• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.3
• /
• pp.392-400
• /
• 1999

In this paper, the electromagnetic immunity of electronic medical equipments was tested by employing a standard test method for medical equipments. In addition, the electromagnetic interference to the medical equipments caused by four different types of mobile phones such as portable transceiver, analog, digital, and PCS cellular phones, have been studied. In this study, 16 medical equipments of 11 different types were investigated. There are a patient monitor, an infusion pump, a neonatal incubator and so on. In the case of the EMS test, the interferences were detected for seven medical equipments of four different types(53.3%) such as the patient monitor. For the two portable transceivers, 12 medical equipments of eight different models (75%) were affected. All medical equipments were satisfied with electromagnetic immunity by analog, digital and PCS cellular phones. The experiment results show that the malfunction of the electronic medical equipments is dependent on the frequency range and the electric field strength of the mobile phones.

• Journal of IKEEE
• /
• v.7 no.2 s.13
• /
• pp.245-252
• /
• 2003

We designed a silicon pressure sensor interface circuit with digital calibration capability. The interface circuit is composed of an analog section and a digital section. The analog section amplifies the weak signal from the sensor and the digital section handles the calibration function and communication function between the chip and outside microcontroller that controls the calibration. The digital section is composed of I2C serial interface, memory, trimming register and controller. The I2C serial interface is optimized to suit the need of on-chip silicon microsensor in terms of number of IO pins and silicon area. The major part of the design is to build a controller circuit that implements the optimized I2C protocol. The designed chip was fabricated through IDEC's MPW. We also made a test board and the test result showed that the chip performs the digital calibration function very well as expected.

• Physical Therapy Rehabilitation Science
• /
• v.10 no.2
• /
• pp.225-234
• /
• 2021

Objective: We aimed to identify the effects of proprioceptive neuromuscular facilitation (PNF) stretching on pain, hip range of motion, and functional disability in patients with chronic low back pain. Design: Randomized controlled trial Methods: In total, 45 patients with chronic low back pain were randomly divided into a conventional stretching group (n=22) and a PNF stretching group (n=23). Both interventions were performed three times per week for 6 weeks. Assessments were made using the visual analog scale, Flexion-Abduction-External Rotation test, modified Thomas test, prone hip extension test, and Oswestry disability index before and after the 6-week intervention period. We conducted a paired t-test to compare the within-group findings before and after the intervention. An independent t-test was used to compare the between-group differences. The statistical significance level was set at α=0.05, for all variables. Results: Both groups showed significant improvements in pain, hip range of motion, and functional disability after the intervention (p<0.05). A significant difference was observed in pain, hip range of motion, and functional disability in patients belonging to the PNF stretching group (p<0.05). Conclusions: This study provides evidence that the application of PNF stretching can effectively reduce pain and improve hip range of motion and functional disability in patients with chronic low back pain.

• Journal of the HCI Society of Korea
• /
• v.13 no.3
• /
• pp.17-33
• /
• 2018

Humans process aesthetic functions of objects such as form, size, color, and texture through vision, while at the same time observe them with a symbolic function by a new psychological interpretation based on their past experience. Therefore, it is more important to study and understand the thoughts and psychological influences of how humans perceive with their eyes than what humans simply look with them. With this research purpose in the background, this study will demonstrate in detail the cognitive characteristics of analog and digital images as a symbolic function with a "formative" point of view. Five hypotheses were established, which were proven through the following tests: smartphone, most frequently used in our daily lives, is simplified to a two-dimensional line drawing form, which is set to instances where the R(radius) is applied to the horizontal line of the two-dimensional form of smartphone, where Run-in-R(radius) is applied, and R(radius) rounding is applied to the edges of those shapes. The shapes were combined to form 12 pairs, which was used in a test to the test subjects. As a result, some human characteristics were observed; in specific, some helped prove objectively how humans perceived analog and digital images as psychologically stronger as a symbolic function. If people's thoughts and feelings gained through such study could be stored in database as one value and be provided to product designers, I believe it could be developed into design form as a basic emotional design that consumers desire.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.4
• /
• pp.2217-2224
• /
• 2014

This paper deals with system development which measures 12 channel ECG using medical analog front end(AFE) and discriminates arrythmia through signal analysis. Recently, occurrences of cardiac arrest have been increased. So the need of system that diagnoses an arrythmia which results in cardiac arrest is increasing. There are some drawbacks of conventional 12 channel ECG system that it occupies bulk and consists of complicated circuit. To improve those, we made up the system composed of medical AFE, algorithm for discriminating arrythmia and DSP for signal processing. This system can be monitored 12 channel ECG waveforms and the discriminant analysis result of arrhythmia through 7" LCD and received the input through touch pannel. In this study, we conducted normal operation test about output signal of ECG simulator(normal/abnormal ECG signal) to verify the implemented system and performance evaluation of the optimization process for applying arrhythmia algorithm to an embedded environment.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.9
• /
• pp.2082-2088
• /
• 1995

In this paper, we designed and fabricated the magnetic bearings and built-in type cylindrical capacitive transducers for improving the vibration characteristics of rotating shaft. The eddy current and magnetic field from the electromagnet of the bearing don't affect the measuring signal of the capacitive type transducers so that it is possible to locate the capacitive sensor plates around the magnetic bearing poles and can improve the spillover problem which is induced by the noncollocation of the sensors and actuators. According to the sensitivity calibration schemes using a X-Y table, the cylindrical capacitive transducers have a good linearities in the .+-.70.mu.m range from the geometric center of the sensor plates. The measured results also show high displacement sensitivities of the sensors. According to the performance test of the magnetic bearing which is controlled by the analog PD controllers, we found that the built-in capacitive transducer system successfully measures the journal displacement in the magnetic field and therefore the magnetic bearing system supports the rotating shaft up to 12,000 rpm.

• Journal of Biosystems Engineering
• /
• v.11 no.1
• /
• pp.8-16
• /
• 1986

This study was carried out to develop a microcomputer-based data acquisition system for engine performance test. A low-cost data acquisition system was developed utilizing an "APPLE II PLUS" microcomputer. The developed system consists of microcomputer, RPM counter included frequency-to-voltage converter, preamplifier for two load cells and 8-bit analog-to-digital converter with 16 chnnels. The system simultaneously measures engine speed by means of photointerrupter, torque and fuel consumption by means of load cells with variable sample numbers, sampling intervals and repetitions. The system collects, processes and provides data for storing on the $4{\frac{1}{4}}$ inch floppy disk as well as for writing out on the printer.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.272-275
• /
• 1992

Recently, the digital circuit technique has had great success and gained importance in all industries. For the measurement of degree of freshness of plant and animal's tissue, many devices has been developed. But it's data was inaccurate and it had difficulty in making database because it was depend on analog circuit technique. The purpose of this paper is the development of a device based on digital circuit for measurement of freshness degree of wet fish such that its accuracy is very trustworthy and it can be measured in a short time. The device is developed by using micro-computer with some interface modules of A-D/D-A converter and digital circuit with IC modules and its effectiveness has been evaluated through two experimental results of electrical Q-value test and chemical K-value test.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.161-163
• /
• 1997

Heatcycle testing for aluminum connector is very important. But because of connecting or disconnecting the test circuit, measuring resistance is difficult. Also the previous measuring resistance instrument is analog type. So measuring method is difficult. And four measuring points for one test circuit cause difficulty in automation. In this paper we developed the automatic system for measuring resistance. Automation will allow more information to be gathered, which will lead to the connector aging process being better understood and controlled.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.11a
• /
• pp.295-296
• /
• 2011

The DRM+ is the newest digital radio standard for in-band environment. Although various state of the art technologies are adopted, the performance evaluation information is not sufficient. It is hard that many countries and stations considering the DRM+ as their digital radio standard check the performance of DRM+. To evaluate the performance of the DRM+ system, this paper depicts the laboratory trial results of DRM+ standard. In the laboratory trial, the rack type DRM+ test bed is built. To reflect the practical broadcasting environment, various tests are executed. Many countries and stations can efficiently use these test results, which are considering converting their analog radio broadcasting to digital broadcasting.