Prof. Oh-Kyong Kwon of Electrical and Computer Engineering is a Vice President of National Academy of Engineering of Korea (NAEK), Director of Integrated Electronics Laboratory at Hanyang University (HYU), and Fellow of the Society of Information Display (SID) whose research interests lie in the five fields of display electronics, power electronics, high-speed interface, sensor readout technologies, and bio-medical electronics. As a graduate of HYU, Kwon has devoted himself to research for the development of smart power integrated circuit technologies for automotive and display electronics.
3-D ultrasonic imaging systems do not use ionizing radiation, unlike x-rays. Thus, there is no risk of harmful radiation exposure to the patient. Since the 3-D ultrasound images are captured in real-time, they demonstrate the structure and movement of the body's internal organs and even show the blood flowing through the blood vessels. Nonetheless, in reality, there is still a predicament in implementing a compact system through the conventional system structure as there are too many cables used to connect thousands of ultrasound transducers and front-end circuits.
As a solution to the problem, Kwon, in his recently published IEEE journal this month, introduced an integrated ultrasound chip (IUC), which adopts a three-side buttable architecture to integrate numerous capacitive micro machined ultrasonic transducers (CMUTs) and a reconfigurable 16 ⅹ 16 transceiver array to configure the transmitting and receiving patterns of a CMUT array. Additionally, Kwon proposed the implementation of a static sequential access memory (SSAM) block in order to reduce the loading time of the configuration data for the 2 ⅹ N IUC array. With the IUC which can reconfigure transmitting and receiving array patterns and extend them to a larger array, Kwon was able to optimize the image signal-to-noise ratio (SNR) and frame rate for a given target image.
In the process, Kwon employed the digital pulse width control scheme to integrate the transceiver underneath each CMUT. The state-of-the-art digital pulse had been useful since it occupied only a small area in contrast to the previously developed analog pulse width control scheme which occupied a large area due to its large capacitor. Moreover, to measure the transmitting pressure of the IUC, the IUC was immersed in bean oil. The speed of ultrasound in bean oil had been comparable with the speed of ultrasound in the human body and this allowed the research team to estimate the attenuation and diffraction losses and the receiving gain of the IUC.
Through the process, Kwon and his research team illustrated a three-side buttable IUC which integrates a 16 ⅹ 16 reconfigurable transceiver and CMUT array. According to him, the proposed IUC demonstrates three significant advantages over previously reported works. First, the reconfigurable transceiver array enables optimization of the image SNR and frame rate for a given target image by producing various transmitting and receiving array patterns. Second, 2 ⅹ N extension of the IUC allows the integration of numerous CMUTs. Lastly, the SSAM produces a simple interface of the 2 ⅹ N IUC array and lessens the configuration data-loading time, which is highly effective. With the IUC demonstrating the aforementioned advantages, Kwon and his research team introduce a new chapter in the 3-D ultrasound imaging systems.
Currently, Kwon is involved in a vast array of projects. In collaboration with Samsung Advanced Institute of Technology (SAIT), he has been making substantial efforts to design the internal circuit of 3-D ultrasonic imaging systems which could be utilized in creating 2D and 3D videos. Also, the pixel circuits and driving methods for high image quality Active Matrix Organic Light Emitting Diodes (AMOLED) display and OLED-on-Silicon micro display which allow a 3-D view on tiny devices. Meanwhile, Kwon and his research team have been making advancements in the field of Power Electronics. They have been making single input multiple output (SIMO) DC-DC converter for mobile applications. Kwon predicts the highly efficient power and advanced battery management capacity will be integrated in a multitude of electronic devices. In addition, he has been conducting a series of project reports on CMOS X-ray detectors for medical CT applications. The bio-signal monitoring system he has been developing will be utilized in the medical industries for medical check-ups of patients.
"I plan to focus on my research for specialized displays and electronic sensors in the future. Particularly, I look forward to developing portable sensors which will be highly useful in our industries today. At the same time, I want to apply the technology in developing head-mounted display (HMD) such as Google Glass. In the end, engineering is all about practical application of science and technology," Kwon commented.