• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.5
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• pp.481-488
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• 2015

It is difficult to see a therapeutic effect from cardiovascular disease treatment methods in the case of a hardened chronic total occlusion (CTO), owing to the calcification of the deposition materials. However, lesion cells, such as CTOs, can be selectively necrotized without affecting the normal tissue using high-intensity ultrasound focused on one point. In this study, a phantom CTO was necrotized by a high-intensity focused ultrasound (HIFU) energy system, and the acoustic characteristics in the focal region were analyzed. An experimental HIFU device was constructed to discover the appropriate conditions for the necrosis of a phantom CTO. The transfer characteristics of the ultrasound changed in the focal region by the density difference of the phantom CTO. These changes were acoustically analyzed to choose the available frequency band for each density. On-off temperature control in the focal region was applied to prevent rapid temperature rises, which would otherwise affect normal tissue.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.711-717
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• 2007

Location information will become increasingly important for future Pervasive Computing applications. Location tracking system of a moving device can be classified into two types of architectures: an active mobile architecture and a passive mobile architecture. In the former, a mobile device actively transmits signals for estimating distances to listeners. In the latter, a mobile device listens signals from beacons passively. Although the passive architecture such as Cricket location system is inexpensive, easy to set up, and safe, it is less precise than the active one. In this paper, we present a passive location system using Cricket Mote sensors which use RF and ultrasonic signals to estimate distances. In order to improve accuracy of the passive system, the transmission speed of ultrasound was compensated according to air temperature at the moment. Upper and lower bounds of a distance estimation were set up through measuring minimum and maximum distances that ultrasonic signal can reach to. Distance estimations beyond the upper and the lower bounds were filtered off as errors in our scheme. With collecting distance estimation data at various locations and comparing each distance estimation with real distance respectively, we proposed an equation to compensate the deviation at each point. Equations for proposed algorithm were derived to calculate relative coordinates of a moving device. At indoor and outdoor tests, average location error and average location tracking period were 3.5 cm and 0.5 second, respectively, which outperformed Cricket location system of MIT.

• The Korean Journal of Pain
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• v.37 no.3
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• pp.201-210
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• 2024

The application of ultrasound (US) in pain medicine has been a rapidly growing field since the 2000s. Musculoskeletal injections, peripheral nerve blocks, and neuraxial injections under US guidance have been acknowledged for managing chronic pain. Although many studies on US-guided pain procedures have been published, there needs to be a classification system to evaluate which image device, the US or fluoroscopy, is clinically and technically better in various pain interventions. Therefore, this narrative review introduces the classification system for the US-guided pain procedures according to their clinical and technical outcomes and designates US-guided pain procedures into one of the four categories by reviewing previous prospective randomized comparative trials.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.457-463
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• 2014

Ultrasound measurements of backfat thickness (UBF), longissimus muscle area (ULMA) and marbling score (UMS) and carcass measurements of carcass weight (CW), backfat thickness (BF), longissimus muscle area (LMA), and marbling score (MS) on 7,044 Hanwoo steers were analyzed to estimate genetic parameters. Data from Hanwoo steers that were raised, finished in Hoengseong-gun, Gangwon-do (province) and shipped to slaughter houses during the period from October 2010 to April 2013 were evaluated. Ultrasound measurements were taken at approximately three months before slaughter by an experienced operator using a B-mode real-time ultrasound device (HS-2000, FHK Co. Ltd., Tokyo, Japan) with a 3.5 MHz linear probe. Ultrasound scanning was on the left side between 13th rib and the first lumbar vertebrae. All slaughtering processes and carcass evaluations were performed in accordance with the guidelines of beef grading system of Korea. To estimate genetic parameters, multiple trait animal models were applied. Fixed effects included in the models were: the effects of farm, contemporary group effects (year-season at the time of ultrasound scanning in the models for UBF, ULMA, and UMS, and year-season at slaughter in the models for CW, BF, LMA, and MS), the effects of ultrasound technicians as class variables and the effects of the age in days at ultrasound scanning or at slaughtering as linear covariates, respectively for ultrasound and carcass measures. Heritability estimates obtained from our analyses were 0.37 for UBF, 0.13 for ULMA, 0.27 for UMS, 0.44 for CW, 0.33 for BF, 0.36 for LMA and 0.54 MS, respectively. Genetic correlations were strongly positive between corresponding traits of ultrasound and carcass measures. Genetic correlation coefficient between UBF and BF estimate was 0.938, between ULMA and LMA was 0.767 and between UMS and MS was 0.925. These results suggest that ultrasound measurement traits are genetically similar to carcass measurement traits.

• Journal of Applied Reliability
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• v.15 no.1
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• pp.27-32
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• 2015

Functional safety is part of the overall safety relating to the equipment under control (EUC) and the EUC control system that depends on the correct functioning of the electrical/electronic/programmable electronic (E/E/PE) safety-related systems. Since the complexity of the medical equipment is increased, manufactures have to obtain functional safety as well as basic safety. This study proposes a perspective for applying functional safety to medical equipment. The research is carried out with respect to overall safety life-cycle of functional safety and essential performance of the medical equipment. The relationship between functional safety and essential performance is identified centered on the safety function. The essential performance using E/E/PE systems is defined as a safety function of functional safety. This approach is applied to a ultrasound imaging system as a case study.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.313-320
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• 1998

Tri-phasic pulsatile flow is the general flow pattern of human circulary system. In emulating the various situation of cardiovascular system, it is essential to make tri-phasic source flow. To emulate tri-phasic pulsatile flow, we used electro-hydronic style LVAD(Left Ventricular Assist Device) with glass phantom and rubber tube. We have selected control parameters and examined the changing effect of each parameter by using Doppler ultrasound. In this experiment, it was shown that the distal compliance and the break time were the major factors to form tri-phasic flow. The results make it possible to emulate and explain the various situation of human vascular system. In this point, this results will be an useful method in the clinic application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.417-420
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• 2005

The spirometer is a medical device that measures the instantaneous velocity of the respiratory gas flow capacity. It is used for testing the condition of the lung and patient monitoring. It measures the absolute capacity difference that includes the flow capacity signal. In this paper, by using an ultrasound sensor that reduce the error caused by the inertia and pressure it has improved the transmission and receiving signal. This has enabled patients with weal respiratory to use the spirometer. Also, by using the embedded hardware system, a precise and prompt detection system was implemented.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.221-225
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• 2017

To evaluate the performance of ultrasound imaging system, we investigated the change of spatial resolution according to changing sonic velocity change parameter provided by ultrasound equipment. Ultrasound phantom images were obtained using a 3.0 ~ 5.0 MHz convex transducer in an ultrasound diagnostic device used at a medical institution located at Iksan. N-365 multi-purpose ultrasound phantom was used to measure longitudinal distance measurement accuracy and longitudinal and transverse resolution. In the same manner, the sonic velocity of the ultrasound equipment was changed from 1580 m/sec to 1400 m/sec in six steps, and the full width at half maximum(FWHM) was measured using the image J program to determine whether the measured values were different. As a result, lateral resolution was measured from 1.91 mm to 5.3 mm according to the speed change, and the smallest FWHM was 1.91 mm at 1420 m/sec. The axial resolution was measured from 1.03 mm to 1.14 mm according to the speed change, and the smallest FWHM was 1.03 mm at 1400 m/sec. The slower the sound velocity of the ultrasound equipment, the shorter the length of longitudinal measurement.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.63-71
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• 2021

Using fossil fuels in existing industrial systems causes a variety of social problems. Recently, many studies have been conducted on bio-refineries, which aim to actively utilize biomass to reduce the use of fossil fuels and solve various social problems. Among them, research using microalgae as a third-generation biomass has attracted considerable attention. Microalgae use inorganic matter to produce organic matter, and cell destruction is necessary to extract useful organic materials from microalgae. The extracted organic materials are currently used in various industrial fields. Numerous cell-destruction methods exist. We have investigated cell disruption by sonication, especially its efficiency. Ultrasound is a sound wave with frequencies above 20 kHz, and destroys cells by sending high energy through a cavitation that occurs, according to the characteristics of the sound wave. The Dunaliella salina microalgae used in this study was cultured in a flat-type photobioreactor. Experiments were performed using a batch low-frequency processing device. Logistic model was applied to analyze the results of cell-destruction experiments using ultrasound. The proper conditions for the most efficient cell destruction were OD 1.4(microalgae concentration)), 54watt(output power) and 200mL(microalgae capacity).

• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.564-569
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• 2022

Blood-Brain Barrier (BBB) is the brain protecting system blocking the inflow of harmful substances into brain parenchyma from brain blood vessel. However, the BBB has a negative effect on the treatment of various brain diseases such as Alzheimer's dementia or brain tumors because it also prevents drug delivery into brain parenchyma. To overcome this problem, a brain drug delivery technique using Focused Ultrasound (FUS) which allows BBB to be temporarily opened by inducing the acoustic cavitation effect of microbubbles has been developed. Thus far, various studies using the FUS technique has been conducted to improve drug delivery efficiency, and therefore, this paper discusses recently developed drug delivery technologies using the FUS-induced BBB opening.