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Basic Study on High Frequency Ultrasound Imaging of Shellfish in Sediment 高周波超音波を用いた内生二枚貝音響可視化のための基礎的 検討
| Content Provider | Semantic Scholar |
|---|---|
| Author | Suganuma, Hiroki Mizuno, Katsunori Asada, Akira |
| Copyright Year | 2017 |
| Abstract | Asari (Ruditapes philippinarum) is a shellfish of a few centimeters in size, which lives in relatively shallow layer in sediment. The shellfish is not only an indispensable aquatic resource for humans but also important species which has purification function in underwater ecosystem. In Japan, the shellfish has greatly decreased in recent years [1]. Thus, it is necessary to establish a resource management method and a system for monitoring their lifecycle. However, sediment makes it difficult to survey the shellfish efficiently. In general, digging is used for the survey, however, the method requires huge effort and time. In addition, it always destructs a survey site. Therefore, an efficient and non-destructive survey method is required. Acoustic sensing has been applied to detect buried objects in sediment as one of the efficient methods. Buried wooden shipwrecks under the seabed were detected by using chirp signals with 1.5-13 kHz swept pulse [2]. Mizuno et al. visualized aquatic plant’s root in sediment as three-dimensional acoustic image using transducer that transmits a pulse with a center frequency of 100 kHz [3]. Thus, in most cases, wavelengths are much longer than grain sizes. However, in the case of detection of the shellfish, it is required to use high-frequency ultrasound which provides a wavelength closer to grain size. In addition, the shellfish lives in sediment with various grain sizes. The difference in grain size dramatically changes sound velocity and attenuation [4]. The different velocities deform pulse waves and a high attenuation deteriorates the contrast of acoustic images. Therefore, it is necessary to develop an effective acoustic visualizing method by using high-frequency ultrasound. The objective of this paper is to improve the visibility of acoustic image deteriorated by changing sound velocity and attenuation with different grain sizes. We observed reflected waves from an aluminum square pillar and a shellfish buried in glass beads (GB) with different grain sizes. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.use-jp.org/proceedings/USE17/pdf/1P6-5.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
