• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.5
• /
• pp.284-288
• /
• 2016

Among the various physiological information that could be obtained from human body, heartbeat rate is a commonly used vital sign in the clinical milieu. Photoplethysography (PPG) sensor is incorporated into many wearable healthcare devices because of its advantages such as simplicity of hardware structure and low-cost. However, healthcare device employing PPG sensor has been issued in susceptibility of light and motion artifact. In this paper, to develop the real-time heart rate measurement device that is less sensitive to the external noises, we have fabricated an ultra-small wireless LC resonant pressure sensor by MEMS process. After performance evaluation in linearity and repeatability of the MEMS pressure sensor, heartbeat waveform and rate on radial artery were obtained by using resonant frequency-pressure conversion method. The measured data using the proposed heartbeat rate measurement system was validated by comparing it with the data of an commercialized heart rate measurement device. Result of the proposed device was agreed well to that of the commercialized device. The obtained real time heartbeat wave and rate were displayed on personal mobile system by bluetooth communication.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.2
• /
• pp.1201-1216
• /
• 2017

In this study, we described the development of a methodology to measure tip-pinch strength on the paretic hand rehabilitation device and aimed to investigate reliability of the device. FSR sensors were embedded on the device, and tip pinch strength was estimated with data collected from the sensors using a developed equation while participants were demonstrating tip pinch. Reliability tests included inter-rater, test-retest, and inter-instrument reliability. B&L Engineering pinch gauge was utilized for the comparison. Thirty-seven healthy students participated in the experiment. Both inter-rater and test-retest reliability were excellent as Intraclass Correlation Coefficients (ICCs) were greater than 0.9 (p<0.01). There were no statistically significant differences in tip-pinch strengths. Inter-instrument reliability analysis confirmed good correlation between the two instruments (r = 0.88, p < 0.01). The findings of this study suggest that the two instruments are not interchangeable. However, the tip-pinch mechanism used in the paretic hand rehabilitation device is reliable that can be used to evaluate tip pinch strength in clinical environment and can provides a parameter that monitors changes in the hand functions.

• International Neurourology Journal
• /
• v.22 no.4
• /
• pp.228-236
• /
• 2018

Neuromodulation was introduced for patients with poor outcomes from the existing traditional treatment approaches. It is well-established as an alternative, novel treatment option for voiding dysfunction. The current system of neuromodulation uses an open-loop system that only delivers continuous stimulation without considering the patient's state changes. Though the conventional open-loop system has shown positive clinical results, it can cause problems such as decreased efficacy over time due to neural habituation, higher risk of tissue damage, and lower battery life. Therefore, there is a need for a closed-loop system to overcome the disadvantages of existing systems. The closed-loop neuromodulation includes a system to monitor and stimulate micturition reflex pathways from the lower urinary tract, as well as the central nervous system. In this paper, we reviewed the current technological status to measure biomarker for closed-loop neuromodulation systems for voiding dysfunction.

• Journal of Biomedical Engineering Research
• /
• v.44 no.4
• /
• pp.264-274
• /
• 2023

Purpose: The objective is to extract insights that can contribute to the formulation of harmonized international policies and support measures for innovative medical devices and management systems. This study aims to propose effective strategies for future medical device innovation and healthcare delivery. Results: It investigates technological advancements, regulatory approval systems, insurance policies, and successful commercialization cases in South Korea, the United States, and the European Union. In 2018, the FDA implemented insurance coverage for Software as a Medical Device (SaMD) and recognized insurance coverage for Digital Therapeutics (DTx). Germany is a country that ensures permanent reimbursement for healthcare applications since 2020, making it the first country to provide legal health insurance coverage for fostering a digital ecosystem. Conclusion: The findings of this research highlight the importance of cultivating a supportive regulatory and environmental framework to facilitate the adoption of innovative medical devices. Continuous support for research and development (R&D) efforts by companies, along with the validation of clinical effectiveness, is crucial.

• Journal of Biomedical Engineering Research
• /
• v.38 no.3
• /
• pp.111-115
• /
• 2017

Blood pressure is one of the important vital signs for monitoring the medical condition of a patient. Automated NIBP(non-invasive blood pressure) monitoring devices calculate systolic and diastolic blood pressures from the oscillation in cuff pressure caused by a pulsation of an artery. To validate the NIBP devices, we developed a simulator to supply the oscillometric waveforms obtained from human subjects. The simulator provided pressure pulses to device-under-test and device readings were compared to the auscultatory references. Fully automated simulation system including OCR(optical character recognition) were developed and used for NIBP monitoring devices. The validation results using the simulator agreed well with previous clinical validation. More validation studies using the standardized oscillometric waveforms would be required for the replacement of clinical trials to validate a new automated NIBP monitoring device.

• Korean Journal of Oriental Medicine
• /
• v.13 no.1 s.19
• /
• pp.93-100
• /
• 2007

TObjectives: Develop a sham moxibustion and determine whether subjects can distinguish a sham moxibustion from a real moxibustion. Design: Single-blinded, randomized, placebo-controlled clinical trial Methods: Sham and real moxibustion resemble each other in appearance, burning procedure, but the base of the sham moxibustion isolates the moxa-producing heat and smoke. This device was tested in a clinical trial in which subjects received moxibustion at Zhongwan(CV12), Mingmen(GV4), Quchi(LI11), Zusanli(ST36), Taichong(LR3)), Hegu(LI4). Volunteers(n=32) were given pre-treatment questionnaire to assess their experience in getting moxibustion therapy and performing it. They randomized into treatment(n=16) or sham controlled group(n=16), received moxibustion according their groups. After treatments, the effectiveness of blinding was assessed. Results: There were no significant differences between two groups in sex, age, moxibustion experience. In the treatment group and the sham group, the number of subjects who believed they received real moxibustion or sham is not different significantly.(P=.668) The consistency of a moxibustion type which subjects received actually and the their guess about that, isn't different significantly in two groups.(P=.465) Conclusion: The sham moxibustion was successfully validated in this study, The results demonstrate that this sham moxibustion blinds subjects and can be used as effective placebo-control in moxibustion clinical trials.

• Clinical and Experimental Pediatrics
• /
• v.53 no.12
• /
• pp.1012-1017
• /
• 2010

Purpose: Transcatheter closure has become an effective therapy in most patients with patent ductus arteriosus (PDA). However, there are difficulties in transcatheter closure of PDA in small children. We reviewed clinical outcomes of transcatheter closure of PDA in children weighing less than 10 kg in a single center. Methods: Between January 2003 and December 2009, 314 patients with PDA underwent transcatheter closure in our institute. Among them, 115 weighed less than 10 kg. All of these patients underwent transcatheter closure of PDA using either COOK Detachable $Coil^{(R)}$, PFM Nit-$Occlud^{(R)}$, or Amplatzer duct $occluder^{(R)}$. A retrospective review of the treatment results and complications was performed. Results: The mean age of patients was $9.1{\pm}5.9$ months (median, 8 months), and mean weight was $7.6{\pm}1.8kg$ (median, 7.8 kg). The mean diameter of PDA was $3.2{\pm}1.4mm$ (median, 3 mm). Complete occlusion occurred in 113 patients (98%). One patient was sent to surgery because of a failed attempt at device closure, and another patient had a small residual shunt after device placement. The average mean length of hospital stay was $3.0{\pm}3.3$ days, and mean follow-up duration was $21.0{\pm}19.6$ months. There were no major complications in any of the patients. Conclusion: Transcatheter closure of PDA is considered safe and efficacious in infants weighing less than 10 kg. With sufficient experience and further effort, transcatheter closure of PDA can be accepted as the gold standard of treatment for this group of patients.

• Journal of Trauma and Injury
• /
• v.21 no.2
• /
• pp.128-135
• /
• 2008

Purpose: As the care of surgical patients becomes increasingly complex and catheter-based techniques are more frequently applied, the pattern of iatrogenic vascular injuries may be increasing. Major vascular injuries can jeopardize a patient's life or limb survival. The purpose of this study was to examine the current etiology and prognosis for iatrogenic vascular injuries. Methods: We reviewed medical records of 29 cases of iatrogenic vascular injury that were treated Seoul National University Bundang Hospital between October 2003 and October 2008. We studied clinical variables including demographics, cause of injury, clinical presentations, management and prognosis. Results: The mean age was 60.8 years (range: 25-86), and the male to female ratio was 1.9 : 1. The causes of injuries were operation related complication in 18 cases (62.1%), endovascular intervention and diagnostic angiography in 11 cases (37.9%). The types of vascular injury were partial severance in 14 cases, pseudoaneurysm in 8, arteriovenous fistula (AVF) in 3, thrombosis in 2, complete severance in 2. Especially, device related complication including percutaneous closing device were occurred in 9 and the others came from inadvertent physician's procedure. Primary repair were done in 12 cases, end-to-end anastomosis in 5, interposition graft in 4, ligation in 2, patch angioplasty in 1, peudoaneurysm excision and arteriorrhaphy in 1, hematoma evacuation in 1, and endovascular repair in 3. There were 2 cases of mortality, one of them due to hemorrhagic shock and the other due to septic shock. Conclusion: Proper selection of treatment modalities should be important to have better outcome according to the type of injury as well as anatomical location. Each physician should be familiar to new device as well as patient's topographical feature. Immediate referral to vascular specialist is also essential to reduce morbidity.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.21 no.4
• /
• pp.345-355
• /
• 2021

Background: This study aimed to evaluate the efficacy of external vibrating devices and counterstimulation on a child's dental anxiety, apprehension, and pain perception during local anesthetic administration. Methods: This was a prospective, randomized, parallel-arm, single-blinded interventional, clinical trial. One hundred children aged 4-11 years, requiring pulp therapy or extraction under local anesthesia (LA), were recruited and allocated equally into two groups (1:1) based on the interventions used: Group BD (n = 50) received vibration using a Buzzy^® device {MMJ Labs, Atlanta, GE, USA} as a behavior guidance technique; Group CS (n = 50) received counterstimulation for the same technique. Anxiety levels [Venham's Clinical Anxiety Rating Scale (VCARS), Venham Picture Test (VPT), Pulse oximeter {Gibson, Fingertip Pulse Oximeter}, Beijing, China)] were assessed before, during, and after LA administration, while pain perception [Wong-Baker Faces Pain Rating Scale (WBFPS), Visual Analogue Scale (VAS)] was evaluated immediately after injection. Statistical analysis was performed using the Student's t-test to assess the mean difference between the two groups and the repeated measures ANOVA for testing the mean difference in the pulse rates. Statistical significance was set at P < 0.05. Results: Significant differences in mean pulse rate values were observed in both groups. In contrast, the children in the BD group had higher diminution (P < 0.05), whereas the mean VCARS and VPT scores were conspicuous (P < 0.05). Based on the mean WBFPS and VAS scores, delayed pain perception after LA injection was more prominent in the BD group than in the CS group. Conclusion: External vibration using a Buzzy^® device is comparatively better than counterstimulation in alleviating needle-associated anxiety in children requiring extraction and pulpectomy.

• Journal of Convergence for Information Technology
• /
• v.12 no.5
• /
• pp.225-236
• /
• 2022

The purpose of this study is to provide clinical information and quantitative data through clinical research on lip balm containing propolis extract and lip application with LED device. Participants in this study were selected as test products for women aged 19 to 50 in Seoul and Gyeonggi Province, and to investigate the effects of LED devices and lip creams on the lips to improve lip elasticity, lip moisture, lip keratin, and lip moisture lasting for 12 hours. Before using the product, immediately after use, after 6 hours of use, after 12 hours of use, and after 2 weeks of use, the use test items are measured and the safety, efficacy, and preference survey of the product is analyzed. The results derived through a series of research procedures are as follows. It has been shown to help lip elasticity, lip moisture, lip keratin improvement, and lip moisture lasting for 12 hours when used once or 2 weeks.