• Korean Journal of Veterinary Research
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• v.55 no.1
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• pp.47-52
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• 2015

The purpose of this study was to determine if contrast media would enhance visualization of the endocardium for assessment of left ventricle (LV) function. In addition, differences between pre- and post-contrast evaluation for the cardiac output measurements including the modified Simpson's method and automated contour tracking (ACT) method were examined. Ten clinically healthy adult beagle dogs (three males and seven females) between 2~3 years old and weighing 6.6~10.8 kg were used. Echocardiographic examinations were performed to compare pre- and post-contrast LV endocardium visualization using a segmental scoring method. Two different methods for measuring cardiac output were also compared. LV visualization was significantly enhanced in post-contrast echocardiography (p < 0.01). Significant differences between pre- and post-contrast measurements for the modified Simpson's method (p < 0.05) were also observed. No significant difference was found for the ACT method. Contrast echocardiography provides better LV chamber opacification and significantly improves wall segment visualization. Furthermore, contrast echocardiography for measuring cardiac output is helpful for the modified Simpson's method.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.384-390
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• 2012

Echocardiographic measurements of cardiac output, including the modified Simpson's method, Automated Contour Tracking(ACT) method, and left ventricular outflow method are well described methods of evaluating cardiac function due to its reliability and the benefits of its non-invasive technique in human medicine. The purpose of this study was to evaluate the accuracy of an echocardiography estimate of cardiac output in isoflurane-anesthetized beagle dogs and was to compare the ACT method to the other methods used in measurement of cardiac output. In healthy beagle dogs, cardiac output results by echocardiography estimate methods showed an excellent correlations with those by the thermodilution method (The modified Simpson's method : r = 0.815, $r^2=0.665$, y = 0.434x + 0.311 ; ACT method : r = 0.86, $r^2=0.748$, y = 0.391x + 0.242 ; ventricular outflow method : r = 0.691, $r^2=0.478$, y = 0.593x + 0.242). Among the results obtained, the ACT method showed the highest correlation coefficient. In conclusion, our study demonstrated that echocardiography estimate methods did not prove to be suitable in accurately measuring absolute cardiac output values but showed an excellent correlation with thermodilution method. Therefore, by using the measurement of cardiac output as supplemental data, echocardiography estimate methods can be used for detection and correction of hemodynamic disturbances during emergency and anesthesia in veterinary practice.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.8-13
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• 2015

One of the most usual indicators to measure the performance of any inventory policy is the mean physical stock. In general, when estimating the mean physical stock in periodic review inventory systems, approximate approaches are often utilized by practitioners and researchers. The mean physical stock is generally calculated by a simple approximation. Still these simple methods are frequently used to analyze various single stockpoint and multi-echelon inventory systems. However, such a simple approximation can be very inaccurate. This is particularly true for low service levels. Even though exact methods to calculate the mean physical stock have been derived, they are available for specific cases only and computationally not very efficient, and therefore less useful in practice. In literature, approximate approaches, such as the simple, the linear, and Simpson approximations, were derived for the periodic review inventory systems that allow backorders. This paper modifies the approximate approaches for the lost sales case and evaluates the modified approximate approaches. Through computational experiments, average (and maximum) percentage deviations of mean physical stock between the exact method and the modified approximations are compared in the periodic review inventory system with lost sales. The same comparison between the modified and the original approximations are also conducted, in order to examine the performance of modified approximations. The results show that all modified approximations perform well for high service levels, but also that the performance may deteriorate fast with decreasing service level. The modified Simpson approximation is clearly better. In addition, the comparison between the modified and the original approximations in the periodic review inventory system with lost sales shows that the modified approximation outperforms the original approximation.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.264-267
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• 2013

Stroke volume (SV) is an important parameter for monitoring of a critically ill animal and is echocardiographically measured using the modified Simpson's method, automated contour tracking (ACT) method and left ventricular outflow method. The purpose of this study was to evaluate the effect of anesthesia (isoflurane) on the SV during echocardiographic examination and to evaluate the feasibility of ACT method for measuring the stroke volume without anesthesia (conscious state). Ten clinically healthy adult Beagle dogs (3 male and 7 female, weighing 6.6-10.8 kg, aged 2-3 years old) were enrolled. Our study found that the dogs anesthetized have a significantly lower SV, compared to the SV of dogs unanesthetized, regardless of methods measuring SV. In addition, in the dogs without anesthesia, the SV measured by ACT method was significantly lower than the other two methods. This result implies that the anesthesia may significantly lower the SV. Thus, the measurement of SV under anesthesia may not be adequate in veterinary field. Furthermore because the ACT method measured SV significantly lower than other two methods, this method may be inappropriate for measuring SV in even conscious dogs.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.205-212
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• 2011

In this paper, we have proposed a method for quantization of the stratification strength in the sea water and analysing the distributions of the maximum stratification depths calculated by the method at the seas near the Korean peninsular. For calculating the stratification strength, modified and applied the potential energy anomaly formular which was suggested by Simpson in 1977. The data had been collected by NFRDI from 1971 to 2008 were used to determine the maximum vertical density gradient depth and the relative potential energy anomaly at that depth. In the East Sea, the stratification depth has become deepened about 20m in February and April since 1971. In Yellow-South Sea, the maximum density gradient depth has been deepened about 10m only in December during the same period and the difference of the stratification depth between summer and winter has been enlarged. These trends of variation of stratification strength and depth near the Korean peninsular should be investigated more carefully and continuously. And the results of these studies could be adopted for the more efficient operation of underwater weapon and detection systems.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.150-154
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• 2010

Purpose: Ejection fraction (EF) is one of the most important factors that evaluate heart function. Recently, according to echocardiography and myocardial perfusion SPECT, the number of gated blood pool scan (planar GBP) is declining. Measurement of left ventricular ejection fraction using gated blood pool SPECT (GBPS) is known as relatively correspond with echocardiography. We compared EF derived from plnar GBP, GBPS and echocadiography using modified simpson method to determine the accuracy. Materials and Methods: From January 2007 to June 2010, planar GBP and GBPS were performed on 34 patients who admitted to Pusan National University Hospital (men 23, women 11, mean age $52.6{\pm}27.2$). Each patient was injected with $^{99m}{TcO_4}^-$ of 20 mCi after pyrophosphate injection and then scanned using both planar GBP and GBPS techniques. For image analysis, we use ADAC Laboratories, Ver. 4.20 software. The result analyzed was processed by SPSS 17.0 Win statistic program and statistical method applied in data analysis is one-way anova, Tukey's post hoc test, pearson correlation test. Results: One-way anova test show no significant difference (planar GBP $56.3{\pm}13.9%$; GBPS $60.4{\pm}16.0%$; echocardiography $59.1{\pm}14.4%$, p=0.486, p>0.05). Tukey's post hoc test show no significant difference (planar GBP-echocardiography p=0.697; GBPS-echocardiography p=0.928; planar GBP-GBPS p=0.469, p>0.05). Values for EF obtained with planar GBP and GBPS correlated well with those obtained with echocardiography (planar-echocardiography r=0.697; GBPS-echocardiography r=0.928; planar GBP-GBPS r=0.469). Conclusion: The problems of accuracy and reproducibility for planar GBP still remain. But planar GBP is a safe and non-invasive method. In addition, planar GBP is useful to evaluate patient with low resolution echocardiography images. GBPS is not appicated clinically. but GBPS can be obtain various left ventricular functional parameters. planar GBP, GBPS and echocardiography show a good correlation between each other. Therefore, planar GBP and GBPS are useful for evaluating left ventricular ejection fraction.