• 전기학회논문지
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• 제57권4호
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• pp.729-734
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• 2008

Vibroarthrographic(VAG) signals, emitted by human knee joints, are non-stationary and multi-component in nature and time-frequency distributions(TFD) provide powerful means to analyze such signals. The objective of this paper is to classify VAG signals, generated during joint movement, into two groups(normal and patient group) using the characteristic parameters extracted by time-frequency transform, and to evaluate the classification accuracy. Noise within TFD was reduced by singular value decomposition and back-propagation neural network(BPNN) was used for classifying VAG signals. The characteristic parameters consist of the energy parameter, energy spread parameter, frequency parameter, frequency spread parameter by Wigner-Ville distribution and the amplitude of frequency distribution, the mean and the median frequency by fast Fourier transform. Totally 1408 segments(normal 1031, patient 377) were used for training and evaluating BPNN. As a result, the average value of the classification accuracy was 92.3(standard deviation ${\pm}0.9$)%. The proposed method was independent of clinical information, and showed good potential for non-invasive diagnosis and monitoring of joint disorders such as osteoarthritis and chondromalacia patella.

• 전기학회논문지
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• 제64권4호
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• pp.592-597
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• 2015

3D-IC is a novel semiconductor packaging technique stacking dies to improve the performance as well as the overall size. TSV is ideal for 3D-IC because it is convenient for stacking and excellent in electrical characteristics. However, due to high-density and micro-size of TSVs, they should be tested with a non-invasive manner. Thus, we introduce a TSV test method on test prober without a direct contact in this paper. A capacitive coupling effect between a probe tip and TSV is used to discriminate small TSV faults like voids and pin-holes. Through EM simulation, we can verify the size of eye-patterns with various frequencies is good for TSV test tools and non-contact test will be promising.

• 분석과학
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• 제11권1호
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• pp.47-53
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• 1998

본 연구는 당뇨병 진단방법의 개선을 위하여 채혈을 직접적으로 하지 않고 혈당을 측정할 수 있도록 하기 위하여 근적외선 분광법을 적용하였다. 본 연구를 위하여 근적외선 분광법을 이용하여 1 mg/dL에서 200 mg/dL 사이의 표준 시료 80개 글루코오스 흡수 스팩트럼을 측정하고 이를 정량하여 표준 농도와의 상관관계를 비교하였을 때 1.8 mg/dL 오차범위에서 매우 우수하였다. 그리고 실제 혈액중에 존재할 수 있는 전해질 및 피부에 의한 산란의 영향을 연구하였을 때 모두 2.8 mg/dL 및 3.8 mg/dL의 표준오차를 나타내었다. 특히 실제 피부에 적용하기 위하여 검량곡선에 비직선성을 유발하는 빛의 산란 현상에 관한 모델링을 통하여 정확도를 향상시키는 통계적인 방법을 제시하였다.

• Medical Lasers
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• 제8권2호
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• pp.59-63
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• 2019

Background and Objectives High-intensity focused ultrasound (HIFU) has been developed as an effective, non-invasive, skin-tightening method in response to the increasing demand for improvements in skin laxity and tightening with minimal risk and recovery time. This study evaluated the efficacy and safety of HIFU for non-invasive skin tightening of crow's feet wrinkles, with the aim of determining how long the tightening can be maintained. Materials and Methods Between January and March 2019, 21 female patients with crow's feet wrinkles were treated with HIFU. The treatment involved 200 shots, three times every 2 weeks. Three blinded, experienced plastic surgeons and patients evaluated satisfaction at 2 weeks after the first procedure, 2 weeks after the second procedure, 2 weeks after the third procedure, and 6 weeks after the first procedure based on photographs according to the Global Aesthetic Improvement Scale (GAIS). The Friedman test was used to compare data. Results Of the 21 patients treated using HIFU, one was lost to follow-up for nonstudy-related reasons. Therefore, 20 patients were evaluated and ranged in age from 28 to 48 years. Plastic surgeons' GAIS scores were 2.6, 2.3, 1.7, and 1.3 and patients' GAIS scores were 2.6, 2.2, 1.8, and 1.4 at 2 weeks after the first procedure, 2 weeks after the second procedure, 2 weeks after the third procedure, and 6 weeks after the third procedure. No serious adverse effects were observed. Conclusion The aging face with crow's feet wrinkles can be improved by using HIFU, while minimizing epidermal and dermal injury.

• IEIE Transactions on Smart Processing and Computing
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• 제6권4호
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• pp.246-252
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• 2017

Non-invasive and non-restrictive methods for measuring the physiological functions of the human body are useful for health care, security, and surveillance. In this paper, a new method that extracts human heartbeat information by utilizing ultra-wideband (UWB) impulse radar is proposed. The amplitude spectra of received radar pulses reflected from the human body are accumulated at specific time intervals, and chirp z-transform (CZT) is used to extract the heartbeat frequency from the amplitude spectra. The heartbeat frequency can be extracted with high-frequency resolution in the frequency band of the heartbeat of interest using CZT. Experimental results to verify the performance of the proposed method show that a highly accurate extraction of the heartbeat frequency is possible using this method.

• 재활치료과학
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• 제10권2호
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• pp.37-51
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• 2021

목적 : 본 연구는 주로 침흘림을 보이는 뇌성마비 아동에게 비침습적인 치료적 중재와 침흘림 측정방법의 경향 분석 등에 대한 국외 문헌들을 중심으로 종합적으로 분석하고자 하였다. 연구방법 : 본 연구는 최근 15년 간(2005-2019) 국외 논문을 검색하여 총 265편의 논문이 검색되었다. 1차 제목 및 초록을 중심으로 44편의 논문이 선정되었고, 2차 원문 검색을 통해 10편의 논문이 최종적으로 선정되었다. 결과 : 선정된 논문의 PEDro Scale은 평균 6점으로 높은 편이었다. 전반적인 동향을 분석한 결과 연구대상자는 뇌성마비가 주를 이루었고, 행동수정에 비해 구강감각운동의 치료적 중재가 최근에 활발하게 연구되고 있었다. 행동수정과 구강감각운동 중재방법은 대상자의 나이, 인지수준, 대상자 수, 연구설계, 치료시간과 기간에서 차이가 있음을 확인하였다. 침흘림 측정방법은 빈도와 심각성을 동시에 확인하는 연구가 주를 이루는 것으로 나타났다. 결론 : 본 연구에서는 침흘림을 보이는 뇌성마비 아동에게 실시한 비침습적인 중재 중 대표적인 행동수정과 구강감각운동 중재에 대해서 분석하였고, 이러한 자료를 통해 행동수정과 구강감각운동치료를 통한 침흘림 프로그램 계획 시 적절한 치료적 중재방법을 선택하는데 도움이 될 수 있는 정보제공 및 근거를 마련하였다.

• 한국의학물리학회지:의학물리
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• 제11권2호
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• pp.101-107
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• 2000

펄스옥시메트리는 서로 다른 두 파장의 빛을 이용하여 동맥혈의 산소포화도를 측정하는 비침습성의 광에 의한 측정 방법이다. 동맥혈의 맥동성분은 정맥혈, 피부 그리고 기타의 비맥동성분들에 의해 감쇠되는 직류 성분에 중첩되어 있다. 본 논문에서는 맥동 성분의 적분비를 이용하여 산소포화도를 계산하는 알고리즘을 사용하였다. 알고리즘에서는, 심장의 수축과 관련되는 맥동신호의 1/2 싸이클만을 이용한다. 이용하는 시간은 1 cycle의 약 1/4이다. 1/4 주기를 이용하는 본 알고리즘은 기존의 방식과 유사한 결과가 나타났다. 신호의 진폭이 낮고, 시간의 점유가 많은 부분을 계산에서 배제했기 때문에, 동잡음의 영향이 감소되었다.

• 대한후두음성언어의학회지
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• 제12권2호
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• pp.133-139
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• 2001

Background and Objectives : There are so many methods to investigate the causes of voice disorders. However, they were almost invasive or non-physiologic methods. And none of them showed the laryngeal movements. Phonation pharyngogram is non-invasive method to see the laryngeal movement directly. Authors studied to evaluate the availability of phonation pharyngogram in laryngeal nodule. Materials and Methods : 30 laryngeal nodules and 10 control groups were evaluated. Acoustic analysis and maximum phonation time were measured and pharyngogram was taken during sustaining /a/ phonation immediately after swallowing the barium. We measured the width of hypopharyngeal wall, shape of hypopharyngeal wall and pyriform sinus apex, level difference between both true vocal folds, angle of subglottis, location of true vocal folds, elevated distance of vocal folds and shape of c-spine. Results : Jitter, Shimmer of laryngeal nodule were higher than control group and maximum phonation time was shorter in laryngeal nodule. There was a significance in width of hypopharyngeal wall, shape of pyriform sinus apex, level difference between both true vocal folds, elevated distance of vocal folds and shape of c-spine. Conclusions : Authors knew that there were differences when we used the phonation pharyngogram between normal group and laryngeal nodule group.

• 대한한방내과학회지
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• 제31권3호
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• pp.612-619
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• 2010

Background : Low level laser therapy may be an effective method to protect tissue damage in acute stroke. Recently, series of clinical studies on the basis of animal experiments report efficacy and safety of laser therapy at early stages of acute stroke. Laser promotes mitochondrial ATP synthesis to reduce cell death by ischemic infarction. Objectives : To report possibility of non-invasive laser therapy for acute stroke by reviewing literature about its effectiveness, safety and mechanism. Methods : We searched papers using PubMed and 'Web of Knowledge' of Thomson ISI, using the keywords "Laser Therapy, Low-Level" and "Stroke". Limitations were last 10 years of publications and only in English. Search range includes RCTs, clinical reports, reviews and animal experiments. Papers not matched with inclusion criteria were excluded. Results : A total 223 studies were found, 203 excluded during title and extract screening. After scanning 20 papers the final 2 serial RCTs were selected and analyzed. They reported that transcranial laser therapy led in neuroprotective effect for acute stroke patents. Clinical evaluation factors showed favorable trend and initial safety. Conclusions : Non-invasive laser secured safety of clinical application. It may be a favorable choice for the acute stage of stroke.

• 한국전문물리치료학회지
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• 제22권2호
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• pp.70-80
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• 2015

The spinal cord is highly complex, consisting of a specialized neural network that comprised both neuronal and non-neuronal cells. Any kind of injury and/or insult to the spinal cord leads to a series of damaging events resulting in motor and/or sensory deficits below the level of injury. As a result, muscle paralysis (or paresis) leading to muscle atrophy or shrinking of the muscle along with changes in muscle fiber type, and contractile properties have been observed. Traditionally, histology had been used as a gold standard to characterize spinal cord injury (SCI)-induced adaptation in spinal cord and skeletal muscle. However, histology measurements is invasive and cannot be used for longitudinal analysis. Therefore, the use of conventional magnetic resonance imaging (MRI) is promoted to be used as an alternative non-invasive method, which allows the repeated measurements over time and secures the safety against radiation by using radiofrequency pulse. Currently, many of pathological changes and adaptations occurring after SCI can be measured by MRI methods, specifically 3-dimensional MRI with the advanced diffusion tensor imaging technique. Both techniques have shown to be sensitive in measuring morphological and structural changes in skeletal muscle and the spinal cord.