• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.1-7
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• 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
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• v.17 no.2
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• pp.188-192
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• 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.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.503-509
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• 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.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.51-54
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• 1989

In last several years, a number of volume localization techniques, such as ISIS, VSE, SPARS and STEAM etc., have been developed for the MR spectroscopy. These localizing techniques, however, require application of several RF pulses for the 3-D volume selection and suffer from T1 and T2 decays due to relatively long RF excitation time. In this paper, we propose a single-shot RF pulse localization technique to achieve the localized 3-D volume selection. This technique combines the cylindrical volume selection technique with a radial gradient coil with single-shot RF pulse and the oscillating selection gradient technique, so thai it minimizes the volume selection time. We report some experimental results obtained with the proposed method which appears promising for 3-D volume imaging and localized spectroscopy.

• Korean Journal of Acupuncture
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• v.27 no.1
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• pp.1-12
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• 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.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.03a
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• pp.175-175
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• 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.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.5
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• pp.1-6
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• 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.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.395-398
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• 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.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.197-202
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• 1998

The human pulse wave is a vital biosignal that includes the diagnostic data related with the heart and the cardiovascular system of human body. Based on the mechanical transducing method, a pulse detection transducer using optical fiber was developed to acquire the pulses non-invasively. To improve the detection efficiency, we proposed a new design that consists of two combinational parts; detecting part, which is in contact with the pulsating skin and transmits the displacement motion of the pulsating skin to the sensing part, and sensing part, which converts the physical quantity transmitted from the detecting part to electronic signal. By using the new method, we confirmed that the proposed transducer can detect the C point(incisura) and the T wave(tidal wave) which is not easily detected by existing transducers.

• Korean Journal of Oriental Medicine
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• v.14 no.3
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• pp.121-126
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• 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.