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1.
BMC Musculoskelet Disord ; 25(1): 80, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245729

RESUMO

BACKGROUND: Gait disorders and as a consequence, robotic rehabilitation techniques are becoming increasingly prevalent as the population ages. In the area of rehabilitation robotics, using lightweight single hip joint exoskeletons are of significance. Considering no prior systematic review article on clinical outcomes, we aim to systematically review powered hip exoskeletons in terms of gait parameters and metabolic expenditure effects. METHODS: Three databases of PubMed, Scopus, and Web of science were searched for clinical articles comparing outcomes of gait rehabilitation using hip motorized exoskeleton with conventional methods, on patients with gait disorder or healthy individuals. Of total number of 37 reviewed articles, 14 trials were quantitatively analyzed. Analyses performed in terms of gait spatiotemporal parameters like speed (self-speed and maximum speed), step length, stride length, cadence, and oxygen consumption. RESULTS: Improved clinical outcomes of gait spatiotemporal parameters with hip joint exoskeletons are what our review's findings show. In terms of gait values, meta-analysis indicates that rehabilitation with single hip joint exoskeleton enhanced parameters of maximum speed by 0.13 m/s (0.10-0.17) and step length by 0.06 m (0.05-0.07). For the remaining investigated gait parameters, no statistically significant difference was observed. Regarding metabolic parameters, oxygen consumption was lower in individuals treated with hip exoskeleton (- 1.23 ml/min/kg; range - 2.13 to - 0.32). CONCLUSION: Although the analysis demonstrated improvement with just specific gait measures utilizing powered hip exoskeletons, the lack of improvement in all parameters is likely caused by the high patient condition heterogeneity among the evaluated articles. We also noted in patients who rehabilitated with the hip exoskeleton, the oxygen cost was lower. More randomized controlled trials are needed to verify both the short- and long-term clinical outcomes, including patient-reported measures. LEVEL OF EVIDENCE: Level I (systematic review and meta-analysis).


Assuntos
Exoesqueleto Energizado , Marcha , Articulação do Quadril , Humanos , Robótica , Caminhada
2.
Sensors (Basel) ; 20(16)2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823505

RESUMO

Due to occlusion or detached markers, information can often be lost while capturing human motion with optical tracking systems. Based on three natural properties of human gait movement, this study presents two different approaches to recover corrupted motion data. These properties are used to define a reconstruction model combining low-rank matrix completion of the measured data with a group-sparsity prior on the marker trajectories mapped in the frequency domain. Unlike most existing approaches, the proposed methodology is fully unsupervised and does not need training data or kinematic information of the user. We evaluated our methods on four different gait datasets with various gap lengths and compared their performance with a state-of-the-art approach using principal component analysis (PCA). Our results showed recovering missing data more precisely, with a reduction of at least 2 mm in mean reconstruction error compared to the literature method. When a small number of marker trajectories is available, our findings showed a reduction of more than 14 mm for the mean reconstruction error compared to the literature approach.


Assuntos
Algoritmos , Marcha , Movimento , Humanos , Monitorização Fisiológica , Movimento (Física) , Análise de Componente Principal
3.
Opt Lett ; 43(14): 3297-3300, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30004490

RESUMO

We introduce the concept of the inverse prism as the dual of the conventional prism and deduce from this duality an implementation of it based on temporal discontinuity and spatial dispersion provided by anisotropy. Moreover, we show that this inverse prism exhibits the following three unique properties: chromatic refraction birefringence, ordinary monochromatic and extraordinary polychromatic temporal refraction, and linear-to-Lissajous polarization transformation.

4.
Opt Express ; 24(11): 11376-86, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27410066

RESUMO

We propose an optical dimer formed from two spherical lenses bound by the pressure that light exerts on matter. With the help of the method of force tracing, we find the required graded-index profiles of the lenses for the existence of the dimer. We study the dynamics of the opto-mechanical interaction of lenses under the illumination of collimated light beams and quantitatively validate the performance of proposed dimer. We also examine the stability of dimer due to the lateral misalignments and we show how restoring forces bring the dimer into lateral equilibrium. The dimer can be employed in various practical applications such as optical manipulation, sensing and imaging.

5.
J Oral Pathol Med ; 45(1): 58-62, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25808210

RESUMO

BACKGROUND: Natural killer (NK) cells are important immune effector cells against tumors especially in the absence or reducing MHC class I antigen. Downregulation of CD16 receptor is accompanied by decreasing NK cell-killing activity. It has also been shown that some of tumor cells can evade from immune system through producing transforming growth factor beta (TGF-ß) and affect prognosis. The objective of this study was to evaluate the prognostic significance of CD57(+) and CD16(+) cells and TGF-ß expression in samples of oral squamous cell carcinoma (OSCC). METHODS: CD57, CD16, and TGF-ß expressions were examined immunohistochemically in 57 cases of OSCC. The relationship between markers' expression and clinicopathologic data using bivariate and multivariate analysis was assessed. RESULTS: Multivariate analysis revealed that CD57 expression [HR 17.34 (95% CI 3.815-78.830); P < 0.001] and mode of invasion [HR 0.362 (95% CI 0.138-0.947); P = 0.038] correlated with survival rate, but no relation between CD57 expression and mode of invasion was seen (P = 0.96). Furthermore, no correlation between CD57, CD16, and TGF-ß expression was found. CONCLUSION: These findings suggest that CD57 expression and mode of invasion are independent prognostic factors of survival in OSCC patients.


Assuntos
Antígenos CD57/biossíntese , Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias Bucais/metabolismo , Receptores de IgG/biossíntese , Fator de Crescimento Transformador beta/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Regulação para Baixo , Feminino , Proteínas Ligadas por GPI/biossíntese , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Imuno-Histoquímica , Irã (Geográfico)/epidemiologia , Células Matadoras Naturais/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Prognóstico , Carcinoma de Células Escamosas de Cabeça e Pescoço , Taxa de Sobrevida
6.
Arch Bone Jt Surg ; 12(4): 296-297, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38716179

RESUMO

Despite recent advancements in bionic upper limb prostheses technology, the rejection rate by users remains unacceptably high. Various factors contribute to this issue, such as limited functionality, complex control mechanisms, and discomfort, with most of these concerns being documented solely through self-assessment surveys. In this article, we introduce our proposed four components for an integrated bionic hand aimed at making it closely resemble a natural hand. These components include an integrated intramedullary stem, a kineticomyographic motor control system, sensory feedback for stereognosis, and sensory feedback for proprioception.

7.
Ann Biomed Eng ; 52(8): 1991-1999, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38503946

RESUMO

Thumb carpometacarpal joint space changes when the surrounding soft tissues including the capsule, ligaments, and tendons are stretched or pulled away. When at rest, joint forces originate from passive contraction of muscles and the involvement of joint capsule and ligaments. Previous biomechanical models of hand and finger joints have mostly focused on the assessment of joint properties when muscles were active. This study aims to present an experimental-numerical biomechanical model of thumb carpometacarpal joint to explore the contribution of tendons, ligaments, and other soft tissues in the passive forces during distraction. Five fresh cadaveric specimens were tested using a distractor device to measure the applied forces upon gradual distraction of the intact joint. The subsequent step involved inserting a minuscule sensor into the joint capsule through a small incision, while preserving the integrity of tendons and ligaments, in order to accurately measure the fundamental intra-articular forces. A numerical model was also used to calculate the passive forces of tendons and ligaments. Before the separation of bones, the forces exerted by tendons and ligaments were relatively small compared to the capsule force, which accounted for approximately 92% of the total applied force. Contribution of tendons and ligaments, however, increased by further distraction. The passive force contribution by tendons at 2-mm distraction was determined less than 11%, whereas it reached up to 74% for the ligaments. The present study demonstrated that the ligament-capsule complex plays significant contribution in passive forces of thumb carpometacarpal joint during distraction.


Assuntos
Articulações Carpometacarpais , Modelos Biológicos , Tendões , Polegar , Humanos , Articulações Carpometacarpais/fisiologia , Articulações Carpometacarpais/cirurgia , Polegar/fisiologia , Tendões/fisiologia , Fenômenos Biomecânicos , Masculino , Ligamentos/fisiologia , Feminino , Idoso , Pessoa de Meia-Idade , Ligamentos Articulares/fisiologia
8.
J Hand Surg Eur Vol ; 49(4): 436-443, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37882683

RESUMO

Distraction is a new treatment for trapeziometacarpal joint osteoarthritis. The purpose of this study was to test the efficiency of magnetic distraction using a new internal distractor in cadavers. The distractor consists of two magnets embedded inside titanium capsules that are implanted on either side of the trapeziometacarpal joint with the same poles facing each other, so that the force between the magnets distracts the joint. Intra-articular forces were recorded pre-implantation, immediately after implantation and again 10 minutes later. We also studied the changes in the forces before and after the procedure in different thumb positions. Our findings show that the trapeziometacarpal joint could be offloaded in all the studied trapeziometacarpal positions.


Assuntos
Osteoartrite , Humanos , Polegar , Cadáver , Fenômenos Magnéticos
9.
BMC Biomed Eng ; 6(1): 7, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39085924

RESUMO

TRIAL DESIGN: This study is a pilot randomized clinical trial aimed to investigate the effect of using Hip Exoskeleton Assistive (HEXA) robot compared to conventional physiotherapy on the quality of walking, disability, and quality of life of stroke patients with hemiplegia. METHODS: In this study, 24 patients were randomly assigned to the intervention group (robotic physiotherapy with HEXA robot), or control group (conventional physiotherapy). In each session, both groups received 30 min of conventional physiotherapy including electrotherapy and conventional exercises, and then the intervention group did gait training for 30 min with the HEXA robot and the control group for 30 min without the HEXA robot. The treatment program was 12 sessions, 3 times a week. Before the 1st and after the 12th sessions, both groups were evaluated for walking quality, disability, and quality of life. RESULTS: The results showed that the main effect of time was significant (P < 0.05) in all outcomes and patients in both groups achieved significant improvement in all outcomes after the intervention. The main effect of the group was also significant in the outcomes of 6MWT (P < 0.05) and TUG (P < 0.05), and the intervention group patients experienced more distance and speed in these two tests. This study was approved by the ethics committee of Mashhad University of Medical Sciences (IR.MUMS.FHMPM.REC.1400.079 dated 28th Jan 2022). The trial was registered with the clinical trials site of www.IRCT.ir (IRCT20210730052024N1) on January 28th 2022. CONCLUSION: It seems that the HEXA robot can effectively improve walking capacity and speed.

10.
Nat Commun ; 14(1): 7874, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38036499

RESUMO

Quantum fluctuations (QFs) caused by zero-point phonon vibrations (ZPPVs) are known to prevent the occurrence of polar phases in bulk incipient ferroelectrics down to 0 K. On the other hand, little is known about the effects of QFs on the recently discovered topological patterns in ferroelectric nanostructures. Here, by using an atomistic effective Hamiltonian within classical Monte Carlo (CMC) and path integral quantum Monte Carlo (PI-QMC), we unveil how QFs affect the topology of several dipolar phases in ultrathin Pb(Zr0.4Ti0.6)O3 (PZT) films. In particular, our PI-QMC simulations show that the ZPPVs do not suppress polar patterns but rather stabilize the labyrinth, bimeron and bubble phases within a wider range of bias field magnitudes. Moreover, we reveal that quantum fluctuations induce a quantum critical point (QCP) separating a hexagonal bubble lattice from a liquid-like state characterized by spontaneous motion, creation and annihilation of polar bubbles at cryogenic temperatures. Finally, we show that the discovered quantum melting is associated with anomalous physical response, as, e.g., demonstrated by a negative longitudinal piezoelectric coefficient.

11.
Sci Rep ; 13(1): 18387, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884628

RESUMO

In 2018, during our first clinical study on the kineticomyographic (KMG)-controlled bionic hand, we implanted three magnetic tags inside the musculotendinous junction of three paired extensor-flexor transferred tendons. However, the post-operative tissue adhesions affected the independent movements of the implanted tags and consequently the distinct patterns of the obtained signals. To overcome this issue, we modified our surgical procedure from a one-stage tendon transfer to a two-stage. During the first surgery, we created three tunnels using silicon rods for the smooth tendon gliding. In the second stage, we transferred the same three pairs of the forearm agonist-antagonist tendons through the tunnels and implanted the magnetic tags inside the musculotendinous junction. Compared to our prior clinical investigation, fluoroscopy and ultrasound evaluations revealed that the surgical modification in the current study yielded more pronounced independent movements in two specific magnetic tags associated with fingers (maximum 5.7 mm in the first trial vs. 28 mm in the recent trial with grasp and release) and thumb (maximum 3.2 mm in the first trial vs. 9 mm in the current trial with thumb flexion-extension). Furthermore, we observed that utilizing the flexor digitorum superficialis (FDS) tendons for the flexor component in finger and thumb tendon transfer resulted in more independent movements of the implanted tags, compared with the flexor digitorum profundus (FDP) in the prior research. This study can help us plan for our future five-channel bionic limb design by identifying the gestures with the most significant independent tag displacement.


Assuntos
Biônica , Tendões , Tendões/cirurgia , Dedos , Transferência Tendinosa/métodos , Músculo Esquelético
12.
Int J Health Care Qual Assur ; 25(3): 166-76, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22755472

RESUMO

PURPOSE: Improving hospital service access and mothers' care are said to be the best approaches for decreasing maternal mortality. This study aims to evaluate prenatal care (PNC) and suggest ways to improve hospital and health center maternity services. DESIGN/METHODOLOGY/APPROACH: This was a cross-sectional descriptive study to evaluate prenatal care services in three domains: service structure; care process; and outcomes. Using non-randomized quota sampling, 600 PNC clients were assessed in 12 pre-natal clinics. Two checklists were used to assess facilities and care process and a questionnaire to assess client satisfaction. Validity and reliability were assessed and confirmed. FINDINGS: Six hundred subjects, averaging 29.3 (+/- 9.4) weeks pregnancy, were included. Assessing different care processes demonstrated the following compliance to standards: counseling process 55.5 per cent (+/- 21.2); history-taking 48.71 per cent (+/- 11.4); vital signs assessment 53.4 per cent (+/- 10.6); general examination 30.2 per cent (+/- 13.3); obstetrical examination 91.8 per cent (+/- 27); blood tests 93.8 per cent (+/- 21.9); urinary tests 86.9 per cent (+/- 26.3); clients' education about peri-natal-risk 39.7 per cent (+/- 27.1). Results showed that 0.54 per cent (+/- 13.1) of clients were satisfied with care processes. RESEARCH LIMITATIONS/IMPLICATIONS: Clients and providers were informed about the study's evaluation processes, which may have affected the results. PRACTICAL IMPLICATIONS: Study method and results can be used to improve PNC services. ORIGINALITY/VALUE: This is the first time a study has focused on Iranian PNC structures, processes and outcomes.


Assuntos
Hospitais Universitários/organização & administração , Cuidado Pré-Natal/organização & administração , Qualidade da Assistência à Saúde/organização & administração , Estudos Transversais , Feminino , Humanos , Irã (Geográfico) , Serviços de Saúde Materna/organização & administração , Educação de Pacientes como Assunto , Satisfação do Paciente , Gravidez , Avaliação de Processos em Cuidados de Saúde , Qualidade da Assistência à Saúde/normas , Reprodutibilidade dos Testes
13.
Int Dent J ; 72(3): 360-365, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34134900

RESUMO

OBJECTIVES: This study assessed relationships between oral health care workforce and dental health in 12-year-olds in a developing health care system in Iran from 1992 to 2014 and compared these findings with the most recent corresponding findings in selected countries. METHODS: Data regarding oral health care workers from 1962 to 2014 were extracted from the comprehensive human resource data bank of the Shahid Beheshti Research Institute of Dental Sciences. Data regarding decayed, missing, and filled permanent teeth (DMFT) of 12-year-olds, extracted from official statistics, described dental health. Comparisons with other countries utilised the database of the World Health Organization. Changes in the DMFT index with fluctuations in the number of oral health care workers were investigated using exploratory data analysis methods. Associations of DMFT with the density of the oral health care workforce were evaluated using a multiple linear regression model. RESULTS: The trend in supply of dental workforce in Iran began to expand in the 1970s and, after a reduction in 2003 to 2007, reached a peak by 2014. Means of DMFT indices of 12-year-olds in Iran fluctuated between 1.50 and 2.40 from 1992 to 2014. The relationship between the dentist to population ratio and the DMFT index of 12-year-olds showed a downwards trend (r = -0.994; P < .001) until 1998 and afterwards an upwards trend (r = 0.887; P < .001). Globally, the DMFT index decreased in countries with a preventively-oriented oral health care workforce. CONCLUSIONS: Increased numbers of dentists have no significant impact on improving dental health in 12-year-olds. To promote dental health, the system providing health services should implement a preventively-oriented approach when planning for the oral health workforce.


Assuntos
Cárie Dentária , Estudos Transversais , Índice CPO , Atenção à Saúde , Cárie Dentária/epidemiologia , Dentição Permanente , Humanos , Saúde Bucal , Recursos Humanos
14.
Sci Rep ; 12(1): 14805, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-36045214

RESUMO

Sensing the proper signal could be a vital piece of the solution to the much evading attributes of prosthetic hands, such as robustness to noise, ease of connectivity, and intuitive movement. Towards this end, magnetics tags have been recently suggested as an alternative sensing mechanism to the more common EMG signals. Such sensing technology, however, is inherently invasive and hence only in simulation stages of magnet localization to date. Here, for the first time, we report on the clinical implementation of implanted magnetic tags for an amputee's prosthetic hand from both the medical and engineering perspectives. Specifically, the proposed approach introduces a flexor-extensor tendon transfer surgical procedure to implant the tags, artificial neural networks to extract human intention directly from the implanted magnet's magnetic fields -in short KineticoMyoGraphy (KMG) signals- rather than localizing them, and a game strategy to examine the proposed algorithms and rehabilitate the patient with his new prosthetic hand. The bionic hand's ability is then tested following the patient's intended gesture type and grade. The statistical results confirm the possible utility of surgically implanted magnetic tags as an accurate sensing interface for recognizing the intended gesture and degree of movement between an amputee and his bionic hand.


Assuntos
Amputados , Membros Artificiais , Algoritmos , Biônica , Eletromiografia/métodos , Gestos , Mãos , Humanos , Movimento
15.
J Am Acad Audiol ; 32(5): 295-302, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34082462

RESUMO

BACKGROUND: Dichotic listening deficit (DLD) is a common sign in children showing learning problem and is identified during auditory processing assessment. A dichotic listening training program was developed in which the weak ear lags behind the strong ear in time and has certain practices for switching attention between the ears and auditory memory. PURPOSE: The aim of the present study was to evaluate the effectiveness of this treatment program on dichotic performance of primary school children showing DLD. RESEARCH DESIGN: A pre/post clinical trial without control study. STUDY SAMPLE: Twenty-five primary school children, aged 7 to 12 years (mean = 9.3 years), showing DLD. DATA COLLECTION AND ANALYSIS: Several primary schools referred the children with learning difficulty to us. We defined learning difficulty as a score of 2 and lower on a five-point scale in at least two primary school courses in the current semester. The children with DLD participated in listening practices three times a week for 10 weeks, each session lasting for 30 minutes. The practices started with one pair of dichotic digits and ended in practice with sentences. The weak ear lag varied from 100 to 1,000 milliseconds. In the last stage of the practices, the precued and postcued directed response aimed at strengthening auditory memory and switching attention between the ears. The results obtained by the tests of dichotic digits, competing words, and competing sentences before and after the intervention were compared using paired t-test. Hedges's g was calculated as the effect size. RESULTS: Comparison of the results of pretraining and those of posttraining revealed that the average dominant ear (DE) and nondominant ear (NDE) scores in dichotic listening tests improved significantly with medium-to-large effect sizes. It was also found that the mean change in the NDE score of the children was significantly greater than that of the DE score for all the tests. CONCLUSIONS: Dichotic interaural time difference training that employed dichotic lag phenomenon followed by directed response practices significantly improved the DE and the NDE scores of the schoolchildren with DLD.


Assuntos
Percepção Auditiva , Testes com Listas de Dissílabos , Aprendizagem , Atenção , Criança , Humanos , Idioma
16.
J Opt Soc Am A Opt Image Sci Vis ; 27(12): 2558-62, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21119739

RESUMO

The Hamiltonian of an optical medium is important in both the design and the description of optical devices in the geometrical optics limit. The results calculated in this article show in detail how ray tracing in anisotropic materials in arbitrary coordinate systems and curved spaces can be carried out. Writing Maxwell's equations in the most general form, we derive a coordinate-free form for the eikonal equation and hence the Hamiltonian of a general purpose medium. The expression works for both orthogonal and non-orthogonal coordinate systems, and we show how it can be simplified for biaxial and uniaxial media in orthogonal coordinate systems. In order to show the utility of the equations in a real case, we study both the isotropic and the uniaxially transmuted birefringent Eaton lens and derive the ray trajectories in spherical coordinates for each case.

17.
Clin Exp Hypertens ; 32(3): 159-65, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20504123

RESUMO

The Objective of this study was to assess possible association of history of migraine with pre-eclampsia (PE). This was a retrospective study to compare history of migraine in 90 women affected by PE with 90 women without PE as the control group. They recruited by a nonrandomized consecutive sampling method. Data were collected by a questionnaire including demographic, medical, obstetrics, and migraine assessment sections. Data were analyzed using SPSS. Results showed an increased risk of PE in women with history of migraine (odds ratio: 2.87; p < 0.05). Result demonstrated that migraine history in the case group is 14/4% and in control group is 5/6%. Gestational age (GA) at delivery and weight of neonate (WN) were significantly lower compared to control (GA: 37.3 +/- 2.6 vs. 38.7+/- 1.3 weeks T test; P < 0.01) (WN: 2930 +/- 690 vs. 3330 +/- 420; T test; P < 0.0). Cesarean section was more frequent in the PE group compared to the control group [37 (42%) vs. 14 (15.6%)]; chi square; p < 0.01]. The association of migraine with PE is the result of some similar mechanism leading to endothelial dysfunction. Frequent reports of an association between migraine and PE in different populations suggest a history of migraine as a risk factor for PE/gestational hypertension (GH).


Assuntos
Transtornos de Enxaqueca/complicações , Pré-Eclâmpsia/fisiopatologia , Adulto , Estudos de Casos e Controles , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Irã (Geográfico)/epidemiologia , Transtornos de Enxaqueca/epidemiologia , Pré-Eclâmpsia/epidemiologia , Gravidez , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
18.
J Craniofac Surg ; 21(6): 1816-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21119429

RESUMO

OBJECTIVE: The aim of this study was to review cases of malignant tumors of jaw bones diagnosed in 2 pathology centers in Tehran, Iran, during a 10-year period. MATERIALS AND METHODS: Patients' records were seen at 2 teaching pathology centers of Shahid Beheshti University between March 1999 and March 2009 with histologic diagnosis of any type of malignant jaw tumors. The records were analyzed for frequency, age, sex, site, as well as clinical, radiographic, and histopathologic findings. RESULTS: Of 30,706 biopsies, 4767 (15.5%) were diagnosed as oral and maxillofacial lesions. Among these, 720 cases were tumoral and 67 cases were malignant jaw tumors. Osteosarcoma (41.79%) was the most common tumor in this review, which was followed by mucoepidermoid carcinoma and ameloblastic carcinoma, respectively. Patients' ages ranged from 9 to 71 years, with a mean of 38 years and male predominance. CONCLUSIONS: There are limited studies on malignant jaw tumors in literature, but comparing our result with the available data, there were differences regarding frequency and age distribution. This may be related to racial and geographic characteristics. More studies on other population are needed.


Assuntos
Neoplasias Maxilomandibulares/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Biópsia , Carcinoma Mucoepidermoide/epidemiologia , Criança , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Linfoma/epidemiologia , Masculino , Neoplasias Mandibulares/epidemiologia , Neoplasias Maxilares/epidemiologia , Pessoa de Meia-Idade , Tumores Odontogênicos/epidemiologia , Osteossarcoma/epidemiologia , Plasmocitoma/epidemiologia , Estudos Retrospectivos , Fatores Sexuais , Adulto Jovem
19.
J Biomed Opt ; 25(10)2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33111509

RESUMO

SIGNIFICANCE: Raman spectroscopy (RS) applied to surgical guidance is attracting attention among scientists in biomedical optics. Offering a computational platform for studying depth-resolved RS and probing molecular specificity of different tissue layers is of crucial importance to increase the precision of these techniques and facilitate their clinical adoption. AIM: The aim of this work was to present a rigorous analysis of inelastic scattering depth sampling and elucidate the relationship between sensing depth of the Raman effect and optical properties of the tissue under interrogation. APPROACH: A new Monte Carlo (MC) package was developed to simulate absorption, fluorescence, elastic, and inelastic scattering of light in tissue. The validity of the MC algorithm was demonstrated by comparison with experimental Raman spectra in phantoms of known optical properties using nylon and polydimethylsiloxane as Raman-active compounds. A series of MC simulations were performed to study the effects of optical properties on Raman sensing depth for an imaging geometry consistent with single-point detection using a handheld fiber optics probe system. RESULTS: The MC code was used to estimate the Raman sensing depth of a handheld fiber optics system. For absorption and reduced scattering coefficients of 0.001 and 1 mm - 1, the sensing depth varied from 105 to 225 µm for a range of Raman probabilities from 10 - 6 to 10 - 3. Further, for a realistic Raman probability of 10 - 6, the sensing depth ranged between 10 and 600 µm for the range of absorption coefficients 0.001 to 1.4 mm - 1 and reduced scattering coefficients of 0.5 to 30 mm - 1. CONCLUSIONS: A spectroscopic MC light transport simulation platform was developed and validated against experimental measurements in tissue phantoms and used to predict depth sensing in tissue. It is hoped that the current package and reported results provide the research community with an effective simulating tool to improve the development of clinical applications of RS.


Assuntos
Tecnologia de Fibra Óptica , Análise Espectral Raman , Simulação por Computador , Método de Monte Carlo , Imagens de Fantasmas , Espalhamento de Radiação
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