IDAGENE APARECIDA CESTARI
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/65, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/65, Hospital das Clínicas, Faculdade de Medicina - Líder
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Siamese Convolutional Neural Network for Heartbeat Classification Using Limited 12-Lead ECG Datasets(2023) VASCONCELLOS, Eduardo M. M.; FERREIRA, Bruno Georgevich; LEANDRO, Jorge S.; NETO, Baldoino F. S.; CORDEIRO, Filipe Rolim; CESTARI, Idagene A.; GUTIERREZ, Marco A.; SOBRINHO, Alvaro; CORDEIRO, Thiago D.The Electrocardiogram (ECG) is a low-cost exam commonly used to diagnose abnormalities in the cardiac cycle. Over the years, the scientific community has investigated the automatic classification of ECG signals driven by advanced Machine Learning (ML) techniques. Despite recent scientific advances, annotating large and diverse datasets to support the training of ML techniques is still very time-consuming and error-prone. Indeed, ML techniques whose training does not require extensive and well-annotated datasets are becoming even more prominent. Therefore, it is possible to correctly identify and classify abnormalities in the cardiac cycle (e.g., rare cardiologic disturbs) using limited data available in ECG datasets. However, the classification of heartbeats from digital tracings of ECG signals containing 12 leads from imbalanced datasets is challenging due to many existing heart diseases. This study investigates the few-shot learning paradigm based on Siamese Convolutional Neural Networks (SCNN), popular in imaging classification problems, to classify 12-Lead ECG heartbeats using a few training samples with supervised information. The proposed SCNN model presented an accuracy of up to 95% in a public dataset based on the hold-out validation method, implemented for different combinations of similarity and loss functions. Besides, using the 7-fold cross-validation method, the model presented a mean area under the curve of 89%. We also compared the class-by-class classification results with those of similar methods available in the literature, obtaining the same or better results based on performance metrics such as accuracy, precision, recall, and specificity.
- Three-way bladder catheter prototype for bladder washing(2022) VILCHEZ, L. F. S.; COSTA, M. P. F. Da; CIACCIO, M. C. De Mello; CESTARI, I. A.; GUERRA, G. M.The main postoperative complications of Transurethral Resection of the Prostate (TURP) are urinary retention by blood clots in the probe and exogenous contamination of the urinary system by manipulation of the healthcare professional when performing the bladder washing technique. The aim of this study was to develop a prototype for keeping the urinary system closed during bladder washes and to measure the internal pressures of the three-way Indwelling Urinary Catheter (IDC) during the bladder washing technique. This was a technological study based on the Rozenfeld's Product Development Process model. Functionality tests were carried out through experiments in a controlled environment in the laboratory. The prototype showed satisfactory results regarding the preservation of the urinary system closed during the bladder washing technique. It was possible to obtain specific pressures from the three-way IDC at three different moments: unobstructed catheter, partially obstructed catheter, and totally obstructed catheter. The results obtained demonstrate that the prototype can represent an innovative tool in the area of urology. It met the project's specifications and preserved the urinary system closed during the bladder washing. Moreover, it reduces the risk of urinary system contamination during the technique manipulation. Therefore, the present study showed that the prototype is fully safe regarding the pressures exerted inside the IDC. There is a need to carry out experimental tests in humans to prove the decrease of urinary tract contamination with the use of this prototype. © 2022 Centro Universitario Sao Camilo. All rights reserved.
- Evaluation of Structural Viability of Porcine Tracheal Scaffolds after 3 and 6 Months of Storage under Three Different Protocols(2023) GUIMARAES, Alberto Bruning; CORREIA, Aristides Tadeu; SILVA, Ronaldo Soares da; SANTOS, Elizabete Silva dos; COSTA, Natalia de Souza Xavier; DOLHNIKOFF, Marisa; MAIZATO, Marina; CESTARI, Idagene Aparecida; PEGO-FERNANDES, Paulo Manuel; CARDOSO, Paulo Francisco GuerreiroTracheal replacement with a bioengineered tracheal substitute has been developed for long-segment tracheal diseases. The decellularized tracheal scaffold is an alternative for cell seeding. It is not defined if the storage scaffold produces changes in the scaffold's biomechanical properties. We tested three protocols for porcine tracheal scaffold preservation immersed in PBS and alcohol 70%, in the fridge and under cryopreservation. Ninety-six porcine tracheas (12 in natura, 84 decellularized) were divided into three groups (PBS, alcohol, and cryopreservation). Twelve tracheas were analyzed after three and six months. The assessment included residual DNA, cytotoxicity, collagen contents, and mechanical properties. Decellularization increased the maximum load and stress in the longitudinal axis and decreased the maximum load in the transverse axis. The decellularization of the porcine trachea produced structurally viable scaffolds, with a preserved collagen matrix suitable for further bioengineering. Despite the cyclic washings, the scaffolds remained cytotoxic. The comparison of the storage protocols (PBS at 4 degrees C, alcohol at 4 degrees C, and slow cooling cryopreservation with cryoprotectants) showed no significant differences in the amount of collagen and in the biomechanical properties of the scaffolds. Storage in PBS solution at 4 degrees C for six months did not change the scaffold mechanics.
- The Distensibility of the Human Vena Cava and Its Importance to In Vitro Studies of Venous Compression Syndromes: A Search for a Suitable Polymer for 3-Dimensional Printing(2023) PUECH-LEAO, Pedro; TORRES, Inez O.; SILVA, Erasmo S. da; CESTARI, Ismar N.; CESTARI, Idagene A.; ROSA, Jhenyfer M. da; NAHAS, William C.; LUCCIA, Nelson DeBackground: Venous compression syndromes are clinical conditions in which the large veins are compressed by other anatomical structures. Laboratory simulations may help us better understand the hemodynamics in venous compressions by creating situations similar to those seen in vivo. The aim of this study is to produce a model of the caval bifurcation using a polymer with distensibility similar to the human vena cava. Methods: Fragments of the inferior vena cava were collected from 13 deceased kidney donors (aged 15-37 years) and were tested for deformation (strain) when subjected to distension at 50 N/cm2. Strips of 5 different polymers-thermic polyurethane and Agilus30 with Vero Magenta (AV) (in 3 different hardnesses) and silicone-were subjected to the same biomechanical tests and compared with the vena cava. A model of the caval bifurcation was produced with 3-D printing. Results: The deformation (strain) of the vena cava wall was 0.16 & PLUSMN; 0.9 when submitted to stress close to 50 N/cm2. Silicone showed a strain higher than the standard deviation of venous fragments. The strain of AV resin 95 Shore was lower than the standard deviation of the venous fragments. AV Resins 70 and 85 Shore showed strains within the standard deviation of the venous specimen, with 70 Shore being closest to the mean venous strain. Therefore, this material was selected for modeling the caval bifurcation. The computed tomography scan image generated a computer model of the caval bifurcation and was printed in 3 dimensions. In addition, the segments of 2 adjacent vertebrae were also printed to reference the compression site. Conclusions: The 3-D printing of large veins can produce models with anatomy and biome-chanics similar to those of human veins and opens a field of investigation into the hemody-namics of venous compression syndromes. Polymers with Shore A70 appear to have biomechanical properties similar to those of the vena cava wall. The model obtained in this study can be used in several in vitro studies of May-Thurner Syndrome.
- Performance Evaluation of Geometrically Different Pediatric Arterial Cannulae in a Pediatric Cardiopulmonary Bypass Model(2024) CARVALHO, Gabriela B. de O.; CANEO, Luiz Fernando; MATTE, Gregory; CRUZ, Caio Henrique de A.; SILVA, Everton Neri da; CARLETTO, Luciana P.; CASTRO, Ana Vitoria C. X. de; SILVA, Betina G. Madueno; POLICARPO, Valeria C.; CESTARI, Idagene A.; JATENE, Fabio B.; JATENE, Marcelo BiscegliObjective: To define a reference chart comparing pressure drop vs. flow generated by a set of arterial cannulae currently utilized in cardiopulmonary bypass conditions in pediatric surgery.Methods: Cannulae from two manufacturers were selected considering their design and outer and inner diameters. Cannula performance was evaluated in terms of pressure drop vs. flow during simulated cardiopulmonary bypass conditions. The experimental circuits consisted of a Jostra HL-20 roller pump, a Quadrox-i pediatric oxygenator (Maquet Cardiopulmonary AG, Rastatt, Germany), and a custom pediatric tubing set. The circuit was primed with lactated Ringer's solution only (first condition) and with human packed red blood cells added (second condition) to achieve a hematocrit of 30%. Cannula sizes 8 to 16 Fr were inserted into the cardiopulmonary bypass circuit with a ""Y"" connector. The flow was adjusted in 100 ml/min increments within typical flow ranges for each cannula. Pre-cannula and post-cannula pressures were measured to calculate the pressure drop.Results: Utilizing a pressure drop limit of 100 mmHg, our results suggest a recommended flow limit of 500, 900, 1400, 2600, and 3100 mL/min for Braile arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, respectively. For Medtronic DLP arterial cannulae sizes 8, 10, 12, 14, and 16 Fr, the recommended flow limit is 600, 1100, 1700, 2700, and 3300 mL/min, respectively.Conclusion:This study reinforces discrepancies in pressure drop between cannulae of the same diameter supplied by different manufacturers and the importance of independent translational research to evaluate components' performance.
- Safety of an esophageal deviator for atrial fibrillation catheter ablation(2023) PEREIRA, Renner; PISANI, Cristiano; AIELLO, Vera; CESTARI, Idagene; OYAMA, Helena; SANTOS, Osmar; OTUBO, Jorge; MOURA, Daniel; SCANAVACCA, MauricioBACKGROUND Esophageal thermal injury is a complication of atrial fibrillation (AF) ablation, and it can be avoided by esophageal deviation during left atrial posterior wall radiofrequency catheter ablation.OBJECTIVE This study aimed to evaluate the safety of a nitinol-based mechanical esophageal displacement device (MEDD) and its performance.METHODS This preclinical safety study was conducted on 20 pigs, with 10 undergoing radiofrequency AF ablation using the MEDD and 10 serving as a control group under anticoagulation but without radiofrequency application. Esophageal traumatic injuries were classified from 0 to 4 and were grouped as absent (grade 0), minor (grade 1 or 2), moderate (grade 3), or major risk lesions (grade 4) by anatomopathological study. Grades 1 and 2 were considered accept-able. Fluoroscopy was used to measure displacement.RESULTS Five (25%) pigs developed traumatic lesions, 4 with grade 1 and 1 with grade 2 (2-mm superficial ulcer). There was no difference in lesion occurrence between the radiofrequency and control groups (30% and 20%, respectively; P = .43). Under rightward displacement, the right edge moved 23.9 (interquartile range [IQR] 21.3- 26.3) mm and the left edge moved 16.3 (IQR 13.8-18.4) mm (P , .001) from baseline. Under leftward displacement, the right edge moved 13.5 (IQR 10.9-15.3) mm and the left edge moved 16.5 (IQR 12.3-18.5) mm (P = .07). A perforation to the pharyngeal diverticulum occurred in 1 pig, related to an accidental extubation.CONCLUSION In pigs, the MEDD demonstrated safety in relation to esophageal tissue, and successful deviation. Esophageal traumatic injuries were acceptable, but improper manipulation led to pharyngeal lesion.