Dong-Hyun Nam

Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

To measure precise blood pressure (BP) and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

Measurement of Spatial Pulse Wave Velocity by Using a Clip-Type Pulsimeter Equipped with a Hall Sensor and Photoplethysmography

A prototype of a clip-type pulsimeter equipped with a magnetic field-sensing semiconductor Hall sensor was developed. It has a permanent magnet attached in the “Chwan” position to the center of a radial artery. The clip-type pulsimeter is composed of a hardware system measuring voltage signals. To measure spatial pulse wave velocity (SPWV), the signal from the radial artery pulsimeter and that from the photoplethysmography (PPG) were simultaneously compared. The pulse wave data from a clinical test of 39 clinical participants (male:female = 25:14) with a mean age of 24.36 (±2.35) years was analyzed. The mean SPWV, which was simultaneously measured from the radial artery pulsimeter and PPG, was 0.8 m/s. We suggest the SPWV results were higher for men than women, because of the better vascularity of terminal tissue in men. The findings of this research may be useful for developing a biomedical signal storage device for a U-health-care system.

Tongue diagnosis system for quantitative assessment of tongue coating in patients with functional dyspepsia: a clinical trial.

ETHNOPHARMACOLOGICAL RELEVANCE Tongue diagnosis is a significant procedure to examine the physiological and pathological changes of the human body in oriental medicine. However, the conventional method of tongue diagnosis including direct observation of tongue has limitations because of various external factors and subjective factors. Therefore, the current study investigated the usefulness of the tongue diagnosis system (TDS) as a diagnostic tool for evaluating tongue coating thickness (TCT) by assessing the agreement between the TDS and a gold standard established by assessors using the conventional method. MATERIALS AND METHODS The present study was designed as a prospective clinical trial including 60 patients with functional dyspepsia. The TDS was used to capture tongue images twice within a 30-min interval to assess its reproducibility. Tongue coating percentage was measured by the TDS, and TCT was classified as either no coating, thin coating, or thick coating according to the existing diagnostic criteria. After both TDS examinations, the weight of tongue coating was quantitatively measured, and the correlation between the actual quantity of tongue coating and the percentage of the coating measured by the TDS was analyzed using Pearson׳s correlation. After collecting tongue images in all 60 patients, tongue coating was evaluated using a conventional method by 5 well-trained assessors to establish the gold standard for evaluating TCT, which allowed us to assess the diagnostic agreement between the TDS and the gold standard. After 2 weeks, TCT evaluation was repeated by the same assessors using the same images but in a random order. RESULTS The agreement between the TDS and the gold standard for evaluating TCT was almost perfect (weighted kappa, 0.840), as was the reproducibility of the TDS (weighted kappa, 0.851). The percentage of tongue coating measured by the TDS was significantly correlated with the weight of tongue coating (r=0.442, p <0.001). The levels of intra-rater reliability ranged from substantial to almost perfect (range of weighted kappa, 0.777-0.923). The inter-rater reliability of 5 assessors was moderate (weighted kappa, 0.563). CONCLUSIONS The present study demonstrated that the TDS can be used as a diagnostic tool for the objective and standardized evaluation of TCT in actual clinical practice.

Fabrication and Characterization of a Wrist Wearable Cuffless Pulsimeter by Using the Hall Effect Device

A wrist wearable cuffless pulsimeter with a portable and small size apparatus using Hall effect is fabricated. The analysis of the pulse wave measured by the testing product of pulsimeter is done to measure the pulse rate and blood pressure. The blood pressure obtained by the puslimeter is compared with the practical values measured by electronic or mercury liquid blood pressure meters. The detail analysis of a pulse wave measured by a wrist wearable cuffless pulsimeter detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of blood pressure applying for oriental medical apparatus.

Measurement and Analysis of Pulse Wave Using a Clamping Pulsimeter Equipped With Hall Effect Device

We measured signals at the “Guan” region of a radially arterial pulse using the testing product of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure without an unpleasant oppressive feeling due to the use of pressurization.

Coated Tongue Region Extraction using the Fluorescence Response of the Tongue Coating by Ultraviolet Light Source

An effective extraction method for extracting a coated tongue is proposed in this paper, which is used as the diagnostic criteria in the tongue diagnosis. Proposed method uses the fluorescence response characteristics of the coated tongue that is occurred by using the ultraviolet light. Specially, this method can solved the previous problems including the issue in the limits of the diagnosis environment and in the objectivity of the diagnosis results. In our method, original tongue image is acquired by using the ultraviolet light, and binarization is performed by thresholding a valley-points in the histogram that corresponds to the color difference of tongue body and tongue coating. Final view image is presented to the oriental doctor, after applying the canny-edge algorithm to the binary image, and edge image is added to the original image. In order to evaluate the performance of the our proposed method, after building a various tongue image, we compared the true region of coated tongue by the oriental doctor`s hand with the extracted region by the our method. As a result, the proposed method showed the average 87.87% extraction ratio. The shape of the extracted coated tongue region showed also significantly higher similarity.

Smart pulse wave detection system using intelligence

The pulse rate in the human species is a significant factor in oriental medicine. Pulse wave is a potential energy which has been generated by main artery expansion from the left ventricle, transforms into kinetic energy and passes through the vessel wall to the peripheral nervous system. In this paper, observations of patterns will be used to determine the blood circulation pulse wave which has been differentiated twice through the process of APG (Accelerated Photoplethysmo Graph). Moreover in this paper, it proposed the algorithm which diagnoses the patients health condition using intelligence method.

Comparative Analysis of Tongue Indices between Patients with and without a Self-Reported Yin Deficiency: A Cross-Sectional Study

We investigated the hypothesis that Yin-deficient patients have a reddened tongue with less coating. We screened 189 participants aged 20 to 49 years, complaining of headache. To classify patients in terms of Yin deficiency, we used two self-reporting Yin-deficiency questionnaires (Yin-Deficiency Questionnaire and Yin-Deficiency Scale) and diagnosis by a doctor. Based on the tests, a total of 33 subjects were assigned to a Yin-deficient group and 33 subjects were assigned to a nondeficient control group. Tongue images were acquired using a computerized tongue diagnostic system, for evaluating tongue indices. The tongue coating percentage and tongue redness were calculated as the mean a⁎ value of both the whole tongue area (WT a⁎) and the tongue body area (TB a⁎). The tongue coating percentage of the Yin-deficient group (34.79 ± 10.76) was lower than that of the nondeficient group (44.13 ± 14.08). The WT a⁎ value of the Yin-deficient group (19.39 ± 1.52) was significantly higher than that of the nondeficient group (18.21 ± 2.06). However, the difference in the TB a⁎ value between the two groups was not significant. In conclusion, we verified that Yin-deficient patients had less tongue coating and tended to have a more reddish tongue than nondeficient patients.

Pulse wave Measurement System by analyzing a Moving Pulse Image in the Capillary Tube

The pulsimeter is a representative device in the oriental medicine, which can analysis a risk factor in a cardiovascular diseases. However, most of the previous methods have the limit by the contacted sate of the brachial pulse and sensor in the measuring time, the inaccuracy of detected pulse, and the difficulty of pulse analysis. Accordingly, we propose the moving pulse image analysis based pulsimeter that can acquire a pulse of patient in real time by analyzing a moving image. then this video is shot the state change of the T.S. occurred by a pulse in capillary. In order to evaluate the performance of the our pulsimeter, we measured a respective detecting-rate about the essential 5 feature-points in the pulse analysis from the detected original pulse. As a result, the proposed method is very successful.

Reliability, Accuracy, and Use Frequency of Evaluation Methods for Amount of Tongue Coating

ObjectiveTo classify the evaluation methods for amount of tongue coating (TC) and investigate their reliability, accuracy, and frequency of use.MethodsArticles published from 1985 to 2015 were searched for evaluation methods for the amount of TC in PubMed and the Cochrane Library. Only clinical researches were included except protocol articles. The methods were classified according to their characteristics.ResultsFinally, 113 articles were selected. The evaluation method for the amount of TC from the articles was classified into 4 types: intuitive, specificative, computerized, and weighing TC. The reliability in the intuitive and specificative methods (κ =0.33–0.92) showed varying levels among the studies. In general, the amount of TC calculated by the specificative method (Spearman’s r=0.68–0.80) was more strongly related to the directly measured value than to the value estimated by the computerized method (Pearson’s r=0.442). The number of articles published on this topic has increased consistently, and the specificative method was the most frequently used. Despite the higher reliability of the computerized method, it has not been widely used.ConclusionsThe high prevalence of the specificative method would continue in clinical practice because of its convenience and accuracy. However, to establish higher reliability, the limitation of the subjectivity of the assessors should be overcome through calibration training. In the computerized method, novel algorithms are needed to obtain a higher accuracy so that it can help the practitioners confidently estimate the amount of TC.