• 제목/요약/키워드: Neck mechanism

검색결과 132건 처리시간 0.019초

마그네슘 소재를 이용한 차량용 시트의 충격 흡수 기구 개발 (Development of an Energy Absorbing Mechanism for Car Seat using Magnesium Alloys)

  • 신현우;박준규;이규형
    • 한국자동차공학회논문집
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    • 제19권5호
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    • pp.67-75
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    • 2011
  • A new energy absorbing mechanism for car seat was developed to reduce the neck injury in rear impacts. Energy absorbing principle is based on the shear-bolt behavior of thin-walled cast components subjected to static and dynamic loads. Results of shear bolt test using AM60 of Mg alloys showed robust behavior giving an approximately constant mean force during failure processes. Simply designed energy absorbing mechanism was assembled with the recliner between seat backs and seat rails. We have simulated the sled test of seat with dummy under the rear end impact using the finite element method. Results of simulation show that the new seat mechanism reduces thorax acceleration to a considerable extent, but it is not sufficient to mitigate neck injury indices e.g. neck shear force, neck tension force and NIC. With heightened headrest and narrowed backset, the energy absorbing mechanism resulted in good performance of protecting the neck injuries.

Outcomes of open neck injuries

  • Noh, Dongsub;Choi, Jin Ho
    • Journal of Trauma and Injury
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    • 제35권3호
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    • pp.168-172
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    • 2022
  • Purpose: The neck is a particularly critical region for penetrating injuries due to the close proximity of the trachea, esophagus, blood vessels, and the spinal cord. An open neck injury has the potential for serious morbidity and mortality. The purpose of this study is to evaluate the assessment and management of open neck injuries. Methods: In this retrospective study, open neck injury patients who were admitted to the Trauma Center of Daejeon Eulji Medical Center, Eulji University between December 2015 and December 2017 were analyzed for epidemiology, the mechanism of trauma, the injured organ, complications, and mortality. Results: Thirty-two patients presented with open neck injuries. All patients underwent computed tomographic angiography to evaluate their injuries once their vital signs stabilized. Among these patients, 27 required surgical treatment. The most commonly injured organ was the airway. There were five deaths, and the main cause of death was bleeding. Mortality was associated with the initial systolic blood pressure at the hospital and Glasgow Coma Scale. Conclusions: Mortality from open neck injuries was associated with initial systolic blood pressure at the hospital and Glasgow Coma Scale.

두경부암에서 면역회피 기전과 면역항암제 치료 (Immune Evasion Mechanism as a Guide for Immunotherapy in Head and Neck Cancer)

  • 장현
    • 대한두경부종양학회지
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    • 제33권1호
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    • pp.1-5
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    • 2017
  • 두경부 편평상피세포암은 전세계적으로 6번째로 흔하며 예후가 불량한 암종이다. 면역 감시는 두경부암의 발생과 진행을 억제하는 중요한 기전으로 알려져 있다. 두경부암세포는 면역 감시를 T세포의 관용을 유도하거나 체크포인트를 통한 T세포 기능을 억제하는 등의 방법으로 회피할 수 있다. 한편 진행성 두경부암 임상연구에서 체크포인트 억제제는 명확한 항종양효과를 입증하였다. 이처럼 면역항암제가 중요한 암치료 방법으로 떠오르는 이때에 본 종설은 두경부암의 면회회피 기전 및 임상적용근거에 대한 최근 지식을 정리하였다.

폐쇄성 수면 무호흡증의 병인 및 기전 (Pathogenesis and Mechanism of Obstructive Sleep Apnea)

  • 최지호;이승훈;신철
    • 수면정신생리
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    • 제12권2호
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    • pp.105-110
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    • 2005
  • The pathogenesis and mechanism of obstructive sleep apnea (OSA) has been under investigation for over 25 years, but its etiology and mechanism remains elusive. Skeletal (maxillary and/or mandibular hypoplasia or retrodisplacement, inferior displacement of hyoid) and soft tissue (increased volume of soft tissue, adenotonsillar hypertrophy, macroglossia, thickened lateral pharyngeal walls) factors, pharyngeal compliance (increased), pharyngeal muscle factors (impaired strength and endurance of pharyngeal dilators and fixators), sensory factors (impaired mechanoreceptor sensitivity, impaired pharyngeal dilator reflexes), respiratory control system factors (unstable respiratory control) and so on facilitate collapse upper airway. Therefore, OSA may be a heterogeneous disorder, rather than a single disease entity and various pathogenic factors contribute to the OSA varies person to person. As a result, patients may respond to different therapeutic approaches based on the predominant abnormality leading to the sleep-disordered breathing.

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Mechanical properties of top neck mollusks shell nano composite in different environmental conditions

  • Masir, Amin Nouroozi;Darvizeh, Abolfazl;Zajkani, Asghar
    • Advances in materials Research
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    • 제7권3호
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    • pp.185-194
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    • 2018
  • The mechanism of biological materials structure is very complex and has optimal properties compared to engineering materials. Top Neck mollusks shells, as an example of biological materials, have hierarchical structure, which 95 percent of its structure is Aragonite and 5 percent organic materials. This article detected mechanical properties of the Top Neck mollusks shell as a Nano composite using Nano-indentation method in different situations. Research findings indicate that mechanical properties of the Top Neck mollusks shell including elastic modulus and hardness are higher than a fresh one preserved in -50 centigrade and also a Top Neck mollusks shell preserved in environmental conditions. Nano-indentation test results are so close in range, overall, that hardness degree is 3900 to 5200 MPa and elastic modulus is 70 to 85 GPa.

갑상선 수술 중 반회후두신경의 손상 기전에 따른 신경 감시술의 효용성 (Effectiveness of Intraoperative Neuromonitoring According to the Mechanism of Recurrent Laryngeal Nerve Injury During Thyroid Surgery)

  • 신성찬;이병주
    • 대한두경부종양학회지
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    • 제36권1호
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    • pp.9-14
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    • 2020
  • Visual identification of recurrent laryngeal nerve (RLN) is considered as a gold standard of RLN preservation during thyroid surgery. Intraoperative neuromonitoring (IONM) is classified into the intermittent type and continuous type and helps surgeons identify the functional integrity of RLN and predict the postoperative vocal cord function. RLN injury during thyroid surgery is associated with tumor factors and surgeon factors. Tumor factors mean such as direct tumor invasion, adhesion of RLN to the tumor, and compression by a large thyroid tumor. Surgeon factors include nerve transection, stretching, thermal injury, and ligation injury. A recent meta-analysis reported that the IONM could reduce the RLN injury. Considering various nerve injury mechanism, we suggest that using both I-ONM and C-IONM together is more effective method in preventing nerve damage than using I-IONM alone.

실험적 해석을 위한 머리-목 형태의 더미 개발 (Development f head-neck complex dummy for experimental study)

  • 김영은;남대훈;고창훈
    • 대한기계학회논문집A
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    • 제21권7호
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    • pp.1058-1072
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    • 1997
  • A head-neck complex dummy, for measuring brain pressure and reaction force in the cervical spine was developed for experimental study related in injury mechanism. Dummy comprised aluminium-casted head with water filled cavity for simulating brain and mechanical neck assembled with six motion segments. Several kinds of experiments (compression, bending, cyclic modulus, relaxation and constant velocity profile) for the developed mechanical neck showed that this neck model is biomechanically reliable compared with in-vitro test results. As an application of developed head-neck complex dummy, shock absorbing properties of protective helmet was chosen. The experiments showed that the maximum pressure increment of brain after impact was tolerable compared with the guide line for mild brain injury pressure (25psi). Constrast to this results, the reaction force in the neck was high enough to produce failure in the cervical spine.

Correlation between Muscular Fatigue and EMG Activity during the Prolonged Casual Computer Work

  • Cho, Won-Hak;Lee, Woo-Yong;Choi, Hyeon-Ki
    • 비파괴검사학회지
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    • 제29권3호
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    • pp.224-229
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    • 2009
  • An experimental study was conducted to investigate the effects of turtle neck syndrome, so called, on muscular fatigue and muscle activity. Six subjects (males) participated and performed the prolonged casual computer work in the study. EMG signals from six muscles of the dominant neck-back region were acquired and recorded for 10 seconds at the beginning and the end of three hours computer work. EMG was recorded from six muscles by using a computerized data recording and analysis system. Power spectrum function of EMG was calculated off-line by means of a signal processing software package. Power spectrum functions were smoothed with a moving average filter of 21 points and normalized with respect to the maximal value achieved during the trials. Muscle activity and median frequencies of Sternocleidomastoid(SCM) in turtle neck posture was approximately 51%, which were less than those in normal neck posture. SCM also showed the biggest decrease in median frequency. Results will provide the insight into the neck-back injury mechanism of turtle neck patients. Furthermore, they will be helpful in developing rehabilitation programs for restoring patients' neck-back functions.