• Science of Emotion and Sensibility
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• v.27 no.3
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• pp.61-70
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• 2024

This study aimed to investigate the effects of voluntary intrathoracic pressure adjustment during the Valsalva maneuver (VM) on changes in prefrontal brain function and cerebral blood flow dynamics using diagnostic ultrasound and near-infrared spectroscopy (NIRS). Sixteen healthy adults performed VM by adjusting their expiratory pressure. Their regional oxygen saturation (rSO2) and oxidized hemoglobin (HbO) levels were measured to confirm changes in prefrontal lobe function. To confirm hemodynamic changes in cerebral blood vessels, this study measured peak systolic velocity (PSV), heart rate (HR), vascular stiffness (STIFF), and pulse wave velocity (PWV) in the common carotid artery before and after the VM. Results showed significant cerebrovascular physiological changes after 30mmHg VM. In particular, PSV increased significantly following VM, whereas PWV and STIFF significantly decreased. A similar trend was observed in 40mmHg VM to 30mmHg, but no significant change was observed except for HR, which showed a significant decrease. Furthermore, rSO2 tended to increase in the prefrontal region after preforming 30 and 40mmHg VM, but it did not show a significant difference. In contrast, HbO significantly decreased after performing 30 and 40mmHg VM. This trend did not show any difference depending on intrathoracic pressure. In conclusion, VM performance at both intrathoracic pressure levels has the same effect on brain function, but induces difference changes in cerebrovascular vessels' physiological function. Thus, at 40mmHg VM, it interferes with effective vascular relaxation due to high intrathoracic pressure. However, 30mmHg VM has an effective effect on cerebrovascular function by causing a significant increase in the elasticity of arterial blood vessels. Such VM performance can effectively improve cerebrovascular function.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.723-727
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• 1996

An adequate exposure is important in thoracoscopic procedures. The insufflation of $CO_2$has been demonstrated to aid in compressing lung parenchyma, and act as a retractor when combined with changes in patient's position. However, a recent study demonstrated that $CO_2$insufflation during thoracoscopy in the pig has adverse hemodynamic consequences. We prospectively studied 12 patients undergoing thoracoscopy to evaluate the effect of $CO_2$insufflation in the clinical setting. The mean arterial pressure, heart rate, central venous pressure, arterial oxygen saturation, and end-tidal $CO_2$pressure were monitored. Measurements were determined at baseline, at the initiation of one-lung ventilation, and at intrapleural pressure of 5, 10, 15 mmHg and following results were obtained. 1) The insufflation of 5 to 15 mmHg of $CO_2$had no significant effect on the mean arterial pressure, heart rate, arterial oxygen saturation. 2) The end-tidal $CO_2$pressure rose from 31.00$\pm$1.67 mmHg to 38.49$\pm$1.82 mmHg at an intrapleural pressure of 15 mmHg(p<0.05). 3) The central venous pressure rose from 7.75$\pm$0.76 mmHg to 12.83$\pm$1.64 mmHg and 16.16$\pm$l.97mmHg at an intrapleural pressure of 10 and 15 mmHg(p<0.05). 4) The low pressure (<10 mmHg) insufflation is a safe adjunct to the conduct of thoracoscopic surgical procedures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.148-151
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• 2010

심장관련 질환은 현대사회에서 업무 과중과 스트레스에 의해 발병 가능성이 높아지고 있으며, 일상생활 중 건강상태를 지속적으로 모니터링하여 심장질환 관련 응급상황에 대처하기위한 많은 연구들이 수행되고 있다. 본 연구에서는 가정 또는 사무실에서 무구속적인 방법으로 지속적인 심장 활동상태의 모니터링이 가능한 무구속 의자형 심탄도 계측 시스템을 구현하였다. 구현된 시스템에서 계측된 심탄도 신호로부터 건강모니터링을 위한 특징성분을 검출하기위해 웨이브렛 변환과 템플릿 매칭을 혼합한 신호처리방법을 제안하였다. 또한 적응 문턱치를 통해 심탄도 신호에서 심박동을 검출하였으며 심박동의 간격으로부터 HRV(heart rate variabillity)를 계산하였다. 구현된 시스템의 성능평가를 위하여 심전도와 동시에 심탄도를 측정하였으며, 두 신호로부터 심박동 검출 성능을 비교하여 구현된 무구속 의자형 심탄도 계측 시스템의 유용성 및 무자각 건강모니터링의 가능성을 확인하였다. 또한 스트레스에 따른 HRV의 변화를 관찰하기 위하여 피실험자로부터 인위적으로 숨을 참고 강제호기를 통해 흉강내압을 증가시켜 인위적인 육체적 스트레스를 가하는 발살바를 유도하였으며, HRV의 시간 및 주파수 영역에서 도출되는 파라미터들을 평가하여 심탄도 모니터링을 통해 안정 상태와 스트레스 상태의 판별 및 무구속 건강모니터링의 가능성을 평가하였다.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.441-446
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• 2001

Background: Electrical breathing pacing has many advantages over mechanical ventilation. However, clinically permanent diaphragmatic pacing has been applied to limited patients and few temporary pacing has been reported. Our purpose is to investigate the feasibility of temporary electrical diaphragm pacing in explothoracotomy canine cases. Methods: Five dogs were studied under the general anesthesia. Left 5th intercostal space was opened. Self designed temporary pacing leads were placed around the left phrenic nerve and connected to the myostimulator. Chest wall was closed after tube insertion with underwater drainage. Millar catheter was introduced to the aorta and right atrium. Swan-Ganz catheter was introduced to the pulmonary artery. When the self respiration was shallow with deep anesthesia, hemodynamic and tidal volume were measured with the stimulator on. Results: Tidal volume increased from 143.3$\pm$51.3 ml to 272.3$\pm$87.4 ml(p=0.004). Right atrial diastolic pressure decreased from 0.7$\pm$4.0 mmHg to -10.5$\pm$4.7 mmHg(p=0.005). Pulmonary arterial diastolic pressure decreased from 6.1+2.5 mmHg to 1.2$\pm$4.8 mmHg(p<0.001). The height of water level in chest tube to show intrathoracic pressure change was from 10.3$\pm$6.7cmH$_{2}$O to 20.0$\pm$5.3 cmH$_{2}$O. Conclusion: Temporary electrical diaphragmatic pacing is a simple method to assist respiration in explothoracotomy canine cases. Self designed pacing lead is implantable and removable. Negative pressure ventilation has favorable effects on the circulatory system. Therefore, clinical application of temporary breathing pacing is feasible in thoracotomy patients to assist cardiorespiratory function.