World's first system that measures all electrical signals in the body absolutely 'uninterrupted'

□ DGIST (President: Kuk Yang) announced on the 7th (Tuesday) that a research team led by Professor Lee Jung-hyup of the Department of Electrical Engineering and Computer Science succeeded in developing the world's first integrated circuit system converting analog signals into digital signals that can obtain all kinds of bio-electrical signals. This newly developed technology can precisely measure the electrical signals generated by the human body even in an environment with strong external noise. It is expected to be used in various fields such as brain-machine interface technology, which is drawing great attention as a future technology, and medical-health care fields such as ultra-small, high-performance medical devices.

□ Electrical signals generated in the living body are very diverse, such as electrocardiogram (ECG), brain electroencephalogram (EEG), and electro-neurogram (ENG) generated from the heart, and each signal has different signal characteristics. For example, in the case of an electroencephalogram, the signal size is very small at the level of 1 microvolt. On the other hand, in the case of electroneurogram, the frequency range occupied by the signal is very wide compared to other signals. It requires over ten times bandwidth. Due to this difference, the biosignal measurement technology developed so far was able to acquire only a specific signal in a stable environment with almost no noise. It was difficult to expand or apply it to other technological fields.

□ Under such circumstances, Professor Lee Jung-hyup's team successfully developed the 'analog-to-digital signal conversion system' capable of measuring all bioelectrical signals even in a very poor environment where electrical stimulation interference that is up to tens of thousands of times larger than the measured signal and motion artifacts that may be caused by the movement of the subject exist, for the first time in the world. Since the system is developed with semiconductor ICs (Integrated Circuits), it is ultra-low power consuming, compact, and versatile, which makes it very easy to apply to various applications.

□ Professor Lee Jung-hyup's team proposed a low-noise, high-linearity circuit technology based on the 'continuous-time delta-sigma conversion technology' for the successful development of this system. In addition, the team newly developed a circuit technique for increasing input impedance that is robust against parasitic components. As a result, the team’s achievements were recognized as having the best performance in the world at three times or more improvement from the existing world's best biosignal measurement technology.

□ Professor Lee Jung-hyup of the Department of Electrical Engineering and Computer Science at DGIST said, “It is a technology that can be a great help to miniaturization and high performance of existing related medical devices by enabling precise measurement of various biosignals with a single semiconductor IC (integrated circuit) system,” while adding, “It can be applied to various applications such as the next-generation brain-machine interface, micro-wearable diagnostic device, and electronic medicine, which are drawing enormous attention as future technologies.”

□ Meanwhile, the results of this research were presented at the International Solid-State Circuit Conference (ISSCC), the world's top conference in the field of semiconductors, referred to as the 'Semiconductor Olympics' in February. In addition, this research was carried out through the support of the National Research Foundation of Korea for the development of bio fusion source technology and the joint research project of the Institutes of Science and Technology.

Correspondence Author Email Address : jhlee1@dgist.ac.kr