1.Measurement of digital blood flow using impedance plethysmography.
Dong Kyun RAH ; Kuek Shun SHIN ; Jae Duk LEW ; Deok Won KIM
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1992;19(4):602-608
No abstract available.
Electric Impedance*
;
Plethysmography, Impedance*
2.Study on double feedback current source for biologic impedance measurement.
Chao WANG ; Xiangyu WANG ; Hongjun SUN ; Huaxiang WANG
Journal of Biomedical Engineering 2006;23(4):704-707
A double feedback current source for biologic impedance measurement is designed in order to solve the problem on the poor constant-current characteristic under higher frequency and meet the request for the ability to eliminate the direct current signal. The voltage controlled current source based on the second generation current conveyor theory is presented, which has good output impedance and anti-direct current characteristics by using the direct current feedback unit and input buffer. The closed loop control of current amplitude is implemented by means of the direct digital synthesizer and multiplication demodulation technique, which improves the constant-current characteristic of the current source.
Equipment Design
;
Plethysmography, Impedance
;
instrumentation
3.Some changes of rheograph index in the patients with cerebro-vascular insufficient treated with artificial magnetic fields
Journal of Medical and Pharmaceutical Information 2004;0(7):29-62
Studying rheography of 32 patients with cerebrovascular insufficient treated by artificial magnetic fields at Central Military Hospital from June to December 2002. Results: treating by artificial magnetic fields gave significant improvements on the rheographic index such as reduce of time and normalization of /T ratio, increase of Ri index and cerebrovascular volume to normal levels; artificial magnetic fields also improved imagines of rheographic waves. These results demonstrated the improvements in regulation of vascular tonicity, and promoting blood flow at treated areas
Plethysmography, Impedance
;
Cerebrovascular Disorders
;
Therapeutics
;
Magnetics
4.Effects of mice body temperature on pressure inside plethysmograph.
Journal of Zhejiang University. Medical sciences 2011;40(3):315-320
OBJECTIVETo observe temperature and pressure changes inside plethysmograph produced by body temperature of anesthetized mice.
METHODSThe temperature and pressure changes inside whole body plethysmograph generated from anesthetized mice were compared with those from dead mice. The temperature and pressure changes inside body chamber and head chamber of double-chamber with anesthetized mice in body chamber were synchronously measured. The respiratory frequencies and amplitudes of mice inside two kinds of head-out plethysmographs were synchronously measured. One of these two plethysmographs kept sealed all the time and the other was opened to the atmosphere for 1 min every 2 min.
RESULTTemperature and pressure of air in the anesthetized mice chamber increased 1.18 degree and 2.710 mmHg within 6 min, and data from dead mice were 1.17 degree and 2.671 mmHg. There were no significant differences between these two groups. The temperature inside body chamber increased 1.92 degree in 20 min and the pressure was 5.554 mmHg, which were significantly higher than those of head chamber (0.09 degree and 0.627 mmHg). The respiratory frequencies of mice in the sealed head-out plethysmograph increased from 125.04 per min to 168.45 per min, and amplitudes of pressure changes generated from mice breath decreased from 1.090 mmHg to 0.883 mmHg. Significant differences occurred between different observation time points. Meanwhile respiratory frequencies in the open head-out plethysmograph were around 120 per min and amplitude of pressure changes kept about 1 mmHg. There were no significant differences between different time points.
CONCLUSIONIncrease of temperature and pressure inside pressure whole-body plethysmograph are mainly from body temperature of mice, and the increased pressure significantly influences respiration of mice.
Animals ; Body Temperature ; Mice ; Plethysmography, Whole Body ; Pressure ; Temperature
5.Design of a digital respiratory inductive plethysmography system.
Zheng-bo ZHANG ; Wei-Dong WANG ; Hao WU ; Kai-Yuan LI ; Qing ANG
Chinese Journal of Medical Instrumentation 2007;31(3):179-181
A new type of respiratory inductive plethysmography (RIP) has keen designed based on digital demodulation technique with equal relative error. Compared with former amplitude demodulation, digital modulation RIP can obtain more accurate measurements of respiration and reduce the signal interference and distortion. But the system's power consumption is still a problem which needs to be solved in the future design.
Plethysmography
;
methods
;
Signal Processing, Computer-Assisted
;
Tidal Volume
6.Characteristics of Vascular Anatomy and Hemodynamics in Korean Population
Hang Seok CHANG ; Dong Ik KIM ; Seung HUH ; Ki Hyuck PARK ; Chul Hyung LEE ; Do Yul KIM ; Ji Yung MOON ; Eun Sook KIM ; Yong Il KIM ; Byung Boong LEE
Journal of the Korean Society for Vascular Surgery 1997;13(2):171-175
The value of the noninvasive diagnostic methods for vascular disease is worthy of emphasis. In many studies, the diagnostic abnormal findings of the vascular disease were reported. But there were a few studies for normal human vasculatures measuring with noninvasive diagnostic methods. And more, there is few data for vasculature of Oriental people, especially of the Korean population. The authors examed 20 healthy persons without any vascular disease by using the noninvasive vascular diagnostic tool-duplex scan and air plethysmography. The knowledge of the normal data of human vasculature, especially Korean population, will improve the sensitivity and specificity of the noninvasive vascular diagnostic methods. It is not appropriate to presume that this report with analysis of only 20 cases represent the normal data of Korean population. Further collection of the data is needed to define the normal data of vasculature of Korean population.
Blood Vessels
;
Hemodynamics
;
Humans
;
Plethysmography
;
Sensitivity and Specificity
;
Vascular Diseases
7.Correlation between Doppler Ultrasonography and Impedance Plethysmography in Lower Extremity Varicose Vein.
Byung Kyu PARK ; Dong Rak KWON ; Jae Heung PARK ; Ha Noon MOOHN
Journal of the Korean Academy of Rehabilitation Medicine 2002;26(3):337-341
OBJECTIVE: To investigate the diagnostic validity of doppler ultrasonography (US) and impedance plethysmography (IPG) using photoplethysmography for evaluation of varicose vein of the lower extremities. METHOD: One hundred sixty-six limbs in 83 consecutive patients with varicose vein were included. Venous reflux and deep venous lesions were assessed by doppler US. Venous filling time was evaluated using IPG. Diagnostic capabilities of two methods were analyzed using Receiver Operating Characteristic (ROC) curve. RESULTS: Doppler US identified superficial venous reflux in sixty-nine of 119 limbs with varicose vein and no abnor malities in 34 of 47 normal limbs (sensitivity, 58%; specifi-city, 75%). IPG demonstrated superficial venous insufficiency in 75 of the affected limbs and normal refill time in 38 of the normal limbs (sensitivity, 63%; specificity, 81%). Sensitivity was increased to 82% when both tests were used together. Area under the ROC curve was 0.66 in doppler US, 0.72 in IPG, and 0.76 in both tests. Deep venous lesion was found in 31 limbs using the both tests; 15 limbs with doppler US and 18 limbs with IPG. CONCLUSION: IPG was more superior to doppler US in diagnosing venous insufficiency. The combination of both tests provided more accurate diagnostic information in assessing venous valvular function
Electric Impedance*
;
Extremities
;
Humans
;
Lower Extremity*
;
Photoplethysmography
;
Plethysmography
;
Plethysmography, Impedance*
;
ROC Curve
;
Sensitivity and Specificity
;
Ultrasonography
;
Ultrasonography, Doppler*
;
Varicose Veins*
;
Venous Insufficiency
8.Selection of Reference Equations for Lung Volumes and Diffusing Capacity in Korea.
Eun Hee SONG ; Yeon Mok OH ; Sang Bum HONG ; Tae Sun SHIM ; Chae Man LIM ; Sang Do LEE ; Youn Suck KOH ; Woo Sung KIM ; Dong Soon KIM ; Won Dong KIM ; Tae Hyung KIM
Tuberculosis and Respiratory Diseases 2006;61(3):218-226
BACKGROUND: The lung volume and diffusing capacity are influenced by ethnicity. However, there are no equations for predicting the normal lung volume in the adult Korean population, and there is only one equation for diffusing capacity. The aim of this study is to select the most suitable reference equation for the Korean population. METHOD: 30 men and 33 women at Hanyang University Guri Hospital, and 27 men and 34 women at Asan Medical Center in healthy nonsmoking adults were enrolled in this study. The subject's age, gender, height, weight, lung volume by plethysmography, and diffusing capacity by a single breathing method were obtained. The most suitable equation with the lowest sum of residuals between the observed and predicted values for lung volume and diffusing capacity was selected. RESULT: At Hanyang University Guri Hospital, the equations with the lowest sum of residuals in the total lung capacity were ECSC's equation in males (sum of residual: 0.04 L) and Crapo/Morris's equation (-1.04) in women. At the Asan Medical Center, the equations with the lowest sum of residuals in the total lung capacity were Goldman/Becklake's equation in males (sum of residual: -2.35) and the ECSC's equation -4.49) in women. The equations with the lowest sum of residuals in the Diffusing capacity were Roca's equation in males (sum of residual: -13.66 ml/min/mmHg) and Park's in women (25.08) in Hanyang University Guri hospital and Park's equation in all cases in the Asan Medical Center (male: -1.65 , female: -6.46). CONCLUSIONS: Until a reference equstion can be made for healthy Koreans by sampling, ECSC's equation can be used for estimating the lung volume and Park's can be used for estimating the diffusing capacity.
Adult
;
Chungcheongnam-do
;
Female
;
Humans
;
Korea*
;
Lung*
;
Male
;
Plethysmography
;
Respiration
;
Total Lung Capacity
9.Evaluation of Erectile and Endocrine Function before and after Kidney Transplantation.
Tae Kon HWANG ; Jun Chul KIM ; Joung Hoon LEE ; Yong Hyun PARK
Korean Journal of Urology 1990;31(5):722-728
To observe the influence of kidney transplantation (KT) on erectile and endocrine function, we evaluated the PBI, penile pulse volume plethysmography, RigiScan and endocrine study before and after KT in 21 patients. We also interviewed with these patients or their sexual partners before KT. at 3 months and 6 months after KT. 7 cases (33%) were improved, 8 cases (38%) were same and 4 cases(19%) were aggravated in sexual desire and erectile function and 2 cases (10% ) had been suffered from erectile dysfunction since 19 months and 6 years prior to KT. The PBI was changed from 0.97 +/- 0.09 to 0.95 +/- 0.16 and it was not a significant difference. The penile plethysmography was not a good screening test in the evaluation of erectile function in KF. But the Rigiscan could detect all of the tested aggravated cases and it was thought to be a good screening test. In the endocrine studies, testosterone and FSH were decreased and LH and prolactin were increased before KT but testosterone and LH were significantly decreased after KT. It was thought to be the influence of KT and immunosuppressive agent (cyclosporin A). In conclusion, sexual desire and erectile function may be improved by the KT and most reliable screening test was Rigiscan. Endocrine function may be affected by the KT and cyclosporin A.
Cyclosporine
;
Erectile Dysfunction
;
Humans
;
Kidney Transplantation*
;
Kidney*
;
Male
;
Mass Screening
;
Plethysmography
;
Prolactin
;
Sexual Partners
;
Testosterone
;
Transplantation
10.Effects of Acute Hyperglycemia on Endothelium-Dependent Vasodilation in Patients with Diabetes Mellitus or Impaired Glucose Metabolism.
Kyung Woo PARK ; Yong Seok KIM ; Eue Keun CHOI ; Se Il OH ; In Ho CHAE ; Cheol Ho KIM
Journal of the Korean Geriatrics Society 2002;6(2):146-154
BACKGROUND: Although impaired endothelial function is well known in patients with diabetes mellitus, the precise mechanism and the factors that contribute to this dysfunction remain to be clarified. We examined the effect of acute hyperglycemia on patients with impaired glucose metabolism in vivo by plethysmography. METHODS: Seven patients with diabetes mellitus or impaired glucose metabolism were studied. In each patient, endothelial function was examined in the fasting state and at two levels of hyperglycemia, which were achieved by the infusion of glucose, insulin, and somatostatin. Forearm blood flow was measured while acetylcholine was infused in increasing concentrations(7.5, 15, and 30 microgram/min) through the brachial artery. RESULTS: Glucose concentrations increased accordingly at each stage, from 135.3+/-18.4 mg/dl at stage 1(the fasting state), to 239.0+/-15.2 mg/dl at stage 2(the first level of hyperglycemia), and to 378.3+/-25.3 at stage 3 (the second level of hyperglycemia) [p<0.01]. Maximal acetylcholine-dependent vasodilation achieved by infusion of acetylcholine at 30 microgram/min was significantly aftenuated during stages 2 and 3 compared with stage 1(p<0.05 by AVOVA; forearm blood flow ratio was 2.87+/-0.18 and 2.56+/-0.14 versus 3.58+/-0.21, respectively). This was also evident during the infusion of 15 microgram/min and 7.5 microgram/min of acetylcholine. CONCLUSIONS: Endothelium-dependent vasodilation is significantly aftenuated by acute hyperglycemia in patients with diabetes mellitus or impaired glucose metabolism. Our findings suggest that elevated glucose may contribute to the endothelial dysfunction observed in patients with diabetes mellitus or impaired glucose metabolism.
Acetylcholine
;
Brachial Artery
;
Diabetes Mellitus*
;
Endothelium
;
Fasting
;
Forearm
;
Glucose*
;
Humans
;
Hyperglycemia*
;
Insulin
;
Metabolism*
;
Plethysmography
;
Somatostatin
;
Vasodilation*