낙상 검출 시스템 구현

전계록 부산대학교 병원 암연구소 2009 부산대병원학술지 Vol.- No.25

Effective Falls Detection Method Using Two Tri-Axial Accelerometers

Jeon, Gye Rok,Kim, Young Jae,Jeon, Ah Young,Lee, Sang Hoon,Kim, Jae Hyung,Kim, Min Seok,Lee, Seong Ho,Kim, Ji Hyun Trans Tech Publications, Ltd. 2013 Advanced materials research Vol.647 No.-

<P>Falls detection systems have been developed in recent years because falls are detrimental events that can have a devastating effect on health of the elderly population. Current fall detecting methods mainly employ accelerometer to discriminate falls from activities of daily living (ADL). However, this makes it difficult to distinguish real falls from certain fall-like activities such as jogging and jumping. In this paper, an accurate fall detection system was implemented using two tri-axial accelerometers. By attaching the accelerometers on the chest and the abdomen, our system can effectively differentiate between falls and non-fall events.The Diff_Z and Sum_diff_Z parameter resulted in falls detection rate of 100%, respectively.</P>

심전도와 맥파 신호 검출을 위한 일체형 센서 시스템의 구현

전계록(Jeon, Gye-Rok),정동근(Jung, Dong-Keun),김기련(Kim, Gi-Ryun),신범주(Shin, Bum-Joo) 한국산학기술학회 2009 한국산학기술학회논문지 Vol.10 No.5

심전도와 맥파를 측정함으로써 구해질 수 있는 맥파전달시간은 심혈관계의 상태를 진단하기 위한 의미있는 지표가 된다. 그러나 맥파를 측정하는 동안 움직이거나, 측정 시에 가해지는 압력이 부정확할 경우, 잘못된 측정 결과를 얻을 수 있다. 이를 해결하기 위하여 본 논문에서는 심전도, 압력맥파 및 광전용적맥파를 동시에 측정할 수 있는 일체형 센서 시스템과 심전도를 지속적으로 측정할 수 있는 금속 전극을 개발하였으며, 실험을 통해 일체형 센서 시스템 및 금속 전극의 유용성을 입증하였다. The pulse transit time(PTT), which is determined by measuring the electrocardiogram(ECG) and pulse wave, gives comprehensive information about the cardiovascular system. However, a little movement of body and/or inaccurate pressure applied to skin during the measurement of pulse wave leads to acquire incorrect results. To overcome such problem, we developed an integrated sensor system which makes it possible to measure ECG, pressure pulse wave(PPW) and photoplethysmograph(PPG) at the same time. Futhermore, we implemented a new metal electrode which enables to continuously measure ECG. We verified that both integrated sensor system and new electrode provide useful effect.

HRV 신호의 웨이브렛 변환에 의한 마취단계별 마취심도 평가 파라미터 개발

전계록(Jeon, Gye-Rok),김명철(Kim, Myung-Chul),한봉효(Han, Bong-Hyo),예수영(Ye, Soo-Young),노정훈(Ro, Jung-Hoon),백승완(Baik, Seong-Wan) 한국산학기술학회 2009 한국산학기술학회논문지 Vol.10 No.9

본 연구에서는 마취 단계에서 마취 심도 평가를 위한 파라미터 추출을 수행하였다. 연구대상은 평균 나이 42 ± 9.13세, 신체등급 분류상 1 또는 2 등급에 속하는 산부인과 수술 환자를 선택하였다. 투약제로는 Enflurane으로 전신 마취를 시행하였다. HRV 신호는 ECG 신호로부터 R 피크치 검출 알고리즘에 의해 획득 되었다. HRV 데이터는 전처리 단계를 거쳤고, 마취 단계별 마취심도 평가 파라미터를 개발하기 위하여 마취단계를 마취 전, 마취유도, 수술 중, 각성, 마취 후 등으로 구분하여 시행하였다. 본 연구에서는 마취단계에서 웨이브렛 변환을 이용한 HRV신호 분석 알고리듬이 제안되었다. 세 종류의 웨이브렛 함수를 적용한 PSD 분석 결과 마취 단계에 따라 모두 비슷한 양상을 나 타내었으나, 이들 중 Daubeches 10의 실험 결과가 보다 양호하게 관측되어 마취 단계별 마취심도를 평가할 수 있는 특징 파라미터로서 가장 적절하다는 판단하였다. In this study, the parameter extraction for evaluation of the anesthesia depth in each anesthesia stages was conducted. An object of the this experiment study has studied 5 adult patients (mean ± SD age:42 ± 9.13), ASA classification I and Ⅱ, undergoing surgery of obstetrics and gynecology. Anaesthesia was maintained with Enflurane. HRV signal was created by R-peak detection algorithm form ECG signal. The HRV data were preprocessing algorithm. It has tried find out the anesthesia parameter which responds the anesthesia events and shows objective anesthesia depth according to anesthesia stage including pre-anesthesia, induction, maintenance, awake and post-anesthesia. In this study, proposed algorithm to analysis the HRV(heart rate variability) signal using wavelet transform in anesthesia stage. Three sorts of wavelet functions applied to PSD. In the result, all of the results were showed similarly. But experiment results of Daubeches 10 is better. Therefore, this parameter is the best parameter in the evaluation of anesthesia stage.

Emergency Detection System using PDA based on Self-response Algorithm

Jeon, Ah-Young,Park, Jun-Mo,Jeon, Gye-Rok,Ye, Soo-Young,Kim, Jae-Hyung The Korean Institute of Electrical and Electronic 2007 Transactions on Electrical and Electronic Material Vol.8 No.6

The aged are faced with increasing risk for falls. The aged have more fragile bones than others. When falls occur, it is important to detect this emergency state because such events often lead to more serious illness or even death. A implementation of PDA system, for detection of emergency situation, was developed using 3-axis accelerometer in this paper as follows. The signals were acquired from the 3-axis accelerometer, and then transmitted to the PDA through a Bluetooth module. This system can classify human activity, and also detect an emergency state like falls. When the fall occurs, the system generates the alarm on the PDA. If a subject does not respond to the alarm, the system determines whether the current situation is an emergency state or not, and then sends some information to the emergency center in the case of an urgent situation. Three different studies were conducted on 12 experimental subjects, with results indicating a good accuracy. The first study was performed to detect the posture change of human daily activity. The second study was performed to detect the correct direction of fall. The third study was conducted to check the classification of the daily physical activity. Each test lasted at least 1 min. in the third study. The output of the acceleration signal was compared and evaluated by changing various postures after attaching a 3-axis accelerometer module on the chest. The newly developed system has some important features such as portability, convenience and low cost. One of the main advantages of this system is that it is available at home healthcare environment. Another important feature lies in its low cost of manufacture. The implemented system can detect the fall accurately, so it will be widely used in emergency situations.

3축 가속도 센서를 이용한 낙상 검출 시스템 구현

전아영(Jeon, Ah-Young),유주연(Yoo, Ju-Yeon),박근철(Park, Geun-Chul),전계록(Jeon, Gye-Rok) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.5

본 연구에서는 3축 가속도 신호를 이용하여 낙상과 낙상 방향을 검출하는 시스템을 구현하였다. 가속도 신 호는 3축 가속도 센서로부터 획득하였으며, 획득된 신호를 USB 인터페이스를 통하여 PC에 전달하였다. PC에 전송 된 신호를 제안한 알고리즘을 사용하여 낙상을 검출하였으며, 퍼지 분류기를 사용하여 낙상의 방향을 분류하였다. 실 험을 위하여 실험대상군 6명 선정하였으며, 가슴에 가속도계를 부착한 후 실험을 수행하였다. 실험대상자는 5초 동 안 정상 보행을 한 후 4 가지 방향(전․후․좌․우)으로 낙상이 발생하도록 하였으며, 낙상에 소요되는 시간은 최소 2초 로 설정하였다. 본 연구에서 제안된 알고리즘을 이용하여 낙상을 검출하였으며 낙상 발생 후 1초부터 데이터를 분석 하고 퍼지 분류기를 이용하여 낙상방향을 분류하였다. 낙상 검출율은 평균 94.79%이었다. 낙상 방향에 따른 분류율 은 front_fall은 95.83%, back_fall은 100%, left_fall 은 87.5%, right_fall은 95.83%이었다. In this study, the falls detection and direction classification system was implemented using 3-axial acceleration signal. The acceleration signals were acquired from the 3-axial accelerometer(MMA7260Q, Freescale, USA), and then transmitted to the computer through USB interface. The implemented system can detect falls using the newly proposed algorithm, and also classify the direction of falls using fuzzy classifier. The 6 subjects was selected for experiment and the accelerometer was attached on each subject's chest. Each subject walked in normal pace for 5 seconds, and then the fall down according to the four direction(front_fall, back_fall, left_fall and right_fall) during at least 2 second. The falls was easily detect using the newly proposed algorithm in this study. The acquired signals were analyzed after 1 second from generating falls. The fuzzy classifier was used to classify the direction of falls. The mean value of the falls detection rate was 94.79 %. The classifier rate according to falls direction were 95.83% in case of front falls, 100% incase of back falls, 87.5% in case of left falls, and 95.83% in case of right falls.

하부요로증상 진단을 위한 요속 및 요류음 분석 시스템 구현

전계록,정도운,Jeon, Gye-Rok,Jeong, Do-Un 대한의용생체공학회 2010 의공학회지 Vol.31 No.4

The present study proposed a method of measuring uroflow and urophonography at the same time for more accurate diagnosis in case uroflow looks normal due to compensatory function hypertrophy in the expression of early obstruction. In case of early obstruction, there happens turbulent uroflow by the obstruction even if the uroflow looks normal and thus obstruction can be detected by measuring and analyzing signal caused by turbulent flow. We implemented a system that can measure both uroflow and urophonography, and evaluated its performance. In the experiment, we observed changes in uroflow and urophonography according to artificial pressure and the degree of obstruction, and confirmed that it is possible to determine the effect of compensatory function hypertrophy by analyzing urophonographyic parameter under the same uroflow. The results of our experiment show that the effect of compensatory function hypertrophy in the early-stage obstruction of lower urinary tract, which is not detectible with uroflowmetry alone, can be assessed through urophonographic analysis.

Original Articles : Evaluation of an Experimentally Designed Stereotactic Guidance System for Determining Needle Entry Point during Uniplanar Fluoroscopy-guided Intervention

( Jae Heon Lee ),( Gye Rok Jeon ),( Jung Hoon Ro ),( Gyeong Jo Byoen ),( Tae Kyun Kim ),( Kyung Hoon Kim ) 대한통증학회 2012 The Korean Journal of Pain Vol.25 No.2

Background: In discography performed during percutaneous endoscopic lumbar discectomy (PELD) via the posterolateral approach, it is difficult to create a fluoroscopic tunnel view because a long needle is required for discography and the guide-wire used for consecutive PELD interrupts rotation of fluoroscope. A stereotactic system was designed to facilitate the determination of the needle entry point, and the feasibility of this system was evaluated during interventional spine procedures. Methods: A newly designed stereotactic guidance system underwent a field test application for PELD. Sixty patients who underwent single-level PELD at L4-L5 were randomly divided into conventional or stereotactic groups. PELD was performed via the posterolateral approach using the entry point on the skin determined by premeasured distance from the midline and angles according to preoperative magnetic resonance imaging (MRI) findings. Needle entry accuracy provided by the two groups was determined by comparing the distance and angle measured by postoperative computed tomography with those measured by preoperative MRI. The duration and radiation exposure for determining the entry point were measured in the groups. Results: The new stereotactic guidance system and the conventional method provided similarly accurate entry points for discography and consecutive PELD. However, the new stereotactic guidance system lowered the duration and radiation exposure for determining the entry point. Conclusions: The new stereotactic guidance system under fluoroscopy provided a reliable needle entry point for discography and consecutive PELD. Furthermore, it reduced the duration and radiation exposure associated with determining needle entry. (Korean J Pain 2012; 25: 81-88)

Evaluation of an Experimentally Designed Stereotactic Guidance System for Determining Needle Entry Point during Uniplanar Fluoroscopy-guided Intervention

Lee, Jae-Heon,Jeon, Gye-Rok,Ro, Jung-Hoon,Byoen, Gyeong-Jo,Kim, Tae-Kyun,Kim, Kyung-Hoon The Korean Pain Society 2012 The Korean Journal of Pain Vol.25 No.2

Background: In discography performed during percutaneous endoscopic lumbar discectomy (PELD) via the posterolateral approach, it is difficult to create a fluoroscopic tunnel view because a long needle is required for discography and the guide-wire used for consecutive PELD interrupts rotation of fluoroscope. A stereotactic system was designed to facilitate the determination of the needle entry point, and the feasibility of this system was evaluated during interventional spine procedures. Methods: A newly designed stereotactic guidance system underwent a field test application for PELD. Sixty patients who underwent single-level PELD at L4-L5 were randomly divided into conventional or stereotactic groups. PELD was performed via the posterolateral approach using the entry point on the skin determined by premeasured distance from the midline and angles according to preoperative magnetic resonance imaging (MRI) findings. Needle entry accuracy provided by the two groups was determined by comparing the distance and angle measured by postoperative computed tomography with those measured by preoperative MRI. The duration and radiation exposure for determining the entry point were measured in the groups. Results: The new stereotactic guidance system and the conventional method provided similarly accurate entry points for discography and consecutive PELD. However, the new stereotactic guidance system lowered the duration and radiation exposure for determining the entry point. Conclusions: The new stereotactic guidance system under fluoroscopy provided a reliable needle entry point for discography and consecutive PELD. Furthermore, it reduced the duration and radiation exposure associated with determining needle entry.

지식 구조화 경정맥 완전 영양공급 시스템의 개발에 관한 연구 (I)

전계록,최삼길,변건식,Jeon, Gye-Rok,Choe, Sam-Gil,Byeon, Geon-Sik 대한의용생체공학회 1990 의공학회지 Vol.11 No.2

In this paper we have implemented and tested TPN which is system to supply sufficent nutrition to nutritionally deficient patient by means of ES (expert system) a kind of A.1 (artificial intelligence) . This system affords to evaluation of nutritional state of patient which is essential to physi- cian. who performs TPN, decision of performing TPN and management of patient-data & calculation of information needing to making TPN fluid. The features were as follolv 1. we input data, take ideal weight of patient and 24hr's creatlnln In urine according to chart in system compare TSF (triceps skin fold), MAC (mid-arm circumference), AMC (arm muscle circumference) to 5th, 15th, 50th percentile and evaluate the nutritional state of patient. 2. Calculation of protein & nonprotein calorie needing to treament of patient can be made exactly by stress factor, activity factor and body temperature. 3. patient's personal recording needing to management of patient date name of chief doc- tor, name of department of admission, chart number, history can by taken very easily. 4. The way of system operating is pull-down Menu one, It can be processing very efficiently. 5. Date processing in system, we can manage memory volume of computer verlr efficiently using of dynamic allocation variables. 6. We can make it very easy to edit & revise the input data, processed data is saved to diskette in 2 files (TDF, THF) , these are semipermanent preservation.