• Archives of Plastic Surgery
• /
• v.34 no.4
• /
• pp.461-465
• /
• 2007

Purpose: Nasal bone fracture may be the most common fracture among facial trauma. However, diagnosis and treatment tend to be overlooked while the reduction and maintenance of fragments remain complicated. Thus, the results are plagued with high rate of nasal deformity which leads cosmetic and functional discomfort. We took advantage of the fact that the nasal bone is one of the thinnest facial bone while at the same time being located close to the skin and utilized ultrasound in performing reduction of nasal bone. Methods:This method was performed on 25 patients with nasal bone fracture. The CL 15-7 linear array transducer (10-15MHz) ultrasound which provides a total of 7 views (3 axial views and 4 transverse views) of the elevator under the bony fragments was enough for the surgeon to accurately perform the reduction. Results: In our class, an accurate and precise reduction has been made possible by real time images before, during, and after the procedure with the help of ultrasound while reducing the exposure to radiation. Conclusion: Compared to previous methods, satisfaction of patients has increased in the nasal tip, minimal fracture of the side wall and secondary reduction cases. Therefore, the incorporation of ultrasound in the closed reduction of nasal bone may prove to be a useful method.

• The Journal of the Acoustical Society of Korea
• /
• v.38 no.4
• /
• pp.467-475
• /
• 2019

A high-intensity ultrasound wave generates acoustic streaming and acoustic radiation forces when propagating through a medium. An acoustic radiation force generated in a three-dimensional space can produce a solid tactile sensation, delivering spatial information directly to the human skin. We placed 154 ultrasound transmit elements with a frequency of 40 kHz on a concave circular dish, and generated an acoustic radiation force at the focal point by transmitting the ultrasound wave. To feel the tactile sensation better, the transmit elements were excited by sine waves whose amplitude was modulated by a 60 Hz square wave. As an application of ultrasonic tactile sensing, a region where tactile sense is formed in the air is used as an indicator for the position of the hand. We confirmed the utility of ultrasonic tactile feedback by implementing a system that provides the number of fingers to a machine by receiving the shape of the hand at the focal point where the tactile sense is detected.

• Journal of Biomedical Engineering Research
• /
• v.3 no.1
• /
• pp.35-42
• /
• 1982

The objective of this phantom study is to develop a digital method for improving the lateral resolution of B-scan ultrasonographic images irs medical application of ultrasound. By utilizing a discrete state-space modeling approach and Kalman-Buch method for analysis of the transducer's beam profile and the measurement and sampling noise, a stable recursive restoration of the object image was obtained for improved lateral resolution. The point spread function (PSF) was measured for the reflective signals after scanning the small pins located along the depth of interest. One major advantage of the present recursive scheme over the transform method is in its applicability for the space-variant imaging, such as in the case of the rotational movement of transducer.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.26 no.3
• /
• pp.190-197
• /
• 2006

For enhancement of flaw detactability using array transducers, focusing of ultrasonic waves on a target in an inhomogeneous medium or through a complex geometry is important. But focusing can be strongly degraded by geometrical distortion of field radiated by the array transducers or by sound speed fluctuations in the propagating medium. In recent years, the time reversal technique has been proposed. Thus, in this paper, we describe the basic principal of the time reversal technique for focusing. Then, the implementation results of the time reversal technique for ultrasonic inspections using bulk waves and guided waves generated by array transducers are presented.

• Journal of Welding and Joining
• /
• v.15 no.3
• /
• pp.109-117
• /
• 1997

The temperature gradient in weldment changes the transit time and distorts the direction of the ultrasound beam to the higher temperature regions due to the lower sound speed in the hotter regions of the weldment. This paper describes a ray-tracing method for calculating the effects of temperature gradients on ultrasonic propagation in fillet arc weldig. In the method, weldment is conceptually devided into a number of layers and the refraction and sound speed at each layer is calculated using the temperature which calculated from analytical solution. Calculating the time and location of echoes arrived from various interfaces around a molten weld pool determines the optimum location of ultrasonic transducers and the correct position of flaws.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.6
• /
• pp.879-884
• /
• 2012

Photoacoustic Tomography (PAT) is a promising medical imaging modality by reason of its particularity. It combines optical imaging contrast of optical imaging with the spatial resolution of ultrasound imaging and can demonstrate change of biological feature in an image. For that reason, many studies are in progress to apply this technic for diagnosis. But, real-time PAT system is necessary to confirm a biological reaction induced by external stimulation immediately. Thus, we developed a real-time PAT system using linear array transducer and self-developed Data acquisition board (DAQ) resources, To evaluate the feasibility and performance of our proposed system, two type of phantom test were also performed. As a result of those experiments, the proposed system shows enough performance and confirm its usefulness.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.7
• /
• pp.455-461
• /
• 2015

The paper deals with the accuracy comparison between two kinds of ultrasonic paths for flow rate measurement. In the Z-path, two transducers are installed on the opposite sides of each other on a pipe, and the ultrasonic waves generated at one transducer propagate to arrive at the other one only by refraction. In the V-path, two transducers are installed on one side of a pipe, and the ultrasonic waves reflected at the inner wall of the pipe are received. Transit times were confirmed to identify the propagation paths by comparing the theoretically calculated results and measured ones. The flow rate measurements with two kinds of ultrasonic paths appeared very similar. It would be possible to select either of the paths by considering the advantages and disadvantages.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.736-738
• /
• 2014

The paper deals with the accuracy comparison between two kinds of ultrasonic paths for flow rate measurement. In the Z-path, two transducers are installed on the opposite side of each other on a pipe, and the ultrasonic waves generated of one transducer propagate and arrive at the other one only through refraction. In the V-path, two transducers are installed on one side of a pipe, and the ultrasonic waves reflected at the inner wall of the pipe are received. The backgrounds were established to select one path to fit the usage by considering the advantages and disadvantages.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.28B no.10
• /
• pp.822-830
• /
• 1991

In this paper, we propose a new process for ultrasonic B-mode image considering the sound field effects of a concave circuit focused transducer, and aim to remove the speckle pattern which cause the blurring on boundary in ultrasonic B-mode image. We discuss in detail the conception of speckle pattern generation, and the frequency compounding method which is applied to the process for getting a speckle reduced B-mode image. Through the computer simulation, we define the meaning of speckle region, and show the results of reduced speckle pattern. It is discovered in the results that the frequency compounding method is very effective for boundary detection and that the application of the method is limited by various conditions.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.21 no.5
• /
• pp.33-40
• /
• 1984

In the conventional pulsed doppler system, gated CW is used to excite a ultrasonic transducer so that a group of linear RF amplifiers are required to excite a ultrasonic array transducer in the scanning pulsed doppler system. A pulsed doppler system without linear high voltage RF amplifiers, which excites the transducer impulsively, is studied theoretically and experimentally. In this paper, an experimental 8-channel pulsed doppler system is implemented, which uses quadrature defection to detect the direction of motion and can compensate the attenuation effect. The designed pulsed doppler system shows the possibility of real time multichannel doppler flow meter.