• 제목/요약/키워드: 에코 PIV

검색결과 5건 처리시간 0.021초

에코 PIV: in vivo 유동 측정기법 (Echo-PIV: in vivo Flow Measurement Technique)

  • 김형범
    • 한국가시화정보학회지
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    • 제3권1호
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    • pp.26-35
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    • 2005
  • The combination of ultrasound echo images with digital particle image velocimetry (DPIV) method has resulted in a two-dimensional, two-component velocity field measurement technique appropriate for opaque flow conditions including blood flow in clinical applications. Advanced PIV processing algorithms including an iterative scheme and window of offsetting were used to increase spatial resolution. The optimum concentration of the ultrasound contrast agent used for seeding was explored. Velocity validation tests in fully developed laminar pipe flow and pulsatile flow showed good agreement with both optical PIV measurements and the known analytic solution. These studies indicate that echo PIV is a promising technique for the non-invasive measurement of velocity profiles and shear stress.

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에코 PIV를 이용한 맥동 유동에서의 in vitro 전단률 측정 연구 (Non-Invasive Measurement of Shear Rates of Pulsating Pipe Flow Using Echo PIV)

  • 김형범;정인영
    • 대한기계학회논문집B
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    • 제28권12호
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    • pp.1567-1572
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    • 2004
  • Although accurate measurement of velocity profiles, multiple velocity vectors, and shear stress in arteries is important, there is still no easy method to obtain such information in vivo. This study shows the utility of combining ultrasound contrast imaging with particle image velocimetry (PIV) for non-invasive measurement of velocity vectors. The steady flow analytical solution and optical PIV measurements (for pulsatile flow) were used for comparison. When compared to the analytical solution, both echo PIV and optical PIV resolved the steady velocity profile well. Error in shear rate as measured by echo PIV (8%) was comparable to the error of optical PIV (6.5%). In pulsatile flow, echo PIV velocity profiles agreed well with optical PIV profiles. Echo PIV followed the general profile of pulsatile shear stress across the artery but underestimated wall shear at certain time points. These studies indicate that echo PIV is a promising technique for the non-invasive measurement of velocity profiles and shear stress.

초음파 조영제를 애용한 Echo PIV 기법의 개발 (Development of Echo PIV Using Ultrasound Contrast Agent)

  • 김형범
    • 대한기계학회논문집B
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    • 제28권12호
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    • pp.1528-1534
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    • 2004
  • The combination of ultrasound echo images with digital particle image velocimetry (DPIV) methods has resulted in a two-dimensional, two-component velocity field measurement technique appropriate for opaque flow conditions including blood flow in clinical applications. Advanced PIV processing algorithms including an iterative scheme and window offsetting were used to increase spatial resolution. The optimum concentration of the ultrasound contrast agent used for seeding was explored. Velocity validation tests in fully developed laminar pipe flow result of echo PIV showed good agreement with both optical PIV measurements and the known analytic solution based on a volume flow measurement.

급성 골수성 백혈병 소아환자에서 초음파 검사에서 낭미충증으로 오인된 표피 포도알균에 의한 파종 감염 병변이 발생한 증례 (Disseminated Septic Lesions Caused by Staphylococcus epidermidis Mimicking Cysticercosis Detected on Ultrasonography in a Pediatric Patient with Acute Myeloid Leukemia)

  • 이재민;최준식;유건희;김예진;김선자
    • Pediatric Infection and Vaccine
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    • 제27권2호
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    • pp.134-139
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    • 2020
  • 표피 포도알균은 사람 피부에 있는 정상균이나, 체내 이물질을 가진 사람이나 면역 저하자에게는 심각한 감염을 일으킬 수 있다. 13세 남자가 발열, 근육통으로 입원하였고 두피, 팔과 다리에 통증이 있는 결절성 병변이 만져졌다. 혈액검사에서 범혈구 감소증과 모세포 80% 소견을 보였고 급성 골수성 백혈병으로 진단되었다. 전신 자기공명영상 검사에서 가장자리 조영 증강을 보이는 다발 낭성 병변이, 초음파 검사에서 에코성 낭성 병변과 그 내부의 에코성 결절이 팔과 다리의 근육 내부에서 관찰되어, 낭미충증이 강력히 의심되었다. 그러나 초음파 유도하 조직 검사에서 농양이 확인되었고, 조직 배양검사에서 표피 포도알균이 동정되었다. 저자들은 백혈병 환자에서 낭미충증으로 오인되었던 표피 포도알균에 의한 전신 다발 병변이 발생한 예를 경험하였기에 보고하는 바이다.