Engenharia Biomédica

URI permanente para esta coleçãohttps://repositorioacademico.universidadebrasil.edu.br/handle/123456789/915

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Análise e otimização dos algoritmos para angiografia por tomografia por coerência óptica e desenvolvimento de Phantom por impressão 3D
(Universidade Brasil, 2021) Rodrigues, Karina de Cássia; Amaral, Marcelo Magri; Almeida, Vilson Rosa de
Skin grafts are surgically applied to repair skin lesions such as burns and extensive necrosis. The success of this surgical procedure is associated with good blood supply in the grafted region. Thus, the assessment of angiogenesis during the tissue repair process is essential for its prognosis. The development of non-invasive evaluation techniques is extremely important for the success of this procedure. One of the promising techniques is Optical Coherence Tomography Angiography (OCT-A), a non invasive technique that can be used to obtain images of the vascularization of biological tissues. The adoption of this technique as a clinical practice in dermatology involves reducing its cost, and the use of equipment with a low acquisition rate (low cost) is a possible path. Thus, this work aimed to implement and optimize algorithms for obtaining angiography images by optical coherence tomography (OCT-A) for applications in images acquired with low acquisition rate and cost equipment. To test those methods, it is requiring the use of phantom that simulate the behavior of the microvascular system. Thus, this work also aimed at the development of a phantom to simulate a microvascular system using 3D printing technology. Phantoms containing microchannels were designed and printed on polylactic acid (PLA) using a 3D printer by fused filament deposition. These PLA phantoms were imaged with the OCT system (OQLabScope - Lumedica, USA). Seven different OCT-A methods were implemented (HFM, STS, CM, SV, OSV, ISC and UHS-OMAG) and compared against their processing time, signal-to-noise ratio, contrast, and contrast-to-noise ratio. The OSV and CM methods showed better overall performance based on these parameters, but CM shown higher processing time. An optimization of the CM method was proposed in this work, reducing the processing time by 99.2%, a significant gain for the algorithm that presented better performances in contrast.
Avaliação dos níveis de ansiedade em estudantes universitários
(Universidade Brasil, 2021) Meneses, Aline Martins Diolindo; Santos, Laurita dos; Amaral, Marcelo Magri
Introduction: University admission is considered an anxiety generating experience to students due to the educational method transition stage from High School to University. Anxiety is a psychopathology incident in University students in which the symptomatology affects the formal learning construction, generating psychological illness. Scientific studies show a higher incidence of anxiety disorders in the health field students compared to the general population, pointing out the need for IES’ to evaluate the students’ psychological conditions, offering support services. Goal: Assess the anxiety signs and symptoms and its correlation with sociodemographic and lifestyle characteristics in University students. Methods: It is about an analytical and cross sectional study, conducted with 120 University students. The data was collectedthrough the following instruments: Sociodemographic and lifestyle questionnaire, BeckAnxiety Inventory (BAI) and saliva collection and salivary cortisol dosage. The researchwas approved by the Ethics and Research Committee of Universidade Brasil, under the opinion number 3.732.897. Results: A total of 120 students were a part of the study,106 being female and 14 being male students. The average age was 26.4 years old (Median:23.00; Standard deviation: 9.174; Min: 18; Max: 55). Out of the students, 77.5% are single and 76.7% have no kids. For the use of BAI, 16.7% of students had minimal anxiety, 13.3% had mild anxiety, 16.6% moderate anxiety and 53.3% severe anxiety. Regarding the dosage of salivary cortisol in the collected samples, 89.2% of students were within standard limits (under 0.736 µg / dL); 7.8% of students had cortisolvalues above the reference values. Conclusion: The data collected in the studyrevealeda high occurrence of students with signs and symptoms of anxiety disorders.The results reinforce the need for IES’ to include actions to identify students in psychological distress in their practices, concomitant with the adoption of pedagogicalpractices that envision their mental health.
Desenvolvimento de processo de desinfecção por Ozônio e conservação de pele de Lithobates Catesbeianus para enxerto cutâneo em modelo animal
(Universidade Brasil, 2021) Moraes, Dione Natureza de; Amaral, Marcelo Magri; Pavinatto, Adriana
Skin replacement is an important step in the treatment of various etiologies. Currently, there are several types of grafts available on the market, each with its own specificities, being used after a clinical study on the patient's health status. The use of bullfrog skin (Lithobates Catesbeianus) has shown promise as a possible skin graft, due to its cellular composition, high concentration of collagen, water and nutrients, biocompatibility, biological interaction with the substrate with the release of tissue biomodulators. In this work, a protocol for the sterilization and preservation of the bullfrog (Lithobates Catesbeianus) skins was developed, and its efficacy as a skin graft in an animal model was evaluated. Sterilization with ozone and conservation in 4 different ozonized solutions (saline solution, tea tree oil, copaiba oil and chitosan) were tested. The protocol of ozone disinfection and conservation in ozonized copaiba oil kept the skin inert to any microorganism for a period of twelve months. The evaluation in animal model was performed by histological analysis and by optical coherence tomography. These analyzes show promising results for future clinical applications, the skin proved to be excellent for use as a xenograft, as there was good graft adhesion, presence of fibroblasts and formation of a newly formed dermis. Compared to the autograft (control), this xenograft showed a greater presence of inflammatory infiltrates, which indicates the beginning of granulation tissue growth.
Laser Speckle Contrast Analysis (LASCA) aplicada à avaliação de estresse
(Universidade Brasil, 2024) Carvalho, Claudia Maria Sousa de; Amaral, Marcelo Magri; Santos, Laurita dos
Despite being physiologically normal, exaggerated and continuous exposure to stress, which exceeds the individual's tolerance capacity, can result in harm to health. The objective of this study was to apply the optical technique Laser Speckle Contrast Analysis (LASCA) to assess stress. This is a cross-sectional, descriptive, experimental study, with a quantitative approach, developed with undergraduate and postgraduate students, at a Higher Education Institution, in São Paulo (SP). The sample consisted of 27 (twenty-seven) participants, randomly distributed. The inclusion criteria were: undergraduate and postgraduate students, of both sexes, aged 18 or over, regularly enrolled. Those who self-reported having cardiovascular complications or using medication that altered cardiovascular functioning, suspected or confirmed pregnancy, physical limitations and women in their menstrual period were excluded. Data collection took place in June and August 2021 and all protective measures were adopted in relation to the coronavirus pandemic. Participants underwent cardiac signal acquisition to analyze heart rate variability, obtained using an electrocardiogram and a Polar V800 heart rate monitor, for 15 minutes. Simultaneously, the LASCA application was developed to obtain images using the MoorFLPI (Full-Field Laser Perfusion Imager) equipment. Next, participants underwent a physical effort test using an electric treadmill for 15 minutes, following the Bruce protocol. After resting for 5 minutes, cardiac signals and LASCA images were collected again, following the same protocols as in the initial phase. The project was approved by the Ethics and Research Committee of Universidade Brasil, under Opinion No. 4.724.843. Equivalent results were found regarding HRV measurements when comparing the LASCA technique and conventional methods, enabling the capture of signs of physiological changes present in the individual's state of stress. Thus, the results point to the feasibility of the LASCA technique to obtain images compatible with the heart rate pulsation pattern from the stress generated in situations of physical effort.
Modelo preditivo do nível glicêmico por monitoramento em tempo real em indivíduos portadores de diabetes mellitus tipo II
(Universidade Brasil, 2022) Mourão, Marcelo Henrique de Vasconcelos; Amaral, Marcelo Magri; Santos, Laurita dos
This research deals with a prediction of the glycemic levels of people with Diabetes Mellitus II, collected through a continuous glycemic monitoring system, based on the architecture of LSTM neural networks. Diabetes, one of the non-communicable chronic diseases, is characterized by hyperglycemia in the bloodstream generated by insulin resistance. The control of this disease can occur through carbohydrate counting according to the glycemic level, which according to the anthropometric evaluation is quantified by the physician. However, this approach is not always well accepted by diabetics, who end up adhering to medication for their control. Despite this, some diabetics end up using continuous blood glucose monitoring sensors, which favored verifying whether the glycemic data collected every 15 minutes could be predicted. The glycemia of 20 patients was measured over a period of 14 days using real-time monitoring. During this period, eating habits were recorded to count ingested carbohydrates, using the carbohydrate counting app created by SBD. Using an artificial intelligence model (LSTM) a blood glucose prediction model was created. With this model, it was verified that the predicted values followed the real glycemic movement, anticipating 5 hours with glycemic data of 12 continuous hours, that is, 20 predicted observations and 48 observations collected by the glycemia sensor for each individual. A general predictive model was performed with 20 volunteers and two personalized ones. The glycemic data of the collected diabetics had a positive performance, as the predicted values followed the glycemic movement, with a glycemic peak of 170 mg/dL at 9 am and 180 mg/dL at 1 pm, converging with the data obtained from the blood count. of carbohydrates, physical and anthropometric evaluation, observed with the peaks of glycemia, lifestyles of the volunteers and the total carbohydrates consumed daily. The glycemic data of non-diabetics had a positive performance, given that the predicted data followed the actual glycemic movement. This model, therefore, can predict several applications directly in rehabilitation, contributing as one of the important instruments for improving the patient's quality of life.
Uso do biopolímero de fibrina heterólogo associado ou não à fotobiomodulação no processo de reparo tendíneo
(Universidade Brasil, 2020) Dutra Jr., Enéas de Freitas; Tim, Carla Roberta; Amaral, Marcelo Magri
Introduction: The tendons are susceptible to injuries, and the calcaneal tendon is frequently injured. However, there is much controversy about the treatment of tendon injuries. In this perspective, the use of heterologous fibrin biopolymer (HFB), a homeostatic agent that has been used in several types of surgeries and a surgical strategy for the treatment of tendon injuries. In addition, non-surgical treatment using laser photobiomodulation therapy (PBMT) has been shown to be effective in the repair process. Objective: To evaluate the effect of heterologous fibrin biopolymer associated or not with photobiomodulation in the tendon repair process. Methodology: 84 Rattus norvegicus belonging to the Wistar strain were used. The animals were randomly divided into 4 experimental groups with N=21 animals in each: Control (CG); Heterologous fibrin biopolymer (HFB); Photobiomodulation (PBM); Heterologous fibrin biopolymer + Photobiomodulation (HFB + PBM). The groups were subdivided into 3 experimental periods: 7, 14 and 21 days. The animals received HFB immediately after partial tendon transection. PBM started the lesion induction for 24 hours and was followed for 7, 14, 21 days. For PBM, a 660 nm, 40 mW, 0.23 J and 6 second laser was used. The volume of the edema was evaluated, immediately before the tendon transection; 24 hours after tendon transection; on the day of euthanasia, following their respective experimental periods. The descriptive histopathological analysis and through the Bonar scale in the partially transected tendon region and the quantification of blood vessels were performed using slides stained with Hematoxylin and Eosin (HE). Collagen quantification was performed using slides stained with Masson's trichrome. Results: The results of the edema volume showed that, 24 hours after partial transection of the calcaneus tendon, there was no statistical difference between the experimental groups. After the three experimental periods, it was observed that the treatment groups were effective in reducing edema when compared to control. A histological analysis revealed that PBM had a major tendon injury after 7 days. However, in the periods of 14 and 21 days, the PBM had a better repair process compared to the GC, while the HFB and HFB + PBM had a better repair process when compared to the GC in the 3 experimental periods. PBM showing a greater number of blood vessels after 7, 14 and 21 days. In the quantification of collagen, there was no statistical difference between the groups, in the 3 experimental periods. Conclusion: The results obtained with the HFB and PBM treatments, granted or associated, were effective in reducing the volume of the edema, stimulating the repair process. However, the use of HFB alone is more effective in promoting the tendon repair process. Thus, this study consolidates previous studies of tendon repair with this new HFB. Clinical futures will be included to validate this proposal.