• International Journal of Control, Automation, and Systems
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• v.3 no.1
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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.

• Journal of Acupuncture Research
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• v.18 no.6
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• pp.135-140
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• 2001

Objective : To investigate the effects of Acupuncture therapy on the migraineur by way of the change of the Cerebral blood flow. Methods : 6 migraineurs were inserted in acupoints on GV16, G20, S8 during 2 weeks. and, Mean Velocity (MV) and Pulsatility Index (PI) of MCA, PCA, ACA, BA were measured before and after treatments of 2 weeks, respectively. Results : MV of MCA of the migraineurs was decreased very much by 13.3%, and PI was decreased much by 10.4%. However, MV and PI of BA changed little. Conclusion : It is observed that Acupuncture therapy reduces pains of migraineur through decreasing Cerebral blood flow like MCA.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.293-300
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• 2009

Objective: This study was aimed to investigate whether uterine blood flow on the day of embryo transfer can be a predictor of pregnancy outcome in human IVF. Methods: Fifty-one patients undergoing IVF program were included in this study. Serum estradiol levels were measured on the day of hCG administration and uterine pulsatility index (PI) and resistance index (RI) was examined for at embryo transfer of day 3. Results: Of 51 cycles, 22 cycles were clinically pregnant (43.1%) and the implantation rate was 14.7%. Uterine PI and RI had a significant inverse correlation with serum estradiol levels (p<0.05). These uterine blood flows were not significantly different between pregnant and nonpregnant groups. The pregnancy rate was slightly higher in patients with PI more than 3.0 compared to those with PI of 3.0 or less, but there was no significant difference. Conclusion: These results suggest that uterine PI and RI at the day of embryo transfer could not be a good predictor of pregnancy in IVF treatment. But they had an inverse correlation with serum estradiol levels on the day of hCG administration.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.983-988
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• 2003

Purpose : Syncope appears to be common. However, the mechanism of syncope is not clear. Increased vagal activity and withdrawal of sympathetic stimulation cause hypotension, bradycardia and finally loss of consciousness. The purpose of this study was to evaluate changes of cerebral blood flow velocity, blood pressure, and heart rate during tilt test in children with vasovagal syncope. Methods : Sixty four children with a past history of syncope were evaluated. The stand up test was performed for 15 minutes after a rest at supine position for 10 minutes, followed by an $80^{\circ}$ tilt test lasting 45 minutes. If presyncope(lightheadedness, nausea, blurred vision, or sweating) or syncope occurred, the study was discontinued. 12-lead electrocardiography, echocardiography, and electroencephalography were performed. Transcranial Doppler study was performed at the middle cerebral artery with 2 MHz continuous Doppler probe in 10 children with positive tilt test. Systolic, diastolic, mean cerebral blood flow velocity, integral, and pulsatility index were measured with blood pressure, heart rate, and $O_2$ saturation. Results : The positive rate of tilt test was 31.3%(20/64). Systolic, diastolic, and mean cerebral blood flow velocity decreased significantly in absence of hypotension or bradycardia during presyncope. Time velocity integral of cerebral artery also decreased significantly. Conclusion : Decreased cerebral blood flow velocity can predict the presyncope manifestation. Impairment of autoregulation of cerebral blood flow might play an important role in the pathophysiology of vasovagal syncope.

• Korean Journal of Veterinary Research
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• v.39 no.1
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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 Veterinary Clinics
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• v.20 no.3
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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.

• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.63-71
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• 1991

Noninvasive techniques for antenatal detection of the fetal development and well-being such as biophysical profile, non-stress and stress test remain major challenges in modem obstetric practice. To obtain and analyze umbilical artery velocity waveform by pulsed-wave doppler ultrasound, a total of 160 determinations were carried out on 157 normal pregnant women between 16th to 41st week gestation. The ratio of peak systolic to end-diastolic flow velocity(S/D ratio), pulsatility index and resistance index were measured as indices of the resistance in feto-placental circulation. The results were as follows : As gestation advances, the, mean values for peak systolic and end-diastolic velocities raised progressively. As gestation advances, the mean values for the S/D ratio declined progressively, exhibiting high diastolic flow velocity caused by low resistance. Pulsatility index, and resistance index were also declined progressively, as gestation advances. The analysis of umbilical artery blood flow velocity waveforms provides a new noninvasive technique to evaluate fetal development and well-being, and may be expected a reliable method for assessment of fetal life.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.14 no.2
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• pp.85-100
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• 2010

Objectives: The purpose of this study was to evaluate diagnostic value of Transcranial Doppler Ultrasound about risk factor of stroke by comparing blood flow between patients with metabolic syndrome(MS group) and Normal group. Methods: 62 metabolic syndrome patients and 106 healthy adults were selected who had no cerebrovascular diseases, cardiovascular diseases and other systemic diseases. We measured the mean velocity(Vm), peak systolic velocity(Vs) and pulsatility index(PI) of MCA, ACA, PCA, VA, ICA in two groups using TCD. All subjects were divided by gender and age. Results: In comparing Ms group with normal group, Vm in the MCA, ACA, PCA, ICA and Vs in the MCA, ICA were lower in MS group. In all vessels, PI of MS group were higher than that of Normal group. In all vessels, Vm and Vs revealed negative correlation with age and PI revealed positive correlation with age. In 20-39 year olds, there was decrease in the Vs and Vm and increase of PI of MS group in comparison with normal group. There was significant difference in the Vm of PCA, ICA, Vs of MCA, PCA, ICA and PI of MCA, ACA. In 40-59 year olds, Vm in the MCA, ACA, ICA and Vs in the MCA, ACA were lower in MS group. PI in the MCA, ACA, PCA, ICA were higher in MS group. In 60-79 year olds, Vm of MCA, PCA, ICA was decreased in MS group than Normal group with no statistical signification. Vs in the MCA was lower and PI in the PCA was higher in MS group. In male, Vm of PCA and Vs of MCA were lower and PI of MCA, ACA, PCA, ICA were higher in MS group. In female, Vm of MCA, PCA, ICA and Vs of MCA, ICA were lower and PI of ACA, PCA, VA, ICA were higher in MS group. Conclusions: The significant difference in Vm, Vs, PI between MS group and normal group suggests hemodynamic disorder. Screening and prognosing high risk group can be done through TCD and this can be used to prevent stroke. More detailed study will be needed.

• Korean Journal of Adult Nursing
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• v.26 no.2
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• pp.171-180
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• 2014

Purpose: This study was to investigate the effects of upper meridian massage on cerebral blood flow, emotions, and sleep of the institutionalized elderly. Methods: This study was a nonequivalent control group pre- and post-test design. The participants were 50 elderly (26 in the experimental group; 24 in the control group) living in the institutions. Data were collected between July 9 and September 1, 2011. The data were analyzed using descriptive statistics, t-test, and $x^2$-test, Repeated Measures ANOVA, and Cronbach's ${\alpha}$ coefficient. Each participant in the experimental group received the upper meridian massage for 10 minutes, 4 times per week for 2 weeks. Each participant's cerebral blood flow and self-reported questionnaires were tested before treatment, after 1 week and 2 weeks during treatment sessions. Results: There were significant differences in sleep and emotions after 1 week and 2 weeks during treatment sessions. But cerebral blood flow measured by common carotid artery pulsatility index (CCA PI) and common carotid artery resistance index (CCA RI) demonstrated significant differences in 2 week point in time. Conclusion: These results indicated that upper meridian massage could be an effective intervention for improving cerebral blood flow, emotions, and sleep of the institutionalized elderly.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.3
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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.