• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2013년도 제47차 동계학술대회논문집 21권1호
• /
• pp.281-282
• /
• 2013

맥박을 측정하는 방법 중 하나인 PPG(photoplethysmography) 센서는 설계가 비교적 간편하며 사용이 편한 장점이 있지만, 움직임으로 인한 동잡음에 취약하다는 단점이 있다. 본 논문에서는 동잡음으로 인한 센서와 손가락 사이의 밀착되는 압력의 변화를 측정하여 왜곡된 신호를 보상하였다. PPG센서와 손가락 사이의 압력을 측정하기 위하여 FSR(force sensing resistor)센서를 이용하여 측정하였으며, 측정된 압력과 왜곡된 PPG 신호 비교를 통해 왜곡된 PPG신호와 FSR센서에서 얻은 압력 사이의 연관성을 확인하였고, 신호처리를 통하여 왜곡된 신호를 보상 시켰다. 이와 같은 방법으로 PPG신호를 보상하게 된다면 웨어러블한 환경에서의 적용뿐만 아니라 헬스케어로 응용이 가능할 것으로 보인다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1963-1967
• /
• 2003

Communication device to use slight movement for serious disabled is proposed. This device is developed mainly for patients suffering from ALS or a cerebral infarction. They often have communication difficulty because of deterioration of muscular functions. Features of this device are that the device is wearable on the user’s body and that it detects the movement of eyebrow. Because of these features, it is quite easy to install the sensor on the patient’s body, not like the conventional sensors. Furthermore, an adaptive communication software is incorporated. A feature of this software is that the arrangement and size of the button and window on the display can be optimized depending on the user's physical ability. In the field test it is confirmed that the communication device developed in this study is successfully helped the people with disability for increasing their communication ability.

• 한국컴퓨터정보학회논문지
• /
• 제22권2호
• /
• pp.9-19
• /
• 2017

Useful continuous sensing applications are increasingly emerging as a new class of mobile applications. Meanwhile, open, multi-use sensor devices are newly adopted beyond smartphones, and provide huge opportunities to expand potential application categories. In this upcoming environment, uncoordinated use of sensor devices would cause severe imbalance in power consumption of devices, and thus result in early shutdown of some sensing applications depending on power-hungry devices. In this paper, we propose EnergyCordy, a novel inter-device energy use coordination system; with a system-wide holistic view, it coordinates the energy use of concurrent sensing applications over multiple sensor devices. As its key approach, we propose a relaxed sensor association; it decouples the energy use of an application from specific sensor devices leveraging multiple context inference alternatives, allowing flexible energy coordination at runtime. We demonstrated the effectiveness of EnergyCordy by developing multiple example applications over custom-designed wearable senor devices. We show that EnergyCordy effectively coordinates the power usage of concurrent sensing applications over multiple devices and prevent undesired early shutdown of applications.

• 센서학회지
• /
• 제26권1호
• /
• pp.56-59
• /
• 2017

This paper presents the Inkjet-printed strain gauge using PEDOT:PSS. The strain gauge (width 0.6 mm, length 20 mm, thickness $0.3{\mu}m$) was printed on the PET film using PEDOT:PSS ink. The resistance variation of the fabricated strain gauge was measured by the digital multi-meter with the displacement range of -4 to 10 mm. As the measured result, resistance variation (${\Delta}R/R_0$) has approximately 0.75%, linearity of 99.87%. The fabricated strain gauge is expected to the various applications such as tape type pressure sensor, PMS(pressure mapping sensor), wearable devices.

• 센서학회지
• /
• 제23권6호
• /
• pp.402-408
• /
• 2014

Heart rate is one of the most important signal to monitor the health condition of the patient or exerciser. Various wearable devices have been developed for the continuous monitoring of ECG signal from human body during exercise. Among these, ECG chest belt has been widely used. However wearing chest belt with ECG sensor is uncomfortable in normal life due to the electrode contact between metal electrodes of ECG sensor and skin of the human body. So we develop the royal healthcare backpack that can measure ECG signal without skin contact by using capacitor-type ECG sensor. The position of the measurement point is critical to collect a clear ECG signal in the capacitive ECG measurement from backpack. Various tests were conducted to find the optimal ECG measurement position which has less noise and could get strong and clear ECG signal during exercise, walking, hiking, mountain climbing and cycling.

• 반도체디스플레이기술학회지
• /
• 제6권4호
• /
• pp.43-47
• /
• 2007

In this paper, we propose a novel sensor system for measuring the arterial pulse in an oral cavity. In order to measure pulse wave in oral cavity, the proposed system is designed with reflection type arterial wave sensor, not by using transmission type arterial pulse wave sensor. Driving circuit through pulse current is designed for solving self-heating problem of LED. The effectiveness of the proposed sensor system is compared with pulse wave between pulse wave of oral cavity and other body parts as well as with characteristic measurements. The experiment shows that the proposed sensor system is adaptive to capturing consecutive and meaningful biometric signals through the variation of pulse wave changes in oral cavity when exercising. The study result expects to design and develop mobile sensors which could be adapted to healthcare devices.

• 센서학회지
• /
• 제25권4호
• /
• pp.257-263
• /
• 2016

Among several technologies related to human brain, Brain Computer Interface (BCI) system is one of the most notable technologies recently. Conventional BCI for direct communication between human brain and machine are discomfort because normally electroencephalograghy(EEG) signal is measured by using multichannel EEG sensor. In this study, we propose 2-channel EEG sensor-based application control system which is more convenience and low complexity to wear to get EEG signal. EEG sensor module and system algorithm used in this study are developed and designed and one of the BCI methods, Motor Imagery (MI) is implemented in the system. Experiments are consisted of accuracy measurement of MI classification and driving control test. The results show that our simple wearable system has comparable performance with studies using multi-channel EEG sensor-based system, even better performance than other studies.

• Journal of Multimedia Information System
• /
• 제2권4호
• /
• pp.327-332
• /
• 2015

Recently, as microcomputers and sensors have been miniaturized due to dropdown of their market rates, this lead to a favorable environment for implementing the Internet of Things. Smart clothing refers to a system which can be wearable or portable, and allows people to communicate or conduct sensing. Applying the Internet of things, the role of the server computer is to receive and process data obtained from the sensor. An ordinary PC can act as a server but during the implementation of IoT, a PC has limited application due to a large size and the inconvenient portability. This study proposes a model that allows a variety of functions while implementation with the server from the sensing using the Arduino and Raspberry Pi. If we apply this proposed model, everyone can easily and inexpensively experience mobile IoT system.

• 한국생산제조학회지
• /
• 제22권3_1spc호
• /
• pp.622-628
• /
• 2013

This paper describes the development of a thigh-muscle strength-assistance robot, which is a kind of wearable robot. For practicality and commercialization, we proposed three fundamental concepts: the reduction of the thigh-muscle strength, minimized degree of dependence on a powered actuator, and complete wearer safety. Based on these concepts, a spring and link bar mechanism was conceived as a novel idea. The movement of the thigh is transferred to the spring mechanism through the link bar; hence, the elastic force of the spring assists the thigh muscle. Using forse sensing resistor (FSR) sensors and a powered cam mechanism, the muscle assistance is automatically activated and deactivated according to the wearer's movement. The specific mechanisms of the robot are addressed in detail, and the effectiveness is verified by experiments.

• 한국정밀공학회지
• /
• 제26권12호
• /
• pp.146-153
• /
• 2009

One of the most important issues in the wearable healthcare sensors is to minimize the motion artifacts in the vital signals for continuous monitoring. This paper presents a reflected type photoplethysmograph (PPG) sensor for monitoring heart rates at the artery of the wrist. Active noise cancellation algorithm was applied to compensate the distorted signals by motions with Least Mean Square (LMS) adaptive filter algorithms, using acceleration signals from a MEMS accelerometer. Experiments with a watch type PPG sensor were performed to validate the proposed algorithm during typical daily motions such as walking and running. The developed sensor is suitable for ubiquitous healthcare system and monitoring vital arterial signals during surgery.