KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Chunhakam, Puripak

Search Results

Now showing 1 - 4 of 4
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Bluetooth Breathing Sound Detection Device Based on Time and Frequency Domain Analyze
    (2022-04-20)
    Chunhakam, Puripak
    ;
    Panpho, Phakakorn
    ;
    Wardkein, Paramote
    In this paper, a wearable and simple system for breathing sounds detection from the left and right External Auditory Canal (EAC) was proposed. This system consists of two main parts: 1) Hardware design for detecting input breathing sound signal and 2) software design for processing and displaying the output results. Two condenser microphones are used to detect breathing sound and the detected signal is transmitted to the main processor by a Bluetooth channel. Two main proposed algorithms to detect breathing sounds and evaluate the number of respirations were presented: the first algorithm employs sound signals in the time domain to detect breathing sound with power window threshold scanning and count breathing pulses. For the second one, Fast Fourier transforms (FFT) along with detecting the maximum magnitude of its low-frequency elements in the breathing frequency band is presented and it is interpreted as respiration rate. The results of both algorithms show that the system can accurately monitor breathing. The percentage of error for the 1st and 2nd algorithms was 6.77% and 5.00%, respectively. The experimental results presented that this breathing detection system can measure and provide the breathing and respiration rate as expected.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    A New Bluetooth Wireless Speech Microphone from the Outer Ears
    (2022-01-01)
    Chunhakam, Puripak
    ;
    Wardkien, Paramote
    ;
    Boonjan, Surapol
    Today, microphones are essential equipment in variety of activities such as meetings, conferences, remote online learning. One problem with today's microphones is that ambient noise makes audio data unclear. In this article, we present a microphone that picks up sound of speech from the outer ear. It consists of two condenser microphone sensors mounted on the left and right ears like an earphone. Two different signals for the left and right ears are amplified by an instrumentation amplifier. Because it is attached to the outer ear, environmental noise is reduced. Moreover, the amplified signal is transmitted with a Bluetooth transmitter to transmit signals without wires causing comfort and flexibility to use. The results show that speech frequencies can be obtained over a wide frequency range and that environmental noise is canceled as expected.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Breathing sound detection from the external auditory canal with condenser microphones
    (2021-05-19)
    Chunhakam, Puripak
    ;
    Tuwanuti, Panwit
    ;
    Sangpisit, Wipa
    ;
    Wardkien, Paramote
    Breathing disorders or sleep apnea is one of the major causes of death that can be diagnosed through breathing while the patient is asleep. At present, breathing detectors are inconvenient for wearing and annoying in the activity of daily life. Therefore, in this research, we present a method for detecting the respiratory sound of breathing from the external auditory canal. This sound is produced by the flowing of air through the respiratory tract and the sound travel through the eardrum to the organs to the external auditory canal by using a condenser microphone to detect the sound of inhalation and exhalation, the detector is shaped like an earphone which does not disturb sleep and does not cause a nuisance to the wearer. Because we are already used to wearing headphones for listening to music while sleeping. This proposed breathing detection system prototype consists of a condenser microphone, amplifier, and signal processing was performed by using the MATLAB program to detect the peak of the breath signal and interpret the peak of the signal as breathing. The results showed that the system can accurately monitor the breathing with an error of about 9.81%
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    GPS Positon Predicting System by Kalman Filter with Velocity from OBD and Direction from Magnetometer
    (2021-03-10)
    Chunhakam, Puripak
    ;
    Pummarin, Phurit
    ;
    Jeen-Im, Purichaya
    ;
    Wardkien, Paramote
    ;
    Wisartpong, Pichet
    In this research, the GPS position system improving in a good and bad environment with Kalman filter is presented. Which proposed system consist of a GPS L26-DR module, GY-26 compass sensor for detected direction, and request velocity data from ECU with OBD-II and used as an input to Kalman filter to predict a more accurate position. The proposed system operates with two modes, the first mode is the mode that received normally position data, the received position data is fed to be an input of the Kalman system to improve that position data. If it loses the GPS position, the last position received from GPS will be used as an input to Kalman filter to predict the next position and after that, the previous predicted position data is feedback as an input to Kalman filter, and it repeats the process until the system can receive good GPS signals once again. The second one operates as the first mode in a normal situation, but the difference is, when it loses the GPS position, velocity data from a vehicle, direction from compass module and the last GPS position will be used to predict the next position. When it gets normally GPS position data, the GPS position is fed to an input of the Kalman filter. The results show that the first model has more errors than the second one but it's better than only conventional GPS positioning.