• Journal of Sensor Science and Technology
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• v.30 no.2
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• pp.109-113
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• 2021

In this study, an automated culture media replacement system was developed to analyze changes in the contraction characteristics of cardiomyocytes according to the state of the culture media. For the long-term storage of culture media, a Peltier refrigerator with a temperature of 5 to 8℃ was provided and a pH of 7.4 was maintained. The cell culture media of the cardiomyocytes was continuously replaced using interlocking pumps at a flow rate of 0.83 μl/h. The cardiomyocytes in which the culture media was replaced automatically demonstrated lower heartbeats per minute compared to samples in which there was no replacement. However, these cardiomyocytes moved more uniformly and produced greater displacement in one heartbeat cycle. It was observed that the sarcomere length of the cardiomyocytes increased due to the automated culture media replacement system. These cardiomyocytes were found to demonstrate better maturation compared to the control group. The maturation of cardiomyocytes was verified through staining images. The proposed automated culture media replacement system generates a uniform heart rate and improvements in contraction force. Based on the study, patient-specific drug toxicity assessments can be conducted using differentiated cardiomyocytes in induced pluripotent stem cells.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.105-112
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• 2010

In this paper, the bio-signals, such as EEG, ECG were measured with a sensor and their characters were drawn out and analyzed. With results from the analysis, four emotion of rest, concentration, tension and depression were inferred. In order to assess one's emotion, the characteristic vectors were drawn out by applying various ways, including the frequency analysis of the bio-signals like the measured EEG and HRV. RBFN, a neural network of the complex structure of unsupervised and supervised learning, was applied to classify and infer the deducted information. Through experiments, the system suggested in this thesis showed better capability to classify and infer than other systems using a different neural network. As follow-up research tasks, the recognizance rate of the measured bio-signals should be improved. Also, the technology which can be applied to the wired or wireless sensor measuring the bio-signals more easily and to wearable computing should be developed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.67-71
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• 2007

Recently, a health care need according to the increase of an advanced age population is increasing. The requirement about a health care monitoring is increasing rapidly from general people as well as patient. The requisition about a medical treatment technique and a medical treatment information service is the trend to be expanding. That can be possible minimizing the inconvenience of the patient to take a medical service and continuously monitoring the status of the patient to take a health care service. This paper discusses an implementation of wireless physiological signal monitoring system for health care. The system are composed of the sensor node and monitoring program. The sensor node has the physiological signal measurement part and the wireless communication part. The remote monitoring system has a monitoring program that are communicating the sensor node using bluetooth. The sensor node measured the ECG, pulse wave, blood pressure, Sp02, and heart rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1401-1407
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• 2008

Recently, a health care need according to the increase of an advanced age population is increasing. The requirement about a health care monitoring is increasing rapidly from general people as well as patient. The requisition about a medical treatment technique and a medical treatment information service is the trend to be expanding. That can be possible minimizing the inconvenience of the patient to take a medical service and continuously monitoring the status of the patient to take a health care service. This paper discusses an implementation of wireless physiological signal monitoring system for health care. The system are composed of the sensor node and monitoring program. The sensor node has the physiological signal measurement part and the wireless communication part. The remote monitoring system has a monitoring program that are communicating the sensor node using bluetooth. The sensor node measured the ECG, pulse wave, blood pressure, SpO2, and heart rate.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.1
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• pp.1-6
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• 2024

Spiders detect even tiny vibrations through their vibrational sensory organs. Leveraging their exceptional vibration sensing abilities, they can detect vibrations caused by prey or predators to plan attacks or perceive threats, utilizing them for survival. This paper introduces a nanoscale crack-based sensor mimicking the spider's sensory organ. Inspired by the slit sensory organ used by spiders to detect vibrations, the sensor with the cracks detects vibrations and pressure with high sensitivity. By controlling the depth of these cracks, they developed a sensor capable of detecting external mechanical signals with remarkable sensitivity. This sensor achieves a gauge factor of 16,000 at 2% strain with an applied tensile stress of 10 N. With high signal-to-noise ratio, it accurately recognizes desired vibrations, as confirmed through various evaluations of external force and biological signals (speech pattern, heart rate, etc.). This underscores the potential of utilizing biomimetic technology for the development of new sensors and their application across diverse industrial fields.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.5
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• pp.171-180
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• 2023

The three major sleep disorders in Korea are snoring, sleep apnea, and insomnia. Lack of sleep is the root of all diseases. Some of the most serious potential problems associated with sleep deprivation are cardiovascular problems, cognitive impairment, obesity, diabetes, colitis, prostate cancer, etc. To solve these problems, the Korean government provided low-cost national health insurance benefits for polysomnography tests in July 2018. However, insomnia patients still have problems getting treated in terms of time, space, and economic perspectives. Therefore, it would be better for insomnia patients to be allowed to test at home. The measuring device can measure six biosignals (eye movement, tossing and turning, body temperature, oxygen saturation, heart rate, and audio). A gyroscope sensor (MPU9250, InvenSense, USA) was used for eye movement, tossing, and turning. The input range of the sensor was in 258°/sec to 460°/sec, and the data range was in the input range. Body temperature, oxygen saturation range, and heart rate were measured by a sensor (MAX30102, Analog Devices, USA). The body temperature was measured in 30 ℃ to 45 ℃, and the oxygen saturation range was 0% for the unused state and 20 % to 90 % for the used state. The heart rate measurement range was in 40 bpm to 180 bpm. The measurement of audio signal was performed by an audio sensor (AMM2742-T-R, PUIaudio, USA). The was -42 dB ±1 dB frequency range was 20 Hz to 20 kHz. The measured data was successfully received in wireless network conditions. The system configuration was consisted of a PC and a mobile app for bio-signal measurement and data collection. The measured data was collected by mobile phones and desktops. The data collected can be used as preliminary data to determine the stage of sleep and perform the screening function for sleep induction and sleep disturbances. In the future, this convenient sleep measurement device could be beneficial for treating insomnia.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.196-201
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• 2016

Rehabilitation exercises are the treatments designed to help patients who are in the process of recovery from injury or illness to restore their body functions back to the original status. However, many patients suffering from chronic diseases have found difficulties visiting hospitals for the rehabilitation program due to lack of transportation, cost of the program, their own busy schedules, etc. Also, the program usually contains a few medical check-ups which can cause patients to feel uncomfortable. In this paper, we develop a remote rehabilitation system with bio-signals by a stereo camera. A Kinect stereo camera manufactured by Microsoft corporation was used to recognize the body movement of a patient by using its infrared(IR) camera. Also, we detect the chest area of a user from the skeleton data and process to gain respiratory status. ROI coordinates are created on a user's face to detect photoplethysmography(PPG) signals to calculate heart rate values from its color sensor. Finally, rehabilitation exercises and bio-signal detecting features are combined into a Windows application for the cost effective and high performance remote rehabilitation system.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.7-14
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• 2014

Noncontact electrocardiogram (ECG) measurement using capacitive-coupled technique is a very reliable long-term noninvasive health-care remote monitoring system. It can be used continuously without interrupting the daily activities of the user and is one of the most promising developments in health-care technology. However, ECG signal is a very small electric signal. A robust system is needed to separate the clean ECG signal from noise in the measurement environment. Noise may come from many sources around the system, for example, bad contact between the sensor and body, common-mode electrical noise, movement artifacts, and triboelectric effect. Thus, in this paper, the extended Kalman filter (EKF) is applied to denoise a real-time ECG signal in capacitive-coupled sensors. The ECG signal becomes highly stable and noise-free by combining the common analog signal processing and the digital EKF in the processing step. Furthermore, to achieve ubiquitous monitoring, android-based application is developed to process the heart rate in a realtime ECG measurement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.193-198
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• 2017

Recently, as interest in health increases, various wearable devices such as smart watch and smart band which can measure user's biometric information are being studied. Conventional wearable devices service the measured biometric information in a form that provides simple monitoring, disease prevention, and exercise amount. However, the user is Lack to deal with the dangerous situation. In this paper, we propose a hazard notification system to address these problems. The biometric information measured by the acceleration sensor and the heart rate sensor is transmitted to the application through the Arduino in real time. It identifies the risk situation through sensor priority measurement and risk situation identification algorithm. If a dangerous situation occurs, a notification message is sent to the guardian indicating the current location of the user. Therefore, it can be expected that if a dangerous situation occurs to a user who needs protection, he can respond promptly.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.386-393
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• 1999

Objective : Cardiopulmonary exercise testing in patients with heart and lung problems is used to assess functional capacity, evaluate responses to medical treatment, plan for exercise therapy, assess progression of disease process, and determine prognosis. Particularly in the patients with lung cancer, the exercise pulmonary function test gives significant physiologic assessment of the lung resection candidate. Common exercise modalities are running and cycling. Until now, the comparison of two tests mainly has been done in normal person and patients with cardiac diseases. This study is designed to compare the treadmill and bicycle exercise pulmonary function test in patients with respiratory diseases. Methods : Twenty one patients underwent a progressively incremental exercise test to the symptom-limited stage with the treadmill (Vmax29 Sensor Medics, USA) and the bicycle(model No. 2,900 Sensor Medics, USA) with 7 days apart between the two tests. Measurements were made of the metabolic, cardiorespiratory parameters, blood gases, and symptoms. Results : The results of the treadmill exercise showed significant elevation in the $VO_2$max, VEmax, and anaerobic threshold compared to those of bicycle exercise. In contrast, the results of the breathing and heart rate reserve showed the reverse. Conclusion : These results suggest that the type of exercise should be taken into consideration when interpreting exercise test in patients with respiratory diseases.