• Journal of the Optical Society of Korea
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• 제13권1호
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• pp.166-170
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• 2009

NIRS (Near-infrared spectroscopy) is a relatively, new, non-invasive, and non-ionizing method of measuring hemodynamic responses in thick biological tissues such as the cerebral cortex. In this study, we measured the hemodynamic responses of the rat barrel cortex to whisker stimulation by using a frequency-domain NIRS system. We designed multiple optical probes comprising multi-mode optical fibers and manipulating arms, both of which can be easily applied to small animals. Various electrical stimulations were applied to rat whiskers at different voltage levels and stimulation frequencies. Our results show that the hemodynamic responses are highly dependent on the stimulation voltage level, and not so much on stimulation frequency. This paper suggests that NIRS technology is highly suitable for the study of small animal brains.

• 전기학회논문지
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• 제61권7호
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• pp.1049-1055
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• 2012

We measure the hemodynamic responses during the 4 kinds of tasks on the motor cortex in the right and left human brain by using near-infrared spectroscopy. The experimental results show that the change of concentration of oxy-hemoglobin is larger than that of deoxy-hemoglobin and the change of concentration of chromophores induced by finger and arm related task show more activations than that of leg.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.427-428
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• 2009

Optical imaging offers excellent spatio-temporal sensitivity that is unparalleled by any other perfusion based imaging techniques. We used in vivo optical recording of intrinsic signals (ORIS) to map neurovascular hemodynamics of perfusion, oximetry and membrane potential during epileptic events in rat and mouse neocortex. Studies of hemodynamic changes with ORIS alone were also performed in human. Laboratory studies in rodent epilepsy models have demonstrated a persistent increase in deoxygenated hemoglobin (Hbr) and a decrease in tissue oxygenation during interictal spikes and ictal events. This "epileptic dip", like the "initial dip" recorded during normal sensory processing, implies that the enormous rise in cerebral blood flow (CBF) is inadequate to meet the increased metabolic demands associated with synchronized epileptic activity. These findings are critically important to the interpretation of the perfusion-based imaging studies, such as fMRI. In addition, we visualized the effect of direct cortical electrical stimulation, an alterative epilepsy treatment. The optical data following direct cortical electrical stimulation showed that hemodynamic signals are sensitive to different electrical stimulation parameters. Furthermore, our recent data demonstrated that the application of unilateral electrical stimulation is able to elicit bilateral hemodynamic responses in rat neocortex.

• The Korean Journal of Pain
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• 제10권1호
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• pp.58-63
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• 1997

Background : Endotracheal intubation is one of the methods most securely establishing airway. But accompanying hemodynamic responses are harmful to coronary or cerebral vascular disease patients. These hemodynamic responses are regarded as the results of sympathetic stimulation due to pharyngolaryngeal stimulation, and sympathetic blocking method-stellate ganglion block- may be obtundate these hemodynamic responses. Methods : 75 patients of ASA physical status I-II were selected. There were 40 patients normotensive (Group I), 35 patients hypertensive (Group II) Group I, steliate ganglion block was performed on 20 patients (Group I-S) the remainder had no procedure (Group I-O). Group II, 18 patients received SG3 (Group II-S), 17 patients had no procedure (Group II-O). SGB was performed with 1% lidocaine 8 ml on right stellate genglion after patient's consent. Blood pressure (IIP) and pulse rate(PR) were first measured in the pre-anesthesia room. Follow up BP and PR are checked immediately following SGB and every 5 minutes for subsequent 20 minutes, then after arrival at operatig room, then immediately after intubation and at 3, 5, 10, 15 and 20 minutes after incubation. Results : All group experienced significantly increased blood pressure and pulse rate upon arrival at the pre-anesthesetic and opeating rooms, as compared to when patients rates in the ward. After intubation and for subsequent 5 minutes, significant changes were measured. Patients then recovered to preblock value. In Group I, no statistical significance was recorded between subgroup I-S and I-O. However in Group II, there were significant differences between sub-group II-S and II-O. In evaluating pulse rate changes, there were no significant differences between Group I-S and I-O; nor II-S and II-O. Conclusion : The proper diagnosis of Stellate Ganglion Block had some measure of protective effect on hemodynamics following endotracheal intubation, especially in hypertensive patients.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권4호
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• pp.195-202
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• 2020

Background: Nasotracheal intubation is the most commonly used method to secure the field of view when performing surgery on the oral cavity or neck. Like orotracheal intubation, nasotracheal intubation uses a laryngoscope. Hemodynamic change occurs due to the stimulation of the sympathetic nervous system. Recently, video laryngoscope with a camera attached to the end of the direct laryngoscope blade has been used to minimize this change. In this study, we investigated the optimal effect-site concentration (Ce) of remifentanil for minimizing hemodynamic responses during nasotracheal intubation with a video laryngoscope. Methods: Twenty-one patients, aged between 19 and 60 years old, scheduled for elective surgery were included in this study. Anesthesia was induced by slowly injecting propofol. At the same time, remifentanil infusion was initiated at 3.0 ng/ml via target-controlled infusion (TCI). When remifentanil attained the preset Ce, nasotracheal intubation was performed using a video laryngoscope. The patient's blood pressure and heart rate were checked pre-induction, right before and after intubation, and 1 min after intubation. Hemodynamic stability was defined as an increase in systolic blood pressure and heart rate by 20% before and after nasotracheal intubation. The response of each patient determined the Ce of remifentanil for the next patient at an interval of 0.3 ng/ml. Results: The Ce of remifentanil administered ranged from 2.4 to 3.6 ng/ml for the patients evaluated. The estimated optimal effective effect-site concentrations of remifentanil were 3.22 and 4.25 ng/ml, that were associated with a 50% and 95% probability of maintaining hemodynamic stability, respectively. Conclusion: Nasotracheal intubation using a video laryngoscope can be successfully performed in a hemodynamically stable state by using the optimal remifentanil effect-site concentration (Ce₅₀, 3.22 ng/ml; Ce₉₅, 4.25 ng/ml).

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2000년도 추계학술대회 및 정기총회
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• pp.19-19
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• 2000

Most renal diseases progress by consecutive cell responses such as hypertrophy, hyperplsia, proliferation, defferentiation, sclerosis, fibrosis and other cellular degenerative process. These cellular responses are mediated by the activation of various mitogens such as vasoconstrictors, growth factors, hormone, genotoxins and cytokines through mechanical, hemodynamic, immunological injury as well as metabolic abnormality. (omitted)

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.650-652
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• 2017

the aim of this study was to observe the combined effect of the CRT and LVAD on electromechanical cardiac behavior under LBBB and RBBB conditions computationally. We performed simulation by using advanced electromechanics model of failing ventricle combined with lumped model represents circulatory system, CRT and LVAD. We analyzed seven failing ventricle model including normal sinus rhythm, LBBB, LBBB coupled with CRT, LBBB coupled with CRT and LVAD, RBBB, RBBB coupled with CRT, and RBBB coupled with CRT and LVAD. We compared the effect from CRT and the effect from combined CRT and LVAD to both under LBBB and RBBB conditions. The results showed that the combined CRT and LVAD contributed a better hemodynamic compared to single CRT. This combined system synchronized the electrical activation greatly under LBBB and slightly under RBBB. It also shortened mechanical activation time which resulted short electromechanical delay. More importantly, the combined system produced better mechanical responses under both LBBB and RBBB conditions.

• Current Optics and Photonics
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• 제4권1호
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• pp.57-62
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• 2020

The selection of anesthetic agent is important in preclinical studies, since each agent affects the systemic hemodynamics in different ways. For that reason, we hypothesized that different anesthetic agents will result in different vaginal hemodynamic response and temperature during sexual arousal, in an animal model. To validate the hypothesis, animal experiments were performed using female rats with two anesthetic agents widely used in preclinical studies: ketamine and isoflurane. Our previously developed near-infrared-spectroscopy-based probe was used to measure the changes of oxyhemoglobin (OHb), deoxyhemoglobin (RHb), and total hemoglobin (THb) concentrations along with temperature from the animal vaginal wall. As a control, saline was administered to both isoflurane- and ketamine-anesthetized animals, and did not show any significant changes in OHb, RHb, THb, or temperature. However, an administration of apomorphine (APO, 80 ㎍/kg) induced increases of OHb (63 ± 28 μM/DPF), RHb (35 ± 20 μM/DPF), and THb (98 ± 49 μM/DPF) in ketamine-anesthetized animals, while decreases of OHb (52 ± 76 μM/DPF) and THb (38 ± 30 μM/DPF) and an increase of RHb (28 ± 51 μM/DPF) were found in isoflurane-anesthetized animals. The vaginal temperature decreased from the baseline in both ketamine-(0.42℃) and isoflurane-(1.22℃)anesthetized animals. These results confirmed our hypothesis, and suggest that a preclinical study monitoring hemodynamic responses under anesthesia should employ an appropriate anesthetic agent for the study.

• 한국엔터테인먼트산업학회논문지
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• 제13권2호
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• pp.197-205
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• 2019

최근 몇 년간 흡연율이 감소했지만, 흡연은 여전히 전 세계적으로 조기사망과 건강상의 문제를 일으키는 주요 요인 중 하나이다. 장기간의 흡연은 대동맥의 경직도를 증가시키는데, 혈관이 경직되면 심장에서 발생한 전진 맥파와 말초에서 심장으로 돌아오는 반사파의 속도가 빨라져서 반사파가 중심동맥에 일찍 도착하여 중심동맥의 수축기 맥압이 증가하게 되고 수축기 혈압이 상승하게 된다. 본 연구는 남성 흡연자와 비흡연자를 대상으로 심폐기능을 포함한 건강관련체력과 동맥경직도를 반영하는 파형증대지수와 맥파전달속도의 차이를 검증하고, 흡연자의 운동전 흡연습관에 따른 심폐기능과 동맥경직도에 미치는 반응을 비교하기 위하여 시행되었다. 연구 대상은 심폐질환이 없는 만 20세 이상 29세 이하 남성으로, 만 5년 이상 흡연한 흡연자 12명과 흡연 경험이 없는 비흡연자 12명으로 총 24명을 대상으로 하였다. 본 연구의 결과를 종합하여 볼 때, 젊은 성인들의 흡연습관은 동맥의 경직도를 예측할 수 있는 파형증가 지수와 맥파전달속도에는 영향을 주지 않는 것으로 나타났다. 또한 운동 참여 전 흡연에 따른 혈역학 반응과 동맥경직도에서도 두 집단 간 유의한 차이를 나타내지는 않았다. 하지만 생존율의 예언지표인 최대 산소섭취량은 흡연자가 비흡연자에 비해 유의하게 낮게 나타났다. 이는 흡연습관이 혈관의 노화가 일어나지 않은 젊은 성인에게는 동맥 경직도의 변화를 일으킬 만큼 영향을 주지는 않지만 인체의 산소 운반능력을 감소시켜 심폐기능의 저하가 진행되고 있음을 의미하는 것으로 판단된다.

• 감성과학
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• 제27권3호
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• pp.83-88
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• 2024

이 연구의 목적은 이완을 유도하는 향과 고농도 산소를 결합한 자극이 심리적/생리적 반응에 미치는 영향을 탐구하는 것이다. 같은 향 조건 하에서 산소 농도를 조절했을 때 나타나는 뇌혈류 반응과 각성도가 관찰되었다. 실험에 사용된 향은 라벤더 오일(이완 향)이었고, 산소 농도로는 일반 농도 산소(21%)와 고농도 산소(30%)가 사용되었다. 실험은 총 12명의 성인 남성을 대상으로 휴식 기간(5분)과 자극 기간(5분)을 반복하여 실시되었다. 뇌혈류 반응을 관찰하기 위해 비어-램버트(Beer-Lambert) 법칙에 따라 헤모글로빈(HbO) 농도가 추출되었다. 각성도는 5점 척도 설문지를 사용하여 평가되었다. 두 자극(라벤더+21%, 라벤더+30%) 간 비교를 위해 쌍체 t-검정이 실시되었다. 결과적으로 라벤더+30%에서 라벤더+21%에 비해 전두엽의 HbO 농도가 증가하고 각성도가 감소하였다. 이 결과들은 기존의 향 자극에 고농도 산소가 추가된 복합 자극이 더 많은 뇌 활성화와 이완을 유도할 수 있음을 시사한다.