• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.39-42
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• 1991

Two types of speech signal processores (SSP) for cochlea prosthesis are designed. One is designed using cochlear model and the other is designed using Information (formant, pitch, intensity) extraction method. For these, cochlear model and acoustic information extraction method are proposed. The result shows SSP of cochlear model type contain more acoustic cues than that of information extraction type.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.247-249
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• 2007

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60㎐ power-line noise, amplifier, and a level circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• 대한골관절종양학회지
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• 제17권2호
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• pp.79-86
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• 2011

목적: 골육종 치료에 있어서 사지 구제술이 보편화되었다. 이 중 수술 수기가 간편하고, 기능적인 회복이 빠른 종양 대치물을 재건 방법으로 사용하고 있을 뿐만 아니라, 다른 생물학적 구제술이나 관절 고정술 등의 합병증으로 인하여 이차적으로 종양 대치술을 사용되고 있다. 본 연구는 광범위 절제술 이후, 일차적으로 종양 대치술을 시행하는 방법의 장기 추시상 결과를 환자 및 종양 대치물의 생존, 기능적 결과, 합병증 측면에서 보고하고자 한다. 대상 및 방법: 1989년 2월부터 2006년 12월까지 본원에서 골육종으로 진단받은 158예 중, 5년 이상 추시관찰이 가능하고 일차적으로 종양 대치물을 이용한 재건술을 시행하였던 48예를 대상으로 하였다. 추시 기간은 최소 60개월에서 최대 179개월이었다. 남자 28예, 여자 20예 였으며, 평균 나이는 22.4 (11-71세)였다. 병리학적 분류상 전형적인 중심성 골육종 46예, 골막성 2예이었다. 골육종 부위는 근위 경골 26예, 원위 대퇴골 20예, 대퇴골 간부, 경골 간부 각 1예이었다. 종양 대치물의 종류는 41예에서 조립형 종양 대치물을, 7예에서는 확장형 종양 대치물을 이용하여 재건술을 시행하였다. 술 후 기능적 평가를 위해 Musculoskeletal Tumor Society (MSTS) Grading System을 이용하였으며, 환자 및 종양 대치물의 생존율, 합병증에 대해 분석하였다. 결과: 환자의 5년 전체 생존율은 77.7%이었고, 5년 무병 생존율은 68.9%이었다. 종양 대치물의 생존율은 68%이었다. 일차적 치환술을 시행한 48예 중 총 20예에서 합병증이 발생하였으며, 감염이 10예로 가장 많았다. 수술적 치료 술 후 MSTS 기능적 평가는 74.1%이었다. 결론: 일차적 종양 대치술의 장기 추시 결과상 골종양 절제 후 재건 방법으로 생존율, 기능적 평가 및 합병증 측면에서 효과적인 방법이라고 사료된다.

• Journal of Chest Surgery
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• 제27권10호
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• pp.862-867
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• 1994

We experienced two cases of dissecting aneurysm[DeBakey type III] of the thoracic aorta treated using intraluminal sutureless graft. Controversy still exists about the exact timing of surgical intervention for dissection of the descending thoracic aorta. The surgical indication of dissecting aneurysm[DeBakey type III] is continuous flow in the false lumen, continuous chest pain, compromise of arterial supply to a specific organ or limb, or extension of the dissection while the patient is receiving satisfactory medical treatment. Surgical therapy for dissection of the aorta has had a high mortality. One contributing factor has been hemorrhage from the prosthesis and the suture lines. Recently, a new method of treatment with a intraluminal sutureless graft that requires no end-to-end anastomosis has been developed. In our cases, cardiopulmonary bypass and circulatory arrest was utilized in repairing dissecting aneurysm of descending aorta[DeBakey type III] in order to avoid the aortic cross clamping because of friable aortic intima. The basic technique consists of vertical incision of descending aorta in the area of intimal tear and inserting the whole ringed graft into the true lumen of the dissected aorta and circumferentially ligating the aorta against the groove in the rings. Postoperative course was uneventful.

• 대한치과보철학회지
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• 제40권4호
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• pp.374-385
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• 2002

A total of 605 implant fixture prosthesis delivered by 3 clinics and 2 laboratories were examined in this study, The object of this study was to determine the proper length of screw head. The depth of access hole were measured and compared to the type of fixture, abutment, gold screw and prosthesis. The results were as follows : 1 The average number of fixtures per patient were 2.97. 2. The number of fixture installed in the upper posterior area are 327(55.56 %), the upper posterior area 171 (28.25%). 3. The depth of access hole is 4.23 mm in shallow area, and 5.46 mm in deep area and the differences were 1.23 mm. 4. The average depth of the aceess hole of the UCLA abutment were 5.02 mm. 5. The number of 4-5 mm access hole depth were 60(22.39%) in abutment screw level and the number of 4-5 mm depth in fixture level were 101 (29.19%). 6. In the shape of screw head, hexed type were 576(95.21%), slotted type were 29(4.79%).

• 대한전기학회논문지:시스템및제어부문D
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• 제55권12호
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• pp.550-557
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• 2006

This paper proposes a dry-type surface myoelectric sensor for the myoelectric hand prosthesis. The designed surface myoelectric sensor is composed of skin interface and processing circuits. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper is proposed two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22mm is selected. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value(MAV) circuit. Using SUS440, six prototype skin interface with different reference electrode shape and IED is fabricated, and their output characteristics are evaluated by output signal obtained from the forearm of a healthy subject. The experimental results show that the skin interface with parallel bar shape and the 18mm IED has a good output characteristics. The fabricated dry-type surface myoelectric sensor is evaluated for the upper-limb amputee.

• 대한치과보철학회지
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• 제51권2호
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• pp.107-112
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• 2013

치관높이 공간이 과도할 경우 임플란트 몸체 혹은 구성물의 실패와 같은 고정성 보철물의 생역학적 합병증이 증가하며 치관 높이 공간이 12 mm 이상으로 과도한 경우는 고정성 보철물 선택에 유의하여야 한다. 고정성 보철물을 제작 시 치아들이 길어지므로 심미적 부위에서는 치은 색조를 띠는 재료를 사용해야 할 필요가 있다. 이러한 경우, 유지와 위생 관리가 적절하지 못하게 형성된 고정성 보철물은 음식물, 치태, 치석을 정체시키고 염증과 감염이 발생될 수 있으며 만성 염증과 감염으로 인해 외과적인 개선이 필요할 수 있다. 본 증례에서, 과도한 치관높이 공간을 가진 환자에게 발음 및 심미성을 고려하여 보철물 제작 후 보철물 주위의 치은 염증 및 부종이 발생하였으며, 그 원인이 구강위생을 어렵게 하는 보철물의 디자인으로 판단되어 치간공극을 충분히 형성한 임시 보철물을 장착 후 2개월 동안의 관찰 기간을 거치며 특이할 만한 이상 소견이 없음을 확인하였고 자가 위생 관리가 용이한 디자인으로 지르코니아 하부구조에 도재를 축성한 고정성 보철물로 구강회복을 시행하였으며, 일련의 치료과정을 통하여 부적절한 연조직 반응이 관찰 되지 않고 기능적인 면에서 만족스러운 결과를 얻을 수 있었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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• pp.165-166
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• 2011

conical type의 sputtering 시스템으로 3차원 치과 보철물 위에 균일한 Ti 박막의 증착을 시도하였으며, 증착 변수에 따른 Ti 박막의 특성을 조사하였다.

• 대한치과보철학회지
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• 제46권3호
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• pp.290-297
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• 2008

STATEMENT OF PROBLEM: Implant-supported fixed cantilever prostheses are influenced by various biomechanical factors. The information that shows the effect of implant number and position of cantilever on stress in the supporting bone is limited. PURPOSE: The purpose of this study was to investigate the effect of implant number variation and the effect of 2 different cantilever types on stress distribution in the supporting bone, using 3-dimensional finite element analysis. MATERIAL AND METHODS: A 3-D FE model of a mandibular section of bone with a missing second premolar, first molar, and second molar was developed. $4.1{\times}10$ mm screw-type dental implant was selected. 4.0 mm height solid abutments were fixed over all implant fixtures. Type III gold alloy was selected for implant-supported fixed prostheses. For mesial cantilever test, model 1-1 which has three $4.1{\times}10$ mm implants and fixed prosthesis with no pontic, model 1-2 which has two $4.1{\times}10$ mm implants and fixed prosthesis with a central pontic and model 1-3 which has two $4.1{\times}10$ mm implants and fixed prosthesis with mesial cantilever were simulated. And then, 155N oblique force was applied to the buccal cusp of second premolar. For distal cantilever test, model 2-1 which has three $4.1{\times}10$ mm implants and fixed prosthesis with no pontic, model 2-2 which has two $4.1{\times}10$ mm implants and fixed prosthesis with a central pontic and model 2-3 which has two $4.1{\times}10$ mm implants and fixed prosthesis with distal cantilever were simulated. And then, 206N oblique force was applied to the buccal cusp of second premolar. The implant and superstructure were simulated in finite element software(Pro/Engineer wildfire 2.0). The stress values were observed with the maximum von Mises stresses. RESULTS: Among the models without a cantilever, model 1-1 and 2-1 which had three implants, showed lower stress than model 1-2 and 2-2 which had two implants. Although model 2-1 was applied with 206N, it showed lower stress than model 1-2 which was applied with 155N. In models that implant positions of models were same, the amount of applied occlusal load largely influenced the maximum von Mises stress. Model 1-1, 1-2 and 1-3, which were loaded with 155N, showed less stress than corresponding model 2-1, 2-2 and 2- 3 which were loaded with 206N. For the same number of implants, the existence of a cantilever induced the obvious increase of maximum stress. Model 1-3 and 2-3 which had a cantilever, showed much higher stress than the others which had no cantilever. In all models, the von Mises stresses were concentrated at the cortical bone around the cervical region of the implants. Meanwhile, in model 1-1, 1-2 and 1-3, which were loaded on second premolar position, the first premolar participated in stress distribution. First premolars of model 2-1, 2-2 and 2-3 did not participate in stress distribution. CONCLUSION: 1. The more implants supported, the less stress was induced, regardless of applied occlusal loads. 2. The maximum von Mises stress in the bone of the implant-supported three unit fixed dental prosthesis with a mesial cantilever was 1.38 times that with a central pontic. The maximum von Mises stress in the bone of the implant-supported three-unit fixed dental prosthesis with a distal cantilever was 1.59 times that with a central pontic. 3. A distal cantilever induced larger stress in the bone than a mesial cantilever. 4. A adjacent tooth which contacts implant-supported fixed prosthesis participated in the stress distribution.

• 대한치과의사협회지
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• 제54권3호
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• pp.198-205
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• 2016

The purpose of this paper was to investigate the significance of splinted and non-splinted implant-supported restorations with an internal connection for multiple consecutively missing teeth. Upon examination of the effects of fixture-abutment connection, the distribution of occlusal load was favorable in splinted implant-prosthesis with an external connection, but effect of strain distribution was not significant in splinted implant-prosthesis with an internal connection. In splinted implant-prostheses for short implants, strain distribution was not affected by the method of retention. For cement-retained prostheses, the effect of strain distribution due to splinting was not significant. In clinical studies, non-splinted prostheses with an internal connection for multiple consecutively missing teeth showed high survival rate, mild marginal bone loss, and stable periodontal condition. However, failure to achieve optimal proximal contact between single-unit prostheses may lead to food impaction, and veneer fracture may be inevitable when the framework provides inadequate support in the proximal region. In conclusion, splinted implant-prosthesis is not an indication in all cases, and clinical consideration of its use should be based on the patient's oral condition, such as location and number of implants, formation of proximal contact, canine guidance, existence of parafunctional habit, and oral hygiene, when multiple consecutively missing teeth are replaced by internal connection type implant.