• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.40-45
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• 2008

Therapeutic ultrasound which is developed for rehabilitation therapy have already been used for healing joint contracture, synechia, acute and chronic inflammatory diseases. Medical devices for pain-relief and healing using therapeutic ultrasound are actively being developed. This study measured the change of PTT with the transmitted ultrasound through the human body to find out the increase of compliance of blood vessels. Measurement method of PTT in this study is employed as useful ways to acquire physiological information of patients in the clinical case in order to measure the change of mechanical characteristics of blood vessels. This study confirmed the PTT change of rehabilitation patients through the thermal effects of ultrasound by using PTT and also found that it is possible to increase PTT by adjusting the warm water and ultrasound. The increase of PTT means the decrease of the pulse wave velocity from the cardiovascular system to the peripheral arteries. The physiological effects occurred using the warm water and ultrasound.

• 비파괴검사학회지
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• 제33권5호
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• pp.479-486
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• 2013

• 한국의학물리학회지:의학물리
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• 제19권4호
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• pp.227-230
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• 2008

본 연구에서는 2차원 초음파 시스템의 체적 측정 정확성을 측정하기 위한 초음파 팬텀을 설계 및 제작하였다. 팬텀은 체적 측정용 타겟과 백그라운드 물질로 구성되었다. 백그라운드 물질은 agarose gel과 물을 혼합하여 만들었다. 타켓은 모양과 부피를 변화시키기 위하여 신축성 있는 물질로 선택하였고 타겟에 물을 채운 후 백그라운드 물질에 삽입하였다. 2차원 초음파 시스템의 정확성을 평가하기 위하여 세가지 형태의 타겟(구형, 2가지 형태의 타원형, 삼각 기둥형)을 제작하였다. 타원형의 경우, 하나는 길이와 폭의 크기가 비슷하도록 제작하였고(타원 1) 다른 하나는 길이가 폭보다 2배 이상인 모양(타원 2)으로 제작하였다. 각각 형태의 타겟 부피는 94 cc에서 450 cc까지 변화하였고 2차원 초음파 장비(128XP, ACUSON)를 이용하여 정확성을 측정하였다. 구 모양의 타겟에 삽입된 물의 실제 체적과 측정된 체적 간의 차는 6.7에서 11% 이다. 타원형 타겟의 경우 타원 1은 9.2에서 10.5% 사이의 차이를 보이는데 타원 2의 경우는 25.7%의 오차가 있다. 삼각기둥 형태의 경우는 실제체적과 측정체적간 20.8에서 35%의 차이를 보였다. 쉽고 간편한 방법의 초음파 팬텀의 제작 방법을 소개하였고 제작된 팬텀을 이용할 경우 초음파 시스템의 부피 측정 정확성을 평가할 수 있음을 입증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.760-768
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• 2004

The present study was undertaken to evaluate the accuracy of ultrasonography in early pregnancy diagnosis in goats. Ultrasonographic scanning with real time B-mode ultrasound machine having 5 MHz linear array transducer was performed on gravid uterus (n=24) obtained from slaughterhouse (Group I). Crown rump length (CRL) measured by ultrasound was found significantly different (p<0.05) with actual CRL measured after dissection in early pregnancy. However, age predicted by ultrasound through the measurement of CRL was found highly correlated (r=0.92) with age measured after dissection through CRL and the weight of fetus. Ages predicted by ultrasound through the measurement of trunk diameter (TD) and uterine diameter (UD) and ages measured after dissection were found highly and equally correlated (r=0.98) and did not differ significantly. Data from six does synchronized (Group II) with PGF2$\alpha$ (Estrumate) at 11 days apart were collected through ultrasound from 17 to 42 days post breding. The correlation between CRL and gestational age was high (r=0.97) in day 30 to 42 post breeding. A high coefficient of correlation (r=0.98) was also observed between predicated age by ultrasound and actual age calculated after kidding. The correlation between CRL and gestational age by the formula Y=(a+bX) i.e. Y=24.42+0.39 X where Y=gestational age and X=CRL, was recorded very high (r=0.99). Accuracy of ultrasonography was lowest on day 17 to 19 (66%) and reached 100% on day 34. Data from 30 does (group III) randomly subjected to only one time ultrasounds scanning to assess the accuracy of pregnancy diagnosis were also obtained. Ages predicted by TD and UD measurements were observed to be non-significantly different with actual age obtained after kidding and correlation between ages predicted by TD and UD measurement with actual age after kidding was found equally and highly correlated (r=0.98). The operator's accuracy in the whole experiment including all three groups was found to be 92%. The sensitivity was 93% and specificity was 86%. From the present study, it was observed that CRL was the most reliable parameter to find out gestational age in early pregnancy and the new formula derived was found very accurate to find out gestational age. TD and UD were also found to be equally reliable parameter to find out gestational age in mid and late stage of pregnancy through ultrasonography. It was concluded that ultrasonography by real time B mode with 5 MHz transrectal transducer was found to be reliable, safe and accurate and practicable means in diagnosing early pregnancy diagnosis as early as 25 days post breeding.

• 대한물리의학회지
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• 제16권2호
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• pp.45-52
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• 2021

PURPOSE: This study examined the imaging procedure of pectoralis minor muscle thickness and assessed the intra- and inter-rater reliability of the muscle thickness measured by two raters using rehabilitative ultrasound imaging (RUSI) in healthy individuals. METHODS: Fifteen participants (aged 21 - 28, seven females, and eight males) were involved in the study. The primary rater palpated the coracoid process and the fourth rib, defined as the width of the index finger lateral to the sternum to avoid breast tissues, and lined the two landmarks. The second examiner checked 1 / 3 (1st point) and 1 / 2 (2nd point) of the line length as measurement points. The two raters obtained right side muscle images of the participants at a standardized sitting position using RUSI with a 7.5 MHz linear transducer at 40mm depth. For intra-rater reliability, the principal rater took three images per point and tried to take one more with an interval. For the inter-rater reliability, the other rater performed the same tasks as the principal rater on the same day. The reliability was analyzed using the intra-class correlation coefficient (ICC), the standard error of the measurement (SEM), and Bland and Altman plots. RESULTS: The reliability at all points was excellent for the same rater (ICC_3,1 = .973 - .978, SEM = .042 - .046), and between raters (ICC_2,1 = .939 - .959, SEM = .059 - .097). CONCLUSION: These findings show that the RUSI could be reliable for examining the pectoralis minor muscle thickness in healthy individuals at all measurement sites.

• 한국방사선학회논문지
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• 제16권3호
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• pp.289-294
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• 2022

본 연구는 CT와 USG 스캔 데이터를 이용하여 팬텀 실험과 환자 스캔 데이터를 활용하는 임상실험으로 체적 측정의 정확도 및 유용성을 알아보았다. 그 결과 CT와 USG 스캔 데이터 모두 다양한 체적의 실제 원형 팬텀의 체적과 유의한 차이가 없었으며(p>0.05), 동일 환자의 방광 체적 측정 결과 CT 데이터는 236.9±2.1, USG 영상은 236.9±1로 측정되어 통계분석 결과 유의한 차이가 없는 것으로 분석되었다(p>0.05). 본 결과의 임상 적용은 추가 임상실험이 필요하지만, 환자 피폭, 검사자의 스캔 기술, 그리고 CT 재구성 경험 등을 고려하여 CT 또는 초음파 장치를 선택 적용한다면 의료영상을 활용한 체적 측정의 유용성 측면에서 기초자료로 적용 가치가 있을 것으로 사료된다.

• 대한의용생체공학회:의공학회지
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• 제14권3호
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• pp.273-282
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• 1993

This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.451-454
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• 2011

수중에서 추진되는 초고속 로켓 모터에 적용이 가능한 해수반응 금속연료 (Hydro-Reactive metal Fuel, 이하 HRF) 추진제는 연료의 적재량을 증가시키기 위해 채용하는 추진제이다. 하지만, 현재까지 HRF 추진제에 대한 연소속도 측정 기술 개발에 대한 연구는 미비한 상태이다. 본 연구팀은 연소 속도를 측정하는 기법들 중, 한 번의 실험으로 압력 변화에 따른 연소속도 측정이 가능한 초음파 법을 개발하여 고체 추진제의 연소속도를 측정하고 신뢰성을 검증하였다. 본 논문에서는 기 개발된 시스템을 이용하여 HRF 추진제의 연소 속도를 측정하였다.

• International Journal of Vascular Biomedical Engineering
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• 제3권1호
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• pp.6-13
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• 2005

Individual clinical significance of each layer of CCA (common carotid artery) has not been well studied. We intended to measure the intima thickness (IT), media thickness (MT), and intima-media thickness (IMT) of CCA separately and tried to analyze the clinical significance. One hundred fifty one consecutive patients (mean age: $57{\pm}15$ years; 77 males, 74 females) underwent CCA scanning using high-resolution ultrasound. The images were off-line analyzed using B-mode ultrasound image processing, devised for individual measurement of IT and MT as well as IMT. The mean coefficients of variation of new method measuring IT, MT, and IMT separately were 0.16% for IMT and 0.21% for both IT and MT. The IT (p < 0.01), MT (p < 0.01) as well as IMT (p < 0.001) of patients with atherosclerotic disease were significantly thicker than that of the patients without atherosclerotic disease. Patients with hypertension showed significantly thicker IT (p < 0.01), MT (p < 0.001), and IMT (p < 0.001) than that of the patients without hypertension. However, only IT was thicker in patients with smoking (p<0.01) than that of the patients without smoking.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.247-250
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• 2006

기존 연구를 통해 고체추진제 연소속도 측정을 위한 초음파 측정 시스템 및 연소속도 산정 기법을 개발하였으며, 개발 시스템을 적용하여 composite 추진제의 연소속도를 측정하였다. 본 연구에서는 연소 압력 증가에 따라 연소속도가 비선형적으로 변하는 double base형 고체 추진제 인 N-5와 AA-2 고체추진제의 연소속도를 개발 시스템을 이용하여 측정하였으며, 스트랜드버너법으로 측정된 값과의 비교를 통해 측정결과의 신뢰성을 평가하였다.