Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- A Deep Learning-Based Computational Framework for the analysis of neurofibrillary tangles in post-mortem brain micrographs from alzheimer’s patients using object detection and semi-automatic segmentation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06) Hernández Morales, José Eduardo; Cantoral Ceballos, José Antonio; emipsanchez; González Mendoza, Miguel; Gutiérrez Rodríguez, Andrés Eduardo; School of Engineering and Sciences; Campus Monterrey; Ontiveros Torres, Miguel ÁngelNeurofibrillary tangles (NFTs) are a pathological hallmark of Alzheimer’s disease (AD) and related tauopathies, consisting of abnormal accumulations of the tau protein. Immunofluorescence microscopy remains the standard method for visualizing these aggregates, yet its manual interpretation is time-consuming and prone to variability. Their precise quantification is crucial for understanding disease progression, as it allows researchers to correlate NFT burden with cognitive decline, providing valuable insights into the underlying mechanisms of neurodegeneration. However, the labor-intensive nature of manual assessment and its susceptibility to observer variability limit scalability, highlighting the need for automated, reproducible methodologies in large-scale studies. To address these limitations, we present a deep learning-based computational framework for automated detection, segmentation, and quantitative analysis of NFTs in post-mortem brain micrographs from AD patients. Our approach integrates state-of-the-art object detectors—YOLO11/v12, Faster R-CNN, and transformerbased DETR/RT-DETR—with the Segment Anything Model (SAM) to refine bounding boxes into pixel-accurate masks. Evaluated on a curated dataset of over 900 hippocampal and entorhinal micrographs, our framework achieves an mAP50 of 0.81 for detection and a mean IoU of 0.86 for segmentation. Additionally, we conduct a comprehensive NFT burden analysis across brain regions, highlighting the hippocampal subiculum as the most affected area. These results demonstrate the potential of deep learning to enable high-throughput and reproducible NFT quantification, supporting large-scale neuropathological studies.
- Object detection-based surgical instrument tracking in laparoscopy videos(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Guerrero Ramírez, Cuauhtemoc Alonso; Ochoa Ruiz, Gilberto; emipsanchez; González Mendoza, Miguel; Hinojosa Cervantes, Salvador Miguel; Falcón Morales, Luis Eduardo; School of Engineering and Sciences; Campus Monterrey; Medina Pérez, Miguel ÁngelMinimally invasive surgery (MIS) has transformed surgery by offering numerous advantages over traditional open surgery, such as reduced pain, minimized trauma, and faster recovery times. However, endoscopic MIS procedures remain highly operator-dependent, demanding significant skill from the surgical team to ensure a positive postoperative outcome for the patient. The implementation of computer vision techniques such as reliable surgical instru ment detection and tracking can be leveraged for applications such as intraoperative decision support, surgical navigation assistance, and surgical skill assessment, which can significantly improve patient safety. The aim of this work is to implement a Multiple Object Tracking (MOT) benchmark model for the task of surgical instrument tracking in laparoscopic videos. To this end, a new dataset is introduced, m2cai16-tool-tracking, based on the m2cai16-tool locations dataset, specifically designed for surgical instrument tracking. This dataset includes both bounding box annotations for instrument detection and unique tracking ID annotations for multi-object tracking. This work employs ByteTrack, a state-of-the-art multiple-object tracking algorithm that follows the tracking-by-detection paradigm. ByteTrack predicts tool positions and associates object detections across frames, allowing consistent tracking of each instrument. The object detection step is performed using YOLOv4, a state-of-the-art object detection model known for real-time performance. YOLOv4 is first trained on the m2cai16-tool-locations dataset to establish a baseline performance and then on the custom m2cai16-tool-tracking dataset, al lowing to compare the detection performance of the custom dataset with an existing object detection dataset. YOLOv4 generates bounding box predictions for each frame in the laparo scopic videos. The bounding box detections serve as input for the ByteTrack algorithm, which assigns unique tracking IDs to each instrument to maintain their trajectories across frames. YOLOv4 achieves robust object detection performance on the m2cai16-tool-locations dataset, obtaining a mAP50 of 0.949, a mAP75 of 0.537, and a mAP50:95 of 0.526, with a real-time inference speed of 125 fps. However, detection performance on the m2cai16-tool tracking dataset is slightly lower, with a mAP50 of 0.839, mAP75 of 0.420, and mAP50:95 of 0.439, suggesting that differences in data partitioning impact detection accuracy. This lower detection accuracy for the tracking dataset likely affects the tracking performance of ByteTrack, reflected in a MOTP of 76.4, MOTA of 56.6, IDF1 score of 22.8, and HOTAscore of 23.0. Future work could focus on improving the object detection performance to enhance tracking quality. Additionally, including appearance-based features into the track ing step could improve association accuracy of detections across frames and help maintain consistent tracking even in challenging scenarios like occlusions. Such improvements could enhance tracking reliability to support surgical tasks better.
- Exploring Anchor-Free Object Detection for Surgical Tool Detection in Laparoscopic Videos: A Comparative Study of CenterNet++ and Anchor-Based Models(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Aparicio Viveros, Carlos Alfredo; Ochoa Ruiz, Gilberto; emipsanchez; Hinojosa Cervantes, Salvador Miguel; Falcón Morales, Luis Eduardo; González Mendoza, Miguel; School of Engineering and Sciences; Campus MonterreyMinimally Invasive Surgery (MIS) has transformed modern medicine, offering reduced re covery times, minimal scarring, and lower risks of infection. However, MIS procedures alsopresent unique challenges, particularly in visualizing and manipulating surgical tools within a limited field of view. As a solution, this thesis investigates anchor-free deep learning mod els for real-time surgical tool detection in laparoscopic videos, proposing CenterNet++ as apotential improvement over traditional anchor-based methods. The hypothesis guiding thiswork is that anchor-free detectors, by avoiding predefined anchor boxes, can more effectively handle the diverse shapes, sizes, and positions of surgical tools. The primary objective of this thesis is to evaluate the performance of CenterNet++ in surgical tool detection compared to popular anchor-based models, specifically Faster R-CNN and YOLOv4, using the m2cai16-tool-locations dataset. CenterNet++ is examined in dif ferent configurations—including complete and real-time optimized (Fast-CenterNet++) ver sions—and tested against Faster R-CNN and YOLOv4 to assess trade-offs in accuracy and efficiency. Experimental results demonstrate that while CenterNet++ achieves high precision, particularly in scenarios requiring meticulous localization, its inference speed is significantly slower than YOLOv4, which attained real-time speeds at 128 FPS. CenterNet++’s unique keypoint refinement mechanism, though beneficial for localization, impacts its computational efficiency, highlighting areas for further optimization. To bridge this gap, several architectural improvements are proposed based on YOLOv4’s streamlined design. These include integrating modules like Spatial Pyramid Pooling (SPP) and Path Aggregation Network (PANet), along with reducing input resolution in the Fast CenterNet++ configuration. Additionally, future work is suggested to explore CenterNet++ in larger, more complex datasets and to develop semi-supervised learning approaches that could mitigate the limitations of annotated surgical datasets. In conclusion, this thesis contributes a comprehensive evaluation of anchor-free models for surgical tool detection, providing a foundation for further advancements in real-time, high precision object detection for surgical assistance. The findings underscore the potential of anchor-free models, such as CenterNet++, to meet the evolving demands of MIS with targeted architectural adaptations.
- Deep learning applied to the detection of traffic signs in embedded devices(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-06) Rojas García, Javier; Fuentes Aguilar, Rita Quetziquel; emimmayorquin; Morales Vargas, Eduardo; Izquierdo Reyes, Javier; School of Engineering and Sciences; Campus Eugenio Garza SadaComputer vision is an integral component of autonomous vehicle systems, enabling tasks such as obstacle detection, road infrastructure recognition, and pedestrian identification. Autonomous agents must perceive their environment to make informed decisions and plan and control actuators to achieve predefined goals, such as navigating from point A to B without incidents. In recent years, there has been growing interest in developing Advanced Driving Assistance Systems like lane-keeping assistants, emergency braking mechanisms, and traffic sign detection systems. This growth is driven by advancements in Deep Learning techniques for image processing, enhanced hardware capabilities for edge computing, and the numerous benefits promised by autonomous vehicles. This work investigates the performance of three recent and popular object detectors from the YOLO series (YOLOv7, YOLOv8, and YOLOv9) on a custom dataset to identify the optimal architecture for TSD. The objective is to optimize and embed the best-performing model on the Jetson Orin AGX platform to achieve real-time performance. The custom dataset is derived from the Mapillary Traffic Sign Detection dataset, a large-scale, diverse, and publicly available resource. Detection of traffic signs that could potentially impact the longitudinal control of the vehicle is focused on. Results indicate that YOLOv7 offers the best balance between mean Average Precision and inference speed, with optimized versions running at over 55 frames per second on the embedded platform, surpassing by ample margin what is often considered real-time (30 FPS). Additionally, this work provides a working system for real-time traffic sign detection that could be used to alert unattentive drivers and contribute to reducing car accidents. Future work will explore further optimization techniques such as quantization-aware training, conduct more thorough real-life scenario testing, and investigate other architectures, including vision transformers and attention mechanisms, among other proposed improvements.
- Deep learning applied to the detection of traffic signs in embedded devices(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-06) Rojas García, Javier; Fuentes Aguilar, Rita Quetziquel; emimmayorquin; Morales Vargas, Eduardo; Izquierdo Reyes, Javier; School of Engineering and Sciences; Campus Eugenio Garza SadaComputer vision is an integral component of autonomous vehicle systems, enabling tasks such as obstacle detection, road infrastructure recognition, and pedestrian identification. Autonomous agents must perceive their environment to make informed decisions and plan and control actuators to achieve predefined goals, such as navigating from point A to B without incidents. In recent years, there has been growing interest in developing Advanced Driving Assistance Systems like lane-keeping assistants, emergency braking mechanisms, and traffic sign detection systems. This growth is driven by advancements in Deep Learning techniques for image processing, enhanced hardware capabilities for edge computing, and the numerous benefits promised by autonomous vehicles. This work investigates the performance of three recent and popular object detectors from the YOLO series (YOLOv7, YOLOv8, and YOLOv9) on a custom dataset to identify the optimal architecture for TSD. The objective is to optimize and embed the best-performing model on the Jetson Orin AGX platform to achieve real-time performance. The custom dataset is derived from the Mapillary Traffic Sign Detection dataset, a large-scale, diverse, and publicly available resource. Detection of traffic signs that could potentially impact the longitudinal control of the vehicle is focused on. Results indicate that YOLOv7 offers the best balance between mean Average Precision and inference speed, with optimized versions running at over 55 frames per second on the embedded platform, surpassing by ample margin what is often considered real-time (30 FPS). Additionally, this work provides a working system for real-time traffic sign detection that could be used to alert unattentive drivers and contribute to reducing car accidents. Future work will explore further optimization techniques such as quantization-aware training, conduct more thorough real-life scenario testing, and investigate other architectures, including vision transformers and attention mechanisms, among other proposed improvements.
- A novel dataset and deep learning method for automatic exposure correction in endoscopic imaging(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-12-01) García Vega, Carlos Axel; Falcón Morales, Luis Eduardo; puemcuervo, emipsanchez; Daul, Christian; González Mendoza, Miguel; Roshan Biswal, Rajesh; School of Engineering and Sciences; Campus Estado de México; Ochoa Ruiz, GilbertoEndoscopy is such an important medical practice that one of the most common type of cancer worldwide, cause of many deaths, can be diagnosed and treated since through this imaging technique clinicians can diagnose cancerous lesions in hollow organs. Nonetheless, endo- scopic images are often affected by sudden illumination changes which entail regions with overexposure, underexposure or even both errors, in accordance with the light source pose and the lumen texture of the inner walls. These poor light conditions can carry several negative consequences either for the examination itself or on the performance of Computed-assisted Diagnosis (CAD) or Computed-aided Surgery (CAS). However, almost no effort has been done for deploy endoscopic image enhancement methods that can perform adequately (even when both errors appear simultaneously) and in real-time. The contribution of the present work in overall aims to enhance the quality of Field-of-View (FoV) from endoscopic ex- aminations and Computed-assisted Diagnosis through real-time Deep Learning techniques, however, for achieving this general objective, we first built a reliable reference-based dataset Endo4IE, evaluates and validated by experts, to be an standard dataset for IE purposes, due to the lack of this dataset in the literature. Afterwards, we evaluated IE methods on our dataset to find out a prospect method for our case-of-study, in this case LMSPEC originally introduced to enhance images from natural scenes. We made adaptations over the objective function of the prospect method to obtain better performance regarding to structure and less artifacts in the enhanced frame. Finally, we tested on the Endo4IE dataseta and evaluate with state-of- the-art metrics against the baseline method, thus the proposed implementation has yielded a significant improvement over LMSPEC reaching a SSIM increase of 4.40% and 4.21% for overexposed and underexposed images, respectively. Regarding PSNR, an improvement of 3.83% for over-exposed and just 0.01% below with respect to LMSPEC.
- EfficientDet and fuzzy logic for an emergency brake driver assistant system based on traffic lights using a Jetson TX2 and a ZED stereo camera(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-04) García Escalante, Andrés Ricardo; FUENTES AGUILAR, RITA QUETZIQUEL; 229297; Fuentes Aguilar, Rita Quetziquel; puelquio, emipsanchez; Terashima Marín, Hugo; Falcón Morales, Luis Eduardo; Álvarez González, Rodolfo Rubén; Escuela de Ingeniería y Ciencias; Campus Monterrey; Carbajal, Oscar Eleno EspinosaA study developed by the University of West Virginia analyzed the vehicle collisions, these occur due to the slow reaction time (RT) of humans. The study involved human RT under specific conditions, they found out that fully aware drivers have an estimated RT between 0.70 to 0.075 seconds, unexpected but normal situations like a lead car brake’s lights, is 1.25 seconds, and for surprising events is estimated to be around 1.50 seconds. Therefore, the presented work provides a solution to implement an Advanced Driver Assistant System (ADAS) level 1 called Emergency Brake Driver Assistant System based on Traffic Lights (EBDASTL) using a Jetson TX2 and a ZED Stereo camera to detect Traffic Light States (TLSs), estimate the distance to a Traffic Light (TL), and perform a brake decision based on the TLS and TLD that can have a better response time than human RT in surprising events. The main contribution of this research project is the implementation of a single ADAS that has three stages. The Traffic Light State Detection Model (TLSDM) stage using EfficientDet D0. The Traffic Light Distance (TLD) stage using a ZED Stereo camera, and the Traffic Light Decision-Making (TLDM) stage using Fuzzy Logic. Up to date there is not a related work that have the three stages. The second main contribution is the on Road test performed in Queretaro Mexico, where all the components of the EBDASTL have been mounted in a car and tested in a real-world scenario. The experiment consisted of detecting red and green TLSs at six different positions (5, 7, 9, 11, 13, and 15 meters from the TL). The TLSDM achieved a mean Average Precision of 96% for distances lower than 13 meters, and 89.50% for 15 meters. The TLD achieved an overall Root Mean Squared Error (RMSE) of 0.84 for all distances. The TLDM provided a smooth brake profile. Finally, the EBDASTL provided a response time of 0.23 seconds.