• International Journal of Vascular Biomedical Engineering
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• v.1 no.1
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• pp.3-12
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• 2003

Ultrasonic pulsed Doppler velocimetry has become a standard international method of classifying carotid disease. Because the measured angle adjusted velocity increases as the Doppler angle increases, examinations should be performed at a convenient standard Doppler examination angle. An angle of 60 degrees is achievable throughout most examinations. Multiple Doppler viewing angles allow the acquisition of velocity vectors during the cardiac cycle, revealing the complex velocity patterns. Ultrasonic velocimetry (whether Doppler or time domain) is based on changes in the phase of the ultrasound echo. Other examinations can be done based on the echo phase. Slow motions of organs such as the brain can be used to monitor changes in edema. Measurements of tissue strain due to the pulsatile filling of the arterioles. This plethysmographic imaging method can display differences in tissue perfusion because of different tissue types and changes in autonomic activity.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.407-412
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• 1997

In this paper, we present a new method to diagnose the characteristics of the soft tissue, especially a liver. In order to diagnose the characteristics of a liver, it is necessary to evaluate the propagation delay time and propagation velocity of bending vibration In a liver. For this purpose, we measure the propagation velocity of bending vibration in a liver for low frequency forced vibration using a standard ultrasonic Doppler diagnosis equipment. We have carried out preliminary experiments by using an ultrasonic probe of 3.5MHz and obtained some results. This new measurement method developed here can be applied to new research and medical fields for acoustic non-invasive diagnosis of soft tissue.

• Journal of Biomedical Engineering Research
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• v.7 no.2
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• pp.169-182
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• 1986

Pulsed ultrasonic Doppler system is a useful diagnostic instrument to measure blood-flow-velocity, velocity profile, and volume-blood-flow. This system is more powerful compare with 2-dimensional B-scan tissue image. A system has been deve- loped and ii being evaluated using TMS 32010 DSP. We use this DSP for the purpose of real-time spectrum analyzer to obtain spectrogram in singlegate pulsed Doppler system and for the serial comb filter to cancel clutter and zero crossing counter to estimate Doppler mean frequency in multigate pulsed Doppler system. The Doppler shift of the backscattered signals is sensed in a phase detector. This Doppler signal corresponds to the mean velocity over a some region in space defined by the ultrasonic beam dimensions, transmitted pulse duration, and transducer ban(iwidth. Multi- gate pulsed Doppler system enable the transcutaneous and simultaneous assessment of the velocities in a number of adjacent sample volumes as a continuous function of time. A multigate pulsed Doppler system processing the information originating from presented.

• Journal of Veterinary Clinics
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• v.36 no.3
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• pp.155-158
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• 2019

Morphologic changes or functional impairments of the papillary muscle (PM) can influence mitral valve competence. The purpose of this study was to investigate PM size and contractile function using two-dimensional and color tissue Doppler echocardiography in normal dogs. 35 unsedated Beagle dogs without cardiovascular disease were examined. The vertical (VD) and horizontal diameter (HD) of the posterior and anterior PM was measured at end-diastole, and compared with the thickness of the left ventricular posterior wall (LVPWd). Longitudinal systolic movement of the PM was quantified as myocardial velocity and strain using tissue Doppler. The VD, HD, and ratios (VD/LVPWd, HD/LVPWd, VD/HD) were significantly greater in the posterior than anterior PM (P < 0.001). The VD and HD of posterior PM and the HD of anterior PM were significantly correlated with LVPWd (r = 0.47, 0.44, and 0.42, respectively). Body weight was significantly correlated with VD of posterior PM (r = 0.37). The peak systolic tissue velocity of the PM was $4.93{\pm}1.25cm/sec$ and peak strain was $-30.83{\pm}11.92%$. PM size and systolic function can be quantitatively assessed using two-dimensional and tissue Doppler. The establishment of these objective PM measurements may be useful to evaluate morphological and functional abnormalities of the canine PM.

• The Journal of the Acoustical Society of Korea
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• v.29 no.1E
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• pp.11-27
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• 2010

Nowadays, ultrasound Doppler imaging is widely used in assessing cardiovascular functions in the human body. However, a major drawback of ultrasonic Doppler methods is that they can provide information on blood flow velocity along the ultrasound beam propagation direction only. Thus, the blood flow velocity is estimated differently depending on the angle between the ultrasound beam and the flow direction. In order to overcome this limitation, there have been many researches devoted to estimating both axial and lateral velocities. The purpose of this article is to survey various two-dimensional velocity estimation methods in the context of Doppler imaging. Some velocity vector estimation methods can also be applied to determine tissue motion as required in elastography. The discussion is mainly concerned with the case of estimating a two-dimensional in-plane velocity vector involving the axial and lateral directions.

• Journal of Biomedical Engineering Research
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• v.7 no.2
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• pp.139-146
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• 1986

Pulsed ultrasonic Doppler system is a useful diagnostic instrument to measure blood-flow-velocity, velocity profile, and volume-blood-flow. This system is more powerful compare with 2-dimensional B-scan tissue image. A system has been deve- loped and ii being evaluated using TMS 32010 DSP. We use this DSP for the purpose of real-time spectrum analyzer to obtain spectrogram in singlegate pulsed Doppler system and for the serial comb filter to cancel clutter and zero crossing counter to estimate Doppler mean frequency in multigate pulsed Doppler system. The Doppler shift of the backscattered signals is sensed in a phase detector. This Doppler signal corresponds to the mean velocity over a some region in space defined by the ultrasonic beam dimensions, transmitted pulse duration, and transducer ban(iwidth. Multi- gate pulsed Doppler system enable the transcutaneous and simultaneous assessment of the velocities in a number of adjacent sample volumes as a continuous function of time. A multigate pulsed Doppler system processing the information originating from presented.

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1202-1210
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• 2006

Purpose : A quantitative and easily measured Doppler index of combined systolic and diastolic ventricular myocardial performance (Tei index) was recently proposed as a potentially useful predictor of global myocardial performance. However, presence of heart rate fluctuation makes it unreliable. Therefore, the modified Tei index was introduced by using tissue Doppler imaging (TDI) which enables measuring contraction and relaxation velocities from myocardium simultaneously. The purpose of this study was to investigate the effectiveness of the modified Tei index in the evaluation of global cardiac function. Methods : Forty eight patients in the acute phase of Kawasaki disease (KD) were studied. These patients were divided into two groups according to the modified Tei index. TDI and conventional echocardiography were performed. Systolic velocity, systolic displacement, E' velocity, E' displacement, A' velocity and A' displacement were measured at the base, mid-septum and the apex of the interventricular septum. Ejection fraction (EF), Tei index and modified Tei index were estimated. Results : Modified Tei index correlated negatively with systolic displacement, E' displacement and A' displacement at the base. Modified Tei index correlated positively with ESR and CRP. EF and Tei index were normal in KD patients. Conclusion : Modified Tei index is a safe, feasible and sensitive index for evaluating global ventricular functions in spite of normal EF and Tei index in KD.

• Clinical and Experimental Pediatrics
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• v.58 no.6
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• pp.218-223
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• 2015

Purpose: Idiopathic scoliosis is a structural lateral curvature of the spine of unknown etiology. The relationship between degree of spine curvature and cardiopulmonary function has not yet been investigated. The purpose of this study was to determine the association between scoliosis and cardiopulmonary characteristics. Methods: Ninety children who underwent preoperative pulmonary or cardiac evaluation at a single spine institution over 41 months were included. They were divided into the thoracic-dominant scoliosis (group A, n=78) and lumbar-dominant scoliosis (group B, n=12) groups. Scoliosis severity was evaluated using the Cobb method. In each group, relationships between Cobb angles and cardiopulmonary markers such as forced vital capacity (FVC), forced expiratory volume in one second ($FEV_1$), $FEV_1$/FVC, left ventricular ejection fraction, pulmonary artery flow velocity, and tissue Doppler velocities (E/E', E'/A') were analyzed by correlation analysis linear regression. Results: In group A, 72 patients (92.3%) underwent pulmonary function tests (PFTs), and 41 (52.6%) underwent echocardiography. In group B, 9 patients (75.0%) underwent PFT and 8 (66.7%) underwent echocardiography. Cobb angles showed a significant negative correlation with FVC and $FEV_1$ in group A (both P<0.05), but no such correlation in group B, and a significant negative correlation with mitral E/A ratio (P<0.05) and tissue Doppler E'/A' (P<0.05) in group A, with a positive correlation with mitral E/A ratio (P<0.05) in group B. Conclusion: Pulmonary and cardiac function was significantly correlated with the degree of scoliosis in patients with thoracic-dominant scoliosis. Myocardial diastolic function might be impaired in patients with the most severe scoliosis.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.417-423
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• 2006

Purpose : The objectives of this study were to assess ventricular function by tissue Doppler imaging in children who were receiving chemotherapy or who had received chemotherapy, and to apply repeated tissue Doppler imaging to make an early assessment in cardiac toxicity studies. Methods : This study was conducted on 23 oncology patients on-treatment or off-treatment from April 2005 to July 2005 at Dongsan Medical Center, Keimyung University. All patients(group 1) were divided into two groups, fractional shortening(FS) over 29 percent(group 2) and FS under 28 percent (group 3) in the first category. These same patients were also divided into the following groups : group treated with anthracyclin(group 4) and group treated without anthracyclin(group 5). Deceleration time(DT), isovolumic relaxation time(IVRT), FS, peak early diastolic(E), and peak late diastolic (A) velocity of transmitral flow were measured by M-mode and pulsed wave Doppler. Systolic(Sm), peak early diastolic(Em), and peak late diastolic(Am) velocity in apical 4-chamber and 2-chamber views were measured by tissue Doppler imaging. The author calculated a modified Tei index, E/A, E/Em ratio by using measured values. Results : Twenty three patients were enrolled : 12 boys and 11 girls. The average age of patients was 8 years and 4 months. Thirteen out of 23 patients were in the group treated with anthracyclin (group 4) and 6 had FS under 28 percent(group 3). E/Em ratio showed a significant difference between group 1 and control group($6.46{\pm}1.85$ vs $7.06{\pm}1.64$, P<0.05). Other parameters had no difference statistically. Conclusion : This study showed that the change of cardiac function developed earlier in diastolic function than in systolic function, as E/Em ratio reflecting the mean LV diastolic pressure showed a significant difference between the control group and chemotherapy groups. Echocardiography using tissue Doppler imaging is a non-invasive, comfortable and reliable method for post-chemotherapy follow up.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.99-106
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• 2010

The purpose of this study was to identify the effects of manipulation on the velocity of cerebral blood flow and level of pain in cervicogeinc headache patients. The velocity of cerebral blood flow of 30 cervicogeinc headache patients(male=15, female=15, age=$24.00{\pm}3.60$) and 33 normal subjects(male=15, female=18, age=$23.27{\pm}3.00$) was compared. The 30 cervicogeinc headache patients were divided into suboccipitalis relaxation group, cervical manipulation group, and placebo group, and each were given different interventions. The velocity of cerebral blood flow and pain level was measured before intervention, and 1, 2, 3 weeks after intervention. The velocity of cerebral blood flow was measured with the Transcranial Doppler(TCD), and pain level was measured with visual analog scale(VAS). Blood flow velocity of middle cerebral artery in cervicogeinc headache patients was slower than those in healthy subjects. Physical therapy intervention did not have significant effect on velocity of cerebral blood flow, but slowly decreased at intervention for pain level increased. The suboccipitalis relaxation group and cervical manipulation group showed significant effect in decreasing pain level compared to the placebo group(p<.05). Directly applied manipulation therapy in the neck area not only has effect on joint of cervical and soft tissue but also on blood vessels and nerves which pass the neck area, and because of those results of manual therapy seems to help recovery.