• Journal of Chest Surgery
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• 제43권4호
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• pp.399-403
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• 2010

배경: 비디오흉강경수술은 폐를 허탈시켜 흉강내의 공간을 확보함으로써 시행되는데 흉막유착은 이러한 공간을 확보하는데 커다란 장애요인이 되어 폐손상 및 출혈을 유발할 수 있으며, 개흉술로 전환하는 원인이 되기도 한다. 흉강경수술을 시행하기 전에 흉막유착 유무를 확인하면 투관침의 위치선정 및 삽입방법을 포함한 수술과정을 계획하는데 매우 유용한 정보를 얻을 수 있다. 대상 및 방법: 2009년 6월부터 2009년 11월까지 비디오흉강경수술을 시행한 24명의 환자에서 수술 전에 흉막유착을 확인하기 위하여 초음파검사를 시행하고 흉강경수술시의 소견과 비교하였다. 검사부위는 투관침 삽입부위인 전액와선에서 후액와선까지의 흉부 측면을 주로 검사하였으며, 경우에 따라서는 흉부 전면이나 후면을 관찰하기도 하였다. 결과: 환자는 다한증 6예, 간질성폐병변 8예, 폐종양 5예, 종격동종양 2예, 말초폐동맥색전증 1예, 전이성폐종양 1예, Sarcoidosis 1예로 구성되었다. 초음파검사를 통해 흉막유착이 없다고 진단한 22예 중 4예는 검사부위와 동떨어진 곳에 일부 국한되어 경미한 유착이 있었으나 투관침 삽입부위와는 관련이 없었다. 흉막유착이 있다고 진단한 2예는 수술시 동일한 소견이었다. 수술중 투관침 삽입으로 인한 폐손상은 없었으며 개흉으로의 전환도 없었다. 결론: 초음파검사는 짧은 시간내에 검사가 이루어지며, 비디오흉강경수술을 계획하고 시행하는데 초음파를 이용한 흉막유착 여부의 확인은 매우 유익한 시술법이라고 사료된다.

• 한국음향학회지
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• 제22권8호
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• pp.622-628
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• 2003

최근 안과 또는 피부과의 의료진단분야에 도입하기 위한 수십 μm 이하의 높은 공간분해능을 갖는 수십 MHz 대역의 초음파 트랜스듀서에 대한 연구가 활발히 수행되고 있다. 본 해설에서는 그 연구의 배경 및 트랜스듀서의 구조와 특성, 그리고 그것을 이용하여 얻은 영상에 대하여 간략하게 소개하였다.

• The Journal of the Acoustical Society of Korea
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• 제29권3E호
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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.

• 대한의용생체공학회:의공학회지
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• 제26권6호
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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.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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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.

• 대한의용생체공학회:의공학회지
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• 제39권4호
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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.

• 대한의용생체공학회:의공학회지
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• 제17권4호
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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.

• 대한의용생체공학회:의공학회지
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• 제27권1호
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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.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6177-6186
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• 2015

Sensitivity and specificity are the two most important indicators in selection of medical imaging devices for cancer screening. Breast images taken by conventional or digital mammography, ultrasound, MRI and optical mammography were collected from 2,143,852 patients. They were then studied and compared for sensitivity and specificity results. Optical mammography had the highest sensitivity (p<0.001 and p<0.006) except with MRI. Digital mammography had the highest specificity for breast cancer imaging. A comparison of specificity between digital mammography and optical mammography was significant (p<0.021). If two or more breast diagnostic imaging tests are requested the overall sensitivity and specificity will increase. In this literature review study patients at high-risk of breast cancer were studied beside normal or sensitive women. The image modality performance of each breast test was compared for each.