Physical attributes of the river basin of Roncador river associated to the landscape change in the municipality of Magé, Rio de Janeiro-Brazil / Atributos físicos da bacia hidrográfica do rio Roncador associados a mudança da paisagem no município de Magé, Rio de Janeiro-Brasil

The objective of this study was to conduct a temporal analysis of biophysical attributes of the river basin of Rio Roncador, located in the municipality of Magé, Rio de Janeiro. SRTM data were used for the determination of the river basin morphometry and two images of the orbital platform Landsat5 TM sensor (01/28/1986 and 02/15/2010) applied the SEBAL algorithm to characterize the landscape dynamics. The results indicate that The river basin has a drainage area equivalent to 186.21 km2, perimeter 101.78 km, circularity index equal to 0.22, form factor 0.26 and compares index 2.09. These results indicate that the river basin is not prone to flooding, mainly due to its elongated form. It was possible to verify that in the interval of 24 years, degradation occurred in the region beyond the change in the coverage of the soil of the river basin. The results indicated a tendency of reduction in the areas of permanent preservation -13.4% of the river basin. It is concluded that anthropogenic actions were able to alter the surface cover of the soil and that, by the way, may have influenced the water dynamics of the river basin.

O objetivo deste estudo foi realizar uma análise temporal de atributos biofísicos da bacia hidrográfica do Rio Roncador, localizado no município de Magé, Rio de Janeiro. Utilizaram-se dados do SRTM para a determinação da morfometria da bacia hidrográfica e duas imagens da plataforma orbital Landsat5 sensor TM (28/01/1986 e 15/02/2010) aplicado o algoritmo SEBAL para caracterizar a dinâmica da paisagem nesse período. Os resultados indicam que a bacia hidrográfica possui uma área de drenagem equivalente a 186,21 km2, perímetro de 101,78 km, índice de circularidade igual a 0,22, fator forma de 0,26 e índice de compacidade de 2,09. Estes resultados indicam que a bacia hidrográfica não é propícia a enchentes, devido principalmente a sua forma alonga. Foi possível verificar que no intervalo de 24 anos ocorreu degradação na região além da mudança na cobertura do solo da bacia hidrográfica. Os resultados obtidos indicaram uma tendência de redução nas áreas de preservação permanente de -13,4% da bacia hidrográfica. Conclui-se que ações antropogênicas foram capazes de alterar a cobertura superficial do solo e que por sinal podem ter influenciado a dinâmica hídrica da bacia hidrográfica.

Evaluation of Triamcinolone Injection and Subcision as a First-Line Non-Surgical Treatment of Post-Traumatic Acute Trap-Door Deformity

BACKGROUND: Trap-door deformity is a biophysical phenomenon in which U-, C-, or V-shaped linear scars tend to become depressed and the tissue circumscribed by them tends to bulge. The aim of the present study was to demonstrate the efficacy of triamcinolone acetonide (TCA) injection and subcision as a first-line treatment for post-traumatic acute trap-door deformity. METHODS: In trap-door deformity patients, a subcision was made by cutting the fibrotic band along the scar line in the depression using a 22-gauge needle. TCA was administered. An intralesional injection was made along areas of scarring that were difficult to penetrate with the needle. Scar quality parameters were assessed at each follow-up by a single observer and the patient, using the patient and observer scar assessment scale (POSAS) with an additional question about bulging. RESULTS: The average POSAS score per question on the observer scale improved from 6.6±1.31 to 3.6±1.08, and the average POSAS score per question on the patient scale improved from 5.5±1.57 to 2.5±1.26. The average bulging score on the observer scale decreased from 6.0±0.98 to 3.0±0.83, and that on the patient scale decreased from 5.0±1.67 to 2.0±1.30. The average general opinion score on the observer scale decreased from 5.5±1.12 to 3.5±0.91, and that on the patient scale decreased from 6.0±1.84 to 2.0±0.79. CONCLUSIONS: Better outcomes can be obtained by using both TCA and subcision as the first-line therapy for post-traumatic acute trap-door deformity.

Crioablación: aplicaciones clínicas en la electrofisiología cardiaca a partir de sus bases biofísicas / Cryoablation: Clinical applications in cardiac electrophysiology from their biophysical bases

Resumen: La crioablación es una energía alternativa a la radiofrecuencia para la ablación de diferentes arritmias, en la que sus propiedades biofísicas únicas ofrecen un perfil de seguridad mayor. Desde su utilización para el tratamiento quirúrgico de diversas arritmias hasta su conceptualización en la técnica transcatéter actual, la crioablación ha probado no solo ser una fuente segura de energía, sino una fuente eficaz a largo plazo. Mientras que la radiofrecuencia ha sido la energía más utilizada para el aislamiento de venas pulmonares en la ablación de fibrilación auricular, los avances tecnológicos con criobalón han logrado simplificar el procedimiento sin sacrificar su eficacia. La crioablación ha sido ampliamente utilizada para arritmias localizadas en sitios de alto riesgo, como la ablación de la taquicardia por reentrada intranodal AV y vías accesorias septales por su nulo riesgo teórico de bloqueo AV completo. Esta revisión tiene la intención de dar a conocer las aplicaciones clínicas de la criotermia a través del entendimiento profundo de sus bases biofísicas.

Abstract: Cryoablation is an energy alternative to radiofrequency for ablation of various arrhythmias, where its unique biophysical properties offer a greater safety profile. Since its first use for the surgical treatment of different arrhythmias until its conceptualization in the current technical transcatheter, cryoablation has proven not to be only a safe source of energy, but also an effective source in the long-term. While the radiofrequency has been the energy most used for isolation of pulmonary veins in atrial fibrillation ablation, technological advances in cryoballon have managed to simplify the procedure without sacrificing its effectiveness. Cryoablation has been widely used for arrhythmias located in high-risk locations, such as the ablation of the atrioventricular nodal reentrant tachycardia and septal accessory pathways, due to its theoretical null risk of complete AV block. This review intends to give the clinical applications of the cryothermy through a thorough understanding of their biophysical basis.

Factores bioquímicos y biofísicos que intervienen o interfieren en el arte de curar / Biochemical and biophysical factors involved or interfere in the art of healing

El propósito de este trabajo es revisar los factores bioquímicos y biofísicos que intervienen o interfieren en el tratamiento homeopático y cómo la alimentación deficiente o mal equilibrada puede convertirse en un obstáculo para la curación. Hemos observado que el abordaje de temas relacionados con la alimentación surge en laconsulta homeopática desde el motivo de consulta de una patología relacionada,como dislipemia, diabetes (DBT), obesidad, hipertensión arterial (HTA), etcétera, odesde los deseos y aversiones. Pero raramente se aborda el tipo de alimentación en la consulta, pudiendo ser este punto un fuerte obstáculo.

The purpose of this paper is to review the biochemical and biophysical factors involved or interfere in the homeopathic treatment and how poor or poorly balanced diet can become an obstacle to healing. We noted that addressing issues related to food arises in the homeopathic consultation from the complaint of a related disease , such as dyslipidemia , diabetes ( DBT ), obesity , high blood pressure ( hypertension ) , etc., or from the desires and dislikes. But the type of power rarely addressed in the consultation, this point can be a major obstacle.

Juan César García: social medicine as project and endeavor / Juan César García: a medicina social como projeto e realização

This paper analyses some aspects of the trajectory of the Argentinian physician and sociologist Juan César García (1932-1984) in the field of Latin American Social Medicine. Three dimensions constituting his basic orientations are highlighted: the elaboration of systematic and reflective social thought; a critical attitude in questioning teaching and professional practices; a commitment to the institutionalization and dissemination of health knowledge.

O artigo analisa aspectos da trajetória de Juan César García (1932-1984), médico e sociólogo argentino, no campo da medicina social latino-americana. Destaca três dimensões que constituem as suas orientações básicas no campo da saúde: a elaboração de um pensamento sobre o social, sistemático e reflexivo; uma atitude crítica na problematização do ensino e das práticas profissionais; um compromisso com a institucionalização e divulgação do saber sanitário.

Intervención motivacional en psicología de la salud: revisión de sus fundamentos conceptuales, definición, evolución y estado actual / Motivational intervention in health psychology: a review of the conceptual foundations, definition, evolution and current state

Se presenta una conceptualización acerca de la Intervención Motivacional basada en el análisis de los acontecimientos propios del Proceso Motivacional y se mencionan algunas microteorías motivacionales que proponen diversos constructos hipotéticos y variables intermediarias que explican el curso que sigue la conducta saludable en el estilo de vida de las personas, conformando lo que se considera como una Dimensión Psicológica de la Promoción y de la Prevención en Salud. Se hace un intento de definición de la Intervención Motivacional y se propone un modelo de Formulación Motivacional para darle contexto y fundamento. Se describen los temas a los que se ha aplicado la Intervención Motivacional a lo largo de la existencia formal y sistemática de este concepto, y los temas de análisis teórico y metodológico actuales, para lo cual se toman los reportes que incluyen ambos términos (Motivational, & Intervention) en los resúmenes de publicaciones indizadas en la base de datos Medline, en el período 1991-2013...

A conceptualization is presented of Motivational Intervention based upon the analysis of occurrences which are part and parcel of the Motivational Process, and some motivational micro-theories are mentioned as well which propose a variety of hypothetical constructs and intervening variables accounting for the course that healthy behavior follows within the lifestyles of people, comprising what is considered to be a Psychological Dimension of Health Promotion and Prevention. An approach to the definition of Motivational Intervention is provided, and to support it and contextualize it, a model of Motivational Formulation is proposed. The topics to which Motivational Intervention has been applied throughout the formal and systematic existence of the concept are described, as well as issues of current theoretical and methodological analyses, by analyzing reports including both terms (Motivational, & Intervention) in the abstracts of indexed publications in the Medline database, between 1991 and 2013...

Meridian essence: modern thought / 中国结合医学杂志

Meridian essence has been investigated through anatomy, electrophysiology, biophysics, and biochemistry. Various hypotheses of meridian essence exist, but no hypothesis can truly reflect the internal character of Chinese medicine (CM). The research of meridian essence requires a holistic viewpoint and innovative awareness. Initially, any hypothesis regarding meridian essence should begin with observation of the human body. Secondly, the research should arise from the meridians' physical functions and pathological changes, so as to maintain the fundamental nature of the meridians themselves. Thirdly, the research should be based upon the theory of CM, yet coupled with the integration of modern techniques to deepen our understanding of the scientific contents of meridians. Fourthly, theoretical research should be combined closely with clinical practice, in order to test the achievements in actual conditions. Lastly, more attention should be given to negative results in studies to more accurately discover the real essence of meridians.

Cavitation and boiling of bubbles at the focal region during high intensity focused ultrasound exposure / 生物医学工程学杂志

High intensity focused ultrasound (HIFU) is a very complex transient process and can cause tissue coagulation necrosis. The cavitation and boiling behaviour of bubbles in the focal region play very important roles throughout an injury process. This paper reviews the research done by domestic and foreign scholars on behaviours of bubbles in HIFU irradiation process and summarizes in the focal region bubble cavitation and boiling generation, related detective means and relationships with hyperecho, temperature rise of the focus and injury shape.

Treatment of early stage avascular necrosis of the femoral head / 中国骨伤

Avascular necrosis is a progressively devastating disease and primarily affects weight-bearing joints. The hip is the most commonly affected joint. In early stage, nonoperative (including pharmacologic intervention and biophysical treatments) and operative modalities for protecting hip joint have become the main therapeutic methods. However there is still no satisfied mothod with reasonable effect. According to the treatment of the avascular necrosis of the femoral head of the pre-collapse stage, core decompression with modification of technique is still one of the safest and most commonly employed procedures. Recently there have been attempts to enhance the effect of core decompression with use of various growth and differentiation factors. Which is the hot spot of current research. Early diagnosis is the key to the treatment of the avascular necrosis of the femoral head. Comprehensive treatment which is based on the core decompression is still the main treatment of today.

Avaliação biofísica complementar da vitalidade fetal / Additional biophysical evaluation of fetal surveillance

O nascimento de um feto saudável sempre constituiu um dos principais objetivos da Obstetrícia. Nos dias atuais, vários procedimentos têm sido utilizados com esta finalidade, porém, apesar da evolução dos métodos diagnósticos e da melhor compreensão da fisiopatologia do sofrimento fetal, ainda existem lacunas no conhecimento sobre o comportamento do feto frente à hipóxia. Outro fator complicador na avaliação do sofrimento fetal é o grande número de doenças maternas com diferentes fisiopatologias que podem interferir no bem-estar fetal. Esta revisão tem como objetivo descrever os principais métodos de avaliação biofísica da vitalidade fetal, com base nas melhores evidências científicas correntemente disponíveis na literatura, e incluindo níveis de evidências e graus de recomendação. Será abordada a avaliação da vitalidade fetal nos casos de insuficiência placentária, não sendo estudadas as situações especiais, como diabetes e gestação múltipla. Evidencia-se uma falta de consenso sobre qual procedimento deve ser utilizado na avaliação da vitalidade fetal, na prática clínica diária. As sociedades internacionais recomendam a realização da doplervelocimetria, da cardiotocografia e do perfil biofísico fetal apenas em gestantes de alto risco, com suspeita de insuficiência placentária ou com restrição de crescimento intrauterino

The birth of a healthy baby has always been an important goal of Obstetrics. Nowadays, many procedures have been used for this purpose, but despite great development in diagnostic methods and better understanding of pathophysiology of fetal distress, there are still gaps in knowledge about fetal behavior in situations of hypoxia. Another complicating factor in the assessment of fetal distress is the large number of maternal diseases with different pathophysiology, which can compromise fetal well-being. This review aims at describing the main methods for fetal assessment, based on the best scientific evidence currently available, including levels of evidence and grades of recommendation. Only fetal evaluation in cases of placental insufficiency will be addressed, and special situations such as diabetes and multiple pregnancies will not be studied. Current evidences show a lack of consensus on what is the best procedure to assess fetal well-being in clinical practice. International societies recommend the performance of Doppler velocimetry, cardiotocography, and fetal biophysical profile only in high-risk pregnancies with suspected placental insufficiency or restricted intrauterine growth

Polimorfismos nos genes MMP2, MMP13, CYP1A1, GSTM1 e EMX2 e endometriose / Polymorphisms in MMP2, MMP13, CYP1A1, GSTM1 and EMX2 and endometriosis

A endometriose é uma doença que afeta de 10 a 15% das mulheres em idade fértil. Trata-se de uma doença crônica dependente de estrogênio, caracterizada pela presença de tecido endometrial fora da cavidade uterina. É uma doença multifatorial e poligênica que ainda apresenta etiologia desconhecida. Estudos moleculares relacionam a suscetibilidade à endometriose com polimorfismos genéticos específicos. Os principais genes estudados são responsáveis pelos mecanismos biológicos da doença, como por exemplo, metabolismo do estrogênio, receptores hormonais e detoxificação celular. O objetivo do presente artigo é revisar as pesquisas relacionadas aos genes CYP1A1, MMP2, MMP13, GSTM1 e EMX2, para avaliar as possíveis implicações na patogênese da endometriose

Endometriosis is a disease that affects 10 to 15% of women on reproductive age. It is an estrogen-dependent chronic disease, which is characterized by the presence of endometrial tissue outside the uterine cavity. It is a polygenic and multifactorial disease that still has unknown etiology. Molecular studies relate susceptibility to specific genetic polymorphisms with endometriosis. The main studied genes are responsible for the biological mechanisms of disease, such as estrogen metabolism, hormone receptors, and cellular detoxification. The aim of this paper is to review the research related to CYP1A1, MMP2, MMP13, GSTM1, and EMX2 genes, in order to assess the possible implications in the pathogenesis of endometriosis

Lifting-thrusting and rotating manipulations: a comparison on energy input / 中国针灸

Through the energy input model of lifting-thrusting and rotating manipulations, using the theory of energy density, energy flux density and sound intensity level in physics, the average energy flux intensity and frequency distributions of average poynting's vector were calculated respectively within the range of infrasound. According to the distribution table, it was discovered that both of the energy flux density and sound intensity level during the process of acupuncture were high. And it was concluded that the essence of meridians was probably fascial tissues which were rich in elastic fibers and collagenous fibers. The heat-producing needling with reinforcing effect (setting the moutain on fire) which focused on forceful thrusting was held to be the result of the action of same position solitary wave. And the coolness-producing needling with reducing effect (thorough heavenly cool) emphasized on the manipulation of forceful lifting was considered as the action of opposite position solitary wave. The energy input of lifting-thrusting manipulation is comparatively larger than the rotating method, however without significant difference. The speed of manipulations applied is regarded to have greater impact on energy transmission. And the energy produced by rotating manipulation can be better transmitted through meridians.

Application of Fourier transform profilometry in 3D-surface reconstruction / 生物医学工程学杂志

With the improvement of system frame and reconstruction methods in fluorescent molecules tomography (FMT), the FMT technology has been widely used as an important experimental tool in biomedical research. It is necessary to get the 3D-surface profile of the experimental object as the boundary constraints of FMT reconstruction algorithms. We proposed a new 3D-surface reconstruction method based on Fourier transform profilometry (FTP) method under the blue-purple light condition. The slice images were reconstructed using proper image processing methods, frequency spectrum analysis and filtering. The results of experiment showed that the method properly reconstructed the 3D-surface of objects and has the mm-level accuracy. Compared to other methods, this one is simple and fast. Besides its well-reconstructed, the proposed method could help monitor the behavior of the object during the experiment to ensure the correspondence of the imaging process. Furthermore, the method chooses blue-purple light section as its light source to avoid the interference towards fluorescence imaging.

Fetal biophysical profile; as a tool to predict fetal outcome

To evaluate fetal Biophysical Profile as an effective technique for the assessment of fetal condition and to improve fetal outcome by early detection of fetal hypoxia. Co relational study: The study was carried out for a period of one year from Oct 2004-Oct 2005 at Obstetrics and Gynecology Department of Fatima memorial hospital Lahore. All patients with history of sluggish fetal movements and clinical suspicion of IUGR, were underwent BPP from 32-42weeks. 100 patients were selected and their BPP score was recorded and were followed till delivery. Those who went into spontaneous labor and who were induced monitored during labor and at any sign of fetal distress immediate caesarean section performed. APGAR score of newborn was noted at one and five minutes and those having poor APGAR score were resuscitated and were followed till one week after delivery. APGAR score was compared with BPP score, During this study 100 BPP were performed. 34patients were primigravidas and 66 were multigravidas. Among 100 patients 73hada BPP score of 9-10/10,21 patients had a score of 7-8/10 and 6 patients had 4-6/10. In 2 patients with 4/10 score emergency caesarean section led to the delivery of neonates with APGAR score of 8 at 5 minutes. Majority of patients with normal BPS of 8-9/10 had good APGAR score of 7-8/10.0nly 8 patients having BPP of 9-10/10 had poor APGAR score 6/10 or <6/10. The fetal BPP appears to be an effective technique for assessment of fetal condition

Efeitos da anemia materna na cardiotocografia computadorizada e perfil biofísico fetal / Effects of maternal anemia on computerized cardiotocography and fetal biophysical profile

OBJETIVOS: avaliar a influência dos níveis de hemoglobina (Hb) materna nos padrões da frequência cardíaca fetal (FCF) e no perfil biofísico fetal (PBF) em gestações a termo. MÉTODOS: gestantes portadoras de anemia (Hb<11,0 g/dL) foram avaliadas prospectivamente, entre a 36ª e a 40ª semana de gestação, no período compreendido entre janeiro de 2008 e março de 2009. O Grupo Controle foi constituído por gestantes de termo, saudáveis, com valores normais de hemoglobina (Hb>11,0 g/dL). Foram excluídos casos com anomalias ou restrição do crescimento fetal. A avaliação da FCF foi realizada pela cardiotocografia computadorizada (Sistema8002-Sonicaid) e análise do traçado com 30 minutos de exame. O PBF foi realizado em todas as pacientes. Foram utilizados os testes t de Student, teste do χ2 e teste exato de Fisher. O nível de significância utilizado foi de 0,05. RESULTADOS: A média da Hb materna no grupo com anemia (n=18) foi de 9,4 g/dL (DP=1,4 g/dL) e no Grupo Controle 12,4 g/dL (DP=1,3 g/dL). Quanto aos parâmetros da cardiotocografia, não foi constatada diferença significativa nas médias entre os grupos com anemia e controle, respectivamente: FCF basal (131,3 bpm versus 133,7 bpm, p=0,5), acelerações da FCF > 10 bpm (7,9 versus. 8,2, p=0,866), acelerações da FCF > 15 bpm (5,2 versus 5,4, p=0,9), episódios de alta variação da FCF (17,1 versus 15,5 min, p=0,5), episódios de baixa variação da FCF (4,4 versus 3,6 min, p=0,6), e variação de curto prazo (10,5 versus 10,9 ms, p=0,5). Em ambos os grupos, todas as pacientes apresentaram PBF normal. CONCLUSÕES: este estudo sugere que a anemia materna leve ou moderada, sem outras comorbidades maternas ou fetais, não se associa a anormalidades nos parâmetros do perfil biofísico fetal e da FCF analisada pela cardiotocografia computadorizada.

PURPOSES: to evaluate the influence of maternal hemoglobin (Hb) levels in the patterns of fetal heart rate (FHR) and in the fetal biophysical profile (FBP) in term gestations. METHODS: pregnant women with anemia (Hb<11.0 g/dL) were prospectively evaluated between the 36th and the 40th week of gestation, from January 2008 to March 2009. The Control Group was composed of term and healthy pregnant women, with normal values of hemoglobin (Hb>11,0 g/dL). Cases of anomalies or fetal growing restrictions were excluded. The FHR evaluation was performed by computerized cardiotocography (8002 System-Sonicaid), and by record analysis during 30 minutes of exam. The FBP was done in all the patients. Student's, χ2 and Fisher's exact tests were used, with 0.05 significance level. RESULTS: The average of maternal Hb in the group with anemia (n=18) was 9.4 g/dL (DP=1.4 g/dL), and in the control group, 12.4g/dL (DP=1.3 g/dL). There has been no significant mean differences between groups concerning the cardiotocography parameters, respectively: basal FHR(131.3 versus 133.7 bpm, p=0.5), FHR accelerations > 10b pm (7.9 versus 8.2, p=0.866), FHR accelerations > 15 bpm (5.2 versus. 5.4, p=0.9), episodes of high variation of the FHR (17.1 versus 15.5 min, p=0,5), episodes of variation of the FHR (4.4 versus 3.6 min, p=06), and short term variation (10.5 versus 10.9 ms, p=0.5). In both groups, all patients presented normal FBP. CONCLUSIONS: this study suggests that light or moderate maternal anemia, without other maternal or fetal comorbidity, is not associated with abnormalities in the parameters of fetal biophysical profile and of the FHR analyzed by computerized cardiotocography.

Association of single nucleotide polymorphisms in VEGF gene with the risk of endometriosis and adenomyosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of single nucleotide polymorphisms (SNPs) in VEGF gene with the risk of endometriosis and adenomyosis.</p><p><b>METHODS</b>Genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 344 endometriosis patients, 174 adenomyosis patients, 360 frequency-matched control women of endometriosis and 199 frequency-matched control women of adenomyosis.</p><p><b>RESULTS</b>No significant difference was found in allele frequencies and genotype distributions of the -460C/T polymorphism between patients (endometriosis and adenomyosis) and control women (all P value > 0.05). However, there were significant differences in genotype and allele distributions of the VEGF -1154G/A polymorphism between patients (endometriosis and adenomyosis) and control women (all P value < 0.05). The genotype frequencies of the VEGF -1154 AA, GA, and GG in endometriosis patients and control women were 1.7%, 28.8%, 69.5% and 5.8%, 32.8%, 61.4%, respectively; and the A and G allele frequencies in the two groups were 16.1%, 83.9% and 22.2%, 77.8%, respectively. The genotype frequencies of the VEGF -1154 AA, GA, and GG in adenomyosis patients and control women were 2.9%, 23.6%, 73.6% and 7.0%, 34.2%, 58.8%, respectively; and the A and G allele frequencies in the two groups were 14.7%, 85.3% and 24.1%, 75.9% respectively. Compared with GA+ AA genotype, GG genotypes could significantly increase the risk of endometriosis (OR:1.43,95%CI:1.05-1.96) and adenomyosis (OR:1.95,95%CI:1.26-3.03).</p><p><b>CONCLUSION</b>The VEGF -1154G/A polymorphism was associated with susceptibility to endometriosis and adenomyosis, and the GG genotype could significantly increase the risk of developing endometriosis and adenomyosis. However, the VEGF -460C/T polymorphism was not associated with susceptibility to endometriosis and adenomyosis in the population studied.</p>

Analysis of microwave-induced thermoacoustic signals and research-development preprocessor / 生物医学工程学杂志

According to the results of analyzing the microwave-induced thermoacoustic signals, the amplitude and frequency were estimated and the designing parameters of preprocessor were decided. Based on the parameters, the signals preprocessor was designed with the band pass frequency ranging from 50 KHz to 3MHz, the gain ranging from 55 dB to 105 dB and the output noise being 1.32 V when the input was zero and the gain was 105 dB. The de-noising method of thermoacoustic signals was also discussed. The signals can be picked up by the preprocessor combined with the digital multipoint average method. The amplitude of signals is only 5 microV or even less. The results indicated that the preprocessor can meet the needs of thermoacoustic signals acquisition in bandwidth, gain and noise control.