RSSI와 영역추정을 이용한 위치측정 기법

하봉수 ( Bong-soo Ha ),홍원기 ( Won-kee Hong ),차경애 ( Kyung-ae Cha ) 한국정보처리학회 2006 한국정보처리학회 학술대회논문집 Vol.13 No.2

무선 센서네트워크 기술은 유비쿼터스(Ubiquitous) 컴퓨팅을 구현하기 위한 핵심 기술로 인식된다. 컴퓨터가 사용자 눈에 보이지 않아도 언제 어디서나 사용 가능한 유비쿼터스 컴퓨팅을 실현하기 위해서는 무선 센서노드를 이용한 상황정보와 위치정보가 필수적이다. 하지만 무선 센서네트워크를 구성하는 하드웨어는 저전력, 저가, 소형의 특성을 가지고 있으므로, 한정된 자원을 이용하여 위치정보를 얻는데 어려움이 크다. 본 논문에서는 이러한 무선 센서네트워크의 특성에 적합한 위치인식 기법으로 근거리 무선통신인 Zigbee(IEEE 802.15.4)기반의 영역추정기법과 RSSI정보를 이용한 좌표 정합(整合)기법을 통하여 위치정확도와 위치측정시간을 개선한 위치정보 획득기법을 제안하였다. 제안하는 알고리즘은 전체 테이블에서 RSSI를 이용한 좌표정합 기법보다 약 14.46%정확도가 증가하였으며, 영역별로 신뢰성이 증가된 RSSI 좌표 테이블 구축 시 정확도는 더 증가할 것으로 예상된다.

뇌하수체선종 환자에서 감마나이프를 이용한 정위적 방사선 치료

차봉수(Bong Soo Cha),이현철(Hyun Chul Lee),최동훈(Dong Hoon Choi),송영득(Young Duk Song),이은직(Eun Jig Lee),임승길(Sung Kil Lim),박용구(Yong Gu Park),김경래(Kyung Rai Kim),정상섭(Sang Seop Chung),허갑범(Kap Bum Huh),정윤석(Yoon Sok 대한내과학회 1995 대한내과학회지 Vol.49 No.1

N/A Objectives : Stereotactic radiosurgery using gamma-knife in adjunct to transsphenoidal pituitary surgery is recently being used for treatment of pituitary adenomas and it poses as an effective and safe treatment modality. We present our experience and preliminary results of gamma-knife treatment of the patients with pituitary adenomas. Methods: Between May, 1992 and March, 1994, 20 patients with pituitary adenoma were treated with gamma-knife at Yonsei Medical Center. Among them, 15 cases who have had follow-up for more than 6 months were included in our study. 13 of 15 cases had endocrinologically active tumors(4 prolactin secreting, 4GH secreting, 5 ACTH secreting), and two patients had clinically non-functioning adenomas. Hormonal and radiological studies and clinical features were followed up. Results: After gamma-knife surgery, the hormonal level was decreased in eleven of thirteen patients with functioning pituitary adenomas and the size of tumor was decreased in seven of fifteen patients and eleven of fifteen patients were improved clinically. There was more favorable results in Cushing's disease than in other pituitary adenomas. There was no severe complication associated with gamma-knife surgery, Conclusion : Based on our initial clinical experience, we believe that gamma-knife stereotactic radio surgery is safe and effective alternative to conventional neurosurgery in selected patients with pituitary adenomas and further study might be warranted.

컴퓨터단층촬영으로 측정한 복강내 지방조직 길이와 내장지방 면적, 내장지방/피하지방 면적비 및 내장지방/골격근 면적비와의 비교

김수경 ( Soo Kyung Kim ),김세화 ( Se Hwa Kim ),이유미 ( Yu Mie Rhee ),최성희 ( Seung Hee Choi ),조유리 ( You Lee Cho ),안철우 ( Chul Woo Ahn ),차봉수 ( Bong Soo Cha ),임승길 ( Sung Kil Lim ),김경래 ( Kyung Rae Kim ),이현철 ( Hyun 대한내과학회 2003 대한내과학회지 Vol.64 No.1

배경 : 내장지방의 과잉 축적은 대사 증후군 및 심혈관계 질환 등의 발생에 중요한 역할을 한다. 이런 내장지방을 평가하는데 컴퓨터단층촬영이 좋은 방법으로 알려져 있으나, 고가이며, 방사선에 노출되며 그리고 쉽게 임상에서 이용하기 어렵다는 점에서 널리 사용되기에는 많은 제한점을 갖고 있다. 따라서 비교적 손쉽게 사용할 수 있는 비침습적인 평가 방법이 요구되고 있다. 본 연구에서는 내장비만을 평가하는데 복부 초음파의 유용성을 평가하기에 앞서, 컴퓨터단층촬영 Background : Visceral fat accumulation plays a major role in metabolic syndrome and increased cardiovascular risks. Clinical evaluation of visceral fat by CT is not widely used because of high cost, low availability, and ionizing radiation risk, and alter

원저 : 비만 여성에서 Sibutramine이 혈중 Adipocytokine에 미치는 영향

윤수지 ( Soo Jee Yoon ),김철식 ( Chul Sik Kim ),박종숙 ( Jong Suk Park ),남주영 ( Joo Young Nam ),김똘미 ( Dol Mi Kim ),김경욱 ( Kyung Wook Kim ),안철우 ( Chul Woo Ahn ),차봉수 ( Bong Soo Cha ),임승길 ( Sung Kil Lim ),이현철 ( Hyu 대한비만학회 2004 The Korean journal of obesity Vol.13 No.1

연구배경: 본 연구에서는 비만 여성에서 sibutramine이 체성분 변화와 혈중 adiponectin 농도 및 인슐린 저항성에 미치는 영향을 알아보고자 하였다. 방법: 다른 질환을 동반하지 않은 28명의 비만 여성(BMI>25㎏/㎡)을 대상으로 하였고, 평균 연령은 34.5±13.7세, 평균 체질량지수는 31.0±4.1㎏/㎡였다. 12주간 매일 10㎎의 sibutramine을 복용하도록 하였고, 공복 후 혈청 총 콜레스테롤, 중성지방, 고밀도지단백 콜 Background: The aim of this study was to evaluate the effects of sibutramine on serum adiponenctin levels, body mass index, body composition and insulin resistance in obesity women. Methods: Twenty-eight healthy, non-diabetic, obese(BMI>25㎏/㎡) women(mean

최신지견 : 흡연과 당뇨병

문재훈 ( Jae Hoon Moon ),차봉수 ( Bong Soo Cha ) 대한당뇨병학회 2009 임상당뇨병 Vol.10 No.2

휴대용 근적외선 분황분석기를 이용한 비침투 혈당 측정

강나루(Na Roo Kang),우영아(Young Ah Woo),차봉수(Bong Soo Cha),이현철(Hyun Chul Lee),김효진(Hyo Jin Kim) 대한약학회 2002 약학회지 Vol.46 No.5

The purpose of this study is to develop a non-invasive blood glucose measurement method by a portable near infrared (NIR) system which was newly integrated by our lab. The portable NIR system includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector, which was developed by a microchip technology based on the lithography: Reflectance NIR spectra of different parts of human body (finger tip, earlobe, and inner lip) were recorded by using a fiber optic probe. The spectra were collected over the spectral range 1100~1740 nm. Partial least squares regression (PLSR) was applied for the calibration and validation for the determination of blood glucose. The calibration model from earlobe spectra presented better results, showing good correlation with a glucose oxidase method which is a mostly used standard method. This model predicted the glucose concentration for validation set with a SEP of 33 mg/Dl. This study indicated the feasibility for non-invasive monitoring of blood glucose by a portable near ifrared system.

증례 : 두 종류의 항체를 보유한 자가면역성 저혈당 1예

전성완 ( Sung Wan Chun ),이병완 ( Byung Wan Lee ),강은석 ( Eun Seok Kang ),차봉수 ( Bong Soo Cha ),이은직 ( Eun Jig Lee ),임승길 ( Sung Kil Lim ),이현철 ( Hyun Chul Lee ) 대한당뇨병학회 2009 임상당뇨병 Vol.10 No.2

자가항체로 인한 고인슐린성 저혈당증을 특징으로 하는 자가면역 저혈당은 인슐린 자가면역 증후군과 B형 인슐린저항성으로 나뉘며, 서로 다른 임상적 특성을 보인다. 저자들은 glucocorticoid 치료에 반응하지 않는 자가면역성 저혈당증에 대해 두 가지 종류의 인슐린 항체가 함께 존재함을 확인하고 cyclophosphamide 충격요법으로 저혈당이 호전된 73세 여자 환자 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Autoimmune hypoglycemia is rare kind of autoimmune disease caused by either anti-insulin antibodies (insulin autoimmune syndrome, IAS) or anti-insulin receptor antibodies (type B insulin resistance, type-B IR). We experienced an extremely rare case of the IAS accompanied by type-B IR. A 73-year-old woman presented with recurrent severe hypoglycemic symptoms at dawn for one month was admitted to the Severance hospital. She had several medical histories including 30 years of hypertension, 15 years of type 2 diabetes, and 4 years of coronary artery disease before admission. She had never received an insulin injection. Hypoglycemia was diagnosed at 10 hours in the 72-hour fasting test with glucose, insulin, and C-peptide levels of 42 mg/dL, 280.31 μU/mL, and 7.70 ng/mL, respectively. The insulin autoantibody titer was 130 μU/mL and quantitative assay for insulin receptor antibody was positive. Insulinoma was ruled out by imaging techniques and calcium stimulation test. She has no evidence of other diseases associated with altered immunity. Despite of treatment with prednisolone, symptomatic hypoglycemic events persisted at fasting state. Early induction of 300 mg cyclophosphamide therapy resulted in remission of hypoglycemia accompanied by suppressed antibody titer. The changes in autoantibodies might result in alleviation of the symptoms of hypoglycemia and improvement in insulin and C-peptide levels. (Korean Clinical Diabetes J 10:123-128, 2009)

예후결정인자를 고려한 갑상선 미소암(微小癌)의 임상상

이준호 ( Jun Ho Lee ),이시훈 ( Si Hoon Lee ),이유미 ( Yu Mie Rhee ),안철우 ( Chul Woo Ahn ),차봉수 ( Bong Soo Cha ),김경래 ( Kyung Rae Kim ),이현철 ( Hyun Chul Lee ),김승일 ( Seung Il Kim ),박정수 ( Cheong Soo Park ),임승길 ( Sung 대한내과학회 2005 대한내과학회지 Vol.69 No.5

목적 : 갑상선 초음파 검사와 미세침흡인세포검사가 널리 시행되면서 갑상선 미소암의 빈도가 많이 증가하였다. 갑상선암의 예후를 결정하는 인자는 여러 가지가 있는데 환자의 성별, 진단 당시의 연령, 종양의 다발성이나 양측성, 주위 조직으로의 침범 유무, 임파선 침범 유무, 원격전이 유무가 중요한 것으로 받아 들여지고 있다. 한편 최근 TNM 병기 기준이 갱신되면서 임파선의 전이 정도가 강조되었다. 이에 갑상선 미소암의 경우 이런 예후인자들이 나타나는 양상과 새로운 병기 기준을 적용해 보았을 때의 병기 변화를 알아 보기 위해 본 연구를 시행하였다. 방법 : 2004년 1월 1일부터 12월 31일까지 신촌 세브란스병원에서 갑상선 미소암으로 수술을 한 302명의 환자를 대상으로 하여 수술 기록을 포함한 임상 기록을 조사하여 보았다. 특히 일반적으로 알려져 있는 갑상선암의 예후결정인자가 나타나는 양상을 알아보기 위해 미세침흡인세포검사 결과와 수술 후 조직병리검사 결과를 포함시켜 조사하였다. 결과 : 갑상선암으로 수술한 환자 601명 중 미소암은 302명(50.2%)이었고, 그 중 여자가 275명(91.1%)으로 압도적으로 많았다. 종양의 수가 2개 이상인 다발성으로 보인 경우는 80명(26.5%)이었고, 양측성인 경우는 50명(16.6%)이었다. 조직 형태는 300건이 유두암으로 거의 전부를 차지하였고, 여포암과 수질암은 각각 1건 뿐이었다. 주위 조직으로 침입을 한 경우가 85명(28.1%)이었고, 임파선을 침범한 경우가 91명(30.1%)이었지만, 원격전이가 있는 경우는 없었다. 새로운 병기 기준의 적용으로 제 3 병기에서 제 IVA 병기로 바뀐 경우가 7명(2.3%), 제 3 병기 그대로인 경우가 65명(21.5%)이었다. 결론 : 갑상선암은 미소암이라도 불량한 예후인자를 가지고 있는 경우가 많고, 높은 병기를 가지고 있는 경우도 많으므로 수술요법, 방사성요오드 치료 및 갑상선호르몬 억제요법 등 보다 적극적인 치료가 바람직할 것으로 사료된다. Background : The incidence of thyroid microcarcinoma is increasing due to the more frequent use and improvement of ultrasonography and fine-needle aspiration biopsy. There are several prognostic factors for thyroid carcinomas. The patient`s sex, age at diagnosis, muliplicity or bilaterality of tumor masses, extrathyroidal extensions, lymph node metastasis, and presence of distant metastases are considered the most important. Since the recent update of the TNM (Tumor, Node, Metastasis) staging system, the importance of lymph node metastasis is increased. There are, however, a paucity of studies on thyroid microcarcinomas in the Korean population. Methods : We reviewed and analyzed the records of 302 patients diagnosed with, and treated for, thyroid microcarcinomas from January through December 2004. Results : 302 (50.2%) out of the 601 cases of thyroid cancers were microcarcinomas. Women comprised 275 (91.1%) of these cases. Eighty cases (26.5%) contained multiple tumor masses (>2), and 50 (16.6%) cases exhibited bilaterality. Evaluation of the histology revealed that nearly all of the cases (300 of 302) were of the papillary type. There was only one case each of the follicular and medullary histological type. There were 85 (28.1%) cases of extrathyroidal extensions, and 91 cases (30.1%) of lymph node metastasis, but no cases of distant metastases. Conclusions : Thyroid microcarcinomas have bad prognostic factors and appear to exist at relatively higher cancer stages. Therefore, it is important to treat them as early and as vigorously as possible with extensive surgery, radioactive iodine therapy, and thyroxine suppression.(Korean J Med 69:503-509, 2005)

제 2 형 당뇨병 환자 및 당뇨병과 심혈관질환이 없는 성인을 대상으로 조사한 심혈관계질환의 위험인자와 혈청 high sensitivity C - reactive protein 사이의 관련성 비교

김형진(Hyeung Jin Kim),배상운(S. W. Pae),김대중(Dae Jung Kim),김수경(Soo Kyung Kim),김세화(Se Hwa Kim),이유미(Yu Mie Rhee),정상수(Sang Su Chung),안철우(Chul Woo Ahn),차봉수(Bong Soo Cha),송영득(Young Duk Song),임승길(Sung Kil Lim),김경 대한내과학회 2002 대한내과학회지 Vol.63 No.1

N/A Background: High sensitivity C-reactive protein (hsCRP) is more sensitive than standard CRP assay for evaluation of risk of coronary heart diseases and other atherosclerotic events. But, there were no data of association of serum hsCRP with risk factors of cardiovascular diseases and nonalcoholic fatty liver in Korean type 2 diabetic and nondiabetic subjects. Methods: A hundred type 2 diabetic subjects (51 men and 49 women) from Severance Hospital and 200 nondiabetic subjects participating medical checkup in Health Promotion Center (105 men and 95 women) were recruited and subjects with acute illnesses and chronic inflammatory diseases such as upper respiratory infection, rheumatoid arthritis, osteoarthritis, or viral hepatitis were excluded. A standardized interview was conducted by trained personnel; detailed information was collected on medical history, dietary habits and lifestyle characteristics, including smoking, alcohol and physical activity. Body mass index (BMI) was computed and biochemical study were undergone using fasting blood. All subjects were done abdominal ultrasonography for evaluation of fatty liver. Serum hsCRP concentration was measured by Nephelometer AnalyzerⅡ (Behring Co.) and a lower detection limit of test was 0.18 mg/L. Results: There was no difference in sex, BMI, presence of fatty liver, concentration of total cholesterol, triglyceride, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and uric acid between diabetic and nondiabetic subjects. Age, total colesterol/HDL-C ratio, fasting blood glucose and incidence of hypertension were higher in diabetic than nondiabetic subjects, but a rate of smoking was higher in nondiabetic than diabetic subjects. The mean concentration of serum hsCRP was remarkably increased in type 2 diabetic subjects than nondiabetic subjects (1.34±1.87 vs 0.71±0.80 mg/L, p<0.05). After adjustment of different variables between both groups, there was significantly difference of the concentration of serum hsCRP (p<0.05). In nondiabetic subjects, by univariate analysis, there was a positive correlation between hsCRP and age (r=0.26, p<0.05), BMI (r=0.34, p<0.05), systolic blood pressure (r=0.21, p<0.05), diastolic blood pressure (r=0.16, p<0.05), triglyceride (r=0.27, p<0.05), total cholesterol/HDL-C ratio (r=0.22, p<0.05), uric acid (r=0.15, p<0.05) and a negative correlation between serum hsCRP and HDL-C (r=-0.16, p<0.05). Interestingly, subjects with fatty liver had shown increased serum hsCRP concentration than subjects without fatty liver (0.99±0.96 vs 0.58±0.69 mg/L, p<0.05). But there were no correlation of serum hsCRP with the history of smoking, sex, physical activity, fasting plasma glucose and presence of hypertension. After multiple regression analysis, only BMI and age were associated with serum hsCRP. In diabetic subjects, there were significant correlation of serum hsCRP with HDL-C and fasting plasma glucose, but other risk factors of cardiovascular diseases and fatty liver were not. When we compared serum hsCRP according to numbers of risk factors of cardiovascular diseases in nondiabetic subjects, group without risk factors had 0.41±0.55 mg/L, group with one risk factor had 0.48±0.40 mg/L, group with two risk factors had 0.75±0.88 mg/L, group with three risk factors had 1.08±0.87 mg/L and group with four risk factors had 1.55±1.21 mg/L. There was significant difference of serum hsCRP according to numbers of risk factors of cardiovascular diseases (p<0.05). Conclusion: Serum hsCRP is correlated with risk factors of cardiovascular diseases and may be useful tool for prediction of accelerated, atherosclerotic process in nondiabetic subjects. Although there is association of serum hsCRP with few risk factors of cardiovascular diseases, serum hsCRP is elevated in diabetic subjects. Therefore it is necessary to evaluate usefulness of serum hsCRP using carefully selected diabetic subjects. In addition, our study had show

증례 : 부신우연종으로 오인된 간세포암종 1예

이준호 ( Jun Ho Lee ),이유미 ( Yu Mie Rhee ),석재연 ( Jae Yeon Seok ),박영년 ( Young Nyun Park ),차봉수 ( Bong Soo Cha ),이현철 ( Hyun Chul Lee ),임승길 ( Sung Kil Lim ) 대한내과학회 2005 대한내과학회지 Vol.69 No.-

부신우연종은 부신과 무관한 문제로 시행한 영상학적 검사 도중에 우연히 발견된 부신의 종양을 말한다. 1980년대초 이후 고해상도 영상촬영술의 광범위한 이용의 결과로 부신우연종은 흔한 임상적인 문제가 되었다. 그러나 가성부신종양으로 불리는 몇 가지 경우는 부신종양으로 오인되는 수가 있는데, 대개 좌측에 위치하는 경우가 보고되어 있지만 우측 가성부신종양은 국내에서는 아직까지 보고된 바가 없다. 이에 저자 등은 우측에 위치한 부신종양으로 오인된 간세포암종 환자를 경험하게 되어 보고하는 바이다. Adrenal incidentalomas are adrenal masses discovered incidentally at the time of imaging procedures performed for nonadrenal problems. Since the early 1980s, incidentally discovered adrenal masses have become a common clinical problem as a result of the more idespread use of high resolution imaging procedures such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography. However, several conditions, called pseudoadrenal masses, can be occasionally misdiagnosed as an adrenal mass. Pseudoadrenal masses are usually located at the left side, but we have experienced a right-side pseudoadrenal mass. We report a patient with a hepatocellular carcinoma simulating a right adrenal mass. To our knowledge, this is extremely rare and the first case reported in Korea. It was possible to make a final diagnosis only after ultrasound-guided liver biopsy. (Korean J Med 69:S793-S797, 2005)