• 한국정밀공학회지
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• 제26권6호
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• pp.131-135
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• 2009

In this study, we performed the compressive strength test of trabecular bone in knee joint for measuring the elastic modulus and ultimate strength. The main knee joint is femorotibial articulation between the lateral and medial femorotibial condyle. In the case of osteoarthritis, some patients have only medial condylar osteoarthritis. We performed the mechanical test for comparison the difference of the each condylar strength. We used diamond core-drill and linear precision saw for making the specimens. Specimens were cored from both condyle in distal femur and proximal tibia in fresh cadaver (male 10, female 12), and tested by universal test machine with temperature control saline circulation system. Results of the test in distal femoral parts, averaged elastic modulus was $360.61{\pm}159.40MPa$ for male, $150.89{\pm}70.65MPa$ for female. Averaged ultimate strength was $6.79{\pm}2.91MPa$ for male, $2.89{\pm}1.31MPa$ for female. Male was 2.4 times stronger than female. In the proximal tibial parts, averaged elastic modulus was $108.80{\pm}52.88MPa$ for male, $73.45{\pm}55.06MPa$ for female. Averaged ultimate strength was $2.59{\pm}1.39MPa$ for male, $1.75{\pm}1.16MPa$ for female. Male was 1.5 times stronger than female. In the distal femoral condyle, medial condyle had more strength than lateral condyle at middle region. But lateral condyle had more strength than medial condyle at anterior & posterior regions (p<0.02). In the proximal tibial condyle, medial condyle had more strength than lateral condyle. (p<0.01).

• Journal of Pharmaceutical Investigation
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• 제30권1호
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• pp.27-32
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• 2000

Various release test methods have been applied for the evaluation of nicotine release in vitro from commercial patches. However, whether and how the release data reflect the permeation of nicotine across the skin, is not fully elucidated. To predict in vivo bioavailability from in vitro release tests, correlation between in vitro release and in vitro skin permeation was assessed in the present study. Release of nicotine from three commercial patches was measured for 24 hours under nine experimental conditions which were classified depending on the apparatus (i.e., paddle over disk, cylinder and reciprocating holder) and dissolution media (i.e., phosphate buffer pH 7.4, water and the 1 % phosphoric acid pH 1.5). In vitro permeation of nicotine from the patches across the human cadaver skin was also measured using a diffusion cell. The release of nicotine was better explained by the Higuchi's equation rather than by the first order rate equation. Correlation between the release rate and the in vitro skin permeation differed among the patches. However, in general, the cylinder method, in which water is used as a dissolution medium, showed the highest correlation among the nine release test conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.518-521
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• 2005

We performed the mechanical test for obtaining properties of femoral head. Tested sample was male and 35 years old. We measured bone mineral density by dual X-ray absorption method(DEXA). Results of DEXA, he has normal condition of bone density. His BMD $1.159g/cm^2$ and T-Score is 1.6. Tested femurs were harvested by surgical method from donated cadaver. We made 9 specimens in femoral head, 8 specimens in neck used by diamond core drill. Then we performed compressive test in saline solution at $38^{\circ}C$. We obtained results that elastic modulus of femoral head was 0.439GPa, neck was 0.459GPa. Compressive strength of femoral head was 7.441 MPa, neck was 7.095MPa. There was no significant difference of mechanical properties between left and right femoral head & neck. Invested local properties of femoral head have more strength superior and anterior side, femoral neck has more strength in superior and inferior side but other side except for superior has more weakness along the lateral side.

• 대한기계학회논문집
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• 제18권8호
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• pp.1952-1966
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• 1994

The body segment parameters of twelve young male Korean were measured to compare with the results of foreign cadaver studies. A human body was assumed to have fourteen body segments. The mass of each segment was measured with a water immersion test and the mass center of a segment was determined on the balance platform by changing postures. In the case of Korean, because of the difference in body proportion, the mass center of whole-body is located further from the distal end of head(Korean : 44.9% vs. Caucasian : 41.2%), and the mass center of each segment also located in different proportional locations. The existing regression equations, which can estimate segment mass based upon the anthropometric dimensions, estimates segment mass (the mass of shank) for Korean with 13% error. Therefore, it is not recommended to estimate the mass, and the moment of inertia of body segment of Korean based on the existing equations. However, the density information of body constituents was similar enough to apply it to Korean density. It was validated by the comparison between the results of the direct immersion method and 3-dimensional volume reconstruction of segment form the cross sectional images of CT-scan. The average body density measured form twelve subjects was $1.035{\;}kg/m^3$ and showed deceasing trendency.

• Imaging Science in Dentistry
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• 제36권1호
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• pp.49-54
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• 2006

Purpose : To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. Materials and Methods : One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant differences between the direct measurements and those using the 3D images (p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. Conclusion : The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissues thickness more easily in forensic science and anthropology.

• Imaging Science in Dentistry
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• 제36권2호
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• pp.89-94
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• 2006

Purpose : To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. Materials and Methods : One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed; 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. Conclusion : The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

• Journal of Korean Neurosurgical Society
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• 제39권5호
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• pp.360-365
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• 2006

Objective : This is a cadaver study to assess the accuracy of three cervical screw insertion techniques; the blind technique [Group I], the laminotomy technique [Group II], and the funnel technique [Group III]. Methods : Ten human cadavers embalmed with formaldehyde were prepared. After exposing the spinous processes, the laminas and the lateral masses, titanium alloy transpedicular screws were inserted from C3 to C7. A total of 100 pedicles were ramdomly assigned to one of three techniques [the blind technique : 31 screws, the laminotomy technique : 51 screws, the funnel technique: 18 screws]. Axial computed tomography with 1-mm slices, and sagittal and coronal reformation were performed to identify the accuracy of the screw insertion and the anatomic relationships. Results : In Group I, 9 screws [29%] were either contained within or penetrated less than 1mm, which were rated as successful. In Group II, 24 screws [47%] were successful. In Group III, 16 screws [89%] were successful. In the multiple comparison, there was a statistically significant difference between Groups I and III and between Groups II and III [$X^2$ test and Bonfenoni test]. Conclusion : The funnel technique can help a surgeon's understanding about the cervical pedicle more precisely than the other two techniques. The funnel technique is less dependent on lateral soft tissue retraction state.

• 대한기계학회논문집A
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• 제36권9호
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• pp.1033-1039
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• 2012

인공관절은 관절부의 뼈가 파괴되거나 관절 손상을 입어 관절로서의 기능을 할 수 없게 된 경우에 사용된다. 고관절용 인공관절 시스템의 일차안정성을 평가하기 위해서는 인공관절이 삽입된 직후 인공관절에 반복하중을 가하여 대퇴골과 인공관절 사이의 상대변위를 측정하게 된다. 이때, 정확한 안정성을 평가하기 위해서는 인공관절이 대퇴골을 파고드는 변위와 대퇴골에서 인공관절이 회전한 각의 변화량을 정확히 측정하여야 한다. 본 연구에서는 고관절용 인공관절 시스템의 일차안정성을 평가하기 위해 새로운 상대 변위측정 방식을 제안하고 이를 이용하여 수술 방법의 차이 및 대퇴골 자체 강성의 차이에 따른 일차 안정성을 사체에서 얻은 대퇴골 실험을 통해 비교 평가하였다.

• 대한의용생체공학회:의공학회지
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• 제23권3호
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• pp.217-225
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• 2002

이식형 인공중이는 일반적인 공기전도형 보청기가 가지는 난점인 고이득에서의 왜곡과 음향 피이드백에 의한 링잉 현상을 해결할 수 있는 동시에 음질과 주파수 특성 및 청음명료도가 우수하다 본 논문에서는 마이크로머시닝 기술을 이용하여 차동 전자 트랜스듀서를 제작한 후 이를 사용하여 이식형 인공중이 시스템을 구현하였다. 제작된 시스템을 이용하여 무부하 진동실험. 사체를 이용한 부하진동실험 및 살아있는 개를 이용하여 동물이식실험을 실시함으로써 이의 성능을 확인하였다. 무부하 진동실험을 통하여 제작된 트랜스듀서는 입력되는 소리신호와 같은 형태의 진동을 일으킴을 확인하였고, 사체의 이소골에 트랜스듀서를 이식하고 부하실험을 실시함으로써 트랜스듀서의 이소골 구동능력과 진동특성을 조사하였다. 그리고 개를 이용하여 동물이식실험을 실시한 후 뇌간 유발 반응검사를 실시함으로써 생체 내에서의 이식형 인공중이의 동작을 확인하였다. 이를 통하여 제작된 차동 전자 트랜스듀서를 이용한 이식형 인공중이 시스템의 성능을 검증하였고 난청자에게 적용할 경우에도 잘 동작할 수 있음을 증명함으로써 임상실험을 실시할 수 있는 근거를 마련하였다.

• Journal of Chest Surgery
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• 제36권8호
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• pp.595-601
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• 2003

다한증 환자의 가장 효과적인 치료방법은 흉강경 최소절개를 이용한 교감신경 차단술로 알려져 있다. 하지만 수술 후 발생하는 보상성 다한증과 무한증이 수술의 만족도를 감소시키는 중요한 요인이므로 환자에게 적극적인 수술 적응을 하기가 어렵다 합병증을 줄이기 위한 방법으로 교감신경의 선택적인 교통가지 차단술을 시행하였으나 시술의 어려움과 혈관 손상으로 인한 출혈의 위험성으로 보편화되지 못하였다. 본원에서는 사체를 이용하여 새로운 수술기법을 연구하고 이를 임상에 적용하여 좋은 결과를 얻었기에 보고한다. 대상 및 방법:포르말린 처리를 하기 전 사체 3구를 대상으로 실험하였다. 앙와위에서 전흉부를 모두 절제한 후 양측 흉부 교감신경을 노출시켰다. 교감신경의 분지와 교통가지의 위치를 확인하였고 2번째와 3번째 교통가지에 클립을 이용한차단술을 시행하였다. 교통가지 차단술 후 교감신경절을 포함한 교감신경을 절제하여 교통가지의 차단 정도를 관찰하였다. 임상적용은 25명의 환자에서 시행하였으며 평균 연령은 21세였다. 수술은 전신마취와 양측 페 환기를 하고 반 좌위 자세에서 시행하였다 4번째 늑간에 2 mm 흉강경을 삽입하였고 겨드랑이에 5 mm 트로카를 삽입하고 내시경용 클립을 이용하여 2번째와 3번째 교감 신경절 교통가지를 차단하였다. 수술 후 전화 설문 조사를 통하여 합병증의 유무, 만족도, 보상성 다한증의 발생 정도를 관찰하였다. 결과: 사체 3구에서 모두 교감신경 교통가지의 차단을 완벽하게 시행할 수 있었다 임상환자에서 모두 수술로 증세의 호전이 있었으며 기존의 교통가지 절제술에 비하여 수술 시간을 단축할 수 있었고 수술로 인한 합병증은 발생하지 않았다. 수술 후 수부 다한증은 모든 환자에서 호전되었으나 4명의 환자는 수술의 만족도가 감소하였다. 보상성 다한증은 15명의 환자(60%)에서 중증 이상으로 발생하였고 6명의 환자는 없거나 잘 느끼지 못하는 정도로 발생하였다. 미각다한증은 2명의 환자에서 발생하였으나 정도는 심하지 않았다 걸론: 본 연구의 수술방법은 2개의 피부 절개와 하모닉 스칼펠, 클립을 사용하여 쉽게 교감신경의 교통가지를 차단할 수 있었고 교통가지 절제술에 비하여 수술시간 및 출혈의 위험성을 감소시킬 수 있었다. 또한 교감신경 절제술에 비하여 비슷한 정도의 수술 성공률을 보이면서 보상성 다한증의 정도나 발생 빈도를 줄일 수 있어 우수한 수술 방법이라 생각한다.