• Title/Summary/Keyword: Adjacent segment

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Variation of Paraspinal Muscle Forces according to the Lumbar Motion Segment Fusion during Upright Stance Posture (직립상태 시 요추 운동분절의 유합에 따른 척추주변 근력의 변화)

  • Kim, Young-Eun;Choi, Hae-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.2
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    • pp.130-136
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    • 2010
  • For stability analysis of the lumbar spine, the hypothesis presented is that the disc has stress sensors driving feedback mechanism, which could react to the imposed loads by adjusting the contraction of the muscles. Fusion in the motion segment of the lumbar spinal column is believed to alter the stability of the spinal column. To identify this effect finite element (FE) models combined with optimization technique was applied and quantify the role of each muscle and reaction forces in the spinal column with respect to the fusion level. The musculoskeletal FE model was consisted with detailed whole lumbar spine, pelvis, sacrum, coccyx and simplified trunk model. Vertebral body and pelvis were modeled as a rigid body and the rib cage was constructed with rigid truss element for the computational efficiency. Spinal fusion model was applied to L3-L4, L4-L5, L5-S1 (single level) and L3-L5 (two levels) segments. Muscle architecture with 46 local muscles was used as acting directions. Minimization of the nucleus pressure deviation and annulus fiber average axial stress deviation was selected for cost function. As a result, spinal fusion produced reaction changes at each motion segment as well as contribution of each muscle. Longissimus thoracis and psoas major muscle showed dramatic changes for the cases of L5-S1 and L3-L5 level fusion. Muscle force change at each muscle also generated relatively high nucleus pressure not only at the adjacent level but at another level, which can explain disc degeneration pattern observed in clinical study.

Two-Path Language Modeling Considering Word Order Structure of Korean (한국어의 어순 구조를 고려한 Two-Path 언어모델링)

  • Shin, Joong-Hwi;Park, Jae-Hyun;Lee, Jung-Tae;Rim, Hae-Chang
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.8
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    • pp.435-442
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    • 2008
  • The n-gram model is appropriate for languages, such as English, in which the word-order is grammatically rigid. However, it is not suitable for Korean in which the word-order is relatively free. Previous work proposed a twoply HMM that reflected the characteristics of Korean but failed to reflect word-order structures among words. In this paper, we define a new segment unit which combines two words in order to reflect the characteristic of word-order among adjacent words that appear in verbal morphemes. Moreover, we propose a two-path language model that estimates probabilities depending on the context based on the proposed segment unit. Experimental results show that the proposed two-path language model yields 25.68% perplexity improvement compared to the previous Korean language models and reduces 94.03% perplexity for the prediction of verbal morphemes where words are combined.

A Comparison of Anterior Cervical Discectomy and Fusion versus Fusion Combined with Artificial Disc Replacement for Treating 3-Level Cervical Spondylotic Disease

  • Jang, Seo-Ryang;Lee, Sang-Bok;Cho, Kyoung-Suok
    • Journal of Korean Neurosurgical Society
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    • v.60 no.6
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    • pp.676-683
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    • 2017
  • Objective : The purpose of this study is to evaluate the efficacy and safety of 3-level hybrid surgery (HS), which combines fusion and cervical disc replacement (CDR), compared to 3-level fusionin patient with cervical spondylosis involving 3 levels. Methods : Patients in the anterior cervical discectomy and fusion (ACDF) group (n=30) underwent 3-level fusion and the HS group (n=19) underwent combined surgery with fusion and CDR. Clinical outcomes were evaluated using the visual analogue scale for the arm, the neck disability index (NDI), Odom criteria and postoperative complications. The cervical range of motion (ROM), fusion rate and adjacent segments degeneration were assessed with radiographs. Results : Significant improvements in arm pain relief and functional outcome were observed in ACDF and HS group. The NDI in the HS group showed better improvement 6 months after surgery than that of the ACDF group. The ACDF group had a lower fusion rate, higher incidence of device related complications and radiological changes in adjacent segments compared with the HS group. The better recovery of cervical ROM was observed in HS group. However, that of the ACDF group was significantly decreased and did not recover. Conclusion : The HS group was better than the ACDF group in terms of NDI, cervical ROM, fusion rate, incidence of postoperative complications and adjacent segment degeneration.

The Changes in Range of Motion after a Lumbar Spinal Arthroplasty with Charite$^{TM}$ in the Human Cadaveric Spine under Physiologic Compressive Follower Preload: A Comparative Study between Load Control Protocol and Hybrid Protocol

  • Kim, Se-Hoon;Chang, Ung-Kyu;Chang, Jae-Chil;Chun, Kwon-Soo;Lim, T. Jesse;Kim, Daniel H.
    • Journal of Korean Neurosurgical Society
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    • v.46 no.2
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    • pp.144-151
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    • 2009
  • Objective: To compare two testing protocols for evaluating range of motion (ROM) changes in the preloaded cadaveric spines implanted with a mobile core type Charite$^{TM}$ lumbar artificial disc. Methods: Using five human cadaveric lumbosacral spines (L2-S2), baseline ROMs were measured with a bending moment of 8 Nm for all motion modes (flexion/extension, lateral bending, and axial rotation) in intact spine. The ROM was tracked using a video-based motion-capturing system. After the Charite$^{TM}$ disc was implanted at the L4-L5 level, the measurement was repeated using two different methods: 1) loading up to 8 Nm with the compressive follower preload as in testing the intact spine (Load control protocol), 2) loading in displacement control until the total ROM of L2-S2 matches that when the intact spine was loaded under load control (Hybrid protocol). The comparison between the data of each protocol was performed. Results: The ROMs of the L4-L5 arthroplasty level were increased in all test modalities (p < 0.05 in bending and rotation) under both load and hybrid protocols. At the adjacent segments, the ROMs were increased in all modes except flexion under load control protocol. Under hybrid protocol, the adjacent segments demonstrated decreased ROMs in all modalities except extension at the inferior segment. Statistical significance between load and hybrid protocols was observed during bending and rotation at the operative and adjacent levels (p< 0.05). Conclusion: In hybrid protocol, the Charite$^{TM}$ disc provided a relatively better restoration of ROM, than in the load control protocol, reproducing clinical observations in terms of motion following surgery.

The Effect of Posteroanterior Joint Mobilization Applied to The 3rd Lumbar Vertebra Movement of Adjacent Segmental in Healthy Individuals

  • Kang-O Oh;Sang-Yeol Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.3
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    • pp.240-250
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    • 2023
  • Objective: The purpose of this study was to characterize the movement of adjacent segments that occurred when posteroanterior joint mobilization was applied to the 3rd lumbar and thereby to provide basic clinical data. Design: Randomized controlled trial design. Methods: While the subjects were receiving posteroanterior joint mobilization of the 3rd lumbar vertebra, LD (lumbar displacement), LID (lumbar intervertebral distance), LIA (lumbar intervertebral angle), and LLA (lumbar lordosis angle) were measured using X-ray, and the data were then analyzed. Changes before and after posteroanterior joint mobilization were analyzed using a paired-sample t-test, and a one-way ANOVA of variance was performed to determine the difference between segmental movements. In addition, Pearson's correlation analysis was performed to determine the correlation between segmental movements. Results: The results revealed that there was a significant change in LD before and after the application of joint mobilization of the 3rd lumbar in all lumbar vertebrae (p<0.000), among which the 2nd lumbar vertebra, an adjacent segment, showed the most significant change. A significant change in LIA angle was observed in all segments (p<0.000), with the most significant change observed between the 2nd and 3rd lumbar vertebrae. There was a significant change in LLA before and after the application of posteroanterior joint mobilization (p<0.000). The correlation analysis showed a high correlation between displacement of the 3rd lumbar vertebra and displacement of all the other lumbar vertebrae. Conclusions: The presence of kinematic movements of the lumbar vertebrae when segmental movements were generated through the application of posteroanterior joint mobilization of the 3rd lumbar vertebra.

Effects of Root of Cibotii Rhizoma on Neuronal Damage of Spinal Cord Contusion Injury in Rats (구척(狗脊)이 흰쥐의 척수압박에 의한 신경세포 손상에 미치는 영향)

  • Park, Won-Sang;Kim, Eun-Seok;Shin, Jung-Won;Kim, Bum-Hoi;Kim, Seong-Joon;Kang, Hee;Sohn, Nak-Won
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.2
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    • pp.1-15
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    • 2010
  • Objectives : This study was performed to evaluate the effects of root of Cibotii rhizoma(CR) ethanol extract on the tissue and neuronal damage of the spinal cord injury(SCI). Methods : SCI was induced by mechanical contusion following laminectomy of 10th thoracic vertebra in Sprague-Dawley rats. CR was orally given once a day for 7 days after SCI. Tissue damage and nerve fiber degeneration were examined with cresyl violet and luxol fast blue(LFS) histochemistry. HSP72(as neuronal damage marker), MAP2(as nerve fiber degeneration marker), c-Fos(immediate early gene), and Bax(pro-apoptotic molecule) expressions were examined using immuno-histochemistry. Individual immuno-positive cells expressing HSP72, MAP2, c-Fos and Bax were observed on the damaged level and the upper thoracic and lower lumbar spinal segments. Results : 1. CR reduced degeneration of nerve fibers and motor neuron shrinkage in the ventral horn of the lower lumbar spinal segment, but generally it did not seem to ameliorate the tissue injury following SCI. 2. CR reduced demyelination in the ventral and lateral funiculus of the lower lumbar spinal segment. 3. CR reduced HSP72 expression on the neurons in the peri-central canal gray matter adjacent to the damaged region. 4. CR strengthened MAP2 expression on the motor neurons in the ventral horn and on nerve fibers in the lateral funiculus of the lower lumbar spinal segment. 5. CR reduced c-Fos positive cells in the peri-lesion and the dorsal horn of the damaged level and in the ventral horn of the lower lumbar spinal segment. 6. CR reduced Bax positive cells in the peri-lesion and the dorsal horn of the damaged level and in the ventral horn of the lower lumbar spinal segment. Conclusions : These results suggest that CR plays an inhibitory role against secondary neuronal damage and nerve fiber degeneration. following SCI.

An evaluation of the pipe failure impact in a water distribution system considering subsystem isolation (상수관 파괴시 관망의 부분적 격리를 고려한 피해범위 산정)

  • Jun, Hw-Andon
    • Journal of Korea Water Resources Association
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    • v.39 no.2 s.163
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    • pp.89-98
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    • 2006
  • To evaluate the pipe failure impact, current methodologies consider only a broken pipe as the impacted area. However, these approaches are accurate if the broken pipe is the only area isolated from tile system. Depending on the number and locations of on-off valves, more pipes which are adjacent to a broken pipe may be isolated. Using the concept of Segment suggested by Walski, the methodology evaluating the pipe failure impact incorporated with on-off valve locations has been suggested by Jun. However, a segment cannot account for all possible pipe failure impacted areas since it does not consider additional failures, namely the network topological failure and the hydraulic pressure failure. For this reason, a methodology which can consider the network topology and hydraulic pressure limitation as well as on-off valve locations is suggested. The suggested methodology is applied to a real network to verify its applicability As results, it is found that a single pipe failure can affect huge areas depending on the configuration of on-off valves and the network topology. Thus, the applicability of the suggested methodology for evaluating the pipe failure impacts on a water distribution network is proved.

The Change of Motion Ranges of Adjacent Vertebral Joints after Lumbar Fusion Operation (요추 고정수술 후 인접척추 운동범위의 변화)

  • Yeo, Sang-Jun;Park, Seung-Won;Kim, Young-Baeg;Hwang, Sung-Nam;Choi, Duck-Young;Suk, Jong-Sik;Chung, Dong-Kue;Min, Byung-Kook
    • Journal of Korean Neurosurgical Society
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    • v.29 no.11
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    • pp.1456-1460
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    • 2000
  • Objectives : Transpedicular screw fixation has become an important method for internal fixation in variety of disorders. However, acceleration of degeneration at the adjacent segment in any follow. The goal of this study is to review the change of motion ranges of vertebral joints adjacent to fused level in lumbar spine. Methods : This study consists of 22 patients with degenerative spinal instability. Treatment of spinal instability includes posterior fusion with transpedicular screw fixation or transpedicular screw fixation with posterior lumbar interbody fusion. The flexion-extension angle(FEA) was measured from dynamic views of lumbar spine taken both at preoperative and post operative period. Results : The FEA of upper vertebral joint adjacent(FEA-u) to a fused L4-5 level was increased(p=0.010). The FEA-u was increased in case of L5-S1 fusion(p=0.025). The change of FEA-u in case of L5-S1 fusion was greater than that in L4-5 fusion(p=0.013). Conclusion : After L4-5 fusion, there seems to be more meaningful increase in FEA of L3-4 than that of L5-S1. The reason may be due to the damage of L3-4 facet joints during the operation, the other possible explanation may be the anatomical stability of L5-S1 vertebral joint. The change of FEA-u of L5-S1 fusion is increased more than that of L4-5 fusion. Because there are compensations in the adjacent vertebrae both above and below the fused L4-5, the compensatory motion in FEA-u of L5-S1 fusion was greater than that of the L4-5 fusion.

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Thermal Image Mosaicking Using Optimized FAST Algorithm

  • Nguyen, Truong Linh;Han, Dong Yeob
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.1
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    • pp.41-53
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    • 2017
  • A thermal camera is used to obtain thermal information of a certain area. However, it is difficult to depict all the information of an area in an individual thermal image. To form a high-resolution panoramic thermal image, we propose an optimized FAST (feature from accelerated segment test) algorithm to combine two or more images of the same scene. The FAST is an accurate and fast algorithm that yields good positional accuracy and high point reliability; however, the major limitation of a FAST detector is that multiple features are detected adjacent to one another and the interest points cannot be obtained under no significant difference in thermal images. Our proposed algorithm not only detects the features in thermal images easily, but also takes advantage of the speed of the FAST algorithm. Quantitative evaluation shows that our proposed technique is time-efficient and accurate. Finally, we create a mosaic of the video to analyze a comprehensive view of the scene.

On Detecting the Transition Regions of Phonemes by Using the Asymmetrical Rate of Speech Waveforms (음성파형의 비대칭율을 이용한 음소의 전이구간 검출)

  • Bae, Myung-Jin;Lee, Eul-jae;Ann, Sou-Guil
    • The Journal of the Acoustical Society of Korea
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    • v.9 no.4
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    • pp.55-65
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    • 1990
  • To recognize continued speech, it is necessary to segment the connected acoustic signal into phonetic units, In this paper, as a parameter to detect transition regions in continued speech, we propose a new asymmetrical rate. The suggested rate represents a change rate of magnitude of speech signals. As comparing this rate with other rate in adjacent frame, the state of the frame can be distinguished between steady state and transient state.

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