• Title/Summary/Keyword: Model surgery

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Characteristics of Animal Shoulder Models for Rotator Cuff Experiments

  • Kim, Min-Cheol;Kim, Myung-Sun
    • Clinics in Shoulder and Elbow
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    • v.18 no.1
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    • pp.52-58
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    • 2015
  • Animal shoulder models are important in the investigation of the natural history of various pathologic conditions and for evaluation of the effectiveness of different treatments and biomaterials. The characteristics of animal shoulder models that may be used for rotator cuff related experiments are different with regard to the anatomy, behavioral pattern, advantages and disadvantages in application to each other. The lower primates and all the non-primate species, except the tree kangaroo, were neither functional overhead nor had a true rotator cuff. Utilizing more advanced primates, or perhaps even the tree kangaroo would be ideal and the most relevant to man as they possess a true rotator cuff. However, ethical concerns, costs, and many limitations in obtaining primates generally preclude the use of these animals for such research. Finally we should consider the differences in comparative anatomy and behavioral pattern of each animal model during performance or interpretation of rotator cuff experiments.

Facial Feature Extraction with Its Applications

  • Lee, Minkyu;Lee, Sangyoun
    • Journal of International Society for Simulation Surgery
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    • v.2 no.1
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    • pp.7-9
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    • 2015
  • Purpose In the many face-related application such as head pose estimation, 3D face modeling, facial appearance manipulation, the robust and fast facial feature extraction is necessary. We present the facial feature extraction method based on shape regression and feature selection for real-time facial feature extraction. Materials and Methods The facial features are initialized by statistical shape model and then the shape of facial features are deformed iteratively according to the texture pattern which is selected on the feature pool. Results We obtain fast and robust facial feature extraction result with error less than 4% and processing time less than 12 ms. The alignment error is measured by average of ratio of pixel difference to inter-ocular distance. Conclusion The accuracy and processing time of the method is enough to apply facial feature based application and can be used on the face beautification or 3D face modeling.

Reconstructing 3-D Facial Shape Based on SR Imagine

  • Hong, Yu-Jin;Kim, Jaewon;Kim, Ig-Jae
    • Journal of International Society for Simulation Surgery
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    • v.1 no.2
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    • pp.57-61
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    • 2014
  • We present a robust 3D facial reconstruction method using a single image generated by face-specific super resolution technique. Based on the several consecutive frames with low resolution, we generate a single high resolution image and a three dimensional facial model based on it. To do this, we apply PME method to compute patch similarities for SR after two-phase warping according to facial attributes. Based on the SRI, we extract facial features automatically and reconstruct 3D facial model with basis which selected adaptively according to facial statistical data less than a few seconds. Thereby, we can provide the facial image of various points of view which cannot be given by a single point of view of a camera.

Pathogenetic Overlapping of Renovascular Hypertension Developed in a Child with Takayasu Arteritis: 'One-clip, One and Half-kidney Model'

  • Lee, Su Jeong;Baek, Hee Sun;Jang, Hea Min;Kim, Hyung-Kee;Huh, Seung;Cho, Min Hyun
    • Childhood Kidney Diseases
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    • v.20 no.1
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    • pp.33-36
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    • 2016
  • There are two pathogenic models of renovascular hypertension (RVH) originating from renal artery stenosis. We noted a case of a boy who had severe hypertension with atrophic left kidney, hypertrophic right kidney, a segmental stricture of the abdominal aorta, and total occlusion of the right renal artery. Due to the atrophic change of the contralateral, unclipped left kidney, this patient presented with various clinical manifestations related to both models of pathogenesis of RVH occurring at the same time. We conclude that this patient presented with the middle stage of the two RVH pathogenetic models, so called the 'one-clip, one and half-kidney model.'

Effect of Dietary Calcium on Spinal Bone Fusion in an Ovariectomized Rat Model

  • Cho, Jae-Hoon;Cho, Dae-Chul;Yu, Song-Hee;Jeon, Young-Hoon;Sung, Joo-Kyung;Kim, Kyoung-Tae
    • Journal of Korean Neurosurgical Society
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    • v.52 no.4
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    • pp.281-287
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    • 2012
  • Objective : To evaluate the effect of calcium supplementation on spinal bone fusion in ovariectomized (OVX) rats. Methods : Sixteen female Sprague Dawley rats underwent bilateral ovariectomy at 12 weeks of age to induce osteoporosis and were randomly assigned to two groups : control group (n=8) and calcium-supplemented group (OVX-Ca, n=8). Autologous spinal bone fusion surgery was performed on both groups 8 weeks later. After fusion surgery, the OVX-Ca group was supplemented with calcium in drinking water for 8 weeks. Blood was obtained 4 and 8 weeks after fusion surgery. Eight weeks after fusion surgery, the rats were euthanized and the L4-5 spine removed. Bone fusion status and fusion volume were evaluated by manual palpation and three-dimensional computed tomography. Results : The mean fusion volume in the L4-5 spine was significantly greater in the OVX-Ca group ($71.80{\pm}8.06mm^3$) than in controls ($35.34{\pm}8.24mm^3$) (p<0.01). The level of osteocalcin, a bone formation marker, was higher in OVX-Ca rats than in controls 4 weeks ($610.08{\pm}10.41$ vs. $551.61{\pm}12.34$ ng/mL) and 8 weeks ($552.05{\pm}19.67$ vs. $502.98{\pm}22.76$ ng/mL) after fusion surgery (p<0.05). The level of C-terminal telopeptide fragment of type I collagen, a bone resorption marker, was significantly lower in OVX-Ca rats than in controls 4 weeks ($77.07{\pm}12.57$ vs. $101.75{\pm}7.20$ ng/mL) and 8 weeks ($69.58{\pm}2.45$ vs. $77.15{\pm}4.10$ ng/mL) after fusion surgery (p<0.05). A mechanical strength test showed that the L4-5 vertebrae in the OVX-Ca group withstood a 50% higher maximal load compared with the controls (p<0.01). Conclusion : Dietary calcium given to OVX rats after lumbar fusion surgery improved fusion volume and mechanical strength in an ovariectomized rat model.

THE THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION AND DISPLACEMENT IN MANDIBLE ACCORDING TO TREATMENT MODALITIES OF MANDIBULAR ANGLE FRACTURES (하악각 골절의 치료 방법에 따른 하악골의 응력 분포 및 변위에 관한 삼차원 유한요소법적 연구)

  • Ku, Je-Hoon;Kim, Il-Kyu;Chang, Jae-Won;Yang, Jung-Eun;Sasikala, Balaraman;Wang, Boon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.3
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    • pp.207-217
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    • 2010
  • The purpose of this study was to evaluate the effects of the stress distribution and displacement in mandible according to treatment modalities of mandibular angle fractures, using a three dimensional finite element analysis. A mechanical model of an edentulous mandible was generated from 3D scan. A 100-N axial load and four masticatory muscular supporting system were applied to this model. According to the number, location and materials of titanium and biodegradable polymer plates, the experimental groups were divided into five types. Type I had a single titanium plate in the superior border of mandibular angle, type II had two titanium plates in the superior tension border and in the inferior compression border of mandibular angle, type III had a single titanium plate in the ventral area of mandibular angle, type IV had a single biodegradable polymer plate in the superior border of mandibular angle, type V had a single biodegradable polymer plate in the ventral area of mandibular angle. The results obtained from this study were follows: 1. Stress was concentrated on the condylar neck of the fractured side except Type III. 2. The values of von-Mises stress of the screws were the highest in the just-posterior screw of the fracture line, and in the just-anterior screw of Type III. 3. The displacement of mandible in Type III was 0.04 mm, and in Type I, II, IV, and V were 0.10 mm. 4. The plates were the most stable in the ventral area of mandibular angle (Type III, V). In conclusion, the ventral area of mandibular angle is the most stable location in the fixation of mandibular angle fractures, and the just- posterior and/or the just-anterior screws of the fracture line must be longer than the other, and surgeons have to fix accurately these screws, and the biodegradable polymer plate also was suitable for the treatment of mandible angle fracture.

The Significance of Lymphatic, Venous, and Neural Invasion as Prognostic Factors in Patients with Gastric Cancer (위암 환자의 예후인자로서 림프관 정맥 및 신경 침범의 의의)

  • Kim Chi-Ho;Jang Seok-Won;Kang Su-Hwan;Kim Sang-Woon;Song Sun-Kyo
    • Journal of Gastric Cancer
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    • v.5 no.2
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    • pp.113-119
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    • 2005
  • Purpose: Some controversies exist over the prognostic values of lymphatic, venous, and neural invasion in patients with gastric cancer. This study was conducted to confirm the prognostic values of these histopathologic factors in gastric cancer patients who received a gastrectomy. Materials and Methods: Data for clinicopathologic factors and clinical outcomes were collected retrospectively from the medical records of 1,018 gastric cancer patients who received a gastrectomy at Yeungnam University Medical Center between January 1995 and December 1999. A statistical analysis was done using the SPSS program for Windows (Version 10.0, SPSS Inc., USA). The Kaplan-Meier method was used for the survival analysis. Prognostic factors were analyzed by using a multivariate analysis with Cox proportional hazard regression model. Results: Ages ranged from 21 to 79 (median age, 56). A univariate analysis revealed that age, tumor size, location, gross type, depth of invasion, extent of gastrectomy or lymph node dissection, lymph node metastasis, distant metastasis, lymphatic invasion, venous invasion, neural invasion, pathologic stage, histologic type, and curability of surgery had statistical significance. Among these factors, lymph node metastasis, curability of surgery, neural invasion, lymphatic invasion, and depth of invasion were found to be independent prognostic factors by using a multivariate analysis. Venous invasion showed no prognostic value in the multivariate analysis. Conclusion: Neural invasion and lymphatic invasion are useful parameters in determining a prognosis for gastric cancer patients.

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An Analysis on the Effectiveness of Hospital Revenues Per Bed by Shortening Length of Stay (재원일별 진료비 변화 및 재원일수 단축의 의료수입 중대 효과)

  • Lee, Hae-Jong;Kim, Young-Hoon;Lee, Eun-Pyo;Kim, Seoung-Woo;Jeoung, Beoung-Han
    • Korea Journal of Hospital Management
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    • v.3 no.1
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    • pp.100-120
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    • 1998
  • Tertiary been increasing rapidly. There has been shortage of beds in hospitals and effective management of beds had to b considered. For the efficient utilization of the exsisting hospital beds, bed turnover rate ha to be high and their length of stay in hospital has to be shortened. The sample of this study was in-patients admitted in 13 clinical departments of a tertiar hospital in Wonju. Daily medical fees through length of stay in hospital were observed an we analyzed the increase of hospital revenues per bed for the shortening of length of stay. The results of the analysis were as follows: 1. The average length of stay by dept. was 11.0 in dept. of internal medicine. 12.4 in dept. of general surgery, 7.1 in dept. of gynecoloty, 6.8 in dept. of pediatrics, 26.1 in dept. of nervous surgery, 21.6 in dept. of orthopedic surgery, 25.5 in dept. of plastic sersury, 7.6 in dept. of ophthalmology, 7.1 in dept. of E.N.T, 8.1 in dept. dermatoloty, 9.0 in dept. urology. 2. The trend of daily medical fees of in-patients was the highest from the first day to the third day. Because most necessary examination and various treatment or operation took place in these period. 3. The estimative model for medical fees by the length of stay at each clinical department was inferred. 4. The increased revenue per bed by shortening the length of stay was calculated by the estimative model. Shortening one day would increase 305,999 thousand won in dept. of internal medicine 232,138 thousand won in dept. of general surgery., 177,795 thousand won in dept. of gynecology medicine, 69,031 thousand won in dept. of pediatrics 360,381 thousand won in dept. of nervous surgery 211.339 thousand won in dept. of orthopedic surgery, 100,249 thousand won in dept of plastic surgery, 10,569 thousand won in dept. of ophthalmology -814,122 thousand won in dept. of E.N.T, 1,582 thousand won in dept. of dermatology, -5,821 thousand won in dept. of urology. It is expected that they can improve their profitability by shortening the length of stay of the in-patients.

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A STUDY ABOUT EARLY OSTEOCONDUCTIVITY OF POROUS ALLOPLASTIC CARBONAPATITE AND ANORGANIC BOVINE XENOGRAFT IN CANINE MAIXLLIARY AUGMENTATION MODEL (탄산아파타이트로 된 인공골과 소뼈에서 유래한 무기질 골의 초기 골전도에 대한 연구)

  • Kim, Do-Kyun;Cho, Tae-Hyung;Song, Yun-Mi;Pan, Hui;Lee, Su-Yeon;Jin, Im-Geon;Kim, In-Sook;Hong, Kug-Sun;Hwang, Soon-Jung
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.29 no.6
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    • pp.485-493
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    • 2007
  • Introduction: Although several types of calcium-phosphate coumpound have been frequently applied to osseous defects at maxillofacial area for many years, there is a controversy about its efficiency on bone conductivity comprared to xenograft bone substitute. Alloplastic carbonapatite has been introduced to improve disadvantages of hydroxyapatite and to mimic natural bone containing carbon elements. However, a preclinical study about its efficiency of osteoconductivity has not been reported. This study was performed to evaluate the early osteoconductive potential of synthetic carbonapatite with multiple pores relative to anorganic bovine xenograft. Materials and methods: Total 5 beagle dogs were used for maxillary augmentation model. The control (anorganic bovine xenograft) and experimental groups (synthetic carbonapatite) were randomly distributed in the mouth split design. After bone graft, all animals were sacrificed 4 weeks after surgery. Histological specimens with Masson Trichrome staining were made and histomorphometrically analysed with image analyser. The statistical analysis was performed using paired t-test. Results: In both groups, all animals had no complications. The experimental group showed relatively much new bone formation around and along the bone substitutes, whereas it was clearly reduced in the control group. The ratios of new bone area to total area, to material area and to the residual area excluding materials were higher in the experimental group ($0.13{\pm}0.03,\;0.40{\pm}0.13,\;0.20{\pm}0.06$ respectively) than in the control group ($0.01{\pm}0.01,\;0.03{\pm}0.02,\;0.03{\pm}0.03$, respectively). And the differences between both groups were statistically significant (p<0.001, <0.01, <0.01, respectively), while the ratio of material area to total area in two groups was not significant. Conclusion: Carbonapatite showed a high osteoconductivity in the early stage of bone healing compared to bovine derived anorganic bone substitute. This study suggests that this bone materials can be applied as a reliable bone substitute in the clinical treatment.

Dual Preconditioning Effect of Dexamethasone and Epinephrine on TRAM flap Survival in Rats (덱사메타손과 에피네프린의 이중 전처치가 횡복직근피판 생존에 미치는 영향)

  • Kim, Jae Woo;Kim, Jun Hyuk;Ahn, Hyoung Sik;Shin, Ho Sung;Choi, Hwan Jun;Lee, Young Man
    • Archives of Plastic Surgery
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    • v.34 no.2
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    • pp.163-168
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    • 2007
  • Purpose: The flap delay is a widely used technique to increase the flap survival. Dexamethasone is a well-known drug to have a positive impact on the flap survival. The objective of this study is to investigate the dual synergic effect of epinephrine as a chemical delay agent plus dexamethasone on the TRAM flap survival in rat model. Methods: Forty Sparague-Dawley rats were divided into 4 groups evenly and a right inferior epigastic vessel pedicled TRAM flap, sized $5.0{\times}3.0cm$, was elevated on each upper abdomen. In the control group(N=10), 2 ml saline was injected on transverse abdominis muscle for a week before the flap elevation. In surgical delay group(N=10) all superior pedicles and left inferior pedicle were ligated a week before the flap elevation. In epinephrine group (N=10), 1 : 50000 epinephrine mixed saline was injected to transverse abdominis muscle every day for a week before flap elevation. In epinephrine plus dexamethasone group (N=10), the same procedure as that of epinephrine group was conducted for a week and 2.5 ml/kg dexamethasone was injected transverse abdominis muscle 2 hours before the flap elevation. On the seventh day after flap elevation, the survival area of flaps were measured and the vessel numbers in upper dermis of flap were counted through histologic slides. Results: The results were as follows: the mean percentage of the flap survival area of surgical delay group ($60.5{\pm}2.44%$), epinephrine group ($75{\pm}4.43%$), and epinephrine plus dexamethasone group ($87{\pm}1.94%$) were higher than that of the control group ($35{\pm}6.06%$) significantly(p<0.05). In case of the vessel number though histologic slides, epinephrine group ($79.3{\pm}5.57$) and epinephrine plus dexamethasone group ($96.3{\pm}14.05$) were higher than that of the control group ($44.8{\pm}8.82$) significantly(p<0.05), but the surgical delay group ($54{\pm}4.23$) showed no significant difference (p>0.05) compared to that of the control group. Conclusion: The results indicated that epinephrine plus dexamethasone injection before the flap elevation could be used to increase the TRAM flap survival area in rat model.