Chih-Chung Wu

A wireless gait analysis system by digital textile sensors

This paper studies the feasibility of spatio-temporal gait analysis based upon digital textile sensors. Digitized legs and feet patterns of healthy subjects and their relations with spatio-temporal gait parameters were analyzed. In the first experiment, spatio-temporal gait parameters were determined during over ground walking. In the second experiment, predicted running, backward walking, walking up stairs and walking down stairs parameters were determined. From the results of the experiments, it is concluded that, for healthy subjects, the duration of subsequent stride cycles and left/right steps, the estimations of step length, cadence, walking speed, central of pressure and central of mass trajectory, can be obtained by analyzing the digital signals from the textile sensors on pants and socks. These parameters are easily displayed in several different graphs allowing the user to view the parameters during gait. Finally, the digital data are easily to analyze the feature of activity recognition.

Sleeping ECG and body position monitoring system

A textile-based ECG system for sleeper is presented. The electrode in the system is supported by a foam pad to ensure good contact as well as comfort to the wearer, and a flexible rubber to ensure that the electrode will electrically connect to the wearer only when pressed. Eight electrodes are multiplexed such that exactly two electrodes are pressed to connect the wearer no matter how the wearer lies. When the wearer lies in different positions, he/she will press different two electrodes, and then the morphology of the output ECG signal will be different accordingly. By this feature, the system can not only detect ECG but also determine the position of the sleeper.

Textile-based capacitive sensor for a wireless wearable breath monitoring system

A capacitive sensor is demonstrated as the key component of a wearable breath monitoring system. Its capacitance varies proportional to the pressure acting on it with high linearity and wide working range. All of the components of the sensor, including conductors, insulator, and conductive wires, are textile materials and are thus as soft as ordinary clothes; therefore, the sensor is also washable and durable. By installing one sensor on the chest and another on the lower abdomen, thoracic and abdominal breathing can be detected independently with little crosstalk. Driven by a low-power NE556 oscillator, the capacitances of both sensors can be detected digitally and then transmitted by a Bluetooth low-energy wireless communication module to a smartphone. Thus, a wearable breath monitoring system is implemented to provide continuous and real time breath signal monitoring without mobility constraints.

Dancing game by digital textile sensor, accelerometer and gyroscope

A novel dancing game, comprised of pressure sensors on socks with accelerometer and gyroscope to detect the movement of the player, is presented. The firmware in microcontroller can judge the movement of the player with enough accuracy such that the player would not be limited by wires and resident equipments. We designed a novel wearable entertainment system to provide a mixed reality game in which users can play dancing game.

Textile-based breath-sensing belt

A textile-based breath-sensing belt is presented. Four textile-based, clip type tension sensors, switching at different tension, are installed on a belt such that four-stage digitized pneumograph can be generated, from which both the breath rate and amplitude of the wearer can be estimated. The belt is washable, low-cost, easy and comfortable to wear, and suitable for healthcare, sports, interactive games, breath therapy.

Textile-based monitoring system for biker

A wearable monitoring system for biker is presented, with textile-based clip type tension sensors on belt and pants to detect bikers breath and steps, respectively, and an accelerometer, together with clip type sensors to detect falling down and other biking conditions. The clip type sensors are fully made of textile, so they are washable, durable, low cost, easily installed on ordinary clothing, and comfortable. The clip sensors and the accelerometer are able to output signals to a microcontroller to derive breath rate, step counts, posture, and flatness of road. The microcontroller will then transmit the information through Bluetooth interface to a PDA for further analyzing and send messages through mobile telephone when necessary. The system provides information about bikers physical condition, movement of bicycle, and road condition, which are important for both health and safety of modern citizen.

Game interface using digital textile sensors, accelerometer and gyroscope

Pressure sensors connecting with accelerometer and gyroscope through conductive, washable fabric, is designed into a dancing game to detect movements of a player. The firmware in microcontroller mounted on a belt can judge the players movements with enough accuracy that the player would not be limited by conventional wires and resident equipments as used in other popular dancing games. This novel wearable entertainment system provides a mixed reality game interface in which users can dance through 3 Modes with increasing sophistication.

A textile-based capacitive breath-sensing system

A textile-based breath-sensing system and the testing results with different postures are described. Two electrodes are placed on a belt, loosely buckled for user comfort, to charge and discharge a capacitor modeled off human movement of breathing. For most conditions of daily activities, the system has demonstrated capable of providing accurate measurement of respiratory rates.

A breathing game with capacitive textile sensors

Computer games are developed to encourage practice of thoracic or abdominal breathing for physiological and pathological treatment. It is demonstrated by using an exercise shirt embedded with two sets of dual sensors controlled by LM555 and PIC24FJ256 microprocessors, with animated display onto a computer screen. Results and future work are discussed.

Performance assessment of active electrode applied in wearable physiological monitoring system

A novel wearable physiological monitoring system is presented in this paper. The related signal and noise characteristics obtained by the system under electromagnetic and body motion interferences are analyzed and the performance of the active electrode circuit is assessed. It is concluded that the active electrode can eliminate the noise caused by electromagnetic interference significantly, but has less effect on body motion interference.