Research

  • Measuring Core Body
    Temperature from
    the Back of the Body

    Today, taking a bath is not only a means to keep clean, but also to reduce fatigue and stress. However, taking a bath with hot water for a long time can also be dangerous, leading to scalding or even a heart attack. To prevent these risks, several studies based on measuring bio-signals have been conducted, but due to high prices, difficulty of use, and restricted functions, these studies’ recommendations cannot be easily adopted by the public. Therefore, developing accurate methods to measure bathing temperature and bathing time should be the most direct approach to solve these problems. In this study, a smart bath assistive device based on an inner water temperature measurement function is proposed. Prior to development of the device, a bathing environment was emulated with six temperature sensors affixed to different depths to find the optimal depth for measuring bathing temperature. According to the measurement results, the device was designed in a mushroom shape with the cap part floating on the water’s surface and housing the electronic components, and temperature sensors within the stem part were immersed in the water approximately 5 cm below the surface to measure the inner water temperature. Due to the low-power consuming Advanced RISC Machine (ARM) processor and waterproof design, the device is able to float in hot water and monitor the bathing temperature variation over a long period of time. The device was compared alongside a commercial analog bathing thermometer to verify the performance of temperature measurements. In addition, a compensation algorithm was developed and programmed into the device to improve the accuracy of measurements. Processed data is transmitted by Bluetooth to a dedicated Android app for data display and storage. The final results show that the proposed device is highly accurate and stable for monitoring bathing temperature.

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  • Smart Sleep
    Assitant Lamp

    Children struggle to fall asleep by themselves because of their physiological characteristics. Therefore, re-search has been carried on various devices (such as a smartphone) to assist in improving the sleep quality of children. However, all such devices need to be controlled by parents and do not have functions for monitoring the sleep environment. In this paper, a smart sleep-lighting system that includes a sleep-lighting device and a smartphone dongle is developed to improve the sleep environment of children. The temperature, humidity, and luminance of the sleep environment are monitored and analyzed by the sleep-lighting device to control multi-color light and audio components. The colored light emitted by the multi-color light can be ad-justed to improve the sleep atmosphere. Also, the audio component can play white noise to induce sleep. In addition, parents can use a smartphone dongle with a multi-channel wireless communication method to monitor and control one or more lighting de-vices in different locations in real time. For environmental monitoring, average difference between proposed device and commercial sensor from chamber setting temperature 15 °C to 35 °C was 0.588 °C ± 0.10 ˚C, and average error value of the humidity measurement was 0.74 % at 40% ~ 60 % RH. Also, the manufactured sleep-lighting device shows good performance in multi-color light emission, and playing of white noise. As result, the smartphone connected to the proposed smartphone dongle enables monitoring and control of the proposed lighting device in a wireless well. The manufactured sleep-lighting device has a high-precision temperature and humidity sensor and a lumi-nance sensor that can accurately monitor the sleeping environment. The lighting device can play white noise to induce sleep in children. Also, a multi-color LED light is operated via a smartphone application to improve the sleep atmosphere. The measured data will be sent to the lighting device and processed together with sleep environment data in order to improve the sleep quality. Additionally, the final system will be tested for real end-users with clinical experiments by sleep research center of a university hospital.

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  • Measuring Core Body
    Temperature from
    the Back of the Body

    To measure skin temperature accurately, a semiconductor-based microtemperature sensor with a maximum accuracy of ±0.3°C was chosen and controlled by a high-performance/low-power consumption Acorn-Reduced Instruction Set Computing Machine (ARM) architecture microcontroller to build the temperature measuring device. Relying on a 2.4 GHz multichannel Gaussian frequency shift keying (GFSK) RF communication technology, up to 100 proposed temperature measuring devices can transmit the data to one receiver at the same time. .e shell of the proposed wireless temperature-measuring device was manufactured via a 3D printer, and the device was assembled to conduct the performance tests and in vivo experiments. .e performance test was conducted with a K-type temperature sensor in a temperature chamber to observe temperature measurement performance. .e results showed an error value between two devices was less than 0.1°C from 25 to 40°C. For the in vivo experiments, the device was attached on the back of 10 younger male subjects to measure skin temperature to investigate the relationship with ear temperature. According to the experimental results, an algorithm based on the curve-fitting method was implemented in the proposed device to estimate the core body temperature by the measured skin temperature value. .e algorithm was established as a linear model and set as a quadratic formula with an interpolant and with each coefficient for the equation set with 95% confidence bounds. For evaluating the goodness of fit, the sum of squares due to error (SSE), R-square, adjusted R-square, and root mean square error (RMSE) values were 33.0874, 0.0212, 0.0117, and 0.3998, respectively. As the experimental results have shown, the mean value for an error between ear temperature and estimated core body temperature is about ±0.19°C, and the mean bias is 0.05 ± 0.14°C when the subjects are in steady status.

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  • Capacitive Sensor for
    automatically measuring
    tumbler water level

    Drinking water has several advantages that have already been established, such as improving blood circulation, reducing acid in the stomach, etc. However, due to people not noticing the amount of water they consume every time they drink, most people drink less water than the recommended daily allowance. In this paper, a capacitive sensor for developing an automatic tumbler to measure water level is proposed. Different than in previous studies, the proposed capacitive sensor was separated into two sets: the main sensor for measuring the water level in the tumbler, and the reference sensor for measuring the incremental level unit. In order to confirm the feasibility of the proposed idea, and to optimize the shape of the sensor, a 3D model of the capacitive sensor with the tumbler was designed and subjected to Finite Element Analysis (FEA) simulation. According to the simulation results, the electrodes were made of copper and assembled in a tumbler manufactured by a 3D printer. The tumbler was filled with water and was subjected to experiments in order to assess the sensor’s performance. The comparison of experimental results to the simulation results shows that the measured capacitance value of the capacitive sensor changed linearly as the water level varied. This proves that the proposed sensor can accurately measure the water level in the tumbler. Additionally, by use of the curve fitting method, a compensation algorithm was found to match the actual level with the measured level. The experimental results proved that the proposed capacitive sensor is able to measure the actual water level in the tumbler accurately. A digital control part with micro-processor will be designed and fixed on the bottom of the tumbler for developing a smart tumbler.

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  • Using Formant Comparison Method
    to Design a Korean Pronunciation
    Self-Study System for Chinese Learner

    Because of Korean popular spread abroad rapidly through China, Korean language study has been became very popular. However, the pronunciation has many difference between Korean and Chinese. Therefore, the Chinese learners are difficult to study and exercise the Korean pronunciation exactly by themselves. Even if the learner study the Korean with a teacher, the teacher cannot supervise the learner all the time. Formant is an acoustic resonance of the human vocal tract that is able to know the sound production of the speaker. In this paper, using formant comparison method to design a Korean pronunciation self-study system for Chinese learner was presented. Through the developed algorithm, the formants are measured as amplitude peaks in the frequency spectrum of the Chinese leaner’s voice, the results can be explained by a spectrogram and comparison with the standard pronunciation to find the error of pronunciation automatically. The algorithm was designed by a Matlab program and conduct an experiment to test the performance. The experimental results shown the designed algorithm is able to measure the formant of the sound wave accurately, and the Chinese learners can find the reason of the error pronunciation easily by the designed comparison method. In the future, the presented system will be developed for more languages and transplanted to the mobile device.

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  • Implementation of adjustive latency
    compensation in a binaural hearing aid
    to prevent latency due to wireless transmission
    for using with multi-media devices

    Binaural hearing aid has become an important topic in recent research on hearing aids. It employs two hearing aids, one for each ear. However, a short latency between the outputs of the two hearing aids will occur owing to the wireless data transmission between two aids. In this study, an adjustive latency compensation was designed and implemented in a binaural hearing aids to prevent the latency. It includes a static part for the basic transmission time, and the length of an adjustive part can be adjusted depending on the transmission time change caused by a transmission failed. Therefore, a time measurement program with real time clock was designed to measure the time of every data package transmission. As the experimental results show, the proposed compensation is able to ensure synchronization between the two hearing aids even when a transient failure in the wireless communication between two hearing aids occurred.

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  • portable iontophoretic drug delivery
    device with in-vitro experiments for
    androgeneticalopecia treatment

    an iontophoresis method to treat the androgenetic alopecia with in-vitro experiment. To treat this condition, the drugs for alopecia treatment need to be delivered into the scalp. Therefore, iontophoretic stimulation was used in a portable drug delivery device to enhance the penetration of the drug delivery. Methodology: The designed device consisted of a drug container, an iontophoretic stimulation part and a rechargeable part. The iontophoretic part included a voltage boosted circuit, a protection circuit to achieve the iontophoresis effect and to protect the device. The device was tested with an oscilloscope and an in-vitro experiment was also performed to test the operation of the device. According to the experiment’s results, the iontophoresis circuit board performed well as did the designed drug delivery device. And the results of the in-vitro experiment also performed well with the penetration enhanced drug delivery via stimulation with the iontophoresis method. The presented portable iontophoretic device enhances the penetration of the drug delivery as proven by the experiment. Also, a positive feature of the device is that it allows patients to use it everywhere by themselves. Improving the device’s functionality and usage safety will be researched in the future.

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