• International Journal of Control, Automation, and Systems
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• 제3권1호
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• pp.100-108
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• 2005

This work presents a novel control index to regulate the pump speed of an axial flow blood pump for the left ventricular assist device (LVAD). The control index is based on the characterization of pump operating conditions such as normal or suction status. The pump operating characteristics reveal that a certain pulsatility relationship between the pump pressure difference and the pump flow is a unique index to identify the pump operating status under the diverse pump operating environments.

• 대한한방내과학회지
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• 제20권1호
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• pp.222-231
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• 1999

Uwhangchungsimwon(UC) has been used in the treatment of a wide variety of conditions including stroke, hypertension, arteriosclerosis, autonomic imbalance, mental instablity, etc in Korean traditional hospitals, In particular it is often initialy chosen for emergency care of acute stroke. The aim of this study was to evaluate the effect of UC on cerebral hemodynamics. Using transcranial Doppler ultrasound, we studied changes of mean flow velocity and pulsatility index(PI) of middle cerebral arteries (MCAs) from 11 health young volunteers who were administrated with 1 pill UC and 11 health controls who were not. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with breath-holding index(BHI). Systolic blood pressure, diastolic blood pressure, and heart rate were measured using ambulatory blood pressure monitoring(ABPM). In UC administration group, the evaluation was performed during basal condition. and repeated at 20, 40, and 60 min after administration. In controls, the evaluation was performed at corresponding time intervals. Mean flow velocity in middle cerebral artery, systolic blood pressure, diastolic blood pressure, and heart rate did not change during the observation period and were not different between these two groups. However, administration of UC was associated with decreases in PI by $3.6{\sim}12.4%$ in BHI by $17.9{\sim}24.8%$ compared with pre-administration period. Decreases in PI and BHI with UC were significantly different compared with control group (p<0.05). These results indicate that UC decreases PI and BHI in cerebral artery, which is due to a dilation of cerebral resistance vessels.

• 대한임상검사과학회지
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• 제36권1호
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• 비파괴검사학회지
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• 제32권5호
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• pp.494-501
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• 2012

본 논문에서는, 두 나이군의 인체 요골동맥과 경동맥에서 초음파 혈액 영상을 측정하여 혈액에코박동지수를 분석했고, 또한 뇌졸중 환자와 대조군의 요골동맥과 경동맥에서 초음파 혈액 영상을 측정하여 혈액에코박동지수를 비교했다. 요골동맥의 혈액에코박동지수는 젊은 세대와 나이 많은 세대가 각각 $0.13{\pm}0.11$, $0.16{\pm}0.03$로 유사한 반면, 경동맥에서는 각각 $0.70{\pm}0.21$, $0.32{\pm}0.01$로 젊은 세대에서 더 높게 나타났고, 피험자 별로 더 높은 분산을 보였다. 뇌졸중 환자와 대조군의 혈액에코박동지수는 요골동맥($0.22{\pm}0.02$, $0.16{\pm}0.03$)과 경동맥($0.35{\pm}0.02$, $0.32{\pm}0.01$) 모두 환자군에서 더 높게 나타났다. 이와 유사하게, 섬유소원 농도 역시 요골동맥과 경동맥 모두 대조군($264{\pm}38$, $257{\pm}43mg/dl$)보다 환자군($336{\pm}61$, $340{\pm}126mg/dl$)에서 더 높게 나타났다. 본 연구의 결과는 향후 적혈구 응집과 뇌졸중의 상관성에 대한 초음파 연구의 가능성을 제시하고 있으며, 적혈구 응집의 생체 내 측정은 임상학적으로 유용하게 활용될 수 있을 것으로 기대된다.

• The Korean Journal of Pain
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• 제9권1호
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• pp.57-62
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• 1996

Stellate ganglion block(SGB) improves cutaneous blood flow of the head and neck region and upper extremity. For this reason, SGB has been performed in neural and circulatory disorders. But there is controversy on the cerebral blood flow regulation by sympathetic innervation. We investigated the hypothesis that cerebral blood flow could be affected by blocking ipsilateral sympathetic innervation of cerebral blood flow could be affected by blocking ipsilateral sympathetic innervation of cerebral vasculature. In 10 volunteers, the blood flow velocity and pulsatility index(PI) of middle cerebral artery(MCA) was measured using Transcranial Doppler Flowmeter, before and 15 minutes after SGB, at block side and opposite side. The blood flow velocity of MCA at block side was increased from $62.60{\pm}7.60$ cm/s to $72.80{\pm}8.01$ cm/s(P<0.01) and the PI at block side decreased from $0.75{\pm}0.12$ to $0.60{\pm}0.11$(P<0.05). But the blood flow velocity and PI at opposite side did not change. This study demonstrated that the cerebral blood flow could be increased by SGB, the preganglionic nerve fibers of which synapse with other cervical sympathetic ganglions.

• 대한임상검사과학회지
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• 제42권3호
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• pp.155-160
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• 2010

Transcranial Doppler ultrasonography (TCD) allows measurement of blood flow velocity to be made from the basal intracerebral vessels. Blood flow velocity in TCD is highly affected not only by blood vessel diameter, blood flow volume, blood viscosity, but also age and sex. Therefore, the study is focused on the correlation between TCD measurement index and sex/age. Subjects were 214 (male 147, famale 67) who had TCD for headache and stroke evaluations at Dongguk University Ilsan Hospital neurology department from December 2009 to April 2010. Sex did not show significant differences with mean flow velocity (MFV), peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and resistance index (RI) in middle cerebral artery (MCA). Although age also did not show significant differences with MFV and PSFV, EDFV has statistically decreased with age, and PI and RI has statistically increased with age. In addition, age showed significant correlation with MFV, EDFV, PI and RI, but not with PSFV. Therefore, TCD is definitely correlated with age and sex, so that those influencial factors must be considered when being tested.

• Clinical and Experimental Reproductive Medicine
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• 제36권4호
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• pp.293-300
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• 2009

목 적: 본 연구는 배아이식일의 자궁동맥혈류가 인간 체외수정술에서 임신예후의 예측인자가 될 수 있는지 알아보기 위해 시행되었다. 연구방법: 51회의 체외수정술 주기에 대해 전향적인 임상 관찰로 시행되었으며 혈청 estradiol 농도는 hCG 투여일에 측정되었고, 자궁동맥 박동율 (PI)과 저항율 (RI)은 배아이식 3일째에 측정되었다. 결 과: 51회의 주기 중 22주기에서 임상적으로 임신이 확인되었고 (43.1%), 착상률은 14.7%였다. 자궁동맥 PI와 RI는 혈청 estradiol 농도과 의미 있는 음의 상관관계 (p<0.05)를 보였으며 자궁혈류량은 임신된 그룹과 임신 되지 않은 그룹에서 차이가 없었다. 임신율은 PI가 3.0 이상인 군에서 PI가 3.0 이하인 군보다 조금 높게 측정되었으나 통계학적인 유의성은 없었다. 결 론: 배아이식일의 자궁동맥 PI와 RI는 체외수정술에서 임신의 예측인자로는 효용성이 떨어지지만 estradiol 농도와는 음의 상관관계를 보여 자궁혈류와 estradiol 농도가 상관관계가 있음을 알 수 있다.

• 대한수의학회지
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• 제39권1호
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• pp.230-239
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• 1999

Digital color doppler ultrasonographic system(DCDUS) has a lot of diagnostic functions. One of these is a detection of low velocity vessels in the organs of abdominal cavity. The purpose of study was to determine the clinical usefulness of DCDUS. Interlobar artery resistive index(RI), pulsatility index(PI) and systolic diastolic ratio(SDr) were measured for diagnosis of obstructed urinary tract. RI, PI and SDr were a measure of intrarenal blood flow impedance. This study was consisted of 2 groups. The normal group was studied in 16 normal adult dogs and the study group was studied 7 dogs with surgically induced, unilateral ureteral obstruction. In the study group, parameters were checked in normal condition and on 1, 2, 3, 5, 7 and 10th day after ligation. The result were summarized as follows. In the normal group, RI, PI and SDr of the left kidney was $0.65{\pm}0.04$, $1.25{\pm}0.12$ and $292.45{\pm}29.40$, respectively. RI, PI and SDr of the right kidney were $0.64{\pm}0.05$, $1.28{\pm}0.20$ and $282.25{\pm}37.26$, respectively. In the study group, RI of the left kidney induced ligation was increased significantly on 1, 2, 3, 5, 7 and 10th day. RI of the left kidney on 1, 2, 3, 5, 7 and 10th day were $0.75{\pm}0.05$, $0.71{\pm}0.03$, $0.74{\pm}0.04$, $0.74{\pm}0.02$, $0.73{\pm}0.02$ and $0.73{\pm}0.04$, respectively. PI of the left kidney was increased significantly on 1, 3, 5 and 7th day. PI of the left kidney on 1, 3, 5 and 7th day were $1.57{\pm}0.21$, $1.54{\pm}0.24$, $1.60{\pm}0.15$ and $1.60{\pm}0.26$, respectively. SDr of the left kidney increased significantly on 1, 2, 3, 5 and 7th day. SDr of the left kidney on 1, 2, 3, 5 and 7th day were $412.18{\pm}86.69$, $352.14{\pm}47.05$, $399.77{\pm}65.54$, $369.43{\pm}48.34$ and $365.57{\pm}22.46$, respectively(p<0.05). In the study group, RI of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5, 7 and 10th day. PI of the left kidney was more increased than that of the right kidney on 1, 3, 5, and 7th day. SDr of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5 and 7th day(p<0.05). RI was effective in the diagnosis of an acute unilateral ureteral obstruction. PI and SDr were insufficient in the diagnosis of an acute unilateral ureteral obstruction.

• Journal of Yeungnam Medical Science
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• 제8권1호
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• pp.63-71
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• 1991

저자들은 1990년 5월 1일부터 1991년 4월 30일까지 영남대학교 의과대학 부속병원 산부인과에 정기검진을 위해 내원한 157명의 정상 임산부를 대상으로 제대동맥에서 시행한 도플러초음파 160회의 검사 결과를 엄신 주수에 따라 분석하여 다음과 같은 결과를 얻었다. 제대동맥의 최고 수축기 혈류속도는 임신이 진행함에 따라 증가 양상을 보임으로써 임신이 증가함에 따라 제대 동맥 혈류량은 증가함을 관찰할 수 있었다. 임신이 진행함에 따라 제대태반 순환계 말초 저항이 점차적으로 감소함으로 인해 제대동액 이완기말 혈류속도도 중가 양상을 보였다. S/D ratio는 최고 수축기 혈류속도의 증가에도 불구하고 이완기말 혈류속도의 점차적인 증가로 인하여 임신이 진행함에 따라 오히려 감소함을 관찰할 수 있었다. 임신이 지속함에 따라 PI, RI도 감소하는 양상을 보였다.

• 한국임상수의학회지
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• 제20권3호
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• pp.334-340
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• 2003

For the study of the hemodynamic changes of the cranial pancreaticoduodenal arterial flow(cPDAF) in the dog with acute pancreatitis, acute pancreatitis was experimentally induced in 10 dogs by the injection of oleic acid into the accessory pancreatic duct. The parameters of cPDAF were measured by transcutaneous pulsed-wave Doppler ultrasonography. The hemodynamic changes included resistive indexe(RI), pulsatility index(PI) and maximum velocity (Vmax). Ultrasonographic scans were performed before the induction of pancreatitis and once daily for five days after the induction. The RI, PI and Vmax were increased with day as follows; the RI prior to induction was 0.625$\pm$0.096 (mean$\pm$SD), the PI was 1.117$\pm$0.289 and the Vmax was 0.349$\pm$0.094 m/s. After five days, the RI was 0.727$\pm$0.051 (p<0.0l), the PI was 1.480$\pm$0.284 (p<0.0l) and the Vmax was 0.585:$\pm$0.114 m/s (p<0.00l). These results show that there is some relation between the increase of the RI, PI and Vmax of cPDAF and the progress of acute pancreatitis in dogs. Therefore, the measurements of the hemodynamic changes of cPDAF may be a valuable technique for the evaluation of acute pancreatitis in dogs.