Micro -computed tomography를 이용한 골다공증의새로운 형태학적 연구기법

고창용,우대곤,김한성,이법이 대한체질인류학회 2005 대한체질인류학회지 Vol.18 No.4

Osteoporosis is a major health-care problem for aging communities. And postmenopausal osteoporosis is a common disorder characterized by an increase in bone resorption relative to bone formation, generally in conjunction with an increased rate of bone turnover.Twenty female rats were used as rat model of osteoporosis. They randomly were divided into two groups:a normal control group, and calcium-free diet groups treated with bilateral ovariectomy. The animals were sacrified at 12 weeks after treatment. In the rats with osteoporosis, there was significant thining and loss of trabeculae, accompanied by a disconnection of trabeculae. And acid mucopolysaccharides were decreased in osteoporotic animals. In order to setup conditions of invivo micro-CT, proper anesthetic is ketamine (50 mg/kg)/xylazine (6 mg/kg). And proper breathing rate of experimental animals is 1.3~1.6/sec. Our finding suggest that bilateral ovariectomy and calcium-free diet induce decrease in thickeness of trabecular bone and decrease in acid mucopolysaccharide, therefore cause weakness of bone. And micro-CT imaging system is useful to evaluate trabecular bone. Anesthetic time, anesthetics and respiration rate also signify much in micro-CT imaging system. 골다공증모델동물의 뼈잔기둥의 조직변화 및 골다공증모델연구에서 생체 내 미세 단층 촬영시스템(SKYSCAN1076, Skyscan, Belgium)을 적용하기 적합한 실험조건을 알아보고자 본시험을 수행하였다.암컷 흰쥐에게 난소적출과 저칼슘식이요법 (calcium free diet)을 시행하여 골다공증을 유발하였다. 골다공증의 유발된 흰쥐를 관류고정한후 허리뼈를 적출하여 탈회과정을 거친후 조직표본을 제작하여 골다공증모델동물의 뼈잔기둥에 대한 조직학적변화를 관찰하였다. 또한 흰쥐의 넷째 허리뼈를 35 µm의 해상도로 미세단층촬영을 시행하였다.골다공증 유발후 12주후에 척추뼈를 적출한후, 조직소견은 척추뼈의 뼈잔기둥의 두께가 감소하였고 일부 뼈잔기둥에서는 단락이 관찰되었으며, 뼈잔기둥내 산성점액질이 감소된 양상이 관찰되었다. 생체 내 미세 단층 촬영시스템의 평균 촬영시간은 20분정도 소요되었으며, pentobarbital, chloral hydrate, ketamine/xylazine 등의 마취제를 사용한 결과 ketamine/xylazine을 사용시 촬영에 가장 적절한 호흡주기(1.3~1.6/sec)를 유지하였으며, 마취제의 농도는 ketamine은 체중 kg당 50 mg, xylazine은 체중 kg당 6mg이 적정한 농도였다.이상의 결과를 종합한바, 난소적출과 저칼슘식이요법은 뼈잔기둥의 두께감소 및 산성점액질의 감소를 초래하여 뼈를 약화시키는 것으로 사료되며, 또한 고화질 생체내 미세단층촬영시스템을 이용하여 골다공증모델동물연구하는데 있어, 마취시간, 마취제 및 호흡주기가 중요한 요인이 되리라 사료된다.

New Wearable Exoskeleton for Gait Rehabilitation Assistance Integrated with Mobility System

고창용,고주원,김형주,임도형 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.7

Gait and mobility in patients with gait impairment are important in maintaining and improving their physical and psychological health and to return to society. Thus, the aims of the current study were to develop and evaluate a new wearable exoskeleton for gait rehabilitation assistance integrated with a mobility system (RehabWheel) for patients with gait impairment. A wearable exoskeleton was controlled by artificial pneumatic muscles to mimic joint movement; appropriate gait training was then undertaken. In total, 13 healthy males participated in evaluating RehabWheel by comparing joint angle kinematics and muscle activation patterns during walking over ground with RehabWheel and normal gaits. The joint angle kinematics of the hip and knee joints with RehabWheel were similar to those of normal gait despite differences in their magnitude. Additionally, muscle activations in the hip and knee joints were less during RehabWheel gait than normal gait and were associated with joint kinematics. These findings indicate that RehabWheel may have potential for incorporation into gait rehabilitative training assistance combined with a wheelchair platform for movement. This study is valuable for the initial identification of the practical feasibility of this new mobility system with both mobility and gait rehabilitation functions.

Beyond Pain

고창용 한국재활복지공학회 2021 한국재활복지공학회 학술대회논문집 Vol.2021 No.4

저강도 초음파 조사 부위의 골 소실 억제 효과 -골 밀도 및 형태학적 특성 평가

고창용,서동현,김효선,김한성,김상희,김진만,김기원,임도형,Ko, Chang-Yong,Seo, Dong-Hyun,Kim, Hyo-Seon,Kim, Han-Sung,Kim, Sang-Hee,Kim, Jin-Man,Kim, Ki-Won,Lim, Do-Hyung 대한의용생체공학회 2009 의공학회지 Vol.30 No.1

Purpose : The aim of this study is to evaluate a possibility of clinical application for the effects of low intensity ultrasound stimulation (LIUS) in morphological characteristics (i.e., structure, bone mineral density) of bone on osteoporotic fracturesprevention. Materials and Methods : Eight virgin 14-week-old ICR mice (approximate weight 25g) were used and ovariectomized (OVX) to induce osteoporosis. Right tibia (US) for each mouse served as the LIUS (1.5MHz frequency, 1.0 kHz pulse repetition on frequency, $30mW/cm^2$ intensity, $200{\mu}s$ pulse length, and stimulation for 20 minutes a day and 5 days a week over a 6-week period). Left tibia (CON) for each mouse served as the non-stimulated controls. Structural parameters and bone mineral density ($g/cm^3$) on trabecular bone of tibiae were calculated and measured from images derived in-vivo micro computed tomography (micro-CT) at 0 week and after 6weeks. Results : The BV/TV and Tb.N in US group were significantly bigger than those in CON group. The Tb.Pf in US group, moreover, was significantly smaller than that in CON group (p<0.05).For the others structural parameters and BMD, however, there were no significant difference between US group and CON group (p>0.05). Conclusion : The LIUS might prevent bone loss and keep bone connectivity in osteoporotic bones. Therefore, the LIUS might prevent effectively the osteoporotic fractures in clinics.

Deterioration of Trabecular Bone Microarchitecture in the Lumbar Vertebrae in Growing Male Mice Following Sciatic Neurectomy

고창용,김한성,정영진,서동현,이상대 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.12

Sciatic nerve injury (SNI) can lead to significant bone loss in the lower extremities. However, the effects of SNI on the lumbarvertebrae are controversial. The present study aimed to evaluate the longitudinal effects of SNI on the lumbar vertebrae. Twenty-four12-week-old male C57BL/6 mice (24.55±0.17 g) were randomly assigned to 3 groups (8 mice each) and underwent unilateral sciaticneurectomy (USN group), bilateral sciatic neurectomy (BSN group), or no surgery (CON group). The third (L3) and fourth (L4)lumbar vertebrae were scanned by in-vivo micro-computed tomography (ìCT) preoperatively and at 14 and 28 days postoperatively. Using μCT images, structural parameters and bone mineralization density distribution of the trabecular bone were analyzed amongthe 3 groups. In the BSN group, structural and material properties of L3 and L4 worsened after 14 days. Deterioration in the structuralproperties of L3 was observed at 28 days in the USN group, whereas no changes were observed in L4. These results implied that SNIcan cause considerable deterioration in the microarchitecture of trabecular bone in the lumbar vertebrae. However, differences in themagnitude and rate of the deterioration and its onset period are observed between cases of unilateral and bilateral SNI.

농지담보법(農地擔保法)의 문제점(問題點)과 대처방안(對處方案)

고창용 농협대학교 협동조합경영연구소 1985 협동조합경영연구 Vol.7 No.-

최소 침습적 레이저 치료 시스템의 골손실 치료 효과

고창용,정병조,김한성,류연항,강동연 한국조직공학과 재생의학회 2009 조직공학과 재생의학 Vol.6 No.13

Unloading, such as denervation, resulted in bone loss. The aim of this study is to evaluate effects of minimally invasive laser therapy system (MILTS) for treatment of bone loss during unloading. Nineteen 6-week-old ICR female mice (approximate weight 24 g) were used. Twelve mice served as sciatic neurectomy (denervation group, DENER) for right hind limb and seven mice served as control (wild type group, WT). Six mice were directly irradiated laser (wavelength: 660 nm, optical power: 10 mW, energy density: 3J) on bone by using minimal invasive laser probe in DENER group for 2weeks. The other six mice in DENER group served as sham treatment (sham group, SHAM). The mice were scanned at 0 week, before denervation, after 2weeks and after 4weeks by using in vivo micro-CT. Structural parameters and volume bone mineral density (vBMD, g/cm3) in the trabecular bone were measured. The vBMD(11%,p < 0.01), BV/TV (57%,p < 0.01), Tb.Th (23%,p < 0.05) and Tb.N (57%,p < 0.01) were significantly bigger and the Tb.Sp (42%,p < 0.05), SMI (62%,p < 0.05) and Tb.Pf (41%,p < 0.01) were significantly smaller in LASER group compared with SHAM group after 2weeks irradiation of laser. These results showed that the MILTS might keep bone quantity as well as quality during unloading. Therefore, the MILTS might be used for treatment of bone loss during unloading. Unloading, such as denervation, resulted in bone loss. The aim of this study is to evaluate effects of minimally invasive laser therapy system (MILTS) for treatment of bone loss during unloading. Nineteen 6-week-old ICR female mice (approximate weight 24 g) were used. Twelve mice served as sciatic neurectomy (denervation group, DENER) for right hind limb and seven mice served as control (wild type group, WT). Six mice were directly irradiated laser (wavelength: 660 nm, optical power: 10 mW, energy density: 3J) on bone by using minimal invasive laser probe in DENER group for 2weeks. The other six mice in DENER group served as sham treatment (sham group, SHAM). The mice were scanned at 0 week, before denervation, after 2weeks and after 4weeks by using in vivo micro-CT. Structural parameters and volume bone mineral density (vBMD, g/cm3) in the trabecular bone were measured. The vBMD(11%,p < 0.01), BV/TV (57%,p < 0.01), Tb.Th (23%,p < 0.05) and Tb.N (57%,p < 0.01) were significantly bigger and the Tb.Sp (42%,p < 0.05), SMI (62%,p < 0.05) and Tb.Pf (41%,p < 0.01) were significantly smaller in LASER group compared with SHAM group after 2weeks irradiation of laser. These results showed that the MILTS might keep bone quantity as well as quality during unloading. Therefore, the MILTS might be used for treatment of bone loss during unloading.

Trabecular Bone Loss in Lumbar Vertebrae and Tibiae following Sciatic Nerve Injury: Correlation between Baseline Bone Quantity (BV/TV) and the Magnitude and Rate of Bone Loss

고창용,김한성,정영진,서동현,Jürgen Schreiber,임도형 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.9

The aim of this study was to determine whether sciatic nerve injury (SNI) can cause trabecular bone loss in not only the tibia, but also the lumbar vertebrae, and to investigate the correlation between baseline bone quantity (BV/TV, bone volume fraction) and the magnitude and rate of bone loss. Sixteen male C57BL/6 mice were used. Sciatic neurectomy (SNx) was carried out on both hind limbs of eight mice. The tibiae (T) and fourth lumbar vertebrae (L4) were scanned by in-vivo micro-computed tomography (micro-CT) before and at 2 weeks and 4 weeks after SNx. At 2 weeks and 4 weeks, BV/TVs in T and L4 were significantly lower in the SNx group than the non-SNx group (p < 0.05). There were significant negative correlations between BV/TV at 0 weeks and the relative variations in L4 at 2 weeks or in T at 4 weeks (p < 0.05). These results indicate that SNI can cause significant bone loss in the lumbar vertebrae and tibiae. The magnitude and rate of bone loss following SNI is affected by baseline bone quantity.

Comparison of Ankle Angle Adaptations of Prosthetic Feet with and without Adaptive Ankle Angle during Level Ground, Ramp, and Stair Ambulations of a Transtibial Amputee: A Pilot Study

고창용,김솔비,김종권,장윤희,김신기,류제청,문무성 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

This study aimed to investigate kinetics and kinematics of the ankle joint during level ground, ramp, and stair ambulations usingdifferent types of adaptive ankle feet (AAFs), Proprio-FootTM (Össur, IcEland), élan foot (Endolite, USA), and Echelon foot (Endolite,USA). A transtibial amputee was asked to walk on a level ground, a ramp with a 7o slope, and a stair of height 15 cm. The ankleangle and symmetry index (SI) based on the symmetry of the external work performed were measured for AAFs and ambulation. Thesingle support time and stance phase during ambulation were higher for AAFs than the fixed ankle foot. During level ambulation,dorsiflexion increased for all AAFs. During slope ascent ambulation, dorsiflexion increased for the élan foot and Proprio-FootTM, aswell as during the swing phase of the Echelon foot. During slope descent ambulation, the maximum dorsiflexion decreased for theProprio-FootTM. During stair ascent, the élanElan foot and Proprio-FootTM feet improved the dorsiflexion. During stair descent, allAAFs improved the dorsiflextion. Furthermore, SI increased for most of the adaptive ankle feet for all terrain conditions. These resultsindicate that AAFs can be used to improve the kinetics and kinematics of the ankle on the involved side.

IN-VIVO MICRO-CT와 미세 유한요소법를 이용한 쥐의 골다공증 해면골과 피질골의 구조적 특성 추적관찰 및 기계적 특성 분석

고창용,우대곤,김한성,이법이,탁계래 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.5월