• Journal of Yeungnam Medical Science
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• v.41 no.1
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• pp.56-57
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• 2024

• Journal of Chest Surgery
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• v.43 no.4
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• pp.399-403
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• 2010

Background: Video-Assisted Thoracic Surgery can be performed with the lung collapsed. During the procedure, pleural adhesion may result in lung injury, bleeding, and thoracotomy conversion. Identifying the presence of pleural adhesion before surgery can make it easy to plan trocar introduction and perform the procedure. Material and Method: Between June 2009 and November 2009, we performed ultrasound in 24 patients to detect pleural adhesion before surgery and compared the results with the operative findings. We primarily examined the lateral chest, where the trocar would be inserted, and, occasionally, the anterior or posterior chest. Result: Patient diseases were: 6 hyperhidroses, 8 interstitial lung diseases, 5 lung cancers, 2 mediastinal tumors, 1 peripheral pulmonary embolism, 1 metastatic lung cancer, and 1 sarcoidosis. Of the 22 patients who did not have pleural adhesions on ultrasound, four revealed mild adhesions not related to the trocar insertion sites. However, ultrasound showed pleural adhesions in two patients, consistent with the operative findings. There was no air leak or thoracotomy conversion related with trocar insertion. Conclusion: Ultrasound requires only a few minutes to detect the presence of the pleural adhesion and was very useful in identifying the pleural adhesion before VATS.

• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.622-628
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• 2003

Recently, ultrasound transducers in several tens MHz band, which can give the spatial resolution higher than several tens micrometers, have been intensively studying for applying to medical diagnostic fields of ophthalmology and dermatology. In this paper, the background of the studies, structures and characteristics of the transducers, and images obtained by the transducers are briefly reviewed.

• The Journal of the Acoustical Society of Korea
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• v.29 no.3E
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• pp.111-118
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• 2010

Three-dimensional ultrasound imaging is a new, exciting technology that allows physicians to use ultrasound to view pathology as a volume, thereby enhancing comprehension of patient anatomy. In this paper, a brief history of the 3-D ultrasound imaging is described in accordance with the development of transducer technology. Then, two representative types of 3-D imaging transducers are reviewed with description of the concept and operation principle of each type: mechanical transducer and matrix array transducer. The mechanical transducer is detailed into free-hand scanning and sequential scanning types. Advantages of each transducer over the other and the technical issues for further performance enhancement are also presented.

• Journal of Biomedical Engineering Research
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• v.26 no.6
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• pp.351-356
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• 2005

Respiration measurement method using an ultrasound sensor is influenced very little by an error of inertia and pressure. This device measures the amount and flow of respiration using a delivery speed difference of the ultrasound waves that are a return format by the pneumatic stream that is a flogging of ultrasound waves during transmission and receipt as having used a characteristic of ultrasound waves. This paper examines improving the sensor's sensitivity during transmission and receipt of the signal. Because the measurement must be performed on patients, clinicians need to be sure that it is accurately measuring even very weak breathing.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.70-71
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• 1998

In this paper, We proposed fast ultrasound image compression based on characteristics of ultrasound images. In the proposed method, wavelet transform is performed for non-zero coefficients selectively. It codes zero-tree symbols using conditional pdf (probability density function) as orientation of bands. It normalizes wavelet coefficients with threshold of each wavelet band and encodes those using a uniform quantizer. Experimental results show that the proposed method is the proposed method is superior in PSNR to LuraTech's method by about 1.0 dB, to JPEG by about 5.0 dB for $640\times480$ 24bits color ultrasound image.

• Journal of Biomedical Engineering Research
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• v.39 no.4
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• pp.153-160
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• 2018

3D ultrasound bladder scanners are getting popular in hospitals for the patients with bladder dysfunction. A current bladder scanner adopts a mechanical scan to acquire 3D images and requires two motors and complicated mechanical devices. In this paper, we propose a new ultrasound bladder scanner using hand-motion scan. Instead of two motors and mechanical devices, it has a motion sensor to record transducer positions during hand-motion scan. The experiments with a bladder phantom and volunteers showed similar measurement accuracy to a conventional 3D ultrasound bladder scanner. We expect that the proposed method will reduce the cost and size of the bladder scanner.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.433-442
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• 1996

Since one texture property(i.e coarseness, orientation, regularity, granularity) for ultrasound liver ages was not sufficient enough to classify the characteristics of livers, we used multi texture vectors tracted from ultrasound liver images and a statistical classifier. Multi texture vectors are selected among the feature vectors of the normal liver, fat liver and cirrhosis images which have a good separability in those ultrasound liver images. The statistical classifier uses multi texture vectors as input vectors and classifies ultrasound liver images for each multi texture vector by the Bayes decision rule. Then the decision of the liver disease is made by choosing the maximum value from the averages of a posteriori probability for each multi texture vector In our simulation, we obtained higtler correct ratio than that of other methods using single feature vector, for the test set the correct ratio is 94% in the normal liver, 84% in the fat liver and 86% in the cirrhosis liver.

• Journal of Biomedical Engineering Research
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• v.27 no.1
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• pp.6-13
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• 2006

Ultrasound visualization is a typical diagnosis method to examine organs, soft tissues and fetus data. It is difficult to visualize ultrasound data because the quality of the data might be degraded by artifact and speckle noise, and gathered with non-linear sampling. Rendering speed is too slow since we can not use additional data structures or procedures in rendering stage. In this paper, we use several visualization methods for fast rendering of ultrasound data. First method, denoted as adaptive ray sampling, is to reduce the number of samples by adjusting sampling interval in empty space. Secondly, we use early ray termination scheme with sufficiently wide sampling interval and low threshold value of opacity during color compositing. Lastly, we use bilinear interpolation instead of trilinear interpolation for sampling in transparent region. We conclude that our method reduces the rendering time without loss of image quality in comparison to the conventional methods.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.289-292
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• 1996

The 2-way beam simulation for the diagnostic ultrasound is performed with simplified computation by approximating the transducer and the system. The results show that the simulation program can be used as a good system design tool.