• 제목/요약/키워드: Mechanical stimulation

검색결과 194건 처리시간 0.028초

전신진동이 골다공증이 유발된 쥐 해면골에 미치는 영향 - 골다공증 치료제 효과와 비교 (Effect of Whole Body Vibration on Osteoporotic Trabecular Bone of Rats - Compared with the Effect of Actonel)

  • 고창용;이태우;우대곤;김효선;김한성;이법이;임도형
    • 한국정밀공학회지
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    • 제25권5호
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    • pp.148-154
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    • 2008
  • Pharmacotherapy was mainly used to treat osteoporosis. However, some researches showed that pharmacotherapy could induce unexpected adverse effects. Some studies showed that whole body vibration affected beneficially osteoporosis. This paper studied the effect of whole body vibration fur osteoporosis compared with the effect of pharmacotherapy. 10 female rats were used and allocated into 4 group, CON, SHAM, DRUG, and WBV. Rats except SHAM group were ovariectomised to induce osteoporosis. Rats in WBV group were stimulated in whole body vibration at magnitude of $1mm_{peak-peak}$ and frequency 45Hz, for 8 weeks (30 min/day, 5 days/week). Rat in DRGU group was orally administered the Actonel (0.58mg/Kg), for 8 weeks (5days/week). The $4^{th}$ lumbar in rats were scanned at a resolution of $35{\mu}m$ at baseline, before stimulation, and 8 weeks after stimulation by In-vivo micro computed tomography. For detecting and tracking changes of biomechanical characteristics (morphological and mechanical characteristics) in lumbar trabecuar bone of rats, structural parameters were measured and calculated from acquiring images and finite element analysis was performed. In the results, loss of quantity and change of structure of trabecular bone in WBV group were smaller than those in both CON and SHAM groups. In addition, mechanical strength in WBV group was stronger than that in both CON and SHAM groups. In contrast, biomechanical characteristics in WBV group were similar with those in DRUG group. These results showed that reasonable whole body vibration was likely to treat osteoporosis and be substituted partly for drug treatment.

Fuzzy sliding-mode control of a human arm in the sagittal plane with optimal trajectory

  • Ardakani, Fateme Fotouhi;Vatankhah, Ramin;Sharifi, Mojtaba
    • ETRI Journal
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    • 제40권5호
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    • pp.653-663
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    • 2018
  • Patients with spinal cord injuries cannot move their limbs using their intact muscles. A suitable controller can be used to move their arms by employing the functional electrical stimulation method. In this article, a fuzzy exponential sliding-mode controller is designed to move a musculoskeletal human arm model to track an optimal trajectory in the sagittal plane. This optimal arm trajectory is obtained by developing a policy for the central nervous system. In order to specify the optimal trajectory between two points, two dynamic and static optimal criteria are applied simultaneously. The first dynamic objective function is defined to minimize the joint torques, and the second static optimization is offered to minimize the muscle forces at each moment. In addition, fuzzy logic is used to tune the sliding-surface parameter to enable an appropriate tracking performance. Simulation results are evaluated and compared with experimental data for upward and downward movements of the human arm.

저출력 레이저조사가 동통반응에 미치는 영향 (EFFECT OF LOW - POWER LASER IRRADIATION ON PAIN RESPONSE)

  • 김성교;윤수한;이종흔
    • Restorative Dentistry and Endodontics
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    • 제16권2호
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    • pp.85-98
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    • 1991
  • The aim of this study was to investigate the effect of low - power laser used in the medical field for various purposes to suppress pain responses evoked by noxious electrical or mechanical stimuli. After both inferior alveolar nerves and the left anterior digastric muscle of cats under general anesthesia were exposed, a recording electrode for the jaw opening reflex was inserted into the anterior digastric muscle. The right inferior alveolar nerve was dissected under a surgical microscope until the response of the functional single nerve could be evoked by the electrical stimulation of the dental pulp or oral mucosa. The electrical stimulus was applied with a rectangular pulse of 10 ms duration for measuring the threshold intensity of a single nerve fiber in the inferior alveolar nerve which responds to stimulation of dental pulp and oral mucosa. Then a pulse of 1 ms duration was applied for determination of conduction velocity. A noxious mechanical stimulus to the oral mucosa was applied by clamping the receptive field with an arterial clamp. The Ga-As diodide laser(wave length, 904 nm ; frequency, 1,000 Hz) was irradiated to the prepared tooth cavity, inferior alveolar nerve and oral mucosa as a pulse wave of 2 mW for 6 minutes. This was followed by a continuous wave of 15 mW for 3 minutes. The action potential of the nerve and EMG of the digastric muscle evoked by the noxious electrical stimulus and nerve response to noxious mechanical stimulus were compared at intervals of before, immediately after, and at 5, 10, 20, 40, 60 minutes after laser irradiation. The results were as follows: The conduction velocity of the intrapulpal $A{\delta}$- nerve fiber recorded from the inferior alveolar nerve before irradiation had a mean value of $6.68{\pm}2.07m/sec$. The laser irradiation did not affect the conduction velocity of the AS - nerve fiber and did not change the threshold intensity or amplitude of the action potential either. The EMG of the digastric muscle evoked by noxious electrical stimulation to the tooth was not changed by the laser irradiation, whether in latency, threshold intensity or amplitude. The laser irradiated to the receptive field of the oral mucosa which was subjected to noxious stimuli did not affect the amplitude of the action potential or the frequency either.

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토마토 육묘 시 물리적 자극 및 약제 처리가 묘의 소질과 수량에 미치는 영향 (Effects of Mechanical Stimulation and Chemical Treatments on Growth of Seedlings and Yield of Tomato)

  • 최영하;이한철;박동금;권준국;이재한
    • 원예과학기술지
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    • 제19권3호
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    • pp.320-324
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    • 2001
  • 고온기 토마토(cv. House-momotaro)육묘 시에 묘의 도장을 방지하기 위해 물리적 자극방법으로 Impedance와 Brushing 처리를, 화학약제로는 Diniconazole과 Hexaconazole을 이용하여 묘의 생육조절 효과 및 정식 후의 생육 및 수량에 미치는 영향을 조사하였다. Diniconazole 처리에 의해 육묘 시의 묘의 초장, 엽면적, 생체중 등이 감소되었다. Diniconazole I 처리구에서는 정식 후 생육이 억제되고 수량이 감소되었으나 Diniconazole II 처리구에서는 Control과 비슷한 생육과 수량성을 보였다. Hexaconazole 처리는 묘의 초장을 감소시키나 Diniconazole 처리에 비해 그 정도가 약하였다. 정식 후의 생육은 Control과 큰 차이가 없었으나 착과수가 적고 기형주 발생이 많아 수량이 적었다. Impedance 처리 또한 묘의 초장을 감소시켰으나 정식 후 수확개시기가 늦고 기형주 발생이 많아 수량이 적었다. Brushing 처리는 묘의 초장만 감소시킬 뿐 정식 후 생육 및 수량은 Control과 차이가 거의 없었다. 따라서 Diniconazole의 적절한 사용(Diniconazole II)과 Brushing 처리는 토마토의 수량을 크게 감소시키지 않고 묘의 도장을 억제시킬 수 있어 실용성을 기대할 수 있었다.

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역학적 강도 분석을 이용한 저강도 초음파의 조사 부위의 골다공증 골절 방지 효과 평가 (In vivo Evaluation of Osteoporotic Fracture Prevention of the site to which low Intensity Ultrasound is Irradiated using Mechanical Strength Simulations)

  • 우대곤;김치훈;박지형;고창용;김한성;김진만;김상희;임도형
    • 대한의용생체공학회:의공학회지
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    • 제30권2호
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    • pp.135-141
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    • 2009
  • Purpose: The aim of present study is to evaluate a possibility of clinical application for the effect of low intensity ultrasound stimulation (LIUS) in mechanical characteristics of bone on osteoporotic fractures prevention. Materials and Methods: Eight virgin ICR mice (14 weeks old, approximate weight 25g) were ovariectomized (OVX) to induce osteoporosis. The right hind limbs were then stimulated with LIDS (US Group), whereas left hind limbs were not stimulated (CON Group). Both hind limbs of all mice were scanned by in-vivo micro-CT to acquire two-dimensional (2D) images at 0 week before stimulation and 3 weeks and 6 weeks after stimulation. Three-dimensional (3D) finite element (FE) models generated by scanned 2D images were used to determine quantitatively the effect of LIUS on strength related to bone structure. Additionally, distributions of Hounsfield units and elastic moduli, which are related to the bone quality, for the bones in the US and CON groups were determined to analyze quantitatively a degree of improvement of bone qualities achieved by LIUS. Results: The result of FE analysis showed that the structural strength in US Group was significantly increased over time (p<0.05), while that in CON Group was statistically constant over time (p>0.05). High values of Hounsfield units obtained from voxels on micro-CT images and high values of elastic moduli converted from the Hounsfield units were dominantly appeared in US Group compared with those in CON Group. Conclusion: These finding indicated that LIUS would improve the mechanical characteristics of osteoporotic bone via the effects of bone structure (bone strength) and quality (Hounsfield unit and elastic modulus). Therefore, the LIUS may decrease effectively the risk of osteoporotic fracture in clinics.

흰쥐의 척수에서 Glutamate가 매개하는 Nociceptive Response에 있어서 Protein kinase C의 관련성 (The Involvement of Protein kinase C in Glutamate-Mediated Nociceptive Response at the Spinal Cord of Rats)

  • 김성정;박전희;이영욱;양성준;이종은;이병천;손의동;허인회
    • 약학회지
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    • 제43권2호
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    • pp.263-273
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    • 1999
  • When glutamate was infected intrathecally, the result is similar to those produced by TPA injected. The involvement of protein kinase C (PKC) in the nociceptive responses in rat dorsal horn neurons of lumbar spinal cord was studied. In test with formalin, a PKC inhibitor (chelerythrine) inhibited dose-dependently the formalin-induced behavior response. Neomycin also inhibited it significantly. But, a PKC activator (12-O-tetradecanoylphorbol-13-ester, TPA) showed reverse effect. When gluatamate was injected intrathecally, we observed the result is smilar to those produced by TPA injection. On the other hand, intrathecal injection of glutamate induced thermal and mechanical hyperalgesia. In Tail-flick test, we examined the involvement of PKC on the glutamate-indeced thermal hyperalgesia. Chelerythrine showed an inhibitory effect and TPA enhanced thermal response. Glutamate decreased the mechanical threshold significantly. A pretreatment of chelerythrine and neomycin inhibited glutamate-induced mechanical hyperalgesia, but the effect of neomycin was not significant. TPA had little effect on the mechanical nociceptive response. These results suggest that the PKC activation through metabotropic receptor at postsynaptic region of spinal cord dorsal horn neurons may influence on the persistent nociception produced by chemical stimulation with formalin, thermal and mechanical hyperalgesia induced by glutamate.

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복합재료 전극을 가진 전기활성고분자 구동기의 설계 (Design of an Actuator Using Electro-active Polymer (EAP) Actuator with Composite Electrodes)

  • 김동욱;장승환
    • Composites Research
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    • 제32권5호
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    • pp.211-215
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    • 2019
  • 정적인 상태인 체외 환경(in vitro)에서의 세포배양 과정은 실제 생체 내 환경에서의 세포발달과정과는 많은 차이가 존재한다. 따라서, 체내 환경의 정밀한 모사를 위해서는, 기계적인 자극을 세포에 전달하여 줄 수 있는 동적 세포배양장치가 필수적이다. 하지만 기존의 동적 세포배양장치에는 튜브, 펌프, 모터 등의 비교적 복잡한 장치들을 필요로 하였으며, 전달되는 기계적 자극도 단순한 형태였다. 본 연구에서는 단순한 장치로 구동되는 동적 세포배양장치를 위하여 전기활성고분자(EAP) 구동기를 동력원으로 하는 소형 동적 세포배양장치를 설계하였다. 이 장치는 다양한 기계적 자극을 세포에 전달하는 것이 가능하다.

Lymphotoxin β 수용체를 통한 fibroblastic reticular cell의 stress fiber 변화와 myosin의 연관성 (Alteration of Stress Fiber in Fibroblastic Reticular Cells via Lymphotoxin β Receptor Stimulation is Associated with Myosin)

  • 김민환;김연희;최우봉;이종환
    • 생명과학회지
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    • 제25권5호
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    • pp.585-593
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    • 2015
  • Stress fiber (SF) 변화는 세포외부의 결합인자와 세포 수용체와 결합후 리모델링을 위해 액틴골격에 신호를 전달하며 일어난다. 이 연관은 결합장소에서 기계적 활동과 신호전달활동을 조절하는 다양한 스케폴드들과 신호 전달자에 의해 매게된다. Heterotrimeric transmembrane lymphotoxin α1β2 (LTα1β2)는 용해성 homotrimeric LT α를 포함하는 tumor necrosis factor (TNF) 계로 림프조직을 구성하는데 중요한 역할을 한다. LTα1β2와 LTβR의 결합은 fibroblastic reticular cell (FRC)에서 신호전달을 촉발한다. Agonistic anti-LTβR antibody 단독 혹은 LTα 그리고 TNFα의 조합으로 LTβR 자극은 세포의 액틴과 형태적 변화를 보았다. Agonistic anti-LTβR antibody의 FRC에서 작용을 통한 세포골격 재배열이 myosin과의 관련성을 확인하기위해 myosin light chain kinase (MLCK)의 저해제인 ML-7과 myosin light chains (MLC)와 myosin phosphatase target subunit 1 (MYPT1)의 인산화에 대한 효과를 확인하였다. MLCK 저해는 액틴 세포골격 재배열과 세포형태 변화를 유도하였다. 또한, MLC와 MYPT1인산화가 LTβR 자극에 의해 줄어드는 것을 확인하였다. DNA chip 분석은 myosin and actin 구성선분이 전사체 수준에서도 줄어드는 것을 보였다. 결론적으로 LTβR 자극은 FRC에서 SF변화는 myosin과 관련되어 있다는 것을 제시한다.

관절통에 관한 동물모델에서 약침에 의한 기계적 자극에 대한 관절 감각신경 활동의 억제 (Inhibition of Articular Sensory Activities to Mechanical Stimulation by Aqua-acupuncture in an Animal Model of Arthritic Pain)

  • 심인섭;조형준;함대현;이혜정;이배환
    • 감성과학
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    • 제8권2호
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    • pp.155-160
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    • 2005
  • 본 연구는 관절통 모델에서 웅담 우황과 웅담 우황 사향의 약침액의 효과를 검사하기 위해 수행되었다. 할로탄 마취하에서 관절통은 수컷 쥐의 관절강내에 $2\%$ carrageenan을 주입하여 유발시켰다. 운동자극에 대한 감각신경의 반응은 약침을 시술하기 전과 후에 기록하였다. 경혈에 주입한 약침은 유해한 운동 자극에 대한 신경의 반응을 억제시켰다 족삼리에 시술한 약침은 합곡에 비해 유해한 자극에 대한 관절 감각신경의 반응을 더 많이 억제시켰다. 이러한 결과는 웅담 우황과 웅담 우황 사향의약침이 관절통을 완화하는 데 효과적인 치료법을 제공할 수 있다는 것을 시사한다.

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염증유발 백서에서 전침자극과 미세전류자극의 항-통각과민 효과 (Anti-hyperalgesic Effects of Electroacupuncture Combination of Microcurrent Stimulation in Rat with Induced Inflammation)

  • 김영필;이정우;서삼기;윤세원;윤희종;김태열
    • The Journal of Korean Physical Therapy
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    • 제19권1호
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    • pp.67-78
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    • 2007
  • Purpose: The purpose of this study were to examine the anti-hyperalgesic effects of combination of electroacupuncture and microcurrent on anti-hyperalgesia in local hyperalgesia zone. Methods: It used 24 rats for experiment, divided them into control group, electroacupuncture group (EA group), microcurrent group (MC group), combination of electroacupuncture with microcurrent (EA+MC group), caused hyperalgesia by injecting ${\lambda}-carrageenan$ into hindpaw. Thickness of hindpaw, mechanical pain threshold (MPT), thermal pain threshold (TPT), noxious flexion withdrawal reflex (NFR) and somatosensory evoked potential (SEP) were measured immediately after induction, at 24 hours, 48 hours and 72 hours after induction. The electrical stimulation was given once a day for three days, 20min per session. Results: Change of thickness, MPT, and TPT showed significant difference in all groups compared to control group. In particular, there were remarkable difference in EA+ME group. In particular there were remarkable differences in EA group and EA+MC group. Change of NFR(% threshold, % reaction time, % RMS) and SEP showed mainly significant differences in EA group and EA+ME group compared to control group. In particular, there were remarkable difference in EA+ME group. Conclusion: The above results suggest that appropriate combination of microcurrent with electroacupuncture for pain control will be very desirable.

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