0.3-fold. sFRLV hypertrophy ≥ 1.33 was reached in 35 (66%) patients. Three independent radiomic features, i.e. liver-, spleen- and bone marrow-associated, differentiated well between responders and non-responders. A logistic regression model revealed the highest accuracy (area under the curve 0.875) for the prediction of response, with sensitivity of 1.0 and specificity of 0.5. Decision curve analysis revealed a positive net benefit when applying the model. CONCLUSIONS: This proof-of-concept study provides first evidence of a potential predictive value of baseline multi-organ radiomics CT data for FRL hypertrophy after PVE.


Assuntos
Embolização Terapêutica , Neoplasias Hepáticas , Humanos , Veia Porta/patologia , Estudos Retrospectivos , Fígado/cirurgia , Hepatectomia/métodos , Neoplasias Hepáticas/cirurgia , Hipertrofia/patologia , Hipertrofia/cirurgia , Resultado do Tratamento
7.
Hepatol Commun ; 7(10)2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37708430

RESUMO

BACKGROUND: The number of complications in patients admitted for cirrhosis has increased over time. Portal hypertension is the driver of many complications of cirrhosis. TIPS placement is the most effective treatment of portal hypertension. The aim of this study was to analyze the use and impact of TIPS placement in the last decade in a nationwide study in Germany. METHODS: We analyzed 14,598 admissions of patients for TIPS insertions in Germany from 2007 to 2018 using the DRG system, 12,877 out of 2,000,765 total admissions of patients with cirrhosis. All diagnoses and procedures were coded according to ICD-10-CM and OPS codes. The data were analyzed, focusing on the number of admissions and in-hospital mortality. RESULTS: The number of TIPS placements increased over the last decade. In-hospital mortality of cirrhotic patients with TIPS decreased when it was placed for severe bleeding (15.2% [TIPS] vs. 19.5% [endoscopy treatment]), ascites (8.7% [TIPS] vs. 14.4% [paracentesis]), and hepatorenal syndrome (HRS) (17.1% [TIPS] vs. 43.3% [no-TIPS]). In the case of bleeding, TIPS significantly decreased in-hospital mortality and also in ascites and HRS. During hospitalization, 22.6% admissions of patients with TIPS insertion showed HE. However, in-hospital mortality in patients admitted with HE grades 1 or 2 and TIPS was lower than in patients without TIPS. In the logistic regression, a higher HE grade(3 and 4), infection, and circulatory disease were found to be independently associated with in-hospital mortality in patients with TIPS insertion. CONCLUSION: Our nationwide study demonstrates that TIPS insertion is increasingly used in Germany. TIPS improves outcomes, especially in patients with ascites and HRS, regardless of lower HE grades, while higher HE grades, infection, and circulatory diseases seem to be associated with risk of in-hospital mortality.


Assuntos
Doenças Cardiovasculares , Hipertensão Portal , Humanos , Ascite , Alemanha/epidemiologia , Cirrose Hepática/complicações
8.
Sensors (Basel) ; 23(15)2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37571674

RESUMO

In this work, we introduce a novel approach to model the rain and fog effect on the light detection and ranging (LiDAR) sensor performance for the simulation-based testing of LiDAR systems. The proposed methodology allows for the simulation of the rain and fog effect using the rigorous applications of the Mie scattering theory on the time domain for transient and point cloud levels for spatial analyses. The time domain analysis permits us to benchmark the virtual LiDAR signal attenuation and signal-to-noise ratio (SNR) caused by rain and fog droplets. In addition, the detection rate (DR), false detection rate (FDR), and distance error derror of the virtual LiDAR sensor due to rain and fog droplets are evaluated on the point cloud level. The mean absolute percentage error (MAPE) is used to quantify the simulation and real measurement results on the time domain and point cloud levels for the rain and fog droplets. The results of the simulation and real measurements match well on the time domain and point cloud levels if the simulated and real rain distributions are the same. The real and virtual LiDAR sensor performance degrades more under the influence of fog droplets than in rain.

9.
Pneumologie ; 77(8): 461-543, 2023 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-37406667

RESUMO

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.


Assuntos
Antiasmáticos , Asma , Feminino , Gravidez , Humanos , Óxido Nítrico , Asma/terapia , Asma/tratamento farmacológico , Antiasmáticos/uso terapêutico , Biomarcadores , Dessensibilização Imunológica
10.
Artigo em Inglês | MEDLINE | ID: mdl-37174176

RESUMO

The increasing risk of disasters worldwide poses challenges both to health care infrastructures and to home care providers, who must maintain decentralised services for those in need of long-term care for as long as possible, even under adverse circumstances. However, both the kind of organisational precautions that home care providers consider in preparation for disasters and the available evidence on the effectiveness of these precautions remain largely unclear. An integrative literature review was thus performed via a systematic search of several international databases in order to identify original research on organisational disaster planning by home care providers and to determine the evidence base of this research. The quality of the included studies was assessed using the Mixed Methods Appraisal Tool. Of the 286 results, 12 articles met the inclusion criteria and presented results from nine studies on disaster planning. Three overarching types of activities carried out by home care providers were identified inductively. The overall scientific quality of the studies was moderate, and none investigated the effectiveness of disaster planning by home care providers. Despite the variety of possible activities that home care providers already consider, evidence on how to make organisational disaster planning effective and sustainable remains lacking.


Assuntos
Planejamento em Desastres , Desastres , Serviços de Assistência Domiciliar , Humanos , Planejamento em Desastres/métodos , Registros
12.
Sensors (Basel) ; 23(6)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36991824

RESUMO

Measurement performance evaluation of real and virtual automotive light detection and ranging (LiDAR) sensors is an active area of research. However, no commonly accepted automotive standards, metrics, or criteria exist to evaluate their measurement performance. ASTM International released the ASTM E3125-17 standard for the operational performance evaluation of 3D imaging systems commonly referred to as terrestrial laser scanners (TLS). This standard defines the specifications and static test procedures to evaluate the 3D imaging and point-to-point distance measurement performance of TLS. In this work, we have assessed the 3D imaging and point-to-point distance estimation performance of a commercial micro-electro-mechanical system (MEMS)-based automotive LiDAR sensor and its simulation model according to the test procedures defined in this standard. The static tests were performed in a laboratory environment. In addition, a subset of static tests was also performed at the proving ground in natural environmental conditions to determine the 3D imaging and point-to-point distance measurement performance of the real LiDAR sensor. In addition, real scenarios and environmental conditions were replicated in the virtual environment of a commercial software to verify the LiDAR model's working performance. The evaluation results show that the LiDAR sensor and its simulation model under analysis pass all the tests specified in the ASTM E3125-17 standard. This standard helps to understand whether sensor measurement errors are due to internal or external influences. We have also shown that the 3D imaging and point-to-point distance estimation performance of LiDAR sensors significantly impacts the working performance of the object recognition algorithm. That is why this standard can be beneficial in validating automotive real and virtual LiDAR sensors, at least in the early stage of development. Furthermore, the simulation and real measurements show good agreement on the point cloud and object recognition levels.

13.
J Am Acad Orthop Surg ; 31(9): 470-476, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36801893

RESUMO

INTRODUCTION: Orthobiologics are increasingly used to augment healing of tissues. Despite growing demand for orthobiologic products, many health systems do not enjoy substantial savings expected with high-volume purchases. The primary goal of this study was to evaluate an institutional program designed to (1) prioritize high-value orthobiologics and (2) incentivize vendor participation in value-driven contractual programs. METHODS: A three-step approach was used to reduce costs through optimization of orthobiologics supply chain. First, surgeons with orthobiologics expertise were engaged in key supply chain purchasing decisions. Second, eight orthobiologics formulary categories were defined. Capitated pricing expectations were established for each product category. Capitated pricing expectations were established for each product using institutional invoice data and market pricing data. In comparison with similar institutions, products offered by multiple vendors were priced at a lower benchmark (10th percentile of market price) than more rare products priced at the 25th percentile of the market price. Pricing expectations were transparent to vendors. Third, a competitive bidding process required vendors to submit pricing proposals for products. Clinicians and supply chain leaders jointly awarded contracts to vendors that met pricing expectations. RESULTS: Compared with our projected estimate of $423,946 savings using capitated product prices, our actual annual savings was $542,216. Seventy-nine percent of savings came from allograft products. Although the number of total vendors decreased from 14 to 11, each of the nine returning vendors received a larger, three-year institutional contract. Average pricing decreased across seven of the eight formulary categories. DISCUSSION: This study demonstrates a three-step replicable approach to increase institutional savings for orthobiologic products, engaging clinician experts, and strengthening relationships with select vendors. Vendor consolidation permits a symbiotic win-win relationship: Health systems achieve increased value by reducing unnecessary complexity of multiple contracts, and vendors obtain larger contracts with increased market share. LEVEL OF EVIDENCE: Level IV study.


Assuntos
Comércio , Negociação , Humanos , Custos e Análise de Custo
15.
J Orthop Trauma ; 37(6): 304, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36728607

RESUMO

OBJECTIVE: To determine whether market-based pricing could be coupled with surgeon integration into negotiation strategies to achieve lower pricing levels for orthopaedic trauma implants. A secondary aim was to identify specific types of implants that may offer larger opportunities for cost savings. METHODS: Market pricing levels were reviewed from 2 industry implant databases. This information was used by surgeons and supply chain management at our institution to select appropriate target pricing levels (25th percentile) for commonly used orthopaedic trauma implants. Target price values were provided to the existing 12 vendors used by our institution with a clear expectation that vendors meet these thresholds. RESULTS: Benchmark modeling projected a potential savings of 20.0% over our prior annual spend on trauma implants. After 2 rounds of negotiation, savings amounted to 23.0% of prior annual spend. Total savings exceeded 1,000,000 USD with 11 of 12 vendors (91.7%) offering net savings. Total percent savings were highest for external fixators, drill bits, and K-wires. Plates and screws comprised the greatest proportion of our prior annual spend and achieved similar savings. CONCLUSION: A surgeon and supply chain coordinated effort led to major cost savings without a need for consolidation of vendors. LEVEL OF EVIDENCE: Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.


Assuntos
Ortopedia , Cirurgiões , Humanos , Próteses e Implantes , Redução de Custos
17.
Front Med (Lausanne) ; 9: 1066412, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36582288

RESUMO

Objectives: To evaluate the safety and outcome of image-guided sclerotherapy for treating venous malformations (VMs) of the face. Materials and methods: A multicenter cohort of 68 patients with VMs primarily affecting the face was retrospectively investigated. In total, 142 image-guided sclerotherapies were performed using gelified ethanol and/or polidocanol. Clinical and imaging findings were assessed to evaluate clinical response, lesion size reduction, and complication rates. Sub-analyses of complication rates depending on type and injected volume of the sclerosant as well as of pediatric versus adult patient groups were conducted. Results: Mean number of procedures per patient was 2.1 (±1.7) and mean follow-up consisted of 8.7 months (±6.8 months). Clinical response (n = 58) revealed a partial relief of symptoms in 70.7% (41/58), 13/58 patients (22.4%) presented symptom-free while only 4/58 patients (6.9%) reported no improvement. Post-treatment imaging (n = 52) revealed an overall objective response rate of 86.5% (45/52). The total complication rate was 10.6% (15/142) including 4.2% (7/142) major complications, mostly (14/15, 93.3%) resolved by conservative means. In one case, a mild facial palsy persisted over time. The complication rate in the gelified ethanol subgroup was significantly higher compared to polidocanol and to the combination of both sclerosants (23.5 vs. 6.0 vs. 8.3%, p = 0.01). No significant differences in complications between the pediatric and the adult subgroup were observed (12.1 vs. 9.2%, p = 0.57). Clinical response did not correlate with lesion size reduction on magnetic resonance imaging (MRI). Conclusion: Image-guided sclerotherapy is effective for treating VMs of the face. Clinical response is not necessarily associated with size reduction on imaging. Despite the complex anatomy of this location, the procedures are safe for both adults and children.

18.
Sensors (Basel) ; 22(19)2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36236655

RESUMO

This work introduces a process to develop a tool-independent, high-fidelity, ray tracing-based light detection and ranging (LiDAR) model. This virtual LiDAR sensor includes accurate modeling of the scan pattern and a complete signal processing toolchain of a LiDAR sensor. It is developed as a functional mock-up unit (FMU) by using the standardized open simulation interface (OSI) 3.0.2, and functional mock-up interface (FMI) 2.0. Subsequently, it was integrated into two commercial software virtual environment frameworks to demonstrate its exchangeability. Furthermore, the accuracy of the LiDAR sensor model is validated by comparing the simulation and real measurement data on the time domain and on the point cloud level. The validation results show that the mean absolute percentage error (MAPE) of simulated and measured time domain signal amplitude is 1.7%. In addition, the MAPE of the number of points Npoints and mean intensity Imean values received from the virtual and real targets are 8.5% and 9.3%, respectively. To the author's knowledge, these are the smallest errors reported for the number of received points Npoints and mean intensity Imean values up until now. Moreover, the distance error derror is below the range accuracy of the actual LiDAR sensor, which is 2 cm for this use case. In addition, the proving ground measurement results are compared with the state-of-the-art LiDAR model provided by commercial software and the proposed LiDAR model to measure the presented model fidelity. The results show that the complete signal processing steps and imperfections of real LiDAR sensors need to be considered in the virtual LiDAR to obtain simulation results close to the actual sensor. Such considerable imperfections are optical losses, inherent detector effects, effects generated by the electrical amplification, and noise produced by the sunlight.

19.
Diagn Interv Radiol ; 28(5): 486-494, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36218151

RESUMO

PURPOSE This study aimed to evaluate the safety and outcome of image-guided embolization for treating arteriovenous malformations (AVMs) of the hand using ethylene-vinyl alcohol copolymer (EVOH). METHODS A retrospective, multicenter cohort of 15 patients with AVMs of the hand treated with 35 imageguided embolotherapies using EVOH was investigated. Clinical history, symptomatology, and imaging findings were assessed to evaluate clinical outcome (symptom-free, partial relief of pain, no improvement of pain, and clinical progression despite embolization), lesion devascularization (total, 100%; near-total, 90%-99%; substantial, 70%-90%; partial, 30%-70%; and failure, 0%-30%), and peri- and postprocedural complication rates (major complications classified according to CIRSE guidelines). Substratification analysis was performed with respect to the involvement of different anatomical compartments and the injected volume of the embolic agent. RESULTS Patients were treated for pain (93.3%), skin ulceration (46.7%), and local bleeding (33.3%). The mean number of embolotherapies was 2.3 (±1.1) in 3 patients, a planned surgical resection was conducted after embolization. Clinical outcome after a median follow-up of 18 months revealed an overall response of 11/15 patients (73.3%). Imaging at last follow-up revealed 70%- 99% reduced vascularization in 12/15 patients (80%) including 2 patients (13.3%) with a neartotal devascularization of 90%-99%. Peri- and postprocedural complications occurred in 8.5% and 31.5%, respectively, including 17.1% major complications, in 1 case requiring a previously unplanned resection. Involvement of the finger was associated with increased rates of persistent symptoms compared to the other groups (P=.049). No significant difference between the embolic agent volume injected and complication rates was found (P=.372). CONCLUSION Image-guided embolization using EVOH-based liquid embolic agents is effective for treating AVMs of the hand in the mid-term.


Assuntos
Malformações Arteriovenosas , Embolização Terapêutica , Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/terapia , Embolização Terapêutica/métodos , Humanos , Dor/tratamento farmacológico , Polivinil/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento
20.
Sensors (Basel) ; 22(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36080914

RESUMO

In this paper, we investigate the application of using software-defined radio (SDR) and surface acoustic wave (SAW) device for wireless measurement of the response of in situ sensors. SDR uses software to realize different communication functions. After collecting the magnitude and phase of the response at discrete frequencies, we apply inverse Fourier transform to analyze the time domain responses which, in turn, allows for monitoring the changes of the response of the in situ sensor. We employ microwave signal flow graph concepts to improve the quality of the received signals. Comparing the normalized results obtained by SDR with those obtained from a commercial vector network analyzer (VNA), we demonstrate that the results are sufficiently close, and the SDR-based experiments can provide satisfactory measurement of the in-situ sensors. The objective is to eventually employ this wireless measurement system for soil nutrient sensing.


Assuntos
Software , Tecnologia sem Fio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...