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Öğe A 45° tilted 3D-printed scanner for compact side-view laser scanning endoscopy(Springer Heidelberg, 2020) Savas, Janset; Altinsoy, Melisa; Gokdel, Yigit Daghan; Ferhanoglu, Onur; Civitci, FehmiSide viewing, miniaturized laser scanning endoscopes are powerful tools in providing sub-cellular level resolution and multi-layered imaging of the walls of body cavities. Yet, the level of miniaturization for such devices is significantly hampered by the necessity for 45 degrees placement of the whole scanner unit with respect to the cavity axis. With its rapid and low-cost production capability, 3D printing can be employed in addressing the challenge of producing a laser scanner, whose scanning head makes 45 degrees, or any desired angle, with the scanner unit. Producing a 10 x 10 mm(2) scanner device with tilted scan head (as opposed to the conventional design with identical size) enabled size shrinkage of a near fully 3D-printed laser scanning imager by x 1.5 in diameter (from 17 to 11 mm). We also share the initial results on 5 x 5 mm(2) total die size scanners, having literally identical die size with their MEMS counterparts, and discuss the road steps in producing < 8-mm diameter laser scanning devices with these scanners using 3D printing technology. The frame-rate improvement strategies are discussed in detail. Furthermore overall resolution and frame-rate values that can be achieved with the presented 3D printed scanners are tabulated and compared to MEMS counterparts. Overall with their low cost, easy and rapid fabrication, 3D printed actuators are great candidates for opto-medical imaging applications.Öğe A Fully Automated SPICE-Compatible Netlist Extraction From Image Using Deep Learning and Image Preprocessing Techniques(Ieee-Inst Electrical Electronics Engineers Inc, 2026) Peker, Omer Baran; Toker, Emre; Ocal, Dogukan; Dalyan, Tugba; Afacan, Engin; Gokdel, Yigit DaghanThis paper presents an automated framework for generating SPICE compatible netlists from both printed and hand-drawn circuit diagrams. The system combines advanced image preprocessing, deep learning based object detection, and contour based node analysis to address challenges such as inconsistent drawing styles, illumination variations, and non-standardized symbols. A unified preprocessing module incorporating denoising, contrast enhancement, adaptive thresholding, morphological filtering, and skeletonization ensures robust inputs for downstream tasks. Multiple YOLO (You Only Look Once) architectures were trained and evaluated, demonstrating strong performance across subtasks: YOLOv8L achieved 97.50% for transistor detection, YOLOv11L reached 98.55% for terminal segmentation, YOLOv11X attained 96.13% for voltage segmentation, and YOLOv8L obtained 99.23% for ground detection. These results confirm the framework's reliability in symbol interpretation. Beyond component-level recognition, the system integrates a specialized transistor terminal segmentation model and an advanced contour-based node detection module, enabling the accurate extraction of connectivity, even in dense, multi-component circuits. A novel validation mechanism further enhances robustness by fully automated simulating generated netlists in LTSpice and comparing node voltages with those of reference designs. Experimental evaluation demonstrates superior performance on printed diagrams (93.33% accuracy) and competitive performance on hand-drawn sketches (85.33% accuracy), despite stylistic irregularities. Overall, the proposed pipeline provides a scalable and accurate end-to-end solution, reducing human error and ensuring functional equivalence. Its ability to process complex, large-scale hand-drawn schematics under diverse conditions highlights its contributions to Electronic Design Automation (EDA), industrial applications, and intelligent design assistance. In addition, the framework incorporates a fast and fully automated validation stage, where generated netlists are systematically simulated in LTspice and compared against reference designs. This ensures both structural correctness and functional equivalence, further enhancing robustness and reliability.Öğe A Mathematical Programming Approach for IoT-Enabled, Energy-Efficient Heterogeneous Wireless Sensor Network Design and Implementation(Mdpi, 2024) Taparci, Ertugrul; Olcay, Kardelen; Akmandor, Melike Ozlem; Kabakulak, Banu; Sarioglu, Baykal; Gokdel, Yigit DaghanThe Internet of Things (IoT) is playing a pivotal role in transforming various industries, and Wireless Sensor Networks (WSNs) are emerging as the key drivers of this innovation. This research explores the utilization of a heterogeneous network model to optimize the deployment of sensors in agricultural settings. The primary objective is to strategically position sensor nodes for efficient energy consumption, prolonged network lifetime, and dependable data transmission. The proposed strategy incorporates an offline model for placing sensor nodes within the target region, taking into account the coverage requirements and network connectivity. We propose a two-stage centralized control model that ensures cohesive decision making, grouping sensor nodes into protective boxes. This grouping facilitates shared resource utilization, including batteries and bandwidth, while minimizing box number for cost-effectiveness. Noteworthy contributions of this research encompass addressing connectivity and coverage challenges through an offline deployment model in the first stage, and resolving real-time adaptability concerns using an online energy optimization model in the second stage. Emphasis is placed on the energy efficiency, achieved through the sensor consolidation within boxes, minimizing data transmission hops, and considering energy expenditures in sensing, transmitting, and active/sleep modes. Our simulations on an agricultural farmland highlights its practicality, particularly focusing on the sensor placement for measuring soil temperature and humidity. Hardware tests validate the proposed model, incorporating parameters from the real-world implementation to enhance calculation accuracy. This study provides not only theoretical insights but also extends its relevance to smart farming practices, illustrating the potential of WSNs in revolutionizing sustainable agriculture.Öğe An Electronic Control and Image Acquisition System for Laser Scanning Microscopy(IEEE, 2015) Gumus, Gokhan; Sarioglu, Baykal; Gokdel, Yigit DaghanThis paper presents an electronic system that controls the entire operation of a laser scanning microscopy system through a DAQ card. Proposed system does not only create the required electro-coil driving signal peculiar to magnetically actuated micro-scanner that enables the raster-scanning movement, but also is responsible from the image acquisition part by both serially gathering the laser intensity data and using it to construct a meaningful microscopy image. Micro-scanner which is fabricated using Ni as the structural material is utilized in the system. The microscanner's slow and fast scan frequencies are measured to be 250 Hz and 1560 Hz, respectively. Model of the DAQ card used in the system is NI-6356 which has maximum 5 mA current and 10 V voltage outputs. A power amplifier circuit with LM 386 is designed and added to the system for increasing field-of-view of the micro-scanner. The operation of the proposed system is demonstrated by acquiring data and constructing images from the USAF resolution target.Öğe Disposable Piezoresistive MEMS Airflow Sensor for Chronic Respiratory Disease Detection(Ieee-Inst Electrical Electronics Engineers Inc, 2025) Aygul, Beril; Ulgaz, Sena; Yilmaz, Berkay; Akcan, Omer Gokalp; Erdil, Kuter; Gokdel, Yigit DaghanThis paper details the design, fabrication, and characterization of a novel disposable MEMS airflow sensor, employing Bare Conductive electric paint deposited on Whatman 3MM chromatography paper through silk screen printing. The sensor achieves rapid fabrication within 30 minutes. It demonstrates a sensitivity of 1.8 kPa(-1) , a resolution of 27.6 kPa, and a limit of detection (LoD) of 48.94 kPa, with an operational pressure range from 27.6 to 137.9 kPa. An electronic readout circuit transduces electrical resistance variations into voltage signals, which are monitored via a digital multimeter and analyzed on a PC. The sensor's disposable nature mitigates nosocomial infection risks and enhances hygiene, making it ideal for monitoring respiratory conditions such as asthma and COPD. With a material cost of under 0.1, the sensor is highly suitable for scalable, cost-sensitive biomedical applications. Experimental validation confirms the reliability and precision of this proof-of-concept device in airflow measurement. 2024-0148Öğe Performance Analysis of Histogram-Threshold Method for Cancer Detection(IEEE, 2014) Koc, Gamze; Gokdel, Yigit Daghan; Sarioglu, BaykalIn this paper, histogram-threshold method developed for cancer detection using miniaturized confocal microscopy system and its related performance analysis are presented. While doing the performance analysis, the receiver operation characteristics are applied in a novel fashion. Additionally, noise performances of different method are investigated. The highest and lowest success rates with 91.67% and 27.08% are acquired using Entropy Method and Mean Method, respectively.Öğe Performance of a three-dimensional-printed microscanner in a laser scanning microscopy application(Spie-Soc Photo-Optical Instrumentation Engineers, 2018) Oyman, Hilmi Artun; Gokdel, Yigit Daghan; Ferhanoglu, Onur; Yalcinkaya, Arda DenizA magnetically actuated microscanner is used in a laser scanning microscopy application. Stress distribution along the circular-profiled flexure is compared with a rectangular counterpart in finite-element environment. Magnetic actuation mechanism of the scanning unit is explained in detail. Moreover, reliability of the scanner is tested for 3 x 10(6) cycle. The scanning device is designed to meet a confocal microscopy application providing 100 mu m x 100 mu m field of view and <3 mu m lateral resolution. The resonance frequencies of the device were analytically modeled, where we obtained 130- and 268-Hz resonance values for the out-of-plane and torsion modes, respectively. The scanning device provided an optical scan angle about 2.5 deg for 170-mA drive current, enabling the desired field of view for our custom built confocal microscope setup. Finally, imaging experiments were conducted on a resolution target, showcasing the desired scan area and resolution. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)Öğe Reliability of 3D-Printed Dynamic Scanners(IEEE, 2017) Gonultas, Burak Mert; Aygun, Sacid; Khayatzadeh, Ramin; Civitci, Fehmi; Gokdel, Yigit Daghan; Yelten, Mustafa Berke; Ferhanoglu, Onur3D-printed dynamic structures have arisen as a lower cost and easier to fabricate alternative to miniaturized sensor and actuator technologies. Here, we investigate the reliability of a selected 3D-printed laser scanner, which was initially designed for miniaturized confocal imaging, having 1 x 1 cm' footprint. The scan-line, 1 resonant frequency and quality factor of 3 devices were monitored for 100,000,000 (hundred million) cycles, and an average deviation of <6% was observed for all three parameters under investigation, for the devices under test. We conclude that 3D printed dynamic structures are promising candidates for a variety of applications, including optomedical imaging applications that demand disposable and low-cost scanning technologies.Öğe Reliability Testing of 3D-Printed Polyamide Actuators(IEEE-Inst Electrical Electronics Engineers Inc, 2020) Kasap, Gokce; Gokdel, Yigit Daghan; Yelten, Mustafa Berke; Ferhanoglu, Onur3D printing is a rapidly emerging low-cost, high-yield, and high-speed manufacturing technique that has already been utilized in fabricating sensor and actuator devices. Here we investigate the cyclic fatigue and the effect of heating on 10 x 10 mm2-sized, 3D-printed polyamide-based laser scanning electromagnetic actuators, which are intended for integration with miniaturized laser-scanning imagers to yield a wide variety of optical imaging modalities. The tested actuators offer compact sizes and high-scan angles, comparable to their MEMS counterparts. We have tested N = 15 devices, at 5 different total optical scan angles between 40 degrees - 80 degrees, and observed their lifetimes (up to 108 cycles approximate to 10 days each), as well as the variability in their scan angle and mechanical resonance. A selected scanner was also tested under increased temperature conditions up to 60 degrees C for 10 hours, showing no sign of fatigue when returned to room temperature. Overall, it is concluded that 3D printed polymeric actuators are promising low-cost alternatives for short-term use in disposable opto-medical imaging units.Öğe A stainless-steel micro-scanner for rapid 3D confocal imaging(Iop Publishing Ltd, 2019) Oyman, Hilmi Artun; Efe, Baris Can; Icel, Mustafa Akin; Gokdel, Yigit Daghan; Ferhanoglu, Onur; Yalcinkaya, Arda DenizThis paper summarizes the design, fabrication, and characterization of a magnetically actuated stainless-steel based micro-scanner. The out-of-plane deflection of the proposed device is calculated by using a custom depth scan setup. The main advantage of laser cutting technology, which is utilized in manufacturing the proposed steel scanner, is its rapid fabrication capability at low cost, while still offering high frequency scan for imaging and/or ablation with high frame-rates. In the lateral plane, the scanner delivers 5 degrees of total optical scan angle for a current drive of 60 mA for both slow scan and fast scan axes at 998 Hz and 2795 Hz, respectively. Furthermore, the device provides an out-of-plane pumping mode at 1723 Hz that could be utilized for axial scanning to create focal shift at the target. Fabricated scanner is integrated into a confocal microscopy setup and tested with a resolution target and a Convallaria rhizome sample, accomplishing a 240 mu m x 240 mu m field of view with 2.8 mu m resolution. The device offers 218 mu m depth of field (in tissue) and based on acquired resonance frequencies, we estimate rapid scanning of a three-dimensional block of tissue (240 mu m x 240 mu m x 218 mu m size) with approximately 3 block per second with 50% fill rate and total coverage of 87% for 1 s scan. Finally, a custom setup is proposed for 3D imaging and validity of the 3D beam steering of the micro-scanner is tested.Öğe System Integration for Real-Time Laser Scanning Confocal Microscope(IEEE, 2016) Gumus, Gokhan; Sarioglu, Baykal; Gokdel, Yigit DaghanIn this work, a laser scanning confocal microscopy system governed by a software controlled DAQ Card is presented. The presented system can be utilized for scanning a target and displaying the resulting image through a designed graphical user interface (GUI). The system performs two main operations: (1) generation of the actuation signal and (2) image acquisition. The architecture of the proposed system and successful operation of the system is demonstrated by constructing images from USAF51 negative resolution test target. In the experiments, the proposed system is operated at the slow scan frequency (f (s)) of 1 Hz and the fast scan frequency (f (fast)) of 100 Hz with a sampling frequency (f (fast)) of 20 kHz. The experimental results show that 1 mu m lateral resolution is achieved in the proposed system.Öğe Towards 3D printed confocal endoscopy(Spie-Int Soc Optical Engineering, 2016) Savas, Janset; Caliskan, Ahmet; Civitci, Fehmi; Gokdel, Yigit Daghan; Ferhanoglu, OnurA low-cost confocal endoscope was developed consisting of a 3D printed laser scanner, a lens, and a housing. The developed tool, mainly made out of low cost polymer offers a disposable use. The scanner unit is overall 10x10mm and electromagnetically actuated in 2-dimensions using a magnet that is attached to the 3D printed scanner and an external miniaturized coil. Using 3D printer's fabrication advantages the first two vibration modes of the scanner were tailored as out-of-plane displacement and torsion. The scanner employs lissajous scan, with 190 Hz and 340 Hz scan frequencies in the orthogonal directions and we were able to achieve +/- 5 degrees scan angles, respectively, with similar to 100 mA drive current. The lens which has 6-mm diameter and 10-mm focal length is 3D printed with Veroclear material and then polished in order to reach optical quality surface. Profilometer (Dektak) measurements indicate only x2 increase in rms roughness, with respect to a commercial glass lens having identical size and focal length.
