폴리머/ 금속 다층 공정 기술을 이용한 실시간 혈압 모니터링을 위한 유연한 생체 삽입형 센서

임창현,김용준,윤영로,윤형로,신태민,Lim Chang-Hyun,Kim Yong-Jun,Yoon Young-Ro,Yoon Hyoung-Ro,Shin Tae-Min 대한의용생체공학회 2004 의공학회지 Vol.25 No.6

본 논문에서는 폴리머/ 금속 다층 공정 기술 (polymer/metal multi layer processing techniques)을 이용한 실시간 혈압 감지를 위한 유연한 생체 삽입형 센서를 새로이 제안한다. 제안되는 방식의 센서는 기계적으로 유연하기 때문에 혈관의 외벽에 대한 침습성을 감소시켜 부착할 수 있다. 즉, 혈압 측정을 위해 센서를 혈관 내에 설치하던 기존의 방법들에 비해서 혈관 자체에 상처를 주지 않고 혈압의 상대적인 변화를 지속적으로 감지할 수 있다. 성인에게 발생하는 급사의 주된 원인은 협심증, 심근 경색과 같은 혈관 관련 질환이다. 플라크 (plaque)의 생성 등과 관계된 순환계 관련 질환들은 지속적인 혈압 감지를 통해서 예방할 수 있으며 발병 초기에 치료할 수 있다. 본 연구에서 제안하는 혈압감지 방법의 과정은 다음과 같다. 우선, 집적된 센서를 혈관 외벽에 부착한다. 둘째, 실장된 센서가 혈관의 기계적인 수축과 확장을 인식한다. 마지막으로, 센서에 의해 인식된 혈압의 변화를 원격 감지 방법을 통해서 외부 안테나에서 감지하게 된다. 센서 시스템에는 어떠한 능동 소자도 존재하지 않기 때문에 에너지와 혈압 변화 정보는 LC 공진기와 외부 안테나 사이에 발생하는 상호 인덕턴스 원리에 의해서 전달되게 된다. 이러한 측정 원리의 가능성을 확인하기 위해서 실리콘 고무관과 혈액을 이용하여 시험관 실험 (In vitro test)을 진행하였다. 우선, 혈액으로 채운 실리콘 고무관에 센서를 감은 후 피스톤으로 압력을 가하였다. 그리고 이를 통해 가해진 압력 변화에 따른 공진 주파수의 변화를 측정하였다. 가해진 압력이 0부터 213.3 KPa까지 변화하는 동안 2.4 MHz의 공진 주파수가 변했다. 그러므로 생체 삽입형 혈압 센서의 감도는 11.25 KHz/KPa이다. Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

하지에서의 광용적맥파와 말초동맥질환 표지자의 상관관계 연구

임지현,허정현,윤영로,Im, Ji Hyeon,Heo, Jung Hyun,Yoon, Young Ro 대한의용생체공학회 2017 의공학회지 Vol.38 No.3

In this study, photoplethysmography(PPG) was suggested as a way to replace the ankle-brachial index(ABI) in diagnosing PAD. The method using the PPG was presented for the simplification of the PAD diagnosis method which was used before. And the index related to the health condition of the artery from the PPG measured in both big toes of the subjects through the experiment was drawn. The indexes showing the significant relativeness in the Pearson correlation analysis with the ABI were the stiffness index(SI), reflection index(RI); it was confirmed each of them had the correlation coefficient of 0.688, and 0.637 at p < 0.05. The explanation ability of the linear regression equation derived using ABI, SI and RI was 52.5%. The explanation ability of the secondary curve regression equation derived using ABI, squared SI was 54.7%. It is expected to provide patients with significant results and draw the index associated with PAD by measuring PPG easily in the real life instead of the ambulatory care field.

의료용 임베디드 소프트웨어의 제 3 자 기관 평가를 위한 기준 개발

정선영 ( Sun-young Jeong ),윤영로 ( Young-ro Yoon ),신태민 ( Tae-min Shin ) 한국정보처리학회 2006 한국정보처리학회 학술대회논문집 Vol.13 No.2

최근 다양한 기능을 구현하는 임베디드 소프트웨어가 포함된 의료기기의 개발이 증가함에 따라 안전성을 보장하기 위한 제 3 자 인증기관에 의한 의료용 임베디드 소프트웨어의 평가의 필요성이 절실하다. 따라서 본 연구에서는 소프트웨어 평가기준을 제시하는 ISO/IEC 9126 을 바탕으로 의료용 임베디드 소프트웨어의 평가 항목을 선정하고, 이에 적절한 가중치를 산출하여 보다 객관적이고 정량적인 평가를 수행할 수 있는 평가 기준을 개발하고자 한다.

맥파전달속도를 이용한 내중막 두께 추정에 관한 연구

송상하,장승진,김원식,이현숙,윤영로,Song, Sang-Ha,Jang, Seung-Jin,Kim, Wuon-Shik,Lee, Hyun-Sook,Yoon, Young-Ro 대한의용생체공학회 2009 의공학회지 Vol.30 No.5

In this paper, we correct pulse wave velocity(PWV) with heart-rate and derive regression equations to estimate intima-media thickness(IMT). Widely used methods for diagnosis of arteriosclerosis are IMT and PWV. Arterial wall stiffness determines the degree of energy absorbed by the elastic aorta and its recoil in diastole but there is not correlation between sclerosis and IMT in an existing study. In this study, we will correct PWV with heart-rate and get regression equation to estimate IMT using heart-rate correction index(HCI). We executed experiments for this study. Made up question of physical condition and measured electrocardiogram(ECG), photoplethysmogram (PPG) of finger-tip and toe-tip and ultrasound image of carotid artery. Calculated PWV and IMT using ECG, PPG and ultrasound image. We found that every p-value between PWV and IMT is not significant(<0.05). But p-value between IMT and HCI which is a corrected PWV using heart-rate is significant(>0.01). We use HCI and various measured parameter for estimating regression equation and apply backward estimation to select parameters for regression analysis. Result of backward estimation, found that only HCI is possible to derive proper regression equation of IMT. Relationship between PWV and IMT is the second order. Result of regression equation of E-H PWV is $R^2$=0.735, adj $R^2$=0.711. This is the best correlation value. We calculate error of its analysis for verification of earlobe PWV regression equation. Its result is RMSEP=0.0328, MAPE(%) = 4.7622. Like this regression analysis, we know that HCI is useful parameter and relationship between PWV, HCI and IMT. In addition, we are able to suggest possibility which is that we can get different parameter of prediction throughout just one measurement.

폴리머 재료를 이용한 유연 수직/수평 힘 센서 어레이 개발 및 응용

황은수(Eun-Soo Hwang),윤영로(Young-Ro Yoon),윤형로(Hyoung-Ro Yoon),신태민(Tae-Min Shin),김용준(Yong-Jun Kim) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.5

무선 센서네트워크 기반 신호강도 맵을 이용한 재택형 위치인식 및 사용자 식별 시스템

양용주,이정훈,송상하,윤영로,Yang, Yong-Ju,Lee, Jung-Hoon,Song, Sang-Ha,Yoon, Young-Ro 대한의용생체공학회 2007 의공학회지 Vol.28 No.4

Ubiquitous location based services (u-LBS) will be interested to an important services. They can easily recognize object position at anytime, anywhere. At present, many researchers are making a study of the position recognition and tracking. This paper consists of postion recognition and user identification system. The position recognition is based on location under services (LBS) using a signal strength map, a database is previously made use of empirical measured received signal strength indicator (RSSI). The user identification system automatically controls instruments which is located in home. Moreover users are able to measures body signal freely. We implemented the multi-hop routing method using the Star-Mesh networks. Also, we use the sensor devices which are satisfied with the IEEE 802.15.4 specification. The used devices are the Nano-24 modules in Octacomm Co. Ltd. A RSSI is very important factor in position recognition analysis. It makes use of the way that decides position recognition and user identification in narrow indoor space. In experiments, we can analyze properties of the RSSI, draw the parameter about position recognition. The experimental result is that RSSI value is attenuated according to increasing distances. It also derives property of the radio frequency (RF) signal. Moreover, we express the monitoring program using the Microsoft C#. Finally, the proposed methods are expected to protect a sudden death and an accident in home.

RFID와 HL7을 이용한 응급 의료 정보 시스템 설계 및 구현에 관한 연구

홍규석,황성오,이현숙,윤영로,Hong, Kyu-Seog,Hwang, Sung-Oh,Lee, Hyun-Sook,Yoon, Young-Ro 대한의용생체공학회 2007 의공학회지 Vol.28 No.5

In this paper, we designed the RFID(Radio Frequency Identification) Emergency Medical Information System(REMIS). This REMIS offers the emergency patient's medical information using RFID and HL7(Health Level 7) to an emergency medical technician. In emergency situation as like coma, if the communication, from the patient's current location to the hospital, is possible, REMIS offer the medical information of the patient through REMIS server to an emergency medical technician. In the state of communication blocked, REMIS can offer the patient identification and the emergency information through RFID tag, which the patient wear, to an emergency medical technician. When this system was designed, the protection of the patient's medical information and their privacy was considered, and the HL7 was used to be compatible with another medical systems. Therefore, in this paper, REMIS was designed that it is always possible to offer the emergency patient's information to an emergency medical technician regardless of any communication status and to improve the emergency rescue process, effectively.

녹색광을 이용한 반사형 광용적맥파측정기의 주변광 간섭시 신호측정

장기영,고현철,이정직,윤영로,Chang, K.Y.,Ko, H.C.,Lee, J.J.,Yoon, Young Ro 대한의용생체공학회 2014 의공학회지 Vol.35 No.5

The purpose of this study is to verify the utility of reflected photoplethysmography sensor using two green light emitting diodes that influenced by ambient light. Recently it has been studied that green light emitting diode is suitable for light source of reflected photoplethysmography sensor at low temperature and high temperature. Another study showed that, green light is better for monitoring heart rate during motion than led light. However, it has a bad characteristic about ambient light noise. To verify the utility of reflected photoplethysmography sensor using green light emitting diode, this study measures the photoplethysmography signal that is distorted by ambient light and will propose a solution. This study has two parts of research method. One is measurement system that composed sensor and board. The sensor is made up PE-foam and Non-woven fabric for flexible sensor. The photoplethysmography signal is measured by measurement board that composed high-pass filter, low-pass filter and amplifier. Ambient light source is light bulb and white light emitting diode that has three steps brightness. Photoplethysmography signal is measured with lead II electrocardiography signal at the same time and it is measured at the finger and radial artery for 1 minute, 1000 Hz sampling rate. The lead II electrocardiography signal is a standard signal for heart rate and photoplethysmography signal that measured at the finger is a standard signal for waveform. The test is repeated 3 times using three sensor. The data is processed by MATLAB to verify the utility by comparing the correlation coefficient score and heart rate. The photoplethysmography sensor using two green light emitting diodes is shown better utility than using one green light emitting diode and red light emitting diode at the ambient light. The waveform and heart rate that measured by two green light emitting diodes are more identical than others. The amount of electricity used is less than red light emitting diode and error peak detectability factor is the lowest.

제품의 이력 관리를 위한 인터페이스 모듈 및 시스템 구현에 관한 연구

김현우(Kim Hyun Woo),윤영로(Yoon Young Ro) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.6

서포트 벡터 머신을 이용한 심폐소생술 변이의 변화에 따른 제세동 성공률 분석

장승진,황성오,이현숙,윤영로,Jang, Seung-Jin,Hwang, Sung-Oh,Lee, Hyun-Sook,Yoon, Young-Ro 대한의용생체공학회 2007 의공학회지 Vol.28 No.4

Unsatisfied results of return of spontaneous circulation (ROSC) estimates were caused by the fact that the predictability of the predictors was insufficient. This unmet estimate of the predictors may be affected by transitional events due to behaviors which occur during cardiopulmonary resuscitation (CPR). We thus hypothesized that the discrepancy of ROSC estimates found in statistical characteristics due to transitional CPR events, may affect the performance of the predictors, and that the performance of the classifier dichotomizing between ROSC and No-ROSC might be different during CPR. In a canine model (n=18) of prolonged ventricular fibrillation (VF), standard CPR was provided with administration of two doses of epinephrine 0 min or 3 min later of the onset of CPR. For the analysis of the likelihood of a successful defibrillation during CPR, Support Vector Classification was adopted to evaluate statistical peculiarity combining time and frequency based predictors: median frequency, frequency band-limited power spectrum, mean segment amplitude, and zero crossing rates. The worst predictable period showed below about 1 min after the onset of CPR, and the best predictable period could be observed from about 1.5 min later of the administering epinephrine through 2.0-2.2 min. As hypothesized, the discrepancy of statistical characteristics of the predictors was reflected in the differences of the classification performance during CPR. These results represent a major improvement in defibrillation prediction can be achieved by a specific timing of the analysis, as a change in CPR transition.