The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
권호 표지

Thermal Sensitivity of the Bean Curd by Ultrasonic Irradiation

초음파 조사에 의한 두부의 열 감도

  • 조문재 (한국표준과학연구원 음향진동그룹) ;
  • 윤용현 (연세대학교 전기전자공학과) ;
  • 부유천 (한국외국어대학교 전자물리학과) ;
  • 김용태 (한국표준과학연구원 음향진동그룹)
  • Published : 2004.10.01
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Abstract

In this paper, the thermal sensitivity, i .e. the temperature rise per unit acoustic power, was newly defined and proposed as a performance parameter of a tissue mimicking material. Eatable tofu (bean curd) manufactured by a factory was selected as a sample material for the experiment. The temperature changes were measured not only with the variation of ultrasonic irradiation time, acoustic power, depth from the sample surface. and the distance from the source transducer while adjusting the frequency to 8 MHz but also with the variation of frequency while acoustic power. depth from the sample surface. and the distance from the source transducer keeping constant. As a result of a consideration for the transformation of the measured temperature changes to thermal sensitivities. the thermal sensitivity was found to be sufficient to use as a Performance parameter for tissue mimicking material. The tofu as a tissue mimicking material showed the maximum thermal sensitivity at 10 MHz, as is a significant result to imply the possibility that the thermal sensitivity of real human tissue strong1y depends on the frequency.

본 논문에서는 단위 음향파워에 대한 온도 변화인 열 감도 (thermal sensitivity)를 새로이 정의하였으며, 이 물리량으로 조직모사물질의 성능을 평가 할 수 있다는 것을 제안하였다. 실험에 사용된 시료는 공장에서 생산되는 식용 두부이고, 초음파의 주파수를 8 MHz로 고정하고 조사 (irradiation) 시간, 음향파워, 시료 표면으로 부터의 깊이 및 초음파 변환기와의 거리에 따른 온도 변화를 측정하였다. 아울러 깊이와 초음파 변환기와의 거리를 고정하고 일정한 음향파워 조건에서 주파수에 따른 온도 변화도 측정하였다. 측정된 온도변화를 열 감도로 변환하여 고찰한 결과 조직모사물질의 성능인자로 사용하기에 충분한 것으로 판명되었다. 특히 조직모사물질로 선택한 두부는 10 MHz 에서 열 감도가 최대로 나타났으며. 이 결과는 실제 인체 조직에서 열 감도가 주파수에 민감하게 의존 할 수 있다는 가능성을 함축하는 중요한 결과이다.

Keywords

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