• Journal of IKEEE
• /
• v.11 no.4
• /
• pp.293-296
• /
• 2007

A novel sensitive and non-invasive ring-type glucose probe was designed and measured. The magnitude and phase of return loss change with different concentration of the glucose solution inside the loop structure. Ring type probe is more advantageous than open ended probe to measure electrical characteristics under the skin. The maximum difference of return loss was 0.94 for the concentration difference of 0% and 20% at 285MHz and more sensitive in low frequency.

• Journal of IKEEE
• /
• v.24 no.3
• /
• pp.713-718
• /
• 2020

The method of measuring skin active points is a technique for obtaining a lot of biometric information because it is measured with convenience, low cost and non-invasive methods. In this paper, we used in a three electrode measure method that has the advantage of measuring the impedance of the APs under the skin. The impedance measuring method is well illustrated by a simple model of an equivalent electrical circuit that correlates well with experimental results. The characteristic frequencies of APs are about 15-30HZ higher than that of surrounding skin and the values of measured reactance are about 35-77KΩ smaller. This technology analyzed accurately and objectively the reactance and characteristic frequency of APs and the surrounding skin using a non-invasive measuring system.

• Journal of Biomedical Engineering Research
• /
• v.18 no.4
• /
• pp.499-505
• /
• 1997

A non-invasive technique to measure absorption and scattering coefficients was investigated The reflected backscattered light from the surface of phantom and biological tissue was obtained by using a time-correlated single photon counting system in pico-second time domain. The absorption and scattering coefficients were acquired by the time of peak and asymptotic behavior of the time-resolved reflectance curve and agreed well the ones that is obtained with deconvolution method It was found that the approximation method was good for biological medium to calculate optical properties due to its convenience and accuracy.

• Journal of Chest Surgery
• /
• v.39 no.3 s.260
• /
• pp.255-259
• /
• 2006

The operation for esophageal cancer is both complex and challenging, and may be associated with significant morbidity and mortality compared to other oncologic surgeries. Minimally invasive surgeries have been applied on various kinds of surgery to enhance better recovery with minimal surgical complications. But for the esophageal cancer, it has not been actively applied yet. With improvement in instrumentations and increasing experience with endoscopic surgical techniques, minimally invasive surgical approaches to esophageal cancer are being explored to determine feasibility, results and potential advantages. We experienced eight cases of minimally invasive surgery for esophageal cancer and report here focusing on surgical techniques and tips.

• Korean Journal of Head & Neck Oncology
• /
• v.16 no.2
• /
• pp.177-181
• /
• 2000

배경 및 목적: Theodor Kocker에 의해 일반화된 전통적인 갑상선 수술방법은 갑상선 질환의 종류 및 정도, 수술범위와 상관없이 광범위한 수술범위로 인한 조직 손상으로 인해 수술후 환자들의 여러가지 불편감은 물론 경부의 넓은 부위의 통증과 경부 피부부종, 장액종, 혈종 등과 같은 후유증을 동반할 수 있다. 최근 본 저자들은 이같은 전통적 갑상선 수술의 부작용을 최소화하기 위해 작은 피부절개($3{\sim}4.5cm$) 후 피하 피판(subplatysmal skin flap) 없이 직접 갑상선으로 접근하는 새로운 수술기법으로서 최소침습 갑상선 수술기법을 개발하였기에 그 술식을 소개하고 전통적인 갑상선 절제술에 대한 우월성을 확인하고자 본 연구를 시행하였다. 대상 및 방법: 1999년 1월 15일 부터 2000년 1월 14일까지 573예의 갑상선 수술 예 중 최소침습 갑상선절제술이 시행되었던 466예와 1998년 1월 15일부터 1999년 1월 14일까지 전통적 갑상선 수술을 시행한 549예 중 거대 종양(양성>6cm, 악성>5cm), 흉골하 선종, 국소진행암, 재발암, 측경부의 다발성 림프절 전이가 있었던 112예를 제외한 437예의 임상병리적 특성과 피부절개 길이, 수술 시간, 수술중 출혈양, 수술후 진통제 요구빈도 및 재윈기간, 수술 후 합병증 발생빈도를 비교 분석하였다. 결 과: 두 군간의 임상병리적 특성상의 유의한 차이는 없었다. 피부절개 길이($3.7{\pm}0.7cm,\;vs\;9.6{\pm}3.3cm$), 수술 시간($57.6{\pm}11.7$분 vs $85.2{\pm}32.3$분) 수술 중 출혈양($18.4{\pm}15.3ml\;vs\;43.1{\pm}21.8ml$), 수술후 재원기간($1.6{\pm}0.5$일 vs $4.3{\pm}1.6$일), 및 수술후 진통제 요구빈도가 전통적 수술군에 비해 최소침습 수술군에서 통계적으로 유의하게 감소되었으나(p<0.05), 수술후 장액종 및 혈종 형성, 일시적인 음색변화, 일시적인 저칼슘혈증과 같은 합병증의 발생빈도는 각각 4.3%(n=20)와 4.8%(n=21)로 두 군간에 유의한 차이가 없었다. 결 론: 최소침습 갑상선 수술법은 새로운 수술기구의 도입 없이도 갑상선 수술의 충분한 시야를 확보할 수 있고 안전하고 간단하게 시행할 수 있으며, 기존 수술법으로 인한 부작용을 최소화할 수 있어 전통적 인 수술법을 대치할 수 있는 새로운 방법으로 사료된다.

• Journal of Gastric Cancer
• /
• v.9 no.4
• /
• pp.238-245
• /
• 2009

Purpose: Treatment strategies for early gastric carcinoma (EGC) should be based on achieving a complete cure, but clear indications for limited surgery have not been established. We investigated surgical outcomes for early gastric cancer to determine the optimal? treatment strategy for EGC. Materials and Methods: Subjects included 881 patients who underwent curative surgery for EGC between 1986 and 2003. Retrospective uni & multi-variate analysis for prognostic factors, factors affecting lymph node metastasis, and risk factors for cancer recurrence were analyzed. Results: In multivariate survival analyses, age, operation method, macroscopic appearance and lymph node stage proved to be independent prognostic factors. Lymph node metastasis, depth of tumor invasion, tumor size, lymphatic and venous invasion were also significant risk factors in multivariate analyses. In multivariate analyses for cancer recurrence, depth of tumor invasion and lymph node metastasis proved to be significant risk factors. Conclusion: Appropriate surgical treatment with lymph node dissection is necessary for EGC patients with risk factors for lymph node metastasis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.184-187
• /
• 2018

The most important factor in the prevention and treatment of cerebral infarction is to increase cerebral blood flow. Methods for increasing cerebral blood flow include drug-based methods, the surgery, invasive procedures directly inserting medical devices into the artery(NeuroFloTM) and so on. The noninvasive cerebral blood flow increasing device proposed in this paper can reduce the burden on the patient because the probability of complication is low and the treatment level can be determined according to the blood pressure state of the patient. In implementing such a noninvasive cerebral blood flow increasing device, it is important to measure the accurate mean arterial pressure for provision the appropriate level of treatment for the patient. Therefore, to remove a noise, analog and digital filters were used and algorithm for peak value detection, pump control algorithms and so on were.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.8
• /
• pp.1083-1089
• /
• 2018

Surgery to increase cerebral blood flow is one of the treatment methods of cerebral infarction. In order to supplement this invasive method, non-invasive devices have been introduced that use human blood pressure to pressurize the extremities to increase cerebral blood flow. However, the problem of poor speed and accuracy was raised. In this paper, the perfusion index of each arm is measured by applying pressure to both arms using Blood Oxygen Level Sensor to improve the accuracy of measurement and measurement time. The pressure applied to the arm is calculated by using the pressure value obtained from the arm. Like the existing blood pressure measuring cerebral blood flow increasing device, the blood flow can be increased by more than 20% and the measurement time can be shortened, so that it can be selectively used for the patient with cerebral infarction.

• Journal of Genetic Medicine
• /
• v.8 no.1
• /
• pp.1-16
• /
• 2011

Owing to the risk of fetal loss associated with prenatal diagnostic procedures (amniocentesis, chorionic villus sampling), noninvasive prenatal diagnosis (NIPD) is ultimate goal of prenatal diagnosis. The discovery of circulating cell-free fetal DNA (cffDNA) in maternal plasma in 1997 has opened up new probabilities for NIPD by Dr. Lo et al. The last decade has seen great development in NIPD. Fetal sex and fetal RhD status determination by cffDNA analysis is already in clinical use in certain countries. For routine use, this test is limited by the amount of cell-free maternal DNA in blood sample, the lack of universal fetal markers, and appropriate reference materials. To improve the accuracy of detection of fetal specific sequences in maternal plasma, internal positive controls to confirm to presence of fetal DNA should be analyzed. We have developed strategies for noninvasive determination of fetal gender, and fetal RhD genotyping using cffDNA in maternal plasma, using real-time quantitative polymerase chain reaction (RT-PCR) including RASSF1A epigenetic fetal DNA marker (gender-independent) as internal positive controls, which is to be first successful study of this kind in Korea. In our study, accurate detection of fetal gender through gestational age, and fetal RhD genotyping in RhD-negative pregnant women was achieved. In this assay, we show that the assay is sensitive, easy, fast, and reliable. These developments improve the reliability of the applications of circulating fetal DNA when used in clinical practice to manage sex-linked disorders (e.g., hemophilia, Duchenne muscular dystrophy), congenital adrenal hyperplasia (CAH), RhD incompatibility, and the other noninvasive pregnant diagnostic tests on the coming soon. The study was the first successful case in Korea using cffDNA in maternal plasma, which has created a new avenue for clinical applications of NIPD.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.509-510
• /
• 2007