• 한국공작기계학회논문집
• /
• 제10권6호
• /
• pp.1-7
• /
• 2001

It is very important to test circular motion accuracy of NC machine tools as it affects all other machines machined by them in industries. In this paper, it has become possible to detect errors of linear displacement of radial directions for circle tar motion accuracy test using newly assembled magnetic type of linear scale so called Magnescale ball-bar system. It has also organized computer program systems using tick pulses come out from computer for getting error motion data at colt start time interval in circular motion test on NC lathe. Error data gotten from test is expressed to plots and analysed to numerics by various statistical treatments.

• Bulletin of the Korean Chemical Society
• /
• 제17권2호
• /
• pp.188-192
• /
• 1996

It is shown that the inversion of the undamped Bloch equation for an amplitude-modulated broadband π/2 pulse can be precisely treated as an inverse scattering problem for a Schrodinger equation on the positive semiaxis. The pulse envelope is closely related to the central potential and asymptotically the wave function takes the form of a regular solution of the radial Schrodinger equation for s-wave scattering. An integral equation, which allows the calculation of the pulse amplitude (the potential) from the phase shift of the asymptotic solution, is derived. An exact analytical inversion of the integral equation shows that the detuning-independent π/2 pulse amplitude is given by a delta function. The equation also provides a means to calculate numerically approximate π/2 pulses for broadband excitation.

• 대한의용생체공학회:의공학회지
• /
• 제30권6호
• /
• pp.503-509
• /
• 2009

The development of technology has led to ubiquitous health care service, which enables many patients to receive medical services anytime and anywhere. For the ubiquitous health care environment, real-time measurement of biomedical signals is very important, and the medical instruments must be small and portable or wearable. So, such devices have been developed to measure biomedical signals. In this study, we develop the biomedical monitoring device which is sensing the PPG signal, one of the useful signal in the field of ubiquitous healthcare. We design a watch-like biomedical signal monitoring system without a finger probe to prevent the user's inconvenience. This system obtains the PPG from the radial artery using a sensor in the wrist band. But, new device developed in this paper is easy to get the motion artifacts. So, we proposed new algorithm removing the motion artifacts from the PPG signal. The method detects motion artifacts by changing the degree of brightness of the light source. If the brightness of the light source is reduced, the PPG pulses will disappear. When the PPG pulses have disappeared completely, the remaining signal is not the signal that results from the changing blood flow. We believe that this signal is the motion artifact and call it the noise reference signal. The motion artifacts are removed by subtracting the noise reference signal from the input signal. We apply this algorithm to the system, so we can stabilize the biomedical monitoring system we designed.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1989년도 춘계학술대회
• /
• pp.51-54
• /
• 1989

지난 몇년동안 생체에서의 MR 스펙트로 스코피(Mangetic Resonance Spectroscopy)를 위하여 ISIS, VSE, SPARS, STEAM 등과 같은 여러 체적 선택의 방법이 연구되어 왔다. 그러나 이들 3차윈 체적 선택의 방법은 여러 RF 펄스를 사용하여야 되었으며 상대적으로 오랜시간 동안의 RF여기시간(Radio frequency excitation time) 때문에 T1과 T2 감소효과의 영향을 크게 받았다. 본 논문에서는 3차원의 체적을 선택하기 위하여 단일 RF펄스의 사용을 제안하고 있는데, 이 방법은 원통형 체적을 선택하기 위한 방사형 경사 코일 (a radial gradient coil) 방법과 진동자계 (oscillating selection gradient) 방법을 결합하고 있다. 이렇게 하므로 단일 RF 펄스만을 사용하여 체적 선택 시간을 최소화하여 여러 RF 펄스를 사용할 경우 발생하는 파생적인 에코 신호(echo signal)를 피할 수 있었다. 제안된 방법에 의한 실험적 연구결과로서 펜톰(phantom)에 대하여 선택된 체적에 대한 영상과 스펙트럼 (spectrum)을 제시하였다.

• Korean Journal of Acupuncture
• /
• 제27권1호
• /
• pp.1-12
• /
• 2010

Objectives: The purpose of this study is to gain the objective indicators for the classification of hypertension by oriental medical pulse diagnosis, through finding out the parameters which can distinguish the pulse of hypertensive patient from that of normal subject, and characterizes the wiry pulse of hypertension. Methods: 30-59 yr, male, 946 healthy volunteers and 35 hypertensive patients were enrolled in this study. All the hypertensive patients were taking medicine to control the blood pressure and the blood pressure of the hypertension group was not statistically different from that of the normal healthy group. Data were acquired using 3 dimensional pulse imaging analyser(DMP-3000, DAEYOMEDI, KOREA) and analysed according to the age bands and the applied pressure levels. Results: 1. RAI/t, w/t and t2/t decreased with the levels of applied pressure and increased with age in the normal healthy group, not in the hypertension group. 2. RAI/t, w/t, t2/t were significantly higher in the hypertension group than the normal healthy group in the 30-age band, and elasticity coefficient was higher in the hypertension group than the normal healthy group in the 40-age band. 3. Researches on the patients without hypotensive agents are needed to figure out whether these parameters are the components of hypertensive wiry pulse. Conclusions: Analysing the radial pulse at 5 applied pressure levels using 3 dimensional pulse imaging analyser may be useful to differentiate the pulses of the hypertensive patients from those of the normal subjects, and characterize the hypertension.

• 대한견주관절학회:학술대회논문집
• /
• 대한견주관절학회 2008년도 제16차 학술대회
• /
• pp.175-175
• /
• 2008

We report a rare case of late-onset brachial artery occlusion caused by subclavian artery stenosis with excessive scar tissue after open reduction and plate fixation for clavicular fracture. When he referred to us, the right hand were pale and the radial and ulnar pulses at the wrist were absent. CT-angiogram showed compression of subclavian artery by excessive scar tissue beneath the fracture site and angiography revealed stenosis of subclavian artery with thrombus and complete obstruction of blood flow in the brachial artery with emboli. Therefore, we performed embolectomy. 2 years after operation, patient was essentially asymptomatic except mild pain after long standing elevation of arm. We recommend that minimal soft tissue dissection should be needed in the operative treatment of clavicular fracture, especially soft tissue beneath the clavicle should be protected maximally.

• 한국공작기계학회논문집
• /
• 제13권5호
• /
• pp.1-6
• /
• 2004

Measurements of circular motion accuracy of NC lathe have achieved with ball bar systems proposed by Bryan, but the ball bar systems have ifluenced on the measuring data by way of the accuracy of the balls and the contacts of balls and bar seats. Therefore in this study, error data during of circular motion of ATC(Automatic Tool Changer) of NC lathe will be acquired by reading zx plane coordinates using two optical linear scales. Two optical linear scales of measuring unit are fixed on z-x plane of NC lathe, and the moving part is fixed to ATC and then is made to receive data of coordinates of the ATC at constant time intervals using tick pulses comming out from computer. And then, error data files of radial direction of circular motion are calculated with the data read, and the aspect of circular motion are modeled to plots, and are analysed by means of statistical treatments of circularity, means, standard deviations etc.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 추계학술대회
• /
• pp.395-398
• /
• 1997

Human pulse represents the physical characteristics of heart and cardiovascular system. Therefore, malfunctions and errors of heart and cardiovascular system can be determined by using an automatic diagnosis system that can detect the pulse signal. Not only will the computerised system preclude the possibilities of observational errors by giving an accurate measurement with great stability, but minimize the possibilities of misinterpretation by using an automated diagnostic logic. A new combinational fiber-optic sensor, which has a detecting part and a transmitting part was used to acquire radial pulse signal noninvasively. The development of P-5 transducer makes it possible to obtain more effective detection and obvious display of pulse signals in the aspect of reliability. Using P-5 transducer in the field of plethysomography and MAC- JIN, one of our diagnoses in Korean traditional medicine, it is expected that we can ontain quantitative and valuable information or the diagnosis of human pulses.

• 센서학회지
• /
• 제7권3호
• /
• pp.197-202
• /
• 1998

맥파신호는 심장과 심혈관계에 관련된 중요한 정보를 포함하고 있는 중요한 생체신호이다. 본 연구에서는 맥파신호를 비관혈적으로 검출하기 위해 기존의 기계적 변환방식의 개념에 근거하여 광섬유를 이용하는 맥파 검출용 트랜스듀서를 새로이 개발하여 사용하였다. 기계적 변환방식에서 발생될 수 있는 맥동전달 효율을 개선시키기 위해 본 연구에서는 맥동하는 피부와 접촉하여 센서에 전달하는 검출부(detecting part)와, 전달받은 변위운동을 광 출력 변화에 따른 전기 신호로 변환하는 감지부(sensing part)의 두 부분이 조합된 구조를 갖는 설계방식을 제안하였다. 우리는 이러한 조합형 구조의 설계방식을 이용한 결과로 기존의 트랜스듀서로 검출이 어려운 맥파의 C점(절흔)과 T파를 검출할 수 있음을 확인하였다.

• 한국한의학연구원논문집
• /
• 제14권3호
• /
• pp.121-126
• /
• 2008

Pulse diagnosis refers to the process of diagnosing a patient by feeling an artery on the wrist based on the shape that the pulse take s while the hold-down pressure increase. The styloid process artery on the wrist is usually felt, and the pulse is taken on Chon, Gwan and Cheok using three fingers. This study is to examine the structural difference in the location of pulse diagnosis by measuring and analyzing blood diameter, blood depth, and blood flow velocity of the location of pulse diagnosis by using ultrasonic wave (VOLUSION730 PRO, GE Medical, U.S.A). This study also attempted to grasp whether the characteristics of blood vessels differ depending on Body Mass Index (BMI) and analyzed their correlation with Oriental medical pulse diagnosis. The male subjects without cardiovascular diseases were divided into the normal BMI group, the underweight group and the overweight group and 10 people of each group were measured, Blood depth, blood diameter and blood flow velocity at the location of pulse diagnosis (Chon, Gwan, Cheok) of the wrists of left and right hands were measured and the pulse wave was measured by using pulse diagnosis instrument (3-D Mac, DaeyoMedi, Korea).The results of this study showed that the characteristics of blood vessels differ depending on the degrees of obesity, and the characteristics of floating pulse and sinking pulse of Oriental medical pulses were related to the degrees of obesity. This shows that the characteristics of the blood vessels of subjects and BMI information are the major indicators for diagnosis and are the matters that must always be considered when developing the algorithm of pulse diagnosis.