• Title/Summary/Keyword: Partial resonance

Search Result 225, Processing Time 0.02 seconds

Anterior Surgical Approach in Recurrent Cervical Neurenteric Cyst - Case Report - (재발한 경추 신경장성 낭종의 전방경유 치험 - 증 례 보 고 -)

  • Bae, Kwang Ju;Kim, Il-Man
    • Journal of Korean Neurosurgical Society
    • /
    • v.29 no.9
    • /
    • pp.1258-1261
    • /
    • 2000
  • Intraspinal neurenteric cyst is rare congenital lesion derived from disorder of notochord formation. Most of these are located ventral to the spinal cord and conventional posterior approach is considered to be effective method as initial treatment modality. This cyst can recur, but the risk of reccurence after partial removal through long term follow-up has not been determined. We experienced one case of cervical neurenteric cyst which recurred after partial removal through laminectomy. The magnetic resonance imaging and postmyelography computerized tomography revealed an intradural extramedullary cystic lesion anterior to the cervical cord at the fifth cervical vertebra level. We performed anterior cervical corpectomy and cyst was totally removed. The patient's neurological symptom was improved postoperatively. Neurenteric cyst located ventrally to the cervical spinal cord should be removed through anterior route for direct visualization of the relationship between the cyst wall and the spinal cord.

  • PDF

Partial-Thickness Rotator Cuff Tears

  • Shin, Keun-Man
    • The Korean Journal of Pain
    • /
    • v.24 no.2
    • /
    • pp.69-73
    • /
    • 2011
  • Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs.

Analysis of Response of Lumped Mass System Using Sensitivity Method in Frequency Domain (주파수 영역 민감도 방법을 이용한 집중 질량 구조물의 응답 해석)

  • Baek, Moon-Yeol;Kee, Chang-Doo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.14 no.10
    • /
    • pp.164-169
    • /
    • 1997
  • The aim of this paper is to present some results of sensitivity analysis in frequency domain. The sensitivity fonctions in frequency domain is not depend on the external excitation but depend on the frequency of the system's resonance. The sensitivity functions are determined as function of partial derivatives of system transfer functions taken with respect to system design parameters. The logarithmic sensitivity function is the dimensionless sensitivity funciton available, making it useful to compare the influence of various parameters on system variables. Two degree of fredom system is used to illustrate the procedure for sensitivity analysis proposed in this paper.

  • PDF

Partial Thickness Rotator Cuff Tears

  • Shin, Sang-Jin;Seo, Myeong-Jae
    • Clinics in Shoulder and Elbow
    • /
    • v.17 no.2
    • /
    • pp.91-100
    • /
    • 2014
  • Partial-thickness rotator cuff tear (PTRCT) is not single disease entity but one phase of disease spectrum. Symptoms of PTRCT vary from being asymptomatic to severe pain leading to deterioration in quality of life. Pathogenesis of degenerative PTRCT is multifactorial. Whereas articular sided PTRCT is usually caused by internal causes, both internal and external causes have important role in bursal sided PTRCT. A detailed history, clinical examination and magnetic resonance angiography are used in the diagnosis of PTRCT. Treatment of PTRCT is chosen based on age, demands of patients, causes and depth of tear. In most patients, non-operative treatment should be initiated. Whereas debridement can be done for less than 6 mm of articular sided PTRCT and in less than 3 mm of bursal sided PTRCT, repair techniques should be considered for higher grade PTRCT than that. Although the effect of acromioplasty is not clear, acromioplasty may be performed when the extrinsic causes appear to be the cause of tear. Either transtendon repair technique or repair after tear completion provided satisfactory clinical outcomes in treatment of articular sided PTRCT.

Efficacy of Integrated Korean Medicines in the Treatment of Partial Triangular Fibrocartilage Complex Tears: A Case Report

  • Jae-Joon Ha;Myeong-Yeol Yang;Ji-Sun Kim;Hong-Wook Choi;Gyu-Bin Lee;Dong-Ju Yoon;Dong-Jin Kim;Do-Young Kim
    • Journal of Acupuncture Research
    • /
    • v.40 no.4
    • /
    • pp.382-388
    • /
    • 2023
  • The triangular fibrocartilage complex (TFCC) is crucial for stabilizing the ulnar side of the wrist but can be partially torn due to degenerative changes, falling, or sudden injuries. However, only a few studies have focused on the use of Korean medicine treatments for TFCC-related wrist pain. This case report presents the successful outcomes of integrated Korean medicine treatment in a patient with a partial TFCC tear. The diagnosis was confirmed via magnetic resonance imaging, which revealed the tear. Subsequently, the patient received integrated Korean medicine treatments. The assessment of the pain scale scores revealed a significant reduction in wrist pain and an improvement in daily life activities. Based on the findings of this study, integrated Korean medicine treatments have been proven to be an effective treatment option for patients with a partial TFCC tear. However, further research is needed to determine the potential benefits and mechanisms of these treatments in managing TFCC-related wrist pain.

A Rathke's Cleft Cyst Presenting with Apoplexy

  • Kim, Ealmaan
    • Journal of Korean Neurosurgical Society
    • /
    • v.52 no.4
    • /
    • pp.404-406
    • /
    • 2012
  • The occurrence of symptomatic pituitary hemorrhage into a Rathke's cleft cyst (RCC) is extremely rare. The author reports an interesting case of intra- and suprasellar RCC presented with features of pituitary apoplexy. This 62-year-old woman suffered acute headache, mental confusion, and partial hypopituitarism. The characteristics of the magnetic resonance imaging seemed most compatible with a hemorrhagic pituitary adenoma. Transsphenoidal drainage of the cyst contents confirmed the diagnosis of hemorrhagic RCC and resolved the symptoms. All published data on this rare clinical entity are extracted and reviewed.

Global Bifurcations in the Asymmetric Vibrations of a Circular Plate (원판의 비대칭진동의 대역분기해석)

  • 여명환;이원경
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2003.11a
    • /
    • pp.504-514
    • /
    • 2003
  • We investigate global bifurcation in the subharmonic motion of a circular plate with one-to-one internal resonance. A system of autonomous equations are obtained from the partial differential equations governing the system by using Galerkin's procedure and the method of multiple scales. A perturbation method developed by Kovacic and Wiggins is used to find Silnikov type homoclinic orbits. The conditions under which the orbits occur are obtained.

  • PDF

The Study on the ZVS Half-Bridge Converter (영전압 스위칭 하프브리지 컨버터에 관한 연구)

  • Go, S.M.;Kim, Y.;Baek, S.H.;Yoon, S.H.
    • Proceedings of the KIEE Conference
    • /
    • 1998.11a
    • /
    • pp.150-152
    • /
    • 1998
  • ZVS Half-Bridge converter is proposed. This converter is operating in fixed switching frequency to regulate output voltage. The ZVS is maintained by Partial resonance during the OFF interval of both switches. Using self-driven synchronous rectifier, this circuit minimizes the Power loss in the rectification circuit. 50[W] ZVS Half-Bridge converter is simulated and built. Two results has been compared.

  • PDF

Three-Dimensional Volume Analysis of Partial Avascular Necrosis after Talar Neck Fracture (거골 경부 골절 이후 발생한 부분적인 골괴사의 3차원 부피 분석)

  • Na, Woong Chae;Lee, Jun Young;Park, Sang Ha;Park, Hyung Seok
    • Journal of Korean Foot and Ankle Society
    • /
    • v.19 no.4
    • /
    • pp.161-164
    • /
    • 2015
  • Purpose: The purpose of this study is to define the geographic patterns of partial avascular necrosis (AVN) of the talar body and to determine whether there were any predictors of both the location and occurrence of partial AVN. Materials and Methods: Nineteen patients with fracture of the talar neck treated by open reduction and internal fixation and followed up for more than 1 year were analyzed. The radiographs were examined 6 to 8 weeks after the operation for Hawkins sign and if it was not observed, magnetic resonance scans were performed. The three-dimensional analysis was performed using Mimics 17.0 (Materialise). The incidence of collapse and time to operative intervention was recorded. Results: Partial AVN of the talar body was observed in six out of 19 patients. The avascular segment of the talar body was located predominantly in the anterolateral portion. The average volume of the avascular segment was $289mm^3$, and it occupied 1% of total volume of the talus, and 10% of the talar dome. Collapse occurred in one patient in the area of the avascular process. There were no observable trends with regard to Hawkins classification, incidence of collapse, or time to operative intervention to the location of the avascular segment. Conclusion: Partial AVN can occur after fracture of the talar neck. The predominant location of the avascular segment was the anterolateral portion of the talar body. This information may be helpful to understanding the process of avascular necrosis of the talar body.

The Seizure Outcome and Extent of Hippocampal Resection in Anterior Temporal Lobectomy (전측두엽 절제술시 해마체 절제 범위와 경련 예후)

  • Lee, Wan Su;Lee, Jung Kyo;Lee, Sang Am;Kang, Jung Ku;Ko, Tae Seong
    • Journal of Korean Neurosurgical Society
    • /
    • v.29 no.12
    • /
    • pp.1650-1656
    • /
    • 2000
  • Objective : Little consensus exists concerning which temporal lobe structures need to be resected or how much resection should be done during hippocampal resection. The purpose of this study is to identify whether the extent of hippocampal resection influences seizure after anterior temporal lobectomy. Materials and Methods : The extent of hippocampal resection was assessed in 96 patients who underwent temporal lobectomy for medically intractable complex partial seizures originating from a unilateral seizure focus in the anteromesial temporal lobe. Patients who had structural lesion were excluded from the study. Postoperative magnetic resonance imaging in the coronal and saggital planes were used to quantify the extent of the hippocampal and lateral cortical resection. The patients were divided into two groups. Patients who underwent hippocampal resection to the level of the cerebral peduncle were included in the partial resection group, and those who had resection to the level of the colliculus were assigned to total resection group. Seizure outcomes were defined according to the Engel classification and compared between the two groups. Neuropsychologic outcomes in the selected cases were reviewed. Results : The over-all seizure-free outcome(Engel classification 1) was accomplished in 75%(72/96) of the patients (mean duration of follow-up, 36.8 months). The total hippocampectomy group had a statistically superior seizure outcome than the partial hippocampectomy group(87.3% versus 58.5% seizure-free, p-value=0.001). Also, younger patients had a more favorable outcome. Other variables such as laterality, the extent of lateral cortical resection, age at onset and gender were not significant. The pre- and postoperative memory functions were evaluated in 24 patients. A worse postoperative memory outcome was associated with partial hippocampectomy. However this was not acceptable due to a former bias. Conclusion : The result of this study conforms that aggressive hippocampectomy resulted in a better seizure outcome.

  • PDF