Hyoun-Seok Myoung

A new noise reduction method for oscillometric blood pressure measurement

In this paper, a new noise reduction method was proposed for oscillometric blood pressure measurement. The proposed method uses a capacitive sensor and an adaptive filter to minimize blood pressure measurement error. Noise such as undesired external pressure applied to cuff was focused on. Three types of the distorted oscillation signals (no overlap, non-consecutive overlap, consecutive overlap between the noise and the oscillation) were used to compare the conventional method using linear interpolation and the proposed method using the adaptive filter. The proposed method outperformed the conventional method in the case of consecutive overlap between the noise and the oscillation. The proposed method could be useful for measuring blood pressure in such a noisy environment that the subject is being transported.

Development of acupoints discrimination system using electric properties of acupoints and non-acupoints

The conventional acupuncture-point stimulus pattern uses direct current (DC) to discriminate acupuncture point and meridian lines, which are fundamental to diagnosis and treatment in Oriental medicine. However, DC is insufficiently reliable in discriminating these acupuncture points and lines. To overcome these problems, the authors extracted optimal parameters (e.g., square-like waveform with a frequency of 3∼5 kHz) with a single power alternating current (SPAC) stimulus pattern of 1.28V. The SPAC stimulus pattern has little or no effect on cells and the bodys physiological state and minimizes polarization and ionization of cells because it uses low voltage and alternating current. The authors developed a new meridian discrimination system that can be used with the SPAC.

A Unique Electrical Thermal Stimulation System Comparable to Moxibustion of Subcutaneous Tissue

Moxibustion strengthens immunity and it is an effective treatment modality, but, depending on the material quantity, shape, and composition, the thermal strength and intensity can be difficult to control, which may cause pain or epidermal burns. To overcome these limitations, a heat stimulating system which is able to control the thermal intensity was developed. The temperature distributions on epidermis, at 5 mm and 10 mm of depth, in rabbit femoral tissue were compared between moxibustion and the electric thermal stimulation system. The stimulation system consists of a high radio frequency dielectric heating equipment (2 MHz frequency, maximum power 200 W), isolation probe, isolation plate, negative pressure generator, and a temperature assessment system. The temperature was modulated by controlling the stimulation pulse duty ratio, repetition number, and output. There were 95% and 91% temperature distribution correlations between moxibustion and the thermal stimulus at 5 mm and 10 mm of depth in tissue, respectively. Moreover, the epidermal temperature in thermal stimulation was lower than that in moxibustion. These results showed that heat loss by the electric thermal stimulation system is less than that by the traditional moxibustion method. Furthermore, the proposed electric thermal stimulation did not cause adverse effects, such as suppuration or blisters, and also provided subcutaneous stimulation comparable to moxibustion.

Repeatability of the accelerometric-based method to detect step events for hemiparetic stroke patients

This study is to evaluate the repeatability of the accelerometric-method to detect step events for hemiparetic stroke patients. To evaluate this method, four adults with chronic hemiparetic stroke were participated. The repeatability of this method using a single three-axis accelerometer was evaluated with a six optical camera motion capture system. The correlation statistics and Bland-Altman plot were then used to evaluate the agreement between the step-time differences from the accelerometer data and the reflective markers data. The correlation coefficient of each two data was 0.99 (p < 0.001) and retest result was 0.99 (p < 0.001). The mean ± standard deviation (SD) between each two data along with the 95% limits of agreement (LOA = ±1.96 SD) was 2.58±2.37 ms (LOA = −2.07 ms and 7.23 ms), and retest result was 3.73±2.02 ms (LOA = −0.22 ms and 7.68 ms). These results show that the suggested method is useful to detect step events for hemiparetic stroke patients.

Electrical Characterization of Proposed Transpositional Acupoints on the Urinary Bladder Meridian in a Rat Model

Specific electrical characteristicsof acupointswere investigated on the urinary bladder (BL) meridian in 14 rats. BL acupointsand non-acupoints on the back were selected and their electrical voltages were measured by using aSPACsystem.The mean voltages of each point or each line were statistically analyzed by using the ANOVA test.The BL meridian showed voltages higher than those of the reference line (P < .05). Bilateral 1st BL lines presented higher voltages than bilateral 2nd BL lines (P < .05). Most BL acupoints had voltageshigher than those for the corresponding reference points (P < .05). In particular, theright BL16 exhibited the biggest difference from the reference point, followed by the left extra BL point-2, the right BL27, the left BL17, and theleft BL45. Additionally, the distributions of neurofilamentsfor several points were investigated by using immunohistochemistry. There was a trend for the BL acupoints to have larger numbers of neurofilaments than the reference points, and that trend seemed to be directly proportional to the difference in voltage between the points.In conclusion, BL acupoints on the back in ratsexhibited specific electric and histologic characteristics. Therefore, those acupointsmay be utilized to investigate the efficacy of acupuncturewith laboratory animals.

A design of RF stimulator which is similar to temperature distribution by moxibustion (preliminary study)

We developed a novel radio-frequency (RF) stimulator to mimic heat effects similar to the temperature distributions created by moxibustion in porcine tissue. Moxibustion is a traditional Oriental medicine technique using moxa, which is utilized not only to cure disease, but also to increase immunity. However, it may lead to undesired effects including severe pains, blisters, and burns because of the difficulty of controlling heat intensity during the process. To overcome these problems, a novel RF stimulator that can conduct thermal energy to the deep tissue of the body and also easily control the power of heat stimulation was proposed. RF stimulating protocols were designed to mimic the temperature profiles of two types of moxibustion. In our results, the temperature distributions created by the proposed protocols were similar to those attained by moxibustion. It was also shown that the proposed protocols were more effective than moxibustion for transferring heat effects into deep tissues.

Development of Non-contact Home Monitoring System for Infant Respiration to Prevent SIDS

Sudden infant death syndrome(SIDS) continues to be general cause of infant death. Also, apnea is supposed to be one of the main risk factor of SIDS. Therefore, Infant`s respiratory monitoring and real-time apnea detection is very important to prevent SIDS. In this study, we proposed a non-contact home monitoring system for infant`s respiration using Doppler radar in order to prevent SIDS. The respiration data were acquired from a commercialized baby simulator(Simbaby) using a Doppler radar. To evaluate a performance of the proposed system, the simulator was placed in a supine and prone position and the chest belt was used simultaneously as a reference signal. As a result, correlation coefficients between respiration rates of Doppler radar and the chest belt in each position were 0.95(p standard deviation) in supine and in prone from Bland-Altman analysis. The results indicated an excellent performance in detecting apnea with a sensitivity of 100% and a positive predictive value of 100% in each posture respectively. These results demonstrated that a proposed Doppler radar system is suitable for non-contact respiratory monitoring in order to prevent SIDS of infant.

Development of Mobile Monitoring System for Emergency Situation

In this paper, we have developed a mobile biosignal monitoring system which was able to measure and transmit the bio-signal simply for emergency situation and transport of critical care patients inter- or intra-hospital. The developed system was made up of bio-signal measurement modules, wireless communication module, LCD for display, main controller for module integration, and battery. The system was able to measure not only multi-channel ECG signals, diastolic and systolic blood pressure, SpO2, respiration and body temperature but also image of the affected part from a patient or disaster area. The acquired data was transmitted to ultra mobile PC or PDA with a Bluetooth wireless communication. And the data could be transmitted to the central emergency center using CDMA communication via a laptop PC. Additionally, the system includes the real-time automatic algorithm to detect abnormal ECG activity. The experimental test with simulated situation showed the possibility to be effectively used at emergency situation.