Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Emerg Infect Dis ; 29(10): 2180-2182, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37735803

RESUMO

We performed phylogenetic analysis on dengue virus serotype 2 Cosmopolitan genotype in Ho Chi Minh City, Vietnam. We document virus emergence, probable routes of introduction, and timeline of events. Our findings highlight the need for continuous, systematic genomic surveillance to manage outbreaks and forecast future epidemics.


Assuntos
Vírus da Dengue , Vírus da Dengue/genética , Filogenia , Sorogrupo , Vietnã/epidemiologia , Genótipo
2.
Radiographics ; 43(7): e220142, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37319025

RESUMO

The Ovarian-Adnexal Reporting and Data System (O-RADS) MRI risk stratification system provides a standardized lexicon and evidence-based risk score for evaluation of adnexal lesions. The goals of the lexicon and risk score are to improve report quality and communication between radiologists and clinicians, reduce variability in the reporting language, and optimize management of adnexal lesions. The O-RADS MRI risk score is based on the presence or absence of specific imaging features, including the lipid content, enhancing solid tissue, number of loculi, and fluid type. The probability of malignancy ranges from less than 0.5% when there are benign features to approximately 90% when there is solid tissue with a high-risk time-intensity curve. This information can aid in optimizing management of patients with adnexal lesions. The authors present an algorithmic approach to the O-RADS MRI risk stratification system and highlight key teaching points and common pitfalls. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.


Assuntos
Doenças dos Anexos , Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/patologia , Imageamento por Ressonância Magnética/métodos , Fatores de Risco , Idioma , Sistemas de Dados , Doenças dos Anexos/diagnóstico por imagem , Estudos Retrospectivos , Ultrassonografia/métodos
3.
BMC Bioinformatics ; 23(1): 22, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34991453

RESUMO

BACKGROUND: As antibiotic resistance creates a significant global health threat, we need not only to accelerate the development of novel antibiotics but also to develop better treatment strategies using existing drugs to improve their efficacy and prevent the selection of further resistance. We require new tools to rationally design dosing regimens from data collected in early phases of antibiotic and dosing development. Mathematical models such as mechanistic pharmacodynamic drug-target binding explain mechanistic details of how the given drug concentration affects its targeted bacteria. However, there are no available tools in the literature that allow non-quantitative scientists to develop computational models to simulate antibiotic-target binding and its effects on bacteria. RESULTS: In this work, we have devised an extension of a mechanistic binding-kinetic model to incorporate clinical drug concentration data. Based on the extended model, we develop a novel and interactive web-based tool that allows non-quantitative scientists to create and visualize their own computational models of bacterial antibiotic target-binding based on their considered drugs and bacteria. We also demonstrate how Rifampicin affects bacterial populations of Tuberculosis bacteria using our vCOMBAT tool. CONCLUSIONS: The vCOMBAT online tool is publicly available at https://combat-bacteria.org/ .


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Antibacterianos/farmacologia , Bactérias/genética , Simulação por Computador , Modelos Biológicos
4.
Anal Chem ; 93(36): 12391-12399, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34468139

RESUMO

As an immune response to COVID-19 infection, patients develop SARS-CoV-2-specific IgM/IgG antibodies. Here, we compare the performance of a conventional lateral flow assay (LFA) with a surface-enhanced Raman scattering (SERS)-based LFA test for the detection of SARS-CoV-2-specific IgM/IgG in sera of COVID-19 patients. Sensitive detection of IgM might enable early serological diagnosis of acute infections. Rapid detection in serum using a custom-built SERS reader is at least an order of magnitude more sensitive than the conventional LFAs with naked-eye detection. For absolute quantification and the determination of the limit of detection (LOD), a set of reference measurements using purified (total) IgM in buffer was performed. In this purified system, the sensitivity of SERS detection is even 7 orders of magnitude higher: the LOD for SERS was ca. 100 fg/mL compared to ca. 1 µg/mL for the naked-eye detection. This outlines the high potential of SERS-based LFAs in point-of-care testing once the interference of serum components with the gold conjugates and the nitrocellulose membrane is minimized.


Assuntos
COVID-19 , RNA Viral , Anticorpos Antivirais , Humanos , Imunoglobulina G , Imunoglobulina M , SARS-CoV-2 , Sensibilidade e Especificidade
5.
Opt Express ; 29(13): 20913-20929, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34266169

RESUMO

Compressive lensless imagers enable novel applications in an extremely compact device, requiring only a phase or amplitude mask placed close to the sensor. They have been demonstrated for 2D and 3D microscopy, single-shot video, and single-shot hyperspectral imaging; in each case, a compressive-sensing-based inverse problem is solved in order to recover a 3D data-cube from a 2D measurement. Typically, this is accomplished using convex optimization and hand-picked priors. Alternatively, deep learning-based reconstruction methods offer the promise of better priors, but require many thousands of ground truth training pairs, which can be difficult or impossible to acquire. In this work, we propose an unsupervised approach based on untrained networks for compressive image recovery. Our approach does not require any labeled training data, but instead uses the measurement itself to update the network weights. We demonstrate our untrained approach on lensless compressive 2D imaging, single-shot high-speed video recovery using the camera's rolling shutter, and single-shot hyperspectral imaging. We provide simulation and experimental verification, showing that our method results in improved image quality over existing methods.

6.
Proc Natl Acad Sci U S A ; 115(2): 361-366, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29279375

RESUMO

The wMel strain of Wolbachia can reduce the permissiveness of Aedes aegypti mosquitoes to disseminated arboviral infections. Here, we report that wMel-infected Ae. aegypti (Ho Chi Minh City background), when directly blood-fed on 141 viremic dengue patients, have lower dengue virus (DENV) transmission potential and have a longer extrinsic incubation period than their wild-type counterparts. The wMel-infected mosquitoes that are field-reared have even greater relative resistance to DENV infection when fed on patient-derived viremic blood meals. This is explained by an increased susceptibility of field-reared wild-type mosquitoes to infection than laboratory-reared counterparts. Collectively, these field- and clinically relevant findings support the continued careful field-testing of wMel introgression for the biocontrol of Ae. aegypti-born arboviruses.


Assuntos
Aedes/virologia , Vírus da Dengue/fisiologia , Dengue/virologia , Mosquitos Vetores/virologia , Wolbachia/fisiologia , Aedes/microbiologia , Animais , Dengue/sangue , Dengue/transmissão , Humanos , Modelos Logísticos , Mosquitos Vetores/microbiologia , Controle Biológico de Vetores/métodos , Fatores de Tempo , Viremia/sangue , Viremia/virologia
7.
Neurocrit Care ; 35(1): 221-231, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33403579

RESUMO

BACKGROUND/OBJECTIVES: We postulated that renal replacement therapy (RRT) in ICH patients with advanced chronic kidney disease (CKD) is associated with increased frequency and size of perihematomal edema (PHE) expansion and worse patient outcomes. METHODS: The Get With the Guidelines-Stroke Registry was queried for all patients admitted with ICH (N = 1089). Secondary causes, brainstem ICH, and initial HV < 7 cc were excluded. We identified patients with advanced CKD with and without RRT following admission for ICH. ABC/2 formula was used to measure hematoma volume (HV) and PHE. Patient outcomes were 30-day mortality, 90-day modified Rankin Scale score, and discharge disposition. We used propensity scores and optimal matching to adjust for multiple covariates. RESULTS: At 48 h post-ICH, PHE expansion was a significant predictor of poor patient outcomes in our cohort. Patients with CKD who received sustained low-efficacy dialysis (SLED) treatment had larger 48 h PHE growth compared to both untreated CKD group (average treatment effect (ATE), 11.5; 95% CI, 4.9-18.1; p < 0.01) and all untreated patients (ATE, 7.43; 95% CI, 4.7-10.2; p < 0.01). Moreover, patients with RRT had significantly worse functional and mortality outcomes. CONCLUSIONS: SLED treatment in ICH patients with CKD was associated with significant increase in rate and frequency of PHE expansion. Absolute increase in PHE during 48-h post-ICH was associated with increased mortality and worse functional outcomes. Further prospective and multicenter evaluation is needed to differentiate the effects of RRT on hematoma dynamics and patient outcomes from those attributed to CKD.


Assuntos
Edema Encefálico , Terapia de Substituição Renal Híbrida , Edema Encefálico/etiologia , Edema Encefálico/terapia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/terapia , Hematoma , Humanos , Resultado do Tratamento
8.
Forensic Sci Med Pathol ; 17(2): 350-353, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33405071

RESUMO

Identification of the deceased is a critical responsibility of the death investigation system. If visual identification is inconclusive, tattoos can provide secondary identification but may be difficult to visualize at various stages of decomposition. We describe the case of a 35-year-old male found submerged underwater by police after swimming at a pier. The decedent was last seen earlier that day. Signs of immersion including sodden hands, feet, and clothing, wet sand on the torso and legs, and heavy edematous legs were observed. The post-mortem blood alcohol concentration was 427 mg/100 mL; signs of recent traumatic injury were not present. The immediate cause of death was drowning as a consequence of ethanol intoxication. When pulled from the water, the decedent's shoulder tattoo was not visible. Cross-polarized lighting and infrared photography visualized the tattoo to help confirm identity. These photographic methods were compared to hydrogen peroxide and optical coherence tomography techniques and described in detail to assist with future cases.


Assuntos
Tatuagem , Adulto , Autopsia , Concentração Alcoólica no Sangue , Humanos , Iluminação , Masculino , Fotografação
9.
Angew Chem Int Ed Engl ; 59(14): 5454-5462, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-31588641

RESUMO

Experimental results obtained in different laboratories world-wide by researchers using surface-enhanced Raman scattering (SERS) can differ significantly. We, an international team of scientists with long-standing expertise in SERS, address this issue from our perspective by presenting considerations on reliable and quantitative SERS. The central idea of this joint effort is to highlight key parameters and pitfalls that are often encountered in the literature. To that end, we provide here a series of recommendations on: a) the characterization of solid and colloidal SERS substrates by correlative electron and optical microscopy and spectroscopy, b) on the determination of the SERS enhancement factor (EF), including suitable Raman reporter/probe molecules, and finally on c) good analytical practice. We hope that both newcomers and specialists will benefit from these recommendations to increase the inter-laboratory comparability of experimental SERS results and further establish SERS as an analytical tool.

10.
Radiology ; 291(1): 250-258, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30620252

RESUMO

Purpose To evaluate the safety and efficacy of percutaneous transarterial embolization (PTAE) for the treatment of spontaneous soft-tissue hematomas (SSTHs) and identify variables predictive of short-term outcome. Materials and Methods Between 2011 and 2017, the outcome was retrospectively analyzed for 112 patients (mean age ± standard deviation, 72 years ± 14; range, 28-92 years), including 65 women (mean age, 73 years ± 12.7; range, 39-92 years) and 47 men (mean age, 70 years ± 14.9; range, 28-91 years), with SSTH treated with PTAE. Thirty-day mortality, technical and clinical success, simplified acute physiology score (SAPS) II, anticoagulation, embolic agent, hematoma volume and location, serum hemoglobin level, hemodynamic instability, and presence of active bleeding at CT and/or angiography were recorded. Clinical success was defined as cessation of bleeding as determined by hemodynamic stability and/or serum hemoglobin level stabilization after PTAE. Univariable and multivariable analyses were performed by using a Cox model to identify variables associated with time to death. Results Mortality rate was 26.8% (30 of 112 patients), angiographic success rate was 95.5% (107 of 112 patients), and clinical success rate was 83% (93 of 112 patients). For surviving patients, mean SAPS II was 19.6 ± 7.1 (range, 13-31) and mean hematoma volume was 862 cm3 ± 618 (range, 238-1887 cm3). For deceased patients, mean SAPS II was 42 ± 13.2 (range, 18-63) and mean hematoma volume was 1419 cm3 ± 788 (range, 251-3492 cm3). SAPS II (P < .001), hematoma volume (P = .01), and retroperitoneal location (P = .01) were independently associated with fatal outcome. Conclusion Percutaneous transarterial embolization is effective for the emergency treatment of spontaneous soft-tissue hematomas. Simplified acute physiology score II, hematoma volume, and retroperitoneal location are predictors of short-term outcome. © RSNA, 2019 Online supplemental material is available for this article.


Assuntos
Embolização Terapêutica/métodos , Hematoma/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Embolização Terapêutica/mortalidade , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Hematoma/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculares/mortalidade , Doenças Musculares/terapia , Espaço Retroperitoneal , Estudos Retrospectivos , Resultado do Tratamento
11.
Angew Chem Int Ed Engl ; 58(2): 442-446, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30288886

RESUMO

The design of a portable Raman/SERS-LFA reader with line illumination using a custom-made fiber optic probe for rapid, quantitative, and ultrasensitive point-of-care testing (POCT) is presented. The pregnancy hormone human chorionic gonadotropin (hCG) is detectable in clinical samples within only 2-5 s down to approximately 1.6 mIU mL-1 . This acquisition time is several orders of magnitude shorter than those of existing approaches requiring expensive Raman instrumentation, and the method is 15-times more sensitive than a commercially available lateral flow assay (LFA) as the gold standard. The SERS-LFA technology paves the way for affordable, quantitative, and ultrasensitive POCT with multiplexing potential in real-world applications, ranging from clinical chemistry to food and environmental analysis as well as drug and biowarfare agent testing.


Assuntos
Técnicas Biossensoriais/métodos , Sistemas Automatizados de Assistência Junto ao Leito/normas , Análise Espectral Raman/métodos , Química Clínica , Humanos
12.
J Anat ; 231(4): 484-499, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28766716

RESUMO

Differences between hearts of crocodilians and those of mammals and birds are only partly understood because there is no standardised approach and terminology for describing cardiac structure. Whereas most reptiles have an undivided ventricle, crocodilians have a fully septated ventricle. Their hearts, therefore, are more readily comparable with the hearts of mammals and birds. Here, we describe the heart of a crocodile (Crocodylus noliticus). We use the versatile sequential segmental approach to analysis, juxtaposing several key views of the crocodilian heart to the comparable views of human hearts. In crocodiles, the atrial and ventricular septums are complete but, unlike in placental mammals, the atrial septum is without an oval fossa. The myocardial component of the crocodilian ventricular septum dominates, but the membranous septum likely makes up a greater proportion than in any mammal. In the crocodile, the aortic trunk takes its origin from the left ventricle and is not wedged between the atrioventricular junctions. Consequently, there is a common atrioventricular junction, albeit with separate right and left atrioventricular valvar orifices. As in mammals, nonetheless, the crocodilian left atrioventricular valvar orifice is cranial to the right atrioventricular valvar orifice. By applying a method of analysis and terminology usually restricted to the human heart, we build from the considerable existing literature to show neglected and overlooked shared features, such as the offset between the left and right atrioventricular valvar orifices. Such commonalities are surprising given the substantial evolutionary divergence of the archosaur and synapsid lineages, and likely reflect evolutionarily shared morphogenetic programmes.


Assuntos
Jacarés e Crocodilos/anatomia & histologia , Coração/anatomia & histologia , Jacarés e Crocodilos/fisiologia , Animais , Coração/fisiologia
13.
Can Assoc Radiol J ; 68(4): 447-455, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28927740

RESUMO

PURPOSE: Radioactive seed localization (RSL) uses a titanium seed labeled with iodine-125 energy for surgery of nonpalpable breast lesions. RSL facilitates radiology-surgery scheduling and allows for improved oncoplasty compared with wire localization (WL). The purpose of this work was to compare the 2 techniques. METHODS: We performed a retrospective study of all breast lesions operated with RSL between February 2013 and March 2015 at our university institution, and compared with an equivalent number of surgeries performed with a single WL. Imaging and pathology reports were reviewed for information on guidance mode, accuracy of targeting, nature of excised lesion, size and volume of surgical specimen, status of margins, and reinterventions. RESULTS: A total of 254 lesions (247 women) were excised with RSL and compared with 257 lesions (244 women) whose surgery was guided by WL. Both groups were comparable in lesion pathology, guidance mode for RSL or WL positioning, and accuracy of targeting (98% correct). Mean delay between biopsy and surgery was 84 days for RSL versus 103 after WL (P = .04). No differences were noted after RSL or WL for surgical specimen mean weight, largest diameter, and volume excised. For malignancies, the rate of positive margins was comparable (2.8%-3%), with 5 of 10 women in the RSL group who underwent a second surgery displaying residual malignancy compared with 3 of 9 women in the WL group. CONCLUSIONS: RSL is safe and accurate, and has comparable surgical endpoints to WL. Because RSL offers flexible scheduling and facilitated oncoplasty, RSL may replace WL for resection of nonpalpable single breast lesions.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Marcadores Fiduciais , Radioisótopos do Iodo , Mastectomia Segmentar/métodos , Ultrassonografia de Intervenção , Mama/diagnóstico por imagem , Mama/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Titânio
14.
Org Biomol Chem ; 12(36): 7083-91, 2014 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-25087588

RESUMO

Nucleophilic substitution reactions of five-membered ring acetals bearing fused rings reveal that subtle changes in the structure of the fused ring can exert dramatic influences on selectivity. If the fused ring did not constrain the five-membered ring undergoing substitution, selectivity was comparable to what was observed for an unconstrained system (≥92% diastereoselectivity, favoring the product of inside attack on the oxocarbenium ion). If the ring were more constrained by including at least one oxygen atom in the ring, selectivity dropped considerably (to 60% diastereoselectivity in one case). Transition states of the nucleophilic addition of allyltrimethylsilane to selected oxocarbenium ions were calculated using DFT methods. These computational models reproduced the correlation between additional conformational rigidity and selectivity.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Furanos/química , Acetais/química , Transporte de Elétrons , Conformação Molecular , Estereoisomerismo , Compostos de Trimetilsilil/química
15.
Fed Pract ; 41(2): 62-66, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38835922

RESUMO

Background: Independent of age, sex, and body composition, individuals of African American race and individuals with high muscle mass have elevated serum creatinine (sCr) levels on average that may result in overestimation of chronic kidney disease (CKD). We present a misdiagnosed case of CKD based on sCr levels, illustrating the utility of cystatin C (CysC) confirmation testing to answer the question: Can confirmation screening of kidney function with CysC in African American patients and patients with high muscle mass reduce the misdiagnosis of CKD? Case Presentation: A 35-year-old African American man with a history of well-controlled HIV was found to have consistently elevated creatinine (Cr). We diagnosed CKD stage 3A based on the estimated glomerular filtration rate (eGFR). Further evaluation showed isolated elevation of sCr with unremarkable urinalysis and other laboratory tests. sCr elevation predated diagnosis and HIV treatment. A CysC-based eGFR (eGFRcys) test confirmed the absence of CKD. Conclusions: The 2009 CKD Epidemiology Collaboration calculation of eGFR based on sCr concentration uses age, sex, and race, with an updated recommendation in 2021 to exclude race. Both equations are less accurate in African American patients, individuals taking medications that interfere with sCr secretion and assay, and patients taking creatine supplements or high protein intake. These clinical scenarios decrease sCr-based eGFR (eGFRCr) but do not change measured eGFR or eGFRCys. Using sCr and serum cystatin C (eGFRCr-Cys) yields better concordance to measured eGFR across all races than does eGFR estimation based on Cr alone. Confirmation with CysC can avoid misdiagnosis, incorrect dosing of drugs, and inaccurate representation of the fitness for duty.

16.
PLoS One ; 19(5): e0303704, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38748722

RESUMO

There is currently no systematic review of the growing body of literature on using social robots in early developmental research. Designing appropriate methods for early childhood research is crucial for broadening our understanding of young children's social and cognitive development. This scoping review systematically examines the existing literature on using social robots to study social and cognitive development in infants and toddlers aged between 2 and 35 months. Moreover, it aims to identify the research focus, findings, and reported gaps and challenges when using robots in research. We included empirical studies published between 1990 and May 29, 2023. We searched for literature in PsychINFO, ERIC, Web of Science, and PsyArXiv. Twenty-nine studies met the inclusion criteria and were mapped using the scoping review method. Our findings reveal that most studies were quantitative, with experimental designs conducted in a laboratory setting where children were exposed to physically present or virtual robots in a one-to-one situation. We found that robots were used to investigate four main concepts: animacy concept, action understanding, imitation, and early conversational skills. Many studies focused on whether young children regard robots as agents or social partners. The studies demonstrated that young children could learn from and understand social robots in some situations but not always. For instance, children's understanding of social robots was often facilitated by robots that behaved interactively and contingently. This scoping review highlights the need to design social robots that can engage in interactive and contingent social behaviors for early developmental research.


Assuntos
Desenvolvimento Infantil , Cognição , Robótica , Humanos , Lactente , Desenvolvimento Infantil/fisiologia , Cognição/fisiologia , Pré-Escolar , Comportamento Social
17.
medRxiv ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38798319

RESUMO

Dengue virus (DENV) is currently causing epidemics of unprecedented scope in endemic settings and expanding to new geographical areas. It is therefore critical to track this virus using genomic surveillance. However, the complex patterns of viral genomic diversity make it challenging to use the existing genotype classification system. Here we propose adding two sub-genotypic levels of virus classification, named major and minor lineages. These lineages have high thresholds for phylogenetic distance and clade size, rendering them stable between phylogenetic studies. We present an assignment tool to show that the proposed lineages are useful for regional, national and sub-national discussions of relevant DENV diversity. Moreover, the proposed lineages are robust to classification using partial genome sequences. We provide a standardized neutral descriptor of DENV diversity with which we can identify and track lineages of potential epidemiological and/or clinical importance. Information about our lineage system, including methods to assign lineages to sequence data and propose new lineages, can be found at: dengue-lineages.org.

18.
J Org Chem ; 78(13): 6609-21, 2013 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-23738497

RESUMO

A series of fused-bicyclic acetals containing a disiloxane ring was investigated to evaluate the source of selectivity in silyl-protected 2-deoxyribose systems. The disiloxane ring unexpectedly enables the diaxial conformer of the cation to be stabilized by an electronegative atom at C-3. This low energy conformer subsequently undergoes stereoelectronically controlled nucleophilic addition to give substituted tetrahydrofurans with high diastereoselectivity.


Assuntos
Acetais/química , Compostos Bicíclicos com Pontes/química , Desoxirribose/química , Siloxanas/química , Conformação Molecular , Estereoisomerismo
19.
Bioengineering (Basel) ; 10(6)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37370668

RESUMO

Backgrounds and Objective: Facial palsy is a complex pathophysiological condition affecting the personal and professional lives of the involved patients. Sudden muscle weakness or paralysis needs to be rehabilitated to recover a symmetric and expressive face. Computer-aided decision support systems for facial rehabilitation have been developed. However, there is a lack of facial muscle baseline data to evaluate the patient states and guide as well as optimize the rehabilitation strategy. In this present study, we aimed to develop a novel baseline facial muscle database (static and dynamic behaviors) using the coupling between statistical shape modeling and in-silico trial approaches. Methods: 10,000 virtual subjects (5000 males and 5000 females) were generated from a statistical shape modeling (SSM) head model. Skull and muscle networks were defined so that they statistically fit with the head shapes. Two standard mimics: smiling and kissing were generated. The muscle strains of the lengths in neutral and mimic positions were computed and recorded thanks to the muscle insertion and attachment points on the animated head and skull meshes. For validation, five head and skull meshes were reconstructed from the five computed tomography (CT) image sets. Skull and muscle networks were then predicted from the reconstructed head meshes. The predicted skull meshes were compared with the reconstructed skull meshes based on the mesh-to-mesh distance metrics. The predicted muscle lengths were also compared with those manually defined on the reconstructed head and skull meshes. Moreover, the computed muscle lengths and strains were compared with those in our previous studies and the literature. Results: The skull prediction's median deviations from the CT-based models were 2.2236 mm, 2.1371 mm, and 2.1277 mm for the skull shape, skull mesh, and muscle attachment point regions, respectively. The median deviation of the muscle lengths was 4.8940 mm. The computed muscle strains were compatible with the reported values in our previous Kinect-based method and the literature. Conclusions: The development of our novel facial muscle database opens new avenues to accurately evaluate the facial muscle states of facial palsy patients. Based on the evaluated results, specific types of facial mimic rehabilitation exercises can also be selected optimally to train the target muscles. In perspective, the database of the computed muscle lengths and strains will be integrated into our available clinical decision support system for automatically detecting malfunctioning muscles and proposing patient-specific rehabilitation serious games.

20.
Med Biol Eng Comput ; 60(2): 559-581, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35023072

RESUMO

Skull prediction from the head is a challenging issue toward a cost-effective therapeutic solution for facial disorders. This issue was initially studied in our previous work using full head-to-skull relationship learning. However, the head-skull thickness topology is locally shaped, especially in the face region. Thus, the objective of the present study was to enhance our head-to-skull prediction problem by using local topological features for training and predicting. Head and skull feature points were sampled on 329 head and skull models from computed tomography (CT) images. These feature points were classified into the back and facial topologies. Head-to-skull relations were trained using the partial least square regression (PLSR) models separately in the two topologies. A hyperparameter tuning process was also conducted for selecting optimal parameters for each training model. Thus, a new skull could be generated so that its shape was statistically fitted with the target head. Mean errors of the predicted skulls using the topology-based learning method were better than those using the non-topology-based learning method. After tenfold cross-validation, the mean error was enhanced 36.96% for the skull shapes and 14.17% for the skull models. Mean error in the facial skull region was especially improved with 4.98%. The mean errors were also improved 11.71% and 25.74% in the muscle attachment regions and the back skull regions respectively. Moreover, using the enhanced learning strategy, the errors (mean ± SD) for the best and worst prediction cases are from 1.1994 ± 1.1225 mm (median: 0.9036, coefficient of multiple determination (R2): 0.997274) to 3.6972 ± 2.4118 mm (median: 3.9089, R2: 0.999614) and from 2.0172 ± 2.0454 mm (median: 1.2999, R2: 0.995959) to 4.0227 ± 2.6098 mm (median: 3.9998, R2: 0.998577) for the predicted skull shapes and the predicted skull models respectively. This present study showed that more detailed information on the head-skull shape leads to a better accuracy level for the skull prediction from the head. In particular, local topological features on the back and face regions of interest should be considered toward a better learning strategy for the head-to-skull prediction problem. In perspective, this enhanced learning strategy was used to update our developed clinical decision support system for facial disorders. Furthermore, a new class of learning methods, called geometric deep learning will be studied.


Assuntos
Cabeça , Crânio , Face , Cabeça/diagnóstico por imagem , Modelos Estatísticos , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa