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Öğe A 3D-Printed Magnetic Focus Actuator for Laser Scanning Capsule Endoscopy(Ieee, 2024) Erdil, Kuter; Kebapcioglu, Berkay; Erten, Ahmet Can; Yelten, Mustafa Berke; Ferhanoglu, OnurWe report the design, manufacturing, and characterization results of a magnetic focus actuator and integrated circuit driver for use with miniaturized laser scanning capsule endoscopy. The capsule structure comprises: (1) a magnet-attached, SLA-printed focus actuator, (2) a lens and its housing, (3) a laser diode inserted into the electro coil, and (4) an actuator driver IC, which provides alternating current output at 32 Hz by down-converting the crystal frequency multiple times to match the mechanical resonance of the actuator itself. Due to the restricted power provided by the battery within the capsule, the IC is designed to mitigate higher harmonics for improved energy efficiency. Focus actuation tests were conducted following the assembly of the actuator and IC within the capsule, showcasing a total focal shift of 3.22 mm due to the interaction between the electro coil and Nd magnets.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 tactile sensing capsule endoscope employing force sensing cantilevers for tumor diagnosis in the GI tract(Elsevier Science Sa, 2026) Peker, Furkan; Akcan, O. Gokalp; Atak, Dila; Ozata, Ibrahim H.; Uymaz, Derya S.; Balik, Emre; Ferhanoglu, OnurThe correlation between tissue elasticity and histopathological diagnosis has brought attention to the develop ment of biomedical devices for in-vivo measurement of tissue biomechanical properties. Towards this aim, we have developed a tactile sensing capsule endoscope to measure tissue Young's modulus, in situ. Inspired by force microscopy, the capsule comprises four cantilevers that probe the walls of the GI tract using a single miniaturized actuator. The force exerted on the cantilever tip by the tissue is measured using the piezoelectric layer integrated on the cantilevers. The tactile-based modulus sensing capsule was initially tested on ex-vivo animal tissue, fol lowed by healthy and cancerous human specimens. The results clearly delineate the differences in mechanical properties, with a Young's modulus of 11.3 +/- 2.3 kPa for healthy and 26.8 +/- 4.6 kPa for cancerous tissue. Overall, in the realm of tactile-based modulus sensing of tissues, our technology uniquely combines localized, quantitative Young's modulus measurements with the capability to perform multiple measurements throughout the GI tract wall in a single procedure. Moreover, the developed sensor has a compact form factor, in accordance with the capsule dimensions, and simple manufacturing steps using stereolithography. With further improvements, the developed medical device can be utilized as a non-invasive diagnostic tool in the clinic.Öğe Anisotropic and Tunable Vocal Fold Phantom for Biomechanical Modeling(Ieee, 2025) Sarrafzadeh, Afarin; Erdil, Kuter; Tavli, Onur; Ferhanoglu, Onur; Erten, Ahmet C.Modeling the human vocal folds using an accurate vocal fold replica with exact characteristics such as anisotropic behavior and tunable mechanical properties remains challenging. In this study, we have introduced an effective and simplified approach to overcome vocal fold modeling challenges and achieve more realistic samples by using a silicon-based cubic phantom with a natural latex rubber tube embedded in the center of the cube. Young's modulus tunability in the longitudinal direction was achieved with a variation in water-to-air ratio inside the tube within the physiological range of 2 to 40 kPa while maintaining a constant Young's modulus in the transverse direction. Finite element simulations based on COMSOL in addition to experimental testing verified the effectiveness of the method indicating that reaching higher stiffness in the longitudinal direction by increasing the amount of water preserved anisotropic behavior. In summary, the main contribution of this study is introduction of an alternative approach to modelling the vocal fold with precise Young's modulus values within a single sample by adjusting the water ratio, which increases precision in experiments and reduces fabrication times.Öğe Computational and Experimental Modeling of Vocal Fold Pathology in a Realistic Phonation System(Institute of Electrical and Electronics Engineers Inc., 2025) Erdil, Kuter; Tavlı, Onur; Yaran, Hakan; Ferhanoglu, OnurThis study investigates the vibratory behavior of healthy and sulcus vocalis-affected vocal folds through a combined experimental and computational approach. Silicone vocal fold models with tunable mechanical properties are fabricated using a mold-based method. Finite Element Method (FEM) simulations reveal altered resonance patterns caused by sulcus pathology, particularly within the frequency range of 100–140 Hz. An experimental phonation setup employing chopper-modulated airflow and stroboscopic imaging captures the vibratory responses. Initial tests conducted with 15 kPa silicone confirm alterations in resonance modes, demonstrating the system’s potential for analyzing vocal fold disorders. ©2025 IEEE.Öğe Design and Implementation of a Low-Cost High-Performance Syringe Pump System(IEEE, 2017) Coskun, Hilmi; Gul, Ozgur; Ferhanoglu, Onur; Gokdel, Y. DaghanThis study describes design and implementation of a high-performance, low-cost, syringe pump device. Proposed device can be used with different injectors having volumes that are ranging from a common 0.5 mL to a larger 60 mL. This adaptable and programmable syringe pump provides high accuracy and adjustable flow rate in a simple mechanical manner and costs approximately $ 200. Developed system was tested on an optical table in lab conditions. It is measured that system can provide rates up to 0.05 mL/ h, when used on a 0.5 mL syringe whereas the maximum volume 60 mL injector can provide a flow rate of 5.8 mL/ h. Mean flow rate error of the system is calculated as 1.33%. Time-distance plots reveal a high degree of linearity and negligible hysteresis. Thus, the manufactured syringe pump is an excellent candidate as a high-precision liquid delivery system for low-resource settings.Öğe Electromagnetically actuated 3D-printed tunable optical slit device(Optica Publishing Group, 2023) Erdil, Kuter; Gurcuoglu, Oguz; Ferhanoglu, OnurThis paper presents the design, manufacturing, and characterization of a three-dimensional (3D)-printed and electromagnetically actuated adjustable optical slit structure. The device comprises magnet-attached slits connected to the main frame via two springs controlled by external coils. To analyze the forces acting on the springs and simulate the mechanical behavior of the device, we developed both analytical and finite-element models. After fabricating the device using fused deposition, we conducted a series of tests to evaluate its performance. These tests included (1) analyzing the opacity of the slit blade as a function of its thickness, (2) measuring the temperature increase resulting from the power applied to the coils to determine the operable range of the structure, and (3) evaluating the hysteresis, repeatability, and resolution (minimum step) of the device. The experimental works were crucial to assessing the device's practicality and optimizing its performance for specific applications, which reveals a maximum slit width of similar to 450 mu m, with similar to 6.4 mu m step size within this study. Overall, our developed slit device has the potential to be useful in various optics-related laboratories due to its compatibility with conventional 1-inch (25.4 mm) diameter optomechanical mounts, compact form, low power consumption, and rapid prototyping capability with hybrid materials in a cost-friendly fashion, owing to the 3D-printing technology. We discuss an application where the adjustable slit is employed in a combined laser-scanning microscope and a spectrometer, highlighting its versatility and potential for the future. (c) 2023 Optica Publishing GroupÖğe Magnetic actuator driver system for laser scanning capsule endoscopy(Elsevier Gmbh, 2025) Kebapcioglu, Berkay; Erdil, Kuter; Erten, Ahmet Can; Ferhanoglu, Onur; Yelten, Mustafa BerkeThis paper focuses on designing and implementing a power and area-efficient magnetic actuator driver interface integrated circuit for laser scanning capsule endoscopy. The proposed system contains a 3D-printed focus- adjusting actuator embarking a lens, multiple magnets, an external coil, battery, laser, and actuator driver integrated circuit with off-chip components. The actuator features multiple pantograph springs connected to the lens, as well as multiple magnets, enabling precise focusing capability through electromagnetic actuation. A magnetic actuator driver integrated circuit implemented in a commercial 180 nm CMOS process drives the coil at 32 Hz, which is the mechanical resonance frequency of the actuator. A novel control methodology for the driver has been devised, aimed at enhancing driving efficiency and mitigating total harmonic distortion. Simulations and measurements substantiate that the actuator can induce a 3.22 mm focal point displacement while the driver circuit delivers 9.62 mA (RMS) current to the 7.7 mH coil. Under these conditions, the system exhibits an aggregate power consumption of 11.48 mW, thereby achieving a power efficiency of 85.5%.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 Toward fully three-dimensional-printed miniaturized confocal imager(Spie-Soc Photo-Optical Instrumentation Engineers, 2018) Savas, Janset; Khayatzadeh, Ramin; Civitci, Fehmi; Gokdel, Yigit Dakhan; Ferhanoglu, OnurWe present a disposable miniaturized confocal imager, consisting mostly of three-dimensional (3-D)-printed components. A 3-D printed laser scanner with 10x10 mm(2) frame size is employed for Lissajous scan, with 180 and 315 Hz frequencies in orthogonal directions corresponding to +/- 8 deg and +/- 4 deg optical scan angles, respectively. The actuation is done electromagnetically via a magnet attached to the scanner and an external coil. A miniaturized lens with 6-mm clear aperture and 10-mm focal length is 3-D printed and post-processed to obtain desired (<=lambda/5 surface roughness) performance. All components are press-fitted into a 3-D-printed housing having 17 mm width, which is comparable to many of the MEMS-based scanning imagers. Finally, line-scan from a resolution target and two-dimensional scanning in the sample location were demonstrated with the integrated device. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)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.
