• Journal of Biomedical Engineering Research
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• v.44 no.4
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• pp.255-263
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• 2023

Clinical ultrasound (US) is a widely used imaging modality with various clinical applications. However, capturing a large field of view often requires specialized transducers which have limitations for specific clinical scenarios. Panoramic imaging offers an alternative approach by sequentially aligning image sections acquired from freehand sweeps using a standard transducer. To reconstruct a 3D volume from these 2D sections, an external device can be employed to track the transducer's motion accurately. However, the presence of optical or electrical interferences in a clinical setting often leads to incorrect measurements from such sensors. In this paper, we propose a deep learning (DL) framework that enables the prediction of scan trajectories using only US data, eliminating the need for an external tracking device. Our approach incorporates diverse data types, including correlation volume, optical flow, B-mode images, and rawer data (IQ data). We develop a DL network capable of effectively handling these data types and introduce an attention technique to emphasize crucial local areas for precise trajectory prediction. Through extensive experimentation, we demonstrate the superiority of our proposed method over other DL-based approaches in terms of long trajectory prediction performance. Our findings highlight the potential of employing DL techniques for trajectory estimation in clinical ultrasound, offering a promising alternative for panoramic imaging.

• Journal of the Korea Convergence Society
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• v.6 no.2
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• pp.57-64
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• 2015

Inductive Power Transfer (IPT) systems have successfully been developed and used to replace traditional conductive power transfer systems where physical connection is either inconvenient or impossible, such as biomedical implants, undersea vehicles, and contactless battery chargers of robots, for providing power to movable or detachable loads. Inductive Coupling uses magnetic fields to transfer power. There is a primary coil, which generates a magnetic field. Then there is another secondary coil which is composed of a capacitor and a coil, the capacitor creates a circuit with the primary and secondary coils. This paper discusses design method and several implementation alternatives for wireless energy transmission systems. It presents realization examples for these alternatives. Wireless energy transmission is investigated in numerous convergence applications due to its simplicity and advantages.

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.259-270
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• 2022

Artificial intelligence (AI) has been studied in various fields of medical imaging. Currently, top-notch deep learning (DL) techniques have led to high diagnostic accuracy and fast computation. However, they are rarely used in real clinical practices because of a lack of reliability concerning their results. Most DL models can achieve high performance by extracting features from large volumes of data. However, increasing model complexity and nonlinearity turn such models into black boxes that are seldom accessible, interpretable, and transparent. As a result, scientific interest in the field of explainable artificial intelligence (XAI) is gradually emerging. This study aims to review diverse XAI approaches currently exploited in medical imaging. We identify the concepts of the methods, introduce studies applying them to imaging modalities such as computational tomography (CT), magnetic resonance imaging (MRI), and endoscopy, and lastly discuss limitations and challenges faced by XAI for future studies.

• International journal of advanced smart convergence
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• v.7 no.4
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• pp.169-173
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• 2018

Iris diagnosis based on the color and texture information is one of a novel approach which can represent the current state of a certain organ inside body or the health condition of a person. In analysis of the iris images, there are critical image artifacts which can prevent of use interpretation of the iris textures on images. Here, we developed the iris diagnosis system based on a hand-held typed imaging probe which consists of a single camera sensor module with 8M pixels, two pairs of 400~700 nm LED, and a guide beam. Two original images with different light noise pattern were successively acquired in turns, and the light noise-free image was finally reconstructed and demonstrated by the proposed artifact removal approach.

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.80-84
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• 2023

Electrodes are one of the types of biosensors capable of measuring bio signals, such as electrocardiogram (ECG) and electromyogram (EMG) signals. These electrodes are used in various fields and offer the advantage of being able to measure ECG signals without the need for skin attachment, compared to Ag/AgCl electrodes. The purpose of this study was to evaluate the efficacy of conductive textile electrodes in collecting ECG signals in a bed-like environment. Three adult participants were involved, and a total of 30 minutes of ECG signals were collected for each participant. The collected ECG signals were analyzed to determine the heart rate, normLF and a comparison was made between the conductive textile electrodes and Ag/AgCl electrodes. As a result, the change in heart rate and normLF could be observed, and in particular, the difference between the two electrodes decreased. This study confirmed that conductive textile electrodes can effectively collect ECG signals in a bed-like environment. It is hoped that this research will lead to the development of a system that can detect various sleep-related diseases through the use of these electrodes.

• Journal of Biomedical Engineering Research
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• v.44 no.4
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• pp.284-292
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• 2023

This study attempted to observe muscle activity and muscle fatigue among isotonic exercise of Biceps Brachii and Deltoidus Medius, which correspond to upper limb muscles, using metronome. For the experiment, 13 adult men participated to evaluate biosignals (ECG, EMG). For quantitative evaluation, 1RM and MVIC test were carried out and a constant pace isotonic excise session was conducted. Five sets of exercise were performed, and each set proceeded to the failure point while the speed condition (30bpm) was assigned. As a result of the experiment, muscle activity in both muscles was significantly reduced in fifth set compared to first set. Muscle fatigue has been confirmed to occur at a significant level within the set, but there was only a significant difference in both muscles in the first and second sets between sets. This is similar to the results of previous studies that gives the same rest time(2min), but further research is needed to see if the conditions for the number of repetitions are affected. Based on the recent increase of interest in muscle strength exercise, this study was conducted to observe the results by varying the conditions of common exercise.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.305-313
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• 2016

A number of fluorescence imaging techniques for use in the surgical removal of glioma have been developed over the course of the long history of neurosurgery. Various biomarkers, biochemical agents, and detection systems for glioma have also been developed. This review focuses on 5-aminolevulinic acid (5-ALA), which is used to detect glioma. Numerous forms of fluorescence-guided surgery use 5-ALA, which is helpful to the surgeon. The surgical microscope system is the observational method generally used with 5-ALA, while the loupe, endoscope, and exoscope are simpler alternatives. A system is needed for minimal resection and other issues that arise during neurosurgery. Such an enhanced system should be able to detect low-grade tumors and provide information on microinvasive diseases, resulting in an improved survival rate and better surgical skills. Development of systems that fulfill certain needs would help protect the brain function of the patient and broaden the use of such systems in neurosurgery.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.23-29
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• 2015

In this paper, we propose a microscope system for detecting both a tumor and blood vessels in brain tumor surgery as fluorescence images by using multiple light sources and a beam-splitter module. The proposed method displays fluorescent images of the tumor and blood vessels on the same display device and also provides accurate information about them to the operator. To acquire a fluorescence image, we utilized 5-ALA (5-aminolevulinic acid) for the tumor and ICG (Indocyanine green) for blood vessels, and we used a beam-splitter module combined with a microscope for simultaneous detection of both. The beam-splitter module showed the best performance at 600 nm for 5-ALA and above 800 nm for ICG. The beam-splitter is flexible to enable diverse objective setups and designed to mount a filter easily, so beam-splitter and filter can be changed as needed, and other fluorescent dyes besides 5-ALA and ICG are available. The fluorescent images of the tumor and the blood vessels can be displayed on the same monitor through the beam-splitter module with a CCD camera. For ICG, a CCD that can detect the near-infrared region is needed. This system provides the acquired fluorescent image to an operator in real time, matching it to the original image through a similarity transform.

• Journal of Biomedical Engineering Research
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• v.34 no.3
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• pp.141-147
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• 2013

Ultrasonic shears is currently in wide use as an energy device for minimal invasive surgery. There is an advantage of minimizing the carbonization behavior of the tissue due to the vibrational energy transfer system of the transducer by applying a piezoelectric ceramic. However, the vibrational energy transfer system has a pitfall in energy consumption. When the movement of the forceps is interrupted by the tissue, the horn which transfers the vibrational energy of the transducer will be affected. A study was performed to recognize different tissues by measuring the impedance of the transducer of the ultrasonic shears in order to find the factor of energy consumption according to the tissue. In the first stage of the study, the voltage and current of the transducer connecting portion were measured, along with the phase changes. Subsequently, in the second stage, the impedance of the transducer was directly measured. In the final stage, using the handpiece, we grasped the tissue and observed the impedance differences appeared in the transducer To verify the proposed tissue distinguishing method, we used the handpiece to apply a force between 5N and 10N to pork while increasing the value of the impedance of the transducer from 400 ${\Omega}$.. It was found that fat and skin tissue, tendon, liver and protein all have different impedance values of 420 ${\Omega}$, 490 ${\Omega}$, 530 ${\Omega}$, and 580 ${\Omega}$, respectively. Thus, the impedance value can be used to distinguish the type of tissues grasped by the forceps. In the future study, this relationship will be used to improve the energy efficiency of ultrasonic shears.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.146-152
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• 2018

Due to their excellent mechanical durability and high electrical conductivity, carbon and silicon composites are potentially suitable anode materials for Li-ion batteries with high capacity and long lifespan. Nevertheless, the limitations of the composites include their poor ionic diffusion at high current densities during cycling, which leads to low ultrafast performance. In the present study, seeking to improve the ionic diffusion using hydrothermal method, electrospinning, and carbonization, we demonstrate the unique design of excavated carbon and silicon composites (EC/Si). The outstanding energy storage performance of EC/Si electrode provides a discharge specific capacity, impressive rate performance, and ultrafast cycling stability.