arXiv subjects

Ali Anil Demircali

Publications and source records attributed to Ali Anil Demircali.

7 recordsLinked to original sources

arXiv2026

Modular Robotic Catheters for Endovascular Aneurysm Repair

Fenestrated/Branched endovascular aneurysm repair (FEVAR/BEVAR) require surgeons to navigate catheters and guidewires into various branches of the abdominal aorta, before deploying stent grafts to alleviate pressure on the aneurysm. Previous clinical studies suggests that surgeons continue to struggle with vessel access using standard commercial instruments, prolonging the procedural time and inducing further complications. In this work, we present two contributions to solving this problem: 1) A bespoke 2-segment steerable catheter, consisting of 4 degrees of freedom to enhance dexterity. 2) An expandable, modular tendon-driven actuation platform that can accommodate for the redundancies introduced in our system. To fabricate the catheter, we capitalized on thermal fiber drawing, a technique that creates high-aspect ratio devices at scale, and processed the catheter with laser micro-machining to soften its tip. We evaluated the system using simulations, where we investigated the catheter's bending stiffness, then its steerability with in-vitro experiments in vascular phantoms. This handheld, robotic steerable catheter system has the potential to shorten the length of future endovascular surgeries, and give clinicians the tools to resolve challenging clinical cases.

cs.RO↗

arXiv2025

DermaSynth: Rich Synthetic Image-Text Pairs Using Open Access Dermatology Datasets

A major barrier to developing vision large language models (LLMs) in dermatology is the lack of large image--text pairs dataset. We introduce DermaSynth, a dataset comprising of 92,020 synthetic image--text pairs curated from 45,205 images (13,568 clinical and 35,561 dermatoscopic) for dermatology-related clinical tasks. Leveraging state-of-the-art LLMs, using Gemini 2.0, we used clinically related prompts and self-instruct method to generate diverse and rich synthetic texts. Metadata of the datasets were incorporated into the input prompts by targeting to reduce potential hallucinations. The resulting dataset builds upon open access dermatological image repositories (DERM12345, BCN20000, PAD-UFES-20, SCIN, and HIBA) that have permissive CC-BY-4.0 licenses. We also fine-tuned a preliminary Llama-3.2-11B-Vision-Instruct model, DermatoLlama 1.0, on 5,000 samples. We anticipate this dataset to support and accelerate AI research in dermatology. Data and code underlying this work are accessible at https://github.com/abdurrahimyilmaz/DermaSynth.

cs.CV↗

arXiv2025

Fabrication of Fibers with Complex Features Using Thermal Drawing of 3D-Printed Preforms

High-aspect-ratio polymer materials are widely utilized in applications ranging from everyday materials such as clothing to specialized equipment in industrial and medical fields. Traditional fabrication methods, such as extrusion and molding, face challenges in integrating diverse materials and achieving complex geometries. Additionally, these methods are limited in their ability to provide low-cost and rapid prototyping, which are critical for research and development processes. In this work, we investigated the use of commercially available 3D printers to fabricate fiber preforms, which were subsequently thermally drawn into fibers. By optimizing 3D printing parameters, we achieved the fabrication of fibers with diameters as small as 200 um having complex shapes, with features down to a few microns. We demonstrated the versatility of this method by fabricating fibers from diverse set of materials, such as fibers with different stiffnesses and fibers with magnetic characteristics, which are beneficial for developing tendon-driven and magnetically actuated robotic fibers. In addition, by designing novel preform geometries, we produced tapered fibers and fibers with interlocking mechanisms, also tailored for use in medical steerable catheter applications. These advancements highlight the scalability and versatility of this approach, offering a robust platform for producing high-precision polymer fibers for diverse applications.

physics.med-ph↗

arXiv2024

Precise Hybrid-Actuation Robotic Fiber for Enhanced Cervical Disease Treatment

Treatment for high-grade precancerous cervical lesions and early-stage cancers, mainly affecting women of reproductive age, often involves fertility-sparing treatment methods. Commonly used local treatments for cervical precancers have shown the risk of leaving a positive cancer margin and engendering subsequent complications according to the precision and depth of excision. An intra-operative device that allows the careful excision of the disease while conserving healthy cervical tissue would potentially enhance such treatment. In this study, we developed a polymer-based robotic fiber measuring 150 mm in length and 1.7 mm in diameter, fabricated using a highly scalable fiber drawing technique. This robotic fiber utilizes a hybrid actuation mechanism, combining electrothermal and tendon-driven actuation mechanisms, thus enabling a maximum motion range of 46 mm from its origin with a sub-100 μm motion precision. We also developed control algorithms for the actuation methods of this robotic fiber, including predefined path control and telemanipulation, enabling coarse positioning of the fiber tip to the target area followed by a precise scan. The combination of a surgical laser fiber with the robotic fiber allows for high-precision surgical ablation. Additionally, we conducted experiments using a cervical phantom that demonstrated the robotic fiber's ability to access and perform high-precision scans, highlighting its potential for cervical disease treatments and improvement of oncological outcomes.

cs.RO↗

arXiv2021

Mechatronic Investigation of Wound Healing Process by Using Micro Robot

The purpose of this study is to find ideal forces for reducing cell stress in wound healing process by micro robots. Because of this aim, we made two simulations on COMSOL Multiphysics with micro robot to find correct force. As a result of these simulation, we created force curves to obtain the minimum force and friction force that could lift the cells from the surface will be determined. As the potential of the system for two micro robots that have 2 mm x 0.25 mm x 0.4 mm dimension SU-8 body with 3 NdFeB that have 0.25 thickness and diameter, simulation results at maximum force in the x-axis calculated with 4.640 mN, the distance between the two robots is 150 um.

cs.RO↗

arXiv2021

The Effect of Pore Structure in Flapping Wings on Flight Performance

This study investigates the effects of porosity on flying creatures such as dragonflies, moths, hummingbirds, etc. wing and shows that pores can affect wing performance. These studies were performed by 3D porous flapping wing flow analyses on Comsol Multiphysics. In this study, we analyzed different numbers of the porous wing at different angles of inclination in order to see the effect of pores on lift and drag forces. To compare the results 9 different analyses were performed. In these analyses, airflow velocity was taken as 5 m/s, angle of attack as 5 degrees, frequency as 25 Hz, and flapping angle as 30 degrees. By keeping these values constant, the number of pores was changed to 36, 48, and 60, and the pore angles of inclination to 60, 70, and 80 degrees. Analyses were carried out by giving laminar flow to this wing designed in the Comsol Multiphysics program. The importance of pores was investigated by comparing the results of these analyses.

physics.flu-dyn↗

arXiv2020

Comparison of Deep Learning and Traditional Machine Learning Techniques for Classification of Pap Smear Images

A comprehensive study on machine and deep learning techniques for classification of normal and abnormal cervical cells by using pap smear images from Herlev dataset results are presented. This dataset includes 917 images and 7 different classes. All techniques used in this study are modeled by using Google Colab platform with scikit-learn and Keras library inside TensorFlow. In the first study, traditional machine learning methods such as logistic regression, k-Nearest Neighbors (kNN), Support Vector Machine (SVM), Decision Tree, Random Forest and eXtreme Gradient Boosting (XGBoost) are used and compared with each other to find binary classification as normal and abnormal cervical cells. Better results are observed by XGBoost and kNN classifiers among the others with an accuracy of 85%. In the second study, a deep learning model based on Convolutional Neural Network(CNN) is used for the same dataset. Accordingly, accuracies of 99% and 93% are obtained for the training and the test dataset, respectively. In this model, it takes 50 epochs to have these accuracies within 20 minutes of computational time.

eess.IV↗