• Title/Summary/Keyword: thermal stimulation

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Measurement of Internal Temperature Distribution for the Evaluation of Focused Ultrasound (FUS) Stimulation Devices (집속초음파 자극기의 성능평가를 위한 팬텀 내부온도 측정)

  • Doh, Il;Joe, Daniel J.;Kim, Sung Mok;Baik, Kyung Min;Kim, Yong Tae;Park, Seung Min
    • Journal of Biomedical Engineering Research
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    • v.43 no.3
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    • pp.147-152
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    • 2022
  • This research is to measure real-time temperature distribution inside a tissue-mimicking phantom for the safety and effectiveness evaluations of focused ultrasound (FUS) device capable of linear scanning stimulation. Since the focusing area of the FUS stimulation device is smaller than diameter of conventional thermal probe and keeps moving, it is impossible to monitor temperature distribution inside the phantom. By using the phantom with a thin film temperature sensor array inserted, real-time temperature change caused by the FUS device was measured. The translation of the measured temperature peak was also tracked successfully. The present phantom had been experimentally proven to be applicable to validate the performance and safety of the therapeutic ultrasound devices.

Diagnostic Technique for Cast Resin Molded Transformer Windings Using Active Thermography

  • Lim Young-Bae;Jung Jong-Wook;Jung Jin-Soo;Cho Seong-Won
    • Journal of Electrical Engineering and Technology
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    • v.1 no.3
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    • pp.376-380
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    • 2006
  • Temperature distribution measured to estimate the condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current temperature. Because of passive thermography, without the external thermal stimulation, the difference in surface temperature between the region of interest and back ground shows that the results can apply only to the estimation or the monitoring for the condition of loose terminal and the overload pertaining to the rise in temperature. However, a thermal diffusion in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents a nondestructive test using this behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

Diagnostic Technique for Mold Transformer Windings using Thermal Image (열화상을 이용한 몰드변압기 권선표면 진단)

  • Lim, Y.B.;Jung, J.W.;Jung, J.S.;Ko, W.S.
    • Proceedings of the KIEE Conference
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    • 2005.11c
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    • pp.107-109
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    • 2005
  • Temperature distribution measured to estimate condition of an electrical apparatus is an absolute reference for the apparatus conditions and the difference between the reference temperature and the current one. Because a passive thermography without the external thermal stimulation shows the difference in surface temperature between the object and back ground, the results can apply only to the estimation or the monitoring for the condition of terminal loose and the overload pertaining to the rise in temperature. However, a thermal flow in the active thermography is differently generated by the structure and condition of the surface and subsurface. This paper presents the nondestructive testing using the behavior and deals with the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

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Characteristics of time-resolved optically stimulated luminescence (OSL) on Paleolithic paleosol quartz (구석기 고토양층 석영의 시간분해 광자극 냉광 특성 연구)

  • Hong, Duk-Geun;Kim, Ki-Bum;Kim, Myung-Jin
    • Analytical Science and Technology
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    • v.31 no.1
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    • pp.7-13
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    • 2018
  • In this study, we measured the time-resolved optically stimulated luminescence (TR-OSL) of Paleolithic paleosol quartz and evaluated its lifetime. Considering the lifetime dependence on the preheating applied after irradiation, the radiation exposure, and the optical pulse stimulation, we found that the optimum measurement condition for determining the lifetime of paleosol quartz was the optical pulse stimulation at a dwelling time of $250{\mu}s$, pulse width of $10{\mu}s$, and sweep number of 100,000, without preheating after 100 Gy of irradiation. Based on the dependence of the lifetime on the reading temperature, the thermal quenching activation energy ${\Delta}E$ and thermal assistance activation energy $E_a$ were evaluated as $0.60{\pm}0.14eV$ and $0.053{\pm}0.029eV$, respectively. These values were in good agreement with those reported in the literature. Therefore, we concluded that the resulting kinetic parameters for paleosol quartz are quite reliable.

A Study on the Stimulation Transmit of Langmuir Films (Langmuir 막의 자극 전달에 관한 연구)

  • 전동규;이경섭;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.113-117
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    • 1995
  • The mechanism of the displacement current generation for stimulation transmit observed in the present displacement current measurement and theoretically analysed. The orientational change of molecules in monolayers was discussed on the basis of the Maxwell-displacement-current obtained. Maxwell displacement current was generated from monolayers on a water surface by monolayerr compression, and it measuring technique has been applied to the study of monolayers of Dipalmitoylphosphatidyl choline (L-${\alpha}$-DPPC). Finally, We measured that differential thermal analysis(DTA) of sample. Displacement current was generated when the area per molecule about 180${\AA}$$^2$in low pressure, and it was generated when the area per molecule about 110${\AA}$$^2$in high pressure. A result of DTA was showed that temperature at 124.6$^{\circ}C$.

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The Applications of the Duplex Stainless Steel as Hyperthermia Materials

  • Kim, Young-Kon
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.7.1-7.1
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    • 2009
  • The use of Duplex stainless steel as a thermo-implant categorizes into two clinical applications: hyperthermia and thermal ablation or destruction. The goal of hyperthermia is to destroy the heat-sensitive abnormal cells and minimize normal cell death maintaining heat between $42^{\circ}C$ and $46^{\circ}C$. Thermal ablation takes place when the local tissue temperature increases greater than $46^{\circ}C$. This elevated temperature denatures protein irreversibly resulting cellular death. The author introduced several thermo-implants such as thermo-rod, thermo-stent, thermo-coil and thermoacupuncture-needle. Those thermo-implants are made of duplex stainless steel which can produce regulated heat by itself within an induction magnetic field. Thermal ablation characteristics of the thermo-rod on tumor hyperthermia depend on configurations of the thermo-rods and the magnitude of the induction magnetic strength. The exothermic properties of the thermo-implants can be characterized using the calorimetric test and the heat affected zone(HAZ) analyses in vitro. Thermal radiation studies using thermo-coils and thermo-stents show the capability of the occlusion of animal blood vessels and inhibiting the proliferation of the abnormal smooth muscle cell growth and inflammatory cell reactions maintaining the heat between $42^{\circ}C$ and $46^{\circ}C$ minimizing a normal cell death in the study on external iliac artery of the New Zealand White (NZW) rabbit. Thermal stimulation study using thermo-acupuncture needles suggests the potential applications of the automated acupunctural therapies.

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Non-Thermal Atmospheric-Pressure Plasma Possible Application in Wound Healing

  • Haertel, Beate;von Woedtke, Thomas;Weltmann, Klaus-Dieter;Lindequist, Ulrike
    • Biomolecules & Therapeutics
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    • v.22 no.6
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    • pp.477-490
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    • 2014
  • Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

The Role of Somatostatin in Nociceptive Processing of the Spinal Cord in Anesthetized Cats

  • Jung, Sung-Jun;Park, Joo-Min;Lee, Jun-Ho;Lee, Ji-Hye;Kim, Sang-Jeong;Kim, Jun
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.4
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    • pp.365-373
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    • 1999
  • Somatostatin (SOM) is one of the major neuropeptides in dorsal root ganglion cells, but its role in spinal nociceptive process has not been well known. In present study we aimed to investigate the effect of SOM on the response of dorsal horn neurons to the various types of peripheral nociceptive stimuli in anesthetized cats. Using carbon-filament microelectrode, the single cell activities of wide dynamic range neurons were recorded from the lumbosacral enlargement after noxious mechanical (squeeze), thermal (radiant heat lamp) and cold (dry ice) stimulation to the receptive field. Sciatic nerve was stimulated electrically to evoke $A\;{\delta}-$ and C-nociceptive responses. SOM analogue, octreotide $(10\;{\mu}g/kg),$ was applied intravenously and the results were compared with those of morphine (2 mg/kg, MOR). Systemic SOM decreased the cellular responses to the noxious heat and the mechanical stimulation, but increased those to the cold stimulation. In the responses to the electric stimuli of sciatic nerve, $A\;{\delta}-nociceptive$ response was increased by SOM, while C-nociceptive response was decreased. On the other hand, MOR inhibited the dorsal horn cell responses to all the noxious stimuli. From the above results, it is concluded that SOM suppresses the transmission of nociceptive heat and mechanical stimuli, especially via C-fiber, while it facilitates those of nociceptive cold stimuli via $A\;{\delta}-fiber$.

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A Neuroanatomical and Neurophsiolgical basic Study on the Mechanism of Acupuncture in central nervous system (침자기전(鍼刺機轉)의 중추신경계(中樞神經系)에서의 신경해부(神經解剖).생리학적(生理學的) 기초연구(基礎硏究))

  • Kim, Jeong-Heon
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.514-550
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    • 1996
  • There are many theory in acupuncture mechanism, so we must know the detail contents. and then we can use the acupuncture as we know. the follow article will be helpful in this part. 1. Spinal cord are role in intermediate part in somatosensorypathway also in acupuncture stumulating tract 2. Acute pain pathway started in laminae I, V of gray colmn, next are the spinothalamic tract(trigeminal spinothalamic tract in above neck part) and then go to the specific thalamic nucleus. but chronic pain in laminae II, III, VI, VII, next are spinoreticular tract(trigeminal spinoreticular tract in the neck part) and finally to the nonspecific thalamic nucleus. 3. Thalamus is very important area in somatosensory stimuation including acupuncture stumulating sensory also as a pain control center. but except this, there are Hypothalamus, Limbic system Cerebral cortex and Cerebellum as intermediator. as we Know hypothalamus is related to the emotional analgesic system with a limbic system. 4. A ${\delta$ fiber has relationship in Acute, sharp and initial pain, contrary this C fiber is related with Chronic, dull and last pain. 5. In Acupuncture mechanism of pain analgesia, there are two theory, one is gate control theory as large fiber another is stimuation produced analgesia as small diameter fier. 6. In DNIC, the stimulation sources are mechanical, thermal, heating, pain and acupuncture stimulation etc. we call these as a Heterotopic Noxious Stimulation. 7. In DNIC, SRD(Subnucleus reticularis dorsalis)is core nucleus in pain imtermediated analgesic mechanism. 8. Takeshige insisted nonacupuncture point dependent analgesic mechanism and acupuncture point dependent analgesic mechanism. and protested that Stimulation acupuncture piing evoke blocking nomacupuncture point analgesic pathway.

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Hydrate Production Performance Analysis with Multi-Well, Plate-Type Apparatus Using Depressurization and Thermal Methods (다중공 평판형 장비를 이용한 감압법과 열자극법에 의한 하이드레이트 가스 생산성 분석)

  • Lee, Youngsoo;Wang, Jihoon;Park, Jungkyoon;Sung, Wonmo
    • Korean Chemical Engineering Research
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    • v.47 no.1
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    • pp.133-140
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    • 2009
  • This paper presents the experimental study to analyze the pressure and production behavior using depressurization and thermal methods in order to evaluate the hydrate productivity in the 2-D multi-well, plate-type apparatus which has 80 md permeability and 30% hydrate saturation. Injecting methane gas through multi-well allowed to set up the highly saturated hydrate system and combining two different sorts of sands made possible to build up the low permeability system. In this system, both depressurization and electric stimulation methods were applied. When operating pressure was low, according to the depressurization experiments results, the gas recovery was high, however strong pulses which appeared at initial stage of production would damage the operation system. Moreover, cases that hydrate reformed have occurred by endothermic reaction. We have conducted experiments four and six times for the depressurization magnitudes of 140 psi and 320 psi, respectively, to analyze production behavior for the method more in detail. For the cases that the depressurization magnitude was set as 140 psi, the unstable period appears in the results, but stabilized soon. In the experiment results for 320 psi the discontinuous and intermittent behavior has been observed. Thermal stimulation experiments was conducted with depressurizing 80 psi which is the case that shows stable behavior and low recovery. In the results, the gas recovery was high and the energy efficiency was low for long stimulating time. The energy efficiency and gas recovery increased for the soaking time of 1 minute after 2 minute-preheating. In the cases of which the soaking time exceeds 1 minute, energy loss by long soaking time caused low gas recovery and poor energy efficiency.