• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.880-890
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• 2010

The intrasvascular ultrasound (IVUS) imaging technique is used to diagnose cerebrovascular diseases such as stroke. Recently, elasticity imaging methods have been investigated to diagnose blood clots attached to blood vessel intima. However, the IVUS imaging technique is an invasive method that requires a transducer to be inserted into blood vessel. In this paper, strain images are obtained of blood clots attached to blood vessel intima with data acquired from outside the blood vessel using a linear array transducer. In order to measure the displacement of blood vessel accurately, experimental data are acquired by steering ultrasound beams so that they can intersect the blood vessel wall at right angles. The acquired rf data are demodulated to the baseband. The resulting complex baseband signals are then processed by an autocorrelation algorithm to compute the blood vessel movement and thereby produce strain image. This proposed method is verified by experiments on a plastic blood vessel mimicking phantom. The efficacy of the proposed method was verified using a home-made blood vessel mimicking phantom. The blood vessel mimicking phantom was constructed by making a 6 mm diameter hollow cylinder inside it to simulate a blood vessel and adhering 2 mm thick soft plaque to the inner wall of the hollow cylinder. The RF data were acquired using a clinical ultrasound scanner (Accuvix XQ, Medison, Seoul. Korea) with a 7.5 MHz linear array transducer by steering ultrasound beams in steps of $1^{\circ}$ from $-40^{\circ}$ to $40^{\circ}$ for a total of 81 angles. Experimental results show that the plaque region near the blood vessel wall is softer than background tissue. Although the imaging region is restricted due to the limited range of angles for which scan lines are perpendicular to the wall, the feasibility of strain imaging is demonstrated.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.3
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• pp.235-241
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• 2009

Composite wood materials are very sensitive to water and inspection without any coupling medium of a liquid is really needed to wood materials due to the permeation of coupling medium such as water. However, air-coupled ultrasound has obvious advantages over water-coupled experimentation compared with conventional C-scanner. In this work, it is desirable to perform contact-less nondestructive evaluation to assess wood material homogeneity. A wood material was nondestructively characterized with non-contact and contact modes to measure ultrasonic velocity using automated data acquisition software. We have utilized a proposed peak-delay measurement method. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. The variation of ultrasonic velocity was found to be somewhat difference due to air-coupled limitations over conventional scan images. However, conventional C-scan images are well agreed with increasing the resin-infiltrated time as expected. Finally, we have developed a measurement system of an ultrasonic velocity based on data acquisition software for obtaining ultrasonic quantitative data for correlation with C-scan images.

• Journal of Embryo Transfer
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• v.11 no.2
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• pp.103-109
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• 1996

The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle ($\geq$5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.419-431
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• 2000

In this paper, a new beamforming technique is proposed, which can completely eliminate all the artifacts caused by digital scan converter. In the proposed method, named display-pixel-based focusing(DPBF) by the authors, ultrasound waves are focused directly at the display pixels instead of sampling points on the polar coordinate. Consequently. the DPBF system does not require the digital scan converter. To verify the proposed method, we modified a commercial scanner and performed experiments with a 3.5 MHz convex array and a 7.5 MHz linear array. We also defined and measured ICRA/B(Image Coarseness Ratio) to compare the image quality quantitatively. The experimental results with in vivo and in vitro data show that the proposed method improves the ICRA/B considerably, resulting in much smoother and finer images.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.529-537
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• 1994

Sector scanner which has a conical end is used to image through the intercostal space because heart is protected by the ribs. Cardiac data published all around the world were also obtained by sector scanner. Although scanners being used in every small animal practice and animal hospital at college in Korea include convex ape and linear type, linear type is not appropriate f3r cardiac scan because of a wide contact surface. The purpose of this study is to establish ultrasonographic images of normal cardiac structures by measuring shape, size of reflectable cardiac structure according to restraint position in scanning normal heart of the puppies with 6.5 MHz convex scanner(SonoAce 4500, Medison, Korea) used in our veterinary teaching hospital, Seoul national university. Seventeen male and female puppies considered having healthy hear by X-ray and clinical examination are used feom April to July 1994. Scanning point selection of probe head and the distinction of imaged cardiac structures were accomplished by necropsy and cardiac scanning performed through thoracotomy under general anesthesia. At 10 o'clock position of transducer(at an angle of 30$^{\circ}$ between imaginary line from elbow joint to 3rd sternum and probe head, 60$^{\circ}$ from body surface, 4th intercostal space of right thorax) with the marker of scanner toward the head of dogs right atrium, left atrium and left ventricle were observed in 2, 3, 4, 5 intercostal space(2cm from the sternum) of experimental dog positioned ventrodorsally under general anesthesia. Under these conditions, the numerical values of imaged diastolic hear are as follows : the distance from skin to apex(mean$\pm$S.D) 47.53$\pm$6.94mm, thickness of left ventricular wall 6.00$\pm$1.60mm, length of left ventricle 16.27$\pm$5.31mm, width of left ventricle 15,33$\pm$4.25mm, length of left atrium 12.33$\pm$3.82mm, width of left atrium 11. 33$\pm$3.94mm, length of right atrium 1.00$\pm$2.41mm, width of right atrium 11.21$\pm$2.76mm and the area of left ventricle 270.92$\pm$109.81mm$^2$, area of left atrium 98.00$\pm$41.08mm$^2$, area of right atrium 62.75$\pm$21.04mm$^2$.

• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.61-65
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• 2008

Objective: To reduce urinary side effects in prostate cancer patients receiving radiation, patients were asked to drink certain amount of water to maintain bladder volume constant and the bladder volumes were measured weekly using ultrasound scanner. Materials and Methods: Twenty-six patients with prostate cancer who received radiation between December 2002 and August 2007 were enrolled in this study. Thirteen patients were enrolled in experimental group. These patients were asked to drink 450 cc of water, one hour prior to simulation, CT scan, and treatment. The other thirteen patients were given no information about bladder filing. Bladder, prostate, and rectum were contoured on CT and volumes were calculated. 3D conformal treatment planning was performed and effective volumes of bladder were calculated when a prescription dose of 70.2 Gy was delivered. For the patients in experimental group, bladder volumes were measured weekly using ultrasound scanner for 6-8 weeks and the bladder volume variations were analyzed. Results: Average bladder volumes and standard deviations obtained at CT scanning were $283.5{\pm}114.0\;cc$ (40%) and $181.2{\pm}120.1\;cc$ (66%) in experimental and control groups, respectively. Although it was not statistically significant, there was correlation between the bladder volumes measured from CT and ultrasound. The volumes measured using ultrasound scanner were 62% lower than the volumes using CT images on average. There was significant variations in volumes measured weekly for 6-8 weeks. It ranged between 33 - 75 %. Conclusion: Our results showed that it is possible to obtain larger bladder volume if they are asked to drink certain amount of water prior to CT scan. However, patients were unable to maintain constant bladder volumes over the 6-8 weeks of treatment period although they were asked to drink constant amount of water.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.96-102
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• 1990

Diagnostic ultrasound has the advantages of being noninvasive without any known deleterious biologic effect, rapid, painless, inexpensive and easily reproducible. The author used a real time sector scanner (Picker, Artis USA:5-7.5 MHz) for examing of lipoma, abscess, hematoma, lymphnode enlargement etc. and evaluated ultrasonograph as a diagnostic aid in head and neck region.

• Journal of Oral Medicine and Pain
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• v.45 no.3
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• pp.49-55
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• 2020

Purpose: This study investigated the association between the objective indicator of masticatory function assessment and the masseter muscle thickness (MMT) using ultrasound imaging. Methods: A total of 99 subjects (males: 24, females: 75, mean age: 76) were analyzed. The maximum bite force (MBF) was measured with a pressure-sensitive sheet and an image scanner. The mixing ability index (MAI) was calculated by image analysis after asking the subjects to chew a wax specimen. The MMT during rest and clenching were obtained with a diagnostic ultrasound system, and the difference in MMT during rest and MMT during clenching was defined as the difference in masseter muscle thickness (DMMT). Multiple regression analysis was performed to determine the independent variables affecting MBF and MAI. Results: The MBF showed correlation with the number of remaining teeth (β=0.346, p=0.002) and DMMT (β=0.251, p=0.011). The MAI correlated with only the number of remaining teeth (β=0.476, p<0.001). Conclusions: The DMMT reflects the state of masseter muscle contraction, and can be used as a predictor as well as the number of teeth when assessing masticatory function.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2073-2078
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• 2015

This study is investigated for angle of elbow joint influence on grasp strength, confirm change of grasp strength and brachioradialis thickness according to angle of elbow joint in standing. Thirty male and female university students, who participated with agreement in this study, using for electronic dynamometer and convertible ultrasound measure maximum grasp strength and brachioradialis thickness after elbow joint $0^{\circ}$, $90^{\circ}$, $135^{\circ}$ positioning in standing. In average grasp strength was strongest at elbow joint $0^{\circ}$, as the angle of elbow joint increased, was decreased grasp strength, no significant statistically(p<.05). In average brachioradialis thickness was lowest at elbow joint $0^{\circ}$, as the angle of elbow joint increased, was increased brachioradialis thickness, significant statistically(p<.05). These result may indicated that change of elbow joint angle not influence on grasp strength, but influence on brachioradialis thickness.