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Sample records for blood measurement method

  1. Palpatory method of measuring diastolic blood pressure

    Directory of Open Access Journals (Sweden)

    Dinesh Sahu

    2010-01-01

    Conclusion: The palpatory method would be very useful where frequent blood pressure measurement are being done manually like in wards, in busy OPD, patient on treadmill and also whenever stethoscope is not available. The blood pressure can be measured in noisy environment too.

  2. A new method of non-invasive blood pressure measurement

    Science.gov (United States)

    Gu, Liangling; Yang, Yongming; Yu, Chengbo; Guo, Qiaohui; Zhu, Gang

    2005-12-01

    Blood pressure reflects a person's health.It is proposed here that the method of detecting blood pressure may be the key to improving the precision of blood pressure measurements. The oscillometric blood pressure measurement technique is widely used in automatic blood pressure measurement instruments correctly. A method of blood pressure measurement by oscillometric method is first presented. In the oscillometric method, the basic principle of the "feature point" method and the "amplitude characteristic ratios" method is also explained and discussed here. A new method of blood pressure measurement, namely the coefficient difference comparative method, is proposed here,which is based on the feature point method and amplitude characteristic ratios method. The method is proved both effective and reliable through the analysis of many cases and clinical tests. Utilizing Visual C++, software for this new and novel method was developed and passed criterion simulation apparatus test. When applied in hospital situation, its error was +/-5%. It is concluded that the oscillometric blood pressure measurement method can provide better means of blood pressure measurements reference for doctors.

  3. Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs

    DEFF Research Database (Denmark)

    Sandgaard, N C F; Andersen, J L; Holstein-Rathlou, N-H;

    2002-01-01

    We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven t...... of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta....

  4. Near-infrared spectral methods for noninvasively measuring blood glucose

    Science.gov (United States)

    Fei, Sun; Kong, Deyi; Mei, Tao; Tao, Yongchun

    2004-05-01

    Determination of blood glucose concentrations in diabetic patients is a frequently occurring procedure and an important tool for diabetes management. Use of noninvasive detection techniques can relieve patients from the pain of frequent finger pokes and avoid the infection of disease via blood. This thesis discusses current research and analyzes the advantages and shortages of different measurement methods, including: optical methods (Transmission, Polarimetry and scattering), then, we give emphasis to analyze the technology of near-infrared (NIR) spectra. NIR spectral range 700 nm ~2300 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. In this work, we present an outline of noninvasive blood glucose measurement. A near-infrared light beam is passed through the finger, and the spectral components of the emergent beam are measured using spectroscopic techniques. The device includes light sources having the wavelengths of 600 nm - 1800 nm to illuminate the tissue. Receptors associated with the light sources for receiving light and generating a transmission signal representing the light transmitted are also provided. Once a transmission signal is received by receptors, and the high and low values from each of the signals are stored in the device. The averaged values are then analyzed to determine the glucose concentration, which is displayed on the device.

  5. A blood pressure measurement method based on synergetics theory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>The principle for blood pressure measurement using pulse transit time is introduced in this paper.And the math model of synergetics theory is studied in detail.The synergetics theory is applied in the analysis of blood pressure measurement data.The simulation results show that the application of synergetics theory is helpful to judge the normal blood pressure,and the accuracy is up to 80%.

  6. Sensitivity, specificity, and predictive values of a forearm blood pressure measurement method in severe obesity.

    Science.gov (United States)

    Leblanc, Marie-Ève; Cloutier, Lyne; Poirier, Paul

    2015-04-01

    For blood pressure assessment, it has been reported that forearm blood pressure measurement appears to be as valid as an upper-arm blood pressure measurement method in individuals with severe obesity when correlated to the intra-arterial method, considered as the gold standard. Sensitivity, specificity, and predictive values for the presence of systemic hypertension in 25 severely obese patients from 352 blood pressure measurements were calculated. The sensitivity (0.98) and the positive predictive value (0.93) for hypertension on forearm blood pressure measurements are excellent, indicating that the forearm approach is a promising alternative to systemic hypertension diagnosis in severe obesity. PMID:25757220

  7. A simple method of blood pressure measurement in the pig using a neonatal cuff.

    Science.gov (United States)

    Chow, P K; Ng, T H; Heng, D; Mack, P O

    1999-01-01

    The pig is a commonly used large animal model in experimental studies. Few non-invasive techniques exist however for the measurement of blood pressure in the porcine model. This study evaluates the novel use of the easily available neonatal blood pressure cuff for measuring blood pressure in the pig. Six Yorkshire pigs were used for the study. Blood pressure measurements obtained by the application of neonatal blood pressure cuff (Hewlett Packard) around the base of the tail were compared with results obtained from intra-arterial measurements in the normotensive range as well as in experimentally created hypertensive (intravenous dopamine) and hypotensive (hypovolaemic shock) ranges. Results of the two techniques are closely correlated (Pearson's coefficient = 0.95, 0.97, 0.90). Systematic bias was however detected at the extremes of hypertensive and hypotensive blood pressure. Analysis of the limits of agreement (method of Bland and Altman) showed that neonatal blood pressure cuff measurements fall within--2 to 2.5 mmHg of the readings obtained from the invasive technique (95% confidence interval). The neonatal blood pressure cuff technique is a good substitute for the standard invasive intra-arterial measurement of blood pressure in the pig model. PMID:10374020

  8. A simple versatile method for measuring tail cuff systolic blood pressure in conscious rats.

    Science.gov (United States)

    Widdop, R E; Li, X C

    1997-09-01

    1. The non-invasive measurement of tail cuff systolic blood pressure in conscious rats is routinely used in long-term cardiovascular studies. There are a number of commercially available tail cuff systems, however, these apparatus are generally expensive and are dedicated for single-task operations. In the present study, a simple method for measuring systolic blood pressure, which requires only minor modifications to the existing hardware found in most cardiovascular laboratories, is described. 2. Systolic blood pressure measurements were made in the conventional manner by determining the systolic blood pressure which coincided with the restoration of the caudal artery pulse. This was achieved by using an inexpensive piezo-electric pulse transducer to detect the pulse, and this was coupled to a standard data-acquisition system (MacLab, ADInstruments) normally set up to record blood pressure. This method was compared with another established tail cuff method, as well as with direct intra-arterial recordings. 3. It was found that the results obtained using both tail cuff systems were in good agreement when systolic blood pressure was measured in Wistar-Kyoto rats and spontaneously hypertensive rats. In addition, systolic blood pressure was measured over 4 weeks in 2K1C rats and sham-operated rats, with both tail cuff methods producing similar results, which were not significantly different from direct intra-arterial recordings in the same animals. 4. Thus, in the present study, with only minor modifications, the same equipment was used for both direct and indirect determinations of systolic blood pressure. This situation differs from other conventional tail cuff systems since these items are designed for a single purpose. Therefore, the current method using piezo-electric sensor/MacLab-technology should be viewed as a relatively simple, flexible and cheap alternative method to measure tail cuff systolic blood pressure in conscious rats. PMID:9337632

  9. Development of a fluorescent method for simultaneous measurement of glucose concentrations in interstitial fluid and blood

    International Nuclear Information System (INIS)

    Continuous blood glucose monitoring is of great clinical significance to patients with diabetes. One of the effective methods to monitor blood glucose is to measure glucose concentrations of interstitial fluid (ISF). However, a time-delay problem exists between ISF and blood glucose concentrations, which results in difficulty in indicating real-time blood glucose concentrations. Therefore, we developed a fluorescent method to verify the accuracy and reliability of simultaneous ISF and blood glucose measurement, especially incorporating it into research on the delay relationship between blood and ISF glucose changes. This method is based on a competitive reaction among borate polymer, alizarin and glucose. When glucose molecules combine with borate polymers in alizarin–borate polymer competitively, changes in fluorescence intensity demonstrate changes in glucose concentrations. By applying the measured results to the blood and ISF glucose delay relationship, we were able to calculate the time delay as an average of 2.16 ± 2.05 min for ISF glucose changes with reference to blood glucose concentrations. (paper)

  10. Simple Radiowave-Based Method For Measuring Peripheral Blood Flow Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    Project objective is to design small radio frequency based flow probes for the measurement of blood flow velocity in peripheral arteries such as the femoral artery and middle cerebral artery. The result will be the technological capability to measure peripheral blood flow rates and flow changes during various environmental stressors such as microgravity without contact to the individual being monitored. This technology may also lead to an easier method of detecting venous gas emboli during extravehicular activities.

  11. Blood pressure measurement

    Science.gov (United States)

    Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... or your health care provider will wrap the blood pressure cuff snugly around your upper arm. The ...

  12. Comparison of three methods of sampling trout blood for measurements of hematocrit

    Science.gov (United States)

    Steucke, Erwin W., Jr.; Schoettger, Richard A.

    1967-01-01

    Trout blood is frequently collected for hematocrit measurements by excising the caudal fin (Snieszko, 1960), but this technique is impractical if valuable fish are to be sampled or if repeated observations are desired. Schiffman (1959) and Snieszko (1960) collected blood from the dorsal aorta and the heart, but these methods are relatively slow and require the preparation of needles and syringes. The use of pointed capillary tubes for cardiac punctures increases the speed of sampling, but body fluids may dilute the blood (Perkins, 1957; Larsen and Snieszko, 1961; and Normandau, 1962). There is need for methods of sampling which are rapid and which neither influence hematological determinations nor harm the fish.

  13. An Investigation of Pulse Transit Time as a Non-Invasive Blood Pressure Measurement Method

    Science.gov (United States)

    McCarthy, B. M.; O'Flynn, B.; Mathewson, A.

    2011-08-01

    The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.

  14. An Investigation of Pulse Transit Time as a Non-Invasive Blood Pressure Measurement Method

    International Nuclear Information System (INIS)

    The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.

  15. An Investigation of Pulse Transit Time as a Non-Invasive Blood Pressure Measurement Method

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, B M; O' Flynn, B; Mathewson, A, E-mail: brian.mccarthy@tyndall.ie [Tyndall National Institute, UCC, Lee Maltings, Prospect Row, Cork (Ireland)

    2011-08-17

    The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.

  16. [Accuracy of the oscillometric method to measure blood pressure in children

    Science.gov (United States)

    Rego Filho, E A; Mello, S F; Silva, C R; Vituri, D W; Bazoni, E; Gordan, L N

    1999-01-01

    OBJECTIVE: The aim of this study is to analyze the substitution of the standard auscultatory method by the oscillometric blood pressure monitor, independently of the validity of the intraarterial blood pressure measurement. The accuracy of the automatic oscillometric monitor was compared to the auscultatory mercury manometer blood pressure measurement in apparently healthy school age children. METHODS: A device able to perform 3 simultaneous readings are used: one reading by the monitor and the others by two "blind" observers. We studied 72 school age children with the following characteristics: mean age 9.5 (6.1-16.1) and 39 males (54.2%). RESULTS: The difference for the systolic and diastolic blood pressure obtained by the monitor was in average + 6.2 mmHg and + 10.0 mmHg, respectively, when compared to the observer's readings. There was neither a good correlation nor a good agreement between the two observers and the monitor in the blood pressure determination. CONCLUSIONS: We concluded that the substitution of the standard auscultatory method for the non-invasive oscillometric method to measure blood pressure in school age children can not be generally recommended. PMID:14685547

  17. Optimal plane search method in blood flow measurements by magnetic resonance imaging

    Science.gov (United States)

    Bargiel, Pawel; Orkisz, Maciej; Przelaskowski, Artur; Piatkowska-Janko, Ewa; Bogorodzki, Piotr; Wolak, Tomasz

    2004-07-01

    This paper offers an algorithm for determining the blood flow parameters in the neck vessel segments using a single (optimal) measurement plane instead of the usual approach involving four planes orthogonal to the artery axis. This new approach aims at significantly shortening the time required to complete measurements using Nuclear Magnetic Resonance techniques. Based on a defined error function, the algorithm scans the solution space to find the minimum of the error function, and thus to determine a single plane characterized by a minimum measurement error, which allows for an accurate measurement of blood flow in the four carotid arteries. The paper also comprises a practical implementation of this method (as a module of a larger imaging-measuring system), including preliminary research results.

  18. Measurement of blood flow volume of ocular muscles by Xe-133 clearance method

    International Nuclear Information System (INIS)

    The blood flow volume of the ocular muscles was measured in 8 normal volunteers and 12 cases with miscellaneous opthalmic diseases by Xe-133 clearance method. The average of blood flow volume in the normal subjects was 7.45 ± 2.07 ml/min/100 g, and the blood flow volume ratio of right eye to left eye was 0.94 ± 0.07. The blood flow volume of the ocular muscles was decreased in the cases with stenosis of the internal carotid artery (n = 4, 4.3 ± 2.1 ml/min/100 g), glaucoma (n = 3, 4.7 ± 4.1 ml/min/100 g), arterial scleroses (n = 2, 3.8 ± 0.2 ml/min/100 g) and Takayasu's disease (n = 2, 5.6 ± 0.4 ml/min/100 g), and was increased in the acute inflammatory disease (n = 2, 21.5 ± 2.5 ml/min/100 g). Measurement of the blood flow volume of the ocular muscles using Xe-133 clearance method is useful to evaluate the circulatory abnormality in the ophthalmic diseases. (author)

  19. Quantitative measurement of blood circulation in tests of rats using nuclear medical methods

    International Nuclear Information System (INIS)

    The experiments show that is it is possible to quantitatively assess the blood circulation and, within limits, the germinative function of tests by measuring the impulses of an incorporated radionuclide (99-Tc-pertechnetate) using an uptake measuring instrument. This is a rapid and unbloody method to be adopted in human medicine. 'Acute tests' or pre-damaged tests can thus be exactly diagnosed. In the former case the circulation modification and in the latter the evaluation of the germinative function ability is of main interest. The most important measuring criterion is the 15-minute-uptake U; it represents the blood circulation in the tests measured. The germinative function ability is evaluated on the basis of the accumulation activity Nsub(max). (orig./MG)

  20. A Method for Manipulating Blood Glucose and Measuring Resulting Changes in Cognitive Accessibility of Target Stimuli.

    Science.gov (United States)

    Prokosch, Marjorie L; Hill, Sarah E

    2016-01-01

    Much research in social psychology has investigated the impact of bodily energy need on cognition and decision-making. As such, blood glucose, the body's primary energy source, has been of special interest to researchers for years. Fluctuations in blood glucose have been linked to a variety of changes in cognitive and behavioral processes, such as self-control, political attitudes, and eating behavior. To help meet growing interest in the links between bodily energy need and these processes, this manuscript offers a simple methodology to experimentally manipulate blood glucose using a fasting procedure followed by administration of a sugar-sweetened, unsweetened, or artificially-sweetened beverage. This is followed by presentation of a method for measuring resulting changes in implicit cognition using a lexical decision-task. In this task, participants are asked to identify whether strings of letters are words or non-words and response latencies are recorded. Sample results from a recent publication are presented as an example of the applications for the experimental manipulation of blood glucose and the lexical decision task measures. PMID:27585282

  1. Microalbuminuria Measured by three Different Methods, Blood Pressure and Cardiovascular Risk Factors in Elderly Swedish Males

    Directory of Open Access Journals (Sweden)

    Gösta Florvall

    2008-01-01

    Full Text Available Microalbuminuria is associated with hypertension and is a strong risk factor for subsequent chronic disease, both renal and coronary heart disease (CHD, Presently there are several methods available for measurement of microalbuminuria. The aim of this study was to evaluate if the three different methods gave similar information or if one of the assays were superior to the others. Blood pressure, inflammatory markers and cardiovascular mortality and morbidity were correlated with urine albumin analysed with a point-of-care testing (POCT instrument, nephelometric determination of albumin and albumin/creatinine ratio in elderly males. The study population consisted of 103 diabetic and 603 nondiabetic males (age 77 years in a cross-sectional study. We analyzed urine albumin with a HemoCue® Urine Albumin POCT instrument and a ProSpec® nephelometer and albumin/creatinine ratio. There were strong correlations between both systolic and diastolic blood pressure and all three urine albumin methods (p < 0.0001. There were also significant correlations between the different urine albumin measurements and serum amyloid A component, high-sensitivity C-reactive protein and interleukin-6. The three different urine albumin methods studied provided similar information in relation to cardiovascular disease. There was a strong correlation between systolic and diastolic blood pressure and microalbuminuria in both the whole study population and in nondiabetic males emphasizing the role of hypertension in glomerular damage. The good correlation between the studied urine albumin measurements show that all three methods can be used for monitoring urine albumin excretion.

  2. Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Gram, J; Jespersen, J

    2000-01-01

    Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII......:Ag) or estimated with an amidolytic method (FVII:Am). We have investigated whether FVII:Am is a valuable alternative to FVII:Ag. FVII:Ag and FVII:Am were measured in 147 plasma samples from blood donors, patients on oral anticoagulant therapy, postmenopausal women on hormone replacement therapy, in...... after omitting the data from patients on oral anticoagulant therapy, with mean values of 113 U/ml for FVII:Ag and 110 U/ml for FVII:Am (p < 0.01). In a linear regression analysis, the intercept (alpha=-21.50) was different from zero (p < 0.0001) and the slope (beta=1.16) was different from 1.0 (p < 0...

  3. A study on regional cerebral blood flow measurement by 133FXe inhalation method

    International Nuclear Information System (INIS)

    Fundamental and clinical investigations were performed on reliability of Fourier analysis of head clearance curves in regional cerebral blood flow measurement by 133Xe inhalation methods as compared with conventional Obrist analysis. Fourier analysis revealed better reproducibilities determined by computer simulated curves and repetitive measurements in man than Obrist analysis. In the studies of the changes of regional cerebral blood flow from the resting conditions to the conditions of finger movement, listening to verbal material or music and reading aloud in right-handed normal subjects, both F1 (a flow of the fast component of two compartmental model) and ISI (Initial Slope Index: calculated from the initial slope of the wash out curves corrected for recirculation) of Fourier analysis were more sensitive to detect significant changes than Obrist analysis. On the basis of the fact mentioned above, it was concluded that ISI of Fourier analysis was the best index of regional cerebral blood flow. Age-matched normal values of ISI of Fourier analysis were calculated from 132 measurements in 105 normal right-handed subjects, aged 19 to 80 years old (mean 42 years). Mean brain ISI showed significant negative correlation with advancing age (r = -0.70, p < 0.001). The regression line and 95% confidence interval were Y = -0.32X + 69.6 and +- 11.2, respectively. In comparison with the measured values of the patients with cerebrovascular disorders, this age-matched normal values were proved to be sufficient for practical use. Regional ISI also showed significant negative correlations with advancing age in the entire brain (p < 0.001). The regional reduction of ISI with advancing age was significantly greater in the regional distribution of the middle cerebral arteries bilaterally, compared with regions in the distributions of either the anterior cerebral, the posterior cerebral or vertebrobasilar arteries (p < 0.05). (J.P.N.)

  4. A Comparative Study of Blood Glucose Measurements Using Glucometer Readings and the Standard Method in the Diagnosis of Neonatal Hypoglycemia

    Directory of Open Access Journals (Sweden)

    Mohammad Torkaman

    2016-03-01

    Full Text Available Background: Hypoglycemia is one of the most common neonatal disorders, associated with severe complications. There has been a great deal of controversy regarding the definition and screening of hypoglycemia. Therefore, in this study, we aimed to determine a cut-off value for blood glucose level in glucometer readings. Methods: This cross-sectional study was conducted on 238 newborns at risk of hypoglycemia, admitted to Baqiyatallah Hospital of Tehran, Iran in 2012; the subjects were selected via simple sampling. After obtaining informed consents from the newborns’ parents, 1 cc blood samples were sent to the laboratory for measuring the blood glucose level. Moreover, venous blood samples, as well as heel-stick blood samples, were obtained for glucometer measurements. Blood glucose measurements were used to determine the cut-off value by the receiver operating characteristic (ROC curve and make comparisons with the diagnostic criteria for hypoglycemia in the literature. Results: A total of 238 infants with the mean weight of 2869±821.9 g were enrolled in this study. The mean (±SD blood glucose levels were 65.1±22.9, 82.9±24.7, and 84.4±24.8 mg/dl, based on the standard laboratory method, glucometer reading of venous blood samples, and glucometer reading of heel-stick capillary blood samples, respectively. The optimal cut-off point for hypoglycemia was determined as 65 mg/dl, using glucometer-based assessment of heel-stick blood samples. Conclusion: The significant difference in blood glucose levels measured by the laboratory method and outpatient glucometer readings highlights the importance of a cut-off value for rapid assessment and control of blood glucose and timely detection of hypoglycemia. In fact, the cut-off value introduced in the present study could facilitate such measurements.

  5. Validation of a new non-invasive blood pressure measurement method on mice via pulse wave propagation time measurement on a cuff

    OpenAIRE

    Nguyen, Xuan P.; Kronemayer, Ralf; Herrmann, Peter; Mejía, Atila; Daw, Zamira; Nguyen, Xuan D.; Kränzlin, Bettina; Gretz, Norbert

    2011-01-01

    In the present article, we describe the validation of a new non-invasive method for measuring blood pressure (BP) which also enables to determine the three BP values: systolic, diastolic and mean value. Our method is based on the pulse transit time (PTT) measurement along an artery directly at the BP cuff. The accuracy of this method was evaluated by comparison with the direct simultaneous measurement of blood pressure from 40 anesthetized female mice. Close correlation ...

  6. [An automatic non-invasive method for the measurement of systolic, diastolic and mean blood pressure].

    Science.gov (United States)

    Morel, D; Suter, P

    1981-01-01

    A new automatic apparatus for the measurement of arterial pressure by a non-invasive technique was compared with direct intra-arterial measurement in 20 adult patients in a surgical intensive care unit. The apparatus works on the basis of the principle of oscillometry. Blood pressure is determined with a microprocessor by analysis of the amplitude of the oscillations produced by a cuff which is inflated then deflated automatically. Thus mean arterial pressure corresponds to the maximum amplitude. Systolic and diastolic pressures are deduced by extrapolation to zero of the amplitudes on either side of the maximum reading. Mean arterial pressure (AP) proved to be very reliable within the limits studied: 8.0 - 14.7 kPa (60 - 110 mmHg) with a difference in mean direct AP and indirect AP of 0,09 +/- 0.9 kPa SD (0.71 +/- 7 mmHg) and a coefficient of linear correlation between the two methods of r = 0.82. This non-invasive technique determined systolic arterial pressure (sAP) in a less reliable fashion than AP when compared with the invasive technique, with a tendency to flatten the extreme values. The correlation coefficient here was 0.68. Finally, diastolic arterial pressure (dAP) showed a better degree of agreement through with a difference in mean indirect AP and mean direct AP of 1.0 +/- 0.8 kPa (7.6 +/- 6.0 mmHg). These results indicate a good degree of agreement for measurements of mean arterial pressure, clinically the most important, between the two methods used. Measurements of diastolic pressure and above all of diastolic pressure seemed to be less in agreement. This difference could be due to an error in determination of the automatic apparatus tested or to the peripheral site (radial artery) of the intra-arterial catheter used, itself falsifying the humeral arterial pressure. PMID:6113805

  7. Development of a method for measuring blood coagulation using superparamagnetic iron oxide nanoparticles and an alternating magnetic field

    CERN Document Server

    Murase, Kenya

    2016-01-01

    We developed a method for measuring blood coagulation using superparamagnetic iron oxide nanoparticles (SPIONs) and an alternating magnetic field (AMF). The 3rd and 5th harmonic signals from SPIONs mixed with blood induced by AMF were detected using a gradiometer coil. Blood coagulation was induced artificially by adding CaCl2 solution to whole blood of sheep at various temperatures and hematocrits. We calculated the coagulation rate (k) and normalized signal intensity at infinite time (Sinf) by fitting the time course of the normalized 3rd harmonic signal to S(t)=(1-Sinf)exp(-kt)+Sinf. The k values increased significantly with increasing temperature and decreased significantly with increasing hematocrit. The Sinf values decreased significantly with increasing temperature and tended to increase with increasing hematocrit. Blood anticoagulation was induced by adding heparin to the whole blood sampled from mice. There were significant differences in both the 3rd and 5th harmonic signals between groups with and ...

  8. Gastric mucosal blood flow measurement

    International Nuclear Information System (INIS)

    Pertechnetate clearance (C/sub Tc/) by the stomach before and after betazole stimulation was compared to regional measurements of gastric blood flow utilizing nuclide (Chromium-51 and Cerium-141)-labeled microspheres in five piglets. Pertechnetate clearance closely correlated (correlation coefficient 0.926) with mucosal blood flow in the gastric corpus measured by the microsphere technique. Betazole increased blood flow in the corpus region by 100 percent but did not alter this relationship. Except in one experiment, microsphere blood flow valves in the antrum and fundus were unchanged by betazole and did not significantly correlate with pertechnetate clearance. Pertechnetate clearance appears to be a reliable method of determining gastric mucosal blood flow in experimental animals and may be considered as a noninvasive method for measuring such flow in humans. (U.S.)

  9. Oscillometric blood pressure measurement: a simple method in screening for peripheral arterial disease

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels; Bruce, Christopher

    2008-01-01

    Blood pressure at the ankle level is a reliable indicator of peripheral arterial disease (PAD) and the ankle brachial index (ABI) is a useful non-invasive screening tool for the early detection of atherosclerosis. In the first part of the study, systolic blood pressures obtained by oscillometry and...... PAD was sufficiently high in subjects over the age of 60 years to warrant screening. The ankle brachial index based on measurements with an oscillometric device was shown reliable in the exclusion of PAD, thereby fulfilling an important criterion for the use in screening....

  10. Blood presure measurement in LabVIEW

    OpenAIRE

    Pelikán, Ondřej

    2015-01-01

    The aim of this work is to design and create a product for automated measurement of blood pressure by auscultatory method by using a computer. Thesis contains a description of the blood pressure, also there are explained ways of its monitoring, basic rules for its measurement and the methods by which it is possible to measure blood pressure. In the practical part is described measuring system serving to measuring blood pressure by auscultatory method using a computer. There is also shown a de...

  11. Measurement of blood velocity using laser Doppler method for the designing module

    Science.gov (United States)

    Chen, Guo-Liang; Lee, Jen-Ai; Lu, Tung-Wu; Chen, Zhao-Cheng; Chen, Chien-Ming

    2005-04-01

    We built the Dual Beam Mode of the LDA (Laser Doppler Anemometry) frame, set the photodetector at the same side with light source which collect the scattering light of blood cell. It's proper to reduce LDA optical path and convenient for our designing module. The concentration of chicken blood in this study is about 1% and we measured the relations actually between flood velocity and the angle of beams cross on particles, temperature, and the diameter of aqueduct. We found better results while the cross angle was less than 38.8 degree, diameter of aqueduct was 6 mm, and temperature of blood was set to 36 . These parameters can also provide important basis for the LDA module kit that we are designing.

  12. Measurement of specific renocortical blood flow using the 133Xe inhalation method

    International Nuclear Information System (INIS)

    Specific renocortical blood flow is measured in dogs after 133Xe inhalation and compared with intra-arterial injection of 133Xe. The results are very good. The correlation coefficient is 0.964. For 45 healthy test persons (106 kidneys) there is a standard range between 379 and 774 ml (2s range) with a mean value of 577 ml/100 g x min. The values obtained are somewhat higher than those reported for intra-arterial injection. In transplanted kidneys, continuous measurements of specific renocortical blood flow up to 21 days after surgery may make a decisive contribution to early detection of transplant rejection. Examples are given to demonstrate course control of specific renocortical blood flow in transplanted kidneys over several years with satisfactory function of the transplant, acute rejection, and chronic rejection. Even with satisfactory transplant function, specific renocortical blood flow will be about 25 to 30% below the mean value of the healthy test group. With chronic rejection, values are 30 to 70% below average. (orig.)

  13. A venous outflow method for measurement of rapid changes of the cerebral blood flow and oxygen consumption in the rat.

    Science.gov (United States)

    Nilsson, B; Siesjö, B K

    1983-01-01

    A technique for continuous measurement of cerebral venous outflow in the rat is described. The method involves cannulation of one retroglenoid vein close to its exit from the skull, and diversion of cerebral venous blood through a closed extracorporal circuit with a drop recording device, the blood being returned to the central venous circulation via a catheter in the external jugular vein. Occlusion of the contralateral retroglenoid vein increases measured flow and minimizes extracerebral contamination of the diverted cerebral venous blood. The venous outflow system is not further isolated from cerebral or potential extracerebral collaterals. Thus, the mass of tissue drained cannot be exactly defined anatomically. However, the experiments involving changes of PP, arterial CO2 tension, and induction of epileptic seizure activity, and simultaneous indirect measurements with radioactive tracer technique, indicate that significant extracerebral contamination does not occur and that in short term measurements the venous outflow represents cerebral blood flow (CBF) in a constant mass of (dorsal and central, mainly forebrain) cerebral tissue. Measurement of arterial blood pressure and pressure in the cisterna magna allows calculation of cerebral perfusion pressure (PP). By simultaneous measurement of arterial and cerebral venous oxygen content changes in cerebral oxygen consumption (CMRO2) can be calculated. The method has been applied to document several situations of transient CBF and CMRO2 changes. PMID:6658967

  14. Method specificity of non-invasive blood pressure measurement: oscillometry and finger pulse pressure vs acoustic methods.

    Science.gov (United States)

    De Mey, C; Schroeter, V; Butzer, R; Roll, S; Belz, G G

    1995-10-01

    1. The agreement of blood pressure measurements by stethoscope auscultation (SBPa, DBPa-IV and DBPa-V), oscillometry (Dinamap; SBPo, and DBPo) and digital photoplethysmography (Finapres; SBPf, and DBPf) with the graphical analysis of the analogue microphone signals of vascular wall motion sound (SBPg and DBPg) was evaluated in eight healthy subjects in the presence of responses to the intravenous infusion of 1 microgram min-1 isoprenaline. 2. In general, there was good agreement between the SBP/DBP-measurements based on auscultatory Korotkoff-I- and IV-criteria and the reference method; the average method difference in estimating the isoprenaline responses for SBPa-SBPg was: -1.1, 95% CI: -5.4 to 3.1 mm Hg with a within-subject between-method repeatability coefficient (REP) of 11.6 mm Hg and for DBPa-IV-DBPg: 3.5, 95% CI: -0.5 to 6.5 mm Hg, REP: 11.5 mm Hg. The ausculatation of Korotkoff-V substantially overestimated the isoprenaline induced reduction of DBP: method difference DBPa-V-DBPg: -11.3, 95% CI: -17.8 to -4.7 mm Hg, REP: 31.8 mm Hg. 3. Oscillometry yielded good approximations for the SBP response to isoprenaline (average method difference SBPo-SBPg: -2.9, 95% CI: -9.0 to 3.3 mm Hg, REP: 17.6 mm Hg) but was poorly sensitive with regard to the DBP responses: method difference DBPo-DBPg: 6.5, 95% CI: -1.3 to 14.3 mm Hg, REP: 25.7 mm Hg. 4. Whilst the finger pulse pressure agreed well with regard to DBP (method difference for the DBP responses to isoprenaline: DBPf-DBPg: 1.8, 95% CI: -5.1 to 8.6 mm Hg, REP: 18.5 mm Hg) it was rather unsatisfactory with regard to SBP (method difference SBPf-SBPg: -14.1, 95% CI: -28.2 to -0.1 mm Hg, REP: 49.9 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8554929

  15. Portable dynamic light scattering instrument and method for the measurement of blood platelet suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Maurer-Spurej, Elisabeth [Canadian Blood Services and Department of Pathology and Laboratory Medicine and Centre for Blood Research, University of British Columbia, Vancouver, BC (Canada); Brown, Keddie [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC (Canada); Labrie, Audrey [Canadian Blood Services and Department of Pathology and Laboratory Medicine and Centre for Blood Research, University of British Columbia, Vancouver, BC (Canada); Marziali, Andre [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC (Canada); Glatter, Otto [Institute of Chemistry, Karl-Franzens University, Graz (Austria)

    2006-08-07

    No routine test exists to determine the quality of blood platelet transfusions although every year millions of patients require platelet transfusions to survive cancer chemotherapy, surgery or trauma. A new, portable dynamic light scattering instrument is described that is suitable for the measurement of turbid solutions of large particles under temperature-controlled conditions. The challenges of small sample size, short light path through the sample and accurate temperature control have been solved with a specially designed temperature-controlled sample holder for small diameter, disposable capillaries. Efficient heating and cooling is achieved with Peltier elements in direct contact with the sample capillary. Focusing optical fibres are used for light delivery and collection of scattered light. The practical use of this new technique was shown by the reproducible measurement of latex microspheres and the temperature-induced morphological changes of human blood platelets. The measured parameters for platelet transfusions are platelet size, number of platelet-derived microparticles and the response of platelets to temperature changes. This three-dimensional analysis provides a high degree of confidence for the determination of platelet quality. The experimental data are compared to a matrix and facilitate automated, unbiased quality testing.

  16. Micro-particle image velocimetry measurement of blood flow: validation and analysis of data pre-processing and processing methods

    International Nuclear Information System (INIS)

    The intent of this paper is to investigate the application of a pre-processing method previously validated on glycerol to blood flows in microchannels and to compare the accuracy of results obtained when applied to a non-homogeneous fluid such as blood with results from previously applied processing methods for blood data. Comparisons of common processing methods are desired for a clear measure of accuracy in order to make recommendations for various flows. It is hypothesized that increasing the correlation window overlap improves the profile prediction. The amount of correlation window overlap and window shape in the processing of data have a significant effect on the results. Image pre-processing is explored to improve the correlation using the ‘image overlapping’ which is extended to the case of blood and the blood-specific pre-processing ‘base-clipping’ or ‘thresholding’ technique currently applied to blood. Both pre-processing methods are tested with multiple processing methods for two channel geometries: a straight rectangular channel and a Y-channel resulting in a controlled shear flow. The resulting profiles and calculations demonstrate that ‘image-overlapping’ is found to achieve a profile closer to the predicted theoretical profile than current blood pre-processing methods when both are applied to the same set of data and both are superior to conventional cross-correlation on its own. In all cases, pre-processing decreases the smoothness of the predicted profile. The use of ‘image-overlapping’ is shown to have greater accuracy when calculating the shear rate at the wall of the channel as well. (paper)

  17. Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries. (author)

  18. Measurement of cerebral blood flow the blood sampling method using {sup 99m}Tc-ECD. Simultaneous scintigram scanning of arterial blood samples and the brain with a gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Hachiya, Takenori; Inugami, Atsushi [Rehabilitation Center for Physically Disabled Persons and Medical Center for Mental Health-Akita, Kyowa (Japan); Iida, Hidehiro; Mizuta, Yoshihiko; Kawakami, Takeshi; Inoue, Minoru

    1999-01-01

    To measure regional cerebral blood flow (rCBF) by blood sampling using {sup 99m}Tc-ECD we devised a method of measuring the radioactive concentration in arterial blood sample with a gamma camera. In this method the head and a blood sample are placed within the same visual field to record the SPECT data of both specimens simultaneously. The results of an evaluation of the counting rate performance, applying the 30 hours decaying method using {sup 99m}Tc solution showed that this method is not comparable to the well-type scintillation counter and in clinical cases the active concentration in arterial blood sample remained well within the dynamic range. In addition, examination of the influence of scattered radiation from the brain by the dilution method showed that it was negligible at a distance of more than 7.5 cm between the brain and the arterial blood sample. In the present study we placed a head-shaped phantom next to the sample. The results of the examinations suggested that this method is suitable for clinical application, and because it does not require a well-type scintillation counter, it is expected to find wide application. (author)

  19. Concentration measurement of lysosome enzymes in blood by fluorimetric analysis method

    Science.gov (United States)

    Strinadko, Marina M.; Strinadko, Elena M.

    2002-02-01

    The diagnostics of heritable disease series and sugar diabetes, myocardial infarction, collagenosis and kidney diseases widely uses the measurement of lysosomic enzymes in blood. In the present research work the definition procedure of concentration (beta) -glucuronidase with the help of fluorimetric analysis is offered, which allows using microamounts of biological fluids and samples with low enzyme activity which is especially important in paediatric practice. Due to the sharp sensibility of fluorimetric analysis and high speed of luminescent reactions the procedure gives an opportunity to obtain the result in the minimum terms as well as the use of small amounts of reaction mixture. The incubation in large dilution leads thereby to the elimination of influence of endogenic inhibitors and activators.

  20. A method for measuring mean circumferential fiber shortening rate from gated blood pool scans

    International Nuclear Information System (INIS)

    Ejection fraction and ejection rate are easily obtained from gated cardiac images, but no method is available for calculating mean circumferential fiber shortening rate. We assumed that the cube root of left ventricular end-diastolic volume or counts is proportional to the minor axis of the left ventricle at end-diastole or end-systole. Mean circumferential fiber shortening rate is then equal to the [cube root of the end-diastolic volume (count) minus cube root of end-systolic volume (count)] divided by [cube root of end-diastolic volume (count) multiplied by the ejection time]. In 250 contrast ventriculograms, the standard mean circumferential fiber shortening rate (MCFSR) and that derived by the cube root method correlated well (r = 0.94). The mean value of MCFSR (0.85 +- 0.35) was greater than the cube root value (0.75 +- 0.35) (P < 0.001). The regression equation was y = 0.86x + 0.02. Similar correlations were obtained from gated radionuclide images using a semiautomated program (r = 0.93) in 24 subjects or completely automated program (r = 0.85) in 28 patients. The regression equation between MCFSR and that derived from the cube root of counts for the semiautomated program was y = 0.82x + 0.04 and for the automated program was y = 0.84x + 0.004. Similar correlations, slopes, and intercepts were seen using circumferential fractional shortening for angiographic data when correlated with both the semiautomated and automated gated blood pool scan programs. These data indicate that MCFSR and circumferential fractional shortening may be obtained from gated blood pool images using cube root estimates of end-diastolic and end-systolic radii with a high degree of correlation with the standard contrast ventriculographic technique. (orig.)

  1. Gingival blood flow under total combs by functional pressure evaluated with laser-Doppler flowmetry, a non-invasive method of blood flow measurement

    International Nuclear Information System (INIS)

    Gingival blood flow under total-combs by functional pressure evaluated with Laser-Doppler Flowmetry, a non-invasive method of blood flow measurement. Microcirculation of gum's capillary system can be measured non-invasive by Laser-Doppler-Flowmetry (LDF). Circulation, defined by the number of floating erythrocytes per unit of time, is measured by a fibro-optical Laser-Doppler-Flowmetry. The task was to examine, if there is any change of gum's circulation during strain and relief. Circulation on defined measurepoints, divided on the four quadrants, was determined among maximal strain and subsequent relief, on one probationer (complete denture bearer). Before every measure session systemic pressure was taken. LDF-value was taken on top of jaw-comb, in doing so, to get reproducible result and a satisfying fixation of the probe, there was made an artificial limb of the upper and lower comb. In the upper comb a dynamometer-box, which determined minimal and maximal comb pressure, was integrated. The received results of the LDF-measurement, expressed as perfusion units (PU) were lower under applied pressure than by pressure points more distant. Hyperemia, resulting during relief, seemed the more intense, the less perfusion was before. This new, non-invasive kind of circulation measurement seems to be quite predestined to be used for gingival diagnostic under artificial limb in the future. (author)

  2. [14C]butanol distribution: a new method for measurement of spinal cord blood flow

    International Nuclear Information System (INIS)

    [14C]butanol distribution was used to quantitate regional blood flow (SCBF) in the spinal cord (levels T3-5, T7-9, L1-2, L3-S) and in the sciatic nerves (NBF) of control pentobarbital sodium-anesthetized rats (group A), after 1 h of hemorrhagic hypotension (group B), after 15 min of stimulation of one sciatic nerve (group C-1), and after stimulation of one sciatic nerve plus hemorrhage, which maintained mean arterial pressure (MAP) at control (130 mmHg). Group A SCBF ranged from 52.3 +/- 3.5 (L3-S) to 67.4 +/- 2.7 (L1-2) ml.min-1.100 g-1. NBF was 8.0 +/- 0.9 ml.min-1.100 g-1. Group B SCBF was unchanged. NBF fell to 4.0 +/- 0.4 ml.min-1.100 g-1. Group C-1 SCBF was markedly elevated (range 122 +/- 23.1 to 150.1 +/- 18.7 ml.min-1.100 g-1). NBF was 33.5 +/- 4.1 ml.min-1.100 g-1 (stimulated side) and 14.7 +/- 1.4 ml.min-1.100 g-1 (nonstimulated). MAP was elevated (163 +/- 6 mmHg). In group C-2 (MAP was 130 +/- 4 mmHg), SCBF was still elevated at T3-5, L3-S, and marginally elevated at L1-2. NBF was 22.6 +/- 4.7 ml.min-1.100 g-1 (stimulated) but unchanged contralaterally. [14C]butanol distribution provides a sensitive reproducible measure of SCBF and NBF. Autoregulation of SCBF (but not of NBF) occurred in the range 60-160 mmHg MAP. Spinal cord stimulation via the sciatic nerve increased SCBF two- to threefold, but when hypertension was avoided by blood withdrawal, a modest (38%) increase in SCBF still occurred

  3. Methods of measurement of myocardial blood flow in patients: a critical review

    International Nuclear Information System (INIS)

    During the past decade, major progress has been made in the evolution of technology directed toward the accurate measurement of regional myocardial perfusion in patients. The deficiencies of some of the older methods (thermodilution and gas clearance) are better appreciated and improved approaches (Doppler catheters, positron-emission tomography, and digital subtraction angiography) have been developed. The new approaches should play a major role in research and for most applications the older methods will gradually be replaced. Efforts to bring these new methods to community hospitals and practicing cardiologists should be stimulated. Doppler catheters, positron-emission tomography, and digital-subtraction angiography are commercially available and Doppler catheters and digital-subtraction angiography could be easily incorporated into routine cardiac catheterization procedures. The Doppler catheter is the most inexpensive and probably the simplest to apply. In our opinion, routine measurements of coronary flow reserve will significantly improve the care of patients with coronary obstructive disease and other diseases that impair myocardial perfusion. If coronary reserve measurements are used frequently, patient selection for coronary angioplasty and bypass surgery will no longer depend entirely on visual assessment of percent diameter stenosis, a very poor criterion in many situations. Also, patients with chest pain syndromes, normal coronary vessels, and impaired coronary reserve will be identified and perhaps some effective treatment for this condition will be devised. 77 references

  4. Methods of measurement of myocardial blood flow in patients: a critical review

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, M.L.; Wilson, R.F.; White, C.W.

    1987-08-01

    During the past decade, major progress has been made in the evolution of technology directed toward the accurate measurement of regional myocardial perfusion in patients. The deficiencies of some of the older methods (thermodilution and gas clearance) are better appreciated and improved approaches (Doppler catheters, positron-emission tomography, and digital subtraction angiography) have been developed. The new approaches should play a major role in research and for most applications the older methods will gradually be replaced. Efforts to bring these new methods to community hospitals and practicing cardiologists should be stimulated. Doppler catheters, positron-emission tomography, and digital-subtraction angiography are commercially available and Doppler catheters and digital-subtraction angiography could be easily incorporated into routine cardiac catheterization procedures. The Doppler catheter is the most inexpensive and probably the simplest to apply. In our opinion, routine measurements of coronary flow reserve will significantly improve the care of patients with coronary obstructive disease and other diseases that impair myocardial perfusion. If coronary reserve measurements are used frequently, patient selection for coronary angioplasty and bypass surgery will no longer depend entirely on visual assessment of percent diameter stenosis, a very poor criterion in many situations. Also, patients with chest pain syndromes, normal coronary vessels, and impaired coronary reserve will be identified and perhaps some effective treatment for this condition will be devised. 77 references.

  5. Non-invasive method for the aortic blood pressure waveform estimation using the measured radial EBI

    International Nuclear Information System (INIS)

    The paper presents a method for the Central Aortic Pressure (CAP) waveform estimation from the measured radial Electrical Bio-Impedance (EBI). The method proposed here is a non-invasive and health-safe approach to estimate the cardiovascular system parameters, such as the Augmentation Index (AI). Reconstruction of the CAP curve from the EBI data is provided by spectral domain transfer functions (TF), found on the bases of data analysis. Clinical experiments were carried out on 30 patients in the Center of Cardiology of East-Tallinn Central Hospital during coronary angiography on patients in age of 43 to 80 years. The quality and reliability of the method was tested by comparing the evaluated augmentation indices obtained from the invasively measured CAP data and from the reconstructed curve. The correlation coefficient r = 0.89 was calculated in the range of AICAP values from 5 to 28. Comparing to the traditional tonometry based method, the developed one is more convenient to use and it allows long-term monitoring of the AI, what is not possible with tonometry probes.

  6. Intervillous blood flow in normal and complicated late pregnancy measured by means of an intravenous 133Xe method

    International Nuclear Information System (INIS)

    Intervillous blood flow (IVBF) was measured intravenously with a new quantitative 133-Xe method in 50 normal and 74 complicated late pregnancies between the 35th and 42nd weeks. A dose of 2.5 mCi of 133-Xe saline was injected rapidly into the left antecubital vain and flushed immediately with 10 ml of physiological saline. For recording quantitative data from the placenta, a data storage and read-out system with fast television techniques was connected to the scintillation camera. This method may open a new diagnostic area in the management of high risk pregnancies. (author)

  7. Accuracy of the blood pressure measurement.

    Science.gov (United States)

    Rabbia, F; Del Colle, S; Testa, E; Naso, D; Veglio, F

    2006-08-01

    Blood pressure measurement is the cornerstone for the diagnosis, the treatment and the research on arterial hypertension, and all of the decisions about one of these single aspects may be dramatically influenced by the accuracy of the measurement. Over the past 20 years or so, the accuracy of the conventional Riva-Rocci/Korotkoff technique of blood pressure measurement has been questioned and efforts have been made to improve the technique with automated devices. In the same period, recognition of the phenomenon of white coat hypertension, whereby some individuals with an apparent increase in blood pressure have normal, or reduced, blood pressures when measurement is repeated away from the medical environment, has focused attention on methods of measurement that provide profiles of blood pressure behavior rather than relying on isolated measurements under circumstances that may in themselves influence the level of blood pressure recorded. These methodologies have included repeated measurements of blood pressure using the traditional technique, self-measurement of blood pressure in the home or work place, and ambulatory blood pressure measurement using innovative automated devices. The purpose of this review to serve as a source of practical information about the commonly used methods for blood pressure measurement: the traditional Riva-Rocci method and the automated methods. PMID:17016412

  8. Quantitative measurement of blood cells

    International Nuclear Information System (INIS)

    Full text: We are observing and measuring the varying development reaction stages of blood cells to different saline solutions. The imaging process is based on a common path interferometer which is realized with a spatial light modulator (SLM) in the Fourier plane after the microscope objective. With the SLM we can shift the phase of the transmitted light with respect to the phase of signal wave. This principle is used for the phase contrast microscopy method where we take four pictures of the same image with different phase shifts in order to calculate the complex field of the measured cell. This microscope technique obtains quantitative data about the blood cell's surface in different development stages, amplitude and phase differences inside the cell itself. (author)

  9. System for cerebral blood flow measurement using an H215O autoradiographic method and positron emission tomography

    International Nuclear Information System (INIS)

    A system for CBF measurement using an H215O autoradiographic method and positron emission tomography (PET) has been designed and installed as a clinical tool. Following an intravenous injection of H215O, a radioactivity accumulation in the brain tissue for 60 s and a continuous record of radioactivity in arterial blood were measured by a high counting speed PET device and a beta-ray detector, respectively, and CBF was calculated by a table-lookup procedure. First, this method was compared with the C15O2 inhalation steady-state method on 17 cerebrovascular disease patients and four normal subjects. The two values for CBF agreed with each other when H215O autoradiographic method was applied by correction for the dispersion in the measured arterial radioactivity-time curve. However, without the correction, the CBF by the H215O autoradiographic method revealed substantial overestimation by 30.6 +/- 17.5%. A reduced gray/white ratio of CBF was also observed in the H215O autoradiographic method. Second, simulation was performed in order to determine optimal accumulation time by PET scan; the result was that errors due to dispersion and time mismatch became critical as the accumulation time was shortened to less than 60 s

  10. Computer-aided method for automated selection of optimal imaging plane for measurement of total cerebral blood flow by MRI

    Science.gov (United States)

    Teng, Pang-yu; Bagci, Ahmet Murat; Alperin, Noam

    2009-02-01

    A computer-aided method for finding an optimal imaging plane for simultaneous measurement of the arterial blood inflow through the 4 vessels leading blood to the brain by phase contrast magnetic resonance imaging is presented. The method performance is compared with manual selection by two observers. The skeletons of the 4 vessels for which centerlines are generated are first extracted. Then, a global direction of the relatively less curved internal carotid arteries is calculated to determine the main flow direction. This is then used as a reference direction to identify segments of the vertebral arteries that strongly deviates from the main flow direction. These segments are then used to identify anatomical landmarks for improved consistency of the imaging plane selection. An optimal imaging plane is then identified by finding a plane with the smallest error value, which is defined as the sum of the angles between the plane's normal and the vessel centerline's direction at the location of the intersections. Error values obtained using the automated and the manual methods were then compared using 9 magnetic resonance angiography (MRA) data sets. The automated method considerably outperformed the manual selection. The mean error value with the automated method was significantly lower than the manual method, 0.09+/-0.07 vs. 0.53+/-0.45, respectively (p<.0001, Student's t-test). Reproducibility of repeated measurements was analyzed using Bland and Altman's test, the mean 95% limits of agreements for the automated and manual method were 0.01~0.02 and 0.43~0.55 respectively.

  11. Blood Pressure Measurement: Clinic, Home, Ambulatory, and Beyond

    OpenAIRE

    Drawz, Paul E; ABDALLA, MOHAMED; Rahman, Mahboob

    2012-01-01

    Blood pressure has traditionally been measured in the clinic setting using the auscultory method and a mercury sphygmomanometer. Technological advances have led to improvements in measuring clinic blood pressure and allowed for measuring blood pressures outside the clinic. This review outlines various methods for evaluating blood pressure and the clinical utility of each type of measurement. Home blood pressures and 24 hour ambulatory blood pressures have improved our ability to evaluate risk...

  12. Low frequency arterial wall movements for indirect blood pressure measurement in man. Validation of a method for non-invasive assessment of blood pressure under the influence of isoprenaline and angiotensin.

    Science.gov (United States)

    Dietz, U; Belz, G G

    1991-05-01

    In order to measure blood pressure noninvasively, the second derivative of the low frequency wall movements of the brachial artery were registered with a piezo-electric pressure probe during deflation of a Riva-Rocci cuff along with the actual cuff pressure. Two characteristic phenomena of this signal have been suggested to reflect systolic and diastolic blood pressure. Appearance of a positive spike phenomenon (S) was suggested to indicate systolic blood pressure and disappearance of a negative preanacrotic notch (D) to indicate diastolic blood pressure. To prove the validity of these suggestions, these phenomena were assessed in 10 young healthy males during isoprenaline and angiotensin induced changes of blood pressure. Intraarterial (A. radialis) and auscultatory (A. brachialis) blood pressures were recorded simultaneously. Determination of systolic blood pressure with the S phenomenon agreed well with invasive and auscultatory results. Invasive diastolic values agreed well with the cuff pressure at the last signal before disappearance of the preanacrotic notch (D1). Data from auscultation agreed less well with the D1 phenomenon. With increasing doses of isoprenaline, the diastolic measurements (D1) tended to be lower than the invasive ones. However, this discrepancy was far discreeter than that seen with ordinary auscultatory blood pressure measurement. We therefore conclude that registrations of low frequency arterial wall movements yield distinct characteristic spike phenomena useful for measurement of blood pressure in good agreement with the invasive method. In addition, the method provides clearly documented records and should be useful in situations which rely on a valid indirect method. PMID:1898428

  13. Blood distribution measurements

    International Nuclear Information System (INIS)

    The necessity of employing a vascular exploration technique, which is non-aggressive and repetitive, and which gives total and quantitative results led to the exploitation of a rheo-graphic method. An apparatus was constructed for making such measurements. Some appropriate statistics were subsequently determined which allowed the law concerning the establishment of a circulatory index to be determined as well as its statistical distribution and pathological threshold. The results of an examination, which are presented graphically, led to the establishment of a technique (known as cartography) giving the state of the circulation in a member. The application of this technique to persons affected with arteritis allowed the validity of the law and the previously established thresholds to be verified. The apparatus was completely automated and thus gives results which are entirely objective. (author)

  14. Focal cerebral ischemia measured by the intra-arterial 133xenon method. Limitations of 2-dimensional blood flow measurements

    DEFF Research Database (Denmark)

    Skyhøj Olsen, T; Larsen, B; Bech Skriver, E; Enevoldsen, E; Lassen, N A

    1981-01-01

    The limitations of 2-dimensional isotope techniques in the study of focal cerebral ischemia were investigated using the intra-carotid 133 xenon injection method and a 254 multidetector scintillation camera. To make sure that the detectors "look" directly on infarcted areas, only patients with inf...

  15. Improved method for noninvasive measurement of regional cerebral blood flow by 133Xe inhalation. I. description of method and normal values obtained in healthy volunteers

    International Nuclear Information System (INIS)

    A clinical method for noninvasive measurement of regional cerebral blood flow (rCBF) and blood volume (rCBV) is described, based on Obrist's 10 minute, desaturation method after 1 minute inhalation of 133Xe. Sixteen collimated probes are placed over both hemispheres and brain stem-cerebellar regions. End-tidal 133Xe curves are used for correction of recirculation. KEV discriminators are set to record gamma and x-ray activity separately. Values are printed out automatically by a computer on a brain map. Extracerebral contamination is reduced by (1) computing curves from gamma activity, (2) applying pressure on the scalp beneath the probes, (3) 1 minute inhalation of 133Xe and recording desaturation curves for 10 minutes, thereby minimizing slow clearance from extracranial tissues. Normal values for both fast and slow compartments are reproducible and are in good agreement with the carotid injection method. The speech dominant hemisphere has higher flow than the right under conditions described. Posterior portions of the cranium over the cerebellum and brain stem appear to have higher flow gray values than the cerebral cortex. Gray matter flow decreases with advancing age

  16. Endovascular blood flow measurement system

    Science.gov (United States)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper an endovascular measurement system used for intraoperative cerebral blood flow monitoring is described. The system is based on a Volcano ComboMap Pressure and Flow System extended with analogue-to-digital converter and PC laptop. A series of measurements performed in patients with cerebrovascular pathologies allows us to introduce “velocity-pressure” and “flow rate-energy flow rate” diagrams as important characteristics of the blood flow. The measurement system presented here can be used as an additional instrument in neurosurgery for assessment and monitoring of the operation procedure. Clinical data obtained with the system are used for construction of mathematical models and patient-specific simulations. The monitoring of the blood flow parameters during endovascular interventions was approved by the Ethics Committee at the Meshalkin Novosibirsk Research Institute of Circulation Pathology and included in certain surgical protocols for pre-, intra- and postoperative examinations.

  17. Noninvasive blood pressure measurement in large vessels

    International Nuclear Information System (INIS)

    Pulse pressure in the aorta was evaluated by the measurement of pulse wave velocity (PWV) and blood flow velocity (BFV). PWV reflects the elasticity of the vessel and was determined by a time-of-flight method. BFV was measured by analyzing the change of magnetization decay due to flow in multiecho experiments. If one neglects pulse wave reflections at vascular branch points and flow resistance due to blood viscosity, pulse pressure is proportional to PWV and BFV. Noninvasive MR imaging measurements were obtained in 12 patients, all of whom underwent correlative arterial catheterization. Values varied between 35 and 100 mm Hg. The results demonstrated a high correlation between the two methods

  18. A Comparative Study of Blood Glucose Measurements Using Glucometer Readings and the Standard Method in the Diagnosis of Neonatal Hypoglycemia

    OpenAIRE

    Mohammad Torkaman; Gholamreza Bagheri; Ahmad Ahmadi; Amin Saburi

    2016-01-01

    Background: Hypoglycemia is one of the most common neonatal disorders, associated with severe complications. There has been a great deal of controversy regarding the definition and screening of hypoglycemia. Therefore, in this study, we aimed to determine a cut-off value for blood glucose level in glucometer readings. Methods: This cross-sectional study was conducted on 238 newborns at risk of hypoglycemia, admitted to Baqiyatallah Hospital of Tehran, Iran in 2012; the subjects were selected ...

  19. Effects of antipsoriatic treatment on cutaneous blood flow in psoriasis measured by 133Xe washout method and laser Doppler velocimetry

    International Nuclear Information System (INIS)

    In 8 patients with psoriasis vulgaris, the cutaneous blood flow (CBF) was measured simultaneously in both involved and uninvolved psoriatic skin before (i.e., on the first day of hospitalization) and on the 3rd, 7th, 14th, and 28th days of treatment with tar. The 133Xe washout method was used after epicutaneous labeling and compared to the laser Doppler velocimetry (LDV) technique. Control experiments were performed in 10 normal individuals. Before treatment the mean CBF in involved psoriatic skin was 62.6 +/- 18.7 SD ml X (100 g X min)-1, which is significantly higher than CBF of uninvolved skin in psoriatic patients, 9.5 +/- 4.0 SD ml X (100 g X min)-1, (p less than 0.01) and is 13.6 times higher than CBF in the normal individuals (p less than 0.01). Fifty hours following onset of treatment (i.e., after only 2 applications of tar), mean CBF of the involved psoriatic skin had decreased significantly to 35.0 +/- 13.9 SD ml X (100 g X min)-1, (p less than 0.01), which was not statistically different from the CBF on the 7th day. During the following weeks, the CBF in involved psoriatic skin decreased at a more moderate rate than that observed during the first week and was 15.0 +/- 6.1 SD ml X (100 g X min)-1 on the 28th day. This value is not significantly different from the CBF of uninvolved skin in these patients. At the end of treatment, the CBF of the uninvolved skin had decreased significantly (p less than 0.05) in all the patients to values similar to those observed in the skin of normal individuals. A parallel decline was observed in a clinical psoriatic score index; however, it is not known whether the observed decrease in CBF was preceded or succeeded by the clinical improvement

  20. Blood Glucose Measurement Using Bioimpedance Technique

    OpenAIRE

    Kamat, D. K.; Dhanashri Bagul; Patil, P. M.

    2014-01-01

    Bioimpedance measurement is gaining importance in wide field of bioresearch and biomedical systems due to its noninvasive nature. Noninvasive measurement method is very important to decrease infection and physical injuries which result due to invasive measurement. This paper presents basic principle of bioimpedance along with its application for blood glucose analysis and effect of frequency on impedance measurement. Input from bioimpedance sensor is given to amplifier and signal conditioner ...

  1. Non-Invasive Optical Blood Glucose Measurement

    Directory of Open Access Journals (Sweden)

    Megha C.Pande

    2013-07-01

    Full Text Available The method for noninvasively blood glucose monitoring system is discussed in this paper. Lot of research work has been done in developing the device which is completely noninvasive to avoid the pros & cons because of frequent pricking. In this paper we are trying to analyze the noninvasive blood glucose measurement study in the near infrared region which is the most suitable region for blood glucose measurement. For this purpose we use a technique which is similar to pulseoximetry based on near infrared spectrometry .An infrared light of particular wavelength is passed through fingertip containing an arterial pulse component are derived,thus minimizing influences of basal components such as resting blood volume,skin, muscle and bone.

  2. A simplified method for the measurement of nonmetabolized 2-[18F]F-A-85380 in blood plasma using solid-phase extraction

    International Nuclear Information System (INIS)

    Quantification of α4β2* nicotinic acetylcholine receptors using 2-[18F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[18F]FA) and positron emission tomography (PET) imaging requires measurement of nonmetabolized radioligand in blood plasma, which was previously accomplished using high-performance liquid chromatography (HPLC). Here, we introduce a one-step solid-phase extraction (SPE) method for measuring the concentration of nonmetabolized 2-[18F]FA. This method allows many samples to be processed in a short period of time. SPE effectively separated 2-[18F]FA from radioactive metabolites typically observed in blood plasma after administration of radioligand in humans. Measurements of the 2-[18F]FA parent fraction in healthy human volunteers obtained using the SPE method were nearly identical to those obtained using HPLC (1.3±5% average underestimation of SPE), and reproducibility was good within and between runs (2% and 6% coefficient of variation, respectively). SPE recovery of 2-[18F]FA from blood plasma was not appreciably diminished (3±0.6%) by a larger volume of blood plasma loaded onto the cartridge, suggesting the possibility of increasing the plasma sample volume at later times in a PET study to improve measurement sensitivity. 2-[18F]FA was stable in blood stored on ice over 8 h and in saline at low concentrations (18F]FA in healthy human volunteers were estimated as 4.2±0.8 h and 220±70 L, respectively. These results suggest that SPE is the method of choice for the determination of the plasma 2-[18F]FA concentration when measurement of individual metabolites is not required

  3. Effect of sumatriptan on cerebral blood flow during migraine headache. Measurement by sequential SPECT used {sup 99m}Tc-ECD background subtraction method

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Takashi; Torihara, Yoshito; Tsuneyoshi, Noritaka; Ikeda, Yoshitomo [Miyazaki Social Insurance Hospital (Japan)

    2001-07-01

    The present study was designed to examine the effect of sumatriptan on regional cerebral blood flow (CBF) during migraine headache. Nine cases were examined by {sup 99m}Tc-ECD background subtraction method for the absolute value measurement of regional CBF before and after sumatriptan injection. rCBF except for occipital and perioccipital lobes, were increased 10-20% during migraine headache and significant decreases were observed by sumatriptan injection. Two cases of nine had transiently increased systemic blood pressure and cardiac pulse rate, however, all cases improved migraine headache after injection of sumatriptan. (author)

  4. Effect of sumatriptan on cerebral blood flow during migraine headache. Measurement by sequential SPECT used 99mTc-ECD background subtraction method

    International Nuclear Information System (INIS)

    The present study was designed to examine the effect of sumatriptan on regional cerebral blood flow (CBF) during migraine headache. Nine cases were examined by 99mTc-ECD background subtraction method for the absolute value measurement of regional CBF before and after sumatriptan injection. rCBF except for occipital and perioccipital lobes, were increased 10-20% during migraine headache and significant decreases were observed by sumatriptan injection. Two cases of nine had transiently increased systemic blood pressure and cardiac pulse rate, however, all cases improved migraine headache after injection of sumatriptan. (author)

  5. Auscultatory versus oscillometric measurement of blood pressure in octogenarians

    DEFF Research Database (Denmark)

    Rosholm, Jens-Ulrik; Pedersen, Sidsel Arnspang; Matzen, Lars;

    2012-01-01

    Auscultatory measurement using a sphygmomanometer has been the predominant method for clinical estimation of blood pressure, but it is now rapidly being replaced by oscillometric measurement.......Auscultatory measurement using a sphygmomanometer has been the predominant method for clinical estimation of blood pressure, but it is now rapidly being replaced by oscillometric measurement....

  6. Bridging macroscopic and microscopic methods for the measurements of cerebral blood flow: Toward finding the determinants in maintaining the CBF homeostasis.

    Science.gov (United States)

    Kanno, I; Masamoto, K

    2016-01-01

    Methods exist to evaluate the cerebral blood flow (CBF) at both the macroscopic and microscopic spatial scales. These methods provide complementary information for understanding the mechanism in maintaining an adequate blood supply in response to neural demand. The macroscopic CBF assesses perfusion flow, which is usually measured using radioactive tracers, such as diffusible, nondiffusible, or microsphere. Each of them determines CBF based on indicator dilution principle or particle fraction principle under the assumption that CBF is steady state during the measurement. Macroscopic CBF therefore represents averaged CBF over a certain space and time domains. On the other hand, the microscopic CBF assesses bulk flow, usually measures using real-time microscopy. The method assesses hemodynamics of microvessels, ie, vascular dimensions and flow velocities of fluorescently labeled or nonlabeled RBC and plasma markers. The microscopic CBF continuously fluctuates in time and space. Smoothing out this heterogeneity may lead to underestimation in the macroscopic CBF. To link the two measurements, it is needed to introduce a common parameter which is measurable for the both methods, such as mean transit time. Additionally, applying the defined physiological and/or pharmacological perturbation may provide a good exercise to determine how the specific perturbations interfere the quantitative relationships between the macroscopic and microscopic CBF. Finally, bridging these two-scale methods potentially gives a further indication how the absolute CBF is regulated with respect to a specific type of the cerebrovascular tones or capillary flow velocities in the brain. PMID:27130412

  7. Microfluidic-based speckle analysis for sensitive measurement of erythrocyte aggregation: A comparison of four methods for detection of elevated erythrocyte aggregation in diabetic rat blood

    OpenAIRE

    Yeom, Eunseop; Lee, Sang Joon

    2015-01-01

    Biochemical alterations in the plasma and red blood cell (RBC) membrane of diabetic blood lead to excessive erythrocyte aggregation (EA). EA would significantly impede the blood flow and increase the vascular flow resistance contributing to peripheral vascular diseases. In this study, a simple microfluidic-based method is proposed to achieve sensitive detection of hyperaggregation. When a blood sample is delivered into the device, images of blood flows are obtained with a short exposure time ...

  8. Insuring quality during implementation of a SPEDT method of regional cerebral blood flow measurements into daily routine

    International Nuclear Information System (INIS)

    The present aim was to describe a method for quality insurance when a previously experimental technique is implemented for daily clinical use. Regional cerebral blood flow (rCBF) was studied in 24 patients with medically intractable complex partial epilepsy using SPECT of the Tc99m-HMPAO distribution. The colour-coded rCBF images were evaluated visually four times by four observers who classified each data set into one of four ranked classes (normal, slightly - , median - or severely abnormal). The visual analysis was compared to the results obtained by an expert (the standard). After two evaluation rounds a teaching session of image interpretation was performed with emphasis on the most difficult problem cases. The results of the primary evaluation and the yield of the teaching round was assessed by error-points depending on the magnitude of the misinterpretation of each data set. Interobserver discrepancies was analyzed by Friedman's test of variance, while intra-observer variability was evaluated by Wilcoxon's paired non-parametric test. The teaching round improved the performance of the four observers significantly (p=0.0004), but not to the wanted quality standard for all observers. The reproducibility was improved in all, but not significantly. The insurance of quality during implementation of a new diagnostic method can thus be performed in a simple way providing the steering team with identification of problems, as well as inspiration to solution of critical problems. The presented quality insurance method can easily be performed when other imaging modalities are started or when quality control of a routine method is needed. (au)

  9. Automatic blood pressure measuring system (M092)

    Science.gov (United States)

    Nolte, R. W.

    1977-01-01

    The Blood Pressure Measuring System is described. It measures blood pressure by the noninvasive Korotkoff sound technique on a continual basis as physical stress is imposed during experiment M092, Lower Body Negative Pressure, and experiment M171, Metabolic Activity.

  10. Blood Glucose Measurement Using Bioimpedance Technique

    Directory of Open Access Journals (Sweden)

    D. K. Kamat

    2014-01-01

    Full Text Available Bioimpedance measurement is gaining importance in wide field of bioresearch and biomedical systems due to its noninvasive nature. Noninvasive measurement method is very important to decrease infection and physical injuries which result due to invasive measurement. This paper presents basic principle of bioimpedance along with its application for blood glucose analysis and effect of frequency on impedance measurement. Input from bioimpedance sensor is given to amplifier and signal conditioner AD5933. AD5933 is then interfaced with microcontroller LPC1768 using I2C bus for displaying reading on LCD. Results can also be stored in database using UART interface of LPC1768.

  11. Auscultatory versus oscillometric measurement of blood pressure in octogenarians

    DEFF Research Database (Denmark)

    Pedersen, Sidsel Arnspang

    2012-01-01

    Abstract Background. Auscultatory measurement using a sphygmomanometer has been the predominant method for clinical estimation of blood pressure, but it is now rapidly being replaced by oscillometric measurement. Objective. To compare blood pressure by auscultatory and oscillometric measurements in...... patients 80 years. Method. 100 patients had blood pressure measured by auscultation with a sphygmomanometer and by an electronic device using the oscillometric method. For each patient the mean of two blood pressures with each method measured within 15 min were compared. Results. The mean age of...... participants was 85.8 years; 55.8% were women. The correlation coeffi cient for systolic blood pressure was 0.88 and for diastolic 0.79. Differences between auscultatory and oscillometric values were less than 10 mmHg in 70.6% of systolic blood pressures and in 83.2% for diastolic. Arrhythmia and hypertension...

  12. 一种间接测量人体血压值的新方法%A New Method of Measuring Blood Pressure Indirectly

    Institute of Scientific and Technical Information of China (English)

    赵海; 彭海霞; 朱剑; 李学波

    2012-01-01

    现有的脉搏血流参数检测仪需要事先测量人体血压,并且操作不方便,针对这一问题,提出了一种获取人体动脉血压值的新方法.该方法基于动脉血压与光电容积脉搏波特征参数的相关性理论,对特征参数与动脉收缩压和舒张压进行相关性分析,从而获得与收缩压及舒张压相关性较大的几个特征参数;然后利用线性回归的方法得到动脉血压和这几个特征参数的方程,依此求出人体的动脉血压值.该方法同传统测压方法相比,测量方便,可被应用到无创光电检测仪中,具有更广阔的应用前景.%Existing detectors for pulse flow parameters can be used only after blood pressure measurement and their operation is inconvenient. Thus a new method was proposed for measuring the human body arterial blood pressure values. Based on the relationship between arterial blood pressure and the characteristic parameters of the photoelectric volume pulse waves, correlation analysis between the parameters and arterial systolic and diastolic blood pressures was performed to determine which parameters strongly correlate to the arterial systolic and diastolic blood pressures, with the dependence of arterial blood pressure on these parameters obtained by linear regression, and human blood pressure was thus indirectly obtained. Compared with the conventional methods, the proposed one is more convenient, can be applied to non-invasive optical detectors and has more potential applications.

  13. Measurement of in vivo HGPRT-deficient mutant cell frequency using a modified method for cloning human peripheral blood T-lymphocytes

    International Nuclear Information System (INIS)

    Approximately 80 % of human peripheral blood T-lymphocytes could be cloned in the presence of crude Interleukin-2, phytohemagglutinin, and X-irradiated autologous lymphocytes and Raji B-cells. This modified cloning method was used to measure the in vivo frequency of HGPRT-deficient mutant T-lymphocytes. Repeated experiments using blood from the same individuals revealed that the frequency of mutant cells was almost constant for each individual even though the cloning efficiency of lymphocytes varied somewhat from experiment to experiment. Approximately 80 % of both wild-type unselected and 6-thioguanine-resistant colonies had helper/inducer and about 20 % had suppressor/cytotoxic T-lymphocyte markers. No difference was observed in the distribution of lymphocyte subsets between wild and mutant lymphocyte colonies. (author)

  14. A semi-automated method for measuring the evolution of both lumen area and blood flow in carotid from Phase Contrast MRI.

    Science.gov (United States)

    Fasquel, Jean-Baptiste; Lécluse, Aldéric; Cavaro-Ménard, Christine; Willoteaux, Serge

    2015-11-01

    Phase-Contrast (PC) velocimetry Magnetic Resonance Imaging (MRI) is a useful modality to explore cardiovascular pathologies, but requires the automatic segmentation of vessels and the measurement of both lumen area and blood flow evolutions. In this paper, we propose a semi-automated method for extracting lumen boundaries of the carotid artery and compute both lumen area and blood flow evolutions over the cardiac cycle. This method uses narrow band region-based active contours in order to correctly capture the lumen boundary without being corrupted by surrounding structures. This approach is compared to traditional edge-based active contours, considered in related works, which significantly underestimate lumen area and blood flow. Experiments are performed using both a sequence of a homemade phantom and sequences of 20 real carotids, including a comparison with manual segmentation performed by a radiologist expert. Results obtained on the phantom sequence show that the edge-based approach leads to an underestimate of carotid lumen area and related flows of respectively 18.68% and 4.95%. This appears significantly larger than weak errors obtained using the region-based approach (respectively 2.73% and 1.23%). Benefits appear even better on the real sequences. The edge-based approach leads to underestimates of 40.88% for areas and 13.39% for blood flows, compared to limited errors of 7.41% and 4.6% with our method. Experiments also illustrate the high variability and therefore the lack of reliability of manual segmentation. PMID:26453757

  15. Development of brain damage as measured by brain impedance recordings, and changes in heart rate, and blood pressure induced by different stunning and killing methods.

    Science.gov (United States)

    Savenije, B; Lambooij, E; Gerritzen, M A; Korf, J

    2002-04-01

    Poultry are electrically stunned before slaughter to induce unconsciousness and to immobilize the chickens for easier killing. From a welfare point of view, electrical stunning should induce immediate and lasting unconsciousness in the chicken. As an alternative to electroencephalography, which measures brain electrical activity, this study used brain impedance recordings, which measure brain metabolic activity, to determine the onset and development of brain damage. Fifty-six chickens were surgically equipped with brain electrodes and a canula in the wing artery and were subjected to one of seven stunning and killing methods: whole body electrical stunning; head-only electrical stunning at 50, 100 or 150 V; or an i.v. injection with MgCl2. After 30 s, the chickens were exsanguinated. Brain impedance and blood pressure were measured. Extracellular volume was determined from the brain impedance data and heart rate from the blood pressure data. An immediate and progressive reduction in extracellular volume in all chickens was found only with whole body stunning at 150 V. This treatment also caused cardiac fibrillation or arrest in all chickens. With all other electrical stunning treatments, extracellular volume was immediately reduced in some but not all birds, and cardiac fibrillation or arrest was not often found. Ischemic conditions, caused by cessation of the circulation, stimulated this epileptic effect. A stunner setting of 150 V is therefore recommended to ensure immediate and lasting unconsciousness, which is a requirement for humane slaughter. PMID:11989758

  16. Noninvasive measurement of pulmonary blood volume

    International Nuclear Information System (INIS)

    In noninvasive estimation of pulmonary blood volume by radionuclide-angiocardiography, a formula was derived from experiments with heart-lung model, and in vivo experiments PBV = CO x PPT x 0.77. The pulmonary blood volume estimated clinically by this formula was in good agreement with the results obtained invasively before. The compliance (δV/δP) of the pulmonary ''venous'' system was calculated by simultaneous measurement of pressure changes in lung field on leg elevation and changes in pulmonary arterial wedge pressure with Swan-Ganz catheter. The compliances which were calculated in 35 cases of heart diseases by this method were in a considerably good agreement with those which were assessed by analysis of a pulmonary arterial wedge pressure tracing. (Ueda, J.)

  17. Ocular Blood Flow Autoregulation Mechanisms and Methods

    Directory of Open Access Journals (Sweden)

    Xue Luo

    2015-01-01

    Full Text Available The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and varied metabolic demand. In addition, ocular blood flow dysregulation has been demonstrated as an independent risk factor to many ocular diseases. For instance, ocular perfusion pressure plays key role in the progression of retinopathy such as glaucoma and diabetic retinopathy. In this review, different direct and indirect techniques to measure ocular blood flow and the effect of myogenic and neurogenic mechanisms on ocular blood flow are discussed. Moreover, ocular blood flow regulation in ocular disease will be described.

  18. On-line dynamic measurement of blood viscosity, hematocrit and change of blood volume

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To develop an on-line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes,microvascular blood volumes and the total blood volume were observed by means of calculating from the testing result. Methods: Applying traditional viscosity measurement principle and specific wavelength optic density measurement method, an on-line system for the measurement of blood viscosity and hematocrit was developed, and the A/D multifunctionai board and the testing circuit were designed by ourselves. The system was validated by experiments both in vitro and in vivo. Therapeutic effects of hypertonic saline dextran solution (HSD) and Lactatic Ringer's solution at the early stage after burn-blast combined injury were compared by this method. Results: The results showed that the system has attained the goal of the design. The changes of the blood viscosity and hematocrit could be detected effectively and continuously. The changes of macrovascular, microvascular and total blood volume could be calculated approximately. Conclusions: The system and the method can continuously on-line test the blood viscosity and hematocrit, and reveal the change and distribution of blood volumes more accurately and dearly in the therapy process by estimating changes of the macrovascular, microvascular and total blood volumes, respectively. It has confirmed that HSD treatment could increase blood pressure and attenuate tissue edema by significantly increasing total blood volume,improving macrocirculatory and microcirculatory blood volumes. This study suggested that it could be desirable to develop an experiment technique based on the method mentioned above.

  19. Automatic blood pressure measuring system (M091)

    Science.gov (United States)

    1977-01-01

    The Leg Volume Measuring System is used to measure leg calf girth changes that occur during exposure to lower body negative pressure as a result of pooling of blood and other fluids in the lower extremities.

  20. A simplified method of xenon-enhanced CT for regional cerebral blood flow (rCBF) measurement with reference to clinical experiences

    International Nuclear Information System (INIS)

    We introduced a simplified method of xenon-enhanced CT (SXe-CT) for obtaining the topographic regional cerebral blood flow (rCBF) map. In the SXe-CT, we used the method of brief (three to four minutes) inhalation of 40 % xenon. To shorten the period of xenon inhalation, we substituted a predetermined brain-blood partition coefficient (L) in the entire brain for the directly estimated L to calculate the rCBF value. Because of its non-invasiveness and simplicity, the SXe-CT can be applied to the patients with diseases in the central nervous system (CNS) without any difficulties. During the past three years, we performed the SXe-CT on 150 occasions in 100 subjects, including those with moyamoya disease, other ischemic cerebrovascular diseases, arteriovenous malformations and normal pressure hydrocephalus. In this paper, the rCBF values of seven normal healthy adults with a mean age of 24 years are reported and the flow maps of some cases of CNS diseases are presented. The normal mean value of the hemispheres was 53, those of the gray matter were in the range of 38 to 72, those of the white matter were in the range of 26 to 35 and those of the basal ganglia and thalamus were 55 to 88 (values are given in ml/100 g/min). The SXe-CT has potential advantages in obtaining clinically useful rCBF measurements. (author)

  1. Blood Pressure Measurement Guidelines for Physical Therapists

    OpenAIRE

    Frese, Ethel M; Fick, Ann; Sadowsky, H. Steven

    2011-01-01

    Vital sign measurement and assessment are important components of the review of systems in a physical therapy examination for individuals with and without documented cardiopulmonary disease. The measurement of blood pressure gives the therapist information regarding the patient's baseline cardiovascular status, response to exercise/activity, and guides exercise prescription. Accurate measurement of blood pressure is critical for making appropriate clinical decisions especially if physical the...

  2. Measurement of cerebral blood flow by the autoradiographic method with N-isopropyl-4-[I-123] iodoamphetamine. Comparison of radiopharmaceuticals marketed by different companies in Japan

    International Nuclear Information System (INIS)

    Iodine-123-labeled N-isopropyl-4-iodoamphetamine (IMP) is used as a tracer for the measurement of cerebral blood flow (CBF) by single-photon emission computed tomography (SPECT). Two IMP products, IMPA (Nihon Medi-Physics Co., Ltd.) and IMPB (FUJIFILM RI Pharma Co., Ltd.), produced by different radiopharmaceutical companies are marketed for clinical use in Japan. Although no significant difference in whole-body distribution between the two products has been reported, a significant difference in the radioactivity of the octanol-extracted fraction in whole blood between the two products has been reported in humans. In this study, CBF values obtained by the autoradiographic (ARG) method obtained from both IMPA and IMPB were compared in the same human subjects. SPECT studies were performed on 6 healthy subjects with the use of both IMPA and IMPB. Standard input functions used in the ARG method were obtained for both IMPA and IMPB from 5 additional healthy subjects. Significant differences were found between CBF values when SPECT data with IMPA was combined with the standard input function for IMPB (37.7±3.7 mL/100 g/min at a mid-scan time of 30 min) and SPECT data with IMPB was combined with the standard input function for IMPA (50.7±8.9 mL/100 g/min). Nearly the same CBF values were found when SPECT data with IMPA was combined with the standard input function for IMPA (43.1±4.4 mL/100 g/min) and SPECT data with IMPB was combined with the standard input function for IMPB (44.2±7.6 mL/100 g/min). Our results suggest that the appropriate standard input function should be used, according to the IMP product used, in the calculation of CBF by the ARG method. (author)

  3. Accurate, reproducible measurement of blood pressure.

    OpenAIRE

    Campbell, N. R.; Chockalingam, A; Fodor, J. G.; McKay, D. W.

    1990-01-01

    The diagnosis of mild hypertension and the treatment of hypertension require accurate measurement of blood pressure. Blood pressure readings are altered by various factors that influence the patient, the techniques used and the accuracy of the sphygmomanometer. The variability of readings can be reduced if informed patients prepare in advance by emptying their bladder and bowel, by avoiding over-the-counter vasoactive drugs the day of measurement and by avoiding exposure to cold, caffeine con...

  4. Numerical simulation of noninvasive blood pressure measurement.

    Science.gov (United States)

    Hayashi, Satoru; Hayase, Toshiyuki; Shirai, Atsushi; Maruyama, Masaru

    2006-10-01

    In this paper, a simulation model based on the partially pressurized collapsible tube model for reproducing noninvasive blood pressure measurement is presented. The model consists of a collapsible tube, which models the pressurized part of the artery, rigid pipes connected to the collapsible tube, which model proximal and distal region far from the pressurized part, and the Windkessel model, which represents the capacitance and the resistance of the distal part of the circulation. The blood flow is simplified to a one-dimensional system. Collapse and expansion of the tube is represented by the change in the cross-sectional area of the tube considering the force balance acting on the tube membrane in the direction normal to the tube axis. They are solved using the Runge-Kutta method. This simple model can easily reproduce the oscillation of inner fluid and corresponding tube collapse typical for the Korotkoff sounds generated by the cuff pressure. The numerical result is compared with the experiment and shows good agreement. PMID:16995754

  5. Measurement of bone blood flow in sheep

    International Nuclear Information System (INIS)

    Bone blood flow in sheep tibia has been estimated via the measurement of the perfusion limited clearance of 41Ar from the bone mineral matrix following fast neutron activation of 44Ca. Tibia blood flows were estimated for the intact sheep, and after the installation of an intramedullary pressure tap to elevate bone marrow pressure by saline infusion. The results indicate that normal blood flow in the tibia is in the range of 1.1 to 3.7 ml/100ml-min in the intact animal and at normal marrow pressure. With an elevated intramedullary pressure of approximately 100 mmHg, the bone blood flow measured varied around 0.5 to 1.1 ml/100ml-min. 12 refs., 5 figs., 1 tab

  6. Measurement of micronuclei by cytokinesis-block method in human, cattle, goat, pig, rabbit, chicken, fish peripheral blood lymphocytes irradiated in vitro with gamma radiation

    International Nuclear Information System (INIS)

    The frequencies of gamma-ray-induced micronuclei in cytokinesis-blocked lymphocytes at several doses were measured in three donor of seven species. Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors of human, cattle, goat, pig and rabbit. In vitro radiobiological study confirmed that the cytogenetic response obtained in blood from selected breeds of mammalian species can be utilized for application in environmental studies

  7. Method for Reducing Pumping Damage to Blood

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Robert J. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed herein before. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results. The least hemolytic variation for each pump component is preferably selected as an optimized component. If no statistical difference as to blood damage is produced for a variation of a pump component, then the variation that provides preferred hydrodynamic performance is selected. To compare the variation of pump components such as impeller and stator blade geometries, the preferred embodiment of the invention uses a stereolithography technique for realizing complex shapes within a short time period.

  8. Our experience of blood flow measurements using radioactive tracers

    International Nuclear Information System (INIS)

    A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131I or sup(99m)Tc, 113In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers (133Xe, 85Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed

  9. Pulmonary blood volume measured by RI angiocardiography

    International Nuclear Information System (INIS)

    RI angiocardiography (RACG) was performed in 81 patients with heart disease without congestive heart failure at the time, and the results were compared between the groups with mitral valve disease and other diseases. Cardiac output (CO) and pulmonary mean transit time (PMTT) were compared with the results from the dye dilution method in the same patients. PMTT directly measured by RACG was also compared with the peak to peak time (P-PT). P-PT was expressed as the distance from the right to the left peak time in radiocardiography (RCG). There were good correlations between the CO and PMTT obtained from the RI method and those of the dye dilution method (r = 0.90, r = 0.84). The ralationship between PMTT and P-PT in mitral valve disease was different from that of other diseases. The average value of PMTT was 5.2 +- 1.0 seconds, and pulmonary blood volume (PBV) was 315 +- 57 ml/m2 in the control group. The PBV values were markedly increased in patients with mitral stenosis (558 +- 132 ml/m2) and mitral regurgitation (444 +- 119 ml/m2), and were slightly increased in aortic valve disease, congenital shunt disease and cardiomyopathy. The patients with ischemic heart disease had normal PBV. In mitral valve disease, the direct method using PMTT of RACG is more accurate than the presumption method using P-PT of RCG. The determination of PBV by this method is very important to observe hemodynamic states in mitral valve disease. (J.P.N.)

  10. Noninvasive method of estimating human newborn regional cerebral blood flow

    International Nuclear Information System (INIS)

    A noninvasive method of estimating regional cerebral blood flow (rCBF) in premature and full-term babies has been developed. Based on a modification of the 133Xe inhalation rCBF technique, this method uses eight extracranial NaI scintillation detectors and an i.v. bolus injection of 133Xe (approximately 0.5 mCi/kg). Arterial xenon concentration was estimated with an external chest detector. Cerebral blood flow was measured in 15 healthy, neurologically normal premature infants. Using Obrist's method of two-compartment analysis, normal values were calculated for flow in both compartments, relative weight and fractional flow in the first compartment (gray matter), initial slope of gray matter blood flow, mean cerebral blood flow, and initial slope index of mean cerebral blood flow. The application of this technique to newborns, its relative advantages, and its potential uses are discussed

  11. Psychiatric and subjective symptoms and cerebral blood flow in patients with chronic cerebral infarction after treatment with Ca antagonist (nilvadipine). Quantitative measurement of cerebral blood flow by the 123IMP-SPECT ARG method

    International Nuclear Information System (INIS)

    Psychiatric and subjective symptoms such as headache, dizziness, lack of spontaneity, anxiety, and a depressive state are often found in patients with chronic cerebral infarction. Some Ca antagonists are reported to relieve such symptoms. The purpose of the present study was to investigate the relationship between psychiatric and subjective symptoms and cerebral blood flow (CBF) in cerebral infarction and to evaluate the clinical effects of Ca antagonists from the standpoint of the cerebral circulation. Nilvadipine was administered to is patients with chronic cerebral infarction and their CBF was measured by the 123IMP-SPECT ARG method before and at 8 weeks after the nilvadipine treatment. The CBF in patients with hypertension was increased by 11% after giving nilvadipine. Patients without hypertension showed no tendency for elevation of their CBF. Patients who were relieved from some psychiatric symptoms revealed a 14% increase of CBF in all cortical regions, and a significant increase was noted in the frontal and temporal regions. In other patients without changes in psychiatric symptoms, the CBF did not increase in any of the cortical regions. No relationship between symptoms and CBF was observed in any of the patients with subjective symptoms. Our study demonstrated a close correlation between psychiatric symptoms and CBF. We speculate that psychiatric symptoms in chronic cerebral infarction may reflect diffuse brain dysfunctions. We also conclude that nilvadipine is more effective in relieving psychiatric symptoms in patients with hypertensive cerebral infarction. It is inferred that nilvadipine may be more effective in relieving psychiatric symptoms in patients with hypertension. (author)

  12. [Comparison of invasive blood pressure measurement in the aorta with indirect oscillometric blood pressure measurement at the wrist and forearm].

    Science.gov (United States)

    Saul, F; Aristidou, Y; Klaus, D; Wiemeyer, A; Lösse, B

    1995-09-01

    Indirectly measured blood pressure at the wrist or upper arm was compared with directly measured values in the aortic arch during routinely performed diagnostic cardiac catheterization in 100 patients (31-80 years, mean 59.3 years, 60% males). The noninvasive measurements were carried out by oscillometric devices, NAiS Blood Pressure Watch for measurements at the wrist, and Hestia OZ80 at the upper arm. Systolic blood pressure measured at the wrist was 4.3 +/- 14.1 mm Hg, and the diastolic value 6.0 +/- 8.9 mm Hg higher than when measured at the aortic arch; the difference was significant in both cases. Correlation coefficients were 0.85 for systolic and 0.71 for diastolic blood pressure. In 16% of the patients the systolic blood pressure at the wrist differed more than +/- 20 mm Hg. The diastolic blood pressure at the wrist measured more than +/- 20 mm Hg higher than in the aorta in 5% of the patients. At the upper arm mean systolic values were not different to the aorta. The diastolic pressure was 9.3 +/- 9.8 mm Hg higher in the aorta than at the upper arm. To verify the accuracy of values measured with the NAiS Blood Pressure Watch compared with the standard technique at the upper arm, sequential measurements were made at wrist and ipsilateral upper arm in the same group of 100 patients. The systolic blood pressure at the left wrist was 3.4 +/- 13.3 mm Hg higher and the diastolic pressure 3.8 +/- 9.5 mm Hg lower than at the upper arm. Only 53% of systolic values lay within a range of +/- 10 mm Hg. The correspondence between wrist and upper arm values was better for diastolic blood pressure, the values differing by less than +/- 10 mm Hg in two-thirds of patients. Self-measurement of arterial blood pressure with an oscillometric device at the wrist can be recommended only in individual cases with a difference of simultaneously measured values at the upper arm of less than +/- 10 mm Hg for systolic and diastolic blood pressures. The standard method for indirectly

  13. Blood monitoring systems and methods thereof

    Science.gov (United States)

    Mir, Jose (Inventor); Zander, Dennis (Inventor)

    2012-01-01

    A blood monitoring system is capable of monitoring the blood of a subject in vivo. The blood monitoring system comprises: 1) an array of movable microneedle micromachined within associated wells; 2) array of motion actuators able to move each needle in and out of their associated wells; 3) array of microvalves associated with each microneedle able to control the flow of air around the microneedle; 4) an array of chemical sensors inserted into patient by movable microneedles; 5) an array of inductors able to measure chemical concentration in the vicinity of inserted chemical sensors; 6) conducting vias that provide timed actuating signal signals from a control system to each motion actuator; 7) conducting vias that transmit signal produced by array of chemical sensors to the control system for processing, although the blood monitoring system can comprise other numbers and types of elements in other configurations.

  14. Measurement of normal portal venous blood flow by Doppler ultrasound.

    OpenAIRE

    Brown, H S; Halliwell, M; Qamar, M.; Read, A. E.; Evans, J. M.; Wells, P N

    1989-01-01

    The volume flow rate of blood in the portal vein was measured using a duplex ultrasound system. The many errors inherent in the duplex method were assessed with particular reference to the portal vein and appropriate correction factors were obtained by in vitro calibration. The effect of posture on flow was investigated by examining 45 healthy volunteers in three different positions; standing, supine and tilted head down at 20 degrees from the horizontal. The mean volume blood flow in the sup...

  15. Videodensitometry for measuring blood vessel diameter

    International Nuclear Information System (INIS)

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4x3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +-5 per cent in the 7 to 8 mm range. (Auth.)

  16. Videodensitometry for measuring blood vessel diameter.

    Science.gov (United States)

    Hoornstra, K; Hanselman, J M; Holland, W P; De Wey Peters, G W; Zwamborn, A W

    1980-01-01

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4 times 3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +/-5 percent in the 7 to 8 mm range. PMID:7424549

  17. A comparison of two methods to measure coronary flow reserve in the setting of coronary angioplasty: intracoronary blood flow velocity measurements with a Doppler catheter, and digital subtraction cineangiography

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); F. Zijlstra (Felix); G-J. Laarman (GertJan); J.H.C. Reiber (Johan); K.J. Beatt (Kevin); J.R.T.C. Roelandt (Jos)

    1989-01-01

    textabstractIntracoronary blood flow velocity measurements with a Doppler balloon catheter and the radiographic assessment of myocardial perfusion with contrast media, before and after the intracoronary administration of papaverine, have previously been used to investigate regional coronary flow res

  18. Oscillometric blood pressure measurements: A signal analysis

    Science.gov (United States)

    Barbé, K.; Van Moer, W.; Lauwers, L.

    2010-07-01

    In this paper, the oscillometric waveform measured by automatic non-invasive blood pressure meters (NIBP) is analyzed by transforming the data from the time domain to the frequency domain. The signal's spectrum of the oscillometric waveform is in current literature badly understood or explored. The only known link between the oscillometric waveform and the blood pressure is the maximum of the oscillometry's envelope equalling the mean arterial pressure (MAP). This link is established under the assumption that the oscillometry is an AM-signal. Unfortunately, computing the MAP is difficult in practice due to the non-sinusoidal nature of the actual measured signals. In this paper, we construct the best AM-signal approximation of the oscillometry and explore its use to compute the MAP.

  19. Temperature influence on non-invasive blood glucose measurement

    Science.gov (United States)

    Zhang, Xiqin; Yeo, Joon Hock

    2009-02-01

    Regular monitoring of blood sugar level is important for the management of diabetes. The Near-Infra-Red (NIR) spectroscopy method is a promising approach and this involves some form of contact with the body skin. It is noted that the skin temperature does fluctuate with the environment and physiological conditions and the temperature has an influence on the glucose measurement. In this paper, in-vitro and in-vivo investigations on the temperature influence on blood glucose measurement were studied. The in-vitro results from FTIR spectrometer show that sample temperature has significant influence on water absorption, which significantly affects the glucose absorption measurement. The in-vivo results show that when skin temperature around the measurement site is taken into consideration, the prediction of blood glucose level greatly improves.

  20. Prediction Methods for Blood Glucose Concentration

    DEFF Research Database (Denmark)

    Freckmann et al. discusses performance metrics used to characterize the accuracy of continuous glucose measurement devices. This topic is highly relevant for prediction models since many of them rely on the data given by the continuous sensors which are previously calibrated with blood glucose meter...... on the net effect of meals on the blood glucose concentration. By assuming that all major unexplained glycemic excursions can be vi Preface attributed to oral glucose ingestion, a meal vector is estimated which significantly improves the mathematical model. Results are shown on three patients during...... intrasubject variability by using the concept of interval pre-dictions. Instead of predicting a single blood glucose value in the future, a whole solution envelope is determined. With the presented theory it can be guaranteed that the real value is always inside of the envelope and moreover the envelope...

  1. Measurement of limb blood flow using technetium-labelled red blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Parkin, A; Robinson, P.J.; Wiggins, P.A.; Leveson, S.H.; Salter, M.C.P.; Matthews, I.F.; Ware, F.M.

    1986-05-01

    A method for measuring blood flow below the knee during reactive hyperaemia induced by 3 min of arterial occlusion has been developed. Subjects are positioned with lower limbs within the field of view of a gamma camera and pneumatic cuffs are placed below the knees to isolate the blood and induce a hyperaemic response. The remaining blood pool is labelled with /sup 99/Tcsup(m)-labelled red cells. Blood flows have been derived from the initial gradients of time-activity curves and from equilibrium blood sampling. The technique has been validated using a tissue-equivalent leg phantom and peristaltic pump. The method has been applied to a small group of patients with peripheral vascular disease and to normal controls. The mean value (+-SD) of limb perfusion for normal controls was found to be 16.4 +- 3.0 ml/100 ml/min and for patients with intermittent claudication was 5.1 +- 2.6 ml/100 ml/min. Flow measurements are found to correlate with clinical findings and with symptoms. Reproducibility (established by repeated measurements) is high. The method is well tolerated even by patients suffering from rest pain.

  2. The measurement of limb blood flow using technetium-labelled red blood cells

    International Nuclear Information System (INIS)

    A method for measuring blood flow below the knee during reactive hyperaemia induced by 3 min of arterial occlusion has been developed. Subjects are positioned with lower limbs within the field of view of a gamma camera and pneumatic cuffs are placed below the knees to isolate the blood and induce a hyperaemic response. The remaining blood pool is labelled with 99Tcsup(m)-labelled red cells. Blood flows have been derived from the initial gradients of time-activity curves and from equilibrium blood sampling. The technique has been validated using a tissue-equivalent leg phantom and peristaltic pump. The method has been applied to a small group of patients with peripheral vascular disease and to normal controls. The mean value (+-SD) of limb perfusion for normal controls was found to be 16.4+-3.0 ml/100 ml/min and for patients with intermittent claudication was 5.1+-2.6 ml/100 ml/min. Flow measurements are found to correlate with clinical findings and with symptoms. Reproducibility (established by repeated measurements) is high. The method is well tolerated even by patients suffering from rest pain. (author)

  3. Nephron blood flow dynamics measured by laser speckle contrast imaging

    DEFF Research Database (Denmark)

    von Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N;

    2011-01-01

    simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic...

  4. Measurement of methyl tert-butyl ether and tert-butyl alcohol in human blood by purge-and-trap gas chromatography-mass spectrometry using an isotope-dilution method.

    Science.gov (United States)

    Bonin, M A; Ashley, D L; Cardinali, F L; McCraw, J M; Wooten, J V

    1995-01-01

    We developed an isotope-dilution method for measuring methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) in whole human blood using a purge-and-trap gas chromatographic-mass spectrometric method. The labeled analogues for MTBE and TBA were [2H12]methyl tert-butyl ether and [2H9]-tert-butyl alcohol, respectively. Volatiles were removed from the blood by direct helium purging of the liquid; were trapped on a Tenax trap; and were desorbed, cryofocused, and chromatographed on a DB-624 capillary column that was connected directly to the ion source of a mass spectrometer. Detection was by mass analysis using a double-focusing magnetic-sector mass spectrometer operating in the full-scan mode at the medium mass resolution of 3000. For the isotope-dilution method, the minimum detection limits in blood (5-10 mL) are 0.01 microgram/L for MTBE and 0.06 microgram/L for TBA. The isotope-dilution method proved to be a big improvement in recovery, reproducibility, and sensitivity over our previous analytical method, which used the labeled ketone, [4-2H3]-2-butanone, as the internal standard for both MTBE and TBA. The isotope-dilution method has sufficient sensitivity for monitoring blood levels of MTBE and TBA in populations exposed to oxygenated fuels containing MTBE. PMID:7564298

  5. Automatic noninvasive measurement of systolic blood pressure using photoplethysmography

    Directory of Open Access Journals (Sweden)

    Glik Zehava

    2009-10-01

    Full Text Available Abstract Background Automatic measurement of arterial blood pressure is important, but the available commercial automatic blood pressure meters, mostly based on oscillometry, are of low accuracy. Methods In this study, we present a cuff-based technique for automatic measurement of systolic blood pressure, based on photoplethysmographic signals measured simultaneously in fingers of both hands. After inflating the pressure cuff to a level above systolic blood pressure in a relatively slow rate, it is slowly deflated. The cuff pressure for which the photoplethysmographic signal reappeared during the deflation of the pressure-cuff was taken as the systolic blood pressure. The algorithm for the detection of the photoplethysmographic signal involves: (1 determination of the time-segments in which the photoplethysmographic signal distal to the cuff is expected to appear, utilizing the photoplethysmographic signal in the free hand, and (2 discrimination between random fluctuations and photoplethysmographic pattern. The detected pulses in the time-segments were identified as photoplethysmographic pulses if they met two criteria, based on the pulse waveform and on the correlation between the signal in each segment and the signal in the two neighboring segments. Results Comparison of the photoplethysmographic-based automatic technique to sphygmomanometry, the reference standard, shows that the standard deviation of their differences was 3.7 mmHg. For subjects with systolic blood pressure above 130 mmHg the standard deviation was even lower, 2.9 mmHg. These values are much lower than the 8 mmHg value imposed by AAMI standard for automatic blood pressure meters. Conclusion The photoplethysmographic-based technique for automatic measurement of systolic blood pressure, and the algorithm which was presented in this study, seems to be accurate.

  6. How to measure blood pressure manually.

    Science.gov (United States)

    Rushton, Melanie; Smith, Joyce

    2016-01-20

    Rationale and key points This article aims to help nurses to measure blood pressure (BP) manually using an aneroid sphygmomanometer. ▶ BP measurement is an essential clinical skill, and nurses must be competent in performing this procedure and taking accurate readings. ▶ Nurses should be aware of manual BP measurement techniques and understand the patient and environmental factors that may result in inaccurate readings that could compromise patient care. ▶ Nurses should regularly undertake manual BP measurement to ensure they remain competent to perform the procedure. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How reading this article will change your practice. 2. Further learning needs to extend your professional development. Subscribers can upload their reflective accounts at: rcni.com/portfolio . PMID:26786460

  7. The kinetic measurement of phagocyte function in whole blood

    International Nuclear Information System (INIS)

    A technique has been developed for the kinetic measurement on the same blood sample of a variety of functions of phagocytic cells. Adherence to glass, the clearance of a mixture of microorganisms and their subsequent solubilisation, and the secretion of granule contents from the cells were determined. The technique uses carbon-14 labelled and tritium-labelled bacteria which are injected into a perfusion chamber with glass coverslips containing anticoagulated blood. The release of soluble radioactive microboial components into the blood gives a measure of bacterial degradation. The numbers of residual viable intracellular staphylococci were measured at the completion of the study. These methods were used to investigate phagocyte function in 33 normal subjects and 6 patients with chronic granulomatous disease. (Auth.)

  8. Cloud droplet measurement methods

    International Nuclear Information System (INIS)

    All important techniques to measure cloud and fog droplets are mentioned in this compendium. It especially refers to those authors who established and developed measurement methods for cloud droplets and to those whose papers contained cloud droplet size distributions. (orig.)

  9. Quantitative blood flux measurement using MUSIC

    Science.gov (United States)

    Yousefi, Siavash; Qin, Jia; Wang, Ruikang K.

    2014-03-01

    In this paper, we propose a method to quantify red blood cell (RBC) flow through capillary loops and microvessels using optical microangiography (OMAG). Current existing methods of capillary flow quantification either require a very long scanning time (~few minutes) or a large acquisition number per location (+100 scans per location) to form a highresolution spectral estimation. We utilize a model-based super-resolution spectral estimation technique based on principle of orthogonality to quantify moving RBCs within a voxel. The scanning protocol required for our method is very similar to 3D ultrahigh sensitive OMAG that requires few scans per location (8) and can be performed in few seconds that makes it applicable for in vivo experiments. This method is analogous to power Doppler in ultrasonography and estimates the number of red blood cells passing through the beam as opposed to the velocity of the particles. The technique is tested both qualitatively and quantitatively by using OMAG to image microcirculation within mouse ear flap in vivo.

  10. Noise-Measuring Method

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test.......A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test....

  11. Laser Doppler measurement of cutaneous blood flow

    International Nuclear Information System (INIS)

    Laser Doppler velocimetry is an instrument system which has only recently been applied to the evaluation and quantitation of perfusion in the micro-vascular bed. The instrument is based on the Doppler principle, but uses low power laser light rather than the more commonly used ultrasound, and has a sample volume of approximately 1 mm/sup 3/. As it is non-invasive, it can be used on any skin surface or exposed microvascular bed and provides a continuous semi-quantitative measure of microcirculatory perfusion, it has a number of advantages as compared to other cutaneous blood flow measurement techniques. Initial studies have shown that it is easily used, and it has demonstrated good correlation with both xenon radio-isotope clearance and microsphere deposition techniques. Areas of current evaluation and utilization are in most major areas of medicine and surgery and include plastic, vascular and orthopaedic surgery, dermatology, gastro-enterology, rheumatology, burns and anaesthesiology

  12. Methods of Measuring Competitiveness

    OpenAIRE

    Podaºcã Raluca

    2012-01-01

    Any approach to measuring competitiveness and competitive advantages must take account of one hand of the covered analysis: microeconomic, mezoeconomic, macroeconomic, and on the other hand that they are the result of many variables that are interconditioned directly or indirectly. Measurement methods attempt to quantify the impact of competitiveness and the variables considered relevant. Among all methods of measuring global competitiveness stands Global Competitiveness Index and Economic Fr...

  13. Conductimetric method of determining the hematocrit value of blood

    Science.gov (United States)

    Neelakantaswamy, P. S.; Aspar, K. F.; Rajaratnam, A.; Das, N. P.

    1983-09-01

    A simple conductimetric method for measuring the hematocrit value of blood is described. Using a conventional electronic conductivity meter having a two-electrode cell, the conductivity between the electrodes dipped in a diluted sample of the blood is measured and related quantitatively to the strength of suspended erythrocytes (that is, to the hematocrit value) in the test suspension. The extent of diluting the sample prior to the measurement is optimally determined on the basis of theoretical considerations. The merits of this instrumentation in terms of simplicity, economy, and linearity are compared with those of conventional methods of hematocrit determination. Possibilities of improving the present method by using inductive-type conductivity meters and/or by using vhf (very high frequency) resonant circuit sensors are suggested. Relevant theoretical considerations and experimental results are presented.

  14. Automated measurement of retinal blood vessel tortuosity

    Science.gov (United States)

    Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

    2010-03-01

    Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

  15. Blood and Dried Blood Spot Telomere Length Measurement by qPCR: Assay Considerations

    OpenAIRE

    Zanet, DeAnna L.; Sara Saberi; Laura Oliveira; Beheroze Sattha; Izabella Gadawski; Côté, Hélène C. F.

    2013-01-01

    Measurement of telomere length is crucial for the study of telomere maintenance and its role in molecular pathophysiology of diseases and in aging. Several methods are used to measure telomere length, the choice of which usually depends on the type and size of sample to be assayed, as well as cost and throughput considerations. The goal of this study was to investigate the factors that may influence the reliability of qPCR-based relative telomere length measurements in whole blood. Day to day...

  16. Comparison of high-definition oscillometry -- a non-invasive technology for arterial blood pressure measurement -- with a direct invasive method using radio-telemetry in awake healthy cats.

    Science.gov (United States)

    Martel, Eric; Egner, Beate; Brown, Scott A; King, Jonathan N; Laveissiere, Arnaud; Champeroux, Pascal; Richard, Serge

    2013-12-01

    This study compared indirect blood pressure measurements using a non-invasive method, high-definition oscillometry (HDO), with direct measurements using a radio-telemetry device in awake cats. Paired measurements partitioned to five sub-ranges were collected in six cats using both methods. The results were analysed for assessment of correlation and agreement between the two methods, taking into account all pressure ranges, and with data separated in three sub-groups, low, normal and high ranges of systolic (SBP) and diastolic (DBP) blood pressure. SBP data displayed a mean correlation coefficient of 0.92 ± 0.02 that was reduced for low SBP. The agreement level evaluated from the whole data set was high and slightly reduced for low SBP values. The mean correlation coefficient of DBP was lower than for SBP (ie, 0.81 ± 0.02). The bias for DBP between the two methods was 22.3 ± 1.6 mmHg, suggesting that HDO produced lower values than telemetry. These results suggest that HDO met the validation criteria defined by the American College of Veterinary Internal Medicine consensus panel and provided a faithful measurement of SBP in conscious cats. For DBP, results suggest that HDO tended to underestimate DBP. This finding is clearly inconsistent with the good agreement reported in dogs, but is similar to outcomes achieved in marmosets and cynomolgus monkeys, suggesting that this is not related to HDO but is species related. The data support that the HDO is the first and only validated non-invasive blood pressure device and, as such, it is the only non-invasive reference technique that should be used in future validation studies. PMID:23813147

  17. Body mass index and blood pressure measurement during pregnancy.

    LENUS (Irish Health Repository)

    Hogan, Jennifer L

    2012-02-01

    OBJECTIVE: The accurate measurement of blood pressure requires the use of a large cuff in subjects with a high mid-arm circumference (MAC). This prospective study examined the need for a large cuff during pregnancy and its correlation with maternal obesity. METHODS: Maternal body mass index (BMI), fat mass, and MAC were measured. RESULTS: Of 179 women studied, 15.6% were obese. With a BMI of level 1 obesity, 44% needed a large cuff and with a BMI of level 2 obesity 100% needed a large cuff. CONCLUSION: All women booking for antenatal care should have their MAC measured to avoid the overdiagnosis of pregnancy hypertension.

  18. Home blood pressure measurement : reproducibility and relationship with left ventricular mass

    NARCIS (Netherlands)

    Kok, R.H.; Beltman, F.W.; Terpstra, W.F.; Smit, A.J.; May, J.F.; de Graeff, P.A.; Meyboom-de Jong, B.

    1999-01-01

    OBJECTIVE: To evaluate the reproducibility and relationship with left ventricular mass index of home blood pressure in comparison with ambulatory and office blood pressures. METHODS: We measured home, ambulatory and office blood pressures of 84 previously untreated hypertensive patients, aged 60-74

  19. Prediction Methods for Blood Glucose Concentration

    DEFF Research Database (Denmark)

    “Meta-Learning Based Blood Glucose Predictor for DiabeticSmartphone App” by Valeriya Naumova et al. demonstrates how a highly sophisticated glucose prediction model can be ported from a development language running on a PC to a format such that it can be used conveniently by the patients. A unique...... Continuous EEG Monitoring” by Claus Borg Juhl et al. shows how to use EEG signals to predict upcoming hypoglycemic situations in real-time by employing artificial neural networks. The results of a 30-day long clinical study with the implanted device and the developed algorithm are presented. The chapter......-Based Linear Multistep Predictors” by Marzia Cescon et al. uses data-based methods to develop individualized prediction models. The model can be considered as a combination of physiological models to precompute the rate of appearance of injected insulin and ingested carbohydrates in the bloodstream and of data...

  20. The comparison of placental removal methods on operative blood loss

    International Nuclear Information System (INIS)

    On an average 1 litre of blood is lost during Caesarean Section. Many variable techniques have been tried to reduce this blood loss. Many study trials have shown the spontaneous delivery of placenta method to be superior over manual method because of reduced intra operative blood loss and reduced incidence of post operative endometritis. The main objective of our study was to compare the risk of blood loss associated with spontaneous and manual removal of the placenta during caesarean section. This study was conducted at Department of Obstetrics and Gynaecology, Islamic International Medical Complex, Islamabad from September 2004 to September 2005. All Women undergoing elective or emergency caesarean section were included in the study. Exclusion criteria were pregnancy below 37 weeks, severe maternal anaemia, and prolonged rupture of the membranes with fever, placenta praevia, placenta accreta and clotting disorders. Patients were allocated to the two groups randomly. Group A comprised of women in whom the obstetrician waited a maximum of 5 minutes till the placenta delivered spontaneously. In group B the obstetrician manually cleaved out the placenta as soon as the infant was delivered. The primary outcome measures noted were difference in haemoglobin of >2 gm/dl (preoperatively and postoperatively), time interval between delivery of baby and placenta, significant blood loss (>1000 cc), additional use of oxytocics, total operating time and blood transfusions. Data was analysed by SPSS. Statistical tests used for specific comparison were chi square-test and Student's t-test. One hundred and forty-five patients were allocated to two groups randomly. Seventy-eight patients were allocated to group A and 67 patients allocated to group B. Mean maternal age, birth weight, and total operating time were the same in two groups, but blood loss as measured by a difference in haemoglobin of greater then 2 grams/dl was statistically significant. Significant blood loss (>1000 cc

  1. Non Invasive Measurement of Systolic Blood Pressure in Rats: A Simple Technique

    OpenAIRE

    Maria Pauline; Avadhany, Sandhya T.; K.N. Maruthy

    2011-01-01

    Background: Non invasive, simple and economical instrument to measure blood pressure in r365-ats is important in cardiovascular research. Methods: Systolic blood pressure measuring instrument was fabricated using a tail cuff, photoplethysmograph, pressure transducer and PC with Biopac Software for recording. Tail cuff was used to occlude the tail artery, photoplethysmograph picked the blood flow pulses in the rat tail and the pressure transducer measured the cuff pressure and converted it int...

  2. Signal quality measures for unsupervised blood pressure measurement

    International Nuclear Information System (INIS)

    Accurate systolic and diastolic pressure estimation, using automated blood pressure measurement, is difficult to achieve when the transduced signals are contaminated with noise or interference, such as movement artifact. This study presents an algorithm for automated signal quality assessment in blood pressure measurement by determining the feasibility of accurately detecting systolic and diastolic pressures when corrupted with various levels of movement artifact. The performance of the proposed algorithm is compared to a manually annotated reference scoring (RS). Based on visual representations and audible playback of Korotkoff sounds, the creation of the RS involved two experts identifying sections of the recorded sounds and annotating sections of noise contamination. The experts determined the systolic and diastolic pressure in 100 recorded Korotkoff sound recordings, using a simultaneous electrocardiograph as a reference signal. The recorded Korotkoff sounds were acquired from 25 healthy subjects (16 men and 9 women) with a total of four measurements per subject. Two of these measurements contained purposely induced noise artifact caused by subject movement. Morphological changes in the cuff pressure signal and the width of the Korotkoff pulse were extracted features which were believed to be correlated with the noise presence in the recorded Korotkoff sounds. Verification of reliable Korotkoff pulses was also performed using extracted features from the oscillometric waveform as recorded from the inflatable cuff. The time between an identified noise section and a verified Korotkoff pulse was the key feature used to determine the validity of possible systolic and diastolic pressures in noise contaminated Korotkoff sounds. The performance of the algorithm was assessed based on the ability to: verify if a signal was contaminated with any noise; the accuracy, sensitivity and specificity of this noise classification, and the systolic and diastolic pressure

  3. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    OpenAIRE

    Komine Hidehiko; Asai Yoshiyuki; Yokoi Takashi; Yoshizawa Mutsuko

    2012-01-01

    Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes ...

  4. Method and arrangement for angiography of blood vessels

    International Nuclear Information System (INIS)

    A method and apparatus for angiography in which information contained within multiple serial images of contrast medium flowing through a blood vessel is combined to form a single image having improved vessel edge delineation. More specifically, a method is disclosed whereby a contrast medium opaque to X-rays is injected into a blood vessel distant from an artery section of interest, preferably injected into a vein, whereby the contrast medium is mixed with blood prior to its passing through the artery section. Multiple X-ray images are obtained as the contrast medium and blood mixture flows through the artery section. These multiple images are registered with respect to each other according to a landmark contained within the patient, the landmark having a predetermined relationship to the vessel of interest. The landmark could be a bone, catheter or any other material opaque to X-rays. Density measurements are made with respect to each corresponding image segment or element of the multiple images and are combined to synthesize a composite image. The synthesized image has an edge uncertainty equal to that of one of the individual images. (Auth.)

  5. The determination of chromium-50 in human blood and its utilization for blood volume measurements

    International Nuclear Information System (INIS)

    Possible relationships between insufficient blood volume increases during pregnancy and infant mortality could be established with an adequate measurement procedure. An accurate and precise technique for blood volume measurements has been found in the isotope dilution technique using chromium-51 as a label for red blood cells. However, in a study involving pregnant women, only stable isotopes can be used for labeling. Stable chromium-50 can be determined in total blood samples before and after dilution experiments by neutron activation analysis (NAA) or mass spectrometry. However, both techniques may be affected by insufficient sensitivity and contamination problems at the inherently low natural chromium concentrations to be measured in the blood. NAA procedures involving irradiations with highly thermalized neutrons at a fluence rate of 2x1013 n/cm2xs and low background gamma spectrometry are applied to the analysis of total blood. Natural levels of chromium-50 in human and animal blood have been found to be <0.1 ng/mL; i.e., total chromium levels of <3 ng/mL. Based on the NAA procedure, a new approach to the blood volume measurement via chromium-50 isotope dilution has been developed which utilizes the ratio of the induced activities of chromium-51 to the iron-59 in three blood samples taken from each individual, namely blank, labeled and diluted labeled blood. (author)

  6. [Attitude of blood donors towards cholesterol measurement].

    Science.gov (United States)

    Flesland, O; Botten, G; Solheim, B G; Orjasaeter, H

    1992-05-20

    In analyses of cost-effectiveness it is customary to count knowledge of having a high serum cholesterol level as a negative factor. There is little support for this practice in the literature. We have studied the attitude of 305 Norwegian blood donors towards cholesterol testing. 63% stated that they were interested in their serum cholesterol level, and 40% said they knew their own serum cholesterol level. The attitude towards cholesterol testing was clearly positive, both among men and among women, regardless of age. Only one donor stated that she did not want to have her serum cholesterol tested in conjunction with blood donation. PMID:1509430

  7. Measurement of regional cerebral blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

  8. Problems with cerebral blood flow measurement in man

    International Nuclear Information System (INIS)

    Measuring cerebral blood flow in man is usually thought to be of great physiological and pathological interest. Thus, since 30 years, attemps to quantify the cerebral blood flow have given rise to a growing field of research. But, none of the proposed methods has never been currently used as a means of diagnosis or as a test of cerebral function. Methodological and technical difficulties greatly account for this failure. First, a steady flow must be ensured, while measuring it. This requires the operator to keep lung ventilation and cerebral activity to a constant level. Second, the classical models, the stochastic or the compartimental one, imperfectly fit the clearance curves. The calculations based on these models involve systematic errors, specially with low flows. Third, no tracer has been found to quite satisfactory. 133Xe remains the most commonly used radiotracer. But its low solubility in vivo gives low cerebral count-rates. If the actual local partition coefficient is unknown, cerebral blood flow cannot be accurately quantified. Recently, positron emitters have been employed and their advantages begin to be exploited. The most reliable results have been obtained using an intracarotid injection. Finally, the characteristics of the detecting part of the stationary and tomographic systems vary greatly. But, till now, no study has shown what is the best compromise between good statistics and good spatial resolution

  9. Colour measurement and white blood cell recognition

    CERN Document Server

    Gelsema, E S

    1972-01-01

    As a part of a collaboration with NEMCH aimed at the automation of the differential white blood cell count, studies have been made of the different possibilities for using colour to help in the recognition process. Results are presented comparing data obtained with a microspectrophotometer and with a simulated three-colour scanner.

  10. Smartphone-based Continuous Blood Pressure Measurement Using Pulse Transit Time.

    Science.gov (United States)

    Gholamhosseini, Hamid; Meintjes, Andries; Baig, Mirza; Linden, Maria

    2016-01-01

    The increasing availability of low cost and easy to use personalized medical monitoring devices has opened the door for new and innovative methods of health monitoring to emerge. Cuff-less and continuous methods of measuring blood pressure are particularly attractive as blood pressure is one of the most important measurements of long term cardiovascular health. Current methods of noninvasive blood pressure measurement are based on inflation and deflation of a cuff with some effects on arteries where blood pressure is being measured. This inflation can also cause patient discomfort and alter the measurement results. In this work, a mobile application was developed to collate the PhotoPlethysmoGramm (PPG) waveform provided by a pulse oximeter and the electrocardiogram (ECG) for calculating the pulse transit time. This information is then indirectly related to the user's systolic blood pressure. The developed application successfully connects to the PPG and ECG monitoring devices using Bluetooth wireless connection and stores the data onto an online server. The pulse transit time is estimated in real time and the user's systolic blood pressure can be estimated after the system has been calibrated. The synchronization between the two devices was found to pose a challenge to this method of continuous blood pressure monitoring. However, the implemented continuous blood pressure monitoring system effectively serves as a proof of concept. This combined with the massive benefits that an accurate and robust continuous blood pressure monitoring system would provide indicates that it is certainly worthwhile to further develop this system. PMID:27225558

  11. Oxygen tension measurement using an automatic blood gas analyser.

    Science.gov (United States)

    Becket, J; Orchard, C; Chakrabarti, M K; Hall, G M; Gillies, I D; Bourdillon, P J

    1981-08-01

    Two different methods of assessing the reliability of the oxygen electrode of one model of an automatic blood gas analyser (BGA) have been studied. In the first, a single automatic BGA was assessed by using outdated bank blood which was pumped around a small extracorporeal circuit into which known gas mixtures were passed. Oxygen tension was varied between 2 and 16 kPa. In the second, fresh heparinized blood was tonometered with calibrated gases and submitted to the automatic BGA used in the first part of the study and also to three other identical machines. Each of the machines was between 3 and 4 years old.Eighteen different units of blood were used in the first part of the study. The correlation coefficient between the automatic BGA and the Po(2) in the extracorporeal circuit varied between 0.29 and 0.99. 31% of the total of 209 measurements made by the automatic BGA were more than 1.2 kPa from the reference value, 25% of them being between 1.2 and 4.0 kPa from the reference value. In the second part of the study, the correlation coefficient between this automatic BGA and the tonometered blood was 0.96. The correlation coefficients for the 3 other identical BGAs were 0.84, 0.97 and 0.88, indicating that the BGA used in the first part of the study was no worse than any of the others.It is suggested that although clinicians are likely to ignore readings of an automatic BGA that are more than 4.0 kPa from the true value and are likely to repeat the investigation, readings between 1.2 and 4.0 kPa from the true value may adversely affect patient management. PMID:7288796

  12. Cutaneous and subcutaneous blood flow measurements in psoriasis

    International Nuclear Information System (INIS)

    The experiments - published in 7 papers in The Journal of Investigative Dermatology 1983-86 - have demonstrated: 1. The accuracy of the local 133Xe washout method is about 15% for estimation of the cutaneous blood flow (CBF), and about 10% for subcutaneous blood flow measurements (SBF). In measurements of absolute CBF values a graphic curve resolution of the washout curve should alwaus be performed. Otherwise the CBF might be considerably underestimated. 2. CdTe(Cl) mini-detectors can be attached directly to the skin, and might yield measurements of both CBF and SBF that can substitute for those made with conventional detectors. 3. The laser Doppler measurements could not be correlated to quantitative measurements of the CBF. 4. The tissue-to-blood partition coefficient for 133Xe of lesional psoriatic skin (LS) is increased. 5. In untreated, LS of patients with active psoriasis the CBF is about a factor of 10 times higher than the CBF of normal individuals. In non-lesional skin (NLS) of patients with active psoriasis the CBF is about a factor of 2 higher than the CBF of normal individuals. However, the CBF did not differ in NLS of patients with minimal skin manifestations. The high CBF decreases gradualy during antipsoriatic treatment. 6. A paradoxical autoregulation of the CBF was observed in LS. 7. The high CBF is not due to a maximally dilated vascular bed. 8. The SBF in LS areas was a factor of higher than the SBF in normal individuals. 9. A normal, local regulation of the SBF was found. (author)

  13. Occlusion cuff for routine measurement of digital blood pressure and blood flow

    DEFF Research Database (Denmark)

    Lassen, N A; Krähenbühl, B; Hirai, M

    1977-01-01

    A miniaturized blood pressure cuff made of plastic material and applicable to fingers and toes is described. The cuff was compared to rubber cuffs and to bladder-free cuffs. It was found to be more reliable than the former type and much easier to use than the latter type. It is recommended for us...... in conjunction with a mercury-in-Silastic strain gauge for routine measurement of digital blood pressure and blood flow in patients with arterial disease....

  14. Blood pressure self-measurement in the obstetric waiting room

    DEFF Research Database (Denmark)

    Wagner, Stefan; Kamper, Christina H.; Toftegaard, Thomas Skjødeberg;

    2013-01-01

    Background: Pregnant diabetic patients are often required to self- measure their blood pressure in the waiting room before consulta- tion. Currently used blood pressure devices do not guarantee valid measurements when used unsupervised. This could lead to misdi- agnosis and treatment error. The aim...... of this study was to investigate current use of blood pressure self-measurement in the waiting room in order to identify challenges that could influence the resulting data quality. Also, we wanted to investigate the potential for addressing these challenges with e-health and telemedicine technology...... obtain a reliable blood pressure reading. Results: We found that the patients did not adhere to given instructions when performing blood pressure self-measurement in the waiting room. None of the 81 patients adhered to all six inves- tigated recommendations, while around a quarter adhered to five out of...

  15. Placental blood flow measurements with radioisotopes in the pregnant guinea pig

    International Nuclear Information System (INIS)

    In 15 pregnant guinea pigs near term the blood flow (BF) of the myometrium and the placenta as well as the cardiac output were measured with 99Tcsup(m)-labelled microspheres. In front of one placenta the clearance of 133Xe was estimated in the same animal. For the 133Xe measurement a theoretical concept is presented. The mean placental BF is 105ml/(minx100g)(SD:84) for 99Tcsup(m) and 244(SD:80)ml/(minx100g) for 133Xe. The difference in both flow values is assumed to be related to foetal placental BF. The placental blood flow is also related to the location of the placenta in the uterine horn. The ratio of myometrial blood flow to placental blood flow decreased with an increase in the mean arterial blood pressure. The measurements are a preliminary report of an attempt to compare two different methods in measuring placental blood flow. (author)

  16. Electrorheological Methods and Mechanical Properties of Blood

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    Sofia: Avangard Prima, 2015 - (Antonova, N.; Velcheva, I.; Zvetkova, E.), s. 24 ISBN 978-619-160-521-7. [5th Eurosummer School on Biorheology & Symposium on Micro and Nano Mechanics and Mechanobiology of Cells, Tissues and Systems. Varna (BG), 20150901] Institutional support: RVO:67985874 Keywords : viscometric flow * conductivity * blood/RBC suspension microstructural changes Subject RIV: BK - Fluid Dynamics

  17. Electrorheological Methods and Mechanical Properties of Blood

    Czech Academy of Sciences Publication Activity Database

    Antonova, N.; Říha, Pavel; Ivanov, I.

    Sofia : Avangard Prima, 2015 - (Antonova, N.; Velcheva, I.; Zvetkova, E.), s. 24 ISBN 978-619-160-521-7. [5th Eurosummer School on Biorheology & Symposium on Micro and Nano Mechanics and Mechanobiology of Cells, Tissues and Systems. Varna (BG), 20150901] Institutional support: RVO:67985874 Keywords : viscometric flow * conductivity * blood/RBC suspension microstructural changes Subject RIV: BK - Fluid Dynamics

  18. Evaluation of the appropriateness of using glucometers for measuring the blood glucose levels in mice.

    Science.gov (United States)

    Togashi, Yu; Shirakawa, Jun; Okuyama, Tomoko; Yamazaki, Shunsuke; Kyohara, Mayu; Miyazawa, Ayumi; Suzuki, Takafumi; Hamada, Mari; Terauchi, Yasuo

    2016-01-01

    Glucometers are also widely used in diabetes research conducted using animal models. However, the appropriateness of measuring blood glucose levels using glucometers in animal models remains unclear. In this study, we evaluated the consistency between the blood glucose levels measured by 11 models of glucometers and plasma glucose levels measured by a laboratory biochemical test in blood samples collected by retro-orbital sinus puncture or tail-tip amputation. In both blood samples obtained by retro-orbital sinus puncture and those obtained by tail-tip amputation, 10 of the 11 models of glucometers yielded higher glucose values, while 1 yielded lower glucose values, than the plasma glucose values yielded by the laboratory test, the differences being in direct proportion to the plasma glucose values. Most glucometers recorded higher blood glucose levels after glucose loading and lower blood glucose levels after insulin loading in retro-orbital sinus blood as compared to tail vein blood. Our data suggest that the blood glucose levels measured by glucometers in mice tended to be higher than the plasma glucose levels yielded by the biochemical test under the hyperglycemic state, and that differences in the measured levels were observed according to the blood collection method depending on the glycemia status. PMID:27151424

  19. Optoacoustic measurements of human placenta and umbilical blood oxygenation

    Science.gov (United States)

    Nanovskaya, T. N.; Petrov, I. Y.; Petrov, Y.; Patrikeeva, S. L.; Ahmed, M. S.; Hankins, G. D. V.; Prough, D. S.; Esenaliev, R. O.

    2016-03-01

    Adequate oxygenation is essential for normal embryogenesis and fetal growth. Perturbations in the intrauterine oxidative environment during pregnancy are associated with several pathophysiological disorders such as pregnancy loss, preeclampsia, and intrauterine growth restriction. We proposed to use optoacoustic technology for monitoring placental and fetal umbilical blood oxygenation. In this work, we studied optoacoustic monitoring of oxygenation in placenta and umbilical cord blood ex vivo using technique of placenta perfusion. We used a medical grade, nearinfrared, tunable, optoacoustic system developed and built for oxygenation monitoring in blood vessels and in tissues. First, we calibrated the system for cord blood oxygenation measurements by using a CO-Oximeter (gold standard). Then we performed validation in cord blood circulating through the catheters localized on the fetal side of an isolated placental lobule. Finally, the oxygenation measurements were performed in the perfused placental tissue. To increase or decrease blood oxygenation, we used infusion of a gas mixture of 95% O2 + 5% CO2 and 95% N2 + 5% CO2, respectively. In placental tissue, up to four cycles of changes in oxygenation were performed. The optoacoustically measured oxygenation in circulating cord blood and in placental lobule closely correlated with the actual oxygenation data measured by CO-Oximeter. We plan to further test the placental and cord blood oxygenation monitoring with optoacoustics in animal and clinical studies.

  20. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V; Ladefoged, Søren D; Lönn, Lars

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...

  1. Measurement of regional myocardial blood flow with multiple colored microspheres

    International Nuclear Information System (INIS)

    The use of radioactive microspheres (RM) for the measurement of regional myocardial blood flow (RMBF) is limited and inaccessible to many investigators due to radiation safety concerns and radioactive waste disposal problems. Therefore, a new method for the measurement of RMBF using colored microspheres (CM) was developed. Polystyrene spheres (diameter, 15 +/- 0.1 [SD] micron; density, 1.09 g/ml) were dyed with one of five colors. With the injection of CM into the left atrium or into a coronary perfusion line, RMBF and its distribution can be determined. CM are extracted from the myocardium and blood by digestion with potassium hydroxide and subsequent microfiltration. The dyes are then recovered from the CM within a defined volume of a solvent, and their concentrations are determined by spectrophotometry. The separation of composite absorbance spectra by spectrophotometry with the CM technique was as good as the separation of energy spectra by a gamma-counter using the RM technique. Leaching of dye from the CM was less than 0.1% during a 2-month period in vitro. Significant leaching of dye from the microspheres also did not occur during 8 hours in the blood and myocardium of four anesthetized dogs in vivo. For further validation of this method, pairs of CM and RM (15.5 +/- 0.1 [SD] microns) were simultaneously injected under five different RMBF conditions (range, 0-10 ml/[min.g]) into the left anterior descending coronary artery of four anesthetized pigs, with coronary inflow as a flow reference, or into the left atrium of four anesthetized dogs using aortic blood withdrawal as a reference. The relation between RMBF determined by CM and RM was CM = 0.01 + 1.00.RM (r = 0.98, n = 1,080 data points) in the pigs, and CM = -0.19 + 0.92.RM (r = 0.97, n = 1,813 data points) in the dogs. Measurement of RMBF with CM yields values very similar to those of RM

  2. Measurements and Terminology of Different Measure Methods

    Institute of Scientific and Technical Information of China (English)

    FANG Fang; ZHANG Wei-yuan; ZHANG Wen-bin

    2005-01-01

    Body measuring is very important for garment sizing and pattern making. In this paper, we study the difference of the landmarks between the traditional method and 3D scanner and we also select the 19 circumference measurements,29 height and length measurements, 18 breadth and depth measurements and 3 other measurements, which are quite important in fashion body measuring, to compare the terminology of them in these two measuring method. 3D scanners seem better than the traditional method on these aspects, which are the number of measurements, speed,privacy and data accuracy, but they are limited on measuring posture. And there is no uniform standard for the scanners and the definitions of the measurements in the scanners are diversified.

  3. Validation of a liquid chromatography tandem mass spectrometry method to measure oxidized and reduced forms of glutathione in whole blood and verification in a mouse model as an indicator of oxidative stress.

    Science.gov (United States)

    Lee, Sang-Guk; Yim, Jisook; Lim, Yein; Kim, Jeong-Ho

    2016-04-15

    As a possible marker of oxidative stress, many studies have measured whole blood reduced glutathione (GSH) and oxidized glutathione (GSSG). However, large differences in GSH and GSSG levels reported in different studies, calls for a reliable standardized method. In this study, we validate not only analytical performance of new measurement method for GSH and GSSG, but also the clinical utility of these markers in a mouse model with chronic oxidative stress. Twenty mice were randomized into four treatment groups according to iron burden: 0mg, 5mg, 10mg, or 15mg of iron were injected into the peritoneum per day over 4 weeks. To prevent artifactual GSH auto-oxidation, we pretreated the sample with N-ethylmaleimide (NEM) immediately after sample collection. After protein precipitation using sulfosalicylic acid, GSSG and GSH-NEM were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mean GSH/GSSG ratios of the mouse model were 163.1, 31.0, 27.9, and 12.8 for control, 5mg, 10mg, and 15mg injection groups, respectively, showing a decrease in the GSH/GSSG ratios according to the amount of oxidative stress induced. Inter-assay coefficients of variation were 4.1% for GSH-NEM and 7.3% for GSSG. Recoveries were 98.0-105.9% for GSH-NEM and 98.0-107.3% for GSSG. No ion suppression was observed at the retention time for GSH-NEM and GSSG. This study suggests an accurate method that can be used for glutathione measurement using LC-MS/MS, and showed that GSH/GSSG ratio could provide an assessment of the degree of oxidative stress. PMID:26575459

  4. Measurement of Flow Properties of Mammalian Blood with Different Hematocrit Values Using Falling Needle Rheometer

    Directory of Open Access Journals (Sweden)

    Takamasa Suzuki

    2014-08-01

    Full Text Available The development of viscometry with high accuracy and quick operation, as well as the establishment of a data evaluation method by pathology are largely required. Especially, the flow properties of human blood are an important factor in the evaluation of blood disease on the medicine, but the method of viscometry and the data collection are not so easy. This study has been described on the viscosity measurement and their evaluations for mammalian blood (rabbit, pig and horse including human blood. A compact-sized falling needle rheometer (FNR and a flow analysis method using this device for blood have been developed, and the relationship between the apparent viscosity and physical properties (density, hematocrit value of blood have also been evaluated. Measured flow properties of blood are evaluated as a flow curve showing the relationship between the shear stress and shear rate. Observed flow curves of mammalian bloods show three typical fluid regions, these are, the Non-newtonian fluid region for a low shear rate range, the transition region and the Newtonian fluid region for a high shear rate range. Flow properties of blood in the Casson fluid region and the apparent viscosity (μ in the Newtonian fluid region are measured, and they are compared between mammals.

  5. Measurement and Comparison of Organic Compound Concentrations in Plasma, Whole Blood, and Dried Blood Spot Samples

    Science.gov (United States)

    Batterman, Stuart A.; Chernyak, Sergey; Su, Feng-Chiao

    2016-01-01

    The preferred sampling medium for measuring human exposures of persistent organic compounds (POPs) is blood, and relevant sample types include whole blood, plasma, and dried blood spots (DBS). Because information regarding the performance and comparability of measurements across these sample types is limited, it is difficult to compare across studies. This study evaluates the performance of POP measurements in plasma, whole blood and DBS, and presents the distribution coefficients needed to convert concentrations among the three sample types. Blood samples were collected from adult volunteers, along with demographic and smoking information, and analyzed by GC/MS for organochlorine pesticides (OCPs), chlorinated hydrocarbons (CHCs), polychlorinated biphenyls (PCBs), and brominated diphenyl ethers (PBDEs). Regression models were used to evaluate the relationships between the sample types and possible effects of personal covariates. Distribution coefficients also were calculated using physically-based models. Across all compounds, concentrations in plasma were consistently the highest; concentrations in whole blood and DBS samples were comparable. Distribution coefficients for plasma to whole blood concentrations ranged from 1.74 to 2.26 for pesticides/CHCs, averaged 1.69 ± 0.06 for the PCBs, and averaged 1.65 ± 0.03 for the PBDEs. Regression models closely fit most chemicals (R2 > 0.80), and whole blood and DBS samples generally showed very good agreement. Distribution coefficients estimated using biologically-based models were near one and did not explain the observed distribution. Among the study population, median concentrations of several pesticides/CHCs and PBDEs exceeded levels reported in the 2007–2008 National Health and Nutrition Examination Survey, while levels of other OCPs and PBDEs were comparable or lower. Race and smoking status appeared to slightly affect plasma/blood concentration ratios for several POPs. The experimentally

  6. A simplified method for determination of radioactive iron in whole-blood samples

    DEFF Research Database (Denmark)

    Bukhave, Klaus; Sørensen, Anne Dorthe; Hansen, M.

    2001-01-01

    simultaneous determination of Fe-55 and Fe-59 in blood, using a dry-ashing procedure and recrystallization of the remaining iron. The detection Limit of the method permits measurements of 0.1 Bq/ml blood thus allowing detection of Less than 1% absorption from a 40 kBq dose, which is ethically acceptable in...

  7. Indirect measurement of arterial blood pressure: physiotherapists’ theoretical knowledge

    Directory of Open Access Journals (Sweden)

    Marcelle Morgana Vieira de Assis

    2003-12-01

    Full Text Available Blood pressure checking and its theoretical knowledge are crucial to obtain reliable data in clinical examination. Although it is considered a simple technique to be learned and applied, it is not fully dealt with at physiotherapy university courses. Therefore, a wide range of mistakes and misinterpretations are likely to threaten treatment quality. This work aims to evaluate the theory background of physiotherapists for blood pressure measurement. From June to October 2002, 55 physiotherapists answered a 20- question multiple-choice questionnaire on general knowledge related to concepts, anatomy and physiology, suitable equipment, indirect measurement, blood pressure values, mistakes and misinterpretation factors related to blood pressure measurement. The results disclose faulty theory concepts in the sample studied, indicating the need of deeper approach to this complex theme during course and ongoing updating of professionals.

  8. Aspects of the continuous clinical measurement of arterial blood pressure and cardiac output

    International Nuclear Information System (INIS)

    In this paper the authors try to classify circulatory measurements as to certain characteristics such as ''activeness'', ''invasivenesss'', etc. Next they turn to defining some fundamental measurements in the blood circulation and focus attention on the continuous measurement of systemic arterial pressure and flow to finally emphasize the inaccuracy of clinical cardiac output methods. The conclusion is that clinical circulatory measurement methods have accuracies at least an order of magnitude worse than common physical methods used in electrical or mechanical engineering. (Auth.)

  9. Hotel Competitiveness Measurement Methods

    OpenAIRE

    Katalin Juhasz-Dora

    2015-01-01

    Competitiveness is becoming a very common expression used in business administration. The definition and its application still raises some questions due to the complexity of its meaning. The role of the measurement of competitiveness and its effect on performance and profitability is increasing in the field of hospitality and tourism as well. The measurement of hotel competitiveness is a current issue in business life due to globalization, sharing economy and the change in the consumber habit...

  10. A simplified method for determination of radioactive iron in whole-blood samples

    DEFF Research Database (Denmark)

    Bukhave, Klaus; Sørensen, Anne Dorthe; Hansen, M.

    2001-01-01

    humans. The overall recovery of radioiron from blood is more than 90%, and the coefficient of variation, as judged by the variation in the ratio Fe-55/Fe-59 is in the order of 4%. Combined with whole-body counting of 59Fe and direct gamma -counting of Fe-59 on blood samples, this method represents a......For studies on iron absorption in man radioisotopes represent an easy and simple tool. However, measurement of the orbital electron emitting radioiron, Fe-55, in blood is difficult and insufficiently described in the literature. The present study describes a relatively simple method for...... simultaneous determination of Fe-55 and Fe-59 in blood, using a dry-ashing procedure and recrystallization of the remaining iron. The detection Limit of the method permits measurements of 0.1 Bq/ml blood thus allowing detection of Less than 1% absorption from a 40 kBq dose, which is ethically acceptable in...

  11. Proportion and characteristics of patients who measure their blood pressure at home: Nationwide survey in Slovenia

    Directory of Open Access Journals (Sweden)

    Petek-Šter Marija

    2009-01-01

    Full Text Available Introduction. Home blood pressure monitoring has several advantages over blood pressure monitoring at a physician's office, and has become a useful instrument in the management of hypertension. Objective. To explore the rate and characteristics of patients who measure their blood pressure at home. Methods. A sample of 2,752 patients with diagnosis of essential arterial hypertension was selected from 12596 consecutive office visitors. Data of 2,639 patients was appropriate for analysis. The data concerning home blood pressure measurement and patients' characteristics were obtained from the patients' case histories. Results 1,835 (69.5% out of 2,639 patients measured their blood pressure at home. 1,284 (70.0% of home blood pressure patients had their own blood pressure measurement device. There were some important differences between these two groups: home blood pressure patients were more frequently male, of younger age, better educated, from urban area, mostly non-smokers, more likely to have diabetes mellitus and ischemic heart disease and had higher number of co-morbidities and were on other drugs beside antihypertensive medication. Using the logistic regression analysis we found that the most powerful predictors of home blood pressure monitoring had higher education level than primary school OR=1.80 (95% CI 1.37-2.37, non-smoking OR=2.16 (95% CI 1.40-3.33 and having a physician in urban area OR=1.32 (95% CI 1.02-1.71. Conclusion. Home blood pressure monitoring is popular in Slovenia. Patients who measured blood pressure at home were different from patients who did not. Younger age, higher education, non-smoking, having a physician in urban area and longer duration of hypertension were predictors of home blood pressure monitoring.

  12. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  13. Should blood pressure be measured with the cuff on a bare arm?

    NARCIS (Netherlands)

    Thien, T.; Keltjens, E.B.; Lenders, J.W.M.; Deinum, J.

    2015-01-01

    OBJECTIVE: To establish whether the results of blood pressure (BP) measurements are affected by wearing clothing underneath the BP cuff during measurement. METHODS: Normotensive and hypertensive patients (n=133; 65 men) of an outpatient clinic participated in this study. BP was measured according to

  14. Cerebral blood volume measured using near-infrared spectroscopy and radiolabels in the immature lamb brain.

    Science.gov (United States)

    Barfield, C P; Yu, V Y; Noma, O; Kukita, J; Cussen, L J; Oates, A; Walker, A M

    1999-07-01

    Near-infrared spectroscopy (NIRS) is a technique that is increasingly being used for the noninvasive measurement of cerebral blood volume (CBV) in newborn infants, but it has not been fully validated against established methods. These experiments in immature lambs (gestation 92+/-1 d, mean+/-SEM) compared CBV measured using NIRS-derived estimates of oxygenated Hb (n = 5) with CBV estimated with radiolabeled indicators (125I-labeled serum albumin and 51Cr-labeled red blood cells, n = 10). Total brain CBV (mL/100 g tissue) measured using NIRS was 2.5+/-0.2 compared with 2.5+/-0.2 using radiolabels (NS). Regional tissue plasma, red blood cells, and whole blood volumes from radiolabels varied significantly (p cerebellum > cortex > brain stem = midbrain > white matter. Regional plasma and red blood cell distributions were similar to whole blood, being highest in choroid plexus (13.0+/-1.6 and 3.2+/-0.9, respectively), and least in white matter (0.8+/-0.1 and 0, respectively). These data from the immature lamb brain indicate that total CBV measured with NIRS is essentially identical with the volumes obtained using intravascular radiolabels. Among cerebral regions, white matter contributes little to the global blood volume measured with NIRS because its red blood cell content is very low. PMID:10400134

  15. Measurement of directed blood flow by laser speckle

    Science.gov (United States)

    Hirst, Evan R.; Thompson, Oliver B.; Andrews, Michael K.

    2011-03-01

    Recent success in reconciling laser Doppler and speckle measurements of dermal perfusion by the use of multi-exposure speckle has prompted an investigation of speckle effects arising from directed blood flow which might be expected in the small blood vessels of the eye. Unlike dermal scatter, the blood in retinal vessels is surrounded by few small and stationary scatterers able to assist the return of light energy by large-angle scatter. Returning light is expected to come from multiple small angle scatter from the large red blood cells which dominate the fluid. This work compares speckle measurements on highly scattering skin, with measurements on flow in a retinal phantom consisting of a glass capillary which is itself immersed in an index matching fluid to provide a flat air-phantom interface. Brownian motion dominated measurements when small easily levitated scatters were used, and flow was undetectable. With whole-blood, Brownian motion was small and directed flows in the expected region of tens of mm/s were detectable. The nominal flow speed relates to the known pump rate; within the capillary the flow will have a profile reducing toward the walls. The pulsatile effects on laser speckle contrast in the retina are discussed with preliminary multi-exposure measurements on retinal vessels using a fundus camera. Differences between the multiple exposure curves and power spectra of perfused tissue and ordered flow are discussed.

  16. Calcium measurement methods

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-09-01

    Full Text Available Rightly stressed by prof. Wolfgang Walz in the Preface to the series Neuromethods series, the “careful application of methods is probably the most important step in the process of scientific inquiry”. Thus, I strongly suggest to all those interested in calcium signaling and especially to the new-comers in the hot topic of neuroscience (which has so much space even in science-society debate for its implications in legal issues and in the judge-decision process to take profit from this so well edited book. I am saying this since prof. Verkhratsky and prof. Petersen......

  17. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    International Nuclear Information System (INIS)

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 μm2). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0±5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCODSA=COFick. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  18. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)

    2009-11-15

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  19. Superiority of home blood pressure measurements over office measurements for testing antihypertensive drugs.

    Science.gov (United States)

    Vaur; Dubroca; Dutrey-Dupagne; Genès; Chatellier; Bouvier-d'Yvoire; Elkik; Ménard

    1998-04-01

    OBJECTIVE: To compare the effects on office blood pressure and home blood pressure of placebo and active drug administration. DESIGN: After a 2-week wash-out period, patients with mild-to-moderate hypertension entered a 2-week single-blind placebo period and then a 4-week double-blind period. Patients were randomly assigned to be administered either 2 mg trandolapril once daily or its placebo in a 2:1 proportion. Office blood pressure was measured by a physician at the end of each period, using a mercury sphygmomanometer (mean of three consecutive measurements). Home blood pressure was measured during the last week of each period according to standard procedure carefully taught to each patient by the physician. Compliance was checked by using electronic pill boxes. RESULTS: Data for 34 of the 44 patients who entered the study were eligible for analysis. Baseline systolic blood pressure/diastolic blood pressure were significantly (P = 0.0001/P = 0.0001) higher for office blood pressure (161/101 mmHg) than they were for home blood pressure (145/93 mmHg). There was no statistically significant difference between the placebo and active-treatment groups at baseline. During the single-blind period, blood pressures measured at the office and at home did not change significantly. Office blood pressure decreased by 2.7 +/- 10 mmHg for systolic blood pressure and by 0.5 +/- 4 mmHg for diastolic blood pressure whereas home blood pressure increased by 0.8 +/- 6 mmHg for systolic blood pressure and by 0.7 +/- 4 mmHg for diastolic blood pressure. During the double-blind period, office blood pressure fell significantly with trandolapril treatment (systolic by 10.2 +/- 12 mmHg, diastolic by 8.3 +/- 6 mmHg; P = 0.0005/0.0001, versus single-blind placebo period) but this decrease was not significantly different (P = 0.45/0.92) from the fall in members of the placebo group (systolic by 6.9 +/- 9 mmHg, diastolic by 8.0 +/-6 mmHg; P = 0.04/0.002, versus single-blind placebo period

  20. A new method for detecting hemoglobin directly in whole blood using photon attenuation techniques

    International Nuclear Information System (INIS)

    The objective of the proposed work is focused on measuring iron concentration directly in whole blood as tool for estimating hemoglobin and anemic conditions in patients across the world. The investigated method depends on theory of photon attenuation through transmission of low energy in whole blood sample. The mathematical expressions for calculating hemoglobin and iron deficit on blood using photon attenuation are derived. Calculations are carried out for estimating concentration of iron in blood samples taken from children, adults and old patients and therefore measuring their hemoglobin and iron deficit from normal values. Theoretical mass attenuation coefficient values were obtained using the XCOM program. A high-resolution gamma-ray spectrometry based on high purity germanium detector was employed to measure attenuation of strongly collimated monoenergetic gamma beam through blood samples. (author)

  1. Blood pressure measurement in epidemiological investigations in teenagers

    International Nuclear Information System (INIS)

    Background: The use of sphygmomanometers may lead to problems in investigations on health of young people. The purpose of this paper is to present the validation of the blood pressure (BP) collected during the survey 'Youth Heart Health' in Hainaut by using second sample of young people in Hainaut for which BP was measured by a manual taking of tension and by an electronic device. Methods: Validation was done with a control sample of 343 young with five successive BP measures: twice with the mercury sphygmomanometer and three with DXL. We compared the manual and the electronic measures in order to study the correlation between the two methods. The control sample was used in order to compare the BP measurements with the results of the survey on the health of young people in Hainaut. Results: The differences between manual systolic BP and Dinamap measures are significant (differences in averages 3.6 mmHg; d.s. 7.8; 95% CI: 2.8-4.4 mmHg; p < 0.001) and the regression coefficient is -0.015. Diastolic BP is significantly higher with the manual method than with Dinamap (differences in means: 8.2 mmHg; d.s. 7.0; 95% CI: 7.4-8.9 mmHg; p < 0.001) and the coefficient of regression is 0.096. We observe a difference in BP between the general survey and the control group (10.3 mmHg for systolic manual control and of 10.9 mmHg for systolic electronic control; 3.3 mmHg for diastolic manual control and of 11.5 mmHg for diastolic electronic control). Conclusions: The values of BP of the 'Youth Heart Health' are significantly higher. These observations indicate the difficulties in the choice of the tool for measurements of BP in epidemiological investigations in the teenagers. In order to decrease skews of observations in the measurement of BP, it is recommended to use a valid electronic instrument. Dinamap XL is an instrument of choice in such studies of young people. Environmental and organisational factors may also explain the observed difference, which means that survey

  2. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... perfusion velocities, short-term ICCs were 0.79-0.82 and long-term ICCs were 0.06-0.11. Intersession increases in blood glucose were associated with reductions in perfusion velocities (arterial p = 0.0067; venous p = 0.018). CONCLUSION: Oxygen reactivity testing supported that motion-contrast velocimetry is...... a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels...

  3. Measurement of tumor blood flow following neutron irradiation

    International Nuclear Information System (INIS)

    Clinical oncologists and cancer researchers benefit from information on the vascularization or non-vascularization of solid tumors because of blood flow's influence on three popular treatment types: hyperthermia therapy, radiotherapy, and chemotherapy. The objective of this research is the development of a clinically useful tumor blood flow measurements technique. The designed technique is sensitive, has good spatial resolution, in non-invasive and presents no risk to the patient beyond his usual treatment. Tumor blood flow was determined by measuring the washout of positron emitting isotopes created through neutron therapy treatment. In order to do this, several technical and scientific questions were addressed first. These questions have been answered through both theoretical calculation and measurement. The first question was answered through the measurement of macroscopic cross sections for the predominant nuclear reactions in the body. These results correlate well with an independent mathematical prediction of tissue activation and measurements of mouse spleen neutron activation. The second question was addressed by performing cell suspension and protein precipitation techniques on neutron activated mouse spleens. The third and final question was answered by using first physical principles to develop a model mimicking the blood flow system and measurement technique. In a final set of experiments, the above were applied to flow models and animals. The ultimate aim of this project is to apply its methodology to neutron therapy patients

  4. MEASUREMENTS OF THE BLOOD CAPILLARY PRESSURE AND ARTERIAL ELASTICITY

    Institute of Scientific and Technical Information of China (English)

    HuangMengcai; GuZhong; HangWenjing; ZhongQuan; TangFuyong

    1990-01-01

    Describe some new fully automatic instruments for the measurements of the blood capillary pressure (Pcap) and arterial elastic properties in human fingers using a photoelectric plethysmographic technique, With these instruments, the value of Pcap was in good agreement with those reported by other investigators, the arterial elastic properties in human fingers have been successfully measured. The measurements of Pcap and arterial elasticity are now required in clinics because they provide useful and important information for evaluating vascular haemodynamics.

  5. Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment

    DEFF Research Database (Denmark)

    Laugesen, Esben; Knudsen, Søren T; Hansen, Klavs W;

    2016-01-01

    Aortic systolic blood pressure (BP) represents the hemodynamic cardiac and cerebral burden more directly than office systolic BP. Whether invasively measured aortic systolic BP confers additional prognostic value beyond office BP remains debated. In this study, office systolic BP and invasively...

  6. Interscapular brown adipose tissue blood flow in the rat. Determination with 133xenon clearance compared to the microsphere method

    DEFF Research Database (Denmark)

    Astrup, A; Bülow, J; Madsen, J

    1984-01-01

    The xenon clearance method was adapted to continuous measurement of interscapular brown adipose tissue (ISBAT) blood flow in anesthetized rats. The ISBAT-blood partition coefficient for xenon was determined to 3.6 ml X g-1. The blood flow values obtained by Xe clearance were compared with flow...

  7. Investigation of opportunities of the optical non-invasive diagnostics method for the blood sugar control

    Science.gov (United States)

    Lastovskaia, Elena A.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Korotaev, Valery V.

    2015-03-01

    The relevance of noninvasive method for determining the blood sugar is caused by necessity of regular monitoring of glucose levels in diabetic patients blood. Traditional invasive method is painful, because it requires a finger pricking. Despite the active studies in the field of non-invasive medical diagnostics, to date the painless and inexpensive instrument for blood sugar control for personal use doesn't exist. It's possible to measure the concentration of glucose in the blood with help of spectrophotometry method. It consists of registering and analyzing the spectral characteristics of the radiation which missed, reflected or absorbed by the object. The authors proposed a measuring scheme for studying the spectral characteristics of the radiation, missed by earlobe. Ultra-violet, visible and near infrared spectral ranges are considered. The paper presents the description of construction and working principles of the proposed special retaining clip and results of experiment with real patient.

  8. Development of a Phantom Tissue for Blood Perfusion Measurements and Noninvasive Blood Perfusion Estimation in Living Tissue

    OpenAIRE

    Mudaliar, Ashvinikumar

    2007-01-01

    A convenient method for testing and calibrating surface perfusion sensors has been developed. A phantom tissue model is used to mimic the non-directional blood flow of tissue perfusion. A computational fluid dynamics (CFD) model was constructed in Fluent to design the phantom tissue and validate the experimental results. The phantom perfusion system was used with a perfusion sensor based on the clearance of thermal energy. A heat flux gage measures the heat flux response of tissue whe...

  9. [A gas chromatographic method for determining acetaldehyde in cadaver blood].

    Science.gov (United States)

    Savich, V I; Valladares, Kh A; Gusakov, Iu A; Skachko, Z M

    1990-01-01

    Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death. PMID:2087747

  10. [Measurement of blood cholesterol, decentralized, using a Reflotron, or centralized in a laboratory. A comparison].

    Science.gov (United States)

    Christensen, T E; Agner, E; Jensen, S E; Jacobsen, K; Mahnfeldt, M S; Baastrup, A

    1990-11-01

    In connection with an extensive screening programme for blood cholesterol, the cholesterol values in 105 participants were measured on a sample of capillary blood employing a Reflotron and, simultaneously, samples of venous blood were examined by conventional enzymatic analysis in a laboratory. Whereas the day-to-day variation and the scatter involved were quite limited in the laboratory, the variation scatter between the two methods of measurement was 0.65 mmol/l. This figure was, however, no greater than that described between different laboratories in USA. Nevertheless, it is an important problem with the Reflotron method that even slight deviations from the recommended procedure of withdrawing blood involve a systematic risk for erroneously low cholesterol results. PMID:2238225

  11. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch;

    1997-01-01

    to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically...

  12. Laser Doppler flowmetry is valid for measurement of cerebral blood flow autoregulation lower limit in rats

    DEFF Research Database (Denmark)

    Tonnesen, Jan; Pryds, Anders; Larsen, Erik Hviid;

    2005-01-01

    Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim of this st......Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim...... in similar results. We conclude that even though LDF overestimated CBF during haemorrhagic shock caused by controlled haemorrhage, the lower limit autoregulation was correctly identified. The laser Doppler technique provides a reliable method for detection of a wide range of cerebral blood flow changes under...... CO2 challenge. Haemodilution influences the two methods differently causing relative overestimation of blood flow by the laser Doppler technique compared to the 133xenon method....

  13. Examination of four different instruments for measuring the blood lactate concentration

    OpenAIRE

    Medbø, Jon Ingulf; Mamen, Asgeir; Olsen, Ole Holt; Evertsen, Frank

    2000-01-01

    ABSTRACT There is incomplete information on the performance of different instruments used to measure the blood lactate concentration. We have therefore examined instruments from Yellow Springs Instruments (YSI 23L and YSI 1500), and three cheaper and simpler instruments: Dr. Lange’s LP8+, Lactate Pro from Arkray, KDK, and Accusport from Boehringer Mannheim. First a number of blood samples were analysed by standard enzymatic photofluorometry (our control method) and in additi...

  14. Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests

    OpenAIRE

    Felipo, Vicente; Urios, Amparo; Giménez-Garzó, Carla; Cauli, Omar; Andrés-Costa, Maria-Jesús; González, Olga; Serra, Miguel A; Sánchez-González, Javier; Aliaga, Roberto; Giner-Durán, Remedios; Belloch, Vicente; Montoliu Félix, Carmina

    2014-01-01

    AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy.METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE wer...

  15. Use of phase-contrast magnetic resonance angiography to measure blood flow in the ophthalmic artery

    International Nuclear Information System (INIS)

    The aim of this study was to examine the usefulness of phase-contrast magnetic resonance (MR) angiography (PC-MRA) to measure blood flow in the ophthalmic artery. PC-MRA was performed in 16 volunteers with no ophthalmic abnormalities and measurement of blood flow based on the results was attempted. It was possible to measure blood flow in the ophthalmic artery using PC-MRA in all 16 volunteers. The mean (±1 standard deviation) velocity was 9.17±2.28 cm/second, peak systolic velocity was 16.69±3.33 cm/second, and end diastolic velocity was 3.69±2.44 cm/second. The resistivity index was 0.79±0.12, the pulsatility index was 1.49±0.41, and flow was 6.25±2.33 ml/minute. It was possible to identify the ophthalmic artery and a portion of the artery in which blood flow could be measured using MR imaging, a preliminary step to blood flow measurement using MR angiography. In addition to the velocity of blood flow in the ophthalmic artery, measurement of the amount of flow was possible with PC-MRA, which is one advantage of this method. (author)

  16. Cerebral blood flow measurements using electron beam computed tomography (EBT)

    International Nuclear Information System (INIS)

    In close collaboration with the participants of the TEMPUS-Project Nr. 11117 a new technical and theoretical approach was developed to estimate cerebral blood flow using i.v. applied contrast agent and evaluating the cerebral time density curves using EBT as imaging method. This new approach and first clinical results are described. (author)

  17. Simple technique for measuring relative renal blood flow

    International Nuclear Information System (INIS)

    To determine whether externally monitored early renal uptake of 131I-hippurate is proportional to renal blood flow, the renal uptake of 131-hippurate at 1 to 2 min after injection was compared with the renal accumulation of radioactive carbonized microspheres in dogs. A renal artery catheter equipped with a balloon was used to decrease renal blood flow unilaterally. One minute after the intravenous injection of 100 μCi of 131I-hippurate, about 1 μCi of either 85Sr- or 95Nb-labeled carbon microspheres was injected into the left ventricle. Radioactivity was measured over both kidneys. The total radioactivity within each kidney region of interest was corrected for background and integrated over the 1 to 2 min interval after injection. Thirteen measurements of relative renal blood flow were made for seven dogs. The dogs were then killed and both kidneys were excised and counted for the radioactivity of the microspheres. The 1 to 2-min relative renal uptake of 131I-hippurate correlated well with relative microsphere uptake, suggesting that relative renal blood flow can be simply determined from the external measurements of renal uptake of 131I-hippurate

  18. Pulmonary blood flow distribution measured by radionuclide computed tomography

    International Nuclear Information System (INIS)

    Distributions of pulmonary blood flow per unit lung volume were measured in sitting patients with a radionuclide computed tomography (RCT) by intravenously administered Tc-99m macroaggregates of human serum albumin (MAA). Four different types of distribution were distinguished, among which a group referred as type 2 had a three zonal blood flow distribution as previously reported (West and co-workers, 1964). The pulmonary arterial pressure (Pa) and the venous pressure (Pv) were determined in this group of distribution. These values showed satifactory agreements with the pulmonary artery pressure (Par) and the capillary wedged pressure (Pcw) measured by Swan-Ganz catheter in eighteen supine patients. Those good correlations enable to establish a noninvasive methodology for measurement of pulmonary vascular pressures

  19. Methods for analysis of citrinin in human blood and urine.

    Science.gov (United States)

    Blaszkewicz, Meinolf; Muñoz, Katherine; Degen, Gisela H

    2013-06-01

    Citrinin (CIT), produced by several Penicillium, Aspergillus, and Monascus species, has been detected as contaminant in feeds, grains, and other food commodities. CIT can co-occur with ochratoxin A (OTA), a mycotoxin also known for its nephrotoxicity, and this raises concern regarding possible combined effects. But, in contrast to OTA, data on CIT contamination in foods for human consumption are scarce, and CIT biomonitoring has not been conducted so far due a lack of suitable methods for human specimen. Thus, it was the aim of the present study to develop sensitive methods for the analysis of CIT in human blood and urine to investigate human exposure. To this end, we assessed different methods of sample preparation and instrumental analysis for these matrices. Clean-up of blood plasma by protein precipitation followed by LC-MS/MS-based analysis allowed robust detection of CIT (LOD 0.07 ng/mL, LOQ 0.15 ng/mL). For urine, sample clean-up by an immunoaffinity column (CitriTest(®)) proved to be clearly superior to SPE with RP(18) material for subsequent analysis by LC-MS/MS. For CIT and its metabolite dihydrocitrinone (HO-CIT), the LOD and LOQ determined by external calibration curves in matrix were 0.02 and 0.05 ng/mL for CIT, and those for HO-CIT were 0.05 and 0.1 ng/mL urine. The newly developed method was applied in a small pilot study: CIT was present in all plasma samples from 8 German adults, at concentrations ranging from 0.11 to 0.26 ng/mL. The molar (nM) concentrations of CIT are similar to those measured for OTA in these samples as a result of dietary mycotoxin intake. CIT was detected in 8/10 urines (from 4 adults and 6 infants) in a range of 0.16-0.79 ng/mL, and HO-CIT was present in 5/10 samples at similar concentrations. Thus, CIT is excreted in urine as parent compound and also as metabolite. These first results in humans point to the need for further studies on CIT exposure. PMID:23354378

  20. Modeling and Measurement of Correlation between Blood and Interstitial Glucose Changes

    Science.gov (United States)

    Shi, Ting; Li, Dachao; Li, Guoqing; Zhang, Yiming; Xu, Kexin; Lu, Luo

    2016-01-01

    One of the most effective methods for continuous blood glucose monitoring is to continuously measure glucose in the interstitial fluid (ISF). However, multiple physiological factors can modulate glucose concentrations and affect the lag phase between blood and ISF glucose changes. This study aims to develop a compensatory tool for measuring the delay in ISF glucose variations in reference to blood glucose changes. A theoretical model was developed based on biophysics and physiology of glucose transport in the microcirculation system. Blood and interstitial fluid glucose changes were measured in mice and rats by fluorescent and isotope methods, respectively. Computer simulation mimicked curves were fitted with data resulting from fluorescent measurements of mice and isotope measurements of rats, indicating that there were lag times for ISF glucose changes. It also showed that there was a required diffusion distance for glucose to travel from center of capillaries to interstitial space in both mouse and rat models. We conclude that it is feasible with the developed model to continuously monitor dynamic changes of blood glucose concentration through measuring glucose changes in ISF with high accuracy, which requires correct parameters for determining and compensating for the delay time of glucose changes in ISF.

  1. 无创血压检测仪质量控制检测方法分析及应用特点%Analysis on the quality detection method and application characteristics of non-invasive blood pressure measuring instrument

    Institute of Scientific and Technical Information of China (English)

    李秋娟; 李向东; 崔骊

    2013-01-01

    Objective:To investigate the effect of the control quality detection method and common problems of the non-invasive blood pressure. We analyzed the function and characteristics of two kinds of non-invasive blood pressure quality tester to improve quality control testing technology. Methods:We are use the"FLUKE"BP Pump2 noninvasive blood pressure quality detector of US and Olico BP-SiM noninvasive blood pressure testing instrument to test. We analyzed the results of test. Results:The regular quality control can effectively improve the reliability and reduce the failure rate of the non invasive blood pressure monitor. Conclusion:We are Use the two kinds of non-invasive blood pressure quality testing to ensure the quality and safety of multi-parameter monitor. We are monitor the unqualified for clinical through regular inspection, as the same as, we can ensure the accuracy of clinical diagnosis and the life safety of patients.%目的:探讨无创血压检测仪质量控制的检测方法及常见问题,分析两种无创血压质量检测仪的功能和特点,提高质量控制检测技术。方法:采用美国“FLUKE”BP Pump2型无创血压质量检测仪和奥利科BP-SiM型无创血压质量检测仪,对监护仪中无创血压模块进行检测,对结果进行分析。结果:定期的质量控制检测可以有效提高无创血压监护仪的可靠性,降低不合格率。结论:使用两种无创血压质量检测仪保障了多参数监护仪的质量安全。通过定期检测,杜绝了不合格的监护仪在临床的应用,确保了临床诊断的准确性和患者的生命安全。

  2. Measurement of effective hepatic blood flow using 99mTc-PMT SPECT and single blood sampling

    International Nuclear Information System (INIS)

    Effective hepatic blood flow (EHBF) was measured from an uptake constant using single blood sampling and 99mTc-PMT hepatobiliary SPECT data. After intravenous injection of 3 mCi (111MBq) of 99mTc-PMT, serial 1 min SPECT data were obtained for 7 minutes. A time activity curve (TAC) over the heart, that was normalized with the 5 minutes venous sample concentration (%/dose/m1), was used as a blood clearance curve (B(t)). And a TAC of the whole liver, that was normalized with the injected dose of 99mTc-PMT (%/dose), was used as a hepatogram (L(t)). An uptake constant representing EHBF, was estimated from the Rutland's method L. (t)/B(t) was plotted against ∫otB(t)dt/B(t), and the slope of the least square fitted straight line was determined as the uptake constant. In 16 cases, significant correlation was obtained between the 99mTc-PMT hepatic uptake at 5 minutes and the EHBF estimated from the blood clearance (r=0.85,p99mTc-PMT SPECT data enables us to estimate EHBF with single venous sampling and in relatively short acquisition time. This method is thought to be very valuable in clinical practice. (author)

  3. Blood-Pressure Measuring System Gives Accurate Graphic Output

    Science.gov (United States)

    1965-01-01

    The problem: To develop an instrument that will provide an external (indirect) measurement of arterial blood pressure in the form of an easily interpreted graphic trace that can be correlated with standard clinical blood-pressure measurements. From sphygmograms produced by conventional sphygmographs, it is very difficult to differentiate the systolic and diastolic blood-pressure pulses and to correlate these indices with the standard clinical values. It is nearly impossible to determine these indices when the subject is under physical or emotional stress. The solution: An electronic blood-pressure system, basically similar to conventional ausculatory sphygmomanometers, employing a standard occluding cuff, a gas-pressure source, and a gas-pressure regulator and valve. An electrical output transducer senses cuff pressure, and a microphone positioned on the brachial artery under the occluding cuff monitors the Korotkoff sounds from this artery. The output signals present the conventional systolic and diastolic indices in a clear, graphical display. The complete system also includes an electronic timer and cycle-control circuit.

  4. Reliable blood pressure self-measurement in the obstetric waiting room

    DEFF Research Database (Denmark)

    Wagner, Stefan; Kamper, C. H.; Rasmussen, Niels H;

    2014-01-01

    Background: Patients often fail to adhere to clinical recommendations when using current blood pressure self-measurement (BPSM) methods and equipment. As existing BPSM equipment is not able to detect non-adherent behavior, this could result in misdiagnosis and treatment error. To overcome this...... patients scheduled for self-measuring their blood pressure (BP) in the waiting room at an obstetrics department's outpatient clinic to perform an additional BPSM using ValidAid. We then compared the automatically measured and classified values from ValidAid with our manual observations. Results: We found...

  5. Preanalytical Conditions and DNA Isolation Methods Affect Telomere Length Quantification in Whole Blood

    OpenAIRE

    Tolios, Alexander; Teupser, Daniel; Lesca M Holdt

    2015-01-01

    Telomeres are located at chromosome ends and their length (TL) has been associated with aging and human diseases such as cancer. Whole blood DNA is frequently used for TL measurements but the influence of preanalytical conditions and DNA isolation methods on TL quantification has not been thoroughly investigated. To evaluate potential preanalytical as well as methodological bias on TL, anonymized leftover EDTA-whole blood samples were pooled according to leukocyte counts and were incubated wi...

  6. An assessment of various blood collection and transfer methods used for malaria rapid diagnostic tests

    Directory of Open Access Journals (Sweden)

    Baik Fred

    2007-11-01

    Full Text Available Abstract Background Four blood collection and transfer devices commonly used for malaria rapid diagnostic tests (RDTs were assessed for their consistency, accuracy and ease of use in the hands of laboratory technicians and village health workers. Methods Laboratory technicians and village health workers collected blood from a finger prick using each device in random order, and deposited the blood either on filter paper or into a suitable casette-type RDT. Consistency and accuracy of volume delivered was determined by comparing the measurements of the resulting blood spots/heights with the measurements of laboratory-prepared pipetted standard volumes. The effect of varying blood volumes on RDT sensitivity and ease of use was also observed. Results There was high variability in blood volume collected by the devices, with the straw and the loop, the most preferred devices, usually transferring volumes greater than intended, while the glass capillary tube and the plastic pipette transferring less volume than intended or none at all. Varying the blood volume delivered to RDTs indicated that this variation is critical to RDT sensitivity only when the transferred volume is very low. Conclusion None of the blood transfer devices assessed performed consistently well. Adequate training on their use is clearly necessary, with more development efforts for improved designs to be used by remote health workers, in mind.

  7. Prediction methods for blood glucose concentration design, use and evaluation

    CERN Document Server

    Jørgensen, John; Renard, Eric; Re, Luigi

    2016-01-01

    This book tackles the problem of overshoot and undershoot in blood glucose levels caused by delay in the effects of carbohydrate consumption and insulin administration. The ideas presented here will be very important in maintaining the welfare of insulin-dependent diabetics and avoiding the damaging effects of unpredicted swings in blood glucose – accurate prediction enables the implementation of counter-measures. The glucose prediction algorithms described are also a key and critical ingredient of automated insulin delivery systems, the so-called “artificial pancreas”. The authors address the topic of blood-glucose prediction from medical, scientific and technological points of view. Simulation studies are utilized for complementary analysis but the primary focus of this book is on real applications, using clinical data from diabetic subjects. The text details the current state of the art by surveying prediction algorithms, and then moves beyond it with the most recent advances in data-based modeling o...

  8. The measurement of blood speed in the pulmonary artery trunk

    International Nuclear Information System (INIS)

    The paper describes a non invasive methodology for the measurement of blood speed in the pulmonary artery trunk. The methodology has been tested with a moving radioactive tracer (nuclear medicine). An image processing technique is proposed, for detection and analysis of a moving object with variable shape and intensity over time (radioactive bolus). Experiments on the application of the technique in nuclear medicine are critically analysed. (authors)

  9. Measurement of oxygen saturation in venous blood by dynamic near IR spectroscopy

    Science.gov (United States)

    Nitzan, Meir; Babchenko, Anatoly; Khanokh, Boris; Taitelbaum, Haim

    2000-04-01

    A method for the measurement of oxygen saturation in the venous blood, SvO2, based on optical measurements of light absorption in the infrared region is presented. The method consists of applying relatively low external pressure of 25 mm Hg on the forearm, thereby increasing the venous blood volume in the tissue, and comparing the light absorption before and after the external pressure application. SvO2 has been determined from light absorption measurements in two wavelengths, before and after the pressure application, using a formula derived for two adjacent wavelengths. The method has been applied to the hands and fingers of 17 healthy male subjects, using wavelengths of 767 and 811 nm. SaO2, the oxygen saturation for arterial blood, was also obtained from photoplethysmographic measurements in these two wavelengths (pulse oximetry) using the same formula. The mean (+/- SD) value of SaO2 was 94.5%(+/- 3.0). The mean value of SvO2 was 86.2%(+/- 4.1) for the finger and 80.0%(+/- 8.2) for the hand. These SvO2 values are reasonable for the finger and the hand where arterio-venous anastomoses exist. The method enables the measurement of SvO2 in the limbs, a parameter which is related to tissue blood flow and oxygen consumption.

  10. Non-invasive assessment of arterial stiffness using oscillometric blood pressure measurement

    Directory of Open Access Journals (Sweden)

    Komine Hidehiko

    2012-02-01

    Full Text Available Abstract Background Arterial stiffness is a major contributor to cardiovascular diseases. Because current methods of measuring arterial stiffness are technically demanding, the purpose of this study was to develop a simple method of evaluating arterial stiffness using oscillometric blood pressure measurement. Methods Blood pressure was conventionally measured in the left upper arm of 173 individuals using an inflatable cuff. Using the time series of occlusive cuff pressure and the amplitudes of pulse oscillations, we calculated local slopes of the curve between the decreasing cuff pressure and corresponding arterial volume. Whole pressure-volume curve was derived from numerical integration of the local slopes. The curve was fitted using an equation and we identified a numerical coefficient of the equation as an index of arterial stiffness (Arterial Pressure-volume Index, API. We also measured brachial-ankle (baPWV PWV and carotid-femoral (cfPWV PWV using a vascular testing device and compared the values with API. Furthermore, we assessed carotid arterial compliance using ultrasound images to compare with API. Results The slope of the calculated pressure-volume curve was steeper for compliant (low baPWV or cfPWV than stiff (high baPWV or cfPWV arteries. API was related to baPWV (r = -0.53, P r = -0.49, P r = 0.32, P Conclusions These results suggest that our method can simply and simultaneously evaluate arterial stiffness and blood pressure based on oscillometric measurements of blood pressure.

  11. Continuous blood pressure measurement using the pulse transit time: Comparison to intra-arterial measurement.

    Science.gov (United States)

    Patzak, Andreas; Mendoza, Yuri; Gesche, Heiko; Konermann, Martin

    2015-01-01

    Continuous blood pressure (BP) measurement allows the investigation of transient changes in BP and thus may give insights into mechanisms of BP control. We validated a continuous, non-invasive BP measurement based on the pulse transit time (PTT), i.e., BP(PTT), by comparing it with the intra-arterial BP (BP(i.a.)) measurement. Twelve subjects (five females and seven males) were included. BP(i.a.) was obtained from the radial artery using a system from ReCor Medical. Systolic and diastolic BP were calculated using the PTT (BP(PTT), SOMNOscreen). (PTT) was determined from the electrocardiogram and the peripheral pulse wave. The BP was modulated by application of increasing doses of dobutamine (5, 10, 20 μg/kg body mass). Systolic BP(PTT) and systolic BP(i.a.) correlated significantly (R = 0.94). The limits of agreement in the Bland-Altman plot were ± 19 mmHg; the mean values differed by 1 mmHg. The correlation coefficient for the diastolic BP measurements was R = 0.42. The limits of agreement in the Bland-Altman plot were ± 18 mmHg, with a mean difference of 5 mmHg in favour of the BP(PTT). The study demonstrates a significant correlation between the measurement methods for systolic BP. The results encourage the application of PTT-based BP measurement for the evaluation of BP dynamics and pathological BP changes. PMID:25857601

  12. Evaluation of two methods of rapid blood-glucose monitoring by unskilled personnel during surgery

    DEFF Research Database (Denmark)

    Madsbad, S; Adelhøj, B; Bigler, Dennis Richard;

    1984-01-01

    % of the readings below laboratory values -20%. All situations with severe hypoglycaemia were detected with both strips. The study also demonstrates the ineffectiveness of s.c. insulin regimens during surgery. Only 47% of the measured blood glucose values were within the range of 5.5-10 mmol/l and two......The accuracy of two rapid methods of blood-glucose monitoring without (Haemo-glucotest 1-44) and with a reflectance meter (Hypocount B) was compared using a laboratory method. The assessment was carried out by personnel with no previous experience in measuring blood glucose. Eighty-five percent of...... the 92 measurements obtained with the hypocount B were within +/- 20% of the laboratory glucose values. Using haemo-glucotest 1-44 strips, 74% of the readings were within +/- 20% of the reference laboratory values. For values below 5.5 mmol/l, there was a tendency for results to be too low, with 77...

  13. Non-invasive measurement of the blood pressure pulse using multiple PPGs

    Science.gov (United States)

    Seymour, John; Pennington, Gary

    Heart disease, the leading cause of death in the US, may be spotted early on by looking at photoplethysmogram (PPG) data. This experiment explores a new method of continuously monitoring the blood pressure pulse with PPG data. In contrast to the traditional sphygmomanometer (cuff) method, which yields only the systolic and diastolic pressure during measurement, this method tracks the blood pressure pulse wave in a non-invasive continuous manner. This procedure allows for fast, inexpensive, and detailed analysis of the patient's blood pressure implementable on a large scale. We also explore the second derivative of the PPG data. In combination with the above method, the patient's heart risk can be effectively detected. We acknowledge Fisher Endowment Grant support from the Jess and Mildred Fisher College of Science and Mathematics, Towson University.

  14. Evaluation of a method for determination of the subcutaneous blood flow in the forefoot continuously over 24 h

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Bülow, J

    1984-01-01

    A method is presented which allows for continuous registration of forefoot blood flow over 24 h. Blood flow was estimated by the radioactive Xenon washout method and a portable CdTe detector system was used to measure the tracer disappearance rate. Since the semiconductor detector is placed very...

  15. Doppler ultrasound compared with strain gauge for measurement of systolic ankle blood pressure

    DEFF Research Database (Denmark)

    Joensen, Jette Bang; Juul, Søren; Abrahamsen, Jimmi;

    2012-01-01

    This study assesses measurement variation in the measurement of ankle systolic blood pressure (ABP) when measured with Doppler ultrasound and with the strain gauge method. Ninety-seven patients were included. ABP was measured with Doppler ultrasound and with the strain gauge method. The methods...... were compared graphically by scatterplots and analyzed by paired t test, analysis of variance, and Pitman's paired variance ratio test. ABP was measured by strain gauge in all extremities, whereas no Doppler signal was obtainable in 7 limbs (4%). There was no systematic difference in measurements...... between the means of the two measurements. However, a substantial difference of more than 25 mm Hg was found in 15% of limbs and more than 20 mm Hg in 20%. In the majority of patients, measurements of ABP by Doppler ultrasound and the strain gauge method give similar results, but for a minority the...

  16. Definition, significance and measurement of quantities pertaining to the oxygen carrying properties of human blood

    NARCIS (Netherlands)

    Zijlstra, WG; Maas, AHJ; Moran, RF

    1996-01-01

    A consistent set of definitions is given of the principal quantities pertaining to the oxygen transport by the blood, and of their mutual relationships, in relation to the methods used in their measurement. At the core is the correct definition of oxygen saturation, the deviation of which has recent

  17. Comparison of three measures of the ankle-brachial blood pressure index in a general population

    OpenAIRE

    Pan, Cheng-Rui; Staessen, Jan A.; Li, Yan; Wang, Ji-Guang

    2007-01-01

    The ankle-brachial blood pressure index (ABI) predicts cardiovasular disease. To our knowledge, no study has compared manual ABI measurements with an automated electronic oscillometric method in a population sample. We enrolled 946 residents (50.8% women; mean age, 43.5 years) from 8 villages in JingNing County, Zhejiang Province, P.R. China. We computed ABI as the ratio of ankle-to-arm systolic blood pressures from consecutive auscultatory or Doppler measurements at the posterior tibial and ...

  18. Blood pressure measurement: lessons learned from our ancestors.

    Science.gov (United States)

    Karamanou, Marianna; Papaioannou, Theodore G; Tsoucalas, Gregory; Tousoulis, Dimitris; Stefanadis, Christodoulos; Androutsos, George

    2015-01-01

    The profound observations of William Harvey (1578-1657), in blood circulation and the progress of physical science laid the foundation for the development of the Iatrophysical School that contributed to the evolution of clinical sphygmomanometry. The pioneer work of Reverend Stephen Hales (1677-1761) demonstrated the dynamics of the vascular system. One century later the French physician Jean-Léonard-Marie Poiseuille (1797-1867) invented a U-tube mercury manometer and in 1860 the physiologist Etienne- Jules Marey (1830-1904) devised the first portable sphygmograph for recording the pulse wave. The non-invasive techniques of blood pressure measurement were completed by Scipione Riva-Rocci (1896-1937) sphygmomanometer and the description of "Korotkov sounds" by the Russian surgeon Nikolai- Sergeyevich Korotkov (1874-1920). PMID:25341864

  19. Sensorless Viscosity Measurement in a Magnetically-Levitated Rotary Blood Pump.

    Science.gov (United States)

    Hijikata, Wataru; Rao, Jun; Abe, Shodai; Takatani, Setsuo; Shinshi, Tadahiko

    2015-07-01

    Controlling the flow rate in an implantable rotary blood pump based on the physiological demand made by the body is important. Even though various methods to estimate the flow rate without using a flow meter have been proposed, no adequate method for measuring the blood viscosity, which is necessary for an accurate estimate of the flow rate, without using additional sensors or mechanisms in a noninvasive way, has yet been realized. We have developed a sensorless method for measuring viscosity in magnetically levitated rotary blood pumps, which requires no additional sensors or mechanisms. By applying vibrational excitation to the impeller using a magnetic bearing, we measured the viscosity of the working fluid by measuring the phase difference between the current in the magnetic bearing and the displacement of the impeller. The measured viscosity showed a high correlation (R(2)  > 0.992) with respect to a reference viscosity. The mean absolute deviation of the measured viscosity was 0.12 mPa·s for several working fluids with viscosities ranging from 1.18 to 5.12 mPa·s. The proposed sensorless measurement method has the possibility of being utilized for estimating flow rate. PMID:25920684

  20. Correlation of Insulin Resistance with Anthropometric Measures and Blood Pressure in Adolescents

    Science.gov (United States)

    de Morais, Polyana Resende Silva; Sousa, Ana Luiza Lima; Jardim, Thiago de Souza Veiga; Nascente, Flávia Miquetichuc Nogueira; Mendonça, Karla Lorena; Povoa, Thaís Inácio Rolim; Carneiro, Carolina de Souza; Ferreira, Vanessa Roriz; de Souza, Weimar Kunz Sebba Barroso; Jardim, Paulo César Brandão Veiga

    2016-01-01

    Background Blood pressure is directly related to body mass index, and individuals with increased waist circumference have higher risk of developing hypertension, insulin resistance, and other metabolic changes, since adolescence. Objective to evaluate the correlation of blood pressure with insulin resistance, waist circumference and body mass index in adolescents. Methods Cross-section study on a representative sample of adolescent students. One group of adolescents with altered blood pressure detected by casual blood pressure and/or home blood pressure monitoring (blood pressure > 90th percentile) and one group of normotensive adolescents were studied. Body mass index, waist circumference were measured, and fasting glucose and plasma insulin levels were determined, using the HOMA-IR index to identify insulin resistance. Results A total of 162 adolescents (35 with normal blood pressure and 127 with altered blood pressure) were studied; 61% (n = 99) of them were boys and the mean age was 14.9 ± 1.62 years. Thirty-eight (23.5%) adolescents had altered HOMA-IR. The group with altered blood pressure had higher values of waist circumference, body mass index and HOMA-IR (p<0.05). Waist circumference was higher among boys in both groups (p<0.05) and girls with altered blood pressure had higher HOMA-IR than boys (p<0.05). There was a significant moderate correlation between body mass index and HOMA-IR in the group with altered blood pressure (ρ = 0.394; p < 0.001), and such correlation was stronger than in the normotensive group. There was also a significant moderate correlation between waist circumference and HOMA-IR in both groups (ρ = 0.345; p < 0.05). Logistic regression showed that HOMA-IR was as predictor of altered blood pressure (odds ratio - OR = 2.0; p = 0.001). Conclusion There was a significant association of insulin resistance with blood pressure and the impact of insulin resistance on blood pressure since childhood. The correlation and association between

  1. Noninvasive measurement of nutrient portal blood shunting: an experimental study with [14C]ursodeoxycholic acid

    International Nuclear Information System (INIS)

    All of the methods proposed for measuring portal blood flow are either invasive, estimate total rather than nutrient flow, and none has proved reliable in cirrhotic patients. A method has been derived from pharmacokinetic principles used for the calculation of bioavailability of drugs according to the route of administration (i.v. or p.o.) and tested experimentally in 20 pigs. A tracer dose of [14C]ursodeoxycholic acid, a biliary acid with a high-liver first-pass effect, is administered in the duodenum, and serial peripheral blood samples are taken. Later, the same dose of the same drug is administered i.v. The shunt fraction of portal blood F is obtained by the ratio of the areas under the plasma level vs. time curves (AUC) after p.o. and i.v. administrations: (see formula in text). The pigs were divided into three experimental groups. (i) Group I: undisturbed portal flow; (ii) Group II: total diversion of portal blood with an end-to-side portacaval shunt, and (iii) Group III: partial diversion of portal blood through a side-to-side portacaval shunt. Portal flow was measured during surgery with an electromagnetic flowmeter above and below the shunt and the degree of shunting calculated. Results show that the shunt fraction measured with ursodeoxycholic acid is well-correlated with hemodynamic data. No overlap between Groups I and III is observed. It is concluded that the shunt fraction of nutrient portal blood can be measured with this noninvasive method. Minute amounts of ursodeoxycholic acid were used in order to be completely metabolized by the liver, even in spite of hepatocellular dysfunction. Therefore, this method should be valid in cirrhotic patients and be useful to decide the type of portasystemic shunt to propose for the decompression of gastroesophageal varices

  2. Triangulation methods in engineering measurement

    OpenAIRE

    Kyle, S. A.

    1988-01-01

    Industrial surveying and photogrammetry are being increasingly applied to the measurement of engineering objects which have typical dimensions in the range 2-100 metres. Both techniques are examples of the principle of triangulation. By applying photocrammetric concepts to surveying methods and vice-versa, a general approach is established which has a number of advantages. In particular. alternative strategies for constructing and analysing measurement networks are dev...

  3. Radiation protection, measurements and methods

    International Nuclear Information System (INIS)

    The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP)

  4. Exploration of nurses' knowledge regarding correct way of blood pressure measurement

    Directory of Open Access Journals (Sweden)

    Paraskeui Gourni

    2011-01-01

    Full Text Available Blood pressure (BP measurement by the use of sphygmomanometer and auscultation of brachial artery by stethoscope is the most widespread way of measurement in daily clinical practice. The aim of the present study was to explore nurses' knowledge regarding correct way of measurement of blood pressure by the use of a sphygmomanometer. Method and material: The sample –studied consisted of individuals from all levels of nursing personnel. Data were collected by the use the completion of a specially designed questionnaire which apart from demographic variables, it included items concerning knowledge about the correct way of blood pressure measurement. Results: From the 360 participants, 88% (316 were women, while the mean age of the sample-studied was 36,1 years old. 51,4% of the sample-studied was of tertiary education. In terms of the knowledge of participants, 79,6% knew the correct preparation, 98,6% knew that arm position for blood pressure measurement should be on a pillow or a side table and the 94,8% knew the back should be supported on a chair back. 60,9% of the sample-studied knew that at first time, blood pressure (BP should be measured in both arms, while 45,9% didn't know that BP should be measured in arm with higher measurement. 78,2% of the participants knew that the correct measurement includes the use of sphygmomanometer and auscultation of brachial artery by stethoscope. 67,9% knew that body and arm position should be in ankle of 45o degrees and that the cuff should be placed around the upper arm at the same vertical height as the heart. 59,8% knew that the cuff should be placed 2-3 cm above the point of auscultation of brachial artery. 45,1% considered that the arm cuff should be inflated manually until when the height of the column of mercury approaches 200 mmHg. 52,3% knew the correct rhythm (2-3 mmHg/sec that the pressure in the cuff should be released. 88,4% knew the sounds corresponding to the measurement of Systolic blood

  5. Applicability of available methods for incidence estimation among blood donors

    Institute of Scientific and Technical Information of China (English)

    Shtmian Zou; Edward P.Notari IV; Roger Y.Dodd

    2010-01-01

    @@ Abstract Incidence rates of major transfusion transmissible viral infections have been estimated threugh widely used sereconversion approaches and recently developed methods.A quality database for blood donors and donations with the capacity to track donation history of each donor is the basis for incidence estimation and many other epidemiological studies.Depending on available data,difierent ways have been used to determine incidence rates based on conversion from uninfected to infected status among repeat donors.

  6. Monitoring cerebral blood flow during intracranial operations: an intravenous injection method

    Energy Technology Data Exchange (ETDEWEB)

    Wyper, D.J.; Pickard, J.D.; Acar, U.

    1979-01-01

    A method of measuring cerebral blood flow during neurosurgery is described. It is an adaptation of the standard 133Xe intravenous injection method, with computation restricted to data collected over the first 3 min. In addition to a theoretical presentation of a method and an analysis of the effect of residual 133Xe activity when sequential runs are performed in close approximation, the technique is validated experimentally by comparison with intracarotid 133Xe injection in baboons.

  7. A venous outflow method for continuously monitoring cerebral blood flow in the rat.

    Science.gov (United States)

    Morii, S; Ngai, A C; Ko, K R; Winn, H R

    1986-02-01

    We analyzed the retroglenoid venous outflow (VOF) technique in the rat to document the validity of this method of measuring cerebral blood flow (CBF). Stereotypic changes in CBF were obtained with VOF during hypercarbia and hypotension. O2 content of retroglenoid venous blood did not differ significantly from O2 content of blood obtained from the sagittal sinus, suggesting minimal extracerebral contamination of the retroglenoid venous blood. This lack of extracerebral contamination was further analyzed using a double tracer technique (125I-labeled serum albumin, 22Na) that quantitated minimal extracerebral contamination in the retroglenoid vein. CBF measurements were made simultaneously using microsphere and VOF methods, and excellent correlation was found between the two techniques over a wide range of CBF during normoxia, hypoxia, and normoxic hypocarbia and hypercarbia. However, a decrease in the ratio of VOF to microsphere CBF was observed during severe normoxic hypotension (mean arterial pressure = 41 +/- 4 mmHg). VOF represented 18% of total CBF as measured by microsphere method. This study indicates that the retroglenoid outflow technique in rats is a valid method of measuring CBF. PMID:3080902

  8. Non Invasive Measurement of Systolic Blood Pressure in Rats: A Simple Technique

    Directory of Open Access Journals (Sweden)

    Maria Pauline

    2011-10-01

    Full Text Available Background: Non invasive, simple and economical instrument to measure blood pressure in r365-ats is important in cardiovascular research. Methods: Systolic blood pressure measuring instrument was fabricated using a tail cuff, photoplethysmograph, pressure transducer and PC with Biopac Software for recording. Tail cuff was used to occlude the tail artery, photoplethysmograph picked the blood flow pulses in the rat tail and the pressure transducer measured the cuff pressure and converted it into analog voltage. PPG signals were converted into voltage and amplified by the recording system with two channel amplifiers and in addition it also amplified analog voltage converted by the pressure transducer. Results: Calibration of the instrument entailed a simple Bland Altman’s plot of pressure recorded as voltage changes against pressure changes in the mercury sphygmomanometer which is considered as gold standard. A regression value of r=0.9 and p=0.00 was obtained. A pilot study was done on ten female rats. Three blood pressure readings were taken on two occasions. Between - animal variation of BP was 123±7 (mean SD, CV=5.9% and within - animal variation of BP was 120 ±7, CV=5.5%. Conclusion: The tail cuff and PPG based technique to measure systolic blood pressure in rats is simple, economic, accurate and reliable.

  9. Measurement of red blood cell mechanics during morphological changes

    Science.gov (United States)

    Popescu, Gabriel; Park, Yongkeun; Best, Catherine; Dasari, Ramachandra; Feld, Michael; Kuriabova, Tatiana; Henle, Mark; Levine, Alex

    2010-03-01

    The human red blood cell (RBC) membrane, a fluid lipid bilayer tethered to an elastic 2D spectrin network, provides the principal control of the cell's morphology and mechanics. These properties, in turn, influence the ability of RBCs to transport oxygen in circulation. Current mechanical measurements of RBCs rely on external loads. Here we apply a Noncontact optical interferometric technique to quantify the thermal fluctuations of RBC membranes with 3 nm accuracy over a broad range of spatial and temporal frequencies. Combining this technique with a new mathematical model describing RBC membrane undulations, we measure the mechanical changes of RBCs as they undergo a transition from the normal discoid shape to the abnormal echinocyte and spherical shapes. These measurements indicate that, coincident with this morphological transition, there is a significant increase in the membrane's shear and bending moduli. This mechanical transition can alter cell circulation and impede oxygen delivery.

  10. Biviscous blood flow and a new method for velocity profile adjustment

    Science.gov (United States)

    Velazquez, Carlos; Reyes, Adrian

    2015-03-01

    In this paper we describe our proposal of a new numerical procedure for the adjusting of the velocity profile of body fluids with two viscosities. We have focused on the relevant case of the human blood and we have selected a particular model, the biviscous blood model, with the purpose of proving the convenience of our method. We start by describing the convenience of the biviscous stress equation as a model for the blood constitutive equation, then we solve it in the particular case of a stationary flow and use this solutions as the basis of our numerical procedure, which is described afterwards. Then, we present its implementation for analyzing in vivo measurements and exhibit its pertinence. Finally, we explain the design of a programmatic code of an automatic routine which is capable of applying our method and therefore could be used as the basis of an automatic implementation in new diagnosis software within a measurement device.

  11. Sensitivity measures in probabilistic methods

    International Nuclear Information System (INIS)

    The probabilistic methods used in Structural Reliability studies are aimed at I assessing failure probabilities or variable distributions as a function of the input random variables of a model. To quantify the impact of input uncertainties, two main sensitivity study methods, implemented in the PROBAN software structural are available. One measures the sensitivity of ''target'' values to input parameters, whilst the other, which is a typical reliability tool, assesses the stochastic importance of the input variables. These sensitivity measures reveal the impact of change on parameter values. Importance measures are used to restrict the number of initial random variables, thereby improving concentration on major uncertainties. This paper describes the two techniques using methodological examples and presents their main advantages. (author). 13 refs., 13 figs., 8 tabs., 3 appends

  12. Context-aware patient guidance during blood pressure self-measurement

    DEFF Research Database (Denmark)

    Sandager, Puk; Lindahl, Camilla; Schlütter, Jacob Mørup;

    2013-01-01

    The importance of accurate measurement of blood pressure in the screening and management of hypertension during pregnancy is well established. Blood pressure levels can be measured manually by healthcare staff or by using a blood pressure self-measurement device, either at home or in the clinic. In...... blood pressure self-measurement process. Preliminary results indicate that such active and context-aware guidance leads to more reliable measurements by inhibiting non-adherent patient behavior...

  13. Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD.

    Science.gov (United States)

    Sun, Wei; Kechris, Katerina; Jacobson, Sean; Drummond, M Bradley; Hawkins, Gregory A; Yang, Jenny; Chen, Ting-Huei; Quibrera, Pedro Miguel; Anderson, Wayne; Barr, R Graham; Basta, Patricia V; Bleecker, Eugene R; Beaty, Terri; Casaburi, Richard; Castaldi, Peter; Cho, Michael H; Comellas, Alejandro; Crapo, James D; Criner, Gerard; Demeo, Dawn; Christenson, Stephanie A; Couper, David J; Curtis, Jeffrey L; Doerschuk, Claire M; Freeman, Christine M; Gouskova, Natalia A; Han, MeiLan K; Hanania, Nicola A; Hansel, Nadia N; Hersh, Craig P; Hoffman, Eric A; Kaner, Robert J; Kanner, Richard E; Kleerup, Eric C; Lutz, Sharon; Martinez, Fernando J; Meyers, Deborah A; Peters, Stephen P; Regan, Elizabeth A; Rennard, Stephen I; Scholand, Mary Beth; Silverman, Edwin K; Woodruff, Prescott G; O'Neal, Wanda K; Bowler, Russell P

    2016-08-01

    Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10-392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the

  14. Validation of an optical flow algorithm to measure blood flow waveforms in arteries using dynamic digital x-ray images

    Science.gov (United States)

    Rhode, Kawal; Lambrou, Tryphon; Hawkes, David J.; Hamilton, George; Seifalian, Alexander M.

    2000-06-01

    We have developed a weighted optical flow algorithm for the extraction of instantaneous blood velocity from dynamic digital x-ray images of blood vessels. We have carried out in- vitro validation of this technique. A pulsatile physiological blood flow circuit was constructed using sections of silicone tubing to simulate blood vessels with whole blood as the fluid. Instantaneous recording of flow from an electromagnetic flow meter (EMF) provided the gold standard measurement. Biplanar dynamic digital x-ray images of the blood vessel with injection of contrast medium were acquired at 25 fps using a PC frame capture card. Imaging of a Perspex calibration cube allowed 3D reconstruction of the vessel and determination of true dimensions. Blood flow waveforms were calculated off-line on a Sun workstation using the new algorithm. The correlation coefficient between instantaneous blood flow values obtained from the EMF and the x-ray method was r equals 0.871, n equals 1184, p less than 0.0001. The correlation coefficient for average blood flow was r equals 0.898, n equals 16, p less than 0.001. We have successfully demonstrated that our new algorithm can measure pulsatile blood flow in a vessel phantom. We aim to use this algorithm to measure blood flow clinically in patients undergoing vascular interventional procedures.

  15. Hall effect in electrolyte flow measurements: introduction to blood flow measurements.

    Science.gov (United States)

    Szwast, Maciej; Piatkiewicz, Wojciech

    2012-06-01

    The Hall effect has been applied to electrolyte flow measurement. It has been proven that Hall voltage does not depend on electrolyte concentration; however, there is a linear relationship between Hall voltage and flow velocity. Obtained results for electrolyte allow us to suppose that Hall effect can be used to determine blood flow. Research on blood will be conducted as the next step. PMID:22145845

  16. Pulse measurement apparatus and method

    Science.gov (United States)

    Marciante, John R.; Donaldson, William R.; Roides, Richard G.

    2011-10-25

    An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses. An embodiment of the invention is directed to a method for increasing the dynamic range of a pulse measurement by a repetitively-gated electronic sampling device having a rated dynamic range capability, beyond the rated dynamic range of the sampling device; e.g., enhancing the dynamic range of an oscilloscope. The embodied technique can improve the SNR from about 300:1 to 1000:1. A dynamic range enhancement of four to seven bits may be achieved.

  17. Forty Cases of Tumorous Fever Treated with TCM Method of Removing Blood Heat and Dissipating Blood Stasis

    Institute of Scientific and Technical Information of China (English)

    Jia Yantao; Chen Liang; Jia Yingjie; Sun Yiyu; Chen Jun

    2006-01-01

    @@ The TCM method of removing blood heat and dissipating blood stasis, originated in Treatise on Epidemic Febrile Diseases (温热论) by ancient physician Ye Tianshi (叶天士), was adopted for the cases of epidemic febrile diseases with pathogenic heat invading the ying-blood system. We take this therapeutic method to treat 40 cases of tumorous fever with rather good effect. A report follows.

  18. Measurement of local cerebral blood flow with (/sup 14/C)iodoantipyrine in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Jay, T.M.; Lucignani, G.; Crane, A.M.; Jehle, J.; Sokoloff, L.

    1988-02-01

    Local cerebral blood flow was measured in the mouse by means of the (/sup 14/C)iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the (/sup 14/C)iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the (/sup 14/C)iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

  19. Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

    International Nuclear Information System (INIS)

    Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

  20. An investigation of methods for enriching trophoblast from maternal blood.

    Science.gov (United States)

    Johansen, M; Knight, M; Maher, E J; Smith, K; Sargent, I L

    1995-10-01

    Trophoblast deportation is known to occur in normal human pregnancy, but it is not yet clear whether these cells routinely enter the maternal peripheral circulation and are available as a source of fetal DNA for non-invasive prenatal diagnosis of genetic disorders. To resolve this issue requires an efficient method of enriching trophoblast from maternal blood combined with a means to confirm its identity. Five different techniques were tested on ten retroplacental blood samples to determine the most sensitive and operator-efficient method. Lysis of red cells alone gave the best recovery of trophoblast but had to be discounted, together with Ficoll density gradient centrifugation, due to the very low purity and the excessive time required. Fluorescence-activated cell sorting (FACS) of pre-enriched trophoblast resulted in the lowest recovery rate (8 per cent) despite a 3250-fold enrichment and a very high purity. Immunomagnetic beads (Dynabeads) coated with anti-CD16 antibody proved to be the best method for the subsequent immunocytochemical characterization of deported trophoblast. However, IO beads coated with anti-CD45 antibody may be more useful for isolating trophoblast for prenatal diagnosis due to the high purity, enrichment (32-fold), and recovery rate (78 per cent) obtained with this method. PMID:8587860

  1. Quantitative measurement of cerebral blood flow on patients with early syphilis

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ji-Jun; WU Jin-Chang; YANG Yi; TANG Jun; LIU Zeng-Li; SHI Xin

    2005-01-01

    To study quantitative change of cerebral blood flow (CBF) on patients with early syphilis, we have established a method on absolute measurement of rCBF by using SPECT with Ethyl Cysteinate Dimmer (ECD) as imaging agent, and the method was applied to measure rCBF on patients with early syphilis. The rCBF values measured by this method are highly consistent with the values measured by other classical methods such as SPECT (123I-IMP) and PET (15O-H2O). The rCBF values for early syphilis patients and the normal control show some statistical differences.A routine quantitative absolute measurement of rCBF featured with simple procedures is therefore on the way of maturation.

  2. Quantitative measurement of cerebral blood flow on patients with early syphilis

    International Nuclear Information System (INIS)

    To study quantitative change of cerebral blood flow (CBF) on patients with early syphilis, the authors have established a method on absolute measurement of rCBF by using SPECT with Ethyl Cysteinate Dimmer (ECD) as imaging agent, and the method was applied to measure rCBF on patients with early syphilis. The rCBF values measured by this method are highly consistent with the values measured by other classical methods such as SPECT (123I-IMP) and PET(15O-H2O). The rCBF values for early syphilis patients and the normal control show some statistical differences. A routine quantitative absolute measurement of rCBF featured with simple procedures is therefore on the way of maturation. (authors)

  3. Measurement of Placental Blood Flow with 133Xe in Normal and Pathological Human Pregnancy

    International Nuclear Information System (INIS)

    Most authors agree that changes in placental circulation play an important part in the genesis of chronic foetal disorders. However, until recently there was no technique by which a quantitative evaluation of placental haemodynamics could be obtained. Our method of measuring placental blood flow represents one application of the use of radioisotopes for measurements of local blood flows. We use 133Xe in solution in physiological serum. This radioactive gas has the advantage of being inert and instantly diffusible. After radiographic or ultrasonic localization of the placenta, 50 μCi of xenon are injected into it transabdominally. A scintillation detector is used to take the 133Xe clearance curve, which is recorded simultaneously on a linear writer and transmitted to a computer. We have made 111 measurements of placental blood flow - 45 in normal pregnancy, 59 in pathological pregnancy and 7 after perfusion of medication. The measurements made it possible to obtain, for the first time, a quantitative evaluation of placental blood flow in women. The value found for normal pregnancies between the thirty-second and the forty-first weeks was 145 ml/100 g per min. The measurements carried out in pathologically pregnant patients (with arterial hypertension, dysgravidity, urinary infection, diabetes, prolonged pregnancy) showed that such pregnancies are accompanied by a statistically significant diminution of placental blood flow, and that the magnitude of this diminution has a bearing on the clinical condition and the state of the child at birth. This method of measurement, which is easily reproducible in the same patient, is accordingly of interest from two points of view. As far as theoretical studies are concerned, it has made possible a quantitative evaluation of placental blood flow and has supplied proof that the maternal disorders which give rise to chronic foetal disorders are usually accompanied by a diminution in placental blood flow. From the practical

  4. Method for breast cancer diagnosis by phase spectrophotometry of human blood plasma

    Science.gov (United States)

    Mintser, Ozar P.; Oliinychenko, B. P.

    2012-01-01

    The possibility of breast cancer diagnostics by means of phase structure measurements of laser radiation transformed by human blood plasma samples. The theoretical fundamentals of polarization filtration method for direct phase shifts measurements of microscopic images are provided. The optical model of polycrystalline networks of blood plasma proteins is suggested. The results of investigating the interrelation between the values of statistical (statistical moments of the 1st-4th order), correlation (correlation area, asymmetry coefficient and autocorrelation function excess) and fractal (dispersion of logarithmic dependencies of power spectra) parameters are presented. They characterize the coordinate distributions of phase shifts between the orthogonal components of the amplitude in the points of laser images of blood plasma smears and pathological changes in the mammary gland tissue. The diagnostic criteria of breast cancer nascency are determined.

  5. Blood safety measures and the role of central blood institute in Japan

    Institute of Scientific and Technical Information of China (English)

    Kenji Tadokoro

    2010-01-01

    @@ 1 Japanese Blood Programme Japanese Red Cross Blood Service is the sole conductor of blood service in Japan. It collects 5.3 million volun-tary non-remunerated donations from 127 million popu-lations and distributes 18 million units ( one unit = 200 ml,2 million Liter) blood matching the medical needs.A part of plasma is supplied to the JRCBS fractionation center and other 3 commercial manufacturers for pro-duction of plasma derivatives.

  6. Health economics and outcomes methods in risk-based decision-making for blood safety.

    Science.gov (United States)

    Custer, Brian; Janssen, Mart P

    2015-08-01

    Analytical methods appropriate for health economic assessments of transfusion safety interventions have not previously been described in ways that facilitate their use. Within the context of risk-based decision-making (RBDM), health economics can be important for optimizing decisions among competing interventions. The objective of this review is to address key considerations and limitations of current methods as they apply to blood safety. Because a voluntary blood supply is an example of a public good, analyses should be conducted from the societal perspective when possible. Two primary study designs are recommended for most blood safety intervention assessments: budget impact analysis (BIA), which measures the cost to implement an intervention both to the blood operator but also in a broader context, and cost-utility analysis (CUA), which measures the ratio between costs and health gain achieved, in terms of reduced morbidity and mortality, by use of an intervention. These analyses often have important limitations because data that reflect specific aspects, for example, blood recipient population characteristics or complication rates, are not available. Sensitivity analyses play an important role. The impact of various uncertain factors can be studied conjointly in probabilistic sensitivity analyses. The use of BIA and CUA together provides a comprehensive assessment of the costs and benefits from implementing (or not) specific interventions. RBDM is multifaceted and impacts a broad spectrum of stakeholders. Gathering and analyzing health economic evidence as part of the RBDM process enhances the quality, completeness, and transparency of decision-making. PMID:25855475

  7. Blood doping by cobalt. Should we measure cobalt in athletes?

    Directory of Open Access Journals (Sweden)

    Guidi Gian

    2006-07-01

    Full Text Available Abstract Background Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Presentation of the hypothesis Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Testing the hypothesis Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Implications of the hypothesis Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice

  8. [Personal protection measures against blood-sucking insects and ticks].

    Science.gov (United States)

    Orshan, Laor; Wilamowski, Amos; Pener, Hedva

    2010-09-01

    Blood-sucking arthropods are major vectors of various pathogens like viruses, bacteria, protozoa and nematodes. Preventing exposure to the vector is imperative especially when vaccine and prophylactic treatments are not available. Personal protection measures (PPM) are essential and often the only means available when dealing with blood-sucking disease transmitting arthropods. Awareness of the risk in the specific areas of travel is the first step to be taken before and while traveling. PPM include preventive personal behavior, suitable clothing, application of insect repellents to the skin, the use of space repellents, impregnation of clothing, camping gear and bed nets and, when necessary, ground spraying of insecticides. The registered and recommended active ingredients for skin application are Deet, picaridin (icaridin), p-menthane-3,8-diol (PMD) and IR3535. Volatile pyrethrins are used as space repellents while pyrethroids, especially permethrin, are employed for impregnation and for ground spraying. It is recommended to purchase only products registered in Israel or other developed countries. These products should have a detailed label specifying the concentration of the active ingredient, application instructions and the duration of protection. PMID:21302476

  9. Numerical method of characteristics for one-dimensional blood flow

    CERN Document Server

    Acosta, Sebastian; Riviere, Beatrice; Penny, Daniel J; Rusin, Craig G

    2014-01-01

    Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally intensive methods like finite elements and discontinuous Galerkin, while some recent applications require more efficient approaches (e.g. for real-time clinical decision support, phenomena occurring over multiple cardiac cycles, iterative solutions to optimization/inverse problems, and uncertainty quantification). Further, the high speed of pressure waves in blood vessels greatly restricts the time-step needed for stability in explicit schemes. We address both cost and stability by presenting an efficient and unconditionally stable method for approximating solutions to diagonal nonlinear hyperbolic systems. Theoretical analysis of the algorithm is given along with a comparison of our method to a discontinuous Galerkin implementation. Lastly, we demonstrate the ...

  10. Estimation of anti-platelet drugs on human platelet aggregation with a novel whole blood aggregometer by a screen filtration pressure method

    OpenAIRE

    Sudo, Toshiki; Ito, Hideki; Ozeki, Yasushi; Kimura, Yukio

    2001-01-01

    The effects of anti-platelet drugs on human whole blood aggregation were evaluated using a novel whole blood aggregometer by a screen filtration pressure (SFP) method.The SFP whole blood aggregometer was found to successfully detect whole blood aggregation induced by ADP, collagen and TRAP by measuring the SFP of blood samples. The platelet aggregation threshold index (PATI), the concentration of agonist required with an inducing pressure rate of 50%, varied time-dependently after collection ...

  11. Methods of speed measurement. Geschwindigkeitsmessverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Baeumer, K.; Rath, K.; Rogge, H.; Wiegand, H.

    1990-09-27

    In a method, i.e. the operation of a device for contactless measurement of speeds, speed-time curves and decay frequencies in liquid jets and flames two light beams emitted by strong light source are focussed in such a way in the measured volume of a fluid layer or flame layer that the light transmission in the measured volume can be measured at a focal distance s by means of two light-sensitive detectors. Speeds and speed-time curves in injection jets and flames can be inferred from the shift in time s of the transmission curves by means of the equation v=s/t. Furthermore, the recorded transmission-time curve can be used for harmonic analysis studies by means of a digital Fourier analysis (FFT analysis). The speed v or, as the case may be, the speed-time curve in the layer of a fluid or flame and the frequencies f determined with the frequency spectrum permit a calculation of the wavelength according to the wave equation =vxf, and this in turn determines the ball size in jets of fluid and flames.

  12. Evaluation Measures and Methods: Some Intersections.

    Science.gov (United States)

    Elliott, John

    The literature is reviewed for four combinations of evaluation measures and methods: traditional methods with traditional measures (T-Meth/T-Mea), nontraditional methods with traditional measures (N-Meth/T-Mea), traditional measures with nontraditional measures (T-Meth/N-Mea), and nontraditional methods with nontraditional measures (N-Meth/N-Mea).…

  13. 133Xenon absorption into rubber-protected portable cadmium telluride (CdTe(Cl)) detectors invalidating the 133Xenon washout method for measurement of cutaneous and subcutaneous blood flow rates in man.

    Science.gov (United States)

    Sørensen, J L

    1991-01-01

    The importance of 133Xenon absorption into rubber detector caps during cutaneous and subcutaneous blood flow measurement was investigated in 46 experiments involving 38 persons. 133Xenon was administered atraumatically. Cutaneous and subcutaneous washout rates were registered by portable Cadmium Telluride detectors without rubber caps, with rubber caps, and with rubber caps with Mylar membranes interposed between the rubber and the tissue investigated. No difference in rate constants obtained by means of various detector types was detected. The accumulation of 133Xenon in the rubber caps was found to take place within the first few minutes after the detectors had been brought into position. The 133Xenon then diffused back into the tissue exhibiting a great variation regarding rate constants. The 133Xenon diffused form rubber into air and perfused tissue tracing a monoexponential course; and again the rate constants would vary considerably. No correlation was found between elimination rates obtained with detectors with and without 133Xenon polluted caps, and no way of correcting for the 133Xenon content in the rubber caps was found. Relative changes in rate constants could still be recognized, but absolute values were not obtainable. PMID:1789123

  14. Measurement of digital blood pressure after local cooling

    DEFF Research Database (Denmark)

    Nielsen, S L; Lassen, N A

    1977-01-01

    A double-inlet plastic cuff was designed for local cooling and systolic blood pressure measurement on the middle phalanx of the fingers. With a tourniquet on the proximal phalanx of one finger, cooling for 5 min made the digital artery temperature equal the skin temperature. The difference between...... the systolic pressure in a control finger and in the cooled finger give the reopening pressure in the digital arteries. At 30, 25, 20, 15, and 10 degrees C, respectively the percent decrease of the finger pressure was 0.2 (0.2), 1.5 (2.5), 8.5 (3.7), 11.4 (3.4), and 15.3 (3.1) in normal young women...

  15. Why some adult Canadians do not have blood pressure measured.

    Science.gov (United States)

    Amankwah, Ernest; Campbell, Norman R C; Maxwell, Colleen; Onysko, Jay; Quan, Hude

    2007-12-01

    Regular blood pressure (BP) measurements are required to identify people with hypertension and to optimally manage their cardiovascular risk. Analyses of data from the 2000-2001 Canadian Community Health Survey showed that most adult Canadians have had a BP assessment in the previous 2 years and few have never had one. Large numbers of persons without BP recordings were observed, however, among persons who were younger, were male, who did not have either a regular doctor or physician contact in the previous year, who were recent immigrants or visible minorities (nonwhite and non-Aboriginal), and who spoke neither French nor English. Common reasons reported for not having a BP assessment included believing it was not necessary and simply not getting around to it. Education programs targeting those at risk as well as more convenient BP screening may improve awareness and testing. PMID:18046100

  16. Measurement of the nonlinear elasticity of red blood cell membranes

    Science.gov (United States)

    Park, Yongkeun; Best, Catherine A.; Kuriabova, Tatiana; Henle, Mark L.; Feld, Michael S.; Levine, Alex J.; Popescu, Gabriel

    2011-05-01

    The membranes of human red blood cells (RBCs) are a composite of a fluid lipid bilayer and a triangular network of semiflexible filaments (spectrin). We perform cellular microrheology using the dynamic membrane fluctuations of the RBCs to extract the elastic moduli of this composite membrane. By applying known osmotic stresses, we measure the changes in the elastic constants under imposed strain and thereby determine the nonlinear elastic properties of the membrane. We find that the elastic nonlinearities of the shear modulus in tensed RBC membranes can be well understood in terms of a simple wormlike chain model. Our results show that the elasticity of the spectrin network can mostly account for the area compression modulus at physiological osmolality, suggesting that the lipid bilayer has significant excess area. As the cell swells, the elastic contribution from the now tensed lipid membrane becomes dominant.

  17. a New Approach of Dynamic Blood Pressure Measurement Based on the Time Domain Analysis of the Pulse Wave

    Science.gov (United States)

    Zimei, Su; Wei, Xu; Hui, Yu; Fei, Du; Jicun, Wang; Kexin, Xu

    2009-08-01

    In this study the pulse wave characteristics were used as a new approach to measure the human blood pressure. Based the principle of pulse wave and theory of the elastic vascular, the authors analyzed the characteristic of the pulse waveforms and revealed the characteristics points which could be used to represent the blood pressure. In this investigation the relevant mathematical feature was used to identify the relationship between the blood pressure and pulse wave parameters in a more accurate way. It also provided an experimental basis to carry out continuing non-invasive blood pressure monitoring using the pulse wave method.

  18. Measuring and communicating blood loss during obstetric hemorrhage.

    Science.gov (United States)

    Gabel, Kristi T; Weeber, Tracy A

    2012-01-01

    Accurate quantification of blood loss is an essential skill necessary to prevent maternal morbidity and mortality associated with obstetric hemorrhage. Visual estimation of blood has been consistently shown to be extremely inaccurate. The nurse plays a pivotal role in quantifying blood loss after birth, recognizing triggers, mobilizing needed interventions, and providing essential communication. PMID:22548283

  19. Continuous blood pressure monitoring during exercise using pulse wave transit time measurement.

    Science.gov (United States)

    Lass, J; Meigas, K; Karai, D; Kattai, R; Kaik, J; Rossmann, M

    2004-01-01

    This paper gives an overview of a research, which is focused on the development of the convenient device for continuous non-invasive monitoring of arterial blood pressure. The blood pressure estimation method is based on a presumption that there is a singular relationship between the pulse wave propagation time in arterial system and blood pressure. The parameter used in this study is pulse wave transit time (PWTT). The measurement of PWTT involves the registration of two time markers, one of which is based on ECG R peak detection and another on the detection of pulse wave in peripheral arteries. The reliability of beat to beat systolic blood pressure calculation during physical exercise was the main focus for the current paper. Sixty-one subjects (healthy and hypertensive) were studied with the bicycle exercise test. As a result of current study it is shown that with the correct personal calibration it is possible to estimate the beat to beat systolic arterial blood pressure during the exercise with comparable accuracy to conventional noninvasive methods. PMID:17272172

  20. Accuracy of a new bedside method for estimation of circulating blood volume

    DEFF Research Database (Denmark)

    Christensen, P; Waever Rasmussen, J; Winther Henneberg, S

    1993-01-01

    To evaluate the accuracy of a modification of the carbon monoxide method of estimating the circulating blood volume.......To evaluate the accuracy of a modification of the carbon monoxide method of estimating the circulating blood volume....

  1. Monitoring total boron in blood for BNCT by a novel atomic emission method

    International Nuclear Information System (INIS)

    In BNCT the duration and timing of the is adjusted by 10B concentrations in whole blood. Time-frame for determinations is less than 20 minutes. Therefore fast and accurate boron determinations are a prerequisite for BNCT. We present a method based on ICP-AES instrument for whole blood and plasma boron determinations with protein precipitation with trichloroacetic acid as sample pre-treatment and beryllium as an internal standard. The method was compared to established but tedious ICP-mass spectrometric method with wet ashing as a sample pre-treatment. The ICP-AES method is in good agreement (correlation coefficient 0.99) the ICP-MS. Within-day and between-day imprecisions were less than 3,5% CV for whole blood samples. Samples taken during and after BPA-F infusion (290 mg/kg) revealed an uneven distribution between plasma and erythrocytes. The present method is feasible and one of the fastest currently available for BNCT. Our results indicate that BPA-F or its metabolites do not seem to be tightly bound to plasma proteins. It also seems that determination of boron in plasma sample may be preferable than measuring boron in whole blood. (author)

  2. Comparison of oscillometric and intra-arterial blood pressure and pulse measurement.

    Science.gov (United States)

    Rithalia, S V; Edwards, D

    1994-01-01

    Non-invasive oscillometric blood pressure and pulse measured by an Omron HEM-703CP monitor were compared with arterial values obtained from direct measurements of the radial artery. An excellent correlation and agreement was found between the two methods (systolic r = 0.99; diastolic r = 0.97; pulse r = 0.99), although there was some variability among individual subjects. The range of difference between them was 0 to 10 mmHg for systolic and -6 to +5 mmHg for diastolic pressures. When tested on the bench using the Metron QA-1280 non-invasive blood pressure analyser the HEM-703CP monitor rarely exhibited errors exceeding 2-3 mmHg over a measurement range of 50-200 mmHg. PMID:7776359

  3. Measurement of brachial artery endothelial function using a standard blood pressure cuff

    OpenAIRE

    Maltz, Jonathan S.; Tison, Geoffrey H; Alley, Hugh F.; Budinger, Thomas F; Owens, Christopher D.; Olgin, Jeffrey

    2015-01-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, lab-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arg...

  4. Open Photoacoustic Cell for Blood Sugar Measurement: Numerical Calculation of Frequency Response

    OpenAIRE

    Baumann, Bernd; Wolff, Marcus; Teschner, Mark

    2015-01-01

    A new approach for continuous and non-invasive monitoring of the glucose concentration in human epidermis has been suggested recently. This method is based on photoacoustic (PA) analysis of human interstitial fluid. The measurement can be performed in vitro and in vivo and, therefore, may form the basis for a non-invasive monitoring of the blood sugar level for diabetes patients. It requires a windowless PA cell with an additional opening that is pressed onto the human skin. Since signals are...

  5. A 133-xenon inhalation system for cerebral blood-flow measurements in ventilated premature babies

    International Nuclear Information System (INIS)

    We constructed a Xenon-133 inhalation and trapping system in order to measure cerebral blood flow of ventilated premature babies by means of the noninvasive 133Xe clearance method. The completely lead-shielded inhalation device is a closed system driven by the baby's own respirator and can thus be safely used at the patients bedside in the intensive care unit. Reproducible proximal airway concentrations of 133Xe (with or without leaks around the endotracheal tube) were obtained by in vitro simulation. (orig.)

  6. Development of automatic blood extraction device with a micro-needle for blood-sugar level measurement

    Science.gov (United States)

    Kawanaka, Kaichiro; Uetsuji, Yasutomo; Tsuchiya, Kazuyoshi; Nakamachi, Eiji

    2008-12-01

    In this study, a portable type HMS (Health Monitoring System) device is newly developed. It has features 1) puncturing a blood vessel by using a minimally invasive micro-needle, 2) extracting and transferring human blood and 3) measuring blood glucose level. This miniature SMBG (Self-Monitoring of Blood Glucose) device employs a syringe reciprocal blood extraction system equipped with an electro-mechanical control unit for accurate and steady operations. The device consists of a) a disposable syringe unit, b) a non-disposable body unit, and c) a glucose enzyme sensor. The syringe unit consists of a syringe itself, its cover, a piston and a titanium alloy micro-needle, whose inner diameter is about 100µm. The body unit consists of a linear driven-type stepping motor, a piston jig, which connects directly to the shaft of the stepping motor, and a syringe jig, which is driven by combining with the piston jig and slider, which fixes the syringe jig. The required thrust to drive the slider is designed to be greater than the value of the blood extraction force. Because of this driving mechanism, the automatic blood extraction and discharging processes are completed by only one linear driven-type stepping motor. The experimental results using our miniature SMBG device was confirmed to output more than 90% volumetric efficiency under the driving speed of the piston, 1.0mm/s. Further, the blood sugar level was measured successfully by using the glucose enzyme sensor.

  7. Measurement of Mercury Species in Human Blood using Triple Spike Isotope Dilution with SPME-GC-ICP-DRC-MS

    OpenAIRE

    Sommer, Yuliya L.; Verdon, Carl P.; Fresquez, Mark R.; Ward, Cynthia D.; Wood, Elliott B.; Pan, Yi; Caldwell, Kathleen L.; Jones, Robert L.

    2014-01-01

    The measurement of different mercury compounds in human blood can provide valuable information about the type of mercury exposure. To this end, our laboratory developed a biomonitoring method for the quantification of inorganic (iHg), methyl (MeHg) and ethyl (EtHg) mercury in whole blood using a triple spike isotope dilution (TSID) quantification method employing capillary gas chromatography (GC) and inductively coupled dynamic reaction cell mass spectrometry (ICP-DRC-MS). We used a robotic C...

  8. TREATMENT OF HYPERTENSION USING TELEMEDICAL HOME BLOOD PRESSURE MEASUREMENTS

    DEFF Research Database (Denmark)

    Hoffmann-Petersen, N; Lauritzen, T; Bech, J N;

    2015-01-01

    of the measurements and subsequent communication by telephone or E-mail. In the control group, patients received usual care. Primary outcome was reduction in daytime ambulatory blood pressure measurements (ABPM) from baseline to 3 months' follow-up. RESULTS: In both groups, daytime ABPM decreased significantly......: Participants (n = 356) were recruited from a prevalence study among citizens aged 55-64 years in the municipality of Holstebro, Denmark. The study was a randomised, controlled, unblinded 3 months trial. In the intervention group, antihypertensive treatment was based on TBPM with transmission....... The decrease in daytime ABPM in the intervention group was systolic/diastolic, -8  ± 12/-4 ± 7 mmHg. This did not differ significantly from the control group's -8 ± 13/-4 ± 8 mmHg. An equal number of participants obtained normal daytime ABPM, in the intervention group 17% (31/175) versus control 21% (37...

  9. Renewable energy: Method and measures

    International Nuclear Information System (INIS)

    The thesis presents various possibilities for renewable energy in Norway. The wind power would give a practical and economic alternative. The external costs for the wind power would be moderate. In chapter 3 the utility cost analysis for renewable alternatives are studied relative to the macroeconomic efficiency. Some methodical problems and how these analyses are used are reviewed. In the practical utility cost analyses wind power is studied relative to gas power which is the non-renewable alternative present in Norway today. A qualitative part is included. It is not possible to determine whether wind power is preferable to gas power in the macroeconomic perspective. Wind power would be the choice if high environmental and CO2 cleaning costs are expected. The first conclusion to be drawn is that it is difficult to decide whether wind power is the best solution based on cost benefit analysis. However, the alternative seems to be quite robust in the analysis. Due to the central position the energy supplies have in the society this business should be heavily regulated. The sector is also overtaxed as a reduction in consumption is desired. The analysis shows that the system does not function perfectly. The thesis surveys various measures for improving the renewable energy supply and focuses on the wind power. A model for and analysis of the measures are carried out and resulted in a second conclusion. The measures have various properties as to the influence on the market. A subsidy is a fine measure for stimulation production of green power while a tax reduces efficiently the production of black power. A system with green licenses in combination with a subsidy and a tax would be preferable as to increasing the part of renewable energy of the total production. It is therefore necessary to have clearly defined goals and use suitable measures for achieving them. The costs of wind power is falling and it would therefore soon be macroeconomic profitable. It is also

  10. Study on optical measurement conditions for noninvasive blood glucose sensing

    Science.gov (United States)

    Xu, Kexin; Chen, Wenliang; Jiang, Jingying; Qiu, Qingjun

    2004-05-01

    Utilizing Near-infrared Spectroscopy for non-invasive glucose concentration sensing has been a focusing topic in biomedical optics applications. In this paper study on measuring conditions of spectroscopy on human body is carried out and a series of experiments on glucose concentration sensing are conducted. First, Monte Carlo method is applied to simulate and calculate photons" penetration depth within skin tissues at 1600 nm. The simulation results indicate that applying our designed optical probe, the detected photons can penetrate epidermis of the palm and meet the glucose sensing requirements within the dermis. Second, we analyze the influence of the measured position variations and the contact pressure between the optical fiber probe and the measured position on the measured spectrum during spectroscopic measurement of a human body. And, a measurement conditions reproduction system is introduced to enhance the measurement repeatability. Furthermore, through a series of transmittance experiments on glucose aqueous solutions sensing from simple to complex we found that though some absorption variation information of glucose can be obtained from measurements using NIR spectroscopy, while under the same measuring conditions and with the same modeling method, choices toward measured components reduce when complication degree of components increases, and this causes a decreased prediction accuracy. Finally, OGTT experiments were performed, and a PLS (Partial Least Square) mathematical model for a single experiment was built. We can easily get a prediction expressed as RMSEP (Root Mean Square Error of Prediction) with a value of 0.5-0.8mmol/dl. But the model"s extended application and reliability need more investigation.

  11. Measuring skewness of red blood cell deformability distribution by laser ektacytometry

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, S Yu; Priezzhev, A V; Lugovtsov, A E [International Laser Center, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Ustinov, V D [M. V. Lomonosov Moscow State University, Faculty of Computational Mathematics and Cybernetics, Moscow (Russian Federation)

    2014-08-31

    An algorithm is proposed for measuring the parameters of red blood cell deformability distribution based on laser diffractometry of red blood cells in shear flow (ektacytometry). The algorithm is tested on specially prepared samples of rat blood. In these experiments we succeeded in measuring the mean deformability, deformability variance and skewness of red blood cell deformability distribution with errors of 10%, 15% and 35%, respectively. (laser biophotonics)

  12. DETECTION OF BLOOD VESSELS AND MEASUREMENT OF VESSEL WIDTH FOR DIABETIC RETINOPATHY

    Directory of Open Access Journals (Sweden)

    S.Sukanya

    2014-09-01

    Full Text Available The proposed method measures the retinal blood vessel diameter to identify arteriolar narrowing, arteriovenous (AV nicking, branching coefficients to detect early diabetic retinopathy. It utilizes the vessel centerline and edge information to measure the width for a vessel segment. From the input retinal image, the vascular network is extracted using the local entropy thresholding method. The vessel boundaries are extracted using sobel edge detection method. The skeletonization operation is applied to the vascular network and mapping the vessel boundaries and the skeleton image. The branching point detection method is then performed to localize all crossing locations. A rotational invariant mask to search the pixel pairs from the edge image, and calculate the shortest distance pair which provides the vessel width (or diameter for that cross-section. Variation in the width measurement identifies the diabetic retinopathy.

  13. Red blood cell membrane viscoelasticity, agglutination and zeta potential measurements with double optical tweezers

    Science.gov (United States)

    Fontes, Adriana; Fernandes, Heloise P.; Barjas-Castro, Maria L.; de Thomaz, André A.; de Ysasa Pozzo, Liliana; Barbosa, Luiz C.; Cesar, Carlos L.

    2006-02-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. There are techniques, however, to decrease the zeta potential to allow cell agglutination which are the basis of most of the tests of antigen-antibody interactions in blood banks. This report shows the use of a double optical tweezers to measure RBC membrane viscosity, agglutination and zeta potential. In our technique one of the optical tweezers trap a silica bead that binds strongly to a RBC at the end of a RBCs rouleaux and, at the same time, acts as a pico-Newton force transducer, after calibration through its displacement from the equilibrium position. The other optical tweezers trap the RBC at the other end. To measure the membrane viscosity the optical force is measured as a function of the velocity between the RBCs. To measure the adhesion the tweezers are slowly displaced apart until the RBCs disagglutination happens. The RBC zeta potential is measured in two complimentary ways, by the force on the silica bead attached to a single RBC in response to an applied electric field, and the conventional way, by the measurement of terminal velocity of the RBC after released from the optical trap. These two measurements provide information about the RBC charges and, also, electrolytic solution properties. We believe this can improve the methods of diagnosis in blood banks.

  14. Laser speckle imaging of rat retinal blood flow with hybrid temporal and spatial analysis method

    Science.gov (United States)

    Cheng, Haiying; Yan, Yumei; Duong, Timothy Q.

    2009-02-01

    Noninvasive monitoring of blood flow in retinal circulation will reveal the progression and treatment of ocular disorders, such as diabetic retinopathy, age-related macular degeneration and glaucoma. A non-invasive and direct BF measurement technique with high spatial-temporal resolution is needed for retinal imaging. Laser speckle imaging (LSI) is such a method. Currently, there are two analysis methods for LSI: spatial statistics LSI (SS-LSI) and temporal statistical LSI (TS-LSI). Comparing these two analysis methods, SS-LSI has higher signal to noise ratio (SNR) and TSLSI is less susceptible to artifacts from stationary speckle. We proposed a hybrid temporal and spatial analysis method (HTS-LSI) to measure the retinal blood flow. Gas challenge experiment was performed and images were analyzed by HTS-LSI. Results showed that HTS-LSI can not only remove the stationary speckle but also increase the SNR. Under 100% O2, retinal BF decreased by 20-30%. This was consistent with the results observed with laser Doppler technique. As retinal blood flow is a critical physiological parameter and its perturbation has been implicated in the early stages of many retinal diseases, HTS-LSI will be an efficient method in early detection of retina diseases.

  15. Capillary Bedside Blood Glucose Measurement in Neonates: Missing a Diagnosis of Galactosemia

    OpenAIRE

    Özbek, Mehmet Nuri; Öcal, Murat; Tanrıverdi, Sibel; Baysal, Birsen; Deniz, Ahmet; Öncel, Kahraman; Demirbilek, Hüseyin

    2015-01-01

    A number of factors may lead to inaccuracy in measurement of capillary blood glucose with a glucometer. Measurement of other carbohydrate molecules such as galactose and fructose along with glucose can potentially be a cause of error. We report a newborn patient who was referred to our hospital with conjugated bilirubinemia, hepatomegaly and high capillary blood glucose levels measured with a glucometer. Simultaneous biochemical measurements revealed normal blood glucose levels. Further inves...

  16. Automated Methods Of Corrosion Measurements

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch;

    1997-01-01

    The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....

  17. Augmented blood pressure measurement through the noninvasive estimation of physiological arterial pressure variability

    International Nuclear Information System (INIS)

    Current noninvasive blood pressure (BP) measurement methods, such as the oscillometric method, estimate the systolic and diastolic blood pressure (SBP and DBP) at two random instants in time and do not take into account the natural variability in BP. The standard for automated BP devices sets a maximum allowable system error of ±5 mmHg, even though natural BP variability often exceeds these limits. This paper proposes a new approach using simultaneous recordings of the oscillometric and continuous arterial pulse waveforms to augment the conventional noninvasive measurement by providing (1) the mean SBP and DBP over the measurement interval and the associated confidence intervals of the mean, (2) the standard deviation of SBP and DBP over the measurement interval, which indicates the degree of fluctuation in BP and (3) an indicator as to whether or not the oscillometric reading is an outlier. Recordings with healthy subjects demonstrate the potential utility of this approach to characterize BP, to detect outlier measurements, and that it does not suffer from bias relative to the conventional oscillometric method. (paper)

  18. Effectiveness of holographic optical element module sensor in measuring blood prothrombin time

    International Nuclear Information System (INIS)

    A small-form-factor holographic optical element (HOE) module, which was mounted on a dual-stage seesaw actuator, was utilized to evaluate blood coagulation in real time. The method involved assessing the decrease in transmitted light of the blood sample surface when the clotting is formed. The prothrombin time (PT) was measured by illumining and focusing a 635 nm laser beam onto the sample. As the fibrinogen turned into non-solute fibrin, the transmitted efficiency and total intensity of the reflected light from the reflector changed. A low-pass filter suppressed the noise in the coagulation-related transient response to yield accurate signals. Finally, the PT measurements were compared to those made classically using other optical sensors. (paper)

  19. A comparison of blood pressure measurements in newborns.

    LENUS (Irish Health Repository)

    O'Shea, Joyce

    2012-02-01

    Blood pressure monitoring is an essential component of neonatal intensive care. We compared invasive and noninvasive (Dinamap, Marquette, and Dash) recordings in newborns and also noninvasive values obtained from upper and lower limbs. Infants\\' blood pressure was recorded every 6 hours for 72 hours using three noninvasive devices and compared with invasive readings taken simultaneously. Twenty-five babies were enrolled in the study, with birth weights of 560 to 4500 g and gestation 24 + 1 to 40 + 5 weeks. Three hundred thirty-two recordings were obtained. Comparison between invasive and noninvasive readings revealed that all three noninvasive monitors overread mean blood pressure. There was no significant difference between the cuff recordings obtained from the upper or lower limbs. All three noninvasive devices overestimated mean blood pressure values compared with invasive monitoring. Clinicians may be falsely reassured by noninvasive monitoring. Mean blood pressure values obtained from the upper and lower limb are similar.

  20. Capillary bedside blood glucose measurement in neonates: missing a diagnosis of galactosemia.

    Science.gov (United States)

    Özbek, Mehmet Nuri; Öcal, Murat; Tanrıverdi, Sibel; Baysal, Birsen; Deniz, Ahmet; Öncel, Kahraman; Demirbilek, Hüseyin

    2015-03-01

    A number of factors may lead to inaccuracy in measurement of capillary blood glucose with a glucometer. Measurement of other carbohydrate molecules such as galactose and fructose along with glucose can potentially be a cause of error. We report a newborn patient who was referred to our hospital with conjugated bilirubinemia, hepatomegaly and high capillary blood glucose levels measured with a glucometer. Simultaneous biochemical measurements revealed normal blood glucose levels. Further investigation led to a diagnosis of classical galactosemia. Capillary blood glucose level measured with glucometer also dropped to normal values following cessation of breastfeeding and initiation of feeding with a lactose-free formula. PMID:25800483

  1. Tomographic non-invasive measurements of regional cerebral blood flow

    International Nuclear Information System (INIS)

    The measurement of the regional cerebral bloodflow by means of the dynamic single-photon-emissioncomputed tomography is a method of examination which is completely free of risk for the patient, causes no inconvenience and can be repeated whenever it seems necessary. This method gives a quantitative explanation for the distribution of the effective cerebral perfusion and can only be substituted by the very complicated positron-emission-computed tomography. As well as the exact assessment of the hemodynamic relevance of cerebral vascular disease, this method enables us to prove whether or not in various types of psychiatric disorders an interference in the regional perfusion exists. This method can also contribute to the clarification of pathogenic mechanisms, as well as to the nosological classification of specific psychopathological conditions. (orig.)

  2. The measurement of thermal neutron flux depression for determining the concentration of boron in blood

    International Nuclear Information System (INIS)

    Boron neutron capture therapy (BNCT) is a form of targeted radiotherapy that relies on the uptake of the capture element boron by the volume to be treated. The treatment procedure requires the measurement of boron in the patient's blood. The investigation of a simple and inexpensive method for determining the concentration of the capture element 10B in blood is described here. This method, neutron flux depression measurement, involves the determination of the flux depression of thermal neutrons as they pass through a boron-containing sample. It is shown via Monte Carlo calculations and experimental verification that, for a maximum count rate of 1x104 counts/s measured by the detector, a 10 ppm 10B sample of volume 20 ml can be measured with a statistical precision of 10% in 32±2 min. For a source activity of less than 1.11x1011 Bq and a maximum count rate of less than 1x104 counts/s, a 10 ppm 10B sample of volume 20 ml can be measured with a statistical precision of 10% in 58±3 min. It has also been shown that this technique can be applied to the measurement of the concentration of any element with a high thermal neutron cross section such as 157Gd. (author)

  3. Mucosal blood flow measurements using laser Doppler perfusion monitoring

    Institute of Scientific and Technical Information of China (English)

    Dag Arne Lihaug Hoff; Hans Gregersen; Jan Gunnar Hatlebakk

    2009-01-01

    Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level. Ischemia, or the insufficiency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including pain. It is of considerable interest to study perfusion of peripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including peptic ulcer disease, inflammatory bowel disease and chest pain. The basic principle of laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastrointestinal (GI) tract using LDPM. In recent years we have developed a multi-modal catheter device which includes a laser Doppler probe, with the intent primarily to investigate patients suffering from functional chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results.

  4. Simplifying the xenon-enhanced CT technique for measuring cerebral blood flow

    International Nuclear Information System (INIS)

    The authors present their study to simplify the xenon-enhanced CT technique for measuring cerebral blood flow (CBF) by monitoring the end-tidal expired-air xenon concentration (CXe) with use of CT scanning. Measurement of CBF with xenon CT requires that CXe be monitored as a function of time, and with conventional methods, specialized equipment (eg, thermoconductivity meters) is employed. In the proposed technique, CXe is monitored by scanning the patient's expired air concurrent with the brain tissue. A flexible breathing tube is used to channel the expired air through the scan field to enable sampling

  5. Differences in blood pressure measurements in the forearm and upper arm of obese otherwise healthy first year medical students

    Directory of Open Access Journals (Sweden)

    Suganthi V, Navin Rajaratnam, Suzanne Maria D’cruz

    2014-07-01

    Full Text Available Background: The prevalence of obesity is increasing in Indian youth and obesity is associated with complications like systemic hypertension. Often, due to the non-availability of appropriate sized cuffs, standard cuff bladders are used to measure blood pressure in the forearms of obese young adults. Aim: To compare the upper arm arterial blood pressure measured using an appropriate cuff with the forearm arterial blood pressure measured using a standard cuff and conventional sphygmomanometry in obese otherwise healthy first year medical students. Materials and Methods: Blood pressure was measured in 27 obese otherwise healthy first year medical students after five minutes of rest using a mercury sphygmomanometer with the subjects seated and the arm and forearm at heart level, using an appropriate sized cuff for the upper arm according to American Heart Association standards and a standard cuff for the fore arm. Results: A statistically significant difference in both systolic [t-test (paired = -6.921; df = 26; sig = .000 (2- tailed] and diastolic blood pressure [t-test (paired = -8.508; df = 26; sig = .000 (2- tailed] was found, with the blood pressure readings being higher in the forearm. The correlations between upper arm and forearm systolic and diastolic blood pressure were 0.785 (p = .000 and 0.870 (p = .000. Conclusion: Both systolic and diastolic blood pressure measurements were significantly higher in the forearm. Further studies with larger sample size should be conducted to confirm that forearm blood pressure measurements using standard cuff bladders cannot be considered equal to upper arm measurements made using an appropriate sized cuff in all young obese individuals

  6. Use of dried blood for measurement of trans fatty acids

    OpenAIRE

    Ramakrishnan Lakshmy; Dhatwalia Savita; Abraham Ransi; Gupta Ruby; Prabhakaran Dorairaj; Reddy Kolli

    2009-01-01

    Abstract Background Fatty acid measurements especially trans fatty acid has gained interest in recent times. Among the various available biomarkers, adipose tissue is considered to be the best for the long term dietary intake but the invasive nature of tissue aspiration reduces its utility. Phlebotomy is a much less invasive method of sample collection when a large number of participants are involved in the study and therefore is an alternative, most suitable for large population based studie...

  7. Development of radiochemical method of analysis of binding of tritium labeled drotaverine hydrochloride with human blood serum albumin

    International Nuclear Information System (INIS)

    Full text: The albumin, being a basic functional linkage of numerous endogenous and exogenous substances is the most important protein of blood plasma. At the diseases connected to liver disfunction, collected in blood metabolite reduce connecting ability of albumino. The aim of the present research was a development of radiochemical method of determination of ability of albumin to bind the tritium labeled preparation drotaverine hydrochloride (no - spa). We had developed a micromethod of definition of connecting ability of albumin, allowing to analyse 20 mkl of blood serum. The method consists in incubation of tritium labeled drotaverine hydrochloride with blood serum in vitro, the following fractionation of serum proteins by gel - filtration on a microcolumn with Sephadex G-25, and direct measurement of the radioactivity connected to fraction of proteins of blood serum. The method has been tested on a series of blood serum of control group of healthy people and on a series of blood serum of patients with hepatitis B. We received quantitative characteristics of binding of drotaverine hydrochloride with albumin of patients with hepatitis B. It was preliminary established that binding ability of serum albumin of children with various forms of acute virus hepatitis tends to decrease in comparison with group of the control. Advantage of the developed radiochemical method is high precision and the high sensitivity of detection of infringement of binding ability of albumin. Application of tritium labeled drotaverine hydrochloride allows to measure directly levels of binding of a preparation with albumin

  8. The applicability of home blood pressure measurement in clinical practice: A review of literature

    OpenAIRE

    Verberk, Willem J; Kroon, Abraham A.; Jongen-Vancraybex, Heidi A; Peter W de Leeuw

    2007-01-01

    Purpose To review the literature on home blood pressure measurement (HBPM), to examine its validity and applicability for clinical practice and to provide recommendations regarding HBPM assessment. Findings HBPM can eliminate the white coat effect and offers the possibility to obtain multiple measurements under standardized conditions, which increases knowledge of overall blood pressure value. Although it is not entirely capable of replacing ambulatory blood pressure measurement (ABPM), HBPM ...

  9. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (vp) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. vp and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between vp and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  10. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

    2015-07-15

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  11. Quantitative measurement of total cerebral blood flow using 2D phase-contrast MRI and doppler ultrasound

    International Nuclear Information System (INIS)

    To compare of quantitative measurement of the total cerebral blood flow using two-dimensional phase-contrast MR imaging and Doppler ultrasound. In 16 volunteers (mean age, 26 years; mean body weight, 66 kg) without abnormal medical histories, two-dimensional phase-contrast MR imaging was performed at the level of the C2-3 inter vertebral disc for flow measurement of the internal carotid arteries and the vertebral arteries. Volume flow measurements using Doppler ultrasound were also performed at the internal carotid arteries 2cm above the carotid bifurcation, and at the vertebral arteries at the level of the upper pole of the thyroid gland. Flows in the four vessels measured by the two methods were compared using Wilcoxon's correlation analysis and the median score. Total cerebral blood flows were calculated by summing these four vessel flows, and mean values for the 16 volunteers were calculated. Cerebral blood flows measured by 2-D phase-contrast MR imaging and Doppler ultrasounds were 233 and 239 ml/min in the right internal carotid artery, 250 and 248 ml/min in the left internal carotid artery, 62 and 56 ml/min in the right vertebral artery, and 83 and 68 ml/min in the left vertebral artery. Correlation coefficients of the blood flows determined by the two methods were 0.48, 0.54, 0.49, and 0.62 in each vessel, while total cerebral blood flows were 628±68 (range, 517 to 779) ml/min and 612±79 (range, 482 to 804)ml/min, respectively. Total cerebral blood flow was easily measured using 2-D phase-contrast MR imaging and Doppler ultrasound, and the two noninvasive methods can therefore be used clinically for the measurement of total cerebral blood flow

  12. MRI-based blood oxygen saturation measurements in infants and children with congenital heart disease

    International Nuclear Information System (INIS)

    Background: Vessel oxygen saturation can be determined with MR oximetry using an in vivo measurement of signal decay (T2) and the calibration curve relating T2 to blood oxygen saturation (%HbO2), where: 1/T2=1/T2O+K (1-%HbO2/100)2 and K is a constant parameter which correlates with measured fibrinogen levels. The ability to noninvasively measure %HbO2 in cardiac chambers and vessels has enormous potential in children with congenital heart disease (CHD). Objective: The purpose of the study was to prospectively characterize the T2-%HbO2 relationship in infants where T2-%HbO2 is the realtionship between T2 and %HbO2 (blood oxygen saturation) expressed by the equation given above, and to determine whether adult values for K and T2O (where T2O is the T2 of fully oxygenated blood) can be extrapolated to pediatric patients with CHD. A second objective was to apply this method to calculate the %HbO2 in vivo using MR imaging in infants with CHD. Materials and methods: Fifteen patients with CHD undergoing cardiac catheterization (9 male; 6 female), median age 8 months, were recruited for the calibration study. T2O and K were measured directly from blood samples, compared with the values estimated from adult population statistics, and plotted against hematocrit and fibrinogen, respectively. In four studies of infants with CHD, T2 measurements were converted to %HbO2 using the calibration curve. Results: The T2-%HbO2 relationship in infants correlated with the adult calibration statistics (1/T2O vs. hematocrit, r=0.77; K vs. fibrinogen, r=0.61). Our initial in vivo studies demonstrated that the MR oximetry reflected the expected oxygen saturations. Conclusion: Adult values for T2-%HbO2 calibration can be used to measure blood oxygen saturation in vivo in children with CHD. (orig.)

  13. Radionuclide assessment of peripheral hemodynamics: a new technique for measurement of forearm blood volume and flow

    Energy Technology Data Exchange (ETDEWEB)

    Todo, Y.; Tanimoto, M.; Yamamoto, T.; Iwasaki, T.

    1986-02-01

    A new peripheral hemodynamic measurement system using /sup 99m/Tc-labeled red blood cells has been developed. This method was carried out on 22 normal subjects, 29 with coronary artery disease, and two with dilated cardiomyopathy. Peripheral hemodynamic indices obtained from this method included forearm blood volume (FBV), venous capacity (FVC), venous capacity index (VCI), blood flow (FBF), and vascular resistance (FVR), and were compared with the central hemodynamic parameters of left ventricular filling pressure (LVFP), cardiac output (CO), and total systemic vascular resistance (TSVR) obtained with an invasive technique. The normal values were FBV 8.54 +/- 2.04 ml/100 ml; FVC 4.54 +/- 1.23 ml/100 ml; VCI 65.5 +/- 3.8%; FBF 4.26 +/- 0.56 ml/100 ml/min; and FVR 20.9 +/- 4.4 mmHg/ml/100 ml/min. These values were in good agreement with the values reported using conventional plethysmography. The 16 patients with congestive heart failure (NYHA Class II or III) showed significantly lower FBV, FVC, and FBF values and significantly higher VCI and FVR values than the healthy subjects. Capacitance vessel parameters (FBV, FVC, and VCI) and LVFP, FBF and CO, and FVR and TSVR each showed significant correlation; reproducibility was also good. The advantages of this method are (a) the detector does not come in contact with the region being measured; (b) it is possible to ascertain the absolute quantity of blood in the tissue; (c) extravasation of the plasma component can be ignored; and (d) data processing is simple.

  14. Radionuclide assessment of peripheral hemodynamics: a new technique for measurement of forearm blood volume and flow

    International Nuclear Information System (INIS)

    A new peripheral hemodynamic measurement system using /sup 99m/Tc-labeled red blood cells has been developed. This method was carried out on 22 normal subjects, 29 with coronary artery disease, and two with dilated cardiomyopathy. Peripheral hemodynamic indices obtained from this method included forearm blood volume (FBV), venous capacity (FVC), venous capacity index (VCI), blood flow (FBF), and vascular resistance (FVR), and were compared with the central hemodynamic parameters of left ventricular filling pressure (LVFP), cardiac output (CO), and total systemic vascular resistance (TSVR) obtained with an invasive technique. The normal values were FBV 8.54 +/- 2.04 ml/100 ml; FVC 4.54 +/- 1.23 ml/100 ml; VCI 65.5 +/- 3.8%; FBF 4.26 +/- 0.56 ml/100 ml/min; and FVR 20.9 +/- 4.4 mmHg/ml/100 ml/min. These values were in good agreement with the values reported using conventional plethysmography. The 16 patients with congestive heart failure (NYHA Class II or III) showed significantly lower FBV, FVC, and FBF values and significantly higher VCI and FVR values than the healthy subjects. Capacitance vessel parameters (FBV, FVC, and VCI) and LVFP, FBF and CO, and FVR and TSVR each showed significant correlation; reproducibility was also good. The advantages of this method are (a) the detector does not come in contact with the region being measured; (b) it is possible to ascertain the absolute quantity of blood in the tissue; (c) extravasation of the plasma component can be ignored; and (d) data processing is simple

  15. Methods for High Power EM Pulse Measurement

    OpenAIRE

    Fiala, P.; Drexler, P.

    2006-01-01

    There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday...

  16. New method for detection of blood coagulation using fiber-optic sensor

    Science.gov (United States)

    Fediay, Sergey G.; Kuznetzov, Alexsey V.

    1991-07-01

    The detection of blood coagulation is very important in therapeutics and surgery. It is necessary to determine the overall time taken for blood clotting, production rate of thrombin, presence or absence of blood coagulation factors, etc. In this paper a new method for detection of blood coagulation is presented. This method is based on the fiber-optic sensor and allows for the study of different ways of blood clotting (such as blood coagulation and platelets aggregation) separately, thus enhancing the precision of determination. The method for determining the blood coagulation presented possesses high precision in monitoring the process of coagulation. An elaborate mathematical model of the process of blood coagulation has been developed to help the computer handle obtained data.

  17. Arterial blood pressure measurement and pulse wave analysis—their role in enhancing cardiovascular assessment

    International Nuclear Information System (INIS)

    The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. (topical review)

  18. Arterial blood pressure measurement and pulse wave analysis--their role in enhancing cardiovascular assessment.

    Science.gov (United States)

    Avolio, Alberto P; Butlin, Mark; Walsh, Andrew

    2010-01-01

    The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse. PMID:19940350

  19. Diagnostic Methods for Detection of Blood-Borne Candidiasis.

    Science.gov (United States)

    Clancy, Cornelius J; Nguyen, M Hong

    2016-01-01

    β-D-glucan (Fungitell) and polymerase chain reaction-based (T2Candida) assays of blood samples are FDA-approved adjuncts to cultures for diagnosing candidemia and other types of invasive candidiasis, but their clinical roles are unclear. In this chapter, we describe laboratory protocols for performing Fungitell and T2Candida assays. We then discuss step-by-step methods for interpreting test results at the bedside using a Bayesian framework, and for incorporating assays into rational patient management strategies. Prior to interpreting results, clinicians must recognize that test performance varies based on the type of invasive candidiasis being diagnosed. In general, the type of invasive candidiasis that is most likely in a given patient can be identified, and the pretest likelihood of disease estimated. From there, positive and negative predictive values (PPV, NPV) for an assay can be calculated. At a population level, tests can be incorporated into screening strategies for antifungal treatment. NPV and PPV thresholds can be defined for discontinuing antifungal prophylaxis or initiating preemptive treatment, respectively. Using the thresholds, it is possible to assign windows of pretest likelihood for invasive candidiasis (and corresponding patient populations) in which tests are most likely to valuable. At the individual patient level, tests may be useful outside of the windows proposed for screening populations. The interpretive and clinical decision-making processes we discuss will be applicable to other diagnostic assays as they enter the clinic, and to existing assays as more data emerge from various populations. PMID:26519076

  20. Community-based blood pressure measurement by non-health workers using electronic devices: a validation study

    Directory of Open Access Journals (Sweden)

    Daniel D. Reidpath

    2012-06-01

    Full Text Available Introduction: Population monitoring and screening of blood pressure is an important part of any population health strategy. Qualified health workers are expensive and often unavailable for screening. Non-health workers with electronic blood pressure monitors are increasingly used in community-based research. This approach is unvalidated. In a poor, urban community we compared blood pressure measurements taken by non-health workers using electronic devices against qualified health workers using mercury sphygmomanometers. Method: Fifty-six adult volunteers participated in the research. Data were collected by five qualified health workers, and six non-health workers. Participants were randomly allocated to have their blood pressure measured on four consecutive occasions by alternating a qualified health worker with a non-health worker. Descriptive statistics and graphs, and mixed effects linear models to account for the repeated measurement were used in the analysis. Results: Blood pressure readings by non-health workers were more reliable than those taken by qualified health workers. There was no significant difference between the readings taken by qualified health workers and those taken by non-health workers for systolic blood pressure. Non-health workers were, on average, 5–7 mmHg lower in their measures of blood pressure than the qualified health workers (95%HPD: −2.9 to −10.0 for diastolic blood pressure. Conclusion: The results provide empirical evidence that supports the practice of non-health workers using electronic devices for BP measurement in community-based research and screening. Non-health workers recorded blood pressures that differed from qualified health workers by no more than 10 mmHg. The approach is promising, but more research is needed to establish the generalisability of the results.

  1. Evaluation of a content-based retrieval system for blood cell images with automated methods.

    Science.gov (United States)

    Seng, Woo Chaw; Mirisaee, Seyed Hadi

    2011-08-01

    Content-based image retrieval techniques have been extensively studied for the past few years. With the growth of digital medical image databases, the demand for content-based analysis and retrieval tools has been increasing remarkably. Blood cell image is a key diagnostic tool for hematologists. An automated system that can retrieved relevant blood cell images correctly and efficiently would save the effort and time of hematologists. The purpose of this work is to develop such a content-based image retrieval system. Global color histogram and wavelet-based methods are used in the prototype. The system allows users to search by providing a query image and select one of four implemented methods. The obtained results demonstrate the proposed extended query refinement has the potential to capture a user's high level query and perception subjectivity by dynamically giving better query combinations. Color-based methods performed better than wavelet-based methods with regard to precision, recall rate and retrieval time. Shape and density of blood cells are suggested as measurements for future improvement. The system developed is useful for undergraduate education. PMID:20703533

  2. Dynamic Inertia Measurement Method Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critically important inertia measurements are complex and expensive to obtain due to the extensive fixturing and custom instrumentation of conventional...

  3. TSH measurements from blood spots on filter paper: a confirmatory screening test for neonatal hypothyroidism.

    Science.gov (United States)

    Dussault, J H; Parlow, A; Letarte, J; Guyda, H; Laberge, C

    1976-10-01

    A sensitive radioimmunoassay for the measurement of TSH in the eluate of blood spotted on filter paper has been developed. The method is consistently sensitive to 0.1 to 0.25 muU of TSH and enables the detection of values equivalent to 6 to 15 muU/ml of serum. The measurement of TSH in the filter paper spot in all infants with low filter paper spot T4 has permitted rapid confirmation of 10 cases of neonatal hypothyroidism. However, cases of hypothalamic hypothyroidism with low or normal filter paper spot TSH concentrations would have been missed using only this method. Since these patients represent approximately 10% of our neonatal hypothyroid population, we do not recommend this method as a primary screening procedure, but rather as a confirmatory test which will accelerate the diagnosis and therefore the onset of therapy. PMID:956996

  4. Open Photoacoustic Cell for Blood Sugar Measurement: Numerical Calculation of Frequency Response

    CERN Document Server

    Baumann, Bernd; Teschner, Mark

    2015-01-01

    A new approach for continuous and non-invasive monitoring of the glucose concentration in human epidermis has been suggested recently. This method is based on photoacoustic (PA) analysis of human interstitial fluid. The measurement can be performed in vitro and in vivo and, therefore, may form the basis for a non-invasive monitoring of the blood sugar level for diabetes patients. It requires a windowless PA cell with an additional opening that is pressed onto the human skin. Since signals are weak, advantage is taken of acoustic resonances of the cell. Recently, a numerical approach based on the Finite Element (FE) Method has been successfully used for the calculation of the frequency response function of closed PA cells. This method has now been adapted to obtain the frequency response of the open cell. Despite the fact that loss due to sound radiation at the opening is not included, fairly good accordance with measurement is achieved.

  5. Dynamic exploration of myocardial perfusion by coronary blood flow radioisotopic measurement during auricular pacing

    International Nuclear Information System (INIS)

    Reproducibility of the radiocardiographic method using 42 Potassium has been verified. Coronary blood flow has so been measured in 50 control subjects and coronary heart disease patients, at steady state and during auricular pacing at 150 beats per minute. In control subjects group, under auricular pacing coronary blood flow increases by a mean value of 15%; on the other hand it decreases by a mean value of 32% in coronary heart disease patients bearing obvious coronarography lesions. The cardiac output coronary fraction increases by a mean value of 27% in the control subjects group; it remains unchanged in coronary heart disease patients. On the contrary this coronary fraction increases in a significant way after functional aortocoronary bypass

  6. Measurement of interaction forces between red blood cells in aggregates by optical tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Maklygin, A Yu; Priezzhev, A V; Karmenian, A; Nikitin, Sergei Yu; Obolenskii, I S; Lugovtsov, Andrei E; Kisun Li

    2012-06-30

    We have fabricated double-beam optical tweezers and demonstrated the possibility of their use for measuring the interaction forces between red blood cells (erythrocytes). It has been established experimentally that prolonged trapping of red blood cells in a tightly focused laser beam does not cause any visible changes in their shape or size. We have measured the interaction between red blood cells in the aggregate, deformed by optical tweezers.

  7. Preanalytical Conditions and DNA Isolation Methods Affect Telomere Length Quantification in Whole Blood.

    Science.gov (United States)

    Tolios, Alexander; Teupser, Daniel; Holdt, Lesca M

    2015-01-01

    Telomeres are located at chromosome ends and their length (TL) has been associated with aging and human diseases such as cancer. Whole blood DNA is frequently used for TL measurements but the influence of preanalytical conditions and DNA isolation methods on TL quantification has not been thoroughly investigated. To evaluate potential preanalytical as well as methodological bias on TL, anonymized leftover EDTA-whole blood samples were pooled according to leukocyte counts and were incubated with and without actinomycin D to induce apoptosis as a prototype of sample degradation. DNA was isolated from fresh blood pools and after freezing at -80°C. Commercially available kits using beads (Invitrogen), spin columns (Qiagen, Macherey-Nagel and 5prime) or precipitation (Stratec/Invisorb) and a published isopropanol precipitation protocol (IPP) were used for DNA isolation. TL was assessed by qPCR, and normalized to the single copy reference gene 36B4 using two established single-plex and a new multiplex protocol. We show that the method of DNA isolation significantly affected TL (e.g. 1.86-fold longer TL when comparing IPP vs. Invitrogen). Sample degradation led to an average TL decrease of 22% when using all except for one DNA isolation method (5prime). Preanalytical storage conditions did not affect TL with exception of samples that were isolated with the 5prime kit, where a 27% increase in TL was observed after freezing. Finally, performance of the multiplex qPCR protocol was comparable to the single-plex assays, but showed superior time- and cost-effectiveness and required > 80% less DNA. Findings of the current study highlight the need for standardization of whole blood processing and DNA isolation in clinical study settings to avoid preanalytical bias of TL quantification and show that multiplex assays may improve TL/SCG measurements. PMID:26636575

  8. Preanalytical Conditions and DNA Isolation Methods Affect Telomere Length Quantification in Whole Blood.

    Directory of Open Access Journals (Sweden)

    Alexander Tolios

    Full Text Available Telomeres are located at chromosome ends and their length (TL has been associated with aging and human diseases such as cancer. Whole blood DNA is frequently used for TL measurements but the influence of preanalytical conditions and DNA isolation methods on TL quantification has not been thoroughly investigated. To evaluate potential preanalytical as well as methodological bias on TL, anonymized leftover EDTA-whole blood samples were pooled according to leukocyte counts and were incubated with and without actinomycin D to induce apoptosis as a prototype of sample degradation. DNA was isolated from fresh blood pools and after freezing at -80°C. Commercially available kits using beads (Invitrogen, spin columns (Qiagen, Macherey-Nagel and 5prime or precipitation (Stratec/Invisorb and a published isopropanol precipitation protocol (IPP were used for DNA isolation. TL was assessed by qPCR, and normalized to the single copy reference gene 36B4 using two established single-plex and a new multiplex protocol. We show that the method of DNA isolation significantly affected TL (e.g. 1.86-fold longer TL when comparing IPP vs. Invitrogen. Sample degradation led to an average TL decrease of 22% when using all except for one DNA isolation method (5prime. Preanalytical storage conditions did not affect TL with exception of samples that were isolated with the 5prime kit, where a 27% increase in TL was observed after freezing. Finally, performance of the multiplex qPCR protocol was comparable to the single-plex assays, but showed superior time- and cost-effectiveness and required > 80% less DNA. Findings of the current study highlight the need for standardization of whole blood processing and DNA isolation in clinical study settings to avoid preanalytical bias of TL quantification and show that multiplex assays may improve TL/SCG measurements.

  9. Calculation of the Residual Blood Volume after Acute, Non-Ongoing Hemorrhage Using Serial Hematocrit Measurements and the Volume of Isotonic Fluid Infused: Theoretical Hypothesis Generating Study

    OpenAIRE

    Oh, Won Sup; Chon, Sung-Bin

    2016-01-01

    Fluid resuscitation, hemostasis, and transfusion is essential in care of hemorrhagic shock. Although estimation of the residual blood volume is crucial, the standard measuring methods are impractical or unsafe. Vital signs, central venous or pulmonary artery pressures are inaccurate. We hypothesized that the residual blood volume for acute, non-ongoing hemorrhage was calculable using serial hematocrit measurements and the volume of isotonic solution infused. Blood volume is the sum of volumes...

  10. Aortic blood pressure measured via EIT: investigation of different measurement settings.

    Science.gov (United States)

    Braun, Fabian; Proença, Martin; Rapin, Michael; Lemay, Mathieu; Adler, Andy; Grychtol, Bartłomiej; Solà, Josep; Thiran, Jean-Philippe

    2015-06-01

    Electrical impedance tomography (EIT) allows the measurement of intra-thoracic impedance changes related to cardiovascular activity. As a safe and low-cost imaging modality, EIT is an appealing candidate for non-invasive and continuous haemodynamic monitoring. EIT has recently been shown to allow the assessment of aortic blood pressure via the estimation of the aortic pulse arrival time (PAT). However, finding the aortic signal within EIT image sequences is a challenging task: the signal has a small amplitude and is difficult to locate due to the small size of the aorta and the inherent low spatial resolution of EIT. In order to most reliably detect the aortic signal, our objective was to understand the effect of EIT measurement settings (electrode belt placement, reconstruction algorithm). This paper investigates the influence of three transversal belt placements and two commonly-used difference reconstruction algorithms (Gauss-Newton and GREIT) on the measurement of aortic signals in view of aortic blood pressure estimation via EIT. A magnetic resonance imaging based three-dimensional finite element model of the haemodynamic bio-impedance properties of the human thorax was created. Two simulation experiments were performed with the aim to (1) evaluate the timing error in aortic PAT estimation and (2) quantify the strength of the aortic signal in each pixel of the EIT image sequences. Both experiments reveal better performance for images reconstructed with Gauss-Newton (with a noise figure of 0.5 or above) and a belt placement at the height of the heart or higher. According to the noise-free scenarios simulated, the uncertainty in the analysis of the aortic EIT signal is expected to induce blood pressure errors of at least ± 1.4 mmHg. PMID:26007662

  11. Foetal scalp blood sampling during labour for pH and lactate measurements.

    Science.gov (United States)

    Carbonne, Bruno; Pons, Kelly; Maisonneuve, Emeline

    2016-01-01

    Second-line methods of foetal monitoring have been developed in an attempt to reduce unnecessary interventions due to continuous cardiotocography (CTG), and to better identify foetuses that are at risk of intrapartum asphyxia. Very few studies directly compared CTG with foetal scalp blood (FBS) and CTG only. Only one randomised controlled trial (RCT) was published in the 1970s and had limited power to assess neonatal outcome. Direct and indirect comparisons conclude that FBS could reduce the number of caesarean deliveries associated with the use of continuous CTG. The main drawbacks of FBS are its invasive and discontinuous nature and the need for a sufficient volume of foetal blood for analysis, especially for pH measurement, resulting in failure rates reaching 10%. FBS for lactate measurement became popular with the design of test-strip devices, requiring <0.5 mL of foetal blood. RCTs showed similar outcomes with the use of FBS for lactates compared with pH in terms of obstetrical interventions and neonatal outcomes. In conclusion, there is some evidence that FBS reduces the need for operative deliveries. However, the evidence is limited with regard to actual standards, and large RCTs, directly comparing CTG only with CTG with FBS, are still needed. PMID:26253238

  12. Measures of blood pressure and cognition in dialysis patients

    Science.gov (United States)

    There are few reports on the relationship of blood pressure with cognitive function in maintenance dialysis patients. The Cognition and Dialysis Study is an ongoing investigation of cognitive function and its risk factors in six Boston area hemodialysis units. In this analysis, we evaluated the rela...

  13. Important Considerations for Methemoglobin Measurement in Fish Blood: Assay Choice and Storage Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kuntz, Mel Anton; Rodnick, K. J.; J. A. Lacey

    2002-05-01

    Spectrophotometric assays of methaemoglobin (metHb) in rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus, tilapias Tilapia niloticus and Tilapia zillii and white sturgeon Acipenser transmontanus, under baseline conditions, were low (<4%) for each species, and yet higher than human values (<1%). MetHb results for a given fish species varied significantly between assays and two assays were deemed unacceptable for particular animals. For rainbow trout, white sturgeon, and the two species of tilapia, the Dubowski method gave uncharacteristically high estimates of metHb. MetHb could not measured in tilapia blood using the Evelyn & Malloy method due to spectral interference. Only the Horecker & Brackett assay worked well for all species. Storage conditions were extremely important in the quantification of metHb in rainbow trout blood. For consistent values, samples can be stored up to 4 h on ice (0 degrees C) or at least 20 days under liquid nitrogen (-196 degrees C). Auto-oxidation, however, elevates rainbow trout metHb at -20 and -80 degrees C. It should not be assumed that the blood of fishes and humans perform similarly during assays of metHb.

  14. Automated Methods of Corrosion Measurements

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    . Mechanical control, recording, and data processing must therefore be automated to a high level of precision and reliability. These general techniques and the apparatus involved have been described extensively. The automated methods of such high-resolution microscopy coordinated with computerized...

  15. In vitro validation of volumetric blood flow measurement using Doppler flow wire.

    Science.gov (United States)

    Jenni, R; Kaufmann, P A; Jiang, Z; Attenhofer, C; Linka, A; Mandinov, L

    2000-10-01

    Determination of any volumetric blood flow requires assessment of mean blood flow velocity and vessel cross-sectional area. For evaluation of coronary blood flow and flow reserve, however, assessment of average peak velocity alone is widely used, but changes in velocity profile and vessel area are not taken into account. We studied the feasibility of a new method for calculation of volumetric blood flow by Doppler power using a Doppler flow wire. An in vitro model with serially connected silicone tubes of known lumen diameters (1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mm) and pulsatile blood flow ranging from 10 to 200 mL/min was used. A Doppler flow wire was connected to a commercially available Doppler system (FloMap(R), Cardiometrics) for online calculation of the zeroth (M(0)) and the first (M(1)) Doppler moment, as well as mean flow velocity (V(m)). Two different groups of sample volumes (at different gate depths) were used: 1. two proximal sample volumes lying completely within the vessel were required to evaluate the effect of scattering and attenuation on Doppler power, and 2. distal sample volumes intersecting completely the vessel lumen to assess the vessel cross-sectional area. Area (using M(0)) and V(m) (using M(1)/M(0)) obtained from the distal gates were corrected for scattering and attenuation by the data obtained from the proximal gates, allowing calculation of absolute volumetric flow. These results were compared to the respective time collected flow. Correlation between time collected and Doppler-derived flow measurements was 0.98 (p measurements in each individual tube. The mean paired flow difference between the two techniques was 1.5 +/- 9.0 mL/min (ns). Direct volumetric blood flow measurement from received Doppler power using a Doppler flow wire system is feasible. This technique may potentially be of great clinical value because it allows an accurate assessment of coronary flow and flow reserve with a commercially available flow wire system. PMID

  16. Validation of the integration of technology that measures additional “vascular” indices into an ambulatory blood pressure monitoring system

    OpenAIRE

    Kotovskaya, Yulia V; Kobalava, Zhanna D; Orlov, Artemy V

    2014-01-01

    Background The objective of this study was to validate the novel integration of oscillometric (Vasotens®) technology into a BPLab® ambulatory blood pressure (BP) monitoring system to measure central BP, the aortic augmentation index, and pulse wave velocity (PWV) compared with the recommended and widely accepted tonometric method. Methods The ARTERY Society guidelines for comparison of PWV measurement techniques were used as the basis for recruitment of 99 individuals (mean age 44±19 years, 5...

  17. A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Blood-brain barrier (BBB disruption is common following traumatic brain injury (TBI. Dynamic contrast enhanced (DCE MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field and magnetization (M0 distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI, and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI.

  18. Methods for measurement of durability parameters

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1996-01-01

    Present selected methods for measurement of durabilty parameters relating to chlorides, corrosion, moisture and freeze-thaw, primarly on concrete. Advantages and drawbacks of the different methods are included.......Present selected methods for measurement of durabilty parameters relating to chlorides, corrosion, moisture and freeze-thaw, primarly on concrete. Advantages and drawbacks of the different methods are included....

  19. Relationship between blood pressure measurements recorded on patients' charts in family physicians' offices and subsequent 24 hour ambulatory blood pressure monitoring

    Directory of Open Access Journals (Sweden)

    Birtwhistle Richard

    2004-03-01

    Full Text Available Abstract Background In most western countries 20% of adults have hypertension. Reports in the literature suggest that from 31 to 86% of treated patients are not at recommended target levels. However it is important to consider how we are determining whether targets are unmet and the degree to which they are unmet. Our underlying hypothesis is that white coat effect is partially responsible for the reported low rates of control of hypertension by primary care practitioners. Methods The study population consists of 1142 patients who are being assessed for enrolment in two community-based randomized controlled trials. Patients must have essential hypertension, be on antihypertensive medication, and must not have met their blood pressure targets. We are reporting on the proportion of patients who have not achieved target, and the degree to which they have not achieved their target. We also report on the mean daytime blood pressures on 24 hour ABPM and compare these to mean blood pressures found on the patients' charts. Results We identified 3284 patient charts of patients with hypertension. Of these, 1142 were determined to be "out of control" (did not achieve target and 436 agreed to undergo 24 hour ABPM for final determination of eligibility. Overwhelmingly (95.8% of the time it was the systolic blood pressure that was not under control. However, most of the patients who had not achieved target according to our criteria were within 10 mmHg of the recommended targets. Isolated systolic blood pressure was the best predictor of elevated mean daytime blood pressure on 24 hour ABPM. Conclusions At least 35% of patients had not achieved target blood pressure levels and this is primarily due to lack of control of systolic blood pressure. The best predictor of continuing hypertension on 24 hour ABPM was the mean systolic blood pressure on the patients chart. However, only 69% of patients who were uncontrolled according blood pressures recorded in the

  20. A new method to measure local oxygen consumption in human skeletal muscle during dynamic exercise using near-infrared spectroscopy

    OpenAIRE

    Binzoni, Tiziano; Cooper, Chris E; Wittekind, Anna L.; Beneke, Ralph; Elwell, Clare E; Van De Ville, Dimitri; Leung, Terence S.

    2010-01-01

    Near infrared spectroscopy (NIRS) can readily report on changes in blood volume and oxygenation. However, it has proved more problematic to measure real-time changes in blood flow and oxygen consumption. Here we report the development of a novel method using NIRS to measure local oxygen consumption in human muscle. The method utilizes the blood volume changes induced by the muscle pump during rhythmically contracting exercising skeletal muscle. We found that the saturation of the blood during...

  1. Measurement of portal blood flow in healthy individuals: a comparison between magnetic resonance imaging and Doppler ultrasound

    International Nuclear Information System (INIS)

    Objective: To evaluate the inter-observer agreement between Doppler ultrasonography and magnetic resonance imaging in the quantification of portal blood flow in healthy individuals, as well as evaluating the reproducibility of both methods. Materials and methods: A prospective, transverse, observational and self-paired study was developed evaluating 20 healthy volunteers whose portal blood flow was measured by means of Doppler ultrasonography and magnetic resonance imaging performed by two independent observers. Interobserver and inter method agreements were calculated using the intra class and Pearson's correlation coefficients. Results: The agreement between Doppler ultrasonography and magnetic resonance imaging was low (intra class coefficient: 1.9%-18.2%; Pearson's coefficient: 0.1%-13.7%; p=0.565). Mean values for the portal blood flow measured by Doppler ultrasonography and magnetic resonance imaging were respectively 0.768 l/min and 0.742 l/min. Interobserver agreement for quantification of the portal blood flow by Doppler ultrasonography and magnetic resonance imaging was respectively reasonable (intra class coefficient: 43.3%; Pearson's coefficient: 43.0%) and excellent (intra class coefficient: 91.4%; Pearson's coefficient: 93.4%). Conclusion: In the present study, magnetic resonance imaging demonstrated to be a reliable method for quantifying the portal blood flow, with a higher interobserver agreement than Doppler ultrasonography. The inter method agreement was low. (author)

  2. Measuring methods of matrix diffusion

    International Nuclear Information System (INIS)

    In Finland the spent nuclear fuel is planned to be disposed of at large depths in crystalline bedrock. The radionuclides which are dissolved in the groundwater may be able to diffuse into the micropores of the porous rock matrix and thus be withdrawn from the flowing water in the fractures. This phenomenon is called matrix diffusion. A review over matrix diffusion is presented in the study. The main interest is directed to the diffusion of non-sorbing species. The review covers diffusion experiments and measurements of porosity, pore size, specific surface area and water permeability

  3. Flow measurement by ultrasonic method

    International Nuclear Information System (INIS)

    An Ultrasonic Flow Meter (USFM) wasdeveloped to measure flow velocity of high temperature fluid in a pipe. To protect ultrasonic transducers from high temperature, guide rods were used. From the study on mechanical structure and acoustic property, the guide rod and the electronic circuit were improved to have capabilities of temperature compensation, quick response, high accuracy and not to be easily disturbed by bubbles contained in the fluid flow. Using a water flow loop, the test results proved the accuracy of +-1.0 percent and response time of 10 m sec

  4. Was the Driver Drunk? An Instrumental Methods Experiment for the Determination of Blood Alcohol Content

    Science.gov (United States)

    Zabzdyr, Jennifer L.; Lillard, Sheri J.

    2001-09-01

    Introducing forensic scenarios into the instrumental laboratory is a simple yet effective strategy to give students the opportunity to perform realistic experiments and to learn proper analytical techniques. In this laboratory experiment, which is designed for upper-division students in an instrumental methods course, unknown ethanol concentrations are quantitated in simulated serum samples using headspace gas chromatography (GC) with flame ionization detection. For the quantitative determination of blood alcohol content (BAC) in cases where drunk driving is suspected, GC is considered the most reliable method. Furthermore, headspace sampling helps to eliminate interferences from biological matrices such as blood or serum. An unknown sample of ethanol in serum, which brackets the 0.080 g/mL legal limit (e.g., BAC 0.075-0.087 g/mL), is given to the student for measurement. Both external and internal standardization methods are used for calibration. The students calculate serum alcohol concentration based on the measurement of their unknown sample using each calibration curve, and the results from each calibration method are compared and discussed in terms of accuracy. They then use a conversion factor to calculate BAC from serum alcohol concentration and use their results to determine if the "suspected driver" was driving under the influence. See Letter re: this article.

  5. Measurement of Uranium in Blood-Plasma of Bavarian Females

    International Nuclear Information System (INIS)

    It has recently been reported that the water supply in some parts of Bavaria (Germany) contains Uranium. In order to study its effects we have determined the concentrations of U in the blood plasma of 25 females. All the females came from Bavaria and were not on any medication. Blood samples were drawn from a superficial arm vein, centrifuged and plasma extracted. The plasma samples were freeze-dried and analysed in our Analytical Laboratory in Perth, Western Australia by using the technique of ICP-MS. The U contents found varied from less than 0.1 to 8.2 ppb (6.6 ng/L to 543 ng/L)

  6. Accuracy of PET RCBF measurements: effect of time shift between blood and brain radioactivity curves

    International Nuclear Information System (INIS)

    Analytic expressions were derived for estimating the error in PET RCBF measurements associated with the time lag between brain and blood radioactivity following bolus H215O injection and during non-steady-state CO15O inhalation. This lag time reflects the physiological difference in arrival times of 15O activity at brain and radial arterial sampling site as well as the experimentally introduced resistance to flow offered by the arterial catheter/stopcock assembly. Multiple measurements of this time lag ranged between 1 and 10 s. For non-steady-state CO15O PET measurements, estimated errors in RCBF ranged from 0.02 to 30% for delays of 2-8 s and scan lengths of 30-180 s. In the range 20-100 ml min-1 per 100 g, variations in RCBF only marginally affected these errors. Errors increased with longer delays but decreased sharply with scan durations greater than 60 s. For 30-180 s scans, even larger errors are associated with the H215O injection technique (peak blood activity at 10 s): 1-60% for delays of 2-8 s. A 'slow' bolus peaking at 20 s decreased the error by 40%. For the H215O method it is essential to estimate the time shift to within 2 s if accurate flow measurements (error less than 5%) are to be obtained from 40-60 s scans. (author)

  7. Reliability and validity of optoelectronic method for biophotonical measurements

    Science.gov (United States)

    Karpienko, Katarzyna; Wróbel, Maciej S.; UrniaŻ, Rafał

    2013-11-01

    Reliability and validity of measurements is of utmost importance when assessing measuring capability of instruments developed for research. In order to perform an experiment which is legitimate, used instruments must be both reliable and valid. Reliability estimates the degree of precision of measurement, the extent to which a measurement is internally consistent. Validity is the usefulness of an instrument to perform accurate measurements of quantities it was designed to measure. Statistical analysis for reliability and validity control of low-coherence interferometry method for refractive index measurements of biological fluids is presented. The low-coherence interferometer is sensitive to optical path difference between interfering beams. This difference depends on the refractive index of measured material. To assess the validity and reliability of proposed method for blood measurements, the statistical analysis of the method was performed on several substances with known refractive indices. Analysis of low-coherence interferograms considered the mean distances between fringes. Performed statistical analysis for validity and reliability consisted of Grubb's test for outliers, Shapiro-Wilk test for normal distribution, T-Student test, standard deviation, coefficient of determination and r-Pearson correlation. Overall the tests proved high statistical significance of measurement method with confidence level < 0.0001 of measurement method.

  8. A pitfall in the measurement of arterial blood pressure in the ischaemic limb during elevation

    DEFF Research Database (Denmark)

    Bülow, J; Jelnes, Rolf

    1987-01-01

    In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal artery pressures were measured directly in eight patients with occlusion of...... the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the...... lower extremity cannot be determined non-invasively by elevation of the extremity, probably due to collapse of segments of the vascular bed increasing the vascular resistance considerably....

  9. Results of kidney function measurement and blood pressure in population from endemic region of Vitina

    Directory of Open Access Journals (Sweden)

    Stašević Zvonimir

    2008-01-01

    Full Text Available Introduction. The analysis of frequency of kidney diseases, causes of terminal renal failure in patients subjected to repeated dialysis in major dialysis centers in the region of Kosovo and Metohija as well as mortality rate in these patients showed a stable number of patients with kidney diseases, evidencing that the populations of Vitina and Gnjilane were the most commonly affected. These towns are designated as regions with the highest incidence of Balkan endemic nephropathy. The present analysis was aimed at: 1. establishing the incidence rate of hypertension and renal function impairment by using clinical and laboratory analyses in individuals from Vitina and neighboring villages, and 2. investigating the correlation between creatinine clearance, age and arterial blood pressure in the studied group. Material and methods. The analysis included 510 individuals (excluding diabetics over the one-month period during 2004 (201 males with their age ranging from 18 to 90 years. Blood pressure measurements were performed in all the individuals, while renal function was determined by glomerular filtration rate (GFR, as calculated according to Cockcroft-Gault formula. Results. Creatinine clearance was lower than 100 ml/min in 237 (46.5% individuals, out of whom 62 (12% had GFR below 60 ml/min. Among the remaining 273 (53.5% individuals with GFR above 100 ml/min, 68 individuals had GFR above 140 ml/min. The distribution of patients depending on their systolic blood pressure values revealed that systolic blood pressure was lower in 44 subjects and higher in 302 subjects (59%. The correlation test revealed significant association between the studied parameters. The positive correlation between patients' age and kidney function means the higher the age of subjects the lower creatinine clearance value (r=-0.622, p<0.001. The negative correlation of the systolic blood pressure value and kidney function was found, meaning that higher the systolic blood

  10. Time dependent variation of human blood conductivity as a method for an estimation of RBC aggregation.

    Science.gov (United States)

    Antonova, Nadia; Riha, Pavel; Ivanov, Ivan

    2008-01-01

    Time variation of whole human blood conductivity and shear stresses were investigated at rectangular and trapezium-shaped Couette viscometric flow under electric field of 2 kHz. The kinetics of conductivity signals were recorded both under transient flow and after the complete stoppage of shearing at shear rates from 0.94 to 94.5 s(-1) and temperatures T=25 degrees C and 37 degrees C. Contraves Low Shear 30 rotational viscometer as a base unit and a concurrent measuring system, including a device, developed by the conductometric method with a software for measurement of conductivity of biological fluids (data acquisition system), previously described (IFMBE Proceedings Series, Vol. 11, 2005, pp. 4247-4252; Clin. Hemorheol. Microcirc. 35(1/2) (2006), 19-29), were used for the experiments. The obtained experimental relationships show that the human blood conductivity is time, shear rate, hematocrit and temperature dependent under transient flow. It is also dependent on the regime of the applied shear rates. Non-linear curve approximation of the growth and relaxation curves is done. The results show that valuable information could be received about the kinetics of "rouleaux formation" and the time dependences of the blood conductivity follow the structural transformations of RBC aggregates during the aggregation-disaggregation processes. The results suggest that this technique may be used to clarify the mechanism of dynamics of RBC aggregates. PMID:18503112

  11. A simple and efficient method for DNA purification from samples of highly clotted blood.

    Science.gov (United States)

    Xu, Ruyi; Ye, Ping; Luo, Leiming; Wu, Hongmei; Dong, Jin; Deng, Xinxin

    2010-11-01

    Rapid purification of DNA from samples of highly clotted blood is a challenging problem due to the difficulty in recovering and dispersing blood clots. We developed a new method for discarding the serum-separator gel and rapidly dispersing the blood clots. A special disposable tip was inserted into the serum-separator gel so that the serum-separator gel could be discarded. The blood clot obtained was dispersed into small pieces through a copper mesh (pore size, 250 μm) in a special dispersing instrument by centrifugation. After lysis of red blood cells and white blood cells, genomic DNA was concentrated and desalted by isopropanol precipitation. The mean yield of DNA purified from a 0.3-ml blood clot was 22.70 μg in 173 samples of clotted blood cryopreserved for 1 month, and 19.02 μg in 1,372 samples of clotted blood cryopreserved for >6 months. DNA samples were successfully performed through polymerase chain reaction, real time polymerase chain reaction, and melt curve analysis. Their quality was comparable with that purified directly from EDTA-anticoagulated blood. The new method overcomes the difficulties in recovering and dispersing blood clots, allowing efficient purification of DNA from samples of highly clotted blood. PMID:20549389

  12. Deformability measurement of red blood cells using a microfluidic channel array and an air cavity in a driving syringe with high throughput and precise detection of subpopulations.

    Science.gov (United States)

    Kang, Yang Jun; Ha, Young-Ran; Lee, Sang-Joon

    2016-01-01

    Red blood cell (RBC) deformability has been considered a potential biomarker for monitoring pathological disorders. High throughput and detection of subpopulations in RBCs are essential in the measurement of RBC deformability. In this paper, we propose a new method to measure RBC deformability by evaluating temporal variations in the average velocity of blood flow and image intensity of successively clogged RBCs in the microfluidic channel array for specific time durations. In addition, to effectively detect differences in subpopulations of RBCs, an air compliance effect is employed by adding an air cavity into a disposable syringe. The syringe was equally filled with a blood sample (V(blood) = 0.3 mL, hematocrit = 50%) and air (V(air) = 0.3 mL). Owing to the air compliance effect, blood flow in the microfluidic device behaved transiently depending on the fluidic resistance in the microfluidic device. Based on the transient behaviors of blood flows, the deformability of RBCs is quantified by evaluating three representative parameters, namely, minimum value of the average velocity of blood flow, clogging index, and delivered blood volume. The proposed method was applied to measure the deformability of blood samples consisting of homogeneous RBCs fixed with four different concentrations of glutaraldehyde solution (0%-0.23%). The proposed method was also employed to evaluate the deformability of blood samples partially mixed with normal RBCs and hardened RBCs. Thereafter, the deformability of RBCs infected by human malaria parasite Plasmodium falciparum was measured. As a result, the three parameters significantly varied, depending on the degree of deformability. In addition, the deformability measurement of blood samples was successfully completed in a short time (∼10 min). Therefore, the proposed method has significant potential in deformability measurement of blood samples containing hematological diseases with high throughput and precise detection of

  13. A Rapid and Low-Cost Nonlithographic Method to Fabricate Biomedical Microdevices for Blood Flow Analysis

    Directory of Open Access Journals (Sweden)

    Elmano Pinto

    2014-12-01

    Full Text Available Microfluidic devices are electrical/mechanical systems that offer the ability to work with minimal sample volumes, short reactions times, and have the possibility to perform massive parallel operations. An important application of microfluidics is blood rheology in microdevices, which has played a key role in recent developments of lab-on-chip devices for blood sampling and analysis. The most popular and traditional method to fabricate these types of devices is the polydimethylsiloxane (PDMS soft lithography technique, which requires molds, usually produced by photolithography. Although the research results are extremely encouraging, the high costs and time involved in the production of molds by photolithography is currently slowing down the development cycle of these types of devices. Here we present a simple, rapid, and low-cost nonlithographic technique to create microfluidic systems for biomedical applications. The results demonstrate the ability of the proposed method to perform cell free layer (CFL measurements and the formation of microbubbles in continuous blood flow.

  14. Measurement of human blood viscosity by an electromagnetic spinning sphere viscometer.

    Science.gov (United States)

    Furukawa, Koji; Abumiya, Takeo; Sakai, Keiji; Hirano, Miki; Osanai, Toshiya; Shichinohe, Hideo; Nakayama, Naoki; Kazumata, Ken; Aida, Toshimitsu; Houkin, Kiyohiro

    2016-08-01

    We herein applied an electromagnetic spinning sphere (EMS) viscometer to the measurement of human blood viscosity for the first time. We collected blood samples from 100 healthy outpatient volunteers in order to analyse viscosity dependence on blood cell parameters and on the shear rate with a simple approximation formula [ηi (γ)\\, = Ai γ(- pi) + η0]. Viscosity dependence on blood cell parameters was relatively high at a high shear rate, but became lower as the shear rate decreased. The approximation formula with appropriate parameters of Ai and pi nearly faithfully reproduced actual blood rheological behaviour with a standard deviation of 1.5%. The distributions of Ai and pi values were broad, suggesting that the pattern of viscosity dependence on the shear rate varied with individual differences. The results obtained using the EMS viscometer suggest that blood viscosity values are individual-specific and actual individual measurements are important for understanding rheological conditions. PMID:27167739

  15. Uteroplacental blood flow measured by placental scintigraphy during epidural anaesthesia for caesarean section

    International Nuclear Information System (INIS)

    The uteroplacental blood flow was measured before and during epidural anaesthesia for caesarean section in 11 woman. The blood flow was measured with dynamic placental scintigraphy. After an i.v. injection of indium-113m chloride, the gamma radiation over the placenta was recorded with a computer-linked scintillation camera. The uteroplacental blood flow could be calculated from the isotope accumulation curve. The anaesthesia was performed with bupivacaine plain 0.5%, 18-22 ml and a preload of a balanced electrolyte solution 10 ml/kg b.w. was given. The placental blood flow decreased in eight patients and increased in three with a median change of -21%, not being statistically significant. No correlation between maternal blood pressure and placental blood flow was found. (author)

  16. Uteroplacental blood flow measured by placental scintigraphy during epidural anaesthesia for caesarean section

    Energy Technology Data Exchange (ETDEWEB)

    Skjoeldebrand, A.; Eklund, J.; Johansson, H.; Lunell, N.-O.; Nylund, L.; Sarby, B.; Thornstroem, S. (Departments of Anaesthesiology, Obstetrics and Gynaecology and Medical Physics, Karolinska Institute at Huddinge University Hospital, Stockholm (Sweden))

    1990-01-01

    The uteroplacental blood flow was measured before and during epidural anaesthesia for caesarean section in 11 woman. The blood flow was measured with dynamic placental scintigraphy. After an i.v. injection of indium-113m chloride, the gamma radiation over the placenta was recorded with a computer-linked scintillation camera. The uteroplacental blood flow could be calculated from the isotope accumulation curve. The anaesthesia was performed with bupivacaine plain 0.5%, 18-22 ml and a preload of a balanced electrolyte solution 10 ml/kg b.w. was given. The placental blood flow decreased in eight patients and increased in three with a median change of -21%, not being statistically significant. No correlation between maternal blood pressure and placental blood flow was found. (author).

  17. Thirty years of research on diagnostic and therapeutic thresholds for the self-measured blood pressure at home.

    NARCIS (Netherlands)

    Staessen, J.A.; Thijs, L.; Ohkubo, T.; Kikuya, M.; Richart, T.; Boggia, J.; Adiyaman, A.; Dechering, D.G.; Kuznetsova, T.; Thien, Th.; Leeuw, P de; Imai, Y.; O'brien, E.; Parati, G.

    2008-01-01

    OBJECTIVE: The goal of this review study is to summarize 30 years of research on cut-off limits for the self-measured blood pressure. METHODS: We reviewed two meta-analyses, several prospective outcome studies in populations and hypertensive patients, studies in pregnant women, three clinical trials

  18. Invasive and non-invasive methods for cardiac output measurement

    OpenAIRE

    Lavdaniti M.

    2008-01-01

    The hemodynamic status monitoring of high-risk surgical patients and critically ill patients inIntensive Care Units is one of the main objectives of their therapeutic management. Cardiac output is one of the mostimportant parameters for cardiac function monitoring, providing an estimate of whole body perfusion oxygen deliveryand allowing for an understanding of the causes of high blood pressure. The purpose of the present review is thedescription of cardiac output measurement methods as prese...

  19. Transmission line icing measurement on photogrammetry method

    Science.gov (United States)

    Huang, Huan; Ma, Xiaohong; Zhao, Lijin; Du, Hao; Luo, Hong; Mao, Xianyin; Tang, Min; Liu, Yawen

    2015-12-01

    Icing thickness parameter is the basic data for power sector to make decision for icing accident prevention. In this paper, a transmission line icing measurement method is proposed. It used the photogrammetry method to realize icing parameters measurement through the integration of high resolution camera, laser range finder and inertial measurement unit. Compared with traditional icing measurement method, this method is flexible and is the effective supplement of the fixed icing detection terminal. And its high accuracy measurement guarantees the reliability of the icing thickness parameters.

  20. Non-Invasive measurement of blood pressure - Why we should look at BP traces rather than listen to Korotkoff sounds.

    Science.gov (United States)

    Celler, Branko G; Basilakis, Jim; Goozee, Kathryn; Ambikairajah, Eliathamby

    2015-08-01

    Accurate non-invasive measurement of blood pressure in unsupervised environments continues to be a challenge, particularly in the presence of movement artefact, electrical noise and most importantly cardiac arrhythmia which are common in those aged over 65 suffering from a range of chronic conditions. Large intra personal variability in signal morphometry and amplitudes further complicates the development of reliable signal processing algorithms for NIBP measurement. In this paper we demonstrate the effect of this variability and propose that the traditional methods of human blood pressure determination by sphygmomanometry should no longer be considered a gold standard for the calibration of NIBP devices. PMID:26737650

  1. Methods for High Power EM Pulse Measurement

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2006-12-01

    Full Text Available There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday's induction law allows the measurement of generated current. For the same purpose the magneto-optic method can be utilized, with its advantages. For measurement of output microwave pulse of the generator the calorimetric method was designed and realized.

  2. Rapid method for identification of group B streptococci in neonatal blood cultures.

    OpenAIRE

    Holmes, R. L.; Harada, W A

    1981-01-01

    A rapid technique used for the identification of Streptococcus agalactiae, Lancefield group B, from the blood cultures of two neonatal infants is reported. The method utilized the Phadebact Streptococcus Test System (Pharmacia Diagnostics, Piscataway, N.J.) and the supernatant from 13- and 14-h blood cultures. Additional studies with simulated neonatal blood cultures revealed that this method was reproducible. Additional studies also revealed that some non-specific agglutination did occur, wh...

  3. Methods in pharmacology: measurement of cardiac output

    OpenAIRE

    Geerts, Bart F; Aarts, Leon P; Jansen, Jos R.

    2011-01-01

    Many methods of cardiac output measurement have been developed, but the number of methods useful for human pharmacological studies is limited. The ‘holy grail’ for the measurement of cardiac output would be a method that is accurate, precise, operator independent, fast responding, non-invasive, continuous, easy to use, cheap and safe. This method does not exist today. In this review on cardiac output methods used in pharmacology, the Fick principle, indicator dilution techniques, arterial pul...

  4. Modeling Of Blood Vessel Constriction In 2-D Case Using Molecular Dynamics Method

    CERN Document Server

    Rendi, Mohamad; Viridi, Sparisoma

    2013-01-01

    Blood vessel constriction is simulated with particle-based method using a molecular dynamics authoring software known as Molecular Workbench (WM). Blood flow and vessel wall, the only components considered in constructing a blood vessel, are all represented in particle form with interaction potentials: Lennard-Jones potential, push-pull spring potential, and bending spring potential. Influence of medium or blood plasma is accommodated in plasma viscosity through Stokes drag force. It has been observed that pressure p is increased as constriction c is increased. Leakage of blood vessel starts at 80 % constriction, which shows existence of maximum pressure that can be overcome by vessel wall.

  5. Outcome-Driven Thresholds for Home Blood Pressure Measurement International Database of HOme blood pressure in relation to Cardiovascular Outcome

    OpenAIRE

    Niiranen, T. J.; Asayama, K.; Thijs, L; Johansson, J K; Ohkubo, T.; Kikuya, M; Boggia, J.; Hozawa, A.; Sandoya, E.; Stergiou, G. S.; Tsuji, I; Jula, A. M.; Imai, Y.; Staessen, J. A.

    2013-01-01

    The lack of outcome-driven operational thresholds limits the clinical application of home blood pressure (BP) measurement. Our objective was to determine an outcome-driven reference frame for home BP measurement. We measured home and clinic BP in 6470 participants (mean age, 59.3 years; 56.9% women; 22.4% on antihypertensive treatment) recruited in Ohasama, Japan (n=2520); Montevideo, Uruguay (n=399); Tsurugaya, Japan (n=811); Didima, Greece (n=665); and nationwide in Finland (n=2075). In mul...

  6. Development of a laser speckle imaging system for measuring relative blood flow velocity

    Science.gov (United States)

    Smith, Michael S. D.; Packulak, Ernie F.; Sowa, Michael G.

    2006-09-01

    Determining the viability of damaged or surgically reconstructed tissue is critical in most plastic and reconstructive surgery procedures. Information about tissue blood flow in the region in question can make this determination much easier. Laser speckle imaging (LSI) is one technique that could potentially aid in making this determination. LSI is a non-contact full-field imaging technique with simultaneous high spatial and temporal resolution. Tissue is illuminated with diffuse red laser light and the spatial and/or temporal statistics of the resulting speckle pattern can be used to calculate relative flow velocities. We have developed a LSI system that produces relative velocity blood flow images. Bench tests of the system indicate that it may be used to distinguish between normal, decreased, and increased blood flow states of a human finger. The system has also been used to take some initial laboratory measurements using an animal model - an epigastric free flap on a rat. Preliminary results indicate that the method may be used to distinguish states of venous or arterial occlusion from unoccluded states of the skin flap. While further experimentation is necessary, these initial results indicate that LSI could be a useful aid to the plastic surgeon for assessing tissue viability.

  7. Prognostic value of blood pressure measured during hospitalization after acute myocardial infarction: an insight from survival trials

    DEFF Research Database (Denmark)

    Yap, Yee Guan; Duong, Trinh; Bland, J Martin; Malik, Marek; Torp-Pedersen, Christian Tobias; Køber, Lars; Connolly, Stuart J; Gallagher, Mark M; Camm, A John

    2007-01-01

    , CAMIAT, SWORD, TRACE and DIAMOND-MI studies with left ventricular ejection fraction less than 40% or asymptomatic ventricular arrhythmia surviving more than 45 days after MI were pooled. Systolic and diastolic blood pressures and pulse pressures were measured soon after MI (median 6 days, range 0-53 days......BACKGROUND: The prognostic value of blood pressure measured during hospitalization after acute myocardial infarction (MI) has not been investigated, particularly with regard to arrhythmic death. METHODS: A total of 3311 placebo patients (2612 men, median age 64 years; range 23-92) from the EMIAT...... pressure measured during hospitalization after acute MI significantly increased the risk of all-cause mortality [hazard ratio (HR) for 10% increase in systolic blood pressure 0.80, 95% confidence interval (CI) 0.71-0.90; P < 0.001] and arrhythmic mortality (HR 0.73, 95% CI 0.61-0.86; P = 0.001). Reduced...

  8. Heat-washout measurements compared to distal blood pressure and perfusion in orthopaedic patients with foot ulcers

    DEFF Research Database (Denmark)

    Midttun, Mette; Azad, B.B.S.; Broholm, R;

    2015-01-01

    Distal blood pressure and local skin perfusion pressure were compared to measurement of blood flow rate (BFR) measured by the heat-washout method in orthopaedic patients with and without diabetes, all with a foot ulcer in one foot, compared to healthy controls. The correlation was good between heat......-washout and distal blood pressure in patients with diabetes with and without an ulcer (P = 0·024 and 0·059, respectively). The correlation was weak in patients without diabetes with and without an ulcer, most probably due to power problems (P = 0·118 and 0·116, respectively). The correlation in the healthy...... oxygen from the surrounding tissue, and therefore, measurements are easier made in these subjects. BFR in the first toe increased significantly in all patients when the foot was moved from heart level to 50 cm below heart level (P = between 0·03 and 0·05) as previously seen in patients with claudication...

  9. Development of dual micro-PIV system for simultaneous velocity measurements: optical arrangement techniques and application to blood flow measurements

    International Nuclear Information System (INIS)

    Blood rheological characteristics can significantly vary with the motion of red blood cells (RBCs) in plasma. Moreover, RBCs show a complicated behavior in micro vessels. Thus, the determination of either plasma or blood cell velocity distribution has been the primary objective in blood flow analysis. However, the conditions during blood flow analyses are different from the actual physiological conditions, wherein the motion of the two distinct blood phases simultaneously occurs. In this study, we used an in vitro micro-particle image velocimetry, which is a reliable velocity field measurement technique, to evaluate the velocity distribution of plasma and blood cells simultaneously. Blood flow through a rectangular microchannel was determined using special optical filter arrangements and by assuming two different hematocrit values. Using the proposed technique, the averaged parabolic velocity profiles for the RBCs and plasma were successfully obtained and compared. The developed simultaneous measurement technique can be used to predict blood cell and plasma behaviors simultaneously with high accuracy under given clinical conditions. (paper)

  10. Liver kinetics of glucose analogs measured in pigs by PET: importance of dual-input blood sampling

    DEFF Research Database (Denmark)

    Munk, O L; Bass, L; Roelsgaard, K; Bender, D; Hansen, S B; Keiding, S

    2001-01-01

    parameters, because of ignorance of the dual blood supply from the hepatic artery and the portal vein to the liver. METHODS: Six pigs underwent PET after [15O]carbon monoxide inhalation, 3-O-[11C]methylglucose (MG) injection, and [18F]FDG injection. For the glucose scans, PET data were acquired for 90 min......Metabolic processes studied by PET are quantified traditionally using compartmental models, which relate the time course of the tracer concentration in tissue to that in arterial blood. For liver studies, the use of arterial input may, however, cause systematic errors to the estimated kinetic....... Hepatic arterial and portal venous blood samples and flows were measured during the scan. The dual-input function was calculated as the flow-weighted input. RESULTS: For both MG and FDG, the compartmental analysis using arterial input led to systematic underestimation of the rate constants for rapid blood...

  11. Blood flow measurement in human brain by 133Xe inhalation and single photon emission computed tomography

    International Nuclear Information System (INIS)

    Regional cerbral blood flow (rCBF) was studied tomographically in 39 volunteers in the resting state by single photon emission computed tomography with inhalation of 133Xe. In each study, rCBF in 3 slices of 2 cm thickness was measured simultaneously and changes of radioactivity in the brain were stored on the magnetic disk in 32 x 32 matrix. Activity in the arterial blood was measured by a stationary collimated scintillation detector kept over the upper chest on the right side. The algorithm for calculation of tomographic rCBF was based on a combination of ''sequence of picture method'' and ''early picture method''. Mean rCBF and its standard deviation were obtained in each pixel calculated from the rCBF value. The tomographic rCBF map having a resolution element of 17 x 17 x 20 mm were symmetrical in left and right pattern. The average cerebral and, cerebellar blood flow was 56+-8 and 54+-6 ml/100g/min respectively. Correlation between rCBF and PaCO2 was significant (P<0.01; r=0.7) and the one between rCBF and age was also significant (P<0.05; r=-0.3). When visual activation was made in one volunteer, rCBF in the occipital lobe increased and a slight increase was also noted in the frontal area. In auditory activation, rCBF in the temporal lobe increased on both sides. In stroke patients, abnormal findings appeared earlier in the rCBF study than in X-ray CT scan. (J.P.N.)

  12. Rapid and simple method for preparation of genomic DNA from easily obtainable clotted blood.

    OpenAIRE

    Kanai, N; Fujii, T.; Saito, K; Tokoyama, T

    1994-01-01

    A method was developed for the preparation of genomic DNA from clotted blood that is usually discarded after extraction, for other laboratory tests. The method, which involves proteinase K digestion, salt/chloroform extraction and 90% ethanol precipitation of DNA from clotted blood, is rapid, simple, and easy because it does not impose an extra burden on the patient.

  13. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

    1989-06-01

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO/sub 2/ did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow.

  14. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    International Nuclear Information System (INIS)

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

  15. Development of portable health monitoring system for automatic self-blood glucose measurement

    Science.gov (United States)

    Kim, Huijun; Mizuno, Yoshihumi; Nakamachi, Eiji; Morita, Yusuke

    2010-02-01

    In this study, a new HMS (Health Monitoring System) device is developed for diabetic patient. This device mainly consists of I) 3D blood vessel searching unit and II) automatic blood glucose measurement (ABGM) unit. This device has features such as 1)3D blood vessel location search 2) laptop type, 3) puncturing a blood vessel by using a minimally invasive micro-needle, 4) very little blood sampling (10μl), and 5) automatic blood extraction and blood glucose measurement. In this study, ABGM unit is described in detail. It employs a syringe type's blood extraction mechanism because of its high accuracy. And it consists of the syringe component and the driving component. The syringe component consists of a syringe itself, a piston, a magnet, a ratchet and a micro-needle whose inner diameter is about 80μm. And the syringe component is disposable. The driving component consists of body parts, a linear stepping motor, a glucose enzyme sensor and a slider for accurate positioning control. The driving component has the all-in-one mechanism with a glucose enzyme sensor for compact size and stable blood transfer. On designing, required thrust force to drive the slider is designed to be greater than the value of the blood extraction force. Further, only one linear stepping motor is employed for blood extraction and transportation processes. The experimental result showed more than 80% of volume ratio under the piston speed 2.4mm/s. Further, the blood glucose was measured successfully by using the prototype unit. Finally, the availability of our ABGM unit was confirmed.

  16. Emittance measurements by variable quadrupole method

    International Nuclear Information System (INIS)

    The beam emittance is a measure of both the beam size and beam divergence, we cannot directly measure its value. If the beam size is measured at different locations or under different focusing conditions such that different parts of the phase space ellipse will be probed by the beam size monitor, the beam emittance can be determined. An emittance measurement can be performed by different methods. Here we will consider the varying quadrupole setting method.

  17. FCM Based Blood Vessel Segmentation Method for Retinal Images

    Directory of Open Access Journals (Sweden)

    Nilanjan Dey

    2012-06-01

    Full Text Available Segmentation of blood vessels in retinal images providesearly diagnosis of diseases like glaucoma, diabeticretinopathy and macular degeneration. Among thesediseases occurrence of Glaucoma is most frequent and hasserious ocular consequences that can even lead toblindness, if it is not detected early. The clinical criteria forthe diagnosis of glaucoma include intraocular pressuremeasurement, optic nerve head evaluation, retinal nervefiber layer and visual field defects. This form of bloodvessel segmentation helps in early detection for ophthalmicdiseases, and potentially reduces the risk of blindness.The low-contrast images at the retina owing to narrowblood vessels of the retina are difficult to extract. Theselow contrast images are, however useful in revealingcertain systemic diseases. Motivated by the goals ofimproving detection of such vessels, this present workproposes an algorithm for segmentation of blood vessels,and compares the results between expert ophthalmologists’hand-drawn ground-truths and segmented image (i.e. theoutput of the present work. Sensitivity, specificity, positivepredictive value (PPV, positive likelihood ratio (PLR andaccuracy are used to evaluate overall performance. It isfound that this work segments blood vessels successfullywith sensitivity, specificity, PPV, PLR and accuracy of99.62%, 54.66%, 95.08%, 219.72 and 95.03%,respectively.

  18. Blood pressure measurement of all five fingers by strain gauge plethysmography

    DEFF Research Database (Denmark)

    Hirai, M; Nielsen, S L; Lassen, N A

    1976-01-01

    The aim of the present paper was to study the methodological problems involved in measuring systolic blood pressure in all five fingers by the strain gauge technique. In 24 normal subjects, blood pressure at the proximal phalanx of finger I and both at the proximal and the intermediate phalanx of...

  19. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... blood pressure with the development of a practical method to measure it. Physicians began to note associations between hypertension and risk of heart failure, stroke, and kidney failure. Although scientists had yet to prove that lowering blood pressure ...

  20. Measurement of blood pressure, ankle blood pressure and calculation of ankle brachial index in general practice

    DEFF Research Database (Denmark)

    Nexøe, Jørgen; Damsbo, Bent; Lund, Jens Otto;

    2012-01-01

    BACKGROUND: Low ankle brachial index (ABI) is a sensitive measure of 'burden' of atherosclerosis, indicating cardiovascular risk of the asymptomatic patient. Conventionally, ABI values......BACKGROUND: Low ankle brachial index (ABI) is a sensitive measure of 'burden' of atherosclerosis, indicating cardiovascular risk of the asymptomatic patient. Conventionally, ABI values...

  1. Changes in human cerebral blood flow and myocardial blood flow during mental stress measured by dual positron emission tomography

    International Nuclear Information System (INIS)

    Mental stress causes a substantial sympathetic response, thus increasing myocardial blood flow (MBF). However, the effects of mental stress on global cerebral blood flow (CBF) have not been elucidated. In this study, changes in CBF and MBF in relation to mental stress were measured by a dual positron emission tomography system that can measure CBF and MBF simultaneously. CBF and MBF were measured in 10 healthy men with O-15 labeled water at rest (baseline) and during the performance of a mental task that required subtraction of 7s serially from a four-digit number. Baseline global CBF and values obtained during the mental activity were 0.42±0.05 and 0.45±0.06 ml/ml/min (mean±SD), respectively. Baseline MBF and values obtained during mental activity were 0.61±0.12 and 1.09±0.58 ml/ml/min, respectively. Percent changes in CBF and MBF during mental stress were 6±11% and 78±73%, respectively. No significant difference was observed in arterial carbon dioxide tension (PaCO2) level between the mental stress and baseline conditions. MBF, blood pressure, heart rate, and plasma concentrations of adrenaline and noradrenaline increased significantly during mental stress. Sympathetic stimulation is reported to cause cerebral vasoconstriction and reduce CBF in animals. Although such a sympathetic response was observed in relation to mental stress, no significant change in CBF was observed in our subjects. (author)

  2. An Automated Method to Quantify Radiation Damage in Human Blood Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gordon K. Livingston, Mark S. Jenkins and Akio A. Awa

    2006-07-10

    Cytogenetic analysis of blood lymphocytes is a well established method to assess the absorbed dose in persons exposed to ionizing radiation. Because mature lymphocytes circulate throughout the body, the dose to these cells is believed to represent the average whole body exposure. Cytogenetic methods measure the incidence of structural aberrations in chromosomes as a means to quantify DNA damage which occurs when ionizing radiation interacts with human tissue. Methods to quantify DNA damage at the chromosomal level vary in complexity and tend to be laborious and time consuming. In a mass casualty scenario involving radiological/nuclear materials, the ability to rapidly triage individuals according to radiation dose is critically important. For high-throughput screening for dicentric chromosomes, many of the data collection steps can be optimized with motorized microscopes coupled to automated slide scanning platforms.

  3. Four Methods for Calculating Blood-loss after Total Knee Arthroplasty

    Institute of Scientific and Technical Information of China (English)

    Fu-Qiang Gao; Zi-Jian Li; Ke Zhang; Wei Sun; Hong Zhang

    2015-01-01

    Background:Currently,various calculation methods for evaluating blood-loss in patients with total knee arthroplasty (TKA) are applied in clinical practice.However,different methods may yield different results.The purpose of this study was to determine the most reliable method for calculating blood-loss after primary TKA.Methods:We compared blood-loss in 245 patients who underwent primary unilateral TKA from February 2010 to August 2011.We calculated blood-loss using four methods:Gross equation,hemoglobin (Hb) balance,the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula,and Hb-dilution.We determined Pearson's correlation coefficients for the four methods.Results:There were large differences in the calculated blood-loss obtained by the four methods.In descending order of combined correlation coefficient based on calculated blood-loss,the methods were Hb-balance,OSTHEO formula,Hb-dilution,and Gross equation.Conclusions:The Hb-balance method may be the most reliable method of estimating blood-loss after TKA.

  4. Factor analysis of multigated cardiac blood pool scintigram for the measurement of left ventricular ejection fraction

    International Nuclear Information System (INIS)

    Left ventricular ejection fraction (EF) was measured by factor analysis (FA) of multigated cardiac blood pool scintigram in 38 consecutive patients, and compared with that measured by the variable ROI method (EFVROI) with automated left ventricular contour detection. FA was automatically performed without operator intervention with a success rate of 100%. The correlation of EF with EFVROI was significant in the group of 22 patients with normal wall motion (r=0.65, p<0.001), and the entire group of patients (r=0.70, p<0.001), but not significant (p=0.19) in the group of 16 patients with abnormal wall motion. In conclusion, left ventricular ejection fraction can be estimated by factor analysis of MUGA in patients with normal wall motion. (author)

  5. Stable xenon CT measurement of cerebral blood flow in cardiac transplantation candidates: Correlation with cognitive function

    International Nuclear Information System (INIS)

    Thirteen consecutive unselected patients with NYHA class 4 cardiac failure referred for cardiac transplantation underwent neurologic examination and cerebral blood flow measurement (rCBF) using the stable xenon enhanced CT method on a GE9800 system. Eleven men and two women were studied (mean age = 43.8 +- 6.1). On neurological examination, six of the patients demonstrated normal mental function; the remaining seven patients demonstrated memory, language, or learning impairment. There was no difference in mean cardiac output between the groups (4.9 L/min +- 1.68 vs. 4.2L/min +- 1.57). rCBF was significantly reduced in the impaired group. Cognitive impairment in patients with cardiac failure can be correlated with cerebral ischemia. Stable xenon CT measurement of rCBF in transplant candidates may help identify patients requiring more rapid transplantation to prevent permanent cerebral injury

  6. Method of measuring luminescence of a material

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Steven D.

    2015-12-15

    A method of measuring luminescence of a material is disclosed. The method includes applying a light source to excite an exposed material. The method also includes amplifying an emission signal of the material. The method further includes measuring a luminescent emission at a fixed time window of about 10 picoseconds to about 10 nanoseconds. The luminescence may be radio photoluminescence (RPL) or optically stimulated luminescence (OSL).

  7. Near-infrared spectroscopy measurement of blood oxygenation content and its application in sports practice

    Science.gov (United States)

    Xu, Guodong; Gong, Hui; Ge, Xinfa; Luo, Qingming

    2003-12-01

    To research the change characteristics of blood oxygenation content in skeletal muscle, the change regularity between blood oxygenation content and exercise intensity as well as HbO2 and blood lactate acid while taking incremental exercises, we took an in vivo, real-time and continuous measurement on the blood oxygenation content of eight sportsmen when they did incremental exercises of five degrees on a power bicycle using a portable tissue oximeter which is based on the principle of near-infrared spectroscopy(NIRS), simultaneously, we detected the blood lactate acid of subjects after each degree of incremental physical load instantly using a blood lactate analysis equipment. The results showed that the content of HbO2 descended regularly while that of Hb ascended; blood volume decreased; and the density of lactate increased as the intensity of exercises was heightened. The statistics analyses showed that the relationship between HbO2 and blood lactate is rather close (correlation coefficient r=-0.918). With this discovery, a theoretical basis in measuring the relative change of blood oxygenation content non-invasively was evidenced, and a novel technology for assessing the physical situation of sportsman, grasping sports density and evaluating the training effect could be imported.

  8. Revised System to Evaluate Measurement of Blood Chemistry Data From the Japanese National Health and Nutrition Survey and Prefectural Health and Nutrition Surveys

    OpenAIRE

    ,

    2013-01-01

    Background We developed a monitoring system that uses total errors (TEs) to evaluate measurement of blood chemistry data from the National Health and Nutrition Survey (NHNS) and Prefectural Health and Nutrition Surveys (PHNS). Methods Blood chemistry data from the NHNS and PHNS were analyzed by SRL, Inc., a commercial laboratory in Tokyo, Japan. Using accuracy and precision from external and internal quality controls, TEs were calculated for 14 blood chemistry items during the period 1999–201...

  9. Cumulated blood activity measurements and modelling in patients with differentiated thyroid carcinoma

    International Nuclear Information System (INIS)

    Full text of publication follows. Introduction: the purpose of the radioiodine therapy in differentiated thyroid carcinoma (DTC) formulated by the EANM Therapy Committee is to provide advice to nuclear medicine clinicians on how to ablate thyroid remnant or treat inoperable advanced DTC or both employing large 131-iodine activities. The therapy of DTC with radioactive iodine is a standard procedure for the ablation of remnant thyroid tissue following surgery and for the treatment of iodine avid metastases. The level of administered activity in radionuclide therapy is often limited by hematological toxicity resulting from the absorbed dose delivered to the bone marrow. The purpose of this study is to validate models for calculation of an effective half-life (Teff) of 131I, blood and bone marrow dose in patients with DTC. Materials and method: the measurements of 131I concentration in blood samples have been used to estimate the marrow absorbed dose. The administered activity was 100-103 mCi (about 3.7 GBq). In 328 patients, the measurement of the exposure rate was performed at 4, 8, 18, 24, 30, 42, 54, 66 hours after administration of Na131I using well counter ISOMED 1010 for studying the absorbed dose (according to the MIRD schema) and Teff evaluation. To obtain cumulated activity in blood/red marrow two mathematical models of radioisotope elimination were used: mono-exponential and bi-exponential. Results: the majority of the activity is excreted by the patients in the first 24 hours after Na131I administration. The effective half-life of 131I ranged from 2 to 37 hours due to the first model. According to the administrated activity, the evaluation of the total absorbed dose by patients to red marrow ranged from 5.5*10-4 to 3.1*10-1 Gy. Bi-exponential model allows estimating an initial income of the 131I concentration, as well as later excretion. More precise model found 2 subgroups of patients: with fast (∼37%) and slow (∼63%) kinetics of the 131I in the blood

  10. A rapid, non enzymatic method for genomic DNA extraction from whole blood and mammalian tissues

    OpenAIRE

    Adnan F. N Al-azawy

    2011-01-01

    Although several methods have been exist for DNA extraction from blood or animal tissues samples, traditionally most of these methods consume long time and using expensive chemicals such as proteinase K or toxic organic solvent such as phenol. On the other hand, there is no rapid, simple one method for the extraction of genomic DNA from blood and animal tissues samples in the same time. Since the objective of this study was to development easy modified method for DNA extraction from differen...

  11. Phenomenon of declining blood pressure in elderly - high systolic levels are undervalued with Korotkoff method

    Directory of Open Access Journals (Sweden)

    Elmståhl Sölve

    2011-10-01

    Full Text Available Abstract Background Systolic blood pressure (SBP decline has been reported in octogenarians. The aim was to study if it could be observed while measuring SBP with two methods: Korotkoff (K-BP and Strain-Gauge-Finger-Pletysmography (SG-BP, and which of them were more reliable in expressing vascular burden. Methods A cohort of 703 men from a population of Malmö, Sweden, were included in "Men born in 1914-study" and followed-up at ages: 68 and 81 years. 176 survivors were examined with K-BP and SG-BP at both ages, and 104 of them with Ambulatory Blood Pressure at age 81/82. Ankle Brachial Index (ABI was measured on both occasions, and Carotid Ultrasound at age 81. Results From age 68 to 81, mean K-BP decreased in the cohort with mean 8.3 mmHg, while SG-BP increased with 13.4 mmHg. K-BP decreased in 55% and SG-BP in 31% of the subjects. At age 81, K-BP was lower than SG-BP in 72% of subjects, and correlated to high K-BP at age 68 (r = --.22; p Conclusion In contrast to K-BP, values of SG-BP in octogenarians strongly correlated with Ambulatory Blood Pressure. The SG-BP decline in the last decade was rare, and increasing SG-BP better than K-BP reflected advanced atherosclerosis. It should be aware, that K-BP underdetected 46% of subjects with SG-BP equal/higher than 140 mmHg at age 81, which may lead to biased associations with risk factors due to differential misclassification by age.

  12. Application of transcutaneous diffuse reflectance spectroscopy in the measurement of blood glucose concentration

    Institute of Scientific and Technical Information of China (English)

    Wenliang Chen(陈文亮); Rong Liu(刘蓉); Houxin Cui(崔厚欣); Kexin Xu(徐可欣); Lina Lü(吕丽娜)

    2004-01-01

    In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed,and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.

  13. Is it reliable to measure the forearm blood pressure in children?

    Directory of Open Access Journals (Sweden)

    Amar M Taksande

    2015-01-01

    Full Text Available Background: When the upper arm (UA is inaccessible or a standard-sized blood pressure (BP cuff is unavailable, some healthcare workers use the forearm (FA to measure BP with a mercury sphygmomanometer. Objective: The objective was to determine the accuracy of BP measurement in the arm and FA. Design: Prospective, randomized study. Setting: Department of Pediatrics, JNMC, Sawangi (Meghe Participants: A total of 72 children aged 5-15 years. Measurements: Mercury and Automatic (OMRON Tokyo, 108-0075 Japan BP measurements were recorded from the arm and FA at 2 min intervals. Results: In our study, 72 children of both sexes were enrolled. The mean age of the children was 10.13 ± 2.82 years, and 48% were females. Pearson′s correlation coefficient between FA and UA systolic BP (SBP measured by mercury was 0.782, and for diastolic BP (DBP it was 0.824. Similarly, Pearson′s correlation coefficient between FA and UA SBP measured with an automated device (OMRON was 0.843, and for DBP it was 0.846. The average readings for the SBP and DBP were higher in the FA than in the UA by approximately 3 mmHg. There was a statistically significant difference in both SBP and DBP. Conclusions: The FA is an acceptable method of BP monitoring when the UA cannot be accessed. The pressure from FA is probably higher than it would be from UA.

  14. Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Waahlin, Anders

    2012-07-01

    During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

  15. Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

    International Nuclear Information System (INIS)

    During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

  16. Biomarkers measured in buccal and blood leukocyte DNA as proxies for colon tissue global methylation

    OpenAIRE

    Ashbury, Janet E.; Taylor, Sherryl A; Tse, M Yat; Stephen C Pang; Louw, Jacob A; Vanner, Stephen J.; King, Will D

    2014-01-01

    There is increasing interest in clarifying the role of global DNA methylation levels in colorectal cancer (CRC) etiology. Most commonly, in epidemiologic studies, methylation is measured in DNA derived from blood leukocytes as a proxy measure of methylation changes in colon tissue. However, little is known about the correlations between global methylation levels in DNA derived from colon tissue and more accessible tissues such as blood or buccal cells. This cross-sectional study utilized DNA ...

  17. Doctor Reports New Way to Measure Blood Sugar

    Institute of Scientific and Technical Information of China (English)

    林徽英

    2000-01-01

    对“糖尿病”及其危害,本文有一简略说明: Diabetes occurs when blood sugar,or glucose,a source of body fuel,is toohigh and the body is not able to burn it.The disease can lead to blindness,organdiseases,stroke and death. 句中的一个动词burn令我们过目难忘。此外,此疾引起的后果也令人生畏:blindness,organ diseases,stroke and death. 要测得患者的血糖含量,就得验血,就得像本文所讲的那样“pricking(刺;戳)the skin and drawing a tiny amount of blood”。 美国宾夕法尼亚州立大学的研究人员研制了a hand—held ultrasound(超声波)machine,验血者可免受皮肉之苦,而又可测量到准确的血糖含量。 文章末尾有一条信息:美国人中糖尿病患者约占总人口的6%。

  18. Handbook of nuclear safeguards measurement methods

    International Nuclear Information System (INIS)

    This handbook is intended to be a guide to the selection of methods for meeting specific measurement requirements. The information was compiled from a survey of production facilities, the literature, and current exchange programs. The survey included bulk measurements, chemical assay, sampling techniques, isotopic measurements, passive NDA, and active NDA

  19. Contemporary methods of body composition measurement

    DEFF Research Database (Denmark)

    Fosbøl, Marie Ø; Zerahn, Bo

    2015-01-01

    Reliable and valid body composition assessment is important in both clinical and research settings. A multitude of methods and techniques for body composition measurement exist, all with inherent problems, whether in measurement methodology or in the assumptions upon which they are based....... This review is focused on currently applied methods for in vivo measurement of body composition, including densitometry, bioimpedance analysis, dual-energy X-ray absorptiometry, computed tomography (CT), magnetic resonance techniques and anthropometry. Multicompartment models including quantification of trace...

  20. Assessment of microsphere technique for measurement of capillary blood flow in random skin flaps in pigs

    International Nuclear Information System (INIS)

    In this technical paper, we reviewed the theory and methodology of the radioactive microsphere technique for determination of cardiac output and regional blood flow. Furthermore, we described two experiments conducted to assess this technique for measurement of capillary blood flow in skin-flap research. Our experimental data thus far indicated that the radioactive microsphere technique provided highly reproducible measurements for determination of capillary blood flow in 4 X 10 cm acute and delayed random skin flaps constructed in pigs. The advantages and disadvantages of this laboratory technique were also discussed

  1. Identification of Phosphoglycerate Kinase 1 (PGK1 as a reference gene for quantitative gene expression measurements in human blood RNA

    Directory of Open Access Journals (Sweden)

    Unger Elizabeth R

    2011-09-01

    gene expression results from blood RNA collected and processed by different methods with the intention of biomarker discovery. Results of this study should facilitate large-scale molecular epidemiologic studies using blood RNA as the target of quantitative gene expression measurements.

  2. Studies on 133Xe wash-out from human skin: quantitative measurements of blood flow in normal and corticosteroid-treated skin

    International Nuclear Information System (INIS)

    Blood flow was measured by the 133Xe technique in normal and corticosteroid-treated skin. Epicutaneous and intracutaneous methods of tracer application were compared in normal skin. The two labeling methods were equally suitable for measuring cutaneous blood flow provided calculations in both cases were based on a biexponential resolution of the wash-out curve in its cutaneous and subcutaneous components and provided the traumatic hyperemia phase was considered, when intracutaneous application of the tracer was used. Results were invalidated if calculations were based on initial slope of the washout curves. Topical application of beta-methasone valerate resulted in a reduction in cutaneous blood flow as measured by the intracutaneous technique with curve resolution, whereas no effect could be demonstrated when calculations were based on the initial slopes of the curves. The 133Xe technique is a simple and reliable method for measuring cutaneous blood flow, which might prove useful in estimations of penetration ability and potency of topical corticosteroids

  3. Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Anne J M Loonen

    Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

  4. Simultaneous blood flow and blood oxygenation measurements using a combination of diffuse speckle contrast analysis and near-infrared spectroscopy

    Science.gov (United States)

    Seong, Myeongsu; Phillips, Zephaniah; Mai, Phuong Minh; Yeo, Chaebeom; Song, Cheol; Lee, Kijoon; Kim, Jae Gwan

    2016-02-01

    A combined diffuse speckle contrast analysis (DSCA)-near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times (<1 ms) show a higher drop (between 50% and 66%) and recovery of 1/KS2 values after occlusion (approximately 150%), but longer exposure time (3 ms) shows more consistent hemodynamic changes. For four subjects, the 1/KS2 values dropped to an average of 82.1±4.0% during the occlusion period and the average recovery of 1/KS2 values after occlusion was 109.1±0.8%. There was also an approximately equivalent amplitude change in oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=-0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.

  5. Blood Contamination in Saliva: Impact on the Measurement of Salivary Oxidative Stress Markers

    Directory of Open Access Journals (Sweden)

    Natália Kamodyová

    2015-01-01

    Full Text Available Salivary oxidative stress markers represent a promising tool for monitoring of oral diseases. Saliva can often be contaminated by blood, especially in patients with periodontitis. The aim of our study was to examine the impact of blood contamination on the measurement of salivary oxidative stress markers. Saliva samples were collected from 10 healthy volunteers and were artificially contaminated with blood (final concentration 0.001–10%. Next, saliva was collected from 12 gingivitis and 10 control patients before and after dental hygiene treatment. Markers of oxidative stress were measured in all collected saliva samples. Advanced oxidation protein products (AOPP, advanced glycation end products (AGEs, and antioxidant status were changed in 1% blood-contaminated saliva. Salivary AOPP were increased in control and patients after dental treatment (by 45.7% and 34.1%, p<0.01. Salivary AGEs were decreased in patients after microinjury (by 69.3%, p<0.001. Salivary antioxidant status markers were decreased in both control and patients after dental treatment (p<0.05 and p<0.01. One % blood contamination biased concentrations of salivary oxidative stress markers. Saliva samples with 1% blood contamination are visibly discolored and can be excluded from analyses without any specific biochemic detection of blood constituents. Salivary markers of oxidative stress were significantly altered in blood-contaminated saliva in control and patients with gingivitis after dental hygiene treatment.

  6. Endoscopic Doppler ultrasound for measurement of azygos blood flow. Validation against thermodilution and assessment of pharmacological effects of terlipressin in portal hypertension

    DEFF Research Database (Denmark)

    Hansen, Erik Feldager; Bendtsen, Flemming; Brinch, K;

    2001-01-01

    BACKGROUND: Endoscopic ultrasound (EUS) is a new modality allowing real-time flow measurements by means of the Doppler technique. The aim of the study was to evaluate azygos blood flow measurements by endoscopic ultrasound. METHODS: Measurements of azygos blood flow by EUS and by the thermodilution...... technique were compared in 20 patients with portal hypertension. The ability of EUS flowmetry to detect changes in the azygos and portal venous flow after an intravenous dose of 2 mg of terlipressin was evaluated in 13 of the patients in a double-blind, randomized, placebo-controlled, cross-over design....... RESULTS: The EUS Doppler and thermodilution measurements correlated significantly (R=0.81, P < 0.001). The azygos blood flow was found to be 14% higher by the EUS method than by thermodilution. The coefficient of variation of the EUS Doppler measurements of the azygos blood flow was 14.8%. After...

  7. Regional cerebral blood flow in Parkinson's disease measured with N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT

    International Nuclear Information System (INIS)

    N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT studies were performed on 21 patients (13 females; 45-73 yrs) with idiopathic Parkinson's disease (PD) and 10 age-matched normal controls (39-69 yrs). Regional cerebral blood flow (rCBF) was quantitatively measured by the arterial blood sampling method. When compared with normal controls, global CBF, and rCBF in the frontal cortex and in the basal ganglia were reduced 22.1% (p123I-IMP SPECT imaging is useful for evaluation and follow-up of patients with PD. (author)

  8. Noninvasive transthoracic and transesophageal Doppler echocardiographic measurements of human coronary blood flow velocity: In vitro flow phantom validation.

    Science.gov (United States)

    Greene, E R

    2010-01-01

    Coronary angiography is limited in assessing the hemodynamic significance of a coronary lesion or the state of the coronary microcirculation. Noninvasive transthoracic (TTE) and transesophageal (TEE) Doppler echocardiography have been used to measure coronary blood flow velocity and coronary flow reserve and thus the physiology of the coronary vasculature (normal, stable or unstable lesions). A fundamental, in vitro validation of these methods with a tissue and blood mimicking flow phantom has not been reported. Accordingly, Bland-Altman 95% confidence levels for precision (repeated measures) and accuracy (comparison with time collection) were determined for both TTE and TEE measurements of simulated coronary diastolic blood velocities in 2 mm and 4 mm vessels at the normal in vivo depths of 40 mm and 60 mm. The Doppler angle was set at 45 degrees and flow velocities were varied within a normal in vivo range of 0- 150 cm/s. Confidence levels for precisions and accuracies were similar between TTE and TEE and ranged from ± 6 cm/s to ± 13 cm/s or approximately 10-15% over the range of the measured velocities. These in vitro results in a controlled flow phantom suggest that technically adequate TTE and TEE can be used to reliably measure epicardial coronary conduit artery blood flow velocities. PMID:21096876

  9. Regional blood flow during exercise in humans measured by near-infrared spectroscopy and indocyanine green

    DEFF Research Database (Denmark)

    Boushel, R; Langberg, Henning; Olesen, J;

    2000-01-01

    Using near-infrared spectroscopy (NIRS) and the tracer indocyanine green (ICG), we quantified blood flow in calf muscle and around the Achilles tendon during plantar flexion (1-9 W). For comparison, blood flow in calf muscle was determined by dye dilution in combination with magnetic resonance...... imaging measures of muscle volume, and, for the peritendon region, blood flow was measured by (133)Xe washout. From rest to a peak load of 9 W, NIRS-ICG blood flow in calf muscle increased from 2.4+/-0.2 to 74+/-5 ml x 100 ml tissue(-1) x min(-1), similar to that measured by reverse dye (77+/-6 ml x 100...

  10. Novel method for sludge blanket measurements.

    Science.gov (United States)

    Schewerda, J; Förster, G; Heinrichmeier, J

    2014-01-01

    The most widely used methods for sludge blanket measurements are based on acoustic or optic principles. In operation, both methods are expensive and often maintenance-intensive. Therefore a novel, reliable and simple method for sludge blanket measurement is proposed. It is based on the differential pressure measurement in the sludge zone compared with the differential pressure in the clear water zone, so that it is possible to measure the upper and the lower sludge level in a tank. Full-scale tests of this method were done in the secondary clarifier at the waste water treatment plant in Hecklingen, Germany. The result shows a good approximation of the manually measured sludge level. PMID:24569276

  11. Method effects and the meaning of measurement

    Directory of Open Access Journals (Sweden)

    Andrew eMaul

    2013-04-01

    Full Text Available Although the idea of a method effect in psychological measurement seems intuitively straightforward—that is, it is said to occur when any characteristic of a measurement procedure contributes variance to scores beyond what is attributable to variance in the attribute of interest—much of the surrounding conceptual vocabulary remains confused. In part, these confusions can be traced to deeper confusion in the human science literature regarding the meaning of measurement. In particular, the thinking of human scientists about method effects has been shaped by (a received wisdom regarding why method effects are problematic to begin with, and, therefore, what corrective measures are appropriate, (b the formal and implied semantics of psychometric techniques that have been developed to model method effects, and (c general philosophical undercurrents that have contributed to the collective understanding of psychological measurement. Notably, tensions between lines of thought that can be broadly characterized as empiricist and realist have contributed to uneven thinking surrounding the concept of a method effect. In this paper, it is argued that it may be possible to formulate an account of what method effects are that is coherent not only across different research traditions in the human sciences, but also with thinking found in other scientific disciplines; however, doing so requires a more explicit commitment to a realist position on measurement than is generally forthcoming from human scientists. By examining these issues, this paper hopes to contribute to semantic clarity regarding not just method effects, but also the meaning of measurement in psychology.

  12. Towards noninvasive method for the detection of pathological tissue variations by mapping different blood parameters

    Science.gov (United States)

    Abdallah, Omar; Qananwah, Qasem; Abo Alam, Kawther; Bolz, Armin

    2010-04-01

    This paper describes the development of an early detection method for probing pathological tissue variations. The method could be used for classifying various tissue alteration namely tumors tissue or skin disorders. The used approach is based on light scattering and absorption spectroscopy. Spectral content of the scattered light provides diagnostic information about the tissue contents. The importance of this method is using a safe light that has less power than the used in the imaging methods that will enable the frequent examination of tissue, while the exiting modalities have drawbacks like ionization, high cost, time-consuming, and agents' usage. A modality for mapping the oxygen saturation distribution in tissues noninvasively is new in this area of research, since this study focuses on the oxygen molecule in the tissue which supposed to be homogenously distributed through the tissues. Cancers may cause greater vascularization and greater oxygen consumption than in normal tissue. Therefore, oxygen existence and homogeneity will be alternated depending on the tissue state. In the proposed system, the signal was extracted after illuminating the tissue by light emitting diodes (LED's) that emits light in two wavelengths, red (660 nm) and infrared (880 nm). The absorption in these wavelengths is mainly due to oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) while other blood and tissue contents nearly have low effect on the signal. The backscattered signal which is received by a photodiodes array (128 PDs) was measured and processed using LabVIEW. Photoplethysmogram (PPG) signals have been measured at different locations. These signals will be used to differentiate between the normal and the pathological tissues. Variations in hemoglobin concentration and blood perfusion will also be used as an important indication feature for this purpose.

  13. Subcriticality measurement method for AGN-201 reactor

    International Nuclear Information System (INIS)

    In order to verify the feasibility and safety of reactor, reactor physics test is performed. The measurement of control rod worth occupies most of period of reactor physics test. For that reason, the new method has been studied for subcriticality measurement to reduce the test period from the economic point of view. Nevertheless, system that can measure or monitor correct subcriticality of nuclear reactor has not been developed yet. If the accurate subcriticality were measured, more efficient of operation would be available and an necessary conservativeness could be removed. In 1980s, the research about subcriticality measurement methodology was performed about subcritical reactor based accelerator, fast breeder reactor and critical experiment reactor. However, study for the Pressurized Water Reactor has been carried on recently. The crucial problem depends on how to correct the spatial effect about signal, neutron source, detector position and measured weak neutron. As the representative measurement methodology, there are Pulse Neutron Source method(PNM), Neutron Noise Analysis, neutron source multiplication method and so on. This paper shows the theoretical analysis of the modified Neutron Source multiplication method (modified NSM method) which is a subcriticality measurement methodology. In the future, measurement of subcriticality will be perform about AGN-201 reactor

  14. Blood pressure

    Science.gov (United States)

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  15. Methods of measuring residual stresses in components

    International Nuclear Information System (INIS)

    Highlights: ► Defining the different methods of measuring residual stresses in manufactured components. ► Comprehensive study on the hole drilling, neutron diffraction and other techniques. ► Evaluating advantage and disadvantage of each method. ► Advising the reader with the appropriate method to use. -- Abstract: Residual stresses occur in many manufactured structures and components. Large number of investigations have been carried out to study this phenomenon and its effect on the mechanical characteristics of these components. Over the years, different methods have been developed to measure residual stress for different types of components in order to obtain reliable assessment. The various specific methods have evolved over several decades and their practical applications have greatly benefited from the development of complementary technologies, notably in material cutting, full-field deformation measurement techniques, numerical methods and computing power. These complementary technologies have stimulated advances not only in measurement accuracy and reliability, but also in range of application; much greater detail in residual stresses measurement is now available. This paper aims to classify the different residual stresses measurement methods and to provide an overview of some of the recent advances in this area to help researchers on selecting their techniques among destructive, semi destructive and non-destructive techniques depends on their application and the availabilities of those techniques. For each method scope, physical limitation, advantages and disadvantages are summarized. In the end this paper indicates some promising directions for future developments.

  16. Measuring bovine mammary gland blood flow using a transit time ultrasonic flow probe.

    Science.gov (United States)

    Gorewit, R C; Aromando, M C; Bristol, D G

    1989-07-01

    Lactating cattle were used to validate a transit time ultrasonic blood flow metering system for measuring mammary gland arterial blood flow. Blood flow probes were surgically placed around the right external pudic artery. An electromagnetic flow probe was implanted in tandem with the ultrasonic probe in two cows for comparative measurements. The absolute accuracy of the implanted flow probes was assessed in vivo by mechanical means on anesthetized cows after 2 to 3 wk of implantation. The zero offset of the ultrasonic probes ranged from -12 to 8 ml/min. When the ultrasonic probe was properly implanted, the slopes of the calibration curves were linear and ranged from .92 to .95, tracking absolute flow to within 8%. The transit time instrument's performance was examined under a variety of physiological conditions. These included milking and hormone injections. The transit time ultrasonic flow meter accurately measured physiological changes in mammary arterial blood flow in chronically prepared conscious cattle. Blood flow increased 29% during milking. Epinephrine decreased mammary blood flow by 90 to 95%. Oxytocin doses increased mammary blood flow by 15 to 24%. PMID:2674232

  17. A study of regional cerebral blood flow by intravenous injection method of xenon-133

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was determined in man by 133Xe intravenous bolus injection technique. This method is of value especially for patients with stroke. The measuring system constituted of a 16 channel cerebrograph (rCBF 1656, Meditronic, Denmark) and a minicomputer (AI Electronics, Japan). Then, for an estimation of rCBF, two compartment analysis was applied in which a special computer program was used for this purpose. Amount of 133Xe in expired air was used for calculation, since we confirmed that 133Xe clearance in expired air was similar to that in arterial blood except for those patients with obstructive lung disease and so on. In normal adults, rCBF of the gray matter was 67 +- 13 ml/100 g brain/min (95% confidence limits). Patients who had been TIA or RIND, revealed a decrease of rCBF of 33 - 49 ml/100 g brain/min bilaterally, although they did not show any clinical signs at the time of measurement. Contrariwise, two cases of Moya-moya disease showed a normal value of rCBF at their silent periods. (author)

  18. Methods for measurement of cerebral blood flow in man

    DEFF Research Database (Denmark)

    Lassen, N A

    1976-01-01

    technique continues to be useful, modern technical improvements consisting of the use of micropipettes and a stereo microscope in combination with an image splitter and a television camera which allows the accurate assessment of diameter variations of a few percent [22]. Autoradiography of brain slices...

  19. NEW METHOD TO MEASURE PISTON SKIRT DIMENSIONS

    Institute of Scientific and Technical Information of China (English)

    Qin Yuexia; Hu Dejin

    2004-01-01

    The measurement of the middle-convex and varying ellipse profile of a piston skirt is a key technology because of its complex profile and high precision. Generally, a piston is measured on special device after it is machined. High accuracy can be achieved through this off-line measurement, but the result diverges from the actual dimension. Therefore, a no-contact in-site measurement system is proposed. A laser displacement meter is used to measure the profile of the piston skirt. A computer connected to the meter is used to process the measured data. A regression analysis method is used to process the ellipse section data. The method of moving average is used to process the middle-convex curve data. By using the given system, high measurement accuracy can be gained, and the production requirement is met.

  20. Contemporary methods of body composition measurement.

    Science.gov (United States)

    Fosbøl, Marie Ø; Zerahn, Bo

    2015-03-01

    Reliable and valid body composition assessment is important in both clinical and research settings. A multitude of methods and techniques for body composition measurement exist, all with inherent problems, whether in measurement methodology or in the assumptions upon which they are based. This review is focused on currently applied methods for in vivo measurement of body composition, including densitometry, bioimpedance analysis, dual-energy X-ray absorptiometry, computed tomography (CT), magnetic resonance techniques and anthropometry. Multicompartment models including quantification of trace elements by in vivo neutron activation analysis, which are regarded as gold standard methods, are also summarized. The choice of a specific method or combination of methods for a particular study depends on various considerations including accuracy, precision, subject acceptability, convenience, cost and radiation exposure. The relative advantages and disadvantages of each method are discussed with these considerations in mind. PMID:24735332

  1. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    DEFF Research Database (Denmark)

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...... hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...

  2. Test-Retest Repeatability of Myocardial Blood Flow Measurements using Rubidium-82 Positron Emission Tomography

    Science.gov (United States)

    Efseaff, Matthew

    Rubidium-82 positron emission tomography (PET) imaging has been proposed for routine myocardial blood flow (MBF) quantification. Few studies have investigated the test-retest repeatability of this method. Same-day repeatability of rest MBF imaging was optimized with a highly automated analysis program using image-derived input functions and a dual spillover correction (SOC). The effects of heterogeneous tracer infusion profiles and subject hemodynamics on test-retest repeatability were investigated at rest and during hyperemic stress. Factors affecting rest MBF repeatability included gender, suspected coronary artery disease, and dual SOC (p stress, and 0.95 for stress / rest myocardial flow reserve (MFR). Subjects with heterogeneous tracer infusion profiles and hemodynamic conditions had significantly less repeatable MBF measurements at rest, stress, and stress/rest flow reserve (p < 0.05).

  3. Survey of emissivity measurement by radiometric methods.

    Science.gov (United States)

    Honner, M; Honnerová, P

    2015-02-01

    A survey of the state of the art in the field of spectral directional emissivity measurements by using radiometric methods is presented. Individual quantity types such as spectral, band, or total emissivity are defined. Principles of emissivity measurement by various methods (direct and indirect, and calorimetric and radiometric) are discussed. The paper is focused on direct radiometric methods. An overview of experimental setups is provided, including the design of individual parts such as the applied reference sources of radiation, systems of sample clamping and heating, detection systems, methods for the determination of surface temperature, and procedures for emissivity evaluation. PMID:25967774

  4. Inactivation of viruses in labile blood derivatives. II. Physical methods

    International Nuclear Information System (INIS)

    The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated

  5. Combining transcutaneous blood gas measurement and pulse oximetry.

    Science.gov (United States)

    Eberhard, Patrick; Gisiger, P A; Gardaz, J P; Spahn, D R

    2002-01-01

    We are describing the preliminary results of tests performed in adult volunteers and in adult patients during and after general anesthesia with a miniaturized single sensor combining the continuous and non-invasive measurement of oxygen saturaiton by pulse oximetry (SpO2) and transcutaneous PCO2 (OxiCarbo sensor). The sensor is heated to 42 degrees C to arterialize the cutaneous tissue and is applied at the ear lobe with a special low-pressure clip. The results indicate a good agreement between ear lobe PCO2 and arterial PCO2 in the range 35 to 70 mmHg (10 patients, number of measurements 104, regression line TcPCO2 = 1.01 PaCO2 + 0.59 mmHg, bias 1.22 mmHg, SD 3.69 mmHg) and between ear lobe SpO2 and SaO2 (bias 0.44% with SD 0.77% in the range 80% to 100%, bias 1.39% with SD 1.43% in the range 60% to 80%). The ear lobe OxiCarbog sensor detects the SpO2 change 5 to 37 sec faster than a finger sensor and the PCO2 change 9 to 48 sec faster than a transcutaneous sensor fixed at the upper arm. Further improvements versus single sensors are a higher stability of the SpO2 signal and the possibility of performing long term SpO2 and PCO2 measurement at the ear lobe. PMID:11900043

  6. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    DEFF Research Database (Denmark)

    Thomsen, Henrik; Larsson, Elna-Marie; Steffensen, Elena

    2012-01-01

    Background: Perfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion...... glioblastomas. Results: rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r ¼ 0.60) and to the cerebellum (r ¼ 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated...

  7. Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mies, G.; Niebuhr, I.; Hossmann, K.A.

    A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions.

  8. Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques

    International Nuclear Information System (INIS)

    A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions

  9. Gene expression profiling of whole blood: Comparison of target preparation methods for accurate and reproducible microarray analysis

    Directory of Open Access Journals (Sweden)

    Choi Dongseok

    2009-01-01

    Full Text Available Abstract Background Peripheral blood is an accessible and informative source of transcriptomal information for many human disease and pharmacogenomic studies. While there can be significant advantages to analyzing RNA isolated from whole blood, particularly in clinical studies, the preparation of samples for microarray analysis is complicated by the need to minimize artifacts associated with highly abundant globin RNA transcripts. The impact of globin RNA transcripts on expression profiling data can potentially be reduced by using RNA preparation and labeling methods that remove or block globin RNA during the microarray assay. We compared four different methods for preparing microarray hybridization targets from human whole blood collected in PAXGene tubes. Three of the methods utilized the Affymetrix one-cycle cDNA synthesis/in vitro transcription protocol but varied treatment of input RNA as follows: i. no treatment; ii. treatment with GLOBINclear; or iii. treatment with globin PNA oligos. In the fourth method cDNA targets were prepared with the Ovation amplification and labeling system. Results We find that microarray targets generated with labeling methods that reduce globin mRNA levels or minimize the impact of globin transcripts during hybridization detect more transcripts in the microarray assay compared with the standard Affymetrix method. Comparison of microarray results with quantitative PCR analysis of a panel of genes from the NF-kappa B pathway shows good correlation of transcript measurements produced with all four target preparation methods, although method-specific differences in overall correlation were observed. The impact of freezing blood collected in PAXGene tubes on data reproducibility was also examined. Expression profiles show little or no difference when RNA is extracted from either fresh or frozen blood samples. Conclusion RNA preparation and labeling methods designed to reduce the impact of globin mRNA transcripts can

  10. Measurement of cerebral blood flow rate and its relationship with brain function using optical coherence tomography

    Science.gov (United States)

    Liu, Jian; Wang, Yi; Zhao, Yuqian; Dou, Shidan; Ma, Yushu; Ma, Zhenhe

    2016-03-01

    Activity of brain neurons will lead to changes in local blood flow rate (BFR). Thus, it is important to measure the local BFR of cerebral cortex on research of neuron activity in vivo, such as rehabilitation evaluation after stroke, etc. Currently, laser Doppler flowmetry is commonly used for blood flow measurement, however, relatively low resolution limits its application. Optical coherence tomography (OCT) is a powerful noninvasive 3D imaging modality with high temporal and spatial resolutions. Furthermore, OCT can provide flow distribution image by calculating Doppler frequency shift which makes it possible for blood flow rate measurement. In this paper, we applied OCT to measure the blood flow rate of the primary motor cortex in rats. The animal was immobilized and anesthetized with isoflurane, an incision was made along the sagittal suture, and bone was exposed. A skull window was opened on the primary motor cortex. Then, blood flow rate changes in the primary motor cortex were monitored by our homemade spectral domain OCT with a stimulation of the passive movement of the front legs. Finally, we established the relationship between blood flow rate and the test design. The aim is to demonstrate the potential of OCT in the evaluation of cerebral cortex function.

  11. Tunable laser diode system for noninvasive blood glucose measurements.

    Science.gov (United States)

    Olesberg, Jonathon T; Arnold, Mark A; Mermelstein, Carmen; Schmitz, Johannes; Wagner, Joachim

    2005-12-01

    Optical sensing of glucose would allow more frequent monitoring and tighter glucose control for people with diabetes. The key to a successful optical noninvasive measurement of glucose is the collection of an optical spectrum with a very high signal-to-noise ratio in a spectral region with significant glucose absorption. Unfortunately, the optical throughput of skin is low due to absorption and scattering. To overcome these difficulties, we have developed a high-brightness tunable laser system for measurements in the 2.0-2.5 microm wavelength range. The system is based on a 2.3 microm wavelength, strained quantum-well laser diode incorporating GaInAsSb wells and AlGaAsSb barrier and cladding layers. Wavelength control is provided by coupling the laser diode to an external cavity that includes an acousto-optic tunable filter. Tuning ranges of greater than 110 nm have been obtained. Because the tunable filter has no moving parts, scans can be completed very quickly, typically in less than 10 ms. We describe the performance of the present laser system and avenues for extending the tuning range beyond 400 nm. PMID:16390586

  12. Comparative evaluation of different methods for calculation of cerebral blood flow (CBF) in nonanesthetized rabbits

    International Nuclear Information System (INIS)

    The measurement of cerebral blood flow (CBF) by the extracranial detection of the radioactivity of 133Xe injected into an internal carotid artery has proved to be of considerable value for the investigation of cerebral circulation in conscious rabbits. Methods are described for calculating CBF from the curves of clearance of 133Xe, and include exponential analysis (two-component model), initial slope, and stochastic method. The different methods of curve analysis were compared in order to evaluate the fitness with the theoretical model. The initial slope and stochastic methods, compared with the biexponential model, underestimate the CBF by 35% and 46% respectively. Furthermore, the validity of recording the clearance curve for 10 min was tested by comparing these CBF values with those obtained from the whole curve. CBF values calculated with the shortened procedure are overestimated by 17%. A correlation exists between the ''10 min'' CBF values and the CBF calculated from the whole curve; in spite of that, the values are not accurate for limited animal populations or for single animals. The extent of the two main compartments into which the CBF is divided was also measured. There is no correlation between CBF values and the extent of the relative compartment. This fact suggests that these two parameters correspond to different biological entities

  13. Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.

    Directory of Open Access Journals (Sweden)

    Elizabeth Antoine

    Full Text Available Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of the opacity of blood and the thickness of the tissue sample. In order to overcome the limitations of optical method we demonstrate the feasibility of using phase-contrast x-ray imaging to perform microscale particle image velocimetry (PIV measurements of flow in blood perfused hydrated tissue-representative microvessels. However, phase contrast x-ray images significantly depart from the traditional PIV image paradigm, as they have high intensity background, very low signal-to-noise ratio, and volume integration effects. Hence, in order to achieve accurate measurements special attention must be paid to the image processing and PIV cross-correlation methodologies. Therefore we develop and demonstrate a methodology that incorporates image preprocessing as well as advanced PIV cross-correlation methods to result in measured velocities within experimental uncertainty.

  14. [Evaluation of NMR relaxation method as a diagnostic tool for donor blood analysis and patients with hematologic diseases and burns].

    Science.gov (United States)

    Gangardt, M G; Popova, O V; Shmarov, D A; Kariakina, N F; Papish, E A; Kozinets, G I

    2002-08-01

    Diagnostic value of the NMR-relaxation method in the blood plasma was estimated in the patients with different pathologies. The time of hydrogen nuclei longitudinal relaxation (T1) in the health donors of the blood, in the patients with oncopathology (hemoblastoses) and in the cases with anemia and burning disease were investigated. The time of the longitudinal relaxation (T1) was measured by automated NMR-relaxometer "Palma" (Russia). The working frequency was equal to 35 MHz, the temperature was 45 +/- 0.1 degrees C. For the single measurement 0.2 ml of blood obtained from heparinized venous blood 1.5 hours after its taking was used. The time of the longitudinal relaxation (T1) was shown to be 1.78 +/- 0.02 in the health donors, 1.70 +/- 0.06 s in cases with anemia, 1.97 +/- 0.48 c in patients with leucosis, 2.40 +/- 0.12 s in patients with burns. The sensitivity and the specificity of diagnostics of leucosis based upon the results of the only single T1 measurement in blood plasma were concluded to be 75%. It proves the significant T1 change both in patients with anemia and burning disease of the II-III degree. However it is evidently insufficient for selective use of NMR-relaxation blood plasma (serum) in the diagnostics of anemia and leucosis. The data obtained prove also the possibility of use of NMR-relaxation blood plasma (serum) for control of the hemostasis state during treatment or remission. PMID:12362635

  15. Reactor power measuring method and device therefor

    International Nuclear Information System (INIS)

    The present invention concerns measurement of a BWR type reactor power and provides a method of and a device for ensuring accuracy of calibration of sensitivity of neutron detectors and measurement of reactor power even if γ-ray thermometers are failed. Namely, the output signals of the γ-ray thermometers are compared with previously determined judging values to detect failures. The reactor power is measured based on the signals of neutron detectors calibrated by integral thermometers except for neutron detectors calibrated by γ-ray thermometers detected as failed. Calibration for sensitivity of neutron detectors as objects of γ-ray thermometers detected as failed is preferably prohibited. Accuracy of measurement of the reactor power can be ensured by the method described above. If axial power distribution of the reactor core is measured while eliminating the signals of γ-ray thermometers detected as failed, accuracy of the measurement of axial power distribution can be ensured. (N.H.)

  16. Speckle-based measurement of the light scattering by red blood cells in vivo

    Science.gov (United States)

    Fine, I.; Kaminsky, A.

    2011-03-01

    Optical spectroscopy approach, using non-coherent light sources, has become an important tool for non-invasive analysis in vivo. It is based on the assumption that biochemical characteristics of biological system can be determined through the optical coefficients of blood and tissue particles. Thus, in the framework of this approach, the major concern is to express the obtained optical signals in terms the optical coefficients of the single particle of blood or tissue. However, since the light propagation in tissue is dominated by the multiple-scattering component, a direct measurement of single scattering characteristics turns to be a very difficult task. Practically, only the relative changes of absorption and scattering coefficients are measured. We suggested to adopt the dynamic light scattering (DLS) or speckle technique for the determination of the light scattering coefficients of the red blood cells under stasis conditions in vivo. We assumed that under zero flow conditions the RBC movement is driven mostly by the Brownian motion. It was shown, that under appropriate measurement geometry, the measured optical signal can be decomposed into a few major components. The most dominant components are ascribed to the single backscattering and forward scattering coefficients of the red blood cells. In-vitro and in vivo experimental tests have shown a good correspondence between the theoretically estimated and experientially measured results. The obtained results indicate that the DLS technique can be adopted for the determination of blood particles scattering characteristics in addition to the movement and effective viscosity parameters measurement in vivo.

  17. New possibilities for quantitative measurements of regional cerebral blood flow with gold-195m

    International Nuclear Information System (INIS)

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. The energy spectrum of gold-195m shows two strong photon peaks, one at an energy level of 68 keV and a second at an energy-level of 262 keV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres; no look-through effect is seen. The high energy level is good for studies in posterior-anterior positions. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that, not only with freely diffusible indicators like xenon but also with nondiffusible indicators, it is possible to measure quantitatively cerebral blood flow patterns

  18. Method of wide range weak current measurement

    International Nuclear Information System (INIS)

    The authors summarize several traditional methods about weak current measurement and their characteristics, analyze the reason of traditional way which can not accommodate wide range measurement, and introduce a new project that can be used to cover over six grade without changing range, analyze its detail characteristics and get examination results on the circuit using this project

  19. Automatic disease screening method using image processing for dried blood microfluidic drop stain pattern recognition.

    Science.gov (United States)

    Sikarwar, Basant S; Roy, Mukesh; Ranjan, Priya; Goyal, Ayush

    2016-07-01

    This paper examines programmed automatic recognition of infection from samples of dried stains of micro-scale drops of patient blood. This technique has the upside of being low-cost and less-intrusive and not requiring puncturing the patient with a needle for drawing blood, which is especially critical for infants and the matured. It also does not require expensive pathological blood test laboratory equipment. The method is shown in this work to be successful for ailment identification in patients suffering from tuberculosis and anaemia. Illness affects the physical properties of blood, which thus influence the samples of dried micro-scale blood drop stains. For instance, if a patient has a severe drop in platelet count, which is often the case of dengue or malaria patients, the blood's physical property of viscosity drops substantially, i.e. the blood is thinner. Thus, the blood micro-scale drop stain samples can be utilised for diagnosing maladies. This paper presents programmed automatic examination of the dried micro-scale drop blood stain designs utilising an algorithm based on pattern recognition. The samples of micro-scale blood drop stains of ordinary non-infected people are clearly recognisable as well as the samples of micro-scale blood drop stains of sick people, due to key distinguishing features. As a contextual analysis, the micro-scale blood drop stains of patients infected with tuberculosis have been contrasted with the micro-scale blood drop stains of typical normal healthy people. The paper dives into the fundamental flow mechanics behind how the samples of the dried micro-scale blood drop stain is shaped. What has been found is a thick ring like feature in the dried micro-scale blood drop stains of non-ailing people and thin shape like lines in the dried micro-scale blood drop stains of patients with anaemia or tuberculosis disease. The ring like feature at the periphery is caused by an outward stream conveying suspended particles to the edge

  20. Measurement of human blood brain barrier integrity using 11C-inulin and positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) using 11C-inulin was demonstrated to be applicable to the clinical measurement of blood brain barrier permeability and cerebral interstitial fluid volume. Kinetic data were analyzed by application of a two compartment model, in which blood plasma and interstitial fluid spaces constitute the compartments. The blood activity contribution was subtracted from the PET count with the aid of the 11CO inhalation technique. The values we estimated in a human brain were in agreement with the reported values obtained for animal brains by the use of 14C-inulin. (orig.)

  1. The applicability of home blood pressure measurement in clinical practice: A review of literature

    Directory of Open Access Journals (Sweden)

    Willem J Verberk

    2008-01-01

    Full Text Available Willem J Verberk, Abraham A Kroon, Heidi A Jongen-Vancraybex, Peter W de LeeuwUniversity Hospital Maastricht, Department of Internal Medicine and Cardiovascular Research Institute Maastricht (CARIM, Maastricht University, The NetherlandsPurpose: To review the literature on home blood pressure measurement (HBPM, to examine its validity and applicability for clinical practice and to provide recommendations regarding HBPM assessment.Findings: HBPM can eliminate the white coat effect and offers the possibility to obtain multiple measurements under standardized conditions, which increases knowledge of overall blood pressure value. Although it is not entirely capable of replacing ambulatory blood pressure measurement (ABPM, HBPM correlates better with target organ damage and cardiovascular mortality than office blood pressure measurement (OBPM, it enables prediction of sustained hypertension in patients with borderline hypertension, and proves to be an appropriate tool for assessing drug efficacy. Additional advantages of HBPM are that it may increase drug compliance and patient’s awareness of hypertension. Overall, OBPM yield higher blood pressure values than HBPM. Differences between OBPM and HBPM tend to increase with age and are generally higher in patients without antihypertensive treatment than in patients with antihypertensive treatment.Recommendations: Measurements should be performed according to accepted guidelines and recordings should be performed with a memory equipped automatic validated device. From the data reviewed here, we recommend that HBPM be assessed monthly by taking two measurements in the morning within 1 hour after awakening and two in the evening for three consecutive days, the data from the first day should be dismissed. A subject should be labeled hypertensive if his/her HBPM value is equal to or greater than 137 mmHg systolic and/or 84 mmHg diastolic.Keywords: blood pressure, hypertension, self-measurement, home

  2. Blood Transport Method for Chromosome Analysis of Residents Living Near Semipalatinsk Nuclear Test Site

    OpenAIRE

    Rodzi, Mohd; Ihda, Shozo; Yokozeki, Masako; Takeichi, Nobuo; Tanaka, Kimio; Hoshi, Masaharu

    2009-01-01

    A study was conducted to compare the storage conditions and transportation period for blood samples collected from residents living in areas near the Semipalatinsk nuclear test site (SNTS). Experiments were performed to simulate storage and shipping environments. Phytohaemagglutinin (PHA)-stimulated blood was stored in 15-ml tubes (condition A: current transport method) in the absence or in 50-ml flasks (condition B: previous transport method) in the presence of RPMI-1640 and 20% fetal bovine...

  3. Simultaneous Pulmonary and Systemic Blood Pressure and ECG Interval Measurement in Conscious, Freely Moving Rats

    OpenAIRE

    Rey, Markus; Weber, Edgar W; Hess, Patrick D

    2012-01-01

    Here we evaluated the ability of a new, dual blood-pressure telemetry transmitter to simultaneously measure pulmonary and systemic blood pressure and the electrocardiogram in rats. The transmitter was implanted in normotensive and monocrotaline-induced pulmonary hypertensive Wistar rats, with sensing catheters placed in the pulmonary artery (channel 1) and descending aorta (channel 2). Biopotential electrodes were positioned to record an apex-based lead II electrocardiogram. Pulmonary and sys...

  4. Frequency dependence of speckle in continuous-wave ultrasound with implications for blood perfusion measurements.

    OpenAIRE

    Jansson, Tomas; Jurkonis, Rytis; Mast, T. Douglas; Persson, Hans W; Lindström, Kjell

    2002-01-01

    Speckle in continuous wave (CW) Doppler has previously been found to cause large variations in detected Doppler power in blood perfusion measurements, where a large number of blood vessels are present in the sample volume. This artifact can be suppressed by using a number of simultaneously transmitted frequencies and averaging the detected signals. To optimize the strategy, statistical properties of speckle in CW ultrasound need to be known. This paper presents analysis of the frequency separ...

  5. A noise measurement method for transformers

    International Nuclear Information System (INIS)

    A transformer manufacturer (Pauwels International in Mechelen, Belgium) and an automation firm (Simac Techniek in Veldhoven, Netherlands) developed a fast and simple method to measure the sound pressure of transformers, based on the method 'Triggered Intensity', part of the IEC-551 guideline. 5 figs

  6. Method for measuring low activity extensive samples

    International Nuclear Information System (INIS)

    This paper discusses a method of measuring low intensity gamma radiation from extensive sources using solid state detectors. In the first part the variation of the detector efficiency for a point source as a function of source position is measured. It is seen that the angular dependence is particularly important. With this response function known, a semi empirical model is developed for the computation of the efficiency in cases of extensive radiation fields. Measurements are carried out which show the adequacy of the model. The method is suitable for liquid samples such as drinkable water, industrial waste liquids and sewage liquids. It is therefore useful for water quality monitoring and pollution control. ((orig.))

  7. Methods of radon measurement and devices

    International Nuclear Information System (INIS)

    The following topics and instrumentation are discussed: The quantity to be measured; Active measurement methods (scintillation cells, ionisation chambers, electrostatic collection of decay products); Passive measurement methods (charcoal detectors; electret ion chambers; etched track detectors); and Detector considerations for large-scale surveys ('always on' or 'switchable' detectors?; response to radon-220; avoidance of electrostatic effects; quality assurance for passive radon detectors; quality control within the laboratory; external quality assurance; detectors need to be easily deliverable). It is concluded that the ideal detector for large scale surveys of radon in houses is a small, closed detector in a conducting holder which excludes radon-220, supported by rigorous quality assurance procedures. (P.A.)

  8. Standardization of Blood Growth Hormone Levels Measured by Different Kits Using a Linear Structural Relationship

    OpenAIRE

    Saito, Tomohiro; Tachibana, Katsuhiko; Shimatsu, Akira; Katsumata, Noriyuki; HIZUKA, Naomi; Fujieda, Kenji; Yokoya, Susumu; Tanaka, Toshiaki

    2006-01-01

    Accurate and reliable determination of blood growth hormone level is essential in the diagnosis and treatment of short stature children. However, measured levels differed considerably among measurement kits available in Japan until 2003. Therefore, standardization of the measured values was attempted by measuring growth hormone levels in a sample of healthy adult individuals every year using the different kits. A standardization equation was developed for each kit through linear structural re...

  9. Bone blood flow measured by 85 Sr microspheres and bone seeker clearances in the rat

    International Nuclear Information System (INIS)

    This paper investigates further the relationship between the initial bone clearance of a bone-seeking radioisotope or labeled substance and the bone blood flow. The bone blood flow of rats was modified over the widest possible range of physiological values by heating and cooling their hindlimbs. Osseous blood flow was measured by the arteriolar trapping of labeled microspheres of 15 micrometer diameter injected into the left ventricle. The plasma clearances of 45Ca and 99m Tc by bone were measured 10 min after the intravenous injection of radiocalcium and of 99m technetium pyrophosphate. The extraction ratio for 45Ca over the 10-min interval (45Ca clearance/bone plasma flow) was 0.60 for low blood flows, 0.40 for blood flows at rest, and 0.25 for high values of flow. The data for 99m Tc were, respectively, 0.68, 0.34, and 0.22. Initial bone clearances of either substance should not be used to measure the increases in bone blood flow over the values at rest

  10. Methods for Measuring Aggregate Costs of Conflict

    OpenAIRE

    Gardeazabal, Javier

    2010-01-01

    This paper reviews the methods for measuring the economic cost of conflict. Estimating the economic costs of conflict requires a counterfactual calculation, which makes this a very difficult task. Social researchers have resorted to different estimation methods depending on the particular effect in question. The method used in each case depends on the units being analyzed (firms, sectors, regions or countries), the outcome variable under study (aggregate output, market valuation of firms, mar...

  11. New methods of measuring normal acoustic impedance

    OpenAIRE

    Wayman, James L.

    1984-01-01

    In recent years new methods based on signal processing technical have been developed to measure the normal acoustic impedance of materials. These methods proved to be considerably faster easier to implement than the SRW method rhey replace. Mathematical, hardware and software aspects of these techniques are discussed and results obtained over a frequency range of 200-4000 Hz for several architectural materials are presented. NPS Foundation Research Program http://archive....

  12. Measurement of brachial artery endothelial function using a standard blood pressure cuff.

    Science.gov (United States)

    Maltz, Jonathan S; Tison, Geoffrey H; Alley, Hugh F; Budinger, Thomas F; Owens, Christopher D; Olgin, Jeffrey

    2015-11-01

    The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, laboratory-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arguably, comparable (but complementary) value in the assessment of cardiovascular health. Widespread deployment of EFMA assessment is thus a desirable clinical goal. To this end, we propose a device based on modifying the measurement protocol of a standard electronic sphygmomanometer. The protocol involves inflating the cuff to sub-diastolic levels to enable recording of the pulse waveform before and after vasodilatory stimulus. The mechanical unloading of the arterial wall provided by the cuff amplifies the distension that occurs with each pulse, which is measured as a pressure variation in the cuff. We show that the height of the rising edge of each pulse is proportional to the change in lumen area between diastole and systole. This allows the effect of vasodilatory stimuli on the artery to be measured with high sensitivity. We compare the proposed cuff flow-mediated dilation (cFMD) method to ultrasound flow-mediated dilation (uFMD). We find significant correlation (r = 0.55, p = 0.003, N = 27) between cFMD- and uFMD-based metrics obtained when the release of a 5 min cuff occlusion is employed to induce endothelial stimulus via reactive hyperemia. cFMD is approximately proportional to the square of uFMD, representing a typical increase in sensitivity to vasodilation of 300-600%. This study illustrates the potential for an individual to conveniently measure his/her EFMA by using a low-cost reprogrammed home sphygmomanometer. PMID:26393958

  13. Apparatus and method for measuring viscosity

    Science.gov (United States)

    Murphy, Jr., Robert J.

    1986-01-01

    The present invention is directed to an apparatus and method for measuring the viscosity of a fluid. This apparatus and method is particularly useful for the measurement of the viscosity of a liquid in a harsh environment characterized by high temperature and the presence of corrosive or deleterious gases and vapors which adversely affect conventional ball or roller bearings. The apparatus and method of the present invention employ one or more flexural or torsional bearings to suspend a bob capable of limited angular motion within a rotatable sleeve suspended from a stationary frame.

  14. Data Fusion Method for Manufacturing Measurement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A data fusion method of online multisensors is prop os ed in this paper based on artificial neuron. First, the dynamic data fusion mode l on artificial neuron is built. Then the calibration of data fusion is discusse d with self-adaptive weighing technique. Finally performance of the method is d emonstrated by an online vibration measurement case. The results show that the f used data are more stable, sensitive, accurate, reliable than that of single sen sor data.Data Fusion Method for Manufacturing Measure...

  15. A new method of constructing measure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By using a well known result in combinatorics, named K(o)nig Lemma, this paper generalized the method of constructing measure by repeated subdivision, which was a basic tool for fractal geometry. A more general method was presented to construct measure, which was an essential improvement to the existing result. The proof employed a skill similar to that for K(o)nig Lemma, which helped to avoid using the compactness in Euclidean space. Two conditions of the existing method were found not necessary.

  16. COMPANY PERFORMANCE MEASUREMENT AND REPORTING METHODS

    Directory of Open Access Journals (Sweden)

    Nicu Ioana Elena

    2012-12-01

    Full Text Available One of the priorities of economic research has been and remains the re-evaluation of the notion of performance and especially exploring and finding some indicators that would reflect as accurately as possible the subtleties of the economic entity. The main purpose of this paper is to highlight the main company performance measurement and reporting methods. Performance is a concept that raises many question marks concerning the most accurate or the best method of reporting the performance at the company level. The research methodology has aimed at studying the Romanian and foreign specialized literature dealing with the analyzed field, studying magazines specialized on company performance measurement. If the financial performance measurement indicators are considered to offer an accurate image of the situation of the company, the modern approach through non-financial indicators offers a new perspective upon performance measurement, which is based on simplicity. In conclusion, after the theoretical study, I have noticed that the methods of performance measurement, reporting and interpretation are various, the opinions regarding the best performance measurement methods are contradictive and the companies prefer resorting to financial indicators that still play a more important role in the consolidation of the company performance measurement than the non-financial indicators do.

  17. The measurement of digital systolic blood pressure by strain gauge technique

    DEFF Research Database (Denmark)

    Nielsen, P E; Bell, G; Lassen, N A

    1972-01-01

    The systolic blood pressure on the finger, toe, and ankle has been measured by a strain gauge technique in 10 normal subjects aged 17-31 years and 14 normal subjects aged 43-57 years. The standard deviation in repeated measurements lies between 2 and 6 mm Hg. The finger pressure in the younger...

  18. Simultaneous estimation of attenuation and structure parameters of aggregated red blood cells from backscatter measurements

    CERN Document Server

    Franceschini, Emilie; Cloutier, Guy

    2008-01-01

    The analysis of the ultrasonic frequency-dependent backscatter coefficient of aggregating red blood cells reveals information about blood structural properties. The difficulty to apply this technique in vivo is due to the frequency-dependent attenuation caused by intervening tissue layers that distorts the spectral content of backscattering properties from blood microstructures. An optimization method is proposed to simultaneously estimate tissue attenuation and blood structure factor. In an in vitro experiment, the method gave satisfactory estimates with relative errors below 22% for attenuations between 0.101 and 0.317 dB/cm/MHz, signal-to-noise ratios>28 dB and kR<2.7 (k being the wave number and R the aggregate radius).

  19. Automated counting of morphologically normal red blood cells by using digital holographic microscopy and statistical methods

    Science.gov (United States)

    Moon, Inkyu; Yi, Faliu

    2015-09-01

    In this paper we overview a method to automatically count morphologically normal red blood cells (RBCs) by using off-axis digital holographic microscopy and statistical methods. Three kinds of RBC are used as training and testing data. All of the RBC phase images are obtained with digital holographic microscopy (DHM) that is robust to transparent or semitransparent biological cells. For the determination of morphologically normal RBCs, the RBC's phase images are first segmented with marker-controlled watershed transform algorithm. Multiple features are extracted from the segmented cells. Moreover, the statistical method of Hotelling's T-square test is conducted to show that the 3D features from 3D imaging method can improve the discrimination performance for counting of normal shapes of RBCs. Finally, the classifier is designed by using statistical Bayesian algorithm and the misclassification rates are measured with leave-one-out technique. Experimental results show the feasibility of the classification method for calculating the percentage of each typical normal RBC shape.

  20. Effects of Zinc Supplementation on the Anthropometric Measurements, Lipid Profiles and Fasting Blood Glucose in the Healthy Obese Adults

    OpenAIRE

    Sepide Mahluji; Mohammad Asghari Jafarabadi; Nazila Farrin; Yaser Khaje Bishak; Majid Mobasseri; Alireza Ostadrahimi; Laleh Payahoo

    2013-01-01

    Purpose: The aim of this study was to assess the effects of zinc supplementation on anthropometric measures, improving lipid profile biomarkers, and fasting blood glucose level in obese people. Methods: This randomized, double- blind clinical trial was carried out on 60 obese participants in the 18-45 age range for one month. The participants were randomly divided into the intervention group, who received 30 mg/d zinc gluconate, and the placebo group who received 30mg/d starch. Anthropo...

  1. Quantitation of postantibiotic effect by measuring CO2 generation of bacteria with the BACTEC blood culture system.

    OpenAIRE

    Gottfredsson, M; Erlendsdottir, H; Gudmundsson, S.

    1991-01-01

    The duration of the postantibiotic effect (PAE) determined by bacterial CO2 production measured by using the BACTEC NR 730 blood culture system was compared with PAEs determined by standard viability counting. PAEs for Staphylococcus aureus after exposure to dicloxacillin, vancomycin, rifampin, gentamicin, and ciprofloxacin and for Escherichia coli after exposure to ampicillin, gentamicin, and ciprofloxacin were quantitated by the two methods, and an excellent correlation (r = 0.93) was demon...

  2. Flow Measurements in a Blood-Perfused Collagen Vessel Using X-Ray Micro-Particle Image Velocimetry.

    OpenAIRE

    Antoine, Elizabeth; Buchanan, Cara; Fezzaa, Kamel; Lee, Wah-Keat; Rylander, Nichole; Vlachos, Pavlos

    2013-01-01

    Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of th...

  3. Reliability of the Dinamap non-invasive monitor in the measurement of blood pressure of ill Asian newborns.

    Science.gov (United States)

    Chia, F; Ang, A T; Wong, T W; Tan, K W; Fung, K P; Lee, J; Khin, K

    1990-05-01

    Four hundred thirty-one paired sets of readings of systolic and diastolic blood pressure and 438 paired sets of readings of mean arterial BP from 49 ill newborns, including 21 very low birth weight infants, were analyzed for the extent and pattern of agreement and the linear relationship between the Dinamap oscillometric monitor and the direct intraarterial blood pressure readings. Agreement between the two methods was measured by the intraclass correlation, whereas the linear relationship was assessed by the product-moment correlation. The intraclass correlations for systolic, diastolic and mean blood pressures were 0.696, 0.766, and 0.781, respectively. The product-moment correlations for systolic, diastolic and mean blood pressures were 0.706, 0.768, and 0.786, respectively. BP measurements by the Dinamap monitor showed reasonably close agreement to those obtained by the intraarterial mean arterial pressure ranges above 40 mmHg. For mean arterial pressure of 40 mmHg and lower, BP readings by the Dinamap monitor tended to be higher than those obtained by the intraarterial method. These findings appeared to be consistent regardless of the birth weight of the newborn. PMID:2340688

  4. Method of optical self-mixing for pulse wave transit time in comparison with other methods and correlation with blood pressure

    Science.gov (United States)

    Meigas, Kalju; Lass, Jaanus; Kattai, Rain; Karai, Deniss; Kaik, Juri

    2004-07-01

    This paper is a part of research to develop convenient method for continuous monitoring of arterial blood pressure by non-invasive and non-oscillometric way. A simple optical method, using self-mixing in a diode laser, is used for detection of skin surface vibrations near the artery. These vibrations, which can reveal the pulsate propagation of blood pressure waves along the vasculature, are used for pulse wave registration. The registration of the Pulse Wave Transit Time (PWTT) is based on computing the time delay in different regions of the human body using an ECG as a reference signal. In this study, the comparison of method of optical self-mixing with other methods as photoplethysmographic (PPG) and bioimpedance (BI) for PWTT is done. Also correlation of PWTT, obtained with different methods, with arterial blood pressure is calculated. In our study, we used a group of volunteers (34 persons) who made the bicycle exercise test. The test consisted of cycling sessions of increasing workloads during which the HR changed from 60 to 180 beats per minute. In addition, a blood pressure (NIBP) was registered with standard sphygmomanometer once per minute during the test and all NIBP measurement values were synchronized to other signals to find exact time moments where the systolic blood pressure was detected (Korotkoff sounds starting point). Computer later interpolated the blood pressure signal in order to get individual value for every heart cycle. The other signals were measured continuously during all tests. At the end of every session, a recovery period was included until person's NIBP and heart rate (HR) normalized. As a result of our study it turned out that time intervals that were calculated from plethysmographic (PPG) waveforms were in the best correlation with systolic blood pressure. The diastolic pressure does not correlate with any of the parameters representing PWTT. The pulse wave signals measured by laser and piezoelectric transducer are very similar

  5. Track detection methods of radium measurements

    International Nuclear Information System (INIS)

    The principles of tack formation and processing including the description of etching and etch-track evaluation for the preferably used plastic track detectors are discussed. Measuring methods to determine 226Ra activity based either on the mapping of alpha-decaying elements in the complete U-Ra series by alpha-radiography, or on the measurement of uranium alone by neutron induced fissionography, or on the alpha-decay measurement of 222Rn, the first daughter element of radium, and finally on the measurement of alpha-tracks originating from radium itself, which is separated from its parent nuclides are described in detail. (V.N.)

  6. Measurement error models, methods, and applications

    CERN Document Server

    Buonaccorsi, John P

    2010-01-01

    Over the last 20 years, comprehensive strategies for treating measurement error in complex models and accounting for the use of extra data to estimate measurement error parameters have emerged. Focusing on both established and novel approaches, ""Measurement Error: Models, Methods, and Applications"" provides an overview of the main techniques and illustrates their application in various models. It describes the impacts of measurement errors on naive analyses that ignore them and presents ways to correct for them across a variety of statistical models, from simple one-sample problems to regres

  7. A simple DNA coprecipitation method for the detection of diatoms in heart blood.

    Science.gov (United States)

    Seo, Yasuhisa; Sato, Shingo; Kuroki, Kohji; Kishida, Tetsuko

    2013-10-10

    We developed a method for detecting and enumerating diatoms in the heart blood of drowning victims and evaluate its utility for diagnosing death by drowning. For purification of diatoms from blood, the DNA binding ability of the diatom frustule in the presence of a chaotropic agent was utilized. The procedure is basically the same as the commonly used method for DNA purification from blood using Proteinase K treatment and denaturation by a chaotropic agent. DNA adsorbed to the diatom (DNA/diatom complex) is recovered by ethanol precipitation, and the DNA is subsequently digested using DNase. Purified diatoms could be clearly observed under a microscope. Diatoms spiked in the blood of non-drowned cadavers (n=15) were well recovered, and were detected in heart blood from all drowning victims (n=22). The mean number of diatoms found in 5 ml of blood from drowning victims was 7.8±5.8 (mean±SD), and the number of diatoms detected in the blood of the left ventricle (6.1±5.8) was approximately two times higher than that of the right ventricle (3.0±2.7, p<0.05). These results suggest that this simple and safe method can become an effective tool for diagnosing the cause of death as drowning. PMID:24053875

  8. Heterogeneity in white blood cells has potential to confound DNA methylation measurements.

    Directory of Open Access Journals (Sweden)

    Bjorn T Adalsteinsson

    Full Text Available Epigenetic studies are commonly conducted on DNA from tissue samples. However, tissues are ensembles of cells that may each have their own epigenetic profile, and therefore inter-individual cellular heterogeneity may compromise these studies. Here, we explore the potential for such confounding on DNA methylation measurement outcomes when using DNA from whole blood. DNA methylation was measured using pyrosequencing-based methodology in whole blood (n = 50-179 and in two white blood cell fractions (n = 20, isolated using density gradient centrifugation, in four CGIs (CpG Islands located in genes HHEX (10 CpG sites assayed, KCNJ11 (8 CpGs, KCNQ1 (4 CpGs and PM20D1 (7 CpGs. Cellular heterogeneity (variation in proportional white blood cell counts of neutrophils, lymphocytes, monocytes, eosinophils and basophils, counted by an automated cell counter explained up to 40% (p<0.0001 of the inter-individual variation in whole blood DNA methylation levels in the HHEX CGI, but not a significant proportion of the variation in the other three CGIs tested. DNA methylation levels in the two cell fractions, polymorphonuclear and mononuclear cells, differed significantly in the HHEX CGI; specifically the average absolute difference ranged between 3.4-15.7 percentage points per CpG site. In the other three CGIs tested, methylation levels in the two fractions did not differ significantly, and/or the difference was more moderate. In the examined CGIs, methylation levels were highly correlated between cell fractions. In summary, our analysis detects region-specific differential DNA methylation between white blood cell subtypes, which can confound the outcome of whole blood DNA methylation measurements. Finally, by demonstrating the high correlation between methylation levels in cell fractions, our results suggest a possibility to use a proportional number of a single white blood cell type to correct for this confounding effect in analyses.

  9. MEASUREMENT OF VITAMIN B12 CONCENTRATION: A REVIEW ON AVAILABLE METHODS

    OpenAIRE

    Karmi O et al

    2011-01-01

    Vitamin B12 is a water-soluble vitamin. It is one of the eight vitamins of vitamin B complex, needed for blood and cell maturation. It helps maintain healthy nerve cells and red blood cells, and it is needed in DNA replication. Its deficiency may cause megaloblastic anemia (amidst others health issues). For these and many similar reasons, it sometimes becomes necessary to measure its concentration. This article has carefully reviewed the different methods used for measuring vitamin B12 concen...

  10. Integration of optical measurement methods with flight parameter measurement systems

    Science.gov (United States)

    Kopecki, Grzegorz; Rzucidlo, Pawel

    2016-05-01

    During the AIM (advanced in-flight measurement techniques) and AIM2 projects, innovative modern techniques were developed. The purpose of the AIM project was to develop optical measurement techniques dedicated for flight tests. Such methods give information about aircraft elements deformation, thermal loads or pressure distribution, etc. In AIM2 the development of optical methods for flight testing was continued. In particular, this project aimed at the development of methods that could be easily applied in flight tests in an industrial setting. Another equally important task was to guarantee the synchronization of the classical measuring system with cameras. The PW-6U glider used in flight tests was provided by the Rzeszów University of Technology. The glider had all the equipment necessary for testing the IPCT (image pattern correlation technique) and IRT (infrared thermometry) methods. Additionally, equipment adequate for the measurement of typical flight parameters, registration and analysis has been developed. This article describes the designed system, as well as presenting the system’s application during flight tests. Additionally, the results obtained in flight tests show certain limitations of the IRT method as applied.

  11. Regional blood flow with first circulation time-indicator curves: a simplified, physiologic method of interpretation

    International Nuclear Information System (INIS)

    Dynamic computed tomography, digital subtraction angiography, and radionuclide angiography can all be used to evaluate regional blood flow noninvasively. Although regional blood flow cannot be determined uniquely from first circulation time-indicator curves, relative transit time to and through the regions of interest and relative regional blood volume in the regions of interest can be measured and related to relative regional blood flow using a modified Stewart-Hamilton equation. However, for precise mathematical calculation, extrapolation of the first circulation data beyond the point of recirculation is required. Indices of transit time and regional volume that do not require extrapolation were evaluated in an experimental model. The correlation coefficients between the indices of transit time and volume and the more mathematically precise measurements were 0.99 and 0.95, respectively (p < 0.01). It is suggested that these indices, which can also be evaluated visually, are useful in interpreting first circulation time-indicator curves in a physiologic manner

  12. Measurement of anisotropic reflection of flowing blood using optical coherence tomography

    Science.gov (United States)

    Nam, Kweon-Ho; Jeong, Bosu; Jung, In Oh; Ha, Hojin; Kim, Ki Hean; Lee, Sang Joon

    2011-12-01

    Light reflectance of blood is a complex phenomenon affected by hematocrit and red blood cell (RBC) aggregation (rouleaux formation). According to the hypothesis that RBC rouleaux are aligned with the direction of blood flow, the spatial alignment of RBC rouleaux, as well as their size and quantity in the blood, may also affect light reflectance. The present study aims to investigate the effect of the spatial alignment and distribution of RBC rouleaux on light reflection using optical coherence tomography (OCT). Blood flow velocity and reflectance profiles in a rat jugular-femoral bypass loop were simultaneously measured using a Doppler swept-source OCT system at various incident angles from -30 to +30 deg. The reflectance profiles of flowing blood show nonmonotonous decay with a local negative peak at the center of the tube. The profiles vary depending on the incident angle. This angular dependence is stronger at a higher angle of incidence. The anisotropic reflectance of flowing blood is consistent with the hypothesis on the spatial alignment of RBC rouleaux.

  13. Prompt gamma-ray spectrometry for measurement of B-10 concentration in brain tissue and blood

    International Nuclear Information System (INIS)

    Boron-10 (B-10) concentration in the brain tissue and blood was measured continuously for 24 hours after injection of the B-10 compound in live rabbits using prompt gamma-ray spectrometry. Following injection of B-10 compound (Na2B12H11SH, 50mg/kg) dissolved in physiological saline, B-10 concentration was continuously measured in the brain tissue. Intermittently the concentration of B-10 in blood and cerebro-spinal fluid (CSF) was also measured. In 10 minutes after the injection of B-10 compound, the level of B-10 concentration reached the peak of 400-500 ppm in blood and 20-30 ppm in the normal brain tissue. In 60 minutes the level of B-10 concentration rapidly decreased and then a gradual decline was observed. The value was 15-30 ppm at 3 hours after injection, 5-10 ppm at 6 hours and 2-5 ppm at 24 hours in the blood. The concentration in the brain tissue was 3-8 ppm at 3 hours, 2-5 ppm at 6 hours and below 1.5 ppm at 24 hours. B-10 concentration in cerebro-spinal fluid was below 1 ppm. B-10 concentration was also measured in the brain tumor and blood in the human cases at boron neutron capture therapy (BNCT). These data studied by prompt gamma-ray spectrometry are very important and useful to decide the irradiation time. (author)

  14. Measuring density and compressibility of white blood cells and prostate cancer cells by microchannel acoustophoresis

    DEFF Research Database (Denmark)

    Barnkob, Rune; Augustsson, Per; Magnusson, Cecilia; Lilja, Hans; Laurell, Thomas; Bruus, Henrik

    determine the density and compressibility of individual cells enables the prediction and alteration of the separation outcome for a given cell mixture. We apply the method on white blood cells (WBCs) and DU145 prostate cancer cells (DUCs) aiming to improve isolation of circulating tumor cells from blood, an......We present a novel method for the determination of density and compressibility of individual particles and cells undergoing microchannel acoustophoresis in an arbitrary 2D acoustic field. Our method is a critical advancement within acoustophoretic separation of biological cells, as the ability to...... emerging tool in the monitoring and characterizing of metastatic cancer....

  15. Factors affecting radioactive microsphere measurement of blood flow in pregnant guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Myers, S.; Sparks, J.W.; Makowski, E.L.

    1986-10-01

    Comparative blood flow studies were performed in pregnant guinea pigs using radioactive microspheres to test the effects of different sphere sizes on blood flow measurements and the relationship between flows obtained intraoperatively and those performed after 5 days of recovery from anesthesia and surgery. We observed that 1.5% of the cardiac output was shunted through the microcirculation of the carcass, gut, skin and endomyometrium when 15 mu microspheres were used. Intraoperative measurements of heart rate, cardiac output and placental blood flow are significantly lower than measurements made after 5 days recovery. These reductions were ameliorated with the addition of a continuous infusion of isoproterenol and the deletion of atropine from the anesthetic.

  16. MRI-compatible noninvasive continuous blood pressure measurement using fiber optics

    Science.gov (United States)

    Harja, Juha; Myllylä, Teemu S.; Sorvoja, Hannu S. S.; Myllylä, Risto A.; Elseoud, Ahmed A.; Nikkinen, Juha; Kiviniemi, Vesa; Tervonen, Osmo

    2010-02-01

    This report focuses on designing and implementing a non-invasive blood pressure measuring device capable of being used during magnetic resonance imaging. This device is based on measuring pulse wave velocity in arterial blood and using the obtained result to estimate diastolic blood pressure. Pulse transit times are measured by two fibre optical accelerometers placed over chest and carotid artery. The fabricated accelerometer contains two static fibres and a cantilever beam. The free end of the beam is angled at 90 degrees to act as a reflecting surface. Optical fibres are used for both illuminating the surface and receiving the reflected light. Acceleration applied to the sensor causes deflection of the beam, whereupon the amount of reflected light changes. The sensor output voltage is proportional to the intensity of the reflected light. Tests conducted on the electronics and sensors inside an MRI room during scanning proved that the device is MR conditional. No artifacts or distortions were detected.

  17. Factors affecting radioactive microsphere measurement of blood flow in pregnant guinea pigs

    International Nuclear Information System (INIS)

    Comparative blood flow studies were performed in pregnant guinea pigs using radioactive microspheres to test the effects of different sphere sizes on blood flow measurements and the relationship between flows obtained intraoperatively and those performed after 5 days of recovery from anesthesia and surgery. We observed that 1.5% of the cardiac output was shunted through the microcirculation of the carcass, gut, skin and endomyometrium when 15 mu microspheres were used. Intraoperative measurements of heart rate, cardiac output and placental blood flow are significantly lower than measurements made after 5 days recovery. These reductions were ameliorated with the addition of a continuous infusion of isoproterenol and the deletion of atropine from the anesthetic

  18. Risk of malaria transmission through blood transfusion and its detection by serological method

    International Nuclear Information System (INIS)

    Objective: To assess the risk of transmission of malaria through blood transfusion, and compare efficacy of testing by immuno chromatographic (ICT) devices vis a vis peripheral blood film (PBF). Results: Amongst healthy blood donors we did not find even a single case of malaria and there was no report of persistent post transfusion pyrexia. We are unable to comment on species frequency in blood donors. However, amongst known patients of malaria we found a higher frequency of Plasmodium viax(P.v) as compared to Plasmodium falciparum(P.f). Testing by serological method, helped us to diagnose 5% of our patients who were missed by peripheral blood films. Conclusion: Between properly selected voluntary non-remunerated blood donors the incidence of malaria transmission is zero and the blood is safe for transfusion. Serological testing shows good correlation with peripheral blood film detection. In fact, it can detect the disease even when film detection has been unsuccessful. If proper donor selection criteria are observed there is little risk of transmitting malaria through transfusion. However, as the donor pool in the Service is not necessarily totally the of voluntary non-remunerated donors and substantive numbers of replacement/first time, occasionally uneducated/unaware donors, are being bled, screening for malaria will not be totally unrewarding. (author)

  19. Metabolic and kinetic considerations in the use of [125I]HIPDM for quantitative measurement of regional cerebral blood flow

    International Nuclear Information System (INIS)

    The metabolic degradation and the kinetics of the cerebral uptake of N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-[125I]iodobenzyl)-1, 3-propanediamine ([125I]HIPDM) have been studied in conscious, adult male Sprague-Dawley rats to determine its suitability as a tracer for the quantitative measurement of regional CBF (rCBF). rCBF was calculated by the indicator fractionation and the tissue equilibration methods in experiments of different durations up to 1 h. The values of rCBF obtained with [125I]HIPDM were compared with those obtained in concurrent measurements with [14C]iodoantipyrine in the same animals. Results of the experiments demonstrate that [125I]HIPDM is an inadequate tracer for use with the indicator fractionation method and that any method that employs [125I]HIPDM for the determination of rCBF must take into account its metabolic degradation, diffusion limitations, and bidirectional flux across the blood-brain barrier. With the tissue equilibration method, consistent determinations of rCBF may be possible with [125I]HIPDM by measurement of the time course of its concentration in arterial blood, corrected for the presence of 125I-labeled metabolic products, and its concentration in the brain at any time up to 1 h after its administration. The method may be adapted to measure rCBF in humans by means of single-photon emission tomography with [123I]HIPDM

  20. Evaluation of oscillometric and Doppler ultrasonic devices for blood pressure measurements in anesthetized and conscious dogs.

    Science.gov (United States)

    Vachon, Catherine; Belanger, Marie C; Burns, Patrick M

    2014-08-01

    Two non-invasive blood pressure (NIBP) devices (oscillometry and Doppler) were compared to invasive blood pressure using a Bland-Altman analysis, in anesthetized and conscious dogs. When considering the systolic arterial pressure only during general anesthesia, both NIBP devices slightly underestimated the systolic arterial blood pressure however the precision and the limits of agreement for the Doppler were of a greater magnitude. This indicates a worse clinical performance by the Doppler. The performance of both NIBP devices deteriorated as measured in conscious animals. In general, for the oscillometric device, determination of invasive diastolic and mean arterial pressures was better than the invasive systolic arterial pressure. Overall, the oscillometric device satisfied more of the criteria set by the American College of Veterinary Internal Medicine consensus statement. Based upon these results, the oscillometric device is more reliable than the Doppler in the determination of blood pressure in healthy medium to large breed dogs. PMID:24924217

  1. Model for validation of radioimmunoassay kit reagents: measurement of follitropin and lutropin in blood and urine

    International Nuclear Information System (INIS)

    We measured lutropin and follitropin in blood and urine with radioimmunoassay kits from Diagnostic Products Corporation and compared the results with those obtained by use of re agents from the National Institutes of health (NIH) and the World Health Organization (WHO). The urine standard (second IRP-HMG) from WHO, the blood standard (LER-907) from NIH, and the commercial standards all effected similar displacement of trace material when the commercial gonadotropin kit reagents were used. Highly significant correlations were achieved for these hormones in blood or urine on comparing commercial and NIH/WHO reagents. Serial dilutions of urine samples produced similar relative potencies with the commercial reagents. Conversion factors are presented to relate results for LER-907, second IRP, or commercial standards. Commercially available reagents can provide a practical and reliable means of gonadotropin radioimmunoassay in blood or urine

  2. Human performance assessment: methods and measures

    International Nuclear Information System (INIS)

    The Human Error Analysis Project (HEAP) was initiated in 1994. The aim of the project was to acquire insights on how and why cognitive errors occur when operators are engaged in problem solving in advanced integrated control rooms. Since human error had not been studied in the HAlden Man-Machine LABoratory (HAMMLAB) before, it was also necessary to carry out research in methodology. In retrospect, it is clear that much of the methodological work is relevant to human-machine research in general, and not only to research on human error. The purpose of this report is, therefore, to give practitioners and researchers an overview of the methodological parts of HEAP. The scope of the report is limited to methods used throughout the data acquisition process, i.e., data-collection methods, data-refinement methods, and measurement methods. The data-collection methods include various types of verbal protocols, simulator logs, questionnaires, and interviews. Data-refinement methods involve different applications of the Eyecon system, a flexible data-refinement tool, and small computer programs used for rearranging, reformatting, and aggregating raw-data. Measurement methods involve assessment of diagnostic behaviour, erroneous actions, complexity, task/system performance, situation awareness, and workload. The report concludes that the data-collection methods are generally both reliable and efficient. The data-refinement methods, however, should be easier to use in order to facilitate explorative analyses. Although the series of experiments provided an opportunity for measurement validation, there are still uncertainties connected to several measures, due to their reliability still being unknown. (Author). 58 refs.,7 tabs

  3. Global Precipitation Measurement: Methods, Datasets and Applications

    Science.gov (United States)

    Tapiador, Francisco; Turk, Francis J.; Petersen, Walt; Hou, Arthur Y.; Garcia-Ortega, Eduardo; Machado, Luiz, A. T.; Angelis, Carlos F.; Salio, Paola; Kidd, Chris; Huffman, George J.; De Castro, Manuel

    2011-01-01

    This paper reviews the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases. The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used.

  4. Methods and Devices used to Measure Friction

    DEFF Research Database (Denmark)

    Jeswiet, Jack; Arentoft, Mogens; Henningsen, Poul

    2004-01-01

    . To gain a good understanding of the mechanisms at the interface and to be able to verify the friction and tribology models that exist, friction sensors are needed. Designing sensors to measure friction-stress in metal working has been pursued by many researchers. This paper surveys methods, which...... have been tried in the past and discusses some of the recent sensor designs, which can now be used to measure Friction in both production situations and for research purposes....

  5. In Vivo Measurements Of Coronary Blood Volumi By Dye And Inert Gas Dilution Technic

    Science.gov (United States)

    Hoeft, A.; Korb, H.; Wolpers, H. G.

    1984-10-01

    The application of a double fiberoptic device for measurements of arterial and coronary venous dye dilution curves facilitates the determination of coronary mean transit times even under clinical conditions. Since the dye, indocyanine green, is an intravascular tracer, the calculation of tissue blood flow would be possible if the intracoronary blood volume per unit of muscular weight is known. This study was therefore designed to investigate the physiologic range and the influence of coronary vasodilation and different hemodynamic conditions on the amount of myocardial blood volume. All experiments were carried out on anaesthetized close chest mongrel dogs in heart catheterization technic. Myocardial preload, afterload and inotropism and coronary vascular tone were varied by induction of hypo-, normo- and hypervolemia as well as by intravenous application of catecholamines, 13-blocking agents and vasodilating drugs. The determination of coronary blood volume was based on arterial and coronary venous kinetics of the intravascular tracer indocyanine green and the freely diffusible tracers helium and argon. Simultaneous measurements of the dye and the inert gases were obtained by a double fiberoptic system and a twin mass spectrometer, respectively. The intravascular and the tissue mean transit times as well as the coronary blood volume per unit of tissue weight were computed from the impulse response functions obtained by numerical deconvolution of the arterial and coronary venous indicator dilution curves. In contrast to reports of other authors coronary blood volume did not increase to a major extend during coronary vasodilation or elevated afterload. These new results suggest that the variation of coronary blood volume described in the literature is mainly due to methodological errors resulting from monoexponential extrapolation and distortion of the dye signal by the sampling catheter. These systematic errors, which, in particular, lead to an overestimation of

  6. THE USE OF REPEAD MEASUREMENTS METHOD FOR

    Directory of Open Access Journals (Sweden)

    Gürol ZIRHLIOĞLU

    2009-08-01

    Full Text Available The repeated measurements method is used to get information about one or more than one effects of factors by means of repeated experiments in different place, time and materials. In this study, mixed model method related tok repeated measurement is used for the analysis of the Turkish Women’s National Volleyball Team players who participated World Championship which organizated in Japan in 2006 and investigated players perfomance whether changed according to mathces and won points scored. According to the results, it is concluded that significant differences between players’ match performance might be obtained.

  7. Penetration depth time history measurement method

    OpenAIRE

    Liu, C; Ahrens, T. J.

    2000-01-01

    A new method for measuring the depth time history of rigid body penetration into brittle materials under a deceleration of ~10^5 g. The method includes: sabot-projectile, sabot-projectile separation and penetration depth detection systems. Relatively small intrinsic time error (3%) and depth error (0.3–0.7 mm) results. Penetration depth time history in a series of 4140 steel projectile penetrations into a mortar are measured at velocities of 100 to 500 m/sec with sufficient accuracy such that...

  8. Three methods to measure RH bond energies

    International Nuclear Information System (INIS)

    In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies

  9. Evaluation of an immunomagnetic separation method to capture Candida yeasts cells in blood

    Directory of Open Access Journals (Sweden)

    Poulain Daniel

    2008-09-01

    Full Text Available Abstract Background Candida species have become the fourth most-frequent cause of nosocomial bloodstream infections in immunocompromised patients. Therefore, rapid identification of pathogenic fungi to species level has been considered critical for treatment. Conventional diagnostic procedures such as blood culture or biochemical tests are lacking both sensitivity and species specificity, so development of rapid diagnostic is essential. Results An immunomagnetic method involving anti-Candida monoclonal antibodies was developed to capture and concentrate in human blood four different species of Candida cells responsible for invasive yeast infections. In comparison with an automated blood culture, processing time of immunomagnetic separation is shorter, saving at least 24 hours to obtain colonies before identification. Conclusion Thus, this easy to use method provides a promising basis for concentrating all Candida species in blood to improve sensitivity before identification.

  10. Comparison of blood chemistry values for samples collected from juvenile chinook salmon by three methods

    Science.gov (United States)

    Congleton, J.L.; LaVoie, W.J.

    2001-01-01

    Thirteen blood chemistry indices were compared for samples collected by three commonly used methods: caudal transection, heart puncture, and caudal vessel puncture. Apparent biases in blood chemistry values for samples obtained by caudal transection were consistent with dilution with tissue fluids: alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), triglyceride, and K+ were increased and Na+ and Cl- were decreased relative to values for samples obtained by caudal vessel puncture. Some enzyme activities (ALT, AST, LDH) and K+ concentrations were also greater in samples taken by heart puncture than in samples taken by caudal vessel puncture. Of the methods tested, caudal vessel puncture had the least effect on blood chemistry values and should be preferred for blood chemistry studies on juvenile salmonids.

  11. Is it reliable to measure the forearm blood pressure in children?

    OpenAIRE

    Amar M. Taksande; Aishwarya Jadhav; Jyoti Nair

    2015-01-01

    Background: When the upper arm (UA) is inaccessible or a standard-sized blood pressure (BP) cuff is unavailable, some healthcare workers use the forearm (FA) to measure BP with a mercury sphygmomanometer. Objective: The objective was to determine the accuracy of BP measurement in the arm and FA. Design: Prospective, randomized study. Setting: Department of Pediatrics, JNMC, Sawangi (Meghe) Participants: A total of 72 children aged 5-15 years. Measurements: Mercury and Automatic (OMRON Tokyo, ...

  12. Analytical method of PBDES and PCBS from small volume human blood

    Energy Technology Data Exchange (ETDEWEB)

    Fujimine, Y.; Koizumi, A. [Kyoto Univ. (Japan); Mochizuki, A.; Hirai, T. [Otsuka Pharmaceutical, Tokushima (Japan)

    2004-09-15

    In order to conduct the epidemiological survey for children and old peoples, it is necessary to develop/improve the analytical method with which to conduct the analysis in smaller volume of blood samples because the blood volume from these subjects are normally allowed to take less than 5mL. For these purposes, we developed the Small Volume method (SV-method) using HRGC/HRMS for the PCBs and PBDEs analysis. The SV method for PCB can start the analysis only with 1.0 mL of whole blood and that for PBDE with 1.5 mL of whole blood, respectively; these methods showed the ultra high sensitivity. However the SV-method can not determine all isomer of PCBs and PBDEs but only predominant isomers of those chemicals. In the Healthy volunteers examination, the SV-PCB determined 13 isomers and the SV-PBDE method determined 4 isomers, respectively. By the way, SV-PCB and SV-PBDE method determined almost all levels in the sample; SV-PCB is 75% as compared with sum of all PCB isomers level, SV-PBDE is 82% as compared with sum of all PBDE isomers level. In summary, SV-method using HRGC/HRMS can determine approximate and predominant isomers levels of PCBs and PBDEs, making it possible to evaluate the human exposure to these chemicals. In this paper, the method of SV-PCB and SV-PBDE were described with precision date.

  13. Context classification during blood pressure self-measurement using the sensor seat and the audio classification device

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Rasmussen, Niels Holm; Ahrendt, Peter;

    2012-01-01

    Blood pressure self-measurement (BPSM) requires the patient to follow a range of recommendations. Patients must remain silent during measurements, be seated correctly with back support and legs uncrossed, and must have rested at least 5 minutes prior to taking the measurement. Current blood...... process, as well as a sensor seat for measuring patient posture and activity before and during the BPSM process....

  14. Improved method to measure urinary alkoxyacetic acids

    OpenAIRE

    Shih, T. S.; Chou, J. S.; Chen, C Y; Smith, T.J.

    1999-01-01

    OBJECTIVES: To simplify the current preparation of samples, and to improve the specificity and reliability of the conventional analytical methods to measure urinary alkoxyacetic acids. METHODS: Samples containing alkoxyacetic acids including methoxy, ethoxy, and butoxyacetic acids (MAA, EAA, and BAA) were acidified with HCl and extracted with a mixed solvent of methylene chloride and isopropyl alcohol, then analysed by gas chromatography/mass spectrometry (GC/MS). RESULTS: Optimal resul...

  15. Evaluation of renal function in children by radionuclide renography using 99mTc-DTPA and a single blood sample method

    International Nuclear Information System (INIS)

    The method of calculating the glomerular filtration rate (GFR) by the single blood sample method with a gamma camera and well scintillation counter was assessed as a method of quantitative evaluation of renal function in children. The subjects were 16 children suspected of having renal dysfunction. Renography using 99mTc-DTPA with a gamma camera was performed and the radioisotope was counted. Blood samples were taken, and GFR was calculated by measuring the plasma counts with a well counter. The gamma camera values were matched with the well counter values. GFR values by the single blood sample method were compared with GFR values obtained by Gates' method (which is usually used in adults) and Schwarz' method (known as an easy method of calculation in children). GFR by the single blood sample method was conveniently calculated by using the conversion formula obtained from the regression for the relation between the gamma camera and well scintillation counter values. The results suggested that GFR can be calculated and renal function evaluated more accurately by combined use of the single blood sample method during 99mTc-DTPA renography. Renal uptake rate after correction for body surface area correlated with GFR by the single blood sample method. It was possible to establish a formula for calculating GFR in children from the gamma camera data that corresponds to the Gates method for adults. (K.H.)

  16. Minimally invasive blood sampling method for genetic studies on Gopherus tortoises

    OpenAIRE

    García–Feria, L. M.; Ureña–Aranda, C. A.; Espinosa de los Monteros, A.

    2015-01-01

    Obtaining good quality tissue samples is the first hurdle in any molecular study. This is especially true for studies involving management and conservation of wild fauna. In the case of tortoises, the most common sources of DNA are blood samples. However, only a minimal amount of blood is required for PCR assays. Samples are obtained mainly from the brachial and jugular vein after restraining the animal chemically, or from conscious individuals by severe handling methods and clamping. Herein,...

  17. Implementation of a new cost efficacy method for blood irradiation using a non dedicated device

    OpenAIRE

    Foddai Maria; Giordano Carolina; D'Alessio Daniela; Soriani Antonella; Pinnarò Paola; Pinzi Valentina; Strigari Lidia

    2011-01-01

    Abstract Objectives To implement a new cost efficacy internal Service for blood component irradiation, we carried out specific procedures and quality assurance reports using the linear accelerators (LINACs) of the Regina Elena Institute (IRE) Radiotherapy Department instead of a dedicated device. Methods The technical aspects, quality assurance and regulatory requirements of the internal procedure to set up a local irradiated blood bank have been defined. The LINACs of the IRE Radiotherapy De...

  18. Scale Space Methods for Analysis of Type 2 Diabetes Patients' Blood Glucose Values

    OpenAIRE

    Stein Olav Skrøvseth; Fred Godtliebsen

    2011-01-01

    We describe how scale space methods can be used for quantitative analysis of blood glucose concentrations from type 2 diabetes patients. Blood glucose values were recorded voluntarily by the patients over one full year as part of a self-management process, where the time and frequency of the recordings are decided by the patients. This makes a unique dataset in its extent, though with a large variation in reliability of the recordings. Scale space and frequency space techniques are suited to ...

  19. Measurement of cerebral blood flow in the pig by the Xe-133 clearance technique

    International Nuclear Information System (INIS)

    The Xe-133 clearance technique is used to measure cerebral blood flow in the pig, which often serves as an experimental animal for cardiovascular research. The clearance curves are fitted by a two-exponential model. However, the fitted parameters are incompatible with a two-compartmental model: the values found for the parameters depend on the length of the clearance curve analysed. The discrepancies are thought to be consequences of the heterogeneity of cerebral blood flow and of mathematical problems of parameter identification. The non-validity of the relative weight of the fast clearance component as an anatomical or functional parameter is demonstrated. The use of the mean time constant, mean transit time, mean decay constant and initial slope for determination of cerebral blood flow rates is discussed. The mean cerebral blood flow of the anaesthetized pig measured by the clearance technique is found to be lower than the blood flow measured by means of a flow probe around the common carotid artery (with the external carotid artery tied off). The existence of a significant arteriovenous shunt flow is postulated. (orig.)

  20. Determination of the amplitude and phase relationships between oscillations in skin temperature and photoplethysmography-measured blood flow in fingertips

    International Nuclear Information System (INIS)

    temperature, and define possibilities and limitations of temperature measurements as a method of blood flow assessment in extremities. (paper)

  1. Ratio method of measuring W boson mass

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Feng [Stony Brook Univ., NY (United States)

    2010-08-01

    This dissertation describes an alternative method of measuring the W boson mass in DØ experiment. Instead of extracting MW from the fitting of W → ev fast Monte Carlo simulations to W → ev data as in the standard method, we make the direct fit of transverse mass between W → ev data and Z → ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (MW/MZ). Given the precisely measured Z boson mass, W mass is directly fitted from W → ev and Z → ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb-1 DØ Run IIa dataset, ratio method gives MW = 80435 ± 43(stat) ± 26(sys) MeV.

  2. Ratio method of measuring $w$ boson mass

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Feng; /SUNY, Stony Brook

    2010-08-01

    This dissertation describes an alternative method of measuring the W boson mass in D0 experiment. Instead of extracting M{sub W} from the fitting of W {yields} e{nu} fast Monte Carlo simulations to W {yields} e{nu} data as in the standard method, we make the direct fit of transverse mass between W {yields} e{nu} data and Z {yields} ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (M{sub W}/M{sub Z}). Given the precisely measured Z boson mass, W mass is directly fitted from W {yields} e{nu} and Z {yields} ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb{sup -1} D0 Run IIa dataset, ratio method gives M{sub W} = 80435 {+-} 43(stat) {+-} 26(sys) MeV.

  3. Measurement of mercury species in human blood using triple spike isotope dilution with SPME-GC-ICP-DRC-MS.

    Science.gov (United States)

    Sommer, Yuliya L; Verdon, Carl P; Fresquez, Mark R; Ward, Cynthia D; Wood, Elliott B; Pan, Yi; Caldwell, Kathleen L; Jones, Robert L

    2014-08-01

    The measurement of different mercury compounds in human blood can provide valuable information about the type of mercury exposure. To this end, our laboratory developed a biomonitoring method for the quantification of inorganic (iHg), methyl (MeHg), and ethyl (EtHg) mercury in whole blood using a triple-spike isotope dilution (TSID) quantification method employing capillary gas chromatography (GC) and inductively coupled dynamic reaction cell mass spectrometry (ICP-DRC-MS). We used a robotic CombiPAL(®) sample handling station featuring twin fiber-based solid-phase microextraction (SPME) injector heads. The use of two SPME fibers significantly reduces sample analysis cycle times making this method very suitable for high sample throughput, which is a requirement for large public health biomonitoring studies. Our sample preparation procedure involved solubilization of blood samples with tetramethylammonium hydroxide (TMAH) followed by the derivatization with sodium tetra(n-propyl)borate (NaBPr(4)) to promote volatility of mercury species. We thoroughly investigated mercury species stability in the blood matrix during the course of sample treatment and analysis. The method accuracy for quantifying iHg, MeHg, and EtHg was validated using NIST standard reference materials (SRM 955c level 3) and the Centre de Toxicologie du Québec (CTQ) proficiency testing (PT) samples. The limit of detection (LOD) for iHg, MeHg, and EtHg in human blood was determined to be 0.27, 0.12, and 0.16 μg/L, respectively. PMID:24948088

  4. Determination of hepatic fractional clearance of radioactive gold colloids for a measure of effective hepatic blood flow

    International Nuclear Information System (INIS)

    For a measure of effective blood flow, a hepatic fractional clearance of 198Au-colloids was determined, which was obtained from the disappearance rate multiplied by the fraction of injected dose taken up by the liver. The hepatic uptake was determined with a gamma camera. The counts over the liver was corrected for body weight and height. The method was considered sufficiently simple for routine use. 198Au-colloids were obtained from Dainabot Lab. and CIS. The former gave 64% higher values of disappearance rate than the latter, without any change in the organ distribution. A quality control tests were applied over a six-year period to the disappearance rates. Reproducibility within 95 to confidence limits was found for both groups. In 28 normal control subjects, hepatic fractional clearance of the colloids from Dainabot Lab. was 18.5 +- 3.4%/min. In patients with progressed hepatic disease, both hepatic fractional clearance and final hepatic uptake were decreased, showing that the determination of hepatic uptake is necessary in measuring effective hepatic blood flow by the colloidal clearance method. The influence of splenic uptake is discussed in relation to hepatic blood flow measurement. (author)

  5. Endoscopic Doppler ultrasound for measurement of azygos blood flow. Validation against thermodilution and assessment of pharmacological effects of terlipressin in portal hypertension

    DEFF Research Database (Denmark)

    Bendtsen, Flemming; Brinch, K; Møller, Søren; Henriksen, Jens Henrik Sahl; Becker, Povl Ulrik; Hansen, Erik Feldager

    2001-01-01

    technique were compared in 20 patients with portal hypertension. The ability of EUS flowmetry to detect changes in the azygos and portal venous flow after an intravenous dose of 2 mg of terlipressin was evaluated in 13 of the patients in a double-blind, randomized, placebo-controlled, cross-over design......BACKGROUND: Endoscopic ultrasound (EUS) is a new modality allowing real-time flow measurements by means of the Doppler technique. The aim of the study was to evaluate azygos blood flow measurements by endoscopic ultrasound. METHODS: Measurements of azygos blood flow by EUS and by the thermodilution...... measurement of the azygos blood flow correlate strongly to the measurements by the thermodilution technique, and EUS is moreover well tolerated by the patients. The method is applicable for monitoring pharmacological effects on the superior porto-systemic collateral circulation and portal venous flow in...

  6. Radionuclide left ventricular absolute volume determination by ejection fraction measurement data and a left posterior oblique blood pool image

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Shinichiro (Saitama Medical School, Moroyama (Japan))

    1989-09-01

    A new method for the calculation of left ventricular volumes called the 'semi-geometric' method, was reported by Nichols et al in 1984. This method, however, still had certain limitations for practical use. This paper describes a modified semi-geometric method in which the left ventricular volume was obtained from conventional left ventricular ejection fraction measurement data collected from the modified left anterior oblique position with a caudal tilt of 10 degrees or more and a left posterior oblique blood pool image. The left ventricular end-diastolic volumes obtained by this method were compared with those calculated by combining the thermodilution cardiac output and the left ventricular ejection fraction. The correlation coefficient was r=0.93 (n=20). In the phantom experiment, the true volumes and those obtained by this method showed an excellent correlation (r=0.99). This method is considered accurate and practical. (author).

  7. Methods for the Measurement of Psychological Performance.

    Science.gov (United States)

    Biesheuvel, S., Ed.

    The aim of this handbook is to provide in a brief form comparable methods and guidelines for psychological measurements of all races in different parts of the world living under different environmental stresses. Ancillary individual and group information, psychophysiological, psychomotor, perceptual and high level mental tests are analyzed within…

  8. Blood Pressure Drop Prediction by using HRV Measurements in Orthostatic Hypotension.

    Science.gov (United States)

    Sannino, Giovanna; Melillo, Paolo; Stranges, Saverio; De Pietro, Giuseppe; Pecchia, Leandro

    2015-11-01

    Orthostatic Hypotension is defined as a reduction of systolic and diastolic blood pressure within 3 minutes of standing, and may cause dizziness and loss of balance. Orthostatic Hypotension has been considered an important risk factor for falls since 1960. This paper presents a model to predict the systolic blood pressure drop due to orthostatic hypotension, relying on heart rate variability measurements extracted from 5 minute ECGs recorded before standing. This model was developed and validated with the leave-one-out cross-validation technique involving 10 healthy subjects, and finally tested with an additional 5 healthy subjects, whose data were not used during the training and cross-validation process. The results show that the model predicts correctly the systolic blood pressure drop in 80 % of all experiments, with an error rate below the measurement error of a sphygmomanometer digital device. PMID:26345451

  9. Free thyroxin measured in dried blood spots from normal, low-birth-weight, and hypothyroid neonates.

    Science.gov (United States)

    Lemonnier, F; Masson, J; Laroche, D; Travert, J; Travert, G

    1991-12-01

    We have adapted a new radioimmunoassay for free thyroxin (FT4) measurement in dried blood spots for use in neonatal screening for hypothyroidism. The method is easy, fast, and cheap. Within-assay and between-assay CVs are respectively 9.6% and 13.2%. In 997 neonates three days postpartum with normal thyrotropin concentrations, the mean FT4 concentration was 27.2 pmol/L (SD 7.3 pmol/L). There was no significant difference in mean FT4 concentration between boys and girls. FT4 concentrations increased linearly with birth weight or with gestational age, as expressed by multiple linear regression: FT4 (pmol/L) = 0.0016 birth weight (g) + 0.6931 gestational age (weeks) - 4.8772. Only gestational age significantly affected the FT4 value. For five hypothyroid infants tested on day three postpartum, FT4 values were all below the 1st percentile of values from healthy neonates. Thus, when the neonatal concentration of thyrotropin is above normal, FT4 measured in the same sample can provide a reliable earlier diagnosis of hypothyroidism. PMID:1764786

  10. Techniques for the measurement and monitoring of carbon dioxide in the blood.

    Science.gov (United States)

    Huttmann, Sophie E; Windisch, Wolfram; Storre, Jan H

    2014-05-01

    The relationship between an elevated partial pressure of carbon dioxide (Pco2) and reduced alveolar ventilation resulting from respiratory failure primarily affecting the respiratory pump was first reported during the 1952 Copenhagen polio epidemic. Several methods for Pco2 estimation, such as blood gas analyses, capnography, and transcutaneous Pco2 measurements, have since been developed to assess alveolar ventilation. The clinical setting in which CO2 measurement is valuable includes acute and chronic respiratory failure, transport, cardiopulmonary resuscitation, patient-controlled analgesia, and procedural sedation. The techniques that are currently available differ considerably regarding their accuracy, capacity to facilitate continuous assessment, side effects, availability, and their ability to assess additional information. Importantly, each technique has its own spectrum of indications and applications. Therefore, the different techniques are not competitive but, rather, complementary. As a consequence, it is reasonable to combine different techniques depending on specific clinical scenarios. This review summarizes the physiological background, historical development, instrument-specific technical aspects, and current recommendations for the clinical application of Pco2 assessment. PMID:24701974

  11. PET measured evoked cerebral blood flow responses in an awake monkey

    International Nuclear Information System (INIS)

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments

  12. Studying red blood cell agglutination by measuring membrane viscosity with optical tweezers

    Science.gov (United States)

    Fernandes, Heloise P.; Fontes, Adriana; de Thomaz, André A.; Barbosa, Luiz C.; Barjas-Castro, Maria L.; Cesar, Carlos L.

    2007-09-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycoproteins embedded in a fluid lipid bilayer that are responsible for cell agglutination. Manipulating RBCs rouleaux with a double optical tweezers, we observed that the cells slide easily one over the others but are strongly connected by their edges. An explanation for this behavior could be the fact that when the cells slide one over the others, proteins are dragged through the membrane. It confers to the movement a viscous characteristic that is dependent of the velocity between the RBCs and justifies why is so easy to slide them apart. Therefore, in a first step of this work, by measuring the force as a function of the relative velocity between two cells, we confirmed this assumption and used this viscous characteristic of the RBC rouleaux to determine the apparent membrane viscosity of the cell. As this behavior is related to the proteins interactions, we can use the apparent membrane viscosity to obtain a better understanding about cell agglutination. Methods related to cell agglutination induced by antigen-antibody interactions are the basis of most of tests used in transfusion centers. Then, in a second step of this work, we measured the apparent membrane viscosity using antibodies. We observed that this methodology is sensitive to different kinds of bindings between RBCs. Better comprehension of the forces and bindings between RBCs could improve the sensibility and specificity of the hemagglutination reactions and also guides the development of new potentiator substances.

  13. Sitting and standing blood pressure measurements are not accurate for the diagnosis of orthostatic hypotension.

    LENUS (Irish Health Repository)

    Cooke, J

    2012-01-31

    INTRODUCTION: Orthostatic hypotension (OH) is associated with troublesome symptoms and increased mortality. It is treatable and deserving of accurate diagnosis. This can be time consuming. The current reference standard for its diagnosis is head-up tilt (HUT) testing with continuous beat-to-beat plethysmography. Our objective was to assess the accuracy of sit-stand testing with semi-automatic sphygmomanometry for the diagnosis of OH. DESIGN: Retrospective test of diagnostic accuracy. METHODS: This was a retrospective study performed using a database maintained by a busy syncope unit. HUT testing was performed using an automated tilt table with Finometer monitoring. A 3 min 70 degrees HUT was performed following 5 min supine. Sitting blood pressure (BP) was measured following 3 min rest. Standing BP was measured within 30 s of assuming the upright posture. The results of sit-stand testing were compared with HUT testing as a reference standard. Both tests happened within 5 min of each other and patients underwent no intervention between tests. RESULTS: From a total of 1452 consecutive HUTs, we identified 730 with pre-test measures of sitting and standing BP. The mean age of this group was 70.57 years (SD = 15.1), 62% were female. The sensitivity of sit-stand testing was calculated as 15.5%, specificity as 89.9%, positive predictive value as 61.7%, negative predictive value as 50.2% and the likelihood ratio as 1.6. The area under the Receiver Operator Curve was 0.564. CONCLUSION: We have demonstrated that sit-stand testing for OH has very low diagnostic accuracy. We recommend that the more time-consuming reference standard method of diagnosis be used if the condition is suspected.

  14. Measurement methods for estimating performance of dispersants

    International Nuclear Information System (INIS)

    Experiments were conducted with four test methods used to evaluate the performance of oil spill dispersant agents. Tests were performed with five types of oil and three types of commercially available dispersants. Statistical analyses of the test results on the effects of experimental variables (test method, oil type, dispersant type, and analytical wavelength in ultraviolet spectrophotometric measurements) are presented and discussed. Statistics showed that the means of the results obtained from the study are statistically significant at the 95% confidence level between the test methods for various combinations of dispersants and oil. Preliminary statistical analyses showed that of the four test methods, the swirling flask procedure developed by Environment Canada gave the best estimate of precision (repeatability). Estimates of repeatability obtained from the four methods varied from 19% to 24%. 19 refs., 5 figs., 11 tabs

  15. Measurement of regional extravascular lung density and of pulmonary blood volume with positron emitting isotopes

    International Nuclear Information System (INIS)

    Studies of pulmonary blood volume changes with exercice can be performed after labelling of the blood pool by 11CO inhalation. Positron transaxial tomography permits the quantitative study of density distribution of the chest and of the pulmonary blood volume. This paper represents our preliminary experience with these techniques on models and control patients. We have first verified the linearity of transmission for density distribution below one. The tomographic examination first records a transmission image, then an emission image on the same section. We next normalize emission and transmission values on a region of unit density corresponding to blood: then we substract the emission from the transmission values to measure the extravascular pulmonary density. With crystal probes we record pulmonary blood volume variations before, during and after exercise. Peripheral hemodynamic variations explain the change recorded at the begining and at the end of exercise. Combination of these two techniques should help us to better study the importance of the acute changes in the ''formation'' of pulmonary oedema and its influence on regional pulmonary blood volume

  16. Regional cerebral blood flow measurement using N-isopropyl-p-[123I] iodoamphetamine and rotating gamma camera emission computed tomography

    International Nuclear Information System (INIS)

    Thirty-one regional cerebral blood flow (rCBF) measurements were performed on 26 patients with cerebrovascular accidents using N-Isopropyl-p-[123I] Iodoamphetamine (123I-IMP) and rotating gamma camera emission computed tomography (ECT). The equation for determining rCBF is as follows: F=100.R.Cb/(N.A), where F is rCBF in ml/100 g/min., R is the constant withdrawal rate of arterial blood in ml/min., Cb is the brain activity concentration in μCi/g, A is the total activity (5 min.) in the withdrawal arterial whole blood in μCi and N is the fraction of A that is true tracer activity (0.75). In determining Cb at 5 min. after injection, reconstructed counts from 35 min. to 59 min. were corrected to represent those from 4 min. to 5 min. with the use of time activity curve for the entire brain immediately after injection to 30 min. Reconstructed counts of central region in tomographic image were corrected 118% of the obtained values from the result of the countingrate ratio between peripheral and central regions of interests obtained from phantom study. Brain mean blood flow values were distributed from 11 to 39 ml/100 g/min. In 119 cortical regions obtained from 11 measurements in 9 patients, there was a significant correlation (r=0.41, p123I-IMP and rotating gamma camera ECT and those from 133Xe inhalation method. rCBF measurement using 123I-IMP and rotating gamma camera ECT is not only relatively noninvasive measurement for the entire brain but also three-dimensional evaluation. Besides, it is superior in spatial resolution and accuracy to conventional 133Xe clearance method. (author)

  17. Oscillometric measurement of systolic and diastolic blood pressures validated in a physiologic mathematical model

    Directory of Open Access Journals (Sweden)

    Babbs Charles F

    2012-08-01

    Full Text Available Abstract Background The oscillometric method of measuring blood pressure with an automated cuff yields valid estimates of mean pressure but questionable estimates of systolic and diastolic pressures. Existing algorithms are sensitive to differences in pulse pressure and artery stiffness. Some are closely guarded trade secrets. Accurate extraction of systolic and diastolic pressures from the envelope of cuff pressure oscillations remains an open problem in biomedical engineering. Methods A new analysis of relevant anatomy, physiology and physics reveals the mechanisms underlying the production of cuff pressure oscillations as well as a way to extract systolic and diastolic pressures from the envelope of oscillations in any individual subject. Stiffness characteristics of the compressed artery segment can be extracted from the envelope shape to create an individualized mathematical model. The model is tested with a matrix of possible systolic and diastolic pressure values, and the minimum least squares difference between observed and predicted envelope functions indicates the best fit choices of systolic and diastolic pressure within the test matrix. Results The model reproduces realistic cuff pressure oscillations. The regression procedure extracts systolic and diastolic pressures accurately in the face of varying pulse pressure and arterial stiffness. The root mean squared error in extracted systolic and diastolic pressures over a range of challenging test scenarios is 0.3 mmHg. Conclusions A new algorithm based on physics and physiology allows accurate extraction of systolic and diastolic pressures from cuff pressure oscillations in a way that can be validated, criticized, and updated in the public domain.

  18. Doppler measurements of feto-placental blood stream in pregnant smokers

    Directory of Open Access Journals (Sweden)

    Gordana Bogdanović

    2011-12-01

    Full Text Available Introduction: Doppler analysis of the feto-placental and fetal circulation give dynamic information on the condition of the bloodstream during pregnancy, and early detection of fetal hypoxia. The objectives of the study were: testing whether there is influence of smoking on feto-placental circulation; determining whether there is a link to a number of smoked cigarettes during the day; assessing the benefits of Doppler ultrasonographic screening in detection of fetal hypoxia in pregnant women who smoke during pregnancy.Methods: 300 pregnancies were included in the prospective research. With regard to a number of smoked cigarettes the pregnant women were divided into three groups: I. the first group (moderate smokers consisted of 100 pregnant women who smoked up to 15 cigarettes a day during pregnancy; II. the second group (heavy smokers 100 pregnant women who smoked more than 15 cigarettes a day during pregnancy and III. the third group (control group 100 pregnant women who did not smoke during pregnancy. All pregnant women underwent Doppler measurements of blood circulation (determination of resistance index – RI in the umbilical artery, fetal aorta and middle cerebral artery.Results: The intensity of smoking has influence to circulation because RI in the umbilical artery and fetal aorta is increased and RI is decreased in the middle cerebral artery in pregnant women heavy smokers in comparison to pregnant women moderate smokers.Conclusion: Doppler sonography of the blood vessels could have an important role in detection of hypoxia and monitoring of the condition of the fetus of pregnant women who smoked during pregnancy.

  19. Measurement of changes in blood oxygenation using Multispectral Optoacoustic Tomography (MSOT) allows assessment of tumor development

    Science.gov (United States)

    Tomaszewski, Michal R.; Quiros-Gonzalez, Isabel; Joseph, James; Bohndiek, Sarah E.

    2016-03-01

    The ability to evaluate tumor oxygenation in the clinic could indicate prognosis and enable treatment monitoring, since oxygen deficient cancer cells are more resistant to chemotherapy and radiotherapy. MultiSpectral Optoacoustic Tomography (MSOT) is a hybrid technique combining the high contrast of optical imaging with the spatial resolution and penetration depth similar to ultrasound. We aim to demonstrate that MSOT can be used to monitor the development of tumor vasculature. To establish the relationship between MSOT derived imaging biomarkers and biological changes during tumor development, we performed MSOT on nude mice (n=10) bearing subcutaneous xenograft U87 glioblastoma tumors using a small animal optoacoustic tomography system. The mice were maintained under inhalation anesthesia during imaging and respired oxygen content was modified between 21% and 100%. The measurements from early (week 4) and late (week 7) stages of tumor development were compared. To further explore the functionality of the blood vessels, we examined the evolution of changes in the abundance of oxy- and deoxyhemoglobin in the tumors in response to a gas challenge. We found that the kinetics of the change in oxygen saturation (SO2) were significantly different between small tumors and the healthy blood vessels in nearby normal tissue (p=0.0054). Furthermore, we showed that there was a significant difference in the kinetics of the gas challenge between small and large tumors (p=0.0015). We also found that the tumor SO2 was significantly correlated (p=0.0057) with the tumor necrotic fraction as assessed by H&E staining in histology. In the future, this approach may be of use in the clinic as a method for tumor staging and assessment of treatment response.

  20. Measurement of regional hepatic blood flow and scintigraphic imaging of portal circulation with /sup 133/Xe

    Energy Technology Data Exchange (ETDEWEB)

    Kroiss, A. (Krankenanstalt der Stadt Wien Rudolfstiftung (Austria) 1. Medizinische Abt.)

    1980-01-01

    Regional hepatic blood flow has been determined by 4 methods with the aid of /sup 133/Xe washout technique: 1. scintisplenoportography (direct application of /sup 133/Xe into the spleen by means of a thin needle); 2. arterial method (/sup 133/Xe is injected into the A. hepatica by means of a catheter); 3. retrograde-venous method (/sup 133/Xe administered by an occluding hepatic vein catheter); 4. percutaneous intrahepatic method (/sup 133/Xe administered directly into the parenchyma by means of a Chiba needle). It was possible to demonstrate that hepatic blood flow values established with the aid of /sup 133/Xe are independent of the form of application (scintisplenoportography, arterial method, retrograde-venous method).

  1. Bayesian methods for measures of agreement

    CERN Document Server

    Broemeling, Lyle D

    2009-01-01

    Using WinBUGS to implement Bayesian inferences of estimation and testing hypotheses, Bayesian Methods for Measures of Agreement presents useful methods for the design and analysis of agreement studies. It focuses on agreement among the various players in the diagnostic process.The author employs a Bayesian approach to provide statistical inferences based on various models of intra- and interrater agreement. He presents many examples that illustrate the Bayesian mode of reasoning and explains elements of a Bayesian application, including prior information, experimental information, the likelihood function, posterior distribution, and predictive distribution. The appendices provide the necessary theoretical foundation to understand Bayesian methods as well as introduce the fundamentals of programming and executing the WinBUGS software.Taking a Bayesian approach to inference, this hands-on book explores numerous measures of agreement, including the Kappa coefficient, the G coefficient, and intraclass correlation...

  2. EVALUATION OF METHODS FOR ANALYSIS OF HUMAN FAT, SKIN, NAILS, HAIR, BLOOD AND URINE

    Science.gov (United States)

    The research program surveyed and evaluated the methods and procedures to identify and quantitate chemical constituents in human tissues and fluids including fat, skin, nails, hair, blood, and urine. These methods have been evaluated to determine their ease and rapidity, as well ...

  3. Impact of red blood cell transfusion on global and regional measures of oxygenation.

    Science.gov (United States)

    Roberson, Russell S; Bennett-Guerrero, Elliott

    2012-01-01

    Anemia is common in critically ill patients. Although the goal of transfusion of red blood cells is to increase oxygen-carrying capacity, there are contradictory results about whether red blood cell transfusion to treat moderate anemia (e.g., hemoglobin 7-10 g/dL) improves tissue oxygenation or changes outcomes. Whereas increasing levels of anemia eventually lead to a level of critical oxygen delivery, increased cardiac output and oxygen extraction are homeostatic mechanisms the body uses to prevent a state of dysoxia in the setting of diminished oxygen delivery due to anemia. In order for cardiac output to increase in the face of anemia, normovolemia must be maintained. Transfusion of red blood cells increases blood viscosity, which may actually decrease cardiac output (barring a state of hypovolemia prior to transfusion). Studies have generally shown that transfusion of red blood cells fails to increase oxygen uptake unless oxygen uptake/oxygen delivery dependency exists (e.g., severe anemia or strenuous exercise). Recently, near-infrared spectroscopy, which approximates the hemoglobin saturation of venous blood, has been used to investigate whether transfusion of red blood cells increases tissue oxygenation in regional tissue beds (e.g., brain, peripheral skeletal muscle). These studies have generally shown increases in near-infrared spectroscopy derived measurements of tissue oxygenation following transfusion. Studies evaluating the effect of transfusion on the microcirculation have shown that transfusion increases the functional capillary density. This article will review fundamental aspects of oxygen delivery and extraction, and the effects of red blood cell transfusion on tissue oxygenation as well as the microcirculation. PMID:22238040

  4. Evaluation of endoscopic laser Doppler flowmetry for measurement of human gastric blood flow

    International Nuclear Information System (INIS)

    Endoscopic measurement of gastric blood perfusion by laser Doppler flowmetry (LDF) has been evaluated in 28 patients and 15 healthy vounteers. During the recordings it was necessary to keep the probe in light contact with the mucosa to obtain stable curves and to avoid artificial Doppler signals caused by relative movements between the gastric wall and the probe. Gastric distention by air insufflation did not influence the recorded flow level significantly when air insufflation was moderate. The intravenous injection of 0.6 mg atropine did not cause any significant alteration in recorded blood flow, and this drug may be used as premedication before endoscopic blood flow measurements. Recordings with both 4 kHz and 12 kHz bandwidth of the LDF instruments showed a relative constant relationship for different flow levels, the flow values measured with 12 kHz being about twice the corresponding values measured with 4 kHz. With 12 kHz bandwith more of the disturbance signal is recorded, which makes analysis of endoscopic recorded flow curves difficult and inaccurate. It is therefore recommended to use 4 kHz bandwidth during endoscopic measurements in conscious humans. Blood flow measurements from both sides of the gastric wall were consistently of the same order of magnitude (r=0.91), and the endoscopically recorded output signal increased in three of five patients when a reflecting mirror was placed at the serosal side. The results indicate that endoscopic LDF usually represents blood perfusion in all layers of the gastric wall

  5. Invasive and non-invasive methods for cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Lavdaniti M.

    2008-01-01

    Full Text Available The hemodynamic status monitoring of high-risk surgical patients and critically ill patients inIntensive Care Units is one of the main objectives of their therapeutic management. Cardiac output is one of the mostimportant parameters for cardiac function monitoring, providing an estimate of whole body perfusion oxygen deliveryand allowing for an understanding of the causes of high blood pressure. The purpose of the present review is thedescription of cardiac output measurement methods as presented in the international literature. The articles documentthat there are many methods of monitoring the hemodynamic status of patients, both invasive and non-invasive, themost popular of which is thermodilution. The invasive methods are the Fick method and thermodilution, whereasthe non-invasive methods are oeshophaegeal Doppler, transoesophageal echocardiography, lithium dilution, pulsecontour, partial CO2 rebreathing and thoracic electrical bioimpedance. All of them have their advantages and disadvantages,but thermodilution is the golden standard for critical patients, although it does entail many risks. The idealsystem for cardiac output monitoring would be non-invasive, easy to use, reliable and compatible in patients. A numberof research studies have been carried out in clinical care settings, by nurses as well as other health professionals, for thepurpose of finding a method of measurement that would have the least disadvantages. Nevertheless, the thermodilutiontechnique remains the most common approach in use today.

  6. CALF BLOOD-FLOW AND POSTURE - DOPPLER ULTRASOUND MEASUREMENTS DURING AND AFTER EXERCISE

    NARCIS (Netherlands)

    VANLEEUWEN, BE; BARENDSEN, GJ; LUBBERS, J; DEPATER, L

    1992-01-01

    To investigate the joint effects of body posture and calf muscle pump, the calf blood flow of eight healthy volunteers was measured with pulsed Doppler equipment during and after 3 min of rhythmic exercise on a calf ergometer in the supine, sitting, and standing postures. Muscle contractions serious

  7. Blood species identification using Near-Infrared diffuse transmitted spectra and PLS-DA method

    Science.gov (United States)

    Zhang, Linna; Zhang, Shengzhao; Sun, Meixiu; Wang, Zhennan; Li, Hongxiao; Li, Yingxin; Li, Gang; Lin, Ling

    2016-05-01

    Blood species identification is of great significance for blood supervision and wildlife investigations. The current methods used to identify the blood species are destructive. Near-Infrared spectroscopy method is known for its non-invasive properties. In this research, we combined Near-Infrared diffuse transmitted spectra and Partial Least Square Discrimination Analysis (PLS-DA) to identify three blood species, including macaque, human and mouse. Blind test and external test were used to assess the PLS-DA model. The model performed 100% accuracy in its identification between three blood species. This approach does not require a specific knowledge of biochemical features for each individual class but relies on a spectroscopic statistical differentiation of the whole components. This is the first time to demonstrate Near-Infrared diffuse transmitted spectra have the ability to identify the species of origin of blood samples. The results also support a good potential of absorption and scattering spectroscopy for species identification in practical applications for real-time detection.

  8. Validation of a microfluorimetric method for quantitation of L-Histidine in peripheral blood

    International Nuclear Information System (INIS)

    Histidinemia is a rare inherited metabolic disorder characterized by deficient histidase enzyme, which results in elevated histidine levels in blood, urine and cerebrospinal fluid and, sometimes, hyperalaninemia. Histidinemia clinical picture varies from mental retardation and speech disorders to absence of any symptoms. This disease can be diagnosed by histidine-level-in-blood-quantitating tests using different analytical methods such as spectrofluorimetry and High Pressure Liquid Chromatography. An analytical method using SUMA Technology was developed and validated at our laboratory to determine L-Histidine in blood: serum and dried blood spot (adult and neonatal) so as to use it in Histidinemia screening in children with speech disorders. This paper presents selectivity, linearity, accuracy and precision data. The calibration curve showed linearity ranging 1-12 mg/dL or 64.5-774 μM, and correlation coefficient (r) and determination coefficient (r2) higher than 0.99 for each biological matrix studied were obtained. Accuracy (repeatability and intermediate accuracy assays) was demonstrated, variation coefficients lower than 20 % being obtained. Accuracy was assessed by determining absolute recovery percentage. Assay recoveries were 97.83 -105.50 % (serum), 93-121.50 % (adult spot dried blood) and 86.50-104.50 % (neonatal spot dried blood)

  9. Measurements of Intracellular Ca2+ Content and Phosphatidylserine Exposure in Human Red Blood Cells: Methodological Issues

    Directory of Open Access Journals (Sweden)

    Mauro C. Wesseling

    2016-06-01

    Full Text Available Background/Aims: The increase of the intracellular Ca2+ content as well as the exposure of phosphatidylserine (PS on the outer cell membrane surface after activation of red blood cells (RBCs by lysophosphatidic acid (LPA has been investigated by a variety of research groups. Carrying out experiments, which we described in several previous publications, we observed some discrepancies when comparing data obtained by different investigators within our research group and also between batches of LPA. In addition, we found differences comparing the results of double and single labelling experiments (for Ca2+ and PS. Furthermore, the results of PS exposure depended on the fluorescent dye used (annexin V-FITC versus annexin V alexa fluor® 647. Therefore, it seems necessary to investigate these methodological approaches in more detail to be able to quantify results and to compare data obtained by different research groups. Methods: The intracellular Ca2+ content and the PS exposure of RBCs separated from whole blood have been investigated after treatment with LPA (2.5 µM obtained from three different companies (Sigma-Aldrich, Cayman Chemical Company, and Santa Cruz Biotechnology Inc.. Fluo-4 and x-rhod-1 have been used to detect intracellular Ca2+ content, annexin V alexa fluor® 647 and annexin V-FITC have been used for PS exposure measurements. Both parameters (Ca2+ content, PS exposure were studied using flow cytometry and fluorescence microscopy. Results: The percentage of RBCs showing increased intracellular Ca2+ content as well as PS exposure changes significantly between different LPA manufacturers as well as on the condition of mixing of LPA with the RBC suspension. Furthermore, the percentage of RBCs showing PS exposure is reduced in double labelling compared to single labelling experiments and depends also on the fluorescent dye used. Finally, data on Ca2+ content are slightly affected whereas PS exposure data are not affected significantly

  10. Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

    International Nuclear Information System (INIS)

    Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[123I]iodoamphetamine (IMP) and 99mTc-hexamethylpropylene-amine-oxime (HMPAO). In this paper, I mentioned the charachteristics, clinical usage and imitation of these two radiolabeled agents. The advantage of 123I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of 123I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of 123I-IMP. Comparing the rCBF measured by 123I-IMP with that by 133Xe inhalation SPECT method, we have to consider PaCO2 when both SPECT studies are performed, because PaCO2 is one of the big factors which make effects on the alteration of rCBF. 123I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume is one of the important information obtained by the SPECT study with 123I-IMP, which represent the degree of retention, i.e. binding potential of 123I-IMP in the brain tissue. I introduced the usage of the distribution volume of 123I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of 99m Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence 99mTc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author)

  11. Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo (Niigata Univ. (Japan). School of Medicine)

    1994-04-01

    Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

  12. Minimally invasive blood sampling method for genetic studies on Gopherus tortoises

    Directory of Open Access Journals (Sweden)

    García–Feria, L. M.

    2015-04-01

    Full Text Available Obtaining good quality tissue samples is the first hurdle in any molecular study. This is especially true for studies involving management and conservation of wild fauna. In the case of tortoises, the most common sources of DNA are blood samples. However, only a minimal amount of blood is required for PCR assays. Samples are obtained mainly from the brachial and jugular vein after restraining the animal chemically, or from conscious individuals by severe handling methods and clamping. Herein, we present a minimally invasive technique that has proven effective for extracting small quantities of blood, suitable for genetic analyses. Furthermore, the samples obtained yielded better DNA amplification than other cell sources, such as cloacal epithelium cells. After two years of use on wild tortoises, this technique has shown to be harmless. We suggest that sampling a small amount of blood could also be useful for other types of analyses, such as physiologic and medical monitoring.

  13. An improved method of measuring heart rate using a webcam

    Science.gov (United States)

    Liu, Yi; Ouyang, Jianfei; Yan, Yonggang

    2014-09-01

    Measuring heart rate traditionally requires special equipment and physical contact with the subject. Reliable non-contact and low-cost measurements are highly desirable for convenient and comfortable physiological self-assessment. Previous work has shown that consumer-grade cameras can provide useful signals for remote heart rate measurements. In this paper a simple and robust method of measuring the heart rate using low-cost webcam is proposed. Blood volume pulse is extracted by proper Region of Interest (ROI) and color channel selection from image sequences of human faces without complex computation. Heart rate is subsequently quantified by spectrum analysis. The method is successfully applied under natural lighting conditions. Results of experiments show that it takes less time, is much simpler, and has similar accuracy to the previously published and widely used method of Independent Component Analysis (ICA). Benefitting from non-contact, convenience, and low-costs, it provides great promise for popularization of home healthcare and can further be applied to biomedical research.

  14. Computational methods for industrial radiation measurement applications

    International Nuclear Information System (INIS)

    Computational methods have been used with considerable success to complement radiation measurements in solving a wide range of industrial problems. The almost exponential growth of computer capability and applications in the last few years leads to a open-quotes black boxclose quotes mentality for radiation measurement applications. If a black box is defined as any radiation measurement device that is capable of measuring the parameters of interest when a wide range of operating and sample conditions may occur, then the development of computational methods for industrial radiation measurement applications should now be focused on the black box approach and the deduction of properties of interest from the response with acceptable accuracy and reasonable efficiency. Nowadays, increasingly better understanding of radiation physical processes, more accurate and complete fundamental physical data, and more advanced modeling and software/hardware techniques have made it possible to make giant strides in that direction with new ideas implemented with computer software. The Center for Engineering Applications of Radioisotopes (CEAR) at North Carolina State University has been working on a variety of projects in the area of radiation analyzers and gauges for accomplishing this for quite some time, and they are discussed here with emphasis on current accomplishments

  15. Neutronic method of soil moisture measurement

    International Nuclear Information System (INIS)

    The neutronic method is first outlined: analysis of neutron-nucleus interaction phenomena shows that the neutronic parameters of damp soils depend on the water itself, then on the dry density and the total chemical composition. A physical model representing the neutron moisture gage is worked out next, which leads to the establishment of a simple new mathematical expression applicable to two-dimensional geometry using the multigroup theory diffusion approximation. Following a brief description of the principle and technology of moisture gages two essential problems are dealt with: the calibration curve established by a quick and reliable method involving direct measurement of the thermal neutron constants of soils, and the measurement volume which must be approached by the use of a two-dimensional physical model to describe the geometrical conditions correctly. The problem of the vertical and horizontal resolution power of the neutron probe and the limiting case of surface measurements are discussed. Some possibilities offered by epithermal and fast neutron detection are suggested: epicadmic information represents a step forward as a complement to the thermal measurement since it supplies the principle of a moisture-gage independent of the dry density and allows the calibration curves of conventional instruments to be determined in situ. An experimental study of fast neutron space-energy distribution is described extended and specified by a physical model constructed on a Monte Carlo code; this gives the basis of a technique to measure water contents by fast neutron transmission

  16. Differences in blood pressure measurements in the forearm and upper arm of obese otherwise healthy first year medical students

    OpenAIRE

    Suganthi V, Navin Rajaratnam, Suzanne Maria D’cruz

    2014-01-01

    Background: The prevalence of obesity is increasing in Indian youth and obesity is associated with complications like systemic hypertension. Often, due to the non-availability of appropriate sized cuffs, standard cuff bladders are used to measure blood pressure in the forearms of obese young adults. Aim: To compare the upper arm arterial blood pressure measured using an appropriate cuff with the forearm arterial blood pressure measured using a standard cuff and conventional sphygmomanometry i...

  17. Electric Field Quantitative Measurement System and Method

    Science.gov (United States)

    Generazio, Edward R. (Inventor)

    2016-01-01

    A method and system are provided for making a quantitative measurement of an electric field. A plurality of antennas separated from one another by known distances are arrayed in a region that extends in at least one dimension. A voltage difference between at least one selected pair of antennas is measured. Each voltage difference is divided by the known distance associated with the selected pair of antennas corresponding thereto to generate a resulting quantity. The plurality of resulting quantities defined over the region quantitatively describe an electric field therein.

  18. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    Science.gov (United States)

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

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

    OpenAIRE

    Jong-Gu Choi; Keun-Ho Kim; Woo-Beom Lee; Dong-Hyun Nam; Il-Ho Son; You-Sik Hong; Sang-Suk Lee

    2011-01-01

    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...

  20. Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - Position statement of the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability.

    Science.gov (United States)

    Stergiou, George S; Parati, Gianfranco; Vlachopoulos, Charalambos; Achimastos, Apostolos; Andreadis, Emanouel; Asmar, Roland; Avolio, Alberto; Benetos, Athanase; Bilo, Grzegorz; Boubouchairopoulou, Nadia; Boutouyrie, Pierre; Castiglioni, Paolo; de la Sierra, Alejandro; Dolan, Eamon; Head, Geoffrey; Imai, Yutaka; Kario, Kazuomi; Kollias, Anastasios; Kotsis, Vasilis; Manios, Efstathios; McManus, Richard; Mengden, Thomas; Mihailidou, Anastasia; Myers, Martin; Niiranen, Teemu; Ochoa, Juan Eugenio; Ohkubo, Takayoshi; Omboni, Stefano; Padfield, Paul; Palatini, Paolo; Papaioannou, Theodore; Protogerou, Athanasios; Redon, Josep; Verdecchia, Paolo; Wang, Jiguang; Zanchetti, Alberto; Mancia, Giuseppe; O'Brien, Eoin

    2016-09-01

    Office blood pressure measurement has been the basis for hypertension evaluation for almost a century. However, the evaluation of blood pressure out of the office using ambulatory or self-home monitoring is now strongly recommended for the accurate diagnosis in many, if not all, cases with suspected hypertension. Moreover, there is evidence that the variability of blood pressure might offer prognostic information that is independent of the average blood pressure level. Recently, advancement in technology has provided noninvasive evaluation of central (aortic) blood pressure, which might have attributes that are additive to the conventional brachial blood pressure measurement. This position statement, developed by international experts, deals with key research and practical issues in regard to peripheral blood pressure measurement (office, home, and ambulatory), blood pressure variability, and central blood pressure measurement. The objective is to present current achievements, identify gaps in knowledge and issues concerning clinical application, and present relevant research questions and directions to investigators and manufacturers for future research and development (primary goal). PMID:27214089