• Title/Summary/Keyword: midpoint method

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Wedge Shape Cage in Posterior Lumbar Interbody Fusion : Focusing on Changes of Lordotic Curve

  • Kim, Joon-Seok;Oh, Seong-Hoon;Kim, Sung-Bum;Yi, Hyeong-Joong;Ko, Yong;Kim, Young-Soo
    • Journal of Korean Neurosurgical Society
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    • v.38 no.4
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    • pp.255-258
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    • 2005
  • Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

Free Hand Insertion Technique of S2 Sacral Alar-Iliac Screws for Spino-Pelvic Fixation : Technical Note, Acadaveric Study

  • Park, Jong-Hwa;Hyun, Seung-Jae;Kim, Ki-Jeong;Jahng, Tae-Ahn
    • Journal of Korean Neurosurgical Society
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    • v.58 no.6
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    • pp.578-581
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    • 2015
  • A rigid spino-pelvic fixation to anchor long constructs is crucial to maintain the stability of long fusion in spinal deformity surgery. Besides obtaining immediate stability and proper biomechanical strength of constructs, the S2 alar-iliac (S2AI) screws have some more advantages. Four Korean fresh-frozen human cadavers were procured. Free hand S2AI screw placement is performed using anatomic landmarks. The starting point of the S2AI screw is located at the midpoint between the S1 and S2 foramen and 2 mm medial to the lateral sacral crest. Gearshift was advanced from the desired starting point toward the sacro-iliac joint directing approximately $20^{\circ}$ angulation caudally in sagittal plane and $30^{\circ}$ angulation horizontally in the coronal plane connecting the posterior superior iliac spine (PSIS). We made a S2AI screw trajectory through the cancellous channel using the gearshift. We measured caudal angle in the sagittal plane and horizontal angle in the coronal plane. A total of eight S2AI screws were inserted in four cadavers. All screws inserted into the iliac crest were evaluated by C-arm and naked eye examination by two spine surgeons. Among 8 S2AI screws, all screws were accurately placed (100%). The average caudal angle in the sagittal plane was $17.3{\pm}5.4^{\circ}$. The average horizontal angle in the coronal plane connecting the PSIS was $32.0{\pm}1.8^{\circ}$. The placement of S2AI screws using the free hand technique without any radiographic guidance appears to an acceptable method of insertion without more radiation or time consuming.

Lifetime Improvement of Wireless Sensor Network using the Distribution of a Transmission Distance in the SEP (SEP에서 전송 거리 분배를 이용한 무선 센서 네트워크 수명 개선)

  • Lee, Chang-Hee;Lee, Jong-Yong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.133-138
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    • 2015
  • In this paper, we propose a method for improving the lifetime of the sensor network SEP through the wireless sensor network divided into two spaces by reducing the transmission distance of the cluster head in the layer in the distance. With reference to the position information of the node, the base station divides the layer based on the midpoint of the nearest node and the furthest distance away from the base station node. And the cluster head in the outer layer far from the base station is transmitted the data to the base station via the cluster head in the inner layer base station to transmit data. That is, we are proposed the layered SEP by reducing the transmission distance of the cluster head in the outer layer for the energy consumption to a minimum. The proposed algorithm is verified by comparison with the existing SEP.

Buttock Augmentation with Elastomer Implants (엘라스토머 임플란트를 사용한 엉덩이 확대 성형술)

  • Park, Bong-Kwon;Kim, Youn-Hwan;Ahn, Hee-Chang
    • Archives of Plastic Surgery
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    • v.38 no.2
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    • pp.182-188
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    • 2011
  • Purpose: The buttocks region has been associated with allure and sex appeal for centuries. Gluteal implants enable buttocks remodeling in a way that is not possible in other methods. One of the reasons that render gluteal implant surgeries unpopular is the fear of complications, the main problems being seroma, wound dehiscence, extrusion, and a visible or palpable implant. The authors present the XYZ technique, which provides anatomical reference points to guide the intramuscular dissection procedure in a feasible and safe way, resulting in a lower complication rate. Methods: The XYZ procedure was done for buttock augmentation on 8 patients from December 2009 to June 2010. Patient's ages ranged from 27 to 44 with a mean age of 36. Seven patients were applied the 250cc sized Elastomer implants with one patient 290cc sized implant. Preoperative marking was done with the patients in the standing position. Bisection of the gluteus maximus muscle was done at the midpoint thickness to create a plane for implant insertion, which is called the sandwich plane. Results: The 8 cases were performed safely without major complications. However one patient had minor wound dehiscence, and was managed with conservative treatment. Another patient had a discomfort on the buttocks for a long time. The patients were followed up for average 6 months. All patients were satisfied with the aesthetic results. Conclusion: In performing the XYZ technique for gluteal augmentation, the surgeon must split the muscle into two equal halves with anatomical reference points to guide the muscle detachment in a symmetrical way at an adequate depth. This method provides a guideline for the surgeon in determining the ideal plane during intramuscular dissection and gives predictable results with low complication rates. Intramuscular gluteoplasty with gluteal implants offers predictable, aesthetically pleasing results without contour irregularities and only a low incidence of major complications.

Development of GUI Environment Using a Commercial Program for Truss Structure of Approximate Optimization (상용프로그램을 사용한 트러스 구조물 근사최적설계 GUI 환경 개발)

  • 임오강;이경배
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.4
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    • pp.431-437
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    • 2003
  • In this paper, an approximate optimization program based on GUI(graphic user interface) environment is developed. This program is coded by using Fortran and Visual basic. Fortran is used to Progress approximate optimization process. Visual basic is used to make user environment for user to use conveniently. Inside of this program, it uses two independent programs. One is commercial program, ANSYS, and the other is optimization program, PLBA(Pshenichny-Lim-Belegundu Arora). The former is used to obtain approximate equation of stress and displacement of a structure. The latter is used to solve approximate optimization. This algorithm uses second-order information of a function and active set strategy. This program is connecting ANSYS and PLBA. And it progress the process repeatedly until it obtain optimum value. As a method of approximate optimization, sequential design domain(SDD) is introduced. SDD starts with a certain range which is offseted from midpoint of an initial design domain and then SDD of the next step is determined by optimal point of a prior step.

Augmented reality and dynamic infrared thermography for perforator mapping in the anterolateral thigh

  • Cifuentes, Ignacio Javier;Dagnino, Bruno Leonardo;Salisbury, Maria Carolina;Perez, Maria Eliana;Ortega, Claudia;Maldonado, Daniela
    • Archives of Plastic Surgery
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    • v.45 no.3
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    • pp.284-288
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    • 2018
  • Dynamic infrared thermography (DIRT) has been used for the preoperative mapping of cutaneous perforators. This technique has shown a positive correlation with intraoperative findings. Our aim was to evaluate the accuracy of perforator mapping with DIRT and augmented reality using a portable projector. For this purpose, three volunteers had both of their anterolateral thighs assessed for the presence and location of cutaneous perforators using DIRT. The obtained image of these "hotspots" was projected back onto the thigh and the presence of Doppler signals within a 10-cm diameter from the midpoint between the lateral patella and the anterior superior iliac spine was assessed using a handheld Doppler device. Hotspots were identified in all six anterolateral thighs and were successfully projected onto the skin. The median number of perforators identified within the area of interest was 5 (range, 3-8) and the median time needed to identify them was 3.5 minutes (range, 3.3-4.0 minutes). Every hotspot was correlated to a Doppler sound signal. In conclusion, augmented reality can be a reliable method for transferring the location of perforators identified by DIRT onto the thigh, facilitating its assessment and yielding a reliable map of potential perforators for flap raising.

Feasibility of Ultrasound-Guided Lumbar and S1 Nerve Root Block: A Cadaver Study (초음파 유도하 요추 및 제1천추 신경근 차단술의 타당성 연구)

  • Kim, Jaewon;Park, Hye Jung;Lee, Won Ihl;Won, Sun Jae
    • Clinical Pain
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    • v.18 no.2
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    • pp.59-64
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    • 2019
  • Objective: This study evaluated the feasibility of ultrasound-guided lumbar nerve root block (LNRB) and S1 nerve root block by identifying spread patterns via fluoroscopy in cadavers. Method: A total of 48 ultrasound-guided injections were performed in 4 fresh cadavers from L1 to S1 roots. The target point of LNRB was the midpoint between the lower border of the transverse process and the facet joint at each level. The target point of S1 nerve root block was the S1 foramen, which can be visualized between the median sacral crest and the posterior superior iliac spine, below the L5-S1 facet joint. The injection was performed via an in-plane approach under real-time axial view ultrasound guidance. Fluoroscopic validation was performed after the injection of 2 cc of contrast agent. Results: The needle placements were correct in all injections. Fluoroscopy confirmed an intra-foraminal contrast spreading pattern following 41 of the 48 injections (85.4%). The other 7 injections (14.6%) yielded typical neurograms, but also resulted in extra-foraminal patterns that occurred evenly in each nerve root, including S1. Conclusion: Ultrasound-guided injection may be an option for the delivery of injectate into the S1 nerve root, as well as lumbar nerve root area.

Intra-Rater and Inter-Rater Reliability of Various Forward Head Posture Measurements

  • Yoo, Won-Gyu;Kim, Min-Hee;Yi, Chung-Hwi
    • Physical Therapy Korea
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    • v.12 no.4
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    • pp.41-47
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    • 2005
  • The purpose of this study was to determine the intra-rater and inter-rater reliability of various forward head posture measurements. Ten healthy adults (age, $20.4{\pm}2.2$ yrs; height, $164.0{\pm}5.5$ cm; weight, $58.7{\pm}7.3$ kg) participated in the study. They were free of injury and neurologic deficits in the upper extremities and neck at the time of testing. The subjects were asked to perform head forward posture by under the guidance of physical therapists. Markers were placed on the C7 spinous process, mastoid process, tragus of the ear, outer canthus, and forehead. Measurement 1 for forward head posture assessment was measured as the angle between the horizontal line through C7 and the line connecting the C7 spinous process with the tragus of the ear. Measurement 2 was measured as the angle between the C7 spinous process, the mastoid process and the outer canthus. Measurement 3 was measured as two kinds of angles the HT (head tilt) angle is between the line from the midpoint of forehead to the tragus line and Y-axis at the tragus point. The NF (neck flexion) angle is between the line from the tragus to the C7 line and the Y-axis at the C7. Intra-rater, inter-rater reliability and coefficient of variation was assessed by comparing the measured values from three kinds of measurements of forward head posture. The intra-rater reliability was indicated by intraclass correlation coefficients [ICC(1,1)] and inter-rater reliability was shown by intraclass correlation coefficients [ICC(3,k)]. The results of study were as follows: ICC(1,1) values for intra-rater reliability of three measurements were in the 'excellent' category. ICC(3,k) values for inter-rater reliability of three measurements were also in the 'excellent' category. The coefficient of variation of method 2 had a lower value than method 1 and method 3. This data means that the measured value of method 2 was less scattered. Further research is needed to determine whether the validity of all measurements is revealed in the 'excellent' category.

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A Literature Review of Application of Sifeng Point (EX-UE 10) in Children (소아에서 사봉혈(四縫穴) 활용에 대한 문헌 조사)

  • Lee, Boram;Shin, Hye Jin;Lee, Jihong;Chang, Gyu Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.32 no.3
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    • pp.72-89
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    • 2018
  • Objectives The objective of this study is to investigate the application of Sifeng point (EX-UE 10) in children and to make suggestions for domestic research and clinical application by reviewing relevant randomized controlled trials. Methods Eight electronic databases including English, Chinese, Korean databases were comprehensively searched for randomized controlled trials evaluating the effects of Sifeng point in children up to May 2, 2018. We extracted the year of publication, country, target diseases or symptoms, location of Sifeng, acupuncture method; such as acupuncture tool and depth of insertion, and frequency, number, and duration of the treatment. Results Fifty studies were included for analysis. All the included studies were conducted in China, and studies were published from 1962 to 2017. The most frequent target symptom was anorexia (46%). In addition, Sifeng point was used for digestive diseases or symptoms such as diarrhea, constipation, and mesenteric lymphadenitis, as well as respiratory diseases or symptoms such as cough, cold, acute bronchiolitis, recurrent respiratory tract infections, bronchopneumonia, and asthmatic bronchitis. Also, allergic diseases such as chronic urticaria, and other variety of symptoms such as malnutrition, fever, and iron-deficiency anemia were treated with the Sifeng point. The location of Sifeng points was inconsistent, and the most common location of the Sifeng point was the midpoint of transverse creases of the proximal interphalangeal joints of the index, middle, ring and little fingers (84.2%). The most commonly used acupuncture tool was three-edged needle (40.9%). All included studies have the method of squeezing out blood or mucus from the Sifeng points. The treatment was mostly conducted once per week (35.4%), mostly repeated for 4 times (32.6%). The most common treatment duration was 4 weeks (18.6%). Conclusions We could identify acupuncture method and various indications for the Sifeng points treatment. Based on this study, there is a need for the clinical application and related researches on the Sifeng points in children in Korea. In addition, the treatment location of Sifeng point should be standardized.

Geophysical Imaging of Alluvial Water Table and the underlying Layers of Weathered and Soft Rocks (충적층 지하수면 및 그 하부의 풍화암/연암의 경계면 파악을 위한 복합 지구물리탐사)

  • Ju, Hyeon-Tae;Lee, Chul-Hee;Kim, Ji-Soo
    • The Journal of Engineering Geology
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    • v.25 no.3
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    • pp.349-356
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    • 2015
  • Although geophysical methods are useful and generally provide valuable information about the subsurface, it is important to recognize their limitations. A common limitation is the lack of sufficient contrast in physical properties between different layers. Thus, multiple methods are commonly used to best constrain the physical properties of different layers and interpret each section individually. Ground penetrating radar (GPR) and shallow seismic reflection (SSR) methods, used for shallow and very shallow subsurface imaging, respond to dielectric and velocity contrasts between layers, respectively. In this study, we merged GPR and SSR data from a test site within the Cheongui granitic mass, where the water table is ~3 m deep all year. We interpreted the data in combination with field observations and existing data from drill cores and well logs. GPR and SSR reflections from the tops of the sand layer, water table, and weathered and soft rocks are successfully mapped in a single section, and they correlate well with electrical resistivity data and SPS (suspension PS) well-logging profiles. In addition, subsurface interfaces in the integrated section correlate well with S-wave velocity structures from multi-channel analysis shear wave (MASW) data, a method that was recently developed to enhance lateral resolution on the basis of CMP (common midpoint) cross-correlation (CMPCC) analysis.